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Sample records for extracellular recombinant fragment

  1. Ligand-receptor assay for evaluation of functional activity of human recombinant VEGF and VEGFR-1 extracellular fragment.

    Science.gov (United States)

    Leopol'd, A V; Baklaushev, V P; Korchagina, A A; Shein, S A; Grinenko, N F; Pavlov, K A; Ryabukhin, I A; Chekhonin, V P

    2012-04-01

    cDNA encoding VEGF and Ig-like extracellular domains 2-4 of VEGFR-1 (sFlt-1(2-4)) were cloned into prokaryotic expression vectors pET32a and pQE60. Recombinant proteins were purified (metal affinity chromatography) and renatured. Chemiluminescent study for the interaction of recombinant VEGF and sFlt-1(2-4) showed that biotinylated VEGF specifically binds to the polystyrene-immobilized receptor extracellular fragment. Biotinylated recombinant sFlt-1 interacts with immobilized VEGF. Analysis of the interaction of immobilized recombinant VEGFR-1 and VEGF with C6 glioma cells labeled with CFDA-SE (vital fluorescent dye) showed that recombinant VEGFR-1 also binds to native membrane-associated VEGF. Recombinant VEGF was shown to bind to specific receptors expressed on the surface of C6 glioma cells. Functional activity of these proteins was confirmed by ligand-receptor assay for VEGF and VEGFR-1 (sFlt-1) and quantitative chemiluminescent detection.

  2. Extracellular secretion of recombinant proteins

    Science.gov (United States)

    Linger, Jeffrey G.; Darzins, Aldis

    2014-07-22

    Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.

  3. DMPD: Fragments of extracellular matrix as mediators of inflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18243041 Fragments of extracellular matrix as mediators of inflammation. Adair-Kirk...l) Show Fragments of extracellular matrix as mediators of inflammation. PubmedID 18243041 Title Fragments of... extracellular matrix as mediators of inflammation. Authors Adair-Kirk TL, Senior

  4. Hadron correlations from recombination and fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-04-01

    We review the formalism of quark recombination applied to the hadronization of a quark-gluon plasma. Evidence in favour of the quark recombination model is outlined. Recent work on parton correlations, leading to detectable correlations between hadrons, is discussed. Hot spots from completely quenched jets are a likely source of such correlations which appear to be jet like. It will be discussed how such a picture compares with measurement of associated hadron yields at RHIC.

  5. Microbial platform technology for recombinant antibody fragment production: A review.

    Science.gov (United States)

    Gupta, Sanjeev Kumar; Shukla, Pratyoosh

    2017-02-01

    Recombinant antibody fragments are being used for the last few years as an important therapeutic protein to cure various critical and life threatening human diseases. Several expression platforms now days employed for the production of these recombinant fragments, out of which bacterial system has emerged a promising host for higher expression. Since, a small antibody fragment unlike full antibody does not require human-like post-translational modification therefore it is potentially expressed in prokaryotic production system. Recently, small antibody fragments such as scFvs (single-chain variable fragments) and Fabs (antibody fragments) which does not require glycosylation are successfully produced in bacteria and have commercially launched for therapeutic use as these fragments shows better tissue penetration and less immunogenic to human body compared to full-size antibody. Recently developed Wacker's ESETEC secretion technology is an efficient technology for the expression and secretion of the antibody fragment (Fab) exceeded up to 4.0 g/L while scFv up to 3.5 g/L into the fermentation broth. The Pfenex system and pOP prokaryotic expression vector are another platform used for the considerably good amount of antibody fragment production successfully. In this review, we summarize the recent progress on various expression platforms and cloning approaches for the production of different forms of antibody fragments in E. coli.

  6. Recombination plus fragmentation model at RHIC: elliptic flow

    Energy Technology Data Exchange (ETDEWEB)

    Nonaka, C [Department of Physics, Duke University, Durham, NC 27708 (United States); Fries, R J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Mueller, B [Department of Physics, Duke University, Durham, NC 27708 (United States); Bass, S A [Department of Physics, Duke University, Durham, NC 27708 (United States); RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Asakawa, M [Department of Physics, Osaka University, Toyonaka 560-0043 (Japan)

    2005-04-01

    We discuss hadron production in relativistic heavy-ion collisions in the framework of the recombination and fragmentation model. We propose elliptic flow as a useful tool for exploring final interactions of resonances, the hadron structure of exotic particles and the phase structure of the reaction.

  7. Immobilized Metal Affinity Chromatography Co-Purifies TGF-β1 with Histidine-Tagged Recombinant Extracellular Proteins

    Science.gov (United States)

    Kaur, Jasvir; Reinhardt, Dieter P.

    2012-01-01

    Extracellular recombinant proteins are commonly produced using HEK293 cells as histidine-tagged proteins facilitating purification by immobilized metal affinity chromatography (IMAC). Based on gel analyses, this one-step purification typically produces proteins of high purity. Here, we analyzed the presence of TGF-β1 in such IMAC purifications using recombinant extracellular fibrillin-1 fragments as examples. Analysis of various purified recombinant fibrillin-1 fragments by ELISA consistently revealed the presence of picomolar concentrations of active and latent TGF-β1, but not of BMP-2. These quantities of TGF-β1 were not detectable by Western blotting and mass spectrometry. However, the amounts of TGF-β1 were sufficient to consistently trigger Smad2 phosphorylation in fibroblasts. The purification mechanism was analyzed to determine whether the presence of TGF-β1 in these protein preparations represents a specific or non-specific co-purification of TGF-β1 with fibrillin-1 fragments. Control purifications using conditioned medium from non-transfected 293 cells yielded similar amounts of TGF-β1 after IMAC. IMAC of purified TGF-β1 and the latency associated peptide showed that these proteins bound to the immobilized nickel ions. These data clearly demonstrate that TGF-β1 was co-purified by specific interactions with nickel, and not by specific interactions with fibrillin-1 fragments. Among various chromatographic methods tested for their ability to eliminate TGF-β1 from fibrillin-1 preparations, gel filtration under high salt conditions was highly effective. As various recombinant extracellular proteins purified in this fashion are frequently used for experiments that can be influenced by the presence of TGF-β1, these findings have far-reaching implications for the required chromatographic schemes and quality controls. PMID:23119075

  8. Designer genes. Recombinant antibody fragments for biological imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wu, A.M.; Yazaki, P.J. [Beckman Research Institute of the City of Hope, Duarte, CA (United States). Dept. of Molecular Biology

    2000-09-01

    Monoclonal antibodies (MAbs), with high specificity and high affinity for their target antigens, can be utilized for delivery of agents such as radionuclides, enzymes, drugs or toxins in vivo. However, the implementation of radiolabeled antibodies as magic bullets for detection and treatment of diseases such as cancer has required addressing several shortcomings of murine MAbs. These include their immunogenicity, sub-optimal targeting and pharmacokinetic properties, and practical issues of production and radiolabeling. Genetic engineering provides a powerful approach for redesigning antibodies for use in oncologic applications in vivo. Recombinant fragments have been produced that retain high affinity for target antigens, and display a combination of rapid, high-level tumor targeting with concomitant clearance from normal tissues and the circulation in animal models. An important first step was cloning and engineering of antibody heavy and light chain variable domains into single-chain Fvs (molecular weight, 25-17 kDa), in which the variable regions are joined via a synthetic linker peptide sequence. Although scFvs themselves showed limited tumor uptake in preclinical and clinical studies, they provide a useful building block for intermediate sized recombinant fragments. Covalently linked dimers or non-covalent dimers of scFvs (also known as diabodies) show improved targeting and clearance properties due to their higher molecular weight (55kDa) and increased avidity. Further gains can be made by generation of larger recombinant fragments, such as the minibody, an scFv-C{sub H}3 fusion protein that self-assembles into a bivalent dimer of 80 kDa. A systematic evaluation of scFv, diabody, minibody, and intact antibody (based on comparison of tumor uptakes, tumor: blood activity ratios, and calculation of an Imaging Figure of Merit) can form the basis for selection of combinations of recombinant fragments and radionuclides for imaging applications. Ease of engineering

  9. Designer genes. Recombinant antibody fragments for biological imaging

    International Nuclear Information System (INIS)

    Wu, A.M.; Yazaki, P.J.

    2000-01-01

    Monoclonal antibodies (MAbs), with high specificy and high affinity for their target antigens, can be utilized for delivery of agents such as radionuclides, enzymes, drugs or toxins in vivo. However, the implementation of radiolabeled antibodies as magic bullets for detection and treatment of diseases such as cancer has required addressing several shortcomings of murine MAbs. These include their immunogenicity, sub-optimal targeting and pharmacokinetic properties, and practical issues of production and radiolabeling. Genetic engineering provides a powerful approach for redesigning antibodies for use in oncologic applications in vivo. Recombinant fragments have been produced that retain high affinity for target antigens, and display a combination of rapid, high-level tumor targeting with concomitant clearance from normal tissues and the circulation in animal models. An important first step was cloning and engineering of antibody heavy and light chain variable domains into single-chain Fvs (molecular weight, 25-17 kDa), in which the variable regions are joined via a synthetic linker peptide sequence. Although scFvs themselves showed limited tumor uptake in preclinical and clinical studies, they provide a useful building block for intermediate sized recombinant fragments. Covalently linked dimers or non-covalent dimers of scFvs (also known as diabodies) show improved targeting and clearance properties due to their higher molecular weight (55kDa) and increased avidity. Further gains can be made by generation of larger recombinant fragments, such as the minibody, an scFv-C H 3 fusion protein that self-assembles into a bivalent dimer of 80 kDa. A systematic evaluation of scFv, diabody, minibody, and intact antibody (based on comparison of tumor uptakes, tumor: blood activity ratios, and calculation of an Imaging Figure of Merit) can form the basis for selection of combinations of recombinant fragments and radionuclides for imaging applications. Ease of engineering and

  10. The matrikine N-α-PGP couples extracellular matrix fragmentation to endothelial permeability

    NARCIS (Netherlands)

    Hahn, Cornelia S; Scott, David W; Xu, Xin; Roda, Mojtaba Abdul; Payne, Gregory A; Wells, J Michael; Viera, Liliana; Winstead, Colleen J; Bratcher, Preston; Sparidans, Rolf W; Redegeld, Frank A; Jackson, Patricia L; Folkerts, Gert; Blalock, J Edwin; Patel, Rakesh P; Gaggar, Amit

    2015-01-01

    The compartmentalization and transport of proteins and solutes across the endothelium is a critical biologic function altered during inflammation and disease, leading to pathology in multiple disorders. The impact of tissue damage and subsequent extracellular matrix (ECM) fragmentation in regulating

  11. Extracellular matrix fragmentation in young, healthy cartilaginous tissues.

    Science.gov (United States)

    Craddock, R J; Hodson, N W; Ozols, M; Shearer, T; Hoyland, J A; Sherratt, M J

    2018-02-09

    Although the composition and structure of cartilaginous tissues is complex, collagen II fibrils and aggrecan are the most abundant assemblies in both articular cartilage (AC) and the nucleus pulposus (NP) of the intervertebral disc (IVD). Whilst structural heterogeneity of intact aggrecan ( containing three globular domains) is well characterised, the extent of aggrecan fragmentation in healthy tissues is poorly defined. Using young, yet skeletally mature (18-30 months), bovine AC and NP tissues, it was shown that, whilst the ultrastructure of intact aggrecan was tissue-dependent, most molecules (AC: 95 %; NP: 99.5 %) were fragmented (lacking one or more globular domains). Fragments were significantly smaller and more structurally heterogeneous in the NP compared with the AC (molecular area; AC: 8543 nm2; NP: 4625 nm2; p tissue-invariant. Molecular fragmentation is considered indicative of a pathology; however, these young, skeletally mature tissues were histologically and mechanically (reduced modulus: AC: ≈ 500 kPa; NP: ≈ 80 kPa) comparable to healthy tissues and devoid of notable gelatinase activity (compared with rat dermis). As aggrecan fragmentation was prevalent in neonatal bovine AC (99.5 % fragmented, molecular area: 5137 nm2) as compared with mature AC (95.0 % fragmented, molecular area: 8667 nm2), it was hypothesised that targeted proteolysis might be an adaptive process that modified aggrecan packing (as simulated computationally) and, hence, tissue charge density, mechanical properties and porosity. These observations provided a baseline against which pathological and/or age-related fragmentation of aggrecan could be assessed and suggested that new strategies might be required to engineer constructs that mimic the mechanical properties of native cartilaginous tissues.

  12. Extracellular matrix fragmentation in young, healthy cartilaginous tissues

    Directory of Open Access Journals (Sweden)

    RJ Craddock

    2018-02-01

    Full Text Available Although the composition and structure of cartilaginous tissues is complex, collagen II fibrils and aggrecan are the most abundant assemblies in both articular cartilage (AC and the nucleus pulposus (NP of the intervertebral disc (IVD. Whilst structural heterogeneity of intact aggrecan ( containing three globular domains is well characterised, the extent of aggrecan fragmentation in healthy tissues is poorly defined. Using young, yet skeletally mature (18-30 months, bovine AC and NP tissues, it was shown that, whilst the ultrastructure of intact aggrecan was tissue-dependent, most molecules (AC: 95 %; NP: 99.5 % were fragmented (lacking one or more globular domains. Fragments were significantly smaller and more structurally heterogeneous in the NP compared with the AC (molecular area; AC: 8543 nm2; NP: 4625 nm2; p < 0.0001. In contrast, fibrillar collagen appeared structurally intact and tissue-invariant. Molecular fragmentation is considered indicative of a pathology; however, these young, skeletally mature tissues were histologically and mechanically (reduced modulus: AC: ≈ 500 kPa; NP: ≈ 80 kPa comparable to healthy tissues and devoid of notable gelatinase activity (compared with rat dermis. As aggrecan fragmentation was prevalent in neonatal bovine AC (99.5 % fragmented, molecular area: 5137 nm2 as compared with mature AC (95.0 % fragmented, molecular area: 8667 nm2, it was hypothesised that targeted proteolysis might be an adaptive process that modified aggrecan packing (as simulated computationally and, hence, tissue charge density, mechanical properties and porosity. These observations provided a baseline against which pathological and/or age-related fragmentation of aggrecan could be assessed and suggested that new strategies might be required to engineer constructs that mimic the mechanical properties of native cartilaginous tissues.

  13. Chimeric recombinant antibody fragments in cardiac troponin I immunoassay.

    Science.gov (United States)

    Hyytiä, Heidi; Heikkilä, Taina; Brockmann, Eeva-Christine; Kekki, Henna; Hedberg, Pirjo; Puolakanaho, Tarja; Lövgren, Timo; Pettersson, Kim

    2015-03-01

    To introduce a novel nanoparticle-based immunoassay for cardiac troponin I (cTnI) utilizing chimeric antibody fragments and to demonstrate that removal of antibody Fc-part and antibody chimerization decrease matrix related interferences. A sandwich-type immunoassay for cTnI based on recombinant chimeric (mouse variable/human constant) antigen binding (cFab) antibodies and intrinsically fluorescent nanoparticles was developed. To test whether using chimeric antibody fragments helps to avoid matrix related interferences, samples (n=39) with known amounts of triglycerides, bilirubin, rheumatoid factor (RF) or human anti-mouse antibodies (HAMAs) were measured with the novel assay, along with a previously published nanoparticle-based research assay with the same antibody epitopes. The limit of detection (LoD) was 3.30ng/L. Within-laboratory precision for 29ng/L and 2819ng/L cTnI were 13.7% and 15.9%, respectively. Regression analysis with Siemens ADVIA Centaur® yielded a slope (95% confidence intervals) of 0.18 (0.17-1.19) and a y-intercept of 1.94 (-1.28-3.91) ng/L. When compared to a previously published nanoparticle-based assay, the novel assay showed substantially reduced interference in the tested interference prone samples, 15.4 vs. 51.3%. A rheumatoid factor containing sample was decreased from 241ng/L to fragments enabled the development of a sensitive (LoD=3.3ng/L) immunoassay for the detection of cTnI and decreased matrix related interferences, thus resulting in a lower number of falsely elevated cTnI-values. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  14. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix

    OpenAIRE

    Hui Liang; Xiaoran Li; Bin Wang; Bing Chen; Yannan Zhao; Jie Sun; Yan Zhuang; Jiajia Shi; He Shen; Zhijun Zhang; Jianwu Dai

    2016-01-01

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of ...

  15. Biomarkers of the extracellular matrix and of collagen fragments.

    Science.gov (United States)

    Chalikias, Georgios K; Tziakas, Dimitrios N

    2015-03-30

    A great body of evidence has shown that extracellular matrix (ECM) alterations are present in the major types of cardiac diseases: ischemic heart disease, heart disease associated with pressure overload, heart disease associated with volume overload, and intrinsic myocardial disease or cardiomyopathy. Collagen, type I and III, is the principal structural protein found in the myocardium and its pro- or telopeptides are released into the circulation during the course of cardiovascular diseases. Therefore, these peptides may reflect collagen synthesis and break-down and also represent a much more useful tool to address ECM changes from a distance. Clinical trials have been performed during recent years to examine the usage of these peptides as diagnostic or prognostic biomarkers in heart failure (HF) patients. This review aims to summarize published data concerning cardiac ECM and its circulating biomarkers. Studies that focused on collagen metabolism related biomarkers in patients with HF are analyzed. Finally, limitations associated with the clinical use of the aforementioned biomarkers are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Binding of recombinant apolipoprotein(a) to extracellular matrix proteins

    NARCIS (Netherlands)

    van der Hoek, Y. Y.; Sangrar, W.; Côté, G. P.; Kastelein, J. J.; Koschinsky, M. L.

    1994-01-01

    Elevated levels of lipoprotein(a), which consists of apolipoprotein(a) [apo(a)] covalently linked to a low-density lipoprotein-like moiety, is an independent risk factor for the development of atherosclerosis. We show that a recombinant form of apo(a) [r-apo(a)] binds strongly to fibronectin and

  17. Biglycan fragmentation in pathologies associated with extracellular matrix remodeling by matrix metalloproteinases

    DEFF Research Database (Denmark)

    Genovese, Federica; Barascuk, Natasha; Larsen, Lise Skakkebæk

    2013-01-01

    The proteoglycan biglycan (BGN) is involved in collagen fibril assembly and its fragmentation is likely to be associated with collagen turnover during the pathogenesis of diseases which involve dysregulated extracellular matrix remodeling (ECMR), such as rheumatoid arthritis (RA) and liver fibrosis...

  18. A Novel Molecular Diagnostic of Glioblastomas: Detection of an Extracellular Fragment of Protein Tyrosine Phosphatase μ

    Directory of Open Access Journals (Sweden)

    Susan M. Burden-Gulley

    2010-04-01

    Full Text Available We recently found that normal human brain and low-grade astrocytomas express the receptor protein tyrosine phosphatase mu (PTPμ and that the more invasive astrocytomas, glioblastoma multiforme (GBM, downregulate full-length PTPμ expression. Loss of PTPμ expression in GBMs is due to proteolytic cleavage that generates an intracellular and potentially a cleaved and released extracellular fragment of PTPμ. Here, we identify that a cleaved extracellular fragment containing the domains required for PTPμ-mediated adhesion remains associated with GBM tumor tissue. We hypothesized that detection of this fragment would make an excellent diagnostic tool for the localization of tumor tissue within the brain. To this end, we generated a series of fluorescently tagged peptide probes that bind the PTPμ fragment. The peptide probes specifically recognize GBM cells in tissue sections of surgically resected human tumors. To test whether the peptide probes are able to detect GBM tumors in vivo, the PTPμ peptide probes were tested in both mouse flank and intracranial xenograft human glioblastoma tumor model systems. The glial tumors were molecularly labeled with the PTPμ peptide probes within minutes of tail vein injection using the Maestro FLEX In Vivo Imaging System. The label was stable for at least 3 hours. Together, these results indicate that peptide recognition of the PTPμ extracellular fragment provides a novel molecular diagnostic tool for detection of human glioblastomas. Such a tool has clear translational applications and may lead to improved surgical resections and prognosis for patients with this devastating disease.

  19. Recombinant expression in E. coli of human FGFR2 with its transmembrane and extracellular domains

    Directory of Open Access Journals (Sweden)

    Adam Bajinting

    2017-06-01

    Full Text Available Fibroblast growth factor receptors (FGFRs are a family of receptor tyrosine kinases containing three domains: an extracellular receptor domain, a single transmembrane helix, and an intracellular tyrosine kinase domain. FGFRs are activated by fibroblast growth factors (FGFs as part of complex signal transduction cascades regulating angiogenesis, skeletal formation, cell differentiation, proliferation, cell survival, and cancer. We have developed the first recombinant expression system in E. coli to produce a construct of human FGFR2 containing its transmembrane and extracellular receptor domains. We demonstrate that the expressed construct is functional in binding heparin and dimerizing. Size exclusion chromatography demonstrates that the purified FGFR2 does not form a complex with FGF1 or adopts an inactive dimer conformation. Progress towards the successful recombinant production of intact FGFRs will facilitate further biochemical experiments and structure determination that will provide insight into how extracellular FGF binding activates intracellular kinase activity.

  20. Recombinant Kinase Production and Fragment Screening by NMR Spectroscopy.

    Science.gov (United States)

    Han, Byeonggu; Ahn, Hee-Chul

    2016-01-01

    During the past decade fragment-based drug discovery (FBDD) has rapidly evolved and several drugs or drug candidates developed by FBDD approach are clinically in use or in clinical trials. For example, vemurafenib, a V600E mutated BRAF inhibitor, was developed by utilizing FBDD approach and approved by FDA in 2011. In FBDD, screening of fragments is the starting step for identification of hits and lead generation. Fragment screening usually relies on biophysical techniques by which the protein-bound small molecules can be detected. NMR spectroscopy has been extensively used to study the molecular interaction between the protein and the ligand, and has many advantages in fragment screening over other biophysical techniques. This chapter describes the practical aspects of fragment screening by saturation transfer difference NMR.

  1. A recombinant dromedary antibody fragment (VHH or nanobody) directed against human Duffy antigen receptor for chemokines.

    Science.gov (United States)

    Smolarek, Dorota; Hattab, Claude; Hassanzadeh-Ghassabeh, Gholamreza; Cochet, Sylvie; Gutiérrez, Carlos; de Brevern, Alexandre G; Udomsangpetch, Rachanee; Picot, Julien; Grodecka, Magdalena; Wasniowska, Kazimiera; Muyldermans, Serge; Colin, Yves; Le Van Kim, Caroline; Czerwinski, Marcin; Bertrand, Olivier

    2010-10-01

    Fy blood group antigens are carried by the Duffy antigen receptor for chemokines (DARC), a red cells receptor for Plasmodium vivax broadly implicated in human health and diseases. Recombinant VHHs, or nanobodies, the smallest intact antigen binding fragment derivative from the heavy chain-only antibodies present in camelids, were prepared from a dromedary immunized against DARC N-terminal extracellular domain and selected for DARC binding. A described VHH, CA52, does recognize native DARC on cells. It inhibits P. vivax invasion of erythrocytes and displaces interleukin-8 bound to DARC. The targeted epitope overlaps the well-defined DARC Fy6 epitope. K (D) of CA52-DARC equilibrium is sub-nanomolar, hence ideal to develop diagnostic or therapeutic compounds. Immunocapture by immobilized CA52 yielded highly purified DARC from engineered K562 cells. This first report on a VHH with specificity for a red blood cell protein exemplifies VHHs' potentialities to target, to purify, and to modulate the function of cellular markers.

  2. Recombinant fragment of an antibody tailored for direct radioiodination

    Czech Academy of Sciences Publication Activity Database

    Sedláček, Juraj; Fábry, Milan; Sieglová, Irena; Král, Vlastimil; Uhnáková, Bronislava; Mudra, M.; Kronrád, L.; Sawicka, A.; Mikolajczak, R.; Řezáčová, Pavlína

    2012-01-01

    Roč. 55, č. 1 (2012), s. 52-56 ISSN 0362-4803 R&D Projects: GA MPO 2A-2TP1/076; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z50520514 Keywords : I125 labelling * single-chain antibody variable fragment * tyrosine-rich polypeptide segment * fusion protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.240, year: 2012

  3. DNA fragmentation and cytotoxicity by recombinant human tumor necrosis factor in L929 fibroblast cells

    International Nuclear Information System (INIS)

    Kosaka, T.; Kuwabara, M.; Koide, F.

    1992-01-01

    Induction of cell DNA fragmentation by treatment of recombinant human Tumor Necrosis Factor alpha (rhTNF alpha) was examined by using mouse L929 cells derived from mouse fibroblast cells. The amount of DNA fragments derived from rhTNF alpha-treated cells, detected by alkaline elution technique, was smaller than that derived from X-irradiated cells. The rhTNF alpha caused the DNA fragmentation depending on its incubation time and concentration. The DNA damage caused by rhTNF alpha treatment correlated with its cytotoxicity. This result suggested that the DNA fragmentation is one of causes of cell death. The treatment with proteinase K of DNA obtained from rhTNF alpha-treated cells did not increase the amount of DNA fragmentation, which indicates that rhTNF alpha causes DNA-fragmentation but not DNA-protein cross-linking

  4. Angiogenic Type I Collagen Extracellular Matrix Integrated with Recombinant Bacteriophages Displaying Vascular Endothelial Growth Factors.

    Science.gov (United States)

    Yoon, Junghyo; Korkmaz Zirpel, Nuriye; Park, Hyun-Ji; Han, Sewoon; Hwang, Kyung Hoon; Shin, Jisoo; Cho, Seung-Woo; Nam, Chang-Hoon; Chung, Seok

    2016-01-21

    Here, a growth-factor-integrated natural extracellular matrix of type I collagen is presented that induces angiogenesis. The developed matrix adapts type I collagen nanofibers integrated with synthetic colloidal particles of recombinant bacteriophages that display vascular endothelial growth factor (VEGF). The integration is achieved during or after gelation of the type I collagen and the matrix enables spatial delivery of VEGF into a desired region. Endothelial cells that contact the VEGF are found to invade into the matrix to form tube-like structures both in vitro and in vivo, proving the angiogenic potential of the matrix. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. ADJUVANT PROPERTIES OF NANOPARTICLES IMMOBILIZED RECOMBINANT DIPHTHERIA TOXOID FRAGMENT

    Directory of Open Access Journals (Sweden)

    T. O. Chudina

    2017-08-01

    Full Text Available The aim of the research was to compare the characteristics of nanoparticles with different chemical structure and size (colloidal gold Gold 1 and Gold 2, calcium phosphate CaP and poly(lactideco-glykolid PLGA 1 and 2 to find the most efficient carriers of antigen — recombinant diphtheria toxoid for per os immunization. According to the MTT test, all studied particles show no significant cytotoxic impact on the studied cells in vitro, with the exception of CaP nanoparticles, which in high concentrations have cytotoxic effect on the U937 cells, and Gold nanoparticles 1 and 2, that are able to inhibit growth of the L929 cells. The most effective phagocytosis by macrophage-like cells J774 is observed for PLGA nanoparticles 1 and 2 with the immobilized antigen, while Gold nanoparticles 1 and 2 with antigen can interact with the surface of these cells without being phagocytated by them. In BALB/c mice immunized per os with antigen immobilized on PLGA 1 and 2 as well as Gold 2 carriers, the concentration of specific IgA antibodies in blood significantly increases after the second immunization, compared with controls. In the group of mice treated with PLGA 2 conjugated antigen, the concentration of specific IgG in blood after the third immunization also increases. These results show the promise of nanoparticles PLGA 1 and 2 as adjuvant for immunization per os.

  6. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix.

    Science.gov (United States)

    Liang, Hui; Li, Xiaoran; Wang, Bin; Chen, Bing; Zhao, Yannan; Sun, Jie; Zhuang, Yan; Shi, Jiajia; Shen, He; Zhang, Zhijun; Dai, Jianwu

    2016-02-17

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of cetuximab was fused with CBD (CBD-Fab) and expressed in Pichia pastoris. CBD-Fab maintained antigen binding and anti-tumor activity of cetuximab and obtained a collagen-binding ability in vitro. The results also showed CBD-Fab was mainly enriched in tumors and had longer retention time in tumors in A431 s.c. xenografts. Furthermore, CBD-Fab showed a similar therapeutic efficacy as cetuximab in A431 xenografts. Although CBD-Fab hasn't showed better therapeutic effects than cetuximab, its smaller molecular and special target may be applicable as antibody-drug conjugates (ADC) or immunotoxins.

  7. Development of a recombinant toxin fragment vaccine for Clostridium difficile infection.

    Science.gov (United States)

    Karczewski, Jerzy; Zorman, Julie; Wang, Su; Miezeiewski, Matthew; Xie, Jinfu; Soring, Keri; Petrescu, Ioan; Rogers, Irene; Thiriot, David S; Cook, James C; Chamberlin, Mihaela; Xoconostle, Rachel F; Nahas, Debbie D; Joyce, Joseph G; Bodmer, Jean-Luc; Heinrichs, Jon H; Secore, Susan

    2014-05-19

    Clostridium difficile infection (CDI) is the major cause of antibiotic-associated diarrhea and pseudomembranous colitis, a disease associated with significant morbidity and mortality. The disease is mostly of nosocomial origin, with elderly patients undergoing anti-microbial therapy being particularly at risk. C. difficile produces two large toxins: Toxin A (TcdA) and Toxin B (TcdB). The two toxins act synergistically to damage and impair the colonic epithelium, and are primarily responsible for the pathogenesis associated with CDI. The feasibility of toxin-based vaccination against C. difficile is being vigorously investigated. A vaccine based on formaldehyde-inactivated Toxin A and Toxin B (toxoids) was reported to be safe and immunogenic in healthy volunteers and is now undergoing evaluation in clinical efficacy trials. In order to eliminate cytotoxic effects, a chemical inactivation step must be included in the manufacturing process of this toxin-based vaccine. In addition, the large-scale production of highly toxic antigens could be a challenging and costly process. Vaccines based on non-toxic fragments of genetically engineered versions of the toxins alleviate most of these limitations. We have evaluated a vaccine assembled from two recombinant fragments of TcdB and explored their potential as components of a novel experimental vaccine against CDI. Golden Syrian hamsters vaccinated with recombinant fragments of TcdB combined with full length TcdA (Toxoid A) developed high titer IgG responses and potent neutralizing antibody titers. We also show here that the recombinant vaccine protected animals against lethal challenge with C. difficile spores, with efficacy equivalent to the toxoid vaccine. The development of a two-segment recombinant vaccine could provide several advantages over toxoid TcdA/TcdB such as improvements in manufacturability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Enhancement of extracellular expression of Bacillus naganoensis pullulanase from recombinant Bacillus subtilis: Effects of promoter and host.

    Science.gov (United States)

    Song, Wan; Nie, Yao; Mu, Xiao Qing; Xu, Yan

    2016-08-01

    Pullulanase plays an important role in industrial applications of starch processing. However, extracellular production of pullulanase from recombinant Bacillus subtilis is yet limited due to the issues on regulatory elements of B. subtilis expression system. In this study, the gene encoding B. naganoensis pullulanase (PUL) was expressed in B. subtilis WB800 under the promoter PHpaII in the shuttle vector pMA0911. The extracellular activity of expressed pullulanase was 3.9 U ml(-1) from the recombinant B. subtilis WB800/pMA0911-PHpaII-pul. To further enhance the yield of PUL, the promoter PHpaII in pMA0911 was replaced by a stronger constitutive promoter P43. Then the activity was increased to 8.7 U ml(-1) from the recombinant B. subtilis WB800/pMA0911-P43-pul. Effect of host on pullulanase expression was further investigated by comparison between B. subtilis WB600 and B. subtilis WB800. In addition to the available B. subtilis WB800 recombinants, the constructed plasmids pMA0911-PHpaII-pul and pMA0911-P43-pul were transformed into B. subtilis WB600, respectively. Consequently, the extracellular production of PUL was significantly enhanced by B. subtilis WB600/pMA0911-P43-pul, resulting in the extracellular pullulanase activity of 24.5 U ml(-1). Therefore, promoter and host had an impact on pullulanase expression and their optimization would be useful to improve heterologous protein expression in B. subtilis. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Isolation and expression of recombinant antibody fragments to the biological warfare pathogen Brucella melitensis.

    Science.gov (United States)

    Hayhurst, Andrew; Happe, Scott; Mabry, Robert; Koch, Zephyr; Iverson, Brent L; Georgiou, George

    2003-05-01

    Brucella melitensis is a highly infectious animal pathogen able to cause a recurring debilitating disease in humans and is therefore high on the list of biological warfare agents. Immunoglobulin genes from mice immunized with gamma-irradiated B. melitensis strain 16M were used to construct a library that was screened by phage display against similarly prepared bacteria. The selected phage particles afforded a strong enzyme-linked immunosorbent assay (ELISA) signal against gamma-irradiated B. melitensis cells. However, extensive efforts to express the respective single chain antibody variable region fragment (scFv) in soluble form failed due to: (i) poor solubility and (ii) in vivo degradation of the c-myc tag used for the detection of the recombinant antibodies. Both problems could be addressed by: (i) fusing a human kappa light chain constant domain (Ck) chain to the scFv to generate single chain antibody fragment (scAb) antibody fragments and (ii) by co-expression of the periplasmic chaperone Skp. While soluble, functional antibodies could be produced in this manner, phage-displaying scFvs or scAbs were still found to be superior ELISA reagents for immunoassays, due to the large signal amplification afforded by anti-phage antibodies. The isolated phage antibodies were shown to be highly specific to B. melitensis and did not recognize Yersinia pseudotuberculosis in contrast to the existing diagnostic monoclonal YST 9.2.1.

  10. Improved protection conferred by vaccination with a recombinant vaccinia virus that incorporates a foreign antigen into the extracellular enveloped virion

    International Nuclear Information System (INIS)

    Kwak, Heesun; Mustafa, Waleed; Speirs, Kendra; Abdool, Asha J.; Paterson, Yvonne; Isaacs, Stuart N.

    2004-01-01

    Recombinant poxviruses have shown promise as vaccine vectors. We hypothesized that improved cellular immune responses could be developed to a foreign antigen by incorporating it as part of the extracellular enveloped virion (EEV). We therefore constructed a recombinant vaccinia virus that replaced the cytoplasmic domain of the B5R protein with a test antigen, HIV-1 Gag. Mice immunized with the virus expressing Gag fused to B5R had significantly better primary CD4 T-cell responses than recombinant virus expressing HIV-Gag from the TK-locus. The CD8 T-cell responses were less different between the two groups. Importantly, although we saw differences in the immune response to the test antigen, the vaccinia virus-specific immune responses were similar with both constructs. When groups of vaccinated mice were challenged 30 days later with a recombinant Listeria monocytogenes that expresses HIV-Gag, mice inoculated with the virus that expresses the B5R-Gag fusion protein had lower colony counts of Listeria in the liver and spleen than mice vaccinated with the standard recombinant. Thus, vaccinia virus expressing foreign antigen incorporated into EEV may be a better vaccine strategy than standard recombinant vaccinia virus

  11. Characterization of a recombinant humanized anti-cocaine monoclonal antibody and its Fab fragment.

    Science.gov (United States)

    Kirley, Terence L; Norman, Andrew B

    2015-01-01

    Variations of post-translational modifications are important for stability and in vivo behavior of therapeutic antibodies. A recombinant humanized anti-cocaine monoclonal antibody (h2E2) was characterized for heterogeneity of N-linked glycosylation and disulfide bonds. In addition, charge heterogeneity, which is partially due to the presence or absence of C-terminal lysine on the heavy chains, was examined. For cocaine overdose therapy, Fab fragments may be therapeutic, and thus, a simplified method of generation, purification, and characterization of the Fab fragment generated by Endoproteinase Lys-C digestion was devised. Both the intact h2E2 antibody and purified Fab fragments were analyzed for their affinities for cocaine and 2 of its metabolites, benzoylecgonine and cocaethylene, by fluorescence quenching of intrinsic antibody tyrosine and tryptophan fluorescence resulting from binding of these drugs. Binding constants obtained from fluorescence quenching measurements are in agreement with recently published radioligand and ELISA binding assays. The dissociation constants determined for the h2E2 monoclonal and its Fab fragment are approximately 1, 5, and 20 nM for cocaethylene, cocaine, and benzoylecgonine, respectively. Tryptophan fluorescence quenching (emission at 330 nm) was measured after either excitation of tyrosine and tryptophan (280 nm) or selective excitation of tryptophan alone (295 nm). More accurate binding constants are obtained using tryptophan selective excitation at 295 nm, likely due to interfering absorption of cocaine and metabolites at 280 nm. These quenching results are consistent with multiple tryptophan and tyrosine residues in or near the predicted binding location of cocaine in a previously published 3-D model of this antibody's variable region.

  12. A recombinant estrogen receptor fragment-based homogeneous fluorescent assay for rapid detection of estrogens.

    Science.gov (United States)

    Wang, Dan; Xie, Jiangbi; Zhu, Xiaocui; Li, Jinqiu; Zhao, Dongqin; Zhao, Meiping

    2014-05-15

    In this work, we demonstrate a novel estrogenic receptor fragment-based homogeneous fluorescent assay which enables rapid and sensitive detection of 17β-estradiol (E2) and other highly potent estrogens. A modified human estrogenic receptor fragment (N-His × 6-hER270-595-C-Strep tag II) has been constructed that contains amino acids 270-595 of wild-type human estrogenic receptor α (hER270-595) and two specific tags (6 × His and Strep tag II) fused to the N and C terminus, respectively. The designed receptor protein fragment could be easily produced by prokaryotic expression with high yield and high purity. The obtained protein exhibits high binding affinity to E2 and the two tags greatly facilitate the application of the recombinant protein. Taking advantage of the unique spectroscopic properties of coumestrol (CS), a fluorescent phytoestrogen, a CS/hER270-595-based fluorescent assay has been developed which can sensitively respond to E2 within 1.0 min with a linear working range from 0.1 to 20 ng/mL and a limit of detection of 0.1 ng/mL. The assay was successfully applied for rapid detection of E2 in the culture medium of rat hippocampal neurons. The method also holds great potential for high-throughput monitoring the variation of estrogen levels in complex biological fluids, which is crucial for investigation of the molecular basis of various estrogen-involved processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. In vitro Ca(2+)-dependent maturation of milk-clotting recombinant Epr: minor extracellular protease: from Bacillus licheniformis.

    Science.gov (United States)

    Ageitos, José Manuel; Vallejo, Juan Andrés; Serrat, Manuel; Sánchez-Pérez, Angeles; Villa, Tomás G

    2013-06-01

    The minor extracellular protease (Epr) is secreted into the culture medium during Bacillus licheniformis, strain USC13, stationary phase of growth. Whereas, B. subtilis Epr has been reported to be involved in swarming; the B. licheniformis protease is also involved in milk-clotting as shown by the curd forming ability of culture broths expressing this protein. The objectives of this study are the characterization of recombinant B. licheniformis Epr (minor extracellular protease) and the determination of its calcium-dependent activation process. In this work, we have cloned and expressed B. licheniformis Epr in Escherichia coli. We were also able to construct a tridimensional model for Epr based on its homology to Thermococcus kodakarensis pro-tk-subtilisin 2e1p, fervidolysin from Fervidobacterium pennivorans 1rv6, and B. lentus 1GCI subtilisin. Recombinant Epr was accumulated into inclusion bodies; after protein renaturation, Epr undergoes an in vitro calcium-dependent activation, similar to that described for tk protease. The recombinant Epr is capable of producing milk curds with the same clotting activity previously described for the native B. licheniformis Epr enzyme although further rheological and industrial studies should be carried out to confirm its real applicability. This work represents for the first time that Epr may be successfully expressed in a non-bacilli microorganism.

  14. In vitro neutralisation of rotavirus infection by two broadly specific recombinant monovalent llama-derived antibody fragments

    NARCIS (Netherlands)

    F. Aladin (Farah); A.W.C. Einerhand (Sandra); J. Bouma (Janneke); S. Bezemer (Sandra); P. Hermans (Pim); D. Wolvers (Danielle); K. Bellamy (Kate); L.G.J. Frenken (Leon); J. Gray (Jim); M. Iturriza-Gómara (Miren)

    2012-01-01

    textabstractRotavirus is the main cause of viral gastroenteritis in young children. Therefore, the development of inexpensive antiviral products for the prevention and/or treatment of rotavirus disease remains a priority. Previously we have shown that a recombinant monovalent antibody fragment

  15. Dendritic cell activation and maturation induced by recombinant calreticulin fragment 39-272.

    Science.gov (United States)

    Li, Yue; Zeng, Xiaoli; He, Lijuan; Yuan, Hui

    2015-01-01

    Dendritic cells (DC) are the most potent antigen-presenting cells for initiating immune responses. DC maturation can be induced by exposing of immature DC to pathogen products or pro-inflammatory factor, which dramatically enhances the ability of DC to activate Ag-specific T cells. In this study, a recombinant calreticulin fragment 39-272 (rCRT/39-272) covering the lectin-like N domain and partial P domain of murine CRT has been expressed and purified in Escherichia coli. Functional analysis studies revealed that rCRT/39-272 has potent immunostimulatory activities in both activating human monocytes and B cells to secrete cytokines. rCRT/39-272 can drive the activation of bone marrow derived DC in TLR4/CD14 dependent way, as indicated by secretion of cytokines IL-12/IL-23 (p40) and IL-1β. Exposure of DC to rCRT/39-272 induces P-Akt, suggesting that rCRT/39-272 induces maturation of DC through PI3K/Akt signaling pathway. The results suggest that soluble rCRT/39-272 is a potent stimulatory agent to DC maturation in TLR4/CD14 and PI3K/Akt dependent pathway. It may play important roles in initiating cellular immunity in vivo and the T cell response in vitro. Thus it could be used for study of DC-based tumor vaccines.

  16. Isolation and characterisation of Ebolavirus-specific recombinant antibody fragments from murine and shark immune libraries.

    Science.gov (United States)

    Goodchild, Sarah A; Dooley, Helen; Schoepp, Randal J; Flajnik, Martin; Lonsdale, Stephen G

    2011-09-01

    Members of the genus Ebolavirus cause fulminating outbreaks of disease in human and non-human primate populations with a mortality rate up to 90%. To facilitate rapid detection of these pathogens in clinical and environmental samples, robust reagents capable of providing sensitive and specific detection are required. In this work recombinant antibody libraries were generated from murine (single chain variable domain fragment; scFv) and nurse shark, Ginglymostoma cirratum (IgNAR V) hosts immunised with Zaire ebolavirus. This provides the first recorded IgNAR V response against a particulate antigen in the nurse shark. Both murine scFv and shark IgNAR V libraries were panned by phage display technology to identify useful antibodies for the generation of immunological detection reagents. Two murine scFv were shown to have specificity to the Zaire ebolavirus viral matrix protein VP40. Two isolated IgNAR V were shown to bind to the viral nucleoprotein (NP) and to capture viable Zaire ebolavirus with a high degree of sensitivity. Assays developed with IgNAR V cross-reacted to Reston ebolavirus, Sudan ebolavirus and Bundibugyo ebolavirus. Despite this broad reactivity, neither of IgNAR V showed reactivity to Côte d'Ivoire ebolavirus. IgNAR V was substantially more resistant to irreversible thermal denaturation than murine scFv and monoclonal IgG in a comparative test. The demonstrable robustness of the IgNAR V domains may offer enhanced utility as immunological detection reagents in fieldable biosensor applications for use in tropical or subtropical countries where outbreaks of Ebolavirus haemorrhagic fever occur. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  17. X-ray studies of recombinant anti-testosterone Fab fragments: the use of PEG 3350 in crystallization.

    Science.gov (United States)

    Valjakka, J; Hemminki, A; Teerinen, T; Takkinen, K; Rouvinen, J

    2000-02-01

    Recombinant anti-testosterone wild-type Fab fragment and mutant Fab fragments with high binding selectivity developed by protein engineering have been crystallized with and without ligands. Crystals of these Fab fragments were obtained by the vapour-diffusion technique at room temperature using solutions of PEG 3350 with various biological buffers and with a wide pH range. So far, five data sets have been collected from crystals of three Fab-antigen complexes and from two uncomplexed Fab fragments, with resolutions ranging from 2.10 to 3.1 A. Crystallization conditions for Fab fragments were found by using modifications of the low ionic strength PEG 3350 series. Suitable concentrations of PEG 400, MPD and glycerol solutions for use as cryoprotectants in PEG 3350 solutions have been determined. One useful observation was that PEG 3350 is able to work alone as a cryoprotectant. The screening protocol used requires a smaller amount of protein material to achieve auspicious pre-crystals than previously. Results support the claim that PEG 3350 is more suitable for the crystallization of Fab fragments than higher molecular weight PEGs.

  18. Bioprocess development for extracellular production of recombinant human interleukin-3 (hIL-3) in Pichia pastoris.

    Science.gov (United States)

    Dagar, Vikas Kumar; Adivitiya; Devi, Nirmala; Khasa, Yogender Pal

    2016-10-01

    Human interleukin-3 (hIL-3) is a therapeutically important cytokine involved in the maturation and differentiation of various cells of the immune system. The codon-optimized hIL-3 gene was cloned in fusion with the N-terminus α-mating factor signal peptide of Saccharomyces cerevisiae under an inducible alcohol oxidase 1 (AOX1) and constitutive glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter. A Zeocin concentration up to 2000 mg/L was used to select hyper-producers. The shake flask cultivation studies in the Pichia pastoris GS115 host resulted a maximum recombinant hIL-3 expression level of 145 mg/L in the extracellular medium under the control of AOX1 promoter. The batch fermentation strategy allowed us to attain a fairly pure glycosylated hIL-3 protein in the culture supernatant at a final concentration of 475 mg/L with a high volumetric productivity of 4.39 mg/L/h. The volumetric product concentration achieved at bioreactor level was 3.28 folds greater than the shake flask results. The 6x His-tagged protein was purified using Ni-NTA affinity chromatography and confirmed further by western blot analysis using anti-6x His tag antibody. The glycosylation of recombinant hIL-3 protein was confirmed in a PNGase F deglycosylation reaction where it showed a molecular weight band pattern similar to E. coli produced non-glycosylated hIL-3 protein. The structural properties of recombinant hIL-3 protein were confirmed by CD and fluorescence spectroscopy where protein showed 40 % α-helix, 12 % β-sheets with an emission maxima at 343 nm. MALDI-TOF-TOF analysis was used to establish the protein identity. The biological activity of purified protein was confirmed by the human erythroleukemia TF-1 cell proliferation assay.

  19. Massive Pulmonary Embolism: Treatment with Thrombus Fragmentation and Local Fibrinolysis with Recombinant Human-Tissue Plasminogen Activator

    International Nuclear Information System (INIS)

    Stock, Klaus Wilhelm; Jacob, Augustinus Ludwig; Schnabel, Karl Jakob; Bongartz, Georg; Steinbrich, Wolfgang

    1997-01-01

    Purpose: To report the results of thrombus fragmentation in combination with local fibrinolysis using recombinant human-tissue plasminogen activator (rtPA) in patients with massive pulmonary embolism. Methods: Five patients with massive pulmonary embolism were treated with thrombus fragmentation followed by intrapulmonary injection of rtPA. Clot fragmentation was performed with a guidewire, angiographic catheter, and balloon catheter. Three patients had undergone recent surgery; one of them received a reduced dosage of rtPA. Results: All patients survived and showed clinical improvement with a resultant significant (p < 0.05) decrease in the pulmonary blood pressure (mean systolic pulmonary blood pressure before treatment, 49 mmHg; 4 hr after treatment, 28 mmHg). Angiographic follow-up in three patients revealed a decrease in thrombus material and an increase in pulmonary perfusion. Two patients developed retroperitoneal hematomas requiring transfusion. Conclusion: Clot fragmentation and local fibrinolysis with rtPA was an effective therapy for massive pulmonary embolism. Bleeding at the puncture site was a frequent complication

  20. Recombiner

    International Nuclear Information System (INIS)

    Kikuchi, Nobuo.

    1983-01-01

    Purpose: To shorten the pre-heating time for a recombiner and obtain a uniform temperature distribution for the charged catalyst layer in a BWR type reactor. Constitution: A pre-heating heater is disposed to the outer periphery of a vessel for a recombiner packed with catalysts for recombining hydrogen and oxygen in gases flowing through a radioactive gaseous wastes processing system. Heat pipes for transmitting the heat applied to said container to the catalyst are disposed vertically and horizontally within the container. Different length of the heat pipes are combined. In this way, pre-heating time for the recombiner before the operation start and before the system switching can be shortened and the uniform pre-heating for the inside of the recombiner is also made possible. Further, heater control in the pre-heating can be carried out effectively and with ease. (Moriyama, K.)

  1. A recombinant, fully human monoclonal antibody with antitumor activity constructed from phage-displayed antibody fragments

    NARCIS (Netherlands)

    Huls, GA; Heijnen, IAFM; Cuomo, ME; Koningsberger, JC; Boel, E; de Vries, ARV; Loyson, SAJ; Helfrich, W; Henegouwen, GPV; van Meijer, M; de Kruif, J; Logtenberg, T

    A single-chain Fv antibody fragment specific for the tumor-associated Ep-CAM molecule was isolated from a semisynthetic phage display library and converted into an intact, fully human IgG1 monoclonal antibody (huMab), The purified huMab had an affinity of 5 nM and effectively mediated tumor cell

  2. Recombiner

    International Nuclear Information System (INIS)

    Osumi, Morimichi.

    1979-01-01

    Purpose: To provide a recombiner which is capable of converting hydrogen gas into water by use of high-frequency heating at comparatively low temperatures and is safe and cheap in cost. Constitution: Hydrogen gas is introduced from an outer pipeline to the main structure of a recombiner, and when it passes through the vicinity of the central part of the recombiner, it is reacted with copper oxide (CuO 2 ) heated to a temperature more than 300 0 C by a high-frequency heater, and converted gently into water by reduction operation (2H 2 + CuO 2 → Cu + 2H 2 O). The thus prepared water is exhausted through the outer pipeline to a suppression pool. A part of hydrogen gas which has not been converted completely into water by the reaction and is remaining as hydrogen is recovered through exhaust nozzles and again introduced into the main structure of the recombiner. (Yoshino, Y.)

  3. Extracellular overexpression of recombinant Thermobifida fusca cutinase by alpha-hemolysin secretion system in E. coli BL21(DE3

    Directory of Open Access Journals (Sweden)

    Su Lingqia

    2012-01-01

    Full Text Available Abstract Background Extracellular expression of proteins has an absolute advantage in a large-scale industrial production. In our previous study, Thermobifida fusca cutinase, an enzyme mainly utilized in textile industry, was expressed via type II secretory system in Escherichia coli BL21(DE3, and it was found that parts of the expressed protein was accumulated in the periplasmic space. Due to the fact that alpha-hemolysin secretion system can export target proteins directly from cytoplasm across both cell membrane of E. coli to the culture medium, thus in the present study we investigated the expression of cutinase using this alpha-hemolysin secretion system. Results T. fusca cutinase was fused with the specific signal peptide of alpha-hemolysin scretion system and expressed in E. coli BL21(DE3. In addition, HlyB and HlyD, strain-specific translocation components of alpha-hemolysin secretion system, were coexpressed to facilitate the enzyme expression. The cultivation of this engineered cell showed that cutinase activity in the culture medium reached 334 U/ml, which is 2.5 times that from type II secretion pathway under the same culture condition. The recombinant cutinase was further purified. Biochemical characterization of purified enzyme, which had an α-hemolysin secretion pathway signal peptide attached, had substrate specificity, pH and temperature profile, as well as application capability in bioscouring similar to that of wild-type cutinase. Conclusions In the present study, T. fusca cutinase was successfully secreted to the culture media by α-hemolysin secretion system. This is the first report of cutinase being efficiently secreted by this pathway. Due to the limited cases of successful expression of industrial enzyme by E. coli α-hemolysin secretion system, our study further explored the utilization of this pathway in industrial enzymes.

  4. Use of Full-Length Recombinant Calflagin and Its C Fragment for Improvement of Diagnosis of Trypanosoma cruzi Infection†

    Science.gov (United States)

    Marcipar, Iván S.; Roodveldt, Cintia; Corradi, Gerardo; Cabeza, María L.; Brito, Maria Edileuza F.; Winter, Lucile M. Floeter; Marcipar, Alberto J.; Silber, Ariel M.

    2005-01-01

    Serological diagnosis of Trypanosoma cruzi infection is hampered by issues related to test specificity due to the cross-reactivity of most antigens with proteins of related parasites such as Leishmania spp. The recombinant calflagins are considered relevant antigens for the diagnosis of infection by Trypanosoma cruzi. In the present work, we describe two genes coding for putative calflagins in Leishmania major with the N-terminal moieties presenting high similarity with T. cruzi genes. This fact raised questions about their role in some cross-recognition of this antigen by sera from Leishmania spp.-infected individuals. The complete T. cruzi calflagin and two fragments of the protein, consisting of 146 amino acids of the N-terminal and 65 amino acids of the C-terminal regions, were expressed and evaluated against a panel of sera, which included well-characterized samples from T. cruzi, and Leishmania-infected patients. We were able to show that sera from Leishmania (Viannia) braziliensis-infected individuals recognized the recombinant full-length calflagin. Both the N-terminal and the complete protein presented the same high sensitivity (98.5% of sera from T. cruzi-infected patients was detected) but different specificities (94% and 98%, respectively, when evaluated against sera from people not infected by T. cruzi, including 15 sera from people infected with L. braziliensis). The C-terminal fragment presented low sensitivity (70%) but 100% specificity. We propose the use of these antigens in two sequential assays to optimize the serological diagnosis of T. cruzi infection in humans in geographic areas where Leishmania spp. infection is coendemic. PMID:16272476

  5. [The comparison of heparan sulfate and its fragments on the protection against extracellular histones during the pathogenesis of acute respiratory distress syndrome].

    Science.gov (United States)

    Zhang, Y L; Guan, L; Zheng, Y M; Zhao, Z M; Mao, L J; Li, S Q; Zhao, J Y

    2018-01-20

    Objective: In order to explore the role of heparan sulfate (HS) during the pathogenesis of acute respiratory distress syndrome (ARDS) , the protective effect of HS and its fragments against extracellular histones was compared. Methods: Calf thymus histones (CTH) were injected via femoral vein to induce ARDS in rats. HS, HS fragments or saline was intraperitoneally injected (10mg/kg, Q6h, 24h) to test the protective effect against CTH. The ratio of wet/dry lung weight, protein content in bronchoalveolar lavage fluid (BALF) , total leukocyte and neutrophil count in BALF were measured. Results: After CTH injection, the ratio of wet/dry lung weight (5.7±0.95) was much higher than the saline control group (3.1±0.15). The protein content (0.47±0.086mg/ml) , total leukocyte[ (97.4±15.6l) ×10(4)/ml] and neutrophil (18±3.4/LPF) in BALF were obviously increased compared with the saline control group. The intervention of HS evidently decreased ratio of wet/dry lung weight (4.2±0.41) , protein content[ (0.26±0.019) mg/ml], leukocyte[ (61.3±5.74) ×10(4)/ml] and neutrophil (12±1.8/LPF) in BALF. HS fragments also decreased ratio of wet/dry lung weight, protein content, leukocyte and neutrophil count in BALF though the strength was much less than HS. Conclusion: HS and its fragments could provide protection against extracellular histones during the pathogenesis of ARDS. For the protective effect full length HS was much better than HS fragments.

  6. Targeted Multiplex Imaging Mass Spectrometry with Single Chain Fragment Variable (scfv) Recombinant Antibodies

    Science.gov (United States)

    Thiery, Gwendoline; Mernaugh, Ray L.; Yan, Heping; Spraggins, Jeffrey M.; Yang, Junhai; Parl, Fritz F.; Caprioli, Richard M.

    2012-10-01

    Recombinant scfv antibodies specific for CYP1A1 and CYP1B1 P450 enzymes were combined with targeted imaging mass spectrometry to simultaneously detect the P450 enzymes present in archived, paraffin-embedded, human breast cancer tissue sections. By using CYP1A1 and CYP1B1 specific scfv, each coupled to a unique reporter molecule (i.e., a mass tag) it was possible to simultaneously detect multiple antigens within a single tissue sample with high sensitivity and specificity using mass spectrometry. The capability of imaging multiple antigens at the same time is a significant advance that overcomes technical barriers encountered when using present day approaches to develop assays that can simultaneously detect more than a single antigen in the same tissue sample.

  7. Recombiner

    International Nuclear Information System (INIS)

    Saalfrank, H.

    1985-01-01

    Air containing hydrogen can be oxidized by heating in a container called a recombiner, in order to avoid the collection of hydrogen. The container is long and a large number of straight heating bars are arranged in parallel in it and they are flanged to a lid. The heating bars are surrounded by tubes, in order to obtain good heat transfer by a narrow annular gap. (orig.) [de

  8. Expression of a humanized SZ-63 McAb functional recombinant Fab fragment in E. Coli

    International Nuclear Information System (INIS)

    Xia Lijun; Gu Jianming; Zhang Xiaoming; Liu Yue; Wan Haiying; Li Peixia; Ruan Changgeng

    1995-06-01

    MRNA was selected on oligo(dT)-cellulose from total RNA isolated from SZ-63 hybridoma cells by CsCl ultracentrifugation. cDNA coding for heavy and light variable regions were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR). The amplified fragments were then cloned and sequenced by the 32 P labelled sanger dideoxy-mediated chain-termination method. The nucleotides of VH and Vκ are 354 and 321 respectively, the amino acid sequence of heavy and light chain of SZ-63 were also deduced. Then, linking the variable genes of SZ-63 with human immunoglobulin γ 1 CH and κ VL genes, constructing pHEN1-63 Fab/Hu chimera for expression and transforming E. coli HB2151. The expressed chimeric SZ-63 Fab was soluble. Both ELISA and Western blot results showed the expression products could specifically bind with cross-linked fibrin and the content in expression culture was about 225 μg/L. (5 figs.)

  9. Recombinant phosphatidylserine-binding nanobodies for targeting of extracellular vesicles to tumor cells : a plug-and-play approach

    NARCIS (Netherlands)

    Kooijmans, Sander A A; Gitz-Francois, Jerney J J M; Schiffelers, Raymond M; Vader, Pieter

    2018-01-01

    Extracellular vesicles (EVs) are increasingly being recognized as candidate drug delivery systems due to their ability to functionally transfer biological cargo between cells. However, manipulation of targeting properties of EVs through engineering of the producer cells can be challenging and

  10. High level extracellular production of a recombinant alkaline catalase in E. coli BL21 under ethanol stress and its application in hydrogen peroxide removal after cotton fabrics bleaching.

    Science.gov (United States)

    Yu, Zhenxiao; Zheng, Hongchen; Zhao, Xingya; Li, Shufang; Xu, Jianyong; Song, Hui

    2016-08-01

    The effects of induction parameters, osmolytes and ethanol stress on the productivity of the recombinant alkaline catalase (KatA) in Escherichia coli BL21 (pET26b-KatA) were investigated. The yield of soluble KatA was significantly enhanced by 2% ethanol stress. And a certain amount of Triton X-100 supplementation could markedly improved extracellular ratio of KatA. A total soluble catalase activity of 78,762U/mL with the extracellular ratio of 92.5% was achieved by fed-batch fermentation in a 10L fermentor, which was the highest yield so far. The purified KatA showed high stability at 50°C and pH 6-10. Application of KatA for elimination of H2O2 after cotton fabrics bleaching led to less consumption of water, steam and electric power by 25%, 12% and 16.7% respectively without productivity and quality losing of cotton fabrics. Thus, the recombinant KatA is a promising candidate for industrial production and applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Characterizing the Range of Extracellular Protein Post-Translational Modifications in a Cellulose-Degrading Bacteria Using a Multiple Proteolyic Digestion/Peptide Fragmentation Approach

    Energy Technology Data Exchange (ETDEWEB)

    Dykstra, Andrew B [ORNL; Rodriguez, Jr., Miguel [ORNL; Raman, Babu [Dow Chemical Company, The; Cook, Kelsey [ORNL; Hettich, Robert {Bob} L [ORNL

    2013-01-01

    Post-translational modifications (PTMs) are known to play a significant role in many biological functions. The focus of this study is to characterize the post-translational modifications of the cellulosome protein complex used by the bacterium Clostridium thermocellum to better understand how this protein machine is tuned for enzymatic cellulose solubilization. To enhance comprehensive characterization, the extracellular cellulosome proteins were analyzed using multiple proteolytic digests (trypsin, Lys-C, Glu-C) and multiple fragmentation techniques (collisionally-activated dissociation, electron transfer dissociation, decision tree). As expected, peptide and protein identifications were increased by utilizing alternate proteases and fragmentation methods, in addition to the increase in protein sequence coverage. The complementarity of these experiments also allowed for a global exploration of PTMs associated with the cellulosome based upon a set of defined PTMs that included methylation, oxidation, acetylation, phosphorylation, and signal peptide cleavage. In these experiments, 85 modified peptides corresponding to 28 cellulosome proteins were identified. Many of these modifications were located in active cellulolytic or structural domains of the cellulosome proteins, suggesting a level of possible regulatory control of protein function in various cellulotyic conditions. The use of multiple enzymes and fragmentation technologies allowed for independent verification of PTMs in different experiments, thus leading to increased confidence in PTM identifications.

  12. Modified cytokeratins expressed on the surface of carcinoma cells undergo endocytosis upon binding of human monoclonal antibody and its recombinant Fab fragment

    DEFF Research Database (Denmark)

    Ditzel, H J; Garrigues, U; Andersen, C B

    1997-01-01

    display selection and the human Fab fragment was expressed in bacteria. Analysis by confocal laser scanning microscopy demonstrated that COU-1 bound in a uniform punctate pattern to the surface of viable carcinoma cells stained at 4 degrees C, and binding increased significantly when cells were cultured...... was significantly reduced. Similar results were obtained using intact IgM COU-1 and the recombinant Fab fragment. Immunohistological studies indicated that COU-1, in contrast to murine monoclonal antibodies against normal cytokeratin 8 and 18, could differentiate between malignant and normal colon epithelia...

  13. Integrin specificity and enhanced cellular activities associated with surfaces presenting a recombinant fibronectin fragment compared to RGD supports.

    Science.gov (United States)

    Petrie, Timothy A; Capadona, Jeffrey R; Reyes, Catherine D; García, Andrés J

    2006-11-01

    Biomimetic strategies focusing on presenting short bioadhesive oligopeptides, including the arginine-glycine-aspartic acid (RGD) motif present in numerous adhesive proteins, on a non-fouling support have emerged as promising approaches to improve cellular activities and healing responses. Nevertheless, these bio-inspired strategies are limited by low activity of the oligopeptides compared to the native ligand due to the absence of complementary or modulatory domains. In the present analysis, we generated well-defined biointerfaces presenting RGD-based ligands of increasing complexity to directly compare their biological activities in terms of cell adhesion strength, integrin binding and signaling. Mixed self-assembled monolayers of alkanethiols on gold were optimized to engineer robust supports that present anchoring groups for ligand tethering within a non-fouling, protein adsorption-resistant background. Controlled bioadhesive interfaces were generated by tethering adhesive ligands via standard peptide chemistry. On a molar basis, biointerfaces functionalized with the FNIII7-10 recombinant fragment presenting the RGD and PHSRN adhesive motifs in the correct structural context exhibited significantly higher adhesion strength, FAK activation, and cell proliferation rate than supports presenting RGD ligand or RGD-PHSRN, an oligopeptide presenting these two sites separated by a polyglycine linker. Moreover, FNIII7-10-functionalized surfaces displayed specificity for alpha5beta1 integrin, while cell adhesion to supports presenting RGD or RGD-PHSRN was primarily mediated by alphavbeta3 integrin. These results are significant to the rational engineering of bioactive materials that convey integrin binding specificity for directed cellular and tissue responses in biomedical and biotechnological applications.

  14. A Recombinant Fragment of Human Surfactant Protein D induces Apoptosis in Pancreatic Cancer Cell Lines via Fas-Mediated Pathway.

    Science.gov (United States)

    Kaur, Anuvinder; Riaz, Muhammad Suleman; Murugaiah, Valarmathy; Varghese, Praveen Mathews; Singh, Shiv K; Kishore, Uday

    2018-01-01

    Human surfactant protein D (SP-D) is a potent innate immune molecule, which is emerging as a key molecule in the recognition and clearance of altered and non-self targets. Previous studies have shown that a recombinant fragment of human SP-D (rfhSP-D) induced apoptosis via p53-mediated apoptosis pathway in an eosinophilic leukemic cell line, AML14.3D10. Here, we report the ability of rfhSP-D to induce apoptosis via TNF-α/Fas-mediated pathway regardless of the p53 status in human pancreatic adenocarcinoma using Panc-1 (p53 mt ), MiaPaCa-2 (p53 mt ), and Capan-2 (p53 wt ) cell lines. Treatment of these cell lines with rfhSP-D for 24 h caused growth arrest in G1 cell cycle phase and triggered transcriptional upregulation of pro-apoptotic factors such as TNF-α and NF-κB. Translocation of NF-κB from the cytoplasm into the nucleus of pancreatic cancer cell lines was observed via immunofluorescence microscopy following treatment with rfhSP-D as compared to the untreated cells. The rfhSP-D treatment caused upregulation of pro-apoptotic marker Fas, as analyzed via qPCR and western blot, which then triggered caspase cascade, as evident from cleavage of caspase 8 and 3 analyzed via western blot at 48 h. The cell number following the rfhSP-D treatment was reduced in the order of Panc-1 (~67%) > MiaPaCa-2 (~60%) > Capan-2 (~35%). This study appears to suggest that rfhSP-D can potentially be used to therapeutically target pancreatic cancer cells irrespective of their p53 phenotype.

  15. Dissociative Recombination of HD+ - State-to-State Experimental Investigation Using Fragment Imaging and Storage Ring Techniques

    International Nuclear Information System (INIS)

    Amitay, Z.; Baer, A.; Dahan, M.; Levin, J.; Vager, Z.; Zajfman, D.

    1998-01-01

    When a molecular ion collides with a free electron it can capture the electron and dissociate. The resulting process of Dissociative Recombination (DR) is a process of great significance in a wide variety of plasma environments. In this process, the capture of a free electron leads to the formation of an highly excited state of the neutral molecule, which then dissociates into neutral fragments with kinetic energy and, possibly, internal excitation depending on the energy balance of the reaction. Despite its importance, the DR process is still not yet completely understood theoretically. This is mainly due to the complexity of the nature and dynamics of highly excited molecular states, especially when several channels are involved, as is usually the situation in DR. from experimental point of view, for direct comparison between experiment and theory, this complexity requires detailed experimental data, including the knowledge of both the initial state of the molecular ion, to which DR is very sensitive, and of the final quantum states of the DR products. Inherent un- certainties in the initial vibrational excitation of the laboratory molecular ions was the main drawback of the experiments conducted over the years to, study DR. A substantial progress in the understanding of the DR process was achieved with the introduction (about five years ago) of a new experimental approach, which uses heavy-ion storage ring technique. In a storage ring, one can store many molecular ions for a time which is long enough to allow complete radiative deexcitation of tile initial electronic and vibrational excitation coming from the ion source. Those vibrationally cold ions are then merged with an intense electron beam to measure their DR cross section. Further experimental progress was the inclusion of two and three-dimensional molecular imaging techniques [1] for the measurement of the branching ratio to different final quantum states of the neutral DR fragments. This talk will

  16. Extracellular secretion of a recombinant therapeutic peptide by Bacillus halodurans utilizing a modified flagellin type III secretion system

    CSIR Research Space (South Africa)

    Berger, E

    2011-08-01

    Full Text Available further 3.5-fold increase in the secretion of recombinant peptide fusions. Conclusions: The type III flagellar secretion system of B. halodurans has been shown to successfully secrete a therapeutic peptide as a heterologous flagellin fusion. Improvements...

  17. Effect of culture medium, host strain and oxygen transfer on recombinant Fab antibody fragment yield and leakage to medium in shaken E. coli cultures

    Science.gov (United States)

    2013-01-01

    Background Fab antibody fragments in E. coli are usually directed to the oxidizing periplasmic space for correct folding. From periplasm Fab fragments may further leak into extracellular medium. Information on the cultivation parameters affecting this leakage is scarce, and the unpredictable nature of Fab leakage is problematic regarding consistent product recovery. To elucidate the effects of cultivation conditions, we investigated Fab expression and accumulation into either periplasm or medium in E. coli K-12 and E. coli BL21 when grown in different types of media and under different aeration conditions. Results Small-scale Fab expression demonstrated significant differences in yield and ratio of periplasmic to extracellular Fab between different culture media and host strains. Expression in a medium with fed-batch-like glucose feeding provided highest total and extracellular yields in both strains. Unexpectedly, cultivation in baffled shake flasks at 150 rpm shaking speed resulted in higher yield and accumulation of Fabs into culture medium as compared to cultivation at 250 rpm. In the fed-batch medium, extracellular fraction in E. coli K-12 increased from 2-17% of total Fab at 250 rpm up to 75% at 150 rpm. This was partly due to increased lysis, but also leakage from intact cells increased at the lower shaking speed. Total Fab yield in E. coli BL21 in glycerol-based autoinduction medium was 5 to 9-fold higher at the lower shaking speed, and the extracellular fraction increased from ≤ 10% to 20-90%. The effect of aeration on Fab localization was reproduced in multiwell plate by variation of culture volume. Conclusions Yield and leakage of Fab fragments are dependent on expression strain, culture medium, aeration rate, and the combination of these parameters. Maximum productivity in fed-batch-like conditions and in autoinduction medium is achieved under sufficiently oxygen-limited conditions, and lower aeration also promotes increased Fab accumulation into

  18. Fcγ1 fragment of IgG1 as a powerful affinity tag in recombinant Fc-fusion proteins: immunological, biochemical and therapeutic properties.

    Science.gov (United States)

    Soleimanpour, Saman; Hassannia, Tahereh; Motiee, Mahdieh; Amini, Abbas Ali; Rezaee, S A R

    2017-05-01

    Affinity tags are vital tools for the production of high-throughput recombinant proteins. Several affinity tags, such as the hexahistidine tag, maltose-binding protein, streptavidin-binding peptide tag, calmodulin-binding peptide, c-Myc tag, glutathione S-transferase and FLAG tag, have been introduced for recombinant protein production. The fragment crystallizable (Fc) domain of the IgG1 antibody is one of the useful affinity tags that can facilitate detection, purification and localization of proteins and can improve the immunogenicity, modulatory effects, physicochemical and pharmaceutical properties of proteins. Fcγ recombinant forms a group of recombinant proteins called Fc-fusion proteins (FFPs). FFPs are widely used in drug discovery, drug delivery, vaccine design and experimental research on receptor-ligand interactions. These fusion proteins have become successful alternatives to monoclonal antibodies for drug developments. In this review, the physicochemical, biochemical, immunological, pharmaceutical and therapeutic properties of recombinant FFPs were discussed as a new generation of bioengineering strategies.

  19. hCGbeta core fragment is a metabolite of hCG: evidence from infusion of recombinant hCG.

    Science.gov (United States)

    Norman, R J; Buchholz, M M; Somogyi, A A; Amato, F

    2000-03-01

    The availability of recombinant human chorionic gonadotrophin (r-hCG) has allowed us to measure its metabolic and renal clearance rates and to study the origin of the beta core fragment of hCG (hCGbetacf). Serum and urine samples were collected from six subjects, after an intravenous injection of 2 mg (equivalent to 44 000 IU Urinary hCG) r-hCG, and assayed for hCG and the beta subunit (hCGbeta). Urine from four of the subjects was also subjected to gel chromatography and assayed for hCGbetacf and hCG. r-hCG, administered as an intravenous dose, was distributed, initially in a volume of 3.4+/-0.7 l (mean+/-s.d.) and then in 6.5+/-1.15 l at steady-state. The disappearance of r-hCG from serum was bi-exponential, with an initial half-life of 4.5+/-0.7 h and a terminal half-life of 29.0+/-4.6 h. The mean residence time was 28. 6+/- 3.6 h and the total systemic clearance rate of r-hCG was 226+/-18 ml/h. The renal clearance rate was 28.75+/-6.2 ml/h (mean+/-s.d). hCGbetacf was detected in all urine samples collected at 6 h intervals. Over the 138 h period of urine collection, 12.9% (range 10.1-17.3% ) of r-hCG injected was recovered as the intact molecule and 1.7% (range 0.8-2.9%) was recovered as the hCGbetacf, in 4 subjects. The molar ratio of hCGbetacf to hCG in urine increased from 3.1+/-1.7%, on day 1, to 76+/-34.3% (mean+/-s.e.m.) on day 5, after r-hCG infusion, suggesting that hCGbetacf is a metabolic product of the infused r-hCG.

  20. The impact of homologous recombination repair deficiency on depleted uranium clastogenicity in Chinese hamster ovary cells: XRCC3 protects cells from chromosome aberrations, but increases chromosome fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Amie L. [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth Street, P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Joyce, Kellie [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Xie, Hong [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Department of Applied Medical Science, University of Southern Maine, 96 Falmouth Street, P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Falank, Carolyne [Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); Maine Center for Toxicology and Environmental Health, University of Southern Maine, 96 Falmouth St., P.O. Box 9300, Portland, ME 04104-9300, United States of America (United States); and others

    2014-04-15

    Highlights: • The role of homologous recombination repair in DU-induced toxicity was examined. • Loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. • XRCC3 protects cell from DU-induced chromosome breaks and fusions. • XRCC3 plays a role in DU-induced chromosome fragmentation of the X chromosome. - Abstract: Depleted uranium (DU) is extensively used in both industry and military applications. The potential for civilian and military personnel exposure to DU is rising, but there are limited data on the potential health hazards of DU exposure. Previous laboratory research indicates DU is a potential carcinogen, but epidemiological studies remain inconclusive. DU is genotoxic, inducing DNA double strand breaks, chromosome damage and mutations, but the mechanisms of genotoxicity or repair pathways involved in protecting cells against DU-induced damage remain unknown. The purpose of this study was to investigate the effects of homologous recombination repair deficiency on DU-induced genotoxicity using RAD51D and XRCC3-deficient Chinese hamster ovary (CHO) cell lines. Cells deficient in XRCC3 (irs1SF) exhibited similar cytotoxicity after DU exposure compared to wild-type (AA8) and XRCC3-complemented (1SFwt8) cells, but DU induced more break-type and fusion-type lesions in XRCC3-deficient cells compared to wild-type and XRCC3-complemented cells. Surprisingly, loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. DU induced selective X-chromosome fragmentation irrespective of RAD51D status, but loss of XRCC3 nearly eliminated fragmentation observed after DU exposure in wild-type and XRCC3-complemented cells. Thus, XRCC3, but not RAD51D, protects cells from DU-induced breaks and fusions and also plays a role in DU-induced chromosome fragmentation.

  1. The impact of homologous recombination repair deficiency on depleted uranium clastogenicity in Chinese hamster ovary cells: XRCC3 protects cells from chromosome aberrations, but increases chromosome fragmentation

    International Nuclear Information System (INIS)

    Holmes, Amie L.; Joyce, Kellie; Xie, Hong; Falank, Carolyne

    2014-01-01

    Highlights: • The role of homologous recombination repair in DU-induced toxicity was examined. • Loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. • XRCC3 protects cell from DU-induced chromosome breaks and fusions. • XRCC3 plays a role in DU-induced chromosome fragmentation of the X chromosome. - Abstract: Depleted uranium (DU) is extensively used in both industry and military applications. The potential for civilian and military personnel exposure to DU is rising, but there are limited data on the potential health hazards of DU exposure. Previous laboratory research indicates DU is a potential carcinogen, but epidemiological studies remain inconclusive. DU is genotoxic, inducing DNA double strand breaks, chromosome damage and mutations, but the mechanisms of genotoxicity or repair pathways involved in protecting cells against DU-induced damage remain unknown. The purpose of this study was to investigate the effects of homologous recombination repair deficiency on DU-induced genotoxicity using RAD51D and XRCC3-deficient Chinese hamster ovary (CHO) cell lines. Cells deficient in XRCC3 (irs1SF) exhibited similar cytotoxicity after DU exposure compared to wild-type (AA8) and XRCC3-complemented (1SFwt8) cells, but DU induced more break-type and fusion-type lesions in XRCC3-deficient cells compared to wild-type and XRCC3-complemented cells. Surprisingly, loss of RAD51D did not affect DU-induced cytotoxicity or genotoxicity. DU induced selective X-chromosome fragmentation irrespective of RAD51D status, but loss of XRCC3 nearly eliminated fragmentation observed after DU exposure in wild-type and XRCC3-complemented cells. Thus, XRCC3, but not RAD51D, protects cells from DU-induced breaks and fusions and also plays a role in DU-induced chromosome fragmentation

  2. Protective vaccination with a recombinant fragment of Clostridium botulinum neurotoxin serotype A expressed from a synthetic gene in Escherichia coli.

    OpenAIRE

    Clayton, M A; Clayton, J M; Brown, D R; Middlebrook, J L

    1995-01-01

    A completely synthetic gene encoding fragment C, a approximately 50-kDa fragment, of botulinum neurotoxin serotype A was constructed from oligonucleotides. The gene was expressed in Escherichia coli, and full-sized product was produced as judged by Western blot (immunoblot) analysis. Crude extracts of E. coli expressing the gene were used to vaccinate mice and evaluate their survival against challenge with active toxin. Mice given three subcutaneous vaccinations were protected against an intr...

  3. Identification, recombinant production and partial biochemical characterization of an extracellular cold-active serine-metalloprotease from an Antarctic Pseudomonas isolate

    Directory of Open Access Journals (Sweden)

    Natalia Fullana

    2017-08-01

    Full Text Available Cold-adapted enzymes are generally derived from psychrophilic microorganisms and have features that make them very attractive for industrial and biotechnological purposes. In this work, we identified a 50 kDa extracellular protease (MP10 from the Antarctic isolate Pseudomonas sp. AU10. The enzyme was produced by recombinant DNA technology, purified using immobilized metal affinity chromatography and partially characterized. MP10 is an alkaline thermosensitive serine-metallo protease with optimal activity at pH 8.0 and 40 ℃, in the presence of 1.5 mM Ca2+. MP10 showed 100% residual activity and stability (up to 60 min when incubated with 7% of non-ionic surfactants (Triton X-100, Tween-80 and Tween-20 and 1.5% of the oxidizing agent hydrogen peroxide. The 3D MP10 structure was predicted and compared with the crystal structure of mesophilic homologous protease produced by Pseudomonas aeruginosa PA01 (reference strain and other proteases, showing similarity in surface area and volume of proteins, but a significantly higher surface pocket area and volume of MP10. The observed differences presumably may explain the enhanced activity of MP10 for substrate binding at low temperatures. These results give insight to the potential use of MP10 in developing new biotechnologically processes active at low to moderate temperatures, probably with focus in the detergent industry.

  4. A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

    International Nuclear Information System (INIS)

    Qi, Zhi; Pan, Chungen; Lu, Hong; Shui, Yuan; Li, Lin; Li, Xiaojuan; Xu, Xueqing; Liu, Shuwen; Jiang, Shibo

    2010-01-01

    Research highlights: → One recombinant mimetics of gp41 prehairpin fusion intermediate (PFI) consisting of gp41 N46 sequence, foldon and IgG Fc, designated N46FdFc, was expressed. → N46FdFc-induced antibodies in mice that neutralized HIV-1 infection, inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. → These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines. -- Abstract: HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.

  5. Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin.

    Directory of Open Access Journals (Sweden)

    José-Daniel Aroca-Aguilar

    Full Text Available Myocilin is an extracellular glycoprotein of poorly understood function. Mutations of this protein are involved in glaucoma, an optic neuropathy characterized by a progressive and irreversible visual loss and frequently associated with elevated intraocular pressure. We previously showed that recombinant myocilin undergoes an intracellular proteolytic processing by calpain II which cleaves the central region of the protein, releasing one N- and one C-terminal fragment. Myocilin cleavage is reduced by glaucoma mutations and it has been proposed to participate in intraocular pressure modulation. To identify possible factors regulating the proteolytic processing of recombinant myocilin, we used a cellular model in which we analyzed how different culture medium parameters (i.e., culture time, cell density, pH, bicarbonate concentration, etc. affect the presence of the extracellular C-terminal fragment. Extracellular bicarbonate depletion associated with culture medium acidification produced a reversible intracellular accumulation of full-length recombinant myocilin and incremented its intracellular proteolytic processing, raising the extracellular C-terminal fragment percentage. It was also determined that myocilin intracellular accumulation depends on its N-terminal region. These data suggest that aqueous humor bicarbonate variations could also modulate the secretion and cleavage of myocilin present in ocular tissues.

  6. The recombinant C-terminal fragment of tetanus toxin protects against cholinotoxicity by intraseptal injection of β-amyloid peptide (25-35) in rats.

    Science.gov (United States)

    Patricio-Martínez, A; Mendieta, L; Martínez, I; Aguilera, J; Limón, I D

    2016-02-19

    The recombinant C-terminal domain of tetanus toxin (Hc-TeTx) is a new non-toxic peptide of the tetanus toxin that exerts a protective action against glutamate excitotoxicity in motoneurons. Moreover, its efficacy as a neuroprotective agent has been demonstrated in several animal models of neurodegeneration. The eleven amino acids in the β amyloid peptide (Aβ25-35) mimic the toxic effects of the full β amyloid peptide (Aβ1-42), causing the impairment of the cholinergic system in the medial septum (MS) which, in turn, alters the septo-hippocampal pathway and leads to learning and memory impairments. The aim of this study was to examine the neuroprotective effects of the Hc-TeTx fragment against cholinotoxicity. The Hc-TeTx fragment (100 ng) was injected into the rats intercranially, with the Aβ(25-35) (2 μg) then injected into their MS. The animals were tested for spatial learning and memory in the eight-arm radial maze. The brains were removed to assess cholinergic markers, such as choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), and to explore neurodegeneration in the MS and hippocampus, using amino-cupric silver and H&E staining. Finally, capase-3, a marker of apoptosis, was examined in the MS. Our results clearly demonstrate that the application of Hc-TeTx prevents the loss of cholinergic markers (ChAT and AChE), the activation of capase-3, and neurodegeneration in the MS and the CA1 and CA3 subfields of the hippocampus. All these improvements were reflected in spatial learning and memory performance, and were significantly higher compared with animals treated with Aβ(25-35). Interestingly, the single administration of Hc-TeTx into the MS modified the ChAT and AChE expression that affect cognitive processes, without inducing neurodegeneration or an increase in capase-3 expression in the MS and hippocampus. In summary, our findings suggest that the recombinant Hc-TeTx fragment offers effective protection for the septo-hippocampal pathway

  7. Novel camelid antibody fragments targeting recombinant nucleoprotein of Araucaria hantavirus: a prototype for an early diagnosis of Hantavirus Pulmonary Syndrome.

    Directory of Open Access Journals (Sweden)

    Soraya S Pereira

    Full Text Available In addition to conventional antibodies, camelids produce immunoglobulins G composed exclusively of heavy chains in which the antigen binding site is formed only by single domains called VHH. Their particular characteristics make VHHs interesting tools for drug-delivery, passive immunotherapy and high-throughput diagnosis. Hantaviruses are rodent-borne viruses of the Bunyaviridae family. Two clinical forms of the infection are known. Hemorrhagic Fever with Renal Syndrome (HFRS is present in the Old World, while Hantavirus Pulmonary Syndrome (HPS is found on the American continent. There is no specific treatment for HPS and its diagnosis is carried out by molecular or serological techniques, using mainly monoclonal antibodies or hantavirus nucleoprotein (N to detect IgM and IgG in patient serum. This study proposes the use of camelid VHHs to develop alternative methods for diagnosing and confirming HPS. Phage display technology was employed to obtain VHHs. After immunizing one Lama glama against the recombinant N protein (prNΔ₈₅ of a Brazilian hantavirus strain, VHH regions were isolated to construct an immune library. VHHs were displayed fused to the M13KO7 phage coat protein III and the selection steps were performed on immobilized prNΔ₈₅. After selection, eighty clones recognized specifically the N protein. These were sequenced, grouped based mainly on the CDRs, and five clones were analyzed by western blot (WB, surface plasmon resonance (SPR device, and ELISA. Besides the ability to recognize prNΔ85 by WB, all selected clones showed affinity constants in the nanomolar range. Additionaly, the clone KC329705 is able to detect prNΔ₈₅ in solution, as well as the native viral antigen. Findings support the hypothesis that selected VHHs could be a powerful tool in the development of rapid and accurate HPS diagnostic assays, which are essential to provide supportive care to patients and reduce the high mortality rate associated with

  8. Immunogenicity of seven new recombinant yellow fever viruses 17D expressing fragments of SIVmac239 Gag, Nef, and Vif in Indian rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Mauricio A Martins

    Full Text Available An effective vaccine remains the best solution to stop the spread of human immunodeficiency virus (HIV. Cellular immune responses have been repeatedly associated with control of viral replication and thus may be an important element of the immune response that must be evoked by an efficacious vaccine. Recombinant viral vectors can induce potent T-cell responses. Although several viral vectors have been developed to deliver HIV genes, only a few have been advanced for clinical trials. The live-attenuated yellow fever vaccine virus 17D (YF17D has many properties that make it an attractive vector for AIDS vaccine regimens. YF17D is well tolerated in humans and vaccination induces robust T-cell responses that persist for years. Additionally, methods to manipulate the YF17D genome have been established, enabling the generation of recombinant (rYF17D vectors carrying genes from unrelated pathogens. Here, we report the generation of seven new rYF17D viruses expressing fragments of simian immunodeficiency virus (SIVmac239 Gag, Nef, and Vif. Studies in Indian rhesus macaques demonstrated that these live-attenuated vectors replicated in vivo, but only elicited low levels of SIV-specific cellular responses. Boosting with recombinant Adenovirus type-5 (rAd5 vectors resulted in robust expansion of SIV-specific CD8(+ T-cell responses, particularly those targeting Vif. Priming with rYF17D also increased the frequency of CD4(+ cellular responses in rYF17D/rAd5-immunized macaques compared to animals that received rAd5 only. The effect of the rYF17D prime on the breadth of SIV-specific T-cell responses was limited and we also found evidence that some rYF17D vectors were more effective than others at priming SIV-specific T-cell responses. Together, our data suggest that YF17D - a clinically relevant vaccine vector - can be used to prime AIDS virus-specific T-cell responses in heterologous prime boost regimens. However, it will be important to optimize rYF17D

  9. Expression, purification and characterization of the recombinant chimeric IgE Fc-fragment opossum-human-opossum (OSO), an active immunotherapeutic vaccine component.

    Science.gov (United States)

    Xu, Bingze; Lundgren, Mats; Magnusson, Ann-Christine; Fuentes, Alexis

    2010-11-01

    The active vaccine component recombinant chimeric IgE Fc-fragment opossum-human-opossum (OSO) has been expressed in CHO-K1 cells. It contains two identical polypeptide chains with 338 amino acid residues in each chain connected by two disulfide bridges. The cell lines were adapted to suspension culture in a serum-free medium. An expression level of 60 mg/L was obtained after 8 days in a shaking flask at a temperature of 31.5 degrees C. The OSO protein has been purified to homogeneity by a combination of three chromatographic steps. Virus inactivation and reduction by solvent detergent treatment and nano-filtration were included in the process. The residual host cell protein content was less than 50 ng/mg OSO as analyzed by ELISA. Purity was analyzed by SDS-PAGE under reducing and non-reducing conditions and was estimated by densitometry to be above 99.0%. The dimer content was less than 0.1% as estimated by analytical size exclusion chromatography. The molecular mass, as estimated by SDS-PAGE, is 90 kDa. A value of around 74 kDa was calculated from its amino acid composition. This indicates that the protein is heavily glycosylated containing around 18% carbohydrate. Isoelectric focusing in polyacrylamide gel disclosed a ladder type band pattern with pI values in the pH-range 7.0-8.3, indicating a variation in the sialic acid content. The OSO protein is not stable at temperatures above 40 degrees C and at pH values below 4 indicating that virus inactivation by incubating the protein solution at higher temperature or at lower pH is not possible. Copyright 2010 Elsevier Inc. All rights reserved.

  10. Instruments for oral disease-intervention strategies : recombinant Lactobacillus casei expressing tetanus toxin fragment C for vaccination or myelin proteins for oral tolerance induction in multiple sclerosis

    NARCIS (Netherlands)

    Maassen, C.B.M.; Laman, J.D.; Heijne den Bak-Glashouwer, M.J.; Tielen, F.J.; Holten-Neelen, J.C.P.A. van; Hoogteijling, L.; Antonissen, C.; Leer, R.J.; Pouwels, P.H.; Boersma, W.J.A.; Shaw, D.M.

    1999-01-01

    Lactobacillus strains possess properties that make them attractive candidates as vehicles for oral administration of therapeutics. In this report we describe the construction and analysis of recombinant Lactobacillus casei applicable in oral vaccination against an infectious disease (tetanus) and in

  11. Production of a Recombinant E. coli Expressed Malarial Vaccine from the C-Terminal Fragment of Plasmodium Falciparum 3D7 Merozoite Surface Protein-1

    National Research Council Canada - National Science Library

    Angov, Evelina

    2000-01-01

    .... Since antibody is likely the effector mechanism induced by MSP-(42), it is important to insure that recombinant vaccines based upon this antigen be folded correctly and contain T-helper epitopes that will enhance induction of humoral responses...

  12. Implication of extracellular zinc exclusion by recombinant human calprotectin (MRP8 and MRP14) from target cells in its apoptosis-inducing activity.

    Science.gov (United States)

    Yui, Satoru; Nakatani, Yuichi; Hunter, Michael J; Chazin, Walter J; Yamazaki, Masatoshi

    2002-06-01

    Calprotectin is a calcium-binding and zinc-binding protein complex that is abundant in the cytosol of neutrophils. This factor is composed of 8 and 14 kDa subunits, which have also been termed migration inhibitory factor-related proteins MRP8 and MRP14. We previously reported that rat calprotectin purified from inflammatory neutrophils induces apoptosis of various tumor cells or normal fibroblasts in a zinc-reversible manner. The present study was undertaken to elucidate which subunit is responsible for the apoptosis-inducing activity, and to explore the mechanism of zinc-reversible apoptosis induction. The apoptosis-inducing activity of recombinant human MRP8 (rhMRP8) and recombinant human MRP14 (rhMRP14) was examined against EL-4 lymphoma cells in vitro. To determine whether zinc deprivation by calprotectin was essential for the cytotoxicity, the activity of calprotectin was tested under conditions where physical contact between the factor and the cells was precluded by a low molecular weight cut-off dialysis membrane. The cytotoxicity of rhMRP14 against EL-4 cells was first detected at 10 microM in a standard medium, whereas rhMRP8 caused only marginal cytotoxicity at 40 microM. A mixture of both proteins showed higher specific activity (onset of cytotoxicity at 5 microM). When the cells were cultured in divalent cation-depleted medium, each dose-response curve was shifted to about a four-fold lower concentration range. Calprotectin was found to induce cell death even when the complex and the target cells were separated by dialysis membrane. A membrane-impermeable zinc chelator, diethylenetriamine pentaacetic acid (DTPA), also induced target cell apoptosis in a similar time-course as calprotectin. Moreover, the activities of calprotectin and DTPA were completely inhibited by the presence of zinc ions. These data indicate that calprotectin has higher specific activity to induce apoptosis than the Individual subunits, and that the mechanism is exclusion of zinc

  13. Production of a Recombinant E. coli Expressed Malarial Vaccine from the C-Terminal Fragment of Plasmodium Falciparum 3D7 Merozoite Surface Protein-1

    National Research Council Canada - National Science Library

    Angov, Evelina

    2000-01-01

    .... However, it appears to lack T-helper epitopes. Since antibody is likely the effector mechanism induced by MSP1-19, it is important to insure that recombinant vaccines based on this antigen be folded correctly and contain T-helper epitopes...

  14. Isolation of Mal d 1 and Api g 1 - specific recombinant antibodies from mouse IgG Fab fragment libraries - Mal d 1-specific antibody exhibits cross-reactivity against Bet v 1.

    Science.gov (United States)

    Haka, Jaana; Niemi, Merja H; Iljin, Kristiina; Reddy, Vanga Siva; Takkinen, Kristiina; Laukkanen, Marja-Leena

    2015-05-27

    Around 3-5% of the population suffer from IgE-mediated food allergies in Western countries and the number of food-allergenic people is increasing. Individuals with certain pollen allergies may also suffer from a sensitisation to proteins in the food products. As an example a person sensitised to the major birch pollen allergen, Bet v 1, is often sensitised to its homologues, such as the major allergens of apple, Mal d 1, and celery, Api g 1, as well. Development of tools for the reliable, sensitive and quick detection of allergens present in various food products is essential for allergic persons to prevent the consumption of substances causing mild and even life-threatening immune responses. The use of monoclonal antibodies would ensure the specific detection of the harmful food content for a sensitised person. Mouse IgG antibody libraries were constructed from immunised mice and specific recombinant antibodies for Mal d 1 and Api g 1 were isolated from the libraries by phage display. More detailed characterisation of the resulting antibodies was carried out using ELISA, SPR experiments and immunoprecipitation assays. The allergen-specific Fab fragments exhibited high affinity towards the target recombinant allergens. Furthermore, the Fab fragments also recognised native allergens from natural sources. Interestingly, isolated Mal d 1-specific antibody bound also to Bet v 1, the main allergen eliciting the cross-reactivity syndrome between the birch pollen and apple. Despite the similarities in Api g 1 and Bet v 1 tertiary structures, the isolated Api g 1-specific antibodies showed no cross-reactivity to Bet v 1. Here, high-affinity allergen-specific recombinant antibodies were isolated with interesting binding properties. With further development, these antibodies can be utilised as tools for the specific and reliable detection of allergens from different consumable products. This study gives new preliminary insights to elucidate the mechanism behind the pollen

  15. Development of an immunoassay for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) based upon the recombinant Fab fragment of 2,4-D specific antibody

    Science.gov (United States)

    Nguyen, Van C.; Nguyen, Thi D. T.; Dau, Hung A.; Tham, Thu N.; Quyen, Dinh T.; Bachmman, Till; Schmid, Rolf D.

    2001-09-01

    To develop an immunoassay and further an immunosensor for 2,4-D based upon recombinant antibody, the Fab fragments of 2,4-D specific antibody were expressed in E. coli. Western blotting analysis of the periplasmic cell fractions shown that under the non-reducing condition only a single protein band at a molecular mass of 45-kDa, corresponding to the whole Fab fragment was detected. Antigen binding activity for 2,4-D was found only in the extract of cells bearing the 2,4-D plasmid. An immunoassay based on the competitive reaction of 2,4-D and enzyme tracer with 2,4-D Fab fragments immobilized on micro titer plates via rabbit anti-mouse IgC was developed. Using this assay, 2,4-D could be detected at concentration range of 0.5 (mu) g/1 to 10(mu) g/1. The center point of the 2,4-D test was found at a concentration of 5 (mu) g/l. The assay was applied for detection of 2,4-D in spiked orange samples, resulting in recovery rate of 90 percent. The immunoassay could be applied to monitor human exposure to 2,4-D from contamination in fruit samples.

  16. Fragmentation of extracellular matrix by hypochlorous acid

    DEFF Research Database (Denmark)

    Woods, Alan A; Davies, Michael Jonathan

    2003-01-01

    /chloramide decomposition, with copper and iron ions being effective catalysts, and decreased by compounds which scavenge chloramines/chloramides, or species derived from them. The effect of such matrix modifications on cellular behaviour is poorly understood, though it is known that changes in matrix materials can have...... profound effects on cell adhesion, proliferation, growth and phenotype. The observed matrix modifications reported here may therefore modulate cellular behaviour in diseases such as atherosclerosis where MPO-derived oxidants are generated....

  17. Detection and quantification of microcystins (cyanobacterial hepatotoxins) with recombinant antibody fragments isolated from a naïve human phage display library.

    Science.gov (United States)

    McElhiney, J; Lawton, L A; Porter, A J

    2000-12-01

    Single-chain antibody fragments against the cyanobacterial hepatotoxin microcystin-LR were isolated from a naive human phage display library and expressed in Escherichia coli. In competition enzyme-linked immunosorbent assay (ELISA), the most sensitive antibody clone selected from the library detected free microcystin-LR with an IC(50) value of 4 microM. It was found to cross react with three other microcystin variants - microcystin-RR, microcystin-LW and microcystin-LF - and detected microcystins in extracts of the cyanobacterium Microcystis aeruginosa, found to contain the toxins by high-performance liquid chromatography (HPLC). The quantification of microcystins in these extracts by ELISA and HPLC showed good correlation. Although the antibody isolated in this study was considerably less sensitive than the polyclonal and monoclonal antibodies already available for microcystin detection, phage display technology represents a cheaper, more rapid alternative for the production of anti-microcystin antibodies than the methods currently in use.

  18. Nuclease-mediated double-strand break (DSB) enhancement of small fragment homologous recombination (SFHR) gene modification in human-induced pluripotent stem cells (hiPSCs).

    Science.gov (United States)

    Sargent, R Geoffrey; Suzuki, Shingo; Gruenert, Dieter C

    2014-01-01

    Recent developments in methods to specifically modify genomic DNA using sequence-specific endonucleases and donor DNA have opened the door to a new therapeutic paradigm for cell and gene therapy of inherited diseases. Sequence-specific endonucleases, in particular transcription activator-like (TAL) effector nucleases (TALENs), have been coupled with polynucleotide small/short DNA fragments (SDFs) to correct the most common mutation in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene, a 3-base-pair deletion at codon 508 (delF508), in induced pluripotent stem (iPS) cells. The studies presented here describe the generation of candidate TALENs and their co-transfection with wild-type (wt) CFTR-SDFs into CF-iPS cells homozygous for the delF508 mutation. Using an allele-specific PCR (AS-PCR)-based cyclic enrichment protocol, clonal populations of corrected CF-iPS cells were isolated and expanded.

  19. Human recombinant Fab fragment from combinatorial libraries of a B-cell lymphoma patient recognizes core protein of chondroitin sulphate proteoglycan 4.

    Science.gov (United States)

    Egami, Yoko; Narushima, Yuta; Ohshima, Motohiro; Yoshida, Akira; Yoneta, Naruki; Masaki, Yasufumi; Itoh, Kunihiko

    2018-01-01

    CD antigens are well known as therapeutic targets of B-cell lymphoma. To isolate therapeutic antibodies that recognize novel targets other than CD antigens, we constructed a phage display combinatorial antibody Fab library from bone marrow lymphocytes of B-cell lymphoma patient. To eliminate antibodies reactive with known B-cell lymphoma antigen, non-hematopoietic and patient's sera reactive HeLaS3 cells was selected as a target of whole cell panning. Five rounds of panning against live HeLaS3 cells retrieved single Fab clone, termed AHSA (Antibody to HeLa Surface Antigen). Using phage display random peptide library, LSYLEP was identified as an epitope sequence of AHSA. LC-MS/MS analysis of AHSA-precipitated HeLaS3 cell lysates detected several fragments corresponding to the sequence of chondroitin sulphate proteoglycan 4 (CSPG4) core protein. Since LSYLEP sequence was at the position of 313-318 of CSPG4, we considered that CSPG4 was AHSA-associated antigen. Double staining of CSPG4-postive MDA-MB-435S cells with AHSA and anti-CSPG4 rabbit antibody showed identical staining position, and reduced AHSA reactivity was observed in CSPG4-siRNA treated MDA-MB-435S cells. In conclusion, we retrieved a human Fab from antibody library of B-cell lymphoma patient, and identified CSPG4 as a recognizing antigen. AHSA may have potential benefits for development of CSPG4-targeting theranostics for B-cell lymphoma. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  20. Chloroform-Methanol Residue of Coxiella burnetii Markedly Potentiated the Specific Immunoprotection Elicited by a Recombinant Protein Fragment rOmpB-4 Derived from Outer Membrane Protein B of Rickettsia rickettsii in C3H/HeN Mice.

    Directory of Open Access Journals (Sweden)

    Wenping Gong

    Full Text Available The obligate intracellular bacteria, Rickettsia rickettsii and Coxiella burnetii, are the potential agents of bio-warfare/bio-terrorism. Here C3H/HeN mice were immunized with a recombinant protein fragment rOmp-4 derived from outer membrane protein B, a major protective antigen of R. rickettsii, combined with chloroform-methanol residue (CMR extracted from phase I C. burnetii organisms, a safer Q fever vaccine. These immunized mice had significantly higher levels of IgG1 and IgG2a to rOmpB-4 and interferon-γ (IFN-γ and tumor necrosis factor-α (TNF-α, two crucial cytokines in resisting intracellular bacterial infection, as well as significantly lower rickettsial loads and slighter pathological lesions in organs after challenge with R. rickettsii, compared with mice immunized with rOmpB-4 or CMR alone. Additionally, after challenge with C. burnetii, the coxiella loads in the organs of these mice were significantly lower than those of mice immunized with rOmpB-4 alone. Our results prove that CMR could markedly potentiate enhance the rOmpB-4-specific immunoprotection by promoting specific and non-specific immunoresponses and the immunization with the protective antigen of R. rickettsii combined with CMR of C. burnetii could confer effective protection against infection of R. rickettsii or C. burnetii.

  1. Dermal extracellular lipid in birds.

    Science.gov (United States)

    Stromberg, M W; Hinsman, E J; Hullinger, R L

    1990-01-01

    A light and electron microscopic study of the skin of domestic chickens, seagulls, and antarctic penguins revealed abundant extracellular dermal lipid and intracellular epidermal lipid. Dermal lipid appeared ultrastructurally as extracellular droplets varying from less than 1 micron to more than 25 microns in diameter. The droplets were often irregularly contoured, sometimes round, and of relatively low electron density. Processes of fibrocytes were often seen in contact with extracellular lipid droplets. Sometimes a portion of such a droplet was missing, and this missing part appeared to have been "digested away" by the cell process. In places where cells or cell processes are in contact with fact droplets, there are sometimes extracellular membranous whorls or fragments which have been associated with the presence of fatty acids. Occasionally (in the comb) free fat particles were seen in intimate contact with extravasated erythrocytes. Fat droplets were seen in the lumen of small dermal blood and lymph vessels. We suggest that the dermal extracellular lipid originates in the adipocyte layer and following hydrolysis the free fatty acids diffuse into the epidermis. Here they become the raw material for forming the abundant neutral lipid contained in many of the epidermal cells of both birds and dolphins. The heretofore unreported presence and apparently normal utilization of abundant extracellular lipid in birds, as well as the presence of relatively large droplets of neutral lipid in dermal vessels, pose questions which require a thorough reappraisal of present concepts of the ways in which fat is distributed and utilized in the body.

  2. Extracellular Expression in Aspergillus niger of an Antibody Fused to Leishmania sp. Antigens.

    Science.gov (United States)

    Magaña-Ortíz, Denis; Fernández, Francisco; Loske, Achim M; Gómez-Lim, Miguel A

    2018-01-01

    Nucleoside hydrolase and sterol 24-c-methyltransferase, two antigenic proteins of Leishmania sp., were expressed in Aspergillus niger. Genetic transformation of conidia was achieved using underwater shock waves. scFv antibody addressed to DEC205, a receptor of dendritic cells, was fused to two proteins of Leishmania sp. Receptor 205 has a relevant role in the immune system in mammals; it can modulate T cell response to different antigens. Extracellular expression strategy of recombinant antibody was achieved using a fragment of native glucoamylase A (514 aa) as a carrier. Fermentations in shake flasks showed that the recombinant protein (104 kDa) was expressed and secreted only when maltose was used as carbon source; on the contrary, the expression was highly repressed in presence of xylose. Noteworthy, recombinant protein was secreted without glucoamylase-carrier and accumulation at intracellular level was not observed. The results presented here demonstrate the high value of Aspergillus niger as biotechnological platform for recombinant antibodies against Leishmania sp. at low cost. To the best of our knowledge, this is the first report about the recombinant expression of antigenic proteins of Leishmania sp. in filamentous fungi. The protein obtained can be used to explore novel strategies to induce immunity against Leishmania sp. or it can be employed in diagnostic kits to detect this neglected disease.

  3. Jet fragmentation

    International Nuclear Information System (INIS)

    Saxon, D.H.

    1985-10-01

    The paper reviews studies on jet fragmentation. The subject is discussed under the topic headings: fragmentation models, charged particle multiplicity, bose-einstein correlations, identified hadrons in jets, heavy quark fragmentation, baryon production, gluon and quark jets compared, the string effect, and two successful models. (U.K.)

  4. Production of a phage-displayed single chain variable fragment ...

    African Journals Online (AJOL)

    Abstract. Purpose: To develop specific single chain variable fragments (scFv) against ... libraries. The binding ability of the selected scFv antibody fragments against the IBDV particles was ..... Hermelink H, Koscielniak E. A human recombinant.

  5. Recombinant Programming

    OpenAIRE

    Pawlak , Renaud; Cuesta , Carlos; Younessi , Houman

    2004-01-01

    This research report presents a promising new approach to computation called Recombinant Programming. The novelty of our approach is that it separates the program into two layers of computation: the recombination and the interpretation layer. The recombination layer takes sequences as inputs and allows the programmer to recombine these sequences through the definition of cohesive code units called extensions. The output of such recombination is a mesh that can be used by the interpretation la...

  6. QGP and Modified Jet Fragmentation

    International Nuclear Information System (INIS)

    Wang, Xin-Nian

    2005-01-01

    Recent progresses in the study of jet modification in hotmedium and their consequences in high-energy heavy-ion collisions are reviewed. In particular, I will discuss energy loss for propagating heavy quarks and the resulting modified fragmentation function. Medium modification of the parton fragmentation function due to quark recombination are formulated within finite temperature field theory and their implication on the search for deconfined quark-gluon plasma is also discussed

  7. [Cloning of Clostridium perfringens alpha-toxin gene and extracellular expression in Escherichia coli].

    Science.gov (United States)

    Inoue, Masaharu; Kikuchi, Maho; Komoriya, Tomoe; Watanabe, Kunitomo; Kouno, Hideki

    2007-01-01

    Clostridium perfringens (C. perfringens) is a Gram-positive bacterial pathogen that widely propagets in the soil and the gastrointestinal tract of human and animals. This bacteria causes food poisoning, gas gangrene and other various range of infectious diseases. But there is no standard diagnosis method of C. perfringens. In order to develop a new type of immunoassay for clinical purpose, we studied expression and extracellular secretion of recombinant alpha-toxin having enzyme activity in E. coli expression system. Cloning was carried out after PCR amplification from C. perfringens GAI 94074 which was clinical isolate. Three kinds of fragment were cloned using pET100/D-TOPO vector. These fragments coded for ribosome binding site, signal peptide, and alpha-toxin gene respectively. Recombinant pET100 plasmid transformed into TOP 10 cells and the obtained plasmids were transformed into BL21 (DE3) cells. Then, the transformants were induced expression with IPTG. In conclusion, we successfully cloned, expressed and exteracellular secreted C. perfringens alpha-toxin containing signal peptide. Biologically, the obtained recombinant protein was positive for phospholipase C activity.

  8. Nuclear fragmentation

    International Nuclear Information System (INIS)

    Chung, K.C.

    1989-01-01

    An introduction to nuclear fragmentation, with emphasis in percolation ideas, is presented. The main theoretical models are discussed and as an application, the uniform expansion approximation is presented and the statistical multifragmentation model is used to calculate the fragment energy spectra. (L.C.)

  9. Mini review: Recombinant production of tailored bio-pharmaceuticals in different Bacillus strains and future perspectives.

    Science.gov (United States)

    Lakowitz, Antonia; Godard, Thibault; Biedendieck, Rebekka; Krull, Rainer

    2018-05-01

    Bio-pharmaceuticals like antibodies, hormones and growth factors represent about one-fifth of commercial pharmaceuticals. Host candidates of growing interest for recombinant production of these proteins are strains of the genus Bacillus, long being established for biotechnological production of homologous and heterologous proteins. Bacillus strains benefit from development of efficient expression systems in the last decades and emerge as major industrial workhorses for recombinant proteins due to easy cultivation, non-pathogenicity and their ability to secrete recombinant proteins directly into extracellular medium allowing cost-effective downstream processing. Their broad product portfolio of pharmaceutically relevant recombinant proteins described in research include antibody fragments, growth factors, interferons and interleukins, insulin, penicillin G acylase, streptavidin and different kinases produced in various cultivation systems like microtiter plates, shake flasks and bioreactor systems in batch, fed-batch and continuous mode. To further improve production and secretion performance of Bacillus, bottlenecks and limiting factors concerning proteases, chaperones, secretion machinery or feedback mechanisms can be identified on different cell levels from genomics and transcriptomics via proteomics to metabolomics and fluxomics. For systematical identification of recurring patterns characteristic of given regulatory systems and key genetic targets, systems biology and omics-technology provide suitable and promising approaches, pushing Bacillus further towards industrial application for recombinant pharmaceutical protein production. Copyright © 2017. Published by Elsevier B.V.

  10. Blood extracellular DNA after irradiation

    International Nuclear Information System (INIS)

    Vladimirov, V.G.; Tishchenko, L.I.; Surkova, E.A.; Vasil'eva, I.N.

    1993-01-01

    It has been shown that blood extracellular DNA of irradiated rats largely consists of the low-molecular DNA and its oligomers. Molecular masses of oligomers are multiple to molecular mass of monomer fragment with nucleosome size. The low-molecular DNA has linear form. The average content of GC-pairs in low-molecular DNA is higher than in total rat's DNA (48.5% against 41.5%). The low-molecular DNA is a part of complex containing RNA, acidic proteins and lipids. It is assumed that the formation of low-molecular DNA is a result of Ca/Mg - dependent nuclear endonuclease action

  11. Controlled fragmentation

    International Nuclear Information System (INIS)

    Arnold, Werner

    2002-01-01

    Contrary to natural fragmentation, controlled fragmentation offers the possibility to adapt fragment parameters like size and mass to the performance requirements in a very flexible way. Known mechanisms like grooves inside the casing, weaken the structure. This is, however, excluded for applications with high accelerations during launch or piercing requirements for example on a semi armor piercing penetrator. Another method to achieve controlled fragmentation with an additional grid layer is presented with which the required grooves are produced 'just in time' inside the casing during detonation of the high explosive. The process of generating the grooves aided by the grid layer was studied using the hydrocode HULL with respect to varying grid designs and material combinations. Subsequent to this, a large range of these theoretically investigated combinations was contemplated in substantial experimental tests. With an optimised grid design and a suitable material selection, the controlled fragment admits a very flexible adaptation to the set requirements. Additional advantages like the increase of perforation performance or incendiary amplification can be realized with the grid layer

  12. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  13. Chameleon fragmentation

    International Nuclear Information System (INIS)

    Brax, Philippe; Upadhye, Amol

    2014-01-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ 4 and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments

  14. Genetic Recombination

    Science.gov (United States)

    Whitehouse, H. L. K.

    1973-01-01

    Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

  15. Baculovirus display of functional antibody Fab fragments.

    Science.gov (United States)

    Takada, Shinya; Ogawa, Takafumi; Matsui, Kazusa; Suzuki, Tasuku; Katsuda, Tomohisa; Yamaji, Hideki

    2015-08-01

    The generation of a recombinant baculovirus that displays antibody Fab fragments on the surface was investigated. A recombinant baculovirus was engineered so that the heavy chain (Hc; Fd fragment) of a mouse Fab fragment was expressed as a fusion to the N-terminus of baculovirus gp64, while the light chain of the Fab fragment was simultaneously expressed as a secretory protein. Following infection of Sf9 insect cells with the recombinant baculovirus, the culture supernatant was analyzed by enzyme-linked immunosorbent assay using antigen-coated microplates and either an anti-mouse IgG or an anti-gp64 antibody. A relatively strong signal was obtained in each case, showing antigen-binding activity in the culture supernatant. In western blot analysis of the culture supernatant using the anti-gp64 antibody, specific protein bands were detected at an electrophoretic mobility that coincided with the molecular weight of the Hc-gp64 fusion protein as well as that of gp64. Flow cytometry using a fluorescein isothiocyanate-conjugated antibody specific to mouse IgG successfully detected the Fab fragments on the surface of the Sf9 cells. These results suggest that immunologically functional antibody Fab fragments can be displayed on the surface of baculovirus particles, and that a fluorescence-activated cell sorter with a fluorescence-labeled antigen can isolate baculoviruses displaying specific Fab fragments. This successful baculovirus display of antibody Fab fragments may offer a novel approach for the efficient selection of specific antibodies.

  16. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2017-01-01

    The PhD project Bespoke Fragments is investigating the space emerging in the exploration of the relationship between digital drawing and fabrication, and the field of materials and their properties and capacities. Through a series of different experiments, the project situates itself in a shuttli...

  17. Rock fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S.; Green, S.J.; Hakala, W.W.; Hustrulid, W.A.; Maurer, W.C. (eds.)

    1976-01-01

    Experts in rock mechanics, mining, excavation, drilling, tunneling and use of underground space met to discuss the relative merits of a wide variety of rock fragmentation schemes. Information is presented on novel rock fracturing techniques; tunneling using electron beams, thermocorer, electric spark drills, water jets, and diamond drills; and rock fracturing research needs for mining and underground construction. (LCL)

  18. Architectural fragments

    DEFF Research Database (Denmark)

    Bang, Jacob Sebastian

    2018-01-01

    I have created a large collection of plaster models: a collection of Obstructions, errors and opportunities that may develop into architecture. The models are fragments of different complex shapes as well as more simple circular models with different profiling and diameters. In this contect I have....... I try to invent the ways of drawing the models - that decode and unfold them into architectural fragments- into future buildings or constructions in the landscape. [1] Luigi Moretti: Italian architect, 1907 - 1973 [2] Man Ray: American artist, 1890 - 1976. in 2015, I saw the wonderful exhibition...... "Man Ray - Human Equations" at the Glyptotek in Copenhagen, organized by the Philips Collection in Washington D.C. and the Israel Museum in Jerusalem (in 2013). See also: "Man Ray - Human Equations" catalogue published by Hatje Cantz Verlag, Germany, 2014....

  19. Intermediate Fragment

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

  20. Fragmentation based

    Directory of Open Access Journals (Sweden)

    Shashank Srivastava

    2014-01-01

    Gaining the understanding of mobile agent architecture and the security concerns, in this paper, we proposed a security protocol which addresses security with mitigated computational cost. The protocol is a combination of self decryption, co-operation and obfuscation technique. To circumvent the risk of malicious code execution in attacking environment, we have proposed fragmentation based encryption technique. Our encryption technique suits the general mobile agent size and provides hard and thorny obfuscation increasing attacker’s challenge on the same plane providing better performance with respect to computational cost as compared to existing AES encryption.

  1. Bespoke Fragments

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2016-01-01

    , investigating levels of control and uncertainty encountering with these. Through tangible experiments, the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect's digital drawing and workflow. The project sees this expansion as an opportunity to connect...... architectural designs, tectonics and aesthetics. In this Ph.D.-project a series a physical, but conceptual, experiment plays the central role in the knowledge production. The experiments result in materialised architectural fragments and tangible experiences. However, these creations also become the driving...

  2. Shaping Synapses by the Neural Extracellular Matrix

    Directory of Open Access Journals (Sweden)

    Maura Ferrer-Ferrer

    2018-05-01

    Full Text Available Accumulating data support the importance of interactions between pre- and postsynaptic neuronal elements with astroglial processes and extracellular matrix (ECM for formation and plasticity of chemical synapses, and thus validate the concept of a tetrapartite synapse. Here we outline the major mechanisms driving: (i synaptogenesis by secreted extracellular scaffolding molecules, like thrombospondins (TSPs, neuronal pentraxins (NPs and cerebellins, which respectively promote presynaptic, postsynaptic differentiation or both; (ii maturation of synapses via reelin and integrin ligands-mediated signaling; and (iii regulation of synaptic plasticity by ECM-dependent control of induction and consolidation of new synaptic configurations. Particularly, we focused on potential importance of activity-dependent concerted activation of multiple extracellular proteases, such as ADAMTS4/5/15, MMP9 and neurotrypsin, for permissive and instructive events in synaptic remodeling through localized degradation of perisynaptic ECM and generation of proteolytic fragments as inducers of synaptic plasticity.

  3. Framing Fragmentation

    DEFF Research Database (Denmark)

    Bundgaard, Charlotte

    2009-01-01

    Contemporary industrialized architecture based on advanced information technology and highly technological production processes, implies a radically different approach to architecture than what we have experienced in the past. Works of architecture composed of prefabricated building components......, contain distinctive architectural traits, not only based on rational repetition, but also supporting composition and montage as dynamic concepts. Prefab architecture is an architecture of fragmentation, individualization and changeability, and this sets up new challenges for the architect. This paper...... tries to develop a strategy for the architect dealing with industrially based architecture; a strategy which exploits architectural potentials in industrial building, which recognizes the rules of mass production and which redefines the architect’s position among the agents of building. If recent...

  4. Spectrum Recombination.

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    1984-01-01

    Describes several methods of executing lecture demonstrations involving the recombination of the spectrum. Groups the techniques into two general classes: bringing selected portions of the spectrum together using lenses or mirrors and blurring the colors by rapid movement or foreshortening. (JM)

  5. Constraints from jet calculus on quark recombination

    International Nuclear Information System (INIS)

    Jones, L.M.; Lassila, K.E.; Willen, D.

    1979-01-01

    Within the QCD jet calculus formalism, we deduce an equation describing recombination of quarks and antiquarks into mesons within a quark or gluon jet. This equation relates the recombination function R(x 1 ,x 2 ,x) used in current literature to the fragmentation function for producing that same meson out of the parton initiating the jet. We submit currently used recombination functions to our consistency test, taking as input mainly the u-quark fragmentation data into π + mesons, but also s-quark fragmentation into K - mesons. The constraint is well satisfied at large Q 2 for large moments. Our results depend on one parameter, Q 0 2 , the constraint equation being satisfied for small values of this parameter

  6. Recombinant Collagenlike Proteins

    Science.gov (United States)

    Fertala, Andzej

    2007-01-01

    A group of collagenlike recombinant proteins containing high densities of biologically active sites has been invented. The method used to express these proteins is similar to a method of expressing recombinant procollagens and collagens described in U. S. Patent 5,593,859, "Synthesis of human procollagens and collagens in recombinant DNA systems." Customized collagenous proteins are needed for biomedical applications. In particular, fibrillar collagens are attractive for production of matrices needed for tissue engineering and drug delivery. Prior to this invention, there was no way of producing customized collagenous proteins for these and other applications. Heretofore, collagenous proteins have been produced by use of such biological systems as yeasts, bacteria, and transgenic animals and plants. These products are normal collagens that can also be extracted from such sources as tendons, bones, and hides. These products cannot be made to consist only of biologically active, specific amino acid sequences that may be needed for specific applications. Prior to this invention, it had been established that fibrillar collagens consist of domains that are responsible for such processes as interaction with cells, binding of growth factors, and interaction with a number of structural proteins present in the extracellular matrix. A normal collagen consists of a sequence of domains that can be represented by a corresponding sequence of labels, e.g., D1D2D3D4. A collagenlike protein of the present invention contains regions of collagen II that contain multiples of a single domain (e.g., D1D1D1D1 or D4D4D4D4) chosen for its specific biological activity. By virtue of the multiplicity of the chosen domain, the density of sites having that specific biological activity is greater than it is in a normal collagen. A collagenlike protein according to this invention can thus be made to have properties that are necessary for tissue engineering.

  7. Origin and differentiation of a special fragment from Capra hircus ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... regions of the special fragment in the GenBank of NCBI. A total number of 80 fragments with identity ... recombined during the long period of evolution within and among species, and might be related to ..... and their association to coat color phenotypes in horses (Equus caballus). Mammalian Genome, 12: ...

  8. Sensitization of interferon-γ induced apoptosis in human osteosarcoma cells by extracellular S100A4

    International Nuclear Information System (INIS)

    Pedersen, Kjetil Boye; Andersen, Kristin; Fodstad, Øystein; Mælandsmo, Gunhild Mari

    2004-01-01

    S100A4 is a small Ca 2+ -binding protein of the S100 family with metastasis-promoting properties. Recently, secreted S100A4 protein has been shown to possess a number of functions, including induction of angiogenesis, stimulation of cell motility and neurite extension. Cell cultures from two human osteosarcoma cell lines, OHS and its anti-S100A4 ribozyme transfected counterpart II-11b, was treated with IFN-γ and recombinant S100A4 in order to study the sensitizing effects of extracellular S100A4 on IFN-γ mediated apoptosis. Induction of apoptosis was demonstrated by DNA fragmentation, cleavage of poly (ADP-ribose) polymerase and Lamin B. In the present work, we found that the S100A4-expressing human osteosarcoma cell line OHS was more sensitive to IFN-γ-mediated apoptosis than the II-11b cells. S100A4 protein was detected in conditioned medium from OHS cells, but not from II-11b cells, and addition of recombinant S100A4 to the cell medium sensitized II-11b cells to apoptosis induced by IFN-γ. The S100A4/IFN-γ-mediated induction of apoptosis was shown to be independent of caspase activation, but dependent on the formation of reactive oxygen species. Furthermore, addition of extracellular S100A4 was demonstrated to activate nuclear factor-κB (NF-κB). In conclusion, we have shown that S100A4 sensitizes osteosarcoma cells to IFN-γ-mediated induction of apoptosis. Additionally, extracellular S100A4 activates NF-κB, but whether these events are causally related remains unknown

  9. Expression of recombinant Antibodies

    Directory of Open Access Journals (Sweden)

    André eFrenzel

    2013-07-01

    Full Text Available Recombinant antibodies are highly specific detection probes in research, diagnostics and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines and transgenic plants are promising to obtain antibodies with human-like post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications.

  10. Recombination pattern reanalysis of some HIV-1 circulating recombination forms suggest the necessity and difficulty of revision.

    Directory of Open Access Journals (Sweden)

    Lei Jia

    Full Text Available Recombination is one of the major mechanisms underlying the generation of HIV-1 variability. Currently 61 circulating recombinant forms of HIV-1 have been identified. With the development of recombination detection techniques and accumulation of HIV-1 reference stains, more accurate mosaic structures of circulating recombinant forms (CRFs, like CRF04 and CRF06, have undergone repeated analysis and upgrades. Such revisions may also be necessary for other CRFs. Unlike previous studies, whose results are based primarily on a single recombination detection program, the current study was based on multiple recombination analysis, which may have produced more impartial results.Representative references of 3 categories of intersubtype recombinants were selected, including BC recombinants (CRF07 and CRF08, BG recombinants (CRF23 and CRF24, and BF recombinants (CRF38 and CRF44. They were reanalyzed in detail using both the jumping profile hidden Markov model and RDP3.The results indicate that revisions and upgrades are very necessary and the entire re-analysis suggested 2 types of revision: (i length of inserted fragments; and (ii number of inserted fragments. The reanalysis also indicated that determination of small regions of about 200 bases or fewer should be performed with more caution.Results indicated that the involvement of multiple recombination detection programs is very necessary. Additionally, results suggested two major challenges, one involving the difficulty of accurately determining the locations of breakpoints and the second involving identification of small regions of about 200 bases or fewer with greater caution. Both indicate the complexity of HIV-1 recombination. The resolution would depend critically on development of a recombination analysis algorithm, accumulation of HIV-1 stains, and a higher sequencing quality. With the changes in recombination pattern, phylogenetic relationships of some CRFs may also change. All these results may

  11. Universal elements of fragmentation

    International Nuclear Information System (INIS)

    Yanovsky, V. V.; Tur, A. V.; Kuklina, O. V.

    2010-01-01

    A fragmentation theory is proposed that explains the universal asymptotic behavior of the fragment-size distribution in the large-size range, based on simple physical principles. The basic principles of the theory are the total mass conservation in a fragmentation process and a balance condition for the energy expended in increasing the surface of fragments during their breakup. A flux-based approach is used that makes it possible to supplement the basic principles and develop a minimal theory of fragmentation. Such a supplementary principle is that of decreasing fragment-volume flux with increasing energy expended in fragmentation. It is shown that the behavior of the decreasing flux is directly related to the form of a power-law fragment-size distribution. The minimal theory is used to find universal asymptotic fragment-size distributions and to develop a natural physical classification of fragmentation models. A more general, nonlinear theory of strong fragmentation is also developed. It is demonstrated that solutions to a nonlinear kinetic equation consistent with both basic principles approach a universal asymptotic size distribution. Agreement between the predicted asymptotic fragment-size distributions and experimental observations is discussed.

  12. Extracellular Gd-CA

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Marckmann, Peter

    2008-01-01

    Until recently it was believed that extracellular gadolinium-based contrast agents were safe for both the kidneys and all other organs within the dose range up to 0.3 mmol/kg body weight. However, in 2006, it was demonstrated that some gadolinium-based contrast agents may trig the development...... gadolinium-based agent (3-7% versus 0-1% per injection) in patients with reduced renal function. Prevalence after exposure to two gadodiamide injections is as high as 36% in patients with chronic kidney disease (CKD) stage 5. No report of NSF after the most stable agents has been reported in the peer...

  13. A Cholera Conjugate Vaccine Containing O-specific Polysaccharide (OSP of V. cholerae O1 Inaba and Recombinant Fragment of Tetanus Toxin Heavy Chain (OSP:rTTHc Induces Serum, Memory and Lamina Proprial Responses against OSP and Is Protective in Mice.

    Directory of Open Access Journals (Sweden)

    Md Abu Sayeed

    Full Text Available Vibrio cholerae is the cause of cholera, a severe watery diarrhea. Protection against cholera is serogroup specific. Serogroup specificity is defined by the O-specific polysaccharide (OSP component of lipopolysaccharide (LPS.Here we describe a conjugate vaccine for cholera prepared via squaric acid chemistry from the OSP of V. cholerae O1 Inaba strain PIC018 and a recombinant heavy chain fragment of tetanus toxin (OSP:rTTHc. We assessed a range of vaccine doses based on the OSP content of the vaccine (10-50 μg, vaccine compositions varying by molar loading ratio of OSP to rTTHc (3:1, 5:1, 10:1, effect of an adjuvant, and route of immunization.Immunized mice developed prominent anti-OSP and anti-TT serum IgG responses, as well as vibriocidal antibody and memory B cell responses following intramuscular or intradermal vaccination. Mice did not develop anti-squarate responses. Intestinal lamina proprial IgA responses targeting OSP occurred following intradermal vaccination. In general, we found comparable immune responses in mice immunized with these variations, although memory B cell and vibriocidal responses were blunted in mice receiving the highest dose of vaccine (50 μg. We found no appreciable change in immune responses when the conjugate vaccine was administered in the presence or absence of immunoadjuvant alum. Administration of OSP:rTTHc resulted in 55% protective efficacy in a mouse survival cholera challenge model.We report development of an Inaba OSP:rTTHc conjugate vaccine that induces memory responses and protection against cholera in mice. Development of an effective cholera conjugate vaccine that induces high level and long-term immune responses against OSP would be beneficial, especially in young children who respond poorly to polysaccharide antigens.

  14. Universality of fragment shapes.

    Science.gov (United States)

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-03-16

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism.

  15. Anomalous nuclear fragments

    International Nuclear Information System (INIS)

    Karmanov, V.A.

    1983-01-01

    Experimental data are given, the status of anomalon problem is discussed, theoretical approaches to this problem are outlined. Anomalons are exotic objects formed following fragmentation of nuclei-targets under the effect of nuclei - a beam at the energy of several GeV/nucleon. These nuclear fragments have an anomalously large cross section of interaction and respectively, small free path, considerably shorter than primary nuclei have. The experimental daa are obtained in accelerators following irradiation of nuclear emulsions by 16 O, 56 Fe, 40 Ar beams, as well as propane by 12 C beams. The experimental data testify to dependence of fragment free path on the distance L from the point of the fragment formation. A decrease in the fragment free path is established more reliably than its dependence on L. The problem of the anomalon existence cannot be yet considered resolved. Theoretical models suggested for explanation of anomalously large cross sections of nuclear fragment interaction are variable and rather speculative

  16. Accelerated extracellular matrix turnover during exacerbations of COPD

    DEFF Research Database (Denmark)

    Sand, Jannie M B; Knox, Alan J; Lange, Peter

    2015-01-01

    progression. Extracellular matrix (ECM) turnover reflects activity in tissues and consequently assessment of ECM turnover may serve as biomarkers of disease activity. We hypothesized that the turnover of lung ECM proteins were altered during exacerbations of COPD. METHODS: 69 patients with COPD hospitalised...... of circulating fragments of structural proteins, which may serve as markers of disease activity. This suggests that patients with COPD have accelerated ECM turnover during exacerbations which may be related to disease progression....

  17. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  18. The evolutionary value of recombination is constrained by genome modularity.

    Directory of Open Access Journals (Sweden)

    Darren P Martin

    2005-10-01

    Full Text Available Genetic recombination is a fundamental evolutionary mechanism promoting biological adaptation. Using engineered recombinants of the small single-stranded DNA plant virus, Maize streak virus (MSV, we experimentally demonstrate that fragments of genetic material only function optimally if they reside within genomes similar to those in which they evolved. The degree of similarity necessary for optimal functionality is correlated with the complexity of intragenomic interaction networks within which genome fragments must function. There is a striking correlation between our experimental results and the types of MSV recombinants that are detectable in nature, indicating that obligatory maintenance of intragenome interaction networks strongly constrains the evolutionary value of recombination for this virus and probably for genomes in general.

  19. Cloning, bacterial expression and crystallization of Fv antibody fragments

    Science.gov (United States)

    E´, Jean-Luc; Boulot, Ginette; Chitarra, V´ronique; Riottot, Marie-Madeleine; Souchon, H´le`ne; Houdusse, Anne; Bentley, Graham A.; Narayana Bhat, T.; Spinelli, Silvia; Poljak, Roberto J.

    1992-08-01

    The variable Fv fragments of antibodies, cloned in recombinant plasmids, can be expressed in bacteria as functional proteins having immunochemical properties which are very similar or identical with those of the corresponding parts of the parent eukaryotic antibodies. They offer new possibilities for the study of antibody-antigen interactions since the crystals of Fv fragments and of their complexes with antigen reported here diffract X-rays to a higher resolution that those obtained with the cognate Fab fragments. The Fv approach should facilitate the structural study of the combining site of antibodies and the further characterization of antigen-antibody interactions by site-directed mutagenesis experiments.

  20. Fission fragment angular momentum

    International Nuclear Information System (INIS)

    Frenne, D. De

    1991-01-01

    Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs

  1. Photoionization and Recombination

    Science.gov (United States)

    Nahar, Sultana N.

    2000-01-01

    Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. The same eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring consistency between cross sections and rates. The theoretical treatment of (e + ion) recombination subsumes both the non-resonant recombination ("radiative recombination"), and the resonant recombination ("di-electronic recombination") processes in a unified scheme. In addition to the total, unified recombination rates, level-specific recombination rates and photoionization cross sections are obtained for a large number of atomic levels. Both relativistic Breit-Pauli, and non-relativistic LS coupling, calculations are carried out in the close coupling approximation using the R-matrix method. Although the calculations are computationally intensive, they yield nearly all photoionization and recombination parameters needed for astrophysical photoionization models with higher precision than hitherto possible, estimated at about 10-20% from comparison with experimentally available data (including experimentally derived DR rates). Results are electronically available for over 40 atoms and ions. Photoionization and recombination of He-, and Li-like C and Fe are described for X-ray modeling. The unified method yields total and complete (e+ion) recombination rate coefficients, that can not otherwise be obtained theoretically or experimentally.

  2. Polarity of recombination in transformation of Streptococcus pneumoniae.

    Science.gov (United States)

    Pasta, F; Sicard, M A

    1999-03-16

    In transformation of Streptococcus pneumoniae DNA enters the cell as single-strand fragments and integrates into the chromosome by homologous recombination. Deletions and insertions of a few hundred base pairs frequently stop the recombination process of a donor strand. In this work we took advantage of such interruptions of recombination to compare the transformation efficiencies of the segments 5'- and 3'-ward from a deletion. The deletion was created in the center of a fragment of the ami locus, and sites around the deletion were labeled by a frameshift generating a restriction site. Heteroduplexes were constructed containing two restriction sites on one strand and two different ones on the complementary strand. ami+ bacteria were transformed with such heteroduplexes. ami- transformants were isolated and individually underwent amplification of the transformed ami region. We have obtained two kinds of amplification products: short when the deletion was integrated, long when recombination stops at the deletion. Each long fragment was tested by the four restriction enzymes to detect which strand and which side of the deletion had recombined. We found that 80% of the cuts were located 5' to the deletion, showing that, in vivo, the 5' side is strongly favored by recombination. Further results suggest that exchanges occurring from 5' to 3' relative to the donor strand are more efficient than in the opposite direction, thus accounting for the 5' preference.

  3. Extracellular matrix structure.

    Science.gov (United States)

    Theocharis, Achilleas D; Skandalis, Spyros S; Gialeli, Chrysostomi; Karamanos, Nikos K

    2016-02-01

    Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation, and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. String fragmentation; La fragmentation des cordes

    Energy Technology Data Exchange (ETDEWEB)

    Drescher, H.J.; Werner, K. [Laboratoire de Physique Subatomique et des Technologies Associees - SUBATECH, Centre National de la Recherche Scientifique, 44 - Nantes (France)

    1997-10-01

    The classical string model is used in VENUS as a fragmentation model. For the soft domain simple 2-parton strings were sufficient, whereas for higher energies up to LHC, the perturbative regime of the QCD gives additional soft gluons, which are mapped on the string as so called kinks, energy singularities between the leading partons. The kinky string model is chosen to handle fragmentation of these strings by application of the Lorentz invariant area law. The `kinky strings` model, corresponding to the perturbative gluons coming from pQCD, takes into consideration this effect by treating the partons and gluons on the same footing. The decay law is always the Artru-Menessier area law which is the most realistic since it is invariant to the Lorentz and gauge transformations. For low mass strings a manipulation of the rupture point is necessary if the string corresponds already to an elementary particle determined by the mass and the flavor content. By means of the fragmentation model it will be possible to simulate the data from future experiments at LHC and RHIC 3 refs.

  5. Dimensional crossover in fragmentation

    Science.gov (United States)

    Sotolongo-Costa, Oscar; Rodriguez, Arezky H.; Rodgers, G. J.

    2000-11-01

    Experiments in which thick clay plates and glass rods are fractured have revealed different behavior of fragment mass distribution function in the small and large fragment regions. In this paper we explain this behavior using non-extensive Tsallis statistics and show how the crossover between the two regions is caused by the change in the fragments’ dimensionality during the fracture process. We obtain a physical criterion for the position of this crossover and an expression for the change in the power-law exponent between the small and large fragment regions. These predictions are in good agreement with the experiments on thick clay plates.

  6. Recombinant carcinoembryonic antigen as a reporter gene for molecular imaging

    International Nuclear Information System (INIS)

    Kenanova, Vania; Barat, Bhaswati; Olafsen, Tove; Chatziioannou, Arion; Herschman, Harvey R.; Wu, Anna M.; Braun, Jonathan

    2009-01-01

    Reporter genes can provide a way of noninvasively assessing gene activity in vivo. However, current reporter gene strategies may be limited by the immunogenicity of foreign reporter proteins, endogenous expression, or unwanted biological activity. We have developed a reporter gene based on carcinoembryonic antigen (CEA), a human protein with limited normal tissue expression. To construct a CEA reporter gene for PET, a CEA minigene (N-A3) was fused to the extracellular and transmembrane domains of the human FcγRIIb receptor. The NA3-FcγRIIb recombinant gene, driven by a CMV promoter, was transfected in Jurkat (human T cell leukemia) cells. Expression was analyzed by flow cytometry, immunohistochemistry (IHC), and microPET imaging. Flow cytometry identified Jurkat clones stably expressing NA3-FcγRIIb at low, medium, and high levels. High and medium NA3-FcγRIIb expression could also be detected by Western blot. Reporter gene positive and negative Jurkat cells were used to establish xenografts in athymic mice. IHC showed staining of the tumor with high reporter gene expression; medium and low N-A3 expression was not detected. MicroPET imaging, using an anti-CEA 124 I-labeled single-chain Fv-Fc antibody fragment, demonstrated that only high N-A3 expression could be detected. Specific accumulation of activity was visualized at the N-A3 positive tumor as early as 4 h. MicroPET image quantitation showed tumor activity of 1.8 ± 0.2, 15.2 ± 1.3, and 4.6 ± 1.2 percent injected dose per gram (%ID/g) at 4, 20, and 48 h, respectively. Biodistribution at 48 h demonstrated tumor uptake of 4.8 ± 0.8%ID/g. The CEA N-A3 minigene has the potential to be used as a reporter gene for imaging cells in vivo. (orig.)

  7. Recombination of cluster ions

    Science.gov (United States)

    Johnsen, Rainer

    1993-01-01

    Some of our recent work on molecular band emissions from recombination of molecular dimer ions (N4(+) and CO(+) CO) is discussed. Much of the experimental work was done by Y. S. Cao; the results on N4(+) recombination have been published. A brief progress report is given on our ongoing measurements of neutral products of recombination using the flowing-afterglow Langmuir-probe technique in conjunction with laser-induced fluorescence.

  8. Embedded Fragments Registry (EFR)

    Data.gov (United States)

    Department of Veterans Affairs — In 2009, the Department of Defense estimated that approximately 40,000 service members who served in OEF/OIF may have embedded fragment wounds as the result of small...

  9. Physics of projectile fragments

    International Nuclear Information System (INIS)

    Minamisono, Tadanori

    1982-01-01

    This is a study report on the polarization phenomena of the projectile fragments produced by heavy ion reactions, and the beta decay of fragments. The experimental project by using heavy ions with the energy from 50 MeV/amu to 250 MeV/amu was designed. Construction of an angle-dispersion spectrograph for projectile fragments was proposed. This is a two-stage spectrograph. The first stage is a QQDQQ type separator, and the second stage is QDQD type. Estimation shows that Co-66 may be separated from the nuclei with mass of 65 and 67. The orientation of fragments can be measured by detecting beta-ray. The apparatus consists of a uniform field magnet, an energy absorber, a stopper, a RF coil and a beta-ray hodoscope. This system can be used for not only this purpose but also for the measurement of hyperfine structure. (Kato, T.)

  10. Fragmentation Main Model

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The fragmentation model combines patch size and patch continuity with diversity of vegetation types per patch and rarity of vegetation types per patch. A patch was...

  11. Stone fragmentation by ultrasound

    Indian Academy of Sciences (India)

    Unknown

    In the present work, enhancement of the kidney stone fragmentation by using ultrasound is studied. The cavi- ... ment system like radiation pressure balance, the power is given by ... Thus the bubble size has direct relationship with its life and.

  12. Fragment capture device

    Science.gov (United States)

    Payne, Lloyd R.; Cole, David L.

    2010-03-30

    A fragment capture device for use in explosive containment. The device comprises an assembly of at least two rows of bars positioned to eliminate line-of-sight trajectories between the generation point of fragments and a surrounding containment vessel or asset. The device comprises an array of at least two rows of bars, wherein each row is staggered with respect to the adjacent row, and wherein a lateral dimension of each bar and a relative position of each bar in combination provides blockage of a straight-line passage of a solid fragment through the adjacent rows of bars, wherein a generation point of the solid fragment is located within a cavity at least partially enclosed by the array of bars.

  13. DNA fragmentation in spermatozoa

    DEFF Research Database (Denmark)

    Rex, A S; Aagaard, J.; Fedder, J

    2017-01-01

    Sperm DNA Fragmentation has been extensively studied for more than a decade. In the 1940s the uniqueness of the spermatozoa protein complex which stabilizes the DNA was discovered. In the fifties and sixties, the association between unstable chromatin structure and subfertility was investigated....... In the seventies, the impact of induced DNA damage was investigated. In the 1980s the concept of sperm DNA fragmentation as related to infertility was introduced as well as the first DNA fragmentation test: the Sperm Chromatin Structure Assay (SCSA). The terminal deoxynucleotidyl transferase nick end labelling...... (TUNEL) test followed by others was introduced in the nineties. The association between DNA fragmentation in spermatozoa and pregnancy loss has been extensively investigated spurring the need for a therapeutic tool for these patients. This gave rise to an increased interest in the aetiology of DNA damage...

  14. Fragment Impact Toolkit (FIT)

    Energy Technology Data Exchange (ETDEWEB)

    Shevitz, Daniel Wolf [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Key, Brian P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Garcia, Daniel B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-05

    The Fragment Impact Toolkit (FIT) is a software package used for probabilistic consequence evaluation of fragmenting sources. The typical use case for FIT is to simulate an exploding shell and evaluate the consequence on nearby objects. FIT is written in the programming language Python and is designed as a collection of interacting software modules. Each module has a function that interacts with the other modules to produce desired results.

  15. Some recent developments in the recombination model

    International Nuclear Information System (INIS)

    Hwa, R.C.

    1979-01-01

    A critical review of the recombination model for hadron production at low P/sub T/ is first given, emphasizing not so much the successes as unanswered questions that the model faces. A systematic program to answer some of the basic questions is then developed. The theoretical framework is quantum chromodynamics. First, in what may appear as a digression, the possibility of formation of valence quark clusters (called valons) in a nucleon due to gluon bremsstrahlung and quark-pair creation is considered. Evidences are found not only for the valons in neutrino scattering data, but also indications for their momentum distribution in a nucleon. When similar considerations are applied to a meson, the meaning of the recombination function is discussed and its normalization as well as its shape are determined. Next, the problem of quark decay in a hard scattering process (e.g., pion production in e + e - annihilation) is considered. The joint distribution of partons in a quark jet is determined in QCD. The quark decay function for pions in the recombination model is then obtained with excellent fit to the data. Similar investigation is applied to the problem of photoproduction of pions in the fragmentation region; again good agreement with data is achieved. The results indicate the reliability of the recombination model when the two-parton distributions can be calculated in QCD. Finally, hadron initiated reactions are considered. A duality between quark recombination and valon fragmentation is suggested. The picture is consistent with dual Regge model. A possible way to determine the inclusive distribution in the context of QCD is suggested

  16. Neutrophil extracellular traps and bacterial biofilms in middle ear effusion of children with recurrent acute otitis media--a potential treatment target.

    Directory of Open Access Journals (Sweden)

    Ruth B Thornton

    Full Text Available BACKGROUND: Bacteria persist within biofilms on the middle ear mucosa of children with recurrent and chronic otitis media however the mechanisms by which these develop remain to be elucidated. Biopsies can be difficult to obtain from children and their small size limits analysis. METHODS: In this study we aimed to investigate biofilm presence in middle ear effusion (MEE from children with recurrent acute otitis media (rAOM and to determine if these may represent infectious reservoirs similarly to those on the mucosa. We examined this through culture, viability staining and fluorescent in situ hybridisation (FISH to determine bacterial species present. Most MEEs had live bacteria present using viability staining (32/36 and all effusions had bacteria present using the universal FISH probe (26/26. Of these, 70% contained 2 or more otopathogenic species. Extensive DNA stranding was also present. This DNA was largely host derived, representing neutrophil extracellular traps (NETs within which live bacteria in biofilm formations were present. When treated with the recombinant human deoxyribonuclease 1, Dornase alfa, these strands were observed to fragment. CONCLUSIONS: Bacterial biofilms, composed of multiple live otopathogenic species can be demonstrated in the MEEs of children with rAOM and that these contain extensive DNA stranding from NETs. The NETs contribute to the viscosity of the effusion, potentially contributing to its failure to clear as well as biofilm development. Our data indicates that Dornase alfa can fragment these strands and may play a role in future chronic OM treatment.

  17. Crystallization and preliminary crystallographic analysis of Gibberella zeae extracellular lipase

    International Nuclear Information System (INIS)

    Sun, Yuna; Li, Ming; Zhang, Yan; Liu, Lifang; Liu, Ye; Liu, Zheng; Li, Xumei; Lou, Zhiyong

    2008-01-01

    G. zeae extracellular lipase has been overexpressed, purified and crystallized. Diffraction data were collected to 2.8 Å resolution. Fusarium head blight, one of the most destructive crop diseases, is mainly caused by Fusarium graminearum (known in its sexual stage as Gibberella zeae). F. graminearum secretes various extracellular enzymes that have been hypothesized to be involved in host infection. One of the extracellular enzymes secreted by this organism is the G. zeae extracellular lipase (GZEL), which is encoded by the FGL1 gene. In order to solve the crystal structure of GZEL and to gain a better understanding of the biological functions of the protein and of possible inhibitory mechanisms of lipase inhibitors, recombinant GZEL was crystallized at 291 K using PEG 3350 as a precipitant. A data set was collected to 2.8 Å resolution from a single flash-cooled crystal (100 K). The crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 78.4, b = 91.0, c = 195.8 Å, α = β = γ = 90°. The presence of four molecules was assumed per asymmetric unit, which gave a Matthews coefficient of 2.6 Å 3 Da −1

  18. Nucleases from Prevotella intermedia can degrade neutrophil extracellular traps.

    Science.gov (United States)

    Doke, M; Fukamachi, H; Morisaki, H; Arimoto, T; Kataoka, H; Kuwata, H

    2017-08-01

    Periodontitis is an inflammatory disease caused by periodontal bacteria in subgingival plaque. These bacteria are able to colonize the periodontal region by evading the host immune response. Neutrophils, the host's first line of defense against infection, use various strategies to kill invading pathogens, including neutrophil extracellular traps (NETs). These are extracellular net-like fibers comprising DNA and antimicrobial components such as histones, LL-37, defensins, myeloperoxidase, and neutrophil elastase from neutrophils that disarm and kill bacteria extracellularly. Bacterial nuclease degrades the NETs to escape NET killing. It has now been shown that extracellular nucleases enable bacteria to evade this host antimicrobial mechanism, leading to increased pathogenicity. Here, we compared the DNA degradation activity of major Gram-negative periodontopathogenic bacteria, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. We found that Pr. intermedia showed the highest DNA degradation activity. A genome search of Pr. intermedia revealed the presence of two genes, nucA and nucD, putatively encoding secreted nucleases, although their enzymatic and biological activities are unknown. We cloned nucA- and nucD-encoding nucleases from Pr. intermedia ATCC 25611 and characterized their gene products. Recombinant NucA and NucD digested DNA and RNA, which required both Mg 2+ and Ca 2+ for optimal activity. In addition, NucA and NucD were able to degrade the DNA matrix comprising NETs. © 2016 The Authors Molecular Oral Microbiology Published by John Wiley & Sons Ltd.

  19. Applications of recombinant antibodies in plant pathology.

    Science.gov (United States)

    Ziegler, Angelika; Torrance, Lesley

    2002-09-01

    Summary Advances in molecular biology have made it possible to produce antibody fragments comprising the binding domains of antibody molecules in diverse heterologous systems, such as Escherichia coli, insect cells, or plants. Antibody fragments specific for a wide range of antigens, including plant pathogens, have been obtained by cloning V-genes from lymphoid tissue, or by selection from large naive phage display libraries, thus avoiding the need for immunization. The antibody fragments have been expressed as fusion proteins to create different functional molecules, and fully recombinant assays have been devised to detect plant viruses. The defined binding properties and unlimited cheap supply of antibody fusion proteins make them useful components of standardized immunoassays. The expression of antibody fragments in plants was shown to confer resistance to several plant pathogens. However, the antibodies usually only slowed the progress of infection and durable 'plantibody' resistance has yet to be demonstrated. In future, it is anticipated that antibody fragments from large libraries will be essential tools in high-throughput approaches to post-genomics research, such as the assignment of gene function, characterization of spatio-temporal patterns of protein expression, and elucidation of protein-protein interactions.

  20. Purification and Characterization of Recombinant Vaccinia L1R Protein from Escherichia coli

    Science.gov (United States)

    2016-08-01

    RECOMBINANT VACCINIA L1R PROTEIN FROM ESCHERICHIA COLI 1. INTRODUCTION 1.1 Background Vaccinia virus (VACV) is the active component of the...the preparation of the recombinant VACV L1R protein fragment by denaturing , refolding, and purifying material expressed into inclusion bodies in...PURIFICATION AND CHARACTERIZATION OF RECOMBINANT VACCINIA L1R PROTEIN FROM ESCHERICHIA COLI ECBC-TR-1370

  1. Identification of a receptor for extracellular renalase.

    Directory of Open Access Journals (Sweden)

    Ling Wang

    Full Text Available An increased risk for developing essential hypertension, stroke and diabetes is associated with single nucleotide gene polymorphisms in renalase, a newly described secreted flavoprotein with oxidoreductase activity. Gene deletion causes hypertension, and aggravates acute ischemic kidney (AKI and cardiac injury. Independent of its intrinsic enzymatic activities, extracellular renalase activates MAPK signaling and prevents acute kidney injury (AKI in wild type (WT mice. Therefore, we sought to identity the receptor for extracellular renalase.RP-220 is a previously identified, 20 amino acids long renalase peptide that is devoid of any intrinsic enzymatic activity, but it is equally effective as full-length recombinant renalase at protecting against toxic and ischemic injury. Using biotin transfer studies with RP-220 in the human proximal tubular cell line HK-2 and protein identification by mass spectrometry, we identified PMCA4b as a renalase binding protein. This previously characterized plasma membrane ATPase is involved in cell signaling and cardiac hypertrophy. Co-immunoprecipitation and co-immunolocalization confirmed protein-protein interaction between endogenous renalase and PMCA4b. Down-regulation of endogenous PMCA4b expression by siRNA transfection, or inhibition of its enzymatic activity by the specific peptide inhibitor caloxin1b each abrogated RP-220 dependent MAPK signaling and cytoprotection. In control studies, these maneuvers had no effect on epidermal growth factor mediated signaling, confirming specificity of the interaction between PMCA4b and renalase.PMCA4b functions as a renalase receptor, and a key mediator of renalase dependent MAPK signaling.

  2. Neutrophil Extracellular Trap-Related Extracellular Histones Cause Vascular Necrosis in Severe GN.

    Science.gov (United States)

    Kumar, Santhosh V R; Kulkarni, Onkar P; Mulay, Shrikant R; Darisipudi, Murthy N; Romoli, Simone; Thomasova, Dana; Scherbaum, Christina R; Hohenstein, Bernd; Hugo, Christian; Müller, Susanna; Liapis, Helen; Anders, Hans-Joachim

    2015-10-01

    Severe GN involves local neutrophil extracellular trap (NET) formation. We hypothesized a local cytotoxic effect of NET-related histone release in necrotizing GN. In vitro, histones from calf thymus or histones released by neutrophils undergoing NETosis killed glomerular endothelial cells, podocytes, and parietal epithelial cells in a dose-dependent manner. Histone-neutralizing agents such as antihistone IgG, activated protein C, or heparin prevented this effect. Histone toxicity on glomeruli ex vivo was Toll-like receptor 2/4 dependent, and lack of TLR2/4 attenuated histone-induced renal thrombotic microangiopathy and glomerular necrosis in mice. Anti-glomerular basement membrane GN involved NET formation and vascular necrosis, whereas blocking NET formation by peptidylarginine inhibition or preemptive anti-histone IgG injection significantly reduced all aspects of GN (i.e., vascular necrosis, podocyte loss, albuminuria, cytokine induction, recruitment or activation of glomerular leukocytes, and glomerular crescent formation). To evaluate histones as a therapeutic target, mice with established GN were treated with three different histone-neutralizing agents. Anti-histone IgG, recombinant activated protein C, and heparin were equally effective in abrogating severe GN, whereas combination therapy had no additive effects. Together, these results indicate that NET-related histone release during GN elicits cytotoxic and immunostimulatory effects. Furthermore, neutralizing extracellular histones is still therapeutic when initiated in established GN. Copyright © 2015 by the American Society of Nephrology.

  3. Fragmentation of relativistic nuclei

    International Nuclear Information System (INIS)

    Cork, B.

    1975-06-01

    Nuclei with energies of several GeV/n interact with hadrons and produce fragments that encompass the fields of nuclear physics, meson physics, and particle physics. Experimental results are now available to explore problems in nuclear physics such as the validity of the shell model to explain the momentum distribution of fragments, the contribution of giant dipole resonances to fragment production cross sections, the effective Coulomb barrier, and nuclear temperatures. A new approach to meson physics is possible by exploring the nucleon charge-exchange process. Particle physics problems are explored by measuring the energy and target dependence of isotope production cross sections, thus determining if limiting fragmentation and target factorization are valid, and measuring total cross sections to determine if the factorization relation, sigma/sub AB/ 2 = sigma/sub AA/ . sigma/sub BB/, is violated. Also, new experiments have been done to measure the angular distribution of fragments that could be explained as nuclear shock waves, and to explore for ultradense matter produced by very heavy ions incident on heavy atoms. (12 figures, 2 tables)

  4. Land fragmentation and production diversification

    NARCIS (Netherlands)

    Ciaian, Pavel; Guri, Fatmir; Rajcaniova, Miroslava; Drabik, Dusan; Paloma, Sergio Gomez Y.

    2018-01-01

    We analyze the impact of land fragmentation on production diversification in rural Albania. Albania represents a particularly interesting case for studying land fragmentation as the fragmentation is a direct outcome of land reforms. The results indicate that land fragmentation is an important driver

  5. Further Insights into the Catalytical Properties of Deglycosylated Pyranose Dehydrogenase from Agaricus meleagris Recombinantly Expressed in Pichia pastoris

    OpenAIRE

    Yakovleva, Maria E.; Killyeni, Aniko; Seubert, Oliver; Conghaile, Peter O.; MacAodha, Domhnall; Leech, Donal; Gonaus, Christoph; Popescu, Ionel Catalin; Peterbauer, Clemens K.; Kjellstrom, Sven; Gorton, Lo

    2013-01-01

    The present study focuses on fragmented deglycosylated pyranose dehydrogenase (fdgPDH) from Agaricus meleagris recombinantly expressed in Pichia pastoris. Fragmented deglycosylated PDH is formed from the deglycosylated enzyme (dgPDH) when it spontaneously loses a C-terminal fragment when stored in a buffer solution at 4 °C. The remaining larger fragment has a molecular weight of ∼46 kDa and exhibits higher volumetric activity for glucose oxidation compared with the deglycosylated and glycosyl...

  6. Heavy fragment radioactivity

    International Nuclear Information System (INIS)

    Silisteanu, I.

    1991-06-01

    The effect of collective mode excitation in heavy fragment radioactivity (HFR) is explored and discussed in the light of current experimental data. It is found that the coupling and resonance effects in fragment interaction and also the proper angular momentum effects may lead to an important enhancing of the emission process. New useful procedures are proposed for the study of nuclear decay properties. The relations between different decay processes are investigated in detail. We are also trying to understand and explain in a unified way the reaction mechanisms in decay phenomena. (author). 17 refs, 4 figs, 3 tabs

  7. Novel serological neo-epitope markers of extracellular matrix proteins for the detection of portal hypertension

    DEFF Research Database (Denmark)

    Leeming, Diana Julie; Karsdal, M A; Byrjalsen, I

    2013-01-01

    The hepatic venous pressure gradient (HVPG) is an invasive, but important diagnostic and prognostic marker in cirrhosis with portal hypertension (PHT). During cirrhosis, remodelling of fibrotic tissue by matrix metalloproteinases (MMPs) is a permanent process generating small fragments of degrade...... extracellular matrix (ECM) proteins known as neoepitopes, which are then released into the circulation....

  8. Resonances in dissociative recombination: Trends and patterns

    Energy Technology Data Exchange (ETDEWEB)

    Orel, A E; Ngassam, V; Royal, J [Department of Applied Science, University of California, Davis (United States); Roos, J B; Larson, A, E-mail: aeorel@ucdavis.ed [Department of Theoretical Chemistry, Royal Institute of Technology, Stockholm (Sweden)

    2009-11-15

    In dissociative recombination, the kinetic energy of the incident electron is transferred into excitation of the electrons of the target ion and then into kinetic energy of the fragments. In general, this proceeds via a resonance where the electron is temporarily trapped by the ion, leading to efficient energy transfer. The study of dissociative recombination is the study of these resonances, Rydberg states converging to the ground and excited states of the ion. For a number of systems, we have studied the electronic states involved in dissociative recombination, including the ground and excited states of the ion, the resonant states and the bound Rydberg states of the system, by combining electron scattering calculations with multi-reference configuration interaction quantum chemistry calculations. We will report on trends and patterns in these resonance states. We will discuss studies of dissociative recombination of the rare-gas ions, moving down the periodic table from He{sup +}{sub 2} to Ne{sup +}{sub 2} to Ar{sup +}{sub 2}, where the ground electronic state of the ion is constant, but its polarizability increases. We will also present results on isoelectronic polyatomic systems, such as HCO{sup +} and HCNH{sup +}, as well as the effects of changing the electronic structure slightly such as HCN{sup +}/HNC{sup +} and H{sub 2}CO{sup +}.

  9. Sortilin Fragments Deposit at Senile Plaques in Human Cerebrum

    Directory of Open Access Journals (Sweden)

    Xia Hu

    2017-06-01

    Full Text Available Genetic variations in the vacuolar protein sorting 10 protein (Vps10p family have been linked to Alzheimer’s disease (AD. Here we demonstrate deposition of fragments from the Vps10p member sortilin at senile plaques (SPs in aged and AD human cerebrum. Sortilin changes were characterized in postmortem brains with antibodies against the extracellular and intracellular C-terminal domains. The two antibodies exhibited identical labeling in normal human cerebrum, occurring in the somata and dendrites of cortical and hippocampal neurons. The C-terminal antibody also marked extracellular lesions in some aged and all AD cases, appearing as isolated fibrils, mini-plaques, dense-packing or circular mature-looking plaques. Sortilin and β-amyloid (Aβ deposition were correlated overtly in a region/lamina- and case-dependent manner as analyzed in the temporal lobe structures, with co-localized immunofluorescence seen at individual SPs. However, sortilin deposition rarely occurred around the pia, at vascular wall or in areas with typical diffuse Aβ deposition, with the labeling not enhanced by section pretreatment with heating or formic acid. Levels of a major sortilin fragment ~15 kDa, predicted to derive from the C-terminal region, were dramatically elevated in AD relative to control cortical lysates. Thus, sortilin fragments are a prominent constituent of the extracellularly deposited protein products at SPs in human cerebrum.

  10. PELE fragmentation dynamics

    NARCIS (Netherlands)

    Verreault, J.; Hinsberg, N.P. van; Abadjieva, E.

    2013-01-01

    An analytical model that describes the PELE fragmentation dynamics is presented and compared with experimental results from literature. The model accounts for strong shock effects and detailed interactions taking place between the filling – the inner core of the ammunition – and the target

  11. Cryobiology of coral fragments.

    Science.gov (United States)

    Hagedorn, Mary; Farrell, Ann; Carter, Virginia L

    2013-02-01

    Around the world, coral reefs are dying due to human influences, and saving habitat alone may not stop this destruction. This investigation focused on the biological processes that will provide the first steps in understanding the cryobiology of whole coral fragments. Coral fragments are a partnership of coral tissue and endosymbiotic algae, Symbiodinium sp., commonly called zooxanthellae. These data reflected their separate sensitivities to chilling and a cryoprotectant (dimethyl sulfoxide) for the coral Pocillopora damicornis, as measured by tissue loss and Pulse Amplitude Modulated fluorometry 3weeks post-treatment. Five cryoprotectant treatments maintained the viability of the coral tissue and zooxanthellae at control values (1M dimethyl sulfoxide at 1.0, 1.5 and 2.0h exposures, and 1.5M dimethyl sulfoxide at 1.0 and 1.5h exposures, P>0.05, ANOVA), whereas 2M concentrations did not (Pzooxanthellae. During the winter when the fragments were chilled, the coral tissue remained relatively intact (∼25% loss) post-treatment, but the zooxanthellae numbers in the tissue declined after 5min of chilling (Pzooxanthellae numbers declined in response to chilling alone (P0.05, ANOVA), but it did not protect against the loss of zooxanthellae (Pzooxanthellae are the most sensitive element in the coral fragment complex and future cryopreservation protocols must be guided by their greater sensitivity. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Fragments of the Past

    OpenAIRE

    Peter Szende; Annie Holcombe

    2016-01-01

    With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  13. Synthesis of arabinoxylan fragments

    DEFF Research Database (Denmark)

    Underlin, Emilie Nørmølle; Böhm, Maximilian F.; Madsen, Robert

    , or production of commercial chemicals which are mainly obtained from fossil fuels today.The arbinoxylan fragments have a backbone of β-1,4-linked xylans with α-L-arabinose units attached at specific positions. The synthesis ultilises an efficient synthetic route, where all the xylan units can be derived from D...

  14. Fragmented Work Stories

    DEFF Research Database (Denmark)

    Humle, Didde Maria; Reff Pedersen, Anne

    2015-01-01

    stories. We argue that meaning by story making is not always created by coherence and causality; meaning is created by different types of fragmentation: discontinuities, tensions and editing. The objective of this article is to develop and advance antenarrative practice analysis of work stories...

  15. Fragments of the Past

    Directory of Open Access Journals (Sweden)

    Peter Szende

    2016-10-01

    Full Text Available With travel being made more accessible throughout the decades, the hospitality industry constantly evolved their practices as society and technology progressed. Hotels looked for news ways up service their customers, which led to the invention of the Servidor in 1918. Once revolutionary innovations have gone extinct, merely becoming fragments of the past.

  16. Efficient Extracellular Expression of Phospholipase D in Escherichia Coli with an Optimized Signal Peptide

    Science.gov (United States)

    Yang, Leyun; Xu, Yu; Chen, Yong; Ying, Hanjie

    2018-01-01

    New secretion vectors containing the synthetic signal sequence (OmpA’) was constructed for the secretory production of recombinant proteins in Escherichia coli. The E. coli Phospholipase D structural gene (Accession number:NC_018658) fused to various signal sequence were expressed from the Lac promoter in E. coli Rosetta strains by induction with 0.4mM IPTG at 28°C for 48h. SDS-PaGe analysis of expression and subcellular fractions of recombinant constructs revealed the translocation of Phospholipase D (PLD) not only to the medium but also remained in periplasm of E. coli with OmpA’ signal sequence at the N-terminus of PLD. Thus the study on the effects of various surfactants on PLD extracellular production in Escherichia coli in shake flasks revealed that optimal PLD extracellular production could be achieved by adding 0.4% Triton X-100 into the medium. The maximal extracellular PLD production and extracellular enzyme activity were 0.23mg ml-1 and 16U ml-1, respectively. These results demonstrate the possibility of efficient secretory production of recombinant PLD in E. coli should be a potential industrial applications.

  17. Activated recombinant adenovirus proteinases

    Science.gov (United States)

    Anderson, Carl W.; Mangel, Walter F.

    1999-08-10

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

  18. Hadron correlations from recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-01-01

    Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.

  19. Chromosomal Fragmentation in "Escherichia Coli": Its Absence in "mutT" Mutants and Its Mechanisms in "seqA" Mutants

    Science.gov (United States)

    Rotman, Ella Rose

    2009-01-01

    Chromosomal fragmentation in "Escherichia coli" is a lethal event for the cell unless mended by the recombinational repair proteins RecA, RecBCD, and RuvABC. Certain mutations exacerbate problems that cause the cell to be dependent on the recombinational repair proteins for viability. We tested whether the absence of the MutT protein caused…

  20. Nuclear uptake of an amino-terminal fragment of apolipoprotein E4 promotes cell death and localizes within microglia of the Alzheimer's disease brain.

    Science.gov (United States)

    Love, Julia E; Day, Ryan J; Gause, Justin W; Brown, Raquel J; Pu, Xinzhu; Theis, Dustin I; Caraway, Chad A; Poon, Wayne W; Rahman, Abir A; Morrison, Brad E; Rohn, Troy T

    2017-01-01

    Although harboring the apolipoprotein E4 ( APOE4 ) allele is a well known risk factor in Alzheimer's disease (AD), the mechanism by which it contributes to disease risk remains elusive. To investigate the role of proteolysis of apoE4 as a potential mechanism, we designed and characterized a site-directed cleavage antibody directed at position D151 of the mature form of apoE4 and E3. Characterization of this antibody indicated a high specificity for detecting synthesized recombinant proteins corresponding to the amino acid sequences 1-151 of apoE3 and E4 that would generate the 17 kDa (p17) fragment. In addition, this antibody also detected a ~17 kDa amino-terminal fragment of apoE4 following incubation with collagenase and matrix metalloproteinase-9 (MMP-9), but did not react with full-length apoE4. Application of this amino-terminal apoE cleavage-fragment (nApoECFp17) antibody, revealed nuclear labeling within glial cells and labeling of a subset of neurofibrillary tangles in the human AD brain. A quantitative analysis indicated that roughly 80% of labeled nuclei were microglia. To confirm these findings, cultured BV2 microglia cells were incubated with the amino-terminal fragment of apoE4 corresponding to the cleavage site at D151. The results indicated efficient uptake of this fragment and trafficking to the nucleus that also resulted in significant cell death. In contrast, a similarly designed apoE3 fragment showed no toxicity and primarily localized within the cytoplasm. These data suggest a novel cleavage event by which apoE4 is cleaved by the extracellular proteases, collagenase and MMP-9, generating an amino-terminal fragment that is then taken up by microglia, traffics to the nucleus and promotes cell death. Collectively, these findings provide important mechanistic insights into the mechanism by which harboring the APOE4 allele may elevate dementia risk observed in AD.

  1. Relevance of extracellular DNA in rhizosphere

    Science.gov (United States)

    Pietramellara, Giacomo; Ascher, Judith; Baraniya, Divyashri; Arfaioli, Paola; Ceccherini, Maria Teresa; Hawes, Martha

    2013-04-01

    One of the most promising areas for future development is the manipulation of the rhizosphere to produce sustainable and efficient agriculture production systems. Using Omics approaches, to define the distinctive features of eDNA systems and structures, will facilitate progress in rhizo-enforcement and biocontrol studies. The relevance of these studies results clear when we consider the plethora of ecological functions in which eDNA is involved. This fraction can be actively extruded by living cells or discharged during cellular lysis and may exert a key role in the stability and variability of the soil bacterial genome, resulting also a source of nitrogen and phosphorus for plants due to the root's capacity to directly uptake short DNA fragments. The adhesive properties of the DNA molecule confer to eDNA the capacity to inhibit or kill pathogenic bacteria by cation limitation induction, and to facilitate formation of biofilm and extracellular traps (ETs), that may protect microorganisms inhabiting biofilm and plant roots against pathogens and allelopathic substances. The ETs are actively extruded by root border cells when they are dispersed in the rhizosphere, conferring to plants the capacity to extend an endogenous pathogen defence system outside the organism. Moreover, eDNA could be involved in rhizoremediation in heavy metal polluted soil acting as a bioflotation reagent.

  2. Fragments of Time

    DEFF Research Database (Denmark)

    Christiansen, Steen Ledet

    Time travel films necessarily fragment linear narratives, as scenes are revisited with differences from the first time we saw it. Popular films such as Back to the Future mine comedy from these visitations, but there are many different approaches. One extreme is Chris Marker's La Jetée - a film...... made almost completely of still images, recounting the end of the world. These stills can be viewed as fragments that have survived the end of the world and now provide the only access to the events that occured. Shane Carruth's Primer has a different approach to time travel, the narrative diegesis...... that is presented; how do we understand such films and to what extent is it even possible to make sense of a film that has no real beginning, middle or end?...

  3. Fragmentation of atomic systems

    International Nuclear Information System (INIS)

    Bohn, J.L.; Fano, U.

    1996-01-01

    We report recent progress toward a nonperturbative formulation of many-body quantum dynamics that treats all constituent particles on an equal footing. This formulation is capable of detailing the evolution of a system toward the diverse fragments into which it can break up. We illustrate the general concept with the simple example of the simultaneous excitation of both electrons in a helium atom. copyright 1996 The American Physical Society

  4. Modelling the fragmentation mechanisms

    International Nuclear Information System (INIS)

    Bougault, R.; Durand, D.; Gulminelli, F.

    1998-01-01

    We have investigated the role of high amplitude collective motion in the nuclear fragmentation by using semi-classical macroscopic, as well as, microscopic simulations (BUU). These studies are motivated by the search of instabilities responsible for nuclear fragmentation. Two cases were examined: the bubble formation following the collective expansion of the compressed nucleus in case of very central reactions and, in the case of the semi-central collisions, the fast fission of the two partners issued from a binary reaction, in their corresponding Coulomb field. In the two cases the fragmentation channel is dominated by the inter-relation between the Coulomb and nuclear fields, and it is possible to obtain semi-quantitative predictions as functions of interaction parameters. The transport equations of BUU type predicts for central reactions formation of a high density transient state. Of much interest is the mechanism subsequent to de-excitation. It seems reasonable to conceive that the pressure stocked in the compressional mode manifests itself as a collective expansion of the system. As the pressure is a increasing function of the available energy one can conceive a variety of energy depending exit channels, starting from the fragmentation due the amplification of fluctuations interior to the spinodal zone up to the complete vaporization of the highly excited system. If the reached pressure is sufficiently high the reaction final state may preserve the memory of the entrance channel as a collective radial energy superimposed to the thermal disordered motion. Distributions of particles in the configuration space for both central and semi-central reactions for the Pb+Au system are presented. The rupture time is estimated to the order of 300 fm/c, and is strongly dependent on the initial temperature. The study of dependence of the rupture time on the interaction parameters is under way

  5. Hot nuclei and fragmentation

    International Nuclear Information System (INIS)

    Guerreau, D.

    1993-01-01

    A review is made of the present status concerning the production of nuclei above 5 MeV temperature. Considerable progress has been made recently on the understanding of the formation and the fate of such hot nuclei. It appears that the nucleus seems more stable against temperature than predicted by static calculations. However, the occurrence of multifragment production at high excitation energies is now well established. The various experimental features of the fragmentation process are discussed. (author) 59 refs., 12 figs

  6. Excited nuclei fragmentation

    International Nuclear Information System (INIS)

    Ngo, C.

    1986-11-01

    Experimental indications leading to the thought of a very excited nucleus fragmentation are resumed. Theoretical approaches are briefly described; they are used to explain the phenomenon in showing off they are based on a minimum information principle. This model is based on time dependent Thomas-Fermi calculation which allows the mean field effect description, and with a site-bound percolation model which allows the fluctuation description [fr

  7. Recombinant Immunotoxin Therapy of Solid Tumors: Challenges and Strategies.

    Science.gov (United States)

    Shan, Liang; Liu, Yuanyi; Wang, Paul

    2013-01-01

    Immunotoxins are a group of protein-based therapeutics, basically comprising two functional moieties: one is the antibody or antibody Fv fragment that allows the immunotoxin to bind specifically to target cells; another is the plant or bacterial toxin that kills the cells upon internalization. Immunotoxins have several unique features which are superior to conventional chemotherapeutics, including high specificity, extraordinary potency, and no known drug resistance. Development of immunotoxins evolves with time and technology, but significant progress has been achieved in the past 20 years after introduction of recombinant DNA technique and generation of the first single-chain variable fragment of monoclonal antibodies. Since then, more than 1,000 recombinant immunotoxins have been generated against cancer. However, most success in immunotoxin therapy has been achieved against hematological malignancies, several issues persist to be significant barriers for effective therapy of human solid tumors. Further development of immunotoxins will largely focus on the improvement of penetration capability to solid tumor mass and elimination of immunogenicity occurred when given repeatedly to patients. Promising strategies may include construction of recombinant antibody fragments with higher binding affinity and stability, elimination of immunodominant T- and B-cell epitopes of toxins, modification of immunotoxins with macromolecules like poly(ethylene glycol) and liposomes, and generation of immunotoxins with humanized antibody fragments and human endogenous cytotoxic enzymes. In this paper, we briefly reviewed the evolution of immunotoxin development and then discussed the challenges of immunotoxin therapy for human solid tumors and the potential strategies we may seek to overcome the challenges.

  8. Fragments of Citrullinated and MMP-degraded Vimentin and MMP-degraded Type III Collagen Are Novel Serological Biomarkers to Differentiate Crohn's Disease from Ulcerative Colitis

    DEFF Research Database (Denmark)

    Mortensen, Joachim Høg; Godskesen, Line Elbjerg; Jensen, Michael Dam

    2015-01-01

    BACKGROUND AND AIMS: A hallmark of inflammatory bowel disease [IBD] is chronic inflammation, which leads to excessive extracellular matrix [ECM] remodelling and release of specific protein fragments, called neoepitopes. We speculated that the biomarker profile panel for ulcerative colitis [UC...

  9. Azimuthal Anisotropies in Nuclear Fragmentation

    International Nuclear Information System (INIS)

    Dabrowska, A.; Szarska, M.; Trzupek, A.; Wolter, W.; Wosiek, B.

    2002-01-01

    The directed and elliptic flow of fragments emitted from the excited projectile nuclei has been observed for 158 AGeV Pb collisions with the lead and plastic targets. For comparison the flow analysis has been performed for 10.6 AGeV Au collisions with the emulsion target. The strong directed flow of heaviest fragments is found. Light fragments exhibit directed flow opposite to that of heavy fragments. The elliptic flow for all multiply charged fragments is positive and increases with the charge of the fragment. The observed flow patterns in the fragmentation of the projectile nucleus are practically independent of the mass of the target nucleus and the collision energy. Emission of fragments in nuclear multifragmentation shows similar, although weaker, flow effects. (author)

  10. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system

  11. Antibody fragments directed against different portions of the human neural cell adhesion molecule L1 act as inhibitors or activators of L1 function.

    Directory of Open Access Journals (Sweden)

    Yan Wang

    Full Text Available The neural cell adhesion molecule L1 plays important roles in neuronal migration and survival, neuritogenesis and synaptogenesis. L1 has also been found in tumors of different origins, with levels of L1 expression correlating positively with the metastatic potential of tumors. To select antibodies targeting the varied functions of L1, we screened the Tomlinson library of recombinant human antibody fragments to identify antibodies binding to recombinant human L1 protein comprising the entire extracellular domain of human L1. We obtained four L1 binding single-chain variable fragment antibodies (scFvs, named I4, I6, I13, and I27 and showed by enzyme-linked immunosorbent assay (ELISA that scFvs I4 and I6 have high affinity to the immunoglobulin-like (Ig domains 1-4 of L1, while scFvs I13 and I27 bind strongly to the fibronectin type III homologous (Fn domains 1-3 of L1. Application of scFvs I4 and I6 to human SK-N-SH neuroblastoma cells reduced proliferation and transmigration of these cells. Treatment of SK-N-SH cells with scFvs I13 and I27 enhanced cell proliferation and migration, neurite outgrowth, and protected against the toxic effects of H(2O(2 by increasing the ratio of Bcl-2/Bax. In addition, scFvs I4 and I6 inhibited and scFvs I13 and I27 promoted phosphorylation of src and Erk. Our findings indicate that scFvs reacting with the immunoglobulin-like domains 1-4 inhibit L1 functions, whereas scFvs interacting with the fibronectin type III domains 1-3 trigger L1 functions of cultured neuroblastoma cells.

  12. Universality of projectile fragmentation model

    International Nuclear Information System (INIS)

    Chaudhuri, G.; Mallik, S.; Das Gupta, S.

    2012-01-01

    Presently projectile fragmentation reaction is an important area of research as it is used for the production of radioactive ion beams. In this work, the recently developed projectile fragmentation model with an universal temperature profile is used for studying the charge distributions of different projectile fragmentation reactions with different projectile target combinations at different incident energies. The model for projectile fragmentation consists of three stages: (i) abrasion, (ii) multifragmentation and (iii) evaporation

  13. Extracellular vesicles: Exosomes, microvesicles, and friends

    NARCIS (Netherlands)

    Raposo, G.; Stoorvogel, W.|info:eu-repo/dai/nl/074352385

    2013-01-01

    Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for

  14. Recombinational repair: workshop summary

    International Nuclear Information System (INIS)

    Howard-Flanders, P.

    1983-01-01

    Recombinational repair may or may not be synonymous with postreplication repair. Considerable progress has been made in the study of the relevant enzymes, particularly those from bacteria. In this workshop we focus on the recombination enzyme RecA protein. What structural changes take place in the protein and in DNA during repair. How does homologous pairing take place. How is ATP hydrolysis coupled to the stand exchange reaction and the formation of heteroduplx DNA. Turning to another enzyme needed for certain kinds of bacterial recombination, we will ask whether the purified recB protein and recC protein complement each other and are sufficient for exonuclease V activity. In higher cells, we would like to know whether sister exchanges, which occur in bacteria after uv irradiation, are also seen in animal cells

  15. Virtual fragment preparation for computational fragment-based drug design.

    Science.gov (United States)

    Ludington, Jennifer L

    2015-01-01

    Fragment-based drug design (FBDD) has become an important component of the drug discovery process. The use of fragments can accelerate both the search for a hit molecule and the development of that hit into a lead molecule for clinical testing. In addition to experimental methodologies for FBDD such as NMR and X-ray Crystallography screens, computational techniques are playing an increasingly important role. The success of the computational simulations is due in large part to how the database of virtual fragments is prepared. In order to prepare the fragments appropriately it is necessary to understand how FBDD differs from other approaches and the issues inherent in building up molecules from smaller fragment pieces. The ultimate goal of these calculations is to link two or more simulated fragments into a molecule that has an experimental binding affinity consistent with the additive predicted binding affinities of the virtual fragments. Computationally predicting binding affinities is a complex process, with many opportunities for introducing error. Therefore, care should be taken with the fragment preparation procedure to avoid introducing additional inaccuracies.This chapter is focused on the preparation process used to create a virtual fragment database. Several key issues of fragment preparation which affect the accuracy of binding affinity predictions are discussed. The first issue is the selection of the two-dimensional atomic structure of the virtual fragment. Although the particular usage of the fragment can affect this choice (i.e., whether the fragment will be used for calibration, binding site characterization, hit identification, or lead optimization), general factors such as synthetic accessibility, size, and flexibility are major considerations in selecting the 2D structure. Other aspects of preparing the virtual fragments for simulation are the generation of three-dimensional conformations and the assignment of the associated atomic point charges.

  16. Sex in a test tube: testing the benefits of in vitro recombination.

    Science.gov (United States)

    Pesce, Diego; Lehman, Niles; de Visser, J Arjan G M

    2016-10-19

    The origin and evolution of sex, and the associated role of recombination, present a major problem in biology. Sex typically involves recombination of closely related DNA or RNA sequences, which is fundamentally a random process that creates but also breaks up beneficial allele combinations. Directed evolution experiments, which combine in vitro mutation and recombination protocols with in vitro or in vivo selection, have proved to be an effective approach for improving functionality of nucleic acids and enzymes. As this approach allows extreme control over evolutionary conditions and parameters, it also facilitates the detection of small or position-specific recombination benefits and benefits associated with recombination between highly divergent genotypes. Yet, in vitro approaches have been largely exploratory and motivated by obtaining improved end products rather than testing hypotheses of recombination benefits. Here, we review the various experimental systems and approaches used by in vitro studies of recombination, discuss what they say about the evolutionary role of recombination, and sketch their potential for addressing extant questions about the evolutionary role of sex and recombination, in particular on complex fitness landscapes. We also review recent insights into the role of 'extracellular recombination' during the origin of life.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. © 2016 The Author(s).

  17. Neutralisation and binding of VHS virus by monovalent antibody fragments

    DEFF Research Database (Denmark)

    Cupit, P.M.; Lorenzen, Niels; Strachan, G.

    2001-01-01

    We have previously reported the cloning and characterisation of the heavy and light chain variable domain genes encoding three monoclonal antibodies (Mabs) that bind viral haemorrhagic septicaemia virus (VHSV). Two of these antibodies, 3F1H10 and 3F1A2 both neutralised the virus though 3F1A2...... appeared to recognise a broader range of virus isolates. The variable domains of these two antibodies differ by only four residues (Lorenzen et al., 2000a. Fish Shellfish Immunol. 10, 129-142). To further study the mechanism of neutralisation, Fab fragments as well as a series of recombinant bacterial...... single chain antibody (scAb) fragments were generated from the three anti-VHSV Mabs and their variable domain genes, respectively. Fabs and scAbs derived from the neutralising Mabs were both able to neutralise the VHSV type 1 isolate DK-F1. In addition, a series of scAb fragments were produced using...

  18. An Archeology of Fragments

    Directory of Open Access Journals (Sweden)

    Gerald L. Bruns

    2014-10-01

    Full Text Available This is a short (fragmentary history of fragmentary writing from the German Romantics (F. W. Schlegel, Friedrich Hölderlin to modern and contemporary concrete or visual poetry. Such writing is (often deliberately a critique of the logic of subsumption that tries to assimilate whatever is singular and irreducible into totalities of various categorical or systematic sorts. Arguably, the fragment (parataxis is the distinctive feature of literary Modernism, which is a rejection, not of what precedes it, but of what Max Weber called “the rationalization of the world” (or Modernity whose aim is to keep everything, including all that is written, under surveillance and control.

  19. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Legrain, R.

    1984-08-01

    Projectile and nuclear fragmentation are defined and processes referred to are recalled. The two different aspects of fragmentation are considered but the emphasis is also put on heavy ion induced reactions. The preliminary results of an experiment performed at GANIL to study peripheral heavy ions induced reactions at intermediate energy are presented. The results of this experiment will illustrate the characteristics of projectile fragmentation and this will also give the opportunity to study projectile fragmentation in the transition region. Then nuclear fragmentation is considered which is associated with more central collisions in the case of heavy ion induced reactions. This aspect of fragmentation is also ilustrated with two heavy ion experiments in which fragments emitted at large angle have been observed

  20. Lower sperm DNA fragmentation after r-FSH administration in functional hypogonadotropic hypogonadism.

    Science.gov (United States)

    Ruvolo, Giovanni; Roccheri, Maria Carmela; Brucculeri, Anna Maria; Longobardi, Salvatore; Cittadini, Ettore; Bosco, Liana

    2013-04-01

    An observational clinical and molecular study was designed to evaluate the effects of the administration of recombinant human FSH on sperm DNA fragmentation in men with a non-classical form of hypogonadotropic hypogonadism and idiopathic oligoasthenoteratozoospermia. In the study were included 53 men with a non-classical form of hypogonadotropic hypogonadism and idiopathic oligoasthenoteratozoospermia. In all patients, sperm DNA fragmentation index (DFI), assessed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) in situ DNA nick end-labelling (TUNEL) assay, was evaluated before starting the treatment with 150 IU of recombinant human FSH, given three times a week for at least 3 months. Patients' semen analysis and DNA fragmentation index were re-evaluated after the 3-month treatment period. After recombinant human FSH therapy, we did not find any differences in terms of sperm count, motility and morphology. The average DNA fragmentation index was significantly reduced (21.15 vs 15.2, p15 %), while no significant variation occurred in the patients with DFI values ≤ 15 %. Recombinant human FSH administration improves sperm DNA integrity in hypogonadotropic hypogonadism and idiopathic oligoasthenoteratozoospermia men with DNA fragmentation index value >15 % .

  1. Fragmentation of random trees

    International Nuclear Information System (INIS)

    Kalay, Z; Ben-Naim, E

    2015-01-01

    We study fragmentation of a random recursive tree into a forest by repeated removal of nodes. The initial tree consists of N nodes and it is generated by sequential addition of nodes with each new node attaching to a randomly-selected existing node. As nodes are removed from the tree, one at a time, the tree dissolves into an ensemble of separate trees, namely, a forest. We study statistical properties of trees and nodes in this heterogeneous forest, and find that the fraction of remaining nodes m characterizes the system in the limit N→∞. We obtain analytically the size density ϕ s of trees of size s. The size density has power-law tail ϕ s ∼s −α with exponent α=1+(1/m). Therefore, the tail becomes steeper as further nodes are removed, and the fragmentation process is unusual in that exponent α increases continuously with time. We also extend our analysis to the case where nodes are added as well as removed, and obtain the asymptotic size density for growing trees. (paper)

  2. Parton recombination model

    International Nuclear Information System (INIS)

    Hwa, R.C.

    1978-08-01

    Low P/sub T/ meson production in hadronic collisions is described in the framework of the parton model. The recombination of quark and antiquark is suggested as the dominant mechanism in the large x region. Phenomenological evidences for the mechanism are given. The application to meson initiated reactions yields the quark distribution in mesons. 21 references

  3. Chapter 15. transforming lepidopteran insect cells for continuous recombinant protein expression

    Science.gov (United States)

    The baculovirus expression vector system (BEVS) is widely used to produce large quantities of recombinant proteins. However, yields of extracellular and membrane-bound proteins obtained with this system often are very low, possibly due to the adverse effects of baculovirus infection on the host ins...

  4. Construction of recombinant DNA clone for bovine viral diarrhea virus

    International Nuclear Information System (INIS)

    Yeo, S.G.; Cho, H.J.; Masri, S.A.

    1992-01-01

    Molecular cloning was carried out on the Danish strain of bovine viral diarrhea virus (BVDV) to construct strategy for the diagnostic tools and effective vaccine of BVD afterwards. A recombinant DNA clone (No. 29) was established successfully from cDNA for viral RNA tailed with adenine homopolymer at 3 -end. 32 P-labeled DNA probes of 300~1, 800bp fragments, originating from the clone 29, directed specific DNA-RNA hybridization results with BVDV RNA. Recombinant DNA of the clone 29 was about 5,200bp representing 41.6% of the full length of Danish strain's RNA, and restriction sites were recognized for EooR I, Sst I, Hind III and Pst I restriction enzymes in the DNA fragment

  5. Fragment-based lead generation: identification of seed fragments by a highly efficient fragment screening technology

    Science.gov (United States)

    Neumann, Lars; Ritscher, Allegra; Müller, Gerhard; Hafenbradl, Doris

    2009-08-01

    For the detection of the precise and unambiguous binding of fragments to a specific binding site on the target protein, we have developed a novel reporter displacement binding assay technology. The application of this technology for the fragment screening as well as the fragment evolution process with a specific modelling based design strategy is demonstrated for inhibitors of the protein kinase p38alpha. In a fragment screening approach seed fragments were identified which were then used to build compounds from the deep-pocket towards the hinge binding area of the protein kinase p38alpha based on a modelling approach. BIRB796 was used as a blueprint for the alignment of the fragments. The fragment evolution of these deep-pocket binding fragments towards the fully optimized inhibitor BIRB796 included the modulation of the residence time as well as the affinity. The goal of our study was to evaluate the robustness and efficiency of our novel fragment screening technology at high fragment concentrations, compare the screening data with biochemical activity data and to demonstrate the evolution of the hit fragments with fast kinetics, into slow kinetic inhibitors in an in silico approach.

  6. Genetic characterization of somatic recombination in Trichoderma pseudokoningii

    Directory of Open Access Journals (Sweden)

    Barcellos Fernando Gomes

    2003-01-01

    Full Text Available Crossing experiments via hyphal anastomosis between two strains contrasting for auxotrophic markers of Trichoderma pseudokoningii were conducted to characterize the somatic recombination process in this specie. Four crossings were made and a total of 1052 colonies obtained from conidial suspensions of the heterokaryotic colonies were analyzed. Sixty-eight recombinant colonies, from four growing generations, were analyzed for the auxotrophic markers. Of the 68 colonies analyzed, 58 were stable after four generations and the remainders were unstable, reverting to one of the parentals. Most of the recombinant colonies were unstable through subculture and after four growing generations they showed the leu ino met markers (auxotrophic for leucin, inositol and metionin respectively. The unstable recombinant colonies showed irregular growing borders, sparse sporulation and frequent sector formation. The results suggest the occurrence of recombination mechanisms in the heterokaryon (somatic recombination, different from those described for the parasexual cycle or parameiosis. Therefore, we proposed the ocurrence of nuclei degradation from one parental (non prevalent parental in the heterokaryon and that the resulting chromosomal fragments may be incorporated into whole nuclei of the another parental (prevalent parental. However the parameiosis as originally described cannot be excluded.

  7. Genetic recombination in plant-infecting messenger-sense RNA viruses: overview and research perspectives

    Directory of Open Access Journals (Sweden)

    Jozef Julian Bujarski

    2013-03-01

    Full Text Available RNA recombination is one of the driving forces of genetic variability in (+-strand RNA viruses. Various types of RNA-RNA crossovers were described including crosses between the same or different viral RNAs or between viral and cellular RNAs. Likewise, a variety of molecular mechanisms are known to support RNA recombination, such as replicative events (based on internal or end-to-end replicase switchings along with nonreplicative joining among RNA fragments of viral and/or cellular origin. Such mechanisms as RNA decay or RNA interference are responsible for RNA fragmentation and trans-esterification reactions which are likely accountable for ligation of RNA fragments. Numerous host factors were found to affect the profiles of viral RNA recombinants and significant differences in recombination frequency were observed among various RNA viruses. Comparative analyses of viral sequences allowed for the development of evolutionary models in order to explain adaptive phenotypic changes and co-evolving sites. Many questions remain to be answered by forthcoming RNA recombination research. (i How various factors modulate the ability of viral replicase to switch templates, (ii What is the intracellular location of RNA-RNA template switchings, (iii Mechanisms and factors responsible for non-replicative RNA recombination, (iv Mechanisms of integration of RNA viral sequences with cellular genomic DNA, and (v What is the role of RNA splicing and ribozyme activity. From an evolutionary stand point, it is not known how RNA viruses parasitize new host species via recombination, nor is it obvious what the contribution of RNA recombination is among other RNA modification pathways. We do not understand why the frequency of RNA recombination varies so much among RNA viruses and the status of RNA recombination as a form of sex is not well documented.

  8. Genetic recombination in plant-infecting messenger-sense RNA viruses: overview and research perspectives.

    Science.gov (United States)

    Bujarski, Jozef J

    2013-01-01

    RNA recombination is one of the driving forces of genetic variability in (+)-strand RNA viruses. Various types of RNA-RNA crossovers were described including crosses between the same or different viral RNAs or between viral and cellular RNAs. Likewise, a variety of molecular mechanisms are known to support RNA recombination, such as replicative events (based on internal or end-to-end replicase switchings) along with non-replicative joining among RNA fragments of viral and/or cellular origin. Such mechanisms as RNA decay or RNA interference are responsible for RNA fragmentation and trans-esterification reactions which are likely accountable for ligation of RNA fragments. Numerous host factors were found to affect the profiles of viral RNA recombinants and significant differences in recombination frequency were observed among various RNA viruses. Comparative analyses of viral sequences allowed for the development of evolutionary models in order to explain adaptive phenotypic changes and co-evolving sites. Many questions remain to be answered by forthcoming RNA recombination research. (1) How various factors modulate the ability of viral replicase to switch templates, (2) What is the intracellular location of RNA-RNA template switchings, (3) Mechanisms and factors responsible for non-replicative RNA recombination, (4) Mechanisms of integration of RNA viral sequences with cellular genomic DNA, and (5) What is the role of RNA splicing and ribozyme activity. From an evolutionary stand point, it is not known how RNA viruses parasitize new host species via recombination, nor is it obvious what the contribution of RNA recombination is among other RNA modification pathways. We do not understand why the frequency of RNA recombination varies so much among RNA viruses and the status of RNA recombination as a form of sex is not well documented.

  9. Making Recombinant Monoclonal Antibody And Radiolabelling For Medical Purpose

    International Nuclear Information System (INIS)

    Nguyen Thi Thu; Duong Van Dong; Vo Thi Cam Hoa; Bui Van Cuong; Chu Van Khoa; Vu Bich Huong; Le Quang Huan

    2008-01-01

    Recombinant monoclonal antibody labeling with 131 I specific to tumor cell has been studied and prepared for treatment of Hodgkin lymphoma. In this study, a recombinant monoclonal antibody with two specific properties is a hybrid molecule created by coupling an antibody variable fragments with peptide melittin. The gene coding the antibody fragment has been obtained from human synthetic Fv libraries using for panning and screening on populations of lymphocytes fragmented from human blood cells with Hodgkin diseases. The gene encoding peptit melittin has been cloned from honeybee Apis cerana DNA. The gene coding recombinant monoclonal antibody has been expressed in E.coli BL21 (DE3) at 37 o C and was induced with 0.6 mM IPTG. The recombinant compound has been purified by affinity chromatography with HiTrap affinity column. The obtained recombinant monoclonal antibody has showed cytolytic activities when added to cell culture medium for LU cancer cell line with the amount of 100 - 200 mg/ml. This monoclonal antibody is labeled with 131 I using chloramine T procedure. ChT mass for the oxidation of 50 μg monoclonal antibody in 76 MBq was 10 μg. Sodium metabisulfite was used as a reducing agent. Reaction time was above 3 mins. The radiochemical purity was determined using electrophoresis and TLC methods. Radiochemical yield was > 97%. Radiochemical purity after purification was > 99%. Nuclear purity was > 99%. Stability of the label antibody was 12 days. This is the product promise potential used in the diagnostic and therapeutic of Hodgkin lymphoma. (author)

  10. Fragmented medial coronoid process

    International Nuclear Information System (INIS)

    Juhasz, Cs.; Juhasz, T.

    1997-01-01

    Fragmented medial coronoid process: (FCP) is often considered to be part of the osteochondrosis dissecans complex, but trauma and growth discrepancies between the radius and ulna are proposed as causes. There is little to clinically differentiate FCP, from osteochondrosis dissecans (OCD) of the elbow. Pain on, flexion-extension of the elbow and lateral rotation of the paw is a little more consistent in FCP. Radiographic examination of the elbow is important despite the, fact that radiographic signs of the FCP are often nonspecific. Excessive osteoarthrosis and superimposition of the radial head and coronoid process make identification of the FCP difficult. Craniocaudal, flexed mediolateral and 25 degree craniocaudal-lateromedial views are necessary for diagnosis. Osteophyte production is more dramatic with FCP than with OCD and suggests therefore the occurrence of OCP in many cases. Although the detached process may be seen on any view, the oblique projection offers the least obstructed view. Exposure of the joint is identical to that for OCD, that means a medial approach with osteotomy of the epicondyle. In most cases the process is loose enough to be readily apparent, but in some it is necessary to exert force on the process in order to find the cleavage plane. It is necessary to remove the osteophytes as well and to inspect and irrigate the joint carefully to remove cartilage fragments before closure. Confinement is advisable for 4 weeks before returning the dog to normal activity. The outlook for function is good if the FCP is removed before secondary degenerative joint disease is well established

  11. Extracellular Vesicles in Hematological Disorders

    Directory of Open Access Journals (Sweden)

    Anat Aharon

    2014-10-01

    Full Text Available Extracellular vesicles (EVs, comprised of exosomes, microparticles, apoptotic bodies, and other microvesicles, are shed from a variety of cells upon cell activation or apoptosis. EVs promote clot formation, mediate pro-inflammatory processes, transfer proteins and miRNA to cells, and induce cell signaling that regulates cell differentiation, proliferation, migration, invasion, and apoptosis. This paper will review the contribution of EVs in hematological disorders, including hemoglobinopathies (sickle cell disease, thalassemia, paroxysmal nocturnal hemoglobinuria, and hematological malignancies (lymphomas, myelomas, and acute and chronic leukemias.

  12. Feline immunodeficiency virus (FIV) env recombinants are common in natural infections.

    Science.gov (United States)

    Bęczkowski, Paweł M; Hughes, Joseph; Biek, Roman; Litster, Annette; Willett, Brian J; Hosie, Margaret J

    2014-09-17

    Recombination is a common feature of retroviral biology and one of the most important factors responsible for generating viral diversity at both the intra-host and the population levels. However, relatively little is known about rates and molecular processes of recombination for retroviruses other than HIV, including important model viruses such as feline immunodeficiency virus (FIV). We investigated recombination in complete FIV env gene sequences (n = 355) isolated from 43 naturally infected cats. We demonstrated that recombination is abundant in natural FIV infection, with over 41% of the cats being infected with viruses containing recombinant env genes. In addition, we identified shared recombination breakpoints; the most significant hotspot occurred between the leader/signal fragment and the remainder of env. Our results have identified the leader/signal fragment of env as an important site for recombination and highlight potential limitations of the current phylogenetic classification of FIV based on partial env sequences. Furthermore, the presence of abundant recombinant FIV in the USA poses a significant challenge for commercial diagnostic tests and should inform the development of the next generation of FIV vaccines.

  13. Fractal statistics of brittle fragmentation

    Directory of Open Access Journals (Sweden)

    M. Davydova

    2013-04-01

    Full Text Available The study of fragmentation statistics of brittle materials that includes four types of experiments is presented. Data processing of the fragmentation of glass plates under quasi-static loading and the fragmentation of quartz cylindrical rods under dynamic loading shows that the size distribution of fragments (spatial quantity is fractal and can be described by a power law. The original experimental technique allows us to measure, apart from the spatial quantity, the temporal quantity - the size of time interval between the impulses of the light reflected from the newly created surfaces. The analysis of distributions of spatial (fragment size and temporal (time interval quantities provides evidence of obeying scaling laws, which suggests the possibility of self-organized criticality in fragmentation.

  14. Manufacturing of recombinant therapeutic proteins in microbial systems.

    Science.gov (United States)

    Graumann, Klaus; Premstaller, Andreas

    2006-02-01

    Recombinant therapeutic proteins have gained enormous importance for clinical applications. The first recombinant products have been produced in E. coli more than 20 years ago. Although with the advent of antibody-based therapeutics mammalian expression systems have experienced a major boost, microbial expression systems continue to be widely used in industry. Their intrinsic advantages, such as rapid growth, high yields and ease of manipulation, make them the premier choice for expression of non-glycosylated peptides and proteins. Innovative product classes such as antibody fragments or alternative binding molecules will further expand the use of microbial systems. Even more, novel, engineered production hosts and integrated technology platforms hold enormous potential for future applications. This review summarizes current applications and trends for development, production and analytical characterization of recombinant therapeutic proteins in microbial systems.

  15. Fluctuations in the fragmentation process

    International Nuclear Information System (INIS)

    Botet, R.; Ploszajczak, M.

    1993-01-01

    Some general framework of sequential fragmentation is presented, as provided by the newly proposed Fragmentation - Inactivation - Binary model, and to study briefly its basic and universal features. This model includes as particular cases most of the previous kinetic fragmentation models. In particular it is discussed how one arrives in this framework to the critical behaviour, called the shattering transition. This model is then compared to recent data on gold multifragmentation at 600 MeV/nucl. (authors) 20 refs., 5 figs

  16. MRI of displaced meniscal fragments

    International Nuclear Information System (INIS)

    Dunoski, Brian; Zbojniewicz, Andrew M.; Laor, Tal

    2012-01-01

    A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

  17. MRI of displaced meniscal fragments

    Energy Technology Data Exchange (ETDEWEB)

    Dunoski, Brian [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Zbojniewicz, Andrew M.; Laor, Tal [University of Cincinnati College of Medicine, Department of Radiology, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States)

    2012-01-15

    A torn meniscus frequently requires surgical fixation or debridement as definitive treatment. Meniscal tears with associated fragment displacement, such as bucket handle and flap tears, can be difficult to recognize and accurately describe on MRI, and displaced fragments can be challenging to identify at surgery. A displaced meniscal fragment can be obscured by synovium or be in a location not usually evaluated at arthroscopy. We present a pictorial essay of meniscal tears with displaced fragments in patients referred to a pediatric hospital in order to increase recognition and accurate interpretation by the radiologist, who in turn can help assist the surgeon in planning appropriate therapy. (orig.)

  18. Extracellular nucleotide signaling in plants

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, Gary [Univ. of Missouri, Columbia, MO (United States)

    2016-09-08

    Over the life of this funded project, our research group identified and characterized two key receptor proteins in plants; one mediating the innate immunity response to chitin and the other elucidating the key receptor for extracellular ATP. In the case of chitin recognition, we recently described the quaternary structure of this receptor, shedding light on how the receptor functions. Perhaps more importantly, we demonstrated that all plants have the ability to recognize both chitin oligomers and lipochitooligosacchardes, fundamentally changing how the community views the evolution of these systems and strategies that might be used, for example, to extend symbiotic nitrogen fixation to non-legumes. Our discovery of DORN1 opens a new chapter in plant physiology documenting conclusively that eATP is an important extracellular signal in plants, as it is in animals. At this point, we cannot predict just how far reaching this discovery may prove to be but we are convinced that eATP signaling is fundamental to plant growth and development and, hence, we believe that the future will be very exciting for the study of DORN1 and its overall function in plants.

  19. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  20. Structural characterization by NMR of the natively unfolded extracellular domain of beta-dystroglycan: toward the identification of the binding epitope for alpha-dystroglycan.

    Science.gov (United States)

    Bozzi, Manuela; Bianchi, Marzia; Sciandra, Francesca; Paci, Maurizio; Giardina, Bruno; Brancaccio, Andrea; Cicero, Daniel O

    2003-11-25

    Dystroglycan (DG) is an adhesion molecule playing a crucial role for tissue stability during both early embriogenesis and adulthood and is composed by two tightly interacting subunits: alpha-DG, membrane-associated and highly glycosylated, and the transmembrane beta-DG. Recently, by solid-phase binding assays and NMR experiments, we have shown that the C-terminal domain of alpha-DG interacts with a recombinant extracellular fragment of beta-DG (positions 654-750) independently from glycosylation and that the linear binding epitope is located between residues 550 and 565 of alpha-DG. In order to elucidate which moieties of beta-DG are specifically involved in the complex with alpha-DG, the ectodomain has been recombinantly expressed and purified in a labeled ((13)C,(15)N) form and studied by multidimensional NMR. Although it represents a natively unfolded protein domain, we obtained an almost complete backbone assignment. Chemical shift index, (1)H-(15)N heteronuclear single-quantum coherence and nuclear Overhauser effect (HSQC-NOESY) spectra and (3)J(HN,H)(alpha) coupling constant values confirm that this protein is highly disordered, but (1)H-(15)N steady-state NOE experiments indicate that the protein presents two regions of different mobility. The first one, between residues 659 and 722, is characterized by a limited degree of mobility, whereas the C-terminal portion, containing about 30 amino acids, is highly flexible. The binding of beta-DG(654-750) to the C-terminal region of the alpha subunit, alpha-DG(485-620), has been investigated, showing that the region of beta-DG(654-750) between residues 691 and 719 is involved in the interaction.

  1. Expression and evaluation of IgE-binding capacity of recombinant Pacific mackerel parvalbumin

    OpenAIRE

    Hamada, Yuki; Tanaka, Hiroyuki; Sato, Ayako; Ishizaki, Shoichiro; Nagashima, Yuji; Shiomi, Kazuo

    2004-01-01

    Background: Parvalbumin is the major and cross-reactive allergen in fish. Sufficient amounts of IgE-reactive recombinant fish parvalbumin are needed for diagnosis and immunotherapy of fish allergy. Methods: A DNA fragment corresponding to parvalbumin of the Pacific mackerel Scomber japonicus was synthesized and cloned into the expression vector pGEX-6p-3 to produce glutathione S-transferase (GST)-fusion parvalbumin in Escherichia coli. The GST-free recombinant parvalbumin was purified usin...

  2. Fragmentation of molecular ions in slow electron collisions

    Energy Technology Data Exchange (ETDEWEB)

    Novotny, Steffen

    2008-06-25

    The fragmentation of positively charged hydrogen molecular ions by the capture of slow electrons, the so called dissociative recombination (DR), has been investigated in storage ring experiments at the TSR, Heidelberg, where an unique twin-electron-beam arrangement was combined with high resolution fragment imaging detection. Provided with well directed cold electrons the fragmentation kinematics were measured down to meV collision energies where pronounced rovibrational Feshbach resonances appear in the DR cross section. For thermally excited HD{sup +} the fragmentation angle and the kinetic energy release were studied at variable precisely controlled electron collision energies on a dense energy grid from 10 to 80 meV. The anisotropy described for the first time by Legendre polynomials higher 2{sup nd} order and the extracted rotational state contributions were found to vary on a likewise narrow energy scale as the rotationally averaged DR rate coefficient. Ro-vibrationally resolved DR experiments were performed on H{sub 2}{sup +} produced in distinct internal excitations by a novel ion source. Both the low-energy DR rate as well as the fragmentation dynamics at selected resonances were measured individually in the lowest two vibrational and first three excited rotational states. State-specific DR rates and angular dependences are reported. (orig.)

  3. Fragmentation of molecular ions in slow electron collisions

    International Nuclear Information System (INIS)

    Novotny, Steffen

    2008-01-01

    The fragmentation of positively charged hydrogen molecular ions by the capture of slow electrons, the so called dissociative recombination (DR), has been investigated in storage ring experiments at the TSR, Heidelberg, where an unique twin-electron-beam arrangement was combined with high resolution fragment imaging detection. Provided with well directed cold electrons the fragmentation kinematics were measured down to meV collision energies where pronounced rovibrational Feshbach resonances appear in the DR cross section. For thermally excited HD + the fragmentation angle and the kinetic energy release were studied at variable precisely controlled electron collision energies on a dense energy grid from 10 to 80 meV. The anisotropy described for the first time by Legendre polynomials higher 2 nd order and the extracted rotational state contributions were found to vary on a likewise narrow energy scale as the rotationally averaged DR rate coefficient. Ro-vibrationally resolved DR experiments were performed on H 2 + produced in distinct internal excitations by a novel ion source. Both the low-energy DR rate as well as the fragmentation dynamics at selected resonances were measured individually in the lowest two vibrational and first three excited rotational states. State-specific DR rates and angular dependences are reported. (orig.)

  4. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  5. Recombination epoch revisited

    International Nuclear Information System (INIS)

    Krolik, J.H.

    1989-01-01

    Previous studies of cosmological recombination have shown that this process produces as a by-product a highly superthermal population of Ly-alpha photons which retard completion of recombination. Cosmological redshifting was thought to determine the frequency distribution of the photons, while two-photon decay of hydrogen's 2s state was thought to control their numbers. It is shown here that frequency diffusion due to photon scattering dominate the cosmological redshift in the frequency range near line center which fixes the ratio of ground state to excited state population, while incoherent scattering into the far-red damping wing effectively destroys Ly-alpha photons as a rate which is competitive with two-photon decay. The former effect tends to hold back recombination, while the latter tends to accelerate it; the net results depends on cosmological parameters, particularly the combination Omega(b) h/sq rt (2q0), where Omega(b) is the fraction of the critical density provided by baryons. 18 references

  6. Dielectronic recombination theory

    International Nuclear Information System (INIS)

    LaGattuta, K.J.

    1991-01-01

    A theory now in wide use for the calculation of dielectronic recombination cross sections (σ DR ) and rate coefficients (α DR ) was one introduced originally by Feshbach for nuclear physics applications, and then later adapted for atomic scattering problems by Hahn. In the following, we briefly review this theory in a very general form, which allows one to account for the effects of overlapping and interacting resonances, as well as continuum-continuum coupling. An extension of our notation will then also allow for the inclusion of the effects of direct radiative recombination, along with a treatment of the interference between radiative and dielectronic recombination. Other approaches to the calculation of σ DR have been described by Fano and by Seaton. We will not consider those theories here. Calculations of α DR have progressed considerably over the last 25 years, since the early work of Burgess. Advances in the reliability of theoretical predictions have also been promoted recently b a variety of direct laboratory measurements of σ DR . While the measurements of σ DR for δn ≠ 0 excitations have tended to agree very well with calculations, the case of δn = 0 has been much problematic. However, by invoking a mechanism originally proposed by Jacobs, which takes into account the effect of stray electric fields on high Rydberg states (HRS) participating in the DR process, new calculations have improved the agreement between theory and experiment for these cases. Nevertheless, certain discrepancies still remain

  7. Efficient secretory expression of recombinant proteins in Escherichia coli with a novel actinomycete signal peptide.

    Science.gov (United States)

    Cui, Yanbing; Meng, Yiwei; Zhang, Juan; Cheng, Bin; Yin, Huijia; Gao, Chao; Xu, Ping; Yang, Chunyu

    2017-01-01

    In well-established heterologous hosts, such as Escherichia coli, recombinant proteins are usually intracellular and frequently found as inclusion bodies-especially proteins possessing high rare codon content. In this study, successful secretory expression of three hydrolases, in a constructed inducible or constitutive system, was achieved by fusion with a novel signal peptide (Kp-SP) from an actinomycete. The signal peptide efficiently enabled extracellular protein secretion and also contributed to the active expression of the intracellular recombinant proteins. The thermophilic α-amylase gene of Bacillus licheniformis was fused with Kp-SP. Both recombinants, carrying inducible and constitutive plasmids, showed remarkable increases in extracellular and intracellular amylolytic activity. Amylase activity was observed to be > 10-fold in recombinant cultures with the constitutive plasmid, pBSPPc, compared to that in recombinants lacking Kp-SP. Further, the signal peptide enabled efficient secretion of a thermophilic cellulase into the culture medium, as demonstrated by larger halo zones and increased enzymatic activities detected in both constructs from different plasmids. For heterologous proteins with a high proportion of rare codons, it is difficult to obtain high expression in E. coli owing to the codon bias. Here, the fusion of an archaeal homologue of the amylase encoding gene, FSA, with Kp-SP resulted in > 5-fold higher extracellular activity. The successful extracellular expression of the amylase indicated that the signal peptide also contributed significantly to its active expression and signified the potential value of this novel and versatile signal peptide in recombinant protein production. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Thermodynamical string fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Nadine [Theoretical Particle Physics, Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, Lund, SE-223 62 (Sweden); School of Physics and Astronomy, Monash University,Wellington Road, Clayton, VIC-3800 (Australia); Sjöstrand, Torbjörn [Theoretical Particle Physics, Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, Lund, SE-223 62 (Sweden)

    2017-01-31

    The observation of heavy-ion-like behaviour in pp collisions at the LHC suggests that more physics mechanisms are at play than traditionally assumed. The introduction e.g. of quark-gluon plasma or colour rope formation can describe several of the observations, but as of yet there is no established paradigm. In this article we study a few possible modifications to the Pythia event generator, which describes a wealth of data but fails for a number of recent observations. Firstly, we present a new model for generating the transverse momentum of hadrons during the string fragmentation process, inspired by thermodynamics, where heavier hadrons naturally are suppressed in rate but obtain a higher average transverse momentum. Secondly, close-packing of strings is taken into account by making the temperature or string tension environment-dependent. Thirdly, a simple model for hadron rescattering is added. The effect of these modifications is studied, individually and taken together, and compared with data mainly from the LHC. While some improvements can be noted, it turns out to be nontrivial to obtain effects as big as required, and further work is called for.

  9. Extracellular histones identified in crocodile blood inhibit in-vitro HIV-1 infection.

    Science.gov (United States)

    Kozlowski, Hannah N; Lai, Eric T L; Havugimana, Pierre C; White, Carl; Emili, Andrew; Sakac, Darinka; Binnington, Beth; Neschadim, Anton; McCarthy, Stephen D S; Branch, Donald R

    2016-08-24

    It has been reported that crocodile blood contains potent antibacterial and antiviral properties. However, its effects on HIV-1 infection remain unknown. We obtained blood from saltwater crocodiles to examine whether serum or plasma could inhibit HIV-1 infection. We purified plasma fractions then used liquid chromatography-mass spectrometry to identify the inhibitory protein factor(s). We then analyzed the ability of recombinant proteins to recapitulate HIV-1 inhibition and determine their mechanism of action. Crocodylus porosus plasma was tested for inhibition of Jurkat T-cell HIV-1 infection. Inhibitor(s) were purified by reverse-phase chromatography then identified by protein liquid chromatography-mass spectrometry. Anti-HIV-1 activity of purified plasma or recombinant proteins were measured by p24 enzyme-linked immunosorbent assay and luciferase readouts, and mechanism of action was determined by measuring HIV-1 RNA, cDNA and transcription (using 1G5 cells). Crocodile plasma contains potent inhibitors of HIV-1IIIB infection, which were identified as histones. Recombinant human histones H1 and H2A significantly reduced HIV-1JR-FL infection (IC50 of 0.79 and 0.45 μmol/l, respectively), whereas H4 enhanced JR-FL luciferase activity. The inhibitory effects of crocodile plasma, recombinant H1 or recombinant H2A on HIV-1 infection were during or post-viral transcription. Circulating histones in crocodile blood, possibly released by neutrophil extracellular traps, are significant inhibitors of HIV-1 infection in-vitro. Extracellular recombinant histones have different effects on HIV-1 transcription and protein expression and are downregulated in HIV-1 patients. Circulating histones may be a novel resistance factor during HIV-1 infection, and peptide versions should be explored as future HIV-1 therapeutics that modulate viral transcription.

  10. Analysis of extracellular RNA by digital PCR

    Directory of Open Access Journals (Sweden)

    Kenji eTakahashi

    2014-06-01

    Full Text Available The transfer of extracellular RNA is emerging as an important mechanism for intracellular communication. The ability for the transfer of functionally active RNA molecules from one cell to another within vesicles such as exosomes enables a cell to modulate cellular signaling and biological processes within recipient cells. The study of extracellular RNA requires sensitive methods for the detection of these molecules. In this methods article, we will describe protocols for the detection of such extracellular RNA using sensitive detection technologies such as digital PCR. These protocols should be valuable to researchers interested in the role and contribution of extracellular RNA to tumor cell biology.

  11. Extracellular Molecules Involved in Cancer Cell Invasion

    International Nuclear Information System (INIS)

    Stivarou, Theodora; Patsavoudi, Evangelia

    2015-01-01

    Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion

  12. Extracellular Molecules Involved in Cancer Cell Invasion

    Directory of Open Access Journals (Sweden)

    Theodora Stivarou

    2015-01-01

    Full Text Available Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  13. Fab antibody fragment-functionalized liposomes for specific targeting of antigen-positive cells

    Czech Academy of Sciences Publication Activity Database

    Ohradanova-Repic, A.; Nogueira, E.; Hartl, I.; Gomes, A.C.; Preto, A.; Steinhuber, E.; Muehlgrabner, V.; Repic, M.; Kuttke, M.; Zwirzitz, A.; Prouza, M.; Suchánek, M.; Wozniak-Knopp, G.; Hořejší, Václav; Schabbauer, G.; Cavaco-Paulo, A.; Stockinger, H.

    2018-01-01

    Roč. 14, č. 1 (2018), s. 123-130 ISSN 1549-9634 Institutional support: RVO:68378050 Keywords : Active targeting * Liposome functionalization * Immunoliposome * Antibody engineering * Recombinant Fab antibody fragment Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Cell biology Impact factor: 5.720, year: 2016

  14. Polymer fragmentation in extensional flow

    Energy Technology Data Exchange (ETDEWEB)

    Maroja, Armando M.; Oliveira, Fernando A.; Ciesla, Michal; Longa, Lech

    2001-06-01

    In this paper we present an analysis of fragmentation of dilute polymer solutions in extensional flow. The transition rate is investigated both from theoretical and computational approaches, where the existence of a Gaussian distribution for the breaking bonds has been controversial. We give as well an explanation for the low fragmentation frequency found in DNA experiments.

  15. An Algebra for Program Fragments

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    1985-01-01

    Program fragments are described either by strings in the concrete syntax or by constructor applications in the abstract syntax. By defining conversions between these forms, both may be intermixed. Program fragments are constructed by terminal and nonterminal symbols from the grammar and by variab...

  16. Fracture mechanics model of fragmentation

    International Nuclear Information System (INIS)

    Glenn, L.A.; Gommerstadt, B.Y.; Chudnovsky, A.

    1986-01-01

    A model of the fragmentation process is developed, based on the theory of linear elastic fracture mechanics, which predicts the average fragment size as a function of strain rate and material properties. This approach permits a unification of previous results, yielding Griffith's solution in the low-strain-rate limit and Grady's solution at high strain rates

  17. Anti-coagulation effect of Fc fragment against anti-β2-GP1 antibodies in mouse models with APS.

    Science.gov (United States)

    Xie, Weidong; Zhang, Yaou; Bu, Cunya; Sun, Shijing; Hu, Shaoliang; Cai, Guoping

    2011-01-01

    Anti-beta (2)-glycoprotein I (anti-β2-GP1) is one of the important pathogenesis factors responsible for thrombosis formation in patients with antiphospholipid syndrome (APS). Administration of intravenous immunoglobulin (IVIg) is a common method used to inhibit the abnormal antibody levels and decrease the mortality of APS in emergency situations. We hypothesize that the Fc fragment of IgG is the molecular structure responsible for these effects. The present study investigates the beneficial effects of both recombinant and natural human Fc fragments of heterogeneous IgG against human anti-β2-GP1 antibodies in mouse models with APS. Results showed that both recombinant and natural human Fc fragments moderately but significantly decreased the levels of serum anti-β2-GP1 antibodies and had anti-coagulation effects in human β2-GP1-immunized mice. Furthermore, both recombinant and natural human Fc fragments inhibited thrombosis formation and decreased mortality in mouse models infused intravenously with human anti-β2GP1 antibodies from patients with APS. Findings suggest that the Fc fragment might be one of the active structural units of heterogeneous IgG. Thus, recombinant human Fc fragment administration may be a useful treatment for individuals with APS. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Mass spectrometry for fragment screening.

    Science.gov (United States)

    Chan, Daniel Shiu-Hin; Whitehouse, Andrew J; Coyne, Anthony G; Abell, Chris

    2017-11-08

    Fragment-based approaches in chemical biology and drug discovery have been widely adopted worldwide in both academia and industry. Fragment hits tend to interact weakly with their targets, necessitating the use of sensitive biophysical techniques to detect their binding. Common fragment screening techniques include differential scanning fluorimetry (DSF) and ligand-observed NMR. Validation and characterization of hits is usually performed using a combination of protein-observed NMR, isothermal titration calorimetry (ITC) and X-ray crystallography. In this context, MS is a relatively underutilized technique in fragment screening for drug discovery. MS-based techniques have the advantage of high sensitivity, low sample consumption and being label-free. This review highlights recent examples of the emerging use of MS-based techniques in fragment screening. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  19. Fission fragment spins and spectroscopy

    International Nuclear Information System (INIS)

    Durell, J.L.

    1988-01-01

    Prompt γ-ray coincidence experiments have been carried out on γ-rays emitted from post-neutron emission fission fragments produced by the aup 19F + 197 Au and 18 O + 232 Th reactions. Decay schemes have been established for even-even nuclei ranging from 78 Se to 148 Nd. Many new states with spin up to ∼ 12h have been observed. Apart from providing a wealth of new information on the spectroscopy of neutron-rich nuclei, the data have been analyzed to determine the average spin of primary fission fragments as a function of fragment mass. The results suggest that the fragment spins are determined by the temperature and shape of the primary fragments at or near to scission

  20. Fragment-based drug design.

    Science.gov (United States)

    Feyfant, Eric; Cross, Jason B; Paris, Kevin; Tsao, Désirée H H

    2011-01-01

    Fragment-based drug design (FBDD), which is comprised of both fragment screening and the use of fragment hits to design leads, began more than 15 years ago and has been steadily gaining in popularity and utility. Its origin lies on the fact that the coverage of chemical space and the binding efficiency of hits are directly related to the size of the compounds screened. Nevertheless, FBDD still faces challenges, among them developing fragment screening libraries that ensure optimal coverage of chemical space, physical properties and chemical tractability. Fragment screening also requires sensitive assays, often biophysical in nature, to detect weak binders. In this chapter we will introduce the technologies used to address these challenges and outline the experimental advantages that make FBDD one of the most popular new hit-to-lead process.

  1. Characterization of Vesicular Stomatitis Virus Recombinants That Express and Incorporate High Levels of Hepatitis C Virus Glycoproteins

    OpenAIRE

    Buonocore, Linda; Blight, Keril J.; Rice, Charles M.; Rose, John K.

    2002-01-01

    We generated recombinant vesicular stomatitis viruses (VSV) expressing genes encoding hybrid proteins consisting of the extracellular domains of hepatitis C virus (HCV) glycoproteins fused at different positions to the transmembrane and cytoplasmic domains of the VSV G glycoprotein (E1G and E2G). We show that these chimeric proteins are transported to the cell surface and incorporated into VSV virions efficiently. We also generated VSV recombinants in which the gene encoding the VSV G protein...

  2. A new crystal structure fragment-based pharmacophore method for G protein-coupled receptors

    DEFF Research Database (Denmark)

    Fidom, Kimberley; Isberg, Vignir; Hauser, Alexander Sebastian

    2015-01-01

    and receptor residue pairs, from crystal structure complexes. We describe the procedure to collect a library with more than 250 fragments covering 29 residue positions within the generic transmembrane binding pocket. We describe how the library fragments are recombined and inferred to build pharmacophores...... for new targets. A validating retrospective virtual screening of histamine H1 and H3 receptor pharmacophores yielded area-under-the-curves of 0.88 and 0.82, respectively. The fragment-based method has the unique advantage that it can be applied to targets for which no (homologous) crystal structures...... or ligands are known. 47% of the class A G protein-coupled receptors can be targeted with at least four-element pharmacophores. The fragment libraries can also be used to grow known ligands or for rotamer refinement of homology models. Researchers can download the complete fragment library or a subset...

  3. On the function of chitin synthase extracellular domains in biomineralization.

    Science.gov (United States)

    Weiss, Ingrid M; Lüke, Florian; Eichner, Norbert; Guth, Christina; Clausen-Schaumann, Hauke

    2013-08-01

    Molluscs with various shell architectures evolved around 542-525 million years ago, as part of a larger phenomenon related to the diversification of metazoan phyla. Molluscs deposit minerals in a chitin matrix. The mollusc chitin is synthesized by transmembrane enzymes that contain several unique extracellular domains. Here we investigate the assembly mechanism of the chitin synthase Ar-CS1 via its extracellular domain ArCS1_E22. The corresponding transmembrane protein ArCS1_E22TM accumulates in membrane fractions of the expression host Dictyostelium discoideum. Soluble recombinant ArCS1_E22 proteins can be purified as monomers only at basic pH. According to confocal fluorescence microscopy experiments, immunolabeled ArCS1_E22 proteins adsorb preferably to aragonitic nacre platelets at pH 7.75. At pH 8.2 or pH 9.0 the fluorescence signal is less intense, indicating that protein-mineral interaction is reduced with increasing pH. Furthermore, ArCS1_E22 forms regular nanostructures on cationic substrates as revealed by atomic force microscopy (AFM) experiments on modified mica cleavage planes. These experiments suggest that the extracellular domain ArCS1_E22 is involved in regulating the multiple enzyme activities of Ar-CS1 such as chitin synthesis and myosin movements by interaction with mineral surfaces and eventually by protein assembly. The protein complexes could locally probe the status of mineralization according to pH unless ions and pCO2 are balanced with suitable buffer substances. Taking into account that the intact enzyme could act as a force sensor, the results presented here provide further evidence that shell formation is coordinated physiologically with precise adjustment of cellular activities to the structure, topography and stiffness at the mineralizing interface. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

    OpenAIRE

    L?sser, Cecilia; Th?ry, Clotilde; Buz?s, Edit I.; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; L?tvall, Jan

    2016-01-01

    The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field co...

  5. Fragmentation cross sections outside the limiting-fragmentation regime

    CERN Document Server

    Sümmerer, K

    2003-01-01

    The empirical parametrization of fragmentation cross sections, EPAX, has been successfully applied to estimate fragment production cross sections in reactions of heavy ions at high incident energies. It is checked whether a similar parametrization can be found for proton-induced spallation around 1 GeV, the range of interest for ISOL-type RIB facilities. The validity of EPAX for medium-energy heavy-ion induced reactions is also checked. Only a few datasets are available, but in general EPAX predicts the cross sections rather well, except for fragments close to the projectile, where the experimental cross sections are found to be larger.

  6. A mechanism of gene amplification driven by small DNA fragments.

    Directory of Open Access Journals (Sweden)

    Kuntal Mukherjee

    Full Text Available DNA amplification is a molecular process that increases the copy number of a chromosomal tract and often causes elevated expression of the amplified gene(s. Although gene amplification is frequently observed in cancer and other degenerative disorders, the molecular mechanisms involved in the process of DNA copy number increase remain largely unknown. We hypothesized that small DNA fragments could be the trigger of DNA amplification events. Following our findings that small fragments of DNA in the form of DNA oligonucleotides can be highly recombinogenic, we have developed a system in the yeast Saccharomyces cerevisiae to capture events of chromosomal DNA amplification initiated by small DNA fragments. Here we demonstrate that small DNAs can amplify a chromosomal region, generating either tandem duplications or acentric extrachromosomal DNA circles. Small fragment-driven DNA amplification (SFDA occurs with a frequency that increases with the length of homology between the small DNAs and the target chromosomal regions. SFDA events are triggered even by small single-stranded molecules with as little as 20-nt homology with the genomic target. A double-strand break (DSB external to the chromosomal amplicon region stimulates the amplification event up to a factor of 20 and favors formation of extrachromosomal circles. SFDA is dependent on Rad52 and Rad59, partially dependent on Rad1, Rad10, and Pol32, and independent of Rad51, suggesting a single-strand annealing mechanism. Our results reveal a novel molecular model for gene amplification, in which small DNA fragments drive DNA amplification and define the boundaries of the amplicon region. As DNA fragments are frequently found both inside cells and in the extracellular environment, such as the serum of patients with cancer or other degenerative disorders, we propose that SFDA may be a common mechanism for DNA amplification in cancer cells, as well as a more general cause of DNA copy number variation

  7. [Eukaryotic Expression and Immunogenic Research of Recombination Ebola Virus Membrane Protein Gp-Fc].

    Science.gov (United States)

    Zhang, Xiaoguang; Yang, Ren; Wang, Jiao; Wang, Xuan; Hou, Mieling; An, Lina; Zhu, Ying; Cao, Yuxi; Zeng, Yi

    2016-01-01

    We used 293 cells to express the recombinant membrane protein of the Ebola virus. Then, the immunogenicity of the recombinant protein was studied by immunized BALB/c mice. According to the codon use frequency of humans, the gene encoding the extracellular domain of the Ebola virus membrane protein was optimized, synthesized, and inserted into the eukaryotic expression plasmid pXG-Fc to construct the human IgG Fc and Ebola GP fusion protein expression plasmid pXG-modGP-Fc. To achieve expression, the fusion protein expression vector was transfected into high-density 293 cells using transient transfection technology. The recombinant protein was purified by protein A affinity chromatography. BALB/c mice were immunized with the purified fusion protein, and serum antibody titers evaluated by an indirect enzyme-linked immunosorbent assay (ELISA). Purification and analyses of the protein revealed that the eukaryotic expression vector could express the recombinant protein GP-Fc effectively, and that the recombinant protein in the supernatant of the cell culture was present as a dimer. After immunization with the purified recombinant protein, a high titer of antigen-specific IgG could be detected in the serum of immunized mice by indirect ELISA, showing that the recombinant protein had good immunogenicity. These data suggest that we obtained a recombinant protein with good immunogenicity. Our study is the basis for development of a vaccine against the Ebola virus and for screening of monoclonal antibodies.

  8. Fragmentation functions approach in pQCD fragmentation phenomena

    International Nuclear Information System (INIS)

    Rolli, S.

    1996-07-01

    Next-to-leading order parton fragmentation functions into light mesons are presented. They have been extracted from real and simulated e + e - data and used to predict inclusive single particle distributions at different machines

  9. Recombining overlapping BACs into a single larger BAC

    Directory of Open Access Journals (Sweden)

    Huxley Clare

    2004-01-01

    Full Text Available Abstract Background BAC clones containing entire mammalian genes including all the transcribed region and long range controlling elements are very useful for functional analysis. Sequenced BACs are available for most of the human and mouse genomes and in many cases these contain intact genes. However, large genes often span more than one BAC, and single BACs covering the entire region of interest are not available. Here we describe a system for linking two or more overlapping BACs into a single clone by homologous recombination. Results The method was used to link a 61-kb insert carrying the final 5 exons of the human CFTR gene onto a 160-kb BAC carrying the first 22 exons. Two rounds of homologous recombination were carried out in the EL350 strain of bacteria which can be induced for the Red genes. In the first round, the inserts of the two overlapping BACs were subcloned into modified BAC vectors using homologous recombination. In the second round, the BAC to be added was linearised with the very rare-cutting enzyme I-PpoI and electroporated into recombination efficient EL350 bacteria carrying the other BAC. Recombined BACs were identified by antibiotic selection and PCR screening and 10% of clones contained the correctly recombined 220-kb BAC. Conclusion The system can be used to link the inserts from any overlapping BAC or PAC clones. The original orientation of the inserts is not important and desired regions of the inserts can be selected. The size limit for the fragments recombined may be larger than the 61 kb used here and multiple BACs in a contig could be combined by alternating use of the two pBACLink vectors. This system should be of use to many investigators wishing to carry out functional analysis on large mammalian genes which are not available in single BAC clones.

  10. Recombinant Innovation and Endogenous Transitions

    OpenAIRE

    Koen Frenken; Luis R. Izquierdo; Paolo Zeppini

    2012-01-01

    We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create “short-cuts” which reduce switching costs allowing agents to escape a technological lock-in. As a result, recombinant innovations speed up technological progress allowing transitions that are impossible with only branching ...

  11. A model for projectile fragmentation

    International Nuclear Information System (INIS)

    Chaudhuri, G; Mallik, S; Gupta, S Das

    2013-01-01

    A model for projectile fragmentation is developed whose origin can be traced back to the Bevalac era. The model positions itself between the phenomenological EPAX parametrization and transport models like 'Heavy Ion Phase Space Exploration' (HIPSE) model and antisymmetrised molecular dynamics (AMD) model. A very simple impact parameter dependence of input temperature is incorporated in the model which helps to analyze the more peripheral collisions. The model is applied to calculate the charge, isotopic distributions, average number of intermediate mass fragments and the average size of largest cluster at different Z bound of different projectile fragmentation reactions at different energies.

  12. Gamma Radiation from Fission Fragments

    International Nuclear Information System (INIS)

    Higbie, Jack

    1969-10-01

    The gamma radiation from the fragments of the thermal neutron fission of 235 U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10 -10 sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass

  13. Gamma Radiation from Fission Fragments

    Energy Technology Data Exchange (ETDEWEB)

    Higbie, Jack

    1969-10-15

    The gamma radiation from the fragments of the thermal neutron fission of {sup 235}U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10{sup -10} sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass.

  14. The spectroscopy of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, W.R. [Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    High-resolution measurements on {gamma} rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author) 24 refs., 8 figs., 1 tab.

  15. The spectroscopy of fission fragments

    International Nuclear Information System (INIS)

    Phillips, W.R.

    1998-01-01

    High-resolution measurements on γ rays from fission fragments have provided a rich source of information, unobtainable at the moment in any other way, on the spectroscopy of neutron-rich nuclei. In recent years important data have been obtained on the yrast- and near yrast-structure of neutron-rich fission fragments. We discuss the scope of measurements which can be made on prompt gamma rays from secondary fission fragments, the techniques used in the experiments and some results recently obtained. (author)

  16. On the relict recombination lines

    International Nuclear Information System (INIS)

    Bershtejn, I.N.; Bernshtejn, D.N.; Dubrovich, V.K.

    1977-01-01

    Accurate numerical calculation of intensities and profiles of hydrogen recombination lines of cosmological origin is made. Relie radiation distortions stipulated by recombination quantum release at the irrevocable recombination are investigated. Mean number calculation is given for guantums educing for one irrevocably-lost electron. The account is taken of the educed quantums interraction with matter. The main quantum-matter interrraction mechanisms are considered: electronic blow broadening; free-free, free-bound, bound-bound absorptions Recombination dynamics is investigated depending on hydrogen density and total density of all the matter kinds in the Universe

  17. Bacterial natural transformation by highly fragmented and damaged DNA

    DEFF Research Database (Denmark)

    Overballe-Petersen, Søren; Harms, Klaus; Orlando, Ludovic Antoine Alexandre

    2013-01-01

    for microbes, but not as potential substrate for bacterial evolution. Here, we show that fragmented DNA molecules (≥20 bp) that additionally may contain abasic sites, cross-links, or miscoding lesions are acquired by the environmental bacterium Acinetobacter baylyi through natural transformation. With uptake......DNA molecules are continuously released through decomposition of organic matter and are ubiquitous in most environments. Such DNA becomes fragmented and damaged (often DNA is recognized as nutrient source...... of DNA from a 43,000-y-old woolly mammoth bone, we further demonstrate that such natural transformation events include ancient DNA molecules. We find that the DNA recombination is RecA recombinase independent and is directly linked to DNA replication. We show that the adjacent nucleotide variations...

  18. The dynamics of fragment formation

    International Nuclear Information System (INIS)

    Keane, D.

    1994-09-01

    We demonstrate that in the Quantum Molecular Dynamics model, dynamical correlations can result in the production rate for final state nucleon clusters (and hence composite fragments) being higher than would be expected if statistics and the available phase space were dominant in determining composite formation. An intranuclear cascade or a Boltzmann-Uehling-Uhlenbeck model, combined with a statistical approach in the late stage of the collision to determine composites, provides an equivalent description only under limited conditions of centrality and beam energy. We use data on participant fragment production in Au + Au collisions in the Bevalac's BOS time projection chamber to map out the parameter space where statistical clustering provides a good description. In particular, we investigate momentum-space densities of fragments up to 4 He as a function of fragment transverse momentum, azimuth relative to the reaction plane, rapidity, multiplicity and beam energy

  19. Chemical Production using Fission Fragments

    International Nuclear Information System (INIS)

    Dawson, J. K.; Moseley, F.

    1960-01-01

    Some reactor design considerations of the use of fission recoil fragment energy for the production of chemicals of industrial importance have been discussed previously in a paper given at the Second United Nations International Conference on the Peaceful Uses of Atomic Energy [A/Conf. 15/P.76]. The present paper summarizes more recent progress made on this topic at AERE, Harwell. The range-energy relationship for fission fragments is discussed in the context of the choice of fuel system for a chemical production reactor, and the experimental observation of a variation of chemical effect along the length of a fission fragment track is described for the irradiation of nitrogen-oxygen mixtures. Recent results are given on the effect of fission fragments on carbon monoxide-hydrogen gas mixtures and on water vapour. No system investigated to date shows any outstanding promise for large-scale chemical production. (author) [fr

  20. Robust Object Tracking Using Valid Fragments Selection.

    Science.gov (United States)

    Zheng, Jin; Li, Bo; Tian, Peng; Luo, Gang

    Local features are widely used in visual tracking to improve robustness in cases of partial occlusion, deformation and rotation. This paper proposes a local fragment-based object tracking algorithm. Unlike many existing fragment-based algorithms that allocate the weights to each fragment, this method firstly defines discrimination and uniqueness for local fragment, and builds an automatic pre-selection of useful fragments for tracking. Then, a Harris-SIFT filter is used to choose the current valid fragments, excluding occluded or highly deformed fragments. Based on those valid fragments, fragment-based color histogram provides a structured and effective description for the object. Finally, the object is tracked using a valid fragment template combining the displacement constraint and similarity of each valid fragment. The object template is updated by fusing feature similarity and valid fragments, which is scale-adaptive and robust to partial occlusion. The experimental results show that the proposed algorithm is accurate and robust in challenging scenarios.

  1. Novel immunotoxin: a fusion protein consisting of gelonin and an acetylcholine receptor fragment as a potential immunotherapeutic agent for the treatment of Myasthenia gravis.

    Science.gov (United States)

    Hossann, Martin; Li, Zhuoyu; Shi, Yawei; Kreilinger, Ulrike; Büttner, Jörn; Vogel, Pia D; Yuan, Jingming; Wise, John G; Trommer, Wolfgang E

    2006-03-01

    In continuation of our attempts for antigen-specific suppression of the immune system [I.L. Urbatsch, R.K.M. Sterz, K. Peper, W.E. Trommer, Eur. J. Immunol. 23(1993) 776-779] a novel fusion protein composed of amino acids 4-181 of the extracellular domain of the alpha-subunit of the human muscle acetylcholine receptor and the plant toxin gelonin was expressed in Escherichia coli. The fusion protein formed inclusion bodies but could be solubilized in the presence of guanidinium hydrochloride. After a simple two step purification and refolding procedure, it exhibited a native structure at least in the main immunogenic region as shown by antibodies recognizing a conformational epitope. Half maximal inhibition of translation was achieved at 46 ng/ml as compared to 4.6 ng/ml for native and 2.4 for recombinant gelonin. Its use as therapeutic agent for the treatment of Myasthenia gravis was investigated in an animal model. Female Lewis rats were immunized with complete acetylcholine receptor from the electric ray Torpedo californica and developed thereafter experimental autoimmune M. gravis. Quantitative assessment of the disease was achieved by repetitive stimulation of the Nervus tibialis. Rats showed no symptoms of M. gravis, neither visually nor electrophysiologically after treatment with the fusion protein as determined one and seven weeks after the second application. This approach may also be useful for the therapy of further autoimmune diseases by substituting other autoantigens for the AchR fragment in the fusion protein.

  2. Mapping of the antigenic and allergenic epitopes of Lol p VB using gene fragmentation.

    Science.gov (United States)

    Ong, E K; Knox, R B; Singh, M B

    1995-03-01

    The recombinant proteins of Lol p VA and Lol p VB expressed in E. coli reacted with IgE antibodies from sera of allergic patients and mAbs FMC A7 and PpV1. Cross-absorption analyses using these recombinant proteins showed that Lol p VA and Lol p VB possess both similar and unique IgE binding determinants. Gene fragmentation was utilized to localize the antigenic and allergenic determinants of Lol p VB. When full-length cDNA of Lol p VB was digested into three fragments and expressed as the fusions from the glutathione transferase of pGEX vectors, fragments Met1-Val196 and Asp197-Val339 bound IgE while fragment Met1-Pro96 did not. The data suggest that there are at least two IgE binding determinants in Lol p VB. In addition, only fragment Met1-Val196 reacted with mAb PpV1. The localization of these determinants was further resolved using random fragment expression libraries. The mAb PpV1 determinant was near the N-terminal region of Lol p VB molecule. The IgE binding determinants were distributed in the central region: region I (amino acids 111-195) and II (199-254). These IgE binding determinants are conserved in Lol p VA.

  3. Recent progress on perturbative QCD fragmentation functions

    International Nuclear Information System (INIS)

    Cheung, K.

    1995-05-01

    The recent development of perturbative QCD (PQCD) fragmentation functions has strong impact on quarkonium production. I shall summarize B c meson production based on these PQCD fragmentation functions, as well as, the highlights of some recent activities on applying these PQCD fragmentation functions to explain anomalous J/ψ and ψ' production at the Tevatron. Finally, I discuss a fragmentation model based on the PQCD fragmentation functions for heavy quarks fragmenting into heavy-light mesons

  4. Extracellular DNA metabolism in Haloferax volcanii

    Directory of Open Access Journals (Sweden)

    Scott eChimileski

    2014-02-01

    Full Text Available Extracellular DNA is found in all environments and is a dynamic component of the micro-bial ecosystem. Microbial cells produce and interact with extracellular DNA through many endogenous mechanisms. Extracellular DNA is processed and internalized for use as genetic information and as a major source of macronutrients, and plays several key roles within prokaryotic biofilms. Hypersaline sites contain some of the highest extracellular DNA con-centrations measured in nature–a potential rich source of carbon, nitrogen and phosphorus for halophilic microorganisms. We conducted DNA growth studies for the halophilic archaeon Haloferax volcanii DS2 and show that this model Halobacteriales strain is capable of using exogenous double-stranded DNA as a nutrient. Further experiments with varying medium composition, DNA concentration and DNA types revealed that DNA is utilized primarily as a phosphorus source, that growth on DNA is concentration-dependent and that DNA isolated from different sources is metabolized selectively, with a bias against highly divergent methylated DNA sources. Additionally, fluorescence microscopy experiments showed that labeled DNA colocalized with Haloferax volcanii cells. The gene Hvo_1477 was also identified using a comparative genomic approach as a factor likely to be involved in extracellular DNA processing at the cell surface, and deletion of Hvo_1477 created an H. volcanii strain deficient in its ability to grow on extracellular DNA. Widespread distribution of Hvo_1477 homologs in archaea suggests metabolism of extracellular DNA may be of broad ecological and physiological relevance in this domain of life.

  5. Recombination model and baryon production by pp and πp collisions

    International Nuclear Information System (INIS)

    Takasugi, E.; Tata, X.

    1979-12-01

    The recombination model predictions for baryon production, using modified Kuti-Weisskopf structure functions, are in good agreement with the pp and πp collision data. The indistinguishability of sea quarks naturally accounts for the difference in the p and anti p spectra in the pion fragmentation region. 4 figures, 2 tables

  6. Dissociative recombination of dications

    International Nuclear Information System (INIS)

    Seiersen, K.; Heber, O.; Jensen, M.J.; Safvan, C.P.; Andersen, L. H.

    2003-01-01

    Dissociative recombination (DR) of doubly-charged positive ions has been studied at the heavy ion storage ring ASTRID. Low-energy electrons were scattered on the dication of the N 2 molecule, and the absolute cross section was measured in the energy range of 10 -4 -50 eV. From the measured cross section, a thermal rate coefficient of 5.8x10 -7 cm 3 s -1 at 300 K was extracted. Furthermore, we present new results on the CO 2+ DR rate, and a summary and comparison of measured DR rate coefficients for both the singly and doubly-charged ions of CO, CO 2 , and N 2 is presented

  7. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as w...

  8. Hadron Correlations and Parton Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu

    2007-02-15

    Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.

  9. Auger recombination in sodium iodide

    Science.gov (United States)

    McAllister, Andrew; Kioupakis, Emmanouil; Åberg, Daniel; Schleife, André

    2014-03-01

    Scintillators are an important tool used to detect high energy radiation - both in the interest of national security and in medicine. However, scintillator detectors currently suffer from lower energy resolutions than expected from basic counting statistics. This has been attributed to non-proportional light yield compared to incoming radiation, but the specific mechanism for this non-proportionality has not been identified. Auger recombination is a non-radiative process that could be contributing to the non-proportionality of scintillating materials. Auger recombination comes in two types - direct and phonon-assisted. We have used first-principles calculations to study Auger recombination in sodium iodide, a well characterized scintillating material. Our findings indicate that phonon-assisted Auger recombination is stronger in sodium iodide than direct Auger recombination. Computational resources provided by LLNL and NERSC. Funding provided by NA-22.

  10. A Gateway MultiSite recombination cloning toolkit.

    Directory of Open Access Journals (Sweden)

    Lena K Petersen

    Full Text Available The generation of DNA constructs is often a rate-limiting step in conducting biological experiments. Recombination cloning of single DNA fragments using the Gateway system provided an advance over traditional restriction enzyme cloning due to increases in efficiency and reliability. Here we introduce a series of entry clones and a destination vector for use in two, three, and four fragment Gateway MultiSite recombination cloning whose advantages include increased flexibility and versatility. In contrast to Gateway single-fragment cloning approaches where variations are typically incorporated into model system-specific destination vectors, our Gateway MultiSite cloning strategy incorporates variations in easily generated entry clones that are model system-independent. In particular, we present entry clones containing insertions of GAL4, QF, UAS, QUAS, eGFP, and mCherry, among others, and demonstrate their in vivo functionality in Drosophila by using them to generate expression clones including GAL4 and QF drivers for various trp ion channel family members, UAS and QUAS excitatory and inhibitory light-gated ion channels, and QUAS red and green fluorescent synaptic vesicle markers. We thus establish a starter toolkit of modular Gateway MultiSite entry clones potentially adaptable to any model system. An inventory of entry clones and destination vectors for Gateway MultiSite cloning has also been established (www.gatewaymultisite.org.

  11. Bacterial binding to extracellular proteins - in vitro adhesion

    DEFF Research Database (Denmark)

    Schou, C.; Fiehn, N.-E.

    1999-01-01

    Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis......Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis...

  12. Immunological detection of the type V collagen propeptide fragment, PVCP-1230, in connective tissue remodeling associated with liver fibrosis

    DEFF Research Database (Denmark)

    Vassiliadis, Efstathios; Veidal, Sanne Skovgård; Simonsen, Henrik

    2011-01-01

    AIM: Liver fibrosis involves excessive remodeling and deposition of fibrillar extracellular matrix (ECM) components, which leads to malfunction of the organ, causing significant morbidity and mortality. The aim of this study was to assess whether levels of a type V collagen fragment, the propepti...

  13. Experimental evidence that RNA recombination occurs in the Japanese encephalitis virus

    International Nuclear Information System (INIS)

    Chuang, C.-K.; Chen, W.-J.

    2009-01-01

    Due to the lack of a proofreading function and error-repairing ability of genomic RNA, accumulated mutations are known to be a force driving viral evolution in the genus Flavivirus, including the Japanese encephalitis (JE) virus. Based on sequencing data, RNA recombination was recently postulated to be another factor associated with genomic variations in these viruses. We herein provide experimental evidence to demonstrate the occurrence of RNA recombination in the JE virus using two local pure clones (T1P1-S1 and CJN-S1) respectively derived from the local strains, T1P1 and CJN. Based on results from a restriction fragment length polymorphism (RFLP) assay on the C/preM junction comprising a fragment of 868 nucleotides (nt 10-877), the recombinant progeny virus was primarily formed in BHK-21 cells that had been co-infected with the two clones used in this study. Nine of 20 recombinant forms of the JE virus had a crossover in the nt 123-323 region. Sequencing data derived from these recombinants revealed that no nucleotide deletion or insertion occurred in this region favoring crossovers, indicating that precisely, not aberrantly, homologous recombination was involved. With site-directed mutagenesis, three stem-loop secondary structures were destabilized and re-stabilized in sequence, leading to changes in the frequency of recombination. This suggests that the conformation, not the free energy, of the secondary structure is important in modulating RNA recombination of the virus. It was concluded that because RNA recombination generates genetic diversity in the JE virus, this must be considered particularly in studies of viral evolution, epidemiology, and possible vaccine safety.

  14. A novel complex A/C/G intergenotypic recombinant of hepatitis B virus isolated in southern China.

    Directory of Open Access Journals (Sweden)

    Heling Su

    Full Text Available Hepatitis B virus (HBV genotypes and subgenotypes may vary in geographical distribution and virological features. Previous investigations, including ours, showed that HBV genotypes B and C were respectively predominant in South and North China, while genotypes A and D were infrequently detected and genotype G was not found. In this study, a novel A/C/G intergenotype was identified in patients with chronic HBV infection in Guilin, a city in southern China. Initial phylogenetic analysis based on the S gene suggested the HBV recombinant to be genotype G. However, extended genotyping based on the entire HBV genome indicated it to be an A/C/G intergenotype with a closer relation to genotype C. Breakpoint analysis using the SIMPLOT program revealed that the recombinant had a recombination with a arrangement of genotypes A, G, A and C fragments. Compared with the HBV recombinants harboring one or two genotype G fragments found in Asian countries, this Guilin recombinant was highly similar to the Vietnam (98-99% and Long An recombinants (96-99%, but had a relatively low similarity to the Thailand one (89%. Unlike those with the typical genotype G of HBV, the patients with the Guilin recombinant were seropositive for HBeAg. Moreover, a relatively high HBV DNA viral load (>2 × 10(6 IU/ml was detected in the patients, and the analysis of viral replication capacity showed that the Guilin recombinant strains had a competent replication capacity similar to genotypes B and C strains. These findings can aid in not only the clarification of the phylogenetic origin of the HBV recombinants with the genotype G fragment found in Asian countries, but also the understanding of the virological properties of these complicated HBV recombinants.

  15. Detection of extracellular enzymatic activity in microorganisms ...

    African Journals Online (AJOL)

    Detection of extracellular enzymatic activity in microorganisms isolated from waste vegetable oil contaminated soil using plate methodologies. Eugenia G. Ortiz Lechuga, Isela Quintero Zapata, Katiushka Arévalo Niño ...

  16. Purification and characterization of extracellular amylolytic enzyme ...

    African Journals Online (AJOL)

    DOSS

    2012-10-16

    Oct 16, 2012 ... Available online at http://www.academicjournals.org/AJB ... characterization of extracellular amylases from four ... Somogyi-Nelson's method (Nelson, 1944; Somogyi, 1952). ... The mycelia dry weight of currently studied four.

  17. Neutrophil Extracellular Traps in Ulcerative Colitis

    DEFF Research Database (Denmark)

    Bjerg Bennike, Tue; Carlsen, Thomas Gelsing; Ellingsen, Torkell

    2015-01-01

    microscopy and confocal microscopy. RESULTS: We identified and quantified 5711 different proteins with proteomics. The abundance of the proteins calprotectin and lactotransferrin in the tissue correlated with the degree of tissue inflammation as determined by histology. However, fecal calprotectin did...... not correlate. Forty-six proteins were measured with a statistically significant differences in abundances between the UC colon tissue and controls. Eleven of the proteins with increased abundances in the UC biopsies were associated with neutrophils and neutrophil extracellular traps. The findings were...... validated by microscopy, where an increased abundance of neutrophils and the presence of neutrophil extracellular traps by extracellular DNA present in the UC colon tissue were confirmed. CONCLUSIONS: Neutrophils, induced neutrophil extracellular traps, and several proteins that play a part in innate...

  18. Biochemical and immunological characterization of recombinant allergen Lol p 1.

    Science.gov (United States)

    Tamborini, E; Faccini, S; Lidholm, J; Svensson, M; Brandazza, A; Longhi, R; Groenlund, H; Sidoli, A; Arosio, P

    1997-11-01

    Pollen from perennial rye grass (Lolium perenne), a major cause of type-I allergy worldwide, contains a complex mixture of allergenic proteins among which Lol p 1 is one of the most important. We describe the expression, purification and characterization of a recombinant Lol p 1 overproduced in Escherichia coli. The recombinant allergen, expressed in high yields and purified in milligram amounts, bound to specific IgE antibodies from human sera, induced histamine release from sensitized human basophils, and elicited rabbit antisera that recognize specifically recombinant Lol p 1 and natural Lol p 1 of pollen extract. Recombinant Lol p 1 was used to develop ImmunoCAP assays for analysis of 150 sera that were Radioallergosorbent test positive to L. perenne pollen. In 130 of them (87%) the assay detected a significant level of IgE antibodies to Lol p 1, reaching on average 37% of the level obtained with a test for IgE to the whole grass pollen extract. To map epitopes on Lol p 1, we produced three deletion mutants [des-(116-240)-Lol p 1, des-(1-88)-Lol p 1 and des-(133-189)-Lol p 1], which were efficiently expressed in bacteria. These all showed a strong reactivity with the specific rabbit IgG antibodies, but lacked most or all the allergenic properties of recombinant Lol p 1. A study of the antigenic structure of Lol p 1 was performed using the three deletion mutants and a set of 17-18-residue overlapping synthetic peptides covering the whole allergen sequence. The results indicate that human IgE and rabbit IgG antibodies bind to distinct regions of Lol p 1, and that at least some important IgE epitopes are mainly conformational. The findings suggest that recombinant allergens constitute useful reagents for further development of serological diagnosis of allergy, and that it should be possible to produce immunogenic fragments of allergenic proteins without allergenic properties.

  19. Fragmentation of rotating protostellar clouds

    International Nuclear Information System (INIS)

    Tohline, J.E.

    1980-01-01

    We examine, with a three-dimensional hydrodynamic computer code, the behavior of rotating, isothermal gas clouds as they collapse from Jeans unstable configurations, in order to determine whether they are susceptible to fragmentation during the initial dynamic collapse phase of their evolution. We find that a gas cloud will not fragment unless (a) it begins collapsing from a radius much smaller than the Jeans radius (i.e., the cloud initially encloses many Jeans masses) and (b) irregularities in the cloud's initial structure (specifically, density inhomogeneities) enclose more than one Jeans mass of material. Gas pressure smooths out features that are not initially Jeans unstable while rotation plays no direct role in damping inhomogeneities. Instead of fragmenting, most of our models collapse to a ring configuration (as has been observed by other investigators in two-dimensional, axisymmetric models). The rings appear to be less susceptible to gragmentation from arbitrary perturbations in their structure than has previously been indicated in other work. Because our models, which include the effects of gas pressure, do not readily fragment during a phase of dynamic collapse, we suggest that gas clouds in the galactic disk undergo fragmentation only during quasi-equilibrium phases of their evolution

  20. Three-Body Collision Contributions to Recombination and Collision-Induced Dissociation. II. Kinetics

    International Nuclear Information System (INIS)

    Kendrick, Brian; Pack, Russell T.; Walker, Robert B.

    1998-01-01

    Detailed rate constants for the reaction Ne + Ne + H r e quilibrium Ne 2 + H are generated, and the master equations governing collision-induced dissociation (CID) and recombination are accurately solved numerically. The temperature and pressure dependence are explored. At all pressures, three-body (3B) collisions dominate. The sequential two-body energy-transfer (ET) mechanism gives a rate that is more than a factor of two too small at low pressures and orders of magnitude too small at high pressures. Simpler models are explored; to describe the kinetics they must include direct 3B rates connecting the continuum to the bound states and to the quasibound states. The relevance of the present reaction to more general CID/recombination reactions is discussed. For atomic fragments, the 3B mechanism usually dominates. For diatomic fragments,the 3B and ET mechanism are competitive, and for polyatomic fragments the ET mechanism usually dominates

  1. Simulation of the molecular recombination yield for swift H2+ ions through thin carbon foils

    International Nuclear Information System (INIS)

    Garcia-Molina, Rafael; Barriga-Carrasco, Manuel D.

    2003-01-01

    We have calculated the recombination yield for swift H 2 + molecular ions at the exit of thin amorphous carbon foils, as a function of the dwell time and incident energy. Our results are based on a detailed simulation of the motion through the target of the H 2 + molecular ion (before dissociation takes place) and its constituent fragments (after dissociation), including the following effects: Coulomb repulsion, nuclear scattering, electron capture and loss, as well as self-retarding and wake forces, which provide the relative distance and velocity of the dissociated fragments at the foil exit. The recombination of an H 2 + ion at the exit of the foil depends on the interproton separation and internal energy of the dissociated fragments, and on their probability to capture an electron. Comparison of our results with the available experimental data shows a good agreement

  2. Polarization effects in hadron fragmentation

    International Nuclear Information System (INIS)

    Lednicky, R.

    1984-01-01

    Hadron polarization (spin alignment) and polarization asymmetry are discussed in terms of the quark recombination model with the spin-orbit interaction taken into account. It is shown that predictions of this model are at least in qualitative agreement with experimental data. Various polarization mechanisms in terms of this model and the possibility of their checking are also discussed

  3. The modulation of TRPM7 currents by nafamostat mesilate depends directly upon extracellular concentrations of divalent cations

    Directory of Open Access Journals (Sweden)

    Chen Xuanmao

    2010-12-01

    Full Text Available Abstract Concentrations of extracellular divalent cations (Ca2+ and Mg2+ fall substantially during intensive synaptic transmission as well as during some pathophysiological conditions such as epilepsy and brain ischemia. Here we report that a synthetic serine protease inhibitor, nafamostat mesylate (NM, and several of its analogues, block recombinant TRPM7 currents expressed in HEK293T cells in inverse relationship to the concentration of extracellular divalent cations. Lowering extracellular Ca2+ and Mg2+ also evokes a divalent-sensitive non-selective cation current that is mediated by TRPM7 expression in hippocampal neurons. In cultured hippocampal neurons, NM blocked these TRPM7-mediated currents with an apparent affinity of 27 μM, as well as the paradoxical Ca2+ influx associated with lowering extracellular Ca2+. Unexpectedly, pre-exposure to NM strongly potentiated TRPM7 currents. In the presence of physiological concentrations of extracellular divalent cations, NM activates TRPM7. The stimulating effects of NM on TRPM7 currents are also inversely related to extracellular Ca2+ and Mg2+. DAPI and HSB but not netropsin, blocked and stimulated TRPM7. In contrast, mono-cationic, the metabolites of NM, p-GBA and AN, as well as protease inhibitor leupeptin and gabexate failed to substantially modulate TRPM7. NM thus provides a molecular template for the design of putative modulators of TRPM7.

  4. Sources of extracellular tau and its signaling.

    Science.gov (United States)

    Avila, Jesús; Simón, Diana; Díaz-Hernández, Miguel; Pintor, Jesús; Hernández, Félix

    2014-01-01

    The pathology associated with tau protein, tauopathy, has been recently analyzed in different disorders, leading to the suggestion that intracellular and extracellular tau may itself be the principal agent in the transmission and spreading of tauopathies. Tau pathology is based on an increase in the amount of tau, an increase in phosphorylated tau, and/or an increase in aggregated tau. Indeed, phosphorylated tau protein is the main component of tau aggregates, such as the neurofibrillary tangles present in the brain of Alzheimer's disease patients. It has been suggested that intracellular tau could be toxic to neurons in its phosphorylated and/or aggregated form. However, extracellular tau could also damage neurons and since neuronal death is widespread in Alzheimer's disease, mainly among cholinergic neurons, these cells may represent a possible source of extracellular tau. However, other sources of extracellular tau have been proposed that are independent of cell death. In addition, several ways have been proposed for cells to interact with, transmit, and spread extracellular tau, and to transduce signals mediated by this tau. In this work, we will discuss the role of extracellular tau in the spreading of the tau pathology.

  5. Transcriptome of extracellular vesicles released by hepatocytes.

    Directory of Open Access Journals (Sweden)

    Felix Royo

    Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

  6. In-situ measurements of a highly fragmented comet: WIND STICS Measurements

    Science.gov (United States)

    Lepri, S. T.; Gilbert, J. A.; Gruesbeck, J. R.; Rubin, M.; Gershman, D. J.; Zurbuchen, T.

    2013-12-01

    In this paper, we present in-situ observations of cometary fragments associated with Comet 73P/Schwassmann-Wachmann as it passed very close to the Earth (<0.07AU) in 2006. We examine the spatial distribution of the fragments and the characteristics of the picked up ion velocity distributions. Comet 73P started to disintegrate in 1995, two major components B and C were recovered in 2001, and it burst into more than 36 pieces during its passage near the Earth in 2006. Distant fragmentation members, well-separated from the major identified fragments, passed between the Earth and Sun so that cometary pickup ions and possibly recombined solar wind minor ions convected past the WIND spacecraft in late May 2006. The Suprathermal Ion Composition Spectrometer on WIND provides a rare and detailed 3D glimpse of the newly picked up ion properties.

  7. Memory effects in nuclear fragmentation?

    International Nuclear Information System (INIS)

    Colonna, M.; Di Toro, M.; Guarnera, A.

    1994-01-01

    A general procedure to identify instability regions which lead to multifragmentation events is presented. The dominant mode at the instability point is determined from the knowledge of the mean properties (density and temperature) of the system at that point. For spinodal instabilities the dependence of fragment structures on the dynamical conditions is studied changing the beam energy and the considered equation of state. An important competition between two dynamical effects, expansion of the system and growth of fluctuations, is revealed. It is shown that in heavy-ion central collisions at medium energies memory effects of the configuration formed at the instability time could be observed in the final fragmentation pattern. Some hints towards a fully dynamical picture of fragmentation processes are finally suggested. ((orig.))

  8. Fragmentation properties of 6Li

    International Nuclear Information System (INIS)

    Lovas, R.G.; Kruppa, A.T.; Beck, R.; Dickmann, F.

    1987-01-01

    The α+d and t+τ cluster structure of 6 Li is described in a microscopic α+d cluster model through quantities that enter into the description of cluster fragmentation processes. The states of the separate clusters α, d, t and τ are described as superpositions of Os Slater determinants belonging to different potential size parameters. To describe both the 6 Li and fragment state realistically, nucleon-nucleon forces optimized for the used model state spaces were constructed. The fragmentation properties predicted by them slightly differ from those calculated with some forces of common use provided the latter are modified so as to reproduce the α, d and 6 Li energies. (author) 61 refs.; 9 figs

  9. HFE mRNA expression is responsive to intracellular and extracellular iron loading: short communication.

    Science.gov (United States)

    Mehta, Kosha J; Farnaud, Sebastien; Patel, Vinood B

    2017-10-01

    In liver hepatocytes, the HFE gene regulates cellular and systemic iron homeostasis by modulating cellular iron-uptake and producing the iron-hormone hepcidin in response to systemic iron elevation. However, the mechanism of iron-sensing in hepatocytes remain enigmatic. Therefore, to study the effect of iron on HFE and hepcidin (HAMP) expressions under distinct extracellular and intracellular iron-loading, we examined the effect of holotransferrin treatment (1, 2, 5 and 8 g/L for 6 h) on intracellular iron levels, and mRNA expressions of HFE and HAMP in wild-type HepG2 and previously characterized iron-loaded recombinant-TfR1 HepG2 cells. Gene expression was analyzed by real-time PCR and intracellular iron was measured by ferrozine assay. Data showed that in the wild-type cells, where intracellular iron content remained unchanged, HFE expression remained unaltered at low holotransferrin treatments but was upregulated upon 5 g/L (p HFE and HAMP expressions were elevated only at low 1 g/L treatment (p HFE (p HFE mRNA was independently elevated by extracellular and intracellular iron-excess. Thus, it may be involved in sensing both, extracellular and intracellular iron. Repression of HAMP expression under simultaneous intracellular and extracellular iron-loading resembles non-hereditary iron-excess pathologies.

  10. Sprifermin (rhFGF18) modulates extracellular matrix turnover in cartilage explants ex vivo

    DEFF Research Database (Denmark)

    Reker, Ditte; Kjelgaard-Petersen, Cecilie Freja; Siebuhr, Anne Sofie

    2017-01-01

    Background: Sprifermin (recombinant human fibroblast growth factor 18) is in clinical development as a potential disease-modifying osteoarthritis drug (DMOAD). In vitro studies have shown that cartilage regenerative properties of sprifermin involve chondrocyte proliferation and extracellular matrix...... or placebo at weekly intervals, similar to the dosing regimen used in clinical trials. Pre-culturing with oncostatin M and tumour necrosis factor-a, was also used to induce an inflammatory state before treatment. Metabolic activity was measured using AlamarBlue, and chondrocyte proliferation was visualized...... aggrecanase activity. Results: Sprifermin was able to reach the chondrocytes through the extracellular matrix, as it increased cell proliferation and metabolic activity of explants. ProC2 and CS846 was dose-dependently increased (P

  11. Hands as markers of fragmentation

    Directory of Open Access Journals (Sweden)

    A. Barnard

    2005-07-01

    Full Text Available Margaret Atwood is an internationally read, translated, and critiqued writer whose novels have established her as one of the most esteemed authors in English (McCombs & Palmer, 1991:1. Critical studies of her work deal mainly with notions of identity from psychoanalytical perspectives. This study has identified a gap in current critical studies on Atwood’s works, namely the challenging of textual unity which is paralleled in the challenging of the traditional (single narrative voice. The challenging of textual unity and the single narrative voice brings about the fragmentation of both. This article will focus on the role that hands play as markers of fragmentation in “The Blind Assassin” (2000. In the novel, the writing hand destabilises the narrative voice, since it is not connected to the voice of a single author. If the author of the text – the final signified – is eliminated, the text becomes fragmentary and open, inviting the reader to contribute to the creation of meaning. Hands play a signficant role in foregrounding the narrator’s fragmented identity, and consequently, the fragmentation of the text. We will investigate this concept in the light of Roland Barthes’ notion of the scriptor, whose hand is metaphorically severed from his or her “voice”. Instead of the text being a unified entity, it becomes unstable and it displays the absence of hierarchical textual levels. Based mainly on Barthes’ writings, this article concludes that hands foreground the narrator’s fragmented identity, which is paralleled in the fragmented text.

  12. Arabidopsis GRI is involved in the regulation of cell death induced by extracellular ROS.

    Science.gov (United States)

    Wrzaczek, Michael; Brosché, Mikael; Kollist, Hannes; Kangasjärvi, Jaakko

    2009-03-31

    Reactive oxygen species (ROS) have important functions in plant stress responses and development. In plants, ozone and pathogen infection induce an extracellular oxidative burst that is involved in the regulation of cell death. However, very little is known about how plants can perceive ROS and regulate the initiation and the containment of cell death. We have identified an Arabidopsis thaliana protein, GRIM REAPER (GRI), that is involved in the regulation of cell death induced by extracellular ROS. Plants with an insertion in GRI display an ozone-sensitive phenotype. GRI is an Arabidopsis ortholog of the tobacco flower-specific Stig1 gene. The GRI protein appears to be processed in leaves with a release of an N-terminal fragment of the protein. Infiltration of the N-terminal fragment of the GRI protein into leaves caused cell death in a superoxide- and salicylic acid-dependent manner. Analysis of the extracellular GRI protein yields information on how plants can initiate ROS-induced cell death during stress response and development.

  13. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Baur, G.; Roesel, F.; Trautmann, D.; Shyam, R.

    1983-10-01

    Fragmentation processes in nuclear collisions are reviewed. The main emphasis is put on light ion breakup at nonrelativistic energies. The post- and prior-form DWBA theories are discussed. The post-form DWBA, appropriate for the ''spectator breakup'' describes elastic as well as inelastic breakup modes. This theory can also account for the stripping to unbound states. The theoretical models are compared to typical experimental results to illustrate the various possible mechanisms. It is discussed, how breakup reactions can be used to study high-lying single particle strength in the continuum; how it can yield information about momentum distributions of fragments in the nucleus. (orig.)

  14. Refolding Technologies for Antibody Fragments

    Directory of Open Access Journals (Sweden)

    Tsutomu Arakawa

    2014-05-01

    Full Text Available Refolding is one of the production technologies for pharmaceutical grade antibody fragments. Detergents and denaturants are primarily used to solubilize the insoluble proteins. The solubilized and denatured proteins are refolded by reducing the concentration of the denaturants or detergents. Several refolding technologies have been used for antibody fragments, comprising dilution, dialysis, solid phase solvent exchange and size exclusion chromatography, as reviewed here. Aggregation suppressor or folding-assisting agents, including arginine hydrochloride, ionic liquids and detergents or denaturants at low concentrations, are included in the refolding solvent to enhance refolding yield.

  15. Recombinant constructs of Borrelia burgdorferi

    Energy Technology Data Exchange (ETDEWEB)

    Dattwyler, Raymond J. (Setauket, NY); Gomes-Solecki, Maria J. C. (New York, NY); Luft, Benjamin J. (East Setauket, NY); Dunn, John J.(Bellport, NY)

    2007-02-20

    Novel chimeric nucleic acids, encoding chimeric Borrelia proteins comprising OspC or an antigenic fragment thereof and OspA or an antigenic fragment thereof, are disclosed. Chimeric proteins encoded by the nucleic acid sequences are also disclosed. The chimeric proteins are useful as vaccine immunogens against Lyme borreliosis, as well as for immunodiagnostic reagents.

  16. Fragmentation of atomic clusters: A theoretical study

    International Nuclear Information System (INIS)

    Lopez, M.J.; Jellinek, J.

    1994-01-01

    Collisionless fragmentation of nonrotating model n-atom metal clusters (n=12, 13, and 14) is studied using isoergic molecular-dynamics simulations. Minimum-energy paths for fragmentation are mapped out as functions of the distance between the centers of mass of the fragments. These paths provide information on the fragmentation energies for the different fragmentation channels. Fragmentation patterns (distributions of the fragmentation channel probabilities) and global and channel-specific fragmentation rate constants are computed and analyzed as functions of the internal energy and of the size of the clusters. The trends derived from the dynamics are compared with those obtained using the RRK and TST statistical approaches. The dynamics of the fragmentation process is analyzed in terms of characteristic quantities such as the distance between the centers of mass of the fragments, their relative translational energy, and their interaction energy, all considered as functions of time

  17. Vaccinia virus recombinants expressing chimeric proteins of human immunodeficiency virus and gamma interferon are attenuated for nude mice.

    OpenAIRE

    Giavedoni, L D; Jones, L; Gardner, M B; Gibson, H L; Ng, C T; Barr, P J; Yilma, T

    1992-01-01

    We have developed a method for attenuating vaccinia virus recombinants by expressing a fusion protein of a lymphokine and an immunogen. Chimeric genes were constructed that coded for gamma interferon (IFN-gamma) and structural proteins of the human immunodeficiency virus type 1 (HIV-1). In this study, we describe the biological and immunological properties of vaccinia virus recombinants expressing chimeric genes of murine or human IFN-gamma with glycoprotein gp120, gag, and a fragment of gp41...

  18. Extracellular peptidase hunting for improvement of protein production in plant cells and roots

    Directory of Open Access Journals (Sweden)

    Jérôme eLallemand

    2015-02-01

    Full Text Available Plant-based recombinant protein production systems have gained an extensive interest over the past few years, because of their reduced cost and relative safety. Although the first products are now reaching the market, progress are still needed to improve plant hosts and strategies for biopharming. Targeting recombinant proteins toward the extracellular space offers several advantages in terms of protein folding and purification, but degradation events are observed, due to endogenous peptidases. This paper focuses on the analysis of extracellular proteolytic activities in two production systems: cell cultures and root-secretion (rhizosecretion, in Arabidopsis thaliana and Nicotiana tabacum. Proteolytic activities of extracellular proteomes (secretomes were evaluated in vitro against two substrate proteins: bovine serum albumin (BSA and human serum immunoglobulins G (hIgGs. Both targets were found to be degraded by the secretomes, BSA being more prone to proteolysis than hIgGs. The analysis of the proteolysis pH-dependence showed that target degradation was mainly dependent upon the production system: rhizosecretomes contained more peptidase activity than extracellular medium of cell suspensions, whereas variations due to plant species were smaller. Using class-specific peptidase inhibitors, serine and metallopeptidases were found to be responsible for degradation of both substrates. An in-depth in silico analysis of genomic and transcriptomic data from Arabidopsis was then performed and led to the identification of a limited number of serine and metallo-peptidases that are consistently expressed in both production systems. These peptidases should be prime candidates for further improvement of plant hosts by targeted silencing.

  19. Parton recombination model including resonance production. RL-78-040

    International Nuclear Information System (INIS)

    Roberts, R.G.; Hwa, R.C.; Matsuda, S.

    1978-05-01

    Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references

  20. Parton recombination model including resonance production. RL-78-040

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R. G.; Hwa, R. C.; Matsuda, S.

    1978-05-01

    Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references.

  1. The YARHG domain: an extracellular domain in search of a function.

    Directory of Open Access Journals (Sweden)

    Penny Coggill

    Full Text Available We have identified a new bacterial protein domain that we hypothesise binds to peptidoglycan. This domain is called the YARHG domain after the most highly conserved sequence-segment. The domain is found in the extracellular space and is likely to be composed of four alpha-helices. The domain is found associated with protein kinase domains, suggesting it is associated with signalling in some bacteria. The domain is also found associated with three different families of peptidases. The large number of different domains that are found associated with YARHG suggests that it is a useful functional module that nature has recombined multiple times.

  2. Efficient production of antibody Fab fragment by transient gene expression in insect cells.

    Science.gov (United States)

    Mori, Keita; Hamada, Hirotsugu; Ogawa, Takafumi; Ohmuro-Matsuyama, Yuki; Katsuda, Tomohisa; Yamaji, Hideki

    2017-08-01

    Transient gene expression allows a rapid production of diverse recombinant proteins in early-stage preclinical and clinical developments of biologics. Insect cells have proven to be an excellent platform for the production of functional recombinant proteins. In the present study, the production of an antibody Fab fragment by transient gene expression in lepidopteran insect cells was investigated. The DNA fragments encoding heavy-chain (Hc; Fd fragment) and light-chain (Lc) genes of an Fab fragment were individually cloned into the plasmid vector pIHAneo, which contained the Bombyx mori actin promoter downstream of the B. mori nucleopolyhedrovirus (BmNPV) IE-1 transactivator and the BmNPV HR3 enhancer for high-level expression. Trichoplusia ni BTI-TN-5B1-4 (High Five) cells were co-transfected with the resultant plasmid vectors using linear polyethyleneimine. When the transfection efficiency was evaluated, a plasmid vector encoding an enhanced green fluorescent protein (EGFP) gene was also co-transfected. Transfection and culture conditions were optimized based on both the flow cytometry of the EGFP expression in transfected cells and the yield of the secreted Fab fragments determined by enzyme-linked immunosorbent assay (ELISA). Under optimal conditions, a yield of approximately 120 mg/L of Fab fragments was achieved in 5 days in a shake-flask culture. Transient gene expression in insect cells may offer a promising approach to the high-throughput production of recombinant proteins. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Oxygen-hydrogen recombination system

    International Nuclear Information System (INIS)

    Sato, Shuichiro; Takejima, Masaki.

    1981-01-01

    Purpose: To avoid reduction in the performance of catalyst used for an oxygen-hydrogen recombiner in the off gas processing system of a nuclear reactor. Constitution: A thermometer is provided for the detection of temperature in an oxygen-hydrogen recombiner. A cooling pipe is provided in the recombiner and cooling medium is introduced externally. The cooling medium may be water or air. In accordance with the detection value from the thermometer, ON-OFF control is carried out for a valve to control the flow rate of the cooling medium thereby rendering the temperature in the recombiner to a predetermined value. This can prevent the catalyst from being exposed to high temperature and avoid the reduction in the performance of the catalyst. (Ikeda, J.)

  4. Controlled Release from Recombinant Polymers

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  5. High-level secretion of native recombinant human calreticulin in yeast

    DEFF Research Database (Denmark)

    Čiplys, Evaldas; Žitkus, Eimantas; Gold, Leslie I.

    2015-01-01

    , Saccharomyces cerevisiae and Pichia pastoris. RESULTS: Expression of a full-length human CRT precursor including its native signal sequence resulted in high-level secretion of mature recombinant protein into the culture medium by both S. cerevisiae and P. pastoris. To ensure the structural and functional...... by non-denaturing PAGE. Moreover, limited trypsin digestion yielded identical fragment patterns of calcium-binding recombinant and native CRT suggesting that the yeast-derived CRT was correctly folded. Furthermore, both native and recombinant CRT induced cellular proliferation (MTS assay) and migration...... recombinant CRT protein with yields reaching 75 % of total secreted protein and with production levels of 60 and 200 mg/l from S. cerevisiae and P. pastoris, respectively. Finally, cultivation of P. pastoris in a bioreactor yielded CRT secretion titer to exceed 1.5 g/l of culture medium. CONCLUSIONS: Yeasts...

  6. Hydrogen recombiner development at AECL

    International Nuclear Information System (INIS)

    Dewit, W.A.; Koroll, G.W.; Loesel Sitar, J.; Graham, W.R.C.

    1997-01-01

    Catalytic recombiners have been developed at AECL for the purpose of hydrogen removal in post-accident nuclear containment buildings. The recombiners are based on a particular catalyst designed by AECL which has extraordinary resistance to fouling from water and water vapour and a large thermodynamic range of operation. The catalysts were developed, originally, for the purpose of heavy water manufacturing by way of a catalytic exchange process. Application of these catalyst materials in recombiners for containment applications began in the late 1980's. The first application was a passive recombiner, qualified for use in control of radiolytic hydrogen in the headspace of a pool-type experimental reactor of AECL design in 1988. The passive, or natural convection recombiner concept has continued development to commercial stage for application in power reactor containments. This paper reviews the AECL recombiner development, describes the current model and shows results from tests of full-scale recombiners in the Large Scale Vented Combustion Test Facility at AECL-WL. The AECL recombiner is designed for compactness and ease of engineering into containment. The design is a simple, open-ended rectangular enclosure with catalyst elements arranged inside to promote optimum convective flow driven by heat of recombination at the catalyst surface. Self start, as evidenced by catalyst heating and initiation of flow, is achieved in less than 1% hydrogen, with available oxygen, at room temperature and 100% relative humidity. This low temperature start-up in condensing atmospheres is viewed as the most challenging condition for wet-proofing effectiveness. Cold start-up is a vital performance requirement in containments, such as CANDU, where engineered air-cooling systems are operating and where long-term hydrogen control is required, after containment atmospheres have cooled. Once started, the removal capacity scales linearly with the inlet cross-section area and the partial

  7. Nuclear energy release from fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cheng [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Souza, S.R. [Instituto de Física, Universidade Federal do Rio de Janeiro Cidade Universitária, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Tsang, M.B. [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); National Superconducting Cyclotron Laboratory and Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Feng-Shou, E-mail: fszhang@bnu.edu.cn [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 730000 (China)

    2016-08-15

    It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting {sup 230,232}Th and {sup 235,238}U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for {sup 230,232}Th and {sup 235,238}U are around 0.7–0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

  8. Fission fragment driven neutron source

    Science.gov (United States)

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  9. Developments in SPR Fragment Screening.

    Science.gov (United States)

    Chavanieu, Alain; Pugnière, Martine

    2016-01-01

    Fragment-based approaches have played an increasing role alongside high-throughput screening in drug discovery for 15 years. The label-free biosensor technology based on surface plasmon resonance (SPR) is now sensitive and informative enough to serve during primary screens and validation steps. In this review, the authors discuss the role of SPR in fragment screening. After a brief description of the underlying principles of the technique and main device developments, they evaluate the advantages and adaptations of SPR for fragment-based drug discovery. SPR can also be applied to challenging targets such as membrane receptors and enzymes. The high-level of immobilization of the protein target and its stability are key points for a relevant screening that can be optimized using oriented immobilized proteins and regenerable sensors. Furthermore, to decrease the rate of false negatives, a selectivity test may be performed in parallel on the main target bearing the binding site mutated or blocked with a low-off-rate ligand. Fragment-based drug design, integrated in a rational workflow led by SPR, will thus have a predominant role for the next wave of drug discovery which could be greatly enhanced by new improvements in SPR devices.

  10. Nuclear fragmentation by nucleation approach

    International Nuclear Information System (INIS)

    Chung, K.C.

    1992-01-01

    The nucleation model is used to simulate nuclear fragmentation processes. The critical value of the effective interaction radius is shown to vary linearly with the expansion factor α. The calculated mass and charge distributions are compared with some experimental data. (author)

  11. Neutron multiplicity of fission fragments

    Energy Technology Data Exchange (ETDEWEB)

    Abdelrahman, Y S [Physics department, mu` rah university Al-Karak, (Jordan)

    1995-10-01

    The total average neutron multiplicity of the fission fragments produced by the spontaneous fission of {sup 248} Cm has been measured. This measurement has been done by using a new experimental technique. This technique mainly depends on {gamma}-{gamma} coincidence using a very high resolution high purity germanium (HPGe) detector. 2 figs.

  12. Fragmented nature: consequences for biodiversity

    NARCIS (Netherlands)

    Olff, H.; Ritchie, M.E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species

  13. Fragmented nature : consequences for biodiversity

    NARCIS (Netherlands)

    Olff, Han; Ritchie, Mark E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species

  14. Research of nuclear fragmentation characteristics

    International Nuclear Information System (INIS)

    Richert, J.

    1989-01-01

    Motivations for the study of nuclear fragmentation are presented. Different models and methods which were developed in the past are reviewed, critically discussed and confronted in connection with the experimental information gathered over the past years. Specific aspects related to the onset of the process, its characteristics and the mechanism which governs it are discussed [fr

  15. FRAGMENTED IDENTITIES: THE CULTURAL COLLISION ...

    African Journals Online (AJOL)

    User

    Born in the former French and German colony of. Togo, Komla-Ebri ... of how cultural barriers not only lead to isolation and fragmented identities, but also ..... and, in recreating bits of Italy, in the form of music, cinema and food, absorbs parts of ...

  16. Phthalocyanides sensitized fragmentation of proteins

    Czech Academy of Sciences Publication Activity Database

    Klementová, S.; Tothová, D.; Revaková, R.; Kasková, M.; Wagnerová, Dana Marie

    2001-01-01

    Roč. 5, č. 1 (2001), s. 13-18 ISSN 0972-0626 R&D Projects: GA ČR GA203/96/1322 Institutional research plan: CEZ:AV0Z4032918 Keywords : phthalocyanides * photosensitied fragmentation of proteins Subject RIV: CA - Inorganic Chemistry

  17. Review of Parton Recombination Models

    International Nuclear Information System (INIS)

    Bass, Steffen A

    2006-01-01

    Parton recombination models have been very successful in explaining data taken at RHIC on hadron spectra and emission patterns in Au+Au collisions at transverse momenta above 2 GeV/c, which have exhibited features which could not be understood in the framework of basic perturbative QCD. In this article I will review the current status on recombination models and outline which future challenges need to be addressed by this class of models

  18. Recombinant snake venom prothrombin activators

    OpenAIRE

    L?vgren, Ann

    2012-01-01

    Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need ...

  19. Repair by genetic recombination in bacteria: overview

    International Nuclear Information System (INIS)

    Howard-Flanders, P.

    1975-01-01

    DNA molecules that have been damaged in both strands at the same level are not subject to repair by excision but instead can be repaired through recombination with homologous molecules. Examples of two-strand damage include postreplication gaps opposite pyrimidine dimers, two-strand breaks produced by x-rays, and chemically induced interstrand cross-links. In ultraviolet-irradiated bacteria, and newly synthesized DNA is of length equal to the interdimer spacing. With continued incubation, this low-molecular-weight DNA is joined into high-molecular-weight chains (postreplication repair), a process associated with sister exchanges in bacteria. Recombination is initiated by pyrimidine dimers opposite postreplication gaps and by interstrand cross-links that have been cut by excision enzymes. The free ends at the resulting gaps presumably initiate the exchanges. Postreplication repair in Escherichia coli occurs in recB - and recC - but is greatly slowed in recF - mutants. RecB and recC are the structural genes for exonuclease V, which digests two-stranded DNA by releasing oligonucleotides first from one strand and then from the other. The postreplication sister exchanges in ultraviolet-irradiated bacteria result in the distribution of pyrimidine dimers between parental and daughter strands, indicating that long exchanges involving both strands of each duplex occur. The R1 restriction endonuclease from E. coli has been used to cut the DNA of a bacterial drug-resistance transfer factor with one nuclease-sensitive site, and also DNA from the frog Xenopus enriched for ribosomal 18S and 28S genes. The fragments were annealed with the cut plasmid DNA and ligated, producing a new larger plasmid carrying the eukaryotic rDNA and able to infect and replicate in E. coli

  20. Delayed recombination and cosmic parameters

    International Nuclear Information System (INIS)

    Galli, Silvia; Melchiorri, Alessandro; Bean, Rachel; Silk, Joseph

    2008-01-01

    Current cosmological constraints from cosmic microwave background anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from the cosmic microwave background data. We show that for recent observations of the cosmic microwave background anisotropy, from the Wilkinson microwave anisotropy probe satellite mission (WMAP) 5-year survey and from the arcminute cosmology bolometer array receiver experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, n s , and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z * =1078±11, with uncertainties in the measurement weaker by 1 order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1σ to R=1.734±0.028. From the WMAP5 data we obtain the following constraints on the resonance and ionization sources parameters: ε α i <0.058 at 95% c.l.. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.

  1. Extracellular pH modulates GABAergic neurotransmission in rat hypothalamus.

    Science.gov (United States)

    Chen, Z L; Huang, R Q

    2014-06-20

    Changes in extracellular pH have a modulatory effect on GABAA receptor function. It has been reported that pH sensitivity of the GABA receptor is dependent on subunit composition and GABA concentration. Most of previous investigations focused on GABA-evoked currents, which only reflect the postsynaptic receptors. The physiological relevance of pH modulation of GABAergic neurotransmission is not fully elucidated. In the present studies, we examined the influence of extracellular pH on the GABAA receptor-mediated inhibitory neurotransmission in rat hypothalamic neurons. The inhibitory postsynaptic currents (IPSCs), tonic currents, and the GABA-evoked currents were recorded with whole-cell patch techniques on the hypothalamic slices from Sprague-Dawley rats at 15-26 postnatal days. The amplitude and frequency of spontaneous GABA IPSCs were significantly increased while the external pH was changed from 7.3 to 8.4. In the acidic pH (6.4), the spontaneous GABA IPSCs were reduced in amplitude and frequency. The pH induced changes in miniature GABA IPSCs (mIPSCs) similar to that in spontaneous IPSCs. The pH effect on the postsynaptic GABA receptors was assessed with exogenously applied varying concentrations of GABA. The tonic currents and the currents evoked by sub-saturating concentration of GABA ([GABA]) (10 μM) were inhibited by acidic pH and potentiated by alkaline pH. In contrast, the currents evoked by saturating [GABA] (1mM) were not affected by pH changes. We also investigated the influence of pH buffers and buffering capacity on pH sensitivity of GABAA receptors on human recombinant α1β2γ2 GABAA receptors stably expressed in HEK 293 cells. The pH influence on GABAA receptors was similar in HEPES- and MES-buffered media, and not dependent on protonated buffers, suggesting that the observed pH effect on GABA response is a specific consequence of changes in extracellular protons. Our data suggest that the hydrogen ions suppress the GABAergic neurotransmission

  2. The VERDI fission fragment spectrometer

    Directory of Open Access Journals (Sweden)

    Frégeau M.O.

    2013-12-01

    Full Text Available The VERDI time-of-flight spectrometer is dedicated to measurements of fission product yields and of prompt neutron emission data. Pre-neutron fission-fragment masses will be determined by the double time-of-flight (TOF technique. For this purpose an excellent time resolution is required. The time of flight of the fragments will be measured by electrostatic mirrors located near the target and the time signal coming from silicon detectors located at 50 cm on both sides of the target. This configuration, where the stop detector will provide us simultaneously with the kinetic energy of the fragment and timing information, significantly limits energy straggling in comparison to legacy experimental setup where a thin foil was usually used as a stop detector. In order to improve timing resolution, neutron transmutation doped silicon will be used. The high resistivity homogeneity of this material should significantly improve resolution in comparison to standard silicon detectors. Post-neutron fission fragment masses are obtained form the time-of-flight and the energy signal in the silicon detector. As an intermediary step a diamond detector will also be used as start detector located very close to the target. Previous tests have shown that poly-crystalline chemical vapour deposition (pCVD diamonds provides a coincidence time resolution of 150 ps not allowing complete separation between very low-energy fission fragments, alpha particles and noise. New results from using artificial single-crystal diamonds (sCVD show similar time resolution as from pCVD diamonds but also sufficiently good energy resolution.

  3. Immunogenic properties of Streptococcus agalactiae FbsA fragments.

    Directory of Open Access Journals (Sweden)

    Salvatore Papasergi

    Full Text Available Several species of Gram-positive bacteria can avidly bind soluble and surface-associated fibrinogen (Fng, a property that is considered important in the pathogenesis of human infections. To gain insights into the mechanism by which group B Streptococcus (GBS, a frequent neonatal pathogen, interacts with Fng, we have screened two phage displayed genomic GBS libraries. All of the Fng-binding phage clones contained inserts encoding fragments of FbsA, a protein displaying multiple repeats. Since the functional role of this protein is only partially understood, representative fragments were recombinantly expressed and analyzed for Fng binding affinity and ability to induce immune protection against GBS infection. Maternal immunization with 6pGST, a fragment containing five repeats, significantly protected mouse pups against lethal GBS challenge and these protective effects could be recapitulated by administration of anti-6pGST serum from adult animals. Notably, a monoclonal antibody that was capable of neutralizing Fng binding by 6pGST, but not a non-neutralizing antibody, could significantly protect pups against lethal GBS challenge. These data suggest that FbsA-Fng interaction promotes GBS pathogenesis and that blocking such interaction is a viable strategy to prevent or treat GBS infections.

  4. Extracellular membrane vesicles in blood products-biology and clinical relevance

    Directory of Open Access Journals (Sweden)

    Emilija Krstova Krajnc

    2016-01-01

    Full Text Available Extracellular membrane vesicles are fragments shed from plasma membranes off all cell types that are undergoing apoptosis or are being subjected to various types of stimulation or stress.  Even in the process of programmed cell death (apoptosis, cell fall apart of varying size vesicles. They expose phosphatidylserine (PS on the outer leaflet of their membrane, and bear surface membrane antigens reflecting their cellular origin. Extracellular membrane vesicles have been isolated from many types of biological fluids, including serum, cerebrospinal fluid, urine, saliva, tears and conditioned culture medium. Flow cytometry is one of the many different methodological approaches that have been used to analyze EMVs. The method attempts to characterize the EMVs cellular origin, size, population, number, and structure. EMVs are present and accumulate in blood products (erythrocytes, platelets as well as in fresh frozen plasma during storage. The aim of this review is to highlight the importance of extracellular vesicles as a cell-to-cell communication system and the role in the pathogenesis of different diseases. Special emphasis will be given to the implication of extracellular membrane vesicles in blood products and their clinical relevance. Although our understanding of the role of  EMVs in disease is far from comprehensive, they display promise as biomarkers for different diseases in the future and also as a marker of quality and safety in the quality control of blood products.

  5. Assessment of extracellular dehydration using saliva osmolality.

    Science.gov (United States)

    Ely, Brett R; Cheuvront, Samuel N; Kenefick, Robert W; Spitz, Marissa G; Heavens, Kristen R; Walsh, Neil P; Sawka, Michael N

    2014-01-01

    When substantial solute losses accompany body water an isotonic hypovolemia (extracellular dehydration) results. The potential for using blood or urine to assess extracellular dehydration is generally poor, but saliva is not a simple ultra-filtrate of plasma and the autonomic regulation of salivary gland function suggests the possibility that saliva osmolality (Sosm) may afford detection of extracellular dehydration via the influence of volume-mediated factors. This study aimed to evaluate the assessment of extracellular dehydration using Sosm. In addition, two common saliva collection methods and their effects on Sosm were compared. Blood, urine, and saliva samples were collected in 24 healthy volunteers during paired euhydration and dehydration trials. Furosemide administration and 12 h fluid restriction were used to produce extracellular dehydration. Expectoration and salivette collection methods were compared in a separate group of eight euhydrated volunteers. All comparisons were made using paired t-tests. The diagnostic potential of body fluids was additionally evaluated. Dehydration (3.1 ± 0.5% loss of body mass) decreased PV (-0.49 ± 0.12 L; -15.12 ± 3.94% change), but Sosm changes were marginal ( 0.05). Extracelluar dehydration was not detectable using plasma, urine, or saliva measures. Salivette and expectoration sampling methods produced similar, consistent results for Sosm, suggesting no methodological influence on Sosm.

  6. Extracellular histones in tissue injury and inflammation.

    Science.gov (United States)

    Allam, Ramanjaneyulu; Kumar, Santhosh V R; Darisipudi, Murthy N; Anders, Hans-Joachim

    2014-05-01

    Neutrophil NETosis is an important element of host defense as it catapults chromatin out of the cell to trap bacteria, which then are killed, e.g., by the chromatin's histone component. Also, during sterile inflammation TNF-alpha and other mediators trigger NETosis, which elicits cytotoxic effects on host cells. The same mechanism should apply to other forms of regulated necrosis including pyroptosis, necroptosis, ferroptosis, and cyclophilin D-mediated regulated necrosis. Beyond these toxic effects, extracellular histones also trigger thrombus formation and innate immunity by activating Toll-like receptors and the NLRP3 inflammasome. Thereby, extracellular histones contribute to the microvascular complications of sepsis, major trauma, small vessel vasculitis as well as acute liver, kidney, brain, and lung injury. Finally, histones prevent the degradation of extracellular DNA, which promotes autoimmunization, anti-nuclear antibody formation, and autoimmunity in susceptible individuals. Here, we review the current evidence on the pathogenic role of extracellular histones in disease and discuss how to target extracellular histones to improve disease outcomes.

  7. Percutaneous transhepatic fragmentation of gall stones and extraction of fragments

    International Nuclear Information System (INIS)

    Guenther, R.; Klose, K.; Schmidt, H.D.; Staritz, M.; Mainz Univ.; Mainz Univ.

    1983-01-01

    Attempts at percutaneous removal have been made in 13 patients with solitary and multiple intra- and extra-hepatic biliary duct stones measuring 5 to 30 mm. The stones were fragmented with a Dormia basket and the fragments removed transhepatically. In ten patients the procedure was successful, including one patient with multiple intra-hepatic stones. The procedure can be recommended for cases of calculous obstruction of biliary anastomoses or of stones which could not be removed by endoscopy, or where there is already biliary drainage being carried out, or in patients with a high opertive risk. In two patients, dilatation of the papilla was also carried out, in four patients a stenosis was dilated and in a further two patients, electro-incision of a stenosis was performed. (orig.) [de

  8. Accumulation of linear mitochondrial DNA fragments in the nucleus shortens the chronological life span of yeast.

    Science.gov (United States)

    Cheng, Xin; Ivessa, Andreas S

    2012-10-01

    Translocation of mitochondrial DNA (mtDNA) fragments to the nucleus and insertion of those fragments into nuclear DNA has been observed in several organisms ranging from yeast to plants and mammals. Disruption of specific nuclear genes by de novo insertions of mtDNA fragments has even been linked to the initiation of several human diseases. Recently, we demonstrated that baker's yeast strains with high rates of mtDNA fragments migrating to the nucleus (yme1-1 mutant) exhibit short chronological life spans (CLS). The yeast CLS is determined by the survival of non-dividing cell populations. Here, we show that lack of the non-homologous-end-joining enzyme DNA ligase IV (DNL4) can rescue the short CLS of the yme1-1 mutant. In fission yeast, DNA ligase IV has been shown to be required for the capture of mtDNA fragments during the repair of double-stranded DNA breaks in nuclear DNA. In further analyses using pulse field gel and 2D gel electrophoresis we demonstrate that linear mtDNA fragments with likely nuclear localization accumulate in the yme1-1 mutant. The accumulation of the linear mtDNA fragments in the yme1-1 mutant is suppressed when Dnl4 is absent. We propose that the linear nuclear mtDNA fragments accelerate the aging process in the yme1-1 mutant cells by possibly affecting nuclear processes including DNA replication, recombination, and repair as well as transcription of nuclear genes. We speculate further that Dnl4 protein has besides its function as a ligase also a role in DNA protection. Dnl4 protein may stabilize the linear mtDNA fragments in the nucleus by binding to their physical ends. In the absence of Dnl4 protein the linear fragments are therefore unprotected and possibly degraded by nuclear nucleases. Copyright © 2012 Elsevier GmbH. All rights reserved.

  9. Adhesion of axolemmal fragments to Schwann cells: a signal- and target-specific process closely linked to axolemmal induction of Schwann cell mitosis

    International Nuclear Information System (INIS)

    Sobue, G.; Pleasure, D.

    1985-01-01

    Radioiodinated rat CNS axolemmal fragments adhered to cultured rat Schwann cells by a time-, temperature-, and concentration-dependent process independent of extracellular ionized calcium. Adhesion showed target and signal specificity; axolemmal fragments adhered to endoneurial or dermal fibroblasts to a much lesser extent than to Schwann cells, and plasma membrane fragments from skeletal muscle, erythrocytes, or PNS myelin adhered to Schwann cells to a lesser extent than did axolemmal fragments. Brief trypsinization removed 94 to 97% of bound radioactivity from Schwann cells previously incubated with 125 I-axolemmal fragments for up to 24 hr, indicating that adhesion was largely a surface phenomenon rather than the result of rapid internalization of axolemmal fragments by the Schwann cells. When adhesion was compared to the axolemmal mitogenic response of Schwann cells, the concentration of axolemmal fragments yielding half-maximal adhesion was the same as the concentration producing half-maximal stimulation of Schwann cell mitosis. Trypsin digestion, homogenization, or heating of axolemmal fragments before application to cultured Schwann cells diminished adhesion and axolemmal fragment-induced stimulation of Schwann cell mitosis in a parallel fashion. Whereas adhesion of axolemmal fragments to the surfaces of the cultured Schwann cells reached completion within 4 hr in this assay system, induction of Schwann cell mitosis by the fragments required contact with Schwann cells for a minimum of 6 to 8 hr and reached a maximum when the axolemmal fragments had adhered to the Schwann cells for 24 hr or more

  10. Jet Hadronization via Recombination of Parton Showers in Vacuum and in Medium

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J.; Han, Kyongchol; Ko, Che Ming

    2016-12-15

    We introduce a hadronization algorithm for jet parton showers based on a hybrid approach involving recombination of quarks and fragmentation of strings. The algorithm can be applied to parton showers from a shower Monte Carlo generator at the end of their perturbative evolution. The algorithm forces gluon decays and then evaluates the recombination probabilities for quark-antiquark pairs into mesons and (anti)quark triplets into (anti)baryons. We employ a Wigner phase space formulation based on the assumption of harmonic oscillator wave functions for stable hadrons and resonances. Partons too isolated in phase space to find recombination partners are connected by QCD strings to other quarks. Fragmentation of those remnant strings and the decay of all hadron resonances complete the hadronization process. We find that our model applied to parton showers from the PYTHIA Monte Carlo event generator leads to results very similar to pure Lund string fragmentation. We suggest that our algorithm can be readily generalized to jets embedded in quark-gluon plasma by adding sampled thermal partons from the phase transition hypersurface. The recombination of thermal partons and shower partons leads to an enhancement of pions and protons at intermediate momentum at both RHIC and LHC.

  11. Extracellular matrix metalloproteinase inducer (EMMPRIN) remodels the extracellular matrix through enhancing matrix metalloproteinases (MMPs) and inhibiting tissue inhibitors of MMPs expression in HPV-positive cervical cancer cells.

    Science.gov (United States)

    Xu, Q; Cao, X; Pan, J; Ye, Y; Xie, Y; Ohara, N; Ji, H

    2015-01-01

    PUPOSE OF INVESTIGATION: To study the expression of extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinases (MMPs), and tissue inhibitors of MMP (TIMPs) in uterine cervical cancer cell lines in vitro. EMMPRIN, MMPs, and TIMPs expression were assessed by Western blot and real-time RT-PCR from cervical carcinoma SiHa, HeLa, and C33-A cells. EMMPRIN recombinant significantly increased MMP-2, MMP-9 protein and mRNA expression in SiHa and Hela cells, but not in C33-A cells by Western blot analysis and real-time RT-PCR. EMMPRIN recombinant significantly inhibited TIMP-1 protein and mRNA levels in SiHa and Hela cells, but not in C33-A cells. There was no difference on the TIMP-2 expression in those cells with the treatment of EMMPRIN recombinant. EMMPRIN RNAi decreased MMP-2 and MMP-9 and increased TIMP-1 expression in SiHa and HeLa cells, but not in C33-A cells. There was no change on the expression of TIMP-2 mRNA levels in SiHa, HeLa and C33-A cells transfected with siEMMPRIN. EMMPRIN may induce MMP-2 and MMP-9, and downregulate TIMP-1 in HPV-positive cervical cancer cells in vitro.

  12. Fragments

    Science.gov (United States)

    Moreira, Claudio

    2008-01-01

    This performance autoethnography shows the author's struggle in finding his place, scholarship, voice, and body, into the academic setting. Mixing together memories of his lived experience with sugar cane workers, notes, and leftovers of different fieldworks, plus 6 years of life as grad student at the University of Illinois, the author looks for…

  13. Fragmentation

    Science.gov (United States)

    K.H. Riitters

    2009-01-01

    Effective resource management takes into account the administrative and biophysical settings within which natural resources occur. A setting may be described in many ways; for example, by forest land ownership, by reserved and roadless designation, or by the distribution of human populations in relation to forest (chapter 3). The physical arrangement of forest in a...

  14. Reduced genetic distance and high replication levels increase the RNA recombination rate of hepatitis delta virus.

    Science.gov (United States)

    Lin, Chia-Chi; Yang, Zhi-Wei; Iang, Shan-Bei; Chao, Mei

    2015-01-02

    Hepatitis delta virus (HDV) replication is carried out by host RNA polymerases. Since homologous inter-genotypic RNA recombination is known to occur in HDV, possibly via a replication-dependent process, we hypothesized that the degree of sequence homology and the replication level should be related to the recombination frequency in cells co-expressing two HDV sequences. To confirm this, we separately co-transfected cells with three different pairs of HDV genomic RNAs and analyzed the obtained recombinants by RT-PCR followed by restriction fragment length polymorphism and sequencing analyses. The sequence divergence between the clones ranged from 24% to less than 0.1%, and the difference in replication levels was as high as 100-fold. As expected, significant differences were observed in the recombination frequencies, which ranged from 0.5% to 47.5%. Furthermore, varying the relative amounts of parental RNA altered the dominant recombinant species produced, suggesting that template switching occurs frequently during the synthesis of genomic HDV RNA. Taken together, these data suggest that during the host RNA polymerase-driven RNA recombination of HDV, both inter- and intra-genotypic recombination events are important in shaping the genetic diversity of HDV. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Post-translational modifications of the extracellular matrix are key events in cancer progression: opportunities for biochemical marker development

    DEFF Research Database (Denmark)

    Leeming, D J; Bay-Jensen, A C; Vassiliadis, E

    2011-01-01

    -associated extracellular matrix (ECM) proteins. Furthermore, severe cellular stress and inflammation, caused by cancer, results in generation of PTMs, which will be distributed throughout the ECM. This gives rise to release of protein-specific fragments to the circulation. Here we highlight the importance of remodeling...... of the ECM in cancer and the generation of PTMs, which may be cancer specific and reflect disease progression; thus having potential for biochemical marker development....

  16. Extracellular enzyme kinetics scale with resource availability

    Science.gov (United States)

    Sinsabaugh, Robert L.; Belnap, Jayne; Findlay, Stuart G.; Follstad Shah, Jennifer J.; Hill, Brian H.; Kuehn, Kevin A.; Kuske, Cheryl; Litvak, Marcy E.; Martinez, Noelle G.; Moorhead, Daryl L.; Warnock, Daniel D.

    2014-01-01

    Microbial community metabolism relies on external digestion, mediated by extracellular enzymes that break down complex organic matter into molecules small enough for cells to assimilate. We analyzed the kinetics of 40 extracellular enzymes that mediate the degradation and assimilation of carbon, nitrogen and phosphorus by diverse aquatic and terrestrial microbial communities (1160 cases). Regression analyses were conducted by habitat (aquatic and terrestrial), enzyme class (hydrolases and oxidoreductases) and assay methodology (low affinity and high affinity substrates) to relate potential reaction rates to substrate availability. Across enzyme classes and habitats, the scaling relationships between apparent Vmax and apparent Km followed similar power laws with exponents of 0.44 to 0.67. These exponents, called elasticities, were not statistically distinct from a central value of 0.50, which occurs when the Km of an enzyme equals substrate concentration, a condition optimal for maintenance of steady state. We also conducted an ecosystem scale analysis of ten extracellular hydrolase activities in relation to soil and sediment organic carbon (2,000–5,000 cases/enzyme) that yielded elasticities near 1.0 (0.9 ± 0.2, n = 36). At the metabolomic scale, the elasticity of extracellular enzymatic reactions is the proportionality constant that connects the C:N:P stoichiometries of organic matter and ecoenzymatic activities. At the ecosystem scale, the elasticity of extracellular enzymatic reactions shows that organic matter ultimately limits effective enzyme binding sites. Our findings suggest that one mechanism by which microbial communities maintain homeostasis is regulating extracellular enzyme expression to optimize the short-term responsiveness of substrate acquisition. The analyses also show that, like elemental stoichiometry, the fundamental attributes of enzymatic reactions can be extrapolated from biochemical to community and ecosystem scales.

  17. Energy production using fission fragment rockets

    International Nuclear Information System (INIS)

    Chapline, G.; Matsuda, Y.

    1991-08-01

    Fission fragment rockets are nuclear reactors with a core consisting of thin fibers in a vacuum, and which use magnetic fields to extract the fission fragments from the reactor core. As an alternative to ordinary nuclear reactors, fission fragment rockets would have the following advantages: Approximately twice as efficient if one can directly convert the fission fragment energy into electricity; by reducing the buildup of a fission fragment inventory in the reactor one could avoid a Chernobyl type disaster; and collecting the fission fragments outside the reactor could simplify the waste disposal problem. 6 refs., 4 figs., 2 tabs

  18. MR imaging of intracellular and extracellular deoxyhemoglobin

    International Nuclear Information System (INIS)

    Janick, P.A.; Grossman, R.I.; Asakura, T.

    1989-01-01

    MR imaging was performed on varying concentrations of intracellular and extracellular deoxyhemoglobin as well as varying proportions of deoxyhemoglobin and oxyhemoglobin in vitro at 1.5T with use of standard spin-echo and gradient-refocused spin sequences. This study indicates that susceptibility-induced T2 shortening occurs over a broad range of intracellular deoxyhemoglobin concentrations (maximal at hematocrits between 20% and 45%), reflecting diffusional effects at the cellular level. T2* gradient-echo imaging enhances the observed hypointensity in images of intracellular deoxyhemoglobin. The characteristic MR appearance of acute hemotomas can be modeled by the behavior of intracellular and extracellular deoxyhemoglobin and oxyhemoglobin

  19. Fragmentation of suddenly heated liquids

    International Nuclear Information System (INIS)

    Blink, J.A.

    1985-03-01

    Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate. The x-ray ablated materials must cool and recondense to allow driver beam propagation. The increased surface area caused by fragmentation will enhance the cooling and condensation rates. Relaxation from the suddenly heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The lithium equation of state was used to demonstrate that neutron-induced vaporization uses only a minor fraction of the added heat, much less than would be required to drive the expansion. A 77% expansion of the lithium is required before the rapid vaporization process of spinodal decomposition could begin, and nucleation and growth are too slow to contribute to the expansion

  20. Fragment separator momentum compression schemes

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, Laura, E-mail: bandura@anl.gov [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Erdelyi, Bela [Argonne National Laboratory, Argonne, IL 60439 (United States); Northern Illinois University, DeKalb, IL 60115 (United States); Hausmann, Marc [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Kubo, Toshiyuki [RIKEN Nishina Center, RIKEN, Wako (Japan); Nolen, Jerry [Argonne National Laboratory, Argonne, IL 60439 (United States); Portillo, Mauricio [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Sherrill, Bradley M. [National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  1. Fragment separator momentum compression schemes

    International Nuclear Information System (INIS)

    Bandura, Laura; Erdelyi, Bela; Hausmann, Marc; Kubo, Toshiyuki; Nolen, Jerry; Portillo, Mauricio; Sherrill, Bradley M.

    2011-01-01

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  2. Asymmetry effects in fragment production

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet [Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab (India); Kaur, Varinderjit, E-mail: drvarinderjit@gmail.com [Mata Gujri College, Fatehgarh Sahib-140406, Punjab (India)

    2016-05-06

    The production of different fragments has been studied by taking into account the mass asymmetry of the reaction and employing the momentum dependent interactions. Two different set of asymmetric reactions have been analyzed while keeping At{sub otal} fixed using soft momentum dependent equation of state. Our results indicate that the impact of momentum dependent interactions is different in lighter projectile systems as compared to heavier ones. The comparative analysis of IQMD simulations with the experimental data in case of heavier projectile and lighter target system for the reaction of {sup 197}Au+{sup 27}Al (η = 0.7) at E = 600 MeV/nucleon shows that with the inclusion of MDI we are able, upto some extent, to reproduce the experimental universality of rise and fall of intermediate mass fragments (IMFs).

  3. Fragmentation of percolation cluster perimeters

    Science.gov (United States)

    Debierre, Jean-Marc; Bradley, R. Mark

    1996-05-01

    We introduce a model for the fragmentation of porous random solids under the action of an external agent. In our model, the solid is represented by a bond percolation cluster on the square lattice and bonds are removed only at the external perimeter (or `hull') of the cluster. This model is shown to be related to the self-avoiding walk on the Manhattan lattice and to the disconnection events at a diffusion front. These correspondences are used to predict the leading and the first correction-to-scaling exponents for several quantities defined for hull fragmentation. Our numerical results support these predictions. In addition, the algorithm used to construct the perimeters reveals itself to be a very efficient tool for detecting subtle correlations in the pseudo-random number generator used. We present a quantitative test of two generators which supports recent results reported in more systematic studies.

  4. Fragmented nature: consequences for biodiversity

    OpenAIRE

    Olff, Han; Ritchie, Mark E.

    2002-01-01

    We discuss how fragmentation of resources and habitat operate differently on species diversity across spatial scales, ranging from positive effects on local species coexistence to negative effect on intermediate spatial scales, to again positive effects on large spatial and temporal scales. Species with different size and mobility can be regulated by different processes at the same spatial scale, a principle that may contribute to diversity. Differences in species richness between local commu...

  5. Telomere Restriction Fragment (TRF) Analysis.

    Science.gov (United States)

    Mender, Ilgen; Shay, Jerry W

    2015-11-20

    While telomerase is expressed in ~90% of primary human tumors, most somatic tissue cells except transiently proliferating stem-like cells do not have detectable telomerase activity (Shay and Wright, 1996; Shay and Wright, 2001). Telomeres progressively shorten with each cell division in normal cells, including proliferating stem-like cells, due to the end replication (lagging strand synthesis) problem and other causes such as oxidative damage, therefore all somatic cells have limited cell proliferation capacity (Hayflick limit) (Hayflick and Moorhead, 1961; Olovnikov, 1973). The progressive telomere shortening eventually leads to growth arrest in normal cells, which is known as replicative senescence (Shay et al. , 1991). Once telomerase is activated in cancer cells, telomere length is stabilized by the addition of TTAGGG repeats to the end of chromosomes, thus enabling the limitless continuation of cell division (Shay and Wright, 1996; Shay and Wright, 2001). Therefore, the link between aging and cancer can be partially explained by telomere biology. There are many rapid and convenient methods to study telomere biology such as Telomere Restriction Fragment (TRF), Telomere Repeat Amplification Protocol (TRAP) (Mender and Shay, 2015b) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this protocol paper we describe Telomere Restriction Fragment (TRF) analysis to determine average telomeric length of cells. Telomeric length can be indirectly measured by a technique called Telomere Restriction Fragment analysis (TRF). This technique is a modified Southern blot, which measures the heterogeneous range of telomere lengths in a cell population using the length distribution of the terminal restriction fragments (Harley et al. , 1990; Ouellette et al. , 2000). This method can be used in eukaryotic cells. The description below focuses on the measurement of human cancer cells telomere length. The principle of this method relies on the lack of

  6. Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes

    Directory of Open Access Journals (Sweden)

    Weir Jerry P

    2007-05-01

    Full Text Available Abstract Background Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2 BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. While the BAC mutagenesis procedure is a powerful method to generate HSV-2 recombinants, particularly in the absence of selective marker in eukaryotic culture, the mutagenesis procedure is still difficult and cumbersome. Results Here we describe the incorporation of a phage lambda recombination system into an allele replacement vector. This strategy enables any DNA fragment containing the phage attL recombination sites to be efficiently inserted into the attR sites of the allele replacement vector using phage lambda clonase. We also describe how the incorporation of EGFP into the allele replacement vector can facilitate the selection of the desired cross-over recombinant BACs when the allele replacement reaction is a viral gene deletion. Finally, we incorporate the lambda phage recombination sites directly into an HSV-2 BAC vector for direct recombination of gene cassettes using the phage lambda clonase-driven recombination reaction. Conclusion Together, these improvements to the techniques of HSV BAC mutagenesis will facilitate the construction of recombinant herpes simplex viruses and viral vectors.

  7. PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

    2012-05-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

  8. Meiotic recombination in human oocytes.

    Directory of Open Access Journals (Sweden)

    Edith Y Cheng

    2009-09-01

    Full Text Available Studies of human trisomies indicate a remarkable relationship between abnormal meiotic recombination and subsequent nondisjunction at maternal meiosis I or II. Specifically, failure to recombine or recombination events located either too near to or too far from the centromere have been linked to the origin of human trisomies. It should be possible to identify these abnormal crossover configurations by using immunofluorescence methodology to directly examine the meiotic recombination process in the human female. Accordingly, we initiated studies of crossover-associated proteins (e.g., MLH1 in human fetal oocytes to analyze their number and distribution on nondisjunction-prone human chromosomes and, more generally, to characterize genome-wide levels of recombination in the human female. Our analyses indicate that the number of MLH1 foci is lower than predicted from genetic linkage analysis, but its localization pattern conforms to that expected for a crossover-associated protein. In studies of individual chromosomes, our observations provide evidence for the presence of "vulnerable" crossover configurations in the fetal oocyte, consistent with the idea that these are subsequently translated into nondisjunctional events in the adult oocyte.

  9. Intermittency in 197Au fragmentation

    International Nuclear Information System (INIS)

    Dabrowska, A.; Holynski, R.; Olszewski, A.; Szarska, M.; Wilczynska, B.; Wolter, W.; Wosiek, B.; Cherry, M.L.; Deines-Jones, P.; Jones, W.V.; Sengupta, K.; Wefel, B.

    1995-07-01

    The concept of factorial moments was applied to an analysis of the dynamical fluctuations in the charge distributions of the fragments emitted from gold nuclei with energies 10.6 and < 1.0 GeV/n interacting with emulsion nuclei. Clear evidence for intermittent fluctuations has been found in an analysis using all the particles released from the gold projectile, with a stronger effect observed below 1 GeV/n than at 10.6 GeV/n. For the full data sets, however, the intermittency effect was found to be very sensitive to the singly charged particles, and neglecting these particles strongly reduces the intermittency signal. When the analysis is restricted to the multiply charged fragments, an intermittency effect is revealed only for multifragmentation events, although one that is enhanced as compared to the analysis of all, singly and multiply charged, particles. The properties of the anomalous fractal dimensions suggest a sequential decay mechanism, rather than the existence of possible critical behaviour in the process of nuclear fragmentation. The likely influence of the charge conservation effects and the finite size of decaying systems on the observed intermittency signals was pointed out. (author). 37 refs, 9 figs, 5 tabs

  10. Residual Fragments after Percutaneous Nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Kaan Özdedeli

    2012-09-01

    Full Text Available Clinically insignificant residual fragments (CIRFs are described as asymptomatic, noninfectious and nonobstructive stone fragments (≤4 mm remaining in the urinary system after the last session of any intervention (ESWL, URS or PCNL for urinary stones. Their insignificance is questionable since CIRFs could eventually become significant, as their presence may result in recurrent stone growth and they may cause pain and infection due to urinary obstruction. They may become the source of persistent infections and a significant portion of the patients will have a stone-related event, requiring auxilliary interventions. CT seems to be the ultimate choice of assessment. Although there is no concensus about the timing, recent data suggests that it may be performed one month after the procedure. However, imaging can be done in the immediate postoperative period, if there are no tubes blurring the assessment. There is some evidence indicating that selective medical therapy may have an impact on decreasing stone formation rates. Retrograde intrarenal surgery, with its minimally invasive nature, seems to be the best way to deal with residual fragments.

  11. Fragmentation measurement using image processing

    Directory of Open Access Journals (Sweden)

    Farhang Sereshki

    2016-12-01

    Full Text Available In this research, first of all, the existing problems in fragmentation measurement are reviewed for the sake of its fast and reliable evaluation. Then, the available methods used for evaluation of blast results are mentioned. The produced errors especially in recognizing the rock fragments in computer-aided methods, and also, the importance of determination of their sizes in the image analysis methods are described. After reviewing the previous work done, an algorithm is proposed for the automated determination of rock particles’ boundary in the Matlab software. This method can determinate automatically the particles boundary in the minimum time. The results of proposed method are compared with those of Split Desktop and GoldSize software in two automated and manual states. Comparing the curves extracted from different methods reveals that the proposed approach is accurately applicable in measuring the size distribution of laboratory samples, while the manual determination of boundaries in the conventional software is very time-consuming, and the results of automated netting of fragments are very different with the real value due to the error in separation of the objects.

  12. Generation and Nuclear Translocation of Sumoylated Transmembrane Fragment of Cell Adhesion Molecule L1

    Science.gov (United States)

    Lutz, David; Wolters-Eisfeld, Gerrit; Joshi, Gunjan; Djogo, Nevena; Jakovcevski, Igor; Schachner, Melitta; Kleene, Ralf

    2012-01-01

    The functions of the cell adhesion molecule L1 in the developing and adult nervous system are triggered by homophilic and heterophilic interactions that stimulate signal transductions that activate cellular responses. Here, we show that stimulation of signaling by function-triggering L1 antibodies or L1-Fc leads to serine protease-dependent cleavage of full-length L1 at the plasma membrane and generation of a sumoylated transmembrane 70-kDa fragment comprising the intracellular and transmembrane domains and part of the extracellular domain. The 70-kDa transmembrane fragment is transported from the plasma membrane to a late endosomal compartment, released from endosomal membranes into the cytoplasm, and transferred from there into the nucleus by a pathway that depends on importin and chromatin-modifying protein 1. Mutation of the sumoylation site at Lys1172 or of the nuclear localization signal at Lys1147 abolished L1-stimulated generation or nuclear import of the 70-kDa fragment, respectively. Nuclear import of the 70-kDa fragment may activate cellular responses in parallel or in association with phosphorylation-dependent signaling pathways. Alterations in the levels of the 70-kDa fragment during development and in the adult after spinal cord injury or in a mouse model of Alzheimer disease suggest that this fragment is functionally implicated in development, regeneration, neurodegeneration, tumorigenesis, and possibly synaptic plasticity in the mature nervous system. PMID:22431726

  13. Nonreplicative RNA Recombination of an Animal Plus-Strand RNA Virus in the Absence of Efficient Translation of Viral Proteins.

    Science.gov (United States)

    Kleine Büning, Maximiliane; Meyer, Denise; Austermann-Busch, Sophia; Roman-Sosa, Gleyder; Rümenapf, Tillmann; Becher, Paul

    2017-04-01

    RNA recombination is a major driving force for the evolution of RNA viruses and is significantly implicated in the adaptation of viruses to new hosts, changes of virulence, as well as in the emergence of new viruses including drug-resistant and escape mutants. However, the molecular details of recombination in animal RNA viruses are only poorly understood. In order to determine whether viral RNA recombination depends on translation of viral proteins, a nonreplicative recombination system was established which is based on cotransfection of cells with synthetic bovine viral diarrhea virus (family Flaviviridae) RNA genome fragments either lacking the internal ribosome entry site required for cap-independent translation or lacking almost the complete polyprotein coding region. The emergence of a number of recombinant viruses demonstrated that IRES-mediated translation of viral proteins is dispensable for efficient recombination and suggests that RNA recombination can occur in the absence of viral proteins. Analyses of 58 independently emerged viruses led to the detection of recombinant genomes with duplications, deletions and insertions in the 5' terminal region of the open reading frame, leading to enlarged core fusion proteins detectable by Western blot analysis. This demonstrates a remarkable flexibility of the pestivirus core protein. Further experiments with capped and uncapped genome fragments containing a luciferase gene for monitoring the level of protein translation revealed that even a ∼1,000-fold enhancement of translation of viral proteins did not increase the frequency of RNA recombination. Taken together, this study highlights that nonreplicative RNA recombination does not require translation of viral proteins. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Nonreplicative RNA Recombination of an Animal Plus-Strand RNA Virus in the Absence of Efficient Translation of Viral Proteins

    Science.gov (United States)

    Kleine Büning, Maximiliane; Meyer, Denise; Austermann-Busch, Sophia; Roman-Sosa, Gleyder; Rümenapf, Tillmann

    2017-01-01

    RNA recombination is a major driving force for the evolution of RNA viruses and is significantly implicated in the adaptation of viruses to new hosts, changes of virulence, as well as in the emergence of new viruses including drug-resistant and escape mutants. However, the molecular details of recombination in animal RNA viruses are only poorly understood. In order to determine whether viral RNA recombination depends on translation of viral proteins, a nonreplicative recombination system was established which is based on cotransfection of cells with synthetic bovine viral diarrhea virus (family Flaviviridae) RNA genome fragments either lacking the internal ribosome entry site required for cap-independent translation or lacking almost the complete polyprotein coding region. The emergence of a number of recombinant viruses demonstrated that IRES-mediated translation of viral proteins is dispensable for efficient recombination and suggests that RNA recombination can occur in the absence of viral proteins. Analyses of 58 independently emerged viruses led to the detection of recombinant genomes with duplications, deletions and insertions in the 5′ terminal region of the open reading frame, leading to enlarged core fusion proteins detectable by Western blot analysis. This demonstrates a remarkable flexibility of the pestivirus core protein. Further experiments with capped and uncapped genome fragments containing a luciferase gene for monitoring the level of protein translation revealed that even a ∼1,000-fold enhancement of translation of viral proteins did not increase the frequency of RNA recombination. Taken together, this study highlights that nonreplicative RNA recombination does not require translation of viral proteins. PMID:28338950

  15. Geometrical scaling of jet fragmentation photons

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Koichi, E-mail: koichi.hattori@riken.jp [RIKEN BNL Research Center, Brookhaven National Laboratory, Upton NY 11973 (United States); Theoretical Research Division, Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); McLerran, Larry, E-mail: mclerran@bnl.gov [RIKEN BNL Research Center, Brookhaven National Laboratory, Upton NY 11973 (United States); Physics Dept., Bdg. 510A, Brookhaven National Laboratory, Upton, NY-11973 (United States); Physics Dept., China Central Normal University, Wuhan (China); Schenke, Björn, E-mail: bschenke@bnl.gov [Physics Dept., Bdg. 510A, Brookhaven National Laboratory, Upton, NY-11973 (United States)

    2016-12-15

    We discuss jet fragmentation photons in ultrarelativistic heavy-ion collisions. We argue that, if the jet distribution satisfies geometrical scaling and an anisotropic spectrum, these properties are transferred to photons during the jet fragmentation.

  16. Identification of a heterologous cellulase and its N-terminus that can guide recombinant proteins out of Escherichia coli.

    Science.gov (United States)

    Gao, Dongfang; Wang, Shengjun; Li, Haoran; Yu, Huili; Qi, Qingsheng

    2015-04-10

    The Gram-negative bacterium Escherichia coli has been widely used as a cell factory for the production of proteins and specialty chemicals because it is the best characterized host with many available expression and regulation systems. However, recombinant proteins produced in Escherichia coli are generally intracellular and often found in the form of inclusion bodies. Extracellular production of proteins is advantageous compared with intracellular production because extracellular proteins can be purified more easily and can avoid protease attack, which results in higher product quality. In this study, we found a catalytic domain of a cellulase (Cel-CD) and its N-terminus can be employed as carriers for extracellular production of recombinant proteins. In this report, we identified the catalytic domain of a cellulase (Cel-CD) from Bacillus sp. that can be secreted into the medium from recombinant E. coli BL21 (DE3) in large quantities without its native signal peptide. By subcellular location analysis, we proved that the secretion was a two-step process and the N-terminal sequence of the full length Cel-CD played a crucial function in secretion. Both the Cel-CD and its N-terminal sequence can serve as carriers for efficient extracellular production of select target proteins. Fusion of heterologous proteins with N20 from Cel-CD can carry the target proteins out of the cells with a concentration from 101 to 691 mg/L in flask cultivation. The extracellular recombinant proteins with a relative high purity. The results suggested that this system has a potential application in plant biomass conversion and industrial production of enzymes and therapeutic proteins.

  17. KLK6 proteolysis is implicated in the turnover and uptake of extracellular alpha-synuclein species.

    Science.gov (United States)

    Pampalakis, Georgios; Sykioti, Vasia-Samantha; Ximerakis, Methodios; Stefanakou-Kalakou, Ioanna; Melki, Ronald; Vekrellis, Kostas; Sotiropoulou, Georgia

    2017-02-28

    KLK6 is a serine protease highly expressed in the nervous system. In synucleinopathies, including Parkinson disease, the levels of KLK6 inversely correlate with α-synuclein in CSF. Recently, we suggested that recombinant KLK6 mediates the degradation of extracellular α-synuclein directly and via a proteolytic cascade that involves unidentified metalloproteinase(s). Here, we show that recombinant and naturally secreted KLK6 can readily cleave α-synuclein fibrils that have the potential for cell-to-cell propagation in "a prion-like mechanism". Importantly, KLK6-deficient primary cortical neurons have increased ability for α-synuclein fibril uptake. We also demonstrate that KLK6 activates proMMP2, which in turn can cleave α-synuclein. The repertoire of proteases activated by KLK6 in a neuronal environment was analyzed by degradomic profiling, which also identified ADAMTS19 and showed that KLK6 has a limited number of substrates indicating specific biological functions such as the regulation of α-synuclein turnover. We generated adenoviral vectors for KLK6 delivery and demonstrated that the levels of extracellular α-synuclein can be reduced by neuronally secreted KLK6. Our findings open the possibility to exploit KLK6 as a novel therapeutic target for Parkinson disease and other synucleinopathies.

  18. Electric hydrogen recombiner special tests

    International Nuclear Information System (INIS)

    Wilson, J.F.

    1975-12-01

    Westinghouse has produced an electric hydrogen recombiner to control hydrogen levels in reactor containments following a postulated loss-of-coolant accident. The recombiner underwent extensive testing for NRC qualification (see WCAP 7709-L and Supplements 1, 2, 3, 4). As a result, WCAP 7709-L and Supplements 1, 2, 3, and 4 have been accepted by the NRC for reference in applications not committed to IEEE-323-1974. Supplement 5 and the next supplement will demonstrate conformance to IEEE-323-1974. This supplement describes additional tests, beyond those necessary to qualify the system, which will be referenced in supplement 6. Each test has demonstrated a considerable margin of safety over required performance. Concurrently, the test results increased the fund of technical information on the electric hydrogen recombiner

  19. Optimization of extracellular catalase production from Aspergillus ...

    African Journals Online (AJOL)

    The studies of the effect of each variable and the establishment of a correlation between the response of enzyme activity and variables revealed that the link is a multiple linear regression form. The optimization was carried out through a simplex algorithm. The amount of extracellular catalase produced by the strain in the ...

  20. Managing Brain Extracellular K(+) during Neuronal Activity

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; Stoica, Anca; MacAulay, Nanna

    2016-01-01

    characteristics required to fulfill their distinct physiological roles in clearance of K(+) from the extracellular space in the face of neuronal activity. Understanding the nature, impact and effects of the various Na(+)/K(+)-ATPase isoform combinations in K(+) management in the central nervous system might...... understanding of the pathological events occurring during disease....

  1. Extracellular vesicles: fundamentals and clinical relevance

    Directory of Open Access Journals (Sweden)

    Wael Nassar

    2015-01-01

    Full Text Available All types of cells of eukaryotic organisms produce and release small nanovesicles into their extracellular environment. Early studies have described these vesicles as ′garbage bags′ only to remove obsolete cellular molecules. Valadi and colleagues, in 2007, were the first to discover the capability of circulating extracellular vesicles (EVs to horizontally transfer functioning gene information between cells. These extracellular vesicles express components responsible for angiogenesis promotion, stromal remodeling, chemoresistance, genetic exchange, and signaling pathway activation through growth factor/receptor transfer. EVs represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, signaling proteins, and RNAs. They contribute to physiology and pathology, and they have a myriad of potential clinical applications in health and disease. Moreover, vesicles can pass the blood-brain barrier and may perhaps even be considered as naturally occurring liposomes. These cell-derived EVs not only represent a central mediator of the disease microenvironment, but their presence in the peripheral circulation may serve as a surrogate for disease biopsies, enabling real-time diagnosis and disease monitoring. In this review, we′ll be addressing the characteristics of different types of extracellular EVs, as well as their clinical relevance and potential as diagnostic markers, and also define therapeutic options.

  2. Extracellular space diffusion and extrasynaptic transmission

    Czech Academy of Sciences Publication Activity Database

    Vargová, Lýdia; Syková, Eva

    2008-01-01

    Roč. 57, Suppl.3 (2008), S89-S99 ISSN 0862-8408 R&D Projects: GA MŠk 1M0538; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50390512 Keywords : Diffusion * Extracellular volume * Tortuosity Subject RIV: FH - Neurology Impact factor: 1.653, year: 2008

  3. Integrins and extracellular matrix in mechanotransduction

    Directory of Open Access Journals (Sweden)

    Ramage L

    2011-12-01

    Full Text Available Lindsay RamageQueen’s Medical Research Institute, University of Edinburgh, Edinburgh, UKAbstract: Integrins are a family of cell surface receptors which mediate cell–matrix and cell–cell adhesions. Among other functions they provide an important mechanical link between the cells external and intracellular environments while the adhesions that they form also have critical roles in cellular signal-transduction. Cell–matrix contacts occur at zones in the cell surface where adhesion receptors cluster and when activated the receptors bind to ligands in the extracellular matrix. The extracellular matrix surrounds the cells of tissues and forms the structural support of tissue which is particularly important in connective tissues. Cells attach to the extracellular matrix through specific cell-surface receptors and molecules including integrins and transmembrane proteoglycans. Integrins work alongside other proteins such as cadherins, immunoglobulin superfamily cell adhesion molecules, selectins, and syndecans to mediate cell–cell and cell–matrix interactions and communication. Activation of adhesion receptors triggers the formation of matrix contacts in which bound matrix components, adhesion receptors, and associated intracellular cytoskeletal and signaling molecules form large functional, localized multiprotein complexes. Cell–matrix contacts are important in a variety of different cell and tissue properties including embryonic development, inflammatory responses, wound healing, and adult tissue homeostasis. This review summarizes the roles and functions of integrins and extracellular matrix proteins in mechanotransduction.Keywords: ligand binding, α subunit, ß subunit, focal adhesion, cell differentiation, mechanical loading, cell–matrix interaction

  4. Interaction of acetamiprid with extracellular polymeric substances ...

    African Journals Online (AJOL)

    Extracellular polymeric substances (EPS) are important components of activated sludge and it plays an important role in removing pollutants. The interaction between EPS and organic pollutants is still little known. In the present study, the interaction of soluble/bound EPS with acetamiprid, a neonicotinoid insecticide, was ...

  5. Optimization of extracellular catalase production from Aspergillus ...

    African Journals Online (AJOL)

    aghomotsegin

    extracellular catalase produced by the strain in the optimized medium was about four times higher than ... celial and unicellular fungi in synthetic media (Kurakov et .... covering the appropriate range and the broad calibration kit ... This optimization allowed us to define new cultural con- ..... Ann. New York Academy Sci.

  6. Production of extracellular aspartic protease in submerged ...

    African Journals Online (AJOL)

    Fungal milk-clotting enzymes have gained value as bovine Chymosin substitutes in the cheese industry. In this work, the effects of culture conditions on the production of extracellular milk clotting enzymes from Mucor mucedo DSM 809 in submerged fermentation were studied. The maximum activity was observed after 48 h ...

  7. Extracellular matrix and tissue engineering applications

    NARCIS (Netherlands)

    Fernandes, H.A.M.; Moroni, Lorenzo; van Blitterswijk, Clemens; de Boer, Jan

    2009-01-01

    The extracellular matrix is a key component during regeneration and maintenance of tissues and organs, and it therefore plays a critical role in successful tissue engineering as well. Tissue engineers should recognise that engineering technology can be deduced from natural repair processes. Due to

  8. Evolution equations for extended dihadron fragmentation functions

    International Nuclear Information System (INIS)

    Ceccopieri, F.A.; Bacchetta, A.

    2007-03-01

    We consider dihadron fragmentation functions, describing the fragmentation of a parton in two unpolarized hadrons, and in particular extended dihadron fragmentation functions, explicitly dependent on the invariant mass, M h , of the hadron pair. We first rederive the known results on M h -integrated functions using Jet Calculus techniques, and then we present the evolution equations for extended dihadron fragmentation functions. Our results are relevant for the analysis of experimental measurements of two-particle-inclusive processes at different energies. (orig.)

  9. Polarization and alignment of nucleus fission fragments

    International Nuclear Information System (INIS)

    Barabanov, A.L.; Grechukhin, D.P.

    1987-01-01

    Correlation of fragment orientation with orientation axis of fissile nucleus and with n-vector f vector of fragment divergence is considered. Estimations of polarization and alignment of fission fragments of preliminarily oriented nuclei in correlation (with n-vector f recording) and integral (with n-vector f averaging) experiments were conducted. It is shown that high sensitivity of polarization and fragment alignment to the character of nucleus movement at the stage of descent from barrier to rupture point exists

  10. Glucose-free fructose production from Jerusalem artichoke using a recombinant inulinase-secreting Saccharomyces cerevisiae strain.

    Science.gov (United States)

    Yu, Jing; Jiang, Jiaxi; Ji, Wangming; Li, Yuyang; Liu, Jianping

    2011-01-01

    Using inulin (polyfructose) obtained from Jerusalen artichokes, we have produced fructose free of residual glucose using a recombinant inulinase-secreting strain of Saccharomyces cerevisiae in a one-step fermentation of Jerusalem artichoke tubers. For producing fructose from inulin, a recombinant inulinase-producing Saccharomyce cerevisiae strain was constructed with a deficiency in fructose uptake by disruption of two hexokinase genes hxk1 and hxk2. The inulinase gene introduced into S. cerevisiae was cloned from Kluyveromyces cicerisporus. Extracellular inulinase activity of the recombinant hxk-mutated S. cerevisiae strain reached 31 U ml(-1) after 96 h growth. When grown in a medium containing Jerusalem artichoke tubers as the sole component without any additives, the recombinant yeast accumulated fructose up to 9.2% (w/v) in the fermentation broth with only 0.1% (w/v) glucose left after 24 h.

  11. Conjugation of gold nanoparticles and recombinant human endostatin modulates vascular normalization via interruption of anterior gradient 2-mediated angiogenesis.

    Science.gov (United States)

    Pan, Fan; Yang, Wende; Li, Wei; Yang, Xiao-Yan; Liu, Shuhao; Li, Xin; Zhao, Xiaoxu; Ding, Hui; Qin, Li; Pan, Yunlong

    2017-07-01

    Several studies have revealed the potential of normalizing tumor vessels in anti-angiogenic treatment. Recombinant human endostatin is an anti-angiogenic agent which has been applied in clinical tumor treatment. Our previous research indicated that gold nanoparticles could be a nanoparticle carrier for recombinant human endostatin delivery. The recombinant human endostatin-gold nanoparticle conjugates normalized vessels, which improved chemotherapy. However, the mechanism of recombinant human endostatin-gold nanoparticle-induced vascular normalization has not been explored. Anterior gradient 2 has been reported to be over-expressed in many malignant tumors and involved in tumor angiogenesis. To date, the precise efficacy of recombinant human endostatin-gold nanoparticles on anterior gradient 2-mediated angiogenesis or anterior gradient 2-related signaling cohort remained unknown. In this study, we aimed to explore whether recombinant human endostatin-gold nanoparticles could normalize vessels in metastatic colorectal cancer xenografts, and we further elucidated whether recombinant human endostatin-gold nanoparticles could interrupt anterior gradient 2-induced angiogenesis. In vivo, it was indicated that recombinant human endostatin-gold nanoparticles increased pericyte expression while inhibit vascular endothelial growth factor receptor 2 and anterior gradient 2 expression in metastatic colorectal cancer xenografts. In vitro, we uncovered that recombinant human endostatin-gold nanoparticles reduced cell migration and tube formation induced by anterior gradient 2 in human umbilical vein endothelial cells. Treatment with recombinant human endostatin-gold nanoparticles attenuated anterior gradient 2-mediated activation of MMP2, cMyc, VE-cadherin, phosphorylation of p38, and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in human umbilical vein endothelial cells. Our findings demonstrated recombinant human endostatin-gold nanoparticles might normalize

  12. Photon-hadron fragmentation: theoretical situation

    International Nuclear Information System (INIS)

    Peschanski, R.

    1983-07-01

    Using a selection of new experimental results models of hadronic fragmentation and their phenomenological comparison are presented. Indeed a convenient theory of hadronic fragmentation -for instance based on Q.C.D.- does not exist: low transverse momentum fragmentation involves the badly known hadronic long-range forces. Models should clarify the situation in the prospect of an eventual future theory

  13. Scaling and critical behaviour in nuclear fragmentation

    International Nuclear Information System (INIS)

    Campi, X.

    1990-09-01

    These notes review recent results on nuclear fragmentation. An analysis of experimental data from exclusive experiments is made in the framework of modern theories of fragmentation of finite size objects. We discuss the existence of a critical regime of fragmentation and the relevance of scaling and finite size scaling

  14. Remarks about the hypothesis of limiting fragmentation

    International Nuclear Information System (INIS)

    Chou, T.T.; Yang, C.N.

    1987-01-01

    Remarks are made about the hypothesis of limiting fragmentation. In particular, the concept of favored and disfavored fragment distribution is introduced. Also, a sum rule is proved leading to a useful quantity called energy-fragmentation fraction. (author). 11 refs, 1 fig., 2 tabs

  15. Quark fragmentation in e+e- collisions

    International Nuclear Information System (INIS)

    Oddone, P.

    1984-12-01

    This brief review of new results in quark and gluon fragmentation observed in e + e - collisions concentrates mostly on PEP results and, within PEP, mostly on TPC results. The new PETRA results have been reported at this conference by M. Davier. It is restricted to results on light quark fragmentation since the results on heavy quark fragmentation have been reported by J. Chapman

  16. Self-organized criticality in fragmenting

    DEFF Research Database (Denmark)

    Oddershede, L.; Dimon, P.; Bohr, J.

    1993-01-01

    The measured mass distributions of fragments from 26 fractured objects of gypsum, soap, stearic paraffin, and potato show evidence of obeying scaling laws; this suggests the possibility of self-organized criticality in fragmenting. The probability of finding a fragment scales inversely to a power...

  17. Neighbouring charge fragmentations in low energy fission

    International Nuclear Information System (INIS)

    Montoya, M.

    1986-10-01

    Shell and odd-even effects in fission have been largely studied until now. The structure in fragment mass, charge and kinetic energy distributions of fragments were interpreted as shell and even-odd effects. In this paper, we want to show that the discret change of fragment charge symmetry should produce also structures in those distribution. 19 refs

  18. Intraluminal proteome and peptidome of human urinary extracellular vesicles.

    Science.gov (United States)

    Liu, Xinyu; Chinello, Clizia; Musante, Luca; Cazzaniga, Marta; Tataruch, Dorota; Calzaferri, Giulio; James Smith, Andrew; De Sio, Gabriele; Magni, Fulvio; Zou, Hequn; Holthofer, Harry

    2015-06-01

    Urinary extracellular vesicles (UEVs) are a novel source for disease biomarker discovery. However, Tamm-Horsfall protein (THP) is still a challenge for proteomic analysis since it can inhibit detection of low-abundance proteins. Here, we introduce a new approach that does not involve an ultracentrifugation step to enrich vesicles and that reduces the amount of THP to manageable levels. UEVs were dialyzed and ultrafiltered after reduction and alkylation. The retained fraction was digested with trypsin to reduce the remaining THP and incubated with deoxycholate (DOC). The internal peptidome and internal proteome were analyzed by LC-ESI-MS. A total of 942 different proteins and 3115 unique endogenous peptide fragments deriving from 973 different protein isoforms were identified. Around 82% of the key endosomal sorting complex required for transport components of UEVs generation could be detected from the intraluminal content. Our UEVs preparation protocol provides a simplified way to investigate the intraluminal proteome and peptidome, in particular the subpopulation of UEVs of the trypsin-resistant class of exosomes (positive for tumor susceptibility gene101) and eliminates the majority of interfering proteins such as THP. This method allows the possibility to study endoproteome and endopeptidome of UEVs, thus greatly facilitating biomarker discovery. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Cartilage extracellular matrix as a biomaterial for cartilage regeneration.

    Science.gov (United States)

    Kiyotake, Emi A; Beck, Emily C; Detamore, Michael S

    2016-11-01

    The extracellular matrix (ECM) of various tissues possesses the model characteristics that biomaterials for tissue engineering strive to mimic; however, owing to the intricate hierarchical nature of the ECM, it has yet to be fully characterized and synthetically fabricated. Cartilage repair remains a challenge because the intrinsic properties that enable its durability and long-lasting function also impede regeneration. In the last decade, cartilage ECM has emerged as a promising biomaterial for regenerating cartilage, partly because of its potentially chondroinductive nature. As this research area of cartilage matrix-based biomaterials emerged, investigators facing similar challenges consequently developed convergent solutions in constructing robust and bioactive scaffolds. This review discusses the challenges, emerging trends, and future directions of cartilage ECM scaffolds, including a comparison between two different forms of cartilage matrix: decellularized cartilage (DCC) and devitalized cartilage (DVC). To overcome the low permeability of cartilage matrix, physical fragmentation greatly enhances decellularization, although the process itself may reduce the chondroinductivity of fabricated scaffolds. The less complex processing of a scaffold composed of DVC, which has not been decellularized, appears to have translational advantages and potential chondroinductive and mechanical advantages over DCC, without detrimental immunogenicity, to ultimately enhance cartilage repair in a clinically relevant way. © 2016 New York Academy of Sciences.

  20. Generalized extracellular molecule sensor platform for programming cellular behavior.

    Science.gov (United States)

    Scheller, Leo; Strittmatter, Tobias; Fuchs, David; Bojar, Daniel; Fussenegger, Martin

    2018-04-23

    Strategies for expanding the sensor space of designer receptors are urgently needed to tailor cell-based therapies to respond to any type of medically relevant molecules. Here, we describe a universal approach to designing receptor scaffolds that enables antibody-specific molecular input to activate JAK/STAT, MAPK, PLCG or PI3K/Akt signaling rewired to transgene expression driven by synthetic promoters. To demonstrate its scope, we equipped the GEMS (generalized extracellular molecule sensor) platform with antibody fragments targeting a synthetic azo dye, nicotine, a peptide tag and the PSA (prostate-specific antigen) biomarker, thereby covering inputs ranging from small molecules to proteins. These four GEMS devices provided robust signaling and transgene expression with high signal-to-noise ratios in response to their specific ligands. The sensitivity of the nicotine- and PSA-specific GEMS devices matched the clinically relevant concentration ranges, and PSA-specific GEMS were able to detect pathological PSA levels in the serum of patients diagnosed with prostate cancer.

  1. The quark-recombination model and correlations between hard and soft hadronic processes

    International Nuclear Information System (INIS)

    Ranft, J.

    1978-07-01

    Proceeding from the fact that quark and gluon recombination models make definite predictions for correlations between hard and soft processes, the following experiments are briefly discussed: (i) correlations between deep inelastic antineutrino-proton scattering and particle production in the proton fragmentation region, (ii) correlations between massive lepton pairs and particles produced in the fragmentation regions, and (iii) correlations between large transverse momentum particles and leading protons. In order to present the large transverse momentum - leading proton correlation, a divided correlation function similar to that used for studying short-range correlations of low transverse momentum particles is defined

  2. An Engineered Survival-Selection Assay for Extracellular Protein Expression Uncovers Hypersecretory Phenotypes in Escherichia coli.

    Science.gov (United States)

    Natarajan, Aravind; Haitjema, Charles H; Lee, Robert; Boock, Jason T; DeLisa, Matthew P

    2017-05-19

    The extracellular expression of recombinant proteins using laboratory strains of Escherichia coli is now routinely achieved using naturally secreted substrates, such as YebF or the osmotically inducible protein Y (OsmY), as carrier molecules. However, secretion efficiency through these pathways needs to be improved for most synthetic biology and metabolic engineering applications. To address this challenge, we developed a generalizable survival-based selection strategy that effectively couples extracellular protein secretion to antibiotic resistance and enables facile isolation of rare mutants from very large populations (i.e., 10 10-12 clones) based simply on cell growth. Using this strategy in the context of the YebF pathway, a comprehensive library of E. coli single-gene knockout mutants was screened and several gain-of-function mutations were isolated that increased the efficiency of extracellular expression without compromising the integrity of the outer membrane. We anticipate that this user-friendly strategy could be leveraged to better understand the YebF pathway and other secretory mechanisms-enabling the exploration of protein secretion in pathogenesis as well as the creation of designer E. coli strains with greatly expanded secretomes-all without the need for expensive exogenous reagents, assay instruments, or robotic automation.

  3. The mannosylated extracellular domain of Her2/neu produced in P. pastoris induces protective antitumor immunity

    International Nuclear Information System (INIS)

    Dimitriadis, Alexios; Gontinou, Chrysanthi; Baxevanis, Constantin N; Mamalaki, Avgi

    2009-01-01

    Her2/neu is overexpressed in various human cancers of epithelial origin and is associated with increased metastatic potential and poor prognosis. Several attempts have been made using the extracellular domain of Her2/neu (ECD/Her2) as a prophylactic vaccine in mice with no success in tumor prevention. The extracellular domain of Her2/neu (ECD/Her2) was expressed in yeast P. pastoris, in a soluble highly mannosylated form. The immune response of the immunization with this recombinant ECD/Her2 was analyzed using immunoprecipitation and western blot analysis, proliferation and cytotoxicity assays as well as specific tumor growth assays. Mannosylated ECD/Her2 elicited a humoral response with HER2/neu specific antibodies in vaccinated mice, which were able to reduce the proliferation rate of cancer cells in vitro. Moreover, it elicited a cellular response with Her2/neu-specific CTL capable of lysing tumor cells, in vitro. When immunized Balb/c and HHD mice were challenged with Her2/neu-overexpressing cells, tumor growth was inhibited. Here we report on the efficacy of the extracellular domain of human Her2/neu produced in yeast P. pastoris, which confers mannosylation of the protein, to act as a potent anti-tumor vaccine against Her2/neu overexpressing tumors. Specific cellular and humoral responses were observed as well as efficacy

  4. [Involvement of distal fragment of chromosome 13 in the regulation of sensitivity to ethanol in mice].

    Science.gov (United States)

    Bazovkina, D V; Kulikov, A V

    2015-01-01

    The role of the fragment 57-65 cM of mouse chromosome 13 was studied in the regulation of ethanol action on locomotor activity, anxiety and sensitivity to hypnotic and hypothermic effects of ethanol. We used male mice of recombinant lines AKR/J and AKR.CBA-D13Mit76C, differing only in this fragment. After acute administration of ethanol only AKR mice showed the increase in the length of traveled distance in the open-field test (p mice demonstrated the increase the time spent in the center of open-field arena (p mice. The results suggest the involvement of the distal fragment 57-65 cM of chromosome 13 in the mechanisms of ethanol action in mice.

  5. Fission fragment excited laser system

    Science.gov (United States)

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  6. Fragment emission from modestly excited nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Y. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Souza, R.T. de [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Chen, S.L. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Cornell, E.W. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Davin, B. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Fox, D. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Hamilton, T.M. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Mcdonald, K. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility; Tsang, M.B. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Glasmacher, T. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Dinius, J. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Gelbke, C.K. [Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Handzy, D.O. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry]|[Indiana Univ., Bloomington, IN (United States). Cyclotron Facility]|[Michigan State Univ., East Lansing, MI (United States). National Superconducting Cyclotron Lab.; Hsi, W.C.

    1996-07-08

    Fragment emission patterns occurring in nuclear systems of modest excitation are studied. Exclusive measurement of fragment emission in {sup 14}N+{sup 197}Au reactions at E/A=100, 130 and 156 MeV allows selection of central collisions where a single source dominates the decay. Low threshold measurement of IMF emission for these events allows investigation of the influence of detector threshold effects. The time scale of fragment emission is deduced using fragment-fragment velocity correlations. Comparisons are made to the predictions of a statistical decay model. (orig.).

  7. Velocity distribution of fragments of catastrophic impacts

    Science.gov (United States)

    Takagi, Yasuhiko; Kato, Manabu; Mizutani, Hitoshi

    1992-01-01

    Three dimensional velocities of fragments produced by laboratory impact experiments were measured for basalts and pyrophyllites. The velocity distribution of fragments obtained shows that the velocity range of the major fragments is rather narrow, at most within a factor of 3 and that no clear dependence of velocity on the fragment mass is observed. The NonDimensional Impact Stress (NDIS) defined by Mizutani et al. (1990) is found to be an appropriate scaling parameter to describe the overall fragment velocity as well as the antipodal velocity.

  8. Assessment of small RNA sorting into different extracellular fractions revealed by high-throughput sequencing of breast cell lines

    Science.gov (United States)

    Tosar, Juan Pablo; Gámbaro, Fabiana; Sanguinetti, Julia; Bonilla, Braulio; Witwer, Kenneth W.; Cayota, Alfonso

    2015-01-01

    Intercellular communication can be mediated by extracellular small regulatory RNAs (sRNAs). Circulating sRNAs are being intensively studied for their promising use as minimally invasive disease biomarkers. To date, most attention is centered on exosomes and microRNAs as the vectors and the secreted species, respectively. However, this field would benefit from an increased understanding of the plethora of sRNAs secreted by different cell types in different extracellular fractions. It is still not clear if specific sRNAs are selected for secretion, or if sRNA secretion is mostly passive. We sequenced the intracellular sRNA content (19–60 nt) of breast epithelial cell lines (MCF-7 and MCF-10A) and compared it with extracellular fractions enriched in microvesicles, exosomes and ribonucleoprotein complexes. Our results are consistent with a non-selective secretion model for most microRNAs, although a few showed secretion patterns consistent with preferential secretion. On the contrary, 5′ tRNA halves and 5′ RNA Y4-derived fragments of 31–33 were greatly and significantly enriched in the extracellular space (even in non-mammary cell lines), where tRNA halves were detected as part of ∼45 kDa ribonucleoprotein complexes. Overall, we show that different sRNA families have characteristic secretion patterns and open the question of the role of these sRNAs in the extracellular space. PMID:25940616

  9. Production and recombination of gluons

    International Nuclear Information System (INIS)

    Temiraliev, A.T.

    2006-01-01

    Full text: Nonlinear Markov process of parton production has been considered. The Kolmogorov equation is applied for the evolution equation based on the approximation of independent gluons production in every decay act. We introduced a 'crossing' parameter and used the combination relations to obtain nonlinear recombination equation for the evolution of gluon structure function. (author)

  10. Recombinator of hydrogen and oxygen

    International Nuclear Information System (INIS)

    Stejskal, J.; Klein, O.; Scholtz, G.; Schmidt, P.; Olaussson, A.

    1976-01-01

    Improvements are proposed for the well known reactors for the catalytic recombination of hydrogen and oxygen, which should permit this being used in contiuous operation in nuclear reactors (BWRs). The improvements concern the geometric arrangement of gas-inlet and -outlet pipes, the inclination of the axis of the catalyst container and the introduction of remote operation. (UWI) [de

  11. Improving recombinant protein purification yield

    Science.gov (United States)

    Production of adequate amounts of recombinant proteins is essential for antibody production, biochemical activity study, and structural determination during the post-genomic era. It’s technologically challenging and a limiting factor for tung oil research because analytical reagents such as high qua...

  12. Recombination in hepatitis C virus.

    Science.gov (United States)

    González-Candelas, Fernando; López-Labrador, F Xavier; Bracho, María Alma

    2011-10-01

    Hepatitis C virus (HCV) is a Flavivirus with a positive-sense, single-stranded RNA genome of about 9,600 nucleotides. It is a major cause of liver disease, infecting almost 200 million people all over the world. Similarly to most RNA viruses, HCV displays very high levels of genetic diversity which have been used to differentiate six major genotypes and about 80 subtypes. Although the different genotypes and subtypes share basic biological and pathogenic features they differ in clinical outcomes, response to treatment and epidemiology. The first HCV recombinant strain, in which different genome segments derived from parentals of different genotypes, was described in St. Petersburg (Russia) in 2002. Since then, there have been only a few more than a dozen reports including descriptions of HCV recombinants at all levels: between genotypes, between subtypes of the same genotype and even between strains of the same subtype. Here, we review the literature considering the reasons underlying the difficulties for unequivocally establishing recombination in this virus along with the analytical methods necessary to do it. Finally, we analyze the potential consequences, especially in clinical practice, of HCV recombination in light of the coming new therapeutic approaches against this virus.

  13. Models of fragmentation with composite power laws

    Science.gov (United States)

    Tavassoli, Z.; Rodgers, G. J.

    1999-06-01

    Some models for binary fragmentation are introduced in which a time dependent transition size produces two regions of fragment sizes above and below the transition size. In the first model we assume a fixed rate of fragmentation for the largest fragment and two different rates of fragmentation in the two regions of sizes above and below the transition size. The model is solved exactly in the long time limit to reveal stable time-invariant solutions for the fragment size and mass distributions. These solutions exhibit composite power law behaviours; power laws with two different exponents for fragments in smaller and larger regions. A special case of the model with no fragmentation in the smaller size region is also examined. Another model is also introduced which have three regions of fragment sizes with different rates of fragmentation. The similarities between the stable distributions in our models and composite power law distributions from experimental work on shock fragmentation of long thin glass rods and thick clay plates are discussed.

  14. Extraction of 16th Century Calender Fragments

    DEFF Research Database (Denmark)

    Holck, Jakob Povl; Etheridge, Christian

    at the Cultural Heritage & Archaeometric Research Team, SDU. Upon finding medieval manuscript fragments in the university library’s special collections, scholars at the Centre for Medieval Literature are consulted. In most cases, digital pictures of the finds will circulate in the international community...... fragments may require extensive use of Big Data and other forms of analysis in order to be identified. Usually, the university library prefers not to remove the fragments from their “fragment carriers”. In order to read fragments that are only partially visible or invisible, x-ray technology may be deployed...... of medieval scholars. Thousands of 16th and 17th Century books are stored in the University Library of Southern Denmark. One out of five of these books is expected to contain medieval manuscript fragments or fragments of rare prints, e.g. incunabula....

  15. The formation of planets by disc fragmentation

    Directory of Open Access Journals (Sweden)

    Stamatellos Dimitris

    2013-04-01

    Full Text Available I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar discs may fragment, if they are massive enough and can cool fast enough, but most of the objects that form by fragmentation are brown dwarfs. It may be possible that planets also form, if the mass growth of a proto-fragment is stopped (e.g. if this fragment is ejected from the disc, or suppressed and even reversed (e.g by tidal stripping. I will discuss if it is possible to distinguish whether a planet has formed by disc fragmentation or core accretion, and mention of a few examples of observed exoplanets that are suggestive of formation by disc fragmentation.

  16. Reframing landscape fragmentation's effects on ecosystem services.

    Science.gov (United States)

    Mitchell, Matthew G E; Suarez-Castro, Andrés F; Martinez-Harms, Maria; Maron, Martine; McAlpine, Clive; Gaston, Kevin J; Johansen, Kasper; Rhodes, Jonathan R

    2015-04-01

    Landscape structure and fragmentation have important effects on ecosystem services, with a common assumption being that fragmentation reduces service provision. This is based on fragmentation's expected effects on ecosystem service supply, but ignores how fragmentation influences the flow of services to people. Here we develop a new conceptual framework that explicitly considers the links between landscape fragmentation, the supply of services, and the flow of services to people. We argue that fragmentation's effects on ecosystem service flow can be positive or negative, and use our framework to construct testable hypotheses about the effects of fragmentation on final ecosystem service provision. Empirical efforts to apply and test this framework are critical to improving landscape management for multiple ecosystem services. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Extracellular nucleotide derivatives protect cardiomyctes against hypoxic stress

    DEFF Research Database (Denmark)

    Golan, O; Issan, Y; Isak, A

    2011-01-01

    assures cardioprotection. Treatment with extracellular nucleotides, or with tri/di-phosphate, administered under normoxic conditions or during hypoxic conditions, led to a decrease in reactive oxygen species production. CONCLUSIONS: Extracellular tri/di-phosphates are apparently the molecule responsible...

  18. Involvement of extracellular matrix constituents in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, Andre; Bissell, Mina J

    1995-06-01

    It has recently been established that the extracellular matrix is required for normal functional differentiation of mammary epithelia not only in culture, but also in vivo. The mechanisms by which extracellular matrix affects differentiation, as well as the nature of extracellular matrix constituents which have major impacts on mammary gland function, have only now begun to be dissected. The intricate variety of extracellular matrix-mediated events and the remarkable degree of plasticity of extracellular matrix structure and composition at virtually all times during ontogeny, make such studies difficult. Similarly, during carcinogenesis, the extracellular matrix undergoes gross alterations, the consequences of which are not yet precisely understood. Nevertheless, an increasing amount of data suggests that the extracellular matrix and extracellular matrix-receptors might participate in the control of most, if not all, of the successive stages of breast tumors, from appearance to progression and metastasis.

  19. Structures of endothiapepsin-fragment complexes from crystallographic fragment screening using a novel, diverse and affordable 96-compound fragment library.

    Science.gov (United States)

    Huschmann, Franziska U; Linnik, Janina; Sparta, Karine; Ühlein, Monika; Wang, Xiaojie; Metz, Alexander; Schiebel, Johannes; Heine, Andreas; Klebe, Gerhard; Weiss, Manfred S; Mueller, Uwe

    2016-05-01

    Crystallographic screening of the binding of small organic compounds (termed fragments) to proteins is increasingly important for medicinal chemistry-oriented drug discovery. To enable such experiments in a widespread manner, an affordable 96-compound library has been assembled for fragment screening in both academia and industry. The library is selected from already existing protein-ligand structures and is characterized by a broad ligand diversity, including buffer ingredients, carbohydrates, nucleotides, amino acids, peptide-like fragments and various drug-like organic compounds. When applied to the model protease endothiapepsin in a crystallographic screening experiment, a hit rate of nearly 10% was obtained. In comparison to other fragment libraries and considering that no pre-screening was performed, this hit rate is remarkably high. This demonstrates the general suitability of the selected compounds for an initial fragment-screening campaign. The library composition, experimental considerations and time requirements for a complete crystallographic fragment-screening campaign are discussed as well as the nine fully refined obtained endothiapepsin-fragment structures. While most of the fragments bind close to the catalytic centre of endothiapepsin in poses that have been observed previously, two fragments address new sites on the protein surface. ITC measurements show that the fragments bind to endothiapepsin with millimolar affinity.

  20. Structures of endothiapepsin–fragment complexes from crystallographic fragment screening using a novel, diverse and affordable 96-compound fragment library

    Science.gov (United States)

    Huschmann, Franziska U.; Linnik, Janina; Sparta, Karine; Ühlein, Monika; Wang, Xiaojie; Metz, Alexander; Schiebel, Johannes; Heine, Andreas; Klebe, Gerhard; Weiss, Manfred S.; Mueller, Uwe

    2016-01-01

    Crystallographic screening of the binding of small organic compounds (termed fragments) to proteins is increasingly important for medicinal chemistry-oriented drug discovery. To enable such experiments in a widespread manner, an affordable 96-compound library has been assembled for fragment screening in both academia and industry. The library is selected from already existing protein–ligand structures and is characterized by a broad ligand diversity, including buffer ingredients, carbohydrates, nucleotides, amino acids, peptide-like fragments and various drug-like organic compounds. When applied to the model protease endothiapepsin in a crystallographic screening experiment, a hit rate of nearly 10% was obtained. In comparison to other fragment libraries and considering that no pre-screening was performed, this hit rate is remarkably high. This demonstrates the general suitability of the selected compounds for an initial fragment-screening campaign. The library composition, experimental considerations and time requirements for a complete crystallographic fragment-screening campaign are discussed as well as the nine fully refined obtained endothiapepsin–fragment structures. While most of the fragments bind close to the catalytic centre of endothiapepsin in poses that have been observed previously, two fragments address new sites on the protein surface. ITC measurements show that the fragments bind to endothiapepsin with millimolar affinity. PMID:27139825

  1. Revisiting the Lund Fragmentation Model

    International Nuclear Information System (INIS)

    Andersson, B.; Nilsson, A.

    1992-10-01

    We present a new method to implement the Lund Model fragmentation distributions for multi-gluon situations. The method of Sjoestrand, implemented in the well-known Monte Carlo simulation program JETSET, is robust and direct and according to his findings there are no observable differences between different ways to implement his scheme. His method can be described as a space-time method because the breakup proper time plays a major role. The method described in this paper is built on energy-momentum space methods. We make use of the χ-curve, which is defined directly from the energy momentum vectors of the partons. We have shown that the χ-curve describes the breakup properties and the final state energy momentum distributions in the mean. We present a method to find the variations around the χ-curve, which also implements the basic Lund Model fragmentation distributions (the area-law and the corresponding iterative cascade). We find differences when comparing the corresponding Monte Carlo implementation REVJET to the JETSET distributions inside the gluon jets. (au)

  2. Live recombinant BHV/BRSV vaccine

    NARCIS (Netherlands)

    Keil, G.M.; Rijsewijk, F.A.M.

    1998-01-01

    The present invention refers to synthetic Bovine Respiratory Syncytium virus genes. Also the invention relates to live attenuated Bovine Herpesvirus recombinants carrying such synthetic genes. Furthermore, the invention relates to vaccines based on these live attenuated recombinants, for the

  3. Hadron production at RHIC: recombination of quarks

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-01-01

    We discuss quark recombination applied to the hadronization of a quark gluon plasma. It has been shown that the quark recombination model can explain essential features of hadron production measured in high energy heavy ion collisions.

  4. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Affinity purification of recombinant human plasminogen activator from ... Screening antibody was performed using rhPA milk in an ELISA-elution assay. ... useful for purifying other tPA mutants or other novel recombinant milkderived proteins.

  5. Graded Recombination Layers for Multijunction Photovoltaics

    KAUST Repository

    Koleilat, Ghada I.; Wang, Xihua; Sargent, Edward H.

    2012-01-01

    it to achieve multicolor and spectrally tunable behavior. In series-connected current-matched multijunction devices, the recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron

  6. Recombinant innovation and endogenous technological transitions

    NARCIS (Netherlands)

    Frenken, K.; Izquierdo, L.R.; Zeppini, P.

    2012-01-01

    We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create "short-cuts" which reduce

  7. A new tagging system for production of recombinant proteins in Drosophila S2 cells using the third domain of the urokinase receptor

    DEFF Research Database (Denmark)

    Gårdsvoll, Henrik; Hansen, Line V; Jørgensen, Thomas J D

    2007-01-01

    The use of protein fusion tag technology greatly facilitates detection, expression and purification of recombinant proteins, and the demands for new and more effective systems are therefore expanding. We have used a soluble truncated form of the third domain of the urokinase receptor...... as a convenient C-terminal fusion partner for various recombinant extracellular human proteins used in basic cancer research. The stability of this cystein-rich domain, which structure adopts a three-finger fold, provides an important asset for its applicability as a fusion tag for expression of recombinant...... chromatography procedure using the immobilized anti-uPAR monoclonal antibody R2. An optional enterokinase cleavage site is included between the various recombinant proteins and the linker region of the tag, which enables generation of highly pure preparations of tag-free recombinant proteins. Using this system...

  8. Method for in vitro recombination

    Science.gov (United States)

    Gibson, Daniel Glenn; Smith, Hamilton O

    2013-05-07

    The present invention relates to an in vitro method, using isolated protein reagents, for joining two double-stranded (ds) DNA molecules of interest, wherein the distal region of the first DNA molecule and the proximal region of the second DNA molecule share a region of sequence identity. The method allows the joining of a number of DNA fragments, in a predetermined order and orientation, without the use of restriction enzymes. It can be used, e.g., to join synthetically produced sub-fragments of a gene or genome of interest.

  9. Population inversion in recombining hydrogen plasma

    International Nuclear Information System (INIS)

    Furukane, Utaro; Yokota, Toshiaki; Oda, Toshiatsu.

    1978-11-01

    The collisional-radiative model is applied to a recombining hydrogen plasma in order to investigate the plasma condition in which the population inversion between the energy levels of hydrogen can be generated. The population inversion is expected in a plasma where the three body recombination has a large contribution to the recombining processes and the effective recombination rate is beyond a certain value for a given electron density and temperature. Calculated results are presented in figures and tables. (author)

  10. Regulation of homologous recombination in eukaryotes

    OpenAIRE

    Heyer, Wolf-Dietrich; Ehmsen, Kirk T.; Liu, Jie

    2010-01-01

    Homologous recombination is required for accurate chromosome segregation during the first meiotic division and constitutes a key repair and tolerance pathway for complex DNA damage including DNA double-stranded breaks, interstrand crosslinks, and DNA gaps. In addition, recombination and replication are inextricably linked, as recombination recovers stalled and broken replication forks enabling the evolution of larger genomes/replicons. Defects in recombination lead to genomic instability and ...

  11. Apoptotic Tumor Cell-Derived Extracellular Vesicles as Important Regulators of the Onco-Regenerative Niche

    Directory of Open Access Journals (Sweden)

    Christopher D. Gregory

    2018-05-01

    Full Text Available Cells undergoing apoptosis produce heterogeneous populations of membrane delimited extracellular vesicles (Apo-EVs which vary not only in size—from tens of nanometers to several microns—but also in molecular composition and cargo. Apo-EVs carry a variety of potentially biologically active components, including small molecules, proteins, and nucleic acids. Larger forms of Apo-EVs, commonly termed “apoptotic bodies,” can carry organelles, such as mitochondria and nuclear fragments. Molecules displayed on the surface of extracellular vesicles (EVs can contribute substantially to their size, as well as their functions. Thus far, relatively little is known of the functional significance of Apo-EVs apart from their roles in fragmentation of dying cells and indicated immunomodulatory activities. Here, we discuss EV production by dying tumor cells and consider the possible roles of Apo-EVs in a cell death-driven sector of the tumor microenvironment known as the onco-regenerative niche (ORN. We propose that tumor-derived Apo-EVs are significant vehicles of the ORN, functioning as critical intercellular communicators that activate oncogenic tissue repair and regeneration pathways. We highlight important outstanding questions and suggest that Apo-EVs may harbor novel therapeutic targets.

  12. Extracellular signaling and multicellularity in Bacillus subtilis.

    Science.gov (United States)

    Shank, Elizabeth Anne; Kolter, Roberto

    2011-12-01

    Bacillus subtilis regulates its ability to differentiate into distinct, co-existing cell types in response to extracellular signaling molecules produced either by itself, or present in its environment. The production of molecules by B. subtilis cells, as well as their response to these signals, is not uniform across the population. There is specificity and heterogeneity both within genetically identical populations as well as at the strain-level and species-level. This review will discuss how extracellular signaling compounds influence B. subtilis multicellularity with regard to matrix-producing cannibal differentiation, germination, and swarming behavior, as well as the specificity of the quorum-sensing peptides ComX and CSF. It will also highlight how imaging mass spectrometry can aid in identifying signaling compounds and contribute to our understanding of the functional relationship between such compounds and multicellular behavior. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Biotechnological Aspects of Microbial Extracellular Electron Transfer

    Science.gov (United States)

    Kato, Souichiro

    2015-01-01

    Extracellular electron transfer (EET) is a type of microbial respiration that enables electron transfer between microbial cells and extracellular solid materials, including naturally-occurring metal compounds and artificial electrodes. Microorganisms harboring EET abilities have received considerable attention for their various biotechnological applications, in addition to their contribution to global energy and material cycles. In this review, current knowledge on microbial EET and its application to diverse biotechnologies, including the bioremediation of toxic metals, recovery of useful metals, biocorrosion, and microbial electrochemical systems (microbial fuel cells and microbial electrosynthesis), were introduced. Two potential biotechnologies based on microbial EET, namely the electrochemical control of microbial metabolism and electrochemical stimulation of microbial symbiotic reactions (electric syntrophy), were also discussed. PMID:26004795

  14. Methods to isolate extracellular vesicles for diagnosis

    Science.gov (United States)

    Kang, Hyejin; Kim, Jiyoon; Park, Jaesung

    2017-12-01

    Extracellular vesicles (EVs) are small membrane-bound bodies that are released into extracellular space by diverse cells, and are found in body fluids like blood, urine and saliva. EVs contain RNA, DNA and proteins, which can be biomarkers for diagnosis. EVs can be obtained by minimally-invasive biopsy, so they are useful in disease diagnosis. High yield and purity contribute to precise diagnosis of disease, but damaged EVs and impurities can cause confu sed results. However, EV isolation methods have different yields and purities. Furthermore, the isolation method that is most suitable to maximize EV recovery efficiency depends on the experimental conditions. This review focuses on merits and demerits of several types of EV isolation methods, and provides examples of how to diagnose disease by exploiting information obtained by analysis of EVs.

  15. Construction of a recombinant viral vector containing part of the nucleocapsid protein gene of newcastle disease virus

    Energy Technology Data Exchange (ETDEWEB)

    Bader, D.E.

    1995-09-01

    This report describes the procedures used to clone a 673 base pair gene fragment of the major nucleocapsid protein gene of Newcastle disease virus into a viral vector molecule for the purpose of maintaining a stable, long-term, renewable source of this target sequence for gene probe studies. The gene fragment was prepared by reverse-transcription polymerase chain reaction of Newcastle disease virus RNA and was cloned into the viral DNA vector Ml3mp18 RF to produce a recombinant DNA molecule. The cloned fragment was shown to be present in the recombinant clones based on (i) clonal selection on indicator plates; (ii) restriction enzyme analysis; (iii) gene probe analysis and (iv) nested PCR amplification.

  16. Stem cell extracellular vesicles and kidney injury

    OpenAIRE

    Grange, Cristina; Iampietro, Corinne; Bussolati, Benedetta

    2017-01-01

    Extracellular vesicles (EVs) appear as a new promising cell-free therapy for acute and chronic renal diseases. EVs retain characteristics of the cell of origin and those derived from stem cells may mimic their regenerative properties per se. In fact, EVs contain many active molecules such as proteins and RNA species that act on target cells through different mechanisms, stimulating proliferation and angiogenesis and reducing apoptosis and inflammation. There are several reports that demonstra...

  17. Extracellular deoxyribonuclease production by periodontal bacteria.

    Science.gov (United States)

    Palmer, L J; Chapple, I L C; Wright, H J; Roberts, A; Cooper, P R

    2012-08-01

    Whilst certain bacteria have long been known to secrete extracellular deoxyribonuclease (DNase), the purpose in microbial physiology was unclear. Recently, however, this enzyme has been demonstrated to confer enhanced virulence, enabling bacteria to evade the host's immune defence of extruded DNA/chromatin filaments, termed neutrophil extracellular traps (NETs). As NETs have recently been identified in infected periodontal tissue, the aim of this study was to screen periodontal bacteria for extracellular DNase activity. To determine whether DNase activity was membrane bound or secreted, 34 periodontal bacteria were cultured in broth and on agar plates. Pelleted bacteria and supernatants from broth cultures were analysed for their ability to degrade DNA, with relative activity levels determined using an agarose gel electrophoresis assay. Following culture on DNA-supplemented agar, expression was determined by the presence of a zone of hydrolysis and DNase activity related to colony size. Twenty-seven bacteria, including red and orange complex members Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Streptococcus constellatus, Campylobacter rectus and Prevotella nigrescens, were observed to express extracellular DNase activity. Differences in DNase activity were noted, however, when bacteria were assayed in different culture states. Analysis of the activity of secreted DNase from bacterial broth cultures confirmed their ability to degrade NETs. The present study demonstrates, for the first time, that DNase activity is a relatively common property of bacteria associated with advanced periodontal disease. Further work is required to determine the importance of this bacterial DNase activity in the pathogenesis of periodontitis. © 2011 John Wiley & Sons A/S.

  18. Extracellular matrix component signaling in cancer

    DEFF Research Database (Denmark)

    Multhaupt, Hinke A. B.; Leitinger, Birgit; Gullberg, Donald

    2016-01-01

    Cell responses to the extracellular matrix depend on specific signaling events. These are important from early development, through differentiation and tissue homeostasis, immune surveillance, and disease pathogenesis. Signaling not only regulates cell adhesion cytoskeletal organization and motil...... as well as matrix constitution and protein crosslinking. Here we summarize roles of the three major matrix receptor types, with emphasis on how they function in tumor progression. [on SciFinder(R)]...

  19. The effect of a single recombination event

    DEFF Research Database (Denmark)

    Schierup, Mikkel Heide; Jensen, Thomas Mailund; Wiuf, Carsten

    We investigate the variance in how visible a single recombination event is in a SNP data set as a function of the type of recombination event and its age. Data is simulated under the coalescent with recombination and inference is by the popular composite likelihood methods. The major determinant...

  20. A Bacillus megaterium System for the Production of Recombinant Proteins and Protein Complexes.

    Science.gov (United States)

    Biedendieck, Rebekka

    2016-01-01

    For many years the Gram-positive bacterium Bacillus megaterium has been used for the production and secretion of recombinant proteins. For this purpose it was systematically optimized. Plasmids with different inducible promoter systems, with different compatible origins, with small tags for protein purification and with various specific signals for protein secretion were combined with genetically improved host strains. Finally, the development of appropriate cultivation conditions for the production strains established this organism as a bacterial cell factory even for large proteins. Along with the overproduction of individual proteins the organism is now also used for the simultaneous coproduction of up to 14 recombinant proteins, multiple subsequently interacting or forming protein complexes. Some of these recombinant strains are successfully used for bioconversion or the biosynthesis of valuable components including vitamins. The titers in the g per liter scale for the intra- and extracellular recombinant protein production prove the high potential of B. megaterium for industrial applications. It is currently further enhanced for the production of recombinant proteins and multi-subunit protein complexes using directed genetic engineering approaches based on transcriptome, proteome, metabolome and fluxome data.

  1. Autocrine signal transmission with extracellular ligand degradation

    International Nuclear Information System (INIS)

    Muratov, C B; Posta, F; Shvartsman, S Y

    2009-01-01

    Traveling waves of cell signaling in epithelial layers orchestrate a number of important processes in developing and adult tissues. These waves can be mediated by positive feedback autocrine loops, a mode of cell signaling where binding of a diffusible extracellular ligand to a cell surface receptor can lead to further ligand release. We formulate and analyze a biophysical model that accounts for ligand-induced ligand release, extracellular ligand diffusion and ligand–receptor interaction. We focus on the case when the main mode for ligand degradation is extracellular and analyze the problem with the sharp threshold positive feedback nonlinearity. We derive expressions that link the speed of propagation and other characteristics of traveling waves to the parameters of the biophysical processes, such as diffusion rates, receptor expression level, etc. Analyzing the derived expressions we found that traveling waves in such systems can exhibit a number of unusual properties, e.g. non-monotonic dependence of the speed of propagation on ligand diffusivity. Our results for the fully developed traveling fronts can be used to analyze wave initiation from localized perturbations, a scenario that frequently arises in the in vitro models of epithelial wound healing, and guide future modeling studies of cell communication in epithelial layers

  2. Extracellular proteases of Trichoderma species. A review.

    Science.gov (United States)

    Kredics, L; Antal, Zsuzsanna; Szekeres, A; Hatvani, L; Manczinger, L; Vágvölgyi, Cs; Nagy, Erzsébet

    2005-01-01

    Cellulolytic, xylanolytic, chitinolytic and beta-1,3-glucanolytic enzyme systems of species belonging to the filamentous fungal genus Trichoderma have been investigated in details and are well characterised. The ability of Trichoderma strains to produce extracellular proteases has also been known for a long time, however, the proteolytic enzyme system is relatively unknown in this genus. Fortunately, in the recent years more and more attention is focused on the research in this field. The role of Trichoderma proteases in the biological control of plant pathogenic fungi and nematodes has been demonstrated, and it is also suspected that they may be important for the competitive saprophytic ability of green mould isolates and may represent potential virulence factors of Trichoderma strains as emerging fungal pathogens of clinical importance. The aim of this review is to summarize the information available about the extracellular proteases of Trichoderma. Numerous studies are available about the extracellular proteolytic enzyme profiles of Trichoderma strains and about the effect of abiotic environmental factors on protease activities. A number of protease enzymes have been purified to homogeneity and some protease encoding genes have been cloned and characterized. These results will be reviewed and the role of Trichoderma proteases in biological control as well as their advantages and disadvantages in biotechnology will be discussed.

  3. EXTRACELLULAR VESICLES: CLASSIFICATION, FUNCTIONS AND CLINICAL RELEVANCE

    Directory of Open Access Journals (Sweden)

    A. V. Oberemko

    2014-12-01

    Full Text Available This review presents a generalized definition of vesicles as bilayer extracellular organelles of all celular forms of life: not only eu-, but also prokaryotic. The structure and composition of extracellular vesicles, history of research, nomenclature, their impact on life processes in health and disease are discussed. Moreover, vesicles may be useful as clinical instruments for biomarkers, and they are promising as biotechnological drug. However, many questions in this area are still unresolved and need to be addressed in the future. The most interesting from the point of view of practical health care represents a direction to study the effect of exosomes and microvesicles in the development and progression of a particular disease, the possibility of adjusting the pathological process by means of extracellular vesicles of a particular type, acting as an active ingredient. Relevant is the further elucidation of the role and importance of exosomes to the surrounding cells, tissues and organs at the molecular level, the prospects for the use of non-cellular vesicles as biomarkers of disease.

  4. Autocrine signal transmission with extracellular ligand degradation

    Science.gov (United States)

    Muratov, C B; Posta, F; Shvartsman, S Y

    2009-03-01

    Traveling waves of cell signaling in epithelial layers orchestrate a number of important processes in developing and adult tissues. These waves can be mediated by positive feedback autocrine loops, a mode of cell signaling where binding of a diffusible extracellular ligand to a cell surface receptor can lead to further ligand release. We formulate and analyze a biophysical model that accounts for ligand-induced ligand release, extracellular ligand diffusion and ligand-receptor interaction. We focus on the case when the main mode for ligand degradation is extracellular and analyze the problem with the sharp threshold positive feedback nonlinearity. We derive expressions that link the speed of propagation and other characteristics of traveling waves to the parameters of the biophysical processes, such as diffusion rates, receptor expression level, etc. Analyzing the derived expressions we found that traveling waves in such systems can exhibit a number of unusual properties, e.g. non-monotonic dependence of the speed of propagation on ligand diffusivity. Our results for the fully developed traveling fronts can be used to analyze wave initiation from localized perturbations, a scenario that frequently arises in the in vitro models of epithelial wound healing, and guide future modeling studies of cell communication in epithelial layers.

  5. A family of selfish minicircular chromosomes with jumbled chloroplast gene fragments from a dinoflagellate.

    Science.gov (United States)

    Zhang, Z; Cavalier-Smith, T; Green, B R

    2001-08-01

    Chloroplast genes of several dinoflagellate species are located on unigenic DNA minicircular chromosomes. We have now completely sequenced five aberrant minicircular chromosomes from the dinoflagellate Heterocapsa triquetra. These probably nonfunctional DNA circles lack complete genes, with each being composed of several short fragments of two or three different chloroplast genes and a common conserved region with a tripartite 9G-9A-9G core like the putative replicon origin of functional single-gene circular chloroplast chromosomes. Their sequences imply that all five circles evolved by differential deletions and duplications from common ancestral circles bearing fragments of four genes: psbA, psbC, 16S rRNA, and 23S rRNA. It appears that recombination between separate unigenic chromosomes initially gave intermediate heterodimers, which were subsequently stabilized by deletions that included part or all of one putative replicon origin. We suggest that homologous recombination at the 9G-9A-9G core regions produced a psbA/psbC heterodimer which generated two distinct chimeric circles by differential deletions and duplications. A 23S/16S rRNA heterodimer more likely formed by illegitimate recombination between 16S and 23S rRNA genes. Homologous recombination between the 9G-9A-9G core regions of both heterodimers and additional differential deletions and duplications could then have yielded the other three circles. Near identity of the gene fragments and 9G-9A-9G cores, despite diverging adjacent regions, may be maintained by gene conversion. The conserved organization of the 9G-9A-9G cores alone favors the idea that they are replicon origins and suggests that they may enable the aberrant minicircles to parasitize the chloroplast's replication machinery as selfish circles.

  6. Knowledge-based Fragment Binding Prediction

    Science.gov (United States)

    Tang, Grace W.; Altman, Russ B.

    2014-01-01

    Target-based drug discovery must assess many drug-like compounds for potential activity. Focusing on low-molecular-weight compounds (fragments) can dramatically reduce the chemical search space. However, approaches for determining protein-fragment interactions have limitations. Experimental assays are time-consuming, expensive, and not always applicable. At the same time, computational approaches using physics-based methods have limited accuracy. With increasing high-resolution structural data for protein-ligand complexes, there is now an opportunity for data-driven approaches to fragment binding prediction. We present FragFEATURE, a machine learning approach to predict small molecule fragments preferred by a target protein structure. We first create a knowledge base of protein structural environments annotated with the small molecule substructures they bind. These substructures have low-molecular weight and serve as a proxy for fragments. FragFEATURE then compares the structural environments within a target protein to those in the knowledge base to retrieve statistically preferred fragments. It merges information across diverse ligands with shared substructures to generate predictions. Our results demonstrate FragFEATURE's ability to rediscover fragments corresponding to the ligand bound with 74% precision and 82% recall on average. For many protein targets, it identifies high scoring fragments that are substructures of known inhibitors. FragFEATURE thus predicts fragments that can serve as inputs to fragment-based drug design or serve as refinement criteria for creating target-specific compound libraries for experimental or computational screening. PMID:24762971

  7. Fragmentation of Ceramics in Rapid Expansion Mode

    Science.gov (United States)

    Maiti, Spandan; Geubelle, Philippe H.; Rangaswamy, Krishnan

    The study of the fragmentation process goes back to more than a century, motivated primarily by problems related to mining and ore handling (Grady and Kipp, 1985). Various theories have been proposed to predict the fragmentation stress and the fragment size and distribution. But the investigations are generally case specific and relate to only a narrow set of fragmentation processes. A number of theoretical studies of dynamic fragmentation in a rapidly expanding body can be found in the literature. For example, the study summarized in (Grady, 1982) presents a model based on a simple energy balance concept between the surface energy released due to fracture and the kinetic energy of the fragments. Subsequent refinements of the energy balance model have been proposed by (Glenn and Chudnovsky, 1986), which take into account the strain energy of the fragments and specify a threshold stress below which no fragmentation occurs. These models assume that the fracture events are instantaneous and occur simultaneously. Evidently, these assumptions are quite restrictive and these models can not take into account the transient nature of the fragmentation process after the onset of fracture in the material. A more recent model proposed by (Miller et al., 1999) however takes into account this time-dependent nature of the fragmentation event and the distribution of flaws of various strengths in the original material.

  8. The typical RB76 recombination breakpoint of the invasive recombinant tomato yellow leaf curl virus of Morocco can be generated experimentally but is not positively selected in tomato.

    Science.gov (United States)

    Belabess, Z; Urbino, C; Granier, M; Tahiri, A; Blenzar, A; Peterschmitt, M

    2018-01-02

    TYLCV-IS76 is an unusual recombinant between the highly recombinogenic tomato yellow leaf curl virus (TYLCV) and tomato yellow leaf curl Sardinia virus (TYLCSV), two Mediterranean begomoviruses (Geminiviridae). In contrast with the previously reported TYLCV/TYLCSV recombinants, it has a TYLCSV derived fragment of only 76 nucleotides, and has replaced its parental viruses in natural conditions (Morocco, Souss region). The viral population shift coincided with the deployment of the popular Ty-1 resistant tomato cultivars, and according to experimental studies, has been driven by a strong positive selection in such resistant plants. However, although Ty-1 cultivars were extensively used in Mediterranean countries, TYLCV-IS76 was not reported outside Morocco. This, in combination with its unusual recombination pattern suggests that it was generated through a rare and possibly multistep process. The potential generation of a recombination breakpoint (RB) at locus 76 (RB76) was investigated over time in 10 Ty-1 resistant and 10 nearly isogenic susceptible tomato plants co-inoculated with TYLCV and TYLCSV clones. RB76 could not be detected in the recombinant progeny using the standard PCR/sequencing approach that was previously designed to monitor the emergence of TYLCV-IS76 in Morocco. Using a more sensitive PCR test, RB76 was detected in one resistant and five susceptible plants. The results are consistent with a very low intra-plant frequency of RB76 bearing recombinants throughout the test and support the hypothesis of a rare emergence of TYLCV-IS76. More generally, RBs were more scattered in resistant than in susceptible plants and an unusual RB at position 141 (RB141) was positively selected in the resistant cultivar; interestingly, RB141 bearing recombinants were detected in resistant tomato plants from the field. Scenarios of TYLCV-IS76 pre-emergence are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. A photoactivatable Cre-loxP recombination system for optogenetic genome engineering.

    Science.gov (United States)

    Kawano, Fuun; Okazaki, Risako; Yazawa, Masayuki; Sato, Moritoshi

    2016-12-01

    Genome engineering techniques represented by the Cre-loxP recombination system have been used extensively for biomedical research. However, powerful and useful techniques for genome engineering that have high spatiotemporal precision remain elusive. Here we develop a highly efficient photoactivatable Cre recombinase (PA-Cre) to optogenetically control genome engineering in vivo. PA-Cre is based on the reassembly of split Cre fragments by light-inducible dimerization of the Magnet system. PA-Cre enables sharp induction (up to 320-fold) of DNA recombination and is efficiently activated even by low-intensity illumination (∼0.04 W m -2 ) or short periods of pulsed illumination (∼30 s). We demonstrate that PA-Cre allows for efficient DNA recombination in an internal organ of living mice through noninvasive external illumination using a LED light source. The present PA-Cre provides a powerful tool to greatly facilitate optogenetic genome engineering in vivo.

  10. Particle correlations in the recombination model associated with modified Kuti-Weisskopf structure functions

    International Nuclear Information System (INIS)

    Takasugi, E.; Tata, X.

    1982-01-01

    The recombination model associated with modified Kuti-Weisskopf multiquark structure functions is used to analyze particle production by hadronic collisions. The justification of the use of the impulse approximation in these processes and the universal nature of the recombination process are discussed. Single-meson inclusive production in the fragmentation domains of the proton, the pion, and the kaon is used as an input to determine the primitive structure functions. Our parameter-free predictions for low-p/sub T/ multimeson and associated meson-baryon inclusive production are found to be in good agreement with a large amount of recently obtained correlation data. It is pointed out, however, that reactions involving multivalence recombination fall outside the scope of present considerations

  11. A fragment of alpha-actinin promotes monocyte/macrophage maturation in vitro.

    Science.gov (United States)

    Luikart, S; Wahl, D; Hinkel, T; Masri, M; Oegema, T

    1999-02-01

    Conditioned media (CM) from cultures of HL-60 myeloid leukemia cells grown on extracellular bone marrow matrix contains a factor that induces macrophage-like maturation of HL-60 cells. This factor was purified from the CM of HL-60 cells grown on bone marrow stroma by ammonium sulfate precipitation, then sequential chromatography on DEAE, affi-gel blue affinity, gel exclusion, and wheat germ affinity columns, followed by C-4 reverse phase HPLC, and SDS-PAGE. The maturation promoting activity of the CM was identified in a single 31 kD protein. Amino acid sequence analysis of four internal tryptic peptides of this protein confirmed significant homology with amino acid residues 48-60, 138-147, 215-220, and 221-236 of human cytoskeletal alpha-actinin. An immunoaffinity purified rabbit polyclonal anti-chicken alpha-actinin inhibited the activity of HL-60 conditioned media. A 27 kD amino-terminal fragment of alpha-actinin produced by thermolysin digestion of chicken gizzard alpha-actinin, but not intact alpha-actinin, had maturation promoting activity on several cell types, including blood monocytes, as measured by lysozyme secretion and tartrate-resistant acid phosphatase staining. We conclude that an extracellular alpha-actinin fragment can promote monocyte/macrophage maturation. This represents the first example of a fragment of a cytoskeletal component, which may be released during tissue remodeling and repair, playing a role in phagocyte maturation.

  12. Dynamic effects in fragmentation reactions

    International Nuclear Information System (INIS)

    Bertsch, G. F.; Esbensen, H.

    2002-01-01

    Fragmentation reactions offer a useful tool to study the spectroscopy of halo nuclei, but the large extent of the halo wave function makes the reaction theory more difficult. The simple reaction models based on the eikonal approximation for the nuclear interaction or first-order perturbation theory for the Coulomb interaction have systematic errors that they investigate here, comparing to the predictions of complete dynamical calculations. They find that stripping probabilities are underpredicted by the eikonal model, leading to extracted spectroscopy strengths that are two large. In contrast, the Coulomb excitation is overpredicted by the simple theory. They attribute this to a screening effect, as is well known in the Barkas effect on stopping powers. The errors decrease with beam energy as E(sub beam)(sup -1), and are not significant at beam energies above 50 MeV/u. At lower beam energies, the effects should be taken into account when extracting quantitative spectroscopic strengths

  13. Recombination Catalysts for Hypersonic Fuels

    Science.gov (United States)

    Chinitz, W.

    1998-01-01

    The goal of commercially-viable access to space will require technologies that reduce propulsion system weight and complexity, while extracting maximum energy from the products of combustion. This work is directed toward developing effective nozzle recombination catalysts for the supersonic and hypersonic aeropropulsion engines used to provide such access to space. Effective nozzle recombination will significantly reduce rk=le length (hence, propulsion system weight) and reduce fuel requirements, further decreasing the vehicle's gross lift-off weight. Two such catalysts have been identified in this work, barium and antimony compounds, by developing chemical kinetic reaction mechanisms for these materials and determining the engine performance enhancement for a typical flight trajectory. Significant performance improvements are indicated, using only 2% (mole or mass) of these compounds in the combustor product gas.

  14. Mechanisms of sister chromatid recombination

    International Nuclear Information System (INIS)

    Nakai, Sayaka; Machida, Isamu; Tsuji, Satsuki

    1985-01-01

    Studies using T948 as a model system have been carried out aimed at elucidating the mechanism of sister chromatid recombination (SCR). Characterization of U.V. light- and x-ray-induced SCR, the relationiship between SCR induction and DNA repair using rad mutations, and the relationship between SCR induction and the time of cell division using cdc mutations are presented. It has been supposed that SCR is induced at the phase of S-G 2 following DNA replication, that postreplication break of DNA strands is strongly involved in the induction of SCR, and that induction type of SCR, i.e., conversion type or recombination type, is dependent upon the type of molecular damage of DNA. (Namekawa, K.)

  15. Interface recombination influence on carrier transport

    International Nuclear Information System (INIS)

    Konin, A

    2013-01-01

    A theory of interface recombination in the semiconductor–semiconductor junction is developed. The interface recombination rate dependence on the nonequilibrium carrier densities is derived on the basis of a model in which the interface recombination occurs through the mechanism of trapping. The general relation between the interface recombination parameters at small carrier density deviation from the equilibrium ones is obtained. The validity of this relation is proved considering the generation of the Hall electric field in the extrinsic semiconductor sample. The anomalous Hall electromotive force in a weak magnetic field was investigated and interpreted by means of a new interface recombination model. The experimental data corroborate the developed theory. (paper)

  16. A Rapid and Improved Method to Generate Recombinant Dengue Virus Vaccine Candidates.

    Science.gov (United States)

    Govindarajan, Dhanasekaran; Guan, Liming; Meschino, Steven; Fridman, Arthur; Bagchi, Ansu; Pak, Irene; ter Meulen, Jan; Casimiro, Danilo R; Bett, Andrew J

    2016-01-01

    Dengue is one of the most important mosquito-borne infections accounting for severe morbidity and mortality worldwide. Recently, the tetravalent chimeric live attenuated Dengue vaccine Dengvaxia® was approved for use in several dengue endemic countries. In general, live attenuated vaccines (LAV) are very efficacious and offer long-lasting immunity against virus-induced disease. Rationally designed LAVs can be generated through reverse genetics technology, a method of generating infectious recombinant viruses from full length cDNA contained in bacterial plasmids. In vitro transcribed (IVT) viral RNA from these infectious clones is transfected into susceptible cells to generate recombinant virus. However, the generation of full-length dengue virus cDNA clones can be difficult due to the genetic instability of viral sequences in bacterial plasmids. To circumvent the need for a single plasmid containing a full length cDNA, in vitro ligation of two or three cDNA fragments contained in separate plasmids can be used to generate a full-length dengue viral cDNA template. However, in vitro ligation of multiple fragments often yields low quality template for IVT reactions, resulting in inconsistent low yield RNA. These technical difficulties make recombinant virus recovery less efficient. In this study, we describe a simple, rapid and efficient method of using LONG-PCR to recover recombinant chimeric Yellow fever dengue (CYD) viruses as potential dengue vaccine candidates. Using this method, we were able to efficiently generate several viable recombinant viruses without introducing any artificial mutations into the viral genomes. We believe that the techniques reported here will enable rapid and efficient recovery of recombinant flaviviruses for evaluation as vaccine candidates and, be applicable to the recovery of other RNA viruses.

  17. A Rapid and Improved Method to Generate Recombinant Dengue Virus Vaccine Candidates.

    Directory of Open Access Journals (Sweden)

    Dhanasekaran Govindarajan

    Full Text Available Dengue is one of the most important mosquito-borne infections accounting for severe morbidity and mortality worldwide. Recently, the tetravalent chimeric live attenuated Dengue vaccine Dengvaxia® was approved for use in several dengue endemic countries. In general, live attenuated vaccines (LAV are very efficacious and offer long-lasting immunity against virus-induced disease. Rationally designed LAVs can be generated through reverse genetics technology, a method of generating infectious recombinant viruses from full length cDNA contained in bacterial plasmids. In vitro transcribed (IVT viral RNA from these infectious clones is transfected into susceptible cells to generate recombinant virus. However, the generation of full-length dengue virus cDNA clones can be difficult due to the genetic instability of viral sequences in bacterial plasmids. To circumvent the need for a single plasmid containing a full length cDNA, in vitro ligation of two or three cDNA fragments contained in separate plasmids can be used to generate a full-length dengue viral cDNA template. However, in vitro ligation of multiple fragments often yields low quality template for IVT reactions, resulting in inconsistent low yield RNA. These technical difficulties make recombinant virus recovery less efficient. In this study, we describe a simple, rapid and efficient method of using LONG-PCR to recover recombinant chimeric Yellow fever dengue (CYD viruses as potential dengue vaccine candidates. Using this method, we were able to efficiently generate several viable recombinant viruses without introducing any artificial mutations into the viral genomes. We believe that the techniques reported here will enable rapid and efficient recovery of recombinant flaviviruses for evaluation as vaccine candidates and, be applicable to the recovery of other RNA viruses.

  18. Impact failure and fragmentation properties of metals

    Energy Technology Data Exchange (ETDEWEB)

    Grady, D.E. [Applied Research Associates, Albuquerque, NM (United States); Kipp, M.E. [Sandia National Labs., Albuquerque, NM (United States)

    1998-03-01

    In the present study we describe the development of an experimental fracture material property test method specific to dynamic fragmentation. Spherical test samples of the metals of interest are subjected to controlled impulsive stress loads by acceleration to high velocities with a light-gas launcher facility and subsequent normal impact on thin plates. Motion, deformation and fragmentation of the test samples are diagnosed with multiple flash radiography methods. The impact plate materials are selected to be transparent to the x-ray method so that only test metal material is imaged. Through a systematic series of such tests both strain-to-failure and fragmentation resistance properties are determined through this experimental method. Fragmentation property data for several steels, copper, aluminum, tantalum and titanium have been obtained to date. Aspects of the dynamic data have been analyzed with computational methods to achieve a better understanding of the processes leading to failure and fragmentation, and to test an existing computational fragmentation model.

  19. Fragmentation and flow in central collisions

    International Nuclear Information System (INIS)

    Jacak, B.V.; Doss, K.G.R.; Gustafsson, H.A.

    1987-01-01

    Investigation of the fragmentation mechanism requires the measurement of complicated observables. To identify what part of the reacting system gives rise to the fragments, it would be useful to tag them as participants or spectators. A large acceptance for all the reaction products and an event-by-event measurement of the fragment multiplicity is required to distinguish fragment formation via sequential emission from a large equilibrated system and multifragmentation. In order to address whether fragments are formed early or late in the collision, information about the dynamical evolution of the reaction is necessary. This can be provided by study of the global properties of the events. This paper discusses experimental techniques applicable to studying fragmentation processes. 25 refs., 8 figs

  20. Gallstone fragmentation by control electrohydraulic lithotripsy

    International Nuclear Information System (INIS)

    Tung, G.A.; Mueller, P.R.; Brink, J.A.; Saini, S.; Picus, D.; Simeone, J.F.; Ferrucci, J.T.

    1989-01-01

    The authors have performed in vitro contact electrohydraulic lithotripsy (EHL) of 100 gallstones > 10 mm in diameter to identify physical and technical factors that affect fragmentation success. Ninety-one of 100 stones were fragmented with a 3-F electrode (average, seven shocks; range, 1--42); only 12 stones were fragmented with a single shock. Of the nine stones refractory to 50 shocks, four were > 30 mm in diameter and five stones were densely calcified. The most important variable determining power requirements for fragmentation was gallstone size (R = .58), but radiographic calcification of gallstones was also important (R = .47). Stones < 15 mm tended to produce fragments of left-angle 2 mm; stones right-angle 20 mm tended to produce two to five large discrete fragments (P , .05). In addition, lithotripsy could be conducted equally well in 1:1 dilute diatrizoate contrast agent as in 1:6 normal saline, suggesting that contact EHL could be performed under fluoroscopy

  1. Recombinant Cyclophilins Lack Nuclease Activity

    OpenAIRE

    Manteca, Angel; Sanchez, Jesus

    2004-01-01

    Several single-domain prokaryotic and eukaryotic cyclophilins have been identified as also being unspecific nucleases with a role in DNA degradation during the lytic processes that accompany bacterial cell death and eukaryotic apoptosis. Evidence is provided here that the supposed nuclease activity of human and bacterial recombinant cyclophilins is due to contamination of the proteins by the host Escherichia coli endonuclease and is not an intrinsic property of these proteins.

  2. Clinical targeting recombinant immunotoxins for cancer therapy

    Directory of Open Access Journals (Sweden)

    Li M

    2017-07-01

    Full Text Available Meng Li,1,* Zeng-Shan Liu,1,* Xi-Lin Liu,1,* Qi Hui,2,* Shi-Ying Lu,1 Lin-Lin Qu,1 Yan-Song Li,1 Yu Zhou,1 Hong-Lin Ren,1 Pan Hu1 1Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, China-Japan Union Hospital, The First Hospital, Jilin University, Changchun, 2School of Pharmacy, Wenzhou Medical University, Wenzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Recombinant immunotoxins (RITs are proteins that contain a toxin fused to an antibody or small molecules and are constructed by the genetic engineering technique. RITs can bind to and be internalized by cells and kill cancerous or non-cancerous cells by inhibiting protein synthesis. A wide variety of RITs have been tested against different cancers in cell culture, xenograft models, and human patients during the past several decades. RITs have shown activity in therapy of several kinds of cancers, but different levels of side effects, mainly related to vascular leak syndrome, were also observed in the treated patients. High immunogenicity of RITs limited their long-term or repeat applications in clinical cases. Recent advances in the design of immunotoxins, such as humanization of antibody fragment, PEGylation, and modification of human B- and T-cell epitopes, are overcoming the above mentioned problems, which predict the use of these immunotoxins as a potential therapeutic method to treat cancer patients. Keywords: targeted therapy, hematologic malignancies, solid tumors, vascular leak syndrome, immunogenicity 

  3. Application and expression of HSV gG1 protein from a recombinant strain.

    Science.gov (United States)

    Yan, Hua; Yan, Huishen; Huang, Tao; Li, Guocai; Gong, Weijuan; Jiao, Hongmei; Chen, Hongju; Ji, Mingchun

    2010-11-01

    According to the homologous sequence of glycoprotein G1 (gG1) genes from different strains of herpes simplex virus type 1 (HSV-1), a pair of primers was designed to amplify the gG1 gene fragment by PCR. Both the PCR product and the pGEX-4T-1 vector were digested with EcoR I and Sal I. The gG1 gene fragment was subcloned into the digested pGEX-4T-1 vector to construct a recombinant plasmid (pGEX-4T-1-gG1). The resultant plasmid was identified by dual-enzyme digestion and sequence analysis, and then transformed into Escherichia coli BL21 for expression under the induction of isopropyl β-D-1-thiogalactoside (IPTG). The expressed GST-gG1 fragment was detected by SDS-PAGE and purified by affinity chromatography. The properties of GST-gG1 fragment were evaluated by immunoblot analysis. Enzyme-linked immunosorbent assays (ELISAs) based on the GST-gG1 fragment were used for determining IgG or IgM to HSV-1. The GST-gG1 fragment-specific ELISA was also compared with ELISA with whole-HSV-1 antigen and commercial ELISA kits. The gG1-specific IgG and IFN-γ producing CD8+ T cells were induced in mice immunized with the GST-gG1 fragment. These results indicated that the GST-gG1 fragment could be used for replacing whole-virus antigen to detect IgM and IgG to HSV-1 in human sera, which provided a strategy for developing vaccines to protect HSV-1 infection using gG1 fragment. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  5. Complex fragment emission from hot compound nuclei

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1986-03-01

    The experimental evidence for compound nucleus emission of complex fragments at low energies is used to interpret the emission of the same fragments at higher energies. The resulting experimental picture is that of highly excited compound nuclei formed in incomplete fusion processes which decay statistically. In particular, complex fragments appear to be produced mostly through compound nucleus decay. In the appendix a geometric-kinematic theory for incomplete fusion and the associated momentum transfer is outlined. 10 refs., 19 figs

  6. Fragment Size Distribution of Blasted Rock Mass

    Science.gov (United States)

    Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

    2017-12-01

    Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

  7. Fragmentation of neck-like structures

    International Nuclear Information System (INIS)

    Montoya, C.; Bowman, D.R.; Peaslee, G.F.; Michigan State Univ., East Lansing, MI

    1994-01-01

    Evidence for intermediate mass fragment emission from neck-like structures joining projectile- and target-like residues has been observed for peripheral 129 Xe+ nat Cu collisions at E/A=50 MeV. These framents are emitted primarily at velocities intermediate between those of the projectile and the target. Relative to the charge distribution for fragments evaporated from the projectile-like residue, the distribution for ''neck'' emission shows an enhanced emission for fragments with 4 f < 8. (orig.)

  8. Consequences of recombination on traditional phylogenetic analysis

    DEFF Research Database (Denmark)

    Schierup, M H; Hein, J

    2000-01-01

    We investigate the shape of a phylogenetic tree reconstructed from sequences evolving under the coalescent with recombination. The motivation is that evolutionary inferences are often made from phylogenetic trees reconstructed from population data even though recombination may well occur (mt......DNA or viral sequences) or does occur (nuclear sequences). We investigate the size and direction of biases when a single tree is reconstructed ignoring recombination. Standard software (PHYLIP) was used to construct the best phylogenetic tree from sequences simulated under the coalescent with recombination....... With recombination present, the length of terminal branches and the total branch length are larger, and the time to the most recent common ancestor smaller, than for a tree reconstructed from sequences evolving with no recombination. The effects are pronounced even for small levels of recombination that may...

  9. Fragment-based approaches to TB drugs.

    Science.gov (United States)

    Marchetti, Chiara; Chan, Daniel S H; Coyne, Anthony G; Abell, Chris

    2018-02-01

    Tuberculosis is an infectious disease associated with significant mortality and morbidity worldwide, particularly in developing countries. The rise of antibiotic resistance in Mycobacterium tuberculosis (Mtb) urgently demands the development of new drug leads to tackle resistant strains. Fragment-based methods have recently emerged at the forefront of pharmaceutical development as a means to generate more effective lead structures, via the identification of fragment molecules that form weak but high quality interactions with the target biomolecule and subsequent fragment optimization. This review highlights a number of novel inhibitors of Mtb targets that have been developed through fragment-based approaches in recent years.

  10. Gluon fragmentation in T(1S) decays

    International Nuclear Information System (INIS)

    Bienlein, J.K.

    1983-05-01

    In T(1S) decays most observables (sphericity, charged multiplicity, photonic energy fraction, inclusive spectra) can be understood assuming that gluons fragment like quarks. New results from LENA use the (axis-independent) Fox-Wolfram moments for the photonic energy deposition. Continuum reactions show 'standard' Field-Feynman fragmentation. T(1S) decays show a significant difference in the photonic energy topology. It is more isotropic than with the Field-Feynman fragmentation scheme. Gluon fragmentation into isoscalar mesons (a la Peterson and Walsh) is excluded. But if one forces the leading particle to be isoscalar, one gets good agreement with the data. (orig.)

  11. Measuring the temperature of hot nuclear fragments

    International Nuclear Information System (INIS)

    Wuenschel, S.; Bonasera, A.; May, L.W.; Souliotis, G.A.; Tripathi, R.; Galanopoulos, S.; Kohley, Z.; Hagel, K.; Shetty, D.V.; Huseman, K.; Soisson, S.N.; Stein, B.C.; Yennello, S.J.

    2010-01-01

    A new thermometer based on fragment momentum fluctuations is presented. This thermometer exhibited residual contamination from the collective motion of the fragments along the beam axis. For this reason, the transverse direction has been explored. Additionally, a mass dependence was observed for this thermometer. This mass dependence may be the result of the Fermi momentum of nucleons or the different properties of the fragments (binding energy, spin, etc.) which might be more sensitive to different densities and temperatures of the exploding fragments. We expect some of these aspects to be smaller for protons (and/or neutrons); consequently, the proton transverse momentum fluctuations were used to investigate the temperature dependence of the source.

  12. Kinetics of fragmentation-annihilation processes

    OpenAIRE

    Filipe, JAN; Rodgers, GJ

    1996-01-01

    We investigate the kinetics of systems in which particles of one species undergo binary fragmentation and pair annihilation. In the latter, nonlinear process, fragments react at collision to produce an inert species, causing loss of mass. We analyze these systems in the reaction-limited regime by solving a continuous model within the mean-field approximation. The rate of fragmentation for a particle of mass x to break into fragments of masses y and x-y has the form x(lambda-1) (lambda > 0), a...

  13. Fine-Scale Recombination Maps of Fungal Plant Pathogens Reveal Dynamic Recombination Landscapes and Intragenic Hotspots.

    Science.gov (United States)

    Stukenbrock, Eva H; Dutheil, Julien Y

    2018-03-01

    Meiotic recombination is an important driver of evolution. Variability in the intensity of recombination across chromosomes can affect sequence composition, nucleotide variation, and rates of adaptation. In many organisms, recombination events are concentrated within short segments termed recombination hotspots. The variation in recombination rate and positions of recombination hotspot can be studied using population genomics data and statistical methods. In this study, we conducted population genomics analyses to address the evolution of recombination in two closely related fungal plant pathogens: the prominent wheat pathogen Zymoseptoria tritici and a sister species infecting wild grasses Z. ardabiliae We specifically addressed whether recombination landscapes, including hotspot positions, are conserved in the two recently diverged species and if recombination contributes to rapid evolution of pathogenicity traits. We conducted a detailed simulation analysis to assess the performance of methods of recombination rate estimation based on patterns of linkage disequilibrium, in particular in the context of high nucleotide diversity. Our analyses reveal overall high recombination rates, a lack of suppressed recombination in centromeres, and significantly lower recombination rates on chromosomes that are known to be accessory. The comparison of the recombination landscapes of the two species reveals a strong correlation of recombination rate at the megabase scale, but little correlation at smaller scales. The recombination landscapes in both pathogen species are dominated by frequent recombination hotspots across the genome including coding regions, suggesting a strong impact of recombination on gene evolution. A significant but small fraction of these hotspots colocalize between the two species, suggesting that hotspot dynamics contribute to the overall pattern of fast evolving recombination in these species. Copyright © 2018 Stukenbrock and Dutheil.

  14. Recapitulation of Extracellular LAMININ Environment Maintains Stemness of Satellite Cells In Vitro.

    Science.gov (United States)

    Ishii, Kana; Sakurai, Hidetoshi; Suzuki, Nobuharu; Mabuchi, Yo; Sekiya, Ichiro; Sekiguchi, Kiyotoshi; Akazawa, Chihiro

    2018-02-13

    Satellite cells function as precursor cells in mature skeletal muscle homeostasis and regeneration. In healthy tissue, these cells are maintained in a state of quiescence by a microenvironment formed by myofibers and basement membrane in which LAMININs (LMs) form a major component. In the present study, we evaluated the satellite cell microenvironment in vivo and found that these cells are encapsulated by LMα2-5. We sought to recapitulate this satellite cell niche in vitro by culturing satellite cells in the presence of recombinant LM-E8 fragments. We show that treatment with LM-E8 promotes proliferation of satellite cells in an undifferentiated state, through reduced phosphorylation of JNK and p38. On transplantation into injured muscle tissue, satellite cells cultured with LM-E8 promoted the regeneration of skeletal muscle. These findings represent an efficient method of culturing satellite cells for use in transplantation through the recapitulation of the satellite cell niche using recombinant LM-E8 fragments. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Extracellular production and degradation of superoxide in the coral Stylophora pistillata and cultured Symbiodinium.

    Directory of Open Access Journals (Sweden)

    Eldad Saragosti

    2010-09-01

    Full Text Available Reactive oxygen species (ROS are thought to play a major role in cell death pathways and bleaching in scleractinian corals. Direct measurements of ROS in corals are conspicuously in short supply, partly due to inherent problems with ROS quantification in cellular systems.In this study we characterized the dynamics of the reactive oxygen species superoxide anion radical (O(2(- in the external milieu of the coral Stylophora pistillata. Using a sensitive, rapid and selective chemiluminescence-based technique, we measured extracellular superoxide production and detoxification activity of symbiont (non-bleached and aposymbiont (bleached corals, and of cultured Symbiodinium (from clades A and C. Bleached and non-bleached Stylophora fragments were found to produce superoxide at comparable rates of 10(-11-10(-9 mol O(2(- mg protein(-1 min(-1 in the dark. In the light, a two-fold enhancement in O(2(- production rates was observed in non-bleached corals, but not in bleached corals. Cultured Symbiodinium produced superoxide in the dark at a rate of . Light was found to markedly enhance O(2(- production. The NADPH Oxidase inhibitor Diphenyleneiodonium chloride (DPI strongly inhibited O(2(- production by corals (and more moderately by algae, possibly suggesting an involvement of NADPH Oxidase in the process. An extracellular O(2(- detoxifying activity was found for bleached and non-bleached Stylophora but not for Symbiodinium. The O(2(- detoxifying activity was partially characterized and found to resemble that of the enzyme superoxide dismutase (SOD.The findings of substantial extracellular O(2(- production as well as extracellular O(2(- detoxifying activity may shed light on the chemical interactions between the symbiont and its host and between the coral and its environment. Superoxide production by Symbiodinium possibly implies that algal bearing corals are more susceptible to an internal build-up of O(2(-, which may in turn be linked to oxidative stress

  16. INCREASING OF THE EXPRESSION OF RECOMBINANT scFv-ANTIBODIES EFFICIENCY

    Directory of Open Access Journals (Sweden)

    O.V. Galkin

    2017-10-01

    Full Text Available Obtaining single-chain variable fragments (scFv of recombinant antibodies in E. coli cells is often associated with numerous problems causing low yields or inactive conformation of the product. The aim of this work was to study the influence of staphylococcal protein A fragment fused with scFv antibodies (SpA-tag on the efficiency of expression of final product. Examination of scFv antibodies of different origin and specificity has shown that in similar expression systems fused scFv is synthesized in much higher quantities than free scFv. Furthermore, the scFv antibodies in fused form retained their antigen-binding properties and the SpA fragment the ability to bind other immunoglobulins. Thus, the proposed strategy can be considered effective in improving the efficiency of scFv-antibodies production in E. coli cells.

  17. Extracellular Signatures as Indicators of Processing Methods

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, Karen L.

    2012-01-09

    As described in other chapters within this volume, many aspects of microbial cells vary with culture conditions and therefore can potentially be analyzed as forensic signatures of growth conditions. In addition to changes or variations in components of the microbes themselves, extracellular materials indicative of production processes may remain associated with the final bacterial product. It is well recognized that even with considerable effort to make pure products such as fine chemicals or pharmaceuticals, trace impurities from components or synthesis steps associated with production processes can be detected in the final product. These impurities can be used as indicators of production source or methods, such as to help connect drugs of abuse to supply chains. Extracellular residue associated with microbial cells could similarly help to characterize production processes. For successful growth of microorganisms on culture media there must be an available source of carbon, nitrogen, inorganic phosphate and sulfur, trace metals, water and vitamins. The pH, temperature, and a supply of oxygen or other gases must also be appropriate for a given organism for successful culture. The sources of these components and the range in temperature, pH and other variables has adapted over the years with currently a wide range of possible combinations of media components, recipes and parameters to choose from for a given organism. Because of this wide variability in components, mixtures of components, and other parameters, there is the potential for differentiation of cultured organisms based on changes in culture conditions. The challenge remains how to narrow the field of potential combinations and be able to attribute variations in the final bacterial product and extracellular signatures associated with the final product to information about the culture conditions or recipe used in the production of that product.

  18. Regulation of corneal stroma extracellular matrix assembly.

    Science.gov (United States)

    Chen, Shoujun; Mienaltowski, Michael J; Birk, David E

    2015-04-01

    The transparent cornea is the major refractive element of the eye. A finely controlled assembly of the stromal extracellular matrix is critical to corneal function, as well as in establishing the appropriate mechanical stability required to maintain corneal shape and curvature. In the stroma, homogeneous, small diameter collagen fibrils, regularly packed with a highly ordered hierarchical organization, are essential for function. This review focuses on corneal stroma assembly and the regulation of collagen fibrillogenesis. Corneal collagen fibrillogenesis involves multiple molecules interacting in sequential steps, as well as interactions between keratocytes and stroma matrix components. The stroma has the highest collagen V:I ratio in the body. Collagen V regulates the nucleation of protofibril assembly, thus controlling the number of fibrils and assembly of smaller diameter fibrils in the stroma. The corneal stroma is also enriched in small leucine-rich proteoglycans (SLRPs) that cooperate in a temporal and spatial manner to regulate linear and lateral collagen fibril growth. In addition, the fibril-associated collagens (FACITs) such as collagen XII and collagen XIV have roles in the regulation of fibril packing and inter-lamellar interactions. A communicating keratocyte network contributes to the overall and long-range regulation of stromal extracellular matrix assembly, by creating micro-domains where the sequential steps in stromal matrix assembly are controlled. Keratocytes control the synthesis of extracellular matrix components, which interact with the keratocytes dynamically to coordinate the regulatory steps into a cohesive process. Mutations or deficiencies in stromal regulatory molecules result in altered interactions and deficiencies in both transparency and refraction, leading to corneal stroma pathobiology such as stromal dystrophies, cornea plana and keratoconus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Cloning of human tumor necrosis factor (TNF) receptor cDNA and expression of recombinant soluble TNF-binding protein

    International Nuclear Information System (INIS)

    Gray, P.W.; Barrett, K.; Chantry, D.; Turner, M.; Feldmann, M.

    1990-01-01

    The cDNA for one of the receptors for human tumor necrosis factor (TNF) has been isolated. This cDNA encodes a protein of 455 amino acids that is divided into an extracellular domain of 171 residues and a cytoplasmic domain of 221 residues. The extracellular domain has been engineered for expression in mammalian cells, and this recombinant derivative binds TNFα with high affinity and inhibits its cytotoxic activity in vitro. The TNF receptor exhibits similarity with a family of cell surface proteins that includes the nerve growth factor receptor, the human B-cell surface antigen CD40, and the rat T-cell surface antigen OX40. The TNF receptor contains four cysteine-rich subdomains in the extracellular portion. Mammalian cells transfected with the entire TNF receptor cDNA bind radiolabeled TNFα with an affinity of 2.5 x 10 -9 M. This binding can be competitively inhibited with unlabeled TNFα or lymphotoxin (TNFβ)

  20. The subunit structure of the extracellular hemoglobin of Biomphalaria glabrata

    International Nuclear Information System (INIS)

    Arndt, Marcio H.L.; Naves, Cristiani F.; Xavier, Luciana P.; Santoro, Marcelo M.

    1997-01-01

    Full text. The hemoglobin of Biomphalaria glabrata was purified to homogeneity by a two step purification protocol using a gel filtration column (Superose 6 HR/Pharmacia ) followed by an anion exchange chromatography (MONO-Q Sepharose/Pharmacia). The dissociation products were analysed by a 5 - 15 % Polyacrylamide gel electrophoresis containing Sodium Dodecyl Sulfate (SDS-PAGE) giving a band of 270 K Daltons and a band of 180 K Daltons after reduction with β-mercaptoethanol. The same profile was obtained in a 3.5 % Agarose gel electrophoresis containing SDS (SDS-AGE) showing additional bands of higher molecular weight. These bands were proposed to be monomers, dimers and trimers and, after reduction in a Bidimensional SDS-AGE, the proposed monomers and dimers were decomposed in two and four bands that were interpreted as 1 - 4 chains. The hemoglobin was digested by four different proteases ( Thrombin, Trypsin, Chymotrypsin and Subtilisin ) showing several equivalent fragments with molecular weights multiples of its minimum molecular weight ( 17.7 K Daltons). The circular dichroism spectrum of the protein showed a characteristic high α-helix content. We proposed that this hemoglobin is a pentamer of approx. 360 K Daltons subunits each formed by two 180 K Daltons chains linked in pairs by disulfide bridges and each of these chains comprises ten Heme binding domains. These data were compared to other Planorbidae extracellular hemoglobins. Up to now, the quaternary structure of this hemoglobin (shape and disposition of the subunits) is unknown. It is intended to elucidate its structure by Small Angle X-Ray Scattering in Brazilian National Laboratory of Synchrotron Light (LNLS). (author)

  1. Mechanisms Affecting Population Density in Fragmented Habitat

    Directory of Open Access Journals (Sweden)

    Lutz Tischendorf

    2005-06-01

    Full Text Available We conducted a factorial simulation experiment to analyze the relative importance of movement pattern, boundary-crossing probability, and mortality in habitat and matrix on population density, and its dependency on habitat fragmentation, as well as inter-patch distance. We also examined how the initial response of a species to a fragmentation event may affect our observations of population density in post-fragmentation experiments. We found that the boundary-crossing probability from habitat to matrix, which partly determines the emigration rate, is the most important determinant for population density within habitat patches. The probability of crossing a boundary from matrix to habitat had a weaker, but positive, effect on population density. Movement behavior in habitat had a stronger effect on population density than movement behavior in matrix. Habitat fragmentation and inter-patch distance may have a positive or negative effect on population density. The direction of both effects depends on two factors. First, when the boundary-crossing probability from habitat to matrix is high, population density may decline with increasing habitat fragmentation. Conversely, for species with a high matrix-to-habitat boundary-crossing probability, population density may increase with increasing habitat fragmentation. Second, the initial distribution of individuals across the landscape: we found that habitat fragmentation and inter-patch distance were positively correlated with population density when individuals were distributed across matrix and habitat at the beginning of our simulation experiments. The direction of these relationships changed to negative when individuals were initially distributed across habitat only. Our findings imply that the speed of the initial response of organisms to habitat fragmentation events may determine the direction of observed relationships between habitat fragmentation and population density. The time scale of post-fragmentation

  2. Hydrogen peroxide induce modifications of human extracellular superoxide dismutase that results in enzyme inhibition

    Directory of Open Access Journals (Sweden)

    Randi H. Gottfredsen

    2013-01-01

    Full Text Available Superoxide dismutase (EC-SOD controls the level of superoxide in the extracellular space by catalyzing the dismutation of superoxide into hydrogen peroxide and molecular oxygen. In addition, the enzyme reacts with hydrogen peroxide in a peroxidase reaction which is known to disrupt enzymatic activity. Here, we show that the peroxidase reaction supports a site-specific bond cleavage. Analyses by peptide mapping and mass spectrometry shows that oxidation of Pro112 supports the cleavage of the Pro112–His113 peptide bond. Substitution of Ala for Pro112 did not inhibit fragmentation, indicating that the oxidative fragmentation at this position is dictated by spatial organization and not by side-chain specificity. The major part of EC-SOD inhibited by the peroxidase reaction was not fragmented but found to encompass oxidations of histidine residues involved in the coordination of copper (His98 and His163. These oxidations are likely to support the dissociation of copper from the active site and thus loss of enzymatic activity. Homologous modifications have also been described for the intracellular isozyme, Cu/Zn-SOD, reflecting the almost identical structures of the active site within these enzymes. We speculate that the inactivation of EC-SOD by peroxidase activity plays a role in regulating SOD activity in vivo, as even low levels of superoxide will allow for the peroxidase reaction to occur.

  3. Efficient production of Trastuzumab Fab antibody fragments in Brevibacillus choshinensis expression system.

    Science.gov (United States)

    Mizukami, Makoto; Onishi, Hiromasa; Hanagata, Hiroshi; Miyauchi, Akira; Ito, Yuji; Tokunaga, Hiroko; Ishibashi, Matsujiro; Arakawa, Tsutomu; Tokunaga, Masao

    2018-10-01

    The Brevibacillus expression system has been successfully employed for the efficient productions of a variety of recombinant proteins, including enzymes, cytokines, antigens and antibody fragments. Here, we succeeded in secretory expression of Trastuzumab Fab antibody fragments using B. choshinensis/BIC (Brevibacillus in vivocloning) expression system. In the fed-batch high-density cell culture, recombinant Trastuzumab Fab with amino-terminal His-tag (His-BcFab) was secreted at high level, 1.25 g/liter, and Fab without His-tag (BcFab) at ∼145 mg/L of culture supernatant. His-BcFab and BcFab were purified to homogeneity using combination of conventional column chromatographies with a yield of 10-13%. This BcFab preparation exhibited native structure and functions evaluated by enzyme-linked immunosorbent assay, surface plasmon resonance, circular dichroism measurements and size exclusion chromatography. To our knowledge, this is the highest production of Fab antibody fragments in gram-positive bacterial expression/secretion systems. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Recombinant thrombomodulin protects mice against histone-induced lethal thromboembolism.

    Directory of Open Access Journals (Sweden)

    Mayumi Nakahara

    Full Text Available INTRODUCTION: Recent studies have shown that histones, the chief protein component of chromatin, are released into the extracellular space during sepsis, trauma, and ischemia-reperfusion injury, and act as major mediators of the death of an organism. This study was designed to elucidate the cellular and molecular basis of histone-induced lethality and to assess the protective effects of recombinant thrombomodulin (rTM. rTM has been approved for the treatment of disseminated intravascular coagulation (DIC in Japan, and is currently undergoing a phase III clinical trial in the United States. METHODS: Histone H3 levels in plasma of healthy volunteers and patients with sepsis and DIC were measured using enzyme-linked immunosorbent assay. Male C57BL/6 mice were injected intravenously with purified histones, and pathological examinations were performed. The protective effects of rTM against histone toxicity were analyzed both in vitro and in mice. RESULTS: Histone H3 was not detectable in plasma of healthy volunteers, but significant levels were observed in patients with sepsis and DIC. These levels were higher in non-survivors than in survivors. Extracellular histones triggered platelet aggregation, leading to thrombotic occlusion of pulmonary capillaries and subsequent right-sided heart failure in mice. These mice displayed symptoms of DIC, including thrombocytopenia, prolonged prothrombin time, decreased fibrinogen, fibrin deposition in capillaries, and bleeding. Platelet depletion protected mice from histone-induced death in the first 30 minutes, suggesting that vessel occlusion by platelet-rich thrombi might be responsible for death during the early phase. Furthermore, rTM bound to extracellular histones, suppressed histone-induced platelet aggregation, thrombotic occlusion of pulmonary capillaries, and dilatation of the right ventricle, and rescued mice from lethal thromboembolism. CONCLUSIONS: Extracellular histones cause massive

  5. Parton fragmentation and string dynamics

    International Nuclear Information System (INIS)

    Andersson, B.; Gustafson, G.; Ingelman, G.; Sjoestrand, T.

    1983-01-01

    While much has been learned recently about quark and gluon interactions in the framework of perturbative Quantum Chromodynamics, the relation between calculated parton properties and observed hadron densities involves models where dynamics and jet empirical rules have to be combined. The purpose of this article is to describe a presently successful approach which is based on a cascade jet model using String dynamics. It can readily lead to Monte Carlo jet programmes of great use when analyzing data. Production processes in an iterative cascade approach, with tunneling in a constant force field, are reviewed. Expected differences between quark and gluon jets are discussed. Low transverse momentum phenomena are also reviewed with emphasis on hyperon polarization. In so far as this approach uses a fragmentation scheme based on String dynamics, it was deemed appropriate to also include under the same cover a special report on the Classical theory of relativistic Strings, seen as the classical limit of the Dual Resonance model. The Equations of motion and interaction among strings are presented. (orig.)

  6. Differential recognition of terminal extracellular Plasmodium falciparum VAR2CSA domains by sera from multigravid, malaria-exposed Malian women.

    Science.gov (United States)

    Travassos, Mark A; Coulibaly, Drissa; Bailey, Jason A; Niangaly, Amadou; Adams, Matthew; Nyunt, Myaing M; Ouattara, Amed; Lyke, Kirsten E; Laurens, Matthew B; Pablo, Jozelyn; Jasinskas, Algis; Nakajima, Rie; Berry, Andrea A; Takala-Harrison, Shannon; Kone, Abdoulaye K; Kouriba, Bourema; Rowe, J Alexandra; Doumbo, Ogobara K; Thera, Mahamadou A; Laufer, Miriam K; Felgner, Philip L; Plowe, Christopher V

    2015-06-01

    The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family mediates parasite sequestration in small capillaries through tissue-specific cytoadherence. The best characterized of these proteins is VAR2CSA, which is expressed on the surface of infected erythrocytes that bind to chondroitin sulfate in the placental matrix. Antibodies to VAR2CSA prevent placental cytoadherence and protect against placental malaria. The size and complexity of the VAR2CSA protein pose challenges for vaccine development, but smaller constitutive domains may be suitable for subunit vaccine development. A protein microarray was printed to include five overlapping fragments of the 3D7 VAR2CSA extracellular region. Malian women with a history of at least one pregnancy had antibody recognition of four of these fragments and had stronger reactivity against the two distal fragments than did nulliparous women, children, and men from Mali, suggesting that the C-terminal extracellular VAR2CSA domains are a potential focus of protective immunity. With carefully chosen sera from longitudinal studies of pregnant women, this approach has the potential to identify seroreactive VAR2CSA domains associated with protective immunity against pregnancy-associated malaria. © The American Society of Tropical Medicine and Hygiene.

  7. Study of the fragmentation of astrophysical interest molecules (CnHm) induced by high velocity collision

    International Nuclear Information System (INIS)

    Tuna, Th.

    2008-07-01

    This work shows the study of atom-molecule collision processes in the high velocity domain (v=4,5 a.u). The molecules concerned by this work are small unsaturated hydrocarbons C 1-4 H and C 3 H 2 . Molecules are accelerated with the Tandem accelerator in Orsay and their fragmentation is analyzed by the 4π, 100% efficient detector, AGAT. Thanks to a shape analysis of the current signal from the silicon detectors in association with the well known grid method, we are able to measure all the fragmentation channels of the incident molecule. These dissociation measurements have been introduced in the modelization of two objects of the interstellar medium in which a lot of hydrocarbon molecules have been observed (TMC1, horse-head nebula). We have extended our branching ratios obtained by high velocity collision to other electronic processes included in the chemical database like photodissociation and dissociative recombination. This procedure is feasible under an assumption of the statistical point of view of the molecular fragmentation. The deviations following our modification are very small in the modelization of TMC1 but significant in the photodissociation region. The first part is dedicated to the description of the experimental setting that has enabled us to study the fragmentation of C n H m molecules: the Orsay's Tandem accelerator and the Agat detector. The second part deals with negative ion sources and particularly with the Sahat source that is based on electronic impact and has shown good features for the production of anions and correct stability for its use with accelerators. The third part is dedicated to the experimental results in terms of cross-sections, number of fragments and branching ratios, associated to the various collisional processes. The last part presents an application of our measurement of fragmentation data to astro-chemistry. In this field, the simulation codes of the inter-stellar medium require databases of chemical reactions that

  8. First in-situ measurements of a highly fragmented comet: ACE SWICS and WIND STICS measurements

    Science.gov (United States)

    Lepri, S. T.; Gilbert, J. A.; Rubin, M.; Zurbuchen, T.; Combi, M. R.

    2011-12-01

    While many of the characteristics of comets and their local plasma environment are obtained using remote sensing via spectroscopic methods, space-based mass spectrometers allow a unique opportunity to directly sample cometary material in situ. To date there have been only a handful of in-situ spacecraft encounters with comets, such as 1P/Halley, 103P/Hartley, 81P/Wild and others. Comet 73P/Schwassmann-Wachmann started to disintegrate in 1995, two major components B and C were recovered in 2001, and it burst into more than 36 pieces during its passage near the Earth in 2006. Serendipitously, some very distant fragmentation members, well-separated from the major identified fragments, passed between the Earth and Sun. Cometary pickup ions and possibly recombined solar wind minor ions convected past the Earth in late May 2006 and were observed by both the ACE/SWICS and WIND/STICS mass spectrometers, which are located in halo orbits around the Earth-Sun L1 Lagrange point. Most of these observations took place a few days after the main comet fragments passed through the ecliptic, when their orbits crossed the spacecraft-Sun line, suggesting additional pieces lagging far behind the main fragments. In this paper, we present the first in-situ observation of these pieces that passed very close to the spacecraft (<0.07AU) and conduct a comparative analysis of composition and characteristics of pick-up ions originating from a number of the cometary fragments. We find that the pick-up ion trail related to the comet fragments is much longer than expected. We constrain the C+/O+ and He+/He++ ratio and discuss the implications for the production rates of different fragments.

  9. Extracellular Nm23H1 stimulates neurite outgrowth from dorsal root ganglia neurons in vitro independently of nerve growth factor supplementation or its nucleoside diphosphate kinase activity

    International Nuclear Information System (INIS)

    Wright, K.T.; Seabright, R.; Logan, A.; Lilly, A.J.; Khanim, F.; Bunce, C.M.; Johnson, W.E.B.

    2010-01-01

    Research highlights: → Extracellular Nm23H1 stimulates nerve growth. → Extracellular Nm23H1 provides pathfinding cues to growth cones. → The neurotrophic activity of Nm23H1 is independent of NDP kinase activity. → The neurotrophic activity of Nm23H1 is independent of NGF. -- Abstract: The nucleoside diphosphate (NDP) kinase, Nm23H1, is a highly expressed during neuronal development, whilst induced over-expression in neuronal cells results in increased neurite outgrowth. Extracellular Nm23H1 affects the survival, proliferation and differentiation of non-neuronal cells. Therefore, this study has examined whether extracellular Nm23H1 regulates nerve growth. We have immobilised recombinant Nm23H1 proteins to defined locations of culture plates, which were then seeded with explants of embryonic chick dorsal root ganglia (DRG) or dissociated adult rat DRG neurons. The substratum-bound extracellular Nm23H1 was stimulatory for neurite outgrowth from chick DRG explants in a concentration-dependent manner. On high concentrations of Nm23H1, chick DRG neurite outgrowth was extensive and effectively limited to the location of the Nm23H1, i.e. neuronal growth cones turned away from adjacent collagen-coated substrata. Nm23H1-coated substrata also significantly enhanced rat DRG neuronal cell adhesion and neurite outgrowth in comparison to collagen-coated substrata. These effects were independent of NGF supplementation. Recombinant Nm23H1 (H118F), which does not possess NDP kinase activity, exhibited the same activity as the wild-type protein. Hence, a novel neuro-stimulatory activity for extracellular Nm23H1 has been identified in vitro, which may function in developing neuronal systems.

  10. Extracellular Nm23H1 stimulates neurite outgrowth from dorsal root ganglia neurons in vitro independently of nerve growth factor supplementation or its nucleoside diphosphate kinase activity

    Energy Technology Data Exchange (ETDEWEB)

    Wright, K.T. [Keele University at the RJAH Orthopaedic Hospital, Oswestry, Shropshire (United Kingdom); Seabright, R.; Logan, A. [Neuropharmacology and Neurobiology, School of Clinical and Experimental Medicine, Birmingham University, Birmingham (United Kingdom); Lilly, A.J.; Khanim, F.; Bunce, C.M. [Biosciences, Birmingham University, Birmingham (United Kingdom); Johnson, W.E.B., E-mail: w.e.johnson@aston.ac.uk [Life and Health Sciences, Aston University, Birmingham (United Kingdom)

    2010-07-16

    Research highlights: {yields} Extracellular Nm23H1 stimulates nerve growth. {yields} Extracellular Nm23H1 provides pathfinding cues to growth cones. {yields} The neurotrophic activity of Nm23H1 is independent of NDP kinase activity. {yields} The neurotrophic activity of Nm23H1 is independent of NGF. -- Abstract: The nucleoside diphosphate (NDP) kinase, Nm23H1, is a highly expressed during neuronal development, whilst induced over-expression in neuronal cells results in increased neurite outgrowth. Extracellular Nm23H1 affects the survival, proliferation and differentiation of non-neuronal cells. Therefore, this study has examined whether extracellular Nm23H1 regulates nerve growth. We have immobilised recombinant Nm23H1 proteins to defined locations of culture plates, which were then seeded with explants of embryonic chick dorsal root ganglia (DRG) or dissociated adult rat DRG neurons. The substratum-bound extracellular Nm23H1 was stimulatory for neurite outgrowth from chick DRG explants in a concentration-dependent manner. On high concentrations of Nm23H1, chick DRG neurite outgrowth was extensive and effectively limited to the location of the Nm23H1, i.e. neuronal growth cones turned away from adjacent collagen-coated substrata. Nm23H1-coated substrata also significantly enhanced rat DRG neuronal cell adhesion and neurite outgrowth in comparison to collagen-coated substrata. These effects were independent of NGF supplementation. Recombinant Nm23H1 (H118F), which does not possess NDP kinase activity, exhibited the same activity as the wild-type protein. Hence, a novel neuro-stimulatory activity for extracellular Nm23H1 has been identified in vitro, which may function in developing neuronal systems.

  11. Escherichia coli F4 fimbriae specific lama single-domain antibody fragments effectively inhibit bacterial adhesion in vitro but poorly protect against diarrhea

    NARCIS (Netherlands)

    Harmsen, M.M.; Solt, van C.B.; Hoogendoorn, A.; Zijderveld, van F.G.; Niewold, T.A.; Meulen, van der J.

    2005-01-01

    Oral administration of polyclonal antibodies directed against enterotoxigenic Escherichia coli (ETEC) F4 fimbriae is used to protect against piglet post-weaning diarrhoea. For cost reasons, we aim to replace these polyclonal antibodies by recombinant llama single-domain antibody fragments (VHHs)

  12. Fragmentation of eastern United States forest types

    Science.gov (United States)

    Kurt H. Riitters; John W. Coulston

    2013-01-01

    Fragmentation is a continuing threat to the sustainability of forests in the Eastern United States, where land use changes supporting a growing human population are the primary driver of forest fragmentation (Stein and others 2009). While once mostly forested, approximately 40 percent of the original forest area has been converted to other land uses, and most of the...

  13. Thermodynamics of the fuel fragmentation gas

    International Nuclear Information System (INIS)

    Perez, R.B.; Alsmiller, R.G. Jr.

    1977-01-01

    In the context of nuclear reactor safety studies, a program is in progress at ORNL whereby fuel-fragmentation situations are mocked up by the application of high-current capacitor discharges through solid UO 2 samples. The goal of the present work is to predict such quantities as the number of gas and liquid fragments and their energy distributions. The point of view adopted is that upon fragmentation, a cloud of UO 2 vapor is formed containing ''primeval'' liquid fragments which act as condensation centers. In the evolution of time, fragment growth is controlled by nucleation, coagulation and evaporation processes. Eventually, the vapor-droplet system will reach a situation in which clusters (fragments) of various sizes and UO 2 vapor will coexist in an ''association-disassociation'' equilibrium. Thus, the physical model considered here consists of the identification of the fragmentation gas with an ''imperfect'' vapor, made up of interacting UO 2 vapor and liquid fragments. The results of the study are presented

  14. Momentum sum rules for fragmentation functions

    International Nuclear Information System (INIS)

    Meissner, S.; Metz, A.; Pitonyak, D.

    2010-01-01

    Momentum sum rules for fragmentation functions are considered. In particular, we give a general proof of the Schaefer-Teryaev sum rule for the transverse momentum dependent Collins function. We also argue that corresponding sum rules for related fragmentation functions do not exist. Our model-independent analysis is supplemented by calculations in a simple field-theoretical model.

  15. A note on convex renorming and fragmentability

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. Using the game approach to fragmentability, we give new and simpler proofs of the following known results: (a) If the Banach space admits an equivalent. Kadec norm, then its weak topology is fragmented by a metric which is stronger than the norm topology. (b) If the Banach space admits an equivalent rotund ...

  16. Temperatures of fragment kinetic energy spectra

    International Nuclear Information System (INIS)

    Bauer, W.

    1995-01-01

    Multifragmentation reactions without large compression in the initial state (proton-induced reactions, reverse kinematics, projectile fragmentation) are examined, and it is verified quantitatively that the high temperatures obtained from fragment kinetic energy spectra and lower temperatures obtained from observables such as level population or isotope ratios can be understood in a common framework

  17. Pollen and gene flow in fragmented habitats

    NARCIS (Netherlands)

    Kwak, Manja M.; Velterop, Odilia; van Andel, Jelte

    . Habitat fragmentation affects both plants and pollinators. Habitat fragmentation leads to changes in species richness, population number and size, density, and shape, thus to changes in the spatial arrangement of flowers. These changes influence the amount of food for flower-visiting insects and

  18. Long-term effects of fragmentation and fragment properties on bird species richness in Hawaiian forests

    Science.gov (United States)

    David J. Flaspohler; Christian P. Giardina; Gregory P. Asner; Patrick Hart; Jonathan Price; Cassie Ka’apu Lyons; Xeronimo. Castaneda

    2010-01-01

    Forest fragmentation is a common disturbance affecting biological diversity, yet the impacts of fragmentation on many forest processes remain poorly understood. Forest restoration is likely to be more successful when it proceeds with an understanding of how native and exotic vertebrates utilize forest patches of different size. We used a system of forest fragments...

  19. Effects of nuclear mutations for recombination and repair functions and of caffeine on mitochondrial recombination

    International Nuclear Information System (INIS)

    Fraenkel, A.H.M.

    1974-01-01

    Studies of both prokaryotic and eukaryotic organisms indicate that pathways governing repair of damage to nuclear DNA caused by x-ray or ultraviolet irradiation overlap with those controlling recombination. Fourteen nuclear mutants of Saccharomyces cerevisiae were tested in order to determine whether these mutant genes affected mitochondrial recombination. None of the mutations studied significantly affected mitochondrial recombination. The nuclear recombination and repair pathways studied do not overlap with the nuclear pathway which controls recombination of mitochondrial DNA. A second set of experiments was designed to test the effect of caffeine on both nuclear and mitochondrial recombination in Saccharomyces cerevisiae. (U.S.)

  20. Recombinant Vaccinia Viruses Coding Transgenes of Apoptosis-Inducing Proteins Enhance Apoptosis But Not Immunogenicity of Infected Tumor Cells

    Science.gov (United States)

    Tkachenko, Anastasiya; Richter, Vladimir

    2017-01-01

    Genetic modifications of the oncolytic vaccinia virus (VV) improve selective tumor cell infection and death, as well as activation of antitumor immunity. We have engineered a double recombinant VV, coding human GM-CSF, and apoptosis-inducing protein apoptin (VV-GMCSF-Apo) for comparing with the earlier constructed double recombinant VV-GMCSF-Lact, coding another apoptosis-inducing protein, lactaptin, which activated different cell death pathways than apoptin. We showed that both these recombinant VVs more considerably activated a set of critical apoptosis markers in infected cells than the recombinant VV coding GM-CSF alone (VV-GMCSF-dGF): these were phosphatidylserine externalization, caspase-3 and caspase-7 activation, DNA fragmentation, and upregulation of proapoptotic protein BAX. However, only VV-GMCSF-Lact efficiently decreased the mitochondrial membrane potential of infected cancer cells. Investigating immunogenic cell death markers in cancer cells infected with recombinant VVs, we demonstrated that all tested recombinant VVs were efficient in calreticulin and HSP70 externalization, decrease of cellular HMGB1, and ATP secretion. The comparison of antitumor activity against advanced MDA-MB-231 tumor revealed that both recombinants VV-GMCSF-Lact and VV-GMCSF-Apo efficiently delay tumor growth. Our results demonstrate that the composition of GM-CSF and apoptosis-inducing proteins in the VV genome is very efficient tool for specific killing of cancer cells and for activation of antitumor immunity. PMID:28951871

  1. Nanostructured gold microelectrodes for extracellular recording

    Energy Technology Data Exchange (ETDEWEB)

    Brueggemann, Dorothea; Wolfrum, Bernhard; Maybeck, Vanessa; Offenhaeusser, Andreas [CNI Center of Nanoelectronic Systems for Information Technology and Institute of Bio- and Nanosystems 2, Forschungszentrum Juelich (Germany)

    2010-07-01

    Electrophysiological activity of electrogenic cells is currently recorded with planar bioelectronic interfaces such as microelectrode arrays (MEAs). In this work, a novel concept of biocompatible nanostructured gold MEAs for extracellular signal recording is presented. MEAs were fabricated using clean room technologies, e.g. photolithography and metallization. Subsequently, they were modified with gold nanopillars of approximately 300 to 400 nm in height and 60 nm width. The nanostructuring process was carried out with a template-assisted approach using nanoporous aluminium oxide. Impedance spectroscopy of the resulting nanostructures showed higher capacitances compared to planar gold. This confirmed the expected increase of the surface area via nanostructuring. We used the nanostructured microelectrodes to record extracellular potentials from heart muscle cells (HL1), which were plated onto the chips. Good coupling between the HL1 cells and the nanostructured electrodes was observed. The resulting signal-to-noise ratio of nanopillar-MEAs was increased by a factor of 2 compared to planar MEAs. In future applications this nanopillar concept can be adopted for distinct interface materials and coupling to cellular and molecular sensing components.

  2. Secretory proteins of the pulmonary extracellular lining

    International Nuclear Information System (INIS)

    Gupta, R.P.; Patton, S.E.; Eddy, M.; Smits, H.L.; Jetten, A.M.; Nettesheim, P.; Hook, G.E.R.

    1986-01-01

    The objective of this investigation was to identify proteins in the pulmonary extracellular lining (EL) that are secreted by cells of the pulmonary epithelium. Pulmonary lavage effluents from the lungs of rabbits were centrifuged to remove all cells and particulate materials. Serum proteins were removed by repeatedly passing concentrated lavage effluent fluid through an affinity column containing IgG fraction of goat anti-rabbit (whole serum) antiserum bound to Sepharose-4B. Nonserum proteins accounted for 21.3 +/- 10.3% of the total soluble proteins in pulmonary lavage effluents. Serum free lavage effluents (SFL) contained 25 identifiable proteins as determined by using SDS-PAGE under reducing conditions. Of these proteins approximately 73% was accounted for by a single protein with MW of 66 kd. The secretory nature of the proteins present in SFL was investigated by studying the incorporation of 35 S-methionine into proteins released by lung slices and trachea followed by SDS-PAGE and autoradiography. Many, but not all proteins present in SFL were identified as proteins secreted by pulmonary tissues. The major secretory proteins appeared to have MWs of 59, 53, 48, 43, 24, 14, and 6 kd under reducing conditions. These data demonstrate the presence of several proteins in the pulmonary extracellular lining that appear to be secreted by the pulmonary epithelium

  3. Extracellular histones induce erythrocyte fragility and anemia.

    Science.gov (United States)

    Kordbacheh, Farzaneh; O'Meara, Connor H; Coupland, Lucy A; Lelliott, Patrick M; Parish, Christopher R

    2017-12-28

    Extracellular histones have been shown to play an important pathogenic role in many diseases, primarily through their cytotoxicity toward nucleated cells and their ability to promote platelet activation with resultant thrombosis and thrombocytopenia. In contrast, little is known about the effect of extracellular histones on erythrocyte function. We demonstrate in this study that histones promote erythrocyte aggregation, sedimentation, and using a novel in vitro shear stress model, we show that histones induce erythrocyte fragility and lysis in a concentration-dependent manner. Furthermore, histones impair erythrocyte deformability based on reduced passage of erythrocytes through an artificial spleen. These in vitro results were mirrored in vivo with the injection of histones inducing anemia within minutes of administration, with a concomitant increase in splenic hemoglobin content. Thrombocytopenia and leukopenia were also observed. These findings suggest that histones binding to erythrocytes may contribute to the elevated erythrocyte sedimentation rates observed in inflammatory conditions. Furthermore, histone-induced increases in red blood cell lysis and splenic clearance may be a significant factor in the unexplained anemias seen in critically ill patients. © 2017 by The American Society of Hematology.

  4. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles.

    Science.gov (United States)

    Lässer, Cecilia; Théry, Clotilde; Buzás, Edit I; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; Lötvall, Jan

    2016-01-01

    The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, "Basics of Extracellular Vesicles," uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC) on EVs was launched on 15 August 2016 at the platform "Coursera" and is free of charge.

  5. Extracellular matrix in canine mammary tumors with special focus on versican, a versatile extracellular proteoglycan

    NARCIS (Netherlands)

    Erdélyi, Ildikó

    2006-01-01

    The extracellular matrix (ECM) research has become fundamental to understand cancer. This thesis focuses on the exploration of ECM composition and organization in canine mammary tumors, with a special interest in the large chondroitin-sulfate proteoglycan (PG), versican. Chapter 1 gives an

  6. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Cecilia Lässer

    2016-12-01

    Full Text Available The International Society for Extracellular Vesicles (ISEV has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs. This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC on EVs was launched on 15 August 2016 at the platform “Coursera” and is free of charge.

  7. The Extracellular Matrix of Candida albicans Biofilms Impairs Formation of Neutrophil Extracellular Traps.

    Science.gov (United States)

    Johnson, Chad J; Cabezas-Olcoz, Jonathan; Kernien, John F; Wang, Steven X; Beebe, David J; Huttenlocher, Anna; Ansari, Hamayail; Nett, Jeniel E

    2016-09-01

    Neutrophils release extracellular traps (NETs) in response to planktonic C. albicans. These complexes composed of DNA, histones, and proteins inhibit Candida growth and dissemination. Considering the resilience of Candida biofilms to host defenses, we examined the neutrophil response to C. albicans during biofilm growth. In contrast to planktonic C. albicans, biofilms triggered negligible release of NETs. Time lapse imaging confirmed the impairment in NET release and revealed neutrophils adhering to hyphae and migrating on the biofilm. NET inhibition depended on an intact extracellular biofilm matrix as physical or genetic disruption of this component resulted in NET release. Biofilm inhibition of NETosis could not be overcome by protein kinase C activation via phorbol myristate acetate (PMA) and was associated with suppression of neutrophil reactive oxygen species (ROS) production. The degree of impaired NET release correlated with resistance to neutrophil attack. The clinical relevance of the role for extracellular matrix in diminishing NET production was corroborated in vivo using a rat catheter model. The C. albicans pmr1Δ/Δ, defective in production of matrix mannan, appeared to elicit a greater abundance of NETs by scanning electron microscopy imaging, which correlated with a decreased fungal burden. Together, these findings show that C. albicans biofilms impair neutrophil response through an inhibitory pathway induced by the extracellular matrix.

  8. Vaccine platform recombinant measles virus.

    Science.gov (United States)

    Mühlebach, Michael D

    2017-10-01

    The classic development of vaccines is lengthy, tedious, and may not necessarily be successful as demonstrated by the case of HIV. This is especially a problem for emerging pathogens that are newly introduced into the human population and carry the inherent risk of pandemic spread in a naïve population. For such situations, a considerable number of different platform technologies are under development. These are also under development for pathogens, where directly derived vaccines are regarded as too complicated or even dangerous due to the induction of inefficient or unwanted immune responses causing considerable side-effects as for dengue virus. Among platform technologies are plasmid-based DNA vaccines, RNA replicons, single-round infectious vector particles, or replicating vaccine-based vectors encoding (a) critical antigen(s) of the target pathogens. Among the latter, recombinant measles viruses derived from vaccine strains have been tested. Measles vaccines are among the most effective and safest life-attenuated vaccines known. Therefore, the development of Schwarz-, Moraten-, or AIK-C-strain derived recombinant vaccines against a wide range of mostly viral, but also bacterial pathogens was quite straightforward. These vaccines generally induce powerful humoral and cellular immune responses in appropriate animal models, i.e., transgenic mice or non-human primates. Also in the recent first clinical phase I trial, the results have been quite encouraging. The trial indicated the expected safety and efficacy also in human patients, interestingly independent from the level of prevalent anti-measles immunity before the trial. Thereby, recombinant measles vaccines expressing additional antigens are a promising platform for future vaccines.

  9. Extracellular vesicle-mediated transfer of genetic information between the hematopoietic system and the brain in response to inflammation.

    Directory of Open Access Journals (Sweden)

    Kirsten Ridder

    2014-06-01

    Full Text Available Mechanisms behind how the immune system signals to the brain in response to systemic inflammation are not fully understood. Transgenic mice expressing Cre recombinase specifically in the hematopoietic lineage in a Cre reporter background display recombination and marker gene expression in Purkinje neurons. Here we show that reportergene expression in neurons is caused by intercellular transfer of functional Cre recombinase messenger RNA from immune cells into neurons in the absence of cell fusion. In vitro purified secreted extracellular vesicles (EVs from blood cells contain Cre mRNA, which induces recombination in neurons when injected into the brain. Although Cre-mediated recombination events in the brain occur very rarely in healthy animals, their number increases considerably in different injury models, particularly under inflammatory conditions, and extend beyond Purkinje neurons to other neuronal populations in cortex, hippocampus, and substantia nigra. Recombined Purkinje neurons differ in their miRNA profile from their nonrecombined counterparts, indicating physiological significance. These observations reveal the existence of a previously unrecognized mechanism to communicate RNA-based signals between the hematopoietic system and various organs, including the brain, in response to inflammation.

  10. Crystallization and preliminary crystallographic studies of the single-chain variable fragment of antibody chA21 in complex with an N-terminal fragment of ErbB2

    International Nuclear Information System (INIS)

    Liu, Yang; Zhou, Huihao; Zhu, Juanjuan; Gao, Yongxiang; Niu, Liwen; Liu, Jing; Teng, Maikun

    2009-01-01

    An antibody–antigen complex consisting of a single-chain variable fragment of the potential therapeutic antibody chA21 and an N-terminal fragment (residues 1–192) of the human ErbB2 extracellular domain was expressed, purified and crystallized. X-ray diffraction data were collected to 2.45 Å resolution. ErbB2 is a transmembrane tyrosine kinase, the overexpression of which causes abnormality and disorder in cell signalling and leads to cell transformation. Previously, an anti-ErbB2 single-chain chimeric antibody chA21 that specifically inhibits the growth of ErbB2-overexpressing cancer cells in vitro and in vivo was developed. Here, an antibody–antigen complex consisting of the single-chain variable fragment (scFv) of chA21 and an N-terminal fragment (residues 1–192, named EP I) of the ErbB2 extracellular domain was crystallized using the sitting-drop vapour-diffusion method. An X-ray diffraction data set was collected to 2.45 Å resolution from a single flash-cooled crystal; the crystal belonged to space group P2 1 2 1 2 1

  11. Current fragmentation in deep inelastic scattering

    International Nuclear Information System (INIS)

    Hamer, C.J.

    1975-04-01

    It is argued that the current fragmentation products in deep inelastic electron scattering will not be distributed in a 'one-dimensional' rapidity plateau as in the parton model picture of Feynman and Bjorken. A reaction mechanism with a multiperipheral topology, but which the above configuration might have been achieved, does not in fact populate the current fragmentation plateau; and unless partons are actually observed in the final state, it cannot lead to Bjorken scaling. The basic reason for this failure is shown to be the fact that when a particle is produced in the current fragmentation plateau, the adjacent momentum transfer in the multiperipheral chain becomes large and negative: such processes are inevitably suppressed. Instead, the current fragmentation products are likely to be generated by a fragmentation, or sequential decay process. (author)

  12. The politics of municipal fragmentation in Ghana

    Directory of Open Access Journals (Sweden)

    Abdulai Kuyini Mohammed

    2015-06-01

    Full Text Available The scholarly debate over the rival merits of local government consolidation and fragmentation is an old but enduring one. However, in this debate very little attention has been focused on the political dimension of council amalgamation and fragmentation – yet political considerations play a central role in both the formulation and outcomes of de-concentration policy. The purpose of this article is to fill a gap in the literature by examining local government fragmentation in Ghana from 1988 to 2014. The article does this by identifying the key players and analysing their interests and gains, as well as the tensions arising from the fragmentation exercise. The implications from the Ghanaian case for more general theories of fragmentation are drawn out.

  13. Graph Theory. 1. Fragmentation of Structural Graphs

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2002-12-01

    Full Text Available The investigation of structural graphs has many fields of applications in engineering, especially in applied sciences like as applied chemistry and physics, computer sciences and automation, electronics and telecommunication. The main subject of the paper is to express fragmentation criteria in graph using a new method of investigation: terminal paths. Using terminal paths are defined most of the fragmentation criteria that are in use in molecular topology, but the fields of applications are more generally than that, as I mentioned before. Graphical examples of fragmentation are given for every fragmentation criteria. Note that all fragmentation is made with a computer program that implements a routine for every criterion.[1] A web routine for tracing all terminal paths in graph can be found at the address: http://vl.academicdirect.ro/molecular_topology/tpaths/ [1] M. V. Diudea, I. Gutman, L. Jäntschi, Molecular Topology, Nova Science, Commack, New York, 2001, 2002.

  14. Focused genetic recombination of bacteriophage t4 initiated by double-strand breaks.

    Science.gov (United States)

    Shcherbakov, Victor; Granovsky, Igor; Plugina, Lidiya; Shcherbakova, Tamara; Sizova, Svetlana; Pyatkov, Konstantin; Shlyapnikov, Michael; Shubina, Olga

    2002-10-01

    A model system for studying double-strand-break (DSB)-induced genetic recombination in vivo based on the ets1 segCDelta strain of bacteriophage T4 was developed. The ets1, a 66-bp DNA fragment of phage T2L containing the cleavage site for the T4 SegC site-specific endonuclease, was inserted into the proximal part of the T4 rIIB gene. Under segC(+) conditions, the ets1 behaves as a recombination hotspot. Crosses of the ets1 against rII markers located to the left and to the right of ets1 gave similar results, thus demonstrating the equal and symmetrical initiation of recombination by either part of the broken chromosome. Frequency/distance relationships were studied in a series of two- and three-factor crosses with other rIIB and rIIA mutants (all segC(+)) separated from ets1 by 12-2100 bp. The observed relationships were readily interpretable in terms of the modified splice/patch coupling model. The advantages of this localized or focused recombination over that distributed along the chromosome, as a model for studying the recombination-replication pathway in T4 in vivo, are discussed.

  15. CRMAGE: CRISPR Optimized MAGE Recombineering

    DEFF Research Database (Denmark)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Sommer, Morten Otto Alexander

    2016-01-01

    A bottleneck in metabolic engineering and systems biology approaches is the lack of efficient genome engineering technologies. Here, we combine CRISPR/Cas9 and λ Red recombineering based MAGE technology (CRMAGE) to create a highly efficient and fast method for genome engineering of Escherichia coli...... that are assembled by a USER-cloning approach enabling quick and cost efficient gRNA replacement. CRMAGE furthermore utilizes CRISPR/Cas9 for efficient plasmid curing, thereby enabling multiple engineering rounds per day. To facilitate the design process, a web-based tool was developed to predict both the λ Red...

  16. Adhesion properties of Lactobacillus rhamnosus mucus-binding factor to mucin and extracellular matrix proteins.

    Science.gov (United States)

    Nishiyama, Keita; Nakamata, Koichi; Ueno, Shintaro; Terao, Akari; Aryantini, Ni Putu Desy; Sujaya, I Nengah; Fukuda, Kenji; Urashima, Tadasu; Yamamoto, Yuji; Mukai, Takao

    2015-01-01

    We previously described potential probiotic Lactobacillus rhamnosus strains, isolated from fermented mare milk produced in Sumbawa Island, Indonesia, which showed high adhesion to porcine colonic mucin (PCM) and extracellular matrix (ECM) proteins. Recently, mucus-binding factor (MBF) was found in the GG strain of L. rhamnosus as a mucin-binding protein. In this study, we assessed the ability of recombinant MBF protein from the FSMM22 strain, one of the isolates of L. rhamnosus from fermented Sumbawa mare milk, to adhere to PCM and ECM proteins by overlay dot blot and Biacore assays. MBF bound to PCM, laminin, collagen IV, and fibronectin with submicromolar dissociation constants. Adhesion of the FSMM22 mbf mutant strain to PCM and ECM proteins was significantly less than that of the wild-type strain. Collectively, these results suggested that MBF contribute to L. rhamnosus host colonization via mucin and ECM protein binding.

  17. Atomic excitation and recombination in external fields

    International Nuclear Information System (INIS)

    Nayfeh, M.H.; Clark, C.W.

    1985-01-01

    This volume offers a timely look at Rydberg states of atoms in external fields and dielectronic recombination. Each topic provides authoritative coverage, presents a fresh account of a flourishing field of current atomic physics and introduces new opportunities for discovery and development. Topics considered include electron-atom scattering in external fields; observations of regular and irregular motion as exemplified by the quadratic zeeman effect and other systems; Rydberg atoms in external fields and the Coulomb geometry; crossed-field effects in the absorption spectrum of lithium in a magnetic field; precise studies of static electric field ionization; widths and shapes of stark resonances in sodium above the saddle point; studies of electric field effects and barium autoionizing resonances; autoionization and dielectronic recombination in plasma electric microfields; dielectronic recombination measurements on multicharged ions; merged beam studies of dielectronic recombination; Rydberg atoms and dielectronic recombination in astrophysics; and observations on dielectronic recombination

  18. Construction of a recombinant baculovirus expressing swine hepatitis E Virus ORF2 and preliminary research on its immune effect.

    Science.gov (United States)

    Yang, Z; Hu, Y; Yuan, P; Yang, Y; Wang, K; Xie, L Y; Huang, S L; Liu, J; Ran, L; Song, Z H

    2018-03-01

    In the swine hepatitis E virus (HEV), open reading frame 2 (ORF2) is rich in antigenic determinants and neutralizing epitopes that could induce immune protection. We chose the Bac-to-Bac® Baculovirus Expression System to express fragments containing the critical neutralizing antigenic sites within the HEV ORF2 protein of pigs to obtain a recombinant baculovirus. The fragment of swine HEV ORF2 region (1198-1881bp) was cloned into vector pFastBacTM. A recombinant baculovirus, rBacmid-ORF2, was obtained after transposition and transfection. The molecular mass of the recombinant protein was 26 kDa. Mice were immunized by the intraperitoneal and oral routes with cell lysates of recombinant baculovirus rBacmid-ORF2. Serum and feces of the mice were collected separately at 0, 14, 28, and 42 d after immunization and the antibody levels of IgG and secretory IgA against swine HEV were determined using an enzyme-linked immunosorbent assay. The results suggested that rBacmid-ORF2 induced antibodies of the humoral and mucosal immune responses in mice and that the oral route was significantly superior to the intraperitoneal route. This is the first study to demonstrate that that recombinant baculovirus swine HEV ORF2 could induce humoral and mucosal immune responses in mice. Copyright© by the Polish Academy of Sciences.

  19. Recombinant proteins in therapeutics: haemophilia treatment as an example

    Directory of Open Access Journals (Sweden)

    Liras Antonio

    2008-04-01

    Full Text Available Abstract One of the most spectacular advances in the history of scientific knowledge was the discovery of deoxyribonucleic acid (DNA by Watson and Crick in 1953. This enabled certain proteins to be prepared in this way for their therapeutic use in clinical practice. Today, in the first decade of the 21st century, hundreds of therapeutic proteins have been produced recombinantly and about 50 of them have been approved for clinical use. Because of the specific procedure used for obtaining these products, which is based on expressing a atherapeutica gene from a fragment of DNA in a cell to produce a functional protein that is free from any human or animal component, they are especially acleana and thus the therapy of choice for many current diseases. The immediate question is: why are recombinant products not used more extensively given their high efficacy and maximum safety? In short, we are faced with an interesting but also unfortunate paradox of pharmacology that greater progress in therapeutic procedures is not always associated with greater introduction of those resources that are safest, for the simple reason that they are more costly.

  20. Development of an EGFRvIII specific recombinant antibody

    Directory of Open Access Journals (Sweden)

    Li Gordon

    2010-10-01

    Full Text Available Abstract Background EGF receptor variant III (EGFRvIII is the most common variant of the EGF receptor observed in human tumors. It results from the in frame deletion of exons 2-7 and the generation of a novel glycine residue at the junction of exons 1 and 8. This novel juxtaposition of amino acids within the extra-cellular domain of the EGF receptor creates a tumor specific and immunogenic epitope. EGFRvIII expression has been seen in many tumor types including glioblastoma multiforme (GBM, breast adenocarcinoma, non-small cell lung carcinoma, ovarian adenocarcinoma and prostate cancer, but has been rarely observed in normal tissue. Because this variant is tumor specific and highly immunogenic, it can be used for both a diagnostic marker as well as a target for immunotherapy. Unfortunately many of the monoclonal and polyclonal antibodies directed against EGFRvIII have cross reactivity to wild type EGFR or other non-specific proteins. Furthermore, a monoclonal antibody to EGFRvIII is not readily available to the scientific community. Results In this study, we have developed a recombinant antibody that is specific for EGFRvIII, has little cross reactivity for the wild type receptor, and which can be easily produced. We initially designed a recombinant antibody with two anti-EGFRvIII single chain Fv's linked together and a human IgG1 Fc component. To enhance the specificity of this antibody for EGFRvIII, we mutated tyrosine H59 of the CDRH2 domain and tyrosine H105 of the CDRH3 domain to phenylalanine for both the anti-EGFRvIII sequence inserts. This mutated recombinant antibody, called RAbDMvIII, specifically detects EGFRvIII expression in EGFRvIII expressing cell lines as well as in EGFRvIII expressing GBM primary tissue by western blot, immunohistochemistry (IHC and immunofluorescence (IF and FACS analysis. It does not recognize wild type EGFR in any of these assays. The affinity of this antibody for EGFRvIII peptide is 1.7 × 107 M-1 as

  1. Density dependence of dielectronic recombination in selenium

    International Nuclear Information System (INIS)

    Hagelstein, P.L.; Rosen, M.D.; Jacobs, V.L.

    1986-01-01

    Dielectronic recombination has been found to be the dominant recombination process in the determination of the ionization balance of selenium near the Ne-like sequence under conditions relevant to the exploding-foil EUV laser plasmas. The dielectronic recombination process tends to populate excited levels, and these levels in turn are more susceptible to subsequent excitation and ionization than are the ground-state ions. If one defines an effective recombination rate which includes, in addition to the primary recombination, the subsequent excitation and ionization of the additional excited-state population due to the primary recombination, then this effective recombination rate can be density-sensitive at relatively low electron density. We present results for this effective dielectronic recombination rate at an electron density of 3 x 10/sup 20/ electrons/cm 3 for recombination from Ne-like to Na-like selenium and from F-like to Ne-like selenium. In the former case, the effective recombination rate coefficient is found to be 1.8 x 10/sup -11/ cm 3 /sec at 1.0 keV, which is to be compared with the zero-density value of 2.8 x 10/sup -11/ cm 3 /sec. In the latter case (F-like to Ne-like), the effective recombination rate coefficient is found to be 1.3 x 10/sup -11/ cm 3 /sec, which is substantially reduced from the zero-density result of 3.3 x 10/sup -11/ cm 3 /sec. We have examined the effects of dielectronic recombination on the laser gain of the dominant Ne-like 3p-3s transitions and have compared our results with those presented by Whitten et al. [Phys. Rev. A 33, 2171 (1986)

  2. Exact Solutions of Fragmentation Equations with General Fragmentation Rates and Separable Particles Distribution Kernels

    Directory of Open Access Journals (Sweden)

    S. C. Oukouomi Noutchie

    2014-01-01

    Full Text Available We make use of Laplace transform techniques and the method of characteristics to solve fragmentation equations explicitly. Our result is a breakthrough in the analysis of pure fragmentation equations as this is the first instance where an exact solution is provided for the fragmentation evolution equation with general fragmentation rates. This paper is the key for resolving most of the open problems in fragmentation theory including “shattering” and the sudden appearance of infinitely many particles in some systems with initial finite particles number.

  3. Missing Fragments: Detecting Cooperative Binding in Fragment-Based Drug Design

    Science.gov (United States)

    2012-01-01

    The aim of fragment-based drug design (FBDD) is to identify molecular fragments that bind to alternate subsites within a given binding pocket leading to cooperative binding when linked. In this study, the binding of fragments to human phenylethanolamine N-methyltransferase is used to illustrate how (a) current protocols may fail to detect fragments that bind cooperatively, (b) theoretical approaches can be used to validate potential hits, and (c) apparent false positives obtained when screening against cocktails of fragments may in fact indicate promising leads. PMID:24900472

  4. A simple vector system to improve performance and utilisation of recombinant antibodies

    Directory of Open Access Journals (Sweden)

    Vincent Karen J

    2006-12-01

    Full Text Available Abstract Background Isolation of recombinant antibody fragments from antibody libraries is well established using technologies such as phage display. Phage display vectors are ideal for efficient display of antibody fragments on the surface of bacteriophage particles. However, they are often inefficient for expression of soluble antibody fragments, and sub-cloning of selected antibody populations into dedicated soluble antibody fragment expression vectors can enhance expression. Results We have developed a simple vector system for expression, dimerisation and detection of recombinant antibody fragments in the form of single chain Fvs (scFvs. Expression is driven by the T7 RNA polymerase promoter in conjunction with the inducible lysogen strain BL21 (DE3. The system is compatible with a simple auto-induction culture system for scFv production. As an alternative to periplasmic expression, expression directly in the cytoplasm of a mutant strain with a more oxidising cytoplasmic environment (Origami 2™ (DE3 was investigated and found to be inferior to periplasmic expression in BL21 (DE3 cells. The effect on yield and binding activity of fusing scFvs to the N terminus of maltose binding protein (a solubility enhancing partner, bacterial alkaline phosphatase (a naturally dimeric enzymatic reporter molecule, or the addition of a free C-terminal cysteine was determined. Fusion of scFvs to the N-terminus of maltose binding protein increased scFv yield but binding activity of the scFv was compromised. In contrast, fusion to the N-terminus of bacterial alkaline phosphatase led to an improved performance. Alkaline phosphatase provides a convenient tag allowing direct enzymatic detection of scFv fusions within crude extracts without the need for secondary reagents. Alkaline phosphatase also drives dimerisation of the scFv leading to an improvement in performance compared to monovalent constructs. This is illustrated by ELISA, western blot and

  5. Extracellular RNAs: development as biomarkers of human disease

    Directory of Open Access Journals (Sweden)

    Joseph F. Quinn

    2015-08-01

    Full Text Available Ten ongoing studies designed to test the possibility that extracellular RNAs may serve as biomarkers in human disease are described. These studies, funded by the NIH Common Fund Extracellular RNA Communication Program, examine diverse extracellular body fluids, including plasma, serum, urine and cerebrospinal fluid. The disorders studied include hepatic and gastric cancer, cardiovascular disease, chronic kidney disease, neurodegenerative disease, brain tumours, intracranial haemorrhage, multiple sclerosis and placental disorders. Progress to date and the plans for future studies are outlined.

  6. Rapid purification of recombinant histones.

    Science.gov (United States)

    Klinker, Henrike; Haas, Caroline; Harrer, Nadine; Becker, Peter B; Mueller-Planitz, Felix

    2014-01-01

    The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP) as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  7. The extent and importance of intragenic recombination

    Directory of Open Access Journals (Sweden)

    de Silva Eric

    2004-11-01

    Full Text Available Abstract We have studied the recombination rate behaviour of a set of 140 genes which were investigated for their potential importance in inflammatory disease. Each gene was extensively sequenced in 24 individuals of African descent and 23 individuals of European descent, and the recombination process was studied separately in the two population samples. The results obtained from the two populations were highly correlated, suggesting that demographic bias does not affect our population genetic estimation procedure. We found evidence that levels of recombination correlate with levels of nucleotide diversity. High marker density allowed us to study recombination rate variation on a very fine spatial scale. We found that about 40 per cent of genes showed evidence of uniform recombination, while approximately 12 per cent of genes carried distinct signatures of recombination hotspots. On studying the locations of these hotspots, we found that they are not always confined to introns but can also stretch across exons. An investigation of the protein products of these genes suggested that recombination hotspots can sometimes separate exons belonging to different protein domains; however, this occurs much less frequently than might be expected based on evolutionary studies into the origins of recombination. This suggests that evolutionary analysis of the recombination process is greatly aided by considering nucleotide sequences and protein products jointly.

  8. Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae) provide evidence for pervasive mitochondrial DNA recombination.

    Science.gov (United States)

    Sammler, Svenja; Bleidorn, Christoph; Tiedemann, Ralph

    2011-01-14

    Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i.e., in every generation. The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB

  9. Full mitochondrial genome sequences of two endemic Philippine hornbill species (Aves: Bucerotidae provide evidence for pervasive mitochondrial DNA recombination

    Directory of Open Access Journals (Sweden)

    Bleidorn Christoph

    2011-01-01

    Full Text Available Abstract Background Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle". Results Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni and 22,737 bp (P. panini, they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i.e., in every generation. Conclusions The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB, which has been

  10. On the role of type IX collagen in the extracellular matrix of cartilage: type IX collagen is localized to intersections of collagen fibrils

    OpenAIRE

    1986-01-01

    The tissue distribution of type II and type IX collagen in 17-d-old chicken embryo was studied by immunofluorescence using polyclonal antibodies against type II collagen and a peptic fragment of type IX collagen (HMW), respectively. Both proteins were found only in cartilage where they were co-distributed. They occurred uniformly throughout the extracellular matrix, i.e., without distinction between pericellular, territorial, and interterritorial matrices. Tissues that undergo endochondral bo...

  11. Ecological genomics in Xanthomonas: the nature of genetic adaptation with homologous recombination and host shifts

    KAUST Repository

    Huang, Chao-Li

    2015-03-15

    Background: Comparative genomics provides insights into the diversification of bacterial species. Bacterial speciation usually takes place with lasting homologous recombination, which not only acts as a cohering force between diverging lineages but brings advantageous alleles favored by natural selection, and results in ecologically distinct species, e.g., frequent host shift in Xanthomonas pathogenic to various plants. Results: Using whole-genome sequences, we examined the genetic divergence in Xanthomonas campestris that infected Brassicaceae, and X. citri, pathogenic to a wider host range. Genetic differentiation between two incipient races of X. citri pv. mangiferaeindicae was attributable to a DNA fragment introduced by phages. In contrast to most portions of the genome that had nearly equivalent levels of genetic divergence between subspecies as a result of the accumulation of point mutations, 10% of the core genome involving with homologous recombination contributed to the diversification in Xanthomonas, as revealed by the correlation between homologous recombination and genomic divergence. Interestingly, 179 genes were under positive selection; 98 (54.7%) of these genes were involved in homologous recombination, indicating that foreign genetic fragments may have caused the adaptive diversification, especially in lineages with nutritional transitions. Homologous recombination may have provided genetic materials for the natural selection, and host shifts likely triggered ecological adaptation in Xanthomonas. To a certain extent, we observed positive selection nevertheless contributed to ecological divergence beyond host shifting. Conclusion: Altogether, mediated with lasting gene flow, species formation in Xanthomonas was likely governed by natural selection that played a key role in helping the deviating populations to explore novel niches (hosts) or respond to environmental cues, subsequently triggering species diversification. © Huang et al.

  12. Ecological genomics in Xanthomonas: the nature of genetic adaptation with homologous recombination and host shifts

    KAUST Repository

    Huang, Chao-Li; Pu, Pei-Hua; Huang, Hao-Jen; Sung, Huang-Mo; Liaw, Hung-Jiun; Chen, Yi-Min; Chen, Chien-Ming; Huang, Ming-Ban; Osada, Naoki; Gojobori, Takashi; Pai, Tun-Wen; Chen, Yu-Tin; Hwang, Chi-Chuan; Chiang, Tzen-Yuh

    2015-01-01

    Background: Comparative genomics provides insights into the diversification of bacterial species. Bacterial speciation usually takes place with lasting homologous recombination, which not only acts as a cohering force between diverging lineages but brings advantageous alleles favored by natural selection, and results in ecologically distinct species, e.g., frequent host shift in Xanthomonas pathogenic to various plants. Results: Using whole-genome sequences, we examined the genetic divergence in Xanthomonas campestris that infected Brassicaceae, and X. citri, pathogenic to a wider host range. Genetic differentiation between two incipient races of X. citri pv. mangiferaeindicae was attributable to a DNA fragment introduced by phages. In contrast to most portions of the genome that had nearly equivalent levels of genetic divergence between subspecies as a result of the accumulation of point mutations, 10% of the core genome involving with homologous recombination contributed to the diversification in Xanthomonas, as revealed by the correlation between homologous recombination and genomic divergence. Interestingly, 179 genes were under positive selection; 98 (54.7%) of these genes were involved in homologous recombination, indicating that foreign genetic fragments may have caused the adaptive diversification, especially in lineages with nutritional transitions. Homologous recombination may have provided genetic materials for the natural selection, and host shifts likely triggered ecological adaptation in Xanthomonas. To a certain extent, we observed positive selection nevertheless contributed to ecological divergence beyond host shifting. Conclusion: Altogether, mediated with lasting gene flow, species formation in Xanthomonas was likely governed by natural selection that played a key role in helping the deviating populations to explore novel niches (hosts) or respond to environmental cues, subsequently triggering species diversification. © Huang et al.

  13. Dual Fragment Impact of PBX Charges

    Science.gov (United States)

    Haskins, Peter; Briggs, Richard; Leeming, David; White, Nathan; Cheese, Philip; DE&S MoD UK Team; Ordnance Test Solutions Ltd Team

    2017-06-01

    Fragment impact can pose a significant hazard to many systems containing explosives or propellants. Testing for this threat is most commonly carried out using a single fragment. However, it can be argued that an initial fragment strike (or strikes) could sensitise the energetic material to subsequent impacts, which may then lead to a more violent reaction than would have been predicted based upon single fragment studies. To explore this potential hazard we have developed the capability to launch 2 fragments from the same gun at a range of velocities, and achieve impacts on an acceptor charge with good control over the spatial and temporal separation of the strikes. In this paper we will describe in detail the experimental techniques we have used, both to achieve the dual fragment launch and observe the acceptor charge response. In addition, we will describe the results obtained against PBX filled explosive targets; discuss the mechanisms controlling the target response and their significance for vulnerability assessment. Results of these tests have clearly indicated the potential for detonation upon the second strike, at velocities well below those needed for shock initiation by a single fragment.

  14. Introduction to fragment-based drug discovery.

    Science.gov (United States)

    Erlanson, Daniel A

    2012-01-01

    Fragment-based drug discovery (FBDD) has emerged in the past decade as a powerful tool for discovering drug leads. The approach first identifies starting points: very small molecules (fragments) that are about half the size of typical drugs. These fragments are then expanded or linked together to generate drug leads. Although the origins of the technique date back some 30 years, it was only in the mid-1990s that experimental techniques became sufficiently sensitive and rapid for the concept to be become practical. Since that time, the field has exploded: FBDD has played a role in discovery of at least 18 drugs that have entered the clinic, and practitioners of FBDD can be found throughout the world in both academia and industry. Literally dozens of reviews have been published on various aspects of FBDD or on the field as a whole, as have three books (Jahnke and Erlanson, Fragment-based approaches in drug discovery, 2006; Zartler and Shapiro, Fragment-based drug discovery: a practical approach, 2008; Kuo, Fragment based drug design: tools, practical approaches, and examples, 2011). However, this chapter will assume that the reader is approaching the field with little prior knowledge. It will introduce some of the key concepts, set the stage for the chapters to follow, and demonstrate how X-ray crystallography plays a central role in fragment identification and advancement.

  15. Fragmentation in DNA double-strand breaks

    International Nuclear Information System (INIS)

    Wei Zhiyong; Suzhou Univ., Suzhou; Zhang Lihui; Li Ming; Fan Wo; Xu Yujie

    2005-01-01

    DNA double strand breaks are important lesions induced by irradiations. Random breakage model or quantification supported by this concept is suitable to analyze DNA double strand break data induced by low LET radiation, but deviation from random breakage model is more evident in high LET radiation data analysis. In this work we develop a new method, statistical fragmentation model, to analyze the fragmentation process of DNA double strand breaks. After charged particles enter the biological cell, they produce ionizations along their tracks, and transfer their energies to the cells and break the cellular DNA strands into fragments. The probable distribution of the fragments is obtained under the condition in which the entropy is maximum. Under the approximation E≅E 0 + E 1 l + E 2 l 2 , the distribution functions are obtained as exp(αl + βl 2 ). There are two components, the one proportional to exp(βl 2 ), mainly contributes to the low mass fragment yields, the other component, proportional to exp(αl), decreases slowly as the mass of the fragments increases. Numerical solution of the constraint equations provides parameters α and β. Experimental data, especially when the energy deposition is higher, support the statistical fragmentation model. (authors)

  16. Fragmentation in the branching coral Acropora palmata (Lamarck): growth, survivorship, and reproduction of colonies and fragments.

    Science.gov (United States)

    Lirman

    2000-08-23

    Acropora palmata, a branching coral abundant on shallow reef environments throughout the Caribbean, is susceptible to physical disturbance caused by storms. Accordingly, the survivorship and propagation of this species are tied to its capability to recover after fragmentation. Fragments of A. palmata comprised 40% of ramets within populations that had experienced recent storms. While the survivorship of A. palmata fragments was not directly related to the size of fragments, removal of fragments from areas where they settled was influenced by size. Survivorship of fragments was also affected by type of substratum; the greatest mortality (58% loss within the first month) was observed on sand, whereas fragments placed on top of live colonies of A. palmata fused to the underlying tissue and did not experience any losses. Fragments created by Hurricane Andrew on a Florida reef in August 1992 began developing new growth (proto-branches) 7 months after the storm. The number of proto-branches on fragments was dependent on size, but growth was not affected by the size of fragments. Growth-rates of proto-branches increased exponentially with time (1.7 cm year(-1) for 1993-1994, 2.7 cm year(-1) for 1994-1995, 4.2 cm year(-1) for 1995-1996, and 6.5 cm year(-1) for 1996-1997), taking over 4 years for proto-branches to achieve rates comparable to those of adult colonies on the same reef (6.9 cm year(-1)). In addition to the initial mortality and reduced growth-rates, fragmentation resulted in a loss of reproductive potential. Neither colonies that experienced severe fragmentation nor fragments contained gametes until 4 years after the initial damage. Although A. palmata may survive periodic fragmentation, the long-term effects of this process will depend ultimately on the balance between the benefits and costs of this process.

  17. A perspective on extracellular vesicles proteomics

    Science.gov (United States)

    Rosa-Fernandes, Livia; Rocha, Victória Bombarda; Carregari, Victor Corasolla; Urbani, Andrea; Palmisano, Giuseppe

    2017-11-01

    Increasing attention has been given to secreted extracellular vesicles (EVs) in the past decades, especially in the portrayal of their molecular cargo and role as messengers in both homeostasis and pathophysiological conditions. This review presents the state-of-the-art proteomic technologies to identify and quantify EVs proteins along with their PTMs, interacting partners and structural details. The rapid growth of mass spectrometry-based analytical strategies for protein sequencing, PTMs and structural characterization has improved the level of molecular details that can be achieve from limited amount of EVs isolated from different biological sources. Here we will provide a perspective view on the achievements and challenges on EVs proteome characterization using mass spectrometry. A detailed bioinformatics approach will help us to picture the molecular fingerprint of EVs and understand better their pathophysiological function.

  18. Why regenerative medicine needs an extracellular matrix.

    Science.gov (United States)

    Prestwich, Glenn D; Healy, Kevin E

    2015-01-01

    Regenerative medicine is now coming of age. Many attempts at cell therapy have failed to show significant efficacy, and the umbrella term 'stem cell therapy' is perceived in some quarters as hype or just expensive and unnecessary medical tourism. Here we present a short editorial in three parts. First, we examine the importance of using a semisynthetic extracellular matrix (ECM) mimetic, or sECM, to deliver and retain therapeutic cells at the site of administration. Second, we describe one approach in which biophysical and biochemical properties are tailored to each tissue type, which we call "design for optimal functionality." Third, we describe an alternative approach to sECM design and implementation, called "design for simplicity," in which a deconstructed, minimalist sECM is employed and biology is allowed to perform the customization in situ. We opine that an sECM, whether minimal or instructive, is an essential contributor to improve the outcomes of cell-based therapies.

  19. Extracellular matrix fluctuations during early embryogenesis

    International Nuclear Information System (INIS)

    Szabó, A; Rupp, P A; Rongish, B J; Little, C D; Czirók, A

    2011-01-01

    Extracellular matrix (ECM) movements and rearrangements were studied in avian embryos during early stages of development. We show that the ECM moves as a composite material, whereby distinct molecular components as well as spatially separated layers exhibit similar displacements. Using scanning wide field and confocal microscopy we show that the velocity field of ECM displacement is smooth in space and that ECM movements are correlated even at locations separated by several hundred micrometers. Velocity vectors, however, strongly fluctuate in time. The autocorrelation time of the velocity fluctuations is less than a minute. Suppression of the fluctuations yields a persistent movement pattern that is shared among embryos at equivalent stages of development. The high resolution of the velocity fields allows a detailed spatio-temporal characterization of important morphogenetic processes, especially tissue dynamics surrounding the embryonic organizer (Hensen's node)

  20. Extracellular Matrix Molecules Facilitating Vascular Biointegration

    Directory of Open Access Journals (Sweden)

    Martin K.C. Ng

    2012-08-01

    Full Text Available All vascular implants, including stents, heart valves and graft materials exhibit suboptimal biocompatibility that significantly reduces their clinical efficacy. A range of biomolecules in the subendothelial space have been shown to play critical roles in local regulation of thrombosis, endothelial growth and smooth muscle cell proliferation, making these attractive candidates for modulation of vascular device biointegration. However, classically used biomaterial coatings, such as fibronectin and laminin, modulate only one of these components; enhancing endothelial cell attachment, but also activating platelets and triggering thrombosis. This review examines a subset of extracellular matrix molecules that have demonstrated multi-faceted vascular compatibility and accordingly are promising candidates to improve the biointegration of vascular biomaterials.