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Sample records for apical membrane antigen-1

  1. Identification and characterization of Eimeria tenella apical membrane antigen-1 (AMA1.

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    Lianlian Jiang

    Full Text Available Apical membrane antigen-1 (AMA1 is a micronemal protein of apicomplexan parasites that appears to be essential during the invasion of host cells. In this study, a full-length cDNA of AMA1 was identified from Eimeria tenella (Et using expressed sequence tag and the rapid amplification of cDNA ends technique. EtAMA1 had an open reading frame of 1608 bp encoding a protein of 535 amino acids. Quantitative real-time PCR analysis revealed that EtAMA1 was expressed at higher levels in sporozoites than in the other developmental stages (unsporulated oocysts, sporulated oocysts and second-generation merozoites. The ectodomain sequence was expressed as recombinant EtAMA1 (rEtAMA1 and rabbit polyclonal antibodies raised against the rEtAMA1 recognized a 58-kDa native parasite protein by Western Blotting and had a potent inhibitory effect on parasite invasion, decreasing it by approximately 70%. Immunofluorescence analysis and immunohistochemistry analysis showed EtAMA1 might play an important role in sporozoite invasion and development.

  2. Sequence diversity and natural selection at domain I of the apical membrane antigen 1 among Indian Plasmodium falciparum populations

    OpenAIRE

    Kumar Ashwani; Dev Vas; Das Manoj K; Alam Mohammad T; Garg Sheena; Dash Aditya P; Sharma Yagya D

    2007-01-01

    Abstract Background The Plasmodium falciparum apical membrane antigen 1 (AMA1) is a leading malaria vaccine candidate antigen. The complete AMA1 protein is comprised of three domains where domain I exhibits high sequence polymorphism and is thus named as the hyper-variable region (HVR). The present study describes the extent of genetic polymorphism and natural selection at domain I of the ama1 gene among Indian P. falciparum isolates. Methods The part of the ama1 gene covering domain I was PC...

  3. Solution NMR characterization of apical membrane antigen 1 and small molecule interactions as a basis for designing new antimalarials.

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    Krishnarjuna, Bankala; Lim, San Sui; Devine, Shane M; Debono, Cael O; Lam, Raymond; Chandrashekaran, Indu R; Jaipuria, Garima; Yagi, Hiromasa; Atreya, Hanudatta S; Scanlon, Martin J; MacRaild, Christopher A; Scammells, Peter J; Norton, Raymond S

    2016-06-01

    Plasmodium falciparum apical membrane antigen 1 (PfAMA1) plays an important role in the invasion by merozoites of human red blood cells during a malaria infection. A key region of PfAMA1 is a conserved hydrophobic cleft formed by 12 hydrophobic residues. As anti-apical membrane antigen 1 antibodies and other inhibitory molecules that target this hydrophobic cleft are able to block the invasion process, PfAMA1 is an attractive target for the development of strain-transcending antimalarial agents. As solution nuclear magnetic resonance spectroscopy is a valuable technique for the rapid characterization of protein-ligand interactions, we have determined the sequence-specific backbone assignments for PfAMA1 from two P. falciparum strains, FVO and 3D7. Both selective labelling and unlabelling strategies were used to complement triple-resonance experiments in order to facilitate the assignment process. We have then used these assignments for mapping the binding sites for small molecules, including benzimidazoles, pyrazoles and 2-aminothiazoles, which were selected on the basis of their affinities measured from surface plasmon resonance binding experiments. Among the compounds tested, benzimidazoles showed binding to a similar region on both FVO and 3D7 PfAMA1, suggesting that these compounds are promising scaffolds for the development of novel PfAMA1 inhibitors. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26804042

  4. Polymorphism in the gene encoding the apical membrane antigen-1 (AMA-1) of Plasmodium falciparum. X. Asembo Bay Cohort Project.

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    Escalante, A A; Grebert, H M; Chaiyaroj, S C; Magris, M; Biswas, S; Nahlen, B L; Lal, A A

    2001-04-01

    We have investigated the genetic diversity of the gene encoding the apical membrane antigen-1 (AMA-1) in natural populations of Plasmodium falciparum from western Kenya and compared it with parasite populations from other geographic regions. A total of 28 complete sequences from Kenya, Thailand, India, and Venezuela field isolates were obtained. The genetic polymorphism is not evenly distributed across the gene, which is in agreement with the pattern reported in earlier studies. The alleles from Kenya exhibit 20 and 30% more polymorphism than that found in Southeast Asia and Venezuelan alleles, respectively. Based on the gene genealogies derived from sequencing data, no evidence for allele families was found. We have found evidence supporting limited gene flow between the parasite populations, specifically, between the Southeast Asian and Venezuelan isolates; however, no alleles could be linked to a specific geographic region. This study reveals that positive natural selection is an important factor in the maintenance of genetic diversity for AMA-1. We did not find conclusive evidence indicating intragenic recombination is important in the generation of the AMA-1 allelic diversity. The study provides information on the genetic diversity of the AMA-1 gene that would be useful in vaccine development and testing, as well as in assessing factors that are involved in the generation and maintenance of the genetic diversity in P. falciparum. PMID:11295182

  5. Comparative sequence analysis of domain I of Plasmodium falciparum apical membrane antigen 1 from Saudi Arabia and worldwide isolates.

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    Al-Qahtani, Ahmed A; Abdel-Muhsin, Abdel-Muhsin A; Dajem, Saad M Bin; AlSheikh, Adel Ali H; Bohol, Marie Fe F; Al-Ahdal, Mohammed N; Putaporntip, Chaturong; Jongwutiwes, Somchai

    2016-04-01

    The apical membrane antigen 1 of Plasmodium falciparum (PfAMA1) plays a crucial role in erythrocyte invasion and is a target of protective antibodies. Although domain I of PfAMA1 has been considered a promising vaccine component, extensive sequence diversity in this domain could compromise an effective vaccine design. To explore the extent of sequence diversity in domain I of PfAMA1, P. falciparum-infected blood samples from Saudi Arabia collected between 2007 and 2009 were analyzed and compared with those from worldwide parasite populations. Forty-six haplotypes and a novel codon change (M190V) were found among Saudi Arabian isolates. The haplotype diversity (0.948±0.004) and nucleotide diversity (0.0191±0.0008) were comparable to those from African hyperendemic countries. Positive selection in domain I of PfAMA1 among Saudi Arabian parasite population was observed because nonsynonymous nucleotide substitutions per nonsynonymous site (dN) significantly exceeded synonymous nucleotide substitutions per synonymous site (dS) and Tajima's D and its related statistics significantly deviated from neutrality in the positive direction. Despite a relatively low prevalence of malaria in Saudi Arabia, a minimum of 17 recombination events occurred in domain I. Genetic differentiation was significant between P. falciparum in Saudi Arabia and parasites from other geographic origins. Several shared or closely related haplotypes were found among parasites from different geographic areas, suggesting that vaccine derived from multiple shared epitopes could be effective across endemic countries. PMID:26867816

  6. Sequence diversity and natural selection at domain I of the apical membrane antigen 1 among Indian Plasmodium falciparum populations

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    Kumar Ashwani

    2007-11-01

    Full Text Available Abstract Background The Plasmodium falciparum apical membrane antigen 1 (AMA1 is a leading malaria vaccine candidate antigen. The complete AMA1 protein is comprised of three domains where domain I exhibits high sequence polymorphism and is thus named as the hyper-variable region (HVR. The present study describes the extent of genetic polymorphism and natural selection at domain I of the ama1 gene among Indian P. falciparum isolates. Methods The part of the ama1 gene covering domain I was PCR amplified and sequenced from 157 P. falciparum isolates collected from five different geographical regions of India. Statistical and phylogenetic analyses of the sequences were done using DnaSP ver. 4. 10. 9 and MEGA version 3.0 packages. Results A total of 57 AMA1 haplotypes were observed among 157 isolates sequenced. Forty-six of these 57 haplotypes are being reported here for the first time. The parasites collected from the high malaria transmission areas (Assam, Orissa, and Andaman and Nicobar Islands showed more haplotypes (H and nucleotide diversity π as compared to low malaria transmission areas (Uttar Pradesh and Goa. The comparison of all five Indian P. falciparum subpopulations indicated moderate level of genetic differentiation and limited gene flow (Fixation index ranging from 0.048 to 0.13 between populations. The difference between rates of non-synonymous and synonymous mutations, Tajima's D and McDonald-Kreitman test statistics suggested that the diversity at domain I of the AMA1 antigen is due to positive natural selection. The minimum recombination events were also high indicating the possible role of recombination in generating AMA1 allelic diversity. Conclusion The level of genetic diversity and diversifying selection were higher in Assam, Orissa, and Andaman and Nicobar Islands populations as compared to Uttar Pradesh and Goa. The amounts of gene flow among these populations were moderate. The data reported here will be valuable for the

  7. Cell-mediated immunity elicited by the blood stage malaria vaccine apical membrane antigen 1 in Malian adults: Results of a Phase I randomized trial

    OpenAIRE

    Lyke, Kirsten E; Daou, Modibo; DIARRA, ISSA; Kone, Abdoulaye; Kouriba, Bourema; Thera, Mohamadou A.; Dutta, Sheetij; Lanar, David E.; Heppner, D Gray; Doumbo, Ogobara K.; Plowe, Christopher V.; Sztein, Marcelo B.

    2009-01-01

    The development of a safe and effective malaria vaccine is impeded by the complexity of the Plasmodium life cycle. A vaccine that elicits both cell-mediated and humoral immune responses might be needed for protection against this multistage parasitic infection. Apical membrane antigen 1 (AMA-1) plays a key role in erythrocytic invasion but is also expressed in sporozoites and in late stage liver schizonts, where it may provide a target of protective cell-mediated immunity (CMI). A Phase 1 tri...

  8. High antibody titer against apical membrane antigen-1 is required to protect against malaria in the Aotus model.

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    Sheetij Dutta

    Full Text Available A Plasmodium falciparum 3D7 strain Apical Membrane Antigen-1 (AMA1 vaccine, formulated with AS02(A adjuvant, slowed parasite growth in a recent Phase 1/2a trial, however sterile protection was not observed. We tested this AS02(A, and a Montanide ISA720 (ISA formulation of 3D7 AMA1 in Aotus monkeys. The 3D7 parasite does not invade Aotus erythrocytes, hence two heterologous strains, FCH/4 and FVO, were used for challenge, FCH/4 AMA1 being more homologous to 3D7 than FVO AMA1. Following three vaccinations, the monkeys were challenged with 50,000 FCH/4 or 10,000 FVO parasites. Three of the six animals in the AMA+ISA group were protected against FCH/4 challenge. One monkey did not become parasitemic, another showed only a short period of low level parasitemia that self-cured, and a third animal showed a delay before exhibiting its parasitemic phase. This is the first protection shown in primates with a recombinant P. falciparum AMA1 without formulation in Freund's complete adjuvant. No animals in the AMA+AS02(A group were protected, but this group exhibited a trend towards reduced growth rate. A second group of monkeys vaccinated with AMA+ISA vaccine was not protected against FVO challenge, suggesting strain-specificity of AMA1-based protection. Protection against FCH/4 strain correlated with the quantity of induced antibodies, as the protected animals were the only ones to have in vitro parasite growth inhibitory activity of >70% at 1:10 serum dilution; immuno-fluorescence titers >8,000; ELISA titers against full-length AMA1 >300,000 and ELISA titer against AMA1 domains1+2 >100,000. A negative correlation between log ELISA titer and day 11 cumulative parasitemia (Spearman rank r = -0.780, p value = 0.0001, further confirmed the relationship between antibody titer and protection. High titers of cross-strain inhibitory antibodies against AMA1 are therefore critical to confer solid protection, and the Aotus model can be used to down-select future AMA1

  9. Potential Impact of Seasonal Malaria Chemoprevention on the Acquisition of Antibodies Against Glutamate-Rich Protein and Apical Membrane Antigen 1 in Children Living in Southern Senegal

    DEFF Research Database (Denmark)

    Ndiaye, Magatte; Sylla, Khadime; Sow, Doudou;

    2015-01-01

    -pyrimethamine (SP) combined with amodiaquine (AQ) is a promising strategy to control malaria morbidity in areas of highly seasonal malaria transmission. However, a concern is whether SMC can delay the natural acquisition of immunity toward malaria parasites in areas with intense SMC delivery. To investigate this......, total IgG antibody (Ab) responses to Plasmodium falciparum antigens glutamate-rich protein R0 (GLURP-R0) and apical membrane antigen 1 (AMA-1) were measured by enzyme-linked immunosorbent assay in Senegalese children under the age of 10 years in 2010 living in Saraya and Velingara districts (with SMC...

  10. An Extended Surface Loop on Toxoplasma gondii Apical Membrane Antigen 1 (AMA1 Governs Ligand Binding Selectivity.

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    Michelle L Parker

    Full Text Available Apicomplexan parasites are the causative agents of globally prevalent diseases including malaria and toxoplasmosis. These obligate intracellular pathogens have evolved a sophisticated host cell invasion strategy that relies on a parasite-host cell junction anchored by interactions between apical membrane antigens (AMAs on the parasite surface and rhoptry neck 2 (RON2 proteins discharged from the parasite and embedded in the host cell membrane. Key to formation of the AMA1-RON2 complex is displacement of an extended surface loop on AMA1 called the DII loop. While conformational flexibility of the DII loop is required to expose the mature RON2 binding groove, a definitive role of this substructure has not been elucidated. To establish a role of the DII loop in Toxoplasma gondii AMA1, we engineered a form of the protein where the mobile portion of the loop was replaced with a short Gly-Ser linker (TgAMA1ΔDIIloop. Isothermal titration calorimetry measurements with a panel of RON2 peptides revealed an influential role for the DII loop in governing selectivity. Most notably, an Eimeria tenella RON2 (EtRON2 peptide that showed only weak binding to TgAMA1 bound with high affinity to TgAMA1ΔDIIloop. To define the molecular basis for the differential binding, we determined the crystal structure of TgAMA1ΔDIIloop in complex with the EtRON2 peptide. When analyzed in the context of existing AMA1-RON2 structures, spatially distinct anchor points in the AMA1 groove were identified that, when engaged, appear to provide the necessary traction to outcompete the DII loop. Collectively, these data support a model where the AMA1 DII loop serves as a structural gatekeeper to selectively filter out ligands otherwise capable of binding with high affinity in the AMA1 apical groove. These data also highlight the importance of considering the functional implications of the DII loop in the ongoing development of therapeutic intervention strategies targeting the AMA1-RON

  11. Multilevel Precision-Based Rational Design of Chemical Inhibitors Targeting the Hydrophobic Cleft of Toxoplasma gondii Apical Membrane Antigen 1 (AMA1).

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    Vetrivel, Umashankar; Muralikumar, Shalini; Mahalakshmi, B; Lily Therese, K; Madhavan, H N; Alameen, Mohamed; Thirumudi, Indhuja

    2016-06-01

    Toxoplasma gondii is an intracellular Apicomplexan parasite and a causative agent of toxoplasmosis in human. It causes encephalitis, uveitis, chorioretinitis, and congenital infection. T. gondii invades the host cell by forming a moving junction (MJ) complex. This complex formation is initiated by intermolecular interactions between the two secretory parasitic proteins-namely, apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2) and is critically essential for the host invasion process. By this study, we propose two potential leads, NSC95522 and NSC179676 that can efficiently target the AMA1 hydrophobic cleft, which is a hotspot for targeting MJ complex formation. The proposed leads are the result of an exhaustive conformational search-based virtual screen with multilevel precision scoring of the docking affinities. These two compounds surpassed all the precision levels of docking and also the stringent post docking and cumulative molecular dynamics evaluations. Moreover, the backbone flexibility of hotspot residues in the hydrophobic cleft, which has been previously reported to be essential for accommodative binding of RON2 to AMA1, was also highly perturbed by these compounds. Furthermore, binding free energy calculations of these two compounds also revealed a significant affinity to AMA1. Machine learning approaches also predicted these two compounds to possess more relevant activities. Hence, these two leads, NSC95522 and NSC179676, may prove to be potential inhibitors targeting AMA1-RON2 complex formation towards combating toxoplasmosis. PMID:27445648

  12. The apical plasma membrane of chitin-synthesizing epithelia

    Institute of Scientific and Technical Information of China (English)

    Bernard Moussian

    2013-01-01

    Chitin is the second most abundant polysaccharide on earth.It is produced at the apical side of epidermal,tracheal,fore-,and hindgut epithelial cells in insects as a central component of the protective and supporting extracellular cuticle.Chitin is also an important constituent of the midgut peritrophic matrix that encases the food supporting its digestion and protects the epithelium against invasion by possibly ingested pathogens.The enzyme producing chitin is a glycosyltransferase that resides in the apical plasma membrane forming a pore to extrude the chains of chitin into the extracellular space.The apical plasma membrane is not only a platform for chitin synthases but,probably through its shape and equipment with distinct factors,also plays an important role in orienting and organizing chitin fibers.Here,I review findings on the cellular and molecular constitution of the apical plasma membrane of chitin-producing epithelia mainly focusing on work done in the fruit fly Drosophila melanogaster.

  13. Quantitative analysis of the lipidomes of the influenza virus envelope and MDCK cell apical membrane

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    Gerl, Mathias J.; Sampaio, Julio L; Urban, Severino; Kalvodova, Lucie; Verbavatz, Jean-Marc; Binnington, Beth; Lindemann, Dirk; Lingwood, Clifford A.; Shevchenko, Andrej; Schroeder, Cornelia; Simons, Kai

    2012-01-01

    The influenza virus (IFV) acquires its envelope by budding from host cell plasma membranes. Using quantitative shotgun mass spectrometry, we determined the lipidomes of the host Madin–Darby canine kidney cell, its apical membrane, and the IFV budding from it. We found the apical membrane to be enriched in sphingolipids (SPs) and cholesterol, whereas glycerophospholipids were reduced, and storage lipids were depleted compared with the whole-cell membranes. The virus membrane exhibited a furthe...

  14. Characterisation of a Babesia orientalis apical membrane antigen, and comparison of its orthologues among selected apicomplexans.

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    He, Lan; Fan, Lizhe; Hu, Jinfang; Miao, Xiaoyan; Huang, Yuan; Zhou, Yanqin; Hu, Min; Zhao, Junlong

    2015-04-01

    In the present study, we identified and characterised the complete coding sequence of Babesia orientalis apical membrane antigen 1 (designated Bo-ama1); it is 1803bp in length and encodes a polypeptide of 601 amino acids (aa). The Bo-ama-1 gene product (Bo-AMA1) is predicted to be 67kDa in size and contains a signal peptide. Mature Bo-AMA1 is predicted to have one transmembrane region and a short cytoplasmic tail (C-terminal domain). The extracellular part of Bo-AMA1 has three functional domains (DI, DII and DIII) with 14 conserved cysteine residues. A Bo-AMA1 fragment containing all three of these domains (designated Bo-AMA1-DI/II/III) was cloned into the plasmid vector pET-28a and expressed as a recombinant (His-fusion) protein of 53kDa. Antibodies in the serum from a B. orientalis-infected water buffalo specifically recognised this protein in immunoblotting analysis. Rabbit antibodies raised against the recombinant protein were able to detect native Bo-AMA1 (67kDa) from erythrocytes of B. orientalis-infected water buffalo. Bo-AMA1 is a new member of the AMA1 family and might be a good antigen for the specific detection of antibodies produced in B. orientalis infected cattle. This protein is likely to play critical roles during host cell adherence and invasion by B. orientalis, as the AMA1s reported in other organisms such as Plasmodium falciparum and Toxoplasma gondii. Further research is required to explore the biological functions of this protein and to determine whether its immunisation can induce protective effects in water buffalo against B. orientalis infection. PMID:25732411

  15. Effects of ADH on the apical and basolateral membranes of toad urinary bladder epithelial cells.

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    Donaldson, P J; Leader, J P

    1993-11-01

    Short-circuited urinary bladders from Bufo marinus were supported on their apical surface by an agar mounting method and impaled with microelectrodes via their basolateral membrane. This arrangement provided stable and long-lasting impalements of epithelial cells and yielded reliable membrane potentials and voltage divider ratios (Ra/Rb), where Ra and Rb are apical and basolateral membrane resistances respectively. The membrane potential under short-circuit conditions (Vsc) was -51.4 +/- 2.2 mV (n = 59), while under open-circuit conditions apical membrane potential (Va) and basolateral membrane potential (Vb) were -31.0 +/- 2.4 and 59.5 +/- 2.4 mV, respectively. This yields a "well-shaped" potential profile across the toad urinary bladder, where Va is inversely related to the rate of transport, Isc. Antidiuretic hormone (ADH) produced a hyperpolarisation of Vsc and Vb but had no significant effect on Va. In addition, Ra/Rb was significantly increased by ADH (4.6 +/- 0.5 to 10.2 +/- 3.6). Calculation of individual membrane resistances following the addition of amiloride showed that ADH produced a parallel decrease in Ra and Rb membrane resistance, with the observed increase in Ra/Rb being due to a greater percentage decrease in Rb than in Ra. The ability of ADH to effect parallel changes in apical and basolateral membrane conductance helps to maintain a constant cellular volume despite an increase in transepithelial transport. PMID:8309781

  16. Human Cytomegalovirus Glycoprotein B Contains Autonomous Determinants for Vectorial Targeting to Apical Membranes of Polarized Epithelial Cells

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    Tugizov, Sharof; Maidji, Ekaterina; Xiao, Jianqiao; Zheng, Zhenwei; Pereira, Lenore

    1998-01-01

    We previously reported that human cytomegalovirus (CMV) glycoprotein B (gB) is vectorially transported to apical membranes of CMV-infected polarized human retinal pigment epithelial cells propagated on permeable filter supports and that virions egress predominantly from the apical membrane domain. In the present study, we investigated whether gB itself contains autonomous information for apical transport by expressing the molecule in stably transfected Madine-Darby canine kidney (MDCK) cells ...

  17. A glycophospholipid membrane anchor acts as an apical targeting signal in polarized epithelial cells

    OpenAIRE

    1989-01-01

    Glycosyl-phosphatidylinositol- (GPI) anchored proteins contain a large extracellular protein domain that is linked to the membrane via a glycosylated form of phosphatidylinositol. We recently reported the polarized apical distribution of all endogenous GPI-anchored proteins in the MDCK cell line (Lisanti, M. P., M. Sargiacomo, L. Graeve, A. R. Saltiel, and E. Rodriguez-Boulan. 1988. Proc. Natl. Acad. Sci. USA. 85:9557-9561). To study the role of this mechanism of membrane anchoring in targeti...

  18. A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen‑1.

    Science.gov (United States)

    Torina, Alessandra; Cordaro, Antonio; Blanda, Valeria; D'Agostino, Rosalia; Scimeca, Salvatore; Scariano, Maria E; Sireci, Guido; Lelli, Rossella

    2016-03-31

    Babesiosis due to Babesia bigemina is a relevant tick-borne disease, a ecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA-1) - have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA-1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA-1 codifying region was ampli ed and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA-1 was puri ed by a nity chromatography and used to set up the best condition for an ELISA protocol. Bovine eld sera positive to B. bigemina were used to evaluate the presence of anti-AMA-1 antibodies. In order to verify the assay speci city, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Signi cant di erences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No signi cant reaction was observed with T. annulata positive sera. The results showed that AMA-1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies. PMID:27033532

  19. LLC-PK1 cells express Na+-lactate cotransport in apical membranes after confluency

    International Nuclear Information System (INIS)

    L-[3H]lactate uptake was characterized in LLC-PK1 cell apical membrane vesicles obtained by intensive culture on microcarrier beads. The apical membrane preparation technique involved MgCl2 precipitation. Na+-dependent L-[3H]lactate uptake was present only after confluency; its appearance paralleled the subcellular localization of aminopeptidase in apical membranes. L-[3H]lactate uptake was Na+-dependent and electrogenic. Only the Na+-dependent component of L[3H]lactate uptake was saturable with one family of independent carriers. The apparent affinity constant was 1.1 ± 0.25 mM and the apparent maximal velocity was 29 ± 3 nmol·mg-1·min-1. The Na+-lactate cotransport stoichiometry was 2 Na+ for 1 lactate. The specificity of the L-lactate transport system was compatible with that of the monocarboxylic acid pathway described previously brush-border membranes of kidney cortex and discrete from the tricarboxylic acid carrier, the D-glucose transporter, and the general pathway for anions. The LLC-PK1 cell line appears to be a useful tool for study of the regulation of L-lactate uptake and biosynthesis of the renal monocarboxylic acid transporter

  20. Sequence Analysis of Different Domains of Plasmodium Vivax Apical Membrane Antigen (PvAMA-1 Gene Locus in Iran

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    MR Khoramizade

    2012-02-01

    Full Text Available Background: Plasmodium vivax is responsible for approximately 80 million malaria cases in the world. Apical membrane antigen1 (AMA-1 is a type I integral membrane protein present in all Plasmodium species. AMA-1 interferes in critical steps of invasion of human hepatocytes by sporozoites and red blood cells by merozoites and is one of the most immunodominant antigens for eliciting a protective immune response in human. It is considered as a promising antigen for inclusion in a vaccine against P. vivax. Since more knowledge is needed to lighten the scope of such antigen we compared genetic variation in P. vivax AMA-1from an Iranian isolate with those reported from some of the other malarious countries so far.Methods: P. vivax genomic DNA was extracted from the whole blood of an Iranian patient with patent P. vivax infection. The nucleotide sequence for 446 amino acid (AA residues (42-488 of PvAMA-1 was amplified by PCR and cloned in pUC19 vector for sequencing.Results: Sequence analysis of the antigen showed a high degree of identity (99% with strong homology to the PvAMA-1 gene of P. vivax S3 and SKO814 isolates from India and Korea (Asian isolates respectively, and 96% similarity with P. vivax Sal-1 AMA-1 gene from El Salvador.Conclusions: We cloned and characterized three domains of PvAMA-1 gene from an Iranian patient. Predicted protein sequence of this gene showed some discrepancies in corresponding protein in comparing with similar genes reported from other malarious countries.

  1. Isolation of Highly Enriched Apical Plasma Membranes of the Placental Syncytiotrophoblast

    OpenAIRE

    Robinson, John M.; Ackerman, William E.; Tewari, Arun K.; Kniss, Douglas A.; Dale D Vandre

    2009-01-01

    The human placenta is a complex organ whose proper function is crucial for the development of the fetus. The placenta contains within its structure elements of the maternal and fetal circulatory systems. The interface with maternal blood is the lining of the placenta, that is a unique compartment known as the syncytiotrophoblast. This large syncytial structure is a single cell layer in thickness, and the apical plasma membrane of the syncytiotrophoblast interacts directly with maternal blood....

  2. cAmp activation of apical membrane Cl(-) channels: theoretical considerations for impedance analysis.

    OpenAIRE

    Păunescu, T G; Helman, S I

    2001-01-01

    Transepithelial electrical impedance analysis provides a sensitive method to evaluate the conductances and capacitances of apical and basolateral plasma membranes of epithelial cells. Impedance analysis is complicated, due not only to the anatomical arrangement of the cells and their paracellular shunt pathways, but also in particular to the existence of audio frequency-dependent capacitances or dispersions. In this paper we explore implications and consequences of anatomically related Maxwel...

  3. Homeostasis of the apical plasma membrane during regulated exocytosis in the salivary glands of live rodents

    OpenAIRE

    Masedunskas, Andrius; Sramkova, Monika; Weigert, Roberto

    2011-01-01

    In exocrine organs such as the salivary glands, fluids and proteins are secreted into ductal structures by distinct mechanisms that are tightly coupled. In the acinar cells, the major secretory units of the salivary glands, fluids are secreted into the acinar canaliculi through paracellular and intracellular transport, whereas proteins are stored in large granules that undergo exocytosis and fuse with the apical plasma membranes releasing their content into the canaliculi. Both secretory proc...

  4. Microbial sphingomyelinase induces RhoA-mediated reorganization of the apical brush border membrane and is protective against invasion.

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    Saslowsky, David E; Thiagarajah, Jay R; McCormick, Beth A; Lee, Jean C; Lencer, Wayne I

    2016-04-01

    The apical brush border membrane (BBM) of intestinal epithelial cells forms a highly structured and dynamic environmental interface that serves to regulate cellular physiology and block invasion by intestinal microbes and their products. How the BBM dynamically responds to pathogenic and commensal bacterial signals can define intestinal homeostasis and immune function. We previously found that in model intestinal epithelium, the conversion of apical membrane sphingomyelin to ceramide by exogenous bacterial sphingomyelinase (SMase) protected against the endocytosis and toxicity of cholera toxin. Here we elucidate a mechanism of action by showing that SMase induces a dramatic, reversible, RhoA-dependent alteration of the apical cortical F-actin network. Accumulation of apical membrane ceramide is necessary and sufficient to induce the actin phenotype, and this coincides with altered membrane structure and augmented innate immune function as evidenced by resistance to invasion by Salmonella. PMID:26864627

  5. Dependence of intracellular Na+ concentration on apical and basolateral membrane Na+ influx in frog skin

    International Nuclear Information System (INIS)

    An isotopic method was developed to measure the intracellular Na+ content of the transepithelial Na+ transport pool of frog skin. Isolated epithelia (no corium) were labeled with 24Na either asymmetrically, from apical (Aa) or basolateral (Ab) solutions, or symmetrically (Aab). Transport pool Na+ could be identified from the kinetics of washout of 24Na carried out in the presence of 1 mM ouabain, 100 microM amiloride, and 1 mM furosemide that served to trap cold Na+ and 24Na within the transport pool. In control epithelia, Aab averaged 64.1 neq/cm2 (13.9 mM), and maximal inhibition of apical membrane Na+ entry with 100 microM amiloride caused Aab to decrease to 24.3 neq/cm2 (5.3 mM). Ouabain caused Aab to increase markedly to 303 neq/cm2 in 30 min, whereas amiloride inhibition of apical membrane Na+ entry reduced markedly the rate of increase of Aab caused by ouabain. These data, in part, confirmed the existence of an important basolateral membrane permeability to Na+ that was measured in separate studies of the bidirectional 24Na fluxes at the basolateral membranes of the cells. Both sets of data were supportive of the idea that a significant Na+ recycling exists at the basolateral membranes of the cells that contributes to the Na+ load on the pump and Na+ recycling participates in the regulation of the Na+ concentration of the Na+ transport pool of these epithelial cells

  6. Apical Plasma Membrane Proteins and Endolyn-78 Travel through a Subapical Compartment in Polarized WIF-B Hepatocytes

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    Ihrke, Gudrun; Martin, Greg V.; Shanks, Michael R.; Schrader, Michael; Schroer, Trina A.; Hubbard, Ann L.

    1998-01-01

    We studied basolateral-to-apical transcytosis of three classes of apical plasma membrane (PM) proteins in polarized hepatic WIF-B cells and then compared it to the endocytic trafficking of basolaterally recycling membrane proteins. We used antibodies to label the basolateral cohort of proteins at the surface of living cells and then followed their trafficking at 37°C by indirect immunofluorescence. The apical PM proteins aminopeptidase N, 5′nucleotidase, and the polymeric IgA receptor were ef...

  7. Cholesterol depletion of enterocytes. Effect on the Golgi complex and apical membrane trafficking

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Niels-Christiansen, L L; Thorsen, Evy; Immerdal, Lissi; Danielsen, E M

    2000-01-01

    %. Morphologically, the Golgi complex/trans-Golgi network was partially transformed into numerous 100-200 nm vesicles. By immunogold electron microscopy, aminopeptidase N was localized in these Golgi-derived vesicles as well as at the basolateral cell surface, indicating a partial missorting. Biochemically, the...... rates of the Golgi-associated complex glycosylation and association with rafts of newly synthesized aminopeptidase N were reduced, and less of the enzyme had reached the brush border membrane after 2 h of labeling. In contrast, the basolateral Na(+)/K(+)-ATPase was neither missorted nor raft......-associated. Our results implicate the Golgi complex/trans-Golgi network in raft formation and suggest a close relationship between this event and apical membrane trafficking....

  8. Vectorial insertion of apical and basolateral membrane proteins in polarized epithelial cells revealed by quantitative 3D live cell imaging

    OpenAIRE

    Hua, Wei; Sheff, David; Toomre, Derek; Mellman, Ira

    2006-01-01

    Although epithelial cells are known to exhibit a polarized distribution of membrane components, the pathways responsible for delivering membrane proteins to their appropriate domains remain unclear. Using an optimized approach to three-dimensional live cell imaging, we have visualized the transport of newly synthesized apical and basolateral membrane proteins in fully polarized filter-grown Madin–Darby canine kidney cells. We performed a detailed quantitative kinetic analysis of trans-Golgi n...

  9. Cystic fibrosis: model of pathogenesis based on the apical membrane potential

    Directory of Open Access Journals (Sweden)

    Beatrica Kurbel

    2015-02-01

    Full Text Available A simple model of cystic fibrosis (CF is proposed, based on the apical membrane (ApM potential. The ApM of epithelial cells is highly permeable to sodium and activation of CFTRs makes it permeable to chloride. Calculated ApM potentials of cells with activated cystic fibrosis transmembrane conductance regulators (CFTRs are between the sodium and chloride Nernst values and thus allow rapid absorption of both ions in exocrine glands. In CF patients the potential is near the sodium Nernst value and thus more salt is left in the ducts. Simulation predicts that the sodium driving force increases more than 3.5 times if the ApM permeability for Cl- increases from 5-94% of the sodium permeability. In pancreatic ductal cells basolateral sodium bicarbonate cotransporters (pNBC1 allows influx of bicarbonates with sodium. Bicarbonates are exchanged for intraductal chloride by anion exchanger 1 (AE1 in the ApM. Activated CFTRs let some chloride to leak back to ducts, followed by water that dilutes ductal proteins. Replenished intraductal chloride allows more bicarbonate secretion. In CF patients, pancreatic water and bicarbonate secretion is limited by the intraductal chloride pool.

  10. Small GTPases promote actin coat formation on microsporidian pathogens traversing the apical membrane of Caenorhabditis elegans intestinal cells.

    Science.gov (United States)

    Szumowski, Suzannah C; Estes, Kathleen A; Popovich, John J; Botts, Michael R; Sek, Grace; Troemel, Emily R

    2016-01-01

    Many intracellular pathogens co-opt actin in host cells, but little is known about these interactions in vivo. We study the in vivo trafficking and exit of the microsporidian Nematocida parisii, which is an intracellular pathogen that infects intestinal cells of the nematode Caenorhabditis elegans. We recently demonstrated that N. parisii uses directional exocytosis to escape out of intestinal cells into the intestinal tract. Here, we show that an intestinal-specific isoform of C. elegans actin called ACT-5 forms coats around membrane compartments that contain single exocytosing spores, and that these coats appear to form after fusion with the apical membrane. We performed a genetic screen for host factors required for actin coat formation and identified small GTPases important for this process. Through analysis of animals defective in these factors, we found that actin coats are not required for pathogen exit although they may boost exocytic output. Later during infection, we find that ACT-5 also forms coats around membrane-bound vesicles that contain multiple spores. These vesicles are likely formed by clathrin-dependent compensatory endocytosis to retrieve membrane material that has been trafficked to the apical membrane as part of the exocytosis process. These findings provide insight into microsporidia interaction with host cells, and provide novel in vivo examples of the manner in which intracellular pathogens co-opt host actin during their life cycle. PMID:26147591

  11. Genetic diversity of the Plasmodium falciparum apical membrane antigen I gene in parasite population from the China-Myanmar border area.

    Science.gov (United States)

    Zhu, Xiaotong; Zhao, Zhenjun; Feng, Yonghui; Li, Peipei; Liu, Fei; Liu, Jun; Yang, Zhaoqing; Yan, Guiyun; Fan, Qi; Cao, Yaming; Cui, Liwang

    2016-04-01

    To investigate the genetic diversity of the Plasmodium falciparum apical membrane antigen 1 (PfAMA1) gene in Southeast Asia, we determined PfAMA1 sequences from 135 field isolates collected from the China-Myanmar border area and compared them with 956 publically available PfAMA1 sequences from seven global P. falciparum populations. This analysis revealed high genetic diversity of PfAMA1 in global P. falciparum populations with a total of 229 haplotypes identified. The genetic diversity of PfAMA1 gene from the China-Myanmar border is not evenly distributed in the different domains of this gene. Sequence diversity in PfAMA1 from the China-Myanmar border is lower than that observed in Thai, African and Oceanian populations, but higher than that in the South American population. This appeared to correlate well with the levels of endemicity of different malaria-endemic regions, where hyperendemic regions favor genetic cross of the parasite isolates and generation of higher genetic diversity. Neutrality tests show significant departure from neutrality in the entire ectodomain and Domain I of PfAMA1 in the China-Myanmar border parasite population. We found evidence supporting a substantial continent-wise genetic structure among P. falciparum populations, with the highest genetic differentiation detected between the China-Myanmar border and the South American populations. Whereas no alleles were unique to a specific region, there were considerable geographical differences in major alleles and their frequencies, highlighting further necessity to include more PfAMA1 alleles in vaccine designs. PMID:26825252

  12. Surface heat shock protein 90 serves as a potential receptor for calcium oxalate crystal on apical membrane of renal tubular epithelial cells.

    Science.gov (United States)

    Fong-Ngern, Kedsarin; Sueksakit, Kanyarat; Thongboonkerd, Visith

    2016-07-01

    Adhesion of calcium oxalate monohydrate (COM) crystals on renal tubular epithelial cells is a crucial step in kidney stone formation. Finding potential crystal receptors on the apical membrane of the cells may lead to a novel approach to prevent kidney stone disease. Our previous study identified a large number of crystal-binding proteins on the apical membrane of MDCK cells. However, their functional role as potential crystal receptors had not been validated. The present study aimed to address the potential role of heat shock protein 90 (HSP90) as a COM crystal receptor. The apical membrane was isolated from polarized MDCK cells by the peeling method and recovered proteins were incubated with COM crystals. Western blot analysis confirmed the presence of HSP90 in the apical membrane and the crystal-bound fraction. Immunofluorescence staining without permeabilization and laser-scanning confocal microscopy confirmed the surface HSP90 expression on the apical membrane of the intact cells. Crystal adhesion assay showed that blocking surface HSP90 by specific anti-HSP90 antibody and knockdown of HSP90 by small interfering RNA (siRNA) dramatically reduced crystal binding on the apical surface of MDCK cells (by approximately 1/2 and 2/3, respectively). Additionally, crystal internalization assay revealed the presence of HSP90 on the membrane of endocytic vesicle containing the internalized COM crystal. Moreover, pretreatment of MDCK cells with anti-HSP90 antibody significantly reduced crystal internalization (by approximately 1/3). Taken together, our data indicate that HSP90 serves as a potential receptor for COM crystals on the apical membrane of renal tubular epithelial cells and is involved in endocytosis/internalization of the crystals into the cells. PMID:27115409

  13. Retreatment of endodontically failed tooth with wide-open apex using platelet rich fibrin membrane as matrix and an apical plug of Biodentine™

    Directory of Open Access Journals (Sweden)

    Ajinkya Mansing Pawar

    2015-01-01

    Full Text Available The primary reason for an endodontic failure is the persistence or regrowth of bacteria within the root canal system, and such cases require retreatment. The tooth root development and closure of its apex occurs till 3 years after the eruption. Traumatic injuries during this development period result in endodontic complications. While dealing with a tooth, with an open apex the prime objective was eliminating bacteria from the root canal system with minimum irritation to the periapical tissues and induction of apical closure to produce favorable conditions and to confine the root canal filling within the canal space. Traditionally as supported by literature multiple dressings of calcium hydroxide medicament were advocated to induce apical barrier formation followed by an evolution of the apical artificial barrier technique where the mineral trioxide aggregate (MTA was used. Recently introduced Biodentine™ is similar to MTA with its basic composition, which can be used as its substitute. The main difficulty associated while treating teeth with wide-open apices are preventing the overfilling of the restorative materials that serve as an artificial barrier. Use of a matrix overcomes this challenge. Platelet-rich fibrin (PRF a matrix of autologous fibrin, embedded with a large quantity of platelet and leukocyte cytokines during centrifugation can be successfully used as an apical membrane. The present case, reports a novel procedure of apexification of endodontically failed central incisor with open apex using PRF as apical membrane and Biodentine™.

  14. Apical membrane limits urea permeation across the rat inner medullary collecting duct.

    OpenAIRE

    Star, R A

    1990-01-01

    Urea diffuses across the terminal inner medullary collecting duct (IMCD) via a facilitated transport pathway. To examine the mechanism of transcellular urea transport, membrane-apparent urea (Purea) and osmotic water (Pf) permeabilities of IMCD cells were measured by quantitative light microscopy in isolated IMCD-2 tubules perfused in the absence of vasopressin. Basolateral membrane Pf, determined by addition of raffinose to the bath, was 69 microns/s. Basolateral membrane Purea, determined b...

  15. Biogenesis of the rat hepatocyte plasma membrane in vivo: comparison of the pathways taken by apical and basolateral proteins using subcellular fractionation

    International Nuclear Information System (INIS)

    We have used pulse-chase metabolic radiolabeling with L-[35S]methionine in conjunction with subcellular fractionation and specific protein immunoprecipitation techniques to compare the posttranslational transport pathways taken by endogenous domain-specific integral proteins of the rat hepatocyte plasma membrane in vivo. Our results suggest that both apical (HA 4, dipeptidylpeptidase IV, and aminopeptidase N) and basolateral (CE 9 and the asialoglycoprotein receptor [ASGP-R]) proteins reach the hepatocyte plasma membrane with similar kinetics. The mature molecular mass form of each of these proteins reaches its maximum specific radioactivity in a purified hepatocyte plasma membrane fraction after only 45 min of chase. However, at this time, the mature radiolabeled apical proteins are not associated with vesicles derived from the apical domain of the hepatocyte plasma membrane, but instead are associated with vesicles which, by several criteria, appear to be basolateral plasma membrane. These vesicles: (a) fractionate like basolateral plasma membrane in sucrose density gradients and in free-flow electrophoresis; (b) can be separated from the bulk of the likely organellar contaminants, including membranes derived from the late Golgi cisternae, transtubular network, and endosomes; (c) contain the proven basolateral constituents CE 9 and the ASGP-R, as judged by vesicle immunoadsorption using fixed Staphylococcus aureus cells and anti-ASGP-R antibodies; and (d) are oriented with their ectoplasmic surfaces facing outward, based on the results of vesicle immunoadsorption experiments using antibodies specific for the ectoplasmic domain of the ASGP-R. Only at times of chase greater than 45 min do significant amounts of the mature radiolabeled apical proteins arrive at the apical domain, and they do so at different rates

  16. Endocytosis Is Crucial for Cell Polarity and Apical Membrane Recycling in the Filamentous Fungus Aspergillus oryzae▿

    OpenAIRE

    Higuchi, Yujiro; Shoji, Jun-ya; Arioka, Manabu; Kitamoto, Katsuhiko

    2008-01-01

    Establishing the occurrence of endocytosis in filamentous fungi was elusive in the past mainly due to the lack of reliable indicators of endocytosis. Recently, however, it was shown that the fluorescent dye N-(3-triethylammoniumpropyl)-4-(p-diethyl-aminophenyl-hexatrienyl)pyridinium dibromide (FM4-64) and the plasma membrane protein AoUapC (Aspergillus oryzae UapC) fused to enhanced green fluorescent protein (EGFP) were internalized from the plasma membrane by endocytosis. Although the occurr...

  17. Calcium is not involved in the cAMP-mediated stimulation of Cl- conductance in the apical membrane of Necturus gallbladder epithelium.

    Science.gov (United States)

    Kottra, G

    1995-03-01

    The permeability properties of the forskolin-stimulated Cl- conductance in the apical membrane of Necturus gallbladder epithelium and the possible participation of intracellular Ca2+ in its stimulation have been investigated. The anion selectivity sequence as derived from biionic potential measurements (SCN- > I- approximately NO3- > Br- > Cl- > ISE-) differed from the sequence derived from measurements of apical membrane resistance (NO3- approximately Br- approximately Cl- > SCN- > I- approximately ISE-). Accordingly, the conductance was inhibited by SCN- and I- which, from the potential measurements, appeared to be more permeable than Cl-. This finding agrees with observations of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel reported recently. However, none of the commonly used Cl- channel blockers, such as 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS), anthracene-9-carboxylic acid (9-AC) and glibenclamide reduced this conductance in Necturus gallbladder. In contrast to the situation in most other epithelia, elevation of intracellular Ca2+ concentration ([Ca2+]i) by ionomycin stimulated only K+ conductance and not that of Cl- in the apical cell membrane. Chelation of intracellular Ca2+ did not prevent the stimulation of Cl- conductance by forskolin. This indicates that [Ca2+]i does not have even a permissive role in the cyclic adenosine monophosphate-(cAMP)-mediated stimulation process, as would have been expected if exocytosis was involved. Further evidence against the involvement of exocytosis in the stimulation process came from the observation that the stimulation was not associated with an increase in apical membrane capacitance and was not suppressed by disruption of the cytoskeleton by preincubation of the tissue with cytochalasin D. The data indicate that Necturus gallbladder epithelium contains homologues of the CFTR Cl- channel which reside permanently in the

  18. A membrane fusion protein αSNAP is a novel regulator of epithelial apical junctions.

    Directory of Open Access Journals (Sweden)

    Nayden G Naydenov

    Full Text Available Tight junctions (TJs and adherens junctions (AJs are key determinants of the structure and permeability of epithelial barriers. Although exocytic delivery to the cell surface is crucial for junctional assembly, little is known about the mechanisms controlling TJ and AJ exocytosis. This study was aimed at investigating whether a key mediator of exocytosis, soluble N-ethylmaleimide sensitive factor (NSF attachment protein alpha (αSNAP, regulates epithelial junctions. αSNAP was enriched at apical junctions in SK-CO15 and T84 colonic epithelial cells and in normal human intestinal mucosa. siRNA-mediated knockdown of αSNAP inhibited AJ/TJ assembly and establishment of the paracellular barrier in SK-CO15 cells, which was accompanied by a significant down-regulation of p120-catenin and E-cadherin expression. A selective depletion of p120 catenin effectively disrupted AJ and TJ structure and compromised the epithelial barrier. However, overexpression of p120 catenin did not rescue the defects of junctional structure and permeability caused by αSNAP knockdown thereby suggesting the involvement of additional mechanisms. Such mechanisms did not depend on NSF functions or induction of cell death, but were associated with disruption of the Golgi complex and down-regulation of a Golgi-associated guanidine nucleotide exchange factor, GBF1. These findings suggest novel roles for αSNAP in promoting the formation of epithelial AJs and TJs by controlling Golgi-dependent expression and trafficking of junctional proteins.

  19. NHERF1/EBP50 Controls Morphogenesis of 3D Colonic Glands by Stabilizing PTEN and Ezrin-Radixin-Moesin Proteins at the Apical Membrane

    Directory of Open Access Journals (Sweden)

    Maria-Magdalena Georgescu

    2014-04-01

    Full Text Available Na+/H+ exchanger 3 regulating factor 1/ezrin-radixin-moesin (ERM–binding phosphoprotein 50 (NHERF1/EBP50, an adaptor molecule that interacts with the ERM–neurofibromatosis type 2 family of cytoskeletal proteins through its ERM-binding region and with phosphatase and tensin homolog (PTEN and β-catenin through its PDZ domains, has been recently implicated in the progression of various human malignancies, including colorectal cancer (CRC. We report here that NHERF1 controls gland morphogenesis, as demonstrated in three-dimensional (3D human intestinal glands developing from a single nonpolarized cell. Starting from the early two-cell developmental stage, NHERF1 concentrates at the cellular interface in a central membrane disc that marks the apical pole delimiting the forming lumen. NHERF1 depletion leads to severe disruption of the apical-basal polarity, with formation of enlarged and distorted cell spheroids devoid of a central lumen. This characteristic and the increased number of mitoses in NHERF1-depleted spheroids, including multipolar ones, mimic high-grade dysplasia lesions observed in CRC progression. NHERF1 ERM-binding or PDZ-domain mutants fail to localize apically and impair gland formation most likely by outcompeting endogenous ligands, with the latter mutant completely aborting gland development. Examination of NHERF1 ligands showed that even if both ezrin and moesin colocalized with NHERF1 at the apical membrane, moesin but not ezrin depletion disrupted morphogenesis similarly to NHERF1. NHERF1 depletion resulted also in membrane displacement of PTEN and nuclear translocation of β-catenin, events contributing to polarity loss and increased proliferation. These findings reveal an essential role of NHERF1 in epithelial morphogenesis and polarity and validate this 3D system for modeling the molecular changes observed in CRC.

  20. Calmodulin and CaMKII modulate ENaC activity by regulating the association of MARCKS and the cytoskeleton with the apical membrane.

    Science.gov (United States)

    Alli, Abdel A; Bao, Hui-Fang; Liu, Bing-Chen; Yu, Ling; Aldrugh, Summer; Montgomery, Darrice S; Ma, He-Ping; Eaton, Douglas C

    2015-09-01

    Phosphatidylinositol bisphosphate (PIP2) regulates epithelial sodium channel (ENaC) open probability. In turn, myristoylated alanine-rich C kinase substrate (MARCKS) protein or MARCKS-like protein 1 (MLP-1) at the plasma membrane regulates the delivery of PIP2 to ENaC. MARCKS and MLP-1 are regulated by changes in cytosolic calcium; increasing calcium promotes dissociation of MARCKS from the membrane, but the calcium-regulatory mechanisms are unclear. However, it is known that increased intracellular calcium can activate calmodulin and we show that inhibition of calmodulin with calmidazolium increases ENaC activity presumably by regulating MARCKS and MLP-1. Activated calmodulin can regulate MARCKS and MLP-1 in two ways. Calmodulin can bind to the effector domain of MARCKS or MLP-1, inactivating both proteins by causing their dissociation from the membrane. Mutations in MARCKS that prevent calmodulin association prevent dissociation of MARCKS from the membrane. Calmodulin also activates CaM kinase II (CaMKII). An inhibitor of CaMKII (KN93) increases ENaC activity, MARCKS association with ENaC, and promotes MARCKS movement to a membrane fraction. CaMKII phosphorylates filamin. Filamin is an essential component of the cytoskeleton and promotes association of ENaC, MARCKS, and MLP-1. Disruption of the cytoskeleton with cytochalasin E reduces ENaC activity. CaMKII phosphorylation of filamin disrupts the cytoskeleton and the association of MARCKS, MLP-1, and ENaC, thereby reducing ENaC open probability. Taken together, these findings suggest calmodulin and CaMKII modulate ENaC activity by destabilizing the association between the actin cytoskeleton, ENaC, and MARCKS, or MLP-1 at the apical membrane. PMID:26136560

  1. Common channels for water and protons at apical and basolateral cell membranes of frog skin and urinary bladder epithelia. Effects of oxytocin, heavy metals, and inhibitors of H(+)-adenosine triphosphatase

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, B.; Lacoste, I.; Ehrenfeld, J. (Commissariat a l' Energie Atomique, Villefranche-sur-mer (France))

    1991-04-01

    We have compared the response of proton and water transport to oxytocin treatment in isolated frog skin and urinary bladder epithelia to provide further insights into the nature of water flow and H+ flux across individual apical and basolateral cell membranes. In isolated spontaneous sodium-transporting frog skin epithelia, lowering the pH of the apical solution from 7.4 to 6.4, 5.5, or 4.5 produced a fall in pHi in principal cells which was completely blocked by amiloride, indicating that apical Na+ channels are permeable to protons. When sodium transport was blocked by amiloride, the H+ permeability of the apical membranes of principal cells was negligible but increased dramatically after treatment with antidiuretic hormone (ADH). In the latter condition, lowering the pH of the apical solution caused a voltage-dependent intracellular acidification, accompanied by membrane depolarization, and an increase in membrane conductance and transepithelial current. These effects were inhibited by adding Hg2+ (100 microM) or dicyclohexylcarbodiimide (DCCD, 10(-5) M) to the apical bath. Net titratable H+ flux across frog skin was increased from 30 +/- 8 to 115 +/- 18 neq.h-1.cm-2 (n = 8) after oxytocin treatment (at apical pH 5.5 and serosal pH 7.4) and was completely inhibited by DCCD (10(-5) M). The basolateral membranes of the principal cells in frog skin epithelium were found to be spontaneously permeable to H+ and passive electrogenic H+ transport across this membrane was not affected by oxytocin. Lowering the pH of the basolateral bathing solution (pHb) produced an intracellular acidification and membrane depolarization (and an increase in conductance when the normal dominant K+ conductance of this membrane was abolished by Ba2+ 1 mM). These effects of low pHb were blocked by micromolar concentrations of heavy metals (Zn2+, Ni2+, Co2+, Cd2+, and Hg2+).

  2. Protein-mediated inward translocation of phospholipids occurs in both the apical and basolateral plasma membrane domains of epithelial cells

    NARCIS (Netherlands)

    Pomorski, T.; Herrmann, A.; Müller, P.; van Meer, G.F.B.P.; Burger, K.N.J.

    1999-01-01

    The translocation of spin-labeled analogues of phosphatidylcholine (4- doxylpentanoyl-PC, SLPC), phosphatidylethanolamine (SL-PE), phosphatidylserine (SL-PS), and sphingomyelin (SL-SM) from the outer to the inner leaflet of the plasma membrane bilayer was investigated in dog kidney MDCK II and human

  3. Trace Amine-Associated Receptor 1 Localization at the Apical Plasma Membrane Domain of Fisher Rat Thyroid Epithelial Cells Is Confined to Cilia

    Science.gov (United States)

    Szumska, Joanna; Qatato, Maria; Rehders, Maren; Führer, Dagmar; Biebermann, Heike; Grandy, David K.; Köhrle, Josef; Brix, Klaudia

    2015-01-01

    Background The trace amine-associated receptor 1 (Taar1) is one member of the Taar family of G-protein-coupled receptors (GPCR) accepting various biogenic amines as ligands. It has been proposed that Taar1 mediates rapid, membrane-initiated effects of thyronamines, the endogenous decarboxylated and deiodinated relatives of the classical thyroid hormones T4 and T3. Objectives Although the physiological actions of thyronamines in general and 3-iodothyronamine (T1AM) in particular are incompletely understood, studies published to date suggest that synthetic T1AM-activated Taar1 signaling antagonizes thyromimetic effects exerted by T3. However, the location of Taar1 is currently unknown. Methods To fill this gap in our knowledge we employed immunofluorescence microscopy and a polyclonal antibody to detect Taar1 protein expression in thyroid tissue from Fisher rats, wild-type and taar1-deficient mice, and in the polarized FRT cells. Results With this approach we found that Taar1 is expressed in the membranes of subcellular compartments of the secretory pathway and on the apical plasma membrane of FRT cells. Three-dimensional analyses further revealed Taar1 immunoreactivity in cilial extensions of postconfluent FRT cell cultures that had formed follicle-like structures. Conclusions The results suggest Taar1 transport along the secretory pathway and its accumulation in the primary cilium of thyrocytes. These findings are of significance considering the increasing interest in the role of cilia in harboring functional GPCR. We hypothesize that thyronamines can reach and activate Taar1 in thyroid follicular epithelia by acting from within the thyroid follicle lumen, their potential site of synthesis, as part of a nonclassical mechanism of thyroid autoregulation. PMID:26601071

  4. Endodontic management of nonvital permanent teeth having immature roots with one step apexification, using mineral trioxide aggregate apical plug and autogenous platelet-rich fibrin membrane as an internal matrix: Case series.

    Science.gov (United States)

    Sharma, Vivek; Sharma, Sarang; Dudeja, Pooja; Grover, Shibani

    2016-01-01

    A tooth with blunderbuss canal and open apex can be an endodontic challenge because of difficulty in obtaining an apical seal, and existing thin radicular walls which are susceptible to fracture. To overcome the limitations of traditional long-term calcium hydroxide apexification procedures, nonsurgical one step apexification using an array of materials such as mineral trioxide aggregate (MTA) has been suggested. However, adequate compaction of MTA in teeth with wide open apices can be an arduous task, and an internal matrix is required for controlled placement of MTA against which obturating material can be condensed. Platelet-rich fibrin (PRF), a second generation platelet concentrate containing several growth factors that promotes hard and soft-tissue healing, has been used as an internal matrix to create an apical plug of MTA and hence prevent extrusion of filling materials. This case series presents the endodontic management of immature permanent teeth with open apices using internal matrix of autologous PRF membrane and one step apical barrier placement of MTA. PMID:27041904

  5. 人鼻粘膜上皮细胞Na+通道的初步研究%Sodium channels in the apical membrane of human nasal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    张欣欣; 郭永清; 董震; 杨占泉; 张文杰

    2001-01-01

    Objective To study the electrophysiological properties of sodium channels in the apical membrane of human nasal epithelial cells. Method Nasal epithelial cells of human inferior turbinate from patients with obstructive sleep apnea syndrome were cultured in serum free medium on collagen gel-coated membranes at an air-liquid interface and studied by a patch clamp technique. Results In cell-attached patches, a typical single channel current with a conductance of 21.09pS and reversal potential of -50.96 were recorded. The permeability ratio PNa/PK was more than 5.80. In the presence of 10-4 mmol/L amiloride in the pipette, the incidence of sodium channels decreased from 26.67% to 5.13%. This revealed that a population of channels were inhibited by amiloride at a dose of 10-4 mmol/L. Ca2+ at dose of 10-3 mmol/L did not influence the incidence of sodium channels. There was no obvious association between voltage and the open probability of the channels. Conclusions Our results indicate that most Na+ channels in cell-attached patches of human nasal epithelial cells are amiloride-sensitive and Na+ selective. Only a few channels are amiloride-insensitive. The channels were not activated by extracellular Ca2+ and the open probability followed a voltage-independent manner.%目的 明确人鼻粘膜上皮细胞Na+通道的特性,为研究Na+通道在鼻粘膜病理性改变及治疗中的作用奠定理论基础。 方法 利用膜片钳技术对经无血清气-液界面培养的鼻源性鼾症患者手术切除下鼻甲标本的鼻上皮细胞进行Na+通道基本特性研究。 结果 在细胞贴附式膜片上,可记录到典型的单通道电流,其电导为21.09pS,反转电位为-50.96mV,且77.78%反转电位5.80。在Na+通道抑制剂10-4 mmol/L Amiloride存在于电极液内时,Na+通道发生率从26.7%减少到5.13%(P0.05)。电压对开放概率无明显影响。 结论 在细胞贴附式膜片上,人鼻粘膜上皮细胞具有大

  6. Uptake of triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) and dicamba (3,6-dichloro-2-methoxybenzoic acid) from the apical membranes of the human intestinal Caco-2 cells.

    Science.gov (United States)

    Kimura, Osamu; Tsukagoshi, Kensuke; Hayasaka, Moriaki; Endo, Tetsuya

    2012-01-01

    We investigated whether the uptake of triclopyr (3, 5, 6-trichloro-2-pyridinyloxyacetic acid) and dicamba (3,6-dichloro-2-methoxybenzoic acid) across the apical membrane of Caco-2 cells was mediated via proton-linked monocarboxylic acid transporters (MCTs). The uptake of triclopyr from the apical membranes was fast, pH-, temperature-, and concentration dependent, required metabolic energy to proceed, and was competitively inhibited by monocarboxylic acids such as benzoic acid and ferulic acid (substrates of L-lactic acid-insensitive MCTs), but not by L-lactic acid. Thus, the uptake of triclopyr in Caco-2 cells appears to be mediated mainly via L-lactic acid-insensitive MCTs. In contrast, the uptake of dicamba (a benzoic acid derivative) was slow, and it was both pH- and temperature dependent. Coincubation with ferulic acid did not decrease the uptake of dicamba, although coincubation with benzoic acid moderately decreased it. The uptake of dicamba appears to be mediated mainly via passive diffusion, which is in contrast to the uptake of benzoic acid via MCTs. We speculate that the substituted groups in dicamba may inhibit uptake via MCTs. PMID:21766207

  7. Cdc42 and k-Ras Control Endothelial Tubulogenesis through Apical Membrane and Cytoskeletal Polarization: Novel Stimulatory Roles for GTPase Effectors, the Small GTPases, Rac2 and Rap1b, and Inhibitory Influence of Arhgap31 and Rasa1.

    Directory of Open Access Journals (Sweden)

    Pieter R Norden

    Full Text Available A critical and understudied property of endothelial cells is their ability to form lumens and tube networks. Although considerable information has been obtained concerning these issues, including the role of Cdc42 and Rac1 and their effectors such as Pak2, Pak4, Par6b, and co-regulators such as integrins, MT1-MMP and Par3; many key questions remain that are necessary to elucidate molecular and signaling requirements for this fundamental process. In this work, we identify new small GTPase regulators of EC tubulogenesis including k-Ras, Rac2 and Rap1b that act in conjunction with Cdc42 as well as the key downstream effectors, IQGAP1, MRCKβ, beta-Pix, GIT1, and Rasip1 (which can assemble into multiprotein complexes with key regulators including α2β1 integrin and MT1-MMP. In addition, we identify the negative regulators, Arhgap31 (by inactivating Cdc42 and Rac and Rasa1 (by inactivating k-Ras and the positive regulator, Arhgap29 (by inactivating RhoA which play a major functional role during the EC tubulogenic process. Human EC siRNA suppression or mouse knockout of Rasip1 leads to identical phenotypes where ECs form extensive cord networks, but cannot generate lumens or tubes. Essential roles for these molecules during EC tubulogenesis include; i establishment of asymmetric EC cytoskeletal polarization (subapical distribution of acetylated tubulin and basal membrane distribution of F-actin; and ii directed membrane trafficking of pinocytic vacuoles or other intracellular vesicles along acetylated tubulin tracks to the developing apical membrane surface. Cdc42 co-localizes subapically with acetylated tubulin, while Rac1 and k-Ras strongly label vacuole/ vesicle membranes which accumulate and fuse together in a polarized, perinuclear manner. We observe polarized apical membrane and subapical accumulation of key GTPases and effectors regulating EC lumen formation including Cdc42, Rac1, Rac2, k-Ras, Rap1b, activated c-Raf and Rasip1 to control EC

  8. Plasma membrane-bound AGC3 kinases phosphorylate PIN auxin carriers at TPRXS(N/S) motifs to direct apical PIN recycling

    NARCIS (Netherlands)

    P. Dhonukshe; F. Huang; C.S. Galvan-Ampudia; A.P. Mähönen; J. Kleine-Vehn; J. Xu; A. Quint; K. Prasad; J. Friml; B. Scheres; R. Offringa

    2010-01-01

    Polar membrane cargo delivery is crucial for establishing cell polarity and for directional transport processes. In plants, polar trafficking mediates the dynamic asymmetric distribution of PIN FORMED (PIN) carriers, which drive polar cell-to-cell transport of the hormone auxin, thereby generating a

  9. Aminopeptidase N is directly sorted to the apical domain in MDCK cells

    DEFF Research Database (Denmark)

    Wessels, H P; Hansen, Gert Helge; Fuhrer, C; Look, A T; Sjöström, H; Norén, Ove; Spiess, M

    In different epithelial cell types, integral membrane proteins appear to follow different sorting pathways to the apical surface. In hepatocytes, several apical proteins were shown to be transported there indirectly via the basolateral membrane, whereas in MDCK cells a direct sorting pathway from...... the trans-Golgi-network to the apical membrane has been demonstrated. However, different proteins had been studied in these cells. To compare the sorting of a single protein in both systems, we have expressed aminopeptidase N, which already had been shown to be sorted indirectly in hepatocytes, in...... transfected MDCK cells. As expected, it was predominantly localized to the apical domain of the plasma membrane. By monitoring the appearance of newly synthesized aminopeptidase N at the apical and basolateral surface, it was found to be directly sorted to the apical domain in MDCK cells, indicating that the...

  10. A restricted set of apical proteins recycle through the trans-Golgi network in MDCK cells.

    OpenAIRE

    Brändli, A W; Simons, K

    1989-01-01

    Sorting of newly synthesized proteins destined for the apical plasma membrane takes place in the trans-Golgi network (TGN) in MDCK cells. This process is most likely receptor mediated and requires components that recycle between both compartments. We have developed an assay to detect apical proteins that recycle through the sialyltransferase-containing TGN. Cell surface glycoproteins were exogalactosylated apically using a mutant cell line derived from MDCK, MDCKII-RCAr. The mutant exhibits i...

  11. Roles of external and cellular Cl- ions on the activation of an apical electrodiffusional Cl- pathway in toad skin.

    Science.gov (United States)

    Procopio, J; Lacaz-Vieira, F

    1990-07-01

    This study is concerned with the short-circuit current, Isc, responses of the Cl(-)-transporting cells of toad skin submitted to sudden changes of the external Cl- concentration, [Cl]o. Sudden changes of [Cl]o, carried out under apical membrane depolarization, allowed comparison of the roles of [Cl]o and [Cl]cell on the activation of the apical Cl- pathways. Equilibration of short-circuited skins symmetrically in K-Ringer's solutions of different Cl- concentrations permitted adjustment of [Cl]cell to different levels. For a given Cl- concentration (in the range of 11.7 to 117 mM) on both sides of a depolarized apical membrane, this structure exhibits a high Cl- permeability, P(Cl)apical. On the other hand, for the same range of [Cl]cell but with [Cl]o = 0, P(Cl)apical is reduced to negligible values. These observations indicate that when the apical membrane is depolarized P(Cl)apical is modulated by [Cl]o; in the absence of external Cl- ions, intracellular Cl- is not sufficient to activate P(Cl)apical. Computer simulation shows that the fast Cl- currents induced across the apical membrane by sudden shifts of [Cl]o from a control equilibrium value strictly follow the laws of electrodiffusion. For each experimental group, the computer-generated Isc versus [( Cl]cell - [Cl]o) curve which best fits the experimental data can only be obtained by a unique pair of P(Cl)apical and Rb (resistance of the basolateral membrane), thus allowing the calculation of these parameters. The electrodiffusional behavior of the net Cl- flux across the apical membrane supports the channel nature of the apical Cl- pathways in the Cl(-)-transporting cells. Cl- ions contribute significantly to the overall conductance of the basolateral membrane even in the presence of a high K concentration in the internal solution. PMID:1698229

  12. Copper directs ATP7B to the apical domain of hepatic cells via basolateral endosomes.

    Science.gov (United States)

    Nyasae, Lydia K; Schell, Michael J; Hubbard, Ann L

    2014-12-01

    Physiologic Cu levels regulate the intracellular location of the Cu ATPase ATP7B. Here, we determined the routes of Cu-directed trafficking of endogenous ATP7B in the polarized hepatic cell line WIF-B and in the liver in vivo. Copper (10 µm) caused ATP7B to exit the trans-Golgi network (TGN) in vesicles, which trafficked via large basolateral endosomes to the apical domain within 1 h. Although perturbants of luminal acidification had little effect on the TGN localization of ATP7B in low Cu, they blocked delivery to the apical membrane in elevated Cu. If the vesicular proton-pump inhibitor bafilomycin-A1 (Baf) was present with Cu, ATP7B still exited the TGN, but accumulated in large endosomes located near the coverslip, in the basolateral region. Baf washout restored ATP7B trafficking to the apical domain. If ATP7B was staged apically in high Cu, Baf addition promoted the accumulation of ATP7B in subapical endosomes, indicating a blockade of apical recycling, with concomitant loss of ATP7B at the apical membrane. The retrograde pathway to the TGN, induced by Cu removal, was far less affected by Baf than the anterograde (Cu-stimulated) case. Overall, loss of acidification-impaired Cu-regulated trafficking of ATP7B at two main sites: (i) sorting and exit from large basolateral endosomes and (ii) recycling via endosomes near the apical membrane. PMID:25243755

  13. Membraner

    DEFF Research Database (Denmark)

    Bach, Finn

    2009-01-01

    Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner......Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner...

  14. Membrane domains and polarized trafficking of sphingolipids

    NARCIS (Netherlands)

    Maier, O; Slimane, TA; Hoekstra, D

    2001-01-01

    The plasma membrane of polarized cells consists of distinct domains, the apical and basolateral membrane that are characterized by a distinct lipid and protein content. Apical protein transport is largely mediated by (glyco)sphingolipid-cholesterol enriched membrane microdomains, so called rafts. In

  15. Apical ammonium inhibition of cAMP-stimulated secretion in T84 cells is bicarbonate dependent.

    Science.gov (United States)

    Worrell, Roger T; Best, Alison; Crawford, Oscar R; Xu, Jie; Soleimani, Manoocher; Matthews, Jeffrey B

    2005-10-01

    Normal human colonic luminal (NH(4)(+)) concentration ([NH(4)(+)]) ranges from approximately 10 to 100 mM. However, the nature of the effects of NH(4)(+) on transport, as well as NH(4)(+) transport itself, in colonic epithelium is poorly understood. We elucidate here the effects of apical NH(4)(+) on cAMP-stimulated Cl(-) secretion in colonic T84 cells. In HEPES-buffered solutions, 10 mM apical NH(4)(+) had no significant effect on cAMP-stimulated current. In contrast, 10 mM apical NH(4)(+) reduced current within 5 min to 61 +/- 4% in the presence of 25 mM HCO(3)(-). Current inhibition was not simply due to an increase in extracellular K(+)-like cations, in that the current magnitude was 95 +/- 5% with 10 mM apical K(+) and 46 +/- 3% with 10 mM apical NH(4)(+) relative to that with 5 mM apical K(+). We previously demonstrated that inhibition of Cl(-) secretion by basolateral NH(4)(+) occurs in HCO(3)(-)-free conditions and exhibits anomalous mole fraction behavior. In contrast, apical NH(4)(+) inhibition of current in HCO(3)(-) buffer did not show anomalous mole fraction behavior and followed the absolute [NH(4)(+)] in K(+)-NH(4)(+) mixtures, where K(+) concentration + [NH(4)(+)] = 10 mM. The apical NH(4)(+) inhibitory effect was not prevented by 100 microM methazolamide, suggesting no role for apical carbonic anhydrase. However, apical NH(4)(+) inhibition of current was prevented by 10 min of pretreatment of the apical surface with 500 microM DIDS, 100 microM 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNDS), or 25 microM niflumic acid, suggesting a role for NH(4)(+) action through an apical anion exchanger. mRNA and protein for the apical anion exchangers SLC26A3 [downregulated in adenoma (DRA)] and SLC26A6 [putative anion transporter (PAT1)] were detected in T84 cells by RT-PCR and Northern and Western blots. DRA and PAT1 appear to associate with CFTR in the apical membrane. We conclude that the HCO(3)(-) dependence of apical NH(4)(+) inhibition of secretion is

  16. A transferrin-like GPI-linked iron-binding protein in detergent-insoluble noncaveolar microdomains at the apical surface of fetal intestinal epithelial cells

    DEFF Research Database (Denmark)

    Danielsen, E M; van Deurs, B

    1995-01-01

    ultracryosections of mucosal tissue, the protein was localized to the apical surface of the enterocytes, whereas it was absent from the basolateral plasma membrane. Interestingly, it was mainly found in patches of flat or invaginated apical membrane domains rather than at the surface of microvilli. Caveolae were...

  17. Apical Localization of Sodium-Dependent Glucose Transporter SGLT1 is Maintained by Cholesterol and Microtubules

    OpenAIRE

    Suzuki, Takeshi; Matsuzaki, Toshiyuki; Hagiwara, Haruo; Aoki, Takeo; Tajika-Takahashi, Yukiko; Takata, Kuniaki

    2006-01-01

    A GFP-labeled sodium-dependent glucose transporter SGLT1 (SGLT-GFP) was transfected into MDCK cells. SGLT-GFP was localized at the apical membrane in confluent cells. When cellular cholesterol was depleted by methyl-β-cyclodextrin (MβCD) treatment, the localization of SGLT-GFP gradually switched from apical to whole plasma membrane. Time-lapse microscopy revealed that the effect of MβCD appeared within 30 min, and that the transition of SGLT-GFP to the whole plasma membrane was completed with...

  18. Apical Transport of Influenza A Virus Ribonucleoprotein Requires Rab11-positive Recycling Endosome

    OpenAIRE

    Momose, Fumitaka; Sekimoto, Tetsuya; Ohkura, Takashi; Jo, Shuichi; Kawaguchi, Atsushi; Nagata, Kyosuke; Morikawa, Yuko

    2011-01-01

    Influenza A virus RNA genome exists as eight-segmented ribonucleoprotein complexes containing viral RNA polymerase and nucleoprotein (vRNPs). Packaging of vRNPs and virus budding take place at the apical plasma membrane (APM). However, little is known about the molecular mechanisms of apical transport of newly synthesized vRNP. Transfection of fluorescent-labeled antibody and subsequent live cell imaging revealed that punctate vRNP signals moved along microtubules rapidly but intermittently i...

  19. Deep-apical tubules: dynamic lipid-raft microdomains in the brush-border region of enterocytes

    DEFF Research Database (Denmark)

    Hansen, Gert H; Pedersen, Jens; Niels-Christiansen, Lise-Lotte;

    2003-01-01

    raft microdomains. Deep-apical tubules were positioned close to the actin rootlets of adjacent microvilli in the terminal web region, which had a diameter of 50-100 nm, and penetrated up to 1 microm into the cytoplasm. Markers for transcytosis, IgA and the polymeric immunoglobulin receptor, as well as...... lipid raft-containing compartments, but little is otherwise known about these raft microdomains. We therefore studied in closer detail apical lipid-raft compartments in enterocytes by immunogold electron microscopy and biochemical analyses. Novel membrane structures, deep-apical tubules, were visualized...... the resident brush-border enzyme aminopeptidase N, were present in these deep-apical tubules. We propose that deep-apical tubules are a specialized lipid-raft microdomain in the brush-border region functioning as a hub in membrane trafficking at the brush border. In addition, the sensitivity to...

  20. Surgical treatments for vaginal apical prolapse.

    Science.gov (United States)

    Kong, Mi Kyung; Bai, Sang Wook

    2016-07-01

    Pelvic organ prolapse is a common condition, occurring in up to 11% of women in the United States. Often, pelvic organ prolapse recurs after surgery; when it recurs after hysterectomy, it frequently presents as vaginal apical prolapse. There are many different surgical treatments for vaginal apical prolapse; among them, abdominal sacral colpopexy is considered the gold standard. However, recent data reveal that other surgical procedures also result in good outcome. This review discusses the various surgical treatments for vaginal apical prolapse including their risks and benefits. PMID:27462591

  1. Apical Na+ permeability of frog skin during serosal Cl- replacement.

    Science.gov (United States)

    Leibowich, S; DeLong, J; Civan, M M

    1988-05-01

    Gluconate substitution for serosal Cl- reduces the transepithelial short-circuit current (Isc) and depolarizes short-circuited frog skins. These effects could result either from inhibition of basolateral K+ conductance, or from two actions to inhibit both apical Na+ permeability (PapNa) and basolateral pump activity. We have addressed this question by studying whole-and split-thickness frog skins. Intracellular Na+ concentration (CcNa) and PapNa have been monitored by measuring the current-voltage relationship for apical Na+ entry. This analysis was conducted by applying trains of voltage pulses, with pulse durations of 16 to 32 msec. Estimates of PapNa and CcNa were not detectably dependent on pulse duration over the range 16 to 80 msec. Serosal Cl- replacement uniformly depolarized short-circuited tissues. The depolarization was associated with inhibition of Isc across each split skin, but only occasionally across the whole-thickness preparations. This difference may reflect the better ionic exchange between the bulk medium and the extracellular fluid in contact with the basolateral membranes, following removal of the underlying dermis in the split-skin preparations. PapNa was either unchanged or increased, and CcNa either unchanged or reduced after the anionic replacement. These data are incompatible with the concept that serosal Cl- replacement inhibits PapNa and Na,K-pump activity. Gluconate substitution likely reduces cell volume, triggering inhibition of the basolateral K+ channels, consistent with the data and conclusions of S.A. Lewis, A.G. Butt, M.J. Bowler, J.P. Leader and A.D.C. Macknight (J. Membrane Biol. 83:119-137, 1985) for toad bladder. The resulting depolarization reduces the electrical force favoring apical Na+ entry. The volume-conductance coupling serves to conserve volume by reducing K+ solute loss. Its molecular basis remains to be identified. PMID:2458472

  2. Fetal antigen 1 (FA1), a circulating member of the epidermal growth factor (EGF) superfamily

    DEFF Research Database (Denmark)

    Jensen, Charlotte Harken; Krogh, T N; Støving, René Klinkby;

    1997-01-01

    We describe an ELISA technique for quantification of fetal antigen 1 (FA1), a glycoprotein belonging to the EGF-superfamily. The ELISA is based on immunospecifically purified polyclonal antibodies and has a dynamic range of 0.7-5.3 ng/ml, intra- and inter-assay C.V.s of less than 3.2% and an...

  3. Activation of an apical Cl- conductance by Ca2+ ionophores in cystic fibrosis airway epithelia.

    Science.gov (United States)

    Willumsen, N J; Boucher, R C

    1989-02-01

    Cystic fibrosis (CF) airway epithelia express a defect in adenosine 3',5'-cyclic monophosphate (cAMP)-dependent regulation of apical membrane Cl- channels. Recent patch-clamp studies have raised the possibility that Ca2+ -dependent mechanisms for the activation of Cl- secretion may be preserved in CF airway epithelia. To determine 1) whether intact normal (N1) and CF airway epithelia exhibit a Ca2+ -dependent mechanism for activation of Cl- secretion and 2) whether Ca2+ -dependent mechanism for activation of Cl- secretion and 2) whether Ca2+ -dependent mechanisms initiate Cl- secretion via activation of an apical membrane Cl- conductance (GCl-), nasal epithelia from N1 and CF subjects were cultured on collagen membranes, and responses to isoproterenol or Ca2- ionophores [A23187 10(-6) M; ionomycin (10(-5)M)] were measured with transepithelial and intracellular techniques. Isoproterenol induced activation of an apical membrane GCl- in N1 cultures but was ineffective in CF. In contrast, in both N1 and CF amiloride-pretreated cultures, A23187 induced an increase in the equivalent short-circuit current that was associated with an activation of an apical membrane Gc1- and was bumetanide inhibitable. A23187 addition during superfusion of the lumen with a low Cl- (3 mM) solution reduced intracellular Cl- activity of CF cells. A Ca2+ ionophore of different selectivity properties, ionomycin, was also an effective Cl- secretagogue in both N1 and CF cultures. We conclude that 1) the A23187 induced Cl- secretion via activation of an apical GCl- in N1 human nasal epithelium, and 2) in contrast to an isoproterenol-dependent path, a Ca2+ -dependent path for GCl- activation is preserved in CF epithelia. PMID:2465689

  4. A Comparative Study of Apical Healing of Open Apices Using MTA and Ca(OH2 Apical Plugs in Cats

    Directory of Open Access Journals (Sweden)

    M. H. Zarrabi

    2005-06-01

    Full Text Available Statement of problem: Endodontic treatment of necrotic teeth with open apices is a challenge. After ruling out surgery as a treatment scheme and introduction of the multivisit apexification which in turn had its disadvantages, apical plug seems to be a suitable substitute treatment plan for such cases. Apical plug makes the treatment through formation of a barrier against the obturating material in a single visit.Purpose: The purpose of this study was to compare histologically the periapical healing using MTA and calcium hydroxide apical plugs after intervals of 4 and 12 weeks in cats.Materials and Methods: In this clinical trial study 64 canines of 16 healthy and mature cats were divided into 3 groups after a periapical lesion formation by over instrumentation in the apical area with files up to no.120. The first group included 24 teeth on which MTA apical plug was applied. The second group included 24 teeth on which Ca (OH 2 apical plug was applied. In both groups the canals were filled with gutta percha and sealer. The third group included 16 control teeth whose canals were left empty after instrumentation and debridement. The access cavities of all teeth were sealed with varnish and amalgam and the vital perfusion of cats was performed in 4 and 12 week intervals. Statistical analysis was established by χ2 and independence test.Results: After 4 weeks, periapical healing in the first group was 90%, in the second group 80% and in the third group, it was only 12.5 %. After 12 weeks, periapical healing occurred in 100% of the MTA group, while it was 57.1% in the second and 40%in the third group .Generally, in the study of histological parameters of healing, no statistical significant difference was observed between the 2 experimental groups,although the MTA group results were much better than the Ca (OH 2 group especially at 12 weeks.Conclusion: The use of MTA apical plug is more effective than Ca (OH 2 in treatment of necrotic teeth with open

  5. Shoot Apical Meristem Organization in Several Philippine Species of Selaginella

    OpenAIRE

    Prescillano Zamora; V. B. Bagaoisan-Cosico

    1993-01-01

    This paper reports for the first time the occurrence of two types of shoot apical meristem organization on the main and lateral shoots of eight Philippine species of Selaginella: (1) shoot apical meristem with a single lenticular apical cell in S. cupressina and S. delicatula and (a) shoot apical meristem with a row of several prominent prismatic apical cells in the lateral plane in S. jagorii, S. halconensis), S. involvens (S. polyura, S. peltata), S. flagellifera (S. biformis), S. nummulari...

  6. Apical root resorption in orthodontically treated adults.

    Science.gov (United States)

    Baumrind, S; Korn, E L; Boyd, R L

    1996-09-01

    This study analyzed the relationship in orthodontically treated adults between upper central incisor displacement measured on lateral cephalograms and apical root resorption measured on anterior periapical x-ray films. A multiple linear regression examined incisor displacements in four directions (retraction, advancement, intrusion, and extrusion) as independent variables, attempting to account for observed differences in the dependent variable, resorption. Mean apical resorption was 1.36 mm (sd +/- 1.46, n = 73). Mean horizontal displacement of the apex was -0.83 mm (sd +/- 1.74, n = 67); mean vertical displacement was 0.19 mm (sd +/- 1.48, n = 67). The regression coefficients for the intercept and for retraction were highly significant; those for extrusion, intrusion, and advancement were not. At the 95% confidence level, an average of 0.99 mm (se = +/- 0.34) of resorption was implied in the absence of root displacement and an average of 0.49 mm (se = +/- 0.14) of resorption was implied per millimeter of retraction. R2 for all four directional displacement variables (DDVs) taken together was only 0.20, which implied that only a relatively small portion of the observed apical resorption could be accounted for by tooth displacement alone. In a secondary set of univariate analyses, the associations between apical resorption and each of 14 additional treatment-related variables were examined. Only Gender, Elapsed Time, and Total Apical Displacement displayed statistically significant associations with apical resorption. Additional multiple regressions were then performed in which the data for each of these three statistically significant variables were considered separately, with the data for the four directional displacement variables. The addition of information on Elapsed Time or Total Apical Displacement did not explain a significant additional portion of the variability in apical resorption. On the other hand, the addition of information on Gender to the

  7. Analyses of Interactions Between Heparin and the Apical Surface Proteins of Plasmodium falciparum

    Science.gov (United States)

    Kobayashi, Kyousuke; Takano, Ryo; Takemae, Hitoshi; Sugi, Tatsuki; Ishiwa, Akiko; Gong, Haiyan; Recuenco, Frances C.; Iwanaga, Tatsuya; Horimoto, Taisuke; Akashi, Hiroomi; Kato, Kentaro

    2013-11-01

    Heparin, a sulfated glycoconjugate, reportedly inhibits the blood-stage growth of the malaria parasite Plasmodium falciparum. Elucidation of the inhibitory mechanism is valuable for developing novel invasion-blocking treatments based on heparin. Merozoite surface protein 1 has been reported as a candidate target of heparin; however, to better understand the molecular mechanisms involved, we characterized the molecules that bind to heparin during merozoite invasion. Here, we show that heparin binds only at the apical tip of the merozoite surface and that multiple heparin-binding proteins localize preferentially in the apical organelles. To identify heparin-binding proteins, parasite proteins were fractionated by means of heparin affinity chromatography and subjected to immunoblot analysis with ligand-specific antibodies. All tested members of the Duffy and reticulocyte binding-like families bound to heparin with diverse affinities. These findings suggest that heparin masks the apical surface of merozoites and blocks interaction with the erythrocyte membrane after initial attachment.

  8. Proteome Based Construction of the Lymphocyte Function-Associated Antigen 1 (LFA-1) Interactome in Human Dendritic Cells.

    Science.gov (United States)

    Eich, Christina; Lasonder, Edwin; Cruz, Luis J; Reinieren-Beeren, Inge; Cambi, Alessandra; Figdor, Carl G; Buschow, Sonja I

    2016-01-01

    The β2-integrin lymphocyte function-associated antigen 1 (LFA-1) plays an important role in the migration, adhesion and intercellular communication of dendritic cells (DCs). During the differentiation of human DCs from monocyte precursors, LFA-1 ligand binding capacity is completely lost, even though its expression levels were remained constant. Yet LFA-1-mediated adhesive capacity on DCs can be regained by exposing DCs to the chemokine CCL21, suggesting a high degree of regulation of LFA-1 activity during the course of DC differentiation. The molecular mechanisms underlying this regulation of LFA-1 function in DCs, however, remain elusive. To get more insight we attempted to identify specific LFA-1 binding partners that may play a role in regulating LFA-1 activity in DCs. We used highly sensitive label free quantitative mass-spectrometry to identify proteins co-immunoprecipitated (co-IP) with LFA-1 from ex vivo generated DCs. Among the potential binding partners we identified not only established components of integrin signalling pathways and cytoskeletal proteins, but also several novel LFA-1 binding partners including CD13, galectin-3, thrombospondin-1 and CD44. Further comparison to the LFA-1 interaction partners in monocytes indicated that DC differentiation was accompanied by an overall increase in LFA-1 associated proteins, in particular cytoskeletal, signalling and plasma membrane (PM) proteins. The here presented LFA-1 interactome composed of 78 proteins thus represents a valuable resource of potential regulators of LFA-1 function during the DC lifecycle. PMID:26889827

  9. CAMSAP3 orients the apical-to-basal polarity of microtubule arrays in epithelial cells.

    Science.gov (United States)

    Toya, Mika; Kobayashi, Saeko; Kawasaki, Miwa; Shioi, Go; Kaneko, Mari; Ishiuchi, Takashi; Misaki, Kazuyo; Meng, Wenxiang; Takeichi, Masatoshi

    2016-01-12

    Polarized epithelial cells exhibit a characteristic array of microtubules that are oriented along the apicobasal axis of the cells. The minus-ends of these microtubules face apically, and the plus-ends face toward the basal side. The mechanisms underlying this epithelial-specific microtubule assembly remain unresolved, however. Here, using mouse intestinal cells and human Caco-2 cells, we show that the microtubule minus-end binding protein CAMSAP3 (calmodulin-regulated-spectrin-associated protein 3) plays a pivotal role in orienting the apical-to-basal polarity of microtubules in epithelial cells. In these cells, CAMSAP3 accumulated at the apical cortices, and tethered the longitudinal microtubules to these sites. Camsap3 mutation or depletion resulted in a random orientation of these microtubules; concomitantly, the stereotypic positioning of the nucleus and Golgi apparatus was perturbed. In contrast, the integrity of the plasma membrane was hardly affected, although its structural stability was decreased. Further analysis revealed that the CC1 domain of CAMSAP3 is crucial for its apical localization, and that forced mislocalization of CAMSAP3 disturbs the epithelial architecture. These findings demonstrate that apically localized CAMSAP3 determines the proper orientation of microtubules, and in turn that of organelles, in mature mammalian epithelial cells. PMID:26715742

  10. Incidental apical disease at CT scanning

    International Nuclear Information System (INIS)

    Apical caps are commonly noted on standard radiographs. This paper determines how often abnormalities in the extreme apex of the lung could be identified on CT scans obtained for other reasons. A total of 158 consecutive CT scans were reviewed prospectively. Excluded were patients with obvious upper lobe pleural or parenchymal disease. Apical abnormalities were identified in 74 (46.8%) of the 158 cases. The prevalence increased with age (19% in the 8-39-year age group and 82% in patients older than 80 years). Opacities were unilateral in 44.5% and bilateral in 55.5%. The most common abnormality was linear opacities (95%)

  11. Cleavage of endogenous γENaC and elevated abundance of αENaC are associated with increased Na+ transport in response to apical fluid volume expansion in human H441 airway epithelial cells

    OpenAIRE

    Tan, Chong D.; Selvanathar, Indusha A.; Baines, Deborah L.

    2011-01-01

    Using human H441 airway epithelial cells cultured at air–liquid interface (ALI), we have uniquely correlated the functional response to apical fluid volume expansion with the abundance and cleavage of endogenous α- and γENaC proteins in the apical membrane. Monolayers cultured at ALI rapidly elevated I sc when inserted into fluid-filled Ussing chambers. The increase in I sc was not significantly augmented by the apical addition of trypsin, and elevation was abolished by the protease inhibitor...

  12. Apical dominance in Alstroemeria cultured in vitro

    NARCIS (Netherlands)

    Pumisutapon, P.; Visser, R.G.F.; Klerk, de G.J.M.

    2009-01-01

    Apical dominance in Alstroemeria is studied to develop an improved propagation protocol for this crop. Four types of explants were prepared: an intact rhizome with two intact shoots (+R+2S), an intact rhizome with two decapitated shoots (+R-2S), a decapitated rhizome with two intact shoots (-R+2S),

  13. Cell division activity during apical hook development

    NARCIS (Netherlands)

    Raz, V.; Koornneef, M.

    2001-01-01

    Growth during plant development is predominantly governed by the combined activities of cell division and cell elongation. The relative contribution of both activities controls the growth of a tissue. A fast change in growth is exhibited at the apical hypocotyl of etiolated seedlings where cells gro

  14. Light sheet microscopy for tracking single molecules on the apical surface of living cells.

    Science.gov (United States)

    Li, Yu; Hu, Ying; Cang, Hu

    2013-12-12

    Single particle tracking is a powerful tool to study single molecule dynamics in living biological samples. However, current tracking techniques, which are based mainly on epifluorescence, confocal, or TIRF microscopy, have difficulties in tracking single molecules on the apical surface of a cell. We present here a three-dimensional (3D) single particle tracking technique that is based on prism coupled light-sheet microscopy (PCLSM). This novel design provides a signal-to-noise ratio comparable to confocal microscopy while it has the capability of illuminating at arbitrary depth. We demonstrate tracking of single EGF molcules on the apical surface of live cell membranes from their binding to EGF receptors until they are internalized or photobleached. We found that EGF exhibits multiple diffusion behaviors on live A549 cell membranes. At room temperature, the average diffusion coefficient of EGF on A549 cells was measured to be 0.13 μm(2)/s. Depletion of cellular cholesterol with methyl-β-cyclodextrin leads to a broader distribution of diffusion coefficients and an increase of the average diffusion coefficient at room temperature. This light-sheet based 3D single particle tracking technique solves the technique difficulty of tracking single particles on apical membranes and is able to document the whole "lifetime" of a particle from binding till photobleaching or internalization. PMID:23895420

  15. Transcription factor Fos-related antigen 1 is an effective target for a breast cancer vaccine

    Science.gov (United States)

    Luo, Yunping; Zhou, He; Mizutani, Masato; Mizutani, Noriko; Reisfeld, Ralph A.; Xiang, Rong

    2003-07-01

    Protection against breast cancer was achieved with a DNA vaccine against murine transcription factor Fos-related antigen 1, which is overexpressed in aggressively proliferating D2F2 murine breast carcinoma. Growth of primary s.c. tumor and dissemination of pulmonary metastases was markedly suppressed by this oral DNA vaccine, carried by attenuated Salmonella typhimurium, encoding murine Fos-related antigen 1, fused with mutant polyubiquitin, and cotransformed with secretory murine IL-18. The life span of 60% of vaccinated mice was tripled in the absence of detectable tumor growth after lethal tumor cell challenge. Immunological mechanisms involved activation of T, natural killer, and dendritic cells, as indicated by up-regulation of their activation markers and costimulatory molecules. Markedly increased specific target cell lysis was mediated by both MHC class I-restricted CD8+ T cells and natural killer cells isolated from splenocytes of vaccinated mice, including a significant release of proinflammatory cytokines IFN- and IL-2. Importantly, fluorescence analysis of fibroblast growth factor 2 and tumor cell-induced vessel growth in Matrigel plugs demonstrated marked suppression of angiogenesis only in vaccinated animals. Taken together, this multifunctional DNA vaccine proved effective in protecting against growth and metastases of breast cancer by combining the action of immune effector cells with suppression of tumor angiogenesis. vaccine | tumor | metastases | antiangiogenesis

  16. Type III apical transportation of root canal

    Directory of Open Access Journals (Sweden)

    Shiv P Mantri

    2012-01-01

    Full Text Available Procedural accidents leading to complications such as canal transportation have been ascribed to inapt cleaning and shaping concepts. Canal transportation is an undesirable deviation from the natural canal path. Herewith a case of apical transportation of root canal resulting in endodontic retreatment failure and its management is presented. A healthy 21-year-old young male presented discomfort and swelling associated with painful endodontically retreated maxillary incisor. Radiograph revealed periradicular radiolucency involving underfilled 11 and overfilled 12. Insufficiently obturated 11 exhibited apical transportation of canal. This type III transportation was treated by periradicular surgery and repair using white mineral trioxide aggregate (MTA. Comfortable asymptomatic patient presented uneventful healing at third and fourth month recall visits. A decrease in the size of radiolucency in radiograph supported the clinical finding. In the present case, MTA is useful in repairing the transportation defect. The result of these procedures is predictable and successful.

  17. Shoot Apical Meristem Organization in Several Philippine Species of Selaginella

    Directory of Open Access Journals (Sweden)

    Prescillano Zamora

    1993-06-01

    Full Text Available This paper reports for the first time the occurrence of two types of shoot apical meristem organization on the main and lateral shoots of eight Philippine species of Selaginella: (1 shoot apical meristem with a single lenticular apical cell in S. cupressina and S. delicatula and (a shoot apical meristem with a row of several prominent prismatic apical cells in the lateral plane in S. jagorii, S. halconensis, S. involvens (S. polyura, S. peltata, S. flagellifera (S. biformis, S. nummularia, S. aristata, and S. philippina (endemic.

  18. Auxin at the Shoot Apical Meristem

    OpenAIRE

    Vernoux, Teva; Besnard, Fabrice; Traas, Jan,

    2010-01-01

    Plants continuously generate new tissues and organs through the activity of populations of undifferentiated stem cells, called meristems. Here, we discuss the so-called shoot apical meristem (SAM), which generates all the aerial parts of the plant. It has been known for many years that auxin plays a central role in the functioning of this meristem. Auxin is not homogeneously distributed at the SAM and it is thought that this distribution is interpreted in terms of differential gene expression...

  19. Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis.

    Science.gov (United States)

    Adachi, Makoto; Kiho, Kazuki; Sekine, Genta; Ohta, Takahisa; Matsubara, Makoto; Yoshida, Takakazu; Katsumata, Akitoshi; Tanuma, Jun-ichi; Sumitomo, Shinichiro

    2015-12-01

    Inflammatory myofibroblastic tumors (IMTs) are rare. IMTs of the head and neck occur in all age groups, from neonates to old age, with the highest incidence occurring in childhood and early adulthood. An IMT has been defined as a histologically distinctive lesion of uncertain behavior. This article describes an unusual case of IMT mimicking apical periodontitis in the mandible of a 42-year-old man. At first presentation, the patient showed spontaneous pain and percussion pain at teeth #28 to 30, which continued after initial endodontic treatment. Panoramic radiography revealed a radiolucent lesion at the site. Cone-beam computed tomographic imaging showed osteolytic lesions, suggesting an aggressive neoplasm requiring incisional biopsy. Histopathological examination indicated an IMT. The lesion was removed en bloc under general anesthesia, and the patient manifested no clinical evidence of recurrence for 24 months. Lesions of nonendodontic origin should be included in the differential diagnosis of apical periodontitis. Every available diagnostic tool should be used to confirm the diagnosis. Cone-beam computed tomographic imaging is very helpful for differential diagnosis in IMTs mimicking apical periodontitis. PMID:26602450

  20. Uteroglobin, an apically secreted protein of the uterine epithelium, is secreted non-polarized form MDCK cells and mainly basolaterally from Caco-2 cells

    DEFF Research Database (Denmark)

    Vogel, L K; Suske, G; Beato, M;

    1993-01-01

    A complete cDNA encoding rabbit uteroglobin was constructed and expressed in MDCK and Caco-2 cells. The MDCK cells secrete uteroglobin in approximately equal amounts to the apical and the basolateral side, whereas the Caco-2 cells secrete uteroglobin mainly to the basolateral side. Both MDCK and ...... the endometrial epithelium has an apical default pathway or recognises a sorting signal not recognised by MDCK cells and Caco-2 cells. Our data thus show that a soluble molecule can be secreted at the apical, the basolateral or both membranes depending on the cell type....

  1. Functional Apical Large Conductance, Ca2+-activated, and Voltage-dependent K+ Channels Are Required for Maintenance of Airway Surface Liquid Volume*

    OpenAIRE

    Manzanares, Dahis; Gonzalez, Carlos; Ivonnet, Pedro; Chen, Ren-Shiang; Valencia-Gattas, Monica; Gregory E. Conner; Larsson, H. Peter; Salathe, Matthias

    2011-01-01

    Large conductance, Ca2+-activated, and voltage-dependent K+ (BK) channels control a variety of physiological processes in nervous, muscular, and renal epithelial tissues. In bronchial airway epithelia, extracellular ATP-mediated, apical increases in intracellular Ca2+ are important signals for ion movement through the apical membrane and regulation of water secretion. Although other, mainly basolaterally expressed K+ channels are recognized as modulators of ion transport in airway epithelial ...

  2. Contribution of cubilin and amnionless to processing and membrane targeting of cubilin-amnionless complex

    DEFF Research Database (Denmark)

    Coudroy, Gwénaëlle; Gburek, Jakub; Kozyraki, Renata;

    2005-01-01

    fragments, including a functional "mini" version of cubilin, the processing, sorting, and membrane anchoring of the complex to the apical membrane were investigated. The results show that truncation mutants, including the N-terminal domain of cubilin, did not appear at the plasma membrane but instead were...... cubilin at the apical cell surface. Apical sorting was observed for a broad set of nonoverlapping cubilin fragments without the N-terminal region, in the absence of AMN. The preference for apical sorting disappeared when glycosylation was inhibited by tunicamycin. In conclusion, it is shown that both...

  3. Role of very late antigen-1 in T-cell-mediated immunity to systemic viral infection

    DEFF Research Database (Denmark)

    Ørding Kauffmann, Susanne; Thomsen, Allan Randrup; Christensen, Jan Pravsgaard

    2006-01-01

    The T-cell response to lymphocytic choriomeningitis virus was studied in mice lacking very late antigen-1 (VLA-1). The generation of virus-specific effector T cells was unimpaired in VLA-1(-/-) mice. In the memory phase, VLA-1 deficiency did not influence the number of memory CD8(+) T cells or th...... current findings indicate that the expression of VLA-1 is not pivotal for T-cell-mediated antiviral immunity to a systemic infection....... their distribution between lymphoid and nonlymphoid organs. Regarding a functional role of VLA-1, we found that intracerebral infection of both VLA-1(-/-) and wild-type (wt) mice resulted in lethal T-cell-mediated meningitis, and quantitative and qualitative analyses of the cellular exudate did not...

  4. Evidence for an apical Na-Cl cotransporter involved in ion uptake in a teleost fish

    Science.gov (United States)

    Hiroi, J.; Yasumasu, S.; McCormick, S.D.; Hwang, P.-P.; Kaneko, T.

    2008-01-01

    Cation-chloride cotransporters, such as the Na+/K +/2Cl- cotransporter (NKCC) and Na+/Cl - cotransporter (NCC), are localized to the apical or basolateral plasma membranes of epithelial cells and are involved in active ion absorption or secretion. The objectives of this study were to clone and identify 'freshwater-type' and 'seawater-type' cation-chloride cotransporters of euryhaline Mozambique tilapia (Oreochromis mossambicus) and to determine their intracellular localization patterns within mitochondria-rich cells (MRCs). From tilapia gills, we cloned four full-length cDNAs homologous to human cation-chloride cotransporters and designated them as tilapia NKCC1a, NKCC1b, NKCC2 and NCC. Out of the four candidates, the mRNA encoding NKCC1a was highly expressed in the yolk-sac membrane and gills (sites of the MRC localization) of seawater-acclimatized fish, whereas the mRNA encoding NCC was exclusively expressed in the yolk-sac membrane and gills of freshwater-acclimatized fish. We then generated antibodies specific for tilapia NKCC1a and NCC and conducted whole-mount immunofluorescence staining for NKCC1a and NCC, together with Na+/K+-ATPase, cystic fibrosis transmembrane conductance regulator (CFTR) and Na+/H+ exchanger 3 (NHE3), on the yolk-sac membrane of tilapia embryos acclimatized to freshwater or seawater. The simultaneous quintuple-color immunofluorescence staining allowed us to classify MRCs clearly into four types: types I, II, III and IV. The NKCC1a immunoreactivity was localized to the basolateral membrane of seawater-specific type-IV MRCs, whereas the NCC immunoreactivity was restricted to the apical membrane of freshwater-specific type-II MRCs. Taking account of these data at the level of both mRNA and protein, we deduce that NKCC1a is the seawater-type cotransporter involved in ion secretion by type-IV MRCs and that NCC is the freshwater-type cotransporter involved in ion absorption by type-II MRCs. We propose a novel ion-uptake model by MRCs in

  5. Oncostatin M regulates membrane traffic and stimulates bile canalicular membrane biogenesis in HepG2 cells

    NARCIS (Netherlands)

    Van der Wouden, Johanna M.; Van IJzendoorn, Sven C.D.; Hoekstra, Dick

    2002-01-01

    Hepatocytes are the major epithelial cells of the liver and they display membrane polarity: the sinusoidal membrane representing the basolateral surface, while the bile canalicular membrane is typical of the apical membrane. In polarized HepG2 cells an endosomal organelle, SAC, fulfills a prominent

  6. Apical dominance in Alstroemeria cultured in vitro

    OpenAIRE

    Pumisutapon, P.; Visser, R. G. F.; Klerk, de, L.A.

    2009-01-01

    Apical dominance in Alstroemeria is studied to develop an improved propagation protocol for this crop. Four types of explants were prepared: an intact rhizome with two intact shoots (+R+2S), an intact rhizome with two decapitated shoots (+R-2S), a decapitated rhizome with two intact shoots (-R+2S), and a decapitated rhizome with two decapitated shoots (-R-2S). The explants were cultivated on solid MS medium with 9 µM 6-benzylaminopurine (BAP). -R-2S explants showed the highest and +R+2S the l...

  7. Multimodality imaging in apical hypertrophic cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    Rosario; Parisi; Francesca; Mirabella; Gioel; Gabrio; Secco; Rossella; Fattori

    2014-01-01

    Apical hypertrophic cardiomyopathy(AHCM) is a relatively rare morphologic variant of HCM in which the hypertrophy of myocardium is localized to the left ventricular apex. Symptoms of AHCM might vary from none to others mimic coronary artery disease including acute coronary syndrome, thus resulting in inappropriate hospitalization. Transthoracic echocardiography is the firstline imaging technique for the diagnosis of hypertrophic cardiomyopathies. However, when the hypertrophy of the myocardium is localized in the ventricular apex might results in missed diagnosis. Aim of this paper is to review the different imaging techniques used for the diagnosis of AHCM and their role in the detection and comprehension of this uncommon disease.

  8. Apical accumulation of MARCKS in neural plate cells during neurulation in the chick embryo

    Directory of Open Access Journals (Sweden)

    Arruti Cristina

    2001-04-01

    Full Text Available Abstract Background The neural tube is formed by morphogenetic movements largely dependent on cytoskeletal dynamics. Actin and many of its associated proteins have been proposed as important mediators of neurulation. For instance, mice deficient in MARCKS, an actin cross-linking membrane-associated protein that is regulated by PKC and other kinases, present severe developmental defects, including failure of cranial neural tube closure. Results To determine the distribution of MARCKS, and its possible relationships with actin during neurulation, chick embryos were transversely sectioned and double labeled with an anti-MARCKS polyclonal antibody and phalloidin. In the neural plate, MARCKS was found ubiquitously distributed at the periphery of the cells, being conspicuously accumulated in the apical cell region, in close proximity to the apical actin meshwork. This asymmetric distribution was particularly noticeable during the bending process. After the closure of the neural tube, the apically accumulated MARCKS disappeared, and this cell region became analogous to the other peripheral cell zones in its MARCKS content. Actin did not display analogous variations, remaining highly concentrated at the cell subapical territory. The transient apical accumulation of MARCKS was found throughout the neural tube axis. The analysis of another epithelial bending movement, during the formation of the lens vesicle, revealed an identical phenomenon. Conclusions MARCKS is transiently accumulated at the apical region of neural plate and lens placode cells during processes of bending. This asymmetric subcellular distribution of MARCKS starts before the onset of neural plate bending. These results suggest possible upstream regulatory actions of MARCKS on some functions of the actin subapical meshwork.

  9. Vectorial transport of fexofenadine across Caco-2 cells: involvement of apical uptake and basolateral efflux transporters.

    Science.gov (United States)

    Ming, Xin; Knight, Beverly M; Thakker, Dhiren R

    2011-10-01

    Fexofenadine is a nonsedative antihistamine that exhibits good oral bioavailability despite its zwitterionic chemical structure and efflux by P-gp. Evidence exists that multiple uptake and efflux transporters play a role in hepatic disposition of fexofenadine. However, the roles of specific transporters and their interrelationship in intestinal absorption of this drug are unclear. This study was designed to elucidate vectorial absorptive transport of fexofenadine across Caco-2 cells involving specific apical uptake and efflux transporters as well as basolateral efflux transporters. Studies with cellular models expressing single transporters showed that OATP2B1 expression stimulated uptake of fexofenadine at pH 6.0. Apical uptake of fexofenadine into Caco-2 cells was decreased by 45% by pretreatment with estrone 3-sulfate, an OATP inhibitor, at pH 6.0 but not at pH 7.4, indicating that OATP2B1 mediates apical uptake of fexofenadine into these cells. Examination of fexofenadine efflux from preloaded Caco-2 cells in the presence or absence of (i) the MRP inhibitor MK-571 and (ii) the P-gp inhibitor GW918 showed that apical efflux is predominantly mediated by P-gp, with a small contribution by MRP2, whereas basolateral efflux is predominantly mediated by MRP3. These results also showed that while OSTαβ is functionally active in the basolateral membrane of Caco-2 cells, it does not play a role in the export of fexofenadine. MK-571 decreased the absorptive transport of fexofenadine by 17%. However, the decrease in absorptive transport by MK-571 was 42% when P-gp was inhibited by GW918. The results provide a novel insight into a vectorial transport system mainly consisting of apical OATP2B1 and basolateral MRP3 that may play an important role in delivering hydrophilic anionic and zwitterionic drugs such as pravastatin and fexofenadine into systemic circulation upon oral administration. PMID:21780830

  10. Apical dominance and growth in vitro of Alstroemeria

    OpenAIRE

    Pumisutapon, P.

    2012-01-01

    In Alstroemeria, micropropagation is achieved by axillary bud outgrowth. However, the multiplication rate is rather low (1.2–2.0 per cycle of 4 weeks) due to strong apical dominance. Even though several factors (i.e. culture media, growth regulators, and environmental conditions) have been studied, no significant improvements have been achieved. Basic research on apical dominance mechanism in Alstroemeria is therefore required. This may enhance the understanding how apical dominance con...

  11. Apical hypertrophic cardiomyopathy presenting as acute coronary syndrome.

    Science.gov (United States)

    Abdin, Amr; Eitel, Ingo; de Waha, Suzanne; Thiele, Holger

    2016-06-01

    Apical hypertrophic cardiomyopathy is a rare variant of hypertrophic cardiomyopathy. It is characterized by a local hypertrophy of the apical segments and displays typical electrocardiographic and imaging patterns. The clinical manifestations are variable and range from an asymptomatic course to sudden cardiac death. The most frequent symptom is chest pain and thus apical hypertrophic cardiomyopathy can mimic the symptoms and repolarization disturbances indicative of acute coronary syndrome. PMID:26628684

  12. Experimental evidence for apical dominance in the seagrass Cymodocea nodosa

    OpenAIRE

    Terrados, Jorge; Duarte, Carlos M.; Kenworthy, W. Judson

    1997-01-01

    The existence of apical dominance in the seagrass Cymodocea nodosa (Ucria) Ascherson was elucidated by in situ experimental manipulation. Removal of the apical meristem of a C. nodosa horizontal rhizome promoted an increase in the branching rate of the rhizome which was mostly driven by a change in the growth form of the nearest vertical rhizome into horizontal growth. Although the elongation of the branches increased when the rhizome apical meristem was eliminated, total plant growth was red...

  13. Minimal Apical Enlargement for Penetration of Irrigants to the Apical Third of Root Canal System: A Scanning Electron Microscope Study

    OpenAIRE

    P. Srikanth; Krishna, Amaravadi Gopi; Srinivas, Siva; Reddy, E Sujayeendranatha; Battu, Someshwar; Aravelli, Swathi

    2015-01-01

    Background: The aim of this study was to determine minimal apical enlargement for irrigant penetration into apical third of root canal system using scanning electron microscope (SEM). Materials and Methods: Distobuccal canals of 40 freshly extracted human maxillary first molar teeth were instrumented using crown-down technique. The teeth were divided into four test groups according to size of their master apical file (MAF) (#20, #25, #30, #35 0.06% taper), and two control groups. After final ...

  14. Ribosome Protein L4 is essential for Epstein-Barr Virus Nuclear Antigen 1 function.

    Science.gov (United States)

    Shen, Chih-Lung; Liu, Cheng-Der; You, Ren-In; Ching, Yung-Hao; Liang, Jun; Ke, Liangru; Chen, Ya-Lin; Chen, Hong-Chi; Hsu, Hao-Jen; Liou, Je-Wen; Kieff, Elliott; Peng, Chih-Wen

    2016-02-23

    Epstein-Barr Virus (EBV) Nuclear Antigen 1 (EBNA1)-mediated origin of plasmid replication (oriP) DNA episome maintenance is essential for EBV-mediated tumorigenesis. We have now found that EBNA1 binds to Ribosome Protein L4 (RPL4). RPL4 shRNA knockdown decreased EBNA1 activation of an oriP luciferase reporter, EBNA1 DNA binding in lymphoblastoid cell lines, and EBV genome number per lymphoblastoid cell line. EBV infection increased RPL4 expression and redistributed RPL4 to cell nuclei. RPL4 and Nucleolin (NCL) were a scaffold for an EBNA1-induced oriP complex. The RPL4 N terminus cooperated with NCL-K429 to support EBNA1 and oriP-mediated episome binding and maintenance, whereas the NCL C-terminal K380 and K393 induced oriP DNA H3K4me2 modification and promoted EBNA1 activation of oriP-dependent transcription. These observations provide new insights into the mechanisms by which EBV uses NCL and RPL4 to establish persistent B-lymphoblastoid cell infection. PMID:26858444

  15. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt;

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited in a...

  16. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt;

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited...

  17. Expression, biosynthesis and release of preadipocyte factor-1/ delta-like protein/fetal antigen-1 in pancreatic -cells

    DEFF Research Database (Denmark)

    Friedrichsen, B N; Carlsson, C; Møldrup, A;

    2003-01-01

    Preadipocyte factor-1 (Pref-1)/delta-like protein/fetal antigen-1 (FA1) is a member of the epidermal growth factor-like family. It is widely expressed in embryonic tissues, whereas in adults it is confined to the adrenal gland, the anterior pituitary, the endocrine pancreas, the testis and the...

  18. APICAL TUBERCULOSIS PRESENTING AS PANCOAST TUMOR

    Directory of Open Access Journals (Sweden)

    Praveen

    2014-07-01

    Full Text Available A 73-year-old woman presented with pain in her right shoulder radiating to the right scapula and a tingling sensation of the right arm with involvement of the fourth and fifth finger. Chest x ray showed a well-defined mass in right apical area of lung. HRCT chest showed a well-defined mass in right upper zone in apex destroying the upper 2 ribs. Clinically the diagnosis of Pancoast tumor of the right lung was made. Computed tomographic guided fine needle aspiration cytology was done and it was inconclusive. So gun biopsy was done under ultrasound guidance. The histologic and microbiologic examinations established the diagnosis of tuberculosis (TB.

  19. Reversible transient apical ballooning syndrome with coronary lesions

    Institute of Scientific and Technical Information of China (English)

    Yunshan Cao; Min Zhang; Xiang Li; Ping Xie; Lynn Cronin

    2009-01-01

    Transient apical ballooning syndrome(Tako-Tsubo syndrome or ampulla cardiomyopathy) occurs predominantly in women over 60 years of age with a history of recent physical or psychological stress. We present a case of a male patient with reversible transient apical ballooning syndrome with significant coronary lesions and other ECG changes that did not explain the clinical symptoms.

  20. Apical Hypertrophic Cardiomyopathy in Association with PulmonaryArtery Hypertension

    Directory of Open Access Journals (Sweden)

    Mehdi Peighambari

    2012-09-01

    Full Text Available Apical Hypertrophic Cardiomyopathy is an uncommon condition constituting 1% -2% of the cases with Hypertrophic Cardiomyopathy (HCM diagnosis. We interestingly report two patients with apical hypertrophic cardiomyopathy in association with significant pulmonary artery hypertension without any other underlying reason for pulmonary hypertension. The patients were assessed by echocardiography, cardiac catheterization and pulmonary function parameters study.

  1. Phosphatidylserine-positive particles in the apical domain of sensory hair cells

    Institute of Scientific and Technical Information of China (English)

    SHI Xiao-rui; Alfred Nuttall

    2006-01-01

    Apical membrane recycling has been proposed to be important for normal hair cell function. The current study reports an in vitro work that demonstrates the presence of phosphatidylserine (PS) and PS-positive vesicles labeled by Annexin V in the apical portion of hair cells. The following characteristics of the PS-positive vesicles were noticed using scanning confocal fluorescence microscopy: (1) variable sizes around 200 nm; (2)variable distribution patterns (either uniformly along individual stereocilia in the hair bundle or irregular) in the stereocilia from cell to cell; (3) variable sizes and numbers at locations along the border of the cuticular plate (CP),with a large number of them located at the vestigal kinocilial location; (4) motility with some of the vesicles during the observation period; (5) increase in PS labeling and the number of PS-positive vesicles after loud sound stimulation; and (6) decreased PS labeling and PS-positive vesicle numbers following treatment with LY-294002, a PI3 -kinase inhibitor. These results suggest that the presence of PS-positive vesicles at the apical area of hair cells may be indicative of vesicle shedding or transportation of a protein or rafts.

  2. Genetic interaction of centrosomin and bazooka in apical domain regulation in Drosophila photoreceptor.

    Directory of Open Access Journals (Sweden)

    Geng Chen

    Full Text Available BACKGROUND: Cell polarity genes including Crumbs (Crb and Par complexes are essential for controlling photoreceptor morphogenesis. Among the Crb and Par complexes, Bazooka (Baz, Par-3 homolog acts as a nodal component for other cell polarity proteins. Therefore, finding other genes interacting with Baz will help us to understand the cell polarity genes' role in photoreceptor morphogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Here, we have found a genetic interaction between baz and centrosomin (cnn. Cnn is a core protein for centrosome which is a major microtubule-organizing center. We analyzed the effect of the cnn mutation on developing eyes to determine its role in photoreceptor morphogenesis. We found that Cnn is dispensable for retinal differentiation in eye imaginal discs during the larval stage. However, photoreceptors deficient in Cnn display dramatic morphogenesis defects including the mislocalization of Crumbs (Crb and Bazooka (Baz during mid-stage pupal eye development, suggesting that Cnn is specifically required for photoreceptor morphogenesis during pupal eye development. This role of Cnn in apical domain modulation was further supported by Cnn's gain-of-function phenotype. Cnn overexpression in photoreceptors caused the expansion of the apical Crb membrane domain, Baz and adherens junctions (AJs. CONCLUSIONS/SIGNIFICANCE: These results strongly suggest that the interaction of Baz and Cnn is essential for apical domain and AJ modulation during photoreceptor morphogenesis, but not for the initial photoreceptor differentiation in the Drosophila photoreceptor.

  3. Correlative Analysis of [Ca2+]C and Apical Secretion during Pollen Tube Growth and Reorientation

    OpenAIRE

    Coelho, Pedro Castanho; Malhó, Rui

    2006-01-01

    The maintenance of a cytosolic free calcium gradient (Ca2+]c) and vesicle secretion in the apex of pollen tubes is essential for growth. It has been postulated that high [Ca2+]c levels promote and confine vesicle fusion with the apical plasma membrane and in this study we performed a correlative analysis of both events using specific fluorescent dyes and confocal scanning microscopy. [Ca2+]c was imaged with Calcium Green-1 10 kDa dextran (CG-1) while secretory events were followed with FM1–43...

  4. Genetic diversity and antigenicity variation of Babesia bovis merozoite surface antigen-1 (MSA-1) in Thailand.

    Science.gov (United States)

    Tattiyapong, Muncharee; Sivakumar, Thillaiampalam; Takemae, Hitoshi; Simking, Pacharathon; Jittapalapong, Sathaporn; Igarashi, Ikuo; Yokoyama, Naoaki

    2016-07-01

    Babesia bovis, an intraerythrocytic protozoan parasite, causes severe clinical disease in cattle worldwide. The genetic diversity of parasite antigens often results in different immune profiles in infected animals, hindering efforts to develop immune control methodologies against the B. bovis infection. In this study, we analyzed the genetic diversity of the merozoite surface antigen-1 (msa-1) gene using 162 B. bovis-positive blood DNA samples sourced from cattle populations reared in different geographical regions of Thailand. The identity scores shared among 93 msa-1 gene sequences isolated by PCR amplification were 43.5-100%, and the similarity values among the translated amino acid sequences were 42.8-100%. Of 23 total clades detected in our phylogenetic analysis, Thai msa-1 gene sequences occurred in 18 clades; seven among them were composed of sequences exclusively from Thailand. To investigate differential antigenicity of isolated MSA-1 proteins, we expressed and purified eight recombinant MSA-1 (rMSA-1) proteins, including an rMSA-1 from B. bovis Texas (T2Bo) strain and seven rMSA-1 proteins based on the Thai msa-1 sequences. When these antigens were analyzed in a western blot assay, anti-T2Bo cattle serum strongly reacted with the rMSA-1 from T2Bo, as well as with three other rMSA-1 proteins that shared 54.9-68.4% sequence similarity with T2Bo MSA-1. In contrast, no or weak reactivity was observed for the remaining rMSA-1 proteins, which shared low sequence similarity (35.0-39.7%) with T2Bo MSA-1. While demonstrating the high genetic diversity of the B. bovis msa-1 gene in Thailand, the present findings suggest that the genetic diversity results in antigenicity variations among the MSA-1 antigens of B. bovis in Thailand. PMID:27101782

  5. Negative Regulation of TGFβ Signaling by Stem Cell Antigen-1 Protects against Ischemic Acute Kidney Injury.

    Directory of Open Access Journals (Sweden)

    Troy D Camarata

    Full Text Available Acute kidney injury, often caused by an ischemic insult, is associated with significant short-term morbidity and mortality, and increased risk of chronic kidney disease. The factors affecting the renal response to injury following ischemia and reperfusion remain to be clarified. We found that the Stem cell antigen-1 (Sca-1, commonly used as a stem cell marker, is heavily expressed in renal tubules of the adult mouse kidney. We evaluated its potential role in the kidney using Sca-1 knockout mice submitted to acute ischemia reperfusion injury (IRI, as well as cultured renal proximal tubular cells in which Sca-1 was stably silenced with shRNA. IRI induced more severe injury in Sca-1 null kidneys, as assessed by increased expression of Kim-1 and Ngal, rise in serum creatinine, abnormal pathology, and increased apoptosis of tubular epithelium, and persistent significant renal injury at day 7 post IRI, when recovery of renal function in control animals was nearly complete. Serum creatinine, Kim-1 and Ngal were slightly but significantly elevated even in uninjured Sca-1-/- kidneys. Sca-1 constitutively bound both TGFβ receptors I and II in cultured normal proximal tubular epithelial cells. Its genetic loss or silencing lead to constitutive TGFβ receptor-mediated activation of canonical Smad signaling even in the absence of ligand and to KIM-1 expression in the silenced cells. These studies demonstrate that by normally repressing TGFβ-mediated canonical Smad signaling, Sca-1 plays an important in renal epithelial cell homeostasis and in recovery of renal function following ischemic acute kidney injury.

  6. Mechanisms of lysophosphatidic acid (LPA) mediated stimulation of intestinal apical Cl-/OH- exchange.

    Science.gov (United States)

    Singla, Amika; Dwivedi, Alka; Saksena, Seema; Gill, Ravinder K; Alrefai, Waddah A; Ramaswamy, Krishnamurthy; Dudeja, Pradeep K

    2010-02-01

    Lysophosphatidic acid (LPA), a potent bioactive phospholipid, is a natural component of food products like soy and egg yolk. LPA modulates a number of epithelial functions and has been shown to inhibit cholera toxin-induced diarrhea. Antidiarrheal effects of LPA are known to be mediated by inhibiting chloride secretion. However, the effects of LPA on chloride absorption in the mammalian intestine are not known. The present studies examined the effects of LPA on apical Cl(-)/OH(-) exchangers known to be involved in chloride absorption in intestinal epithelial cells. Caco-2 cells were treated with LPA, and Cl(-)/OH(-) exchange activity was measured as DIDS-sensitive (36)Cl(-) uptake. Cell surface biotinylation studies were performed to evaluate the effect of LPA on cell surface levels of apical Cl(-)/OH(-) exchangers, downregulated in adenoma (DRA) (SLC26A3), and putative anion transporter-1 (SLC26A6). Treatment of Caco-2 cells with LPA (100 muM) significantly stimulated Cl(-)/OH(-) exchange activity. Specific agonist for LPA2 receptor mimicked the effects of LPA. LPA-mediated stimulation of Cl(-)/OH(-) exchange activity was dependent on activation of phosphatidylinositol 3-kinase/Akt signaling pathway. Consistent with the functional activity, LPA treatment resulted in increased levels of DRA on the apical membrane. Our results demonstrate that LPA stimulates apical Cl(-)/OH(-) exchange activity and surface levels of DRA in intestinal epithelial cells. This increase in Cl(-)/OH(-) exchange may contribute to the antidiarrheal effects of LPA. PMID:19910524

  7. Potassium transport across rat alveolar epithelium: evidence for an apical Na+-K+ pump.

    Science.gov (United States)

    Basset, G; Bouchonnet, F; Crone, C; Saumon, G

    1988-06-01

    1. Experiments were performed on rat lungs into which various solutions were instilled whilst the lungs were perfused with either whole blood or Ringer solution. Instillation of ion-free glucose solution led to a net flux of fluid and ions into the alveolar spaces. K+ ions entered faster than Na+ ions and reached a concentration about twice that in the perfusate. Ouabain in the perfusate (basolateral side) prevented the rise in alveolar K+ concentration above that in the perfusate, indicating a transcellular pathway. Ba2+ in the instillate (apical side) hindered the entry of K+ into alveoli, suggesting the presence of apical K+ channels. 2. When Ringer solution was instilled, K+ was continuously removed from the alveoli and the K+ concentration in the instillate remained constant or decreased slightly depending on the rate of fluid absorption. The net K+ efflux from alveoli to blood was 0.23 pmol/(cm2 s). When Ba2+ was added to the instillate the net K+ efflux increased to 0.36 pmol/(cm2 s). Apical ouabain reversed the K+ flux resulting in a net K+ flux of 0.19 pmol/(cm2 s) into the alveoli. This suggests the presence of an Na+-K+-ATPase located in the apical membrane of some alveolar cells. 3. The K+ transport from instillate (Ringer solution) to perfusate was traced by means of 86Rb which was added to the instillate. Ouabain in the instillate did not affect fluid absorption but reduced the apparent 86Rb permeability by 50% although the paracellular permeability (estimated with [3H]mannitol) was unaffected. This also indicates the presence of an apical Na+-K+-ATPase. When ouabain was added to the perfusate, the apparent 86Rb permeability doubled. These findings indicate that recirculation of 86Rb (and K+) occurs due to the activity of both apical and basolateral Na+-K+-ATPases. 4. When ouabain was placed on both sides of the epithelium, preventing transcellular transport, the passive 86Rb permeability was 10.3 x 10(-8) cm/s (assuming an alveolar surface area of

  8. Caveolin-2 Is Required for Apical Lipid Trafficking and Suppresses Basolateral Recycling Defects in the Intestine of Caenorhabditis elegans

    OpenAIRE

    Parker, Scott; Walker, Denise S.; Ly, Sung; Baylis, Howard A.

    2009-01-01

    Caveolins are plasma membrane–associated proteins that colocalize with, and stabilize caveolae. Their functions remain unclear although they are known to be involved in specific events in cell signaling and endocytosis. Caenorhabditis elegans encodes two caveolin genes, cav-1 and cav-2. We show that cav-2 is expressed in the intestine where it is localized to the apical membrane and in intracellular bodies. Using the styryl dye FM4-64 and BODIPY-labeled lactosylceramide, we show that the inte...

  9. Maxillary first premolars: I. Morphology of the apical constriction

    Institute of Scientific and Technical Information of China (English)

    Daming Wu; Younong Wu; Ming Hu

    2009-01-01

    Objective: To investigated the apical constriction morphology of maxillary first premolars in the Chinese population. Methods: Eighty recently extracted human maxillary first premolars from a native Chinese population were used. The number and shape of apical constrictions were recorded under a dental operating microscope (DOM) at 12.5X2.5 magnification. After access preparation, a new K-file was inserted into the canal until the tip of the file was just seen at the apical constriction under the DOM. The teeth with files in the canals were X-rayed from a mesiodistal direction using a direct digital radiography (DDR) system, and the distance between the file tip and the center of radiographic apex was directly measured from the computer screen using DDR measurement software. Results: The percentage of teeth with an apical constriction was 78.5% (102/130). The most common apical constriction shapes were oval (55.9%) and round (35.3%). The mean distance between the apical constriction and the anatomical tip of the root was 0.61 mm, and 84.3% (86/102) were within 1 mm. Conclusion: The most common shape of an apical constriction was oval or round, and the distance to the apex was mostly within 1 mm, indicating that root canal therapy should stop 1 mm from the radiographic apex.

  10. Apical control of conidiation in Aspergillus nidulans.

    Science.gov (United States)

    Oiartzabal-Arano, Elixabet; Perez-de-Nanclares-Arregi, Elixabet; Espeso, Eduardo A; Etxebeste, Oier

    2016-05-01

    The infection cycle of filamentous fungi consists of two main stages: invasion (growth) and dispersion (development). After the deposition of a spore on a host, germination, polar extension and branching of vegetative cells called hyphae allow a fast and efficient invasion. Under suboptimal conditions, genetic reprogramming of hyphae results in the generation of asexual spores, allowing dissemination to new hosts and the beginning of a new infection cycle. In the model filamentous fungus Aspergillus nidulans, asexual development or conidiation is induced by the upstream developmental activation (UDA) pathway. UDA proteins transduce signals from the tip, the polarity site of hyphae, to nuclei, where developmental programs are transcriptionally activated. The present review summarizes the current knowledge on this tip-to-nucleus communication mechanism, emphasizing its dependence on hyphal polarity. Future approaches to the topic will also be suggested, as stimulating elements contributing to the understanding of how apical signals are coupled with the transcriptional control of development and pathogenesis in filamentous fungi. PMID:26782172

  11. Electron-microscopic study of the apical region of the toad bladder epithelial cell.

    Science.gov (United States)

    Sasaki, J; Tilles, S; Condeelis, J; Carboni, J; Meiteles, L; Franki, N; Bolon, R; Robertson, C; Hays, R M

    1984-09-01

    Antidiuretic hormone (ADH) promotes fusion of cytoplasmic tubules with the luminal membrane and delivery of particles from the tubules to the membrane. The particles are believed to be the water-conducting elements in the membrane. We have employed several scanning (SEM) and transmission electron-microscopic (TEM) techniques to study the relationship of the cytoplasmic tubules to the luminal membrane and to the apical cytoskeleton of the toad bladder epithelial cell. This paper reports the results of freeze-crack SEM and tannic acid-fixed TEM studies, as well as studies with a resinless method of embedding. Freeze-cracked epithelial cells reveal that the tubules are anchored in a matrix of cytoskeleton and granules just below the luminal membrane, and many, if not all, retain their anchorage to the matrix after ADH-induced fusion. Tannic acid-fixed specimens show that the tubules in unstimulated cells lie horizontally. Fusion appears to involve an angulation of the tubules, and this may be the major mode of ADH-induced tubule movement. There are suggestions in the tannic acid sections of filamentous attachments of tubules to the surrounding cytoskeleton. In addition there are prominent microfilament bundles running down the microvilli and a dense concentration of filaments just below the luminal membrane. The presence of these filaments is confirmed in the resinless sections, and their possible role in ADH action is discussed. PMID:6433717

  12. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    International Nuclear Information System (INIS)

    Highlights: ► Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. ► A small molecule and a peptide as EBNA1 dimerization inhibitors identified. ► Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. ► Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)’s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459–607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-Jκ binding to the Jκ site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560–574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated with EBNA1 in vitro, and repressed EBNA1-dependent transcription in vivo. Collectively, this study describes two

  13. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Young; Song, Kyung-A [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kieff, Elliott [Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Kang, Myung-Soo, E-mail: mkang@skku.edu [Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States)

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. Black-Right-Pointing-Pointer A small molecule and a peptide as EBNA1 dimerization inhibitors identified. Black-Right-Pointing-Pointer Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. Black-Right-Pointing-Pointer Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)'s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459-607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-J{kappa} binding to the J{kappa} site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560-574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated

  14. Shot and Patronin polarise microtubules to direct membrane traffic and biogenesis of microvilli in epithelia.

    Science.gov (United States)

    Khanal, Ichha; Elbediwy, Ahmed; Diaz de la Loza, Maria Del Carmen; Fletcher, Georgina C; Thompson, Barry J

    2016-07-01

    In epithelial tissues, polarisation of microtubules and actin microvilli occurs along the apical-basal axis of each cell, yet how these cytoskeletal polarisation events are coordinated remains unclear. Here, we examine the hierarchy of events during cytoskeletal polarisation in Drosophila melanogaster epithelia. Core apical-basal polarity determinants polarise the spectrin cytoskeleton to recruit the microtubule-binding proteins Patronin (CAMSAP1, CAMSAP2 and CAMPSAP3 in humans) and Shortstop [Shot; MACF1 and BPAG1 (also known as DST) in humans] to the apical membrane domain. Patronin and Shot then act to polarise microtubules along the apical-basal axis to enable apical transport of Rab11 endosomes by the Nuf-Dynein microtubule motor complex. Finally, Rab11 endosomes are transferred to the MyoV (also known as Didum in Drosophila) actin motor to deliver the key microvillar determinant Cadherin 99C to the apical membrane to organise the biogenesis of actin microvilli. PMID:27231092

  15. IL-13 Production by Regulatory T Cells Protects Against Experimental Autoimmune Encephalomyelitis (EAE) Independent of Auto-Antigen1

    OpenAIRE

    Ochoa-Repáraz, Javier; Rynda, Agnieszka; Ascón, Miguel A.; YANG, Xinghong; Kochetkova, Irina; Riccardi, Carol; Callis, Gayle; Trunkle, Theresa; Pascual, David W.

    2008-01-01

    Treatment with an anti-inflammatory Salmonella vaccine expressing enterotoxigenic E. coli colonization factor antigen 1 (CFA/I) proved effective in stimulating protective, potent CD25+ CD4+ T (Treg) cells in susceptible mice challenged with experimental autoimmune encephalomyelitis (EAE). Since the Salmonella vector was considerably less protective, we questioned whether altering the fimbrial subunit expression to resemble conventional Salmonella expression may impact Treg cell potency. The S...

  16. Thymus cell antigen 1 (Thy1, CD90) is expressed by lymphatic vessels and mediates cell adhesion to lymphatic endothelium

    OpenAIRE

    Jurisic, Giorgia; Iolyeva, Maria; Proulx, Steven T; Halin, Cornelia; Detmar, Michael

    2010-01-01

    The lymphatic vascular system plays an important role in inflammation and cancer progression, although the molecular mechanisms involved are poorly understood. As determined by comparative transcriptional profiling studies of ex vivo isolated mouse intestinal lymphatic endothelial cells versus blood vascular endothelial cells, thymus cell antigen 1 (Thy1, CD90) was expressed at much higher levels in lymphatic endothelial cells than in blood vascular endothelial cells. These findings were conf...

  17. Efficacy of Biodentine as an Apical Plug in Nonvital Permanent Teeth with Open Apices: An In Vitro Study

    Science.gov (United States)

    Bani, Mehmet; Sungurtekin-Ekçi, Elif; Odabaş, Mesut Enes

    2015-01-01

    The aim of this study was to evaluate the apical microleakage of Biodentine and MTA orthograde apical plugs and to compare the effect of thickness of these biomaterials on their sealing ability. A total of eighty maxillary anterior teeth were used. The apices were removed by cutting with a diamond disc (Jota, Germany) 2 mm from the apical root end in an attempt to standardize the working length of all specimens to 15 ± 1 mm. Both materials were placed in 1–4 mm thickness as apical plugs root canal. Root canal leakage was evaluated by the fluid filtration technique. One-way ANOVA was used in order to determine normality of dispersal distribution of parameters; thereafter, results were analyzed by Kolmogorov-Smirnov test. Overall, between microleakage values of MTA and Biodentine regardless of apical plug thickness, no difference was observed. In terms of plug thickness, a statistically significant difference was observed between the subgroups of MTA and Biodentine (p Biodentine was comparable to MTA at any apical plug thickness. PMID:26436090

  18. An efficient method for introducing defined lipids into the plasma membrane of mammalian cells

    OpenAIRE

    1983-01-01

    An efficient method has been devised to introduce lipid molecules into the plasma membrane of mammalian cells. This method has been applied to fuse lipid vesicles with the apical plasma membrane of Madin-Darby canine kidney cells. The cells were infected with fowl plague or influenza N virus. 4 h after infection, the hemagglutinin (HA) spike glycoprotein of the virus was present in the apical plasma membrane of the cells. Lipid vesicles containing egg phosphatidylcholine, cholesterol, and an ...

  19. The phospholipid flippase ATP8B1 mediates apical localization of the cystic fibrosis transmembrane regulator.

    Science.gov (United States)

    van der Mark, Vincent A; de Jonge, Hugo R; Chang, Jung-Chin; Ho-Mok, Kam S; Duijst, Suzanne; Vidović, Dragana; Carlon, Marianne S; Oude Elferink, Ronald P J; Paulusma, Coen C

    2016-09-01

    Progressive familial intrahepatic cholestasis type 1 (PFIC1) is caused by mutations in the gene encoding the phospholipid flippase ATP8B1. Apart from severe cholestatic liver disease, many PFIC1 patients develop extrahepatic symptoms characteristic of cystic fibrosis (CF), such as pulmonary infection, sweat gland dysfunction and failure to thrive. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel essential for epithelial fluid transport. Previously it was shown that CFTR transcript levels were strongly reduced in livers of PFIC1 patients. Here we have investigated the hypothesis that ATP8B1 is important for proper CFTR expression and function. We analyzed CFTR expression in ATP8B1-depleted intestinal and pulmonary epithelial cell lines and assessed CFTR function by measuring short-circuit currents across transwell-grown ATP8B1-depleted intestinal T84 cells and by a genetically-encoded fluorescent chloride sensor. In addition, we studied CFTR surface expression upon induction of CFTR transcription. We show that CFTR protein levels are strongly reduced in the apical membrane of human ATP8B1-depleted intestinal and pulmonary epithelial cell lines, a phenotype that coincided with reduced CFTR activity. Apical membrane insertion upon induction of ectopically-expressed CFTR was strongly impaired in ATP8B1-depleted cells. We conclude that ATP8B1 is essential for correct apical localization of CFTR in human intestinal and pulmonary epithelial cells, and that impaired CFTR localization underlies some of the extrahepatic phenotypes observed in ATP8B1 deficiency. PMID:27301931

  20. The antimicrobial effect of apical box versus apical cone preparation using iodine potassium iodide as root canal dressing

    DEFF Research Database (Denmark)

    Markvart, Merete; Dahlén, Gunnar; Reit, Claes-Erik;

    2013-01-01

    Abstract Purpose. The purpose was to study the reduction of intra-canal microflora in premolars with apical periodontitis instrumented with either apical box or apical cone preparation and to provide measurements of intervention effects to allow proper power calculation in future clinical trials...... appointment 1 week later. Between the treatment sessions, the root canals were sealed with IRM cement. In the laboratory, culture techniques were used to measure microbial growth, which was classified as: none, very sparse, sparse, moderate, heavy or very heavy. Results. Initially, microbes were recovered in...

  1. Monoclonal Antibodies to the Apical Chloride Channel in Necturus Gallbladder Inhibit the Chloride Conductance

    Science.gov (United States)

    Finn, Arthur L.; Tsai, Lih-Min; Falk, Ronald J.

    1989-10-01

    Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The channel or a closely related molecule is present in the membrane whether or not the pathway is open, since, in addition to inhibiting the conductance of the open channel, the antibody also bound to the membrane in the resting state and prevented subsequent opening of the channel. The antibody was shown to recognize, by ELISA, epitopes from the Necturus gallbladder and small intestine. Finally, by Western blot analysis of Necturus gallbladder homogenates, the antibody was shown to recognize two protein bands of Mr 219,000 and Mr 69,000. This antibody should permit isolation and characterization of this important ion channel.

  2. Endometrial apical glycoproteomic analysis reveals roles for cadherin 6, desmoglein-2 and plexin b2 in epithelial integrity.

    Science.gov (United States)

    Singh, H; Aplin, J D

    2015-01-01

    Implantation failure is one of the major causes of infertility and remains a major barrier to assisted reproduction success. Initial receptivity to implantation is regulated by the endometrial luminal epithelium under maternal hormonal control. Identification of epithelial cell surface components involved in embryo attachment will have translational applications in early pregnancy failure, infertility and contraception. In this study, vectorial biotinylation has been used to characterize the apical glycoproteome of Ishikawa cells, a polarized cell line that serves as a model of the implantation-receptive human endometrial luminal epithelium. Of 46 surface-associated glycoproteins detected by mass spectrometry, half are newly reported in this cell type; a subgroup of these were chosen for evaluation in tissue, and all were shown to be expressed apically in vivo in the mid-secretory (implantation) phase of the menstrual cycle, thus validating the model. Eleven adhesion molecules were detected, some already known to be involved in implantation, others novel. Cadherin 6, desmoglein 2 and plexin b2 were surprisingly found in the apical as well as the lateral membrane domain; their knock-down compromised epithelial integrity. This method of targeting glycosylated apical surface moieties in a polarized epithelial culture model shows excellent selectivity and identifies candidate cell adhesion molecules that are also present in vivo in secretory phase endometrial epithelium. PMID:25237006

  3. Pseudoaneurysm of the left ventricle following apical approach TAVI

    OpenAIRE

    Vanezis Andrew P; Baig Mirza K; Mitchel Ian M; Shajar Matloob; Naik Surendra K; Henderson Robert A; Mathew Thomas

    2011-01-01

    Abstract Symptomatic severe aortic stenosis carries a two year survival of only 50%. However many patients are unsuitable for conventional aortic valve replacement as they are considered too high risk due to significant co-morbidities. Transcatheter Aortic Valve Implantation (TAVI) offers a viable alternative for this high risk patient group, either by the femoral or apical route. This article reports a case of a pseudoaneurysm of the left ventricle following an apical approach TAVI in an eld...

  4. Effect of cytokinins on shoot apical meristem in Nicotiana tabacum

    Directory of Open Access Journals (Sweden)

    Uzelac Branka

    2012-01-01

    Full Text Available Cytokinins are involved in plant cell proliferation leading to plant growth and morphogenesis. The size, activity and maintenance of the shoot apical meristem (SAM are defined by a balanced rate of mitotic cell divisions and functional cell differentiation that are controlled by cytokinins. In order to investigate the effect of exogenous cytokinin on SAM, morpho-anatomical changes in the shoot apices of tobacco treated with benzyladenine (BA were compared to those of untreated control plants.

  5. Effect of cytokinins on shoot apical meristem in Nicotiana tabacum

    OpenAIRE

    Uzelac Branka; Janošević Dušica; Stojičić Dragana; Budimir Snežana

    2012-01-01

    Cytokinins are involved in plant cell proliferation leading to plant growth and morphogenesis. The size, activity and maintenance of the shoot apical meristem (SAM) are defined by a balanced rate of mitotic cell divisions and functional cell differentiation that are controlled by cytokinins. In order to investigate the effect of exogenous cytokinin on SAM, morpho-anatomical changes in the shoot apices of tobacco treated with benzyladenine (BA) were compared to those of untreated control...

  6. Haemostatic agents in apical surgery. A systematic review

    Science.gov (United States)

    Clé-Ovejero, Adrià

    2016-01-01

    Background Blood presence in apical surgery can prevent the correct vision of the surgical field, change the physical properties of filling materials and reduce their sealing ability. Objetive To describe which are the most effective and safest haemostatic agents to control bleeding in patients undergoing apical surgery. Material and Methods TWe carried out a systematic review, using Medline and Cochrane Library databases, of human clinical studies published in the last 10 years. Results The agents that proved more effective in bleeding control were calcium sulphate (100%) and collagen plus epinephrine (92.9%) followed by ferric sulphate (60%), gauze packing (30%) and collagen (16.7%). When using aluminium chloride (Expasyl®), over 90% of the apical lesions improved, but this agent seemed to increase swelling. Epinephrine with collagen did not significantly raise either blood pressure or heart rate. Conclusions Despite the use of several haemostatic materials in apical surgery, there is little evidence on their effectiveness and safety. The most effective haemostatic agents were calcium sulphate and epinephrine plus collagen. Epinephrine plus collagen did not seem to significantly raise blood pressure or heart rate during surgery. Aluminium chloride did not increase postoperative pain but could slightly increase postoperative swelling. Randomized clinical trials are needed to assess the haemostatic effectiveness and adverse effects of haemostatic materials in apical surgery. Key words:Haemostasis, apical surgery. PMID:27475689

  7. Healing of apical rarefaction of three nonvital open apex anterior teeth using a white portland cement apical plug

    Directory of Open Access Journals (Sweden)

    Amitabha Chakraborty

    2012-01-01

    Full Text Available The major challenge of performing root canal treatment in an open apex pulp-less tooth is to obtain a good apical seal. MTA has been successfully used to achieve a good apical seal, wherein the root canal obturation can be done immediately. MTA and White Portland Cement has been shown similarity in their physical, chemical and biological properties and has also shown similar outcome when used in animal studies and human trials. In our study, open apex of three non vital upper central incisors has been plugged using modified white Portland cement. 3 to 6 months follow up revealed absence of clinical symptoms and disappearance of peri-apical rarefactions. The positive clinical outcome may encourage the future use of white Portland cement as an apical plug material in case of non vital open apex tooth as much cheaper substitute of MTA.

  8. Five-year longitudinal assessment of the prognosis of apical microsurgery

    DEFF Research Database (Denmark)

    von Arx, Thomas; Jensen, Simon S; Hänni, Stefan;

    2012-01-01

    Apical surgery is an important treatment option for teeth with post-treatment apical periodontitis. Knowledge of the long-term prognosis is necessary when weighing apical surgery against alternative treatments. This study assessed the 5-year outcome of apical surgery and its predictors in a cohor...

  9. Deletion of the anion exchanger Slc26a4 (pendrin) decreases apical Cl−/HCO3− exchanger activity and impairs bicarbonate secretion in kidney collecting duct

    OpenAIRE

    Amlal, Hassane; Petrovic, Snezana; Xu, Jie; Wang, Zhaohui; Sun, Xuming; Barone, Sharon; Soleimani, Manoocher

    2010-01-01

    The anion exchanger Pendrin, which is encoded by SLC26A4 (human)/Slc26a4 (mouse) gene, is localized on the apical membrane of non-acid-secreting intercalated (IC) cells in the kidney cortical collecting duct (CCD). To examine its role in the mediation of bicarbonate secretion in vivo and the apical Cl−/HCO3− exchanger in the kidney CCD, mice with genetic deletion of pendrin were generated. The mutant mice show the complete absence of pendrin expression in their kidneys as assessed by Northern...

  10. Differentiation of Apical Bud Cells in a Newly Developed Apical Bud Transplantation Model Using GFP Transgenic Mice as Donor.

    Directory of Open Access Journals (Sweden)

    Naoki Maruo

    Full Text Available Rodent mandibular incisors have a unique anatomical structure that allows teeth to grow throughout the lifetime of the rodent. This report presents a novel transplantation technique for studying the apical bud differentiation of rodent mandibular incisors. Incisal apical end tissue with green fluorescent protein from transgenic mouse was transplanted to wild type mice, and the development of the transplanted cells were immunohistologically observed for 12 weeks after the transplantation. Results indicate that the green fluorescent apical end tissue replaced the original tissue, and cells from the apical bud differentiated and extended toward the incisal edge direction. The immunostaining with podoplanin also showed that the characteristics of the green fluorescent tissue were identical to those of the original. The green fluorescent cells were only found in the labial side of the incisor up to 4 weeks. After 12 weeks, however, they were also found in the lingual side. Here the green fluorescent cementocyte-like cells were only present in the cementum close to the dentin surface. This study suggests that some of the cells that form the cellular cementum come from the apical tissue including the apical bud in rodent incisors.

  11. Differentiation of Apical Bud Cells in a Newly Developed Apical Bud Transplantation Model Using GFP Transgenic Mice as Donor

    Science.gov (United States)

    Sakagami, Ryuji; Yoshinaga, Yasunori; Okamura, Kazuhiko

    2016-01-01

    Rodent mandibular incisors have a unique anatomical structure that allows teeth to grow throughout the lifetime of the rodent. This report presents a novel transplantation technique for studying the apical bud differentiation of rodent mandibular incisors. Incisal apical end tissue with green fluorescent protein from transgenic mouse was transplanted to wild type mice, and the development of the transplanted cells were immunohistologically observed for 12 weeks after the transplantation. Results indicate that the green fluorescent apical end tissue replaced the original tissue, and cells from the apical bud differentiated and extended toward the incisal edge direction. The immunostaining with podoplanin also showed that the characteristics of the green fluorescent tissue were identical to those of the original. The green fluorescent cells were only found in the labial side of the incisor up to 4 weeks. After 12 weeks, however, they were also found in the lingual side. Here the green fluorescent cementocyte-like cells were only present in the cementum close to the dentin surface. This study suggests that some of the cells that form the cellular cementum come from the apical tissue including the apical bud in rodent incisors. PMID:26978064

  12. Bony change of apical lesion healing process using fractal analysis

    International Nuclear Information System (INIS)

    To investigate the change of bone healing process after endodontic treatment of the tooth with an apical lesion by fractal analysis. Radiographic images of 35 teeth from 33 patients taken on first diagnosis, 6 months, and 1 year after endodontic treatment were selected. Radiographic images were taken by JUPITER computerized Dental X-ray System. Fractal dimensions were calculated three times at each area by Scion Image PC program. Rectangular region of interest (30 x 30) were selected at apical lesion and normal apex of each image. The fractal dimension at apical lesion of first diagnosis (L0) is 0.940 ± 0.361 and that of normal area (N0) is 1.186 ± 0.727 (p1) is 1.076 ± 0.069 and that of normal area (N1) is 1.192 ± 0.055 (p2) is 1.163 ± 0.074 and that of normal area (N2) is 1.225 ± 0.079 (p<0.05). After endodontic treatment, the fractal dimensions at each apical lesions depending on time showed statistically significant difference. And there are statistically significant different between normal area and apical lesion on first diagnosis, 6 months after, 1 year after. But the differences were grow smaller as time flows. The evaluation of the prognosis after the endodontic treatment of the apical lesion was estimated by bone regeneration in apical region. Fractal analysis was attempted to overcome the limit of subjective reading, and as a result the change of the bone during the healing process was able to be detected objectively and quantitatively.

  13. Protective Effect of Vaccination with a Combination of Recombinant Surface Antigen 1 and Interleukin-12 against Toxoplasmosis in Mice

    OpenAIRE

    Letscher-Bru, Valerie; Villard, Odile; Risse, Bernhard; Zauke, Michael; Klein, Jean-Paul; Kien, Truong T.

    1998-01-01

    We studied the immune response induced in mice by recombinant Toxoplasma gondii surface antigen 1 (rSAG1) protein, alone or combined with interleukin-12 (IL-12) as an adjuvant, and the protective effect against toxoplasmosis. Immunization with rSAG1 alone induced a specific humoral type 2 immunity and did not protect the animals from infection. In contrast, immunization with rSAG1 plus IL-12 redirected humoral and cellular immunity toward a type 1 pattern and reduced the brain parasite load b...

  14. Lack of correlation between obturation limits and apical leakage

    Directory of Open Access Journals (Sweden)

    Ricardo Machado

    2013-07-01

    Full Text Available The aim of this paper was to evaluate a possible correlation between obturation limits and leakage. Thirty-six extracted human mandibular incisors were used, characterized by straight and single canals, non-anatomical complexities, absence of previous endodontic treatment, complete root formation and patent foramen. For standardization of the specimens for the leakage analysis, foraminal instrumentation was performed up to a Flexofile #25 (Dentsply-Maillefer, Ballaigues, Switzerland. All specimens were instrumented and filled following the same protocol, and the obturation limits were measured using Axiovision 4.5 Software (Carl Zeiss Vision, Hallbergmoos, Germany. The specimens were then separated into three groups (n = 12 according to the following variables: Group I - obturation limits ranging from 0 mm to 0.76 mm of the main apical foramen. Group II - obturation limits ranging from 0.77 mm to 0.98 mm of the main apical foramen. Group III - obturation limits ranging from 0.99 mm to 1.68 mm of the main apical foramen. Apical leakage was quantified by fluid filtration. The analyses were confronted using Pearson's test (p > 0.05. Groups I, II and III showed Pearson correlation values (r2 of -0.152, -0.186 and 0.058, respectively. No correlation was found between the obturation limits and apical leakage

  15. Utility of malignancy markers in fine-needle aspiration cytology of thyroid nodules: comparison of Hector Battifora mesothelial antigen-1, thyroid peroxidase and dipeptidyl aminopeptidase IV

    OpenAIRE

    De Micco, C; Savchenko, V.; Giorgi, R; Sebag, F; Henry, J-F

    2008-01-01

    The purpose of this study was to compare the diagnostic interest of Hector Battifora mesothelial antigen-1 (HBME-1), thyroid peroxidase (TPO), and dipeptidyl aminopeptidase IV (DPP4) in thyroid fine-needle aspirates obtained from 200 resected thyroid lesions (55 colloid nodules, 54 follicular adenomas, 59 papillary cancers, and 32 follicular carcinomas). Hector Battifora mesothelial antigen-1 or TPO expression (% positive cells) and DPP4 staining score (12-point scale) were evaluated. Receive...

  16. Spontaneous coronary artery dissection associated with apical hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Apical hypertrophic cardiomyopathy (HCM) is a relatively uncommon inherited disease. Spontaneous coronary artery dissection (SCAD) is also uncommonly observed, which often occurs in pregnant or post partum women but is rare in men. This report describes a 38 years old man with apical hypertrophic cardiomyopathy who developed SCAD leading to acute inferior myocardial infarction. After emergent appendectomy operation at another hospital, he was immediately transferred to the Cardiology Department of our hospital due to acute myocardial infarction. He emergently underwent coronary angiography which showed a long dissection involving the right coronary. He underwent an emergent CABG with cardiopulmonary bypass. Postoperative recovery was uneventful and he was discharged. According to our knowledge, no case of spontaneous coronary artery dissection associated with apical hypertrophic cardiomyopathy unrelated to postpartum period or oral contraceptive use has been reported so far. (author)

  17. Specialized membrane biogenesis in mammary epithelial cells

    International Nuclear Information System (INIS)

    The apical membrane of the mammary gland epithelial cell is highly differentiated and adapted to participate in the process of fat secretion. Certain of the apical membrane differentiation antigens are frequently expressed on membrane carcinoma cells, and knowledge of the normal mechanisms by which these antigens are regulated may have implications for a better understanding of tumor antigen expression. Because the apical membrane of the cell is lost during secretion, active membrane biosynthesis must accompany fat secretion, and the cell represents a good model for studying membrane biogenesis in polarized epithelial cells. Experiments have been carried out using primary cultures of cells established from mammary glands of late pregnant mice and also a mouse cell line, COMMA-1-D, that differentiates in an appropriate milieu. When fat globule membranes are purified from mouse milk and the protein composition analyzed by SDS-polyacrylamide gel electrophoresis, four major proteins are identifiable with molecular weights of 55, 67, 90, and 150 kDa. The 67-kDa component was identified as butyrophilin and the 150-kDa one as xanthine oxidase. In addition, a high molecular weight carbohydrate rich glycoprotein, PAS-O, is also present. 3 refs., 3 figs

  18. Early Endosomal Antigen 1 (EEA1) Is an Obligate Scaffold for Angiotensin II-induced, PKC-α-dependent Akt Activation in Endosomes*

    Science.gov (United States)

    Nazarewicz, Rafal Robert; Salazar, Gloria; Patrushev, Nikolay; Martin, Alejandra San; Hilenski, Lula; Xiong, Shiqin; Alexander, R. Wayne

    2011-01-01

    Akt/protein kinase B (PKB) activation/phosphorylation by angiotensin II (Ang II) is a critical signaling event in hypertrophy of vascular smooth muscle cells (VSMCs). Conventional wisdom asserts that Akt activation occurs mainly in plasma membrane domains. Recent evidence that Akt activation may take place within intracellular compartments challenges this dogma. The spatial identity and mechanistic features of these putative signaling domains have not been defined. Using cell fractionation and fluorescence methods, we demonstrate that the early endosomal antigen-1 (EEA1)-positive endosomes are a major site of Ang II-induced Akt activation. Akt moves to and is activated in EEA1 endosomes. The expression of EEA1 is required for phosphorylation of Akt at both Thr-308 and Ser-473 as well as for phosphorylation of its downstream targets mTOR and S6 kinase, but not for Erk1/2 activation. Both Akt and phosphorylated Akt (p-Akt) interact with EEA1. We also found that PKC-α is required for organizing Ang II-induced, EEA1-dependent Akt phosphorylation in VSMC early endosomes. EEA1 expression enables PKC-α phosphorylation, which in turn regulates Akt upstream signaling kinases, PDK1 and p38 MAPK. Our results indicate that PKC-α is a necessary regulator of EEA1-dependent Akt signaling in early endosomes. Finally, EEA1 down-regulation or expression of a dominant negative mutant of PKC-α blunts Ang II-induced leucine incorporation in VSMCs. Thus, EEA1 serves a novel function as an obligate scaffold for Ang II-induced Akt activation in early endosomes. PMID:21097843

  19. Sequence Variation and Immunologic Cross-Reactivity among Babesia bovis Merozoite Surface Antigen 1 Proteins from Vaccine Strains and Vaccine Breakthrough Isolates

    Science.gov (United States)

    LeRoith, Tanya; Brayton, Kelly A.; Molloy, John B.; Bock, Russell E.; Hines, Stephen A.; Lew, Ala E.; McElwain, Terry F.

    2005-01-01

    The Babesia bovis merozoite surface antigen 1 (MSA-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. While antigenic variation has been demonstrated in MSA-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. In this study, sequencing of MSA-1 from two Australian B. bovis vaccine strains and 14 breakthrough isolates from vaccinated animals demonstrated low sequence identity in the extracellular region of the molecule, ranging from 19.8 to 46.7% between the T vaccine strain and eight T vaccine breakthrough isolates, and from 18.7 to 99% between the K vaccine strain and six K vaccine breakthrough isolates. Although MSA-1 amino acid sequence varied substantially among strains, overall predicted regions of hydrophilicity and hydrophobicity in the extracellular domain were conserved in all strains examined, suggesting a conserved functional role for MSA-1 despite sequence polymorphism. Importantly, the antigenic variation created by sequence differences resulted in a lack of immunologic cross-reactivity among outbreak strains using sera from animals infected with the B. bovis vaccine strains. Additionally, sera from cattle hyperinfected with the Mexico strain of B. bovis and shown to be clinically immune did not cross-react with MSA-1 from any other isolate tested. The results indicate that isolates of B. bovis capable of evading vaccine-induced immunity contain an msa-1 gene that is significantly different from the msa-1 of the vaccine strain, and that the difference can result in a complete lack of cross-reactivity between MSA-1 from vaccine and breakthrough strains in immunized animals. PMID:16113254

  20. Detection of apical hypertrophic cardiomyopathy by cardiovascular MRI

    International Nuclear Information System (INIS)

    Objective: To investigate the clinical value of cardiovascular magnetic resonance imaging (cMRI) in identifying apical hypertrophic cardiomyopathy. Methods: Sixty-five patients with typical apical hypertrophic cardiomyopathy (T-AHCM), 51 patients with pre-apical hypertrophic cardiomyopathy (P-AHCM)and 26 normal controls were confirmed by cMRI. All cases underwent electrocardiogram and echocardiography, of which 16 and 34 cases were studied by radionuclide 99Tcm-MIBI SPECT myocardial scanning and coronary angiography plus left ventriculography, respectively. Results: cMRI confirmed all patients with apical hypertrophic cardiomyopathy, but echocardiography missed 96 cases. Two chamber and four chamber views of cine-cMRI were considered as the best position to show detailed structure of cardiac apex. Forty-seven cases showed spade-like configuration of left ventricular cavity in T-AHCM group, but only 15 patients in P-AHCM group presented the same character. T-AHCM group showed higher apical thickness and ratio of the apical wall thickness to that at basal level than P-AHCM group(18.6±2.7) mm vs (13.6±1.0) mm, 2.2±0.5 vs 1.6±0.3, P<0.05), and the ratios of both T-AHCM group and P-AHCM group were significantly higher than that of control group (9.5±1.7) mm, 1.1±0.1, P<0.05). Hypertrophic wall thickening was lesser in T-AHCM group than in P-AHCM group, while the values of both T-AHCM group and P-AHCM group were significantly lesser than that of control one. Conclusion: MRI is the best diagnostic modality for AHCM, which is highly accurate and better than echocardiography, especially for the diagnosis of mild hypertrophy in the early stage. (authors)

  1. Healing of apical rarefaction of three nonvital open apex anterior teeth using a white portland cement apical plug

    OpenAIRE

    Amitabha Chakraborty; Bibhas Dey; Reema Dhar; Prabir Sardar

    2012-01-01

    The major challenge of performing root canal treatment in an open apex pulp-less tooth is to obtain a good apical seal. MTA has been successfully used to achieve a good apical seal, wherein the root canal obturation can be done immediately. MTA and White Portland Cement has been shown similarity in their physical, chemical and biological properties and has also shown similar outcome when used in animal studies and human trials. In our study, open apex of three non vital upper central incisors...

  2. Assessment of apical periodontitis by MRI. A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Geibel, M.A. [Ulm Univ. (Germany). Oral and Maxillofacial Surgery; Schreiber, E.S.; Bracher, A.K.; Rasche, V. [Ulm Univ. (Germany). Internal Medicine II; Hell, E.; Ulrici, J. [Sirona Dental Systems GmbH, Bensheim (Germany). Dental Imaging; Sailer, L.K. [DOC Praxisklinik im Wiley, Neu-Ulm (Germany). MKG; Ozpeynirci, Y. [Ulm Univ. (Germany). Diagnostic and Interventional Radiology

    2015-04-15

    The purpose of this clinical feasibility study was to evaluate the applicability of magnetic resonance imaging (MRI) for the assessment of apical periodontitis in direct comparison with cone beam CT (CBCT). 19 consecutive patients (average age 43 ± 13 years) with 34 lesions in total (13 molars, 14 premolars and 7 front teeth) were enrolled in this feasibility study. Periapical lesions were defined as periapical radiolucencies (CBCT) or structural changes in the spongy bone signal (MRI), which were connected with the apical part of a root and with at least twice the width of the periodontal ligament space. The location and dimension of the lesions were compared between MRI and CBCT. While mainly mineralized tissue components such as teeth and bone were visible with CBCT, complimentary information of the soft tissue components was assessable with MRI. The MRI images provided sufficient diagnostic detail for the assessment of the main structures of interest. Heterogeneous contrast was observed within the lesion, with often a clear enhancement close to the apical foramen and the periodontal gap. No difference for lesion visibility was observed between MRI and CBCT. The lesion dimensions corresponded well, but were slightly but significantly overestimated with MRI. A heterogeneous lesion appearance was observed in several patients. Four patients presented with a well circumscribed hyperintense signal in the vicinity of the apical foramen. The MRI capability of soft tissue characterization may facilitate detailed analysis of periapical lesions. This clinical study confirms the applicability of multi-contrast MRI for the identification of periapical lesions.

  3. [Nonsurgical retreatment in a case of a radiolucent apical lesion].

    Science.gov (United States)

    Vicente Gómez, A; Rodríguez Ponce, A

    1989-01-01

    We present a case of failure that was helpful solved without surgical endodontic treatment. We don't achieve clinical success besides endodontic treatment was twice remade. Finally we decided to put a temporary filling with calcium hydroxide and wait until apical radiolucency disappear and complete our treatment with gutta-percha, sealer and lateral condensation. PMID:2640036

  4. Assessment of apical periodontitis by MRI. A feasibility study

    International Nuclear Information System (INIS)

    The purpose of this clinical feasibility study was to evaluate the applicability of magnetic resonance imaging (MRI) for the assessment of apical periodontitis in direct comparison with cone beam CT (CBCT). 19 consecutive patients (average age 43 ± 13 years) with 34 lesions in total (13 molars, 14 premolars and 7 front teeth) were enrolled in this feasibility study. Periapical lesions were defined as periapical radiolucencies (CBCT) or structural changes in the spongy bone signal (MRI), which were connected with the apical part of a root and with at least twice the width of the periodontal ligament space. The location and dimension of the lesions were compared between MRI and CBCT. While mainly mineralized tissue components such as teeth and bone were visible with CBCT, complimentary information of the soft tissue components was assessable with MRI. The MRI images provided sufficient diagnostic detail for the assessment of the main structures of interest. Heterogeneous contrast was observed within the lesion, with often a clear enhancement close to the apical foramen and the periodontal gap. No difference for lesion visibility was observed between MRI and CBCT. The lesion dimensions corresponded well, but were slightly but significantly overestimated with MRI. A heterogeneous lesion appearance was observed in several patients. Four patients presented with a well circumscribed hyperintense signal in the vicinity of the apical foramen. The MRI capability of soft tissue characterization may facilitate detailed analysis of periapical lesions. This clinical study confirms the applicability of multi-contrast MRI for the identification of periapical lesions.

  5. Chapter Four - Shoot apical meristem form and function. In:

    Science.gov (United States)

    The shoot apical meristem (SAM) generates above-ground aerial organs throughout the lifespan of higher plants. In order to fulfill this function, the meristem must maintain a balance between the self-renewal of a reservoir of central stem cells and organ initiation from peripheral cells. The activit...

  6. Hypertrophic cardiomyopathy with apical left ventricular aneurysm: a case report

    Institute of Scientific and Technical Information of China (English)

    江腾勇; 韩智红; 王京; 吕强; 吴学思

    2002-01-01

    @@ Morphological diversity is one characteristic of hypertrophic cardi omyopathy (HCM), but it is not common that HCM is associated with apical left ve ntricular aneurysm (LVA) without evidence of a coronary artery lesion. We repor t on such a case and review the pathogenesis, manifestations and diagnostic meth ods by collecting the few available papers published on this topic.

  7. Association of serum Epstein-Barr nuclear antigen-1 antibodies and intrathecal immunoglobulin synthesis in early multiple sclerosis.

    Science.gov (United States)

    Pfuhl, Catherina; Oechtering, Johanna; Rasche, Ludwig; Gieß, René M; Behrens, Janina R; Wakonig, Katharina; Freitag, Erik; Pache, Florence C; Otto, Carolin; Hofmann, Jörg; Eberspächer, Bettina; Bellmann-Strobl, Judith; Paul, Friedemann; Ruprecht, Klemens

    2015-08-15

    Multiple sclerosis (MS) is associated with Epstein-Barr virus (EBV) infection. A characteristic feature of MS is an intrathecal synthesis of immunoglobulin (Ig)G. In 90 patients with clinically isolated syndromes/early relapsing-remitting MS, serum antibodies to Epstein-Barr nuclear antigen-1, but not to EBV viral capsid antigen, rubella, or varicella zoster virus, were higher (p=0.03) in those with than those without a calculated intrathecal IgG synthesis >0% and correlated with the percentage (r=0.27, p=0.009) and concentration (r=0.27, p=0.012) of intrathecally produced IgG. These findings suggest a link between EBV infection and the events leading to intrathecal IgG synthesis in patients with MS. PMID:26198934

  8. A rapid method for the evaluation of the ionic permeabilities across epithelial cell membranes.

    Science.gov (United States)

    Movileanu, L

    1999-02-01

    This short note presents a recipe for the calculation of the ionic permeabilities across epithelial cell membranes. The method requires the Goldman-Hodgkin-Katz formalism as well as the consideration of the equivalent electrical circuit for an epithelial cell. The equivalent electrical circuit is solved in terms of the equivalent electromotive forces coupled in series with the ionic resistances of both cell membranes (apical and basolateral). The present procedure is feasible for any leaky epithelial cell membrane with the condition that this membrane (apical or basolateral) does not contain primary or secondary mechanisms for active transport. PMID:10100952

  9. Transient apical dyskinesia with a pacemaker: Electrocardiographic features.

    Science.gov (United States)

    Núñez-Gil, Iván J; Feltes, Gisela I; Mejía-Rentería, Hernán D; Biagioni, Corina; De Agustín, J Alberto; Vivas, David; Fernández-Ortiz, Antonio

    2015-04-01

    Transient apical dyskinesia syndromes present features similar to acute coronary syndromes, but with normal coronary arteries and rapid complete resolution of wall motion alterations. We report the case of a 73-year-old woman who was admitted to hospital because of typical chest pain at rest after her brother's death. She had had a pacemaker implanted in 2001. Troponin levels were elevated and apical hypokinesia was shown by ventriculography and echocardiography, with normal coronary arteries. Evolving ECG alterations were observed in spite of the continued pacing rhythm. All these alterations were fully resolved after discharge. This case shows that, even in the presence of a pacemaker, evolving ECG alterations can be observed in Takotsubo syndrome. PMID:25840647

  10. Apical versus Basal Neurogenesis Directs Cortical Interneuron Subclass Fate

    Directory of Open Access Journals (Sweden)

    Timothy J. Petros

    2015-11-01

    Full Text Available Fate determination in the mammalian telencephalon, with its diversity of neuronal subtypes and relevance to neuropsychiatric disease, remains a critical area of study in neuroscience. Most studies investigating this topic focus on the diversity of neural progenitors within spatial and temporal domains along the lateral ventricles. Often overlooked is whether the location of neurogenesis within a fate-restricted domain is associated with, or instructive for, distinct neuronal fates. Here, we use in vivo fate mapping and the manipulation of neurogenic location to demonstrate that apical versus basal neurogenesis influences the fate determination of major subgroups of cortical interneurons derived from the subcortical telencephalon. Somatostatin-expressing interneurons arise mainly from apical divisions along the ventricular surface, whereas parvalbumin-expressing interneurons originate predominantly from basal divisions in the subventricular zone. As manipulations that shift neurogenic location alter interneuron subclass fate, these results add an additional dimension to the spatial-temporal determinants of neuronal fate determination.

  11. Apical pressures developed by needles for canal irrigation.

    Science.gov (United States)

    Bradford, C E; Eleazer, P D; Downs, K E; Scheetz, J P

    2002-04-01

    Drying instrumented canals with pressurized air may result in patient morbidity or even fatality. Low pressure and side vent needles have been suggested to lessen the danger. This study observed apical pressures from different needles inserted deeply into small round and ovoid canals as instrumentation progressed. Low-pressure (5 psi) air was injected through the needles, and apical pressures were recorded after each instrument. Pressures varied greatly within each test group. Generalities that can be drawn are that binding the needle within the canal gives higher pressures than with the needle slightly short of binding and that pressures were higher with apexes instrumented to size 30 and higher. With the needle tightly bound, neither needle size, needle design, nor canal shape resulted in statistically significant mean pressure differences. With the needle slightly withdrawn, larger bore needles gave higher pressures than small diameter needles. Caution is advised with the clinical use of pressurized air in the drying of root canals. PMID:12043877

  12. Modelling apical constriction in epithelia using elastic shell theory.

    Science.gov (United States)

    Jones, Gareth Wyn; Chapman, S Jonathan

    2010-06-01

    Apical constriction is one of the fundamental mechanisms by which embryonic tissue is deformed, giving rise to the shape and form of the fully-developed organism. The mechanism involves a contraction of fibres embedded in the apical side of epithelial tissues, leading to an invagination or folding of the cell sheet. In this article the phenomenon is modelled mechanically by describing the epithelial sheet as an elastic shell, which contains a surface representing the continuous mesh formed from the embedded fibres. Allowing this mesh to contract, an enhanced shell theory is developed in which the stiffness and bending tensors of the shell are modified to include the fibres' stiffness, and in which the active effects of the contraction appear as body forces in the shell equilibrium equations. Numerical examples are presented at the end, including the bending of a plate and a cylindrical shell (modelling neurulation) and the invagination of a spherical shell (modelling simple gastrulation). PMID:19859751

  13. Diagnosis Toksoplasmosis Kongenital Berdasarkan Gen Surface Antigen-1 Toxoplama gondii Isolat Lokal Menggunakan Polymerase Chain Reaction (DIAGNOSIS OF CONGENITAL TOXOPLASMOSIS BASED ON SURFACE ANTIGEN -1 GENE OF LOCAL ISOLATE TOXOPLASMA GONDII USING POLY

    Directory of Open Access Journals (Sweden)

    Dwi Priyowidodo

    2015-10-01

    Full Text Available Congenital toxoplasmosis has an important role in the transmission of toxoplasmosis in animals andhumans. Thus, a rapid and an accurate diagnostic method is needed. The aim of this study was to conductthe diagnosis technique of congenital toxoplasmosis in mice based on surface antigen-1 (SAG-1 gene oflocal isolates (IS-1 T. gondii using Polymerase Chain Reaction (PCR. A total of 15 pregnant mice Balb/C strain with the aged of eight weeks were used as experimental animal. Mice were intraperitoneallyinfected with 103tachizoit of T. gondii RH strain at day 9th of gestation. Amniotic fluids, blood, fetus, andplacenta then were collected at day 1, 2 , 3, 4 and 5 post infection. DNA was extracted from the abovesamples using PureLinkTM Genomic DNA Kit (Invitrogen, Life Technologies, US, and then amplified byusing specific primer based on SAG-1 gene of the local isolate T. gondii. This study shows that positivePCR result were seen in all samples of amniotic fluids at day 2 up to day 5 post infection. Fetus andplacenta samples also show positive PCR result at 3 up to day 5 post infection. Negative PCR result showsin blood samples, however. To conclude, PCR technique using SAG-1 gene of local isolates T. gondii as atarget gene, could be used to detect congenital toxoplasmosis from infected mouse samples such as, amnionfluids, fetus, and placenta. Further research was needed to apply the PCR method with SAG-1 gene of localisolate T. gondiion the human samples of congenital toxoplasmosis.

  14. Anharmonic apical oxygen vibration in high-Tc superconductors

    International Nuclear Information System (INIS)

    Using time-independent perturbation theory, a theoretical calculation has been performed for the transition temperatures for various high-Tc oxide compounds. It has been assumed that, three electrons are responsible for the superconducting current. Whereas two of these electrons form an exotic bound pair, the third electron causes perturbation H' = βx3 + γx4 with respect to apical oxygen vibrations. From the calculations, the transition temperatures are found to be realistic and comparable with experimental results. (author)

  15. Segmenting the sepal and shoot apical meristem of Arabidopsis thaliana

    OpenAIRE

    Cunha, Alexandre L.; Roeder, Adrienne H. K.; Meyerowitz, Elliot M.

    2010-01-01

    We present methods for segmenting the sepal and shoot apical meristem of the Arabidopsis thaliana plant. We propose a mathematical morphology pipeline and a modified numerical scheme for the active contours without edges algorithm to extract the geometry and topology of plant cells imaged using confocal laser scanning microscopy. We demonstrate our methods in typical images used in the studies of cell endoreduplication and hormone transport and show that in practice they produce highly accura...

  16. Genetic Control of Maize Shoot Apical Meristem Architecture

    OpenAIRE

    Thompson, Addie M.; Crants, James; Schnable, Patrick S.; Yu, Jianming; Timmermans, Marja C. P.; Springer, Nathan M.; Scanlon, Michael J; Muehlbauer, Gary J.

    2014-01-01

    The shoot apical meristem contains a pool of undifferentiated stem cells and generates all above-ground organs of the plant. During vegetative growth, cells differentiate from the meristem to initiate leaves while the pool of meristematic cells is preserved; this balance is determined in part by genetic regulatory mechanisms. To assess vegetative meristem growth and genetic control in Zea mays, we investigated its morphology at multiple time points and identified three stages of growth. We me...

  17. The shoot apical meristem: the dynamics of a stable structure.

    OpenAIRE

    Traas, Jan,; Vernoux, Teva

    2002-01-01

    The shoot apical meristem (SAM) is a group of proliferating, embryonic-type cells that generates the aerial parts of the plant. SAMs are highly organized and stable structures that can function for years or even centuries. This is in apparent contradiction to the behaviour of their constituent cells, which continuously proliferate and differentiate. To reconcile the dynamic nature of the cells with the stability of the overall system the existence of elaborate signalling networks has been pro...

  18. Calcium hydroxide induced apical barrier in fractured nonvital immature permanent incisors

    Directory of Open Access Journals (Sweden)

    Vellore K

    2010-06-01

    Full Text Available Management of trauma to an immature permanent incisor is a challenge, especially when the pulp is necrotic. The aim of this study is to discuss the management of fractured maxillary right and left central incisors with immature root apex. Radiographic evaluation revealed that the tooth 11 had convergent apical walls, whereas tooth 21 had parallel apical walls; both the incisors were treated with pure calcium hydroxide paste to induce apical development. Follow-up clinical and radiographic examinations confirmed apical barrier at 3 months. Radiograph of tooth 11 with convergent roots showed continued apical development, whereas tooth 21 showed apical bridging, following which root canal was completed in both the teeth. Therefore, in view of the simplicity of this method, we believe that calcium hydroxide can be reemphasized as one of the treatment alternatives for fractured nonvital immature permanent incisors to induce apical barrier.

  19. The Epstein-Barr virus nuclear antigen-1 reprograms transcription by mimicry of high mobility group A proteins.

    Science.gov (United States)

    Coppotelli, Giuseppe; Mughal, Nouman; Callegari, Simone; Sompallae, Ramakrishna; Caja, Laia; Luijsterburg, Martijn S; Dantuma, Nico P; Moustakas, Aristidis; Masucci, Maria G

    2013-03-01

    Viral proteins reprogram their host cells by hijacking regulatory components of protein networks. Here we describe a novel property of the Epstein-Barr virus (EBV) nuclear antigen-1 (EBNA1) that may underlie the capacity of the virus to promote a global remodeling of chromatin architecture and cellular transcription. We found that the expression of EBNA1 in transfected human and mouse cells is associated with decreased prevalence of heterochromatin foci, enhanced accessibility of cellular DNA to micrococcal nuclease digestion and decreased average length of nucleosome repeats, suggesting de-protection of the nucleosome linker regions. This is a direct effect of EBNA1 because targeting the viral protein to heterochromatin promotes large-scale chromatin decondensation with slow kinetics and independent of the recruitment of adenosine triphosphate-dependent chromatin remodelers. The remodeling function is mediated by a bipartite Gly-Arg rich domain of EBNA1 that resembles the AT-hook of High Mobility Group A (HMGA) architectural transcription factors. Similar to HMGAs, EBNA1 is highly mobile in interphase nuclei and promotes the mobility of linker histone H1, which counteracts chromatin condensation and alters the transcription of numerous cellular genes. Thus, by regulating chromatin compaction, EBNA1 may reset cellular transcription during infection and prime the infected cells for malignant transformation. PMID:23358825

  20. Characterization of Fetal Antigen 1/Delta-Like 1 Homologue Expressing Cells in the Rat Nigrostriatal System

    DEFF Research Database (Denmark)

    Liechti, Rémy; Ducray, Angélique D; Jensen, Pia;

    2015-01-01

    Fetal antigen 1/delta-like 1 homologue (FA1/dlk1) belongs to the epidermal growth factor superfamily and is considered to be a non-canonical ligand for the Notch receptor. Interactions between Notch and its ligands are crucial for the development of various tissues. Moreover, FA1/dlk1 has been...... adult rats. FA1/dlk1-ir cells were predominantly distributed in the substantia nigra (SN) pars compacta (SNc) and in the ventral tegmental area. Interestingly, the expression of FA1/dlk1 significantly increased in tyrosine hydroxylase (TH)-ir cells during early postnatal development. Co-localization and...... dopaminergic neurons and/or due to the stab wound. Our findings hint to a significant role of FA1/dlk1 in the SNc during early postnatal development. The differential expression of FA1/dlk1 in the SNc and the striatum of dopamine-depleted rats could indicate a potential involvement of FA1/dlk1 in the cellular...

  1. Myeloid-specific Fos-related antigen-1 regulates cigarette smoke-induced lung inflammation, not emphysema, in mice.

    Science.gov (United States)

    Vaz, Michelle; Rajasekaran, Subbiah; Potteti, Haranatha R; Reddy, Sekhar P

    2015-07-01

    Heightened lung inflammation is a cardinal feature of chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS)-induced macrophage recruitment and activation, accompanied by abnormal secretion of a number of inflammatory cytokines and matrix metalloproteinases, play a major role in the pathophysiology of COPD. The Fos-related antigen-1 (Fra-1) transcription factor differentially regulates several cellular processes that are implicated in COPD, such as inflammation and immune responses, cell proliferation and death, and extracellular remodeling. Although CS stimulates Fra-1 expression in the lung, the precise role of this transcription factor in the regulation of CS-induced lung inflammation in vivo is poorly understood. Here, we report that myeloid-specific Fra-1 signaling is important for CS-induced lung macrophagic inflammatory response. In response to chronic CS exposure, mice with Fra-1 specifically deleted in myeloid cells showed reduced levels of CS-induced lung macrophagic inflammation, accompanied by decreased expression levels of proinflammatory cytokines compared with their wild-type counterparts. Consistent with this result, bone marrow-derived Fra-1-null macrophages treated with CS showed decreased levels of proinflammatory mediators and matrix metalloproteinases. Interestingly, deletion of Fra-1 in myeloid cells did not affect the severity of emphysema. We propose that Fra-1 plays a key role in promoting chronic CS-induced lung macrophagic inflammation in vivo, and that targeting this transcription factor may be useful in dampening persistent lung inflammation in patients with COPD. PMID:25489966

  2. Delta-like 1/fetal antigen-1 (Dlk1/FA1) is a novel regulator of chondrogenic cell differentiation via inhibition of the Akt kinase-dependent pathway

    DEFF Research Database (Denmark)

    Chen, Li; Qanie, Diyako; Jafari, Abbas; Taipaleenmaki, Hanna; Jensen, Charlotte H; Säämänen, Anna-Marja; Sanz, Maria Luisa Nueda; Laborda, Jorge; Abdallah, Basem M; Kassem, Moustapha

    2011-01-01

    Delta-like 1 (Dlk1, also known as fetal antigen-1, FA1) is a member of Notch/Delta family that inhibits adipocyte and osteoblast differentiation; however, its role in chondrogenesis is still not clear. Thus, we overexpressed Dlk1/FA1 in mouse embryonic ATDC5 cells and tested its effects on...

  3. Fetal antigen 1, an EGF multidomain protein in the sex hormone-producing cells of the gonads and the microenvironment of germ cells

    DEFF Research Database (Denmark)

    Jensen, Charlotte Harken; Erb, K; Westergaard, L G;

    1999-01-01

    Fetal antigen 1 (FA1), an epidermal growth factor (EGF) multidomain glycoprotein, was investigated in the human reproductive system. Immunohistochemical analysis of the male reproductive system revealed staining for FA1 in the Leydig cells only. Concentrations of FA1 in seminal plasma and serum w...

  4. Specific T-cell recognition of the merozoite proteins rhoptry-associated protein 1 and erythrocyte-binding antigen 1 of Plasmodium falciparum

    DEFF Research Database (Denmark)

    Jakobsen, P H; Hviid, L; Theander, T G;

    1993-01-01

    The merozoite proteins merozoite surface protein 1 (MSP-1) and rhoptry-associated protein 1 (RAP-1) and synthetic peptides containing sequences of MSP-1, RAP-1, and erythrocyte-binding antigen 1, induced in vitro proliferative responses of lymphocytes collected from Ghanaian blood donors living i...

  5. Elevated serum levels of fetal antigen 1,a member of the epidermal growth factor superfamily, in patients with small cell lung cancer

    DEFF Research Database (Denmark)

    Harken Jensen, C; Drivsholm, L; Laursen, I; Teisner, B

    1999-01-01

    Serum levels of fetal antigen 1 (FA1) were quantified pretherapeutically in 16 patients with pneumonia, 30 patients with small cell lung cancer (SCLC) and 10 patients with non-small cell lung cancer (NSCLC) and compared to the normal reference interval (n = 177). Serum FA1 levels were significantly...

  6. SEM investigation of Er:YAG laser apical preparation

    Science.gov (United States)

    Bǎlǎbuc, Cosmin; Todea, Carmen; Locovei, Cosmin; RǎduÅ£ǎ, Aurel

    2016-03-01

    Endodontic surgery involves the incision and flap elevation, the access to the root tip, its resection, the cavity retrograde preparation and filling it with biocompatible material that provides a good seal of the apex[1]. Apicoectomy is compulsory in endodontic surgery. The final stage involves the root retropreparation and the carrying out of the retrograde obturation. In order to perform the retrograde preparation the endodontist can use various tools such as lowspeed conventional handpieces, sonic and ultrasonic equipment. The ideal depth of the preparation should be 3 mm, exceeding this value may affect the long-term success of the obturation [2]. Resection at the depth of 3 mm reduces apical ramifications by 98% and lateral root canals by 93%. The ultrasonic retropreparation has numerous advantages compared to the dental drill. Firstly, the cavity will be in the axis of the tooth which implies a minimum destruction of the root canal morphology. The preparations are precise, and the cutting pattern is perpendicular to the long axis of the root, the advantage being the reduction in the number of dentinal tubules exposed at the resected area [3]. Therefore, the retrograde filling is the procedure when an inert and non-toxic material is compacted in the apically created cavity.[4,5]. The Er:YAG laser is the most common wavelength indicated for dental hard tissue preparation. Its natural selectivity offers a significant advantage compared to the conventional hard tissue preparation [6-9].The purpose of this in vitro study was to investigate the quality of Er:YAG laser apical third preparation using Scanning Electron Microscopy (SEM), in comparison with the conventional ultrasonic method.

  7. Membrane recycling at the infranuclear pole of the outer hair cell

    Science.gov (United States)

    Harasztosi, Csaba; Harasztosi, Emese; Gummer, Anthony W.

    2015-12-01

    Rapid endocytic activity of outer hair cells (OHCs) in the guinea-pig cochlea has been already studied using the fluorescent membrane marker FM1-43. It was demonstrated that vesicles were endocytosed at the apical pole of OHCs and transcytosed to the basolateral membrane and through a central strand towards the nucleus. The significance of endocytic activity in the infranuclear region is still not clear. Therefore, in this study endocytic activity at the synaptic pole of OHCs was investigated. Confocal laser scanning microscopy was used to visualize dye uptake of OHCs isolated from the guinea-pig cochlea. Signal intensity changes were quantified in the apical and basal poles relative to the signal at the membrane. Data showed no significant difference in fluorescent signal intensity changes between the opposite poles of the OHC. These results suggest that endocytic activities in both the basal and the apical poles contribute equally to the membrane recycling of OHCs.

  8. Studies on the isolation, structural analysis and tissue localization of fetal antigen 1 and its relation to a human adrenal-specific cDNA, pG2

    DEFF Research Database (Denmark)

    Jensen, Charlotte Harken; Teisner, Børge; Højrup, Peter;

    1993-01-01

    sequence was back-translated into the appropriate degenerate sequence of nucleic acids, fetal antigen 1 could be partially aligned to a 'human adrenal-specific mRNA, pG2'. The indirect immunoperoxidase technique demonstrated fetal antigen 1 in fetal hepatocytes, glandular cells of fetal pancreas and in...

  9. Manner of Apical Meristem Destruction Affects Growth, Reproduction, and Survival of Sea Oxeye Daisy

    OpenAIRE

    Spirko, Lisa S.; Rossi, Anthony M.

    2015-01-01

    Although herbivory may result in plant death, the mode and timing of damage may produce variable wounding responses in the attacked plant. In this study, effects of different types of apical meristem damage on growth and performance of sea oxeye daisy Borrichia frutescens (L.) DC were compared. Damage involved either clipping or galling of the apical meristem by the gall midge Asphondylia borrichiae Rossi and Strong. Apical dominance was relatively weak before flowering and stronger in short ...

  10. Is the apical growth of Cymodocea nodosa dependent on clonal integration?

    OpenAIRE

    Terrados, Jorge; Duarte, Carlos M.; Kenworthy, W. Judson

    1997-01-01

    The importance of clonal integration for the production of biomass by the apical meristem of Cymodocea nodosa (Ucria) Ascherson was tested in situ by experimental manipulation. The production of new biomass by the apical meristem of a horizontal rhizome, as well as the leaf growth of the remaining shoots, was greatly reduced when the horizontal rhizome was severed, even when up to 11 shoots were left connected to the apical meristem of the rhizome. In contrast, the elimination of up to ...

  11. Selamento apical proporcionado por diferentes cimentos endodônticos

    Directory of Open Access Journals (Sweden)

    Karlel Tristão Marques

    2011-01-01

    Full Text Available To have success in endodontic treatment it is necessary that the sealing airtight as possible of the root canal system, with suitable material such as gutta-percha and sealer. There are sealers of different compositions, which should allow the sealing of the root canal system, preventing recontamination place and favoring the success of endodontic therapy. In this study were evaluated the apical microleakage after obturation using different root canal sealers widely employed in the market, with different compositions. For this study, 85 single rooted teeth premolars which have removed their crowns and root canals prepared and filled using four types of cement: AH Plus, Endofill, Acroseal and Real Seal SE. All samples were sealed and submitted to microleakage with Indian ink; longitudinal cuts made on both sides of the tooth and cleaved; apical images were obtained. The areas of dye penetration were measured on a computer using specific software and subjected to statistical analysis. It was concluded that the Acroseal ® showed the highest mean microleakage with no statistically significant difference in relation to the RealSeal SE®, but with significant differences compared to Endofill ® and AHPlus ®.

  12. Calcium hydroxide as intracanal dressing for teeth with apical periodontitis

    Directory of Open Access Journals (Sweden)

    Sari Dewiyani

    2011-03-01

    Full Text Available Background: Root canal infection and periapical diseases are caused by bacteria and their products. Long term infection may spread bacteria throughout the root canal system. Apical periodontitis caused by infectious microbe that persistent in root canals can cause radiographic and histopathology periapical changes. Chemomechanical preparation and intracanal dressing then are recommended to be conducted and used in between visits to eliminate microbes in root canals. Calcium hydroxide (Ca(OH2 can be used as intracanal dressing since it can be used as musical physical defense barrier to eliminate re-infection in root canal and to disturb nutrition supply for bacterial development. Purpose: The aim of this study is observe the effectiveness of Ca(OH2 in treating endodontic teeth with apical periodontitis. Cases: Case 1 and 3 are about patients whose left posterior mandibular teeth had spontaneous intermittent pain. Case 2 is about a patient whose left posterior maxillary teeth had gingival abscess and fracture history. Based on the radiographic examination, it was known that the filling of root canal was incomplete and there was radiolucency in the apical area. Case management: The cases were treated with triad endodontics, which involves preparation, disinfection by using 2.5% NaOCl as irrigation substance and calcium hydroxide as intracanal dressing, and then the filling of root canal with gutta percha and endomethasone root canal cement. Evaluations were conducted one month, 12 months, and 24 months after the treatment. Conclusion: Calcium hydroxide is effective to be used as intracanal dressing in apical periodontitis cases.Latar belakang: Infeksi saluran akar dan penyakit periapeks disebabkan oleh mikroba dan produknya. Infeksi yang berlangsung lama memungkinkan bakteri masuk ke dalam seluruh sistem saluran akar. Periodontitis apikal disebabkan oleh infeksi persisten mikroba di dalam sistem saluran akar disertai perubahan radiografik dan

  13. Genome-wide analysis of host-chromosome binding sites for Epstein-Barr Virus Nuclear Antigen 1 (EBNA1

    Directory of Open Access Journals (Sweden)

    Wang Pu

    2010-10-01

    Full Text Available Abstract The Epstein-Barr Virus (EBV Nuclear Antigen 1 (EBNA1 protein is required for the establishment of EBV latent infection in proliferating B-lymphocytes. EBNA1 is a multifunctional DNA-binding protein that stimulates DNA replication at the viral origin of plasmid replication (OriP, regulates transcription of viral and cellular genes, and tethers the viral episome to the cellular chromosome. EBNA1 also provides a survival function to B-lymphocytes, potentially through its ability to alter cellular gene expression. To better understand these various functions of EBNA1, we performed a genome-wide analysis of the viral and cellular DNA sites associated with EBNA1 protein in a latently infected Burkitt lymphoma B-cell line. Chromatin-immunoprecipitation (ChIP combined with massively parallel deep-sequencing (ChIP-Seq was used to identify cellular sites bound by EBNA1. Sites identified by ChIP-Seq were validated by conventional real-time PCR, and ChIP-Seq provided quantitative, high-resolution detection of the known EBNA1 binding sites on the EBV genome at OriP and Qp. We identified at least one cluster of unusually high-affinity EBNA1 binding sites on chromosome 11, between the divergent FAM55 D and FAM55B genes. A consensus for all cellular EBNA1 binding sites is distinct from those derived from the known viral binding sites, suggesting that some of these sites are indirectly bound by EBNA1. EBNA1 also bound close to the transcriptional start sites of a large number of cellular genes, including HDAC3, CDC7, and MAP3K1, which we show are positively regulated by EBNA1. EBNA1 binding sites were enriched in some repetitive elements, especially LINE 1 retrotransposons, and had weak correlations with histone modifications and ORC binding. We conclude that EBNA1 can interact with a large number of cellular genes and chromosomal loci in latently infected cells, but that these sites are likely to represent a complex ensemble of direct and indirect EBNA

  14. Stem Cells Antigen-1 Enriches for a Cancer Stem Cell-Like Subpopulation in Mouse Gastric Cancer.

    Science.gov (United States)

    Park, Jun Won; Park, Jung Min; Park, Dong Min; Kim, Dae-Yong; Kim, Hark Kyun

    2016-05-01

    There is a strong need to identify markers to enrich gastric cancer stem cells (CSCs). However, CSC enrichment markers for mouse gastric cancers have not yet been determined. In our previous study, we generated primary mouse gastric cancer cell line NCC-S1 (S1) established from a Villin-cre;Smad4(F/F) ;Trp53(F/F) ;Cdh1(F/wt) mouse and its metastatic variant cell line NCC-S1M (S1M). Interestingly, S1M cells exhibited CSC-like features, such as increased tumorigenic potential and chemoresistance. By comparing gene expression profiles between S1 and S1M cells, we identified Stem Cells Antigen-1 (Sca-1) as a cell surface marker, which was mostly upregulated in S1M. Sca-1 was upregulated in tumorspheres from S1 cells or after cisplatin treatment in S1 cells. Immunofluorescence (IF) analysis showed that approximately 7% of cancer cells exhibited positivity for Sca-1 in primary mouse gastric cancer tissues. An in vivo-limiting dilution assay showed that Sca-1(high) mouse gastric cancer cells demonstrated increased tumorigenicity compared with Sca-1(negative) cells. The Sca-1 expression was downregulated by TGF-β pathway activation and Wnt pathway inhibition in mouse gastric cancer cells. Sca-1(high) cells showed relatively low TGF-β reporter activity and high TCF/LEF1 reporter activity compared with Sca-1(negative) cells. A chromatin immunoprecipitation analysis demonstrated that Sca-1 was a β-catenin/LEF1 target gene. Sca-1(high) allografts were more resistant to cisplatin/fluorouracil chemotherapy than Sca-1(negative) allografts, and overexpressed Bcl-xL. Eighty-five mouse genes overexpressed in Sca-1(high) S1 cells compared with Sca-1(negative) cells clustered 123 pretreatment gastric cancer patient samples according to survival following chemotherapy. Taken together, Sca-1 is a novel CSC enrichment marker that mediates TGF-β and Wnt/β-catenin signaling in mouse gastric cancer. Stem Cells 2016;34:1177-1187. PMID:26869189

  15. Aluminum Tolerance in Wheat (Triticum aestivum L.) (I. Uptake and Distribution of Aluminum in Root Apices).

    Science.gov (United States)

    Delhaize, E.; Craig, S.; Beaton, C. D.; Bennet, R. J.; Jagadish, V. C.; Randall, P. J.

    1993-11-01

    We investigated the uptake and distribution of Al in root apices of near-isogenic wheat (Triticum aestivum L.) lines differing in Al tolerance at a single locus (Alt1: aluminum tolerance). Seedlings were grown in nutrient solution that contained 100 [mu]M Al, and the roots were subsequently stained with hematoxylin, a compound that binds Al in vitro to form a colored complex. Root apices of Al-sensitive genotypes stained after short exposures to Al (10 min and 1 h), whereas apices of Al-tolerant seedlings showed less intense staining after equivalent exposures. Differential staining preceded differences observed in either root elongation or total Al concentrations of root apices (terminal 2-3 mm of root). After 4 h of exposure to 100 [mu]M Al in nutrient solution, Al-sensitive genotypes accumulated more total Al in root apices than Al-tolerant genotypes, and the differences became more marked with time. Analysis of freeze-dried root apices by x-ray microanalysis showed that Al entered root apices of Al-sensitive plants and accumulated in the epidermal layer and in the cortical layer immediately below the epidermis. Long-term exposure of sensitive apices to Al (24 h) resulted in a distribution of Al coinciding with the absence of K. Quantitation of Al in the cortical layer showed that sensitive apices accumulated 5- to 10-fold more Al than tolerant apices exposed to Al solutions for equivalent times. These data are consistent with the hypothesis that Alt1 encodes a mechanism that excludes Al from root apices. PMID:12231972

  16. Direct Measurement of Intrinsic Apical Oxygen Potential in Metallic and Insulating YBa2Cu3O7-σ

    International Nuclear Information System (INIS)

    Using pulsed Raman spectroscopy, we directly examined the intrinsic apical O potential in insulating YBa2Cu3O6.25 and metallic YBa2Cu3O6.9. We selectively excited the apical O vibration mode with ultra short laser pulses to obtain a 'hot' apical O vibration mode in a 'cold' bulk phonon background. Measurements showed that the apical O phonon frequency shift and linewidth change are much smaller in the case of selective heating of the apical O vibration mode compared to bulk heating. The results agree well with theoretical predictions and indicate a strong influence of surrounding lattice ions on the apical O potential. (author)

  17. Evasion of Complement-Mediated Lysis and Complement C3 Deposition Are Regulated by Francisella tularensis Lipopolysaccharide O Antigen1

    OpenAIRE

    Clay, Corey D.; Soni, Shilpa; Gunn, John S.; Schlesinger, Larry S.

    2008-01-01

    The bacterium Francisella tularensis (Ft) is a potential weapon of bioterrorism when aerosolized. Macrophage infection is necessary for disease progression and efficient phagocytosis by human macrophages requires serum opsonization by complement. Microbial complement activation leads to surface deposition of a highly regulated protein complex resulting in opsonization or membrane lysis. The nature of complement component C3 deposition, i.e., C3b (opsonization and lysis) or C3bi (opsonization ...

  18. Cryopreservation of Galanthus elwesii Hook. apical meristems by droplet vitrification.

    Science.gov (United States)

    Maslanka, M; Panis, B; Bach, A

    2013-01-01

    The aim of this study was to develop an efficient cryopreservation protocol for the geophyte giant snowdrop (Galanthus elwesii Hook.) that guarantees a high rate of survival and plant regeneration after cryopreservation. The excised apical meristems were obtained from cultures of in vitro grown bulb scales. Using a vitrification procedure and optimizing the duration of the exposure to the loading solution (LS), meristem post-rewarm survival rates higher than 90 percent were achieved. Also regrowth percentages were very high, ranging from 87 to 91 percent. After optimizing the time of exposure to the plant vitrification solution (PVS2), the survival rate was between 83 and 97 percent. During post-rewarm regeneration, good growth recovery was as high as 76 percent; however, hyperhydration and callusing were also observed. The results demonstrate that cryopreservation of Galanthus elwesii germplasm seems to be feasible. PMID:23435704

  19. Serious arrhythmias in patients with apical hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Okishige, Kaoru; Sasano, Tetsuo; Yano, Kei; Azegami, Kouji; Suzuki, Kou; Itoh, Kuniyasu [Yokohama Red Cross Hospital (Japan)

    2001-05-01

    We report cases of serious arrhythmias associated with apical hypertrophic cardiomyopathy (AHCM). Thirty-one patients were referred to our institute to undergo further assessment of their AHCM from 1988 to 1999. Three patients with nonsustained ventricular tachycardia demonstrated an {sup 123}I-MIBG regional reduction in the tracer uptake. In two patients with ventricular fibrillation (VF), the findings from {sup 123}I-MIBG imaging revealed regional sympathetic denervation in the inferior and lateral regions. Electrophysiologic study demonstrated reproducible induction of VF in aborted sudden death and presyncopal patients, resulting in the need for an implantable defibrillator device and amiodarone in each patient. Patients with refractory atrial fibrillation with a rapid ventricular response suffered from serious congestive heart failure. A prudent assessment and strategy in patients with this disease would be indispensable in avoiding a disastrous outcome. (author)

  20. Serious arrhythmias in patients with apical hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    We report cases of serious arrhythmias associated with apical hypertrophic cardiomyopathy (AHCM). Thirty-one patients were referred to our institute to undergo further assessment of their AHCM from 1988 to 1999. Three patients with nonsustained ventricular tachycardia demonstrated an 123I-MIBG regional reduction in the tracer uptake. In two patients with ventricular fibrillation (VF), the findings from 123I-MIBG imaging revealed regional sympathetic denervation in the inferior and lateral regions. Electrophysiologic study demonstrated reproducible induction of VF in aborted sudden death and presyncopal patients, resulting in the need for an implantable defibrillator device and amiodarone in each patient. Patients with refractory atrial fibrillation with a rapid ventricular response suffered from serious congestive heart failure. A prudent assessment and strategy in patients with this disease would be indispensable in avoiding a disastrous outcome. (author)

  1. Oral microbiota species in acute apical endodontic abscesses

    Science.gov (United States)

    George, Noelle; Flamiatos, Erin; Kawasaki, Kellie; Kim, Namgu; Carriere, Charles; Phan, Brian; Joseph, Raphael; Strauss, Shay; Kohli, Richie; Choi, Dongseok; Craig Baumgartner, J.; Sedgley, Christine; Maier, Tom; Machida, Curtis A.

    2016-01-01

    Background and objectives Acute apical abscesses are serious endodontic diseases resulting from pulpal infection with opportunistic oral microorganisms. The objective of this study was to identify and compare the oral microbiota in patients (N=18) exhibiting acute apical abscesses, originating from the demographic region in Portland, Oregon. The study hypothesis is that abscesses obtained from this demographic region may contain unique microorganisms not identified in specimens from other regions. Design Endodontic abscesses were sampled from patients at the Oregon Health & Science University (OHSU) School of Dentistry. DNA from abscess specimens was subjected to polymerase chain reaction amplification using 16S rRNA gene-specific primers and Cy3-dCTP labeling. Labeled DNA was then applied to microbial microarrays (280 species) generated by the Human Oral Microbial Identification Microarray Laboratory (Forsyth Institute, Cambridge, MA). Results The most prevalent microorganisms, found across multiple abscess specimens, include Fusobacterium nucleatum, Parvimonas micra, Megasphaera species clone CS025, Prevotella multisaccharivorax, Atopobium rimae, and Porphyromonas endodontalis. The most abundant microorganisms, found in highest numbers within individual abscesses, include F. nucleatum, P. micra, Streptococcus Cluster III, Solobacterium moorei, Streptococcus constellatus, and Porphyromonas endodontalis. Strong bacterial associations were identified between Prevotella multisaccharivorax, Acidaminococcaceae species clone DM071, Megasphaera species clone CS025, Actinomyces species clone EP053, and Streptococcus cristatus (all with Spearman coefficients >0.9). Conclusions Cultivable and uncultivable bacterial species have been identified in endodontic abscesses obtained from the Portland, Oregon demographic region, and taxa identifications correlated well with other published studies, with the exception of Treponema and Streptococcus cristae, which were not commonly

  2. Developmental Corneal Innervation: Interactions between Nerves and Specialized Apical Corneal Epithelial Cells

    OpenAIRE

    Kubilus, James K.; Linsenmayer, Thomas F.

    2010-01-01

    During developmental innervation of the chicken cornea, nerves interact with apical corneal epithelial cells to form synapse-like structures. In addition, these apical epithelial cells express class III β-tubulin, an isoform of β-tubulin generally thought to be neuron specific.

  3. Prognostic factors in apical surgery with root-end filling: a meta-analysis

    DEFF Research Database (Denmark)

    von Arx, Thomas; Peñarrocha, Miguel; Jensen, Storgård

    2010-01-01

    Apical surgery has seen continuous development with regard to equipment and surgical technique. However, there is still a shortage of evidence-based information regarding healing determinants. The objective of this meta-analysis was to review clinical articles on apical surgery with root-end fill...

  4. Changes of Root Length and Root-to-Crown Ratio after Apical Surgery

    DEFF Research Database (Denmark)

    von Arx, Thomas; Jensen, Simon S; Bornstein, Michael M

    2015-01-01

    INTRODUCTION: Apical surgery is an important treatment option for teeth with post-treatment periodontitis. Although apical surgery involves root-end resection, no morphometric data are yet available about root-end resection and its impact on the root-to-crown ratio (RCR). The present study assess...

  5. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications for...

  6. Evaluation of apical subtype of hypertrophic cardiomyopathy using cardiac magnetic resonance imaging with gadolinium enhancement.

    Science.gov (United States)

    Kebed, Kalie Y; Al Adham, Raed I; Bishu, Kalkidan; Askew, J Wells; Klarich, Kyle W; Araoz, Philip A; Foley, Thomas A; Glockner, James F; Nishimura, Rick A; Anavekar, Nandan S

    2014-09-01

    Apical hypertrophic cardiomyopathy (HC) is an uncommon variant of HC. We sought to characterize cardiac magnetic resonance imaging (MRI) findings among apical HC patients. This was a retrospective review of consecutive patients with a diagnosis of apical HC who underwent cardiac MRI examinations at the Mayo Clinic (Rochester, MN) from August 1999 to October 2011. Clinical and demographic data at the time of cardiac MRI study were abstracted. Cardiac MRI study and 2-dimensional echocardiograms performed within 6 months of the cardiac MRI were reviewed; 96 patients with apical HC underwent cardiac MRI examinations. LV end-diastolic and end-systolic volumes were 130.7 ± 39.1 ml and 44.2 ± 20.9 ml, respectively. Maximum LV thickness was 19 ± 5 mm. Hypertrophy extended beyond the apex into other segments in 57 (59.4%) patients. Obstructive physiology was seen in 12 (12.5%) and was more common in the mixed apical phenotype than the pure apical (19.3 vs 2.6%, p = 0.02). Apical pouches were noted in 39 (40.6%) patients. Late gadolinium enhancement (LGE) was present in 70 (74.5%) patients. LGE was associated with severe symptoms and increased maximal LV wall thickness. In conclusion, cardiac MRI is well suited for studying the apical form of HC because of difficulty imaging the cardiac apex with standard echocardiography. Cardiac MRI is uniquely suited to delineate the presence or absence of an apical pouch and abnormal myocardial LGE that may have implications in the natural history of apical HM. In particular, the presence of abnormal LGE is associated with clinical symptoms and increased wall thickness. PMID:25037678

  7. HISTOLOGIC AND ELECTRON MICROSCOPIC PERIAPICAL TISSUE EXAMINATION RESULTS IN TEETH WITH CHRONIC APICAL PERIODONTITIS.

    Directory of Open Access Journals (Sweden)

    Angela Gusiyska

    2014-11-01

    Full Text Available Introduction: Key stages in the treatment of chronic apical periodontitis (CAP are the assessment of the status of periapical zone, effective decontamination and subsequent sealing of the root canal space. Purpose: The aim of this article is to analyze histologic and electron microscopic results from periapical tissue examination in teeth with chronic apical periodontitis. Material and Methods: The apices of 43 teeth (n = 43 were examined, allocated in two groups. The teeth were stored in saline solution (9% NaCl supplemented with thymol, at 4°C. The apical portions of the roots were resected at 5 mm coronary. After resection, the apices were fixed to stands for SEM-examination. The periapical lesions (n = 24 were carefully removed with a curette from the root or the apical portion of the alveolar socket and were kept in 10% formalin solution to the preparation of histological samples. Results and Discussion: The results of the performed SEM-examinations of the apical zones showed that in 97.6% of the teeth with radiographically diagnosed CAP, there were external resorption around the apical foramen and associated apertures of varying degrees – from the initial to the advanced stage of apical resorption. Despite the limited number of examined cases, the results obtained confirm the histology and the inaccuracy of diagnostic assumptions in some of the cases, resultant from the radiographic examination only Conclusion: Based on the analysis of results, the following conclusions can be drawn: that external resorption around the apical foramen is established in 97.6% of cases in the teeth with radiographically diagnosed CAP.

  8. Assessment of Root Morphology and Apices of First and Second Maxillary Molars in Tehran Population

    Directory of Open Access Journals (Sweden)

    Mandana Naseri

    2015-12-01

    Full Text Available Introduction: Objective: This study aimed to assess the possible variations in root canal anatomy and topography of the apices of first and second maxillary molars. Materials and methods: A total of 67 first and second maxillary permanent molars were collected. Access cavity was prepared and 2% methylene blue was injected. The teeth were demineralized by 5% nitric acid and cleared with methyl salicylate. Specimens were evaluated under stereomicroscopy and analyzed using the sample t-test. Results: Based on Vertucci’s classification, the mesiobuccal root of maxillary first molars was type I in 87.5% and type IV in 12.5% of the cases. The mesiobuccal root of second maxillary molars was type I in 60%, type II in 8.6%, type IV in 25.7% and type V in 5.7% of cases. In maxillary first and second molars, the distobuccal and palatal roots were type I in 100% of the cases. The distance of the apical constriction from the apical foramen was 0.21±0.09 mm, the distance from the apical constriction tothe anatomic apex was 0.44±0.19 mm and the distance of the apical foramen from the anatomic apex was 0.15±0.15 mm. The mean percentage of delta prevalence was 3.2% in both teeth. Conclusion: The mean distance of the apical foramen and apical constriction from the anatomic apex was less than 0.6 and 1.2 mm, respectively. In maxillary first and second molars, the mean distance of the apical constriction from the apical foramen and anatomic apex was 0.21 and 0.44, respectively and the mean distance of the apical foramen from the anatomic apex was 0.15 mm

  9. Membrane proteomics characterization of brush border membrane proteins of mice intestinal mucosa : case study: cholesterol absorption

    OpenAIRE

    Tsirogianni, Eirini

    2009-01-01

    The epithelial absorbing cells of the small intestinal villi, the enterocytes, are the main protagonists for the transport of nutrients from the intestinal lumen to the interstitial fluids. The oriented flow of nutrients is carried out by different and complementary transport systems present in the apical and the basolateral domains of the enterocyte’s plasma membrane. One of the distinctive characteristics of those intestinal cells is the presence of numerous structurally distinct protrusion...

  10. AMP-activated protein kinase inhibits alkaline pH- and PKA-induced apical vacuolar H+-ATPase accumulation in epididymal clear cells

    OpenAIRE

    Hallows, Kenneth R.; Alzamora, Rodrigo; Li, Hui; Gong, Fan; Smolak, Christy; Neumann, Dietbert; Pastor-Soler, Núria M.

    2009-01-01

    Acidic luminal pH and low [HCO3−] maintain sperm quiescent during maturation in the epididymis. The vacuolar H+-ATPase (V-ATPase) in clear cells is a major contributor to epididymal luminal acidification. We have shown previously that protein kinase A (PKA), acting downstream of soluble adenylyl cyclase stimulation by alkaline luminal pH or HCO3−, induces V-ATPase apical membrane accumulation in clear cells. Here we examined whether the metabolic sensor AMP-activated protein kinase (AMPK) reg...

  11. Pro-oxidant status and matrix metalloproteinases in apical lesions and gingival crevicular fluid as potential biomarkers for asymptomatic apical periodontitis and endodontic treatment response

    Directory of Open Access Journals (Sweden)

    Dezerega Andrea

    2012-03-01

    Full Text Available Abstract Background Oxidative stress and matrix metalloproteinases -9 and -2 are involved in periodontal breakdown, whereas gingival crevicular fluid has been reported to reflect apical status. The aim of this study was to characterize oxidant balance and activity levels of MMP -2 and -9 in apical lesions and healthy periodontal ligament; and second, to determine whether potential changes in oxidant balance were reflected in gingival crevicular fluid from asymptomatic apical periodontitis (AAP-affected teeth at baseline and after endodontic treatment. Methods Patients with clinical diagnosis of AAP and healthy volunteers having indication of tooth extraction were recruited. Apical lesions and healthy periodontal ligaments, respectively, were homogenized or processed to obtain histological tissue sections. Matrix metalloproteinase -9 and -2 levels and/or activity were analyzed by Immunowestern blot, zymography and consecutive densitometric analysis, and their tissue localization was confirmed by immunohistochemistry. A second group of patients with AAP and indication of endodontic treatment was recruited. Gingival crevicular fluid was extracted from AAP-affected teeth at baseline, after endodontic treatment and healthy contralateral teeth. Total oxidant and antioxidant status were determined in homogenized tissue and GCF samples. Statistical analysis was performed using STATA v10 software with unpaired t test, Mann-Whitney test and Spearman's correlation. Results Activity of MMP-2 and MMP-9 along with oxidant status were higher in apical lesions (p Conclusions Apical lesions display an oxidant imbalance along with increased activity of matrix metalloproteinase-2 and -9 and might contribute to AAP progression. Oxidant imbalance can also be reflected in GCF from AAP-affected teeth and was restored to normal levels after conservative endodontic treatment. These mediators might be useful as potential biomarkers for chair-side complementary diagnostic

  12. The apical complex provides a regulated gateway for secretion of invasion factors in Toxoplasma.

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    Nicholas J Katris

    2014-04-01

    Full Text Available The apical complex is the definitive cell structure of phylum Apicomplexa, and is the focus of the events of host cell penetration and the establishment of intracellular parasitism. Despite the importance of this structure, its molecular composition is relatively poorly known and few studies have experimentally tested its functions. We have characterized a novel Toxoplasma gondii protein, RNG2, that is located at the apical polar ring--the common structural element of apical complexes. During cell division, RNG2 is first recruited to centrosomes immediately after their duplication, confirming that assembly of the new apical complex commences as one of the earliest events of cell replication. RNG2 subsequently forms a ring, with the carboxy- and amino-termini anchored to the apical polar ring and mobile conoid, respectively, linking these two structures. Super-resolution microscopy resolves these two termini, and reveals that RNG2 orientation flips during invasion when the conoid is extruded. Inducible knockdown of RNG2 strongly inhibits host cell invasion. Consistent with this, secretion of micronemes is prevented in the absence of RNG2. This block, however, can be fully or partially overcome by exogenous stimulation of calcium or cGMP signaling pathways, respectively, implicating the apical complex directly in these signaling events. RNG2 demonstrates for the first time a role for the apical complex in controlling secretion of invasion factors in this important group of parasites.

  13. Evaluation of the distortion rate of panoramic and peri apical radiographs in erupted third molar inclination

    International Nuclear Information System (INIS)

    Panoramic and peri apical radiographs are normally used in impacted third molar teeth surgeries. The aim of the present study was to evaluate and compare the distortion of the erupted third molar teeth on panoramic and peri apical radiographs. Patients and Methods: A total of 44 radiographs were obtained of 22 patients (age range, 18-24 years) referred to the faculty of dentistry for orthodontic treatment. A plaster cast was prepared and panoramic radiography was taken for all patients to plan the orthodontic treatment and peri apical radiography was taken for investigation of tooth structure details. Therefore, a total of 66 views and samples were studied by two methods: 1) Measuring the angle between the longitudinal plane of the third molar and occlusal plane. 2) Measuring the angle between the longitudinal plane of second and third molar. Finally, 132 records were evaluated by one individual. Results: There was no significant statistical difference between the mean position of the third molar on panoramic, peri apical radiographs and the casts. However, measurements of the third molars on peri apical radiographs were slightly closer to the measurements of the casts compared to the panoramic radiographs. Conclusion: Distortion does not have a specific effect on the diagnosis of the position of the third erupted molars by peri apical or panoramic radiographs, though various studies have shown that these radiographs have an amount of distortion and peri apical radiographical distortion is less than that in panoramic radiography.

  14. Lipid rafts in epithelial brush borders: atypical membrane microdomains with specialized functions

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H

    2003-01-01

    -linked and transmembrane digestive enzymes, most likely as an economizing effort to secure and prolong their digestive capability at the microvillar surface. However, in addition to microvilli, the brush border surface also consists of membrane invaginations between adjacent microvilli, which are the only part...... of the apical surface sterically accessible for membrane fusion/budding events. Many of these invaginations appear as pleiomorphic, deep apical tubules that extend up to 0.5-1 microm into the underlying terminal web region. Their sensitivity to methyl-beta-cyclodextrin suggests them to contain cholesterol...

  15. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  16. Differential subcellular membrane recruitment of Src may specify its downstream signalling

    International Nuclear Information System (INIS)

    Most Src family members are diacylated and constitutively associate with membrane 'lipid rafts' that coordinate signalling. Whether the monoacylated Src, frequently hyperactive in carcinomas, also localizes at 'rafts' remains controversial. Using polarized MDCK cells expressing the thermosensitive v-Src/tsLA31 variant, we here addressed how Src tyrosine-kinase activation may impact on its (i) membrane recruitment, in particular to 'lipid rafts'; (ii) subcellular localization; and (iii) signalling. The kinetics of Src-kinase thermoactivation correlated with its recruitment from the cytosol to sedimentable membranes where Src largely resisted solubilisation by non-ionic detergents at 4 deg. C and floated into sucrose density gradients like caveolin-1 and flotillin-2, i.e. 'lipid rafts'. By immunofluorescence, activated Src showed a dual localization, at apical endosomes/macropinosomes and at the apical plasma membrane. The plasma membrane Src pool did not colocalize with caveolin-1 and flotillin-2, but extensively overlapped GM1 labelling by cholera toxin. Severe (∼ 70%) cholesterol extraction with methyl-β-cyclodextrin (MβCD) did not abolish 'rafts' floatation, but strongly decreased Src association with floating 'rafts' and abolished its localization at the apical plasma membrane. Src activation independently activated first the MAP-kinase - ERK1/2 pathway, then the PI3-kinase - Akt pathway. MAP-kinase - ERK1/2 activation was insensitive to MβCD, which suppressed Akt phosphorylation and apical endocytosis induced by Src, both depending on the PI3-kinase pathway. We therefore suggest that activated Src is recruited at two membrane compartments, allowing differential signalling, first via ERK1/2 at 'non-raft' domains on endosomes, then via PI3-kinase-Akt on a distinct set of 'rafts' at the apical plasma membrane. Whether this model is applicable to c-Src remains to be examined

  17. Variability interexaminer of chronic apical periodontitis diagnostics in panoramic radiographs

    International Nuclear Information System (INIS)

    The accuracy of radiological diagnosis of Apical Periodontitis (AP) is reported between examiners with differents levels of clinical experience using panoramic radiographs. 1032 teeth in 41 panoramic radiographs have been diagnosed. The evaluation of the x-rays and radiological diagnosis is performed by three independent dentists for AP to each tooth. The teeth have presented without radiological signs of AP in 96.6%. The number of teeth classified with an uncertain diagnosis of AP at the has been inversely proportional to the number of years of experience of the examiner. The examiner A has been used as a reference and compared the diagnoses of other examiners.The percentage agreement for all teeth was 95% for examiner B and 94% for examiner C. Kappa for all has been of 0.44 for examiner B and 0.43 for examiner C. The different categories were analyzed separately, the inferior teeth and the anterior teeth have obtained the best results. The level of clinical experience of the examiner has been indifferent in the diagnosis of AP in panoramic radiographs; however, it is important experience in the number of radiographs extras that will be needed to give a radiological diagnosis definitive. The panoramic radiographs were reliable diagnostic tools for AP. (author)

  18. Apical sealing ability of resilon/epiphany system

    Directory of Open Access Journals (Sweden)

    Deepu Roy

    2014-01-01

    Full Text Available Background: Endodontic leakage research focus mainly on the quality of the apical seal of the root canal system and the newly introduced resilon/epiphany system claim to be superior to Gutta-percha in respect to obturation procedure. The aim of this study is to evaluate the root canal obturation completed by resilon/epiphany system. Materials and Methods: A total of 42 teeth were selected and were divided into four groups. Two experimental groups consisted of 15 teeth each and positive control group consisted of eight teeth and negative control group consisted of four teeth. In the experimental groups, Group 1 was obturated with resilon/epiphany system and Group 2 was obturated with Gutta-percha and endofil sealer by lateral condensation technique. The teeth were then immersed in Methelene blue solution and were split longitudinally to access the amount of dye penetrated in the canal. The specimens were viewed under scanning electron microscope to evaluate the adhesion of the obturating material to the root canal walls. Data was subjected to statistical analysis by Analysis of Variance and Bonferroni multiple comparison test at 1% level of significance. Results: The resilon/epiphany system showed better adaptation to the root canal walls, but the difference in dye penetration was not statistically significant when compared to specimens obturated with Gutta-percha and endofil sealer. Conclusion: Although, there was no statistically significant difference between the groups, but resilon/epiphany system showed better adaptation to the root canal walls.

  19. [Therapy of chronic apical periodontitis in the elderly age].

    Science.gov (United States)

    Parfenov, S A

    2013-01-01

    The article is devoted to the actual problem in modern medicine therapy of chronic apical periodontitis in the elderly age. It is shown that periodontitis remains till today the leading cause of tooth extraction in the elderly age; in addition, periodontitis can lead to serious complications such as periostitis, phlegmon, osteomyelitis, which creates additional scientific interest in the study of the above complications at the junction of the two specialties--gerontology and stomatology. In elderly patients regeneration after the periodontal infectious processes takes more time, in this case the traditional approach to treatment of inflammation in the periodontium shows frequent lack of regression of the focus of periapical destruction. Based on the results of the study it is proved that prolonged antiseptic and immune-stimulating effect of therapeutic paste PED used in conjunction with 5% liniment cycloferon, leads to a rapid and marked reduction in inflammatory activity in the affected area both at granulating, and at granulomatous forms of chronic periodontitis, and is accompanied by a significantly larger share of the achieved remission. PMID:24640710

  20. Effect of colchicine on rat small intestinal absorptive cells. II. Distribution of label after incorporation of [3H]fucose into plasma membrane glycoproteins

    International Nuclear Information System (INIS)

    By means of radioautography the influence was tested of various periods (5, 15, 30, 40 min, 2 hr) of pretreatment with colchicine, administered intraperitoneally to rats at a dosage of 0.5 mg/100 g of body weight, on the intracellular pathway of [3H]fucose in absorptive cells of the small intestine. Administration of colchicine for 30 min and longer time intervals causes delay in the insertion of [3H]fucose into the oligosaccharide chains of glycoconjugates in the Golgi apparatus, and results in redistribution of the label apparent over the different portions of the plasma membrane. In controls, at 2 and 4 hr after administration of [3H]fucose the apical plasma membrane is strongly labeled. Colchicine causes equalization of the reaction of apical and basolateral regions of the plasma membrane: the number of silver grains attributable to the apical plasma membrane is reduced; following treatment with colchicine, apical portions of the plasma membrane comprise 31.6 +/- 1.8% of the silver grains, 38.6 +/- 3.8% are attributable to basolateral membrane regions. The colchicine-induced equalization of the density of label of apical and basolateral regions of the plasma membrane, in addition to the occurrence of basolateral microvillus borders, suggests microtubules to be important in the maintenance of the polar organization of small intestinal absorptive cells

  1. AMP-activated protein kinase inhibits alkaline pH- and PKA-induced apical vacuolar H+-ATPase accumulation in epididymal clear cells.

    Science.gov (United States)

    Hallows, Kenneth R; Alzamora, Rodrigo; Li, Hui; Gong, Fan; Smolak, Christy; Neumann, Dietbert; Pastor-Soler, Núria M

    2009-04-01

    Acidic luminal pH and low [HCO(3)(-)] maintain sperm quiescent during maturation in the epididymis. The vacuolar H(+)-ATPase (V-ATPase) in clear cells is a major contributor to epididymal luminal acidification. We have shown previously that protein kinase A (PKA), acting downstream of soluble adenylyl cyclase stimulation by alkaline luminal pH or HCO(3)(-), induces V-ATPase apical membrane accumulation in clear cells. Here we examined whether the metabolic sensor AMP-activated protein kinase (AMPK) regulates this PKA-induced V-ATPase apical membrane accumulation. Immunofluorescence labeling of rat and non-human primate epididymides revealed specific AMPK expression in epithelial cells. Immunofluorescence labeling of rat epididymis showed that perfusion in vivo with the AMPK activators 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR) or A-769662 induced a redistribution of the V-ATPase into subapical vesicles, even in the presence of a luminal alkaline (pH 7.8) buffer compared with that of controls perfused without drug. Moreover, preperfusion with AICAR blocked the PKA-mediated V-ATPase translocation to clear cell apical membranes induced by N(6)-monobutyryl-cAMP (6-MB-cAMP). Purified PKA and AMPK both phosphorylated V-ATPase A subunit in vitro. In HEK-293 cells [(32)P]orthophosphate in vivo labeling of the A subunit increased following PKA stimulation and decreased following RNA interference-mediated knockdown of AMPK. Finally, the extent of PKA-dependent in vivo phosphorylation of the A subunit increased with AMPK knockdown. In summary, our findings suggest that AMPK inhibits PKA-mediated V-ATPase apical accumulation in epididymal clear cells, that both kinases directly phosphorylate the V-ATPase A subunit in vitro and in vivo, and that AMPK inhibits PKA-dependent phosphorylation of this subunit. V-ATPase activity may be coupled to the sensing of acid-base status via PKA and to metabolic status via AMPK. PMID:19211918

  2. Mint essential oil can induce or inhibit potato sprouting by differential alteration of apical meristem.

    Science.gov (United States)

    Teper-Bamnolker, Paula; Dudai, Nativ; Fischer, Ravit; Belausov, Eduard; Zemach, Hanita; Shoseyov, Oded; Eshel, Dani

    2010-06-01

    Sprouting of potatoes during storage, due to tuber dormancy release, is associated with weight loss and softening. Sprout-preventing chemicals, such as chlorpropham (CIPC), can negatively impact the environment and human health. Monthly thermal fogging with mint (Mentha spicata L.) essential oil (MEO) inhibited sprouting in eight potato cultivars during large-volume 6-month storage: the tubers remained firm with 38% lower weight loss after 140 days of storage. The sprout-inhibitory action may be nullified: treated tubers washed with water resumed sprouting within days, with reduced apical dominance. MEO application caused local necrosis of the bud meristem, and a few weeks later, axillary bud (AX) growth was induced in the same sprouting eye. MEO components analysis showed that 73% of its content is the monoterpene R-carvone. Tubers treated with synthetic R-carvone in equivalent dose, 4.5 microl l(-1), showed an inhibitory effect similar to that of MEO. Surprisingly, 0.5 microl l(-1) of MEO or synthetic R-carvone catalyzed AX sprouting in the tuber. To the best of our knowledge, this is the first report of an essential oil vapor inducing early sprouting of potato tubers. R-carvone caused visible damage to the meristem membrane at sprout-inhibiting, but not sprout-inducing doses, suggesting different underlying mechanisms. After 5 days' exposure to R-carvone, its derivatives transcarveol and neo-dihydrocarveol were found in buds of tubers treated with the inhibitory dose, suggesting biodegradation. These experiments demonstrate the potential of MEO vapor as an environmentally friendly alternative to CIPC in stored potatoes and as a research tool for the control of sprouting in plants. PMID:20390295

  3. Frecuencia de periodontitis apical en tratamientos endodónticos de pregrado Frequency of apical periodontitis in endodontic treatment in undergraduate

    OpenAIRE

    León, P; MJ Ilabaca; M Alcota; FE González

    2011-01-01

    La periodontitis apical es una enfermedad de los tejidos periapicales de etiología bacteriana. Su tratamiento requiere erradicar los microorganismos del conducto radicular y obturarlo para lograr la reparación posterior. El objetivo de éste trabajo fue determinar la frecuencia de periodontitis apical en la población que asiste a la clínica de Endodoncia de la Facultad de Odontología de la Universidad de Chile y su relación con diferentes variables: diagnóstico específico, edad, sexo, agudas v...

  4. Depth of planting and apical dominance on cuttings of red pitaya
    Profundidade de plantio e dominância apical na estaquia de pitaia vermelha

    OpenAIRE

    Virna Braga Marques; Rodrigo Amato Moreira; José Darlan Ramos; Neimar Arcanjo de Araújo; Maria do Céu Monteiro da Cruz

    2012-01-01

    This study was conducted to evaluate the effects of planting depth and breaking apical dominance on cutting of red pitaya Hylocereus undatus (Haw.) Britton & Rose. The experiment was conducted in a randomized block design with four replications in a 2x3 factorial, with two kinds of cuttings (with or without apical dominance), cutting not sectioned and sectioned at 5 cm from the upper portion, and three planting depths (1.0, 5.0, and 10.0 cm) and each plot consisted of ten 20 cm long cuttings....

  5. Magnetic Resonance Imaging of Transient Left Ventricular Apical Ballooning Related to Emotional Stress: a Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mu Sook; Choi, Byoung Wook; Choe, Kyu Ok; Chung, Namsik [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2007-02-15

    Transient left ventricular apical ballooning is characterized by transient wall motion abnormalities involving the left ventricular apex and mid-ventricle in the absence of coronary arterial occlusion. A 66-year-old woman presented to the emergency department with chest pain that mimicked acute myocardial infarction. An aortogram showed akinesis from the mid to apical left ventricle with sparing of the basal segments. Four days later, she underwent MRI, which demonstrated characteristic apical contractile dysfunction, the same as the aortogram, without evidence of myocardial infarction on the MRI. Two weeks later, her symptoms were resolved and follow-up echocardiography showed normal ventricular function. We suggest that MRI might be an integrated imaging diagnostic tool for the diagnosis of this syndrome, which demonstrated characteristic apical contractile dysfunction with performing cine MRI, the absence of significant coronary artery stenosis with performing coronary MR angiography and the absence of myocardial infarction with performing contrast enhanced delayed MRI.

  6. Magnetic Resonance Imaging of Transient Left Ventricular Apical Ballooning Related to Emotional Stress: a Case Report

    International Nuclear Information System (INIS)

    Transient left ventricular apical ballooning is characterized by transient wall motion abnormalities involving the left ventricular apex and mid-ventricle in the absence of coronary arterial occlusion. A 66-year-old woman presented to the emergency department with chest pain that mimicked acute myocardial infarction. An aortogram showed akinesis from the mid to apical left ventricle with sparing of the basal segments. Four days later, she underwent MRI, which demonstrated characteristic apical contractile dysfunction, the same as the aortogram, without evidence of myocardial infarction on the MRI. Two weeks later, her symptoms were resolved and follow-up echocardiography showed normal ventricular function. We suggest that MRI might be an integrated imaging diagnostic tool for the diagnosis of this syndrome, which demonstrated characteristic apical contractile dysfunction with performing cine MRI, the absence of significant coronary artery stenosis with performing coronary MR angiography and the absence of myocardial infarction with performing contrast enhanced delayed MRI

  7. Pulp microbiology of complete teeth with idiopathic apical lesions.

    Directory of Open Access Journals (Sweden)

    Patricia Rodríguez

    2009-11-01

    Full Text Available Introduction: Periapical changes named as lesions, in teeth with full crown integrity and without history of trauma, do not show a clear aetiology. Objective: To determine the presence of microorganisms in pulp dental tissue will clarify the cause of its death and therefore the damage to periodontal tissues. Materials and methods: From people between 10 and 39 years old, 23 teeth were selected. The samples were taken with paper points and 0.8 sterile files, and were transported in VMGA III medium, to be processed in the following 24 hours after they were taken and sowed in Brucella-agar. Results: The most affected teeth were upper central incisors, 43.8%. From the 23 studied teeth, microbiological grow was seen on 20 teeth. The following microorganisms species were identified: Fusobacterium spp., 25%, Eubacterium spp., 15%; Peptostreptococcus spp., 10%; Campylobacter spp., 10%; gram negative enteric bacteria, 10%; Porphyromonas gingivalis, 10%; Prevotella intermedia, 5%; Eikenellia corrodens, 5%; Dialister pneumosintes, 5%; and yeasts, 5%. There was no growing evidence of Actinomyces actinomycetemcomitans, Tanerella forsythensis and Streptococcus β  hemolytic. Discussion and conclusions: Sound pulp dental tissue is sterile; an injury over it will cause its inflammation, degeneration, death and bacterial contamination. Results in the present study clearly show the presence of microorganisms in closed apical dental lesions of endodontic origin. In same manner, it was seen that a great part of microorganisms species found can be regarded as periodontal pathogens. This could suggest a management with an endodontic, a periodontic and a pharmacological combined treatment.

  8. Reaction-diffusion pattern in shoot apical meristem of plants.

    Directory of Open Access Journals (Sweden)

    Hironori Fujita

    Full Text Available A fundamental question in developmental biology is how spatial patterns are self-organized from homogeneous structures. In 1952, Turing proposed the reaction-diffusion model in order to explain this issue. Experimental evidence of reaction-diffusion patterns in living organisms was first provided by the pigmentation pattern on the skin of fishes in 1995. However, whether or not this mechanism plays an essential role in developmental events of living organisms remains elusive. Here we show that a reaction-diffusion model can successfully explain the shoot apical meristem (SAM development of plants. SAM of plants resides in the top of each shoot and consists of a central zone (CZ and a surrounding peripheral zone (PZ. SAM contains stem cells and continuously produces new organs throughout the lifespan. Molecular genetic studies using Arabidopsis thaliana revealed that the formation and maintenance of the SAM are essentially regulated by the feedback interaction between WUSHCEL (WUS and CLAVATA (CLV. We developed a mathematical model of the SAM based on a reaction-diffusion dynamics of the WUS-CLV interaction, incorporating cell division and the spatial restriction of the dynamics. Our model explains the various SAM patterns observed in plants, for example, homeostatic control of SAM size in the wild type, enlarged or fasciated SAM in clv mutants, and initiation of ectopic secondary meristems from an initial flattened SAM in wus mutant. In addition, the model is supported by comparing its prediction with the expression pattern of WUS in the wus mutant. Furthermore, the model can account for many experimental results including reorganization processes caused by the CZ ablation and by incision through the meristem center. We thus conclude that the reaction-diffusion dynamics is probably indispensable for the SAM development of plants.

  9. Monoclonal antibodies to the apical chloride channel in Necturus gallbladder inhibit the chloride conductance.

    OpenAIRE

    Finn, A L; Tsai, L M; Falk, R J

    1989-01-01

    Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The...

  10. 24 Hour ST Segment Analysis in Transient Left Ventricular Apical Ballooning

    OpenAIRE

    Frank Bode; Christof Burgdorf; Heribert Schunkert; Volkhard Kurowski

    2013-01-01

    OBJECTIVE: The etiologic basis of transient left ventricular apical ballooning, a novel cardiac syndrome, is not clear. Among the proposed pathomechanisms is coronary vasospasm. Long-term ST segment analysis may detect vasospastic episodes but has not been reported. METHODS: 30 consecutive patients with transient left ventricular apical ballooning, left ventricular dysfunction and normal or near-normal coronary arteries were investigated. A 24-hour Holter ECG was obtained after emergency admi...

  11. Human Coronavirus 229E Infects Polarized Airway Epithelia from the Apical Surface

    OpenAIRE

    Wang, Guoshun; Deering, Camille; Macke, Michael; Shao, Jianqiang; Burns, Royce; Blau, Dianna M.; Holmes, Kathryn V.; Davidson, Beverly L.; Perlman, Stanley; McCray, Paul B.

    2000-01-01

    Gene transfer to differentiated airway epithelia with existing viral vectors is very inefficient when they are applied to the apical surface. This largely reflects the polarized distribution of receptors on the basolateral surface. To identify new receptor-ligand interactions that might be used to redirect vectors to the apical surface, we investigated the process of infection of airway epithelial cells by human coronavirus 229E (HCoV-229E), a common cause of respiratory tract infections. Usi...

  12. Apical ballooning with mid-ventricular obstruction: the many faces of Takotsubo cardiomyopathy

    OpenAIRE

    Spadotto, Veronica; ElMaghawry, Mohamed; Zorzi, Alessandro; Migliore, Federico; Marra, Martina Perazzolo

    2013-01-01

    Takotsubo cardiomyopathy (TTC) is a transient left ventricular dysfunction due to akinesia of the left-ventricular (LV) mid-apical segments (apical ballooning), which can cause severe reduction in LV systolic function. The typical clinical picture of TTC include chest pain, electrocardiographic changes consisting of mild ST-segment elevation followed by diffuse deep T-wave inversion, QTc interval prolongation and mild troponin release in the absence of significant coronary stenoses. The syndr...

  13. Comparison of Apical Axial Derotation between Adolescent Idiopathic and Neuromuscular Scoliosis with Pedicle Screw Instrumentation

    OpenAIRE

    Modi, Hitesh N.; Suh, Seung-Woo; Srinivasalu, S.; Mehta, Satyen; Yang, Jae-Hyuk

    2008-01-01

    Study Design A retrospective study. Purpose To compare outcomes of apical derotation with pedicle screws in idiopathic and neuromuscular scoliosis (NMS). Overview of Literature No information about apical derotation in NMS with pedicle screws is available. Methods We performed deformity correcting surgery using pedicle screw constructs on 12 adolescent idiopathic scoliosis (AIS) patients (mean age 14.1 years) and 16 NMS patients (mean age 16.5 years). Preoperative, postoperative, and final fo...

  14. RNG1 is a Late Marker of the Apical Polar Ring in Toxoplasma gondii

    OpenAIRE

    Tran, Johnson Q.; de Leon, Jessica C.; Li, Catherine; Huynh, My-Hang; Beatty, Wandy; Morrissette, Naomi S.

    2010-01-01

    The asexually proliferating stages of apicomplexan parasites cause acute symptoms of diseases such as malaria, cryptosporidiosis and toxoplasmosis. These stages are characterized by the presence of two independent microtubule organizing centers (MTOCs). Centrioles are found at the poles of the intranuclear spindle. The apical polar ring (APR), a MTOC unique to apicomplexans, organizes subpellicular microtubules which impose cell shape and apical polarity on these protozoa. Here we describe th...

  15. The Dynamics of Soybean Leaf and Shoot Apical Meristem Transcriptome Undergoing Floral Initiation Process

    OpenAIRE

    Wong, Chui E; Mohan B. Singh; Bhalla, Prem L

    2013-01-01

    Flowering process governs seed set and thus affects agricultural productivity. Soybean, a major legume crop, requires short-day photoperiod conditions for flowering. While leaf-derived signal(s) are essential for the photoperiod-induced floral initiation process at the shoot apical meristem, molecular events associated with early floral transition stages in either leaves or shoot apical meristems are not well understood. To provide novel insights into the molecular basis of floral initiation,...

  16. Can loss of apical dominance in potato tuber serve as a marker of physiological age?

    OpenAIRE

    Eshel, Dani; Teper-Bamnolker, Paula

    2012-01-01

    The potato tuber constitutes a model system for the study of dormancy release and sprouting, suggested to be regulated by endogenous plant hormones and their balance inside the tuber. During dormancy, potato tubers cannot be induced to sprout without some form of stress or exogenous hormone treatment. When dormancy is released, sprouting of the apical bud may be inhibited by sprout control agents or cold temperature. Dominance of the growing apical bud over other lateral buds decreases during...

  17. Cell division pattern influences gene expression in the shoot apical meristem

    OpenAIRE

    Wyrzykowska, Joanna; Fleming, Andrew

    2003-01-01

    The shoot apical meristem of angiosperms shows a highly conserved cellular architecture in which a change of cell division orientation correlates with early events of leaf initiation. However, the causal role of this altered cellular parameter in leaf formation is debatable. We have used the dynamin-like protein phragmoplastin as a tool to modify the pattern of cell division within the apical meristem. Taking a microinduction approach, we show that local alteration in cell division orientatio...

  18. Effect of needle insertion depth and apical diameter on irrigant extrusion in simulated immature permanent teeth

    Directory of Open Access Journals (Sweden)

    AKSEL Hacer

    2014-09-01

    Full Text Available The aim of this study was to compare the amount of irrigant extrusion in simulated immature permanent teeth when the apical diameter and needle insertion depth were varied. Thirty single-rooted maxillary incisors with straight root canals were selected. The root length was standardized to a length of 9 mm. The teeth were divided into two experimental groups according to the degree of apical enlargement (n = 15. The apices were enlarged to a diameter of 1.10 mm or 1.70 mm by using a #3 or #6 peeso reamer, respectively, to simulate immature teeth. The irrigation solution was applied 2 or 4 mm short of the working length (WL in each experimental group. The glass vial model was used for the collection of extruded irrigant beyond the root apex. A two-way repeated measures analysis of variance test showed that there was no significant difference between different needle insertion depths (2 and 4 mm short of the WL in the group with an apical diameter of 1.70 mm (p > 0.05. In the group with an apical diameter of 1.10 mm, a 32% increase in irrigant extrusion was observed when the needle was positioned at 2 mm (p < 0.05. Regarding the effect of apical diameter, the group with a diameter of 1.70 mm showed more apical extrusion of the irrigant (34% increase for the needle positioned at 2 mm and 68% increase for the needle positioned at 4 mm. It was observed that the needle insertion depth and apical diameter have a significant effect on irrigant extrusion in immature permanent teeth.

  19. Frecuencia de periodontitis apical en tratamientos endodónticos de pregrado Frequency of apical periodontitis in endodontic treatment in undergraduate

    Directory of Open Access Journals (Sweden)

    P León

    2011-12-01

    Full Text Available La periodontitis apical es una enfermedad de los tejidos periapicales de etiología bacteriana. Su tratamiento requiere erradicar los microorganismos del conducto radicular y obturarlo para lograr la reparación posterior. El objetivo de éste trabajo fue determinar la frecuencia de periodontitis apical en la población que asiste a la clínica de Endodoncia de la Facultad de Odontología de la Universidad de Chile y su relación con diferentes variables: diagnóstico específico, edad, sexo, agudas vs. crónicas, éxito/fracaso del tratamiento y rehabilitación post-tratamiento. Se recolectó información de 292 dientes de pacientes tratados en dicha clínica, analizándose la información de aquellos con dientes diagnosticados con algún tipo de periodontitis apical clasificándolo según la nueva nomenclatura de la asociación de endodoncia americana. La frecuencia de periodontitis apical fue de un 36.7% (92 pacientes, de los cuales un 77.8% presentaron patologías de tipo crónicas. Un 75% de los pacientes pertenecieron al sexo femenino y la 5ta década representó un 34.8% de los pacientes. El 100% de los pacientes que acudieron a control presentó éxito en sus tratamientos según variables clínico-radiográficas, mientras que la restauración más frecuente post-tratamiento fue la resina compuesta (52.4%. Dado el pequeño número de pacientes que concurrieron a la citación de control para determinar el éxito del tratamiento, esta variable debe ser considerada como preliminar. Nuestros resultados mostraron que la condición mas frecuente fue la periodontitis apical de tipo crónica, afectando más a mujeres y a la 5ta década.Apical periodontitis is a microbially induced inflammatory disease of the periapical tissues. Its treatment requires eliminating microorganism from root canal and sealing it properly to induce further tissue repair. The aim of this study was to determine the frequency of apical periodontitis and its distribution by

  20. Protein O-Glucosyltransferase 1 (POGLUT1 Promotes Mouse Gastrulation through Modification of the Apical Polarity Protein CRUMBS2.

    Directory of Open Access Journals (Sweden)

    Nitya Ramkumar

    2015-10-01

    Full Text Available Crumbs family proteins are apical transmembrane proteins with ancient roles in cell polarity. Mouse Crumbs2 mutants arrest at midgestation with abnormal neural plate morphology and a deficit of mesoderm caused by defects in gastrulation. We identified an ENU-induced mutation, wsnp, that phenocopies the Crumbs2 null phenotype. We show that wsnp is a null allele of Protein O-glucosyltransferase 1 (Poglut1, which encodes an enzyme previously shown to add O-glucose to EGF repeats in the extracellular domain of Drosophila and mammalian Notch, but the role of POGLUT1 in mammalian gastrulation has not been investigated. As predicted, we find that POGLUT1 is essential for Notch signaling in the early mouse embryo. However, the loss of mouse POGLUT1 causes an earlier and more dramatic phenotype than does the loss of activity of the Notch pathway, indicating that POGLUT1 has additional biologically relevant substrates. Using mass spectrometry, we show that POGLUT1 modifies EGF repeats in the extracellular domain of full-length mouse CRUMBS2. CRUMBS2 that lacks the O-glucose modification fails to be enriched on the apical plasma membrane and instead accumulates in the endoplasmic reticulum. The data demonstrate that CRUMBS2 is the target of POGLUT1 for the gastrulation epithelial-to-mesenchymal transitions (EMT and that all activity of CRUMBS2 depends on modification by POGLUT1. Mutations in human POGLUT1 cause Dowling-Degos Disease, POGLUT1 is overexpressed in a variety of tumor cells, and mutations in the EGF repeats of human CRUMBS proteins are associated with human congenital nephrosis, retinitis pigmentosa and retinal degeneration, suggesting that O-glucosylation of CRUMBS proteins has broad roles in human health.

  1. Protein O-Glucosyltransferase 1 (POGLUT1) Promotes Mouse Gastrulation through Modification of the Apical Polarity Protein CRUMBS2.

    Science.gov (United States)

    Ramkumar, Nitya; Harvey, Beth M; Lee, Jeffrey D; Alcorn, Heather L; Silva-Gagliardi, Nancy F; McGlade, C Jane; Bestor, Timothy H; Wijnholds, Jan; Haltiwanger, Robert S; Anderson, Kathryn V

    2015-10-01

    Crumbs family proteins are apical transmembrane proteins with ancient roles in cell polarity. Mouse Crumbs2 mutants arrest at midgestation with abnormal neural plate morphology and a deficit of mesoderm caused by defects in gastrulation. We identified an ENU-induced mutation, wsnp, that phenocopies the Crumbs2 null phenotype. We show that wsnp is a null allele of Protein O-glucosyltransferase 1 (Poglut1), which encodes an enzyme previously shown to add O-glucose to EGF repeats in the extracellular domain of Drosophila and mammalian Notch, but the role of POGLUT1 in mammalian gastrulation has not been investigated. As predicted, we find that POGLUT1 is essential for Notch signaling in the early mouse embryo. However, the loss of mouse POGLUT1 causes an earlier and more dramatic phenotype than does the loss of activity of the Notch pathway, indicating that POGLUT1 has additional biologically relevant substrates. Using mass spectrometry, we show that POGLUT1 modifies EGF repeats in the extracellular domain of full-length mouse CRUMBS2. CRUMBS2 that lacks the O-glucose modification fails to be enriched on the apical plasma membrane and instead accumulates in the endoplasmic reticulum. The data demonstrate that CRUMBS2 is the target of POGLUT1 for the gastrulation epithelial-to-mesenchymal transitions (EMT) and that all activity of CRUMBS2 depends on modification by POGLUT1. Mutations in human POGLUT1 cause Dowling-Degos Disease, POGLUT1 is overexpressed in a variety of tumor cells, and mutations in the EGF repeats of human CRUMBS proteins are associated with human congenital nephrosis, retinitis pigmentosa and retinal degeneration, suggesting that O-glucosylation of CRUMBS proteins has broad roles in human health. PMID:26496195

  2. Comparison of Irrigation Penetration into the Apical Part of Canals in Hand and Rotary Instrumentations

    Directory of Open Access Journals (Sweden)

    M. Khabiri

    2007-01-01

    Full Text Available Introduction: The penetration of irrigating solution to the apical one third of canals and removal of debris are dependent on the final size of the instruments and instrumentation techniques used in the canals. The purpose of this study was to evaluate the effect of final instrument size, on irrigation penetration into the apical part of canals in hand K-file instrumentation versus rotary system of Hero 642.Methods and Materials: The mesiobuccal canals of 48 first mandibular molar teeth were selected for this study. The teeth were divided into 2 groups of 24 in each and the mesiobuccal canals were instrumented by hand K-file or rotary system of Hero 642 at 2 stages. After each stage, a contrast medium was injected into the canals and radiographs were taken by RVG system. The irrigation penetration was measured in radiographs by Diamax software. The data were analyzed using t – student test.Results: This study showed that instrumentation up to # 25 file is not enough for irrigation penetration into the apical area. Also by more flaring the canals, more irrigating solution penetrates into the apical part of canals (P 0 0.001, but the difference between hand and rotary systems was not statistically significant (P > 0.05.Discussion: According to this study, instrumentation up to # 30 file results in better irrigation penetration into the apical area. The flaring of the canals is essential for better cleaning and irrigation of apical area.

  3. Calcium-enriched mixture cement as artificial apical barrier: A case series

    Directory of Open Access Journals (Sweden)

    Ali Nosrat

    2011-01-01

    Full Text Available In comparison to the conventional apexification using calcium hydroxide, artificial apical barrier technique is more valuable and less time consuming. This article describes successful use of calcium-enriched mixture (CEM cement as an artificial apical barrier in open apices. In this study, 13 single-rooted teeth with necrotic pulps and open apices were treated non-surgically. After copious irrigation of the root canals with NaOCl 5.25% and gentle filing, based on need for interappointment dressing, treatments were followed by CEM cement (BioniqueDent, Tehran, Iran apical plug insertion in the first or second appointment. All cases were then permanently restored. All subjects were followed until radiographic evidence of periradicular healing was seen (mean 14.5 months. Clinically, all cases were functional and asymptomatic and complete osseous healing was observed in all the teeth. Considering the biological properties of CEM cement, this new endodontic biomaterial might be appropriate to be used as artificial apical barrier in the open apex teeth.

  4. Microarray gene expression profiling of developmental transitions in Sitka spruce (Picea sitchensis) apical shoots.

    Science.gov (United States)

    Friedmann, Michael; Ralph, Steven G; Aeschliman, Dana; Zhuang, Jun; Ritland, Kermit; Ellis, Brian E; Bohlmann, Joerg; Douglas, Carl J

    2007-01-01

    The apical shoot drives the yearly new stem growth of conifer trees, is the primary site for the establishment of chemical and physical defences, and is important in establishing subsequent perennial growth. This organ presents an interesting developmental system, with growth and development progressing from a meristematic tip through development of a primary vascular system, to a base with fully differentiated and lignified secondary xylem on the inside and bark tissue with constitutive defence structures such as resin, polyphenolic phloem parenchyma cells, and sclereids on the outside. A spruce (Picea spp.) microarray containing approximately 16.7K unique cDNAs was used to study transcript profiles that characterize the developmental transition in apical shoots of Sitka spruce (Picea sitchensis) from their vegetative tips to their woody bases. Along with genes involved in cell-wall modification and lignin biosynthesis, a number of differentially regulated genes encoding protein kinases and transcription factors with base-preferred expression patterns were identified, which could play roles in the formation of woody tissues inside the apical shoot, as well as in regulating other developmental transitions associated with organ maturation. Preferential expression of known conifer defence genes, genes encoding defence-related proteins, and genes encoding regulatory proteins was observed at the apical shoot tip and in the green bark tissues at the apical shoot base, suggesting a commitment to constitutive defence in the apical shoot that is co-ordinated with rapid development of secondary xylem. PMID:17220514

  5. Plasma membranes from insect midgut cells

    Directory of Open Access Journals (Sweden)

    Walter R. Terra

    2006-06-01

    Full Text Available Plasma membranes from insect midgut cells are separated into apical and basolateral domains. The apical domain is usually modified into microvilli with a molecular structure similar to other animals. Nevertheless, the microvillar structure should differ in some insects to permit the traffic inside them of secretory vesicles that may budd laterally or pinch-off from the tips of microvilli. Other microvillar modifications are associated with proton-pumping or with the interplay with an ensheathing lipid membrane (the perimicrovilllar membrane observed in the midgut cells of hemipterans (aphids and bugs. The perimicrovillar membranes are thought to be involved in amino acid absorption from diluted diets. The microvillar and perimicrovillar membranes have densities (and protein content that depend on the insect taxon. The role played by the microvillar and perimicrovillar proteins in insect midgut physiology is reviewed here trying to provide a coherent picture of data and highlighting further research areas.As membranas plasmáticas das células intestinais dos insetos apresentam um domínio apical e outro basal. O domínio apical é geralmente modificado em microvilosidades com organização molecular similar a de outros animais, embora possam diferir naqueles insetos que apresentam vesículas secretoras em trânsito que brotam lateralmente ou destacam-se das extremidades das microvilosidades. Outras modificações microvilares estão associadas a bombeamento de prótons ou a interrelações com uma membrana lipídica (a membrana perimicrovilar que reveste as microvilosidades de células intestinais de hemípteros (pulgões e percevejos. Admite-se que as membranas perimicrovilares estejam envolvidas na absorção de aminoácidos a partir de dietas diluídas. As membranas microvilares e perimicrovilares tem densidades distintas (e conteúdo protéico que dependem do táxon do inseto. O papel desempenhado pelas proteínas microvilares e

  6. Expression of apical Na(+)-L-glutamine co-transport activity, B(0)-system neutral amino acid co-transporter (B(0)AT1) and angiotensin-converting enzyme 2 along the jejunal crypt-villus axis in young pigs fed a liquid formula.

    Science.gov (United States)

    Yang, Chengbo; Yang, Xiaojian; Lackeyram, Dale; Rideout, Todd C; Wang, Zirong; Stoll, Barbara; Yin, Yulong; Burrin, Douglas G; Fan, Ming Z

    2016-06-01

    Gut apical amino acid (AA) transport activity is high at birth and during suckling, thus being essential to maintain luminal nutrient-dependent mucosal growth through providing AA as essential metabolic fuel, substrates and nutrient stimuli for cellular growth. Because system-B(0) Na(+)-neutral AA co-transporter (B(0)AT1, encoded by the SLC6A19 gene) plays a dominant role for apical uptake of large neutral AA including L-Gln, we hypothesized that high apical Na(+)-Gln co-transport activity, and B(0)AT1 (SLC6A19) in co-expression with angiotensin-converting enzyme 2 (ACE2) were expressed along the entire small intestinal crypt-villus axis in young animals via unique control mechanisms. Kinetics of Na(+)-Gln co-transport activity in the apical membrane vesicles, prepared from epithelial cells sequentially isolated along the jejunal crypt-villus axis from liquid formula-fed young pigs, were measured with the membrane potential being clamped to zero using thiocyanate. Apical maximal Na(+)-Gln co-transport activity was much higher (p < 0.05) in the upper villus cells than in the middle villus (by 29 %) and the crypt (by 30 %) cells, whereas Na(+)-Gln co-transport affinity was lower (p < 0.05) in the upper villus cells than in the middle villus and the crypt cells. The B(0)AT1 (SLC6A19) mRNA abundance was lower (p < 0.05) in the crypt (by 40-47 %) than in the villus cells. There were no significant differences in B(0)AT1 and ACE2 protein abundances on the apical membrane among the upper villus, the middle villus and the crypt cells. Our study suggests that piglet fast growth is associated with very high intestinal apical Na(+)-neutral AA uptake activities via abundantly co-expressing B(0)AT1 and ACE2 proteins in the apical membrane and by transcribing the B(0)AT1 (SLC6A19) gene in the epithelia along the entire crypt-villus axis. PMID:26984322

  7. Human serum levels of fetal antigen 1 (FA1/Dlk1) increase with obesity, are negatively associated with insulin sensitivity and modulate inflammation in vitro

    DEFF Research Database (Denmark)

    Chacón, M R; Miranda, M; Jensen, C H;

    2008-01-01

    Insulin Resistance), cytokines (sIL-6), adipokines (adiponectin) and circulating soluble fractions of tumor necrosis factor-alpha receptors 1 and 2 (sTNFR1 and sTNFR2). RESULTS: IN the obesity study, levels of FA1 in serum were found to increase with obesity. The S(i) index was negatively dependent on FA1......OBJECTIVE:To investigate fetal antigen 1 (FA1) protein within the context of human obesity and its relation with insulin sensitivity. SUBJECTS: Cross-sectional study that analyses circulating levels of FA1 in two selected human cohorts: n=127 men for the study of FA1 circulating levels in the...... context of obesity and insulin sensitivity (S(i)); and n=61 severely obese women before and after bariatric surgery. The response in vitro to FA1 protein on human cell lines of monocytes, preadipocytes and mature adipocytes was studied. MEASUREMENTS: Anthropometrical parameters: body mass index, waist...

  8. In Vitro Differentiation of Insulin Secreting Cells from Mouse Bone Marrow Derived Stage-Specific Embryonic Antigen 1 Positive Stem Cells

    Directory of Open Access Journals (Sweden)

    Morteza Abouzaripour

    2016-02-01

    Full Text Available Objective: Bone marrow has recently been recognized as a novel source of stem cells for the treatment of wide range of diseases. A number of studies on murine bone marrow have shown a homogenous population of rare stage-specific embryonic antigen 1 (SSEA-1 positive cells that express markers of pluripotent stem cells. This study focuses on SSEA-1 positive cells isolated from murine bone marrow in an attempt to differentiate them into insulin-secreting cells (ISCs in order to investigate their differentiation potential for future use in cell therapy. Materials and Methods: This study is an experimental research. Mouse SSEA-1 positive cells were isolated by Magnetic-activated cell sorting (MACS followed by characterization with flow cytometry. Induced SSEA-1 positive cells were differentiated into ISCs with specific differentiation media. In order to evaluate differentiation quality and analysis, dithizone (DTZ staining was use, followed by reverse transcription polymerase chain reaction (RT-PCR, immunocytochemistry and insulin secretion assay. Statistical results were analyzed by one-way ANOVA. Results: The results achieved in this study reveal that mouse bone marrow contains a population of SSEA-1 positive cells that expresses pluripotent stem cells markers such as SSEA-1, octamer-binding transcription factor 4 (OCT-4 detected by immunocytochemistry and C-X-C chemokine receptor type 4 (CXCR4 and stem cell antigen-1 (SCA-1 detected by flow cytometric analysis. SSEA-1 positive cells can differentiate into ISCs cell clusters as evidenced by their DTZ positive staining and expression of genes such as Pdx1 (pancreatic transcription factors, Ngn3 (endocrine progenitor marker, Insulin1 and Insulin2 (pancreaticβ-cell markers. Additionally, our results demonstrate expression of PDX1 and GLUT2 protein and insulin secretion in response to a glucose challenge in the differentiated cells. Conclusion: Our study clearly demonstrates the potential of SSEA-1

  9. Na+ uptake into colonic enterocyte membrane vesicles

    International Nuclear Information System (INIS)

    Na+ uptake was studied in colonic enterocyte membrane vesicles prepared from normal and dexamethasone-treated rats. Vesicles from rats treated with dexamethasone demonstrated a fivefold greater 22Na+ uptake compared with vesicles from normal rats. Most of the tracer uptake in membranes derived from treated rats occurred through a conductive, amiloride-blockable pathway located in vesicles with low native K+ permeability and high Cl- permeability. Kinetic analysis of the amiloride inhibition curve revealed the presence of two amiloride-blockable pathways, one with a high affinity accounting for 85% of the uptake, and one with a low affinity accounting for only 12% of the uptake. Only the low-affinity pathway was detected with vesicles from normal rats. The high sensitivity to amiloride, the dependence on dexamethasone pretreatment, and the relative permeabilities to K+ and Cl- indicate that most of the 22Na+ uptake in membranes derived from treated rats is through a Na+-specific channel located in apical membrane vesicles. Preincubation of the isolated cells from dexamethasone-treated rats at 37 degree C in Ca2+-free solutions before homogenization and membrane vesicle purification caused a 5- to 10-fold increase in amiloride-blockable 22Na+ uptake compared with vesicles derived from cells maintained at 0 degree C. The addition of Ca2+, but not of Mg2+, to the incubation solution markedly reduced this temperature-dependent enhancement in 22Na+ uptake. These results suggest that Na+ transport in colonic enterocytes from dexamethasone-treated rats is regulated by a Ca2+-dependent, temperature-sensitive process which causes a sustained change in the apical membrane

  10. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  11. Do Parameters Of Irradiation Influences The Apical Sealing Of Er:YAG Laser Apicetomies?

    Science.gov (United States)

    Marques, Aparecida Maria Cordeiro; dos Santos, Jean Nunes; Pinheiro, Antonio Luiz Barbosa

    2011-08-01

    Failures on the sealing of the tooth apex are responsible for many failures of apical surgeries. The Er:YAG laser has been proposed as an alternative for the use of rotator instruments on surgical endodontics. 12 human extracted canines had root endodontic treatment being the apical limit was set at 1mm before the apical foramen and were distributed into 2 groups. On group I, apicectomy was performed with the Er:YAG laser (250 mJ/15 Hz). Apical cut was performed of perpendicular mode with 3mm from the apical foramen. On Group II, the same procedures and the same sequence as above was used, varying only the parameters of the Er:YAG laser (400 mJ/6 Hz). The specimens were divided into groups and fixed, by the cervical third, on wax. Impermeabilization of the residual root apical third was performed following the same procedures used in the cervical third but the residual apex was left free from the impermeabilization. After that, the roots were immersed in a 2% methylene blue solution and placed in a bacteriological oven for 48 h. The segments were visually observed and the one showing greatest level of dye leakage was selected and kept in individual container and coded accordingly. Apical staining was measured using a stereoscopic magnifying glass; a compass; and caliper. The results showed that Group I showed significantly different higher mean level of dye leakage (5.67±4.9, p<0.05). There was a significantly difference between the groups. It is concluded that the apicectomies carried out with 400 mJ/6 Hz showed the smallest infiltration value.

  12. Síndrome do balonamento apical secundário ao uso abusivo de descongestionante nasal Síndrome del abombamiento apical secundario al uso abusivo de descongestionante nasal Apical ballooning syndrome secondary to nasal decongestant abuse

    Directory of Open Access Journals (Sweden)

    Ricardo Wang

    2009-11-01

    Full Text Available Descrevemos um caso típico de síndrome do balonamento apical em uma paciente octogenária com alteração eletrocardiográfica, de contratilidade do ventrículo esquerdo, e que apresentou recuperação da função ventricular. A paciente é portadora de rinite alérgica e fez uso excessivo de descongestionante nasal horas antes do episódio da dor.Describimos un caso típico de síndrome de abombamiento apical en una paciente octogenaria con alteración electrocardiográfica, de contractilidad del ventrículo izquierdo, y que presentó recuperación de la función ventricular. La paciente es portadora de rinitis alérgica y hace uso excesivo de descongestionante nasal horas antes del episodio del dolor.We describe a typical case of apical ballooning syndrome in an octogenarian female patient with left ventricular wall motion abnormality on electrocardiography, whose ventricular function returned to normal. The patient has allergic rhinitis and had used nasal decongestant excessively a few hours prior to the episode of pain.

  13. Membrane potential plays a dual role for chloride transport across toad skin

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Rasmussen, B E

    1983-01-01

    -dependent currents are not caused by a trivial Goldmand-type rectification and ion redistributions following transepithelial potential pertubations. Extended with a dynamic Cl- permeability in the apical membrane according to a Hodgkin-Huxley kinetic scheme, the model predicts voltage clamp data which closely......The Cl- -current through toad skin epithelium depends on the potential in a way consistent with a potential-controlled Cl- permeability. Computer analysis of the Koefoed-Johnsen Ussing two-membrane model provided with constant membrane permeabilities indicates that the voltage- and time...... resemble experimental observations. This extension of the classic frog skin model implies that the Cl- permeability is activated by a voltage change caused by the inward Na+ current through the apical membrane....

  14. Midventricular Hypertrophic Cardiomyopathy with Apical Aneurysm: Potential for Underdiagnosis and Value of Multimodality Imaging

    Directory of Open Access Journals (Sweden)

    Archana Sivanandam

    2016-01-01

    Full Text Available We illustrate a case of midventricle obstructive HCM and apical aneurysm diagnosed with appropriate use of multimodality imaging. A 75-year-old African American woman presented with a 3-day history of chest pain and dyspnea with elevated troponins. Her electrocardiogram showed sinus rhythm, left atrial enlargement, left ventricular hypertrophy, prolonged QT, and occasional ectopy. After medical therapy optimization, she underwent coronary angiography for an initial diagnosis of non-ST segment elevation myocardial infarction. Her coronaries were unremarkable for significant disease but her left ventriculogram showed hyperdynamic contractility of the midportion of the ventricle along with a large dyskinetic aneurysmal apical sac. A subsequent transthoracic echocardiogram provided poor visualization of the apical region of the ventricle but contrast enhancement identified an aneurysmal pouch distal to the midventricular obstruction. To further clarify the diagnosis, cardiac magnetic resonance imaging with contrast was performed confirming the diagnosis of midventricular hypertrophic cardiomyopathy with apical aneurysm and fibrosis consistent with apical scar on delayed enhancement. The patient was medically treated and subsequently underwent elective implantable defibrillator placement in the ensuing months for recurrent nonsustained ventricular tachycardia and was initiated on prophylactic oral anticoagulation with warfarin for thromboembolic risk reduction.

  15. Effects of apical meristem loss on sylleptic branching and growth of hybrid poplar

    Energy Technology Data Exchange (ETDEWEB)

    Zeleznik, Joseph D. [North Dakota State University, Fargo, ND (United States). Plant Sciences Department

    2007-07-15

    The effects of apical meristem loss on the growth and development of hybrid poplar trees was investigated. This was done by clipping back either the apical meristem alone (dividing cells), or the apical meristem plus a small amount of additional stem tissue (expanding cells, <1 cm), at various times during the first growing season. Two clones (NM6-nonsylleptic habit, and DN34-slightly sylleptic habit) were tested at close spacing (0.6 m) in the nursery. Clipping generally increased the number of sylleptic branches formed. Clipping 69 days after planting resulted in the largest number of sylleptic branches while clipping 4 weeks later gave no increase in syllepsis. Clipping temporarily reduced height growth of both clones but total height at the end of the first growing season was not affected by any treatment. There were some slight differences in growth during the second growing season; despite these differences, total stem biomass and total tree biomass after 2 years were not affected by temporary loss of the apical meristem in the first growing season. Results suggest that death or removal of hybrid poplar apical meristems by tip borers or ungulates has no long-term effects on aboveground growth as measured by height or biomass. (author)

  16. In vitro study of apical leakage of root canals after different root apex resection techniques

    Directory of Open Access Journals (Sweden)

    André Augusto Franco MARQUES

    2008-12-01

    Full Text Available Objective:The aim of the present study was to evaluate in vitro apicalmarginal leakage of root canals after three root apex resectiontechniques.Material and methods: Thirty maxillary canines wereprepared chemo-mechanically to a size 40 master apical file, andenlarged by using Gates Glidden burs 2, 3 and 4. Teeth were obturatedby Tagger thermomechanical compaction technique and then dividedinto three groups (n = 10. The first group (GI was 3 mm apicalresected with Endo Z in high speed handpiece. The specimens of secondgroup (GII were 3 mm apical weared with Endo Z, and the third group(GIII had 3 mm apical resected with Er:YAG laser (500 impulse, 12pps and 300 mJ energy. After the apical sections, IRM cement wasplaced into the root-end cavity and teeth of each group were immersedin India ink for 5 days and submitted to decalcification and clarifying for marginal apical microleakage visualization with microscope.Results: The results showed statistically difference (p < 0.01 between GI and the other groups.Conclusion: The root apex cut using Endo Z promotes the lowest values of microleakage when used in apicoectomy.

  17. Estudio sobre la adaptación apical de conos maestros de gutapercha en conductos radiculares instrumentados con limas Lightspeed

    OpenAIRE

    Pumarola Suñé, José; García Campaña, Ana M.; Brau Aguadé, Esteban; Canalda Sahli, Carlos

    2000-01-01

    El objetivo de este trabajo fue establecer la coincidencia entre el calibre del cono maestro apical y la lima maestra apical, así como medir cualitativamente la adaptación de diferentes marcas de conos de gutapercha en el tercio apical de conductos radiculares instrumentados con limas Lightspeed. Se instrumentaron 100 conductos de molares naturales extraídos con el sistema Lightspeed. Las muestras se distribuyeron aleatoriamente en cinco grupos. Cada grupo fue obturado mediante condensación l...

  18. Tissue reaction to Endométhasone sealer in root canal fillings short of or beyond the apical foramen

    Directory of Open Access Journals (Sweden)

    Patrícia Suzuki

    2011-10-01

    Full Text Available OBJECTIVE: This study evaluated the response of periapical tissues to the endodontic sealer Endométhasone in root canal fillings short of or beyond the apical foramen. MATERIAL AND METHODS: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endométhasone, originating 2 experimental groups: G1: Endométhasone/short of the apical foramen; G2: Endométhasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05. RESULTS: Comparing the 2 groups, the best result (p<0.05 was obtained with root canal filling with Endométhasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. CONCLUSIONS: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endométhasone is used as sealer.

  19. Membrane Processes.

    Science.gov (United States)

    Pellegrin, Marie-Laure; Burbano, Marie S; Sadler, Mary E; Diamond, Jason; Baker, Simon; Greiner, Anthony D; Arabi, Sara; Wong, Joseph; Doody, Alexandra; Padhye, Lokesh P; Sears, Keith; Kistenmacher, Peter; Kent, Fraser; Tootchi, Leila; Aguinaldo, Jorge; Saddredini, Sara; Schilling, Bill; Min, Kyungnan; McCandless, Robert; Danker, Bryce; Gamage, Neranga P; Wang, Sunny; Aerts, Peter

    2016-10-01

    This review, for literature published in 2015, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:27620084

  20. Membrane Processes.

    Science.gov (United States)

    Pellegrin, Marie-Laure; Sadler, Mary E; Greiner, Anthony D; Aguinaldo, Jorge; Min, Kyungnan; Zhang, Kai; Arabi, Sara; Burbano, Marie S; Kent, Fraser; Shoaf, Robert

    2015-10-01

    This review, for literature published in 2014, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, fixed film and anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:26420079

  1. The apical oblique view of the clavicle: Its usefulness in neonatal and childhood trauma

    International Nuclear Information System (INIS)

    We analyzed clavicular radiographs of 26 patients with a history of trauma. The apical oblique projection of the clavicle was obtained with the injured side of the patient angled 450 towards the X-ray tube and a 200 cephalad angulation of the X-ray beam. This view proved to be more informative than the routine apical anteroposterior projection. It is especially effective in detecting nondisplaced fractures of the middle third of the clavicle in neonates and children. To verify our findings, we obtained apical anteroposterior and oblique radiographs of a specimen adult of the X-ray beam, the measurements of the projected lengths of the anatomical specimen, especially those of the middle portion of the clavicle, were very close to the corresponding anatomical lengths. (orig.)

  2. Efficacy of three techniques in cleaning the apical portion of curved root canals.

    Science.gov (United States)

    Wu, M K; Wesselink, P R

    1995-04-01

    Various techniques for root canal instrumentation may have different effects in cleaning curved root canals, especially their apical portions. One hundred thirty-five mesiobuccal canals with an average curvature of 25 degrees from human mandibular molars were treated with step-back, crown-down pressureless, or balanced-force techniques with 2% sodium hypochlorite used as an irrigant. The cleaning efficacy of these techniques was evaluated by counting the remaining surface debris under a stereomicroscope with a calibrated eyepiece micrometer. The results indicated that the apical portion of the canal was less clean than the middle and coronal portions regardless of the technique performed and that the balanced-force technique produced a cleaner apical portion of the canal than did the other techniques studied. PMID:7614212

  3. Depth of planting and apical dominance on cuttings of red pitayaProfundidade de plantio e dominância apical na estaquia de pitaia vermelha

    Directory of Open Access Journals (Sweden)

    Virna Braga Marques

    2012-12-01

    Full Text Available This study was conducted to evaluate the effects of planting depth and breaking apical dominance on cutting of red pitaya Hylocereus undatus (Haw. Britton & Rose. The experiment was conducted in a randomized block design with four replications in a 2x3 factorial, with two kinds of cuttings (with or without apical dominance, cutting not sectioned and sectioned at 5 cm from the upper portion, and three planting depths (1.0, 5.0, and 10.0 cm and each plot consisted of ten 20 cm long cuttings. After 60 days of planting, counts of the number of shoots were began weekly and 90 days after planting survival rooting, number and length of shoots, dry weight of shoots and root dry mass were evaluated. Data were subjected to analysis of variance and polynomial regression at 5% significance level. The percentage of rooting and the survival were 100% in all treatments. With increasing depth of planting it was observed linear reduction in numbers of shoots, dry weight of shoot and root dry mass. The cladodes with apical dominance had longer shoots. The planting of red pitaya cuttings at 1 cm of planting depth with apical dominance is more suited to the production of nursery plants. O trabalho foi conduzido com o objetivo de avaliar os efeitos da profundidade de plantio e da quebra de dominância apical na estaquia de pitaia vermelha Hylocereus undatus (Haw. Britton & Rose. O experimento foi instalado no delineamento em blocos casualizados, com quatro repetições no esquema fatorial 2x3, sendo dois tipos de estacas (com e sem dominância apical, estacas não seccionadas e seccionadas a 5 cm da porção superior, e três profundidades de plantio (1,0; 5,0; 10,0 cm e cada parcela foi constituída de dez estacas com 20 cm de comprimento. Após 60 dias do plantio, foram iniciadas as avaliações semanais do número de brotações e aos 90 dias após o plantio foram avaliados sobrevivência, enraizamento, número e comprimento de brotações, massa seca das brota

  4. Thyroid bud morphogenesis requires CDC42- and SHROOM3-dependent apical constriction

    Science.gov (United States)

    Loebel, David A. F.; Plageman, Timothy F.; Tang, Theresa L.; Jones, Vanessa J.; Muccioli, Maria; Tam, Patrick P. L.

    2016-01-01

    ABSTRACT Early development of the gut endoderm and its subsequent remodeling for the formation of organ buds are accompanied by changes to epithelial cell shape and polarity. Members of the Rho-related family of small GTPases and their interacting proteins play multiple roles in regulating epithelial morphogenesis. In this study we examined the role of Cdc42 in foregut development and organ bud formation. Ablation of Cdc42 in post-gastrulation mouse embryos resulted in a loss of apical-basal cell polarity and columnar epithelial morphology in the ventral pharyngeal endoderm, in conjunction with a loss of apical localization of the known CDC42 effector protein PARD6B. Cell viability but not proliferation in the foregut endoderm was impaired. Outgrowth of the liver, lung and thyroid buds was severely curtailed in Cdc42-deficient embryos. In particular, the thyroid bud epithelium did not display the apical constriction that normally occurs concurrently with the outgrowth of the bud into the underlying mesenchyme. SHROOM3, a protein that interacts with Rho GTPases and promotes apical constriction, was strongly expressed in the thyroid bud and its sub-cellular localization was disrupted in Cdc42-deficient embryos. In Shroom3 gene trap mutant embryos, the thyroid bud epithelium showed no apical constriction, while the bud continued to grow and protruded into the foregut lumen. Our findings indicate that Cdc42 is required for epithelial polarity and organization in the endoderm and for apical constriction in the thyroid bud. It is possible that the function of CDC42 is partly mediated by SHROOM3. PMID:26772200

  5. Sequential development of apical-basal and planar polarities in aggregating epitheliomuscular cells of Hydra.

    Science.gov (United States)

    Seybold, Anna; Salvenmoser, Willi; Hobmayer, Bert

    2016-04-01

    Apical-basal and planar cell polarities are hallmarks of metazoan epithelia required to separate internal and external environments and to regulate trans- and intracellular transport, cytoskeletal organization, and morphogenesis. Mechanisms of cell polarization have been intensively studied in bilaterian model organisms, particularly in early embryos and cultured cells, while cell polarity in pre-bilaterian tissues is poorly understood. Here, we have studied apical-basal and planar polarization in regenerating (aggregating) clusters of epitheliomuscular cells of Hydra, a simple representative of the ancestral, pre-bilaterian phylum Cnidaria. Immediately after dissociation, single epitheliomuscular cells do not exhibit cellular polarity, but they polarize de novo during aggregation. Reestablishment of the Hydra-specific epithelial bilayer is a result of short-range cell sorting. In the early phase of aggregation, apical-basal polarization starts with an enlargement of the epithelial apical-basal diameter and by the development of belt-like apical septate junctions. Specification of the basal pole of epithelial cells occurs shortly later and is linked to synthesis of mesoglea, development of hemidesmosome-like junctions, and formation of desmosome-like junctions connecting the basal myonemes of neighbouring cells. Planar polarization starts, while apical-basal polarization is already ongoing. It is executed gradually starting with cell-autonomous formation, parallelization, and condensation of myonemes at the basal end of each epithelial cell and continuing with a final planar alignment of epitheliomuscular cells at the tissue level. Our findings reveal that epithelial polarization in Hydra aggregates occurs in defined steps well accessible by histological and ultrastructural techniques and they will provide a basis for future molecular studies. PMID:26921448

  6. Estudio de la filtración apical de cuatro cementos de obturación

    OpenAIRE

    Roig Cayón, Miguel; Ribot Porta, J. de; Jané Noblom, L.; Canalda Sahli, Carlos

    1996-01-01

    Los autores estudian in vitro la microfiltración apical con cuatro cementos de obturación, mediante la utilización de un colorante y técnicas de diafanización. Analizan dos cementos a base de hidróxido de calcio, y uno de ionómero de vidrio, comparándolos con un cemento clásico a base de óxido de zinc-eugenol. La filtración apical del cemento sellador Apexit fue significativamente superior a la de los cementos Sealapex y Endomethasone. No se observaron diferencias significativas entre los dem...

  7. Apical Ballooning Syndrome (Takotsubo Cardiomyopathy after Permanent Dual-Chamber Pacemaker Implantation

    Directory of Open Access Journals (Sweden)

    Armando Gardini

    2012-01-01

    Full Text Available Apical ballooning syndrome, also called takotsubo cardiomyopathy, has been recently reported. It may mimic acute myocardial infarction and is typically observed in postmenopausal women after stressful events. A 75-year-old female after permanent dual chamber pacemaker implant complained of chest pain with repolarization alterations suggesting acute myocardial ischemia. Echocardiography showed a left ventricle with akinesia of the apical portions and reduced global systolic function. The patient was treated with antithrombotic agents and intravenous nitrates. No coronary lesions were found at angiography. At ventriculography, a typical takotsubo-like shape of the left ventricle was observed. The clinical and echocardiographic picture normalized at discharge.

  8. Gravity-induced buds formation from protonemata apical cells in the mosses

    Science.gov (United States)

    Kyyak, Natalia; Khorkavtsiv, Yaroslava

    The acceleration of moss protonemata development after the exit it to light from darkness is important gravidependent morphogenetic manifestation of the moss protonemata. The accelerated development of mosses shows in transformation of apical protonemata cells into the gametophores buds (Ripetskyj et al., 1999). In order to establish, that such reaction on gravitation is general property of gravisensity species, or its typical only for single moss species, experiments with the following moss species - Bryum intermedium (Ludw.) Brig., Bryum caespiticium Hedw., Bryum argenteum Hedw., Dicranodontium denudatum (Brid.) Britt. were carried out. All these species in response to influence of gravitation were capable to form rich bunches of gravitropical protonemata in darkness, that testified to their gravisensity. After the transference of Petri dishes with gravitropical protonemata from darkness on light was revealed, that in 3 of the investigated species the gametophores buds were absent. Only B. argenteum has reacted to action of gravitation by buds formation from apical cells of the gravitropical protonemata. With the purpose of strengthening of buds formation process, the experiments with action of exogenous kinetin (in concentration of 10 (-6) M) were carried out. Kinetin essentially stimulated apical buds formation of B. argenteum. The quantity of apical buds has increased almost in three times in comparison with the control. Besides, on separate stolons a few (3-4) buds from one apical cell were formed. Experimentally was established, that the gametophores buds formation in mosses is controlled by phytohormones (Bopp, 1985; Demkiv et al., 1991). In conditions of gravity influence its essentially accelerated. Probably, gravity essentially strengthened acropetal transport of phytohormones and formation of attractive center in the protonemata apical cell. Our investigations have allowed to make the conclusion, that gravi-dependent formation of the apical buds is

  9. SEALING ABILITY OF GRAY MTA ANGELUS™, CPM™ AND MBPC USED AS APICAL PLUGS

    OpenAIRE

    Fernando Accorsi Orosco; Clovis Monteiro Bramante; Roberto Brandão Garcia; Norberti Bernadineli; Ivaldo Gomes de Moraes

    2008-01-01

    This study evaluated the sealing ability of apical plugs fabricated with gray MTA AngelusTM sealer, CPM TM sealer and MBPc sealer. The root canals of 98 extracted single-rooted human teeth were instrumented with #5 to #1 Gates Glidden drills according to the crown-down technique until the #1 drill could pass through the apical foramen. The specimens were then prepared with K-files, starting with an ISO 50 until an ISO 90 could be visualized 1 mm beyond the apex. After root canal preparation, ...

  10. Anti-early endosome antigen 1 autoantibodies were detected in a pemphigus-like patient but not in the majority of pemphigus diseases.

    Science.gov (United States)

    Nishikawa, Ryuhei; Takahashi, Hitoshi; Matsuda, Mitsuhiro; Imaoka, Kaoru; Ogawa, Masahiro; Teye, Kwesi; Tsuchisaka, Atsunari; Koga, Hiroshi; Komorowski, Lars; Probst, Christian; Hachiya, Takahisa; Fritzler, Marvin J; Ishii, Norito; Ohata, Chika; Furumura, Minao; Krol, Rafal P; Muro, Yoshinao; Morita, Eishin; Hashimoto, Takashi

    2016-05-01

    Although the major autoantigens in classic pemphigus are desmogleins, sera from various types of pemphigus react with a number of other molecules, including desmocollins and plakin proteins. However, other novel pemphigus-related autoantigens remain to be identified. In this study, immunoblotting for serum from an atypical autoimmune bullous disease patient identified an unknown 175 kDa protein. Subsequent studies using two-dimensional gel electrophoresis, immunoblotting and mass-spectrometry identified the 175 kDa protein as early endosome antigen 1 (EEA1). This finding was confirmed by subsequent immunological studies, including indirect immunofluorescence of skin and cultured keratinocytes, two-dimensional gel electrophoresis and immunoblotting with anti-EEA1 polyclonal antibody, and preabsorption with EEA1 recombinant protein. Finally, we developed a novel BIOCHIP assay using full-length EEA1 recombinant protein to detect anti-EEA1 antibodies. However, none of 35 sera from various types of pemphigus showed anti-EEA1 antibodies in the BIOCHIP assay, with the exception of the serum from the index case. In addition, various findings in the index case did not suggest pathogenic role of anti-EEA1 autoantibodies. Therefore, although we successfully identified the 175 kDa protein reacted by a serum of an atypical pemphigus-like patient as EEA1, novel BIOCHIP study for other pemphigus sera indicated that EEA1 is not a common and pathogenic autoantigen in pemphigus. PMID:26909655

  11. Heat shock factor 1 upregulates transcription of Epstein-Barr Virus nuclear antigen 1 by binding to a heat shock element within the BamHI-Q promoter

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng-Wei [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Wu, Xian-Rui [Department of Surgery, Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou (China); Liu, Wen-Ju; Liao, Yi-Ji [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Lin, Sheng [Laboratory of Integrated Biosciences, School of Life Science, Sun Yat-sen University, Guangzhou (China); Zong, Yong-Sheng; Zeng, Mu-Sheng; Zeng, Yi-Xin [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Mai, Shi-Juan, E-mail: maishj@sysucc.org.cn [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China); Xie, Dan, E-mail: xied@mail.sysu.edu.cn [The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou (China)

    2011-12-20

    Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is essential for maintenance of the episome and establishment of latency. In this study, we observed that heat treatment effectively induced EBNA1 transcription in EBV-transformed B95-8 and human LCL cell lines. Although Cp is considered as the sole promoter used for the expression of EBNA1 transcripts in the lymphoblastoid cell lines, the RT-PCR results showed that the EBNA1 transcripts induced by heat treatment arise from Qp-initiated transcripts. Using bioinformatics, a high affinity and functional heat shock factor 1 (HSF1)-binding element within the - 17/+4 oligonucleotide of the Qp was found, and was determined by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Moreover, heat shock and exogenous HSF1 expression induced Qp activity in reporter assays. Further, RNA interference-mediated HSF1 gene silencing attenuated heat-induced EBNA1 expression in B95-8 cells. These results provide evidence that EBNA1 is a new target for the transcription factor HSF1.

  12. Overexpression of Hepatitis B Virus-binding Protein, Squamous Cell Carcinoma Antigen 1, Extends Retention of Hepatitis B Virus in Mouse Liver

    Institute of Scientific and Technical Information of China (English)

    Hong-Bin XIA; Xi-Gu CHEN

    2006-01-01

    How receptors mediate the entry of hepatitis B virus (HBV) into the target liver cells is poorly understood. Recently, human squamous cell carcinoma antigen 1 (SCCA1) has been found to mediate binding and internalization of HBV to liver-derived cell lines in vitro. In this report, we investigate if SCCA1 is able to function as an HBV receptor and mediate HBV entry into mouse liver. SCCA1 transgene under the control of Rous sarcoma virus promoter was constructed in a minicircle DNA vector that was delivered to NOD/SCID mouse liver using the hydrodynamic technique. Subsequently, HBV-positive human serum was injected intravenously. We demonstrated that approximately 30% of the mouse liver cells expressed a high level of recombined SCCA1 protein for at least 37 d. The HBV surface antigen was found to persist in mouse liver for up to 17 d. Furthermore, HBV genome also persisted in mouse liver, as determined by polymerase chain reaction, for up to 17 d, and in mouse circulation for 7 d. These results suggest that SCAA1 might serve as an HBV receptor or co-receptor and play an important role in mediating HBV entry into hepatocytes, although its role in human HBV infection remains to be determined.

  13. Anti-Leukocyte Function-Associated Antigen 1 Therapy in a Nonhuman Primate Renal Transplant Model of Costimulation Blockade-Resistant Rejection.

    Science.gov (United States)

    Anderson, D J; Lo, D J; Leopardi, F; Song, M; Turgeon, N A; Strobert, E A; Jenkins, J B; Wang, R; Reimann, K A; Larsen, C P; Kirk, A D

    2016-05-01

    Costimulation blockade with the fusion protein belatacept provides a desirable side effect profile and improvement in renal function compared with calcineurin inhibition in renal transplantation. This comes at the cost of increased rates of early acute rejection. Blockade of the integrin molecule leukocyte function-associated antigen 1 (LFA-1) has been shown to be an effective adjuvant to costimulation blockade in a rigorous nonhuman primate (NHP) model of islet transplantation; therefore, we sought to test this combination in an NHP renal transplant model. Rhesus macaques received belatacept maintenance therapy with or without the addition of LFA-1 blockade, which was achieved using a murine-derived LFA-1-specific antibody TS1/22. Additional experiments were performed using chimeric rhesus IgG1 (TS1/22R1) or IgG4 (TS1/22R4) variants, each engineered to limit antibody clearance. Despite evidence of proper binding to the target molecule and impaired cellular egress from the intravascular space indicative of a therapeutic effect similar to prior islet studies, LFA-1 blockade failed to significantly prolong graft survival. Furthermore, evidence of impaired protective immunity against cytomegalovirus was observed. These data highlight the difficulties in translating treatment regimens between organ models and suggest that the primarily vascularized renal model is more robust with regard to belatacept-resistant rejection than the islet model. PMID:26602755

  14. The CD11a partner in Sus scrofa lymphocyte function-associated antigen-1 (LFA-1: mRNA cloning, structure analysis and comparison with mammalian homologues

    Directory of Open Access Journals (Sweden)

    Thomas Anne VT

    2005-10-01

    Full Text Available Abstract Background Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alphaLbeta2, the most abundant and widely expressed beta2-integrin, is required for many cellular adhesive interactions during the immune response. Many studies have shown that LFA-1 is centrally involved in the pathogenesis of several diseases caused by Repeats-in-toxin (RTX -producing bacteria. Results The porcine-LFA-1 CD11a (alpha subunit coding sequence was cloned, sequenced and compared with the available mammalian homologues in this study. Despite some focal differences, it shares all the main characteristics of these latter. Interestingly, as in sheep and humans, an allelic variant with a triplet insertion resulting in an additional Gln-744 was consistently identified, which suggests an allelic polymorphism that might be biologically relevant. Conclusion Together with the pig CD18-encoding cDNA, which has been available for a long time, the sequence data provided here will allow the successful expression of porcine CD11a, thus giving the first opportunity to express the Sus scrofa beta2-integrin LFA-1 in vitro as a tool to examine the specificities of inflammation in the porcine species.

  15. Effects of Intermittent Administration of Parathyroid Hormone (1-34 on Bone Differentiation in Stromal Precursor Antigen-1 Positive Human Periodontal Ligament Stem Cells

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Wang

    2016-01-01

    Full Text Available Periodontitis is the most common cause of tooth loss and bone destruction in adults worldwide. Human periodontal ligament stem cells (hPDLSCs may represent promising new therapeutic biomaterials for tissue engineering applications. Stromal precursor antigen-1 (STRO-1 has been shown to have roles in adherence, proliferation, and multipotency. Parathyroid hormone (PTH has been shown to enhance proliferation in osteoblasts. Therefore, in this study, we aimed to compare the functions of STRO-1(+ and STRO-1(− hPDLSCs and to investigate the effects of PTH on the osteogenic capacity of STRO-1(+ hPDLSCs in order to evaluate their potential applications in the treatment of periodontitis. Our data showed that STRO-1(+ hPDLSCs expressed higher levels of the PTH-1 receptor (PTH1R than STRO-1(− hPDLSCs. In addition, intermittent PTH treatment enhanced the expression of PTH1R and osteogenesis-related genes in STRO-1(+ hPDLSCs. PTH-treated cells also exhibited increased alkaline phosphatase activity and mineralization ability. Therefore, STRO-1(+ hPDLSCs represented a more promising cell resource for biomaterials and tissue engineering applications. Intermittent PTH treatment improved the capacity for STRO-1(+ hPDLSCs to repair damaged tissue and ameliorate the symptoms of periodontitis.

  16. Expression, biosynthesis and release of preadipocyte factor-1/ delta-like protein/fetal antigen-1 in pancreatic beta-cells

    DEFF Research Database (Denmark)

    Friedrichsen, B N; Carlsson, C; Møldrup, Annette;

    2003-01-01

    Preadipocyte factor-1 (Pref-1)/delta-like protein/fetal antigen-1 (FA1) is a member of the epidermal growth factor-like family. It is widely expressed in embryonic tissues, whereas in adults it is confined to the adrenal gland, the anterior pituitary, the endocrine pancreas, the testis and the...... insulin-positive islet cells. We found that Pref-1 was synthesized in normal islets and in RINm5F insulinoma cells and released into the medium in two forms, of which one corresponded to FA1. Both the expression of the mRNA for Pref-1 and the release of the soluble form(s) were stimulated by GH and...... prolactin (PRL). Whereas 2 h exposure to high glucose or 3-isobutyl-1-methylxanthine stimulated insulin release, only a small change was seen in FA1 release, suggesting that the FA1 is released by a different pathway than insulin. However, long-term exposure (48 h) to high glucose increased FA1 secretion...

  17. Structural Analysis of the Plakin Domain of Bullous Pemphigiod Antigen1 (BPAG1) Suggests That Plakins are Members of the Spectrin Superfamily

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson,J.; Ciatto, C.; Shapiro, l.; Liem, R.

    2007-01-01

    Bullous pemphigoid antigen 1 (BPAG1) is a member of the plakin family of proteins. The plakins are multi-domain proteins that have been shown to interact with microtubules, actin filaments and intermediate filaments, as well as proteins found in cellular junctions. These interactions are mediated through different domains on the plakins. The interactions between plakins and components of specialized cell junctions such as desmosomes and hemidesmosomes are mediated through the so-called plakin domain, which is a common feature of the plakins. We report the crystal structure of a stable fragment from BPAG1, residues 226-448, defined by limited proteolysis of the whole plakin domain. The structure, determined by single-wavelength anomalous diffraction phasing from a selenomethionine-substituted crystal at 3.0 {angstrom} resolution, reveals a tandem pair of triple helical bundles closely related to spectrin repeats. Based on this structure and analysis of sequence conservation, we propose that the architecture of plakin domains is defined by two pairs of spectrin repeats interrupted by a putative Src-Homology 3 (SH3) domain.

  18. FRET based quantification and screening technology platform for the interactions of leukocyte function-associated antigen-1 (LFA-1 with intercellular adhesion molecule-1 (ICAM-1.

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    Full Text Available The interaction between leukocyte function-associated antigen-1(LFA-1 and intercellular adhesion molecule-1 (ICAM-1 plays a pivotal role in cellular adhesion including the extravasation and inflammatory response of leukocytes, and also in the formation of immunological synapse. However, irregular expressions of LFA-1 or ICAM-1 or both may lead to autoimmune diseases, metastasis cancer, etc. Thus, the LFA-1/ICAM-1 interaction may serve as a potential therapeutic target for the treatment of these diseases. Here, we developed one simple 'in solution' steady state fluorescence resonance energy transfer (FRET technique to obtain the dissociation constant (Kd of the interaction between LFA-1 and ICAM-1. Moreover, we developed the assay into a screening platform to identify peptides and small molecules that inhibit the LFA-1/ICAM-1 interaction. For the FRET pair, we used Alexa Fluor 488-LFA-1 conjugate as donor and Alexa Fluor 555-human recombinant ICAM-1 (D1-D2-Fc as acceptor. From our quantitative FRET analysis, the Kd between LFA-1 and D1-D2-Fc was determined to be 17.93±1.34 nM. Both the Kd determination and screening assay were performed in a 96-well plate platform, providing the opportunity to develop it into a high-throughput assay. This is the first reported work which applies FRET based technique to determine Kd as well as classifying inhibitors of the LFA-1/ICAM-1 interaction.

  19. Stem cell antigen-1 regulates the tempo of muscle repair through effects on proliferation of α7 integrin-expressing myoblasts

    International Nuclear Information System (INIS)

    Skeletal muscle repair occurs through a programmed series of events including myogenic precursor activation, myoblast proliferation, and differentiation into new myofibers. We previously identified a role for Stem cell antigen-1 (Sca-1) in myoblast proliferation and differentiation in vitro. We demonstrated that blocking Sca-1 expression resulted in sustained myoblast cell division. Others have since demonstrated that Sca-1-null myoblasts display a similar phenotype when cultured ex vivo. To test the importance of Sca-1 during myogenesis in vivo, we employed a myonecrotic injury model in Sca-1-/- and Sca-1+/+ mice. Our results demonstrate that Sca-1-/- myoblasts exhibit a hyperproliferative response consisting of prolonged and accelerated cell division in response to injury. This leads to delayed myogenic differentiation and muscle repair. These data provide the first in vivo evidence for Sca-1 as a regulator of myoblast proliferation during muscle regeneration. These studies also suggest that the balance between myogenic precursor proliferation and differentiation is critical to normal muscle repair

  20. A possible association between early apical resorption of primary teeth and ectodermal characteristics of the permanent dentition

    DEFF Research Database (Denmark)

    Bille, M L B; Kvetny, M J; Kjaer, I

    2008-01-01

    apical resorption in the primary dentition. Panoramic radiographs of 12 children (7 boys and 5 girls) aged 6 years 4 months to 8 years 9 months with unexpected early apical resorption of primary teeth were identified from a dental archive of 588 patients. After written request, follow-up radiographs were...

  1. Uterine receptivity and the plasma membrane transformation

    Institute of Scientific and Technical Information of China (English)

    Christopher R MURPHY

    2004-01-01

    This review begins with a brief commentary on the diversity of placentation mechanisms, and then goes on to examine the extensive alterations which occur in the plasma membrane of uterine epithelial cells during early pregnancy across species. Ultrastructural, biochemical and more general morphological data reveal that strikingly common phenomena occur in this plasma membrane during early pregnancy despite the diversity of placental types-from epitheliochorial to hemochorial, which ultimately form in different species. To encapsulate the concept that common morphological and molecular alterations occur across species, that they are found basolaterally as well as apically, and that moreover they are an ongoing process during much of early pregnancy, not just an event at the time attachment,brane during early pregnancy are key to uterine receptivity.

  2. Comparative evaluation of total RNA extraction methods in Theobroma cacao using shoot apical meristems.

    Science.gov (United States)

    Silva, D V; Branco, S M J; Holanda, I S A; Royaert, S; Motamayor, J C; Marelli, J P; Corrêa, R X

    2016-01-01

    Theobroma cacao is a species of great economic importance with its beans used for chocolate production. The tree has been a target of various molecular studies. It contains many polyphenols, which complicate the extraction of nucleic acids with the extraction protocols requiring a large amount of plant material. These issues, therefore, necessitate the optimization of the protocols. The aim of the present study was to evaluate different methods for extraction of total RNA from shoot apical meristems of T. cacao 'CCN 51' and to assess the influence of storage conditions for the meristems on the extraction. The study also aimed to identify the most efficient protocol for RNA extraction using a small amount of plant material. Four different protocols were evaluated for RNA extraction using one shoot apical meristem per sample. Among these protocols, one that was more efficient was then tested to extract RNA using four different numbers of shoot apical meristems, subjected to three different storage conditions. The best protocol was tested for cDNA amplification using reverse transcription-polymerase chain reaction; the cDNA quality was determined to be satisfactory for molecular analyses. The study revealed that with the best RNA extraction protocol, one shoot apical meristem was sufficient for extraction of high-quality total RNA. The results obtained might enable advances in genetic analyses and molecular studies using reduced amount of plant material. PMID:26985935

  3. Pulp Revascularization in Immature Permanent Tooth with Apical Periodontitis Using Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Katsura Saeki

    2014-01-01

    Full Text Available Mineral trioxide aggregate (MTA is a material that has been used worldwide in several clinical applications, such as apical barriers in teeth with immature apices, repair of root perforations, root-end filling, pulp capping, and pulpotomy. The purpose of this case report was to describe successful revascularization treatment of an immature mandibular right second premolar with apical periodontitis in a 9-year-old female patient. After preparing an access cavity without anesthesia, the tooth was isolated using a rubber dam and accessed. The canal was gently debrided using 5% sodium hypochlorite (NaOCl and 3% hydrogen peroxide irrigant. And then MTA was packed into the canal. X-ray photographic examination showed the dentin bridge 5 months after the revascularization procedure. Thickening of the canal wall and complete apical closure were confirmed 10 months after the treatment. In this case, MTA showed clinical and radiographic success at revascularization treatment in immature permanent tooth. The successful outcome of this case suggests that MTA is reliable and effective for endodontic treatment in the pediatric dentistry.

  4. Responses of Metabolites in Soybean Shoot Apices to Changing Atmospheric Carbon Dioxide Concentrations

    Directory of Open Access Journals (Sweden)

    Richard Sicher

    2012-01-01

    Full Text Available Soybean seedlings were grown in controlled environment chambers with CO2 partial pressures of 38 (ambient and 72 (elevated Pa. Five or six shoot apices were harvested from individual 21- to 24-day-old plants. Metabolites were analyzed by gas chromatography and, out of 21 compounds, only sucrose and fructose increased in response to CO2 enrichment. One unidentified metabolite, Unk-21.03 decreased up to 80% in soybean apices in response to elevated CO2. Levels of Unk-21.03 decreased progressively when atmospheric CO2 partial pressures were increased from 26 to 100 Pa. Reciprocal transfer experiments showed that Unk-21.03, and sucrose in soybean apices were altered slowly over several days to changes in atmospheric CO2 partial pressures. The mass spectrum of Unk-21.03 indicated that this compound likely contained both an amino and carboxyl group and was structurally related to serine and aspartate. Our findings suggested that CO2 enrichment altered a small number of specific metabolites in soybean apices. This could be an important step in understanding how plant growth and development are affected by carbon dioxide enrichment.

  5. Apical Gene Transfer into Quiescent Human and Canine Polarized Intestinal Epithelial Cells by Lentivirus Vectors

    OpenAIRE

    Seppen, Jurgen; Barry, Simon C.; Klinkspoor, J. Henriette; Katen, Louis J.; Lee, Sum P; Garcia, J. Victor; Osborne, William R. A.

    2000-01-01

    Intestinal epithelial cells secrete a protective luminal mucus barrier inhibiting viral gene transfer. Quiescent, polarized monolayers of primary epithelial cells from dog gallbladder and human colon are efficiently transduced through the apical mucus side by lentivirus vectors, suggesting their application to intestinal gene therapy.

  6. Apical Third Morphology and Intrusive Force Application: 3D Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    A. Geramy

    2007-09-01

    Full Text Available Objective: Intrusion as a type of tooth movement is managed by different mechanothera-pies during various treatment stages. The morphology of the apical third of the teeth to be intruded plays an important role in the risk of root resorption due to the raise of stresses.The main goal of this study was to compare various types of apical third of the teeth while loaded by an intrusive force.Materials and Methods: Four 3D Finite element models were designed with all support-ing structures. Normal, needle form, short and sharp apices were considered. Intrusiveforces of 0.5 N were applied and the VonMises stress along the mesial side of the root was assessed.Results: A tendency to show increased stresses at the cervical area of the teeth was no-ticed. The lowest stress was noticed in the blunt apex and the highest findings were shown to be in the needle form apex model.Conclusion: Normal variation in apical third of the teeth in intrusion can cause an in-creased stress level and also increased chance of root resorption which should be consid-ered carefully in force applications.

  7. USAGE OF PASTE FOR TEMPORARY PLACEMENT IN THE TREATMENT OF CHRONIC APICAL PERIODONTITIS

    Directory of Open Access Journals (Sweden)

    A.V. Borysenko

    2012-03-01

    Full Text Available Summary: The aim of the present investigation was usage of medicamental paste with antibacterial and regeneration action for temporary placement in the treatment of chronic apical periodontitis. Materials and method: The medicamental paste for temporary placement of root canals consists of a mixture of metronidazole, Enterosgel (Silm and Alflutop (Biotehnos S.A., Romania. Thë paste was used for the treatment of 30 teeth with chronic apical periodontitis. Final obturation of the root canals was performed with gutta percha cones and sealer. The efficiency of the treatment was appreciated after examination on the basis of clinical and radiographic findings. Results: During the treatment of the 30 teeth, no exacerbations of the pathological process were recorded. Pain after obturation of the root canals was revealed in only 6 (20% of the treated teeth. No pain, pathologic changes of gingiva, good mastication efficiency in all teeth after treatment were revealed. Conclusions: The high clinical efficiency of the medicamental paste with antibacterial and regeneration action at the level of temporary root canals placement in the treatment of chronic apical periodontitis was shown. Keywords: chronic apical periodontitis, medicamental paste for temporary root canals placement, metronidazole, Enterosgel (Silm and Alflutop (Biotehnos S.A., Romania

  8. An improved cryopreservation protocol for pineapple apices using encapsulation-vitrification.

    Science.gov (United States)

    Gámez-Pastrana, R; Martínez-Ocampo, Y; Beristain, C I; González-Arnao, M T

    2004-01-01

    Several modifications to the cryogenic protocols previously described for pineapple apices were performed using vitrification and encapsulation-vitrification. Pregrowth of apices in sucrose-proline before loading significantly reduced the exposure duration to PVS2 and PVS3 required for successful cryopreservation. Encapsulation and treatments with PVS3 at 0 degree C gave the highest survival before and after cooling. Optimal conditions involved the encapsulation of pineapple apices in calcium alginate (3 percent) followed by a 2-d preculture in liquid medium with 0.16 M sucrose + 0.3 M proline for 24 h and then transfer to 0.3 M sucrose + 0.3 M proline for an additional 24 h. After preculture, samples were loaded in 0.75 M sucrose + 1 M glycerol solution at room temperature (25 min) and dehydrated with PVS3 at 0 degree C for 60 min before immersion into liquid nitrogen. Following this procedure 54 percent and 83 percent of apices from MD-2 and Puerto Rico varieties respectively survived. PMID:15660167

  9. A novel mitochondrial ATP8 gene mutation in a patient with apical hypertrophic cardiomyopathy and neuropathy.

    NARCIS (Netherlands)

    Jonckheere, A.I.; Hogeveen, M.; Nijtmans, L.G.J.; Brand, M.A.M. van den; Janssen, A.J.M.; Diepstra, J.H.S.; Brandt, FC van den; Heuvel, L.P.W.J. van den; Hol, F.A.; Hofste, T.G.; Kapusta, L.; Dillmann, U.; Shamdeen, M.G.; Smeitink, J.A.M.; Rodenburg, R.J.T.

    2008-01-01

    PURPOSE: To identify the biochemical and molecular genetic defect in a 16-year-old patient presenting with apical hypertrophic cardiomyopathy and neuropathy suspected for a mitochondrial disorder. METHODS: Measurement of the mitochondrial energy-generating system (MEGS) capacity in muscle and enzyme

  10. Electric current affects the rate of development in isolated apical parts of rape in vitro

    Czech Academy of Sciences Publication Activity Database

    Filek, M.; Koscielniak, J.; Marcińska, I.; Krekule, Jan; Macháčková, Ivana; Dubert, F.

    2006-01-01

    Roč. 50, č. 3 (2006), s. 465-468. ISSN 0006-3134 Institutional research plan: CEZ:AV0Z5038910 Keywords : apical meristem differentiation * flowering factors * vernalization Subject RIV: EF - Botanics Impact factor: 1.198, year: 2006

  11. The ERECTA receptor kinase regulates Arabidopsis shoot apical meristem size, phyllotaxy and floral meristem identity

    Science.gov (United States)

    In plants, the shoot apical meristem (SAM) serves as a reservoir of pluripotent stem cells from which all above ground organs originate. To sustain proper growth, the SAM must maintain homeostasis between the self-renewal of pluripotent stem cells and cell recruitment for lateral organ formation. At...

  12. Feasibility of transapical aortic valve replacement through a left ventricular apical diverticulum

    Directory of Open Access Journals (Sweden)

    Ferrari Enrico

    2013-01-01

    Full Text Available Abstract Transapical aortic valve replacement is an established technique performed in high-risk patients with symptomatic aortic valve stenosis and vascular disease contraindicating trans-vascular and trans-aortic procedures. The presence of a left ventricular apical diverticulum is a rare event and the treatment depends on dimensions and estimated risk of embolisation, rupture, or onset of ventricular arrhythmias. The diagnosis is based on standard cardiac imaging and symptoms are very rare. In this case report we illustrate our experience with a 81 years old female patient suffering from symptomatic aortic valve stenosis, respiratory disease, chronic renal failure and severe peripheral vascular disease (logistic euroscore: 42%, who successfully underwent a transapical 23 mm balloon-expandable stent-valve implantation through an apical diverticulum of the left ventricle. Intra-luminal thrombi were absent and during the same procedure were able to treat the valve disease and to successfully exclude the apical diverticulum without complications and through a mini thoracotomy. To the best of our knowledge, this is the first time that a transapical procedure is successfully performed through an apical diverticulum.

  13. Association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope and smoking status in Brazilian patients with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Michel Alexandre Yazbek

    2011-01-01

    Full Text Available INTRODUCTION: Epstein-Barr virus exposure appears to be an environmental trigger for rheumatoid arthritis that interacts with other risk factors. Relationships among anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status have been observed in patients with rheumatoid arthritis from different populations. OBJECTIVE: To perform an association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status in Brazilian patients with rheumatoid arthritis. METHODS: In a case-control study, 140 rheumatoid arthritis patients and 143 healthy volunteers who were matched for age, sex, and ethnicity were recruited. Anti-Epstein-Barr nuclear antigen-1 antibodies and anti-cyclic citrullinated peptide antibodies were examined using an enzyme-linked immunosorbent assay, and shared epitope alleles were identified by genotyping. Smoking information was collected from all subjects. A comparative analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status was performed in the patient group. Logistic regression analysis models were used to analyze the risk of rheumatoid arthritis. RESULTS: Anti-Epstein-Barr nuclear antigen-1 antibodies were not associated with anti-cyclic citrullinated peptide antibodies, shared epitope alleles, or smoking status. Anti-cyclic citrullinated peptide antibody positivity was significantly higher in smoking patients with shared epitope alleles (OR = 3.82. In a multivariate logistic regression analysis using stepwise selection, only anti-cyclic citrullinated peptide antibodies were found to be independently associated with rheumatoid arthritis (OR = 247.9. CONCLUSION: Anti-Epstein-Barr nuclear antigen-1 antibodies did not increase the risk of rheumatoid arthritis and were not associated with the rheumatoid arthritis risk factors studied. Smoking

  14. Association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope and smoking status in Brazilian patients with rheumatoid arthritis

    Science.gov (United States)

    Yazbek, Michel Alexandre; de Barros-Mazon, Silvia; Rossi, Cláudio Lúcio; Londe, Ana Carolina; Costallat, Lilian Tereza Lavras; Bértolo, Manoel Barros

    2011-01-01

    INTRODUCTION: Epstein-Barr virus exposure appears to be an environmental trigger for rheumatoid arthritis that interacts with other risk factors. Relationships among anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status have been observed in patients with rheumatoid arthritis from different populations. OBJECTIVE: To perform an association analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status in Brazilian patients with rheumatoid arthritis. METHODS: In a case-control study, 140 rheumatoid arthritis patients and 143 healthy volunteers who were matched for age, sex, and ethnicity were recruited. Anti-Epstein-Barr nuclear antigen-1 antibodies and anti-cyclic citrullinated peptide antibodies were examined using an enzyme-linked immunosorbent assay, and shared epitope alleles were identified by genotyping. Smoking information was collected from all subjects. A comparative analysis of anti-Epstein-Barr nuclear antigen-1 antibodies, anti-cyclic citrullinated peptide antibodies, the shared epitope, and smoking status was performed in the patient group. Logistic regression analysis models were used to analyze the risk of rheumatoid arthritis. RESULTS: Anti-Epstein-Barr nuclear antigen-1 antibodies were not associated with anti-cyclic citrullinated peptide antibodies, shared epitope alleles, or smoking status. Anti-cyclic citrullinated peptide antibody positivity was significantly higher in smoking patients with shared epitope alleles (OR = 3.82). In a multivariate logistic regression analysis using stepwise selection, only anti-cyclic citrullinated peptide antibodies were found to be independently associated with rheumatoid arthritis (OR = 247.9). CONCLUSION: Anti-Epstein-Barr nuclear antigen-1 antibodies did not increase the risk of rheumatoid arthritis and were not associated with the rheumatoid arthritis risk factors studied. Smoking and

  15. Memorizing of Gravistimulus in apical protonemal cells of the moss Ceratodon purpureus

    Science.gov (United States)

    Lesniak, Y. I.; Khorkavtsiv, O. Y.; Oksyniuk, U. A.; Demkiv, O. T.

    Moss protonemata sense and realize gravity by apical cells of stolones, the function of gravisensors being performed by amyloplasts which sediment on lower side of the cell wall. The pattern of amyloplasts distribution and dynamics of their sedimentation were described in detail in different moss species (Sack, 1991; 1997; Young, Sack, 1992; Chaban et al., 1998; Schwuchow et al., 2002). The pathways of gravity transduction to growth process remain, however, still-uncleared (Sack, 1997; Kern et al., 2001; Schwuchow et al., 2002). The processes of the perception and transduction of the gravistimulus in the apical cells were uncoupled experimentally. It has been shown in our experiments that susception of gravistimulus takes place under conditions of low temperature, while the growth of apical cells is blocked. Being, however, transferred into usual conditions gravistimulated protonemata realize their gravitropic bend. To receive such effect gravistimulation of different duration, from 15 min to 24 h, was conducted at 20C and the gravistimulated protonemata were then clinorotating for 8-20 h. Gravistimulus manifested itself in bending of tip zone of the stolons only in case of 8-20 h gravistimulation. 15-30 min was found to be uneffective, the stolons bends were not formed. Gravistimulation for 1 h and more proportionally the increased the bend angle. Probably, the gravistimulus may retain in cells for comparatively long time under low temperature being realized only under favourable conditions. The participation of growth substances, in particular that of IAA, in realization of gravistimulus in tip growing protonemal cells remains not quite clear. It has been established that realization of gravistimulus can be experimentally blocked by the inhibitors of calcium channels and pumps, respectively by 0.1--1.0 μ M of verapamil and 1.0--10.0 μ M of sodium orthovanadate. 0.1--1.0 μ M of exogenous IAA and α -NAA did not significantly influence the growth and gravi

  16. Evaluation of the endodontic apical seal after post insertion by synchrotron radiation microtomography

    Energy Technology Data Exchange (ETDEWEB)

    Contardo, L. [Dipartimento di Scienze, Chirurgiche Specialistiche, University of Trieste, Trieste (Italy)]. E-mail: olivo@ts.infn.it; De Luca, M. [Dipartimento di Scienze, Chirurgiche Specialistiche, University of Trieste, Trieste (Italy); Biasotto, M. [Dipartimento di Scienze, Chirurgiche Specialistiche, University of Trieste, Trieste (Italy); Longo, R. [Dipartment of Physics of the University of Trieste and INFN, Trieste (Italy); Olivo, A. [Dipartment of Physics of the University of Trieste and INFN, Trieste (Italy); Pani, S. [Dipartment of Physics of the University of Trieste and INFN, Trieste (Italy); Di Lenarda, R. [Dipartimento di Scienze, Chirurgiche Specialistiche, University of Trieste, Trieste (Italy)

    2005-08-11

    The commonly used methods for evaluating the endodontic apical seal, such as longitudinal and transversal section and diaphanization, show some operative difficulties and intrinsic limitation. This study suggests and describes a new method of analysis using a synchrotron radiation microtomography to analyse the root apex after post insertion, creating a three-dimensional image and analysing sections of the specimen every 5{mu}m. The study was performed at SYRMEP beam line at the Electra Synchrotron in Trieste using monochromatic X-rays of 32KeV. Eleven monoradicular teeth were prepared using NiTi GT Rotary files instruments to an apical size 20 with conicity .06 and divided in four groups: in G1 (n=4) and G2 (n=2), the specimens were endodontically filled with guttapercha and a zinc-oxide sealer, in G3 (n=3) and G4 (n=2) guttapercha and a silicon-based sealer were used. An endodontic post was inserted in specimens of groups 1 and 3 following the manufacturer's instructions. Specimens were analysed using monochromatic X-rays of 32KeV. A CCD detector with pixel dimension pf 5x5{mu}m{sup 2} was used for the acquisition process. Seven hundred and twenty projections were performed over 180{sup o} range using a high-resolution rotator. The projections were reconstructed using standard algorithms for tomographic reconstruction. The apical infiltration was evaluated by verifying if black spots were detectable on the images. The specimens of groups 3 and 4 showed a better apical seal than the ones of groups 1 and 2. Post insertion, when a ZOE-based sealer is used, increases the apical gap even if it does not seem to be clinically relevant and sufficient to be a cause of endodontic failure. The new method for analysis appeared to be effective to detect small defects in endodontic obturation, analysing guttapercha-sealer and sealer-dentin interfaces.

  17. Morphology of bacterial flora in root canals associated with apical abscesses

    Institute of Scientific and Technical Information of China (English)

    Guo Huijie; Gao Chengzhi; Zhang Chengfei; Zheng Shuying; Yue Lin

    2014-01-01

    Background Apical abscess is an inflammatory process in the peri-radicular tissues caused by biofllms in the necrotic root canal systems.Therefore,a comprehensive analysis of the bacterial colonization is required for a better understanding of the pathogenesis.This study aimed to investigate the patterns of bacterial infection of root canals of teeth with apical abscesses and to determine whether histological and microbiological findings correlated with clinical conditions.Methods Eighteen samples from 18 teeth with apical pathological lesions were analyzed.Nine patients with acute apical abscesses experienced severe pain,and nine patients were asymptomatic with a sinus tract.After extraction,each affected root was divided into two halves.One half was processed for histobacteriologic analysis and examined using light microscopy,and the other half was analyzed using scanning electron microscopy (SEM) to determine the patterns of microbial colonization of the root canals.Results The appearance of each sample subjected to SEM was consistent with the histobacteriologic findings despite the presence or absence of clinical symptoms.Intraradicular biofilms comprising cocci,rods,and/or filaments of amorphous materials were observed in the apical third of the main root canals in all samples.The bacterial biofilms covering the main root canal walls also penetrated the dentinal tubules to varying depths.The morphologies of biofilms varied,and a unique pattern of intraradicular infection was not identified.Conclusion Intraradicular infections formed complex and variable multispecies biofilms and their presence did not correlate with clinical symptoms.

  18. CASE OF DIAGNOSIS OF APICAL FORM OF HYPERTROPHIC CARDIOMYOPATHY WITH A PATIENT WITH PROGRESSIVE ANGINA CLINIC

    Directory of Open Access Journals (Sweden)

    N. S. Krylova

    2014-01-01

    Full Text Available Objective of work: to describe the apical form of hypertrophic cardiomyopathy (AFHC developing under the "mask" of the ischemic heart disease not diagnosed for a long period.Materials and methods. Patient B., 73 y.o., female, was brought to the cardiology department with complains of severe pressing pain behind the breastbone caused with no apparent reason and lasting for over 4 hours. The following examination of the patient was performed: electrocardiography (ECG, echocardiography (EchoCG, Holter ECG monitoring, coronary angiography (CAG, ventriculography.Results. The final diagnosis for the patient was set on the basis of the following readings: ECG data (basic rhythm – atrial fibrillation, left ventricle (LV hypertrophy, negative T-waves in leads V1–6, ST segment depression up to 1–2 mm in leads V4–6, EchoCG (hypertrophy of apical segments of the LV with decreasing of its cavity, moderate dilatation of the left atrium, intraventricular obstruction in the apical third of the LV with the maximum pressure gradient of up to 48 mm Hg., CAG (stenotic lesions of coronary arteries were found, ventriculography (LV volume is not increased, no violations of local contractility, narrowing of the LV cavity in the lower third is observed with thinning in the apex, which indicatesexpressed apical hypertrophy of the LV myocard. AFHC, apical form with moderate obstruction in the lower third of the left ventricle. Stress angina syndrome. CAG and ventriculography were main diagnostic methods that allowed setting the final diagnosis.Conclusion. The clinical case sets forth the peculiarities of diagnostics, therapy, and post-therapy management of patients with this form of AFHC.

  19. CASE OF DIAGNOSIS OF APICAL FORM OF HYPERTROPHIC CARDIOMYOPATHY WITH A PATIENT WITH PROGRESSIVE ANGINA CLINIC

    Directory of Open Access Journals (Sweden)

    N. S. Krylova

    2015-01-01

    Full Text Available Objective of work: to describe the apical form of hypertrophic cardiomyopathy (AFHC developing under the "mask" of the ischemic heart disease not diagnosed for a long period.Materials and methods. Patient B., 73 y.o., female, was brought to the cardiology department with complains of severe pressing pain behind the breastbone caused with no apparent reason and lasting for over 4 hours. The following examination of the patient was performed: electrocardiography (ECG, echocardiography (EchoCG, Holter ECG monitoring, coronary angiography (CAG, ventriculography.Results. The final diagnosis for the patient was set on the basis of the following readings: ECG data (basic rhythm – atrial fibrillation, left ventricle (LV hypertrophy, negative T-waves in leads V1–6, ST segment depression up to 1–2 mm in leads V4–6, EchoCG (hypertrophy of apical segments of the LV with decreasing of its cavity, moderate dilatation of the left atrium, intraventricular obstruction in the apical third of the LV with the maximum pressure gradient of up to 48 mm Hg., CAG (stenotic lesions of coronary arteries were found, ventriculography (LV volume is not increased, no violations of local contractility, narrowing of the LV cavity in the lower third is observed with thinning in the apex, which indicatesexpressed apical hypertrophy of the LV myocard. AFHC, apical form with moderate obstruction in the lower third of the left ventricle. Stress angina syndrome. CAG and ventriculography were main diagnostic methods that allowed setting the final diagnosis.Conclusion. The clinical case sets forth the peculiarities of diagnostics, therapy, and post-therapy management of patients with this form of AFHC.

  20. Evaluation of the endodontic apical seal after post insertion by synchrotron radiation microtomography

    International Nuclear Information System (INIS)

    The commonly used methods for evaluating the endodontic apical seal, such as longitudinal and transversal section and diaphanization, show some operative difficulties and intrinsic limitation. This study suggests and describes a new method of analysis using a synchrotron radiation microtomography to analyse the root apex after post insertion, creating a three-dimensional image and analysing sections of the specimen every 5μm. The study was performed at SYRMEP beam line at the Electra Synchrotron in Trieste using monochromatic X-rays of 32KeV. Eleven monoradicular teeth were prepared using NiTi GT Rotary files instruments to an apical size 20 with conicity .06 and divided in four groups: in G1 (n=4) and G2 (n=2), the specimens were endodontically filled with guttapercha and a zinc-oxide sealer, in G3 (n=3) and G4 (n=2) guttapercha and a silicon-based sealer were used. An endodontic post was inserted in specimens of groups 1 and 3 following the manufacturer's instructions. Specimens were analysed using monochromatic X-rays of 32KeV. A CCD detector with pixel dimension pf 5x5μm2 was used for the acquisition process. Seven hundred and twenty projections were performed over 180o range using a high-resolution rotator. The projections were reconstructed using standard algorithms for tomographic reconstruction. The apical infiltration was evaluated by verifying if black spots were detectable on the images. The specimens of groups 3 and 4 showed a better apical seal than the ones of groups 1 and 2. Post insertion, when a ZOE-based sealer is used, increases the apical gap even if it does not seem to be clinically relevant and sufficient to be a cause of endodontic failure. The new method for analysis appeared to be effective to detect small defects in endodontic obturation, analysing guttapercha-sealer and sealer-dentin interfaces

  1. A genome-wide integrative genomic study localizes genetic factors influencing antibodies against Epstein-Barr virus nuclear antigen 1 (EBNA-1.

    Directory of Open Access Journals (Sweden)

    Rohina Rubicz

    Full Text Available Infection with Epstein-Barr virus (EBV is highly prevalent worldwide, and it has been associated with infectious mononucleosis and severe diseases including Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal lymphoma, and lymphoproliferative disorders. Although EBV has been the focus of extensive research, much still remains unknown concerning what makes some individuals more sensitive to infection and to adverse outcomes as a result of infection. Here we use an integrative genomics approach in order to localize genetic factors influencing levels of Epstein Barr virus (EBV nuclear antigen-1 (EBNA-1 IgG antibodies, as a measure of history of infection with this pathogen, in large Mexican American families. Genome-wide evidence of both significant linkage and association was obtained on chromosome 6 in the human leukocyte antigen (HLA region and replicated in an independent Mexican American sample of large families (minimum p-value in combined analysis of both datasets is 1.4×10(-15 for SNPs rs477515 and rs2516049. Conditional association analyses indicate the presence of at least two separate loci within MHC class II, and along with lymphocyte expression data suggest genes HLA-DRB1 and HLA-DQB1 as the best candidates. The association signals are specific to EBV and are not found with IgG antibodies to 12 other pathogens examined, and therefore do not simply reveal a general HLA effect. We investigated whether SNPs significantly associated with diseases in which EBV is known or suspected to play a role (namely nasopharyngeal lymphoma, Hodgkin lymphoma, systemic lupus erythematosus, and multiple sclerosis also show evidence of associated with EBNA-1 antibody levels, finding an overlap only for the HLA locus, but none elsewhere in the genome. The significance of this work is that a major locus related to EBV infection has been identified, which may ultimately reveal the underlying mechanisms by which the immune system regulates infection with this

  2. Identification and expression of Babesia ovis secreted antigen 1 and evaluation of its diagnostic potential in an enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Sevinc, Ferda; Cao, Shinuo; Xuan, Xuenan; Sevinc, Mutlu; Ceylan, Onur

    2015-05-01

    In order to identify immunoreactive proteins that are usable for the immunological diagnosis of Babesia ovis infections, a phage lambda cDNA expression library was constructed and screened using parasite-specific immune serum. Immunoscreening resulted in the identification of a full-length cDNA clone encoding a secreted protein designated Babesia ovis secreted antigen 1 (BoSA1). The full-length BoSA1 cDNA contained a 1,137-bp open reading frame that encoded a protein of 378 amino acids, with a signal peptide and 2 internal repeat domains. The theoretical molecular mass of the mature protein was 42.5 kDa. Recombinant BoSA1 (rBoSA1) protein was expressed in Escherichia coli strain DH5α cells as a glutathione S-transferase (GST) fusion protein and was purified by affinity chromatography. Purified rBoSA1 was tested for reactivity with sera from animals experimentally or naturally infected with B. ovis, in an indirect enzyme-linked immunosorbent assay (ELISA). The results showed that specific antibodies against rBoSA1 were detectable on days 7 and 8 of the experimental infection and were maintained during the sampling period. Additionally, 38 field sera taken from sheep naturally infected with B. ovis gave strong positive reactions in the ELISA between day 20 and day 30 of treatment. As a result, the identified recombinant BoSA1 protein seems to be a promising diagnostic antigen that is usable for the development of serological assays for the diagnosis of ovine babesiosis. This is the first report on the molecular cloning, expression, and potential use of a recombinant antigen for the diagnosis of ovine babesiosis. PMID:25694531

  3. Structure of the major membrane protein complex from urinary bladder epithelial cells by cryo-electron crystallography

    NARCIS (Netherlands)

    Oostergetel, GT; Keegstra, W; Brisson, A

    2001-01-01

    Numerous protein plaques cover the apical surface of mammalian urinary bladder epithelial cells. These plaques contain four integral membrane proteins, called uroplakins, which form a well-ordered array of hexameric complexes. The 3D structure of these naturally occurring 2D crystals was studied by

  4. Comparison of Milk Fat Globule Membrane (MFGM) Proteins of Chianina and Holstein Cattle Breed Milk Samples Through Proteomics Methods

    OpenAIRE

    Lorraine Pariset; Silvia Bongiorni; Alessio Valentini; Lello Zolla; Leonardo Murgiano; Anna Maria Timperio

    2009-01-01

    Identification of proteins involved in milk production is important to understand the biology of lactation. Many studies have advanced the understanding of mammary function and milk secretion, but the critical molecular mechanisms implicated in milk fat secretion is still incomplete. Milk Fat Globules are secreted from the apical surface of the mammary cells, surrounded by a thin membrane bilayer, the Milk Fat Globule Membrane (MFGM), formed by proteins which have been suggested to be cholest...

  5. Axionic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Aurilia, A. (Dept. of Physics, California State Polytechnic Univ., Pomona, CA (United States)); Spallucci, E. (Dipt. di Fisica Teorica, Univ. Trieste (Italy) INFN, Sezione Trieste (Italy))

    1992-05-21

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramand gauge potential B{sub {mu}{nu}}(x) and the ring by a closed string. The interaction between the B{sub {mu}{nu}} field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the HJ theory of electromagnetic strings. (orig.).

  6. Filtración apical versus filtración coronal

    OpenAIRE

    Tabares Martínez, Pablo

    2016-01-01

    La filtración del conducto radicular es la principal causa de los fracasos en endodoncia (19). Esta recontaminación puede producirse a través de dos vías principales de filtración que son los orificios coronal y apical. En la actualidad hay controversia entre diferentes autores sobre cuál es la vía de filtración más importante, si la apical (9, 167) o la coronal (4, 76). Existen diversas técnicas de obturación y materiales de obturación, entre las que puede elegir el clínico en función de cad...

  7. Inadvertent Apical Extrusion of Sodium Hypochlorite with Evaluation by Dental Volumetric Tomography

    Directory of Open Access Journals (Sweden)

    Elif Delve Başer Can

    2015-01-01

    Full Text Available This case report describes the tissue injury caused by inadvertently extruded NaOCl through the apical constriction. A 56-year-old female patient with complaints of pain, swelling, and ecchymosis on the left side of her face was referred to our clinic. The symptoms had emerged following root canal treatment of the maxillary left first premolar, and a soft tissue complication due to apical extrusion of NaOCl was diagnosed. Antibiotics and analgesics were prescribed. DVT images revealed that the buccal root apex had perforated the maxillary bone. The patient was followed up every other day and became asymptomatic on the 10th day. Endodontic therapy was completed with routine procedures. Determining working length precisely and following irrigation protocols meticulously are indispensable to prevent this type of complication. 3D visualization of the affected area may reveal the cause of the incident.

  8. [Endodontic re-treatment or apical surgery, is an evidence-based choice possible?].

    Science.gov (United States)

    de Lange, J

    2016-02-01

    Treatment of a recurrence after an initial endodontic treatment can consist of endodontic re-treatment or apical surgery. The literature reports comparable success rates for these two options. However, randomised controlled trials that are truly comparable to each other are unavailable as a result of which comparison and an informed choice are not really possible. In addition to the treatment outcome, consideration also has to be given to cost-effectiveness and other patient-related factors, such as pain, swelling and medication. Regarding these considerations, too, little reliable information can be found in the literature. Moreover, factors relating to insurance play an important role in the Netherlands, where only apical surgery is covered by the basic healthcare insurance. In conclusion, all of these factors should be carefully considered before proceeding to an individual treatment strategy. PMID:26878715

  9. Multiple Apical Radiolucencies and External Cervical Resorption Associated with Varicella Zoster Virus: A Case Report.

    Science.gov (United States)

    Patel, Kreena; Schirru, Elia; Niazi, Sadia; Mitchell, Philip; Mannocci, Francesco

    2016-06-01

    Varicella zoster virus (VZV) is responsible for the primary infection chickenpox. After the initial infection, it remains latent but can reactivate, resulting in shingles (herpes zoster). Previous reports have implicated VZV in the pathogenesis of apical periodontitis, but the involvement of the virus has not been investigated fully. The present case describes a patient who suffered from a severe episode of shingles and subsequently developed periapical radiolucencies of all the teeth in the affected nerve distribution. Molecular and culture techniques showed the presence of VZV DNA in the root canal system in the absence of bacteria. This confirms that VZV can cause localized pulp necrosis and apical periodontitis. The lesions healed after endodontic treatment, implying chemomechanical debridement using sodium hypochlorite irrigation and a calcium hydroxide interim dressing may be effective against the virus. PMID:27133503

  10. Apical ballooning with mid-ventricular obstruction: the many faces of Takotsubo cardiomyopathy.

    Science.gov (United States)

    Spadotto, Veronica; Elmaghawry, Mohamed; Zorzi, Alessandro; Migliore, Federico; Marra, Martina Perazzolo

    2013-01-01

    Takotsubo cardiomyopathy (TTC) is a transient left ventricular dysfunction due to akinesia of the left-ventricular (LV) mid-apical segments (apical ballooning), which can cause severe reduction in LV systolic function. The typical clinical picture of TTC include chest pain, electrocardiographic changes consisting of mild ST-segment elevation followed by diffuse deep T-wave inversion, QTc interval prolongation and mild troponin release in the absence of significant coronary stenoses. The syndrome often affects post-menopausal women and is triggered by sympathetic overstimulation, like intense physical or emotional stress, so that it is called the "broken heart syndrome". Although left-ventricular systolic dysfunction usually fully recovers within few days, heart failure can still complicate the early phase. We report a case of stress-induced cardiomyopathy that had full recovery after 4 weeks of follow up. The main electrocardiographic, angiographic and imaging features are discussed. PMID:24689016

  11. Apical microleakage of primary teeth root canal filling materials by clearing technique.

    Science.gov (United States)

    Ayhan, H; Alacam, A; Olmez, A

    1996-01-01

    The purpose of this study was to evaluate apical leakage of primary teeth root canals sealed with four different root canal filling materials by clearing technique. Dye penetration ratios of all groups were measured by light microscopy. The mean dye penetration was determined in the group of ZOE to be 0.57 mm. This ratio was 1.05 mm in the group of ZOE + glutaraldehyde (GA). In the groups of Kri I and Ca(OH)2, dye penetrations were 0.47 mm, 0.56 mm respectively. The highest apical leakage value was evaluated in the glutaraldehyde + ZOE group (p<0.05), whereas, no statistical difference was found between the other groups. PMID:8619969

  12. Genome-wide analyses for dissecting gene regulatory networks in the shoot apical meristem.

    Science.gov (United States)

    Bustamante, Mariana; Matus, José Tomás; Riechmann, José Luis

    2016-04-01

    Shoot apical meristem activity is controlled by complex regulatory networks in which components such as transcription factors, miRNAs, small peptides, hormones, enzymes and epigenetic marks all participate. Many key genes that determine the inherent characteristics of the shoot apical meristem have been identified through genetic approaches. Recent advances in genome-wide studies generating extensive transcriptomic and DNA-binding datasets have increased our understanding of the interactions within the regulatory networks that control the activity of the meristem, identifying new regulators and uncovering connections between previously unlinked network components. In this review, we focus on recent studies that illustrate the contribution of whole genome analyses to understand meristem function. PMID:26956505

  13. Micro‐CT analyses of apical enlargement and molar root canal complexity

    DEFF Research Database (Denmark)

    Markvart, M.; Darvann, Tron Andre; Larsen, P.;

    2012-01-01

    Markvart M, Darvann TA, Larsen P, Dalstra M, Kreiborg S, Bjørndal L. Micro‐CT analyses of apical enlargement and molar root canal complexity. International Endodontic Journal, 45, 273–281, 2012. Aim To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical...... enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity. Methodology Maxillary and mandibular molar teeth were scanned using X‐ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a Ra......Ce/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size...

  14. Identifying Patient-Specific Epstein-Barr Nuclear Antigen-1 Genetic Variation and Potential Autoreactive Targets Relevant to Multiple Sclerosis Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Monika Tschochner

    Full Text Available Epstein-Barr virus (EBV infection represents a major environmental risk factor for multiple sclerosis (MS, with evidence of selective expansion of Epstein-Barr Nuclear Antigen-1 (EBNA1-specific CD4+ T cells that cross-recognize MS-associated myelin antigens in MS patients. HLA-DRB1*15-restricted antigen presentation also appears to determine susceptibility given its role as a dominant risk allele. In this study, we have utilised standard and next-generation sequencing techniques to investigate EBNA-1 sequence variation and its relationship to HLA-DR15 binding affinity, as well as examining potential cross-reactive immune targets within the central nervous system proteome.Sanger sequencing was performed on DNA isolated from peripheral blood samples from 73 Western Australian MS cases, without requirement for primary culture, with additional FLX 454 Roche sequencing in 23 samples to identify low-frequency variants. Patient-derived viral sequences were used to predict HLA-DRB1*1501 epitopes (NetMHCII, NetMHCIIpan and candidates were evaluated for cross recognition with human brain proteins.EBNA-1 sequence variation was limited, with no evidence of multiple viral strains and only low levels of variation identified by FLX technology (8.3% nucleotide positions at a 1% cut-off. In silico epitope mapping revealed two known HLA-DRB1*1501-restricted epitopes ('AEG': aa 481-496 and 'MVF': aa 562-577, and two putative epitopes between positions 502-543. We identified potential cross-reactive targets involving a number of major myelin antigens including experimentally confirmed HLA-DRB1*15-restricted epitopes as well as novel candidate antigens within myelin and paranodal assembly proteins that may be relevant to MS pathogenesis.This study demonstrates the feasibility of obtaining autologous EBNA-1 sequences directly from buffy coat samples, and confirms divergence of these sequences from standard laboratory strains. This approach has identified a number of

  15. Comparison of apical debris extrusion of two rotary systems and one reciprocating system

    Directory of Open Access Journals (Sweden)

    Paramasivam Vivekanandhan

    2016-01-01

    Full Text Available Background: Postoperative inflammation and endodontic failure occur due to apical extrusion of debris. Aim: To evaluate the amount of apically extruded debris after preparation of straight root canals in extracted human teeth using three rotary systems. Materials and Methods: Sixty single-rooted human teeth with single root canal and apical foramen were selected and randomly divided into three experimental groups (n = 20 according to the rotary system used: Group 1 - ProTaper, Group 2 - Revo-S, Group 3 - WaveOne. Apical enlargement was done up to size 40/0.06 for Groups 1 and 2 and 40/0.08 for Group 3. For debris collection, each tooth was held in a preweighed Eppendorf tube fixed inside a glass vial through rubber plug. After instrumentation, each tooth was separated from the Eppendorf tube and the debris adhering to the root surface was collected by washing the root with 1 mL of bi-distilled water and incubated at 70°C for 5 days. The dry weight of extruded debris was weighed in an electronic balance. Statistical Analysis: The mean weights of extruded debris were statistically analyzed using GraphPad prism version 6 and the intergroup comparison was done using unpaired t-test. Results: There was a statistically significant difference in the mean debris score among all the three groups - ProTaper (0.00065 g, Revo-S (0.00045 g and WaveOne (0.00089 g. Conclusion: Revo-S system was associated with significantly less debris extrusion compared with ProTaper or WaveOne.

  16. Mechanisms of lysophosphatidic acid (LPA) mediated stimulation of intestinal apical Cl−/OH− exchange

    OpenAIRE

    Singla, Amika; Dwivedi, Alka; Saksena, Seema; Gill, Ravinder K.; Alrefai, Waddah A.; RAMASWAMY, KRISHNAMURTHY; Dudeja, Pradeep K.

    2009-01-01

    Lysophosphatidic acid (LPA), a potent bioactive phospholipid, is a natural component of food products like soy and egg yolk. LPA modulates a number of epithelial functions and has been shown to inhibit cholera toxin-induced diarrhea. Antidiarrheal effects of LPA are known to be mediated by inhibiting chloride secretion. However, the effects of LPA on chloride absorption in the mammalian intestine are not known. The present studies examined the effects of LPA on apical Cl−/OH− exchangers known...

  17. Apical Oxygen Anharmonicity Induced Spontaneous Polarization in YBa2Cu3O7

    International Nuclear Information System (INIS)

    A model suggesting an asymmetric double-well form for the effective vibrational potential for the apical oxygen atoms in YBa2Cu3O7 is formulated in the pseudo-spin representation and its phase diagram is studied. A set of parameters is found for which a spontaneous polarization may occur at a temperature close to the superconducting Tc, implying the possibility of formation of a ferroelectric state in the temperature region 90degK-250degK. (author)

  18. An investigation on the effects of resection angle on apical sea!

    Directory of Open Access Journals (Sweden)

    Razmi H

    2003-08-01

    Full Text Available Statement of Problem: The goal of a successful endodontic surgery is to establish an adequate seal in apical region. Therefore during surgery, root-end resection is essential for an appropriate situation and proper access."nPurpose: The aim of this study was to determine the most appropriate root-end resection angle to establish adequate apical seal in periapical surgery,"nMaterials and Methods: Forty-five intact extracted human maxillary central incisors were randomly divided into three 15-tooth groups. The root canals were instrumented and then obturated using lateral condensation technique. AM roots were resected at 3mm from apical portion. Angles of root resection for each group were 0, 30 and 45 degrees. Then all teeth surfaces, except the cut ones, were covered with nail polish and immersed in methylen blue for 7 days. After 7 days, nail polish was removed from the surfaces and samples were split in buccolingual direction. Then, dye penetration (mm was measured using a stereozoom microscope (Loupe [X4 magnification] and eye lens. In order to analyze the data, unilateral variance analysis was used."nResults: The values of dye penetration were: 7.23±3.34 (0°, 8.46±3.01(30° and 9.74±4.11 (45°. There"nwas no significant difference between three groups (P>0.05. Conclusion: It is suggested that the angle of root-end resection put a limited effect on apical seal if retrograde cavity depth is increased.

  19. 24 hour ST segment analysis in transient left ventricular apical ballooning.

    Directory of Open Access Journals (Sweden)

    Frank Bode

    Full Text Available OBJECTIVE: The etiologic basis of transient left ventricular apical ballooning, a novel cardiac syndrome, is not clear. Among the proposed pathomechanisms is coronary vasospasm. Long-term ST segment analysis may detect vasospastic episodes but has not been reported. METHODS: 30 consecutive patients with transient left ventricular apical ballooning, left ventricular dysfunction and normal or near-normal coronary arteries were investigated. A 24-hour Holter ECG was obtained after emergency admission. ST segment analysis was performed automatically in 2 leads and confirmed by visual inspection. Criteria for an ischemic event were: 1. ST elevation or 2. horizontal or down-sloping ST segments ≥1 min duration and ≥100 µV J+80 point deviation corrected for baseline ST-deviation. RESULTS: Patients presented with ST segment elevation (n = 19 and/or T wave inversion (n = 20 on admission ECG. Ejection fraction was 50±12%. No transient ST elevations were observed during Holter ECG analysis. In 3 patients, 8 transient episodes of ST depression were recorded. Durations of episodes varied between 75 s and 790 s (mean 229 s. Maximal ST deviation averaged -191±71 µV. Ischemic burden was -1 to -22 mVs (mean -8 mVs. 27 patients showed no ischemic events. CONCLUSIONS: ST segment analysis of 24 h Holter recordings revealed minor ischemic events in only 10% of patients with transient left ventricular apical ballooning. Overall, ST segment changes were not indicative of recurrent coronary spasm playing a major role in the genesis of transient left ventricular apical ballooning.

  20. Prevalence of apical periodontitis and endodontic treatment in a Kosovar adult population

    OpenAIRE

    Kamberi Blerim; Hoxha Veton; Stavileci Miranda; Dragusha Edmond; Kuçi Astrit; Kqiku Lumnije

    2011-01-01

    Abstract Background Despite numerous studies on the prevalence of apical periodontitis (AP) and endodontic treatment in diverse geographical populations, there are currently no data on the prevalence of these conditions in populations of adults native to Kosovo. Therefore, little is known about how widespread these conditions are, and whether there is any correlation between root canal treatment and AP. The purpose of our research was to address this anomaly by investigating AP and endodontic...

  1. Uptake and Distribution of Aluminum in Root Apices of Two Rice Varieties under Aluminum Stress

    Directory of Open Access Journals (Sweden)

    MIFTAHUDIN

    2007-09-01

    Full Text Available Aluminum (Al toxicity is the major limiting factor of plant growth and production in acid soils. The target of Al toxicity is the root tip, which affects mainly on root growth inhibition. The aim of this research was to study the uptake and distribution of Al in root apices of two rice varieties IR64 (Al-sensitive and Krowal (Al-tolerant, which were grown on nutrient solution containing 0, 15, 30, 45, and 60 ppm of Al. The root growth was significantly inhibited in both rice varieties at as low as 15 ppm Al concentration. The adventive roots of both varieties showed stunted growth in respons to Al stress. There was no difference in root growth inhibition between both rice varieties as well as among Al concentrations. Al uptake on root apices was qualitatively and quantitatively analyzed. Histochemical staining of roots using hematoxylin showed dark purple color on 1 mm region of Al-treated root apices. Rice var. IR 64 tended to take up more Al in root tip than Krowal did. However, there was no statistically significant difference (p = 0.176 in root Al content of both varieties in response to different concentration and period of Al treatments. Al distribution in root apices was found in the epidermal and subepidermal region in both rice varieties. Based on those results, rice var. Krowal that was previously grouped as Al-tolerant variety has similar root growth and physiological response to Al stress as compared to Al-sensitive variety IR64.

  2. A new approach to supply chain management based on pooling ITIL and APICS Principles and Practices

    Directory of Open Access Journals (Sweden)

    Abdelaali Himi

    2011-07-01

    Full Text Available APICS (Advanced Productivity, Innovation and Competitive Success - The Association for Operations Management is known as the repository providing a set of best practices in Supply Chain Management. The ITIL (Information Technology Infrastructure Library also provides best practices for IT service management. Noting the existence of a similarity between these two standards, this paper identifies the ITIL concepts used in the supply chain context and describe their contributions.

  3. The shoot apical meristem of oil palm (Elaeis guineensis; Arecaceae): developmental progression and dynamics

    OpenAIRE

    Jouannic, Stefan; Lartaud, Marc; Hervé, Jonathan; Collin, Myriam; Orieux, Yves; Verdeil, Jean-Luc; Tregear, James W

    2011-01-01

    Background and Aims Oil palm, an unbranched perennial monocotyledon, possesses a single shoot apical meristem (SAM), which is responsible for the initiation of the entire above-ground structure of the plant. To compare the palm SAM structure with those of other monocots and to study variations in its structure throughout the life of the plant, its organization was characterized from the embryonic stage to that of the reproductive plant. Methods SAM structure was studied by a combination of st...

  4. [Apical root pins of high-karat gold alloys for resected roots].

    Science.gov (United States)

    Handtmann, S; Lindemann, W; Sculte, W

    1989-02-01

    Following earlier studies on corrosion of silver pins in the root canal experience will be presented with the use of high-karat gold pins for apical closure of root amputations. The commercially available standardized Ackermann silver pins were replaced by high-karat gold pins of similar Vicker hardness and inserted in 218 patients with 264 root amputations since 1986. A clinical and radiological follow-up demonstrated a success rate of over 90%. PMID:2598876

  5. Mostre virtuali per il Centro Apice – Una proposta culturale e didattica

    OpenAIRE

    Francesco Tissoni

    2012-01-01

    Intendo presentare in questa sede i primi risultati di un progetto avviato nell’anno accademico 2008-2009 presso l’Università degli Studi di Milano, consistente nella realizzazione, nella forma di tesi di laurea magistrali, di una serie di mostre virtuali dedicate ad alcuni fondi archivistico-librari custoditi presso il Centro Apice – Archivi della Parola, dell’Immagine e della Comunicazione editoriale.

  6. Mostre virtuali per il Centro Apice – Una proposta culturale e didattica

    Directory of Open Access Journals (Sweden)

    Francesco Tissoni

    2012-11-01

    Full Text Available Intendo presentare in questa sede i primi risultati di un progetto avviato nell’anno accademico 2008-2009 presso l’Università degli Studi di Milano, consistente nella realizzazione, nella forma di tesi di laurea magistrali, di una serie di mostre virtuali dedicate ad alcuni fondi archivistico-librari custoditi presso il Centro Apice – Archivi della Parola, dell’Immagine e della Comunicazione editoriale.

  7. Evaluation of the anatomical alterations of lower molars mesial root?s apical third

    Directory of Open Access Journals (Sweden)

    FRÖNER Izabel Cristina

    1999-01-01

    Full Text Available The anatomical apex of the mesial root of the lower molars presents a morphological complexity related to the number and shape of the root canals as well as of the apical foramen and isthmus presence. The knowledge of the complexity of the endodontic system of the molar root area is essencial to select more carefully the best instrumentation and obturation technique, to obtain a more successful endodontic therapy.

  8. Pseudo-acute myocardial infarction due to transient apical ventricular dysfunction syndrome (Takotsubo syndrome)

    OpenAIRE

    Maciel, Bruno Araújo; Cidrão, Alan Alves de Lima; Sousa, Ítalo Bruno dos Santos; Ferreira, José Adailson da Silva; Messias Neto, Valdevino Pedro

    2013-01-01

    Takotsubo syndrome is characterized by predominantly medial-apical transient left ventricular dysfunction, which is typically triggered by physical or emotional stress. The present article reports the case of a 61-year-old female patient presenting with dizziness, excessive sweating, and sudden state of ill feeling following an episode involving intense emotional stress. The physical examination and electrocardiogram were normal upon admission, but the troponin I and creatine kinase-MB concen...

  9. Length and activity of the root apical meristem revealed in vivo by infrared imaging

    OpenAIRE

    Bizet, François; Hummel, Iréne; Bogeat-Triboulot, Marie-Béatrice

    2014-01-01

    Understanding how cell division and cell elongation influence organ growth and development is a long-standing issue in plant biology. In plant roots, most of the cell divisions occur in a short and specialized region, the root apical meristem (RAM). Although RAM activity has been suggested to be of high importance to understand how roots grow and how the cell cycle is regulated, few experimental and numeric data are currently available. The characterization of the RAM is difficult and essenti...

  10. Effect of methods of evaluation on sealing ability of mineral trioxide aggregate apical plug

    OpenAIRE

    Nikhil, Vineeta; Jha, Padmanabh; Suri, Navleen Kaur

    2016-01-01

    Aim: The purpose of the study was to evaluate and compare the sealing ability of mineral trioxide aggregate (MTA) with three different methods. Materials and Methods: Forty single canal teeth were decoronated, and root canals were enlarged to simulate immature apex. The samples were randomly divided into Group MD = MTA-angelus mixed with distilled water and Group MC = MTA-angelus mixed with 2% chlorhexidine, and apical seal was recorded with glucose penetration method, fluid filtration method...

  11. The effect of irrigation solutions on the apical sealing ability in different root canal sealers

    Directory of Open Access Journals (Sweden)

    Emre Bodrumlu

    2010-06-01

    Full Text Available The aim of this study was to assess the effect of three root canal irrigation solutions on the apical sealing ability of three root canal obturation materials: gutta-percha/AH plus or MM-seal and Resilon/Epiphany SE. A total of 100 teeth with single straight root canals were randomly divided into three equal groups of 30 samples each, with the other 10 teeth (5 positive and 5 negative used as controls. Each irrigation group was divided into three groups according to the use of three different root canal obturation materials (n = 10: Gutta-percha with AH plus or MM-seal, Resilon with Epiphany SE. The crowns were removed at the cementoenamel junction with a diamond disc under water coolant. The root canals were prepared using step-back technique and irrigation with either sodium hypochlorite (2.5%, chlorhexidine (2%, or MTAD solutions. The roots were obturated with lateral condensation technique using one of the obturation materials. The root surfaces was coated with two layer nail varnish (except apex, placed in 2% methylene blue dye solution, and centrifuged at 3,000 rpm for 5 minutes. Irrigation solutions affected the apical sealing ability of all the sealers. The chlorhexidine irrigation solution exhibited higher apical leakage values than did MTAD and NaOCl in all canal sealers, although the MTAD irrigation solution groups showed the least leakage values. The apical sealing ability of AH plus, Epiphany SE and MM-seal root canal sealers decreased when the chlorhexidine was used as an irrigation solution.

  12. Apical groove type and molecular phylogeny suggests reclassification of Cochlodinium geminatum as Polykrikos geminatum.

    Directory of Open Access Journals (Sweden)

    Dajun Qiu

    Full Text Available Traditionally Cocholodinium and Gymnodinium sensu lato clade are distinguished based on the cingulum turn number, which has been increasingly recognized to be inadequate for Gymnodiniales genus classification. This has been improved by the combination of the apical groove characteristics and molecular phylogeny, which has led to the erection of several new genera (Takayama, Akashiwo, Karenia, and Karlodinium. Taking the apical groove characteristics and molecular phylogeny combined approach, we reexamined the historically taxonomically uncertain species Cochlodinium geminatum that formed massive blooms in Pearl River Estuary, China, in recent years. Samples were collected from a bloom in 2011 for morphological, characteristic pigment, and molecular analyses. We found that the cingulum in this species wraps around the cell body about 1.2 turns on average but can appear under the light microscopy to be >1.5 turns after the cells have been preserved. The shape of its apical groove, however, was stably an open-ended anticlockwise loop of kidney bean shape, similar to that of Polykrikos. Furthermore, the molecular phylogenetic analysis using 18S rRNA-ITS-28S rRNA gene cistron we obtained in this study also consistently placed this species closest to Polykrikos within the Gymnodinium sensu stricto clade and set it far separated from the clade of Cochlodinium. These results suggest that this species should be transferred to Polykrikos as Polykrikos geminatum. Our results reiterate the need to use the combination of apical groove morphology and molecular phylogeny for the classification of species within the genus of Cochlodinium and other Gymnodiniales lineages.

  13. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis

    OpenAIRE

    Guo, Hongyan; Zhang, Wei; Tian, Hainan; Zheng, Kaijie; Dai, Xuemei; Liu, Shanda; Hu, Qingnan; Wang, Xianling; Liu, Bao; Wang, Shucai

    2015-01-01

    Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance, and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa) CL...

  14. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis

    OpenAIRE

    Hongyan eGuo; Wei eZhang; Hainan eTian; Kaijie eZheng; Xuemei eDai; Shanda eLiu; Qingnan eHu; Xianling eWang; Bao eLiu; Shucai eWang

    2015-01-01

    Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa) CLE...

  15. Sealing ability of grar MTA AngelusTM, CPM TM and MBPc used as apical plugs.

    Science.gov (United States)

    Orosco, Fernando Accorsi; Bramante, Clovis Monteiro; Garcia, Roberto Brandão; Bernadineli, Norberti; Moraes, Ivaldo Gomes de

    2008-01-01

    This study evaluated the sealing ability of apical plugs fabricated with gray MTA Angelus sealer, CPM TM sealer and MBPc sealer. The root canals of 98 extracted single-rooted human teeth were instrumented with #5 to #1 Gates Glidden drills according to the crown-down technique until the #1 drill could pass through the apical foramen. The specimens were then prepared with K-files, starting with an ISO 50 until an ISO 90 could be visualized 1 mm beyond the apex. After root canal preparation, the external surface of each root was rendered impermeable and roots were assigned to 3 experimental groups (n = 30), which received a 5-mm thick apical plug of gray MTA Angelus, CPM and MBPc, and two control groups (n=4). The remaining portion of the canal in the experimental groups was filled by the lateral condensation technique. The teeth of each group, properly identified, were fixed on utility wax by their crowns and were placed in plastic flasks, leaving the apex free and facing upward. The flasks were filled with 0.2% Rhodamine B solution, pH 7.0, so as to completely cover the root apex of all teeth. The sealing ability was analyzed by measuring 0.2% Rhodamine B leakage after all groups had been maintained in this solution for 48 hours. Data were analyzed statistically by Kruskal-Wallis test and Dunn test with a=5%. The results showed that, among the tested materials used for fabrication of apical plugs, MBPc sealer had the least amount of leakage with statistically significant difference (p<0.05). PMID:19089289

  16. Sealing ability of grar MTA AngelusTM, CPM TM and MBPc used as apical plugs

    Directory of Open Access Journals (Sweden)

    Fernando Accorsi Orosco

    2008-02-01

    Full Text Available This study evaluated the sealing ability of apical plugs fabricated with gray MTA AngelusTM sealer, CPM TM sealer and MBPc sealer. The root canals of 98 extracted single-rooted human teeth were instrumented with #5 to #1 Gates Glidden drills according to the crown-down technique until the #1 drill could pass through the apical foramen. The specimens were then prepared with K-files, starting with an ISO 50 until an ISO 90 could be visualized 1 mm beyond the apex. After root canal preparation, the external surface of each root was rendered impermeable and roots were assigned to 3 experimental groups (n = 30, which received a 5-mm thick apical plug of gray MTA AngelusTM, CPM TM and MBPc, and two control groups (n=4. The remaining portion of the canal in the experimental groups was filled by the lateral condensation technique. The teeth of each group, properly identified, were fixed on utility wax by their crowns and were placed in plastic flasks, leaving the apex free and facing upward. The flasks were filled with 0.2% Rhodamine B solution, pH 7.0, so as to completely cover the root apex of all teeth. The sealing ability was analyzed by measuring 0.2% Rhodamine B leakage after all groups had been maintained in this solution for 48 hours. Data were analyzed statistically by Kruskal-Wallis test and Dunn test with a=5%. The results showed that, among the tested materials used for fabrication of apical plugs, MBPc sealer had the least amount of leakage with statistically significant difference (p<0.05.

  17. Argonautes compete for miR165/166 to regulate shoot apical meristem development

    OpenAIRE

    Zhang, Zhonghui; Zhang, Xiuren

    2012-01-01

    Plant stem cells in the shoot apical meristem (SAM) possess the unique abilities of both self-renewal for SAM maintenance and providing undifferentiated daughter cells for initiation and subsequent development of aerial organs. The coordination between stem cell renewal and cell differentiation during organogenesis is regulated by elaborate genetic pathways involving numerous transcription factors and other molecules. In the past decade, microRNAs (miRNAs) have emerged as pivotal regulators i...

  18. Genetic control of morphometric diversity in the maize shoot apical meristem

    OpenAIRE

    Leiboff, Samuel; Li, Xianran; Hu, Heng-Cheng; Todt, Natalie; YANG, JINLIANG; Li, Xiao; Yu, Xiaoqing; Muehlbauer, Gary J.; Timmermans, Marja C. P.; Yu, Jianming; Schnable, Patrick S.; Scanlon, Michael J

    2015-01-01

    The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult trai...

  19. The ERECTA receptor kinase regulates Arabidopsis shoot apical meristem size, phyllotaxy and floral meristem identity

    OpenAIRE

    Mandel, Tali; Moreau, Fanny; Kutsher, Yaarit; Fletcher, Jennifer C; Carles, Cristel C.; Williams, Leor Eshed

    2014-01-01

    In plants, the shoot apical meristem (SAM) serves as a reservoir of pluripotent stem cells from which all above ground organs originate. To sustain proper growth, the SAM must maintain homeostasis between the self-renewal of pluripotent stem cells and cell recruitment for lateral organ formation. At the core of the network that regulates this homeostasis in Arabidopsis are the WUSCHEL (WUS) transcription factor specifying stem cell fate and the CLAVATA (CLV) ligand-receptor system limiting WU...

  20. Comparison of Domain Nucleation Mechanisms in a Minimal Model of Shoot Apical Meristem

    OpenAIRE

    Battogtokh, Dorjsuren; Tyson, John J.

    2016-01-01

    Existing mathematical models of the shoot apical meristem (SAM) explain nucleation and confinement of a stem cell domain by Turing's mechanism, assuming that the diffusion coefficients of the activator (WUSCHEL) and inhibitor (CLAVATA) are significantly different. As there is no evidence for this assumption of differential diffusivity, we recently proposed a new mechanism based on a bistable switch model of the SAM. Here we study the bistable-switch mechanism in detail, demonstrating that it ...

  1. Function and regulation of transcription factors involved in root apical meristem and stem cell maintenance

    OpenAIRE

    Drisch, Rebecca C.; Stahl, Yvonne

    2015-01-01

    Plant roots are essential for overall plant development, growth, and performance by providing anchorage in the soil and uptake of nutrients and water. The primary root of higher plants derives from a group of pluripotent, mitotically active stem cells residing in the root apical meristem (RAM) which provides the basis for growth, development, and regeneration of the root. The stem cells in the Arabidopsis thaliana RAM are surrounding the quiescent center (QC), which consists of a group of rar...

  2. Sample preparation for laser-microdissection of soybean shoot apical meristem

    OpenAIRE

    Wong, Chui E; Mohan B. Singh; Bhalla, Prem L

    2012-01-01

    The shoot apical meristem houses stem cells responsible for the continuous formation of aerial plant organs including leaves and stems throughout the life of plants. Laser-microdissection in combination with high-throughput technology such as next generation sequencing permits an in-depth analysis of molecular events associated with specific cell type of interest. Sample preparation is the most critical step in ensuring good quality RNA to be extracted from samples following laser-microdissec...

  3. Dichotomous branching: the plant form and integrity upon the apical meristem bifurcation

    OpenAIRE

    Gola, Edyta M

    2014-01-01

    The division of the apical meristem into two independently functioning axes is defined as dichotomous branching. This type of branching typically occurs in non-vascular and non-seed vascular plants, whereas in seed plants it presents a primary growth form only in several taxa. Dichotomy is a complex process, which requires a re-organization of the meristem structure and causes changes in the apex geometry and activity. However, the mechanisms governing the repetitive apex divisions are hardly...

  4. The Shoot Apical Meristem Regulatory Peptide CLV3 Does Not Activate Innate Immunity

    OpenAIRE

    Segonzac, Cécile; Nimchuk, Zachary L.; Beck, Martina; Tarr, Paul T.; Robatzek, Silke; Meyerowitz, Elliot M.; Zipfel, Cyril

    2012-01-01

    The Arabidopsis thaliana leucine-rich repeat receptor kinase FLAGELLIN SENSING2 (FLS2) is required for the recognition of bacterial flagellin in innate immunity. Recently, FLS2 was proposed to act as a multispecific receptor recognizing unrelated exogenous and endogenous peptide ligands, including CLAVATA3 (CLV3), a key regulator of shoot meristem stem cell production. Here, we report experimental evidence demonstrating that FLS2 does not recognize CLV3 and that the shoot apical meristem is i...

  5. Diversity of Maize Shoot Apical Meristem Architecture and Its Relationship to Plant Morphology

    OpenAIRE

    Thompson, Addie M.; Yu, Jianming; Timmermans, Marja C. P.; Schnable, Patrick; Crants, James C.; Scanlon, Michael J; Muehlbauer, Gary J.

    2015-01-01

    The shoot apical meristem contains a pool of undifferentiated stem cells and controls initiation of all aerial plant organs. In maize (Zea mays), leaves are formed throughout vegetative development; on transition to floral development, the shoot meristem forms the tassel. Due to the regulated balance between stem cell maintenance and organogenesis, the structure and morphology of the shoot meristem are constrained during vegetative development. Previous work identified loci controlling merist...

  6. Assessment of apically extruded debris and irrigant produced by different nickel-titanium instrument systems

    Directory of Open Access Journals (Sweden)

    Ebru KÜÇÜKYILMAZ

    2015-01-01

    Full Text Available The aim of this study was to evaluate the preparation time and the amounts of apically extruded debris and irrigant using different nickel-titanium instrumentation systems. Forty-five extracted single-rooted mandibular premolar teeth were selected and divided into three groups. The root canals were instrumented according to the manufacturers’ instructions, using a reciprocating single-file system, a single-file rotary system and a multiple-file rotary system. Bidistilled water was used as the irrigant solution. The apically extruded debris and irrigant were collected into preweighed Eppendorf tubes. The amounts of extruded debris and irrigant were assessed with a precision micro-balance. The Eppendorf tubes were incubated at 37°C for 15 days. After the incubation period, they were weighed again to assess the debris extrusion. The time required to prepare the canals was also recorded. The results were statistically analyzed using MANOVA and Bonferroni’s adjustment. Considering the apically extruded debris and irrigant, there were no statistically significant differences among the groups (p > 0.05. The Reciproc group produced the highest debris (0.000632 ± 0.000162 gr and irrigant (0.844587 ± 0.437814 ml extrusion values. While the least extruded debris was observed with OneShape (0,000431 ± 0,000171 gr, the least extruded irrigant was observed with ProTaper system (0.564147 ± 0.370596 ml. Instrumentation was faster using the Reciproc than the other two instruments (70.27 ± 13.38 s (p < 0.05. All of the instrumentation systems used in this study produced apical debris and irrigant extrusion. The reciprocating single-file system tended to produce more debris and irrigant extrusion, compared with the rotary systems. Considering the preparation time, the single-file systems appeared to be advantageous due to their working time.

  7. Comparison of apical debris extrusion of two rotary systems and one reciprocating system

    Science.gov (United States)

    Vivekanandhan, Paramasivam; Subbiya, Arunajatesan; Mitthra, Suresh; Karthick, Arumugam

    2016-01-01

    Background: Postoperative inflammation and endodontic failure occur due to apical extrusion of debris. Aim: To evaluate the amount of apically extruded debris after preparation of straight root canals in extracted human teeth using three rotary systems. Materials and Methods: Sixty single-rooted human teeth with single root canal and apical foramen were selected and randomly divided into three experimental groups (n = 20) according to the rotary system used: Group 1 - ProTaper, Group 2 - Revo-S, Group 3 - WaveOne. Apical enlargement was done up to size 40/0.06 for Groups 1 and 2 and 40/0.08 for Group 3. For debris collection, each tooth was held in a preweighed Eppendorf tube fixed inside a glass vial through rubber plug. After instrumentation, each tooth was separated from the Eppendorf tube and the debris adhering to the root surface was collected by washing the root with 1 mL of bi-distilled water and incubated at 70°C for 5 days. The dry weight of extruded debris was weighed in an electronic balance. Statistical Analysis: The mean weights of extruded debris were statistically analyzed using GraphPad prism version 6 and the intergroup comparison was done using unpaired t-test. Results: There was a statistically significant difference in the mean debris score among all the three groups - ProTaper (0.00065 g), Revo-S (0.00045 g) and WaveOne (0.00089 g). Conclusion: Revo-S system was associated with significantly less debris extrusion compared with ProTaper or WaveOne. PMID:27217638

  8. Comparative evaluation of apical extrusion of bacteria using hand and rotary systems : An in vitro study

    OpenAIRE

    Ghivari, Sheetal B; Kubasad, Girish C; Preethi Deshpande

    2012-01-01

    Aim: To evaluate the bacteria extruded apically during root canal preparation using two hand and rotary instrumentation techniques. Materials and Methods: Eighty freshly extracted mandibular premolars were mounted in bacteria collection apparatus. Root canals were contaminated with the pure culture of Enterococcus fecalis (ATCC 29212) and dried at 37°C for 24 h. Bacteria extruded were collected, incubated in brain heart infusion agar for 24 h at 36°C and the colony forming units (CFU) wer...

  9. Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion

    Science.gov (United States)

    Nevares, Giselle; Xavier, Felipe; Gominho, Luciana; Cavalcanti, Flávia; Cassimiro, Marcely; Romeiro, Kaline; Alvares, Pamella; Queiroz, Gabriela; Sobral, Ana Paula; Gerbi, Marleny; Silveira, Marcia; Albuquerque, Diana

    2015-01-01

    This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n = 20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer's instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α = 5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p < 0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p < 0.001). Cross section and motion influenced the results, despite tip standardization. PMID:26543896

  10. In vitro analysis of the apical deformation, using a different number of files during the instrumentation

    Directory of Open Access Journals (Sweden)

    Lucas da Fonseca Roberti GARCIA

    2009-12-01

    Full Text Available Introduction and objective: The aim of the present study was toevaluate in vitro the apical deformation in roots of crooked lowerincisors with mesio-distal flattening, using a different number of files during the instrumentation. Material and methods: Twenty rootswere randomly divided into two groups (n = 10. Group I: roots wereinitially instrumented with a K #15 file until a #35 file, through stepback technique. During instrumentation, the canals were irrigated with 1 mL of 1% NaOCl between every instrument change. Obturation wasperformed with Grossman sealer by lateral condensation technique.Group II: procedure was similar to group I, except for the files number, using file #40 as memory instrument. After that, each root was 1mm apical weared in order to reveal the filling. A 3 mm cut from the root apex was performed, resulting in samples with the same length, which were examined with an optical microscope (X40. The images captured by the Image Tool software were analyzed and the area occupied by sealer, gutta-percha and possible empty spaces was quantified. Results: Data was submitted to statistical analysis and showed no statistical significant differences between groups I and II (p > 0.05. Conclusion: The variation in the number of files during instrumentation did not promote apical deformation, but resulted in a similar hermetic sealing between the studied groups.

  11. Integrins Regulate Apical Constriction via Microtubule Stabilization in the Drosophila Eye Disc Epithelium

    Directory of Open Access Journals (Sweden)

    Vilaiwan M. Fernandes

    2014-12-01

    Full Text Available During morphogenesis, extracellular signals trigger actomyosin contractility in subpopulations of cells to coordinate changes in cell shape. To illuminate the link between signaling-mediated tissue patterning and cytoskeletal remodeling, we study the progression of the morphogenetic furrow (MF, the wave of apical constriction that traverses the Drosophila eye imaginal disc preceding photoreceptor neurogenesis. Apical constriction depends on actomyosin contractility downstream of the Hedgehog (Hh and bone morphogenetic protein (BMP pathways. We identify a role for integrin adhesion receptors in MF progression. We show that Hh and BMP regulate integrin expression, the loss of which disrupts apical constriction and slows furrow progression; conversely, elevated integrins accelerate furrow progression. We present evidence that integrins regulate MF progression by promoting microtubule stabilization, since reducing microtubule stability rescues integrin-mediated furrow acceleration. Thus, integrins act as a genetic link between tissue-level signaling events and morphological change at the cellular level, leading to morphogenesis and neurogenesis in the eye.

  12. Heterogeneity of myocardial fluoro-18 2-deoxyglucose uptake in patients with apical hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    We have shown that myocardial glucose metabolism is heterogeneous in patients with hypertrophic cardiomyopathy. It is not known, however, whether glucose metabolism is impaired in patients with apical hypertrophic cardiomyopathy, which is fairly common in Japan. We studied 7 patients with apical hypertrophic cardiomyopathy and 5 normal subjects using fluoro-18 2-deoxyglucose (FDG) and positron emission tomography (PET). We calculated regional FDG fractional uptake and the inter-regional coefficient of variation (CV) of FDG fractional uptake in the interventricular septal, anteroapical, and posterolateral regions. The regional FDG fractional uptake was similar in the 2 groups and among the 3 different segments within each group. However, the inter-regional CV of FDG fractional uptake was increased in the anteroapical wall segment of the patient group compared with the control group and also with the other 2 regions in the patient group. The results did not differ when we studied another 5 patients and 6 normal control subjects with a PET scanner with higher spatial resolution. These data suggest that myocardial glucose metabolism may be impaired in the anteroapical wall segment of patients with apical hypertrophic cardiomyopathy. (author)

  13. Master apical file size - smaller or larger: a systematic review of microbial reduction.

    Science.gov (United States)

    Aminoshariae, A; Kulild, J

    2015-11-01

    The purpose of this systematic review was to determine, in patients undergoing root canal treatment, whether apical enlargement of canals affected microbial reduction. A PICO (population, intervention, comparison and outcome) strategy was developed to identify previously published studies dealing with apical size of canal and microbial reduction. The MEDLINE, Embase, Cochrane and PubMed databases were searched. Additionally, the bibliographies of all relevant articles and textbooks were manually searched. Based on inclusion and exclusion criteria, two reviewers independently selected the relevant articles. Due to the variety of methodologies and different techniques used to measure outcome for master apical file enlargement, it was not possible to standardize the research data and to apply a meta-analysis. Seven articles were identified that met the inclusion criteria. Five of the seven articles generally concluded that canal enlargement reduced bioburden in the root canal system. Two articles reported no difference in canals enlarged to size 25 or 40. The results of the systematic review confirmed that more evidence-based research in this area is needed. With the limited information currently available, the best current available clinical evidence suggests that contemporary chemomechanical debridement techniques with canal enlargement techniques do not eliminate bacteria during root canal treatment at any size. PMID:25387434

  14. Diagnosis and planning in apical surgery: use of cone-beam tomography

    Directory of Open Access Journals (Sweden)

    Regina Karla de Pontes Lima

    2010-10-01

    Full Text Available Introduction and objective: The ability to tridimensionally evaluate pathological and anatomical areas, in apical surgery planning, presents a number of advantages. Cone beam computed tomography (CBCT was developed for dental applications. This paper aims to present a literature review on CBCT, highlighting its advantages over both conventional computed tomography (CT and radiography. Moreover, its clinical applications in apical surgery are discussed. Literature review and conclusion: Unlikely CT, CBCT captures a volume of data in a single 360° rotation, providing benefits such as higher accuracy, better resolution, reduced scanning time and reduced radiation dose. In the maxillofacial region, CBCT has been mainly used in the assessment of dento-alveolar pathology and oral traumatology. CBCT provides a better diagnosis and quantitative information on periodontal bone levels than conventional radiography. It has also been used for patients requiring surgical facial reconstruction, orthognathic surgery, dental implants, and more complex tooth extractions. Besides that, it seems to be a significant tool in modern endodontic practice, presenting useful applications in apical surgery.

  15. Effect of nickel titanium file design on the root surface strain and apical microcracks.

    Science.gov (United States)

    Jamleh, Ahmed; Adorno, Carlos G; Ebihara, Arata; Suda, Hideaki

    2016-04-01

    The aim of this study was to determine the effect of nickel titanium file design on the root surface strain generated and apical microcracks caused during canal shaping. Thirty-three mandibular incisors were distributed into LightSpeed X, FlexMaster and a control group. A strain gauge was fixed apically on the proximal root surface to determine the maximum strain during canal shaping. Except for the control group, all root canals were enlarged to size 50. Images were taken after removing the apical 1 and 2 mm of the root end. Mean maximum strain values and presence of microcracks were statistically compared using the t-test and chi-square test, respectively. During canal shaping, the strain increased cumulatively with mean maximum strains of 808.2 ± 228.8 and 525.1 ± 168.9 microstrain in LightSpeed X and FlexMaster, respectively (P = 0.004). Both systems caused comparable microcracks. Although LightSpeed X produced higher maximum strain, no difference in microcrack development was found between both systems. PMID:26420627

  16. Relationship of apical lymph node involvement to survival in resected colon carcinoma.

    Science.gov (United States)

    Malassagne, B; Valleur, P; Serra, J; Sarnacki, S; Galian, A; Hoang, C; Hautefeuille, P

    1993-07-01

    In a prospective study of 197 patients with resected colon carcinoma treated between 1974 and 1985, we explored the relationships between pathologic parameters, and the effect of the latter on survival, to identify the parameter whose systematic measurement would improve the predictive capacity of pathologic staging. Prognostic characteristics were studied by univariate analysis. The results showed significant relationships between the location and number of lymph nodes involved, blood vessel invasion, depth of tumor penetration, and metastases. The five-year survival rates were 45 percent and 17 percent (P < 0.001) for patients without and with apical lymph node involvement, respectively, and 44 percent and 6 percent (P < 0.05) for those with four or less nodes involved and more than four involved, respectively. Among the patients treated by incomplete resection, the respective survival rates of those resected for metastases and of those resected for apical lymph node involvement did not differ significantly. We conclude that the involvement of apical lymph nodes has a significant effect on prognosis and suggest systematic pathologic examination of these nodes to allow simpler and more reproducible selection of patients for treatment by incomplete resection who are at high risk of disease-related death. PMID:8394236

  17. Sample preparation for laser-microdissection of soybean shoot apical meristem

    Directory of Open Access Journals (Sweden)

    Chui E. Wong

    2012-10-01

    Full Text Available The shoot apical meristem houses stem cells responsible for the continuous formation of aerial plant organs including leaves and stems throughout the life of plants. Laser-microdissection in combination with high-throughput technology such as next generation sequencing permits an in-depth analysis of molecular events associated with specific cell type of interest. Sample preparation is the most critical step in ensuring good quality RNA to be extracted from samples following laser-microdissection. Here, we optimized the sample preparation for a major legume crop, soybean. We used Farmer’s solution as a fixative and paraffin as the embedding medium for soybean shoot apical meristem tissue without the use of any specialized equipment. Shorter time for tissue fixation (two days was found to be critical for the preservation of RNA in soybean shoot apical meristem. We further demonstrated the utility of this method for different tissues derived from soybean and rice. The method outlined here shall facilitate studies on crop plants involving laser-microdissection.

  18. Influence of Instruments Used in Root Canal Preparation on Amount of Apically Extruded Debris.

    Science.gov (United States)

    Karataş, Ertuğrul; Ersoy, İbrahim; Gündüz, Hicran Ateş; Uygun, Ahmet Demirhan; Kol, Elif; Çakıcı, Fatih

    2016-08-01

    The aim of the present study was to compare the effects of ProTaper Gold, WaveOne Gold, ProTaper Universal, and WaveOne instruments on the amount of apically extruded debris. Eighty mandibular premolar teeth with straight root canals were selected and assigned to four groups (n = 20). The root canals were instrumented using ProTaper Gold, WaveOne Gold, ProTaper Universal, and WaveOne systems. Eppendorf tubes containing apically extruded debris were weighed three times, and mean values were calculated. The net mass of the extruded debris was calculated by subtracting the initial mass from the final mass. The groups were compared using one-way analysis of variance and Tukey's post hoc tests at a significance level of P < 0.05. The PTG group extruded less debris than the PTU group, and the WOG group extruded less debris than the WO group (P < 0.05). All the instrumentation systems tested in the present study were associated with apical extrusion of debris. PMID:26814380

  19. Hypertrophic cardiomyopathy with midventricular obstruction and apical aneurysm formation in a single family: case report

    Directory of Open Access Journals (Sweden)

    Paraskevaidis Stylianos

    2009-06-01

    Full Text Available Abstract Background Hypertrophic cardiomyopathy (HCM is an extremely heterogeneous disease. An under recognized and very often missed subgroup within this broad spectrum concerns patients with left ventricular (LV apical aneurysms in the absence of coronary artery disease. Case presentation We describe a case of HCM with midventricular obstruction and apical aneurysm formation in 3 patients coming from a single family. This HCM pattern was detected by 2D-echocardiography and confirmed by cardiac magnetic resonance imaging. A cardioverter defibrillator was implanted in one of the patients because of non-sustained ventricular tachycardia detected in 24-h Holter monitoring and an abrupt drop in systolic blood pressure during maximal exercise test. The defibrillator activated 8 months after implantation by suppression of a ventricular tachycardia providing anti-tachycardia pacing. The patient died due to refractory heart failure 2 years after initial evaluation. The rest of the patients are stable after a 2.5-y follow-up period. Conclusion The detection of apical aneurysm by echocardiography in HCM patients may be complicated. Ventricular tachycardia arising from the scarred aneurysm wall may often occur predisposing to sudden death.

  20. Double chambered left ventricle: Unusual presentation with an apical defect in Tl-201 SPECT

    International Nuclear Information System (INIS)

    Methods and result: A left ventricular apical filling defect was found in a whole body Tl-201 scan performed for routine follow-up for surgically cured thyroid cancer in a 51 year old woman .This defect was confirmed in a myocardial SPET after physical exercise and at rest and, thus, an additional ischemic reaction was excluded. The patient had no cardiovascular symptoms, and her ECG at rest and during exercise was unremarkable. Transthoracic and transesophageal echocardiography revealed a double chambered left ventricle (DCLV). A prominent fibrovascular ridge distal to the papillary muscles was seen dividing the left ventricular cavity into a small apical and a large basal part. There was no significant intra-ventricular gradient. The filling defect in the thallium scan in our patient is unusual and suggests that the myocardium within the left ventricular apex - despite its normal wall thickness - showed diminished perfusion at rest. No treatment was necessary and the patient has remained asymptomatic in a three-year follow-up. Conclusion: The etiology of DCLV is unknown. Some of the published cases showed histologically an endocardial fibroelastosis rendering the main chamber non-contractile. This is the first description of an asymptomatic elderly woman with normal ECG in whom a left ventricular apical defect in the thallium scan let to the diagnosis of DCLV

  1. Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion.

    Science.gov (United States)

    Nevares, Giselle; Xavier, Felipe; Gominho, Luciana; Cavalcanti, Flávia; Cassimiro, Marcely; Romeiro, Kaline; Alvares, Pamella; Queiroz, Gabriela; Sobral, Ana Paula; Gerbi, Marleny; Silveira, Marcia; Albuquerque, Diana

    2015-01-01

    This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n = 20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer's instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α = 5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p < 0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p < 0.001). Cross section and motion influenced the results, despite tip standardization. PMID:26543896

  2. Lipopolysaccharide directly alters renal tubule transport through distinct TLR4-dependent pathways in basolateral and apical membranes

    OpenAIRE

    Good, David W.; George, Thampi; Watts, Bruns A.

    2009-01-01

    Bacterial infection of the kidney is associated with renal tubule dysfunction and dysregulation of systemic electrolyte balance. Whether bacterial molecules directly affect renal tubule transport is unknown. We examined the effects of LPS on HCO3− absorption in the isolated rat and mouse medullary thick ascending limb (MTAL). LPS decreased HCO3− absorption when added to bath or lumen. The MEK/ERK inhibitor U0126 eliminated inhibition by bath LPS but had no effect on inhibition by lumen LPS. C...

  3. Plasmid DNA is internalized from the apical plasma membrane of the salivary gland epithelium in live animals

    OpenAIRE

    Sramkova, Monika; Masedunskas, Andrius; Weigert, Roberto

    2012-01-01

    Non viral-mediated gene delivery represents an alternative way to express the gene of interest without inducing immune responses or other adverse effects. Understanding the mechanisms by which plasmid DNAs are delivered to the proper target in vivo is a fundamental issue that needs to be addressed in order to design more effective strategies for gene therapy. As a model system, we have used the submandibular salivary glands in live rats and we have recently shown that reporter transgenes can ...

  4. Robotic membranes

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2008-01-01

    prototypes, Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual...

  5. [Deformations occurring in the apical third of curved root canals during biomechanical preparation using manual impulsion-traction techniques].

    Science.gov (United States)

    Roig Cayón, M; Basilio Monné, J; Canalda Sahli, C

    1990-01-01

    Apical deformations, specially zips and elbows, during instrumentation of the root canals, are studied. The authors study why do they appear, their effect on endodontic therapy, and the way of avoiding them. PMID:1964069

  6. Epstein-Barr virus infection induces bone resorption in apical periodontitis via increased production of reactive oxygen species.

    Science.gov (United States)

    Jakovljevic, Aleksandar; Andric, Miroslav; Miletic, Maja; Beljic-Ivanovic, Katarina; Knezevic, Aleksandra; Mojsilovic, Slavko; Milasin, Jelena

    2016-09-01

    Chronic inflammatory processes in periapical tissues caused by etiological agents of endodontic origin lead to apical periodontitis. Apart from bacteria, two herpesviruses, Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) are recognized as putative pathogens in apical periodontitis. Although previous reports suggest the involvement of EBV in the pathogenesis of apical periodontitis, its exact role in periapical bone resorption has not yet been fully elucidated. We hypothesize that EBV infection in apical periodontitis is capable of inducing periapical bone resorption via stimulation of reactive oxygen species (ROS) overproduction. Increased levels of ROS induce expression of receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL). RANKL binding to receptor activator of nuclear factor κB (RANK) present on the surface of preosteoclasts induces their maturation and activation which consequently leads to bone resorption. The potential benefit of antiviral and antioxidant-based therapies in periapical bone resorption treatment remains to be assessed. PMID:27515196

  7. Takotsubo, discinesia apical transitoria: Presentacion de 4 casos y revisión de la literatura Takotsubo, reversible apical ballooning of the left ventricle: Report of 4 cases

    Directory of Open Access Journals (Sweden)

    Bárbara C. Finn

    2005-10-01

    Full Text Available En 1990 se describió un síndrome caracterizado por discinesia apical transitoria, cambios en el electrocardiograma (ECG, mínima elevación de enzimas cardíacas y arterias coronarias normales. Se presenta con mayor frecuencia en mujeres añosas y es precedido por un evento de estrés, ya sea físico o psíquico. La fisiopatología aún no está aclarada y se proponen diversas teorías. La de mayor peso es la que postula una afección secundaria a la descarga de catecolaminas desencadenada por el estrés, sobre un corazón incapaz de mantener una respuesta inotrópica adecuada. Se presentan cuatro casos de pacientes atendidos en nuestro hospital que se manifestaron con síntomas sugerentes de infarto agudo de miocardio asociados a insuficiencia cardiaca, en el contexto de un episodio estresante. Los síntomas preponderantes fueron dolor precordial opresivo y disnea. En el ECG se evidenciaron tanto supradesnivel del segmento ST, como inversión de la onda T. Todos los pacientes presentaron la imagen ecocardiográfica típica de discinesia apical, y todos tuvieron en la cinecoronariografía coronarias normales. Cabe destacar que tanto el ECG, como el ecocardiograma volvieron a la normalidad a partir de las dos semanas.A syndrome of apical ballooning, with ECG mimicking acute myocardial infarctation, mild or no enzymatic changes, and normal coronary angiogram was described in 1990. It presents mainly in middle aged and elderly women and it is preceded by stress triggering circumstances. Several mechanisms have been proposed although the precise cause remains unclear. The most accepted theory proposes the interaction of catecholamines and an inadequate inotropic response. We report four cases that presented with chest pain and sudden onset of heart failure, all patients had physical or emotional stress as a triggering factor. On ECG, ST segment elevation and inverted T waves were observed in the acute phase. All patients had typical echocardiogram

  8. Calcium-enriched mixture pulpotomy of a human permanent molar with irreversible pulpitis and condensing apical periodontitis

    OpenAIRE

    Saeed Asgary

    2011-01-01

    This case report describes a pulpotomy treatment of a permanent mature molar tooth with established irreversible pulpitis and condensing apical periodontitis, using calcium-enriched mixture (CEM) cement. Clinical examination revealed that the first right lower molar had a large carious lesion with history of spontaneous/lingering pain; radiographic examination showed condensing apical periodontitis. Pulpotomy was opted as the treatment; cervical pulpotomy was carried out. Following hemostasis...

  9. Defects in leaf epidermis of Arabidopsis thaliana plants with CDKA;1 activity reduced in the shoot apical meristem

    OpenAIRE

    Borowska-Wykret, Dorota; Elsner, Joanna; De Veylder, Lieven; Kwiatkowska, Dorota

    2012-01-01

    In Arabidopsis thaliana, like in other dicots, the shoot epidermis originates from protodermis, the outermost cell layer of shoot apical meristem. We examined leaf epidermis in transgenic A. thaliana plants in which CDKA;1.N146, a negative dominant allele of A-type cyclin-dependent kinase, was expressed from the SHOOTMERISTEMLESS promoter, i.e., in the shoot apical meristem. Using cleared whole mount preparations of expanding leaves and sequential in vivo replicas of expanding leaf surface, w...

  10. Mechanically, the shoot apical meristem of Arabidopsis behaves like a shell inflated by a pressure of about 1 MPa

    OpenAIRE

    Beauzamy, Léna; Louveaux, Marion; Hamant, Olivier; Boudaoud, Arezki

    2015-01-01

    In plants, the shoot apical meristem contains the stem cells and is responsible for the generation of all aerial organs. Mechanistically, organogenesis is associated with an auxin-dependent local softening of the epidermis. This has been proposed to be sufficient to trigger outgrowth, because the epidermis is thought to be under tension and stiffer than internal tissues in all the aerial part of the plant. However, this has not been directly demonstrated in the shoot apical meristem. Here we ...

  11. Apical ballooning syndrome complicated by acute severe mitral regurgitation with left ventricular outflow obstruction – Case report

    OpenAIRE

    Celermajer David S; Chandrasegaram Manju D; Wilson Michael K

    2007-01-01

    Abstract Background Apical ballooning syndrome (or Takotsubo cardiomyopathy) is a syndrome of transient left ventricular apical ballooning. Although first described in Japanese patients, it is now well reported in the Caucasian population. The syndrome mimicks an acute myocardial infarction but is characterised by the absence of obstructive coronary disease. We describe a serious and poorly understood complication of Takotsubo cardiomyopathy. Case Presentation We present the case of a 65 year...

  12. Basilar membrane vibration in the gerbil hemicochlea.

    Science.gov (United States)

    Richter, C P; Evans, B N; Edge, R; Dallos, P

    1998-05-01

    Excised gerbil cochleae were cut along the mid-modiolar plane (hemicochlea). Along one-half turn of this preparation, fluorescent microbeads were placed on the basilar membrane (BM). The BM was vibrated with click stimuli (50 micros) produced mechanically by a piezo pusher. The stimulus delivery probe could be positioned either more apical or more basal from the beads. Vibration patterns were measured with a wide bandwidth photomultiplier from the movements of the beads. When the probe was positioned more basal, the responses to click stimuli were brief, damped sinusoids. According to the fast Fourier transforms (FFTs) of the averaged time wave forms, the best frequency between successive beads decreased toward the apex (0.8 octave/mm). Sharpness of tuning of the normalized FFT spectra (NQ10dB) on average was 1.5. Response amplitude at a fixed input level, measured at different beads away from the stimulation site, dropped exponentially (58 dB/mm). In addition, for each individual bead, amplitude dropped linearly with decreasing stimulus intensity. In experiments where the stimulating probe was placed more apical, two major properties were observed: first, beads revealed only the spectral components present in the motion of the probe. Second, magnitude reduction of the displacement of the cochlear partition was greater, on average 155 dB/mm, indicating a lack of significant propagation in the reverse direction. PMID:9582202

  13. Mineral trioxide aggregate apical plug method for the treatment of nonvital immature permanent maxillary incisors: Three case reports

    Directory of Open Access Journals (Sweden)

    Betül Günes

    2012-01-01

    Full Text Available Treatment of nonvital immature permanent teeth with calcium-hydroxide is associated with some difficulties such as weakened tooth fracture, root canal reinfection and long treatment time. Mineral trioxide aggregate (MTA apical plug method is an alternative treatment option for open apices, and has gained popularity in the recent times. In this case report, we have attempted to present successful treatment of three maxillary incisors with open apices and periapical lesions with MTA. After preparing the access cavity, the working length was determined. The root canals were irrigated with 2.5% Sodium hypochlorite (NaOCl and disinfected with calcium-hydroxide for two weeks. MTA was then placed in the apical 3 millimeters of the root canal. The remaining part of the root canal was filled with gutta-percha and the coronal restoration was finished with composite resin. After six months the radiographic examination showed a decrease of periapical lesions. At a 1-year and 18-months follow up, radiological and clinical successful healing of the incisor teeth was seen. MTA seems as an effective material for the apical plug method for the treatment of nonvital immature permanent teeth with open apices.

  14. Sudden Cardiac Arrest in a Patient With Apical Hypertrophic Cardiomyopathy: Case Report and a Brief Review of Literature.

    Science.gov (United States)

    Gupta, Tanush; Paul, Neha; Palaniswamy, Chandrasekar; Balasubramaniyam, Nivas; Aronow, Wilbert S; Kolte, Dhaval; Khera, Sahil; Shah, Amar B; Gass, Alan

    2016-01-01

    Apical hypertrophic cardiomyopathy (HCM) is a phenotypic variant of nonobstructive HCM, in which hypertrophy of the myocardium predominantly involves the left ventricular apex. It is common in Japanese and other Asian populations but is rare in the United States. Apical HCM has a relatively benign prognosis in terms of cardiovascular mortality; however, morbid events such as ventricular aneurysms, apical thrombi, diastolic dysfunction, atrial fibrillation, and myocardial infarction are not uncommon. We report a case of an 18-year-old white man who presented to our hospital after an out-of-hospital cardiac arrest. The patient had a witnessed collapse while playing basketball in the field. He was found to be pulseless and unresponsive by his coach, and cardiopulmonary resuscitation was immediately started. Upon arrival of emergency medical services, an automated external defibrillator advised shock and he was defibrillated thrice. Return of spontaneous circulation was achieved in 15 minutes. He was intubated for airway protection and was brought to the hospital. Therapeutic hypothermia was initiated. He demonstrated good neurological status after active rewarming. Subsequent cardiac magnetic resonance imaging was suggestive of apical HCM with right ventricular involvement. The patient underwent an implantable cardioverter defibrillator placement for secondary prevention and was subsequently discharged. In conclusion, apical HCM can rarely be associated with adverse cardiovascular events. The diagnosis may be missed on transthoracic 2-dimensional cardiac echocardiogram, and cardiac magnetic resonance imaging should be considered to exclude apical HCM in young patients who present after sudden cardiac arrest. PMID:25923227

  15. Characterization of the basolateral membrane conductance of Necturus urinary bladder.

    Science.gov (United States)

    Demarest, J R; Finn, A L

    1987-04-01

    Necturus urinary bladders stripped of serosal muscle and connective tissue were impaled through their basolateral membranes with microelectrodes in experiments that permitted rapid changes in the ion composition of the serosal solution. The transepithelial electrical properties exhibited a marked seasonal variation that could be attributed to variations in the conductance of the shunt pathway, apical membrane selectivity, and basolateral Na+ transport. In contrast, the passive electrical properties of the basolateral membrane remained constant throughout the year. The apparent transference numbers (Ti) of the basolateral membrane for K+ and Cl- were determined from the effect on the basolateral membrane equivalent electromotive force of a sudden increase in the serosal K+ concentration from 2.5 to 50 mM/liter or a decrease in the Cl- concentration from 101 to 10 mM/liter. TK and TCl were 0.71 +/- 0.05 and 0.04 +/- 0.01, respectively. The basolateral K+ conductance could be blocked by Ba2+ (0.5 mM), Cs+ (10 mM), or Rb+ (10 mM), but was unaffected by 3,4-diaminopyridine (100 microM), decamethonium (100 microM), or tetraethylammonium (10 mM). We conclude that a highly selective K+ conductance dominates the electrical properties of the basolateral membrane and that this conductance is different from those found in nerve and muscle membranes. PMID:2438371

  16. LOCALIZATION AND PROTEOMIC CHARACTERIZATION OF CHOLESTEROL-RICH MEMBRANE MICRODOMAINS IN THE INNER EAR

    OpenAIRE

    Thomas, Paul V.; Cheng, Andrew L.; Colby, Candice C.; Liu, Liqian; Patel, Chintan K.; Josephs, Lydia; Duncan, R. Keith

    2014-01-01

    Biological membranes organize and compartmentalize cell signaling into discrete microdomains, a process that often involves stable, cholesterol-rich platforms that facilitate protein-protein interactions. Polarized cells with distinct apical and basolateral cell processes rely on such compartmentalization to maintain proper function. In the cochlea, a variety of highly polarized sensory and non-sensory cells are responsible for the early stages of sound processing in the ear, yet little is kn...

  17. Elevated cAMP increases aquaporin-3 plasma membrane diffusion

    DEFF Research Database (Denmark)

    Marlar, Saw; Christensen, Eva Arnspang; Koffman, Jennifer Skaarup;

    2014-01-01

    exits via basolateral AQP3 and AQP4. Upon long-term stimulation with AVP or during thirst, expression levels of both AQP2 and AQP3 are increased; however, there is so far no evidence for short-term AVP regulation of AQP3 or AQP4. To facilitate the increase in transepithelial water transport, AQP3 may be.......05)]. Immunoelectron microscopy showed no obvious difference in AQP3-EGFP expression levels or localization in the plasma membrane upon forskolin stimulation. Thus AQP3-EGFP diffusion is altered upon increased cAMP, which may correspond to basolateral adaptations in response to the increased apical water readsorption...

  18. Basal and apical regulation of VEGF-A and placenta growth factor in the RPE/choroid and primary RPE

    Science.gov (United States)

    Kaya, Leyla; Flach, Janina; Lassen, Jens; Treumer, Felix; Roider, Johann

    2015-01-01

    Purpose Members of the vascular endothelial growth factor (VEGF) family are strongly involved in pathological processes in the retina, such as age-related macular degeneration and diabetic retinopathy. Cells of the retinal pigment epithelium (RPE) constitutively secrete VEGF-A, and the secretion of placental growth factor (PlGF) has also been described. RPE cells are strongly polarized cells with different secretome at the apical and basal side. In this study, we evaluated the basal and apical regulation of VEGF-A and PlGF secretion in RPE/choroid explants and primary RPE cells. Methods RPE/choroid tissue explants were prepared from porcine eyes and cultivated in modified Ussing chambers, separating apical (RPE) and basal (choroid) supernatant. Primary RPE cells were also prepared from porcine eyes and cultivated on Transwell plates. Explants and cells were treated with inhibitors for VEGFR-2 (SU1498), p38 (SB203580), and the transcription factors nuclear factor-kappa B (NF-κB) and SP-1 (mithramycin), respectively. VEGF-A and PlGF content was evaluated with enzyme-linked immunosorbent assay (ELISA). In addition, western blots were performed. Results In the RPE/choroid, VEGF-A can initially be found on the apical and basal sides with significantly more pronounced secretion on the basal side. VEGF-A secretion is differentially regulated on the apical and basal sides, with the inhibition of SP-1 and NF-κB showing strong effects apically and basally after 24 h and 48 h, the inhibition of p38 displaying its effect mainly on the basal side with some effect apically after 48 h, and the inhibition of VEGFR-2 reducing the secretion of VEGF only on the apical side at 24 h and 48 h. In the RPE cell culture, similar effects were found, with inhibition of NF-κB or SP-1 displaying a strong decrease in VEGF-A on both sides, and p38 inhibition displaying only an inhibitory effect on the basal side. In contrast, an apical effect of VEGFR-2 inhibition was not found. However, the

  19. Serine-stretch protein (SERP) of Plasmodium falciparum corresponds to the exoantigen Ag2, a target of antibodies associated with protection against malaria

    DEFF Research Database (Denmark)

    Jakobsen, P H; Hundt, E; Hansen, Morten Bagge;

    1994-01-01

    protection against malaria. The glycophorin-binding protein, the histidine-rich protein II, the S-antigen, the heat shock protein 70, the ring-infected erythrocyte surface antigen, and the apical membrane antigen-1 were also shown serologically to be present in the mixture of exoantigens....

  20. In vitro analysis of the cement film thickness of two endodontic sealers in the apical region

    Directory of Open Access Journals (Sweden)

    Garcia Lucas da Fonseca

    2009-01-01

    Full Text Available Objectives : The objective of the present study was to evaluate in vitro film thickness of two endodontic sealers containing epoxy-resin and zinc-oxide-eugenol, respectively in the apical region of the root canal system. Materials and Methods : A total of 20 palatine roots of the first maxillary molars were submitted to instrumentation up to a #40 file by the step-back technique and irrigated with 2 ml of NaOCl after each change of file. The roots were divided at random into two groups of 10 elements; one group was sealed with the Sealer 26® cement and the other one with the EndoFill® cement using the classical technique. The roots were abraded in the apical region until exposure of the filling and cut crosswise at 3 mm to obtain samples. The samples were analyzed by optic microscopy with 40X magnification. The images obtained were recorded using the Adobe Premiere 5.1® software and submitted to morphometric analysis using an integration grid that permitted the quantification of the area filled with the sealer or gutta-percha, and eventual empty spaces. Results : Statistical analysis of the data (Kruskal-Wallis test, P < 0.05 revealed no significant differences between the epoxy-resin-based cement Sealer 26® (47.85% and the zinc- oxide- eugenol-based cement EndoFill® (54.16%. Conclusion : We conclude that the two sealers tested showed a similar behavior regarding the cement film thickness in the apical region.

  1. Evaluation of apical extrusion of debris during ultrasonic versus rotary instrumentation

    Directory of Open Access Journals (Sweden)

    Araquam, Karolline Rodrigues

    2009-01-01

    Full Text Available Objetivo: O objetivo deste estudo foi comparar a extrusão apical de debris durante a instrumentação rotatória versus ultra-sônica de canais radiculares. Metodologia: A amostra constituiu-se de 20 pré-molares inferiores com dimensões radiculares similares. Para coleta do material extruído apicalmente durante a instrumentação endodôntica, foram fixados recipientes de resina acrílica na superfície externa das raízes. Todos os dentes tiveram os terços cervical e médio dos canais radiculares preparado com brocas Gates-Glidden. Após odontometria, a instrumentação apical foi realizada com sistema ultra-sônico ou sistema rotatório (n=10/grupo. Os recipientes de resina foram pesados antes e após a instrumentação e a diferença de peso foi considerada a quantidade de material extruído. Os dados foram analisados por teste de Mann-Whitney, ao nível de significância de 0,05. Resultados: Houve grande variabilidade de quantidade de material extruído para ambas as técnicas de instrumentação, com valores de 0,0009 a 0,0860 g. Não houve diferença estatisticamente significante entre os dois grupos (P>0. 05. Conclusão: Pode-se concluir que ambas as técnicas de instrumentação testadas, com ultra-som ou sistema rotatório, apresentaram extrusão apical de debris em quantidade semelhante

  2. Analysis of dental root apical morphology: a new method for dietary reconstructions in primates.

    Science.gov (United States)

    Hamon, NoÉmie; Emonet, Edouard-Georges; Chaimanee, Yaowalak; Guy, Franck; Tafforeau, Paul; Jaeger, Jean-Jacques

    2012-06-01

    The reconstruction of paleo-diets is an important task in the study of fossil primates. Previously, paleo-diet reconstructions were performed using different methods based on extant primate models. In particular, dental microwear or isotopic analyses provided accurate reconstructions for some fossil primates. However, there is sometimes difficult or impossible to apply these methods to fossil material. Therefore, the development of new, independent methods of diet reconstructions is crucial to improve our knowledge of primates paleobiology and paleoecology. This study aims to investigate the correlation between tooth root apical morphology and diet in primates, and its potential for paleo-diet reconstructions. Dental roots are composed of two portions: the eruptive portion with a smooth and regular surface, and the apical penetrative portion which displays an irregular and corrugated surface. Here, the angle formed by these two portions (aPE), and the ratio of penetrative portion over total root length (PPI), are calculated for each mandibular tooth root. A strong correlation between these two variables and the proportion of some food types (fruits, leaves, seeds, animal matter, and vertebrates) in diet is found, allowing the use of tooth root apical morphology as a tool for dietary reconstructions in primates. The method was then applied to the fossil hominoid Khoratpithecus piriyai, from the Late Miocene of Thailand. The paleo-diet deduced from aPE and PPI is dominated by fruits (>50%), associated with animal matter (1-25%). Leaves, vertebrates and most probably seeds were excluded from the diet of Khoratpithecus, which is consistent with previous studies. PMID:22553124

  3. Apices of maxillary premolars observed by swept source optical coherence tomography

    Science.gov (United States)

    Ebihara, Arata; Iino, Yoshiko; Yoshioka, Toshihiko; Hanada, Takahiro; Sunakawa, Mitsuhiro; Sumi, Yasunori; Suda, Hideaki

    2015-02-01

    Apicoectomy is performed for the management of apical periodontitis when orthograde root canal treatment is not possible or is ineffective. Prior to the surgery, cone beam computed tomography (CBCT) examination is often performed to evaluate the lesion and the adjacent tissues. During the surgical procedure, the root apex is resected and the resected surface is usually observed under dental operating microscope (DOM). However, it is difficult to evaluate the details and the subsurface structure of the root using CBCT and DOM. A new diagnostic system, swept source optical coherence tomography (SS-OCT), has been developed to observe the subsurface anatomical structure. The aim of this study was to observe resected apical root canals of human maxillary premolars using SS-OCT and compare the findings with those observed using CBCT and DOM. Six extracted human maxillary premolars were used. After microfocus computed tomography (Micro CT; for gold standard) and CBCT scanning of the root, 1 mm of the apex was cut perpendicular to the long axis of the tooth. Each resected surface was treated with EDTA, irrigated with saline solution, and stained with methylene blue dye. The resected surface was observed with DOM and SS-OCT. This sequence was repeated three times. The number of root canals was counted and statistically evaluated. There was no significant difference in the accuracy of detecting root canals among CBCT, DOM and SS-OCT (p > 0.05, Wilcoxon test). Because SS-OCT can be used in real time during surgery, it would be a useful tool for observing resected apical root canals.

  4. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Hongyan eGuo

    2015-05-01

    Full Text Available Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION gene, as an auxin response gene, and the functional characterization of OsCLE48 in Arabidopsis and rice. OsCLE48 encodes a CLE peptide hormone that is similar to Arabidopsis CLEs. RT-PCR analysis showed that OsCLE48 was induced by exogenously application of IAA (indole-3-acetic acid, a naturally occurred auxin. Expression of integrated OsCLE48p:GUS reporter gene in transgenic Arabidopsis plants was also induced by exogenously IAA treatment. These results indicate that OsCLE48 is an auxin responsive gene. Histochemical staining showed that GUS activity was detected in all the tissue and organs of the OsCLE48p:GUS transgenic Arabidopsis plants. Expression of OsCLE48 under the control of the 35S promoter in Arabidopsis inhibited shoot apical meristem development. Expression of OsCLE48 under the control of the CLV3 native regulatory elements almost completely complemented clv3-2 mutant phenotypes, suggesting that OsCLE48 is functionally similar to CLV3. On the other hand, expression of OsCLE48 under the control of the 35S promoter in Arabidopsis has little, if any effects on root apical meristem development, and transgenic rice plants overexpressing OsCLE48 are morphologically indistinguishable from wild type plants, suggesting that the functions of some CLE peptides may not be fully conserved in Arabidopsis and rice.

  5. Aluminium toxicity targets PIN2 in Arabidopsis root apices: Effects on PIN2 endocytosis, vesicular recycling,and polar auxin transport

    Institute of Scientific and Technical Information of China (English)

    SHEN Hong; HOU NingYan; Markus SCHLICHT; WAN YingLang; Stefano MANCUSO; Frantisek BALUSKA

    2008-01-01

    The most obvious symptom of AI toxicity is the inhibition of root growth.However,the mechanism of AI-inhibiting root growth remains to be elucidated.In this study,auxin transport and vesicle movement of an auxin-efflux carrier (PIN2) were investigated in Arabidopsis roots in response to AI stress.Results indicated that AI inhibited the apical transport of auxin in root tips of Arabidopsis significantly.The severe inhibition was localized in the cells of transition zone,where the concentration of auxin was only 34% that of the control.Brefeldin A (BFA),an inhibitor of vesicle transport,induced the dot-like structure of PIN2 vesicle significantly.Al decreased the size of dot-like structure of PIN2 vesicles.Re-sults of real-time RT-PCR and Western-blotting analysis showed that Al increased the transcript level of PIN2 and the accumulation of PIN2 protein in horizontal direction of plasma membrane,but decreased its distribution in endosomes,suggesting that AI inhibited the transport of PIN2 vesicles from plasma membrane to endosomes.Results of cytoskeleton-depolymering drugs indicated that it was via the pathway of disruption of actin microfilaments that AI inhibited the transport of PIN2 vesicles.Exposed to AI stress,the cells of elongation zone had less AI uptake and less transport frequency of vesicles than cells of transition zone.Taken together,our results suggested that AI inhibited root growth mainly by modulating the transport of PIN2 vesicles between plasma membrane and endosomes,thus block-ing auxin transport and root growth.

  6. Method to Screen Substrates of Apical Sodium-Dependent Bile Acid Transporter

    OpenAIRE

    Rais, Rana; Gonzalez, Pablo M.; Zheng, Xiaowan; Wring, Stephen A.; Polli, James E.

    2008-01-01

    Human apical sodium-dependent bile acid transporter (hASBT) is a potential prodrug target under study. Development of prodrugs that target hASBT may yield compounds with low solubility and/or susceptibility to hydrolysis. A transport uptake method is needed that increases compound solubility and avoids NaOH for cell lysis during postexperimental cell sample preparation. The overall goal was to develop an assay method to screen for hASBT uptake of novel compounds. The first objective was to de...

  7. Skirted Cannula Technique for Apical Cannulation in Implantation of Centrimag Left Ventricular Assist Device.

    Science.gov (United States)

    Shen, Ta-Chung; Tsai, Kuei-Ton; Hu, Chin-Yuan; Chen, Robert Jeen-Chen

    2016-06-01

    The CentriMag, an extracorporeal short-term ventricular assist device designed for treatment of patients with acute cardiogenic shock, is Conformité Européenne-marked in Europe for use up to 30 days. Extended use beyond the licensed period is not uncommon, however. We have developed a skirted cannula technique for apical cannulation in implantation of the Centrimag. This technique allows easy positioning of the cannula and excellent hemostasis. It also offers secure fixation of the cannula so that patients can ambulate and attend rehabilitation programs should extended use be anticipated. PMID:27211964

  8. The effect of irrigation solutions on the apical sealing ability in different root canal sealers

    OpenAIRE

    Emre Bodrumlu; Esra Parlak; Ebru Hazar Bodrumlu

    2010-01-01

    The aim of this study was to assess the effect of three root canal irrigation solutions on the apical sealing ability of three root canal obturation materials: gutta-percha/AH plus or MM-seal and Resilon/Epiphany SE. A total of 100 teeth with single straight root canals were randomly divided into three equal groups of 30 samples each, with the other 10 teeth (5 positive and 5 negative) used as controls. Each irrigation group was divided into three groups according to the use of three differen...

  9. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis.

    Science.gov (United States)

    Guo, Hongyan; Zhang, Wei; Tian, Hainan; Zheng, Kaijie; Dai, Xuemei; Liu, Shanda; Hu, Qingnan; Wang, Xianling; Liu, Bao; Wang, Shucai

    2015-01-01

    Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance, and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa) CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION) gene, as an auxin response gene, and the functional characterization of OsCLE48 in Arabidopsis and rice. OsCLE48 encodes a CLE peptide hormone that is similar to Arabidopsis CLEs. RT-PCR analysis showed that OsCLE48 was induced by exogenously application of IAA (indole-3-acetic acid), a naturally occurred auxin. Expression of integrated OsCLE48p:GUS reporter gene in transgenic Arabidopsis plants was also induced by exogenously IAA treatment. These results indicate that OsCLE48 is an auxin responsive gene. Histochemical staining showed that GUS activity was detected in all the tissue and organs of the OsCLE48p:GUS transgenic Arabidopsis plants. Expression of OsCLE48 under the control of the 35S promoter in Arabidopsis inhibited shoot apical meristem development. Expression of OsCLE48 under the control of the CLV3 native regulatory elements almost completely complemented clv3-2 mutant phenotypes, suggesting that OsCLE48 is functionally similar to CLV3. On the other hand, expression of OsCLE48 under the control of the 35S promoter in Arabidopsis has little, if any effects on root apical meristem development, and transgenic rice plants overexpressing OsCLE48 are morphologically indistinguishable from wild type plants, suggesting that the functions of some CLE peptides may not be fully conserved in Arabidopsis and rice. Taken together, our results showed that OsCLE48 is an auxin responsive peptide hormone gene, and it regulates shoot apical

  10. Morphogenesis in Plants: Modeling the Shoot Apical Meristem, and Possible Applications

    Science.gov (United States)

    Mjolsness, Eric; Gor, Victoria; Meyerowitz, Elliot; Mann, Tobias

    1998-01-01

    A key determinant of overall morphogenesis in flowering plants such as Arabidopsis thaliana is the shoot apical meristem (growing tip of a shoot). Gene regulation networks can be used to model this system. We exhibit a very preliminary two-dimensional model including gene regulation and intercellular signaling, but omitting cell division and dynamical geometry. The model can be trained to have three stable regions of gene expression corresponding to the central zone, peripheral zone, and rib meristem. We also discuss a space-engineering motivation for studying and controlling the morphogenesis of plants using such computational models.

  11. Cytotoxic effects in maize root’s apical meristem under the nickel ions influence

    OpenAIRE

    L. V. Boguslavskaja; N. F. Pavlyukova; O. M. Vinnychenko

    2006-01-01

    Effect of different concentrations of nickel ions (10 - 4, 10 - 5 and 3.4 × 10 - 6 М × l - 1) on the root growth and apical meristem cell division in the seedling of Zea mays L. has been studied. Peculiarities of the nickel ions cytotoxic effect was estimated by the mitotic index, index of aberrations and pycnotic nuclei changes. Toxicity of the nickel ions for the maize meristematic tissues is ascertained.

  12. Exogenously Applied Jasmonic Acid Induces Changes in Apical Meristem Morphology of Potato Stolons

    OpenAIRE

    CENZANO, ANA; Vigliocco, Ana; Kraus, Teresa; ABDALA, GUILLERMINA

    2003-01-01

    Hooked apex stolons and initial swelling stolons of potato plants were treated with 3 × 10–8 mol l–1 jasmonic acid (JA) to study the effect of this compound on histology, cell expansion and tissue differentiation. In hooked apex stolons, JA application increased the meristem thickness and reduced the length of the leaf primordia, whereas in initial swelling stolons narrowing of the apical region, absence of leaf primordia and swelling of the subapical meristem were evident. Early vascular tis...

  13. Cytogenetic effects of acute gamma radiation on leaf and apical meristem of scotch pine

    Energy Technology Data Exchange (ETDEWEB)

    Tikhomirov, F.A.; Fedotov, I.S.; Prister, B.S.; Remezova, M.M.

    1977-01-01

    A study was made of the effect of acute ..gamma..-radiation on incidence of chromosomal aberrations in apical and leaf meristem of the pine in the first and second postradiation vegetation periods. It was found that the radiosensitivity of these tissues is the same. In the second postradiation vegetation period, after exposure to a dosage of 1500-2500 rad, there is normalization of the parameters studied. Restitution of tissues can occur both as a result of recovery of involved meristem cells and by means of differentiation of subapical meristem cells.

  14. Omniphobic Membrane for Robust Membrane Distillation

    Energy Technology Data Exchange (ETDEWEB)

    Lin, SH; Nejati, S; Boo, C; Hu, YX; Osuji, CO; Ehmelech, M

    2014-11-01

    In this work, we fabricate an omniphobic microporous membrane for membrane distillation (MD) by modifying a hydrophilic glass fiber membrane with silica nanoparticles followed by surface fluorination and polymer coating. The modified glass fiber membrane exhibits an anti-wetting property not only against water but also against low surface tension organic solvents that easily wet a hydrophobic polytetrafluoroethylene (PTFE) membrane that is commonly used in MD applications. By comparing the performance of the PTFE and omniphobic membranes in direct contact MD experiments in the presence of a surfactant (sodium dodecyl sulfate, SDS), we show that SDS wets the hydrophobic PTFE membrane but not the omniphobic membrane. Our results suggest that omniphobic membranes are critical for MD applications with feed waters containing surface active species, such as oil and gas produced water, to prevent membrane pore wetting.

  15. Par1b induces asymmetric inheritance of plasma membrane domains via LGN-dependent mitotic spindle orientation in proliferating hepatocytes.

    Directory of Open Access Journals (Sweden)

    Christiaan L Slim

    2013-12-01

    Full Text Available The development and maintenance of polarized epithelial tissue requires a tightly controlled orientation of mitotic cell division relative to the apical polarity axis. Hepatocytes display a unique polarized architecture. We demonstrate that mitotic hepatocytes asymmetrically segregate their apical plasma membrane domain to the nascent daughter cells. The non-polarized nascent daughter cell can form a de novo apical domain with its new neighbor. This asymmetric segregation of apical domains is facilitated by a geometrically distinct "apicolateral" subdomain of the lateral surface present in hepatocytes. The polarity protein partitioning-defective 1/microtubule-affinity regulating kinase 2 (Par1b/MARK2 translates this positional landmark to cortical polarity by promoting the apicolateral accumulation of Leu-Gly-Asn repeat-enriched protein (LGN and the capture of nuclear mitotic apparatus protein (NuMA-positive astral microtubules to orientate the mitotic spindle. Proliferating hepatocytes thus display an asymmetric inheritance of their apical domains via a mechanism that involves Par1b and LGN, which we postulate serves the unique tissue architecture of the developing liver parenchyma.

  16. Fusion of liposomes with the plasma membrane of epithelial cells: Fate of incorporated lipids as followed by freeze fracture and autoradiography of plastic sections

    OpenAIRE

    Knoll, G.; Burger, K.N.J.; Bron, R.; van Meer, G.; Verkleij, A. J.

    1988-01-01

    The fusion of liposomes with the plasma membrane of influenza virus- infected monolayers of an epithelial cell line, Madin-Darby canine kidney cells (van Meer et al., 1985. Biochemistry. 24:3593-3602), has been analyzed by morphological techniques. The distribution of liposomal lipids over the apical and basolateral plasma membrane domains after fusion was assessed by autoradiography of liposomal [3H]dipalmitoylphosphatidylcholine after rapid freezing or chemical fixation and further processi...

  17. Fusion of liposomes with the plasma membrane of epithelial cells: Fate of incorporated lipids as followed by freeze fracture and autoradiography of plastic sections

    OpenAIRE

    Knoll, G; Burger, K.N.J.; Bron, R.; van Meer, G.; Verkleij, A J

    1988-01-01

    The fusion of liposomes with the plasma membrane of influenza virus-infected monolayers of an epithelial cell line, Madin-Darby canine kidney cells (van Meer et al., 1985. Biochemistry, 24: 3593-3602), has been analyzed by morphological techniques. The distribution of liposomal lipids over the apical and basolateral plasma membrane domains after fusion was assessed by autoradiography of liposomal [3H]dipalmitoylphosphatidylcholine after rapid freezing or chemical fixation and further processi...

  18. Fusion of liposomes with the plasma membrane of epithelial cells: fate of incorporated lipids as followed by freeze fracture and autoradiography of plastic sections

    OpenAIRE

    1988-01-01

    The fusion of liposomes with the plasma membrane of influenza virus- infected monolayers of an epithelial cell line, Madin-Darby canine kidney cells (van Meer et al., 1985. Biochemistry. 24:3593-3602), has been analyzed by morphological techniques. The distribution of liposomal lipids over the apical and basolateral plasma membrane domains after fusion was assessed by autoradiography of liposomal [3H]dipalmitoylphosphatidylcholine after rapid freezing or chemical fixation and further processi...

  19. Remodelamento ventricular na estimulação cardíaca apical do ventrículo direito Ventricular remodeling in right ventricular apical pacing

    Directory of Open Access Journals (Sweden)

    Rodrigo Tavares Silva

    2007-02-01

    Full Text Available OBJETIVO: Avaliar a taxa de remodelamento ventricular (RV e a importância de variáveis clínico-funcionais em pacientes com função cardíaca normal submetidos à estimulação artificial apical do ventrículo direito (VD. MÉTODOS: Dentre 268 pacientes consecutivos com BAVT e marcapasso convencional, foram excluídos os portadores de fração de ejeção do ventrículo esquerdo (FEVE 53 mm ao eco-Doppler. O RV foi definido como o conjunto de modificações ecocardiográficas documentadas pelo menos 6 meses pós-implante: aumento >10% no DDVE e redução > 20% na FEVE. As variáveis analisadas foram: cardiopatia de base, classe funcional de insuficiência cardíaca (IC, tempo de estimulação ventricular e duração do QRS. A análise estatística incluiu os testes da razão de verossimilhança, exato de Fisher e a soma de postos de Wilcoxon. O valor de p foi significante quando OBJECTIVE: To determine ventricular remodeling (VR and the role of clinical and functional variables in patients with normal cardiac function who underwent right ventricular apical pacing (RVAP. METHODS: Among the 268 consecutive patients with standard pacemaker due to complete atrioventricular block (CAVB, those with left ventricular ejection fraction (LVEF 53 mm on Doppler echocardiography were excluded. Ventricular remodeling was defined as echocardiographic changes documented at least six months after implantation, namely, a >10% increase in LVEDD and a > 20% decrease in LVEF. The following variables were analyzed: underlying heart disease, NYHA functional class of heart failure (HF, time of ventricular stimulation, and QRS duration. Statistical analysis included likelihood ratio test, Fisher’s exact test, and Wilcoxon rank-sum test. A p value < 0.05 was considered statistically significant. RESULTS: The study included 75 patients, mean age 70.9 ± 14, of whom 22.6% were male. Mean time between both evaluations was 80.2 months. Before implantation, mean LVEF was

  20. Acute Lymphoid Leukemia Cells with Greater Stem Cell Antigen-1 (Ly6a/Sca-1) Expression Exhibit Higher Levels of Metalloproteinase Activity and Are More Aggressive In Vivo

    OpenAIRE

    Yu-Chiao Hsu; Kurt Mildenstein; Kordell Hunter; Olena Tkachenko; Mullen, Craig A.

    2014-01-01

    Stem cell antigen-1 (Ly6a/Sca-1) is a gene that is expressed in activated lymphocytes, hematopoietic stem cells and stem cells of a variety of tissues in mice. Despite decades of study its functions remain poorly defined. These studies explored the impact of expression of this stem cell associated gene in acute lymphoid leukemia. Higher levels of Ly6a/Sca-1 expression led to more aggressive leukemia growth in vivo and earlier death of hosts. Leukemias expressing higher levels of Ly6a/Sca-1 ex...

  1. Fragment Propagation and Colonization Ability Enhanced and Varied at Node Level after Escaping from Apical Dominance in Submerged Macrophytes

    Institute of Scientific and Technical Information of China (English)

    Jinhui Jiang; Shuqing An; Changfang Zhou; Baohua Guan; Zhiyi Sun; Ying Cai; Fude Liu

    2009-01-01

    Aquatic plants develop strong fragment propagation and colonization ability to endure the natural disturbances. However,detailed research of ability to endure the natural disturbances has been lacking to date. Therefore, reproduction (shoot) and colonization (root) of shoot fragments of Potamogeton crispus L. with or without apices were investigated for the effect of apical dominance, and the growth of decapitated shoot fragments at three lengths (2, 4, 6cm) was compared. Meanwhile,fragment propagation at levels of bud position was studied for bud position effect after escaping from apical dominance.The results showed significant increases occurred in the outgrowth of lateral branches on fragments decapitated compared with the fragments with apices, implying that apical dominance exists. Different lengths of fragments showed little difference in biomass allocations, but significant differences were noted in their propagation. Meanwhile, the effect of bud position was verified, due to the significant difference of average reproduction per node among the three length groups. Thus, the present study has made progress in the current understanding of aquatic plant dispersion among natural systems and contributes to improve methods of in vitro propagation for re-implantation purposes.

  2. Ecology of the microbiome of the infected root canal system: a comparison between apical and coronal root segments

    Science.gov (United States)

    Özok, A.R.; Persoon, I.F.; Huse, S.M.; Keijser, B.J.F.; Wesselink, P.R.; Crielaard, W.; Zaura, E.

    2016-01-01

    Aim To evaluate the microbial ecology of the coronal and apical segments of infected root canal systems using a complete sampling technique and next-generation sequencing. Methodology The roots of 23 extracted teeth with apical periodontitis were sectioned in half, horizontally, and cryo-pulverized. Bacterial communities were profiled using tagged 454 pyrosequencing of the 16S rDNA hypervariable V5–V6 region. Results The sequences were classified into 606 taxa (species or higher taxon), representing 24 bacterial phyla or candidate divisions and one archaeal phylum. Proteobacteria were more abundant in the apical samples (proots compared to their coronal counterparts. Conclusions Endodontic infections are more complex than reported previously. The apical part of the root canal system drives the selection of a more diverse and more anaerobe community than the coronal part. The presence of a distinct ecological niche in the apical region explains the difficulty of eradication of the infection, and emphasizes the need that new treatment approaches should be developed. PMID:22251411

  3. Effect of diode laser irradiation on the apical sealing of MTA retrofillings Efeito da irradiação de laser de diodo no selamento apical em retrobturações com MTA

    Directory of Open Access Journals (Sweden)

    Eliana Barbosa de Souza

    2006-09-01

    Full Text Available Apical sealing is essential for the success of paraendodontic surgery, so any procedure that may favor an adequate sealing of the apical remainder should be performed. The purpose of this study was to evaluate the influence of diode laser irradiation on the apical sealing of root-end cavities with MTA retrofillings. Root canals in twenty extracted human teeth were shaped with K-files and filled with gutta-percha. The apexes were cut off and root-end preparations were performed. The roots were divided randomly in 2 groups. Group 1 (ten specimens was retrofilled with MTA. Group 2 was irradiated with diode laser, with 1 W for 20 seconds, on the apical surface and root end cavity before retrofilling with MTA. The specimens had their external surfaces impermeabilized with cyanoacrylate, except for the apical surface, and were then immersed in 1% rhodamine B dye for 72 h and placed in plaster stone. After that, the specimens were submitted to longitudinal abrasion until half of the root remained. The linear dye leakage was observed in these mid-roots between the root canal wall and retrofilling. The linear dye leakage was measured with Image Lab software, and the results were statistically analyzed with Student's t test. There were no statistically significant differences between the two groups (p > 0.05. The diode laser irradiation did not improve the apical sealing of MTA retrofillings under the conditions of this in vitro study.O selamento apical é fundamental para o sucesso da cirurgia parendodôntica. Assim, procedimentos que melhorem o selamento do remanescente apical devem ser utilizados. O objetivo deste estudo foi verificar se a irradiação de laser de diodo poderia aumentar o selamento apical em cavidades retrógradas obturadas com MTA. Foram utilizadas 20 raízes de dentes humanos extraídos que, após preparo com lima tipo K, tiveram seus canais obturados com guta-percha. Os ápices foram cortados e sofreram preparo de cavidades retr

  4. Apical extrusion of debris by supplementary files used for retreatment: An ex vivo comparative study

    Science.gov (United States)

    Pawar, Ajinkya M.; Pawar, Mansing; Metzger, Zvi; Thakur, Bhagyashree

    2016-01-01

    Aim: This study evaluated whether using supplementary files for removing root canal filling residues after ProTaper Universal Retreatment files (RFs) increased the debris extrusion apically. Materials and Methods: Eighty mandibular premolars with single root and canal were instrumented with ProTaper Universal rotary system (SX-F3) and obturated. The samples were divided randomly into four groups (n = 20). Group 1 served as a control; only ProTaper Universal RFs D1–D3 were used, and the extruded debris was weighed. Groups 2, 3, and 4 were the experimental groups, receiving a twofold retreatment protocol: Removal of the bulk, followed by the use of supplementary files. The bulk was removed by RFs, followed by the use of ProTaper NEXT (PTN), WaveOne (WO), and Self-Adjusting File (SAF) for removal of the remaining root filling residues. Debris extruded apically were weighed and compared to the control group. Statistical analysis was performed using one-way analysis of variance (ANOVA) and post hoc Tukey's test. Results: All the three experimental groups presented significant difference (P < .01). The post hoc Tukey's test confirmed that Group 4 (SAF) exhibited significantly less (P < .01) debris extrusion between the three groups tested. Conclusion: SAF results in less extrusion of debris when used as supplementary file to remove root-filling residues, compared to WO and PTN. PMID:27099416

  5. Multiciliated cell basal bodies align in stereotypical patterns coordinated by the apical cytoskeleton.

    Science.gov (United States)

    Herawati, Elisa; Taniguchi, Daisuke; Kanoh, Hatsuho; Tateishi, Kazuhiro; Ishihara, Shuji; Tsukita, Sachiko

    2016-08-29

    Multiciliated cells (MCCs) promote fluid flow through coordinated ciliary beating, which requires properly organized basal bodies (BBs). Airway MCCs have large numbers of BBs, which are uniformly oriented and, as we show here, align linearly. The mechanism for BB alignment is unexplored. To study this mechanism, we developed a long-term and high-resolution live-imaging system and used it to observe green fluorescent protein-centrin2-labeled BBs in cultured mouse tracheal MCCs. During MCC differentiation, the BB array adopted four stereotypical patterns, from a clustering "floret" pattern to the linear "alignment." This alignment process was correlated with BB orientations, revealed by double immunostaining for BBs and their asymmetrically associated basal feet (BF). The BB alignment was disrupted by disturbing apical microtubules with nocodazole and by a BF-depleting Odf2 mutation. We constructed a theoretical model, which indicated that the apical cytoskeleton, acting like a viscoelastic fluid, provides a self-organizing mechanism in tracheal MCCs to align BBs linearly for mucociliary transport. PMID:27573463

  6. RNG1 is a late marker of the apical polar ring in Toxoplasma gondii.

    Science.gov (United States)

    Tran, Johnson Q; de Leon, Jessica C; Li, Catherine; Huynh, My-Hang; Beatty, Wandy; Morrissette, Naomi S

    2010-09-01

    The asexually proliferating stages of apicomplexan parasites cause acute symptoms of diseases such as malaria, cryptosporidiosis and toxoplasmosis. These stages are characterized by the presence of two independent microtubule organizing centers (MTOCs). Centrioles are found at the poles of the intranuclear spindle. The apical polar ring (APR), a MTOC unique to apicomplexans, organizes subpellicular microtubules which impose cell shape and apical polarity on these protozoa. Here we describe the characteristics of a novel protein that localizes to the APR of Toxoplasma gondii which we have named ring-1 (RNG1). There are related RNG1 proteins in Neospora caninum and Sarcocystis neurona but no obvious homologs in Plasmodium spp., Cryptosporidium spp. or Babesia spp. RNG1 is a small, low-complexity, detergent-insoluble protein that assembles at the APR very late in the process of daughter parasite replication. We were unable to knock-out the RNG1 gene, suggesting that its gene product is essential. Tagged RNG1 lines have also allowed us to visualize the APR during growth of Toxoplasma in the microtubule-disrupting drug oryzalin. Oryzalin inhibits nuclear division and cytokinesis although Toxoplasma growth continues, and similar to earlier observations of unchecked centriole duplication in oryzalin-treated parasites, the APR continues to duplicate during aberrant parasite growth. PMID:20658557

  7. Effect of methods of evaluation on sealing ability of mineral trioxide aggregate apical plug

    Directory of Open Access Journals (Sweden)

    Vineeta Nikhil

    2016-01-01

    Full Text Available Aim: The purpose of the study was to evaluate and compare the sealing ability of mineral trioxide aggregate (MTA with three different methods. Materials and Methods: Forty single canal teeth were decoronated, and root canals were enlarged to simulate immature apex. The samples were randomly divided into Group M D = MTA-angelus mixed with distilled water and Group M C = MTA-angelus mixed with 2% chlorhexidine, and apical seal was recorded with glucose penetration method, fluid filtration method, and dye penetration methods and compared. Results: The three methods of evaluation resulted differently. The glucose penetration method showed that M D sealed better than M C , but difference was statistically insignificant (P > 0.05. The fluid filtration method resulted that Group M C was statistically insignificant superior to Group M D (P > 0.05. The dye penetration method showed that Group M C sealed statistically better than Group M D . Conclusion: No correlation was found among the results obtained with the three methods of evaluation. Addition of chlorhexidine enhanced the sealing ability of MTA according to the fluid filtration test and dye leakage while according to the glucose penetration test, chlorhexidine did not enhance the sealing ability of MTA. This study showed that relying on the results of apical sealing by only method can be misleading.

  8. A survey of small RNA population during FR-induced apical hook opening

    Directory of Open Access Journals (Sweden)

    Ying eLi

    2014-04-01

    Full Text Available Photomorphogenesis is a mechanism employed by plants to regulate their architecture and developmental program in response to light conditions. As they emerge into light for the first time, dark-grown seedlings employ a rapid and finely-controlled photomorphogenic signaling network. Small RNAs have increasingly been revealed to play an important role in regulating multiple aspects of plant development, by modulating the stability of mRNAs. The rapid alteration of the mRNA transcriptome is a known hallmark of the de-etiolation response, thus we investigated the small RNA transcriptome during this process in specific seedling tissues. Here we describe a survey of the small RNA expression profile in four tissues of etiolated soybean seedlings, the cotyledons, hypocotyl and the convex and concave sides of the apical hook. We also investigate how this profile responds to a one-hour far-red light treatment. Our data suggests that miRNAs show a different global profile between these tissues and treatments, suggesting a possible role for tissue- and treatment-specific expression in the differential morphology of the seedling on de-etiolation. Further evidence for the role of miRNA in light-regulated development is given by the de-etiolation responses of a hypomorphic ago1 mutant, which displays reduced and delayed photomorphogenic responses in apical hook and cotyledon angle to far-red light.

  9. Postoperative left ventricular apical ballooning: Transient Takotsubo cardiomyopathy following orthotopic liver transplantation

    Science.gov (United States)

    Bedanova, Helena; Orban, Marek; Nemec, Petr

    2013-01-01

    Patient: Female, 51 Final Diagnosis: Takotsubo cardiomyopathy Symptoms: — Medication: — Clinical Procedure: — Specialty: Cardiology • Transplantology Objective: Rare disease Background: Left ventricular apical ballooning syndrome (LVAB), also known as Takotsubo cardiomyopathy, is a cardiac syndrome characterized by transient left ventricular dysfunction in the absence of obstructive atherosclerotic coronary artery disease. An episode of emotional stress, typically in female patients, is believed to precede and trigger the development of this syndrome. Case Report: We report a case of Takotsubo cardiomyopathy that developed after orthotopic liver transplantation in a 51-year-old woman. On D2 (day 2) the patient had severe hemodynamic compromise. Echocardiography showed systolic dysfunction of the left ventricle (LV), with ejection fraction (EF) of 20% and anteroapical akinesis and ballooning of the apical 2/3 of the LV. Troponin T was elevated but other markers of myocardial necrosis were negative, as was coronary angiography. From D7 onward, there was an improvement in the hemodynamics in conjunction with a gradual increase of LV EF. The patient was dismissed from the hospital on D30 with signs of normal cardiac function and LV motion and EF of 50%. Liver function was also excellent. Conclusions: Every major operation, including liver transplantation, is associated with emotional stress for the patient. Therefore, it is necessary to consider Takotsubo cardiomyopathy in the differential diagnosis of heart failure developing early after LT, and clinicians should subsequently use adequate diagnostic and therapeutic measures. PMID:24298303

  10. Auxin controls local cytokinin biosynthesis in the nodal stem in apical dominance.

    Science.gov (United States)

    Tanaka, Mina; Takei, Kentaro; Kojima, Mikiko; Sakakibara, Hitoshi; Mori, Hitoshi

    2006-03-01

    In intact plants, the shoot apex grows predominantly and inhibits outgrowth of axillary buds. After decapitation of the shoot apex, outgrowth of axillary buds begins. This phenomenon is called an apical dominance. Although the involvement of auxin, which represses outgrowth of axillary buds, and cytokinin (CK), which promotes outgrowth of axillary buds, has been proposed, little is known about the underlying molecular mechanisms. In the present study, we demonstrated that auxin negatively regulates local CK biosynthesis in the nodal stem by controlling the expression level of the pea (Pisum sativum L.) gene adenosine phosphate-isopentenyltransferase (PsIPT), which encodes a key enzyme in CK biosynthesis. Before decapitation, PsIPT1 and PsIPT2 transcripts were undetectable; after decapitation, they were markedly induced in the nodal stem along with accumulation of CK. Expression of PsIPT was repressed by the application of indole-3-acetic acid (IAA). In excised nodal stem, PsIPT expression and CK levels also increased under IAA-free conditions. Furthermore, beta-glucuronidase expression, under the control of the PsIPT2 promoter region in transgenic Arabidopsis, was repressed by an IAA. Our results indicate that in apical dominance one role of auxin is to repress local biosynthesis of CK in the nodal stem and that, after decapitation, CKs, which are thought to be derived from the roots, are locally biosynthesized in the nodal stem rather than in the roots. PMID:16507092

  11. Effect of methods of evaluation on sealing ability of mineral trioxide aggregate apical plug

    Science.gov (United States)

    Nikhil, Vineeta; Jha, Padmanabh; Suri, Navleen Kaur

    2016-01-01

    Aim: The purpose of the study was to evaluate and compare the sealing ability of mineral trioxide aggregate (MTA) with three different methods. Materials and Methods: Forty single canal teeth were decoronated, and root canals were enlarged to simulate immature apex. The samples were randomly divided into Group MD = MTA-angelus mixed with distilled water and Group MC = MTA-angelus mixed with 2% chlorhexidine, and apical seal was recorded with glucose penetration method, fluid filtration method, and dye penetration methods and compared. Results: The three methods of evaluation resulted differently. The glucose penetration method showed that MD sealed better than MC, but difference was statistically insignificant (P > 0.05). The fluid filtration method resulted that Group MC was statistically insignificant superior to Group MD (P > 0.05). The dye penetration method showed that Group MC sealed statistically better than Group MD. Conclusion: No correlation was found among the results obtained with the three methods of evaluation. Addition of chlorhexidine enhanced the sealing ability of MTA according to the fluid filtration test and dye leakage while according to the glucose penetration test, chlorhexidine did not enhance the sealing ability of MTA. This study showed that relying on the results of apical sealing by only method can be misleading. PMID:27217635

  12. Anatomy and histology of apical support: a literature review concerning cardinal and uterosacral ligaments.

    Science.gov (United States)

    Ramanah, Rajeev; Berger, Mitchell B; Parratte, Bernard M; DeLancey, John O L

    2012-11-01

    The objective of this work was to collect and summarize relevant literature on the anatomy, histology, and imaging of apical support of the upper vagina and the uterus provided by the cardinal (CL) and uterosacral (USL) ligaments. A literature search in English, French, and German languages was carried out with the keywords apical support, cardinal ligament, transverse cervical ligament, Mackenrodt ligament, parametrium, paracervix, retinaculum uteri, web, uterosacral ligament, and sacrouterine ligament in the PubMed database. Other relevant journal and textbook articles were sought by retrieving references cited in previous PubMed articles. Fifty references were examined in peer-reviewed journals and textbooks. The USL extends from the S2 to the S4 vertebra region to the dorsal margin of the uterine cervix and/or to the upper third of the posterior vaginal wall. It has a superficial and deep component. Autonomous nerve fibers are a major constituent of the deep USL. CL is defined as a perivascular sheath with a proximal insertion around the origin of the internal iliac artery and a distal insertion on the cervix and/or vagina. It is divided into a cranial (vascular) and a caudal (neural) portions. Histologically, it contains mainly vessels, with no distinct band of connective tissue. Both the deep USL and the caudal CL are closely related to the inferior hypogastric plexus. USL and CL are visceral ligaments, with mesentery-like structures containing vessels, nerves, connective tissue, and adipose tissue. PMID:22618209

  13. The apical leakage of mineral trioxide aggregate as the retrograde filling material with various mixing agents

    Directory of Open Access Journals (Sweden)

    Ema Mulyawati

    2010-06-01

    Full Text Available Background: Mineral trioxide aggregate (MTA is relatively considered as a new material in endodontic. It even has been used as retrograde filling material due to its biocompatibility, antibacterial effect, sealing ability and anti-moist effect. Some materials have been used as mixing agent to achieve an appropiate setting of MTA. Purpose: The aim of this study is to investigate the effect of the mixing agents of MTA towards the apical leakage when they are used together as retrograde filling materials. Method: The samples of this research consist of 30 human extracted upper central incisors. First, the crown of each tooth is sectioned. The root canals are prepared by using the conventional technique and then are obturated with gutta percha. After cutting the root apex, 2 mm from apical, class 1 cavities are prepared by using fissure bur with the depth of 3 mm. The samples then are divided into 3 groups with 10 teeth for each. Group I uses aquabidest as mixing agent of MTA (MTA-aquabidest, group II uses saline (MTA-saline, while group III uses 0.12% chlorhexidine (MTA-chlorhexidine. The apex of each group then is filled with the mixing MTA determined already. Afterwards, clearing method is used to evaluate the apical leakage. The apical leakage actually is determined by measuring the depth of methylene blue penetration with stereomicroscope. The statictical analyses of the linear dye penetration then are performed with analysis of varians ANOVA. Result: The dye penetration for both MTA-aquadest and MTA-saline groups indicates the lowest penetration, and there is even a significant difference compared with MTA-0.12% chlorhexidine group (p<0.005. Conclusion: It can be concluded that aquabidest and saline as mixing agents of MTA produce less apical leakage compared with 0.12% chlorhexidine.Latar belakang: Mineral trioxide aggregate (MTA merupakan bahan yang relatif baru dalam bidang endodontik. Bahan tersebut diindikasikan sebagai bahan pengisi

  14. Delayed-enhancement MRI of apical hypertrophic cardiomyopathy: assessment of the intramural distribution and comparison with clinical symptoms, ventricular arrhythmias, and cine MRI

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Yasuo; Fukushima, Yoshimitsu; Kumita, Shinichiro (Dept. of Radiology, Nippon Medical School, Tokyo (Japan)), email: yas-amano@nifty.com; Takayama, Morimasa (Dept. of Cardiology, Sakakibara Heart Inst., Tokyo (Japan)); Kitamura, Mitsunobu (Coronary Care Unit, Chiba-Hokuso Hospital of Nippon Medical School, Chiba (Japan))

    2011-07-15

    Background: Hypertrophic cardiomyopathy (HCM) is reported to show patchy midwall myocardial hyper enhancement on delayed-enhancement magnetic resonance imaging (DE-MRI). The intramural distribution of myocardial hyper enhancement and its correlation with clinical symptoms, ventricular arrhythmias, and cardiac function have not been described for symptomatic apical HCM. Purpose: To evaluate the features and significance of myocardial hyper enhancement on DE-MRI in symptomatic apical HCM. Material and Methods: Thirteen patients with symptomatic apical HCM and their 65 apical segments were investigated. Myocardial hyper enhancement and regional and global functional parameters were determined with MRI. We investigated the intramural distribution and frequencies of this myocardial hyper enhancement and compared them with the patients' clinical symptoms, the presence of ventricular arrhythmias, and cine MRI. Results: Eight (61.5%) patients with symptomatic apical HCM displayed apical myocardial hyper enhancement, and 22 (33.8%) of the 65 apical segments examined showed myocardial hyper enhancement. Of the myocardial hyper enhancement observed, 81.8% showed a subendocardial pattern.The Hyperenhanced apical myocardium had a lower percentage of systolic myocardial thickening, and was associated with serious symptoms (e.g. syncope) and ventricular arrhythmias. Conclusion: Patients with symptomatic apical HCM showed myocardial hyper enhancement involving the subendocardial layer, which might be related to regional systolic dysfunction, serious clinical symptoms, and ventricular arrhythmias

  15. Membranes for energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Peinemann, K.V.; Pereira Nunes, S. (eds.) [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    2008-07-01

    This volume contains the following chapters: 1. Sulfonated poly(arylether)-type polymers as proton exchange membranes: Synthesis and performance; 2. Polyimide ionomer membranes for PEFCs and DMFCs; 3. Membranes for high temperature PEFC based on acid-doped polybenzimidazoles; 4. Membrane for medium temperature PEFC based on Nafion filled with layered metal phosphates and phosphonates 5. Composite membranes for high temperature direct methanol fuel cells; 6. Dense ceramic membranes for hydrogen separation; 7. Membranes in energy systems with CO{sub 2} capture 8. Palladium membranes for hydrogen separation; 9. Membranes for power generation by pressure retarded osmosis.

  16. Line tension at lipid phase boundaries regulates formation of membrane vesicles in living cells

    DEFF Research Database (Denmark)

    Vind-Kezunovic, D.; Nielsen, C.H.; Wojewodzka, U.;

    2008-01-01

    Ternary lipid compositions in model membranes segregate into large-scale liquid-ordered (L(o)) and liquid-disordered (L(d)) phases. Here, we show mum-sized lipid domain separation leading to vesicle formation in unperturbed human HaCaT keratinocytes. Budding vesicles in the apical portion of the....... Based on these observations we describe the energetic requirements for plasma membrane vesiculation. We propose that the decrease in total 'L(o)/L(d)' boundary line tension arising from the coalescence of smaller L(d)-like domains makes it energetically favourable for L(d)-like domains to bend from flat...

  17. Electrophysiology of mycoplasma membranes.

    OpenAIRE

    Schummer, U.; Schiefer, H G

    1983-01-01

    The influence of transmembrane ion fluxes on mycoplasma membrane potentials was studied. Fluorescence intensity of potential-sensitive carbocyanine dyes was calibrated vs. electric membrane potential. Potassium and sodium ion diffusion potentials significantly contributed to mycoplasma membrane potential. Chloride ions were obviously freely permeable across mycoplasma membranes. Under growth conditions the mycoplasma membrane potential was estimated to be delta psi = - 80 mV.

  18. Evaluation of apical deviation in root canals instrumented with K3 and ProTaper systems Avaliação do desvio apical em canais instrumentados pelos sistemas K3 e ProTaper

    Directory of Open Access Journals (Sweden)

    Mariana Diniz Bisi dos Santos

    2006-12-01

    Full Text Available OBJECTIVES: this study evaluated the apical deviation of curved root canals instrumented with K3 and ProTaper systems. MATERIAL AND METHODS: twenty root canals of human maxillary and mandibular first molars were employed, which were divided into 2 groups: group A (10 teeth was instrumented with the K3 system, and group B (10 teeth with the ProTaper system. Evaluation of deviation was performed by double radiographic exposure. Radiographs were achieved before and after instrumentation, with 0.3-second, thus allowing superimposition of images. Three-dimensional computerized tomograph was performed in 3 specimens in each group, as an additional means to evaluate the apical deviation. RESULTS: were evaluated by the parametric test Student-Newman-Keuls at 5%, which did not reveal significance between groups concerning the apical deviation. The results of computerized tomograph images demonstrated that the larger deviation of the root canal occurred at the distolingual area for both systems. CONCLUSIONS: both techniques produced a mild apical deviation. Computerized microtomography was shown to be accurate for experimental endodontics studies.OBJETIVOS: avaliar o desvio apical de canais radiculares curvos instrumentados pelos sistemas K3 e ProTaper. MATERIAIS E MÉTODOS: foram utilizados 20 canais radiculares de primeiros molares superiores e inferiores humanos, os quais foram divididos em 2 grupos, o grupo A (10 dentes foi instrumentado pelo sistema K3 e o grupo B (10 dentes com o sistema ProTaper, a forma de avaliação do desvio foi a dupla exposição radiográfica. As tomadas radiográficas foram feitas antes e após a instrumentação, com um tempo de 0,3 segundos em cada exposição, ocorrendo assim, sobreposição das imagens. Em 3 espécimes, de cada grupo, foi realizada a tomografia computadorizada tridimensional, como forma adicional de avaliar o desvio apical . Os resultados obtidos foram avaliados pelo teste paramétrico Student

  19. Nonsurgical management of an extensive endodontic lesion in an orthodontic patient by calcium-enriched mixture apical plug

    Directory of Open Access Journals (Sweden)

    Saeed Asgary

    2014-01-01

    Full Text Available Periapical lesion is a general term used to describe the periapical inflammatory process that occurs in response to the invasion of micro-organisms in the root canal system as well as inflamed vital pulp. This phenomenon necessitates endodontic intervention and if the necrosis has occurred prior to tooth maturation, wide patency of the apical foramen requires some treatment modalities such as apexification or apical plug. Orthodontic treatment, on the other hand, is cautiously done for previously traumatized teeth due to increased risk for necrosis of the compromised tooth. This article tends to review the successful treatment process with calcium-enriched mixture (CEM cement apical plug for an immature previously traumatized incisor tooth with an extensive periapical lesion, which was under orthodontic treatment as well.

  20. Mid-ventricular obstructive hypertrophic cardiomyopathy with apical aneurysm and sustained ventricular tachycardia: a case report and literature review

    Institute of Scientific and Technical Information of China (English)

    GAO Xiao-jin; KANG Lian-ming; ZHANG Jian; DOU Ke-fei; YUAN Jian-song; YANG Yue-jin

    2011-01-01

    The case is a 54-year-old man with hypertrophic cardiomyopathy, mid-ventricular obstruction, apical aneurysm, and recurrence sustained monomorphic ventricular tachycardia (VT). A coronary angiogram revealed myocardial bridging located in the middle of the left anterior descending coronary artery (LAD), and the left ventriculogram showed an hour-glass appearance of the left ventricular cavity. There was a significant pressure gradient of 60 mmHg across the mid-ventricular obliteration at rest. A successful myectomy of the inappropriate hypertrophy myocardium and excision of the apical aneurysm were performed. Pathologic analysis demonstrated fibrosis in the apical aneurysm and thickened and narrowed vessels in the adjacent area. During the follow-up of eighteen months, the patient remained clinically stable and free from arrhythmic recurrence.

  1. Reciprocal influence of connexins and apical junction proteins on their expressions and functions

    OpenAIRE

    Derangeon, Mickaël; Spray, David C.; Bourmeyster, Nicolas; Sarrouilhe, Denis; Hervé, Jean-Claude

    2008-01-01

    Membranes of adjacent cells form intercellular junctional complexes to mechanically anchor neighbour cells (anchoring junctions), to seal the paracellular space and to prevent diffusion of integral proteins within the plasma membrane (tight junctions) and to allow cell-to-cell diffusion of small ions and molecules (gap junctions). These different types of specialised plasma membrane microdomains, sharing common adaptor molecules, particularly zonula occludens proteins, frequently present inte...

  2. From biological membranes to biomimetic model membranes

    Directory of Open Access Journals (Sweden)

    Eeman, M.

    2010-01-01

    Full Text Available Biological membranes play an essential role in the cellular protection as well as in the control and the transport of nutrients. Many mechanisms such as molecular recognition, enzymatic catalysis, cellular adhesion and membrane fusion take place into the biological membranes. In 1972, Singer et al. provided a membrane model, called fluid mosaic model, in which each leaflet of the bilayer is formed by a homogeneous environment of lipids in a fluid state including globular assembling of proteins and glycoproteins. Since its conception in 1972, many developments were brought to this model in terms of composition and molecular organization. The main development of the fluid mosaic model was made by Simons et al. (1997 and Brown et al. (1997 who suggested that membrane lipids are organized into lateral microdomains (or lipid rafts with a specific composition and a molecular dynamic that are different to the composition and the dynamic of the surrounding liquid crystalline phase. The discovery of a phase separation in the plane of the membrane has induced an explosion in the research efforts related to the biology of cell membranes but also in the development of new technologies for the study of these biological systems. Due to the high complexity of biological membranes and in order to investigate the biological processes that occur on the membrane surface or within the membrane lipid bilayer, a large number of studies are performed using biomimicking model membranes. This paper aims at revisiting the fundamental properties of biological membranes in terms of membrane composition, membrane dynamic and molecular organization, as well as at describing the most common biomimicking models that are frequently used for investigating biological processes such as membrane fusion, membrane trafficking, pore formation as well as membrane interactions at a molecular level.

  3. In vitro sealing ability of white and gray mineral trioxide aggregate (MTA and white Portland cement used as apical plugs

    Directory of Open Access Journals (Sweden)

    Patrícia Zanatta Aranha Coneglian

    2007-06-01

    Full Text Available This study evaluated the sealing ability of apical plugs made of white and gray MTA-Angelus® and white Portland cement placed via the root canal and having different thicknesses (2, 5 and 7 mm. Ninety extracted human single-rooted teeth were instrumented using a size 40 K-file to standardize the foraminal opening by the stepback technique. The teeth were assigned to 3 groups (n=30, according to the material used for fabrication of the apical plugs: A = gray MTA; B = white MTA; C = white Portland cement. The groups were subdivided into groups of 10 teeth each according to the apical plug thickness (2, 5 and 7 mm. Marginal apical dye leakage was assessed using 0.2% Rhodamine B solution in which the specimens were immersed for 72 hours at 37ºC. The roots were sectioned longitudinally in a buccolingual direction for apical plug exposure, and digital photographs were taken and analyzed by Image Tool image-analysis software. Data were analyzed statistically by Kruskal-Wallis and Dunn's tests. Significance level was set at 5%. The least percent leakage was observed for 5- and 7-mm-thick plugs (p0.05 was found between gray MTA and white Portland cement. Among the three materials analyzed, white MTA presented the highest marginal leakage (p<0.05. The findings of the present study showed that gray MTA and Portland cement had better sealing ability than white MTA when used as apical plugs. Dye leakage was smaller for 5- and 7-mm-thick plugs compared to 2-mm-thick plugs.

  4. Carbon monoxide stimulates the apical 70-pS K+ channel of the rat thick ascending limb

    OpenAIRE

    Liu, Huajun; Mount, David B.; Nasjletti, Alberto; Wang, WenHui

    1999-01-01

    We have investigated the expression of heme oxygenase (HO) in the rat kidney and the effects of HO-dependent heme metabolites on the apical 70-pS K+ channel in the thick ascending limb (TAL). Reverse transcriptase–PCR (RT-PCR) and Western blot analyses indicate expression of the constitutive HO form, HO-2, in the rat cortex and outer medulla. Patch-clamping showed that application of 10 μM chromium mesoporphyrin (CrMP), an inhibitor of HO, reversibly reduced the activity of the apical 70-pS K...

  5. The Frequency of Plasmodesmata Increases Early in the Whole Shoot Apical Meristem of Sinapis Alba L. During Floral Transition

    OpenAIRE

    Ormenese, Sandra; Havelange, Andrée; Deltour, Roger; BERNIER, GEORGES

    2000-01-01

    The frequency of plasmodesmata increases in the shoot apical meristem of plants of Sinapis alba L. induced to flower by exposure to a single long day. This increase is observed within all cell layers (L1, L2, L3) as well as at the interfaces between these layers, and it occurs in both the central and peripheral zones of the shoot apical meristem. The extra plasmodesmata are formed only transiently, from 28 to 48 h after the start of the long day, and acropetally since they are detectable in L...

  6. ORGAN BOUNDARY1 defines a gene expressed at the junction between the shoot apical meristem and lateral organs

    OpenAIRE

    Cho, Euna; Zambryski, Patricia C.

    2011-01-01

    We identify a gene, ORGAN BOUNDARY1 (OBO1), by its unique pattern of enhancer- driven GFP expression at the boundaries between the apical meristems and lateral organs in Arabidopsis embryos, seedlings, and mature plants. OBO1 also is expressed at the root apical meristem and in distinct cell files surrounding this area. OBO1 is one of a 10-member plant-specific gene family encoding a single small domain (133 amino acids) with unknown function. One member of this gene family, OBO2, is identica...

  7. Nerve lesions following apical extrusion of non-setting calcium hydroxide: A systematic case review and report of two cases

    DEFF Research Database (Denmark)

    Olsen, Jesper Jared; Thorn, Jens Jørn; Korsgaard, Niels;

    2014-01-01

    We present two cases of apical extrusion of non-setting, calcium hydroxide paste which had been placed as an interappointment root canal dressing during routine endodontic treatment and which resulted in tissue necrosis of a large part of themandible, while. Surgical intervention consisted of...... effects and the use of an injectable system had most often been related to apical extrusion. Consequently, great care should be taken when applying the paste into the canal system. 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved....

  8. Anaerobic membrane bioreactors: Are membranes really necessary?

    OpenAIRE

    Davila, M.; Kassab, G.; Klapwijk, A.; Van, Lier, G

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A self-forming dynamic membrane only requires a support material over which a cake layer is formed, which determines the rejection properties of the system. The present research studies the applicat...

  9. Anaerobic membrane bioreactors: Are membranes really necessary?

    NARCIS (Netherlands)

    Davila, M.; Kassab, G.; Klapwijk, A.; Lier, van J.B.

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A

  10. Estudio histopatológico de las reabsorciones cemento-dentinarias de la región apical de los dientes humanos extraídos con lesión crónica en el periapice A histopathology study of resorption cementum-dentin in the apical region of human teeth extracted chronic apical lesions

    OpenAIRE

    L Nunes da Rosa

    2003-01-01

    Veintiun dientes humanos extraídos con lesión crónica apical fueron analizados por la histopatología buscando determinar la presencia de la reabsorción cemento-dentinaria en la región periapical de estos dientes. En cada diente estudiado fue introducido un instrumento endodoncico para identificar el foramen apical y todos los dientes fueron radiografiados con una técnica estándar de película radiográfica periapical No. 2. Después de la descalcificación de los dientes, éstos fueron sometidos a...

  11. Distribution of calmodulin in corn seedlings - Immunocytochemical localization in coleoptiles and root apices

    Science.gov (United States)

    Dauwalder, M.; Roux, S. J.

    1986-01-01

    Immunofluorescence techniques have been used to study the distribution of calmodulin in several tissues in etiolated corn (Zea mays, var. Bear Hybrid) seedlings. Uniform staining was seen in the background cytoplasm of most cell types. Cell walls and vacuoles were not stained. In coleoptile mesophyll cells the nucleoplasm of most nuclei was stained as was the stroma of most amyloplasts. The lumen border of mature tracheary elements in coleoptiles also stained. In the rootcap the most intensely stained regions were the cytoplasms of columella cells and of the outermost cells enmeshed in the layer of secreted slime. Nuclei in the rootcap cells did not stain distinctly, but those in all cell types of the root meristem did. Also in the root meristem, the cytoplasm of metaxylem elements stained brightly. These results are compared and contrasted with previous data on the localization of calmodulin in pea root apices and epicotyls and discussed in relation to current hypotheses on mechanisms of gravitropism.

  12. Management of immature teeth with apical infections using mineral trioxide aggregate

    Directory of Open Access Journals (Sweden)

    Sivakumar Nuvvula

    2010-01-01

    Full Text Available Traumatic injuries to the young permanent teeth lead to devitalization of the pulp with concomitant arrest in further development of the immature root of the involved tooth. Hermetic seal of the root canal system during obturation is not possible in such cases, due to the lack of an apical constriction. The traditional management technique in such cases has been apexification involving induction of a calcific barrier at the apex using calcium hydroxide, which in turn facilitates obturation of the root canal. However this becomes complicated when there is persistent infection leading to periapical changes. This case report describes the use of mineral trioxide aggregate (MTA for management of a periapically compromised immature tooth.

  13. A novel mitochondrial ATP8 gene mutation in a patient with apical hypertrophic cardiomyopathy and neuropathy.

    Science.gov (United States)

    Jonckheere, An I; Hogeveen, Marije; Nijtmans, Leo; van den Brand, Mariel; Janssen, Antoon; Diepstra, Heleen; van den Brandt, Frans; van den Heuvel, Bert; Hol, Frans; Hofste, Tom; Kapusta, Livia; Dillmann, U; Shamdeen, M; Smeitink, J; Smeitink, J; Rodenburg, Richard

    2009-01-01

    To identify the biochemical and molecular genetic defect in a 16-year-old patient presenting with apical hypertrophic cardiomyopathy and neuropathy suspected for a mitochondrial disorder.Measurement of the mitochondrial energy-generating system (MEGS) capacity in muscle and enzyme analysis in muscle and fibroblasts were performed. Relevant parts of the mitochondrial DNA were analysed by sequencing.A homoplasmic nonsense mutation m.8529G→A (p.Trp55X) was found in the mitochondrial ATP8 gene in the patient's fibroblasts and muscle tissue. Reduced complex V activity was measured in the patient's fibroblasts and muscle tissue, and was confirmed in cybrid clones containing patient-derived mitochondrial DNAWe describe the first pathogenic mutation in the mitochondrial ATP8 gene, resulting in an improper assembly and reduced activity of the complex V holoenzyme. PMID:21686774

  14. Effects of 5-fluorouracil on the mitotic activity of onion root tips apical meristem

    Directory of Open Access Journals (Sweden)

    Waldemar Lechowicz

    2015-05-01

    Full Text Available The effects of various concentrations of 5-FU on the mitotic activity of onion root tips apical meristem were investigated during 24-hour incubation in 5-FU and postincubation in water. The incubation in 5-FU caused a reversible inhibition of mitotic activity, and waves of the partially synchronised mitoses were observed during the period of postincubation. The most pronounced synchronisation of mitoses was obtained after incubation in 100 mg/l. 5-FU but the mitotic index of the resumed mitotic activity amounted to only one half of the control value. 5-FU was found to cause some cytological changes in meristematic cells such as enlargement of the nucleoli, change in the interphasic nuclei structure, appearance of subchromatid and chromatid aberrations and micronuclei. The effects of 5-FU on nucleic acids and the cell division cycle ace discussed and compared with the effects of 5-FUdR.

  15. The effect of irradiation on the cell ultrastructure of the shoot apical meristem in garlic

    International Nuclear Information System (INIS)

    Irradiation with doses of 0.02-0.3 kGy of γ-rays could cause varied damages to the cellular and subcellular structures of the shoot apical meristems in garlic. The irradiated cells were elongated and cell walls were thickened. The highest radio-sensitivity was found in the vacuoles which developed morphological abnormality before the end of dormancy, while the nuclei and nucleoli, which remained intact even after the cell walls were broken, demonstrated the highest resistance to irradiation. The observed morphological damages were of higher magnitude in sprouting period than that in dormancy in which irradiation treatments were conducted, suggesting that metabolism plays an important role in the development of initial irradiation lesions into structural damages in the cells

  16. Transcriptome profiling for discovery of genes involved in shoot apical meristem and flower development

    Directory of Open Access Journals (Sweden)

    Vikash K. Singh

    2014-12-01

    Full Text Available Flower development is one of the major developmental processes that governs seed setting in angiosperms. However, little is known about the molecular mechanisms underlying flower development in legumes. Employing RNA-seq for various stages of flower development and few vegetative tissues in chickpea, we identified differentially expressed genes in flower tissues/stages in comparison to vegetative tissues, which are related to various biological processes and molecular functions during flower development. Here, we provide details of experimental methods, RNA-seq data (available at Gene Expression Omnibus database under GSE42679 and analysis pipeline published by Singh and colleagues in the Plant Biotechnology Journal (Singh et al., 2013, along with additional analysis for discovery of genes involved in shoot apical meristem (SAM development. Our data provide a resource for exploring the complex molecular mechanisms underlying SAM and flower development and identification of gene targets for functional and applied genomics in legumes.

  17. Gingival recession following apical surgery in the esthetic zone: a clinical study with 70 cases

    DEFF Research Database (Denmark)

    von Arx, Thomas; Salvi, Giovanni E; Janner, Simone;

    2009-01-01

    The present study evaluated gingival recession 1 year following apical surgery of 70 maxillary anterior teeth (central and lateral incisors, canines, and first premolars). A visual assessment of the mid-facial aspect of the gingival level and of papillary heights of treated teeth was carried out...... using photographs taken at pre-treatment and 1-year follow-up appointments. In addition, changes in the gingival margin (GM) and clinical attachment levels (CAL) were calculated with the use of clinical measurements, that is, pre-treatment and 1-year follow-up pocket probing depth and level of gingival...... margin. Changes in GM and CAL were then correlated with patient-, tooth-, and surgery-related parameters. The following parameters were found to significantly influence changes in GM and CAL over time: gingival biotype (P < 0.05), with thin biotype exhibiting more gingival recession than thick biotype...

  18. Improved Vision from Severe Compressive Optic Neuropathy by Apical Cavernous Hemangioma.

    Science.gov (United States)

    Kang, Hyera; Takahashi, Yasuhiro; Nishimura, Kunihiro; Yasuda, Muneyoshi; Akutsu, Hiroyoshi; Kakizaki, Hirohiko

    2016-01-01

    A 59-year-old woman had a 1-year history of right vision loss. Her visual acuity was then 0.01 OD, and the critical flicker frequency (CFF) was 8 Hz OD. Goldmann perimetry examination showed inferior suppression of the right visual field center. Funduscopic examination revealed normal coloring of the right optic disc. Imaging studies showed an apical oval tumor. The optic nerve was compressed by both the tumor and the superior rectus muscle/levator palpebrae superioris complex. The tumor was dissected from the surrounding tissues and completely extracted. Histopathologic examination confirmed a cavernous hemangioma. The patient underwent three cycles of postoperative steroid pulse therapy. One year after the surgery, her visual acuity and CFF improved to 1.0 and 32 Hz OD, respectively. Her right visual field was within the normal range. PMID:27099610

  19. Micro-CT analyses of apical enlargement and molar root canal complexity

    DEFF Research Database (Denmark)

    Markvart, Merete; Darvann, Tron Andre; Larsen, Per;

    2012-01-01

    AIM: To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity. METHODOLOGY: Maxillary and mandibular molar teeth were...... scanned using X-ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a RaCe/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root...... canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size and complexity, and consequences of unprepared portions of narrow root canals and intraradicular connections/isthmuses were included in the analyses. One- and two-way anova were...

  20. Prevalence of apical periodontitis and endodontic treatment in a Kosovar adult population

    Directory of Open Access Journals (Sweden)

    Kamberi Blerim

    2011-11-01

    Full Text Available Abstract Background Despite numerous studies on the prevalence of apical periodontitis (AP and endodontic treatment in diverse geographical populations, there are currently no data on the prevalence of these conditions in populations of adults native to Kosovo. Therefore, little is known about how widespread these conditions are, and whether there is any correlation between root canal treatment and AP. The purpose of our research was to address this anomaly by investigating AP and endodontic treatment in an adult Kosovar population based on radiographic examination. Methods The sample used for this study consisted of randomly selected individuals referred to the University Dentistry Clinical Center of Kosovo in the years 2006-2007. Orthopantomographs of 193 patients were evaluated. The periapical status of all teeth (with the exception of third molars was examined according to Ørstavik's Periapical Index. The quality of the root canal filling was rated as 'adequate' or 'inadequate' based on whether all canals were filled, the depth of fill relative to the radiographic apex and the quality of compaction (absence/presence of voids. Data were analyzed statistically using the Chi-square test and calculation of odds ratios. Results Out of 4131 examined teeth, the prevalence of apical periodontitis (AP and endodontic treatment was 12.3% and 2.3%, respectively. Of 95 endodontically-treated teeth, 46.3% were associated with AP. The prevalence of AP increased with age. The prevalence in subjects aged over 60 years old (20.2% was higher than in other age groups. A statistically significant difference was found for the frequency of endodontically-treated teeth associated with AP in the 40-49 year age group (P Conclusions The prevalence of AP and the frequency of endodontically-treated teeth with AP in this Kosovar population are higher than those found in other countries. Inadequate root canal fillings were associated with an increased prevalence of AP.

  1. Influence of intracanal post on apical periodontitis identified by cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Estrela, Carlos; Porto, Olavo Cesar Lyra; Rodrigues, Cleomar Donizeth [Federal University of Goias (UFG), Goiania, GO (Brazil). Dental School; Bueno, Mike Reis [University of Cuiaba (UNIC), MT (Brazil). Dental School; Pecora, Jesus Djalma, E-mail: estrela3@terra.com.b [University of Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Dental School

    2009-07-01

    The determination of the success of endodontic treatment has been often discussed based on outcome obtained by periapical radiography. The aim of this study was to verify the influence of intracanal post on apical periodontitis detected by cone-beam computed tomography (CBCT). A consecutive sample of 1020 images (periapical radiographs and CBCT scans) taken from 619 patients (245 men; mean age, 50.1 years) between February 2008 and September 2009 were used in this study. Presence and intracanal post length (short, medium and long) were associated with apical periodontitis (AP). Chi-square test was used for statistical analyses. Significance level was set at p<0.01. The kappa value was used to assess examiner variability. From a total of 591 intracanal posts, AP was observed in 15.06%, 18.78% and 7.95% using periapical radiographs, into the different lengths, short, medium and long, respectively (p=0.466). Considering the same posts length it was verified AP in 24.20%, 26.40% and 11.84% observed by CBCT scans, respectively (p=0.154). From a total of 1,020 teeth used in this study, AP was detected in 397 (38.92%) by periapical radiography and in 614 (60.19%) by CBCT scans (p<0.001). The distribution of intracanal posts in different dental groups showed higher prevalence in maxillary anterior teeth (54.79%). Intracanal posts lengths did not influenced AP. AP was detected more frequently when CBCT method was used. (author)

  2. Apically extruded debris with three contemporary Ni-Ti instrumentation systems: An ex vivo comparative study

    Directory of Open Access Journals (Sweden)

    Logani Ajay

    2008-01-01

    Full Text Available Aim: To comparatively evaluate the amount of apically extruded debris when ProTaper hand, ProTaper rotary and ProFile systems were used for the instrumentation of root canals. Materials and Methods: Thirty minimally curved, mature, human mandibular premolars with single canals were randomly divided into three groups of ten teeth each. Each group was instrumented using one of the three instrumentation systems: ProTaper hand, ProTaper rotary and ProFile. Five milliliters of sterile water were used as an irrigant. Debris extruded was collected in preweighed polyethylene vials and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre- and postinstrumentation weight of polyethylene vials for each group. Statistical Analysis: The Kruskal-Wallis nonparametric test and Mann-Whitney U test were applied to determine if significant differences existed among the groups ( P < 0.05. Results: All instruments tested produced a measurable amount of debris. No statistically significant difference was observed between ProTaper hand and ProFile system ( P > 0.05. Although ProTaper rotary extruded a relatively higher amount of debris, no statistically significant difference was observed between this type and the ProTaper hand instruments ( P > 0.05. The ProTaper rotary extruded significantly more amount of debris compared to the ProFile system ( P < 0.05. Conclusion: Within the limitations of this study, it can be concluded that all instruments tested produced apical extrusion of debris. The ProTaper rotary extruded a significantly higher amount of debris than the ProFile.

  3. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Nanekrungsan, Kamonporn [Dept. of Dentistry, Overbrook Hospital, Chiang Rai (Thailand); Patanaporn, Virush; Janhom, Apirum; Korwanich, Narumanus [Dept. of Chiang Mai University, Chiang Mai (Thailand)

    2012-09-15

    This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. The periapical radiographs of 564 teeth showed that the average root resorption was 1.39{+-}1.27 (8.24{+-}7.22%) and 1.69{+-}1.14 mm (10.16{+-}6.78%) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

  4. The sound sensation of apical electric stimulation in cochlear implant recipients with contralateral residual hearing.

    Directory of Open Access Journals (Sweden)

    Diane S Lazard

    Full Text Available BACKGROUND: Studies using vocoders as acoustic simulators of cochlear implants have generally focused on simulation of speech understanding, gender recognition, or music appreciation. The aim of the present experiment was to study the auditory sensation perceived by cochlear implant (CI recipients with steady electrical stimulation on the most-apical electrode. METHODOLOGY/PRINCIPAL FINDINGS: Five unilateral CI users with contralateral residual hearing were asked to vary the parameters of an acoustic signal played to the non-implanted ear, in order to match its sensation to that of the electric stimulus. They also provided a rating of similarity between each acoustic sound they selected and the electric stimulus. On average across subjects, the sound rated as most similar was a complex signal with a concentration of energy around 523 Hz. This sound was inharmonic in 3 out of 5 subjects with a moderate, progressive increase in the spacing between the frequency components. CONCLUSIONS/SIGNIFICANCE: For these subjects, the sound sensation created by steady electric stimulation on the most-apical electrode was neither a white noise nor a pure tone, but a complex signal with a progressive increase in the spacing between the frequency components in 3 out of 5 subjects. Knowing whether the inharmonic nature of the sound was related to the fact that the non-implanted ear was impaired has to be explored in single-sided deafened patients with a contralateral CI. These results may be used in the future to better understand peripheral and central auditory processing in relation to cochlear implants.

  5. External apical root resorption in maxillary incisors in orthodontic patients: associated factors and radiographic evaluation

    International Nuclear Information System (INIS)

    This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. The periapical radiographs of 564 teeth showed that the average root resorption was 1.39±1.27 (8.24±7.22%) and 1.69±1.14 mm (10.16±6.78%) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

  6. Influence of intracanal post on apical periodontitis identified by cone-beam computed tomography

    International Nuclear Information System (INIS)

    The determination of the success of endodontic treatment has been often discussed based on outcome obtained by periapical radiography. The aim of this study was to verify the influence of intracanal post on apical periodontitis detected by cone-beam computed tomography (CBCT). A consecutive sample of 1020 images (periapical radiographs and CBCT scans) taken from 619 patients (245 men; mean age, 50.1 years) between February 2008 and September 2009 were used in this study. Presence and intracanal post length (short, medium and long) were associated with apical periodontitis (AP). Chi-square test was used for statistical analyses. Significance level was set at p<0.01. The kappa value was used to assess examiner variability. From a total of 591 intracanal posts, AP was observed in 15.06%, 18.78% and 7.95% using periapical radiographs, into the different lengths, short, medium and long, respectively (p=0.466). Considering the same posts length it was verified AP in 24.20%, 26.40% and 11.84% observed by CBCT scans, respectively (p=0.154). From a total of 1,020 teeth used in this study, AP was detected in 397 (38.92%) by periapical radiography and in 614 (60.19%) by CBCT scans (p<0.001). The distribution of intracanal posts in different dental groups showed higher prevalence in maxillary anterior teeth (54.79%). Intracanal posts lengths did not influenced AP. AP was detected more frequently when CBCT method was used. (author)

  7. Right Ventricular Apical Flattening as an Echocardiographic Screening Tool for Right Ventricular Enlargement.

    Science.gov (United States)

    Buddhe, Sujatha; Ferguson, Mark; Arya, Bhawna; Soriano, Brian D

    2016-03-01

    Right ventricular dilation is a common complication after tetralogy of Fallot (TOF) repair. Traditional echocardiographic assessments are imprecise due to the RV's location and complex geometry. We propose a novel echocardiographic measurement: RV apical flattening (RVAF) as a screening tool to help identify subjects with severe RV dilation. Patients with repaired TOF who had both echocardiograms and CMR's within 6-month interval at our institution were included in the study. The RVAF was measured in the four-chamber echocardiographic view as the minor length of RV cavity at the level of RV apical endocardium. Subjects were divided into two groups (group I: RVEDVi ≥ 150 ml/m(2) and group II; RVEDVi < 150 ml/m(2)). Echocardiogram and CMR data were compared between groups. A total of 75 subjects were included in the study. Mean age was 12.8 ± 3.6 years. Group I had 36 subjects, and group II had 39 subjects. The mean RVAF was significantly higher in group I (2.7 ± 0.5 cm) compared with group II (1.7 ± 0.4 cm; p < 0.001). There was significant correlation between RVAF and RVEDVi (r = 0.81; p < 0.001). By ROC analysis, an RVAF cutoff value of 2.0 cm had 94 % sensitivity and 77 % specificity in identifying severe RV dilation (area under the curve 0.95). RVAF is a simple and effective echocardiographic screening tool to help identify severe RV dilation. In conjunction with other 2D echocardiographic parameters, this technique would help further refine echocardiography-guided patient selection for timing of CMR and pulmonary valve replacement. PMID:26667958

  8. Erythrocyte membrane proteins and membrane skeleton

    Institute of Scientific and Technical Information of China (English)

    LU Yiqin; LIU Junfan

    2007-01-01

    Considerable advances in the research field of erythrocyte membrane were achieved in the recent two decades.New findings in the structure-function correlation and interactions of erythrocyte membrane proteins have attracted extensive attention.Interesting progress was also made in the molecular pathogenesis of erythrocyte membrane disorders.Advances in the composition,function and interaction of erythrocyte membrane proteins,erythrocyte membrane skeleton,and relevant diseases are briefly described and summarized here on the basis of domestic and world literatures.

  9. A preliminary study of the percentage of gutta-percha-filled area in the apical canal filled with vertically compacted warm gutta-percha

    NARCIS (Netherlands)

    Wu, MK; van der Sluis, LWM; Wesselink, PR

    2002-01-01

    Aim The aim of this study was to determine the influence of the width of apical root canals and the depth of heat application during warm vertical compaction on the percentage of gutta-percha-filled area (PGFA) in the apical root canal. Methodology Two groups of extracted human canines (total 60) we

  10. A membrane disdrometer based on membrane vibration

    International Nuclear Information System (INIS)

    Raindrop sizes were indirectly determined through the distinctive vibrations and sounds that occur when raindrops of different sizes impact on a membrane. The relationships between diameter, raindrop kinetic momentum, membrane deflection, and impact force were analyzed. Membrane deflection and vibration models were created, and the optimum membrane diameter and thickness were identified. A prototype membrane disdrometer was developed on the basis of these findings. The relationship between raindrop size and membrane vibration sound pressure was determined experimentally. The fundamental parameter of raindrop size recognition was used. The test results indicate that raindrops 0.4–2.0 mm in diameter can be detected by the proposed membrane disdrometer, and 50 raindrops per second in a zone area of 28.3 cm2 can be detected in natural rain. (paper)

  11. Inducción del cierre apical en el diente con necrosis pulpar y el ápice no formado

    OpenAIRE

    Canalda Sahli, Carlos

    1988-01-01

    Se efectúa una revisión del proceso de apicoformación en dientes con necrosis pulpar y ápice no formado, analizando el mecanismo de cierre apical inducido por el hidróxido de calcio y otras substancias, así como la histopatología del mismo.

  12. Dopamine Induces LTP Differentially in Apical and Basal Dendrites through BDNF and Voltage-Dependent Calcium Channels

    Science.gov (United States)

    Navakkode, Sheeja; Sajikumar, Sreedharan; Korte, Martin; Soong, Tuck Wah

    2012-01-01

    The dopaminergic modulation of long-term potentiation (LTP) has been studied well, but the mechanism by which dopamine induces LTP (DA-LTP) in CA1 pyramidal neurons is unknown. Here, we report that DA-LTP in basal dendrites is dependent while in apical dendrites it is independent of activation of L-type voltage-gated calcium channels (VDCC).…

  13. MHV-A59 enters polarized murine epithelial cells through the apical surface but is released basolaterally

    NARCIS (Netherlands)

    Rossen, J W; Voorhout, W F; Horzinek, M C; van der Ende, A; Strous, G J; Rottier, P J

    1995-01-01

    Coronaviruses have a marked tropism for epithelial cells. Entry and release of the porcine transmissible gastroenteritis virus (TGEV) is restricted to apical surfaces of polarized epithelial cells, as we have recently shown (J. W. A. Rossen, C. P. J. Bekker, W. F. Voorhout, G. J. A. M. Strous, A. va

  14. The importance of apical domination and the size of foliar surface in the acclimatisation process of Chrysanthemum exvitroplantlets

    OpenAIRE

    Adriana PETRUS-VANCEA

    2006-01-01

    In this experiment it was studied the effects of apical domination and foliar surface in Chrysanthemum exvitroplantlets surviving to normal condition of life. I found that the survivor of Chrysanthemum exvitroplantlets has depended of harming rate at which they were exposed.

  15. The importance of apical domination and the size of foliar surface in the acclimatisation process of Chrysanthemum exvitroplantlets

    Directory of Open Access Journals (Sweden)

    Adriana PETRUS-VANCEA

    2006-05-01

    Full Text Available In this experiment it was studied the effects of apical domination and foliar surface in Chrysanthemum exvitroplantlets surviving to normal condition of life. I found that the survivor of Chrysanthemum exvitroplantlets has depended of harming rate at which they were exposed.

  16. Evaluation of Apical Micro-leakage of Different Endodontic Sealers in the Presence and Absence of Moisture.

    Science.gov (United States)

    Ehsani, Maryam; Dehghani, Atena; Abesi, Farida; Khafri, Soraya; Ghadiri Dehkordi, Sara

    2014-01-01

    Background and aims. With availability of hydrophilic sealers, drying of the canals before endodontic obturation is still a matter of debate. The aim of this study was to compare the apical micro-leakage of AH26, Excite DSC, MTA Fillapex, and ZOE sealers in dry and moist root canals. Materials and methods. This experimental study was performed on 90 extracted maxillary central incisors. Rotary files were used for preparation of the canals. Root canals were filled with a single gutta percha cone, using one of the four sealers, under dry and moist root canal conditions (10 teeth in each group). Orifices were sealed with glue wax and all root surfaces were covered with nail polish except the positive control group. After ten days in 100% humidity, teeth were placed in methylene blue, and then were cut in longitudinal axis. Blue color permeability was measured by stereomicroscope in micrometers. Data were analyzed by t-test, ANOVA and Scheffe post hoc test using SPSS V.18 software at P 0.05). Apical micro-leakage was significantly higher in the Excite DSC groups (P < 0.001). Conclusion. AH26 provided the least apical micro-leakage under dry conditions while ZOE had the highest micro-leakage under moist conditions. MTA Fillapex provided acceptable apical seal regardless of moisture. PMID:25346829

  17. Changes in ratio of soluble sugars and free amino nitrogen in the apical meristem during floral transition of tobacco

    Science.gov (United States)

    Rideout, J. W.; Raper, C. D. Jr; Miner, G. S.; Raper CD, J. r. (Principal Investigator)

    1992-01-01

    Under a modification of the nutrient diversion hypothesis, we propose that an inequality in carbohydrate and nitrogen translocation to the apical meristem may be a controlling factor in floral transition. Experiments were conducted in controlled-environment chambers to determine the associations between microscopic characteristics of the transition from vegetative to floral stages of the apical meristem of flue-cured tobacco and to assimilate concentrations in the plant and apical meristem. Low temperature, nitrogen withdrawal, and restriction of nitrogen uptake were used as treatment variables. In all of these stress treatments, flowering occurred at a lesser number of leaves than in control treatments. Low temperature stress accelerated the time of transition to the floral stage as compared with a high temperature control; however, nitrogen stress did not accelerate the time of transition. All stress treatments affected the levels of nitrogen and carbohydrate in whole plants. Most notable was an increase in the percentage of starch and a decrease in the percentage of total soluble carbohydrate induced by the stress treatments. These data indicate that tobacco plants under stress accumulate excess carbohydrate in the form of starch. An apparent inequality in the relative concentrations of carbohydrate and nitrogen in the apical meristem was observed in all treatments at the time of floral transition and is in support of the nutrient diversion hypothesis.

  18. Regrowth patterns and rosette attributes contribute to the differential compensatory responses of Arabidopsis thaliana genotypes to apical damage.

    Science.gov (United States)

    Scholes, D R; Wszalek, A E; Paige, K N

    2016-03-01

    A plant's compensatory performance refers to its ability to maintain or increase its reproductive output following damage. The ability of a plant to compensate depends on numerous factors including the type, severity, frequency and timing of damage, the environmental conditions and the plant's genotype. Upon apical damage, a cascade of hormonal and genetic responses often produces dramatic changes in a plant's growth, development, architecture and physiology. All else being equal, this response is largely dependent on a plant's genotype, with different regrowth patterns displayed by different genotypes of a given species. In this study, we compare the architectural and growth patterns of two Arabidopsis thaliana genotypes following apical damage. Specifically, we characterise regrowth patterns of the genotypes Columbia-4 and Landsberg erecta, which typically differ in their compensation to apical meristem removal. We report that Landsberg erecta suffered reductions in the number of stems produced, maximum elongation rate, a delay in reaching this rate, lower average rosette quality throughout the growing period, and ultimately, less aboveground dry biomass and seed production when damaged compared to undamaged control plants. Columbia-4 had no reductions in any of these measures and maintained larger rosette area when clipped relative to when unclipped. Based on the apparent influence of the rosette on these genotypes' compensatory performances, we performed a rosette removal experiment, which confirmed that the rosette contributes to compensatory performance. This study provides a novel characterisation of regrowth patterns following apical damage, with insights into those measures having the largest effect on plant performance. PMID:26434737

  19. Evaluation of Apical Micro-leakage of Different Endodontic Sealers in the Presence and Absence of Moisture

    Directory of Open Access Journals (Sweden)

    Maryam Ehsani

    2014-09-01

    Full Text Available Background and aims. With availability of hydrophilic sealers, drying of the canals before endodontic obturation is still a matter of debate. The aim of this study was to compare the apical micro-leakage of AH26, Excite DSC, MTA Fillapex, and ZOE sealers in dry and moist root canals. Materials and methods. This experimental study was performed on 90 extracted maxillary central incisors. Rotary files were used for preparation of the canals. Root canals were filled with a single gutta percha cone, using one of the four seal-ers, under dry and moist root canal conditions (10 teeth in each group. Orifices were sealed with glue wax and all root sur-faces were covered with nail polish except the positive control group. After ten days in 100% humidity, teeth were placed in methylene blue, and then were cut in longitudinal axis. Blue color permeability was measured by stereomicroscope in mi-crometers. Data were analyzed by t-test, ANOVA and Scheffe post hoc test using SPSS V.18 software at P 0.05. Apical micro-leakage was significantly higher in the Excite DSC groups (P < 0.001. Conclusion. AH26 provided the least apical micro-leakage under dry conditions while ZOE had the highest micro-leakage under moist conditions. MTA Fillapex provided acceptable apical seal regardless of moisture.

  20. Apical extrusion of debris and irrigants using hand and three rotary instrumentation systems- An in vitro study

    Directory of Open Access Journals (Sweden)

    Koppolu Madhusudhana

    2010-01-01

    Full Text Available Introduction: Sterilization of the root canal is a prime aim of successful endodontics. The cleaning and shaping of the canal is directed as achieving this goal. The extrusion of apical debris has a deleterious effect on the prognosis of root canal treatment. Several instrument designs and instrumentation techniques have been developed to prevent this. Materials and Methods: Forty caries free single rooted human mandibular premolar teeth were divided in four groups of ten teeth each. Teeth in each group were instrumented until the working length with rotary ProTaper, K3, Mtwo systems, and hand K-type stainless steel files. Debris and irrigant extruded from the apical foramen were collected into vials and the amounts were quantitatively determined. The data obtained were analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests. Results: The results show that all instrumentation techniques produced significant amount of extruded debris and irrigant. The engine-driven nickel-titanium systems showed less apical extrusion of debris and irrigant than manual technique. No statistically significant difference was found between the groups at [P > 0.05]. Maximum apical debris and irrigant extrusion was seen with K-file group and least in the Mtwo group. Conclusions: The use of rotary files and techniques to perform instrumentation does show less extrusion of the debris and irrigant from the apex. This can contribute to more successful endodontic therapy.

  1. Ultrathin Polymer Membranes with Patterned, Micrometric Pores for Organs-on-Chips.

    Science.gov (United States)

    Pensabene, Virginia; Costa, Lino; Terekhov, Alexander Y; Gnecco, Juan S; Wikswo, John P; Hofmeister, William H

    2016-08-31

    The basal lamina or basement membrane (BM) is a key physiological system that participates in physicochemical signaling between tissue types. Its formation and function are essential in tissue maintenance, growth, angiogenesis, disease progression, and immunology. In vitro models of the BM (e.g., Boyden and transwell chambers) are common in cell biology and lab-on-a-chip devices where cells require apical and basolateral polarization. Extravasation, intravasation, membrane transport of chemokines, cytokines, chemotaxis of cells, and other key functions are routinely studied in these models. The goal of the present study was to integrate a semipermeable ultrathin polymer membrane with precisely positioned pores of 2 μm diameter in a microfluidic device with apical and basolateral chambers. We selected poly(l-lactic acid) (PLLA), a transparent biocompatible polymer, to prepare the semipermeable ultrathin membranes. The pores were generated by pattern transfer using a three-step method coupling femtosecond laser machining, polymer replication, and spin coating. Each step of the fabrication process was characterized by scanning electron microscopy to investigate reliability of the process and fidelity of pattern transfer. In order to evaluate the compatibility of the fabrication method with organs-on-a-chip technology, porous PLLA membranes were embedded in polydimethylsiloxane (PDMS) microfluidic devices and used to grow human umbilical vein endothelial cells (HUVECS) on top of the membrane with perfusion through the basolateral chamber. Viability of cells, optical transparency of membranes and strong adhesion of PLLA to PDMS were observed, thus confirming the suitability of the prepared membranes for use in organs-on-a-chip devices. PMID:27513606

  2. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  3. Compositional asynchronous membrane systems

    Institute of Scientific and Technical Information of China (English)

    Cosmin Bonchis; Cornel Izbasa; Gabriel Ciobanu

    2007-01-01

    This paper presents an algorithmic way of building complex membrane systems by coupling elementary membranes. Its application seems particularly valuable in the case of asynchronous membrane systems, since the resulting membrane system remains asynchronous. The composition method is based on a handshake mechanism implemented by using antiport rules and promoters.

  4. Composite sensor membrane

    Science.gov (United States)

    Majumdar, Arun; Satyanarayana, Srinath; Yue, Min

    2008-03-18

    A sensor may include a membrane to deflect in response to a change in surface stress, where a layer on the membrane is to couple one or more probe molecules with the membrane. The membrane may deflect when a target molecule reacts with one or more probe molecules.

  5. Brachial plexopathy from stereotactic body radiotherapy in early-stage NSCLC: Dose-limiting toxicity in apical tumor sites

    International Nuclear Information System (INIS)

    Background and purpose: We report frequency of brachial plexopathy in early-stage non-small cell lung cancer treated with stereotactic body radiotherapy. Materials and methods: 276 T1-T2, N0 or peripheral T3, N0 lesions were treated in 253 patients with stereotactic radiotherapy at Indiana University and Richard L. Roudebush VAMC from 1998 to 2007. Thirty-seven lesions in 36 patients were identified as apical lesions, defined as epicenter of lesion superior to aortic arch. Brachial plexus toxicity was scored for these apical lesions according to CTCAE v. 3.0 for ipsilateral shoulder/arm neuropathic pain, motor weakness, or sensory alteration. Results: The 37 apical lesions (19 Stage IA, 16 IB, and 2 IIB) were treated with stereotactic body radiotherapy to a median total dose of 57 Gy (30-72). The associated brachial plexus of 7/37 apical lesions developed grade 2-4 plexopathy (4 pts - grade 2, 2 pts - grade 3, 1 pt - grade 4). Five patients had ipsilateral shoulder/arm neuropathic pain alone, one had pain and upper extremity weakness, and one had pain progressing to numbness of the upper extremity and paralysis of hand and wrist. The median of the maximum brachial plexus doses of patients developing brachial plexopathy was 30 Gy (18-82). Two-year Kaplan-Meier risk of brachial plexopathy for maximum brachial plexus dose >26 Gy was 46% vs 8% for doses ≤26 Gy (p = 0.04 for likelihood ratio test). Conclusions: Stereotactic body radiotherapy for apical lesions carries a risk of brachial plexopathy. Brachial plexus maximum dose should be kept <26 Gy in 3 or 4 fractions.

  6. Estudio histopatológico de las reabsorciones cemento-dentinarias de la región apical de los dientes humanos extraídos con lesión crónica en el periapice A histopathology study of resorption cementum-dentin in the apical region of human teeth extracted chronic apical lesions

    Directory of Open Access Journals (Sweden)

    L Nunes da Rosa

    2003-04-01

    Full Text Available Veintiun dientes humanos extraídos con lesión crónica apical fueron analizados por la histopatología buscando determinar la presencia de la reabsorción cemento-dentinaria en la región periapical de estos dientes. En cada diente estudiado fue introducido un instrumento endodoncico para identificar el foramen apical y todos los dientes fueron radiografiados con una técnica estándar de película radiográfica periapical No. 2. Después de la descalcificación de los dientes, éstos fueron sometidos a la técnica histológica de rutina y evaluados histopatologicamente, observandose un diagnóstico de lesión apical y la presencia o no de re absorción y compensación cemento-dentinaria. De estas lesiones crónicas observadas, nueve eran cistos apicales, cinco granulomas y siete abscesos crónicos. De los veintiun dientes estudiados, veinte presentaron re absorción cementaria y diecisiete presentaron re absorción cemento-dentinaria.Twenty-one human teeth extracted with chronic apicallesions were analyzed histopathologically to determine the presence of resorptions of dentin and cementum in the apical region of these teeth. An endodontic file was introduced in each tooth for identification of the apical foramen and a roentgenography was taken with standard technique in number 2 xRay film. After decalcification the teeth were sectioned and only the apical third was analyzed. The teeth underwent the routine histological technic and histopathologically evaluated, the diagnosis of the chronic apicallesion and the presence or not of dentine and cementum resorption and compensation were observed. Nine of the chronic lesions observed were apical cysts, five granulomas and seven chronic abscesses. Out of twenty-one teeth analyzed, twenty teeth presented cementum resorption and seventeen presented dentine and cementum resorption.

  7. Comparison of Apical Microleakage of Lateral Compaction Technique and Vertical Compaction Technique

    Institute of Scientific and Technical Information of China (English)

    Sahibzada Mohammad Noor; Xie Xiao Li

    2007-01-01

    Objective: The aim of this study was to assess the sealing ability of lateral compaction technique and vertical compaction technique using glucose penetration model. Glucose penetration model (GPM) has only twice been used earlier, hence the second aim of the study was to correlate the results of this study to other results and to validate the efficacy of GPM. Materals and Methods: Fifty three straight anterior human maxillary teeth were randomly divided into five groups.Root canals were prepared using crown down technique. Group A had fourteen teeth. They were compacted using vertical compaction technique. AH plus was used as root canal sealer. Group B had eight teeth. These were also compacted with vertical compaction but without AH plus. Group C had thirteen teeth. All the teeth in group C were compacted using lateral compaction using AH Plus. Group D had eight teeth. The teeth in this group were compacted using lateral compaction technique without AH plus. Group E had ten teeth. This group was assigned as negative control group. The specimen of the negative control group were completely coated with aryldite. The roots of the experimental groups were covered with aryldite, except for the root canal orifices, and apical apices. The coronal end of the decoronated tooth was connected to a plastic tube that contained 18% glucose solution. Leakage along the root filling was measured by the concentration of glucose in apical reservoir at 7, 14, 21 and 28 days intervals respectively after treatment. Results: Using repeated measure ANOVA, the leakage was significantly different among test groups A and C at 7, 14, 21 and 28 days interval respectively(P < 0.001). Data from Groups C and D also varied significantly. No statistical difference was found between groups A, B and D. Glucose concentrations at 21,28 days were higher than that at 7, 14 days in all of the four groups. Conclusion:The sealing ability of lateral compaction technique was found to be better than

  8. Membrane fluids and Dirac membrane fluids

    CERN Document Server

    Ivanov, M G

    2004-01-01

    The relation between two different methods of membrane fluid description is clarified by construction of combined method. Dirac membrane field appears naturally in new approach. It provides a possibility to consider new aspects of electrodynamics-type theories with electric and magnetic sources. The membrane fluid models automatically prohibit simulatenos existence of electric and magnetic currents. Possible applications to the dark energy problem are mentioned.

  9. Sheet Membrane Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Bue, Grant; Trevino, Luis; Zapata, Felipe; Dillion, Paul; Castillo, Juan; Vonau, Walter; Wilkes, Robert; Vogel, Matthew; Frodge, Curtis

    2013-01-01

    A document describes a sheet membrane spacesuit water membrane evaporator (SWME), which allows for the use of one common water tank that can supply cooling water to the astronaut and to the evaporator. Test data showed that heat rejection performance dropped only 6 percent after being subjected to highly contaminated water. It also exhibited robustness with respect to freezing and Martian atmospheric simulation testing. Water was allowed to freeze in the water channels during testing that simulated a water loop failure and vapor backpressure valve failure. Upon closing the backpressure valve and energizing the pump, the ice eventually thawed and water began to flow with no apparent damage to the sheet membrane. The membrane evaporator also serves to de-gas the water loop from entrained gases, thereby eliminating the need for special degassing equipment such as is needed by the current spacesuit system. As water flows through the three annular water channels, water evaporates with the vapor flowing across the hydrophobic, porous sheet membrane to the vacuum side of the membrane. The rate at which water evaporates, and therefore, the rate at which the flowing water is cooled, is a function of the difference between the water saturation pressure on the water side of the membrane, and the pressure on the vacuum side of the membrane. The primary theory is that the hydrophobic sheet membrane retains water, but permits vapor pass-through when the vapor side pressure is less than the water saturation pressure. This results in evaporative cooling of the remaining water.

  10. Clinical application of 64-slice spiral CT for apical hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical application values of 64-row MSCT for apical hypertrophic cardiomyopathy (AHCM). Methods: Twenty-one patients with AHCM were included in this study, 14 patients were diagnosed by echocardiography (UCG), and 7 patients were diagnosed by MRI. All patients underwent MSCT exam, and 5 patients also had ventriculography and coronary angiography. The left ventricular wall thickness in end-systole and end-diastole phases were measured at MSCT workstation, the left ventricular apex thickening rate (LVAT) and the ratio of maximum wall thickness of the left ventricular apex (LVA) to the left ventrieular posterior wall thickness (LVA/LVPW) in end-diastole phase were calculated. The left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) were quantitatively evaluated with cardiac functional analysis software. The results were compared with the measurement results from the normal control group (30 volunteers). The independent-samples t test was used for the statistics. At the same time, the coronary stenosis was measured. Results: Diffuse or partial thickening of the LV apical myocardium were found in the four-chamber view and two-chamber view of MSCT images, which leaded to the deformation of the left ventricle chamber. The LVEDV were (82.6± 11.4) and (108.5±10.6) ml in the AHCM group and the control group, respectively; the LVA were (20.6±3.4) and (9.9±1.5) mm; LVA/LVPW were 2.1±0.5 and 1.1±0.2; the LVAT were (25.6± 4.7)% and (81.5±8.5)%. There were significant differences in LYEDV, LVA, LVA/LVPW and LVAT between the two groups (t=8.32 and 15.29, P 0.05). Five patients had myocardium bridging and 4 patients had coronary stenosis. Conclusion: AHCM can be diagnosed accurately with MSCT, and the cardiac anatomy, function and coronary artery are also assessed simultaneously. (authors)

  11. T1-nerve root neuroma presenting with apical mass and Horner's syndrome

    Directory of Open Access Journals (Sweden)

    Podnar Simon

    2007-03-01

    Full Text Available Abstract Background The appearance of dumbbell neuroma of the first thoracic root is extremely rare. The extradural component of a T1-dumbbell neuroma may present as an apical mass. The diagnosis of hand weakness is complex and may be delayed in T1-neuroma because of absence of the palpable cervical mass. One-stage removal of a T1-root neuroma and its intrathoracic extension demanded an extended posterior midline approach in the sitting position. Case presentation A 51-year old man had suffered a traumatic partial tendon rupture of his wrist flexor muscles 6 years ago. Since the incident he occasionally felt fullness and tenderness in the affected forearm with some tingling in his fingers bilaterally. During the last two years the hand weakness was continuous and hypotrophy of the medial flexor and intrinsic hand muscles had become apparent. Electrophysiological studies revealed an ulnar neuropathy in addition to mild median and radial nerve dysfunction, including a mild contralateral carpal tunnel syndrome. The diagnostic work-up for multiple mononeuropathy in the upper extremity was negative. Repeated electrophysiological studies revealed fibrillations in the C7 paravertebral muscles on the affected side. Chest x-ray revealed a large round apical mass on the affected side. A Horner's syndrome was noted at this point of diagnostic work-up. MRI of the cervical and thoracic spine revealed a dumbbell T1 neuroma enlarging the intervertebral foramen at T1-2 and a 5 cm large extradural tumor with extension into the apex of the ipsilateral lung. The patient underwent surgery in sitting position using a left dorsal midline approach. Although the T1 root could not be preserved, the patient's neurological condition was unchanged after the surgery. Conclusion Extended posterior midline exposure described here using hemilaminectomy, unilateral facetectomy and costo-transversectomy is efficient and safe for one-stage removal of dumbbell tumors at the T1

  12. The Effect of Using Patency File on Apical Transportation in Canals Prepared with Passive Step Back Technique

    Directory of Open Access Journals (Sweden)

    S M Hasheminia

    2004-10-01

    Full Text Available Background: The purpose of this study was to assess the effect of patency file on apical transportation in curved canals prepared with passive step back (P.S.B technique. Methods: This is an interceptive experimental, Invitro, study. Human extracted first permanent molars with 19-23mm length and curvature of 15-35 degrees (Schneider method were considered for use in this study. Simple sampling was done and 35 teeth for each group was selected. In experimental group A canal preparation was done with P.S.B technique and usage of a # 10 file (as Patency file between successive files. In experimental group B preparation was done in the same way except for usage of patency file. Pre and post operative radiographs were taken with similar condition. Radiographs were scanned and changes in canal curvature was determined using four different methods [Schneider, Weine, Long – Axis techniques (L. A.T, and Digital image overlay technique (overlay. T] , using Idrisi for windows and AutoCAD softwares. Results: The mean of canal transportation angle in experimental group A with Schneider, Weine , LAT, and Over Lay techniques was: 7.006 ± 3.478, 12. 285 ± 6.032, 4.376 ± 3.516, 3.147 ± 2.744 respectively. Mean of canal transportation angle in experimental group B with the same methods was also determined: 8.009 ± 4.178, 13.55 ± 7.602, 9.464 ± 5.384, and 9.641 ± 5.382 respectively. T- test statistical analysis shows that there are no significant differences between the mean of canal transportation angles in two groups as measured by Schneider and Weine method (P>0.05. Mann- Whitney test shows that there are statistically significant differences between two groups as measured by LAT and Over Lay techniques (P<0.001. Conclusions: Results of this study shows that patency file in conjunction with P.S.B techniques causes significant reduction in apical transportation angle. Shortcomings of Schneider method in determination of canal curvature and specially

  13. Dormência e dominância apical de diferentes tamanhos de tubérculos de batata Dormancy and apical dominance of different sizes of potato tubers

    Directory of Open Access Journals (Sweden)

    Douglas Renato Müller

    2010-12-01

    Full Text Available O tamanho dos tubérculos de batata produzidos em uma mesma cova é um indicativo da idade fisiológica e do período necessário para o rompimento da dormência e da dominância apical, o que é fundamental para o adequado manejo pós-colheita. O objetivo deste trabalho foi avaliar o período de dormência e de dominância apical em diferentes tamanhos de tubérculos de três clones de batata, produzidos no outono e submetidos a duas temperaturas de armazenamento. Os tubérculos foram produzidos em campo durante o outono de 2008, sendo colhidas dez covas por clone. Os tubérculos de cada cova foram individualmente identificados e avaliados para massa fresca, comprimento e maior e menor diâmetros, divididos em dois lotes de cinco covas e armazenados, respectivamente, nas temperaturas de 10 e 20°C±2°C e 85%±5% de umidade relativa, por 170 dias. O rompimento da dormência e da dominância apical foram anotados quando o tubérculo apresentou, respectivamente, um ou dois brotos. O experimento foi conduzido em um fatorial de três clones (SMINIA00017-6, SMIJ461-1 e Asterix, duas temperaturas de armazenamento (10 e 20°C e três tipos de tubérculo (menor diâmetro inferior a 35mm, entre 35 e 45mm e superior a 45mm, no delineamento experimental inteiramente casualizado. A partir dos resultados, concluiu-se que a idade fisiológica varia com o tamanho dos tubérculos de batata, sendo que tubérculos com diâmetro inferior a 35mm apresentam maior período de dormência. Além disso, foi constatado que a temperatura de armazenamento de 20°C é mais eficaz para o rompimento da dormência do que da dominância apical.The size of potato tubers produced in the same hill is an indicator of the physiological age and the time required to break dormancy and apical dominance, which is essential for the proper post-harvest management. The objective of this study was to evaluate the period of dormancy and apical dominance of different tuber sizes of three

  14. Na+ and K+ transport at basolateral membranes of epithelial cells. I. Stoichiometry of the Na,K-ATPase

    OpenAIRE

    1986-01-01

    The stoichiometry of pump-mediated Na/K exchange was studied in isolated epithelial sheets of frog skin. 42K influx across basolateral membranes was measured with tissues in a steady state and incubated in either beakers or in chambers. The short-circuit current provided estimates of Na+ influx at the apical membranes of the cells. 42K influx of tissues bathed in Cl- or SO4-Ringer solution averaged approximately 8 microA/cm2. Ouabain inhibited 94% of the 42K influx. Furosemide was without eff...

  15. An essential role for the MAL protein in targeting Lck to the plasma membrane of human T lymphocytes

    OpenAIRE

    Antón, Olga; Batista, Alicia; Millán, Jaime; Andrés-Delgado, Laura; Puertollano, Rosa; Correas, Isabel; Alonso, Miguel A.

    2008-01-01

    The MAL protein is an essential component of the specialized machinery for apical targeting in epithelial cells. The src family kinase Lck plays a pivotal role in T cell signaling. We show that MAL is required in T cells for efficient expression of Lck at the plasma membrane and activation of IL-2 transcription. To investigate the mechanism by which MAL regulates Lck targeting, we analyzed the dynamics of Lck and found that it travels to the plasma membrane in specific transport carriers cont...

  16. Expression of soybean nodulin 26 in transgenic tobacco. Targeting to the vacuolar membrane and effects on floral and seed development.

    OpenAIRE

    Zhang, Y.; Roberts, D M

    1995-01-01

    Nodulin 26 is an integral membrane protein of the symbiosome membrane of nitrogen-fixing soybean nodules. We expressed a nodulin 26 cDNA in transgenic tobacco (TN26 tobacco) under the control of the cauliflower mosaic virus 35S promoter to study subcellular targeting and the physiological effect(s) of its expression. Based on Northern and Western blots, the expression of nodulin 26 mRNA and protein in transgenic plants is high in apical shoot sections, flowers, and stems, low in mature leaves...

  17. Membrane Automata with Priorities

    Institute of Scientific and Technical Information of China (English)

    Luděk Cienciala; Lucie Ciencialová

    2004-01-01

    In this paper the one-way P automata with priorities are introduced. Such automata are P systemshere the membranes are only allowed to consume objects from parent membranes, under the given conditions. The result of computation of these systems is the set of multiset sequences consumed by skin membrane intc the system. The rules associated in some order with each membrane cannot modify any objects, they can only move them through membrane. We show that P automata with priorities and two membranes can accept every recursively enumerated language.

  18. A novel Bruch's membrane-mimetic electrospun substrate scaffold for human retinal pigment epithelium cells.

    Science.gov (United States)

    Xiang, Ping; Wu, Kun-Chao; Zhu, Ying; Xiang, Lue; Li, Chong; Chen, Deng-Long; Chen, Feng; Xu, Guotong; Wang, Aijun; Li, Min; Jin, Zi-Bing

    2014-12-01

    Various artificial membranes have been used as scaffolds for retinal pigment epithelium cells (RPE) for monolayer reconstruction, however, long-term cell viability and functionality are still largely unknown. This study aimed to construct an ultrathin porous nanofibrous film to mimic Bruch's membrane, and in particular to investigate human RPE cell responses to the resultant substrates. An ultrathin porous nanofibrous membrane was fabricated by using regenerated wild Antheraea pernyi silk fibroin (RWSF), polycaprolactone (PCL) and gelatin (Gt) and displayed a thickness of 3-5 μm, with a high porosity and an average fiber diameter of 166 ± 85 nm. Human RPE cells seeded on the RWSF/PCL/Gt membranes showed a higher cell growth rate (p < 0.05), and a typical expression pattern of RPE signature genes, with reduced expression of inflammatory mediators. With long-term cultivation on the substrates, RPE cells exhibited characteristic polygonal morphology and development of apical microvilli. Immunocytochemisty demonstrated RPE-specific expression profiles in cells after 12-weeks of co-culture on RWSF/PCL/Gt membranes. Interestingly, the cells on the RWSF/PCL/Gt membranes functionally secreted polarized PEDF and phagocytosed labeled porcine POS. Furthermore, RWSF/PCL/Gt membranes transplanted subsclerally exhibited excellent biocompatibility without any evidence of inflammation or rejection. In conclusion, we established a novel RWSF-based substrate for growth of RPE cells with excellent cytocompatibility in vitro and biocompatibility in vivo for potential use as a prosthetic Bruch's membrane for RPE transplantation. PMID:25220295

  19. Apical sealing of root canal fillings performed with five different endodontic sealers: analysis by fluid filtration

    Directory of Open Access Journals (Sweden)

    Bruno Carvalho de Vasconcelos

    2011-08-01

    Full Text Available OBJECTIVES: To evaluate the sealing ability of five root canal sealers, including two experimental cements (MBP and MTA-Obtura using the fluid filtration method. MATERIAL AND METHODS: Teeth were divided into 5 study groups: G1-AH Plus; G2-Acroseal; G3Sealapex; G4-MBP; G5-MTA-Obtura; and two controls. Chemical-mechanical preparation was performed with ProFile rotary nickel-titanium instruments 1 mm short of the apical foramen. The sealing ability was evaluated by fluid filtration at 15, 30, and 60 days. RESULTS: The statistical analysis showed significant difference between the materials at different periods (p<0.05. AH Plus and MBP had similar leakage values at 15 and 60 days, alternating with significant reduction at 30 days, while the other materials showed progressive increase in leakage values. Acroseal and Sealapex presented the best results at 15 days and the worst at 60 days. CONCLUSIONS: All sealers evaluated presented fluid leakage, with AH Plus and MBP showing the best results at the end of the experimental period. Acroseal, Sealapex, and MTA-Obtura presented increase in leakage values at longer observation periods.

  20. MTA apical barrier: In vitro study of the use of ultrasonic vibration

    Science.gov (United States)

    Escribano-Escrivá, Begona; Manzano-Saiz, Alberto; Giner-Lluesma, Teresa; Collado-Castellanos, Nicolás; Muwaquet-Rodríguez, Susana

    2016-01-01

    Background The apexification is the first alternative treatment on a permanent tooth when, after a tooth trauma and in the presence of immature apex trauma, pulp necrosis occurs. Many studies have demonstrated the efficacy of mineral trioxide aggregate (MTA) as apical sealing material of choice in these cases, but has a degree of filtration as all other materials. The objective of this study was to analyze the seal ability of MTA on the duct walls in immature teeth unirradicular apexes, using indirect vibration. Material and Methods The study was conducted on 45 teeth divided into 3 groups: Group A or control group in which no vibration for placing the MTA was used, Group B and C or groups where indirect vibration analysis was used. All samples were immersed in methylene blue to assess filtration. After performing longitudinal cuts millimetric measuring were made of the degree of filtration, divided into 3 degrees (2mm each grade filtration). Results Results obtained confirm our hypothesis, obtaining lesser degree of filtration those groups in which indirect vibration (Groups B and C) was performed. It was shown that the degree of filtration is closely linked to the degree of adaptation. Conclusions MTA vibration offers better results in its adaptation to the canal walls, significantly reducing the degree of filtration. Key words:Apexification, MTA, filtration, indirect vibration. PMID:27398184

  1. Length and activity of the root apical meristem revealed in vivo by infrared imaging.

    Science.gov (United States)

    Bizet, François; Hummel, Irène; Bogeat-Triboulot, Marie-Béatrice

    2015-03-01

    Understanding how cell division and cell elongation influence organ growth and development is a long-standing issue in plant biology. In plant roots, most of the cell divisions occur in a short and specialized region, the root apical meristem (RAM). Although RAM activity has been suggested to be of high importance to understand how roots grow and how the cell cycle is regulated, few experimental and numeric data are currently available. The characterization of the RAM is difficult and essentially based upon cell length measurements through destructive and time-consuming microscopy approaches. Here, a new non-invasive method is described that couples infrared light imaging and kinematic analyses and that allows in vivo measurements of the RAM length. This study provides a detailed description of the RAM activity, especially in terms of cell flux and cell division rate. We focused on roots of hydroponic grown poplars and confirmed our method on maize roots. How the RAM affects root growth rate is studied by taking advantage of the high inter-individual variability of poplar root growth. An osmotic stress was applied and did not significantly affect the RAM length, highlighting its homeostasis in short to middle-term responses. The methodology described here simplifies a lot experimental procedures, allows an increase in the number of individuals that can be taken into account in experiments, and means new experiments can be formulated that allow temporal monitoring of the RAM length. PMID:25540436

  2. Reverse or inverted apical ballooning in a case of refeeding syndrome

    Institute of Scientific and Technical Information of China (English)

    Pablo; Robles; Isabel; Monedero; Amador; Rubio; Javier; Botas

    2015-01-01

    Takotsubo cardiomyopathy is characterized by the development of transient left ventricular regional wall motion abnormalities,in the absence of significant coronary artery obstruction. This syndrome usually occurs in women and is frequently associated with an intense emotional or physical stress. It usually involves apical segments,but in the recent years atypical forms have been described. Inverted or reverse Takotsubo is a variant in which the basal and midventricular segments are hypokinetic,sparing contractile function of the apex. In this report we describe the case of a 54-year-old woman,with chronic malnutrition,initially admitted because of hypoglycemia and severe electrolyte disturbance due to a refeeding syndrome. Within the next hours she experienced acute cardiac symptoms and developed heart failure with low cardiac output. Electrocardiogram(ECG),elevation of troponin and echocardiographic findings were consistent with inverted Takotsubo cardiomyopathy. To the best of our knowledge,this is the first incidence reported of inverted Takotsubo triggered by refeeding syndrome.

  3. Correlation of apical fluid-regulating channel proteins with lung function in human COPD lungs.

    Directory of Open Access Journals (Sweden)

    Runzhen Zhao

    Full Text Available Links between epithelial ion channels and chronic obstructive pulmonary diseases (COPD are emerging through animal model and in vitro studies. However, clinical correlations between fluid-regulating channel proteins and lung function in COPD remain to be elucidated. To quantitatively measure epithelial sodium channels (ENaC, cystic fibrosis transmembrane conductance regulator (CFTR, and aquaporin 5 (AQP5 proteins in human COPD lungs and to analyze the correlation with declining lung function, quantitative western blots were used. Spearman tests were performed to identify correlations between channel proteins and lung function. The expression of α and β ENaC subunits was augmented and inversely associated with lung function. In contrast, both total and alveolar type I (ATI and II (ATII-specific CFTR proteins were reduced. The expression level of CFTR proteins was associated with FEV1 positively. Abundance of AQP5 proteins and extracellular superoxide dismutase (SOD3 was decreased and correlated with spirometry test results and gas exchange positively. Furthermore, these channel proteins were significantly associated with severity of disease. Our study demonstrates that expression of ENaC, AQP5, and CFTR proteins in human COPD lungs is quantitatively associated with lung function and severity of COPD. These apically located fluid-regulating channels may thereby serve as biomarkers and potent druggable targets of COPD.

  4. Phenotypical and structural characterization of the Arabidopsis mutant involved in shoot apical meristem

    Institute of Scientific and Technical Information of China (English)

    Zhe HU; Ping LI; Jinfang MA; Yunlong WANG; Xinyu WANG; Chongying WANG

    2008-01-01

    An Arabidopsis mutant induced by T-DNA insertion was studied with respect to its phenotype, micro-structure of shoot apical meristem (SAM) and histo-chemical localization of the GUS gene in comparison with the wild type. Phenotypical observation found that the mutant exhibited a dwarf phenotype with smaller organs (such as smaller leaves, shorter petioles), and slower development and flowering time compared to the wild type. Optical microscopic analysis of the mutant showed that it had a smaller and more flattened SAM, with reduced cell layers and a shortened distance between two leaf primordia compared with the wild type. In addi-tion, analysis of the histo-chemical localization of the GUS gene revealed that it was specifically expressed in the SAM and the vascular tissue of the mutant, which suggests that the gene trapped by T-DNA may function in the SAM, and T-DNA insertion could influence the functional activity of the related gene in the mutant, lead-ing to alterations in the SAM and a series of phenotypes in the mutant.

  5. Dental age estimation of growing children by measurement of open apices: A Malaysian formula

    Directory of Open Access Journals (Sweden)

    Navaneetha Cugati

    2015-01-01

    Full Text Available Background: Age estimation is of prime importance in forensic science and clinical dentistry. Age estimation based on teeth development is one reliable approach. Many radiographic methods are proposed on the Western population for estimating dental age, and a similar assessment was found to be inadequate in Malaysian population. Hence, this study aims at formulating a regression model for dental age estimation in Malaysian children population using Cameriere′s method. Materials and Methods: Orthopantomographs of 421 Malaysian children aged between 5 and 16 years involving all the three ethnic origins were digitalized and analyzed using Cameriere′s method of age estimation. The subjects′ age was modeled as a function of the morphological variables, gender (g, ethnicity, sum of normalized open apices (s, number of tooth with completed root formation (N 0 and the first-order interaction between s and N 0 . Results: The variables that contributed significantly to the fit were included in the regression model, yielding the following formula: Age = 11.368-0.345g + 0.553N o -1.096s - 0.380s.N o , where g is a variable, 1 for males and 2 for females. The equation explained 87.1% of total deviance. Conclusion: The results obtained insist on reframing the original Cameriere′s formula to suit the population of the nation specifically. Further studies are to be conducted to evaluate the applicability of this formula on a larger sample size.

  6. Connective Auxin Transport in the Shoot Facilitates Communication between Shoot Apices.

    Science.gov (United States)

    Bennett, Tom; Hines, Geneviève; van Rongen, Martin; Waldie, Tanya; Sawchuk, Megan G; Scarpella, Enrico; Ljung, Karin; Leyser, Ottoline

    2016-04-01

    The bulk polar movement of the plant signaling molecule auxin through the stem is a long-recognized but poorly understood phenomenon. Here we show that the highly polar, high conductance polar auxin transport stream (PATS) is only part of a multimodal auxin transport network in the stem. The dynamics of auxin movement through stems are inconsistent with a single polar transport regime and instead suggest widespread low conductance, less polar auxin transport in the stem, which we term connective auxin transport (CAT). The bidirectional movement of auxin between the PATS and the surrounding tissues, mediated by CAT, can explain the complex auxin transport kinetics we observe. We show that the auxin efflux carriers PIN3, PIN4, and PIN7 are major contributors to this auxin transport connectivity and that their activity is important for communication between shoot apices in the regulation of shoot branching. We propose that the PATS provides a long-range, consolidated stream of information throughout the plant, while CAT acts locally, allowing tissues to modulate and be modulated by information in the PATS. PMID:27119525

  7. Sample Preparation of Arabidopsis thaliana Shoot Apices for Expression Studies of Photoperiod-Induced Genes.

    Science.gov (United States)

    Andrés, Fernando; Torti, Stefano; Vincent, Coral; Coupland, George

    2016-01-01

    Plants produce new organs from a population of pluripotent cells which are located in specific tissues called meristems. One of these meristems, the shoot apical meristem (SAM), gives rise to leaves during the vegetative phase and flowers during the reproductive phase. The transition from vegetative SAM to an inflorescence meristem (IM) is a dramatic developmental switch, which has been particularly well studied in the model species Arabidopsis thaliana. This developmental switch is controlled by multiple environmental signals such as day length (or photoperiod), and it is accompanied by changes in expression of hundreds of genes. A major interest in plant biology is to identify and characterize those genes which are regulated in the stem cells of the SAM in response to the photoperiodic signals. In this sense, techniques such as RNA in situ hybridization (RNA ISH) have been very successfully employed to detect the temporal and spatial expression patterns of genes in the SAM. This method can be specifically optimized for photoperiodic-flowering studies. In this chapter, we describe improved methods to generate plant material and histological samples to be combined with RNA ISH in flowering-related studies. PMID:26867617

  8. Dysfunctional mitochondria regulate the size of root apical meristem and leaf development in Arabidopsis

    Science.gov (United States)

    Hsieh, Wei-Yu; Liao, Jo-Chien; Hsieh, Ming-Hsiun

    2015-01-01

    Mitochondria play an important role in maintaining metabolic and energy homeostasis in the plant cell. Thus, perturbation of mitochondrial structure and function will affect plant growth and development. Arabidopsis slow growth3 (slo3) is defective in At3g61360 that encodes a pentatricopeptide repeat (PPR) protein. Analysis of slo3 mitochondrial RNA metabolism revealed that the splicing of nad7 intron 2 is impaired, which leads to a dramatic reduction in complex I activity. So the SLO3 PPR protein is a splicing factor that is required for the removal of nad7 intron 2 in Arabidopsis. The slo3 mutant plants have obvious phenotypes with severe growth retardation and delayed development. The size of root apical meristem (RAM) is reduced and the production of meristem cells is decreased in slo3. Furthermore, the rosette leaves of slo3 are curled or crinkled, which may be derived from uneven growth of the leaf surface. The underlying mechanisms by which dysfunctional mitochondria affect these growth and developmental phenotypes have yet to be established. Nonetheless, plant hormone auxin is known to play an important role in orchestrating the development of RAM and leaf shape. It is possible that dysfunctional mitochondria may interact with auxin signaling pathways to regulate the boundary of RAM and the cell division arrest front during leaf growth in Arabidopsis. PMID:26237004

  9. Genetic control of morphometric diversity in the maize shoot apical meristem.

    Science.gov (United States)

    Leiboff, Samuel; Li, Xianran; Hu, Heng-Cheng; Todt, Natalie; Yang, Jinliang; Li, Xiao; Yu, Xiaoqing; Muehlbauer, Gary J; Timmermans, Marja C P; Yu, Jianming; Schnable, Patrick S; Scanlon, Michael J

    2015-01-01

    The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate genes. Analyses of candidate genes implicated in hormone transport, cell division and cell size confirm correlations between SAM morphology and trait-associated SNP alleles. Our data illustrate that the microscopic seedling SAM is predictive of adult phenotypes and that SAM morphometric variation is associated with genes not previously predicted to regulate SAM size. PMID:26584889

  10. New insights in shoot apical meristem morphogenesis: Isotropy comes into play

    Science.gov (United States)

    Sassi, Massimiliano; Traas, Jan

    2015-01-01

    The great complexity and plasticity of aerial plant shapes largely results from the activity of the shoot apical meristem (SAM), a group of undifferentiated cells which produces all the aboveground organs of the plant. Organogenesis at the SAM is regulated by the hormone auxin, which, through an integration of active transport, signalling and transcriptional regulation, determines the positional and temporal information dictating where, when, and how a new organ will be formed. At the cellular level, the information stemming from the regulatory molecular networks influences the growth of the cells within the tissue to give rise to the final organ shape. The growth of plant cells is mainly controlled by the cell wall, a rigid structure mainly made of polysaccharides, which surrounds the cells and links them together in an organismal continuum. Over the years, several lines of evidence have pointed at a role for the regulation of the elasticity of the cell wall, downstream of auxin action, in the formation of organs at the SAM. We have recently shown that auxin also induces a shift toward isotropic growth by modulating the organization of cortical microtubules in peripheral SAM cells, which promotes organ formation. Here, we discuss our results and identify new hypotheses to drive future research. PMID:26337646

  11. HANABA TARANU regulates the shoot apical meristem and leaf development in cucumber (Cucumis sativus L.).

    Science.gov (United States)

    Ding, Lian; Yan, Shuangshuang; Jiang, Li; Liu, Meiling; Zhang, Juan; Zhao, Jianyu; Zhao, Wensheng; Han, Ying-Yan; Wang, Qian; Zhang, Xiaolan

    2015-12-01

    The shoot apical meristem (SAM) is essential for continuous organogenesis in higher plants, while the leaf is the primary source organ and the leaf shape directly affects the efficiency of photosynthesis. HANABA TARANU (HAN) encodes a GATA3-type transcription factor that functions in floral organ development, SAM organization, and embryo development in Arabidopsis, but is involved in suppressing bract outgrowth and promoting branching in grass species. Here the function of the HAN homologue CsHAN1 was characterized in cucumber, an important vegetable with great agricultural and economic value. CsHAN1 is predominantly expressed at the junction of the SAM and the stem, and can partially rescue the han-2 floral organ phenotype in Arabidopsis. Overexpression and RNAi of CsHAN1 transgenic cucumber resulted in retarded growth early after embryogenesis and produced highly lobed leaves. Further, it was found that CsHAN1 may regulate SAM development through regulating the WUSCHEL (WUS) and SHOOT MERISTEMLESS (STM) pathways, and mediate leaf development through a complicated gene regulatory network in cucumber. PMID:26320238

  12. Fine Mapping of qPAA8, a Gene Controlling Panicle Apical Development in Rice

    Institute of Scientific and Technical Information of China (English)

    Zhi-Jun Cheng; Bi-Gang Mao; Su-Wei Gao; Ling Zhang; Jiu-Lin Wang; Cai-Lin Lei; Xin Zhang

    2011-01-01

    In rice,one detrimental factor influencing single panicle yield is the frequent occurrence of panicle apical abortion (PAA) under unfavorable climatic conditions.Until now,no detailed genetic information has been available to avoid PAA in rice breeding.Here,we show that the occurrence of PAA is associated with the accumulation of excess hydrogen peroxide.Quantitative trait loci (QTLs) mapping for PAA in an F2 population derived from the cross of L-05261 (PAA line) x IRAT129 (non-PAA variety) identified seven QTLs over a logarithm of the odd (LOD) threshold of 2.5,explaining approximately 50.1% of phenotypic variance for PAA in total.Five of the QTLs with an increased effect from L-05261,were designated as qPAA3-1,qPAA3-2,qPAA4,qPAA5 and qPAA8,and accounted for 6.8%,5.9%,4.2%,13.0% and 12.2%of phenotypic variance,respectively.We found that the PAA in the early heading plants was mainly controlled by qPAA8.Subsequently,using the sub-populations specific for qPAA8 based on markerassisted selection,we further narrowed qPAA8 to a 37.6-kb interval delimited by markers RM22475 and 8-In1 12.These results are beneficial for PAA gene clone.

  13. Connective Auxin Transport in the Shoot Facilitates Communication between Shoot Apices

    Science.gov (United States)

    Bennett, Tom; Hines, Geneviève; van Rongen, Martin; Sawchuk, Megan G.; Scarpella, Enrico; Ljung, Karin

    2016-01-01

    The bulk polar movement of the plant signaling molecule auxin through the stem is a long-recognized but poorly understood phenomenon. Here we show that the highly polar, high conductance polar auxin transport stream (PATS) is only part of a multimodal auxin transport network in the stem. The dynamics of auxin movement through stems are inconsistent with a single polar transport regime and instead suggest widespread low conductance, less polar auxin transport in the stem, which we term connective auxin transport (CAT). The bidirectional movement of auxin between the PATS and the surrounding tissues, mediated by CAT, can explain the complex auxin transport kinetics we observe. We show that the auxin efflux carriers PIN3, PIN4, and PIN7 are major contributors to this auxin transport connectivity and that their activity is important for communication between shoot apices in the regulation of shoot branching. We propose that the PATS provides a long-range, consolidated stream of information throughout the plant, while CAT acts locally, allowing tissues to modulate and be modulated by information in the PATS. PMID:27119525

  14. Dental age estimation of growing children by measurement of open apices: A Malaysian formula

    Science.gov (United States)

    Cugati, Navaneetha; Kumaresan, Ramesh; Srinivasan, Balamanikanda; Karthikeyan, Priyadarshini

    2015-01-01

    Background: Age estimation is of prime importance in forensic science and clinical dentistry. Age estimation based on teeth development is one reliable approach. Many radiographic methods are proposed on the Western population for estimating dental age, and a similar assessment was found to be inadequate in Malaysian population. Hence, this study aims at formulating a regression model for dental age estimation in Malaysian children population using Cameriere's method. Materials and Methods: Orthopantomographs of 421 Malaysian children aged between 5 and 16 years involving all the three ethnic origins were digitalized and analyzed using Cameriere's method of age estimation. The subjects’ age was modeled as a function of the morphological variables, gender (g), ethnicity, sum of normalized open apices (s), number of tooth with completed root formation (N0) and the first-order interaction between s and N0. Results: The variables that contributed significantly to the fit were included in the regression model, yielding the following formula: Age = 11.368-0.345g + 0.553No -1.096s - 0.380s.No, where g is a variable, 1 for males and 2 for females. The equation explained 87.1% of total deviance. Conclusion: The results obtained insist on reframing the original Cameriere's formula to suit the population of the nation specifically. Further studies are to be conducted to evaluate the applicability of this formula on a larger sample size. PMID:26816464

  15. Cytotoxic effect of the debris apically extruded during three different retreatment procedures.

    Science.gov (United States)

    Silva, Emmanuel J N L; Brito, Mônica E; Ferreira, Vivian D; Belladonna, Felipe G; Neves, Aline A; Senna, Plinio M; De-Deus, Gustavo

    2016-01-01

    We evaluated the cytotoxic effects of the debris apically extruded during root canal retreatment on primary human osteoblast (HOb) cells in vitro. TNF-α and IL-1β levels were also measured. We examined three different techniques: conventional hand-files, and Mtwo and Reciproc retreatments. Filled mandibular incisors were prepared for a cytotoxicity assay in an experimental root model. The material was divided into three groups according to the technique used. Ten teeth were used as control. HOb cells were exposed to the extruded content and cytotoxicity was evaluated using the MTT test (assessing cell metabolic activity). TNF-α and IL-1β production was also analyzed using enzyme-linked immunosorbent assay. Then, all the teeth were radiographed and the residual filling material was quantified. Data were subjected to analysis of variance (ANOVA) and Tukey's test (P endodontic retreatment techniques led to a significant upregulation of IL-1β levels (P 0.05). The Reciproc system required less time than the other two methods to remove the root-filling materials (P endodontic retreatment with Reciproc was the least cytotoxic and the least time-consuming method of gutta-percha and sealer removal. (J Oral Sci 58, 211-217, 2016). PMID:27349542

  16. [Daily temperature gradients and processes of organogenesis in apical meristem of Cucumis sativus L].

    Science.gov (United States)

    Markovskaia, E F; Sysoeva, M I; Vasilevskaia, N V

    2007-01-01

    We studied the influence of daily temperature gradients on organogenesis in apical and axil shoot meristems at different developmental stages in Cucumis sativus L. The level of organogenic activity of meristems was determined according to the number of leaf primordia on the main and lateral shoots, number of 2nd order shoots, and rudiments of flowers of different levels of development. At the studied ontogenetic stages (mesotrophic seedling or juvenile state), plants were grown under the controlled conditions: photoperiod 12 h, light intensity 100 Wt/m2, range of mean daily temperatures 20 ... 30 degrees C, and daily temperature gradients -20 ... +20 degrees C. After the temperature treatment, some plants were returned to the optimal, for growth and development, conditions for two weeks (aftereffect). Three types of organogenic activity of meristems in response to the influence of variable daily temperatures were described: stimulation, inhibition, or absence of effect. The phenomenon of stimulation includes two subtypes: optimization, when a maximum effect, observed at other constant temperatures, was attained under the influence of variable temperatures and maximization, when maximum values markedly exceeded those at constant temperatures. The patterns described are preserved on the whole in the aftereffect of daily temperatures. PMID:17352290

  17. Mean apical concentration and duration in the comparative bioavailability of slowly absorbed and eliminated drug preparations.

    Science.gov (United States)

    Pollak, P T; Freeman, D J; Carruthers, S G

    1988-06-01

    Present criteria for comparing bioavailability are inadequate when the Cmax and tmax cannot be reliably identified in individual subjects. Drug formulations which are slowly absorbed and eliminated have concentration-time profiles with a broad apex, increasing the likelihood that samples taken at the apical region of the curve will have statistically indistinguishable concentrations. Using data from a study of three dosage forms of piroxicam, we propose an alternative approach which decreases the influence of sampling bias and analytical error on the identification of the apex of the concentration-time curve and provides a simple tool for describing the shape of the curve around the apex. An adequate frequency of sampling around the expected apex of the concentration-time curve and consideration of the coefficient of variation (CV) of the analytical assay when assessing the observed Cmax are used in defining new parameters. This approach may be useful for studying the relationship of onset and duration of maximal plasma concentration to the efficacy and toxicity of drugs and in developing standards for comparing the bioavailability of slow-release preparations, which is of increasing interest to pharmaceutical companies and regulatory agencies. PMID:3171924

  18. Emerging Role of the Ubiquitin Proteasome System in the Control of Shoot Apical Meristem Function

    Institute of Scientific and Technical Information of China (English)

    Elisabetta Di Giacomo; Giovanna Serino; Giovanna Frugis

    2013-01-01

    The shoot apical meristem (SAM) is a population of undifferentiated cells at the tip of the shoot axis that establishes early during plant embryogenesis and gives rise to all shoot organs throughout the plant's life.A plethora of different families of transcription factors (TFs) play a key role in establishing the equilibrium between cell differentiation and stem cell maintenance in the SAM.Fine tuning of these regulatory proteins is crucial for a proper and fast SAM response to environmental and hormonal cues,and for development progression.One effective way to rapidly inactivate TFs involves regulated proteolysis by the ubiquitin/26S proteasome system (UPS).However,a possible role of UPS-dependent protein degradation in the regulation of key SAM TFs has not been thoroughly investigated.Here,we summarize recent evidence supporting a role for the UPS in SAM maintenance and function.We integrate this survey with an in silico analysis of publicly-available microarray databases which identified ubiquitin ligases that are expressed in specific areas within the SAM,suggesting that they may regulate or act downstream of meristem-specific factors.

  19. Estudio morfológico del extremo apical inactivo de diversas limas mediante microscopía electrónica de barrido

    OpenAIRE

    Canalda Sahli, Carlos; Berástegui, Esther; Arroyo Bote, Sebastiana; Rais, A.; Brau Aguadé, Esteban

    1995-01-01

    Diversas firmas han manufacturado limas con el extremo apical inactivo para permitir efectuar la instrumentación de los conductos con una acción rotatoria. El objetivo de este estudio fue evaluar el extremo apical de estas limas (diámetros 30, 40 y 50) mediante microscopía electrónica de barrido, comparándolas con otras limas clásicas. Se observó en todas ellas un extremo apical sin espiras, a diferencia de las limas K convencionales.

  20. Apical and periapical repair of dogs' teeth with periapical lesions after endodontic treatment with different root canal sealers

    Directory of Open Access Journals (Sweden)

    Leonardo Mário Roberto

    2003-01-01

    Full Text Available The aim of this study was to evaluate the apical and periapical repair after root canal treatment of dogs' teeth with pulp necrosis and chronic periapical lesion using different root canal sealers. After periapical lesion induction, forty-four root canals of 3 dogs were submitted to biomechanical preparation using 5.25% sodium hypochlorite as an irrigating solution. A calcium hydroxide dressing (Calen PMCC was applied for 15 days and the root canals were filled using the lateral condensation technique with gutta-percha points and Sealapex, AH Plus or Sealer Plus for sealing. After 180 days, the animals were sacrificed by anesthetic overdose and the obtained histological sections were stained with hematoxylin-eosin for optical microscopic analysis of the apical and periapical repair. The groups filled with Sealapex and AH Plus had better histological repair (p < 0.05 than the group filled with Sealer Plus, that had unsatisfactory results.

  1. Calcium-enriched mixture pulpotomy of a human permanent molar with irreversible pulpitis and condensing apical periodontitis

    Directory of Open Access Journals (Sweden)

    Saeed Asgary

    2011-01-01

    Full Text Available This case report describes a pulpotomy treatment of a permanent mature molar tooth with established irreversible pulpitis and condensing apical periodontitis, using calcium-enriched mixture (CEM cement. Clinical examination revealed that the first right lower molar had a large carious lesion with history of spontaneous/lingering pain; radiographic examination showed condensing apical periodontitis. Pulpotomy was opted as the treatment; cervical pulpotomy was carried out. Following hemostasis, the radicular pulp stumps were covered with ~2-mm-thick layer of the prepared CEM cement; the tooth was restored with amalgam. Two-year follow-up showed that the treated tooth had been symptomless, and there were no clinical signs/symptoms of either inflammation or infection. Radiographically, the periradicular lesion was completely healed with reconstruction of bone structures to normal appearance; the root canals were not calcified. According to chemical, physical, and biological properties of the CEM cement, this novel biomaterial may be suitable for endodontic treatment.

  2. Activation of embryo during rape (Brassica napus L. seed germination. I. Structure of embryo and organization of root apical meristem

    Directory of Open Access Journals (Sweden)

    Miezcysław Kuraś

    2015-05-01

    Full Text Available The Structure of the mature rape embryo was examined on longitudirna microtome sections, and1, its developmental interpretation is given, based on the author's own studies and literature data. The boundaries between the epicotyl, hypocotyl and radicle are recognized and identified with the limits between the proembryo segments. The radicle Structure and root apical meristem organization are described. In the dermatogen and periblem cell patterns four segments are distinguished, separated successively from the initial cells. Their position is recognized as almost the same on both sides of the root axis and in different embryos. The easily discernible limits between the dermatogen sectors are to be utilized as reference points in studies on the root apical meristem activation and growth during rape seed germination.

  3. Interplay between miRNA regulation and mechanical stress for CUC gene expression at the shoot apical meristem.

    Science.gov (United States)

    Fal, Kateryna; Landrein, Benoit; Hamant, Olivier

    2016-03-01

    The shoot apical meristem is the central organizer of plant aerial organogenesis. The molecular bases of its functions involve several cross-talks between transcription factors, hormones and microRNAs. We recently showed that the expression of the homeobox transcription factor STM is induced by mechanical perturbations, adding another layer of complexity to this regulation. Here we provide additional evidence that mechanical perturbations impact the promoter activity of CUC3, an important regulator of boundary formation at the shoot meristem. Interestingly, we did not detect such an effect for CUC1. This suggests that the robustness of expression patterns and developmental programs is controlled via a combined action of molecular factors as well as mechanical cues in the shoot apical meristem. PMID:26653277

  4. Altered Apical Morphology (Reverse Architecture): Use of Indirect Ultrasonic Technique for Orthograde MTA Placement in Maxillary Premolars

    Science.gov (United States)

    Sonali, Kapoor; Suresh, Agrawal Vineet; Abhishek, Patel; Jenish, Patel

    2016-01-01

    Aim. To report the management and orthograde technique of MTA placement in case of reverse architecture maxillary premolars. Summary. Two cases of 17-year-old and 21-year-old female patients were referred to endodontic speciality for management of maxillary premolar having reverse architecture with wide immature open apex like a bell mouth. In both the cases, after control of intraradicular infection, it was decided to use MTA for apexification and obturation of canals. Orthograde placement of MTA is a challenging procedure in terms of length control and condensation especially in divergent irregular reverse architecture wide open apex. A novel technique with the help of finger plugger, sterilized paper point, and ultrasonic agitation for 3D compaction of MTA at apical reverse architecture was used. Thickening of the canal wall and complete apical closure were confirmed one year after the treatment. PMID:27313910

  5. Poring over membranes

    OpenAIRE

    Williams, Peter A.

    2008-01-01

    A new book on membrane science and technology focuses on the use of atomic force microscopy in the study and characterization of polymer membranes and also provides practical tips on how to undertake an experiment.

  6. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  7. Solvent resistant nanofiltration membranes

    OpenAIRE

    Dutczak, Szymon Maria

    2011-01-01

    This thesis describes preparation and characterization of membranes for organic solvent filtration (OSF). The main aim was developing membranes for solvent resistant nanofiltration (SRNF) with molecular weight cut-off below 500 g mol-1.

  8. Premature rupture of membranes

    Science.gov (United States)

    ... When the water breaks early, it is called premature rupture of membranes (PROM). Most women will go ... th week of pregnancy, it is called preterm premature rupture of membranes (PPROM). The earlier your water ...

  9. Ionene membrane battery separator

    Science.gov (United States)

    Moacanin, J.; Tom, H. Y.

    1969-01-01

    Ionic transport characteristics of ionenes, insoluble membranes from soluble polyelectrolyte compositions, are studied for possible application in a battery separator. Effectiveness of the thin film of separator membrane essentially determines battery lifetime.

  10. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  11. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  12. Impact of a restorative dentistry service on the prescription of apical surgery in a district general hospital.

    OpenAIRE

    Beckett, H.

    1996-01-01

    The case records of a group of patients who had undergone periapical surgery in a district general hospital were examined and compared with the criteria agreed by a group of hospital restorative dentists as to whether apical surgery was appropriate rather than, at least initially, a non-surgical treatment option. Only 65% of the patients met the audit criteria. As a result, changes have been made to clinical practice, including a greater involvement of restorative clinicians in the decision-m...

  13. Operations and Pelvic Muscle Training in the Management of Apical Support Loss (OPTIMAL) Trial: Design and Methods

    OpenAIRE

    Barber, Matthew D.; Brubaker, Linda; Menefee, Shawn; Norton, Peggy; Borello-France, Diane; Varner, Edward; Schaffer, Joseph; Weidner, Alison; Xu, Xiao; Spino, Cathie; Weber, Anne

    2008-01-01

    The primary aims of this trial are: 1) to compare surgical outcomes following sacrospinous ligament fixation to uterosacral vaginal vault suspension in women undergoing vaginal surgery for apical or uterine pelvic organ prolapse and stress urinary incontinence and 2) to examine the effects of a structured perioperative program consisting of behavioral techniques and pelvic floor muscle training compared to usual care. This trial is performed through the Pelvic Floor Disorders Network (PFDN), ...

  14. Orthodontic forces released by low-friction versus conventional systems during alignment of apically or buccally malposed teeth.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Camporesi, Matteo; Defraia, Efisio

    2011-02-01

    The aim of the present study was to analyse the forces released by passive stainless steel self-ligating brackets (SLBs) and by a non-conventional elastomeric ligature-bracket system on conventional brackets ([slide ligatures on conventional brackets (SLCB)]) when compared with conventional elastomeric ligatures on conventional brackets (CLCB) during the alignment of apically or buccally malposed teeth in the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the three different bracket-ligature systems with 0.012-inch super-elastic (SE) nickel-titanium (NiTi) wires in the presence of different amounts of apical or buccal canine misalignment of the canine (ranging from 1.5 to 6 mm). The forces released by each wire/bracket/ligature combination with the three different amounts of apical or buccal canine misalignment were tested 20 times. Comparisons between the different types of wire/bracket/ligature systems were carried out by means of analysis of variance on ranks with Dunnett's post hoc test (P systems. At 3 mm of apical misalignment a significantly greater amount of orthodontic force was released by SLB or SLCB when compared with CLCB, while no significant differences were found among the three systems at 3 mm of buccal canine displacement. When correction of a large amount of misalignment (6 mm) was attempted, a noticeable amount of force for alignment was still generated by the passive SLB and SLCB systems while no force was released in presence of CLCB. PMID:20631083

  15. Surgical Treatment of an Immature Short-Rooted Traumatized Incisor with an Extensive Apical Lesion Using CEM Cement

    OpenAIRE

    Asgary, Saeed; Fazlyab, Mahta

    2015-01-01

    Severe traumatic injuries to immature teeth often cause damage to periodontal ligament as well as dental pulp; pulp necrosis, root resorption and subsequent apical lesion are common consequences. This article reports the surgical management of an infected immature maxillary central incisor associated with a gigantic periradicular lesion and severe root resorption. The tooth had a history of trauma and the patient suffered from purulent sinus tract and tooth mobility. After unsuccessful multi-...

  16. Effect of root resection on sealing ability of orthograde apical plugs of mineral trioxide aggregate and calcium enriched mixture.

    Directory of Open Access Journals (Sweden)

    Saeed Moradi

    2014-08-01

    Full Text Available There is some concern that root resection may alter the seal of the previously set orthograde material. The aim of this study was to evaluate the apical sealing ability of orthograde mineral trioxide aggregate (MTA and calcium enriched mixture (CEM plugs after resection of the roots.The fluid filtration method was carried out on a total of 51 roots in three experimental (n=15 and two control (n=3 groups. The root canals were prepared 3 mm shorter than the working length. In groups A and B, 4 mm of MTA and CEM were placed in an orthograde technique, respectively, and after setting, 3 mm of the root end was resected. In group C, the apical 3 mm of each root was resected, root end preparation was carried out to a depth of 3 mm and filled with MTA. Apical microleakage values of each group were measured. Data was analyzed using Kruskal-Wallis test.Means and standard deviations of apical microleakage in groups A (MTA orthograde, B (CEM orthograde and C (MTA retrograde were 2.31×10(-4 (0.32×10(-4, 3.33×10(-4 (0.29×10(-4 and 4.42×10(-4 (0.40×10(-4 μl.min(-1.cmH2o(-1, respectively. The mean values were greater in group C; however, statistical analysis revealed no significant differences between these groups (P>0.05.Based on the results of this study, when there is an orthograde access to the root canal and surgery is likely to be necessary in the future, MTA and CEM can be placed in an orthograde technique and it just resects the root during surgery.

  17. Effect of Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol on the Sealing Ability of Biodentine Apical Plug

    Science.gov (United States)

    Srivastava, Harshit; Prasad, Ashwini B; Raisingani, Deepak; Soni, Dileep

    2016-01-01

    Introduction Teeth with immature apex are managed by establishing an apical plug using various materials and techniques. However, the use of previously placed intracanal medicament may affect the sealing ability of permanent filling material used as an apical plug. Aim To evaluate the effect of removal of previously placed Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol as an intracanal medicament on the sealing ability of the Biodentine as an apical plug. Materials and Methods A total of 72 recently extracted human permanent teeth with single root were selected and stored in saline at room temperature. The crown portion of each tooth was removed at the level of cemento enamel junction; 14mm root length was taken as standard length. All the roots were submerged in 20% sulphuric acid up to 3 mm from the apex, for four days for root resorption. One sample was cut longitudinally to look for root resorption under stereo microscope. The canal preparation was done; the roots were kept in moist gauze after instrumentation. A total of 71 roots were randomly divided into three groups. GROUP 1:Calcium hydroxide paste, GROUP 2: Chlorhexidine digluconate, GROUP 3: Camphorated Monochlorophenol (CMCP). The medicaments were removed with stainless steel hand files and 0.5% sodium hypochlorite irrigation. After removal of medicament Biodentine was placed in apical third of resorbed roots and the remaining portion of the canals was filled with gutta-percha. All the 71 roots were analysed with fluid filtration method for evaluating microleakage. Results Comparing all the three groups statistically there was no significant difference. The mean values were found more for group 1 followed by group 2 & 3. Conclusion All the groups showed microleakage. Calcium hydroxide showed the maximum microleakage followed by Chlorhexidine digluconate and least with CMCP. PMID:27504409

  18. Induction of differentiation in the shoot apical meristem by transient overexpression of a retinoblastoma-related protein

    OpenAIRE

    Wyrzykowska, Joanna; Schorderet, Martine; Pien, Stéphane; Gruissem, Wilhelm; Fleming, Andrew J.

    2007-01-01

    The shoot apical meristem contains cells that undergo continual growth and division to generate the building blocks for the aerial portion of the plant. As cells leave the meristem, they undergo differentiation to form specific cell types. Most notably, heterotrophic cells of the meristem rapidly gain autotrophic capability by synthesis and assembly of components of the chloroplast. At the same time, cells undergo enlargement via vacuolation. Despite significant advances in the characterizati...

  19. Protein O-Glucosyltransferase 1 (POGLUT1) Promotes Mouse Gastrulation through Modification of the Apical Polarity Protein CRUMBS2

    OpenAIRE

    Ramkumar, Nitya; Harvey, Beth M.; Lee, Jeffrey D.; Alcorn, Heather L.; Silva-Gagliardi, Nancy F.; McGlade, C Jane; Bestor, Timothy H.; Wijnholds, J.; Haltiwanger, Robert S.; Anderson, Kathryn V

    2015-01-01

    Abstract Crumbs family proteins are apical transmembrane proteins with ancient roles in cell polarity. Mouse Crumbs2 mutants arrest at midgestation with abnormal neural plate morphology and a deficit of mesoderm caused by defects in gastrulation. We identified an ENU-induced mutation, wsnp, that phenocopies the Crumbs2 null phenotype. We show that wsnp is a null allele of Protein O-glucosyltransferase 1 (Poglut1), which encodes an enzyme previously shown to add O-glucose to EGF repeats in the...

  20. Evaluation of Apical Micro-leakage of Different Endodontic Sealers in the Presence and Absence of Moisture

    OpenAIRE

    Maryam Ehsani; Atena Dehghani; Farida Abesi; Soraya Khafri; Sara Ghadiri Dehkordi

    2014-01-01

    Background and aims. With availability of hydrophilic sealers, drying of the canals before endodontic obturation is still a matter of debate. The aim of this study was to compare the apical micro-leakage of AH26, Excite DSC, MTA Fillapex, and ZOE sealers in dry and moist root canals. Materials and methods. This experimental study was performed on 90 extracted maxillary central incisors. Rotary files were used for preparation of the canals. Root canals were filled with a single gutta percha...