Study of conjugation and radiolabeling of monoclonal antibody rituximab for use in radionuclide therapy

International Nuclear Information System (INIS)

Massicano, Adriana Vidal Fernandes

2011-01-01

Lymphomas are tumors originated from the transformation of a lymphocyte in the lymphatic system. The most common lymphoma is the Non-Hodgkin Lymphoma (NHL). Advances in immunology and molecular biology have been improving NHL's detection and treatment strategies development, such as Radioimmunotherapy (RIT). Rituximab is an anti-CD20 monoclonal antibody used as immunotherapeutic to treat refractory or relapsed NHL. The goal of the present work was to conjugate this antibody to DOTA-NHS-ester bifunctional chelator and to radiolabel it with 177 Lu radioisotope in order to develop a radio immunotherapeutic agent for NHL's treatment. Different rituximab to DOTA molar ratios (1:5, 1:10, 1:20, 1:50, 1:250, 1:500 and 1:1000) were evaluated in order to determine the best condition for obtaining the highest radiochemical purity of radio immunotherapeutic. The stability of the unlabeled immuno conjugated was evaluated by high performance liquid chromatography (HPLC) for up to 240 days in different storage conditions. The stability of the labeled preparations was evaluated either after storing at 2-8 degree C or incubation in human serum at 37 degree C. The binding to serum proteins was also determined. In vivo studies were performed in healthy Swiss mice, in order to characterize the biological properties of labeled conjugate. Finally, preliminary studies of radio immuno conjugated competitive binding to CD20 positive Raji cells were carried out in order to analyze if the process of conjugation and radiolabeling compromises the immunoreactivity of the antibody. The conjugation applying lower antibody to chelator molar ratios (1:5, 1:10 and 1:20) showed high stability when stored for up to 240 days in different conditions. The HPLC analysis showed that the monoclonal antibody conjugated in molar ratio 1:50 was labeled with higher radiochemical purity (> 95%) when purified in PD-10 column. This conjugate showed reasonable stability at 2-8 degree C. The analysis of the

Measles virus-specified polypeptides in infected cells

International Nuclear Information System (INIS)

Vainionpaepae, R.

1979-01-01

The synthesis of wild-type measles virus-specified polypeptides in Vero cells in pulse-chase experiments, in cells with synchronized protein synthesis by high salt concentration, and in the presence of proteolytic enzyme inhibitors was analyzed by polyacrylamide slab-gel electrophoresis. Six major (L, G, 2, NP, 5 and M) structural polypeptides were identified in infected cells. The results of pulse-chase experiments suggested that most of the structural polypeptides were synthesized at their final length. Polypeptide M was found to be sensitive to trypsin. In TLCK-treated cells its molecular weight was about 1000-2000 daltons higher than in untreated cells. A minor virus-specific polypeptide with a molecular weight of about 23,000 was found as a very faint and diffuse band. In addition, three nonstructural polypeptides with molecular weights of 65,000, 38,000 and 18,000 were also detected. The experiments with proteolytic enzyme inhibitors and with synchronized protein synthesis suggested that the polypeptide with a molecular weight of 65,000 might be a precursor of the structural polypeptide 5. (author)

Antibody conjugate radioimmunotherapy of superficial bladder cancer

International Nuclear Information System (INIS)

Perkins, Alan; Hopper, Melanie; Murray, Andrea; Frier, Malcolm; Bishop, Mike

2002-01-01

The administration of antibody conjugates for cancer therapy is now proving to be of clinical value. We are currently undertaking a programme of clinical studies using the monoclonal antibody C 595 (gG3) which reacts with the MUC1 glycoprotein antigen that is aberrantly expressed in a high proportion of bladder tumours. Radio immuno conjugates of the C 595 antibody have been produced with high radiolabelling efficiency and immuno reactivity using Tc-99 m and In-111 for diagnostic imaging, and disease staging and the cytotoxic radionuclides Cu-67 and Re-188 for therapy of superficial bladder cancer. A Phase I/II therapeutic trail involving the intravesical administration of antibody directly into the bladder has now begun. (author)

Methods for using polypeptides having cellobiohydrolase activity

Science.gov (United States)

Morant, Marc D; Harris, Paul

2016-08-23

The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Polynucleotides encoding polypeptides having beta-glucosidase activity

Science.gov (United States)

Harris, Paul; Golightly, Elizabeth

2010-03-02

The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

Tumour eradication using synchronous thermal ablation and Hsp90 chemotherapy with protein engineered triblock biopolymer-geldanamycin conjugates.

Science.gov (United States)

Chen, Yizhe; Youn, Pilju; Pysher, Theodore J; Scaife, Courtney L; Furgeson, Darin Y

2014-12-01

Hepatocellular carcinoma (HCC) suffers high tumour recurrence rate after thermal ablation. Heat shock protein 90 (Hsp90) induced post-ablation is critical for tumour survival and progression. A combination therapy of thermal ablation and polymer conjugated Hsp90 chemotherapy was designed and evaluated for complete tumour eradication of HCC. A thermo-responsive, elastin-like polypeptide (ELP)-based tri-block biopolymer was developed and conjugated with a potent Hsp90 inhibitor, geldanamycin (GA). The anti-cancer efficacy of conjugates was evaluated in HCC cell cultures with and without hyperthermia (43 °C). The conjugates were also administered twice weekly in a murine HCC model as a single treatment or in combination with single electrocautery as the ablation method. ELP-GA conjugates displayed enhanced cytotoxicity in vitro and effective heat shock inhibition under hyperthermia. The conjugates alone significantly slowed the tumour growth without systemic toxicity. Four doses of thermo-responsive ELP-GA conjugates with concomitant simple electrocautery accomplished significant Hsp90 inhibition and sustained tumour suppression. Hsp90 inhibition plays a key role in preventing the recurrence of HCC, and the combination of ablation with targeted therapy holds great potential to improve prognosis and survival of HCC patients.

Polypeptides having catalase activity and polynucleotides encoding same

Energy Technology Data Exchange (ETDEWEB)

Liu, Ye; Duan, Junxin; Zhang, Yu; Tang, Lan

2017-05-02

Provided are isolated polypeptides having catalase activity and polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

KAUST Repository

Pahovnik, David

2015-09-01

Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization mechanisms using conventional (various amines) as well as some recently developed initiators (hexamethyldisilazane, N-heterocyclic persistent carbenes, etc.) is presented, and their benefits and drawbacks for preparation of polypeptides with well-defined chain lengths and chain-end functionality are discussed. Recent examples from literature are used to illustrate different possibilities for synthesis of pure polypeptide materials with different molecular architectures bearing various functional groups, which are introduced either by modification of amino acids, before they are transformed into corresponding Ncarboxyanhydrides, or by post-polymerization modifications using protective groups and/or orthogonal functional groups. Different approaches for preparation of polypeptide-based hybrid materials are discussed as well using examples from recent literature. Syntheses of simple block copolymers or copolymers with more complex molecular architectures (graft and star copolymers) as well as modifications of nanoparticles and other surfaces with polypeptides are described.

Ligand-protein conjugated quantification assay by UV spectrophotometry in 99mTc indirect labeling

International Nuclear Information System (INIS)

Basualdo, Daniel A.; Rabiller, Graciela; Poch, Carolina; El Tamer, Elias A.

2009-01-01

Objective: Quantify IgG-HYNIC conjugated for obtaining substitution ratio and as a chemical quality control for 99m Tc labeling of this immunoglobulin. Introduction: The Operational Guidance on Hospital Radiopharmacy by IAEA states that the procedures performed in a Radiopharmacy Laboratory fall into three operational levels. At present, Nuclear Medicine Centre of 'Hospital de Clinicas' has an operational level 2b which requires the preparation of radiopharmaceuticals from approved reagent kits and radionuclide generators, and labeling of autologous blood cells. Centre's goal is to reach an operational level 3a, which allows us to compounding radiopharmaceuticals from drugs and radionuclides for diagnosis; modification to existing commercial kits; related research and development. In approach of that goal, we addressed the optimization of conjugation of proteins and peptides with S-HYNIC so as to bring about the procedures involved. In this work, was conjugated nonspecific polyclonal immunoglobulin G (IgG) with S-HYNIC. Our interest was focused in calculate how many HYNIC groups were incorporated per IgG molecule so that in later stages can be obtained a correlate with labeling efficiency. Materials and methods: A sample of IgG-HYNIC conjugate of 0.2 ml was diluted in 4 ml of benzaldehyde o-sulfonic acid (1 mg / ml, 0.1 M NaAc, pH 4.7). The reaction was incubated at room temperature overnight in darkness. As a negative control took 0.2 ml of IgG-HYNIC conjugate in 4 ml of NaAc buffer 0.1 M. 3 ml of benzaldehyde o-sulfonic acid (1 mg / ml 0.1 M NaAc, pH 4.7) was used as blank. The absorption of the hydrazone was read at 343 nm. The hydrazine concentration was calculated using a molar extinction coefficient ε (343 nm) 17000 M-1cm-1. Results: Molar substitution ratio (MSR) was calculated. The MSR indicates the number of HYNIC groups incorporated in the IgG-HYNIC conjugate determined by the spectrophotometric assay. Conclusions: In labeling with a bifunctional

Radiation protection in radionuclide therapies with (90)Y-conjugates: risks and safety.

Science.gov (United States)

Cremonesi, Marta; Ferrari, Mahila; Paganelli, Giovanni; Rossi, Annalisa; Chinol, Marco; Bartolomei, Mirco; Prisco, Gennaro; Tosi, Giampiero

2006-11-01

The widespread interest in (90)Y internal radionuclide treatments has drawn attention to the issue of radiation protection for staff. Our aim in this study was to identify personnel at risk and to validate the protection devices used. (90)Y-MoAb (Zevalin, 15 cases, 1.1 GBq/patient) and (90)Y-peptide ((90)Y-DOTATOC) systemic (i.v., 50 cases, 3.0 GBq/patient) and locoregional (l.r., 50 cases, 0.4 GBq/patient) treatments were considered. Radiolabelling was carried out in a dedicated hot cell. Tele-tongs, shielded (PMMA: polymethylmethacrylate) syringes/vials and an automatic dose fractionating system were used. Operators wore anti-X-ray and anti-contamination gloves, with TLD dosimeters placed over the fingertips. For i.v. administration, activity was administered by a dedicated system; for l.r. administration, during activity infusion in the brain cavity, tongs were used and TLDs were placed over the fingertips. The air kerma-rate was measured around the patients. The use of devices provided a 75% dose reduction, with mean fingertip doses of 2.9 mGy (i.v. MoAbs), 0.6 mGy (i.v. peptides)/radiolabelling procedure and 0.5 mGy/l.r. administration. The mean effective dose to personnel was 5 microSv/patient. The air kerma-rate around the patients administered i.v. (90)Y-peptides were 3.5 (1 h) and 1.0 (48 h) microGy/h at 1 m. Patient hospitalisation of 6 h (l.r.)/48 h (i.v.) guaranteed that the recommended limits of 3 mSv/year to family members and 0.3 mSv/year to the general population (Council Directive 97/43/Euratom) were respected. When specific procedures are adopted, a substantial improvement in (90)Y manipulation is attainable, reducing doses and increasing safety. For the widespread clinical use of (90)Y-conjugates, a completely automatic labelling procedure is desirable.

Elastin-like Polypeptide Linkers for Single-Molecule Force Spectroscopy.

Science.gov (United States)

Ott, Wolfgang; Jobst, Markus A; Bauer, Magnus S; Durner, Ellis; Milles, Lukas F; Nash, Michael A; Gaub, Hermann E

2017-06-27

Single-molecule force spectroscopy (SMFS) is by now well established as a standard technique in biophysics and mechanobiology. In recent years, the technique has benefitted greatly from new approaches to bioconjugation of proteins to surfaces. Indeed, optimized immobilization strategies for biomolecules and refined purification schemes are being steadily adapted and improved, which in turn has enhanced data quality. In many previously reported SMFS studies, poly(ethylene glycol) (PEG) was used to anchor molecules of interest to surfaces and/or cantilever tips. The limitation, however, is that PEG exhibits a well-known trans-trans-gauche to all-trans transition, which results in marked deviation from standard polymer elasticity models such as the worm-like chain, particularly at elevated forces. As a result, the assignment of unfolding events to protein domains based on their corresponding amino acid chain lengths is significantly obscured. Here, we provide a solution to this problem by implementing unstructured elastin-like polypeptides as linkers to replace PEG. We investigate the suitability of tailored elastin-like polypeptides linkers and perform direct comparisons to PEG, focusing on attributes that are critical for single-molecule force experiments such as linker length, monodispersity, and bioorthogonal conjugation tags. Our results demonstrate that by avoiding the ambiguous elastic response of mixed PEG/peptide systems and instead building the molecular mechanical systems with only a single bond type with uniform elastic properties, we improve data quality and facilitate data analysis and interpretation in force spectroscopy experiments. The use of all-peptide linkers allows alternative approaches for precisely defining elastic properties of proteins linked to surfaces.

Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

Science.gov (United States)

Morant, Marc D.; Harris, Paul

2015-10-13

The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Polypeptides having xylanase activity and polynucleotides encoding same

Energy Technology Data Exchange (ETDEWEB)

Spodsberg, Nikolaj

2018-02-06

The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Measles virus polypeptides in purified virions and in infected cells

International Nuclear Information System (INIS)

Vainionpaeae, R.; Ziola, B.; Salmi, A.

1978-01-01

A wild-type measles virus was radiolabeled during growth in VERO cells and purified by two successive potassium tartrate gradient centrifugations. The virion polypeptide composition was determined by SDS-polyacrylamide gel electrophoresis employing two different buffer systems. Six virus-specific polypeptides were consistently detected. The largest (L) had a molecular weight (MW) of greater than 150,000. The second largest polypeptide, G (MW 79,000), was the only glycoprotein found. The proteins designated polypeptide 2 (MW 66 to 70,000) and nucleocapsid protein or NP (MW 61,000) were phosphorylated. The remaining virus-coded proteins were polypeptide 5 (MW 40,000) and the matrix or M protein (MW 37,000). Measles virions also contained a polypeptide (MW 42,000) thought to be actin due to co-migration with this component of uninfected cells. Analysis of in vitro 3 H-acetic anhydride radiolabeled virions confirmed the presence of these seven polypeptides. Acetic anhydride also labeled a protein designated polypeptide 4 (MW 53,000) which was not consistently radiolabeled in vivo, as well as several other minor proteins believed to be cellular in origin. Synthesis of the six virus-specific structural polypeptides was detected in lysates of infected cells by SDS-polyacrylamide slab gel electrophoresis. Virus specificity of polypeptide 4 could not be confirmed due to the similar MW of several cellular polypeptides. Two non-virion, but virus-specified polypeptides, of MW 38,000 and 18,000 were also detected. Synthesis of the virus structural proteins was in the same proportions as the polypeptides found in virions except for under production of polypeptide G and over production of polypeptide 2. (author)

Radionuclide targeting with particular emphasis on urinary bladder carcinoma

International Nuclear Information System (INIS)

Sjoestroem, A.

2001-01-01

The incidence of urinary bladder carcinoma is increasing and many patients die every year of this disease despite assumed radical therapy. Thus, there is a need for improved methods of diagnosis and therapy. Radionuclide targeting is based on achieving specific delivery of radioactive nuclides to tumour cells with minimal damage to surrounding normal tissues. Two possible target structures are the epidermal growth factor (EGF) receptor and the related receptor HER-2. Cellular binding and retention of 125 I-EGF-dextran conjugates was investigated in two bladder carcinoma cell lines. The conjugate bound specifically to the EGF receptor with delayed maximum binding, limited intracellular degradation and prolonged cellular retention compared to 125 I-EGF. EGF was labelled using different radionuclides and methods. All the labelled variants bound specifically to the tumour cells although the cellular binding patterns and retention varied considerably. 111 In-DTPA-EGF had highest cellular retention and in decreasing order 211 At-benzoyl-EGF and 125 I-labelled EGF. Bladder cancer spheroids bound both 125 I-EGF-dextran as well as 125 I-EGF. Conjugate binding increased during a 48 h incubation period and was most prominent in the outer cell layers. The length of the dextran chain appeared not to alter the binding pattern. The expression of EGF receptors and HER-2 in metastases and primary bladder carcinoma tumours was investigated. Both receptors were expressed in the majority of metastases and primary tumours. Targeting the EGF receptor and/or HER-2 in urinary bladder carcinoma is an exciting new concept

Ring-Opening Polymerization of N-Carboxyanhydrides for Preparation of Polypeptides and Polypeptide-Based Hybrid Materials with Various Molecular Architectures

KAUST Repository

Pahovnik, David; Hadjichristidis, Nikolaos

2015-01-01

Different synthetic approaches utilizing ring-opening polymerization of N-carboxyanhydrides for preparation of polypeptide and polypeptide-based hybrid materials with various molecular architectures are described. An overview of polymerization

DOTA-PESIN, a DOTA-conjugated bombesin derivative designed for the imaging and targeted radionuclide treatment of bombesin receptor-positive tumours

International Nuclear Information System (INIS)

Zhang, Hanwen; Maecke, Helmut R.; Schuhmacher, Jochen; Eisenhut, Michael; Waser, Beatrice; Reubi, Jean Claude; Wild, Damian

2007-01-01

We aimed at designing and developing a novel bombesin analogue, DOTA-PEG 4 -BN(7-14) (DOTA-PESIN), with the goal of labelling it with 67/68 Ga and 177 Lu for diagnosis and radionuclide therapy of prostate and other human cancers overexpressing bombesin receptors. The 8-amino acid peptide bombesin (7-14) was coupled to the macrocyclic chelator DOTA via the spacer 15-amino-4,7,10,13-tetraoxapentadecanoic acid (PEG 4 ). The conjugate was complexed with Ga(III) and Lu(III) salts. The GRP receptor affinity and the bombesin receptor subtype profile were determined in human tumour specimens expressing the three bombesin receptor subtypes. Internalisation and efflux studies were performed with the human GRP receptor cell line PC-3. Xenografted nude mice were used for biodistribution. [Ga III /Lu III ]-DOTA-PESIN showed good affinity to GRP and neuromedin B receptors but no affinity to BB3. [ 67 Ga/ 177 Lu]-DOTA-PESIN internalised rapidly into PC-3 cells whereas the efflux from PC-3 cells was relatively slow. In vivo experiments showed a high and specific tumour uptake and good retention of [ 67 Ga/ 177 Lu]-DOTA-PESIN. [ 67 Ga/ 177 Lu]-DOTA-PESIN highly accumulated in GRP receptor-expressing mouse pancreas. The uptake specificity was demonstrated by blocking tumour uptake and pancreas uptake. Fast clearance was found from blood and all non-target organs except the kidneys. High tumour-to-normal tissue ratios were achieved, which increased with time. PET imaging with [ 68 Ga]-DOTA-PESIN was successful in visualising the tumour at 1 h post injection. Planar scintigraphic imaging showed that the 177 Lu-labelled peptide remained in the tumour even 3 days post injection. The newly designed ligands have high potential with regard to PET and SPECT imaging with 68/67 Ga and targeted radionuclide therapy with 177 Lu. (orig.)

Polypeptides having xylanase activity and polynucleotides encoding same

Energy Technology Data Exchange (ETDEWEB)

Spodsberg, Nikolaj; Shaghasi, Tarana

2017-06-20

The present invention relates to polypeptides having xylanase activity, catalytic domains, and carbohydrate binding domains, and polynucleotides encoding the polypeptides, catalytic domains, and carbohydrate binding domains. The present invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, and carbohydrate binding domains.

Phase transitions in polypeptides: analysis of energy fluctuations

DEFF Research Database (Denmark)

Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

2009-01-01

The helix random coil transition in alanine, valine, and leucine polypeptides consisting of 30 amino acids is studied in vacuo using the Langevin molecular dynamics approach. The influence of side chain radicals on internal energy and heat capacity of the polypeptides is discussed. The heat...... of simulation time. This study provides a comparison of methods for the description of structural transitions in polypeptides....

Polypeptides having beta-glucosidase activity and polynucleotides encoding same

Science.gov (United States)

Harris, Paul; Golightly, Elizabeth

2012-11-27

The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

Science.gov (United States)

Maiyuran, Suchindra; Kramer, Randall; Harris, Paul

2013-10-29

The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Chirality-selected phase behaviour in ionic polypeptide complexes

Science.gov (United States)

Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

2015-01-01

Polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation. PMID:25586861

Vasoactive intestinal polypeptide and other preprovasoactive intestinal polypeptide-derived peptides in the female and male genital tract: localization, biosynthesis, and functional and clinical significance

DEFF Research Database (Denmark)

Ottesen, B; Fahrenkrug, J

1995-01-01

Vasoactive intestinal polypeptide, a neuropeptide with wide distribution in the central and peripheral nervous system, has a broad spectrum of biologic actions. The demonstration of vasoactive intestinal polypeptide containing nerve fibers within the female and male genital tract 17 years ago...... indicated a putative role for this peptide in the local nervous control of reproductive functions. The genes encoding the preprovasoactive intestinal polypeptide precursor molecule and the vasoactive intestinal polypeptide receptor have been identified. The gene expression has been studied by the use...... in the genital tracts (i.e., blood flow and nonvascular smooth muscle relaxation). In the ovary vasoactive intestinal polypeptide seems to play an important role as regulator and/or modulator of folliculogenesis and steroidogenesis. In the male genital tract vasoactive intestinal polypeptide seems to participate...

Labelling of TTHA coupled IgG and MCAb with rare earth radionuclides

International Nuclear Information System (INIS)

Wu Younghui; Zhang Yulei; Wu Chuanchu; Wang Xiangyun; Liu Yuanfang

1988-07-01

This article expands a process of labelling G-immunoglobulin (IgG) and monoclonal antibody (MCAb) with rare earth radionuclides. In this labelling process, cycloanhydride (CTTHAA) of Tri-ethyl Tetra-amine Hexa-acetic Acid (TTHA) is employed as a bifunctional chelating conjugate, the metal chelation takes place after CTTHAA has first been linked to IgG, followed by chemical reaction with rare earth radionuclides. Detailed investigations have been carried out to examine the influencing parameters of labelling globulins with rare earth, such as metal to CTTHAA mole-ratio, pH value and labelling time. The immunoreactivity of the labelled compound (RE-TTHA-IgG) has been retained throughout the whole labelling process

Peptides and polypeptides as scaffolds for optoelectronics and biomaterials applications

Science.gov (United States)

Charati, Manoj B.

Peptides and polypeptides are emerging as a new class of biomaterials due to their unique structural, physiochemical, mechanical, and biological properties. The development of peptide and protein-based biomaterials is driven by the convergence of convenient techniques for peptide/protein engineering and its importance in applications as smart biomaterials. The thesis is divided in two parts; the first part highlights the importance of incorporation of non-natural amino acids into peptides and proteins. In particular, incorporation on p-bromophenylalanine in short alpha-helical peptide templates to control the association of chromophores is discussed. In the second part, design of a multi-component, biocompatible polypeptide with superior elasticity is discussed. Part 1. Novel peptide templates to control association of chromophores. Tailor made peptide and protein materials have many versatile applications, as both conformation and functional group position can be controlled. Such control may have intriguing applications in the development of hybrid materials for electroactive applications. A critical need in fabricating devices from organic semiconducting materials is to achieve control over the conformation and distance between two conjugated chains. Controlling chromophore spacing and orientation with required precision over nanometer length scale poses a greater challenge. Here we propose a peptide based template to control the alignment of the methylstilbene and Oxa-PPV chromophores with desired orientations and spacing. The hybrid peptides were characterized via CD, exciton coupled CD, 1H NMR and photoluminescence experiments. It is observed that slight change in the orientation of molecules has pronounced effect on the photo-physical behavior of the molecules. Characterization of the hybrid peptides via circular dichroism (CD) confirmed the helical character of the designed peptides and indicated that inclusion of non-natural amino acids has significant

[New drug developments of snake venom polypeptides and progress].

Science.gov (United States)

Fu, Sihai; Feng, Mei; Xiong, Yan

2017-11-28

The value of snake venom polypeptides in clinical application has drawn extensive attention, and the development of snake polypeptides into new drugs with anti-tumor, anti-inflammatory, antithrombotic, analgesic or antihypertensive properties has become the recent research hotspot. With the rapid development of molecular biology and biotechnology, the mechanisms of snake venom polypeptides are also gradually clarified. Numerous studies have demonstrated that snake venom polypeptides exert their pharmacological effects by regulating ion channels, cell proliferation, apoptosis, intracellular signaling pathway, and expression of cytokine as well as binding to relevant active sites or receptors.

Simulation Studies of LCST-like Phase Transitions in Elastin-like Polypeptides (ELPs) and Conjugates of ELP with Rigid Macromolecules

Science.gov (United States)

Condon, Joshua; Martin, Tyler; Jayaraman, Arthi

We use atomistic (AA) and coarse-grained (CG) molecular dynamics simulations to elucidate the thermodynamic driving forces governing lower critical solution temperature (LCST)-like phase transition exhibited by elastin-like peptides (ELPs) and conjugates of ELP with other macromolecules. In the AA simulations, we study ELP oligomers in explicit water, and mark the transition as the temperature at which they undergo a change in ``hydration'' state. While AA simulations are restricted to small systems of short ELPs and do not capture the chain aggregation observed in experiments of ELPs, they guide the phenomenological CG model development by highlighting the solvent induced polymer-polymer effective interactions with changing temperature. In the CG simulations, we capture the LCST polymer aggregation by increasing polymer-polymer effective attractive interactions in an implicit solvent. We examine the impact of conjugating a block of LCST polymer to another rigid unresponsive macromolecular block on the LCST-like transition. We find that when multiple LCST polymers are conjugated to a rigid polymer block, increased crowding of the LCST polymers shifts the onset of chain aggregation to smaller effective polymer-polymer attraction compared to the free LCST polymers. These simulation results provide guidance on the design of conjugated bio-mimetic thermoresponsive materials, and shape the fundamental understanding of the impact of polymer crowding on phase behavior in thermoresponsive LCST polymer systems.

Caffeine-water-polypeptide interaction in aqueous solution

Science.gov (United States)

Ghabi, Habib; Dhahbi, Mahmoud

1999-04-01

The interaction of caffeine monomer with the synthetic polypeptides polyasparagine (pAg) and polyaspartic acid (pAsp) was studied by UV spectrophotometry. The results show that different types of interactions are possible depending on the nature of polypeptide. The form of the complex was discussed.

Polypeptides having beta-glucosidase activity and polynucleotides encoding the same

Science.gov (United States)

Brown, Kimberly; Harris, Paul

2013-12-17

The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Conjugate whole-body scanning system for quantitative measurement of organ distribution in vivo

International Nuclear Information System (INIS)

Tsui, B.M.W.; Chen, C.T.; Yasillo, N.J.; Ortega, C.J.; Charleston, D.B.; Lathrop, K.A.

1979-01-01

The determination of accurate, quantitative, biokinetic distribution of an internally dispersed radionuclide in humans is important in making realistic radiation absorbed dose estimates, studying biochemical transformations in health and disease, and developing clinical procedures indicative of abnormal functions. In order to collect these data, a whole-body imaging system is required which provides both adequate spatial resolution and some means of absolute quantitation. Based on these considerations, a new whole-body scanning system has been designed and constructed that employs the conjugate counting technique. The conjugate whole-body scanning system provides an efficient and accurate means of collecting absolute quantitative organ distribution data of radioactivity in vivo

Chimeric polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

Science.gov (United States)

Wogulis, Mark; Sweeney, Matthew; Heu, Tia

2017-06-14

The present invention relates to chimeric GH61 polypeptides having cellulolytic enhancing activity. The present invention also relates to polynucleotides encoding the chimeric GH61 polypeptides; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the chimeric GH61 polypeptides.

99mTc-HYNIC-derivatized ternary ligand complexes for 99mTc-labeled polypeptides with low in vivo protein binding

International Nuclear Information System (INIS)

Ono, Masahiro; Arano, Yasushi; Mukai, Takahiro; Fujioka, Yasushi; Ogawa, Kazuma; Uehara, Tomoya; Saga, Tsuneo; Konishi, Junji; Saji, Hideo

2001-01-01

6-Hydrazinopyridine-3-carboxylic acid (HYNIC) is a representative agent used to prepare technetium-99m ( 99m Tc)-labeled polypeptides with tricine as a coligand. However, 99m Tc-HYNIC-labeled polypeptides show delayed elimination rates of the radioactivity not only from the blood but also from nontarget tissues such as the liver and kidney. In this study, a preformed chelate of tetrafluorophenol (TFP) active ester of [ 99m Tc](HYNIC)(tricine)(benzoylpyridine: BP) ternary complex was synthesized to prepare 99m Tc-labeled polypeptides with higher stability against exchange reactions with proteins in plasma and lysosomes using the Fab fragment of a monoclonal antibody and galactosyl-neoglycoalbumin (NGA) as model polypeptides. When incubated in plasma, [ 99m Tc](HYNIC-Fab)(tricine)(BP) showed significant reduction of the radioactivity in high molecular weight fractions compared with [ 99m Tc](HYNIC-Fab)(tricine) 2. When injected into mice, [ 99m Tc](HYNIC-NGA)(tricine)(BP) was metabolized to [ 99m Tc](HYNIC-lysine)(tricine)(BP) in the liver with no radioactivity detected in protein-bound fractions in contrast to the observations with [ 99m Tc](HYNIC-NGA)(tricine) 2. In addition, [ 99m Tc](HYNIC-NGA)(tricine)(BP) showed significantly faster elimination rates of the radioactivity from the liver as compared with [ 99m Tc](HYNIC-NGA)(tricine) 2. Similar results were observed with 99m Tc-labeled Fab fragments where [ 99m Tc](HYNIC-Fab)(tricine)(BP) exhibited significantly faster elimination rates of the radioactivity not only from the blood but also from the kidney. These findings indicated that conjugation of [ 99m Tc](HYNIC)(tricine)(BP) ternary ligand complex to polypeptides accelerated elimination rates of the radioactivity from the blood and nontarget tissues due to low binding of the [ 99m Tc](HYNIC)(tricine)(BP) complex with proteins in the blood and in the lysosomes. Such characteristics would render the TFP active ester of [ 99m Tc](HYNIC)(tricine)(BP) complex

DOTA-PESIN, a DOTA-conjugated bombesin derivative designed for the imaging and targeted radionuclide treatment of bombesin receptor-positive tumours

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hanwen; Maecke, Helmut R. [University Hospital Basel, Division of Radiological Chemistry, Department of Radiology, Basel (Switzerland); Schuhmacher, Jochen; Eisenhut, Michael [German Cancer Research Centre, Department of Radiopharmaceutical Chemistry, Heidelberg (Germany); Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, P.O. Box 62, Berne (Switzerland); Wild, Damian [University Hospital, Clinic and Institute of Nuclear Medicine, Department of Radiology, Basel (Switzerland)

2007-08-15

We aimed at designing and developing a novel bombesin analogue, DOTA-PEG{sub 4}-BN(7-14) (DOTA-PESIN), with the goal of labelling it with {sup 67/68}Ga and {sup 177}Lu for diagnosis and radionuclide therapy of prostate and other human cancers overexpressing bombesin receptors. The 8-amino acid peptide bombesin (7-14) was coupled to the macrocyclic chelator DOTA via the spacer 15-amino-4,7,10,13-tetraoxapentadecanoic acid (PEG{sub 4}). The conjugate was complexed with Ga(III) and Lu(III) salts. The GRP receptor affinity and the bombesin receptor subtype profile were determined in human tumour specimens expressing the three bombesin receptor subtypes. Internalisation and efflux studies were performed with the human GRP receptor cell line PC-3. Xenografted nude mice were used for biodistribution. [Ga{sup III}/Lu{sup III}]-DOTA-PESIN showed good affinity to GRP and neuromedin B receptors but no affinity to BB3. [{sup 67}Ga/{sup 177}Lu]-DOTA-PESIN internalised rapidly into PC-3 cells whereas the efflux from PC-3 cells was relatively slow. In vivo experiments showed a high and specific tumour uptake and good retention of [{sup 67}Ga/{sup 177}Lu]-DOTA-PESIN. [{sup 67}Ga/{sup 177}Lu]-DOTA-PESIN highly accumulated in GRP receptor-expressing mouse pancreas. The uptake specificity was demonstrated by blocking tumour uptake and pancreas uptake. Fast clearance was found from blood and all non-target organs except the kidneys. High tumour-to-normal tissue ratios were achieved, which increased with time. PET imaging with [{sup 68}Ga]-DOTA-PESIN was successful in visualising the tumour at 1 h post injection. Planar scintigraphic imaging showed that the {sup 177}Lu-labelled peptide remained in the tumour even 3 days post injection. The newly designed ligands have high potential with regard to PET and SPECT imaging with {sup 68/67}Ga and targeted radionuclide therapy with {sup 177}Lu. (orig.)

GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

DEFF Research Database (Denmark)

2017-01-01

The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

The study of conjugation of anti-CD20 monoclonal antibody for labeling with metallic or lanthanides radionuclides; Estudo de conjugacao do anticorpo anti-CD20 para marcacao com radionuclideos metalicos ou lantanideos

Energy Technology Data Exchange (ETDEWEB)

Akanji, Akinkunmi Ganiyu

2012-07-01

Lymphomas are malignancies or cancers that start from the malign transformation of a lymphocyte in the lymphatic system. Generally, lymphomas start from the lymph nodes or from the agglomeration of the lymphatic tissues, organs like stomach, intestines, in some cases it can involve the bone marrow and the blood, it can also disseminate to other organs. Lymphomas are divided in two major categories: Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Patient with NHL are generally treated with radiotherapy alone or combined with immunotherapy using monoclonal antibody rituximab (MabThera Registered-Sign ). Currently, monoclonal antibodies (Acm) conjugated with bifunctional chelate agents and radiolabeled with metallic or lanthanides radionuclides are a treatment reality for patients with NHL by the principle of radioimmunotherapy (RIT). This study focused on the conditions of conjugation of Acm rituximab (MabThera Registered-Sign ) with bifunctional chelating agents DOTA and DTPA. Various parameters were studied: method of Acm purification, conditions of Acm conjugation, the method for determination of number of chelate agent coupled to the Acm, method for purification of the conjugated antibody Acm, conditions of labeling of the conjugated antibody with lutetium-177, method of purification of the radiolabeled immuno conjugate, method of radiochemical purity (RP), specific binding in vitro Raji cells (Human Burkitt) and biological distribution performed in normal Balb-c mouse. The three methodologies employed in pre-purification of Acm (dialysis, size exclusion chromatograph and dial filtration) demonstrated to be efficient; they provided sample recovery exceeding 90%. However, the methodology of dial filtration presents minimal sample loss, and gave the final recovery of the sample in micro liters; thereby facilitating sample use in subsequent experiments. Numbers of chelators attached to the Acm molecule was proportional to the molar ratio studied. When we evaluated

Tunable drug loading and release from polypeptide multilayer nanofilms

Science.gov (United States)

Jiang, Bingbing; Li, Bingyun

2009-01-01

Polypeptide multilayer nanofilms were prepared using electrostatic layer-by-layer self-assembly nanotechnology. Small charged drug molecules (eg, cefazolin, gentamicin, and methylene blue) were loaded in polypeptide multilayer nanofilms. Their loading and release were found to be pH-dependent and could also be controlled by changing the number of film layers and drug incubation time, and applying heat-treatment after film formation. Antibioticloaded polypeptide multilayer nanofilms showed controllable antibacterial properties against Staphylococcus aureus. The developed biodegradable polypeptide multilayer nanofilms are capable of loading both positively- and negatively-charged drug molecules and promise to serve as drug delivery systems on biomedical devices for preventing biomedical device-associated infection, which is a significant clinical complication for both civilian and military patients. PMID:19421369

First meeting on the CRP 'standardized high current solid targets for cyclotron production of diagnostic and therapeutic radionuclides'

International Nuclear Information System (INIS)

Winkel, P. van den

2000-01-01

The Cyclotron Department of the VUB has three groups performing research in the field of target development, production of radionuclides and their application in nuclear medicine. 1. The Physics Group is busy on the optimization of beam parameters, on the determination of cross sections and on neutron spectrometry. 2. The Inorganic Radiochemistry Group performs research on solid target electroplating (Tl, Zn, Cd, Rh ... ), on optimisation of target carrier geometry and cooling and on automated PC-controlled radiochemistry (Tl-201, Ga-67, In-111) and recovery systems and the associated software written in Modula-2 and Visual Basic. 3. The Organic Radiochemistry Group develops new techniques for radiolabelling of organic molecules (fatty acids, neuroleptics, synthetic polypeptides...) useful in diagnostic and therapeutic nuclear medicine. All three groups take part in bulk productions of radionuclides

The use of radiocobalt as a label improves imaging of EGFR using DOTA-conjugated Affibody molecule

DEFF Research Database (Denmark)

Garousi, Javad; Andersson, Ken G; Dam, Johan H

2017-01-01

-expressing xenografts in mice. An optimal combination of radionuclide, chelator and targeting protein may further improve the contrast of radionuclide imaging. The aim of this study was to evaluate the targeting properties of radiocobalt-labelled DOTA-ZEGFR:2377. DOTA-ZEGFR:2377 was labelled with (57)Co (T1/2 = 271.8 d......), (55)Co (T1/2 = 17.5 h), and, for comparison, with the positron-emitting radionuclide (68)Ga (T1/2 = 67.6 min) with preserved specificity of binding to EGFR-expressing A431 cells. The long-lived cobalt radioisotope (57)Co was used in animal studies. Both (57)Co-DOTA-ZEGFR:2377 and (68)Ga-DOTA......Several anti-cancer therapies target the epidermal growth factor receptor (EGFR). Radionuclide imaging of EGFR expression in tumours may aid in selection of optimal cancer therapy. The (111)In-labelled DOTA-conjugated ZEGFR:2377 Affibody molecule was successfully used for imaging of EGFR...

Online size-exclusion high-performance liquid chromatography light scattering and differential refractometry methods to determine degree of polymer conjugation to proteins and protein-protein or protein-ligand association states.

Science.gov (United States)

Kendrick, B S; Kerwin, B A; Chang, B S; Philo, J S

2001-12-15

Characterizing the solution structure of protein-polymer conjugates and protein-ligand interactions is important in fields such as biotechnology and biochemistry. Size-exclusion high-performance liquid chromatography with online classical light scattering (LS), refractive index (RI), and UV detection offers a powerful tool in such characterization. Novel methods are presented utilizing LS, RI, and UV signals to rapidly determine the degree of conjugation and the molecular mass of the protein conjugate. Baseline resolution of the chromatographic peaks is not required; peaks need only be sufficiently separated to represent relatively pure fractions. An improved technique for determining the polypeptide-only mass of protein conjugates is also described. These techniques are applied to determining the degree of erythropoietin glycosylation, the degree of polyethylene glycol conjugation to RNase A and brain-derived neurotrophic factor, and the solution association states of these molecules. Calibration methods for the RI, UV, and LS detectors will also be addressed, as well as online methods to determine protein extinction coefficients and dn/dc values both unconjugated and conjugated protein molecules. (c)2001 Elsevier Science.

Star-Shaped Polypeptides: Synthesis and Opportunities for Delivery of Therapeutics.

Science.gov (United States)

Byrne, Mark; Murphy, Robert; Kapetanakis, Antonios; Ramsey, Joanne; Cryan, Sally-Ann; Heise, Andreas

2015-09-17

Significant advances in the synthesis of polypeptides by N-carboxyanhydride (NCA) polymerisation over the last decade have enabled the design of advanced polypeptide architectures such as star-shaped polypeptides. These materials combine the functionality offered by amino acids with the flexibility of creating stable nanoparticles with adjustable cargo space for therapeutic delivery. This review highlights recent advances in the synthesis of star polypeptides by NCA polymerisation followed by a critical review of the applications of this class of polymer in the delivery of therapeutic agents. This includes examples of traditional small-molecule drugs as well as the emerging class of biologics such as genetic therapeutics (gene delivery). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polypeptide profiles of human oocytes and preimplantation embryos.

Science.gov (United States)

Capmany, G; Bolton, V N

1993-11-01

The polypeptides that direct fertilization and early development until activation of the embryonic genome occurs, at the 4-8 cell stage in the human, are exclusively maternal in origin, and are either synthesized during oogenesis or translated later from maternal mRNA. Using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and silver stain, we have visualized and compared the polypeptides present in different populations of human oocytes and cleavage stage embryos obtained after superovulation and insemination in vitro. Two polypeptide patterns were resolved, differing in the region of mol. wt 69 kDa. The distribution of these patterns showed no correlation with the ability of individual oocytes to achieve fertilization and develop normally to the 8-cell stage.

A paclitaxel-loaded recombinant polypeptide nanoparticle outperforms Abraxane in multiple murine cancer models

Science.gov (United States)

Bhattacharyya, Jayanta; Bellucci, Joseph J.; Weitzhandler, Isaac; McDaniel, Jonathan R.; Spasojevic, Ivan; Li, Xinghai; Lin, Chao-Chieh; Chi, Jen-Tsan Ashley; Chilkoti, Ashutosh

2015-08-01

Packaging clinically relevant hydrophobic drugs into a self-assembled nanoparticle can improve their aqueous solubility, plasma half-life, tumour-specific uptake and therapeutic potential. To this end, here we conjugated paclitaxel (PTX) to recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into ~60 nm near-monodisperse nanoparticles that increased the systemic exposure of PTX by sevenfold compared with free drug and twofold compared with the Food and Drug Administration-approved taxane nanoformulation (Abraxane). The tumour uptake of the CP-PTX nanoparticle was fivefold greater than free drug and twofold greater than Abraxane. In a murine cancer model of human triple-negative breast cancer and prostate cancer, CP-PTX induced near-complete tumour regression after a single dose in both tumour models, whereas at the same dose, no mice treated with Abraxane survived for >80 days (breast) and 60 days (prostate), respectively. These results show that a molecularly engineered nanoparticle with precisely engineered design features outperforms Abraxane, the current gold standard for PTX delivery.

Proteolytic processing of poliovirus polypeptides: antibodies to polypeptide P3-7c inhibit cleavage at glutamine-glycine pairs

International Nuclear Information System (INIS)

Hanecak, R.; Semler, B.L.; Anderson, C.W.; Wimmer, E.

1982-01-01

Proteolytic processing of poliovirus polypeptides was examined by the addition of antibodies directed against the viral proteins P3-7c and P2-X to a cell-free translation extract prepared from infected HeLa cells. Antisera to P3-7c specifically inhibited in vitro processing at Gln-Gly pairs. Partial amino acid sequence analysis revealed a second Tyr-Gly pair that is utilized in protein processing. Neither Tyr-Gly cleavage is affected by antibody to P3-7C. Anti-P3-7c antibodies react not only with P3-7c but also with P3-6a and P3-2, two viral polypeptides NH 2 -coterminal with P3-7c. Preimmune and anti-P2-X antibodies had no effect on the processing of poliovirus proteins in vitro. The authors conclude that the activity responsible for processing poliovirus polypeptides at Gln-Gly pairs resides in the primary structure of P3-7c and not in P2-X

UV cross-linking of polypeptides associated with 3'-terminal exons

International Nuclear Information System (INIS)

Stolow, D.T.; Berget, S.M.

1990-01-01

Association of nuclear proteins with chimeric vertebrate precursor RNAs containing both polyadenylation signals and an intron was examined by UV cross-linking. One major difference in cross-linking pattern was observed between this chimeric precursor RNA and precursors containing only polyadenylation or splicing signals. The heterogeneous nuclear ribonucleoprotein (hnRNP) polypeptide C cross-linked strongly to sequences downstream of the A addition site in polyadenylation precursor RNA containing only the polyadenylation signal from the simian virus 40 (SV40) late transcription unit. In contrast, the hnRNP C polypeptide cross-linked to chimeric RNA containing the same SV40 late poly(A) cassette very poorly, at a level less than 5% of that observed with the precursor RNA containing just the poly(A) site. Observation that cross-linking of the hnRNP C polypeptide to elements within the SV40 late poly(A) site was altered by the presence of an upstream intron suggests differences in the way nuclear factors associate with poly(A) sites in the presence and absence of an upstream intron. Cross-linking of C polypeptide to chimeric RNA increased with RNAs mutated for splicing or polyadenylation consensus sequences and under reaction conditions (high magnesium) that inhibited polyadenylation. Furthermore, cross-linking of hnRNP C polypeptide to precursors containing just the SV40 late poly(A) site was eliminated in the presence of competing poly(U); polyadenylation, however, was unaffected. Correlation of loss of activity with high levels of hnRNP C polypeptide cross-linking raises questions about the specificity of the interaction between the hnRNP C polypeptide and polyadenylation precursor RNAs in vitro

Glycosyltransferase glycosylating flavokermesic acid and/or kermesic acid

DEFF Research Database (Denmark)

2016-01-01

An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

GLYCOSYLTRANSFERASE GLYCOSYLATING FLAVOKERMESIC ACID AND/OR KERMESIC ACID

DEFF Research Database (Denmark)

2015-01-01

An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

Biochemical map of polypeptides specified by foot-and-mouth disease virus.

OpenAIRE

Grubman, M J; Robertson, B H; Morgan, D O; Moore, D M; Dowbenko, D

1984-01-01

Pulse-chase labeling of foot-and-mouth disease virus-infected bovine kidney cells revealed stable and unstable viral-specific polypeptides. To identify precursor-product relationships among these polypeptides, antisera against a number of structural and nonstructural viral-specific polypeptides were used. Cell-free translations programmed with foot-and-mouth disease virion RNA or foot-and-mouth disease virus-infected bovine kidney cell lysates, which were shown to contain almost identical pol...

Polypeptide based hydrogels

OpenAIRE

Hanay, Saltuk

2018-01-01

There is a need for biocompatible, biodegradable, 3-D printable and stable hydrogels especially in the areas of tissue engineering, drug delivery, bio-sensing technologies and antimicrobial coatings. The main aim of this Ph.D. work was to fabricate polypeptide based hydrogel which may find a potential application in those fields. Focusing on tyrosine or tryptophan-containing copolypeptides prepared by NCarboxyanhydride (NCA) polymerizations, three different crosslinking strategies have been t...

Simultaneous Polymerization and Polypeptide Particle Production via Reactive Spray-Drying.

Science.gov (United States)

Glavas, Lidija; Odelius, Karin; Albertsson, Ann-Christine

2016-09-12

A method for producing polypeptide particles via in situ polymerization of N-carboxyanhydrides during spray-drying has been developed. This method was enabled by the development of a fast and robust synthetic pathway to polypeptides using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an initiator for the ring-opening polymerization of N-carboxyanhydrides. The polymerizations finished within 5 s and proved to be very tolerant toward impurities such as amino acid salts and water. The formed particles were prepared by mixing the monomer, N-carboxyanhydride of l-glutamic acid benzyl ester (NCAGlu) and the initiator (DBU) during the atomization process in the spray-dryer and were spherical with a size of ∼1 μm. This method combines two steps; making it a straightforward process that facilitates the production of polypeptide particles. Hence, it furthers the use of spray-drying and polypeptide particles in the pharmaceutical industry.

Unique Helicase Determinants in the Essential Conjugative TraI Factor from Salmonella enterica Serovar Typhimurium Plasmid pCU1

Energy Technology Data Exchange (ETDEWEB)

McLaughlin, Krystle J.; Nash, Rebekah P.; Redinbo, Mathew R. (UNC)

2014-06-16

The widespread development of multidrug-resistant bacteria is a major health emergency. Conjugative DNA plasmids, which harbor a wide range of antibiotic resistance genes, also encode the protein factors necessary to orchestrate the propagation of plasmid DNA between bacterial cells through conjugative transfer. Successful conjugative DNA transfer depends on key catalytic components to nick one strand of the duplex DNA plasmid and separate the DNA strands while cell-to-cell transfer occurs. The TraI protein from the conjugative Salmonella plasmid pCU1 fulfills these key catalytic roles, as it contains both single-stranded DNA-nicking relaxase and ATP-dependent helicase domains within a single, 1,078-residue polypeptide. In this work, we unraveled the helicase determinants of Salmonella pCU1 TraI through DNA binding, ATPase, and DNA strand separation assays. TraI binds DNA substrates with high affinity in a manner influenced by nucleic acid length and the presence of a DNA hairpin structure adjacent to the nick site. TraI selectively hydrolyzes ATP, and mutations in conserved helicase motifs eliminate ATPase activity. Surprisingly, the absence of a relatively short (144-residue) domain at the extreme C terminus of the protein severely diminishes ATP-dependent strand separation. Collectively, these data define the helicase motifs of the conjugative factor TraI from Salmonella pCU1 and reveal a previously uncharacterized C-terminal functional domain that uncouples ATP hydrolysis from strand separation activity.

The influence of the side-chain sequence on the structure-activity correlations of immunomodulatory branched polypeptides. Synthesis and conformational analysis of new model polypeptides.

Science.gov (United States)

Mezö, G; Hudecz, F; Kajtár, J; Szókán, G; Szekerke, M

1989-10-01

New branched polypeptides were synthesized for a detailed study of the influence of the side-chain structure on the conformation and biological properties. The first subset of polypeptides were prepared by coupling of tetrapeptides to poly[L-Lys]. These polymers contain either DL-Ala3-X [poly[Lys-(X-DL-Ala3)n

Microreactor and method for preparing a radiolabeled complex or a biomolecule conjugate

Energy Technology Data Exchange (ETDEWEB)

Reichert, David E; Kenis, Paul J. A.; Wheeler, Tobias D; Desai, Amit V; Zeng, Dexing; Onal, Birce C

2015-03-17

A microreactor for preparing a radiolabeled complex or a biomolecule conjugate comprises a microchannel for fluid flow, where the microchannel comprises a mixing portion comprising one or more passive mixing elements, and a reservoir for incubating a mixed fluid. The reservoir is in fluid communication with the microchannel and is disposed downstream of the mixing portion. A method of preparing a radiolabeled complex includes flowing a radiometal solution comprising a metallic radionuclide through a downstream mixing portion of a microchannel, where the downstream mixing portion includes one or more passive mixing elements, and flowing a ligand solution comprising a bifunctional chelator through the downstream mixing portion. The ligand solution and the radiometal solution are passively mixed while in the downstream mixing portion to initiate a chelation reaction between the metallic radionuclide and the bifunctional chelator. The chelation reaction is completed to form a radiolabeled complex.

Induction of protein body formation in plant leaves by elastin-like polypeptide fusions

Directory of Open Access Journals (Sweden)

Joensuu Jussi J

2009-08-01

Full Text Available Abstract Background Elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'VPGXG' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. In addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. This study's main objectives were to determine the general utility of elastin-like polypeptide protein fusions in various intracellular compartments and to elucidate elastin-like polypeptide's mechanism of action for increasing recombinant protein accumulation in the endoplasmic reticulum of plants. Results The effect of elastin-like polypeptide fusions on the accumulation of green fluorescent protein targeted to the cytoplasm, chloroplasts, apoplast, and endoplasmic reticulum was evaluated. The endoplasmic reticulum was the only intracellular compartment in which an elastin-like polypeptide tag was shown to significantly enhance recombinant protein accumulation. Interestingly, endoplasmic reticulum-targeted elastin-like polypeptide fusions induced the formation of a novel type of protein body, which may be responsible for elastin-like polypeptide's positive effect on recombinant protein accumulation by excluding the heterologous protein from normal physiological turnover. Although expressed in the leaves of plants, these novel protein bodies appeared similar in size and morphology to the prolamin-based protein bodies naturally found in plant seeds. The elastin-like polypeptide-induced protein bodies were highly mobile organelles, exhibiting various dynamic patterns of movement throughout the cells, which were dependent on intact actin microfilaments and a functional actomyosin motility system. Conclusion An endoplasmic reticulum-targeted elastin-like polypeptide fusion approach

Basal serum pancreatic polypeptide is dependent on age and gender in an adult population

DEFF Research Database (Denmark)

Brimnes Damholt, M; Rasmussen, B K; Hilsted, L

1997-01-01

This study is the first epidemiologically based study of basal levels of serum pancreatic polypeptide (s-PP). The basal level of serum PP has become a field of interest mainly due to the role of PP as an endocrine tumour marker, and as a marker of pancreatic neuroendocrine function after pancreas...... a monospecific radioimmunoassay. Fasting serum pancreatic polypeptide depended on age and gender. The results demonstrated that fasting pancreatic polypeptide levels increase exponentially with age. Fitted separately for each sex, basal serum pancreatic polypeptide was found to increase by approximately 3% per...... reports on the fasting levels of serum pancreatic polypeptide are most likely due to lack of adjustment for age and gender. Thus, variation due to age and gender should be considered in evaluating fasting levels of serum pancreatic polypeptide. Whether similar considerations are important when evaluating...

Side-chain-controlled self-assembly of polystyrene-polypeptide miktoarm star copolymers

KAUST Repository

Junnila, Susanna

2012-03-27

We show how the self-assembly of miktoarm star copolymers can be controlled by modifying the side chains of their polypeptide arms, using A 2B and A 2B 2 type polymer/polypeptide hybrids (macromolecular chimeras). Initially synthesized PS 2PBLL and PS 2PBLL 2 (PS, polystyrene; PBLL, poly(ε-tert-butyloxycarbonyl-l-lysine) ) miktoarms were first deprotected to PS 2PLLHCl and PS 2PLLHCl 2 miktoarms (PLLHCl, poly(l-lysine hydrochloride)) and then complexed ionically with sodium dodecyl sulfonate (DS) to give the supramolecular complexes PS 2PLL(DS) and PS 2(PLL(DS)) 2. The solid-state self-assemblies of these six miktoarm systems were studied by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and small- and wide-angle X-ray scattering (SAXS, WAXS). The side chains of the polypeptide arms were observed to have a large effect on the solubility, polypeptide conformation, and self-assembly of the miktoarms. Three main categories were observed: (i) lamellar self-assemblies at the block copolymer length scale with packed layers of α-helices in PS 2PBLL and PS 2PBLL 2; (ii) charge-clustered polypeptide micelles with less-defined conformations in a nonordered lattice within a PS matrix in PS 2PLLHCl and PS 2PLLHCl 2; (iii) lamellar polypeptide-surfactant self-assemblies with β-sheet conformation in PS 2PLL(DS) and PS 2(PLL(DS)) 2 which dominate over the formation of block copolymer scale structures. Differences between the 3- and 4-arm systems illustrate how packing frustration between the coil-like PS arms and rigid polypeptide conformations can be relieved by the right number of arms, leading to differences in the extent of order. © 2012 American Chemical Society.

Avian leukosis virus is a versatile eukaryotic platform for polypeptide display

International Nuclear Information System (INIS)

Khare, Pranay D.; Russell, Stephen J.; Federspiel, Mark J.

2003-01-01

Display technology refers to methods of generating libraries of modularly coded biomolecules and screening them for particular properties. Retroviruses are good candidates to be a eukaryotic viral platform for the display of polypeptides synthesized in eukaryotic cells. Here we demonstrate that avian leukosis virus (ALV) provides an ideal platform for display of nonviral polyaeptides expressed in a eukaryotic cell substrate. Different sizes of polypeptides were genetically fused to the extreme N-terminus of the ALV envelope glycoprotein in an ALV infectious clone containing an alkaline phosphatase reporter gene. The chimeric envelope glycoproteins were efficiently incorporated into virions and were stably displayed on the surface of the virions through multiple virus replication cycles. The foreign polypeptides did not interfere with the attachment and entry functions of the underlying ALV envelope glycoproteins. The displayed polypeptides were fully functional and could efficiently mediate attachment of the recombinant viruses to their respective cognate receptors. This study demonstrates that ALV is an ideal display platform for the generation and selection of libraries of polypeptides where there is a need for expression, folding, and posttranslational modification in the endoplasmic reticulum of eukaryotic cells

Polypeptide synthesis in alphavirus-infected aedes albopictus cells during the establishment of persistent infection

International Nuclear Information System (INIS)

Richardson, M.A.; Boulton, R.W.; Raghow, R.S.; Dalgarno, L.

1980-01-01

Polypeptide synthesis was examined in mosquito cells during the establishment of a persistent infection with two alphaviruses, Ross River virus (RRV) and Semliki Forest virus (SFV), and in vertebrate cells cytopathically-infected with the same viruses. In Aedes albopictus cells, RRV reached peak titres at 34-48 hours p.i. At 12 hours 85 per cent of cells assayed as infected by infective centre assay; by 48 hours when persistence was established, virus production was reduced and <5 per cent of cells assayed as infected. There was not shutdown of host polypeptide synthesis during infection. Viral polypeptide synthesis was maximal between 10 and 24 hours p.i. The major viral polypeptides labelled were nucleocapsid protein and envelope protein(s).The precursor polypeptide p95 which was prominent in infected BHK cells was not detected in mosquito cells. Similar results were obtained on SFV infection. During the establishment of persistence there was a coordinate decline in the synthesis of RRV polypeptides, reaching undetectable levels by 72 hours p.i. Subculturing persistently-infected cells led to a small increase in viral polypeptide synthesis and virus titre. In contrast, during RRV growth in BHK cells host protein synthesis was severely inhibited and by 9-11 hours p.i. virus-specific polypeptide synthesis represented more than 90 per cent of total protein synthetic activity. (author)

Country report: Italy (Chinol). Pre-clinical evaluation of a new biotin-DOTA conjugate labeled with 90Y for application in pretargeting clinical protocols

International Nuclear Information System (INIS)

Chinol, Marco

2010-01-01

In the attempt to improve the therapeutic efficacy of radiolabeled mAbs in cancer radioimmunotherapy, various studies have examined the concept of tumor pretargeting. The so called three-step pretargeting technique, employing the avidin–biotin system, was applied in phase I-II clinical trials showing low toxicity and therapeutic efficacy. The final step of the pretargeting protocols consists in the systemic injection of radiolabeled biotin. The worldwide recognized “successful association” is between 90 Y and the tetraazamacrocycle DOTA chelator chemically bound to biotin. Improvements in the structure of the biotin-DOTA conjugate have been reported by our group following a novel approach which simplified the synthetic pattern by reducing the amide group to a methylene group, thus transforming the amide into a secondary amine without affecting the length of the biotin side arm. Preliminary in-vitro experiments, previously published by our group, indicated the potential of the new conjugate. Based on our previous experience with avidin-based pre-targeting followed 90 Y-DOTA-biotin in the locoregional treatment of peritoneal carcinomatosis and malignant glioma suggested that similar radionuclide therapy might be worth investigating as a partial replacement of external beam radiotherapy in breast cancer. We have developed IART® the Intra-operative Avidination for Radionuclide Therapy that relies on the avidin-biotin binding system. In fact, the “avidination” of the anatomical area of the tumor with native avidin, directly injected by the surgeon into and around the tumor bed, provides a target for the radiolabeled biotin intravenously (iv) injected one day later. In order to optimize the overall strategy, further efforts were needed to optimize the use of the labeled new biotin conjugate and to elucidate its chemical and biological properties. In the first 18 months of this CRP, the pre-clinical evaluation of this new reduced biotinamidohexylamine

Radionuclide toxicity

International Nuclear Information System (INIS)

Galle, P.

1982-01-01

The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

A de novo designed 11 kDa polypeptide: model for amyloidogenic intrinsically disordered proteins.

Science.gov (United States)

Topilina, Natalya I; Ermolenkov, Vladimir V; Sikirzhytski, Vitali; Higashiya, Seiichiro; Lednev, Igor K; Welch, John T

2010-07-01

A de novo polypeptide GH(6)[(GA)(3)GY(GA)(3)GE](8)GAH(6) (YE8) has a significant number of identical weakly interacting beta-strands with the turns and termini functionalized by charged amino acids to control polypeptide folding and aggregation. YE8 exists in a soluble, disordered form at neutral pH but is responsive to changes in pH and ionic strength. The evolution of YE8 secondary structure has been successfully quantified during all stages of polypeptide fibrillation by deep UV resonance Raman (DUVRR) spectroscopy combined with other morphological, structural, spectral, and tinctorial characterization. The YE8 folding kinetics at pH 3.5 are strongly dependent on polypeptide concentration with a lag phase that can be eliminated by seeding with a solution of folded fibrillar YE8. The lag phase of polypeptide folding is concentration dependent leading to the conclusion that beta-sheet folding of the 11-kDa amyloidogenic polypeptide is completely aggregation driven.

Methods of separating short half-life radionuclides from a mixture of radionuclides

International Nuclear Information System (INIS)

Bray, L.A.; Ryan, J.L.

1998-01-01

The present invention is a method of obtaining a radionuclide product selected from the group consisting of 223 Ra and 225 Ac, from a radionuclide ''cow'' of 227 Ac or 229 Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ''cow'' forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ''cow'' from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ''cow''. In one embodiment the radionuclide ''cow'' is the 227 Ac, the at least one daughter radionuclide is a 227 Th and the product radionuclide is the 223 Ra and the first nitrate form ion exchange column passes the 227 Ac and retains the 227 Th. In another embodiment the radionuclide ''cow'' is the 229 Th, the at least one daughter radionuclide is a 225 Ra and said product radionuclide is the 225 Ac and the 225 Ac and nitrate form ion exchange column retains the 229 Th and passes the 225 Ra/Ac. 8 figs

Country report: Italy (Chinol). Pre-clinical evaluation of a new biotin-DOTA conjugate labeled with {sup 90}Y for application in pretargeting clinical protocols

Energy Technology Data Exchange (ETDEWEB)

Chinol, Marco

2010-07-01

In the attempt to improve the therapeutic efficacy of radiolabeled mAbs in cancer radioimmunotherapy, various studies have examined the concept of tumor pretargeting. The so called three-step pretargeting technique, employing the avidin–biotin system, was applied in phase I-II clinical trials showing low toxicity and therapeutic efficacy. The final step of the pretargeting protocols consists in the systemic injection of radiolabeled biotin. The worldwide recognized “successful association” is between {sup 90}Y and the tetraazamacrocycle DOTA chelator chemically bound to biotin. Improvements in the structure of the biotin-DOTA conjugate have been reported by our group following a novel approach which simplified the synthetic pattern by reducing the amide group to a methylene group, thus transforming the amide into a secondary amine without affecting the length of the biotin side arm. Preliminary in-vitro experiments, previously published by our group, indicated the potential of the new conjugate. Based on our previous experience with avidin-based pre-targeting followed {sup 90}Y-DOTA-biotin in the locoregional treatment of peritoneal carcinomatosis and malignant glioma suggested that similar radionuclide therapy might be worth investigating as a partial replacement of external beam radiotherapy in breast cancer. We have developed IART® the Intra-operative Avidination for Radionuclide Therapy that relies on the avidin-biotin binding system. In fact, the “avidination” of the anatomical area of the tumor with native avidin, directly injected by the surgeon into and around the tumor bed, provides a target for the radiolabeled biotin intravenously (iv) injected one day later. In order to optimize the overall strategy, further efforts were needed to optimize the use of the labeled new biotin conjugate and to elucidate its chemical and biological properties. In the first 18 months of this CRP, the pre-clinical evaluation of this new reduced biotinamidohexylamine

Radiolysis of polypeptide

International Nuclear Information System (INIS)

Ogura, Isao; Nakamura, Katsuichi; Tanaka, Hiroshi; Takahashi, Katsuhiro; Ozaki, Makoto

1981-01-01

Almost the same results were obtained from the additional dipeptide, Gly-DL-Ala and DL-Ala-DL-Phe, by the γ-irradiation as previous report. Tri and tetrapeptide consisted of the same amino acid signified good stability than the others. Every polypeptide composed from sulfur contained amino acid exhaled the smell of hydrogen sulfide by the irradiation. It seemed that the stability by the difference of position of amino group in amino acid increased in order α, β, γ ... amino acid and that by the existence of hydroxyl group became smaller. (author)

Methods of separating short half-life radionuclides from a mixture of radionuclides

Science.gov (United States)

Bray, Lane A.; Ryan, Jack L.

1998-01-01

The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

The Research on the Impact of Maca Polypeptide on Sport Fatigue.

Science.gov (United States)

Miao, Hua

2015-01-01

In order to study the effect of maca polypeptide on sport fatigue, this paper selected 40 male mice, and they were randomly divided into group A, B, C and D. group A, B and C were fed food with different concentrations of maca polypeptide, and group D was control group. After two weeks of feeding, measured physiological indexes of mice, including blood glucose, urea nitrogen and creatinine. At last gived the experimental results, as well as the analysis. Experimental results show that maca polypeptide can improve the ability of anti-fatigue mice, and in a certain concentration range, the higher the concentration, the better the resistance to fatigue.

Tuning Ice Nucleation with Supercharged Polypeptides

NARCIS (Netherlands)

Yang, Huige; Ma, Chao; Li, Kaiyong; Liu, Kai; Loznik, Mark; Teeuwen, Rosalie; van Hest, Jan C. M.; Zhou, Xin; Herrmann, Andreas; Wang, Jianjun

2016-01-01

Supercharged unfolded polypeptides (SUPs) are exploited for controlling ice nucleation via tuning the nature of charge and charge density of SUPs. The results show that positively charged SUPs facilitate ice nucleation, while negatively charged ones suppress it. Moreover, the charge density of the

Purification of SUMO conjugating enzymes and kinetic analysis of substrate conjugation

Science.gov (United States)

Yunus, Ali A.; Lima, Christopher D.

2009-01-01

SUMO conjugation to protein substrates requires the concerted action of a dedicated E2 ubiquitin conjugation enzyme (Ubc9) and associated E3 ligases. Although Ubc9 can directly recognize and modify substrate lysine residues that occur within a consensus site for SUMO modification, E3 ligases can redirect specificity and enhance conjugation rates during SUMO conjugation in vitro and in vivo. In this chapter, we will describe methods utilized to purify SUMO conjugating enzymes and model substrates which can be used for analysis of SUMO conjugation in vitro. We will also describe methods to extract kinetic parameters during E3-dependent or E3-independent substrate conjugation. PMID:19107417

Radionuclide trap

International Nuclear Information System (INIS)

McGuire, J.C.

1978-01-01

The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition

Radionuclide cisternography

International Nuclear Information System (INIS)

Song, H.H.

1980-01-01

The purpose of this thesis is to show that radionuclide cisternography makes an essential contribution to the investigation of cerebrospinal fluid (CSF) dynamics, especially for the investigation of hydrocephalus. The technical details of radionuclide cisternography are discussed, followed by a description of the normal and abnormal radionuclide cisternograms. The dynamics of CFS by means of radionuclide cisternography were examined in 188 patients in whom some kind of hydrocephalus was suspected. This study included findings of anomalies associated with hydrocephalus in a number of cases, such as nasal liquorrhea, hygromas, leptomeningeal or porencephalic cysts. The investigation substantiates the value of radionuclide cisternography in the diagnosis of disturbances of CSF flow. The retrograde flow of radiopharmaceutical into the ventricular system (ventricular reflux) is an abnormal phenomenon indicating the presence of communicating hydrocephalus. (Auth.)

New peptide receptor radionuclide therapy of invasive cancer cells: in vivo studies using 177Lu-DOTA-AE105 targeting uPAR in human colorectal cancer xenografts

DEFF Research Database (Denmark)

Persson, Morten; Rasmussen, Palle; Madsen, Jacob

2012-01-01

-of-concept for a theranostic approach as treatment modality in a human xenograft colorectal cancer model. MethodsA DOTA-conjugated 9-mer high affinity uPAR binding peptide (DOTA-AE105) was radiolabeled with 64Cu and 177Lu, for PET imaging and targeted radionuclide therapy study, respectively. Human uPAR-positive CRC HT-29...... for the first time the in vivo efficacy of an uPAR-targeted radionuclide therapeutic intervention on both tumor size and its content of uPAR expressing cells thus setting the stage for future translation into clinical use. © 2012 Elsevier Inc. All rights reserved....

Comparison between the polypeptide profile of halophilic bacteria and salt tolerant plants.

Science.gov (United States)

Muñoz, G; González, C; Flores, P; Prado, B; Campos, V

1997-12-01

Changes in the polypeptide profile induced by salt stress in halotolerant and halophilic bacteria, isolated from the Atacama desert (northern Chile), were compared with those in the cotyledons of Prosopis chilensis (Leguminoseae) seedlings, a salt tolerant plant. SDS-PAGE analyses show the presence of four predominant polypeptides, with molecular weights around 78, 70, 60 and 44 kDa respectively, both in bacteria and in cotyledons from P. chilensis seedlings raised under salt stress conditions. Moreover, the 60 and 44 kDa polypeptides seem to be salt responsive, since their concentration increases with increasing NaCl in the growth medium. Our results suggest a common mechanism for salt tolerance in prokaryotes and in eukaryotes.

The mining of toxin-like polypeptides from EST database by single residue distribution analysis.

Science.gov (United States)

Kozlov, Sergey; Grishin, Eugene

2011-01-31

Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed.

Processes for the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity

DEFF Research Database (Denmark)

2016-01-01

The present invention generally relates to the field of biotechnology as it applies to the production of hydroxycinnamic acids using polypeptides having tyrosine ammonia lyase activity. More particularly, the present invention pertains to polypeptides having tyrosine ammonia lyase activity and high...... substrate specificity towards tyrosine, which makes them particularly suitable in the production of p-coumaric acid and other hydroxycinnamic acids. The present invention thus provides processes for the production of p-coumaric acid and other hydroxycinnamic acids employing these polypeptides as well...

Speciation analysis of radionuclides

International Nuclear Information System (INIS)

Salbu, B.

2010-01-01

Full text: Naturally occurring and artificially produced radionuclides in the environment can be present in different physico-chemical forms (i. e. radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, complexing ability etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time dependent transformation processes such as mobilization of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, however, the original distribution of radionuclides deposited in ecosystems will change over time and influence the ecosystem behaviour. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews fractionation techniques which should be utilised for radionuclide speciation purposes. (author)

Fabrication of genetically engineered polypeptide@quantum dots hybrid nanogels for targeted imaging

Science.gov (United States)

Yang, Jie; Yao, Ming-Hao; Zhao, Dong-Hui; Zhang, Xiao-Shuai; Jin, Rui-Mei; Zhao, Yuan-Di; Liu, Bo

2017-08-01

Nanogels have been widely used as multifunctional drug delivery carriers because of high water content, biocompatibility, and high loading capability. We designed and biosynthesized two triblock artificial polypeptides PC10A and PC10ARGD as vehicles for encapsulating hydrophobic materials. These polypeptides can form nanogels by self-assembly when the concentration is below 2% ( w/ v). The physical properties of nanogels, including size, surface potential, and targeting domain, are able to be tuned. Hydrophobic materials from molecular size to nano-size can be loaded into the polypeptide nanogels to form hybrid nanogels. Hydrophobic quantum dots CdSe@ZnS below 10 nM were loaded into the polypeptide nanogels by ultrasonic treatment. Encapsulation endows hydrophobic QDs with good tunability of size, water solubility, stability, targeting, and biocompatibility. PC10ARGD nanogels and PC10ARGD@QDs hybrid nanogels showed excellent biocompatibility, which the cellular viabilities of HeLa and MCF-7 cells treated with 1% PC10ARGD nanogels and PC10ARGD@QDs hybrid nanogels contained 20 nM QDs were above 90 and 80%, respectively. PC10ARGD@QDs hybrid nanogels with an arginine-glycine-aspartic acid motif present efficient receptor-mediated endocytosis in α v β 3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy. These results demonstrate that such polypeptide nanogels as nanocarriers are expected to have great potential applications in biomedicine.

Effect of oxygen on morphogenesis and polypeptide expression by Mucor racemosus

International Nuclear Information System (INIS)

Phillips, G.J.; Borgia, P.T.

1985-01-01

The morphology of Mucor racemosus in cultures continuously sparged with nitrogen gas was investigated. When appropriate precautions were taken to prevent oxygen from entering the cultures, the morphology of the cells was uniformly yeastlike irrespective of the N 2 flow rate. When small amounts of oxygen entered the cultures the resulting microaerobic conditions evoked mycelial development. Polypeptides synthesized by aerobic mycelia, microaerobic mycelia, anaerobic yeasts, and yeasts grown in a CO 2 atmosphere were compared by two-dimensional gel electrophoresis. The results indicated that a large number of differences in polypeptide expression exist when microaerobic mycelia or anaerobic yeasts are compared with aerobic mycelia and that these alterations correlate with a change from an oxidative to a fermentative metabolic mode. The authors hypothesize that oxygen regulates the expression of polypeptides involved in both the metabolic mode and in morphogenesis

Quantitative radionuclide angiocardiography

International Nuclear Information System (INIS)

Scholz, P.M.; Rerych, S.K.; Moran, J.F.; Newman, G.E.; Douglas, J.M.; Sabiston, D.C. Jr.; Jones, R.H.

1980-01-01

This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. Radionuclide angiocardiograms were performed in patients undergoing cardiac catherization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction and end-diastolic volume. To validate the method of volumetric cardiac output calcuation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults. These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function

Structural variation and inhibitor binding in polypeptide deformylase from four different bacterial species.

Science.gov (United States)

Smith, Kathrine J; Petit, Chantal M; Aubart, Kelly; Smyth, Martin; McManus, Edward; Jones, Jo; Fosberry, Andrew; Lewis, Ceri; Lonetto, Michael; Christensen, Siegfried B

2003-02-01

Polypeptide deformylase (PDF) catalyzes the deformylation of polypeptide chains in bacteria. It is essential for bacterial cell viability and is a potential antibacterial drug target. Here, we report the crystal structures of polypeptide deformylase from four different species of bacteria: Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Escherichia coli. Comparison of these four structures reveals significant overall differences between the two Gram-negative species (E. coli and H. influenzae) and the two Gram-positive species (S. pneumoniae and S. aureus). Despite these differences and low overall sequence identity, the S1' pocket of PDF is well conserved among the four enzymes studied. We also describe the binding of nonpeptidic inhibitor molecules SB-485345, SB-543668, and SB-505684 to both S. pneumoniae and E. coli PDF. Comparison of these structures shows similar binding interactions with both Gram-negative and Gram-positive species. Understanding the similarities and subtle differences in active site structure between species will help to design broad-spectrum polypeptide deformylase inhibitor molecules.

The mining of toxin-like polypeptides from EST database by single residue distribution analysis

Directory of Open Access Journals (Sweden)

Grishin Eugene

2011-01-01

Full Text Available Abstract Background Novel high throughput sequencing technologies require permanent development of bioinformatics data processing methods. Among them, rapid and reliable identification of encoded proteins plays a pivotal role. To search for particular protein families, the amino acid sequence motifs suitable for selective screening of nucleotide sequence databases may be used. In this work, we suggest a novel method for simplified representation of protein amino acid sequences named Single Residue Distribution Analysis, which is applicable both for homology search and database screening. Results Using the procedure developed, a search for amino acid sequence motifs in sea anemone polypeptides was performed, and 14 different motifs with broad and low specificity were discriminated. The adequacy of motifs for mining toxin-like sequences was confirmed by their ability to identify 100% toxin-like anemone polypeptides in the reference polypeptide database. The employment of novel motifs for the search of polypeptide toxins in Anemonia viridis EST dataset allowed us to identify 89 putative toxin precursors. The translated and modified ESTs were scanned using a special algorithm. In addition to direct comparison with the motifs developed, the putative signal peptides were predicted and homology with known structures was examined. Conclusions The suggested method may be used to retrieve structures of interest from the EST databases using simple amino acid sequence motifs as templates. The efficiency of the procedure for directed search of polypeptides is higher than that of most currently used methods. Analysis of 39939 ESTs of sea anemone Anemonia viridis resulted in identification of five protein precursors of earlier described toxins, discovery of 43 novel polypeptide toxins, and prediction of 39 putative polypeptide toxin sequences. In addition, two precursors of novel peptides presumably displaying neuronal function were disclosed.

Synthesis of DOTA-conjugated multimeric [Tyr3]octreotide peptides via a combination of Cu(I)-catalyzed "click" cycloaddition and thio acid/sulfonyl azide "sulfo-click" amidation and their in vivo evaluation.

NARCIS (Netherlands)

Yim, C.B.; Dijkgraaf, I.; Merkx, R.; Versluis, C.; Eek, A.; Mulder, G.E.; Rijkers, D.T.; Boerman, O.C.; Liskamp, R.M.

2010-01-01

Herein, we describe the design, synthesis, and biological evaluation of a series of DOTA-conjugated monomeric, dimeric, and tetrameric [Tyr(3)]octreotide-based analogues as a tool for tumor imaging and/or radionuclide therapy. These compounds were synthesized using a Cu(I)-catalyzed 1,3-dipolar

Biosynthesis and characterization of typical fibroin crystalline polypeptides of silkworm Bombyx mori

Energy Technology Data Exchange (ETDEWEB)

Wang Jiannan, E-mail: wangjn@suda.edu.cn [College of Material Engineering, Soochow University, Suzhou 215021 (China); Yan Shuqin [College of Material Engineering, Soochow University, Suzhou 215021 (China); Lu Changde [Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Bai Lun [College of Material Engineering, Soochow University, Suzhou 215021 (China)

2009-05-05

We aimed to investigate the self-organization/self-assembly mechanisms of silkworm fibroin-based material. In the present study, for the first time, we designed and multimerized four DNA 'monomer' sequences from structurally simple fibroin crystalline peptides or analog, [GAGAGX] (X = A, S, Y and V) to encode polypeptides [GAGAGX]{sub 16} (eGA, eGS, eGY and eGV) using a 'head-to-tail' construction strategy. Multimers were cloned into pGEX-KG and fusion proteins GST-[GAGAGX]{sub 16} (KGA, KGS, KGY and KGV) were efficiently expressed in Escherichia coli. These fusion proteins were isolated and purified by GST affinity chromatography and confirmed by SDS-PAGE and Western blot analysis using antibody reactive to GST. The polypeptides were cleavaged from GST fusion proteins by digesting with thrombin enzyme. The composition of the four polypeptides was confirmed by composition analysis of amino acids, and their abilities to form {beta}-sheet structure were determined by ThT fluorescence spectral analysis. The content of {beta}-sheet among the four polypeptides followed the order: eGS > eGV > eGY > eGA.

Radiolabeled, Antibody-Conjugated Manganese Oxide Nanoparticles for Tumor Vasculature Targeted Positron Emission Tomography and Magnetic Resonance Imaging.

Science.gov (United States)

Zhan, Yonghua; Shi, Sixiang; Ehlerding, Emily B; Graves, Stephen A; Goel, Shreya; Engle, Jonathan W; Liang, Jimin; Tian, Jie; Cai, Weibo

2017-11-08

Manganese oxide nanoparticles (Mn 3 O 4 NPs) have attracted a great deal of attention in the field of biomedical imaging because of their ability to create an enhanced imaging signal in MRI as novel potent T 1 contrast agents. In this study, we present tumor vasculature-targeted imaging in mice using Mn 3 O 4 NPs through conjugation to the anti-CD105 antibody TRC105 and radionuclide copper-64 ( 64 Cu, t 1/2 : 12.7 h). The Mn 3 O 4 conjugated NPs, 64 Cu-NOTA-Mn 3 O 4 @PEG-TRC105, exhibited sufficient stability in vitro and in vivo. Serial positron emission tomography (PET) and magnetic resonance imaging (MRI) studies evaluated the pharmacokinetics and demonstrated targeting of 64 Cu-NOTA-Mn 3 O 4 @PEG-TRC105 to 4T1 murine breast tumors in vivo, compared to 64 Cu-NOTA-Mn 3 O 4 @PEG. The specificity of 64 Cu-NOTA-Mn 3 O 4 @PEG-TRC105 for the vascular marker CD105 was confirmed through in vivo, in vitro, and ex vivo experiments. Since Mn 3 O 4 conjugated NPs exhibited desirable properties for T 1 enhanced imaging and low toxicity, the tumor-specific Mn 3 O 4 conjugated NPs reported in this study may serve as promising multifunctional nanoplatforms for precise cancer imaging and diagnosis.

Brachytherapy Using Elastin-Like Polypeptides with (131)I Inhibit Tumor Growth in Rabbits with VX2 Liver Tumor.

Science.gov (United States)

Liu, Xinpei; Shen, Yiming; Zhang, Xuqian; Lin, Rui; Jia, Qiang; Chang, Yixiang; Liu, Wenge; Liu, Wentian

2016-10-01

Brachytherapy is a targeted type of radiotherapy utilized in the treatment of cancers. Elastin-like polypeptides are a unique class of genetically engineered peptide polymers that have several attractive properties for brachytherapy. To explore the feasibility and application of brachytherapy for VX2 liver tumor using elastin-like polypeptides with (131)I so as to provide reliable experimental evidence for a new promising treatment of liver cancer. Elastin-like polypeptide as carrier was labeled with (131)I using the iodogen method. Ten eligible rabbits with VX2 liver tumor were randomly divided into the treatment group (n = 5) and control group (n = 5). The treatment group received brachytherapy using elastin-like polypeptide with (131)I, and in the control group, elastin-like polypeptide was injected into the VX2 liver tumor as a control. Periodic biochemical and imaging surveillances were required to assess treatment efficacy. The stability of elastin-like polypeptide with (131)I in vitro was maintained at over 96.8 % for 96 h. Biochemistry and imaging indicated brachytherapy using elastin-like polypeptide with (131)I for liver tumor can improve liver function and inhibit tumor growth (P Elastin-like polypeptide can be an ideal carrier of (131)I and have high labeling efficiency, radiochemical purity and stability. Brachytherapy using elastin-like polypeptide with (131)I for liver tumor is a useful therapy that possesses high antitumor efficacy advantages.

Moisture absorption and retention properties, and activity in alleviating skin photodamage of collagen polypeptide from marine fish skin.

Science.gov (United States)

Hou, Hu; Li, Bafang; Zhang, Zhaohui; Xue, Changhu; Yu, Guangli; Wang, Jingfeng; Bao, Yuming; Bu, Lin; Sun, Jiang; Peng, Zhe; Su, Shiwei

2012-12-01

Collagen polypeptides were prepared from cod skin. Moisture absorption and retention properties of collagen polypeptides were determined at different relative humidities. In addition, the protective effects of collagen polypeptide against UV-induced damage to mouse skin were evaluated. Collagen polypeptides had good moisture absorption and retention properties and could alleviate the damage induced by UV radiation. The action mechanisms of collagen polypeptide mainly involved enhancing immunity, reducing the loss of moisture and lipid, promoting anti-oxidative properties, inhibiting the increase of glycosaminoglycans, repairing the endogenous collagen and elastin protein fibres, and maintaining the ratio of type III to type I collagen. Copyright © 2012 Elsevier Ltd. All rights reserved.

Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy

Directory of Open Access Journals (Sweden)

Wiebke Sihver

2014-03-01

Full Text Available The epidermal growth factor receptor (EGFR has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment.

Polycondensation of Asparagine-comprising Dipeptides in Aqueous Media-A Simulation of Polypeptide Formation in Primordial Earth Hydrosphere

Science.gov (United States)

Munegumi, Toratane; Tanikawa, Naoya

2017-09-01

Asparagine and aspartic acid might have mutually transformed in the primordial hydrosphere of the earth, if ammonia and aspartic acid had existed in equilibrium. These amino acids seem to contribute to polypeptides, while the simple amino acids glycine and alanine easily form cyclic dipeptides and do not achieve long peptide chains. Asparagine-comprising dipeptides contribute some kinds of activation forms of dipeptides because these can polymerize faster than asparagine only. The new finding of polypeptide formation suggests a pathway of sequential polypeptides to evolve a diversity of polypeptides.

Polycondensation of Asparagine-comprising Dipeptides in Aqueous Media-A Simulation of Polypeptide Formation in Primordial Earth Hydrosphere.

Science.gov (United States)

Munegumi, Toratane; Tanikawa, Naoya

2017-09-01

Asparagine and aspartic acid might have mutually transformed in the primordial hydrosphere of the earth, if ammonia and aspartic acid had existed in equilibrium. These amino acids seem to contribute to polypeptides, while the simple amino acids glycine and alanine easily form cyclic dipeptides and do not achieve long peptide chains. Asparagine-comprising dipeptides contribute some kinds of activation forms of dipeptides because these can polymerize faster than asparagine only. The new finding of polypeptide formation suggests a pathway of sequential polypeptides to evolve a diversity of polypeptides.

Congenital deficiency of two polypeptide subunits of the iron-protein fragment of mitochondrial complex I.

Science.gov (United States)

Moreadith, R W; Cleeter, M W; Ragan, C I; Batshaw, M L; Lehninger, A L

1987-02-01

Recently, we described a patient with severe lactic acidosis due to congenital complex I (NADH-ubiquinone oxidoreductase) deficiency. We now report further enzymatic and immunological characterizations. Both NADH and ferricyanide titrations of complex I activity (measured as NADH-ferricyanide reductase) were distinctly altered in the mitochondria from the patient's tissues. In addition, antisera against complex I immunoprecipitated NADH-ferricyanide reductase from the control but not the patient's mitochondria. However, immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of complex I polypeptides demonstrated that the majority of the 25 polypeptides comprising complex I were present in the affected mitochondria. A more detailed analysis using subunit selective antisera against the main polypeptides of the iron-protein fragments of complex I revealed a selective absence of the 75- and 13-kD polypeptides. These findings suggest that the underlying basis for this patient's disease was a congenital deficiency of at least two polypeptides comprising the iron-protein fragment of complex I, which resulted in the inability to correctly assemble a functional enzyme complex.

Application of Statistical Thermodynamics To Predict the Adsorption Properties of Polypeptides in Reversed-Phase HPLC.

Science.gov (United States)

Tarasova, Irina A; Goloborodko, Anton A; Perlova, Tatyana Y; Pridatchenko, Marina L; Gorshkov, Alexander V; Evreinov, Victor V; Ivanov, Alexander R; Gorshkov, Mikhail V

2015-07-07

The theory of critical chromatography for biomacromolecules (BioLCCC) describes polypeptide retention in reversed-phase HPLC using the basic principles of statistical thermodynamics. However, whether this theory correctly depicts a variety of empirical observations and laws introduced for peptide chromatography over the last decades remains to be determined. In this study, by comparing theoretical results with experimental data, we demonstrate that the BioLCCC: (1) fits the empirical dependence of the polypeptide retention on the amino acid sequence length with R(2) > 0.99 and allows in silico determination of the linear regression coefficients of the log-length correction in the additive model for arbitrary sequences and lengths and (2) predicts the distribution coefficients of polypeptides with an accuracy from 0.98 to 0.99 R(2). The latter enables direct calculation of the retention factors for given solvent compositions and modeling of the migration dynamics of polypeptides separated under isocratic or gradient conditions. The obtained results demonstrate that the suggested theory correctly relates the main aspects of polypeptide separation in reversed-phase HPLC.

Radionuclide fixation mechanisms in rocks

International Nuclear Information System (INIS)

Nakashima, S.

1991-01-01

In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

Generation of polypeptide-templated gold nanoparticles using ionizing radiation.

Science.gov (United States)

Walker, Candace Rae; Pushpavanam, Karthik; Nair, Divya Geetha; Potta, Thrimoorthy; Sutiyoso, Caesario; Kodibagkar, Vikram D; Sapareto, Stephen; Chang, John; Rege, Kaushal

2013-08-13

Ionizing radiation, including γ rays and X-rays, are high-energy electromagnetic radiation with diverse applications in nuclear energy, astrophysics, and medicine. In this work, we describe the use of ionizing radiation and cysteine-containing elastin-like polypeptides (C(n)ELPs, where n = 2 or 12 cysteines in the polypeptide sequence) for the generation of gold nanoparticles. In the presence of C(n)ELPs, ionizing radiation doses higher than 175 Gy resulted in the formation of maroon-colored gold nanoparticle dispersions, with maximal absorbance at 520 nm, from colorless metal salts. Visible color changes were not observed in any of the control systems, indicating that ionizing radiation, gold salt solution, and C(n)ELPs were all required for nanoparticle formation. The hydrodynamic diameters of nanoparticles, determined using dynamic light scattering, were in the range of 80-150 nm, while TEM imaging indicated the formation of gold cores 10-20 nm in diameter. Interestingly, C2ELPs formed 1-2 nm diameter gold nanoparticles in the absence of radiation. Our results describe a facile method of nanoparticle formation in which nanoparticle size can be tailored based on radiation dose and C(n)ELP type. Further improvements in these polypeptide-based systems can lead to colorimetric detection of ionizing radiation in a variety of applications.

Synthetic profiles of polypeptides of human oocytes and normal and abnormal preimplantation embryos.

Science.gov (United States)

Capmany, G; Bolton, V N

1999-09-01

There is considerable variation in the rate of development in vitro of individual preimplantation human embryos. The relationship between the rate of development and patterns of polypeptide synthesis in individual embryos was examined using SDS-PAGE and autoradiography. After incubation in [35S]methionine, 19 polypeptide bands were identified that change between fertilization and the morula stage. Although changes in two of the bands occurred in embryos that were developing normally and in ageing oocytes, and are thus independent of fertilization, the changes identified in the remaining 17 bands occurred only after fertilization. In embryos that were developing abnormally, as assessed by delayed cleavage, cleavage arrest or extensive fragmentation, the alteration in polypeptide synthetic profiles increased with increasing abnormality.

Marine biogeochemistry of radionuclides

International Nuclear Information System (INIS)

Fowler, S.W.

1997-01-01

Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

Characterization of an amidated form of pancreatic polypeptide from the daddy sculpin (Cottus scorpius).

Science.gov (United States)

Conlon, J M; Schmidt, W E; Gallwitz, B; Falkmer, S; Thim, L

1986-12-30

The primary structure of pancreatic polypeptide from the teleostean fish, Cottus scorpius (daddy sculpin) was established as: YPPQPESPGGNASPEDWAKYHAAVRHYVNLITRQRYNH2 The presence of a COOH-terminally alpha-amidated amino acid was established using an HPLC method of general applicability. Although the peptide shows strong homology towards anglerfish pancreatic polypeptide (86%), homology towards porcine peptide YY (PYY) (61%) and porcine neuropeptide Y (NPY) (61%) was greater than towards porcine pancreatic polypeptide (PP) (47%). This result supports suggestions that the gene duplication events which led to PP, NPY and PYY formation took place after the time of divergence of fish and mammals.

Molecular diversity and hypoglycemic polypeptide-P content of Momordica charantia in different accessions and different seasons.

Science.gov (United States)

Tian, Miao; Zeng, Xiang-Qing; Song, Huan-Lei; Hu, Shan-Xin; Wang, Fu-Jun; Zhao, Jian; Hu, Zhi-Bi

2015-04-01

Momordica charantia (MC) has been used for treating diabetes mellitus from ancient times in Asia, Africa and South America. There are many MC accessions in local markets. Polypeptide-P as a main hypoglycemic component in MC was first studied in this experiment to illustrate the different contents in MC of different accessions and different harvesting times. Nineteen MC accessions collected from different regions were clustered into three groups using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers. Content of polypeptide-P in the tested MC accessions was detected by western blot (WB) method. The WB results revealed that polypeptide-P was detected in MC accessions harvested in June and July but not in September and October. Furthermore, Polypeptide-P content corresponded well with the MC accessions. Our results suggest that the MC accessions and the harvesting times or the weather during harvest play significant roles in high content of polypeptide-P. © 2014 Society of Chemical Industry.

The use of radiocobalt as a label improves imaging of EGFR using DOTA-conjugated Affibody molecule.

Science.gov (United States)

Garousi, Javad; Andersson, Ken G; Dam, Johan H; Olsen, Birgitte B; Mitran, Bogdan; Orlova, Anna; Buijs, Jos; Ståhl, Stefan; Löfblom, John; Thisgaard, Helge; Tolmachev, Vladimir

2017-07-20

Several anti-cancer therapies target the epidermal growth factor receptor (EGFR). Radionuclide imaging of EGFR expression in tumours may aid in selection of optimal cancer therapy. The 111 In-labelled DOTA-conjugated Z EGFR:2377 Affibody molecule was successfully used for imaging of EGFR-expressing xenografts in mice. An optimal combination of radionuclide, chelator and targeting protein may further improve the contrast of radionuclide imaging. The aim of this study was to evaluate the targeting properties of radiocobalt-labelled DOTA-Z EGFR:2377 . DOTA-Z EGFR:2377 was labelled with 57 Co (T 1/2  = 271.8 d), 55 Co (T 1/2  = 17.5 h), and, for comparison, with the positron-emitting radionuclide 68 Ga (T 1/2  = 67.6 min) with preserved specificity of binding to EGFR-expressing A431 cells. The long-lived cobalt radioisotope 57 Co was used in animal studies. Both 57 Co-DOTA-Z EGFR:2377 and 68 Ga-DOTA-Z EGFR:2377 demonstrated EGFR-specific accumulation in A431 xenografts and EGFR-expressing tissues in mice. Tumour-to-organ ratios for the radiocobalt-labelled DOTA-Z EGFR:2377 were significantly higher than for the gallium-labelled counterpart already at 3 h after injection. Importantly, 57 Co-DOTA-Z EGFR:2377 demonstrated a tumour-to-liver ratio of 3, which is 7-fold higher than the tumour-to-liver ratio for 68 Ga-DOTA-Z EGFR:2377 . The results of this study suggest that the positron-emitting cobalt isotope 55 Co would be an optimal label for DOTA-Z EGFR:2377 and further development should concentrate on this radionuclide as a label.

Dual-layered nanogel-coated hollow lipid/polypeptide conjugate assemblies for potential pH-triggered intracellular drug release.

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Wen-Hsuan Chiang

Full Text Available To achieve effective intracellular anticancer drug delivery, the polymeric vesicles supplemented with the pH-responsive outlayered gels as a delivery system of doxorubicin (DOX were developed from self-assembly of the lipid/polypeptide adduct, distearin grafted poly(γ-glutamic acid (poly(γ-GA, followed by sequential deposition of chitosan and poly(γ-GA-co-γ-glutamyl oxysuccinimide-g-monomethoxy poly(ethylene glycol in combination with in situ covalent cross-linking on assembly surfaces. The resultant gel-caged polymeric vesicles (GCPVs showed superior performance in regulating drug release in response to the external pH change. Under typical physiological conditions (pH 7.4 and 37 °C at which the γ-GA/DOX ionic pairings remained mostly undisturbed, the dense outlayered gels of GCPVs significantly reduced the premature leakage of the uncomplexed payload. With the environmental pH being reduced from pH 7.4 to 4.7, the drug liberation was appreciably promoted by the massive disruption of the ionic γ-GA/DOX complexes along with the significant swelling of nanogel layers upon the increased protonation of chitosan chain segments. After being internalized by HeLa cells via endocytosis, GCPVs exhibited cytotoxic effect comparable to free DOX achieved by rapidly releasing the payload in intracellular acidic endosomes and lysosomes. This strongly implies the great promise of such unique GCPVs as an intracellular drug delivery carrier for potential anticancer treatment.

Cotranslational structure acquisition of nascent polypeptides monitored by NMR spectroscopy.

Science.gov (United States)

Eichmann, Cédric; Preissler, Steffen; Riek, Roland; Deuerling, Elke

2010-05-18

The folding of proteins in living cells may start during their synthesis when the polypeptides emerge gradually at the ribosomal exit tunnel. However, our current understanding of cotranslational folding processes at the atomic level is limited. We employed NMR spectroscopy to monitor the conformation of the SH3 domain from alpha-spectrin at sequential stages of elongation via in vivo ribosome-arrested (15)N,(13)C-labeled nascent polypeptides. These nascent chains exposed either the entire SH3 domain or C-terminally truncated segments thereof, thus providing snapshots of the translation process. We show that nascent SH3 polypeptides remain unstructured during elongation but fold into a compact, native-like beta-sheet assembly when the entire sequence information is available. Moreover, the ribosome neither imposes major conformational constraints nor significantly interacts with exposed unfolded nascent SH3 domain moieties. Our data provide evidence for a domainwise folding of the SH3 domain on ribosomes without significant population of folding intermediates. The domain follows a thermodynamically favorable pathway in which sequential folding units are stabilized, thus avoiding kinetic traps during the process of cotranslational folding.

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.; Wollongong Univ.; Tomiyoshi, K.; Sekine, T.

1997-01-01

The present status and future directions of research and development on radionuclide generator technology are reported. The recent interest to develop double-neutron capture reactions for production of in vivo generators; neutron rich nuclides for radio-immunotherapeutic pharmaceuticals: and advances with ultra-short lived generators is highlighted. Emphasis is focused on: production of the parent radionuclide; the selection and the evaluation of support materials and eluents with respect to the resultant radiochemical yield of the daughter, and the breakthrough of the radionuclide parent: and, the uses of radionuclide generators in radiopharmaceutical chemistry, biomedical and industrial applications. The 62 Zn → 62 Cu, 66 Ni → 66 Cu, 103m Rh → 103 Rh, 188 W → 188 Re and the 225 Ac → 221 Fr → 213 Bi generators are predicted to be emphasized for future development. Coverage of the 99 Mo → 99m Tc generator was excluded, as it the subject of another review. The literature search ended June, 1996. (orig.)

Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy †

Science.gov (United States)

Sihver, Wiebke; Pietzsch, Jens; Krause, Mechthild; Baumann, Michael; Steinbach, Jörg; Pietzsch, Hans-Jürgen

2014-01-01

The epidermal growth factor receptor (EGFR) has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a) chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b) with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specific targeting properties of this antibody might increase its therapeutic efficiency. This review article gives an overview of the preclinical studies that have been performed with radiolabeled cetuximab for imaging and/or treatment of different tumor models. A particularly promising approach seems to be the treatment with therapeutic radionuclide-labeled cetuximab in combination with external radiotherapy. Present data support an important impact of the tumor micromilieu on treatment response that needs to be further validated in patients. Another important challenge is the reduction of nonspecific uptake of the radioactive substance in metabolic organs like liver and radiosensitive organs like bone marrow and kidneys. Overall, the integration of diagnosis, treatment and monitoring as a theranostic approach appears to be a promising strategy for improvement of individualized cancer treatment. PMID:24603603

Stimuli-Triggered Sol-Gel Transitions of Polypeptides Derived from α-Amino Acid N-Carboxyanhydride (NCA) Polymerizations.

Science.gov (United States)

He, Xun; Fan, Jingwei; Wooley, Karen L

2016-02-18

The past decade has witnessed significantly increased interest in the development of smart polypeptide-based organo- and hydrogel systems with stimuli responsiveness, especially those that exhibit sol-gel phase-transition properties, with an anticipation of their utility in the construction of adaptive materials, sensor designs, and controlled release systems, among other applications. Such developments have been facilitated by dramatic progress in controlled polymerizations of α-amino acid N-carboxyanhydrides (NCAs), together with advanced orthogonal functionalization techniques, which have enabled economical and practical syntheses of well-defined polypeptides and peptide hybrid polymeric materials. One-dimensional stacking of polypeptides or peptide aggregations in the forms of certain ordered conformations, such as α helices and β sheets, in combination with further physical or chemical cross-linking, result in the construction of three-dimensional matrices of polypeptide gel systems. The macroscopic sol-gel transitions, resulting from the construction or deconstruction of gel networks and the conformational changes between secondary structures, can be triggered by external stimuli, including environmental factors, electromagnetic fields, and (bio)chemical species. Herein, the most recent advances in polypeptide gel systems are described, covering synthetic strategies, gelation mechanisms, and stimuli-triggered sol-gel transitions, with the aim of demonstrating the relationships between chemical compositions, supramolecular structures, and responsive properties of polypeptide-based organo- and hydrogels. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Allen, S.E.; Horrill, A.D.; Howard, B.J.; Lowe, V.P.W.; Parkinson, J.A.

1983-07-01

The subject is discussed under the headings: concentration and spatial distribution of radionuclides in grazed and ungrazed saltmarshes; incorporation of radionuclides by sheep grazing on an estuarine saltmarsh; inland transfer of radionuclides by birds feeding in the estuaries and saltmarshes at Ravenglass; radionuclides in contrasting types of coastal pastures and taken up by individual plant species found in west Cumbria; procedures developed and used for the measurement of alpha and gamma emitters in environmental materials. (U.K.)

Radionuclide data

International Nuclear Information System (INIS)

Anon.

1992-01-01

Chapter 8 presents tables on selected alpha, beta, gamma and x-ray emitters by increasing energy; information on specific activity for selected radionuclides; naturally occurring radionuclides; the natural decay series; and the artificially produced neptunium series. A table of alpha emitters is listed by increasing atomic number and by energy. The table of β emitters presented is useful in identifying β emitters whose energies and possibly half-lives have been determined by standard laboratory techniques. It is also a handy guide to β-emitting isotopes for applications requiring specific half-lives and/or energies. Gamma rays for radionuclides of importance to radiological assessments and radiation protection are listed by increasing energy. The energies and branching ratios are important for radionuclide determinations with gamma spectrometry detectors. This section also presents a table of x-ray energies which are useful for radiochemical analyses. A number of nuclides emit x-rays as part of their decay scheme. These x-rays may be counted with Ar proportional counters, Ge planar or n-type Ge co-axial detectors, or thin crystal NaI(T1) scintillation counters. In both cases, spectral measurements can be made and both qualitative and quantitative information obtained on the sample. Nuclear decay data (energy and probability by radiation type) for more than one hundred radionuclides that are important to health physicists are presented in a schematic manner

Nanostructured complexes of polyelectrolytes and charged polypeptides

Czech Academy of Sciences Publication Activity Database

Müller, M.; Ouyang, W.; Bohatá, Karolína; Kessler, B.

2010-01-01

Roč. 12, Sp. Iss. 9 (2010), B519-B528 ISSN 1438-1656. [Sino-German Symposium on Advanced Biomedical Nanostructures /1./. Jena, 26.10.2009-30.10.2009] Institutional research plan: CEZ:AV0Z40500505 Keywords : situ ATR-FTIR * alpha-helical polypeptides * multilayer films Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.746, year: 2010

Evaluation of iodovinyl antibody conjugates: Comparison with a p-iodobenzoyl conjugate and direct radioiodination

International Nuclear Information System (INIS)

Hadley, S.W.; Wilbur, D.S.

1990-01-01

The preparations and conjugations of 2,3,5,6-tetrafluorophenyl 5-[125I/131I]iodo-4-pentenoate (7a) and 2,3,5,6-tetrafluorophenyl 3,3-dimethyl-5-[125I/131I]iodo-4-pentenoate (7b) to monoclonal antibodies are reported. Reagents 7a and 7b were prepared in high radiochemical yield by iododestannylation of their corresponding 5-tri-n-butylstannyl precursors. Radioiodinated antibody conjugates were prepared by reaction of 7a or 7b with the protein at basic pH. Evaluation of these conjugates by several in vitro procedures demonstrated that the radiolabel was attached to the antibody in a stable manner and that the conjugates maintained immunoreactivity. Comparative dual-isotope biodistribution studies of a monoclonal antibody Fab fragment conjugate of 7a and 7b with the same Fab fragment labeled with N-succinimidyl p-[131I]iodobenzoate (PIB, p-iodobenzoate, 2) or directly radioiodinated have been carried out in tumor-bearing nude mice. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 2 demonstrated that the biodistributions were similar in most organs, except the neck tissue (thyroid-containing) and the stomach, which contained substantially increased levels of the 7a label. Coinjection of the Fab conjugate of 7a with the Fab fragment radioiodinated by using the chloramine-T method demonstrated that the biodistributions were remarkably similar, suggesting roughly equivalent in vivo deiodination of these labeled antibody fragments. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 7b indicated that there was ∼ a 2-fold reduction in the amount of in vivo deiodination of the 7b conjugate as compared to the 7a conjugate

GAWK, a novel human pituitary polypeptide: isolation, immunocytochemical localization and complete amino acid sequence.

Science.gov (United States)

Benjannet, S; Leduc, R; Lazure, C; Seidah, N G; Marcinkiewicz, M; Chrétien, M

1985-01-16

During the course of reverse-phase high pressure liquid chromatography (RP-HPLC) purification of a postulated big ACTH (1) from human pituitary gland extracts, a highly purified peptide bearing no resemblance to any known polypeptide was isolated. The complete sequence of this 74 amino acid polypeptide, called GAWK, has been determined. Search on a computer data bank on the possible homology to any known protein or fragment, using a mutation data matrix, failed to reveal any homology greater than 30%. An antibody produced against a synthetic fragment allowed us to detect several immunoreactive forms. The antisera also enabled us to localize the polypeptide, by immunocytochemistry, in the anterior lobe of the pituitary gland.

Biosynthesis and characterization of a non-repetitive polypeptide derived from silk fibroin heavy chain

Energy Technology Data Exchange (ETDEWEB)

Yang, Gaoqiang; Wu, Mingyang; Yi, Honggen; Wang, Jiannan, E-mail: wangjn@suda.edu.cn

2016-02-01

Silk fibroin heavy chain is the major protein component of Bombyx mori silk fibroin and is composed of 12 repetitive and 11 non-repetitive regions, with the non-repetitive domain consisting of a hydrophilic polypeptide chain. In order to determine the biomedical function of the non-repetitive domain or potentially use it to modify hydrophobic biomaterials, high-purity isolation is necessary. Previously, we cloned and extended a gene motif (f(1)) encoding the non-repetitive domain. Here, this motif and its multimers are inserted into a glutathione S-transferase (GST)-tagged fusion-protein expression vector. Motif f(1) and multimers f(4) and f(8) were expressed in Escherichia coli BL21 cells following isopropyl β-D-1-thiogalactopyranoside induction, purified by GST-affinity chromatography, and single bands of purified fusion proteins GST-F(1), GST-F(4), and GST-F(8), were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Target polypeptides F(1), F(4), and F(8), were cleaved clearly from the GST-fusion tag following thrombin digestion. Mass spectrometry results indicate that the molecular weights associated with fusion proteins GST-F(1), GST-F(4), and GST-F(8) are 31.5, 43.8, and 59.0 kDa, respectively, and with the cleaved polypeptides F(1), F(4), and F(8) are 4.8, 16.8, and 32.8 kDa, respectively. The F(1), F(4), and F(8) polypeptide chains are negatively charged with isoelectric points (pI) of 3.3, 3.2, and 3.0, respectively. The molecular weight and pI values of the polypeptide chains are consistent with the predicted values and the amino acid compositions similar to predicted sequences. FTIR and CD results show the molecular conformation of F(1) was mainly random coil, and more stable α-helix structure formed in longer molecular chain. - Highlights: • A non-repetitive domain and its multimers of silk fibroin were expressed by E. coli. • The corresponding target polypeptides F(1), F(4) and F(8) were cleaved clearly. • Their

Radionuclide generators

International Nuclear Information System (INIS)

Lambrecht, R.M.

1983-01-01

The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

Co-conjugation vis-à-vis individual conjugation of α-amylase and glucoamylase for hydrolysis of starch.

Science.gov (United States)

Jadhav, Swati B; Singhal, Rekha S

2013-10-15

Two enzymes, α-amylase and glucoamylase have been individually and co-conjugated to pectin by covalent binding. Both the enzyme systems showed better thermal and pH stability over the free enzyme system with the complete retention of original activities. Mixture of individually conjugated enzymes showed lower inactivation rate constant with longer half life than the co-conjugated enzyme system. Individually conjugated enzymes showed an increase of 56.48 kJ/mole and 38.22 kJ/mole in activation energy for denaturation than the free enzymes and co-conjugated enzymes, respectively. Km as well as Vmax of individually and co-conjugated enzymes was found to be higher than the free enzymes. SDS-polyacrylamide gel electrophoresis confirmed the formation of conjugate and co-conjugate as evident by increased molecular weight. Both the enzyme systems were used for starch hydrolysis where individually conjugated enzymes showed highest release of glucose at 60 °C and pH 5.0 as compared to free and co-conjugated enzyme. Copyright © 2013 Elsevier Ltd. All rights reserved.

Investigation of the pathophysiological mechanisms of migraine attacks induced by pituitary adenylate cyclase-activating polypeptide-38

DEFF Research Database (Denmark)

Amin, Faisal Mohammad; Hougaard, Anders; Schytz, Henrik W

2014-01-01

Pituitary adenylate cyclase-activating polypeptide-38 (PACAP38) and vasoactive intestinal polypeptide are structurally and functionally closely related but show differences in migraine-inducing properties. Mechanisms responsible for the difference in migraine induction are unknown. Here, for the ...

Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

Science.gov (United States)

Widel, M

2017-01-01

For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

The Generation of Dehydroalanine Residues in Protonated Polypeptides: Ion/Ion Reactions for Introducing Selective Cleavages

Science.gov (United States)

Peng, Zhou; Bu, Jiexun; McLuckey, Scott A.

2017-09-01

We examine a gas-phase approach for converting a subset of amino acid residues in polypeptide cations to dehydroalanine (Dha). Subsequent activation of the modified polypeptide ions gives rise to specific cleavage N-terminal to the Dha residue. This process allows for the incorporation of selective cleavages in the structural characterization of polypeptide ions. An ion/ion reaction within the mass spectrometer between a multiply protonated polypeptide and the sulfate radical anion introduces a radical site into the multiply protonated polypeptide reactant. Subsequent collisional activation of the polypeptide radical cation gives rise to radical side chain loss from one of several particular amino acid side chains (e.g., leucine, asparagine, lysine, glutamine, and glutamic acid) to yield a Dha residue. The Dha residues facilitate preferential backbone cleavages to produce signature c- and z-ions, demonstrated with cations derived from melittin, mechano growth factor (MGF), and ubiquitin. The efficiencies for radical side chain loss and for subsequent generation of specific c- and z-ions have been examined as functions of precursor ion charge state and activation conditions using cations of ubiquitin as a model for a small protein. It is noted that these efficiencies are not strongly dependent on ion trap collisional activation conditions but are sensitive to precursor ion charge state. Moderate to low charge states show the greatest overall yields for the specific Dha cleavages, whereas small molecule losses (e.g., water/ammonia) dominate at the lowest charge states and proton catalyzed amide bond cleavages that give rise to b- and y-ions tend to dominate at high charge states. [Figure not available: see fulltext.

Pituitary adenylate cyclase activating polypeptide reduces A-type K+ currents and caspase activity in cultured adult mouse olfactory neurons.

Science.gov (United States)

Han, P; Lucero, M T

2005-01-01

Pituitary adenylate cyclase activating polypeptide has been shown to reduce apoptosis in neonatal cerebellar and olfactory receptor neurons, however the underlying mechanisms have not been elucidated. In addition, the neuroprotective effects of pituitary adenylate cyclase activating polypeptide have not been examined in adult tissues. To study the effects of pituitary adenylate cyclase activating polypeptide on neurons in apoptosis, we measured caspase activation in adult olfactory receptor neurons in vitro. Interestingly, we found that the protective effects of pituitary adenylate cyclase activating polypeptide were related to the absence of a 4-aminopyridine (IC50=144 microM) sensitive rapidly inactivating potassium current often referred to as A-type current. In the presence of 40 nM pituitary adenylate cyclase activating polypeptide 38, both A-type current and activated caspases were significantly reduced. A-type current reduction by pituitary adenylate cyclase activating polypeptide was blocked by inhibiting the phospholipase C pathway, but not the adenylyl cyclase pathway. Our observation that 5 mM 4-aminopyridine mimicked the caspase inhibiting effects of pituitary adenylate cyclase activating polypeptide indicates that A-type current is involved in apoptosis. This work contributes to our growing understanding that potassium currents are involved with the activation of caspases to affect the balance between cell life and death.

Radionuclide cardiography in medical practice

International Nuclear Information System (INIS)

Strangfeld, D.; Mohnike, W.; Schmidt, J.; Heine, H.; Correns, H.J.

1986-01-01

This publication is a compendium on all aspects of radionuclide diagnostics concerning cardiovascular system diseases. Starting with introductory remarks on the control of cardiovascular diseases the contribution of radionuclide cardiology to functional cardiovascular diagnostics as well as pathophysiological and pathobiochemical aspects of radiocardiography are outlined. Radiopharmaceuticals used in radiocardiography, physical and technical problems in application of radionuclides and their measuring techniques are discussed. In individual chapters radionuclide ventriculography, myocardial scintiscanning, circulatory diagnostics, radionuclide diagnostics of arterial hypertension, of thrombosis and in vitro diagnostics of thrombophilia are treated in the framework of clinical medicine

Molecular cloning and protein structure of a human blood group Rh polypeptide

International Nuclear Information System (INIS)

Cherif-Zahar, B.; Bloy, C.; Le Van Kim, C.; Blanchard, D.; Bailly, P.; Hermand, P.; Salmon, C.; Cartron, J.P.; Colin, Y.

1990-01-01

cDNA clones encoding a human blood group Rh polypeptide were isolated from a human bone marrow cDNA library by using a polymerase chain reaction-amplified DNA fragment encoding the known common N-terminal region of the Rh proteins. The entire primary structure of the Rh polypeptide has been deduced from the nucleotide sequence of a 1384-base-pair-long cDNA clone. Translation of the open reading frame indicates that the Rh protein is composed of 417 amino acids, including the initiator methionine, which is removed in the mature protein, lacks a cleavable N-terminal sequence, and has no consensus site for potential N-glycosylation. The predicted molecular mass of the protein is 45,500, while that estimated for the Rh protein analyzed in NaDodSO 4 /polyacrylamide gels is in the range of 30,000-32,000. These findings suggest either that the hydrophobic Rh protein behaves abnormally on NaDodSO 4 gels or that the Rh mRNA may encode a precursor protein, which is further matured by a proteolytic cleavage of the C-terminal region of the polypeptide. Hydropathy analysis and secondary structure predictions suggest the presence of 13 membrane-spanning domains, indicating that the Rh polypeptide is highly hydrophobic and deeply buried within the phospholipid bilayer. These results suggest that the expression of the Rh gene(s) might be restricted to tissues or cell lines expressing erythroid characters

Metabolism of radionuclides in domestic animals

International Nuclear Information System (INIS)

Wirth, E.; Leising, C.

1986-01-01

The reactor accident at Chernobyl has shown that shortly after the contamination of the environment radionuclides can be found in animal products. The main contamination pathways of domestic animas are: uptake of radionuclides by foodstuffs; uptake of radionuclides by contaminated drinking water; uptake of radionuclides by inhalation; uptake of radionuclides through skin; uptake of radionuclides by ingestion of soil particles. Generally the uptake of radionuclides by food is the dominant exposure pathway. In rare cases the inhalation of radionuclides or the uptake by drinking water may be of importance. The metabolism of incorporated radionuclides is comparable to the respective metabolism of essential mass or trace elements or heavy metals. Radioisotopes of essential elements are for instance iron 55, manganese 54, cobalt 58 and cobalt 60. Other elements are typical antagonists to essential elements, e.g. strontium 90 is an antagonist to calcium or cesium 137 to potassium. Lead 210 and plutonium 239 behave similarly as heavy metals. Generally the knowledge of the metabolism of trace and mass elements, of antagonistic and synergistic elements and heavy metals can be applied to these radionuclides

Radionuclide scanning

International Nuclear Information System (INIS)

Shapiro, B.

1986-01-01

Radionuclide scanning is the production of images of normal and diseased tissues and organs by means of the gamma-ray emissions from radiopharmaceutical agents having specific distributions in the body. The gamma rays are detected at the body surface by a variety of instruments that convert the invisible rays into visible patterns representing the distribution of the radionuclide in the body. The patterns, or images, obtained can be interpreted to provide or to aid diagnoses, to follow the course of disease, and to monitor the management of various illnesses. Scanning is a sensitive technique, but its specificity may be low when interpreted alone. To be used most successfully, radionuclide scanning must be interpreted in conjunction with other techniques, such as bone radiographs with bone scans, chest radiographs with lung scans, and ultrasonic studies with thyroid scans. Interpretation is also enhanced by providing pertinent clinical information because the distribution of radiopharmaceutical agents can be altered by drugs and by various procedures besides physiologic and pathologic conditions. Discussion of the patient with the radionuclide scanning specialist prior to the study and review of the results with that specialist after the study are beneficial

Phase transition in polypeptides: a step towards the understanding of protein folding

DEFF Research Database (Denmark)

Yakubovich, Alexander V.; Solov'yov, Ilia; Solov'yov, Andrey V.

2006-01-01

We present a formalism which turns out to be very successful in the description of the polypeptide folding. We consider this process as a first-order phase transition and develop a theory which is free of model parameters and is based solely on fundamental physical principles. It describes...... essential thermodynamical properties of the system such as heat capacity, the phase transition temperature and others from the analysis of the polypeptide potential energy surface calculated within ab initio density functional theory and parameterized by two dihedral angles. This problem is viewed...

Drift-Scale Radionuclide Transport

International Nuclear Information System (INIS)

Houseworth, J.

2004-01-01

The purpose of this model report is to document the drift scale radionuclide transport model, taking into account the effects of emplacement drifts on flow and transport in the vicinity of the drift, which are not captured in the mountain-scale unsaturated zone (UZ) flow and transport models ''UZ Flow Models and Submodels'' (BSC 2004 [DIRS 169861]), ''Radionuclide Transport Models Under Ambient Conditions'' (BSC 2004 [DIRS 164500]), and ''Particle Tracking Model and Abstraction of Transport Process'' (BSC 2004 [DIRS 170041]). The drift scale radionuclide transport model is intended to be used as an alternative model for comparison with the engineered barrier system (EBS) radionuclide transport model ''EBS Radionuclide Transport Abstraction'' (BSC 2004 [DIRS 169868]). For that purpose, two alternative models have been developed for drift-scale radionuclide transport. One of the alternative models is a dual continuum flow and transport model called the drift shadow model. The effects of variations in the flow field and fracture-matrix interaction in the vicinity of a waste emplacement drift are investigated through sensitivity studies using the drift shadow model (Houseworth et al. 2003 [DIRS 164394]). In this model, the flow is significantly perturbed (reduced) beneath the waste emplacement drifts. However, comparisons of transport in this perturbed flow field with transport in an unperturbed flow field show similar results if the transport is initiated in the rock matrix. This has led to a second alternative model, called the fracture-matrix partitioning model, that focuses on the partitioning of radionuclide transport between the fractures and matrix upon exiting the waste emplacement drift. The fracture-matrix partitioning model computes the partitioning, between fractures and matrix, of diffusive radionuclide transport from the invert (for drifts without seepage) into the rock water. The invert is the structure constructed in a drift to provide the floor of the

Immunoassay of serum polypeptide hormones by using 125I-labelled anti(-immunoglobulin G) antibodies.

Science.gov (United States)

Beck, P; Nicholas, H

1975-03-01

1. A technique for indirectly labelling antibodies to polypeptide hormones, by combining them with radioactively labelled anti-(immunoglobulin G) is described. (a) 125I-labelled anti-(rabbit immunoglobulin G) and anti-(guinea-pig immunoglobulin G) antibodies with high specific radioactivity were prepared after purification of the antibodies on immunoadsorbents containing the respective antigens. (b) Rabbit immunoglobulin G antibodies to human growth hormone, porcine glucagon and guinea-pig immunoglobulin G antibodies to bovine insulin and bovine parathyroid hormone were combined with immunoadsorbents containing the respective polypeptide hormone antigen. (c) The immunoglobulin G antibodies to the polypeptide hormones were reacted with 125-I-labelled anti-(immunoglobulin G) antibodies directed against the appropriate species of immunoglobulin G,and the anti-hormone antibodies were combined with the hormone-containing immunoadsorbent. (d) 125I-labelled anti-(immunoglobulin G) antibodies and anti-hormone antibodies were simultaneously eluted from the hormone-containing immunoadsorbent by dilute HCl, pH 2.0. After elution the anti-(immunoglobulin G) antibodies and antihormone antibodies were allowed to recombine at pH 8.0 and 4 degrees C. 2. The resultant immunoglobulin G-anti-immunoglobulin G complex was used in immunoradiometric (labelled antibody) and two-site assays of the respective polypeptide hormone. 3. By using these immunoassays, concentrations down to 90pg of human growth hormone/ml, 100 pg of bovine insulin/ml, 80 pg of bovine parathyroid hormone/ml and 150 pg of glucagon/ml were readily detected. Assays of human plasma for growth hormone and insulin by these methods showed good agreement with results obtained by using a directly 125I-labelled anti-hormone antibody in an immunoradiometric assay of human growth hormone or by radioimmunoassay of human insulin. 4. The method described allows immunoradiometric or two-site assays to be performed starting with as

Chapter 2. Radionuclides in the biosphere

International Nuclear Information System (INIS)

Toelgyessy, J.; Harangozo, M.

2000-01-01

This is a chapter of textbook of radioecology for university students. In this chapter authors deal with role of radionuclides in the biosphere. Chapter consists of next parts: (1) Natural radionuclides in biosphere; (2) Man-made radionuclides in the biosphere; (3) Ecologically important radionuclides; (4) Natural background; (5) Radiotoxicity and (6) Paths of transfer of radionuclides from the source to human

Ligand-Induced Cross-Linking of Z-Elastin-like Polypeptide-Functionalized E2 Protein Nanoparticles for Enhanced Affinity Precipitation of Antibodies.

Science.gov (United States)

Swartz, Andrew R; Sun, Qing; Chen, Wilfred

2017-05-08

Affinity precipitation is an ideal alternative to chromatography for antibody purification because it combines the high selectivity of an affinity ligand with the operational benefits of precipitation. However, the widespread use of elastin-like polypeptide (ELP) capture scaffolds for antibody purification has been hindered by the high salt concentrations and temperatures necessary for efficient ELP aggregation. In this paper, we employed a tandem approach to enhance ELP aggregation by enlarging the dimension of the capturing scaffold and by creating IgG-triggered scaffold cross-linking. This was accomplished by covalently conjugating the Z-domain-ELP (Z-ELP) capturing scaffold to a 25 nm diameter E2 protein nanocage using Sortase A ligation. We demonstrated the isothermal recovery of IgG in the virtual absence of salt due to the significantly increased scaffold dimension and cross-linking from multivalent IgG-E2 interactions. Because IgG cross-linking is reversible at low pH, it may be feasible to achieve a high yielding IgG purification by isothermal phase separation using a simple pH trigger.

Sequence Directionality Dramatically Affects LCST Behavior of Elastin-Like Polypeptides.

Science.gov (United States)

Li, Nan K; Roberts, Stefan; Quiroz, Felipe Garcia; Chilkoti, Ashutosh; Yingling, Yaroslava G

2018-04-30

Elastin-like polypeptides (ELP) exhibit an inverse temperature transition or lower critical solution temperature (LCST) transition phase behavior in aqueous solutions. In this paper, the thermal responsive properties of the canonical ELP, poly(VPGVG), and its reverse sequence poly(VGPVG) were investigated by turbidity measurements of the cloud point behavior, circular dichroism (CD) measurements, and all-atom molecular dynamics (MD) simulations to gain a molecular understanding of mechanism that controls hysteretic phase behavior. It was shown experimentally that both poly(VPGVG) and poly(VGPVG) undergo a transition from soluble to insoluble in aqueous solution upon heating above the transition temperature ( T t ). However, poly(VPGVG) resolubilizes upon cooling below its T t , whereas the reverse sequence, poly(VGPVG), remains aggregated despite significant undercooling below the T t . The results from MD simulations indicated that a change in sequence order results in significant differences in the dynamics of the specific residues, especially valines, which lead to extensive changes in the conformations of VPGVG and VGPVG pentamers and, consequently, dissimilar propensities for secondary structure formation and overall structure of polypeptides. These changes affected the relative hydrophilicities of polypeptides above T t , where poly(VGPVG) is more hydrophilic than poly(VPGVG) with more extended conformation and larger surface area, which led to formation of strong interchain hydrogen bonds responsible for stabilization of the aggregated phase and the observed thermal hysteresis for poly(VGPVG).

Chronic changes in pituitary adenylate cyclase-activating polypeptide and related receptors in response to repeated chemical dural stimulation in rats.

Science.gov (United States)

Han, Xun; Ran, Ye; Su, Min; Liu, Yinglu; Tang, Wenjing; Dong, Zhao; Yu, Shengyuan

2017-01-01

Background Preclinical experimental studies revealed an acute alteration of pituitary adenylate cyclase-activating polypeptide in response to a single activation of the trigeminovascular system, which suggests a potential role of pituitary adenylate cyclase-activating polypeptide in the pathogenesis of migraine. However, changes in pituitary adenylate cyclase-activating polypeptide after repeated migraine-like attacks in chronic migraine are not clear. Therefore, the present study investigated chronic changes in pituitary adenylate cyclase-activating polypeptide and related receptors in response to repeated chemical dural stimulations in the rat. Methods A rat model of chronic migraine was established by repeated chemical dural stimulations using an inflammatory soup for a different numbers of days. The pituitary adenylate cyclase-activating polypeptide levels were quantified in plasma, the trigeminal ganglia, and the trigeminal nucleus caudalis using radioimmunoassay and Western blotting in trigeminal ganglia and trigeminal nucleus caudalis tissues. Western blot analysis and real-time polymerase chain reaction were used to measure the protein and mRNA expression of pituitary adenylate cyclase-activating polypeptide-related receptors (PAC1, VPAC1, and VPAC2) in the trigeminal ganglia and trigeminal nucleus caudalis to identify changes associated with repetitive applications of chemical dural stimulations. Results All rats exhibited significantly decreased periorbital nociceptive thresholds to repeated inflammatory soup stimulations. Radioimmunoassay and Western blot analysis demonstrated significantly decreased pituitary adenylate cyclase-activating polypeptide levels in plasma and trigeminal ganglia after repetitive chronic inflammatory soup stimulation. Protein and mRNA analyses of pituitary adenylate cyclase-activating polypeptide-related receptors demonstrated significantly increased PAC1 receptor protein and mRNA expression in the trigeminal ganglia, but not

Adhesive polypeptides of Staphylococcus aureus identified using a novel secretion library technique in Escherichia coli

Directory of Open Access Journals (Sweden)

Holm Liisa

2011-05-01

Full Text Available Abstract Background Bacterial adhesive proteins, called adhesins, are frequently the decisive factor in initiation of a bacterial infection. Characterization of such molecules is crucial for the understanding of bacterial pathogenesis, design of vaccines and development of antibacterial drugs. Because adhesins are frequently difficult to express, their characterization has often been hampered. Alternative expression methods developed for the analysis of adhesins, e.g. surface display techniques, suffer from various drawbacks and reports on high-level extracellular secretion of heterologous proteins in Gram-negative bacteria are scarce. These expression techniques are currently a field of active research. The purpose of the current study was to construct a convenient, new technique for identification of unknown bacterial adhesive polypeptides directly from the growth medium of the Escherichia coli host and to identify novel proteinaceous adhesins of the model organism Staphylococcus aureus. Results Randomly fragmented chromosomal DNA of S. aureus was cloned into a unique restriction site of our expression vector, which facilitates secretion of foreign FLAG-tagged polypeptides into the growth medium of E. coli ΔfliCΔfliD, to generate a library of 1663 clones expressing FLAG-tagged polypeptides. Sequence and bioinformatics analyses showed that in our example, the library covered approximately 32% of the S. aureus proteome. Polypeptides from the growth medium of the library clones were screened for binding to a selection of S. aureus target molecules and adhesive fragments of known staphylococcal adhesins (e.g coagulase and fibronectin-binding protein A as well as polypeptides of novel function (e.g. a universal stress protein and phosphoribosylamino-imidazole carboxylase ATPase subunit were detected. The results were further validated using purified His-tagged recombinant proteins of the corresponding fragments in enzyme-linked immunoassay and

Geomorphological applications of environmental radionuclides

International Nuclear Information System (INIS)

Quine, T.A.; Walling, D.

1998-01-01

Geomorphologists have shown increasing interest in environmental radionuclides since pioneering studies by Ritchie and McHenry in the USA and Campbell, Longmore and Loughran in Australia. Environmental radionuclides have attracted this interest because they provide geomorphologists with the means to trace sediment movement within the landscape. They, therefore, facilitate investigation of subjects at the core of geomorphology, namely the rates and patterns of landscape change. Most attention has been focussed on the artificial radionuclide caesium-137 ( 137 Cs) but more recently potential applications of the natural radionuclides lead-210 ( 210 Pb) and beryllium-7( 7 Be) have been investigated (Walling et al., 1995; Wallbrink and Murray, 1996a, 1996b). The origin, characteristics and applications of these radionuclides are summarised. These radionuclides are of value as sediment tracers because of three important characteristics: a strong affinity for sediment; a global distribution and the possibility of measurement at low concentration. Geomorphological applications of environmental radionuclides provide unique access to detailed qualitative data concerning landscape change over a range of timescales

Foodstuffs, radionuclides, monitoring

International Nuclear Information System (INIS)

Denisikov, A.I.

2000-01-01

Radionuclide contamination of water and food stuffs as a result of the Chernobyl accident and permissible contents of 90 Sr and 137 Cs are considered in brief. A method of radiation monitoring of food stuffs and water for the radionuclides mentioned is suggested. The method permits employment of the simplest and cheapest radiometric equipment for analysis, whole the high degree of radionuclide concentration using fiber sorbents permits using the instrumentation without expensive shields against external radiation. A description of ion-exchange unit for radiation monitoring of liquid samples of food stuffs or water, is provided [ru

Generator for radionuclide

International Nuclear Information System (INIS)

Weisner, P.S.; Forrest, T.R.F.

1985-01-01

This invention provides a radionuclide generator of the kind in which a parent radionuclide, adsorbed on a column of particulate material, generates a daughter radionuclide which is periodically removed from the column. This invention is particularly concerned with technetium generators using single collection vials. The generator comprises a column, a first reservoir for the eluent, a second reservoir to contain the volume of eluent required for a single elution, and means connecting the first reservoir to the second reservoir and the second reservoir to the column. Such a generator is particularly suitable for operation by vacuum elution

Process for encapsulating radionuclides

International Nuclear Information System (INIS)

Brownell, L.E.; Isaacson, R.E.

1976-01-01

Radionuclides are immobilized in virtually an insoluble form by reacting at a temperature of at least 90 0 C as an aqueous alkaline mixture having a solution pH of at least 10, containing a source of silicon, the radionuclide waste, and a metal cation. The molar ratio of silicon to the metal cation is on the order of unity to produce a gel from which complex metalosilicates crystallize to entrap the radionuclides within the resultant condensed crystal lattice. The product is a silicious stone-like material which is virtually insoluble and nonleachable in alkaline or neutral environment. One embodiment provides for the formation of the complex metalo-silicates, such as synthetic pollucite, by gel formation with subsequent calcination to the solid product; another embodiment utilizes a hydrothermal process, either above ground or deep within basalt caverns, at greater than atmospheric pressures and a temperature between 90 and 500 0 C to form complex metalo-silicates, such as strontium aluminosilicate. Another embodiment provides for the formation of complex metalo-silicates, such as synthetic pollucite, by slurrying an alkaline mixture of bentonite or kaolinite with a source of silicon and the radionuclide waste in salt form. In each of the embodiments a mobile system is achieved whereby the metalo-silicate constituents reorient into a condensed crystal lattice forming a cage structure with the condensed metalo-silicate lattice which completely surrounds the radionuclide and traps the radionuclide therein; thus rendering the radionuclide virtually insoluble

Identification of UDPG-binding polypeptides and purified (1,3)-β-glucan synthase by photoaffinity labelling with 5-azido-UDPG

International Nuclear Information System (INIS)

Frost, D.J.; Wu, A.; Read, S.M.; Wasserman, B.P.; Drake, R.R.; Haley, B.E.

1989-01-01

The photoaffinity probe 5-azido-uridine 5'-β-[ 32 P]-diphosphate glucose was used to identify the major UDPG-binding polypeptide of red beet (1,3)-β-glucan synthase. Glucan synthase was purified from plasma membranes by sequential solubilization with CHAPS followed by product entrapment. Two major polypeptides at 72 and 54 kD were labelled by probe. Labelling of both was abolished with increasing levels of cold UDPG. However, labelling of the 54 kD polypeptide was dependent upon the presence of divalent cations. These data suggest that the 54 kD polypeptide is a substrate-binding and cation-regulated component of the glucan synthase complex

Reagents for Astatination of Biomolecules. 5. Evaluation of hydrazone linkers in 211At- and 125I-labeled closo-decaborate(2-) conjugates of Fab′ as a means of decreasing kidney retention

Science.gov (United States)

Wilbur, D. Scott; Chyan, Ming-Kuan; Hamlin, Donald K.; Nguyen, Holly; Vessella, Robert L.

2011-01-01

Evaluation of monoclonal antibody (MAb) fragments (e.g. Fab′, Fab or engineered fragments) as cancer-targeting reagents for therapy with the α-particle emitting radionuclide astatine-211 (211At) has been hampered by low in vivo stability of the label and a propensity of these proteins localize to kidneys. Fortunately, our group has shown that the low stability of the 211At label, generally a meta- or para-[211At]astatobenzoyl conjugate, on MAb Fab′ fragments can be dramatically improved by use of closo-decaborate(2-) conjugates. However, the higher stability of radiolabeled MAb Fab′ conjugates appears to result in retention of the radioactivity in kidneys. This investigation was conducted to evaluate whether the retention of radioactivity in kidney might be decreased by the use of acid-cleavable hydrazone between the Fab′ and the radiolabeled closo-decaborate(2-) moiety. Five conjugation reagents containing sulfhydryl-reactive maleimide groups, a hydrazone functionality and a closo-decaborate(2-) moiety were prepared. In four of the five conjugation reagents, a discrete polyethylene glycol (PEG) linker was used, and one substituent adjacent to the hydrazone was varied (phenyl, benzoate, anisole or methyl) to provide varying acid-sensitivity. In the initial studies, the five maleimido-closo-decaborate(2-) conjugation reagents were radioiodinated (125I or 131I), then conjugated with an anti-PSMA Fab′ (107-1A4 Fab′). Biodistributions of the five radioiodinated Fab′ conjugates were obtained in nude mice at 1, 4 and 24 h post injection (pi). In contrast to closo-decaborate(2-) conjugated to 107-1A4 Fab′ through a non-cleavable linker, two conjugates containing either a benzoate or a methyl substituent on the hydrazone functionality displayed clearance rates from kidney, liver and spleen that were similar to those obtained with directly radioiodinated Fab′ (i.e. no conjugate). The maleimido-closo-decaborate(2-) conjugation reagent containing a benzoate

The interdomain flexible linker of the polypeptide GalNAc transferases dictates their long-range glycosylation preferences

DEFF Research Database (Denmark)

Rivas, Matilde De Las; Lira-Navarrete, Erandi; Daniel, Earnest James Paul

2017-01-01

The polypeptide GalNAc-transferases (GalNAc-Ts), that initiate mucin-type O-glycosylation, consist of a catalytic and a lectin domain connected by a flexible linker. In addition to recognizing polypeptide sequence, the GalNAc-Ts exhibit unique long-range N- A nd/or C-terminal prior glycosylation ...

High-yield recombinant expression and purification of marginally soluble, short elastin-like polypeptides.

Science.gov (United States)

Bahniuk, Markian S; Alshememry, Abdullah K; Unsworth, Larry D

2016-12-01

The protocol described here is designed as an extension of existing techniques for creating elastin-like polypeptides. It allows for the expression and purification of elastin-like polypeptide (ELP) constructs that are poorly expressed or have very low transition temperatures. DNA concatemerization has been modified to reduce issues caused by methylation sensitivity and inefficient cloning. Linearization of the modified expression vector has been altered to greatly increase cleavage efficiency. The purification regimen is based upon using denaturing metal affinity chromatography to fully solubilize and, if necessary, pre-concentrate the target peptide before purification by inverse temperature cycling (ITC). This protocol has been used to express multiple leucine-containing elastin-like polypeptides, with final yields of 250-660 mg per liter of cells, depending on the specific construct. This was considerably greater than previously reported yields for similar ELPs. Due to the relative hydrophobicity of the tested constructs, even compared with commonly employed ELPs, conventional methods would not have been able to be purify these peptides.

Induction of salivary polypeptides associated with parotid hypertrophy by gallotannins administered topically into the mouse mouth.

Science.gov (United States)

Gho, Francesca; Peña-Neira, Alvaro; López-Solís, Remigio O

2007-02-01

Isoproterenol-induced salivary polypeptides (IISP), a group of proline-rich proteins synthesized by mouse parotids, have been considered as markers for isoproterenol-induced parotid hypertrophy. Rodents fed diets containing high-tannin cereals (sorghum), also develop parotid hypertrophy. To test whether tannins are directly involved in provoking sialotrophic growth, we studied the effect of intraperitoneal and topical oral administrations of tannic acid (TA) on the induction of IISP polypeptides in endogamic mice (A/Snell). TA was characterized by HPLC chromatography and spectral analysis and shown to be composed solely of gallotannins, a complex family of glucose and gallic acid esters. IISP polypeptides were monitored in saliva by SDS-polyacrylamide gel electrophoresis during 36 h after ending TA stimulation. Single daily intraperitoneal administrations of TA for 3 consecutive days (0.033 mg/g bw/day), at variance of parallel administrations of isoproterenol (0.042 mg/g bw/day) failed to induce IISP polypeptides. However, repeated topical applications of TA into the mouse mouths (1.21 mg/g bw divided into three equal doses given at 4-h intervals within a single day) resulted in unequivocal induction of IISP polypeptides. That response was clearly intensified by increasing the stimulation frequency to eight equivalent doses given at 1.5-h intervals within a single day (corresponding to 3.23 mg/g bw) and even further by repeating this protocol for 3 days. Under these productive schemes of stimulations by TA, electrophoretic fractionation of parotid homogenates showed new polypeptide bands migrating in parallel to salivary IISP. These results suggest that topically administered gallotannins are effective inducers of trophic growth in mouse parotids.

Bacteriophytochromes control conjugation in Agrobacterium fabrum.

Science.gov (United States)

Bai, Yingnan; Rottwinkel, Gregor; Feng, Juan; Liu, Yiyao; Lamparter, Tilman

2016-08-01

Bacterial conjugation, the transfer of single stranded plasmid DNA from donor to recipient cell, is mediated through the type IV secretion system. We performed conjugation assays using a transmissible artificial plasmid as reporter. With this assay, conjugation in Agrobacterium fabrum was modulated by the phytochromes Agp1 and Agp2, photoreceptors that are most sensitive in the red region of visible light. In conjugation studies with wild-type donor cells carrying a pBIN-GUSINT plasmid as reporter that lacked the Ti (tumor inducing) plasmid, no conjugation was observed. When either agp1(-) or agp2(-) knockout donor strains were used, plasmid DNA was delivered to the recipient, indicating that both phytochromes suppress conjugation in the wild type donor. In the recipient strains, the loss of Agp1 or Agp2 led to diminished conjugation. When wild type cells with Ti plasmid and pBIN-GUS reporter plasmid were used as donor, a high rate of conjugation was observed. The DNA transfer was down regulated by red or far-red light by a factor of 3.5. With agp1(-) or agp2(-) knockout donor cells, conjugation in the dark was about 10 times lower than with the wild type donor, and with the double knockout donor no conjugation was observed. These results imply that the phytochrome system has evolved to inhibit conjugation in the light. The decrease of conjugation under different temperature correlated with the decrease of phytochrome autophosphorylation. Copyright © 2015 Elsevier B.V. All rights reserved.

Tuning the conformation of synthetic co-polypeptides of serine and glutamic acid through control over polymer composition

NARCIS (Netherlands)

Canning, A.; Pasquazi, A.; Fijten, M.; Rajput, S.; Buttery, L.; Aylott, J.W.; Zelzer, M.

2016-01-01

Ring opening polymerization (ROP) of N-carboxy anhydride (NCA) amino acids presents a rapid way to synthesize high molecular weight polypeptides with different amino acid compositions. The compositional and functional versatility of polypeptides make these materials an attractive choice for

Improvement of Learning and Memory Induced by Cordyceps Polypeptide Treatment and the Underlying Mechanism

Directory of Open Access Journals (Sweden)

Guangxin Yuan

2018-01-01

Full Text Available Our previous research revealed that Cordyceps militaris can improve the learning and memory, and although the main active ingredient should be its polypeptide complexes, the underlying mechanism of its activity remains poorly understood. In this study, we explored the mechanisms by which Cordyceps militaris improves learning and memory in a mouse model. Mice were given scopolamine hydrobromide intraperitoneally to establish a mouse model of learning and memory impairment. The effects of Cordyceps polypeptide in this model were tested using the Morris water maze test; serum superoxide dismutase activity; serum malondialdehyde levels; activities of acetyl cholinesterase, Na+-k+-ATPase, and nitric oxide synthase; and gamma aminobutyric acid and glutamate contents in brain tissue. Moreover, differentially expressed genes and the related cellular signaling pathways were screened using an mRNA expression profile chip. The results showed that the genes Pik3r5, Il-1β, and Slc18a2 were involved in the effects of Cordyceps polypeptide on the nervous system of these mice. Our findings suggest that Cordyceps polypeptide may improve learning and memory in the scopolamine-induced mouse model of learning and memory impairment by scavenging oxygen free radicals, preventing oxidative damage, and protecting the nervous system.

Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers.

Science.gov (United States)

Cho, S; Dong, S; Parent, K N; Chen, M

2016-01-01

Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers. We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs. Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses. A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines. It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.

Radionuclide transfer from mother to embryo

International Nuclear Information System (INIS)

Toader, M.; Vasilache, R.A.; Scridon, R.; Toader, M.L.

1998-01-01

The transfer of radionuclides from mother to embryo is still a matter of high interest. Therefore, the relation was investigated between the amount of radionuclides in the embryo and the dietary intake of the mother, this for two scenarios: a recurrent intake of variable amounts of radionuclides, and a long-term intake of a relatively constant amount of radionuclides, the radionuclide being 137 Cs. In the first case, the amount of radionuclides present in the embryo increases with the age of the embryo and with the intake of the mother. In the second case, no correlation could be found between the age of the embryo and its radioactive content; only the correlation between the intake of the mother and the radionuclide content of the embryo remained. (A.K.)

Kinetics of Internal-Loop Formation in Polypeptide Chains: A Simulation Study

Science.gov (United States)

Doucet, Dana; Roitberg, Adrian; Hagen, Stephen J.

2007-01-01

The speed of simple diffusional motions, such as the formation of loops in the polypeptide chain, places one physical limit on the speed of protein folding. Many experimental studies have explored the kinetics of formation of end-to-end loops in polypeptide chains; however, protein folding more often requires the formation of contacts between interior points on the chain. One expects that, for loops of fixed contour length, interior loops will form more slowly than end-to-end loops, owing to the additional excluded volume associated with the “tails”. We estimate the magnitude of this effect by generating ensembles of randomly coiled, freely jointed chains, and then using the theory of Szabo, Schulten, and Schulten to calculate the corresponding contact formation rates for these ensembles. Adding just a few residues, to convert an end-to-end loop to an internal loop, sharply decreases the contact rate. Surprisingly, the relative change in rate increases for a longer loop; sufficiently long tails, however, actually reverse the effect and accelerate loop formation slightly. Our results show that excluded volume effects in real, full-length polypeptides may cause the rates of loop formation during folding to depart significantly from the values derived from recent loop-formation experiments on short peptides. PMID:17208979

Radionuclide diagnosis of emergency states

International Nuclear Information System (INIS)

Ishmukhametov, A.I.

1985-01-01

Solution of emergency state radionuclide diagnostics from the technical point of view is provided by the application of the mobile quick-operating equipment in combination with computers, by the use of radionuclides with acceptable for emergency medicine characteristics and by development of radionuclide investigation data propcessing express-method. Medical developments include the study of acute disease and injury radioisotope semiotics, different indication diagnostic value determining, comparison of the results, obtained during radionuclide investigation, with clinicolaboratory and instrumental data, separation of methodical complex series

Anthropogenic radionuclides in the environment

Energy Technology Data Exchange (ETDEWEB)

Hu, Q; Weng, J; Wang, J

2007-11-15

Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview of anthropogenic radionuclide contamination in the environment, as well as the salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current development that contribute to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) commercial fuel reprocessing; (5) geological repository of high-level nuclear wastes, and (6) nuclear accidents. Then, we summarize the geochemical behavior for radionuclides {sup 99}Tc, {sup 129}I, and {sup 237}Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment. Biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

Radionuclide daughter inventory generator code: DIG

International Nuclear Information System (INIS)

Fields, D.E.; Sharp, R.D.

1985-09-01

The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs

Role of Side-Chain Molecular Features in Tuning Lower Critical Solution Temperatures (LCSTs) of Oligoethylene Glycol Modified Polypeptides.

Science.gov (United States)

Gharakhanian, Eric G; Deming, Timothy J

2016-07-07

A series of thermoresponsive polypeptides has been synthesized using a methodology that allowed facile adjustment of side-chain functional groups. The lower critical solution temperature (LCST) properties of these polymers in water were then evaluated relative to systematic molecular modifications in their side-chains. It was found that in addition to the number of ethylene glycol repeats in the side-chains, terminal and linker groups also have substantial and predictable effects on cloud point temperatures (Tcp). In particular, we found that the structure of these polypeptides allowed for inclusion of polar hydroxyl groups, which significantly increased their hydrophilicity and decreased the need to use long oligoethylene glycol repeats to obtain LCSTs. The thioether linkages in these polypeptides were found to provide an additional structural feature for reversible switching of both polypeptide conformation and thermoresponsive properties.

Critical review: Radionuclide transport, sediment transport, and water quality mathematical modeling; and radionuclide adsorption/desorption mechanisms

Energy Technology Data Exchange (ETDEWEB)

Onishi, Y.; Serne, R.J.; Arnold, E.M.; Cowan, C.E.; Thompson, F.L. [Pacific Northwest Lab., Richland, WA (United States)

1981-01-01

This report describes the results of a detailed literature review of radionuclide transport models applicable to rivers, estuaries, coastal waters, the Great Lakes, and impoundments. Some representatives sediment transport and water quality models were also reviewed to evaluate if they can be readily adapted to radionuclide transport modeling. The review showed that most available transport models were developed for dissolved radionuclide in rivers. These models include the mechanisms of advection, dispersion, and radionuclide decay. Since the models do not include sediment and radionuclide interactions, they are best suited for simulating short-term radionuclide migration where: (1) radionuclides have small distribution coefficients; (2) sediment concentrations in receiving water bodies are very low. Only 5 of the reviewed models include full sediment and radionuclide interactions: CHMSED developed by Fields; FETRA SERATRA, and TODAM developed by Onishi et al, and a model developed by Shull and Gloyna. The 5 models are applicable to cases where: (1) the distribution coefficient is large; (2) sediment concentrations are high; or (3) long-term migration and accumulation are under consideration. The report also discusses radionuclide absorption/desorption distribution ratios and addresses adsorption/desorption mechanisms and their controlling processes for 25 elements under surface water conditions. These elements are: Am, Sb, C, Ce, Cm, Co, Cr, Cs, Eu, I, Fe, Mn, Np, P, Pu, Pm, Ra, Ru, Sr, Tc, Th, {sup 3}H, U, Zn and Zr.

Preparation and evaluation of a radiogallium complex-conjugated bisphosphonate as a bone scintigraphy agent

International Nuclear Information System (INIS)

Ogawa, Kazuma; Takai, Kenichiro; Kanbara, Hiroya; Kiwada, Tatsuto; Kitamura, Yoji; Shiba, Kazuhiro; Odani, Akira

2011-01-01

Introduction: 68 Ga is a radionuclide of great interest as a positron emitter for positron emission tomography (PET). To develop a new bone-imaging agent with radiogallium, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was chosen as a chelating site and Ga-DOTA complex-conjugated bisphosphonate, which has a high affinity for bone, was prepared and evaluated. Although we are interested in developing 68 Ga-labeled bone imaging agents for PET, in these initial studies 67 Ga was used because of its longer half-life. Methods: DOTA-conjugated bisphosphonate (DOTA-Bn-SCN-HBP) was synthesized by conjugation of 2-(4-isothiocyanatebenzyl)-1,4,7,10-tetraazacyclododecane-1,4,7, 10-tetraacetic acid to 4-amino-1-hydroxybutylidene-1,1-bisphosphonate (alendronate). 67 Ga-DOTA-Bn-SCN-HBP was prepared by coordination with 67 Ga, and its in vitro and in vivo evaluations were performed. Results: 67 Ga-DOTA-Bn-SCN-HBP was prepared with a radiochemical purity of over 95% without purification. 67 Ga-DOTA-Bn-SCN-HBP had great affinity for hydroxyapatite in binding assay. In biodistribution experiments, 67 Ga-DOTA-Bn-SCN-HBP accumulated in bone rapidly but was hardly observed in tissues other than bone. Pretreatment of an excess amount of alendronate inhibited the bone accumulation of 67 Ga-DOTA-Bn-SCN-HBP. Conclusions: 67 Ga-DOTA-Bn-SCN-HBP showed ideal biodistribution characteristics as a bone-imaging agent. These findings should provide useful information on the drug design of bone imaging agents for PET with 68 Ga.

Biosynthesis of insulin-silk fibroin nanoparticles conjugates and in vitro evaluation of a drug delivery system

Science.gov (United States)

Yan, Hai-Bo; Zhang, Yu-Qing; Ma, Yong-Lei; Zhou, Li-Xia

2009-11-01

Silk fibroin derived from Bombyx mori is a biomacromolecular protein with outstanding biocompatibility. When it was dissolved in highly concentrated CaCl2 solution and then the mixture of the protein and salt was subjected to desalting treatments for long time in flowing water, the resulting liquid silk was water-soluble polypeptides with different molecular masses, ranging from 8 to 70 kDa. When the liquid silk was introduced rapidly into acetone, silk protein nanoparticles with a range of 40-120 nm in diameter could be obtained. The crystalline silk nanoparticles could be conjugated covalently with insulin alone with cross-linking reagent glutaraldehyde. In vitro properties of the insulin-silk fibroin nanoparticles (Ins-SFN) bioconjugates were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The optimal conditions for the biosynthesis of Ins-SFN bioconjugates were investigated. The Ins-SFN constructs obtained by 8 h of covalent cross-linking with 0.7% cross-linking reagent and the proportion of insulin and SFN being 30 IU: 15 mg showed much higher recoveries (90-115%). When insulin was coupled covalently with silk nanoparticles, the resistance of the modified insulin to trypsin digestion and in vitro stability in human serum were greatly enhanced as compared with insulin alone. The results in human serum indicated that the half-life in vitro of the biosynthesized Ins-SFN derivatives was about 2.5 times more than that of native insulin. Therefore, the silk protein nanoparticles have the potential values for being studied and developed as a new bioconjugate for enzyme/polypeptide drug delivery system.

Chaperones ameliorate beta cell dysfunction associated with human islet amyloid polypeptide overexpression.

Directory of Open Access Journals (Sweden)

Lisa Cadavez

Full Text Available In type 2 diabetes, beta-cell dysfunction is thought to be due to several causes, one being the formation of toxic protein aggregates called islet amyloid, formed by accumulations of misfolded human islet amyloid polypeptide (hIAPP. The process of hIAPP misfolding and aggregation is one of the factors that may activate the unfolded protein response (UPR, perturbing endoplasmic reticulum (ER homeostasis. Molecular chaperones have been described to be important in regulating ER response to ER stress. In the present work, we evaluate the role of chaperones in a stressed cellular model of hIAPP overexpression. A rat pancreatic beta-cell line expressing hIAPP exposed to thapsigargin or treated with high glucose and palmitic acid, both of which are known ER stress inducers, showed an increase in ER stress genes when compared to INS1E cells expressing rat IAPP or INS1E control cells. Treatment with molecular chaperone glucose-regulated protein 78 kDa (GRP78, also known as BiP or protein disulfite isomerase (PDI, and chemical chaperones taurine-conjugated ursodeoxycholic acid (TUDCA or 4-phenylbutyrate (PBA, alleviated ER stress and increased insulin secretion in hIAPP-expressing cells. Our results suggest that the overexpression of hIAPP induces a stronger response of ER stress markers. Moreover, endogenous and chemical chaperones are able to ameliorate induced ER stress and increase insulin secretion, suggesting that improving chaperone capacity can play an important role in improving beta-cell function in type 2 diabetes.

History of medical radionuclide production.

Science.gov (United States)

Ice, R D

1995-11-01

Radionuclide production for medical use originally was incidental to isotope discoveries by physicists and chemists. Once the available radionuclides were identified they were evaluated for potential medical use. Hevesy first used 32P in 1935 to study phosphorous metabolism in rats. Since that time, the development of cyclotrons, linear accelerators, and nuclear reactors have produced hundreds of radionuclides for potential medical use. The history of medical radionuclide production represents an evolutionary, interdisciplinary development of applied nuclear technology. Today the technology is represented by a mature industry and provides medical benefits to millions of patients annually.

Transfer of fallout radionuclides derived from Fukushima NPP accident: 1 year study on transfer of radionuclides through hydrological processes

Science.gov (United States)

Onda, Yuichi; Kato, Hiroaki; Patin, Jeremy; Yoshimura, Kazuya; Tsujimura, Maki; Wakahara, Taeko; Fukushima, Takehiko

2013-04-01

Previous experiences such as Chernobyl Nuclear Power Plant accident have confirmed that fallout radionuclides on the ground surface migrate through natural environment including soils and rivers. Therefore, in order to estimate future changes in radionuclide deposition, migration process of radionuclides in forests, soils, ground water, rivers should be monitored. However, such comprehensive studies on migration through forests, soils, ground water and rivers have not been conducted so far. Here, we present the following comprehensive investigation was conducted to confirm migration of radionuclides through natural environment including soils and rivers. 1)Study on depth distribution of radiocaesium in soils within forests, fields, and grassland 2)Confirmation of radionuclide distribution and investigation on migration in forests 3)Study on radionuclide migration due to soil erosion under different land use 4)Measurement of radionuclides entrained from natural environment including forests and soils 5)Investigation on radionuclide migration through soil water, ground water, stream water, spring water under different land use 6)Study on paddy-to-river transfer of radionuclides through suspended sediments 7)Study on river-to-ocean transfer of radionuclides via suspended sediments 8)Confirmation of radionuclide deposition in ponds and reservoirs

CDNA encoding a polypeptide including a hevein sequence

Science.gov (United States)

Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

1995-03-21

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

Optical phase conjugation

CERN Document Server

Fisher, Robert A

1983-01-01

This book appears at a time of intense activity in optical phase conjugation. We chose not to await the maturation of the field, but instead to provide this material in time to be useful in its development. We have tried very hard to elucidate and interrelate the various nonlinear phenomena which can be used for optical phase conjugation.

Country report: Cuba. Local Production of 90Y And 188Re Radionuclides and Development of Radiopharmaceuticals for Therapy

International Nuclear Information System (INIS)

Xiques, Abmel; Hernández, Ignacio; Leyva, René; Pérez, Marylaine; Alonso, Luis Michel; Zamora, Minelys

2010-01-01

During the first period of this CRP we could test an efficient and reliable generator system based on ion-chromatography to obtain 90 Y from its parent radionuclide 90 Sr. This production scheme for 90 Y was outlined in the previous CRP related with the development of generator technologies. Quality parameters such as trace metals that can potentially interfere in the labeling of biomoléculas, 90 Y recovery, 90 Sr/ 90 Y ratio and radiation dose to bed matrix were evaluated. The results showed that high recovery and radionuclidic purity could be obtained for 90 Y during its repeated separation from the 90 Sr cow. No replacement or treatment of the cow were necessary and low waste generation and 90 Sr losses less that 0.1% after each run were also observed during the present study. A Fab’ fragment was enzimatically produced and purified from the monoclonal antibody h-R3 (Nimotuzumab®). The fragment and the parent antibody were successfully conjugated with DOTA and labeled with 90 Y. The radioinmunoconjugate thus obtained also exhibited a good 24 h in-vitro stability in an excess of DTPA. A 90 Y radiocoloid was prepared in a cromic phosphate particle for radiosynoviorthesis with promising results in animal models. Two alumina based 188 W/ 188 Re generators were prepared and their eluates were used in the labeling of hR3-DOTA conjugates. Quality control and in vivo evaluation in comparison with 99m Tc-hR3 showed very good results and similar pattern of distribution and pharmacokinetic and will be used in clinical trials for cancer patients. (author)

Strategies to Fabricate Polypeptide-Based Structures via Ring-Opening Polymerization of N-Carboxyanhydrides

Directory of Open Access Journals (Sweden)

Carmen M. González-Henríquez

2017-10-01

Full Text Available In this review, we provide a general and clear overview about the different alternatives reported to fabricate a myriad of polypeptide architectures based on the ring-opening polymerization of N-carbonyanhydrides (ROP NCAs. First of all, the strategies for the preparation of NCA monomers directly from natural occurring or from modified amino acids are analyzed. The synthetic alternatives to prepare non-functionalized and functionalized NCAs are presented. Protection/deprotection protocols, as well as other functionalization chemistries are discussed in this section. Later on, the mechanisms involved in the ROP NCA polymerization, as well as the strategies developed to reduce the eventually occurring side reactions are presented. Finally, a general overview of the synthetic strategies described in the literature to fabricate different polypeptide architectures is provided. This part of the review is organized depending on the complexity of the macromolecular topology prepared. Therefore, linear homopolypeptides, random and block copolypeptides are described first. The next sections include cyclic and branched polymers such as star polypeptides, polymer brushes and highly branched structures including arborescent or dendrigraft structures.

Glucose-dependent Insulinotropic Polypeptide

DEFF Research Database (Denmark)

Christensen, Mikkel B; Calanna, Salvatore; Holst, Jens Juul

2014-01-01

CONTEXT: Patients with type 2 diabetes mellitus (T2DM) have clinically relevant disturbances in the effects of the hormone glucose-dependent insulinotropic polypeptide (GIP). OBJECTIVE: We aimed to evaluate the importance of the prevailing plasma glucose levels for the effect of GIP on responses......: During fasting glycemia (plasma glucose ∼8 mmol/L), GIP elicited significant increments in both insulin and glucagon levels, resulting in neutral effects on plasma glucose. During insulin-induced hypoglycemia (plasma glucose ∼3 mmol/L), GIP elicited a minor early-phase insulin response and increased...... glucagon levels during the initial 30 minutes, resulting in less glucose needed to be infused to maintain the clamp (29 ± 8 vs 49 ± 12 mg × kg(-1), P glucose ∼12 mmol/L), GIP augmented insulin secretion throughout the clamp, with slightly less glucagon...

Conditions and processes affecting radionuclide transport

Science.gov (United States)

Simmons, Ardyth M.; Neymark, Leonid A.

2012-01-01

Characteristics of host rocks, secondary minerals, and fluids would affect the transport of radionuclides from a previously proposed repository at Yucca Mountain, Nevada. Minerals in the Yucca Mountain tuffs that are important for retarding radionuclides include clinoptilolite and mordenite (zeolites), clay minerals, and iron and manganese oxides and hydroxides. Water compositions along flow paths beneath Yucca Mountain are controlled by dissolution reactions, silica and calcite precipitation, and ion-exchange reactions. Radionuclide concentrations along flow paths from a repository could be limited by (1) low waste-form dissolution rates, (2) low radionuclide solubility, and (3) radionuclide sorption onto geological media.

Investigation of Gelatin Polypeptides of Jellyfish (Rhopilema esculentum for Their Antioxidant Activity in vitro

Directory of Open Access Journals (Sweden)

Yong-Liang Zhuang

2010-01-01

Full Text Available Jellyfish gelatin was hydrolyzed by different proteases to obtain antioxidative polypeptides. The gelatin hydrolysate obtained by progressive hydrolysis using trypsin and Properase E exhibited the highest hydrolysis degree and antioxidant activity. Three series of gelatin polypeptides (SCP1, SCP2 and SCP3 were obtained by ultrafiltrating the gelatin hydrolysate through molecular mass cut-off membranes of 10, 6 and 2 kDa, respectively. Amino acid composition analysis showed that SCP3 had the highest total hydrophobic amino acid content. The in vitro antioxidant tests demonstrated that SCP2 had the strongest hydroxyl radical and hydrogen peroxide scavenging activities and metal chelating ability, while SCP3 showed the highest reducing power, antioxidant activity in linoleic acid emulsion system and superoxide anion radical scavenging activity. The results support the feasibility of jellyfish gelatin as a natural antioxidant polypeptide provider, and enzymatic hydrolysis and ultrafiltration could be potent future processing technologies to utilize the abundant jellyfish resource.

Effects on DPPH inhibition of egg-white protein polypeptides treated by pulsed electric field technology.

Science.gov (United States)

Wang, Ke; Wang, Jia; Liu, Bolong; Lin, Songyi; Zhao, Ping; Liu, Jingbo; Jones, Gregory; Huang, Hsiang-Chi

2013-05-01

Egg-white protein polypeptides are potentially used as a functional ingredient in food products. In this study, the effects on DPPH inhibition of egg-white protein polypeptides ranging from 10 to 30 kDa treated by pulsed electric field (PEF) technology were investigated. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) inhibition (%) was used to evaluate the antioxidant activity of polypeptides. In order to develop and optimize a pulsed electric field (PEF) mathematical model for improving the antioxidant activity, we have investigated three variables, including concentration (6, 8 and 10 mg mL(-1)), electric field intensity (10, 20 and 30 kV cm(-1)) and pulse frequency (2000, 2350 and 2700 Hz) and subsequently optimized them by response surface methodology (RSM). The concentration (8 mg mL(-1)), electric field intensity (10 kV cm(-1)) and pulse frequency (2000 Hz) were found to be the optimal conditions under which the DPPH inhibition increased 28.44%, compared to the sample without PEF treatment. Both near-infrared spectroscopy (NIR) and mid-infrared spectroscopy (MIR) were used to analyze the change of functional groups. The results showed that PEF technology could improve the antioxidant activity of antioxidant polypeptides from egg-white protein under the optimized conditions. © 2012 Society of Chemical Industry.

Smart systems related to polypeptide sequences

Directory of Open Access Journals (Sweden)

Lourdes Franco

2016-03-01

Full Text Available Increasing interest for the application of polypeptide-based smart systems in the biomedical field has developed due to the advantages given by the peptidic sequence. This is due to characteristics of these systems, which include: biocompatibility, potential control of degradation, capability to provide a rich repertoire of biologically specific interactions, feasibility to self-assemble, possibility to combine different functionalities, and capability to give an environmentally responsive behavior. Recently, applications concerning the development of these systems are receiving greater attention since a targeted and programmable release of drugs (e.g. anti-cancer agents can be achieved. Block copolymers are discussed due to their capability to render differently assembled architectures. Hybrid systems based on silica nanoparticles are also discussed. In both cases, the selected systems must be able to undergo fast changes in properties like solubility, shape, and dissociation or swelling capabilities. This review is structured in different chapters which explain the most recent advances on smart systems depending on the stimuli to which they are sensitive. Amphiphilic block copolymers based on polyanionic or polycationic peptides are, for example, typically employed for obtaining pH-responsive systems. Elastin-like polypeptides are usually used as thermoresponsive polymers, but performance can be increased by using techniques which utilize layer-by-layer electrostatic self-assembly. This approach offers a great potential to create multilayered systems, including nanocapsules, with different functionality. Recent strategies developed to get redox-, magnetic-, ultrasound-, enzyme-, light- and electric-responsive systems are extensively discussed. Finally, some indications concerning the possibilities of multi-responsive systems are discussed.

Folding and self-assembly of polypeptides: Dynamics and thermodynamics from molecular simulation

Science.gov (United States)

Fluitt, Aaron Michael

Empowered by their exquisite three-dimensional structures, or "folds," proteins carry out biological tasks with high specificity, efficiency, and fidelity. The fold that optimizes biological function represents a stable configuration of the constituent polypeptide molecule(s) under physiological conditions. Proteins and polypeptides are not static, however: battered by thermal motion, they explore a distribution of folds that is determined by the sequence of amino acids, the presence and identity of other molecules, and the thermodynamic conditions. In this dissertation, we apply molecular simulation techniques to the study of two polypeptides that have unusually diffuse distributions of folds under physiological conditions: polyglutamine (polyQ) and islet amyloid polypeptide (IAPP). Neither polyQ nor IAPP adopts a predominant fold in dilute aqueous solution, but at sufficient concentrations, both are prone to self-assemble into stable, periodic, and highly regular aggregate structures known as amyloid. The appearance of amyloid deposits of polyQ in the brain, and of IAPP in the pancreas, are associated with Huntington's disease and type 2 diabetes, respectively. A molecular view of the mechanism(s) by which polyQ and IAPP fold and self-assemble will enhance our understanding of disease pathogenesis, and it has the potential to accelerate the development of therapeutics that target early-stage aggregates. Using molecular simulations with spatial and temporal resolution on the atomic scale, we present analyses of the structural distributions of polyQ and IAPP under various conditions, both in and out of equilibrium. In particular, we examine amyloid fibers of polyQ, the IAPP dimer in solution, and single IAPP fragments at a lipid bilayer. We also benchmark the molecular models, or "force fields," available for such studies, and we introduce a novel simulation algorithm.

Qualidade conjugal: mapeando conceitos

Directory of Open Access Journals (Sweden)

Clarisse Mosmann

2006-12-01

Full Text Available Apesar da ampla utilização do conceito de qualidade conjugal, identifica-se falta de clareza conceitual acerca das variáveis que o compõem. Esse artigo apresenta revisão da literatura na área com o objetivo de mapear o conceito de qualidade conjugal. Foram analisadas sete principais teorias sobre o tema: Troca Social, Comportamental, Apego, Teoria da Crise, Interacionismo Simbólico. Pelos postulados propostos nas diferentes teorias, podem-se identificar três grupos de variáveis fundamentais na definição da qualidade conjugal: recursos pessoais dos cônjuges, contexto de inserção do casal e processos adaptativos. Neste sentido, a qualidade conjugal é resultado do processo dinâmico e interativo do casal, razão deste caráter multidimensional.

Study of radionuclides speciation with biological molecules of interest by spectrometric techniques

International Nuclear Information System (INIS)

Lourenco, V.

2007-07-01

Mechanisms of complexation and accumulation of the radionuclides at the cellular and molecular level are complex and poorly known because the studies on these subjects are scarce. Within the framework of this thesis, we studied the interactions of these cations with biological molecules of interest. We chose to focus on an actinide: uranium (VI) as well as europium as an analogue of trivalent actinides. The selected biological molecules are the phyto-chelatins: their role is to protect cells against intrusions from nonessential heavy metals (thus toxic). These proteins are likely to be implied in the mechanisms of sequestration of radionuclides in living organisms. However, their structure is complex, this is why, in order to better include/understand their reactivity, we extended our studies to lower entities which constitute them (amino acid: glycine, glutamic acid and cysteine; polypeptides: glutathione reduced and oxidized forms). In particular, we determined solution speciation (stoichiometry, structure) as well as the complexing constants associated with the formation with these species. These studies were undertaken by Time Resolved Laser induced Fluorescence (TRLIF), Electro-Spray-Mass Spectrometry (ES-MS), Nuclear Magnetic Resonance (NMR), Fourier Transform Infra-Rouge spectroscopy (FTIR) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS).The determination of the complexation constants enabled us to conclude that the complexing capacity of these molecules with respect to radionuclides was moderate (log 10 K 1 ≤ 3, pH 3 or 6), the formed species are mononuclear with only one ligand molecule (1:1). The interaction is performed via oxygenated (hard) groups. The direct complexation of europium with phyto-chelatins at acidic pH was studied jointly by TRLIF and ES-MS. The complexing capacity of these molecules is much higher than that of GSH from which they result. The interaction of europium with metallothioneins is, on the contrary, lower than

Radionuclides in air, water, and biota

International Nuclear Information System (INIS)

Seymour, A.H.; Nelson, V.A.

1977-01-01

Air, water, and biological samples collected before and after the 1965, 1969, and 1971 underground nuclear detonations at Amchitka Island were analyzed for natural and fallout radionuclides by gamma spectrometry. Selected samples were also analyzed for tritium, 55 Fe, and 90 Sr. The objectives were to search for and identify radionuclides of Amchitka origin in the samples and to contribute to the general knowledge of the distribution of radionuclides in the environment. The studies showed that there has been no escape of radionuclides from the underground sites of the three nuclear detonations at Amchitka Island except for trace quantities of radionuclides, principally tritium, in water and soil gas samples from the immediate vicinity of the surface ground zero for the 1965 event. Two naturally occurring radionuclides, 40 K and 7 Be, were the most abundant radionuclides in the samples, usually by a factor of 10 or more, except for 137 Cs in lichen samples. All levels were well below applicable Radiation Protction Guides, often being near the statistical limit of detection

Phytoremediation of radionuclides: an emerging alternative

International Nuclear Information System (INIS)

Singh, Shraddha

2013-01-01

Proliferation of nuclear power industry, nuclear weapon testing, dismantling of existing nuclear weapons and occasional accidents have contributed to an enhancement in the level of radionuclides in the environment. The radionuclides due to their long half life and transfer through the food chain effect adversely to normal biological systems. Hence, it is essential to effectively remove the radionuclides from contaminated soils and solutions. Phytoremediation - the use of plants for remediation of toxic metals and radionuclides has been recognized as an aesthetically pleasing, low cost and environment friendly in situ method. Phytoremediation is an umbrella term which covers several plant based approaches. Plants have shown the potential of remediation of these radionuclides from spiked solutions, low level nuclear waste and soil. Various aspects of phytoremediation as well as potential of various plants for remediation of radionuclides will be discussed here. (author)

Light Scattering Characterization of Elastin-Like Polypeptide Trimer Micelles

Science.gov (United States)

Tsuper, Ilona; Terrano, Daniel; Maraschky, Adam; Holland, Nolan; Streletzky, Kiril

The elastin-like polypeptides (ELP) nanoparticles are composed of three-armed star polypeptides connected by a negatively charged foldon. Each of the three arms extending from the foldon domain includes 20 repeats of the (GVGVP) amino acid sequence. The ELP polymer chains are soluble at room temperature and become insoluble at the transition temperature (close to 50 ° C), forming micelles. The size and shape of the micelle are dependent on the temperature and the pH of the solution, and on the concentration of the phosphate buffered saline (PBS). The depolarized dynamic light scattering (DDLS) was employed to study the structure and dynamics of micelles at 62 ° C. The solution was maintained at an approximate pH level of 7.3 - 7.5, while varying PBS concentration. At low salt concentrations (60 mM) displayed an apparent elongation of the micelles evident by a significant VH signal, along with a surge in the apparent Rh. A model of micelle growth (and potential elongation) with increase in salt concentration is considered.

Radionuclide migration test using undisturbed aerated soil

International Nuclear Information System (INIS)

Yamamoto, Tadatoshi; Ohtsuka, Yoshiro; Ogawa, Hiromichi; Wadachi, Yoshiki

1988-01-01

As one of the most important part of safety assessment on the shallow land disposal of lowlevel radioactive waste, the radionuclide migration was studied using undisturbed soil samples, in order to evaluate an exact radionuclide migration in an aerated soil layer. Soil samples used in the migration test were coastal sand and loamy soil which form typical surface soil layers in Japan. The aqueous solution containing 60 CoCl 2 , 85 SrCl 2 and 137 CsCl was fed into the soil column and concentration of each radionuclide both in effluent and in soil was measured. Large amount of radionuclides was adsorbed on the surface of soil column and small amount of radionuclides moved deep into the soil column. Difference in the radionuclide profile was observed in the low concentration portion particularly. It is that some fractions of 60 Co and 137 Cs are stable in non-ionic form and move downward through the soil column together with water. The radionuclide distribution in the surface of soil column can be fairly predicted with a conventional migration equation for ionic radionuclides. As a result of radionuclide adsorption, both aerated soil layers of coastal sand and loamy soil have large barrier ability on the radionuclide migration through the ground. (author)

In vitro and in vivo phosphorylation of polypeptides in plasma membrane and tonoplast-enriched fractions from barley roots

International Nuclear Information System (INIS)

Garbarino, J.E.; Hurkman, W.J.; Tanaka, C.K.; DuPont, F.M.

1991-01-01

Phosphorylation of polypeptides in membrane fractions from barley (Hordeum vulgare L. cv CM 72) roots was compared in in vitro and in vivo assays to assess the potential role of protein kinases in modification of membrane transport. Membrane fractions enriched in endoplasmic reticulum, tonoplast, and plasma membrane were isolated using sucrose gradients and the membrane polypeptides separated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. When the membrane fractions were incubated with γ[p 32 P]ATP, phosphorylation occurred almost exclusively in the plasma membrane fraction. Phosphorylation of a band at 38 kilodaltons increased as the concentration of Mg 2+ was decreased from millimolar to micromolar levels. Phosphorylation of bands at 125, 86, 58, 46 and 28 kilodaltons required millimolar Mg 2+ concentrations and was greatly enhanced by Ca 2+ . When roots of intact plants were labeled with [ 32 P]orthophosphate, polypeptides at approximately 135, 166, 90, 46 to 53, 32, 28, and 19 kilodaltons were labeled in the plasma membrane fraction and polypeptides at approximately 73, 66, and 48 kilodaltons were labeled in the tonoplast fraction. Treatment of the roots of intact plants with 150 millimolar NaCl resulted in increased phosphorylation of some polypeptides while treatment with 100 mM NaCl had no effect

Radionuclides in food

International Nuclear Information System (INIS)

Fernandez Gomez, Isis Maria

2008-01-01

The sources of the presence of radionuclides in food are presented: natural radiation and artificial radiation. The transfer of radionuclides through food chains, intakes of radionuclides to the body with its partners effective doses and typical consumption of basic foods of a rural adult population are exposed as main topics. Also the radiation doses from natural sources and exposure to man by ingestion of contaminated food with radionuclides of artificial origin are shown. The contribution of the food ingestion to the man exposure depends on: characteristics of radionuclide, natural conditions, farming practices and eating habits of the population. The principal international organizations in charge of setting guide levels for radionuclides in food are mentioned: standards, rules and the monitoring. It establishes that a guide is necessary for the food monitoring; the alone CODEX ALIMENTARIUS is applicable to emergency situations and the generic action levels proposed by the CODEX not satisfy all needs (no guiding international levels for planned or existing situations such as NORM). There are handled mainly socio-economic and political aspects. Among the actions to be taken are: to assure a public comprehensive information over the risk evaluation in food; to reinforce the collaboration among the different international organizations (WHO, IAEA, ICRP, EC) in relation with the food of set; to give follow-up to the control of the drinkable water and NORM's presence in the food. In addition, it is possible to create the necessary mechanisms to reduce the number of irrelevant measures and bureaucratic useless steps (certificates); to promote the exchange between the different institutions involved in the topic of the food, with relation to the acquired experiences and learned lessons. Likewise, it might examine the possibility of a multidisciplinary approximation (radioactive and not radioactive pollutants); to elaborate a technical guide to assure the

Initial Radionuclide Inventories

Energy Technology Data Exchange (ETDEWEB)

H. Miller

2004-09-19

The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement

Cross-Conjugated n-Dopable Aromatic Polyketone

NARCIS (Netherlands)

Voortman, Thomas P.; Bartesaghi, Davide; Koster, L. Jan Anton; Chiechi, Ryan C.

2015-01-01

This paper describes the synthesis and characterization of a high molecular weight cross-conjugated polyketone synthesized via scalable Friedel Crafts chemistry. Cross-conjugated polyketones are precursors to conjugated polyions; they become orders of magnitude more conductive after a two-electron

Determination of alpha radionuclides in fish

International Nuclear Information System (INIS)

Pernicka, L.; Matel, L.; Rosskopfova, O.

2001-01-01

In atmospheric water, external water and undercurrent the occurrence of radionuclides is usual. It is an important factor of quality of the environment. Plants ingest radionuclides from water and with they everyone. And it arises radioactivity infest food-chain. Radiotoxicity of this radionuclides is very deer sometimes. The sensitive radiochemical procedures for their determination are necessarily important. The poster presents the combined procedure used at our laboratory for determination of alpha radionuclides in biological samples. (authors)

Preparation, radioiodination and in vitro evaluation of a nido-carborane-dextran conjugate, a potential residualizing label for tumor targeting proteins and peptides

International Nuclear Information System (INIS)

Tolmachev, V.; Bruskin, A.; Uppsala University; Sjoeberg, S.; Carlsson, J.; Lundqvist, H.

2004-01-01

Polysaccharides are not degradable by proteolytic enzymes in lysosomes and do not diffuse through cellular membranes. Thus, attached to an internalizing, targeting protein, such polysaccharide linkers, will remain intracellularly after protein degradation. They can be labeled with halogens and provide then a so called residualizing label. Such an approach improves tumor-to-non-tumor radioactivity ratio and, consequently, the results of radionuclide diagnostics and therapy. A new approach to obtain a stable halogenation of the polysaccharide dextran using 7-(3-amino-propyl)-7,8-dicarba-nido-undecaborate (-) (ANC) is presented. Dextran T10 was partially oxidized by metaperiodate, and ANC was coupled to dextran by reductive amination. The conjugate was then labeled with 125 I using either Chloramine-T or IodoGen as oxidants. Labeling efficiency was 69-85%. Stability of the label was evaluated in rat liver homogenates. Under these conditions, the ANC-dextran conjugate was found to be more stable than labeled albumin, which was used as a control protein. (author)

Radionuclide usage survey 1979-80

International Nuclear Information System (INIS)

Woods, M.J.

1980-08-01

Details of a survey by the Life Sciences Working Group of the International Committee for Radionuclide Metrology (ICRM) on radionuclide usage by medical physicists in 11 countries are presented. The results indicate that the radionuclide which will be of most significance in the future will be F-18, Fe-52, Ga-67, Ga-68, Kr-81m, Tc-99m, In-111, I-123, Xe-127 and Tl-201, (U.K.)

Preparation and evaluation of a radiogallium complex-conjugated bisphosphonate as a bone scintigraphy agent

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Kazuma, E-mail: kogawa@p.kanazawa-u.ac.jp [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192 (Japan); Takai, Kenichiro; Kanbara, Hiroya; Kiwada, Tatsuto [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192 (Japan); Kitamura, Yoji; Shiba, Kazuhiro [Advanced Science Research Center, Kanazawa University, Kanazawa 920-8640 (Japan); Odani, Akira [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192 (Japan)

2011-07-15

Introduction: {sup 68}Ga is a radionuclide of great interest as a positron emitter for positron emission tomography (PET). To develop a new bone-imaging agent with radiogallium, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was chosen as a chelating site and Ga-DOTA complex-conjugated bisphosphonate, which has a high affinity for bone, was prepared and evaluated. Although we are interested in developing {sup 68}Ga-labeled bone imaging agents for PET, in these initial studies {sup 67}Ga was used because of its longer half-life. Methods: DOTA-conjugated bisphosphonate (DOTA-Bn-SCN-HBP) was synthesized by conjugation of 2-(4-isothiocyanatebenzyl)-1,4,7,10-tetraazacyclododecane-1,4,7, 10-tetraacetic acid to 4-amino-1-hydroxybutylidene-1,1-bisphosphonate (alendronate). {sup 67}Ga-DOTA-Bn-SCN-HBP was prepared by coordination with {sup 67}Ga, and its in vitro and in vivo evaluations were performed. Results: {sup 67}Ga-DOTA-Bn-SCN-HBP was prepared with a radiochemical purity of over 95% without purification. {sup 67}Ga-DOTA-Bn-SCN-HBP had great affinity for hydroxyapatite in binding assay. In biodistribution experiments, {sup 67}Ga-DOTA-Bn-SCN-HBP accumulated in bone rapidly but was hardly observed in tissues other than bone. Pretreatment of an excess amount of alendronate inhibited the bone accumulation of {sup 67}Ga-DOTA-Bn-SCN-HBP. Conclusions: {sup 67}Ga-DOTA-Bn-SCN-HBP showed ideal biodistribution characteristics as a bone-imaging agent. These findings should provide useful information on the drug design of bone imaging agents for PET with {sup 68}Ga.

Block-conjugate-gradient method

International Nuclear Information System (INIS)

McCarthy, J.F.

1989-01-01

It is shown that by using the block-conjugate-gradient method several, say s, columns of the inverse Kogut-Susskind fermion matrix can be found simultaneously, in less time than it would take to run the standard conjugate-gradient algorithm s times. The method improves in efficiency relative to the standard conjugate-gradient algorithm as the fermion mass is decreased and as the value of the coupling is pushed to its limit before the finite-size effects become important. Thus it is potentially useful for measuring propagators in large lattice-gauge-theory calculations of the particle spectrum

Radionuclides: Accumulation and Transport in Plants.

Science.gov (United States)

Gupta, D K; Chatterjee, S; Datta, S; Voronina, A V; Walther, C

Application of radioactive elements or radionuclides for anthropogenic use is a widespread phenomenon nowadays. Radionuclides undergo radioactive decays releasing ionizing radiation like gamma ray(s) and/or alpha or beta particles that can displace electrons in the living matter (like in DNA) and disturb its function. Radionuclides are highly hazardous pollutants of considerable impact on the environment, food chain and human health. Cleaning up of the contaminated environment through plants is a promising technology where the rhizosphere may play an important role. Plants belonging to the families of Brassicaceae, Papilionaceae, Caryophyllaceae, Poaceae, and Asteraceae are most important in this respect and offer the largest potential for heavy metal phytoremediation. Plants like Lactuca sativa L., Silybum marianum Gaertn., Centaurea cyanus L., Carthamus tinctorius L., Helianthus annuus and H. tuberosus are also important plants for heavy metal phytoremediation. However, transfer factors (TF) of radionuclide from soil/water to plant ([Radionuclide]plant/[Radionuclide]soil) vary widely in different plants. Rhizosphere, rhizobacteria and varied metal transporters like NRAMP, ZIP families CDF, ATPases (HMAs) family like P1B-ATPases, are involved in the radio-phytoremediation processes. This review will discuss recent advancements and potential application of plants for radionuclide removal from the environment.

Method of separating short half-life radionuclides from a mixture of radionuclides

Science.gov (United States)

Bray, L.A.; Ryan, J.L.

1999-03-23

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

Radionuclide transport processes in terrestrial ecosystems

International Nuclear Information System (INIS)

Whicker, F.W.

1983-01-01

Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

Science.gov (United States)

Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

2017-06-01

Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly) n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4 kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1746-1755, 2017. © 2017 Wiley Periodicals, Inc.

Membrane fractions active in poliovirus RNA replication contain VPg precursor polypeptides

International Nuclear Information System (INIS)

Takegami, T.; Semler, B.L.; Anderson, C.W.; Wimmer, E.

1983-01-01

The poliovirus specific polypeptide P3-9 is of special interest for studies of viral RNA replication because it contains a hydrophobic region and, separated by only seven amino acids from that region, the amino acid sequence of the genome-linked protein VPg. Membraneous complexes of poliovirus-infected HeLa cells that contain poliovirus RNA replicating proteins have been analyzed for the presence of P3-9 by immunoprecipitation. Incubation of a membrane fraction rich in P3-9 with proteinase leaves the C-terminal 69 amino acids of P3-9 intact, an observation suggesting that this portion is protected by its association with the cellular membrane. These studies have also revealed two hitherto undescribed viral polypeptides consisting of amino acid sequences of the P2 andf P3 regions of the polyprotein. Sequence analysis by stepwise Edman degradation show that these proteins are 3b/9 (M/sub r/77,000) and X/9 (M/sub r/50,000). 3b/9 and X/9 are membrane bound and are turned over rapidly and may be direct precursors to proteins P2-X and P3-9 of the RNA replication complex. P2-X, a polypeptide void of hydrophobic amino acid sequences but also found associated with membranes, is rapidly degraded when the membraneous complex is treated with trypsin. It is speculated that P2-X is associated with membranes by its affinity to the N-terminus of P3-9

Protein carriers of conjugate vaccines

Science.gov (United States)

Pichichero, Michael E

2013-01-01

The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

Radionuclide Sensors for Water Monitoring

International Nuclear Information System (INIS)

Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

2004-01-01

Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for loW--level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of the short ranges of beta and alpha particle s in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector. Automated microfluidics is used for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field and in situ measurements

Homoallylglycine residues are superior precursors to orthogonally modified thioether containing polypeptides.

Science.gov (United States)

Perlin, Pesach; Gharakhanian, Eric G; Deming, Timothy J

2018-06-12

Homoallylglycine N-carboxyanhydride, Hag NCA, monomers were synthesized and used to prepare polypeptides containing Hag segments with controllable lengths of up to 245 repeats. Poly(l-homoallylglycine), GHA, was found to adopt an α-helical conformation, which provided good solubility in organic solvents and allowed high yield functionalization of its alkene side-chains via radical promoted addition of thiols. The conformations of these derivatives were shown to be switchable between α-helical and disordered states in aqueous media using thioether alkylation or oxidation reactions. Incorporation of GHA segments into block copolymers with poly(l-methionine), M, segments provided a means to orthogonally modify thioether side-chains different ways in separate copolypeptide domains. This approach allows preparation of functional polypeptides containing discrete domains of oxidized and alkylated thioether containing residues, where chain conformation and functionality of each domain can be independently modified.

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Bocock, K.L.

1981-01-01

This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

Artificial radionuclides in soil, flora and fauna

International Nuclear Information System (INIS)

Marej, A.N.

1984-01-01

Sources and ways of soil contamination by radionuclides, as well as the main regularities of radionuclide behaviour in soils, are discussed. Ways of radionuclide uptake by plants are discussed in detail, since radionuclide contamination of vegetation, and agricultural plants and pastures in particular, is one of the main factors, determining sanitary value of environmental contamination by radioactive substances

Salt- and pH-Triggered Helix-Coil Transition of Ionic Polypeptides under Physiology Conditions.

Science.gov (United States)

Yuan, Jingsong; Zhang, Yi; Sun, Yue; Cai, Zhicheng; Yang, Lijiang; Lu, Hua

2018-06-11

Controlling the helix-coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here, we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EG x )-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EG x DMA-Glu) ( x = 1, 2, and 3), show excellent aqueous solubility (>20 mg/mL) regardless of their charge states. Unlike poly-l-lysine that can form a helix only at pH above 10, P(EG x DMA-Glu) undergo a pH-dependent helix-coil switch with their transition points within the physiological range (pH ∼5.3-6.5). Meanwhile, P(EG x DMA-Glu) exhibit an unusual salt-induced helical conformation presumably owing to the unique properties of EG x linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides and represents a facile approach toward stimuli-responsive biopolymers for advanced biological applications.

Conjugated polymer zwitterions and solar cells comprising conjugated polymer zwitterions

Science.gov (United States)

Emrick, Todd; Russell, Thomas; Page, Zachariah; Liu, Yao

2018-06-05

A conjugated polymer zwitterion includes repeating units having structure (I), (II), or a combination thereof ##STR00001## wherein Ar is independently at each occurrence a divalent substituted or unsubstituted C3-30 arylene or heteroarylene group; L is independently at each occurrence a divalent C1-16 alkylene group, C6-30arylene or heteroarylene group, or alkylene oxide group; and R1 is independently at each occurrence a zwitterion. A polymer solar cell including the conjugated polymer zwitterion is also disclosed.

Zonadhesin D3-polypeptides vary among species but are similar in Equus species capable of interbreeding.

Science.gov (United States)

Tardif, Steve; Brady, Heidi A; Breazeale, Kelly R; Bi, Ming; Thompson, Leslie D; Bruemmer, Jason E; Bailey, Laura B; Hardy, Daniel M

2010-02-01

Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acrosomes of spermatozoa from all three Equus species, similar to its localization in other animals. Likewise, in horse and donkey testis, zonadhesin was detected only in germ cells, first in the acrosomal granule of round spermatids and then in the developing acrosomes of elongating spermatids. Among non-Equus species, D3-domain polypeptides of mature, processed zonadhesin varied markedly in size and detergent solubility. However, zonadhesin D3-domain polypeptides in horse, donkey, and zebra spermatozoa exhibited identical electrophoretic mobility and detergent solubility. Equus zonadhesin D3-polypeptides (p110/p80 doublet) were most similar in size to porcine and bovine zonadhesin D3-polypeptides (p105). Sequence comparisons revealed that the horse zonadhesin precursor's domain content and arrangement are similar to those of zonadhesin from other large animals. Partial sequences of horse and donkey zonadhesin were much more similar to each other (>99% identity) than they were to orthologous sequences of human, pig, rabbit, and mouse zonadhesin (52%-72% identity). We conclude that conservation of zonadhesin D3-polypeptide properties correlates with ability of Equus species to interbreed.

Ligand-functionalized degradable polyplexes formed by cationic poly(aspartic acid)-grafted chitosan-cyclodextrin conjugates

Science.gov (United States)

Song, Hai-Qing; Li, Rui-Quan; Duan, Shun; Yu, Bingran; Zhao, Hong; Chen, Da-Fu; Xu, Fu-Jian

2015-03-01

Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE-FA/pDNA, and ternary CCPE-FA/CCPE/pDNA (prepared by layer-by-layer assembly) polyplexes were investigated in detail using different cell lines. The CCPE-based polyplexes displayed much higher transfection efficiencies than the CS-based polyplexes reported earlier by us. The ternary polyplexes of CCPE-FA/CCPE/pDNA produced excellent gene transfection abilities in the folate receptor (FR)-positive tumor cells. This work would provide a promising means to produce highly efficient polyplexes for future gene therapy applications.Polypeptide-based degradable polyplexes attracted considerable attention in drug delivery systems. Polysaccharides including cyclodextrin (CD), dextran, and chitosan (CS) were readily grafted with cationic poly(aspartic acid)s (PAsps). To further enhance the transfection performances of PAsp-based polyplexes, herein, different types of ligand (folic acid, FA)-functionalized degradable polyplexes were proposed based on the PAsp-grafted chitosan-cyclodextrin conjugate (CCPE), where multiple β-CDs were tied on a CS chain. The FA-functionalized CCPE (i.e., CCPE-FA) was obtained via a host-guest interaction between the CD units of CCPE and the adamantane (Ad) species of Ad-modified FA (Ad-FA). The resulting CCPE/pDNA, CCPE

Environmental behaviour of radionuclides and transfer to man

International Nuclear Information System (INIS)

Smith, H.

1982-01-01

The environmental behaviour of the radionuclides making the major contribution to man's irradiation through diet is described. The following stages are emphasized: transfer of radionuclides to plants; transfer of radionuclides to animals; metabolism of inhaled or ingested radionuclides in animals providing food for man; transfer of radionuclides through the aquatic environment; application of food chain models. (43 references)

Analysis of urine composition in type Ⅱ diabetic mice after intervention therapy using holothurian polypeptides

Science.gov (United States)

Li, Yanyan; Xu, Jiajie; Su, Xiurong

2017-07-01

Hydrolysates and peptide fractions (PF) obtained from sea cucumber with commercial enzyme were studied on the hpyerglycemic and renal protective effects on db/db rats using urine metabolomics. Compared with the control group the polypeptides from the two species could significantly reduce the urine glucose and urea. We also tried to address the compositions of highly expressed urinary proteins using a proteomics approach. They were serum albumins, AMBP proteins, negative trypsin, elastase and urinary protein, GAPDH, a receptor of urokinase-type plasminogen activator (uPAR), and Ig kappa chain C region. We used the electronic nose to quickly detect changes in the volatile substances in mice urine after holothurian polypeptides fed, and the results show it can identify the difference between treatment groups with the control group without overlapping. The protein express mechanism of holothurian polypeptides treating diabetes was discussed, and we suggested these two peptides with the hypoglycemic and renal protective activity might be utilized as nutraceuticals.

Research study of conjugate materials; Conjugate material no chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

The paper reported an introductory research on possibilities of new glass `conjugate materials.` The report took up the structure and synthetic process of conjugate materials to be researched/developed, classified them according to structural elements on molecular, nanometer and cluster levels, and introduced the structures and functions. Further, as glasses with new functions to be proposed, the paper introduced transparent and high-strength glass used for houses and vehicles, light modulation glass which realizes energy saving and optical data processing, and environmentally functional glass which realizes environmental cleaning or high performance biosensor. An initial survey was also conducted on rights of intellectual property to be taken notice of in Japan and abroad in the present situation. Reports were summed up and introduced of Osaka National Research Institute, Electrotechnical Laboratory, and National Industrial Research Institute of Nagoya which are all carrying out leading studies of conjugate materials. 235 refs., 135 figs., 6 tabs.

An anti-cancer WxxxE-containing azurin polypeptide inhibits Rac1-dependent STAT3 and ERK/GSK-3β signaling in breast cancer cells.

Science.gov (United States)

Zhang, Zhe; Luo, Zhiyong; Min, Wenpu; Zhang, Lin; Wu, Yaqun; Hu, Xiaopeng

2017-06-27

In our previous study, we characterized a mycoplasmal small GTPase-like polypeptide of 240 amino acids that possesses an N-terminal WVLGE sequence. The N-terminal WVLGE sequence promotes activation of Rac1 and subsequent host cancer cell proliferation. To investigate the function of the WxxxE motif in the interaction with Rac1 and host tumor progression, we synthesized a 35-amino acid WVLGE-containing polypeptide derived from a cell-penetrating peptide derived from the azurin protein. We verified that the WVLGE-containing polypeptide targeted MCF-7 cells rather than MCF-10A cells. However, the WVLGE-containing polypeptide inhibited activation of Rac1 and induced cellular phenotypes that resulted from inhibition of Rac1. In addition, the WVLGE-containing polypeptide down-regulated phosphorylation of the STAT3 and ERK/GSK-3β signaling pathways, and this effect was abolished by either stimulation or inhibition of Rac1 activity. We also found that the WVLGE-containing polypeptide has a Rac1-dependent potential to suppress breast cancer growth in vitro and in vivo. We suggest that by acting as a Rac1 inhibitor, this novel polypeptide may be useful for the treatment of breast cancer.

Radioactivity: radionuclides in foods

International Nuclear Information System (INIS)

Simpson, R.E.; Baratta, E.J.; Jelinek, C.F.

1977-01-01

The results are summarized of the analysis for strontium-90, cesium-137, iodine-131, ruthenium-106, and potassium-40, a naturally occurring radionuclide, in samples of total diet and selected import commodities in the foods compliance program of the Food and Drug Administration. On the basis of the radionuclide intake guidelines established by the Federal Radiation Council (FRC), the low content of radionuclides found in the total diet samples for fiscal years 1973 and 1974 demonstrates the need for surveillance only at the present level. The low levels of radionuclides found in a limited number of edible imported commodities indicate that their contribution to the total diet would not increase the levels of these radionuclides above those recommended for only periodic surveillance by the FRC. The potassium levels, determined from potassium-40 activity, found in meats and fish agree with the value for normal muscle tissue for the reference man reported by the International Commission on Radiation Protection. Of the other commodities, nuts contained the highest levels, while sugar, beverages, and processed foods contained the lowest levels of potassium. Although cesium and potassium are chemical analogs with similar metabolic properties, because of their variable content in some leafy samples as a result of surface contamination, a correlation between cesium-137 levels and the cesium-137-to-potassium ratio was inconclusive

Inverse problem in radionuclide transport

International Nuclear Information System (INIS)

Yu, C.

1988-01-01

The disposal of radioactive waste must comply with the performance objectives set forth in 10 CFR 61 for low-level waste (LLW) and 10 CFR 60 for high-level waste (HLW). To determine probable compliance, the proposed disposal system can be modeled to predict its performance. One of the difficulties encountered in such a study is modeling the migration of radionuclides through a complex geologic medium for the long term. Although many radionuclide transport models exist in the literature, the accuracy of the model prediction is highly dependent on the model parameters used. The problem of using known parameters in a radionuclide transport model to predict radionuclide concentrations is a direct problem (DP); whereas the reverse of DP, i.e., the parameter identification problem of determining model parameters from known radionuclide concentrations, is called the inverse problem (IP). In this study, a procedure to solve IP is tested, using the regression technique. Several nonlinear regression programs are examined, and the best one is recommended. 13 refs., 1 tab

Radionuclide Retention in Concrete Wasteforms

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

2012-09-24

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

Gold nanorod-mediated hyperthermia enhances the efficacy of HPMA copolymer-90Y conjugates in treatment of prostate tumors

International Nuclear Information System (INIS)

Buckway, Brandon; Frazier, Nick; Gormley, Adam J.; Ray, Abhijit; Ghandehari, Hamidreza

2014-01-01

Introduction: The treatment of prostate cancer using a radiotherapeutic 90 Y labeled N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer can be enhanced with localized tumor hyperthermia. An 111 In labeled HPMA copolymer system for single photon emission computerized tomography (SPECT) was developed to observe the biodistribution changes associated with hyperthermia. Efficacy studies were conducted in prostate tumor bearing mice using the 90 Y HPMA copolymer with hyperthermia. Methods: HPMA copolymers containing 1, 4, 7, 10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) were synthesized by reversible addition-fragmentation transfer (RAFT) copolymerization and subsequently labeled with either 111 In for imaging or 90 Y for efficacy studies. Radiolabel stability was characterized in vitro with mouse serum. Imaging and efficacy studies were conducted in DU145 prostate tumor bearing mice. Imaging was performed using single photon emission computerized tomography (SPECT). Localized mild tumor hyperthermia was achieved by plasmonic photothermal therapy using gold nanorods. Results: HPMA copolymer-DOTA conjugates demonstrated efficient labeling and stability for both radionuclides. Imaging analysis showed a marked increase of radiolabeled copolymer within the hyperthermia treated prostate tumors, with no significant accumulation in non-targeted tissues. The greatest reduction in tumor growth was observed in the hyperthermia treated tumors with 90 Y HPMA copolymer conjugates. Histological analysis confirmed treatment efficacy and safety. Conclusion: HPMA copolymer-DOTA conjugates radiolabeled with both the imaging and treatment radioisotopes, when combined with hyperthermia can serve as an image guided approach for efficacious treatment of prostate tumors

Sediment and radionuclide transport in rivers: radionuclide transport modeling for Cattaraugus and Buttermilk Creeks, New York

International Nuclear Information System (INIS)

Onishi, Y.; Yabusaki, S.B.; Kincaid, C.T.; Skaggs, R.L.; Walters, W.H.

1982-12-01

SERATRA, a transient, two-dimensional (laterally-averaged) computer model of sediment-contaminant transport in rivers, satisfactorily resolved the distribution of sediment and radionuclide concentrations in the Cattaraugus Creek stream system in New York. By modeling the physical processes of advection, diffusion, erosion, deposition, and bed armoring, SERATRA routed three sediment size fractions, including cohesive soils, to simulate three dynamic flow events. In conjunction with the sediment transport, SERATRA computed radionuclide levels in dissolved, suspended sediment, and bed sediment forms for four radionuclides ( 137 Cs, 90 Sr, 239 240 Pu, and 3 H). By accounting for time-dependent sediment-radionuclide interaction in the water column and bed, SERATA is a physically explicit model of radionuclide fate and migration. Sediment and radionuclide concentrations calculated by SERATA in the Cattaraugus Creek stream system are in reasonable agreement with measured values. SERATRA is in the field performance phase of an extensive testing program designed to establish the utility of the model as a site assessment tool. The model handles not only radionuclides but other contaminants such as pesticides, heavy metals and other toxic chemicals. Now that the model has been applied to four field sites, including the latest study of the Cattaraugus Creek stream system, it is recommended that a final model be validated through comparison of predicted results with field data from a carefully controlled tracer test at a field site. It is also recommended that a detailed laboratory flume be tested to study cohesive sediment transport, deposition, and erosion characteristics. The lack of current understanding of these characteristics is one of the weakest areas hindering the accurate assessment of the migration of radionuclides sorbed by fine sediments of silt and clay

Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

Science.gov (United States)

Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

2014-12-01

Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

Misonidazole-glutathione conjugates in CHO cells

International Nuclear Information System (INIS)

Varghese, A.J.; Whitmore, G.F.

1984-01-01

Misonidazole, after reduction to the hydroxylamine derivative, reacts with glutathione (GSH) under physiological conditions. The reaction product has been identified as a mixture of two isomeric conjugates. When water soluble extracts of CHO cells exposed to misonidazole under hypoxic conditions are subjected to HPLC analysis, misonidazole derivatives, having the same chromatographic properties as the GSH-MISO conjugates, were detected. When CHO cells were incubated with misonidazole in the presence of added GSH, a substantial increase in the amount of the conjugate was detected. When extracts of CHO cells exposed to misonidazole under hypoxia were subsequently exposed to GSH, an increased formation of the conjugate was observed. A rearrangement product of the hydroxylamine derivative of misonidazole is postulated as the reactive intermediate responsible for the formation of the conjugate

Modelling conjugation with stochastic differential equations

DEFF Research Database (Denmark)

Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Hasman, Henrik

2010-01-01

Enterococcus faecium strains in a rich exhaustible media. The model contains a new expression for a substrate dependent conjugation rate. A maximum likelihood based method is used to estimate the model parameters. Different models including different noise structure for the system and observations are compared......Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two...... using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared...

cDNA encoding a polypeptide including a hevein sequence

Energy Technology Data Exchange (ETDEWEB)

Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

2000-07-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

cDNA encoding a polypeptide including a hevein sequence

Energy Technology Data Exchange (ETDEWEB)

Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

1999-05-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 12 figs.

cDNA encoding a polypeptide including a hevein sequence

Energy Technology Data Exchange (ETDEWEB)

Raikhel, Natasha V. (Okemos, MI); Broekaert, Willem F. (Dilbeek, BE); Chua, Nam-Hai (Scarsdale, NY); Kush, Anil (New York, NY)

1999-05-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

cDNA encoding a polypeptide including a hevein sequence

Energy Technology Data Exchange (ETDEWEB)

Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

1995-03-21

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1,018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 11 figures.

Functional polypeptides obtained by living ring opening polymerizations of N-carboxyanhydrides

NARCIS (Netherlands)

Habraken, G.J.M.

2011-01-01

N-Carboxyanhydride ring opening polymerization (NCA ROP) is a method to prepare polypeptides with a high degree of polymerization in large quantities. The living polymerization technique of NCA ROP gave the opportunity to synthesize many polymer architectures with well-defined blocks and copolymers

Side-chain-controlled self-assembly of polystyrene-polypeptide miktoarm star copolymers

KAUST Repository

Junnila, Susanna; Houbenov, Nikolay; Karatzas, A.; Hadjichristidis, Nikolaos; Hirao, Akira; Iatrou, Hermis; Ikkala, Olli T.

2012-01-01

polypeptide-surfactant self-assemblies with β-sheet conformation in PS 2PLL(DS) and PS 2(PLL(DS)) 2 which dominate over the formation of block copolymer scale structures. Differences between the 3- and 4-arm systems illustrate how packing frustration between

Study of local conformation and molecular movements of homo-polypeptides in aqueous solutions by using magnetic resonance and relaxation

International Nuclear Information System (INIS)

Perly, Bruno

1980-01-01

The objective of this research thesis is to study local conformations and mobilities of some typical homo-polypeptides by using techniques of magnetic resonance. By using these techniques, it is possible to make highly local observations of molecular elements which allows very efficient analysis of structural and dynamic properties of several biologically important compounds to be performed, and the study of their interactions. After a presentation of the general properties of the studied polypeptides, of magnetic resonance and of magnetic relaxation, the author presents some elements of macromolecular dynamics and movement models. Then, he reports the study of local conformations and structural transitions, applications of spin marking to the dynamic study of polypeptides, a dynamic study of the polypeptide skeleton under the form of statistic balls, the study of local movements of side chains by using nuclear relaxation, the study of the coupling of movements of main and side chains, and of the nuclear relaxation induced by a radical spin marker

Measurement of radionuclides in waste packages

Science.gov (United States)

Brodzinski, R.L.; Perkins, R.W.; Rieck, H.G.; Wogman, N.A.

1984-09-12

A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

Poly(2-oxazoline)-Antibiotic Conjugates with Penicillins.

Science.gov (United States)

Schmidt, Martin; Bast, Livia K; Lanfer, Franziska; Richter, Lena; Hennes, Elisabeth; Seymen, Rana; Krumm, Christian; Tiller, Joerg C

2017-09-20

The conjugation of antibiotics with polymers is rarely done, but it might be a promising alternative to low-molecular-weight derivatization. The two penicillins penicillin G (PenG) and penicillin V (PenV) were attached to the end groups of different water-soluble poly(2-oxazoline)s (POx) via their carboxylic acid function. This ester group was shown to be more stable against hydrolysis than the β-lactam ring of the penicillins. The conjugates are still antimicrobially active and up to 20 times more stable against penicillinase catalyzed hydrolysis. The antibiotic activity of the conjugates against Staphylococcus aureus in the presence of penicillinase is up to 350 times higher compared with the free antibiotics. Conjugates with a second antimicrobial function, a dodecyltrimethylammonium group (DDA-X), at the starting end of the PenG and PenV POx conjugates are more antimicrobially active than the conjugates without DDA-X and show high activity in the presence of penicillinase. For example, the conjugates DDA-X-PEtOx-PenG and DDA-X-PEtOx-PenV are 200 to 350 times more active against S. aureus in the presence of penicillinase and almost as effective as the penicillinase stable cloxacollin (Clox) under these conditions. These conjugates show even greater activity compared to cloxacollin without this enzyme present. Further, both conjugates kill Escherichia coli more effectively than PenG and Clox.

Speciation of radionuclides in the environment

International Nuclear Information System (INIS)

Gunten, H.R. von; Benes, P.

1994-02-01

Methods for the determination of the speciation of radionuclides in aerosols, in aquatic solutions, in sediments, soils and rocks are reviewed. At present, most of the results about speciation are deduced from model calculations, model experiments, and separation of species (forms) of radionuclides, e.g., by sequential extraction procedures. Methods of direct determination of speciation of radionuclides (e.g. by laser induced spectroscopy) are in general not yet sensitive enough for a measurement of the very low concentrations of radionuclides in the environment. The methodological part of this paper is followed by a review of the very abundant literature about speciation of important radionuclides in the environment, i.e. in the atmosphere, hydrosphere and lithosphere. The review does not include the biosphere. Literature up to spring 1993 is included (with a few more recent additions). (author)

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1983-01-01

Radionuclide migration have been studied in natural fissures orieted parallel to the axis of granite drill cores. A short pulse of the radionuclides solution was injected at one end of the fissure and the temporal change in radionuclide concentration of the eluate measured. After several hundred fissure volumes water had been pumped through the fissure following the radionuclide pulse the activity distribution on the fissure surfaces was measured. From the retardation of 152 Eu, 235 Np and 237 Pu it is concluded that these radionuclides are transported in the oxidation states Eu(III), Pu(IV) and Np(V). The distribution coefficients K sub (d) calculated from flow and activity distribution data on the basis of geometric surface area/volume ratios are of the same order as published K sub (d) values obtained from batch equilibrium experiments. (Author)

Measurement of anthropogenic radionuclides in the atmosphere with a radionuclide monitoring network for nuclear tests

International Nuclear Information System (INIS)

Yonezawa, Chushiro; Yamamoto, Yoichi

2011-01-01

A worldwide radionuclide monitoring network for nuclear tests has detected the anthropogenic radioactive materials released in the atmosphere due to the accident of the Fukushima Daiichi Nuclear Power Plant impacted by the Great East Japan Earthquake on March 11, 2011. After four months have passed since the accident occurred, most overseas stations do not detect the radionuclides of Fukushima origin any more. The Takasaki station in Japan, however, is still detecting them every day. This paper describes radionuclide monitoring stations and the network of them as part of the International Monitoring System (IMS) in the Comprehensive Nuclear Test Ban Treaty (CTBT), as well as the measurement results of radionuclide particulates and radioactive isotopes of xenon released from the Fukushima Daiichi Nuclear Power Plant with the monitoring network. (J.P.N.)

Radionuclide behavior in water saturated porous media: Diffusion and infiltration coupling of thermodynamically and kinetically controlled radionuclide water - mineral interactions

International Nuclear Information System (INIS)

Spasennykh, M.Yu.; Apps, J.A.

1995-05-01

A model is developed describing one dimensional radionuclide transport in porous media coupled with locally reversible radionuclide water-mineral exchange reactions and radioactive decay. Problems are considered in which radionuclide transport by diffusion and infiltration processes occur in cases where radionuclide water-solid interaction are kinetically and thermodynamically controlled. The limits of Sr-90 and Cs-137 migration are calculated over a wide range of the problem variables (infiltration velocity, distribution coefficients, and rate constants of water-mineral radionuclide exchange reactions)

Common spectrum of polypeptides occurs in secretion granule membranes of different exocrine glands

International Nuclear Information System (INIS)

Cameron, R.S.; Cameron, P.L.; Castle, J.D.

1986-01-01

A highly purified membrane preparation from rat parotid secretion granules has been used as a comparative probe to examine the extent of compositional overlap in granule membranes of three other exocrine secretory tissues - pancreatic, lacrimal, and submandibular - from several standpoints. First, indirect immunofluorescent studies using a polyclonal polyspecific anti-parotid granule membrane antiserum has indicated a selective staining of granule membrane profiles in all acinar cells of all tissues. Second, highly purified granule membrane subfractions have been isolated from each exocrine tissue; comparative two-dimensional (isoelectric focusing; SDS) PAGE of radioiodinated granule membranes has identified 10-15 polypeptides of identical pI and apparent molecular mass. These species are likely to be integral membrane components since they are not extracted by either saponin-sodium sulfate or sodium carbonate (pH 11.5) treatments, and they do not have counterparts in the granule content. Finally, the identity among selected parotid and pancreatic radioiodinated granule membrane polypeptides has been documented using two-dimensional peptide mapping of chymotryptic and tryptic digests. These findings clearly indicate that exocrine secretory granules, irrespective of the nature of stored secretion, comprise a type of vesicular carrier with a common (and probably refined) membrane composition. Conceivably, the polypeptides identified carry out general functions related to exocrine secretion

A vector Wiener filter for dual-radionuclide imaging

International Nuclear Information System (INIS)

Links, J.M.; Prince, J.L.; Gupta, S.N.

1996-01-01

The routine use of a single radionuclide for patient imaging in nuclear medicine can be complemented by studies employing two tracers to examine two different processes in a single organ, most frequently by simultaneous imaging of both radionuclides in two different energy windows. In addition, simultaneous transmission/emission imaging with dual-radionuclides has been described, with one radionuclide used for the transmission study and a second for the emission study. There is thus currently considerable interest in dual-radionuclide imaging. A major problem with all dual-radionuclide imaging is the crosstalk between the two radionuclides. Such crosstalk frequently occurs, because scattered radiation from the higher energy radionuclide is detected in the lower energy window, and because the lower energy radionuclide may have higher energy emissions which are detected in the higher energy window. The authors have previously described the use of Fourier-based restoration filtering in single photon emission computed tomography (SPECT) and positron emission tomography (PET) to improve quantitative accuracy by designing a Wiener or other Fourier filter to partially restore the loss of contrast due to scatter and finite spatial resolution effects. The authors describe here the derivation and initial validation of an extension of such filtering for dual-radionuclide imaging that simultaneously (1) improves contrast in each radionuclide's direct image, (2) reduces image noise, and (3) reduces the crosstalk contribution from the other radionuclide. This filter is based on a vector version of the Wiener filter, which is shown to be superior [in the minimum mean square error (MMSE) sense] to the sequential application of separate crosstalk and restoration filters

Approximate error conjugation gradient minimization methods

Science.gov (United States)

Kallman, Jeffrey S

2013-05-21

In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Koushik; Balog, Eva Rose M.; Sista, Prakash; Williams, Darrick J.; Martinez, Jennifer S., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov; Rocha, Reginaldo C., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov [Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kelly, Daniel [Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-02-01

We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP) as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca{sup 2+} or Cu{sup 2+}, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

Directory of Open Access Journals (Sweden)

Koushik Ghosh

2014-02-01

Full Text Available We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca2+ or Cu2+, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

Radionuclides in Canada goose eggs

International Nuclear Information System (INIS)

Rickard, W.H.; Sweany, H.A.

1975-01-01

Low levels of radionuclides were measured in Canada goose eggs taken from deserted nests from Columbia River islands on the Energy Research and Development Administration's Hanford Reservation. Potassium-40, a naturally occurring radionuclide, was the most abundant radionuclide measured in egg contents and egg shell. Strontium-90 was incorporated into egg shells and cesium-137 into inner egg contents. Manganese-54, cobalt-60, and zinc-65 were more abundant in inner egg contents than in egg shell. Cerium-144 was detected in egg shell but not in inner shell

Sensors and Automated Analyzers for Radionuclides

International Nuclear Information System (INIS)

Grate, Jay W.; Egorov, Oleg B.

2003-01-01

The production of nuclear weapons materials has generated large quantities of nuclear waste and significant environmental contamination. We have developed new, rapid, automated methods for determination of radionuclides using sequential injection methodologies to automate extraction chromatographic separations, with on-line flow-through scintillation counting for real time detection. This work has progressed in two main areas: radionuclide sensors for water monitoring and automated radiochemical analyzers for monitoring nuclear waste processing operations. Radionuclide sensors have been developed that collect and concentrate radionuclides in preconcentrating minicolumns with dual functionality: chemical selectivity for radionuclide capture and scintillation for signal output. These sensors can detect pertechnetate to below regulatory levels and have been engineered into a prototype for field testing. A fully automated process monitor has been developed for total technetium in nuclear waste streams. This instrument performs sample acidification, speciation adjustment, separation and detection in fifteen minutes or less

Radionuclide deposition control

International Nuclear Information System (INIS)

1980-01-01

A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

Preparation, structural analysis and bioactivity of ribonuclease A-albumin conjugate: tetra-conjugation or PEG as the linker.

Science.gov (United States)

Li, Chunju; Lin, Qixun; Wang, Jun; Shen, Lijuan; Ma, Guanghui; Su, Zhiguo; Hu, Tao

2012-12-31

Ribonuclease A (RNase A) is a therapeutic enzyme with cytotoxic action against tumor cells. Its clinical application is limited by the short half-life and insufficient stability. Conjugation of albumin can overcome the limitation, whereas dramatically decrease the enzymatic activity of RNase A. Here, three strategies were proposed to prepare the RNase A-bovine serum albumin (BSA) conjugates. R-SMCC-B (a conjugate of four RNase A attached with one BSA) and R-PEG-B (a mono-conjugate) were prepared using Sulfo-SMCC (a short bifunctional linker) and mal-PEG-NHS (a bifunctional PEG), respectively. Mal-PEG-NHS and hexadecylamine (HDA) were used to prepare the mono-conjugate, R-HDA-B, where HDA was adopted to bind BSA. The PEG linker can elongate the proximity between RNase A and BSA. In contrast, four RNase A were closely located on BSA in R-SMCC-B. R-SMCC-B showed the lowest K(m) and the highest relative enzymatic activity and k(cat)/K(m) in the three conjugates. Presumably, the tetravalent interaction of RNase A in R-SMCC-B can increase the binding affinity to its substrate. In addition, the slow release of BSA from R-HDA-B may increase the enzymatic activity of R-HDA-B. Our study is expected to provide strategies to develop protein-albumin conjugate with high therapeutic potential. Copyright © 2012 Elsevier B.V. All rights reserved.

Radionuclide transfer

International Nuclear Information System (INIS)

Gerber, G.B.

1993-01-01

The research project described here had the aim to obtain further information on the transfer of nuclides during pregnancy and lactation. The tests were carried out in mini-pigs and rats receiving unchanging doses of radionuclides with the food. The following findings were revealed for the elements examined: Fe, Se, Cs and Zn were characterized by very high transfer levels in the mother, infant and foetus. A substantial uptake by the mother alone was observed for Co, Ag and Mn. The uptake by the foetus and infant here was 1 to 10 times lower. A preferential concentration in certain tissues was seen for Sr and Tc; the thyroid levels of Tc were about equally high in mothers and infants, while Sr showed less accumulation in the maternal bone. The lanthanide group of substances (Ce, Eu and Gd as well as Y and Ru) were only taken up to a very limited extent. The uptake of the examined radionuclides (Fe, Co, Ag, Ce) with the food ingested was found here to be ten times greater in rats as compared to mini-pigs. This showed that great caution must be observed, if the behaviour of radionuclides in man is extrapolated from relevant data obtained in rodents. (orig./MG) [de

Well-defined (co)polypeptides bearing pendant alkyne groups

KAUST Repository

Zhao, Wei

2016-03-18

A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

Well-defined (co)polypeptides bearing pendant alkyne groups

KAUST Repository

Zhao, Wei; Gnanou, Yves; Hadjichristidis, Nikolaos

2016-01-01

A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of acetylene-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups. This method provides an efficient way to synthesize novel alkyne-functionalized homopolypeptides (A) and copolypeptides, such as AB diblock (B: non-functionalized), ABA triblock and star-AB diblock, as well as linear and star random copolypeptides, precursors of a plethora complex macromolecular architectures by click chemistry.

Radionuclides in the study of marine processes

International Nuclear Information System (INIS)

Kershaw, P.J.; Woodhead, D.S.

1991-01-01

For many years, the radioactive properties of the naturally occurring radionuclides have been used to determine their distributions in the marine environment and, more generally, to gain an understanding of the dynamic processes which control their behaviour in attaining these distributions. More recently the inputs from human activities of both natural and artificial (i.e. man-made) radionuclides have provided additional opportunities for the study of marine processes on local, regional and global scales. The primary objective of the symposium is to provide a forum for an open discussion of the insights concerning processes in the marine environment which can be gained from studies of radionuclide behaviour. Papers have been grouped within the following principal themes; the uses of radionuclides as tracers of water transport; scavenging and particulate transport processes in the oceans as deduced from radionuclide behaviour; processes in the seabed and radionuclides in biological systems. (Author)

Chemical speciation of radionuclides migrating in groundwaters

International Nuclear Information System (INIS)

Robertson, D.; Schilk, A.; Abel, K.; Lepel, E.; Thomas, C.; Pratt, S.; Cooper, E.; Hartwig, P.; Killey, R.

1994-04-01

In order to more accurately predict the rates and mechanisms of radionuclide migration from low-level waste disposal facilities via groundwater transport, ongoing studies are being conducted at field sites at Chalk River Laboratories to identify and characterize the chemical speciation of mobile, long-lived radionuclides migrating in groundwaters. Large-volume water sampling techniques are being utilized to separate and concentrate radionuclides into particular, cationic, anionic, and nonionic chemical forms. Most radionuclides are migrating as soluble, anionic species that appear to be predominantly organoradionuclide complexes. Laboratory studies utilizing anion exchange chromatography have separated several anionically complexed radionuclides, e.g., 60 Co and 106 Ru, into a number of specific compounds or groups of compounds. Further identification of the anionic organoradionuclide complexes is planned utilizing high resolution mass spectrometry. Large-volume ultra-filtration experiments are characterizing the particulate forms of radionuclides being transported in these groundwaters

Zonadhesin D3-Polypeptides Vary among Species but Are Similar in Equus Species Capable of Interbreeding1

Science.gov (United States)

Tardif, Steve; Brady, Heidi A.; Breazeale, Kelly R.; Bi, Ming; Thompson, Leslie D.; Bruemmer, Jason E.; Bailey, Laura B.; Hardy, Daniel M.

2009-01-01

Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acrosomes of spermatozoa from all three Equus species, similar to its localization in other animals. Likewise, in horse and donkey testis, zonadhesin was detected only in germ cells, first in the acrosomal granule of round spermatids and then in the developing acrosomes of elongating spermatids. Among non-Equus species, D3-domain polypeptides of mature, processed zonadhesin varied markedly in size and detergent solubility. However, zonadhesin D3-domain polypeptides in horse, donkey, and zebra spermatozoa exhibited identical electrophoretic mobility and detergent solubility. Equus zonadhesin D3-polypeptides (p110/p80 doublet) were most similar in size to porcine and bovine zonadhesin D3-polypeptides (p105). Sequence comparisons revealed that the horse zonadhesin precursor's domain content and arrangement are similar to those of zonadhesin from other large animals. Partial sequences of horse and donkey zonadhesin were much more similar to each other (>99% identity) than they were to orthologous sequences of human, pig, rabbit, and mouse zonadhesin (52%–72% identity). We conclude that conservation of zonadhesin D3-polypeptide properties correlates with ability of Equus species to interbreed. PMID:19794156

Permanent Electric Dipole-Dipole Interactions in Lyotropic Polypeptide Liquid Crystals

OpenAIRE

MORI, Norio; Norio, MORI; Research Associate, Department of Industrial Chemistry

1981-01-01

The interaction energy between two adjacent α-helical molecules was calculated taking into account for permanent electric dipoles locating orl the helical core of a polymer mainchain in order to explain the cholesteric structure of lyotropic polypeptide liquid crystals. It was concluded that the dipole-dipole interactions were responsible for the formation of the cholesteric structure.

Chemical de-conjugation for investigating the stability of small molecule drugs in antibody-drug conjugates.

Science.gov (United States)

Chen, Tao; Su, Dian; Gruenhagen, Jason; Gu, Christine; Li, Yi; Yehl, Peter; Chetwyn, Nik P; Medley, Colin D

2016-01-05

Antibody-drug conjugates (ADCs) offer new therapeutic options for advanced cancer patients through precision killing with fewer side effects. The stability and efficacy of ADCs are closely related, emphasizing the urgency and importance of gaining a comprehensive understanding of ADC stability. In this work, a chemical de-conjugation approach was developed to investigate the in-situ stability of the small molecule drug while it is conjugated to the antibody. This method involves chemical-mediated release of the small molecule drug from the ADC and subsequent characterization of the released small molecule drug by HPLC. The feasibility of this technique was demonstrated utilizing a model ADC containing a disulfide linker that is sensitive to the reducing environment within cancer cells. Five reducing agents were screened for use in de-conjugation; tris(2-carboxyethyl) phosphine (TCEP) was selected for further optimization due to its high efficiency and clean impurity profile. The optimized de-conjugation assay was shown to have excellent specificity and precision. More importantly, it was shown to be stability indicating, enabling the identification and quantification of the small molecule drug and its degradation products under different formulation pHs and storage temperatures. In summary, the chemical de-conjugation strategy demonstrated here offers a powerful tool to assess the in-situ stability of small molecule drugs on ADCs and the resulting information will shed light on ADC formulation/process development and storage condition selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Elastin-like polypeptides: Therapeutic applications for an emerging class of nanomedicines.

Science.gov (United States)

Despanie, Jordan; Dhandhukia, Jugal P; Hamm-Alvarez, Sarah F; MacKay, J Andrew

2016-10-28

Elastin-like polypeptides (ELPs) constitute a genetically engineered class of 'protein polymers' derived from human tropoelastin. They exhibit a reversible phase separation whereby samples remain soluble below a transition temperature (T t ) but form amorphous coacervates above T t . Their phase behavior has many possible applications in purification, sensing, activation, and nanoassembly. As humanized polypeptides, they are non-immunogenic, substrates for proteolytic biodegradation, and can be decorated with pharmacologically active peptides, proteins, and small molecules. Recombinant synthesis additionally allows precise control over ELP architecture and molecular weight, resulting in protein polymers with uniform physicochemical properties suited to the design of multifunctional biologics. As such, ELPs have been employed for various uses including as anti-cancer agents, ocular drug delivery vehicles, and protein trafficking modulators. This review aims to offer the reader a catalogue of ELPs, their various applications, and potential for commercialization across a broad spectrum of fields. Copyright © 2015. Published by Elsevier B.V.

Mobility and Bioavailability of Radionuclides in Soils

International Nuclear Information System (INIS)

Iurian, A.; Olufemi Phaneuf, M.; Mabit, L.

2016-01-01

It is crucial to understand the behavior of radionuclides in the environment, their potential mobility and bioavailability related to long-term persistence, radiological hazards, and impact on human health. Such key information is used to develop strategies that support policy decisions. The environmental behavior of radionuclides depends on ecosystem characteristics. A given soil’s capacity to immobilize radionuclides has been proved to be the main factor responsible for their resulting activity concentrations in plants. The mobility and bioavailability of radionuclides in soils is complex, depending on clay-sized soil fraction, clay mineralogy, organic matter, cation exchange capacity, pH and quantities of competing cations. Moreover, plant species have different behaviors regarding radionuclide absorption depending on soil and plan characteristics

Radionuclides deposition over Antarctica

International Nuclear Information System (INIS)

Pourchet, M.; Magand, O.; Frezzotti, M.; Ekaykin, A.; Winther, J.-G.

2003-01-01

A detailed and comprehensive map of the distribution patterns for both natural and artificial radionuclides over Antarctica has been established. This work integrates the results of several decades of international programs focusing on the analysis of natural and artificial radionuclides in snow and ice cores from this polar region. The mean value (37±20 Bq m -2 ) of 241 Pu total deposition over 28 stations is determined from the gamma emissions of its daughter 241 Am, presenting a long half-life (432.7 yrs). Detailed profiles and distributions of 241 Pu in ice cores make it possible to clearly distinguish between the atmospheric thermonuclear tests of the fifties and sixties. Strong relationships are also found between radionuclide data ( 137 Cs with respect to 241 Pu and 210 Pb with respect to 137 Cs), make it possible to estimate the total deposition or natural fluxes of these radionuclides. Total deposition of 137 Cs over Antarctica is estimated at 760 TBq, based on results from the 90-180 deg. East sector. Given the irregular distribution of sampling sites, more ice cores and snow samples must be analyzed in other sectors of Antarctica to check the validity of this figure

Unraveling origins of the heterogeneous curvature dependence of polypeptide interactions with carbon nanostructures.

Science.gov (United States)

Jana, Asis K; Tiwari, Mrityunjay K; Vanka, Kumar; Sengupta, Neelanjana

2016-02-17

Emerging nanotechnology has rapidly broadened interfacial prospects of biological molecules with carbon nanomaterials (CNs). A prerequisite for effectively harnessing such hybrid materials is a multi-faceted understanding of their complex interfacial interactions as functions of the physico-chemical characteristics and the surface topography of the individual components. In this article, we address the origins of the curvature dependence of polypeptide adsorption on CN surfaces (CNSs), a phenomenon bearing an acute influence upon the behavior and activity of CN-protein conjugates. Our benchmark molecular dynamics (MD) simulations with the amphiphilic full-length amyloid beta (Aβ) peptide demonstrate that protein adsorption is strongest on the concave (inner) CN surface, weakest on the convex (outer) surface, and intermediary on the planar surface, in agreement with recent experimental reports. The curvature effects, however, are found to manifest non-uniformly between the amino acid subtypes. To understand the underlying interplay of the chemical nature of the amino acids and surface topography of the CNs, we performed high-level quantum chemical (QM) calculations with amino acid analogs (AAA) representing their five prominent classes, and convex, concave and planar CN fragments. Molecular electrostatic potential maps reveal pronounced curvature dependence in the mixing of electron densities, and a resulting variance in the stabilization of the non-covalently bound molecular complexes. Interestingly, our study revealed that the interaction trends of the high-level QM calculations were captured well by the empirical force field. The findings in this study have important bearing upon the design of carbon based bio-nanomaterials, and additionally, provide valuable insights into the accuracy of various computational techniques for probing non-bonded interfacial interactions.

Radionuclides in the food chain

International Nuclear Information System (INIS)

Harley, J.H.; Schmidt, G.D.

1988-01-01

Radionuclides in the Food Chain reviews past experience in meeting the challenge of radionuclide contamination of foodstuffs and water sources and, in the wake of the reactor accidents at Chernobyl and Three Mile Island, presents current concepts and programs relating to measurement, surveillance, effects, risk management, evaluation guidelines, and control and regulatory activities. This volume, based on a symposium sponsored by the International Life Sciences Institute in association with the International Institute for Applied Systems Analysis, which brought together both radiation experts and food industry policymakers, examines such vital topics as structural problems in large-scale crisis-managment systems; dose assessment from man-made sources; international recommendations on radiation protection; airborne contamination, as well as aquatic and soilborne radionuclides; food-chain contamination from testing nuclear devices; long-term health effects of radionuclides in food and water supplies; and use of mathematical models in risk assessment and management. (orig.)

Idaho radionuclide exposure study: Literature review

International Nuclear Information System (INIS)

Baker, E.G.; Freeman, H.D.; Hartley, J.N.

1987-10-01

Phosphate ores contain elevated levels of natural radioactivity, some of which is released to the environment during processing or use of solid byproducts. The effect of radionuclides from Idaho phosphate processing operations on the local communities has been the subject of much research and study. The literature is reviewed in this report. Two primary radionuclide pathways to the environment have been studied in detail: (1) airborne release of volatile radionuclides, primarily 210 Po, from calciner stacks at the two elemental phosphorus plants; and (2) use of byproduct slag as an aggregate for construction in Soda Springs and Pocatello. Despite the research, there is still no clear understanding of the population dose from radionuclide emissions, effluents, and solid wastes from phosphate processing plants. Two other potential radionuclide pathways to the environment have been identified: radon exhalation from phosphogypsum and ore piles and contamination of surface and ground waters. Recommendations on further study needed to develop a data base for a complete risk assssment are given in the report

Photoluminescence in conjugated polymers

International Nuclear Information System (INIS)

Furst, J.E.; Laugesen, R.; Dastoor, P.; McNeill, C.

2002-01-01

Full text: Conjugated polymers combine the electronic and optical properties of semiconductors with the processability of polymers. They contain a sequence of alternate single and double carbon bonds so that the overlap of unhybridised p z orbitals creates a delocalised ρ system which gives semiconducting properties with p-bonding (valence) and p* -antibonding (conduction) bands. Photoluminesence (PL) in conjugated polymers results from the radiative decay of singlet excitons confined to a single chain. The present work is the first in a series of studies in our laboratory that will characterize the optical properties of conjugated polymers. The experiment involves the illumination of thin films of conjugated polymer with UV light (I=360 nm) and observing the subsequent fluorescence using a custom-built, fluorescence spectrometer. Photoluminesence spectra provide basic information about the structure of the polymer film. A typical spectrum is shown in the accompanying figure. The position of the first peak is related to the polymer chain length and resolved multiple vibronic peaks are an indication of film structure and morphology. We will also present results related to the optical degradation of these materials when exposed to air and UV light

Bio-Conjugates for Nanoscale Applications

DEFF Research Database (Denmark)

Villadsen, Klaus

Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

Some parameters of radionuclide kinetics

International Nuclear Information System (INIS)

Prokof'ev, O.N.; Smirnov, V.A.; Belen'kij, E.I.

1978-01-01

Numerical values of the rates of radionuclide absorption into, and elimination from, bovine organs were determined. Kinetic rate constants of radionuclides such as 89 Sr, 99 Mo, 131 I, 132 Tl, and 140 Be were calculated. The calculations were done for muscle, liver, and kidney

Radionuclide - Soil Organic Matter Interactions

DEFF Research Database (Denmark)

Carlsen, Lars

1985-01-01

Interactions between soil organic matter, i.e. humic and fulvic acids, and radionuclides of primary interest to shallow land burial of low activity solid waste have been reviewed and to some extent studied experimentally. The radionuclides considered in the present study comprise cesium, strontium...

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1984-01-01

Radionuclide migration has been studied in natural fissures running parallel to the axes of granitic drill cores. A short pulse of radionuclide solution was injected at one end of the fissure and the temporal change in radionuclide concentration of the eluate measured. At the end of each experiment the fissure was opened and the radionuclide distribution on the fissure surfaces measured. The retardation of 241 Am(III) at pH 8.2 as well as the variation in 235 Np(V) retardation with pH are found to be in good agreement with K d-values obtained in batch experiments. The reduction of (TcO - 4 ) to Tc(IV) leads as expected to increasing retardation.(author)

Radionuclide migration in water reservoirs

International Nuclear Information System (INIS)

Rodionova, L.F.

1983-01-01

Toxicity degree and radiation effect of different radionuclides depend on multiple factors, whose interaction can strengthen or weaken the effects through the mechanism of nuclide accumulation by hydrobiontes. Stage of development of an aquatic organism, its age, mass and sex as well as lifetime and residence time of the organism in the given medium are of importance. The radionuclide build up depends on illumination, locale of the bioobject residence, on the residence nature. The concentration of radionuclides in aquatic organisms and bionts survival depend on a season, temperature of the residence medium, as well as salinity and mineral composition of water influence

Interplay of alternative conjugated pathways and steric interactions on the electronic and optical properties of donor-acceptor conjugated polymers

KAUST Repository

Lima, Igo T.; Risko, Chad; Aziz, Saadullah Gary; Da Silva Filho, Demé trio A Da Silva; Bredas, Jean-Luc

2014-01-01

Donor-acceptor π-conjugated copolymers are of interest for a wide range of electronic applications, including field-effect transistors and solar cells. Here, we present a density functional theory (DFT) study of the impact of varying the conjugation pathway on the geometric, electronic, and optical properties of donor-acceptor systems. We consider both linear ("in series"), traditional conjugation among the donor-acceptor moieties versus structures where the acceptor units are appended orthogonally to the linear, donor-only conjugated backbone. Long-range-corrected hybrid functionals are used in the investigation with the values of the tuned long-range separation parameters providing an estimate of the extent of conjugation as a function of the oligomer architecture. Considerable differences in the electronic and optical properties are determined as a function of the nature of the conjugation pathway, features that should be taken into account in the design of donor-acceptor copolymers.

Radionuclide Air Emissions Report for 2012

Energy Technology Data Exchange (ETDEWEB)

Wahl, Linnea [Ernest Orlando Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

2013-05-01

Berkeley Lab operates facilities where radionuclides are produced, handled, store d, and potentially emitted . These facilities are subject to the EPA radioactive air emission regulations in 40 CFR 61, Subpart H (EPA 1989a). Radionuclides may be emitted from stacks or vents on buildings where radionuclide production or use is authorized or they may be emitted as diffuse sources. In 2012, all Berkeley Lab sources were minor sources of radionuclides (sources resulting in a potential dose of less than 0.1 mrem/yr [0.001 mSv/yr]) . These minor sources include d about 140 stack sources and no diffuse sources . T here were no unplanned airborne radionuclide emissions from Berkeley Lab operations . Emissions from minor sources were measured by sampling or monitoring or were calculated based on quantities used, received for use, or produced during the year. Using measured and calculated emissions, and building- specific and common parameters, Laboratory personnel applied the EPA -approved computer code s, CAP88-PC and COMPLY , to calculate doses to the maximally exposed individual (MEI) at any offsite point where there is a residence, school, business, or office. Because radionuclides are used at three noncontiguous locations (the main site, Berkeley West Bio center, and Joint BioEnergy Institute), three different MEIs were identified.

Characterization of mutants expressing thermostable D1 and D2 polypeptides of photosystem II in the cyanobacterium Synechococcus elongatus PCC 7942.

Science.gov (United States)

Haraguchi, Norihisa; Kaseda, Jun; Nakayama, Yasumune; Nagahama, Kazuhiro; Ogawa, Takahira; Matsuoka, Masayoshi

2018-06-08

Photosystem II complex embedded in thylakoid membrane performs oxygenic photosynthesis where the reaction center D1/D2 heterodimer accommodates all components of the electron transport chain. To express thermostable D1/D2 heterodimer in a cyanobacterium Synechococcus elongatus PCC 7942, we constructed a series of mutant strains whose psbA1 and psbD1 genes encoding, respectively, the most highly expressed D1 and D2 polypeptides were replaced with those of a thermophilic strain, Thermosynechococcus vulcanus. Because the C-terminal 16 amino acid sequences of D1 polypeptides should be processed prior to maturation but diverge from each other, we also constructed the psbA1ΔC-replaced strain expressing a thermostable D1 polypeptide devoid of the C-terminal extension. The psbA1/psbD1-replaced strain showed decreased growth rate and oxygen evolution rate, suggesting inefficient photosystem II. Immunoblot analyses for thermostable D1, D2 polypeptides revealed that the heterologous D1 protein was absent in thylakoid membrane from any mutant strains with psbA1, psbA1ΔC, and psbA1/psbD1-replacements, whereas the heterologous D2 protein was present in thylakoid membrane as well as purified photosystem II complex from the psbA1/psbD1-replaced strain. In the latter strain, the compensatory expression of psbA3 and psbD2 genes was elevated. These data suggest that heterologous D2 polypeptide could be combined with the host D1 polypeptide to form chimeric D1/D2 heterodimer, whereas heterologous D1 polypeptide even without the C-terminal extension was unable to make complex with the host D2 polypeptide. Since the heterologous D1 could not be detected even in the whole cells of psbA1/psbD1-replaced strain, the rapid degradation of unprocessed or unassembled heterologous D1 was implicated. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Molecular Targets for Targeted Radionuclide Therapy

International Nuclear Information System (INIS)

Mather, S.J.

2009-01-01

Molecular targeted radionuclide cancer therapy is becoming of increasing importance, especially for disseminated diseases. Systemic chemotherapies often lack selectivity while targeted radionuclide therapy has important advantages as the radioactive cytotoxic unit of the targeting vector is specifically directed to the cancer, sparing normal tissues. The principle strategy to improve cancer selectivity is to couple therapeutic agents to tumour-targeting vectors. In targeted radionuclide therapy (TRT), the cytotoxic portion of the conjugates normally contains a therapeutic radiometal immobilised by a bifunctional chelator. The aim is therefore to use as ligand-targeted therapeutics vectors coupled to Auger-, alpha- and/or beta-emitting radionuclides. An advantage of using radiation instead of chemotherapeutics as the cytotoxic agent is the so called 'crossfire effect'. This allows sterilisation of tumour cells that are not directly targeted due to heterogeneity in target molecule expression or inhomogeneous vector delivery. However, before the targeting ligands can be selected, the target molecule on the tumour has to be selected. It should be uniquely expressed, or at least highly overexpressed, on or in the target cells relative to normal tissues. The target should be easily accessible for ligand delivery and should not be shed or down- regulated after ligand binding. An important property of a receptor (or antigen) is its potential to be internalized upon binding of the ligand. This provides an active uptake mechanism and allows the therapeutic agent to be trapped within the tumour cells. Molecular targets of current interest include: Receptors: G-protein coupled receptors are overexpressed on many major human tumours. The prototype of these receptors are somatostatin receptors which show very high density in neuroendocrine tumours, but there are many other most interesting receptors to be applied for TRT. The targeting ligands for these receptors are

Radionuclide supply of the progeny via mother's milk

International Nuclear Information System (INIS)

Ovcharenko, E.P.

1982-01-01

While examining transition of radioactive substances from material organism to milk and then radionuclide administration with milk to progeny, a number of relationships had been revealed. They are similar to those discovered by the author during his study on transplacental radionuclide kinetics. The quantity of transition through placental and milk barriers of group 2 Periodical system radionuclides is inversally proportional to radionuclide mass number. There is evidence for the increase of radionuclide transition per different kinds of animal progeny mass unit during pregnancy as well as during lactation [ru

Radionuclide Retention in Concrete Wasteforms

Energy Technology Data Exchange (ETDEWEB)

Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

2011-09-30

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

Double-hydrophobic elastin-like polypeptides with added functional motifs: Self-assembly and cytocompatibility.

Science.gov (United States)

Le, Duc H T; Tsutsui, Yoko; Sugawara-Narutaki, Ayae; Yukawa, Hiroshi; Baba, Yoshinobu; Ohtsuki, Chikara

2017-09-01

We have recently developed a novel double-hydrophobic elastin-like triblock polypeptide called GPG, designed after the uneven distribution of two different hydrophobic domains found in elastin, an extracellular matrix protein providing elasticity and resilience to tissues. Upon temperature trigger, GPG undergoes a sequential self-assembling process to form flexible beaded nanofibers with high homogeneity and excellent dispersibility in water. Given that GPG might be a potential elastin-mimetic material, we sought to explore the biological activities of this block polypeptide. Besides GPG, several functionalized derivatives were also constructed by fusing functional motifs such as KAAK or KAAKGRGDS at the C-terminal of GPG. Although the added motifs affected the kinetics of fiber formation and β-sheet contents, all three GPGs assembled into beaded nanofibers at the physiological temperature. The resulting GPG nanofibers preserved their beaded structures in cell culture medium; therefore, they were coated on polystyrene substrates to study their cytocompatibility toward mouse embryonic fibroblasts, NIH-3T3. Among the three polypeptides, GPG having the cell-binding motif GRGDS derived from fibronectin showed excellent cell adhesion and cell proliferation properties compared to other conventional materials, suggesting its promising applications as extracellular matrices for mammalian cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2475-2484, 2017. © 2017 Wiley Periodicals, Inc.

Water, soil, crops and radionuclides. Studies on the behavior of radionuclides in the terrestrial environments

International Nuclear Information System (INIS)

Uchida, Shigeo

2008-01-01

In order to predict the migration of artificially-produced radionuclides into a human body and its radiation dose rates of human body and to decrease the exposed radiation doses of human body, the behavior of radionuclides in the environment must be elucidated. In National Institute of Radiological Sciences (NIRS), the environmental radioecological research group of Nakaminato Laboratory for Marine Radioecology has progressed the survey and research on the behavior of artificially-produced radionuclides in the terrestrial environment. This article describes the research results (the radioactivity of water, soil, and crops) made so far at Nakaminato Laboratory for Marine Radioecology. (M.H.)

Country report: Cuba. Local Production of {sup 90}Y And {sup 188}Re Radionuclides and Development of Radiopharmaceuticals for Therapy

Energy Technology Data Exchange (ETDEWEB)

Xiques, Abmel; Hernández, Ignacio; Leyva, René; Pérez, Marylaine; Alonso, Luis Michel; Zamora, Minelys [Centro de Isotopos (CENTIS) (Cuba)

2010-07-01

During the first period of this CRP we could test an efficient and reliable generator system based on ion-chromatography to obtain {sup 90}Y from its parent radionuclide {sup 90}Sr. This production scheme for {sup 90}Y was outlined in the previous CRP related with the development of generator technologies. Quality parameters such as trace metals that can potentially interfere in the labeling of biomoléculas, {sup 90}Y recovery, {sup 90}Sr/{sup 90}Y ratio and radiation dose to bed matrix were evaluated. The results showed that high recovery and radionuclidic purity could be obtained for {sup 90}Y during its repeated separation from the {sup 90}Sr cow. No replacement or treatment of the cow were necessary and low waste generation and {sup 90}Sr losses less that 0.1% after each run were also observed during the present study. A Fab’ fragment was enzimatically produced and purified from the monoclonal antibody h-R3 (Nimotuzumab®). The fragment and the parent antibody were successfully conjugated with DOTA and labeled with {sup 90}Y. The radioinmunoconjugate thus obtained also exhibited a good 24 h in-vitro stability in an excess of DTPA. A {sup 90}Y radiocoloid was prepared in a cromic phosphate particle for radiosynoviorthesis with promising results in animal models. Two alumina based {sup 188}W/{sup 188}Re generators were prepared and their eluates were used in the labeling of hR3-DOTA conjugates. Quality control and in vivo evaluation in comparison with {sup 99m}Tc-hR3 showed very good results and similar pattern of distribution and pharmacokinetic and will be used in clinical trials for cancer patients. (author)

Formulation optimization and in vivo proof-of-concept study of thermosensitive liposomes balanced by phospholipid, elastin-like polypeptide, and cholesterol.

Directory of Open Access Journals (Sweden)

Sun Min Park

Full Text Available One application of nanotechnology in medicine that is presently being developed involves a drug delivery system (DDS employing nanoparticles to deliver drugs to diseased sites in the body avoiding damage of healthy tissue. Recently, the mild hyperthermia-triggered drug delivery combined with anticancer agent-loaded thermosensitive liposomes was widely investigated. In this study, thermosensitive liposomes (TSLs, composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol-2000] (DSPE-PEG, cholesterol, and a fatty acid conjugated elastin-like polypeptide (ELP, were developed and optimized for triggered drug release, controlled by external heat stimuli. We introduced modified ELP, tunable for various biomedical purposes, to our thermosensitive liposome (e-TSL to convey a high thermoresponsive property. We modulated thermosensitivity and stability by varying the ratios of e-TSL components, such as phospholipid, ELP, and cholesterol. Experimental data obtained in this study corresponded to results from a simulation study that demonstrated, through the calculation of the lateral diffusion coefficient, increased permeation of the lipid bilayer with higher ELP concentrations, and decreased permeation in the presence of cholesterol. Finally, we identified effective drug accumulation in tumor tissues and antitumor efficacy with our optimized e-TSL, while adjusting lag-times for systemic accumulation.

Architecture effects on multivalent interactions by polypeptide-based multivalent ligands

Science.gov (United States)

Liu, Shuang

protein materials, including structural as well as functional proteins. Therefore, polypeptide-based multivalent scaffolds are used to display ligands to assess the contribution of different architectural parameters to the multivalent binding events. In this work, a family of alanine-rich alpha-helical glycopolypeptides was designed and synthesized by a combination of protein engineering and chemical coupling, to display two types of saccharide ligands for two different multivalent binding systems. The valencies, chain length and spacing between adjacent ligands of these multivalent ligands were designed in order to study architecture effects on multivalent interactions. The polypeptides and their glycoconjugates were characterized via various methods, including SDS-PAGE, NMR, HPLC, amino acid analysis (AAA), MALDI, circular dichroism (CD) and GPC. In the first multivalent binding system, cholera toxin B pentamer (CT B5) was chosen to be the protein receptor due to its well-characterized structure, lack of significant steric interference of binding to multiple binding sites, and requirement of only simple monosaccharide as ligands. Galactopyranoside was incorporated into polypeptide scaffolds through amine-carboxylic acid coupling to the side chains of glutamic acid residues. The inhibition and binding to CT B5 of these glycopolypeptide ligands were evaluated by direct enzyme-linked assay (DELA). As a complement method, weak affinity chromatography (WAC) was also used to evaluate glycopolypeptides binding to a CT B5 immobilized column. The architecture effects on CT B 5 inhibition are discussed. In the second system, cell surface receptor L-selectin was targeted by polypeptide-based multivalent ligands containing disulfated galactopyranoside ligands, due to its important roles in various immunological activities. The effects of glycopolypeptide architectural variables L-selectin shedding were evaluated via ELISA-based assays. These polypeptide-based multivalent ligands

Abscess detection with radionuclides

International Nuclear Information System (INIS)

Alavi, J.B.

1988-01-01

Radionuclide studies may aid in the diagnosis and localization of intra-abdominal infections. Despite the introduction of new radiographic and ultrasound methods, there are several clinical situations in which radionuclide scans have proved useful. Those include detection of postoperative intra-abdominal abscess, evaluation of liver abscess, differentiation between pancreatic pseudocyst or abscess, evaluation of fever of unknown origin, and evaluation of inflammatory bowel disease. Each clinical situation is discussed separately here

Organometallic B12-DNA conjugate

DEFF Research Database (Denmark)

Hunger, Miriam; Mutti, Elena; Rieder, Alexander

2014-01-01

Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

The Conjugate Acid-Base Chart.

Science.gov (United States)

Treptow, Richard S.

1986-01-01

Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

Natural and Synthetic Barriers to Immobilize Radionuclides

International Nuclear Information System (INIS)

Um, W.

2011-01-01

The experiments of weathering of glass waste form and the reacted sediments with simulated glass leachates show that radionuclide sequestration can be significantly enhanced by promoting the formation of secondary precipitates. In addition, synthetic phosphate-bearing nanoporous material exhibits high stability at temperature and has a very high K d value for U(VI) removal. Both natural and synthetic barrier materials can be used as additional efficient adsorbents for retarding transport of radionuclides for various contaminated waste streams and waste forms present at U. S. Department of Energy clean-up sites and the proposed geologic radioactive waste disposal facility. In the radioactive waste repository facility, natural or synthetic materials are planned to be used as a barrier material to immobilize and retard radionuclide release. The getter material can be used to selectively scavenge the radionuclide of interest from a liquid waste stream and subsequently incorporate the loaded getters in a cementitious or various monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides form monolithic waste forms by being emplaced as a backfill barrier material around the wastes or waste form to minimize the potential around the wastes or waste form to minimize the potential hazard of leached radioactive wastes. The barrier material should be highly efficient to sequester radionuclides and possess physical and chemical stability for long-term exposure to severe weathering conditions. Because potential leaching of radionuclides depends on various environmental and weathering conditions of the near-field repository, the barrier materials must be durable and not disintegrate under a range of moisture, temperature, pressure, radiation, Eh, ph. and

Therapy for incorporated radionuclides: scope and need

International Nuclear Information System (INIS)

Smith, V.H.

1981-03-01

In the United States the recent termination of funding for research on therapy for incorporated radionuclides has virtually halted progress on improved or new agents and procedures for removing radioactivity from the body. Research was eliminated, but is still needed on new removal agents, improved delivery system, in vitro test systems, and the toxicology of treatments. For many radionuclides, no adequate therapy exists. The relationship between radionuclide removal and reduction in cancer risk is still unanswered. Without proper research support, needed improvements in the treatment for incorporated radionuclides in the US are uncertain

Phytoremediation of soils contaminated with radionuclides

International Nuclear Information System (INIS)

Yamaguchi, Isamu

2004-01-01

Aiming at efficient phytoremediation of soils contaminated with radionuclides, we examined the effect of soil microbes on the uptake ability of plants using the multitracer technique to find that tomato rhizofungi in Fusarium spp. can stimulate the uptake of 85 Sr and 137 Cs by the plants. The synergic effect of a nonpathogenic strain of F. oxysporum on the uptake of radionuclides by plants proved to be enhanced by introducing a phytochelatin synthase gene into the fungus. Since soil contamination by radionuclides is still an unsolved problem in many parts of the world. Studies on phytoremediation of polluted soil environment will be important for developing effective strategies and devising adequate techniques to reduce human risks caused by food contamination of radionuclides. (author)

REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy ...

African Journals Online (AJOL)

REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy. AOK Johnson. Abstract. Conjugated hyperbilirubinaemia exists when the conjugated serum bilirubin level is more than 2 mg/dl or more than 20 per cent of the total serum bilirubin. It is always pathological in early infancy. The causes are many and diverse ...

National Low-Level Waste Management Program Radionuclide Report Series

International Nuclear Information System (INIS)

Rudin, M.J.; Garcia, R.S.

1992-02-01

This volume serves as an introduction to the National Low-Level Radioactive Waste Management Program Radionuclide Report Series. This report includes discussions of radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha-emitting transuranics with half-lives greater than five years). Each report includes information regarding radiological and chemical characteristics of specific radionuclides. Information is also included discussing waste streams and waste forms that may contain each radionuclide, and radionuclide behavior in the environment and in the human body. Not all radionuclides commonly found at low-level radioactive waste sites are included in this report. The discussion in this volume explains the rationale of the radionuclide selection process

Effect of Chelator Conjugation Level and Injection Dose on Tumor and Organ Uptake of 111In Labeled MORAb-009, an Anti-mesothelin Antibody

Science.gov (United States)

Shin, I. S.; Lee, S.-M.; Kim, H. S.; Yao, Z.; Regino, C.; Sato, N.; Cheng, K. T.; Hassan, R.; Campo, M. F.; Albone, E. F.; Choyke, P. L.; Pastan, I.; Paik, C. H.

2012-01-01

Introduction Radiolabeling of a monoclonal antibody (mAb) with a metallic radionuclide requires the conjugation of a bifunctional chelator to the mAb. The conjugation, however, can alter the physical and immunological properties of the mAb, consequently affecting its tumor targeting pharmacokinetics. In this study, we investigated the effect of the amount of 2-(p-isothiocyanatobenzyl)-cyclohexyl-diethylenetriamine-pentaacetic acid (CHX-A″) conjugated to MORAb-009, a mAb directed against mesothelin and the effect of MORAb dose on the biodistribution of 111In labeled MORAb-009. Methods We used nude mice bearing A431/K5 tumor as a mesothelin-positive tumor model and A431 tumor as a mesothelin-negative control. To find the optimal level of CHX-A″ conjugation, CHX-A″-MORAb-009 conjugates with 2.4, 3.5, and 5.5 CHX-A″ molecules were investigated. To investigate the effect of injected MORAb-009 dose on neutralizing the shed-mesothelin in the circulation, the biodistribution studies were performed after the i.v. co-injection of the 111In labeled MORAb-009 (2.4 CHX-A″/MORAb-009) with three different doses, 0.2, 2, and 30 μg of MORAb-009. Results The tumor uptake in A431/K5 tumor was 4 times higher than that in A431 tumor, indicating that the tumor uptake in A431/K5 was mesothelin-mediated. The conjugate with 5.5 CHX-A″ showed a lower isoelectric point (pI) and lower immunoreactivity (IR) than the 2.4 CHX-A″ conjugate. These differences were reflected in biodistribution of the 111In label. The 111In labeled MORAb-009 conjugated with 2.4 CHX-A″ produced higher tumor uptake, and lower liver and spleen uptakes than the 5.5 CHX-A″ conjugate. The biodistribution studies also revealed that the tumor uptake was significantly affected by the injected MORAb-009 dose and tumor size. The 30 μg dose produced higher tumor uptake than the 0.2 and 2 μg doses whereas the 30 μg dose produced lower liver and spleen uptakes than the 0.2 μg dose. Conclusion This study

Radionuclide Retention in Concrete Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

2010-09-30

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

Application of optical phase conjugation to plasma diagnostics (invited)

International Nuclear Information System (INIS)

Jahoda, F.C.; Anderson, B.T.; Forman, P.R.; Weber, P.G.

1985-01-01

Several possibilities for plasma diagnostics provided by optical phase conjugation and, in particular, self-pumped phase conjugation in barium titanate (BaTiO 3 ) are discussed. These include placing a plasma within a dye laser cavity equipped with a phase conjugate mirror for intracavity absorption measurements, time differential refractometry with high spatial resolution, and simplified real-time holographic interferometry. The principles of phase conjugation with particular reference to photorefractive media and the special advantages of self-pumped phase conjugation are reviewed prior to the discussion of the applications. Distinctions are made in the applications between those for which photorefractive conjugators are essential and those for which they only offer experimental simplification relative to other types of phase conjugators

Remediation of radionuclide pollutants through biosorption - an overview

Energy Technology Data Exchange (ETDEWEB)

Das, Nilanjana [Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore (India)

2012-01-15

The development of nuclear science and technology has led to the increase of nuclear wastes containing radionuclides to be released and disposed in the environment. Pollution caused by radionuclides is a serious problem throughout the world. To solve the problem, substantial research efforts have been directed worldwide to adopt sustainable technologies for the treatment of radionuclide containing wastes. Biosorption represents a technological innovation as well as a cost effective excellent remediation technology for cleaning up radionuclides from aqueous environment. A variety of biomaterials viz. algae, fungi, bacteria, plant biomass, etc. have been reported for radionuclide remediation with encouraging results. This paper reviews the achievements and current status of radionuclide remediation through biosorption which will provide insights into this research frontier. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Radionuclide injury to the lung

International Nuclear Information System (INIS)

Dagle, G.E.; Sanders, C.L.

1984-01-01

Radionuclide injury to the lung has been studied in rats, hamsters, dogs, mice and baboons. Exposure of the lung to high dose levels of radionuclides produces a spectrum of progressively more severe functional and morphological changes, ranging from radiation pneumonitis and fibrosis to lung tumors. These changes are somewhat similar for different species. Their severity can be related to the absorbed radiation dose (measured in rads) produced by alpha, beta or gamma radiation emanating from various deposited radionuclides. The chemicophysical forms of radionuclides and spatial-temporal factors are also important variables. As with other forms of injury to the lung, repair attempts are highlighted by fibrosis and proliferation of pulmonary epithelium. Lung tumors are the principal late effect observed in experimental animals following pulmonary deposition of radionuclides at dose levels that do not result in early deaths from radiation pneumonitis or fibrosis. The predominant lung tumors described have been of epithelial origin and have been classified, in decreasing frequency of occurrence, as adenocarcinoma, bronchioloalveolar carcinoma, epidermoid carcinomas and combined epidermoid and adenocarcinoma. Mesothelioma and fibrosarcoma have been observed in rats, but less commonly in other species. Hemangiosarcomas were frequently observed in dogs exposed to beta-gamma emitters, and occasionally in rats exposed to alpha emitters. These morphologic changes in the lungs of experimental animals were reviewed and issues relevant to the prediction of human hazards discussed. 88 references

cDNA encoding a polypeptide including a hev ein sequence

Energy Technology Data Exchange (ETDEWEB)

Raikhel, Natasha V. (Okemos, MI); Broekaert, Willem F. (Dilbeek, BE); Chua, Nam-Hai (Scarsdale, NY); Kush, Anil (New York, NY)

2000-07-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

A pH- and temperature-responsive bioresorbable injectable hydrogel based on polypeptide block copolymers for the sustained delivery of proteins in vivo.

Science.gov (United States)

Turabee, Md Hasan; Thambi, Thavasyappan; Duong, Huu Thuy Trang; Jeong, Ji Hoon; Lee, Doo Sung

2018-02-27

Sustained delivery of protein therapeutics is limited owing to the fragile nature of proteins. Despite its great potential, delivery of proteins without any loss of bioactivity remains a challenge in the use of protein therapeutics in the clinic. To surmount this shortcoming, we report a pH- and temperature-responsive in situ-forming injectable hydrogel based on comb-type polypeptide block copolymers for the controlled delivery of proteins. Polypeptide block copolymers, composed of hydrophilic polyethylene glycol (PEG), temperature-responsive poly(γ-benzyl-l-glutamate) (PBLG), and pH-responsive oligo(sulfamethazine) (OSM), exhibit pH- and temperature-induced sol-to-gel transition behavior in aqueous solutions. Polypeptide block copolymers were synthesized by combining N-carboxyanhydride-based ring-opening polymerization and post-functionalization of the chain-end using N-hydroxy succinimide ester activated OSM. The physical properties of polypeptide-based hydrogels were tuned by varying the composition of temperature- and pH-responsive PBLG and OSM in block copolymers. Polypeptide block copolymers were non-toxic to human embryonic kidney cells at high concentrations (2000 μg mL -1 ). Subcutaneous administration of polypeptide block copolymer sols formed viscoelastic gel instantly at the back of Sprague-Dawley (SD) rats. The in vivo gels exhibited sustained degradation and were found to be bioresorbable in 6 weeks without any noticeable inflammation at the injection site. Anionic characteristics of hydrogels allow efficient loading of a cationic model protein, lysozyme, through electrostatic interaction. Lysozyme-loaded polypeptide block copolymer sols readily formed a viscoelastic gel in vivo and sustained lysozyme release for at least a week. Overall, the results demonstrate an elegant approach to control the release of certain charged proteins and open a myriad of therapeutic possibilities in protein therapeutics.

The vertical distribution of radionuclides in a Ribble Estuary saltmarsh: transport and deposition of radionuclides

International Nuclear Information System (INIS)

Brown, J.E.; McDonald, P.; Parker, A.; Rae, J.E.

1999-01-01

Routine discharges of low-level liquid radioactive waste by British Nuclear Fuels plc (BNFL) at Sellafield and Springfields have resulted in enhanced levels of radionuclides in sediments of the Ribble Estuary, NW England, UK. Variations in radionuclide concentrations ( 137 Cs, 230 Th, and 239240 Pu) with depth in a mature saltmarsh core were analysed in order to investigate historical discharge trends and waste-dispersal mechanisms. Core samples from Longton/Hutton Marsh were analysed by gamma-spectrometry and α-spectrometry for radionuclides and by laser granulometry to establish grain-size variations with depth. Distinct subsurface maxima were present for 137 Cs and 239240 Pu with activities as high as 4500 Bq kg -1 for 137 Cs and 600 Bq kg -1 for 239240 Pu. Thorium-230 exhibited complex activity profiles with depth, specific activities ranging between 200 and 2400 Bq kg -1 . The vertical distributions of Sellafield-derived radionuclides ( 137 Cs and 239240 Pu) in mature saltmarsh deposits reflect the time-integrated discharge pattern from Sellafield, implying a transport mechanism that has involved the mixing of sediment labelled with radioactivity from recent discharges and sediment labelled from historical discharge events before deposition. A mechanism involving the transport of contaminated silt therefore seems to dominate. The vertical distribution of Springfields-derived 230 Th in the same areas reflects the annual gross-α discharge pattern from BNFL Springfields. In contrast to the Sellafield-derived radionuclides, a fairly rapid transport mechanism from source to sink is implied, with little or no time for mixing with radionuclides discharged years earlier. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Interpretation of biological-rate coefficients derived from radionuclide content, radionuclide concentration and specific activity experiments

International Nuclear Information System (INIS)

Vanderploeg, H.A.; Booth, R.S.

1976-01-01

Rigorous expressions are derived for the biological-rate coefficients (BRCs) determined from time-dependent measurements of three different dependent variables of radionuclide tracer experiments. These variables, which apply to a single organism, are radionuclide content, radionuclide concentration and specific activity. The BRCs derived from these variables have different mathematical expressions and, for high growth rates, their numerical values can be quite different. The precise mathematical expressions for the BRCs are presented here to aid modelers in selecting the correct parameters for their models and to aid experiments in interpreting their results. The usefulness of these three variables in quantifying elemental uptakes and losses by organisms is discussed. (U.K.)

Research on sorption behavior of radionuclides under shallow land environment. Mechanism and standard methodologies for measurement of distribution coefficients of radionuclides

International Nuclear Information System (INIS)

Sakamoto, Yoshiaki; Tanaka, Tadao; Takebe, Shinichi; Nagao, Seiya; Ogawa, Hiromichi; Komiya, Tomokazu; Hagiwara, Shigeru

2001-01-01

This study consists of two categories' research works. One is research on sorption mechanism of radionuclides with long half-life, which are Technetium-99, TRU elements and U series radionuclides, on soil and rocks, including a development of database of distribution coefficients of radionuclides. The database on the distribution coefficients of radionuclides with information about measurement conditions, such as shaking method, soil characteristics and solution composition, has been already opened to the public (JAERI-DATABASE 20001003). Another study is investigation on a standard methodology of the distribution coefficient of radionuclide on soils, rocks and engineering materials in Japan. (author)

Radionuclides in the environment: Risks and opportunities

International Nuclear Information System (INIS)

Elzerman, A.W.

1993-01-01

Environmental chemistry plays a critical role in the open-quotes nuclear ageclose quotes. It makes a vital contribution to understanding of the sources, fate and effects of radionuclides in the environment, both man-made and natural. Risk assessment of radionuclides in the environment relies heavily on the tools of environmental chemistry. On the other hand, radionuclides provide unique opportunities to exploit in environmental chemistry investigations due to their well-defined sources, traceability in environmental processes, analytical sensitivities, and open-quotes built-inclose quotes radioactive decay open-quotes clocksclose quotes. In some cases naturally present radionuclides are utilized, while in others tracers are deliberately added or have already been added by the nuclear fuel cycle or nuclear testing. Several examples in each of these categories are discussed to spotlight the current status of environmental chemistry and radionuclides in the environment as an example application

Organic anion transporting polypeptide 1B transporters modulate hydroxyurea pharmacokinetics

OpenAIRE

Walker, Aisha L.; Lancaster, Cynthia S.; Finkelstein, David; Ware, Russell E.; Sparreboom, Alex

2013-01-01

Hydroxyurea is currently the only FDA-approved drug that ameliorates the pathophysiology of sickle cell anemia. Unfortunately, substantial interpatient variability in the pharmacokinetics (PK) of hydroxyurea may result in variation of the drug's efficacy. However, little is known about mechanisms that modulate hydroxyurea PK. Recent in vitro studies identifying hydroxyurea as a substrate for organic anion transporting polypeptide (OATP1B) transporters prompted the current investigation assess...

RIVER-RAD, Radionuclide Transport in Surface Waters

International Nuclear Information System (INIS)

1996-01-01

1 - Description of program or function: RIVER-RAD assesses the potential fate of radionuclides released to rivers. The model is simplified in nature and is intended to provide guidance in determining the potential importance of the surface water pathway, relevant transport mechanisms, and key radionuclides in estimating radiological dose to man. 2 - Method of solution: A compartmental linear transfer model is used in RIVER-RAD. The river system model in the code is divided into reaches (compartments) of equal size, each with a sediment compartment below it. The movement of radionuclides is represented by a series of transfers between the reaches, and between the water and sediment compartments of each reach. Within each reach (for both the water and sediment compartments), the radionuclides are assumed to be uniformly mixed. Upward volatilization is allowed from the water compartment, and the transfer of radionuclides between the reaches is determined by the flow rate of the river. Settling and resuspension velocities determine the transfer of absorbed radionuclides between the water and sediment compartments. Radioactive decay and decay-product buildup are incorporated into all transport calculations for all radionuclide chains specified by the user. Each nuclide may have unique input and removal rates. Volatilization and radiological decay are considered as linear rate constants in the model. 3 - Restrictions on the complexity of the problem: None noted

EBS Radionuclide Transport Abstraction

International Nuclear Information System (INIS)

Schreiner, R.

2001-01-01

The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M and O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations determined by other

Radionuclide carrier

International Nuclear Information System (INIS)

Hartman, F.A.; Kretschmar, H.C.; Tofe, A.J.

1978-01-01

A physiologically acceptable particulate radionuclide carrier is described. It comprises a modified anionic starch derivative with 0.1% to 1.5% by weight of a reducing agent and 1 to 20% by weight of anionic substituents

Chapter 13. Radionuclides in medicine

International Nuclear Information System (INIS)

Toelgyessy, J.; Harangozo, M.

2000-01-01

This is a chapter of textbook of radioecology for university students. In this chapter authors deal with problems connected with using of radionuclides in medicine. Methods of treatment with using of radionuclides are reviewed. Chapter consists of next parts: (1) Remotion of thyroid gland; (2) Treatment of cerebrally tumour in nuclear reactor; (3) Artificial heart

Naturally occurring radionuclides in food

International Nuclear Information System (INIS)

Djujic, I.

1995-01-01

The naturally occurring radionuclides are the major source of radiation exposure to humans. The principal way of natural radiation exposure is the inhalation of 222 Rn decay products (about 85% of the total). The remainder is equally divided between internally deposited radionuclides, cosmic and terrestrial sources. In the present study, the content of 40 K, 210 Pb, 226 Ra, 230 Th, 232 Th and 238 U in representative food samples (milk, pork, beef, potatoes, wheat and corn flour) and samples of different food items that do not represent entire national production but provide interesting additional data for approximative calculation of naturally occurring radionuclide intake is presented. Daily weight of food eaten, participation of food groups, as well as daily intake by food of mentioned naturally occurring radionuclides in the Serbian diet was obtained on the base of house hold budget surveys. The result obtained for daily intake estimates in mBq for Serbian population are 78.1 ( 40 K), 38.2( 210 Pb), 52.3( 226 Ra), 2.0( 230 Th) and 12.5( 238 U). (author)

Radionuclide Sensors for Subsurface Water Monitoring. Final report

International Nuclear Information System (INIS)

Timothy DeVol

2006-01-01

Contamination of the subsurface by radionuclides is a persistent and vexing problem for the Department of Energy. These radionuclides must be measured in field studies and monitored in the long term when they cannot be removed. However, no radionuclide sensors existed for groundwater monitoring prior to this team's research under the EMSP program. Detection of a and b decays from radionuclides in water is difficult due to their short ranges in condensed media

Uptake by plants of radionuclides from FUSRAP waste materials

International Nuclear Information System (INIS)

Knight, M.J.

1983-04-01

Radionuclides from FUSRAP wastes potentially may be taken up by plants during remedial action activities and permanent near-surface burial of contaminated materials. In order to better understand the propensity of radionuclides to accumulate in plant tissue, soil and plant factors influencing the uptake and accumulation of radionuclides by plants are reviewed. In addition, data describing the uptake of the principal radionuclides present in FUSRAP wastes (uranium-238, thorium-230, radium-226, lead-210, and polonium-210) are summarized. All five radionuclides can accumulate in plant root tissue to some extent, and there is potential for the translocation and accumulation of these radionuclides in plant shoot tissue. Of these five radionuclides, radium-226 appears to have the greatest potential for translocation and accumulation in plant shoot tissue. 28 references, 1 figure, 3 tables

Uptake by plants of radionuclides from FUSRAP waste materials

Energy Technology Data Exchange (ETDEWEB)

Knight, M.J.

1983-04-01

Radionuclides from FUSRAP wastes potentially may be taken up by plants during remedial action activities and permanent near-surface burial of contaminated materials. In order to better understand the propensity of radionuclides to accumulate in plant tissue, soil and plant factors influencing the uptake and accumulation of radionuclides by plants are reviewed. In addition, data describing the uptake of the principal radionuclides present in FUSRAP wastes (uranium-238, thorium-230, radium-226, lead-210, and polonium-210) are summarized. All five radionuclides can accumulate in plant root tissue to some extent, and there is potential for the translocation and accumulation of these radionuclides in plant shoot tissue. Of these five radionuclides, radium-226 appears to have the greatest potential for translocation and accumulation in plant shoot tissue. 28 references, 1 figure, 3 tables.

Determination of natural occurring radionuclides concentrations

International Nuclear Information System (INIS)

Stajic, J.; Markovic, V.; Krstic, D.; Nikezic, D.

2011-01-01

Tobacco smoke contains certain concentrations of naturally occurring radionuclides from radioactive chains of uranium and thorium - 214 Pb, 214 Bi, 228 Ac, 208 Tl, 226 Ra, 232 Th and 40 K. Inhaling of tobacco smoke leads to internal exposure of man. In order to estimate absorbed dose of irradiation it is necessary to determine concentrations of radionuclides present in the tobacco leaves. In this paper specific activities of naturally occurring radionuclides were measured in tobacco samples from cigarettes which are used in Serbia. [sr

Manual of bioassay procedures for radionuclides

International Nuclear Information System (INIS)

Pleskach, S.; Petkau, A.

1986-06-01

A monitoring program is described by which atomic radiation workers ar monitored for internal contamination with radionuclides in the workplace. The program involves analytical procedures for measuring alpha, beta and gamma activity in biological specimens, usually urine. Radionuclides are identified by their characteristic radiation using liquid scintillation counting, and alpha, beta and gamma spectrometry. Examples of calculating the minimum detectable activity for specific radionuclides are given and used to derive call-in-criteria in accordance with which the different groups of workers are monitored each month

Radionuclides in ground-level air

International Nuclear Information System (INIS)

Sinkko, K.

1987-01-01

In the air surveillance programme the concentrations of artificial radionuclides are monitored in the air close to the ground to obtain the necessary basic data for estimating the exposure of the Finnish population to fall-out radionuclides and also to detect atmospheric traces of radioactive materials caused by their use or production. Airborne dust is collected on filters with high-volume air samplers and the concentrations of gamma-emitting radionuclides in the air are evaluated. In the first quarter of 1986 only long-lived cesium, caused by earlier atmospheric nuclear explosions was detected. The concentrations of cesium were very low. In January and March a small amount of short-lived, fresh fission and activation products were also observed

Methotrexate and epirubicin conjugates as potential antitumor drugs

Directory of Open Access Journals (Sweden)

Szymon Wojciech Kmiecik

2017-07-01

Full Text Available Introduction: The use of hybrid molecules has become one of the most significant approaches in new cytotoxic drug design. This study describes synthesis and characterization of conjugates consisting of two well-known and characterized chemotherapeutic agents: methotrexate (MTX and epirubicin (EPR. The synthesized conjugates combine two significant anticancer strategies: combinatory therapy and targeted therapy. These two drugs were chosen because they have different mechanisms of action, which can increase the anticancer effect of the obtained conjugates. MTX, which is a folic acid analog, has high cytotoxic properties and can serve as a targeting moiety that can reach folate receptors (FRs overexpresing tumor cells. Combination of nonselective drugs such as EPR with MTX can increase the selectivity of the obtained conjugates, while maintaining the high cytotoxic properties.Materials and methods: Conjugates were purified by RP-HPLC and the structure was investigated by MS and MS/MS methods. The effect of the conjugates on proliferation of LoVo, LoVo/Dx, MCF-7 and MV-4-11 human cancer cell lines was determined by SRB or MTT assay.Results: The conjugation reaction results in the formation of monosubstituted (α, γ and disubstituted MTX derivatives. In vitro proliferation data demonstrate that the conjugates synthesized in our study show lower cytotoxic properties than both chemotherapeutics used alone.Discussion: Epirubicin cytotoxicity was not observed in obtained conjugates. Effective drugs release after internalization needs further investigation.

Modified inorganic nanoparticles as vehicles for alpha emitters in radionuclide therapy

International Nuclear Information System (INIS)

Piotrowska, A.; Leszczuk, E.; Koźmiński, P.; Bilewicz, A.; Morgenstern, A.; Bruchertseifer, F.

2014-01-01

The TiO 2 nanoparticles have unique properties like: high specific surface, high affinity for multivalent cations and simple way of synthesis, which are useful in the process of labelling. Commercially available (e.g. P-25 Degussa) and synthesised in our laboratory nanoparticles were used in experiments. The nanoparticles were characterized by TEM, SEM, DLS and NanoSight techniques. In the experiments, two different methods of labeling are tested. The first one was based on the possibility of formation strong bonds with certain cations on the surface of the nanoparticles. In the 65 second one, TiO 2 nanoparticles were doped with 225 Ac during the process of synthesis. In both cases, high yields of labelling (>99%) was obtained. Afterwards, the stability of labelled nanoparticles was examined in 0.9 % NaCl, 10 -3 M EDTA, solutions of biologically active substances (cysteine, glutathione) and human serum. In case of TiO 2 nanoparticles labelled with 225 Ac, which was built in the crystalline structure, the leakage of 225 Ac and its daughter radionuclides was not significant in any of solutions, even when the incubation time was extended to 10 days. In the case of nanoparticles with adsorbed 225 Ac on surface the leakage in serum was slightly higher, but still insignificant. Also the NaA nanozeolite as a carrier for radium radionuclides has been studied. 224 Ra and 225 Ra, the α-particle emitting radionuclides, have been absorbed in the nanometer-sized NaA zeolite through simple ion-exchange. 224,225 Ra-nanozeolites have shown very good stability in solutions containing: physiological salt, EDTA, amino acid and human serum. To make NaA nanozeolite particles dispersed in water their surface has been modified with silane coupling agent containing poly (ethylene glycol) (PEG) molecules. To obtain conjugates specific for receptors on glioma cancer cells short peptide substance P were covalently attached to the PEG-TiO 2 and PEG-nanozeolite surface. The obtained

Selected radionuclides important to low-level radioactive waste management

International Nuclear Information System (INIS)

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237

Selected radionuclides important to low-level radioactive waste management

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.

Measurements for modeling radionuclide transfer in the aquatic environment

International Nuclear Information System (INIS)

Kahn, B.

1976-01-01

Analytical methods for measuring radionuclides in the aquatic environment are discussed for samples of fresh water and seawater, fish and shellfish, biota such as algae, plankton, seaweed, and aquatic plants, and sediment. Consideration is given to radionuclide collection and concentration, sample preservation, radiochemical and instrumental analysis, and quality assurance. Major problems are the very low environmental levels of the radionuclides of interest, simultaneous occurrence of radionuclides in several chemical and physical forms and the numerous factors that affect radionuclide levels in and transfers among media. Some radionuclides of importance in liquid effluents from nuclear power stations are listed, and sources of radiochemical analytical methods are recommended

Statistical analysis of fallout radionuclides transfer to paddy-field rice

International Nuclear Information System (INIS)

Takahashi, T.; Morisawa, S.; Inoue, Y.

1996-01-01

Radionuclides released from nuclear facilities to atmosphere are transported through various pathways in biosphere and cause human exposure. Among these radionuclides transfer pathways, an ingestion of crops containing radionuclides is one of the dominant pathway for human exposure. For the safety assessment of nuclear facilities, it is important to understand the behavior of radionuclides in agricultural environment and to describe them in a mathematical model. In this paper, a statistical model is proposed for estimating the concentration of fallout radionuclides in paddy-field rice, the staple food for Japanese people. For describing behavior of fallout radionuclides in a paddy-field, a dynamic model and a statistical model have been proposed respectively. The model used in this study has been developed assuming that the amount of radionuclides transfer to brown rice (hulled rice) or polished rice through direct deposition of airborne radionuclides (the direct deposition pathway) and root uptake from a paddy soil (the root uptake pathway) are proportional to the deposition flux of radionuclides and concentration of radionuclides in paddy soil respectively. That is, the model has two independent variables; the deposition flux of radionuclides and the concentration of radionuclides in the paddy soil, and has single dependent variable; the concentration of radionuclides in brown rice or polished rice. The regression analysis is applied by using environmental monitoring data. Then the distribution of radionuclides between rice-bran (skin part of rice crop) and polished rice (core part) through both the direct deposition pathway and the root uptake pathway are evaluated by the model. (author)

Accumulation of radionuclides by lichen symbionts

Energy Technology Data Exchange (ETDEWEB)

Nifontova, M G; Kulikov, N V [AN SSSR, Sverdlovsk. Inst. Ehkologii Rastenij i Zhivotnykh

1983-01-01

The aim of investigation is the quantitative estimation of ability and role of separate symbionts in the accumulation of radionuclides. As investigation volumes, durably cultivated green lichen alga Trebouxia erici and lichen fungi extracted from Cladonia rangiferina, Parmelia caperata and Acarospora fuscata are used. The accumulation of radioactive isotopes with fungi and seaweeds is estimated according to accumulation coefficients (AC) which are the ratio of radiation concentration in plants and agarized medium. Radionuclide content (/sup 90/Sr and /sup 137/Cs) is determined radiometrically. A special series of experiments is done to investigate radionuclide accumulation dependences with lichen seaweed and fungi on light conditions. It is shown that both symbionts of lichen-seaweed and fungus take part in the accumulation of radionuclide from outer medium (atmospheric fall-out and soil). However fungus component constituting the base of structural organization of thallus provides the greater part of radionuclides accumulated by the plant. Along with this the violation of viability of seaweed symbionts particularly in the case of light deficiency brings about the reduction of /sup 137/Cs sorption by seaweeds and tells on the total content of radiocesium in plant thallus.

Targeted Radionuclide Therapy

Directory of Open Access Journals (Sweden)

David Cheng

2011-10-01

Full Text Available Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Targeted Radionuclide Therapy

Energy Technology Data Exchange (ETDEWEB)

Ersahin, Devrim, E-mail: devrimersahin@yahoo.com; Doddamane, Indukala; Cheng, David [Department of Diagnostic Radiology, School of Medicine, Yale University, 333 Cedar St., New Haven, CT 06520 (United States)

2011-10-11

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Radionuclides in foods

International Nuclear Information System (INIS)

1994-01-01

This report contains data on the levels of radionuclides in the UK foodchain. Most data derive from monitoring programmes that exist around nuclear sites, and in some cases date back to the 1960s. Some comparative data from site operator and government-run programmes are included. Data from monitoring undertaken after the Chernobyl accident are summarised. General monitoring of the foodchain for both artificial and natural radionuclides, and the results of relevant government-sponsored research are also described. The report includes basic information on radioactivity in the environment, radiation protection standards and describes what measures are taken to routinely monitor the foodchain and assess public risk. (Author)

Targeted Radionuclide Therapy

International Nuclear Information System (INIS)

Ersahin, Devrim; Doddamane, Indukala; Cheng, David

2011-01-01

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose

Radionuclides in house dust

Energy Technology Data Exchange (ETDEWEB)

Fry, F A; Green, N; Dodd, N J; Hammond, D J

1985-04-01

Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

Radionuclide accumulation peculiarities demonstrated by vegetable varieties

International Nuclear Information System (INIS)

Kruk, A.V.; Goncharenko, G.G.; Kilchevsky, A.V.

2004-01-01

This study focused on ecological and genetic aspects of radionuclide accumulation demonstrated by a number of vegetable varieties. The researches resulted in determining the cabbage varieties which were characterised by the minimal level of radionuclide accumulation. It was shown that the above varieties manifested the relation between radionuclide accumulation and morphobiological characteristics such as vegetation period duration and yield criteria. The study specified the genotypes with high ecological stability as regards to radionuclide accumulation: 'Beloruskaya 85' cabbage and 'Dokhodny' tomato showed the best response to Cs 137, while 'Beloruskaya 85', 'Rusinovka', 'Amager 611' cabbage varieties and 'Sprint' tomato showed the minimal level of Sr 90 accumulation. (authors)

2008 LANL radionuclide air emissions report

Energy Technology Data Exchange (ETDEWEB)

Fuehne, David P.

2009-06-01

The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2008. This report meets the reporting requirements established in the regulations.

2010 LANL radionuclide air emissions report /

Energy Technology Data Exchange (ETDEWEB)

Fuehne, David P.

2011-06-01

The emissions of radionuclides from Department of Energy Facilities such as Los Alamos National Laboratory (LANL) are regulated by the Amendments to the Clean Air Act of 1990, National Emissions Standards for Hazardous Air Pollutants (40 CFR 61 Subpart H). These regulations established an annual dose limit of 10 mrem to the maximally exposed member of the public attributable to emissions of radionuclides. This document describes the emissions of radionuclides from LANL and the dose calculations resulting from these emissions for calendar year 2010. This report meets the reporting requirements established in the regulations.

Preparation of porous materials for radionuclides capture

International Nuclear Information System (INIS)

Bajzikova, Anna; Smrcek, Stanislav; Kozempel, Jan; Vlk, Martin; Barta, Jan

2015-01-01

Porous materials showing promise for radionuclide capture from water at contaminated sites were prepared. Nanoporous materials (size of pores 1-100 nm) and some polymers are well suited to this purpose owing their affinity for selected radionuclides. Nanoporous metal oxides and silica gel with styrene-divinylbenzene-TODGA-modified surface were prepared, characterized and tested for radionuclide ( 227 Ac, 227 Th, 223 Ra) capture efficiency. (orig.)

Radionuclide Data Centre. Tasks and problems of obtaining the most reliable values of the nuclear physics characteristics of radionuclides and radiation physics parameters of radionuclide sources

International Nuclear Information System (INIS)

Chechev, V.P.

1994-01-01

Information is provided on the establishment of the Radionuclide Data Centre under the V.G. Khlopin Radium Institute. Its functions and areas of activity are discussed. The paper focuses on the procedure of obtaining the evaluated values of the decay and radiative characteristics of the widely used radionuclides. (author)

Human dose pathways of radionuclides in forests

International Nuclear Information System (INIS)

Rantavaara, A.

2009-01-01

Forest soil, understorey vegetation and trees are all sources of radionuclides and human radiation doses after contaminating atmospheric deposition. People are exposed to radiation externally from sources outside the body and internally via ingestion and inhalation of radionuclides. Understorey vegetation contributes to ingestion doses through berries, herbs, wild honey, mushrooms and game meat; also trees provide feed to terrestrial birds and big game. During stay in forests people are subject to external radiation from forest floor and overstorey, and they may inhale airborne radioactive aerosol or gaseous radionuclides in ground level air. In the early phase of contamination also resuspended radionuclides may add to the internal dose of people via inhalation. People in Nordic countries are most exposed to radiation via ingestion of radionuclides in wild foods. The distribution of radionuclides in forests is changed by environmental processes, and thereby also the significance of various dose pathways to humans will change with time. External exposure is received in living environment from contaminated stemwood used as building timber and for manufacturing of furniture and other wood products. The aim of this paper is to outline the significance of various human dose pathways of radionuclides in forests considering the public and workers in forestry and production of bioenergy. Examples on effective doses are given based on two historical events, atmospheric nuclear weapon tests (mostly in 1950's and in 1960's) and the Chernobyl nuclear power plant accident in 1986. (au)

General program for the advancement of the radionuclide technology

International Nuclear Information System (INIS)

1979-12-01

The 'General Program for the Advancement of the Radionuclide Technology' was elaborated in 1978 by the 'Arbeitsgemeinschaft zur Foerderung der Radionuklidtechnik' (AFR) (Association for the Promotion of Radionuclide Technology). In addition to an inventory of the major applications of radionuclide technology, this General Program includes a comprehensive description of tasks relating to the central topics of raw materials, environment, technology and materials, health and nutrition, scientific developments of radionuclide technology. The 'General Program for the Advancement of the Radionuclide Technology' serves inter alia as a basis of evaluation in opinions on funding applications filed with the Federal Ministry for Research and Technology (BMFT) with respect to the provision of advanced techniques involving radionuclides for industrial application. (orig.) [de

Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins

OpenAIRE

Deming, TJ

2017-01-01

Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-cont...

NMR study of the cooperative behavior of thermotropic model polypeptides

Czech Academy of Sciences Publication Activity Database

Kurková, Dana; Kříž, Jaroslav; Rodríguez-Cabello, J. C.; Arias, F. J.

2007-01-01

Roč. 56, č. 2 (2007), s. 186-194 ISSN 0959-8103 R&D Projects: GA AV ČR IAA400500604 Grant - others:Spanish Ministry of Science and Culture(ES) A002/02; MAT2000-1764-C02; MAT2001-1853-C02-01; MAT2003- Institutional research plan: CEZ:AV0Z40500505 Keywords : thermotropic polymers * cooperativity * synthetic polypeptides Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.557, year: 2007

Theoretical estimation of absorbed dose to organs in radioimmunotherapy using radionuclides with multiple unstable daughters

International Nuclear Information System (INIS)

Hamacher, K.A.; Sgouros, G.

2001-01-01

The toxicity and clinical utility of long-lived alpha emitters such as Ac-225 and Ra-223 will depend upon the fate of alpha-particle emitting unstable intermediates generated after decay of the conjugated parent. For example, decay of Ac-225 to a stable element yields four alpha particles and seven radionuclides. Each of these progeny has its own free-state biodistribution and characteristic half-life. Therefore, their inclusion for a more accurate prediction of absorbed dose and potential toxicity requires a formalism that takes these factors into consideration as well. To facilitate the incorporation of such intermediates into the dose calculation, a previously developed methodology (model 1) has been extended. Two new models (models 2 and 3) for allocation of daughter products are introduced and are compared with the previously developed model. Model 1 restricts the transport to a function that yields either the place of origin or the place(s) of biodistribution depending on the half-life of the parent radionuclide. Model 2 includes the transient time within the bloodstream and model 3 incorporates additional binding at or within the tumor. This means that model 2 also allows for radionuclide decay and further daughter production while moving from one location to the next and that model 3 relaxes the constraint that the residence time within the tumor is solely based on the half-life of the parent. The models are used to estimate normal organ absorbed doses for the following parent radionuclides: Ac-225, Pb-212, At-211, Ra-223, and Bi-213. Model simulations are for a 0.1 g rapidly accessible tumor and a 10 g solid tumor. Additionally, the effects of varying radiolabled carrier molecule purity and amount of carrier molecules, as well as tumor cell antigen saturation are examined. The results indicate that there is a distinct advantage in using parent radionuclides such as Ac-225 or Ra-223, each having a half-life of more than 10 days and yielding four alpha

Radionuclides in house dust

CERN Document Server

Fry, F A; Green, N; Hammond, D J

1985-01-01

Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, alt...

Geochemistry and radionuclide migration

International Nuclear Information System (INIS)

Isherwood, D.

1978-01-01

Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

Multivalent peptidic linker enables identification of preferred sites of conjugation for a potent thialanstatin antibody drug conjugate.

Directory of Open Access Journals (Sweden)

Sujiet Puthenveetil

Full Text Available Antibody drug conjugates (ADCs are no longer an unknown entity in the field of cancer therapy with the success of marketed ADCs like ADCETRIS and KADCYLA and numerous others advancing through clinical trials. The pursuit of novel cytotoxic payloads beyond the mictotubule inhibitors and DNA damaging agents has led us to the recent discovery of an mRNA splicing inhibitor, thailanstatin, as a potent ADC payload. In our previous work, we observed that the potency of this payload was uniquely tied to the method of conjugation, with lysine conjugates showing much superior potency as compared to cysteine conjugates. However, the ADC field is rapidly shifting towards site-specific ADCs due to their advantages in manufacturability, characterization and safety. In this work we report the identification of a highly efficacious site-specific thailanstatin ADC. The site of conjugation played a critical role on both the in vitro and in vivo potency of these ADCs. During the course of this study, we developed a novel methodology of loading a single site with multiple payloads using an in situ generated multi-drug carrying peptidic linker that allowed us to rapidly screen for optimal conjugation sites. Using this methodology, we were able to identify a double-cysteine mutant ADC delivering four-loaded thailanstatin that was very efficacious in a gastric cancer xenograft model at 3mg/kg and was also shown to be efficacious against T-DM1 resistant and MDR1 overexpressing tumor cell lines.

Multivalent peptidic linker enables identification of preferred sites of conjugation for a potent thialanstatin antibody drug conjugate.

Science.gov (United States)

Puthenveetil, Sujiet; He, Haiyin; Loganzo, Frank; Musto, Sylvia; Teske, Jesse; Green, Michael; Tan, Xingzhi; Hosselet, Christine; Lucas, Judy; Tumey, L Nathan; Sapra, Puja; Subramanyam, Chakrapani; O'Donnell, Christopher J; Graziani, Edmund I

2017-01-01

Antibody drug conjugates (ADCs) are no longer an unknown entity in the field of cancer therapy with the success of marketed ADCs like ADCETRIS and KADCYLA and numerous others advancing through clinical trials. The pursuit of novel cytotoxic payloads beyond the mictotubule inhibitors and DNA damaging agents has led us to the recent discovery of an mRNA splicing inhibitor, thailanstatin, as a potent ADC payload. In our previous work, we observed that the potency of this payload was uniquely tied to the method of conjugation, with lysine conjugates showing much superior potency as compared to cysteine conjugates. However, the ADC field is rapidly shifting towards site-specific ADCs due to their advantages in manufacturability, characterization and safety. In this work we report the identification of a highly efficacious site-specific thailanstatin ADC. The site of conjugation played a critical role on both the in vitro and in vivo potency of these ADCs. During the course of this study, we developed a novel methodology of loading a single site with multiple payloads using an in situ generated multi-drug carrying peptidic linker that allowed us to rapidly screen for optimal conjugation sites. Using this methodology, we were able to identify a double-cysteine mutant ADC delivering four-loaded thailanstatin that was very efficacious in a gastric cancer xenograft model at 3mg/kg and was also shown to be efficacious against T-DM1 resistant and MDR1 overexpressing tumor cell lines.

DKPRO: A radionuclide decay and reprocessing code

International Nuclear Information System (INIS)

Wootan, D.; Schmittroth, F.A.

1997-01-01

The DKPRO code solves the general problem of modeling complex nuclear wastes streams using ORIGEN2 radionuclide production files. There is a continuing need for estimates of Hanford radionuclides. Physical measurements are one basis; calculational estimates, the approach represented here, are another. Given a known nuclear fuel history, it is relatively straightforward to calculate radionuclide inventories with codes such as the widely-used Oak Ridge National Laboratory code ORIGEN2

Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

DEFF Research Database (Denmark)

Wirth, P J; Luo, L D; Fujimoto, Y

1992-01-01

; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-myc/v-raf)-induced transformation of RLE cells. Two-dimensional mapping of [35S]methionine-labeled whole cell lysate, cell-free in vitro translation products and [32P]orthophosphate-labeled polypeptides revealed subsets of polypeptides specific...... for each transformation modality. A search of the RLE protein database indicated the specific subcellular location for the majority of these transformation-sensitive proteins. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin......- and intermediate filament-related polypeptides (vimentin, beta-tubulin, the cytokeratins, and actin) were observed among the various transformant cell lines. Immunoprecipitation and Western immunoblot analysis of tropomyosin expression in four individual AFB-, as well as four spontaneously induced, and each...

Transfer of radionuclides into human milk

International Nuclear Information System (INIS)

Steiner, M.; Wirth, E.

1998-01-01

Up until now the potential radiation exposure to breast-fed babies due to contaminated human milk has not been taken into account, when deriving international limit values and reference levels for radionuclides in foodstuffs, in air at monitored work places or for exposures in the medical field. It was the aim of the research project 'Transfer of radionuclides into human milk' to quantify the transfer of incorporated radionuclides into mother's milk, and develop simple models to estimate the radiation exposure of babies through the ingestion of human milk. The study focused on considerations of the radiation exposure due to the ingestion of contaminated foodstuffs by the mother, the inhalation of radionuclides at monitored work places, and the administration of radiopharmaceuticals to breast-feeding mothers. The blocking of infant thyroid glands by stable iodine in the case of accidental releases of radioiodine was considered as well. (orig.) [de

Radionuclide migration in crystalline rock fractures

International Nuclear Information System (INIS)

Hoelttae, P.

2002-01-01

Crystalline rock has been considered as a host medium for the repository of high radioactive spent nuclear fuel in Finland. The geosphere will act as an ultimate barrier retarding the migration of radionuclides to the biosphere if they are released through the technical barriers. Radionuclide transport is assumed to take place along watercarrying fractures, and retardation will occur both in the fracture and within the rock matrix. To be able to predict the transport and retardation of radionuclides in rock fractures and rock matrices, it is essential to understand the different phenomena involved. Matrix diffusion has been indicated to be an important mechanism, which will retard the transport of radionuclides in rock fractures. Both dispersion and matrix diffusion are processes, which can have similar influences on solute breakthrough curves in fractured crystalline rock. In this work, the migration of radionuclides in crystalline rock fractures was studied by means of laboratory scale column methods. The purpose of the research was to gain a better understanding of various phenomena - particularly matrix diffusion - affecting the transport and retardation behaviour of radionuclides in fracture flow. Interaction between radionuclides and the rock matrix was measured in order to test the compatibility of experimental retardation parameters and transport models used in assessing the safety of underground repositories for spent nuclear fuel. Rock samples of mica gneiss and of unaltered, moderately altered and strongly altered tonalite represented different rock features and porosities offering the possibility to determine experimental boundary limit values for parameters describing both the transport and retardation of radionuclides and rock matrix properties. The dominant matrix diffusion behaviour was demonstrated in porous ceramic column and gas diffusion experiments. Demonstration of the effects of matrix diffusion in crystalline rock fracture succeeded for the

Formation of a [sup(99m)Tc]polypeptide hormone: characterization and chemical quality control by ampholyte displacement radiochromatography

International Nuclear Information System (INIS)

Sundrehagen, E.

1983-01-01

Sup(99m)Tc-complexes with the polypeptide hormone secretin in very low concentration were formed by the concentrated hydrochloric acid/vacuum evaporation/gentisic acid method. The sup(99m)Tc-secretin was characterized by a modified ampholyte radiochromatographic procedure, in addition to thin layer chromatography, gel chromatography and paper electrophoresis. High radiochemical purity and specific radioactivity were obtained. In vivo distribution studies were performed, and the conditions necessary for application of [sup(99m)Tc]polypeptides as scintigraphic agents are discussed. (author)

In Vitro Evaluation of Third Generation PAMAM Dendrimer Conjugates

Directory of Open Access Journals (Sweden)

Mohammad Najlah

2017-10-01

Full Text Available The present study compares the use of high generation G3 and low generation G0 Polyamidoamine (PAMAM dendrimers as drug carriers of naproxen (NAP, a poorly water soluble drug. Naproxen was conjugated to G3 in different ratios and to G0 in a 1:1 ratio via a diethylene glycol linker. A lauroyl chain (L, a lipophilic permeability enhancer, was attached to G3 and G0 prodrugs. The G3 and G0 conjugates were more hydrophilic than naproxen as evaluated by the measurement of partitioning between 1-octanol and a phosphate buffer at pH 7.4 and pH 1.2. The unmodified surface PAMAM-NAP conjugates showed significant solubility enhancements of NAP at pH 1.2; however, with the number of NAP conjugated to G3, this was limited to 10 molecules. The lactate dehydrogenase (LDH assay indicated that the G3 dendrimer conjugates had a concentration dependent toxicity towards Caco-2 cells. Attaching naproxen to the surface of the dendrimer increased the IC50 of the resulting prodrugs towards Caco-2 cells. The lauroyl G3 conjugates showed the highest toxicity amongst the PAMAM dendrimer conjugates investigated and were significantly more toxic than the lauroyl-G0-naproxen conjugates. The permeability of naproxen across monolayers of Caco-2 cells was significantly increased by its conjugation to either G3 or G0 PAMAM dendrimers. Lauroyl-G0 conjugates displayed considerably lower cytotoxicity than G3 conjugates and may be preferable for use as a drug carrier for low soluble drugs such as naproxen.

Gastroesophageal reflux in children: radionuclide gastroesophagography

International Nuclear Information System (INIS)

Blumhagen, J.D.; Rudd, T.G.; Christie, D.L.

1980-01-01

Sixty-five symptomatic infants and children underwent radionuclide gastroesophagography, acid reflux testing, and barium esophagography with water-siphon testing to evaluate the clinical efficacy of the scintigraphic technique in detecting gastroesophageal reflux. After ingesting /sup 99m/Tc sulfur colloid in fruit juice, patients rested beneath the gamma camera for 30 to 60 min while esophageal activity was monitored continuously. By using the acid reflux test as a standard of comparison, the senstivity of radionuclide gastroesophagography was 75%. Because of its physiologic nature, low radiation exposure, and convenience, radionuclide gastroesophagography warrants further evaluation as a screening test for gastroesophageal reflux

Soil - plant experimental radionuclide transfer factors

International Nuclear Information System (INIS)

Dobrin, R.I.; Dulama, C.N.; Toma, Al.

2006-01-01

Some experimental research was performed in our institute to assess site specific soil-plant transfer factors. A full characterization of an experimental site was done both from pedo-chemical and radiological point of view. Afterwards, a certain number of culture plants were grown on this site and the evolution of their radionuclide burden was then recorded. Using some soil amendments one performed a parallel experiment and the radionuclide root uptake was evaluated and recorded. Hence, transfer parameters were calculated and some conclusions were drawn concerning the influence of site specific conditions on the root uptake of radionuclides. (authors)

Sources of anthropogenic radionuclides in the environment: a review

International Nuclear Information System (INIS)

Hu Qinhong; Weng Jianqing; Wang Jinsheng

2010-01-01

Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview on sources of anthropogenic radionuclides in the environment, as well as a brief discussion of salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current developments that have lead, or could potentially contribute, to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) uranium mining and milling; (5) commercial fuel reprocessing; (6) geological repository of high-level nuclear wastes that include radionuclides might be released in the future, and (7) nuclear accidents. Then, we briefly summarize the inventory of radionuclides 99 Tc and 129 I, as well as geochemical behavior for radionuclides 99 Tc, 129 I, and 237 Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment; biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

NARCIS (Netherlands)

Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

Tetrafullerene conjugates for all-organic photovoltaics

NARCIS (Netherlands)

Fernández, G.; Sánchez, L.; Veldman, D.; Wienk, M.M.; Atienza, C.M.; Guldi, D.M.; Janssen, R.A.J.; Martin, N.

2008-01-01

The synthesis of two new tetrafullerene nanoconjugates in which four C60 units are covalently connected through different -conjugated oligomers (oligo(p-phenylene ethynylene) and oligo(p-phenylene vinylene)) is described. The photovoltaic (PV) response of these C60-based conjugates was evaluated by

Transuranic radionuclides dispersed into the aquatic environment, a bibliography

Energy Technology Data Exchange (ETDEWEB)

Noshkin, V.E.; Stoker, A.C.; Wong, Kai M. [and others

1994-04-01

The purpose of this project was to compile a bibliography of references containing environmental transuranic radionuclide data. Our intent was to identify those parameters affecting transuranic radionuclide transport that may be generic and those that may be dependent on chemical form and/or environmental conditions (i.e., site specific) in terrestrial, aquatic and atmospheric environments An understanding of the unique characteristics and similarities between source terms and environmental conditions relative to transuranic radionuclide transport and cycling will provide the ability to assess and predict the long term impact on man and the environment. An additional goal of our literature review, was to extract the ranges of environmental transuranic radionuclide data from the identified references for inclusion in a data base. Related to source term, these ranges of data can be used to calculate the dose to man from the radionuclides, and to perform uncertainty analyses on these dose assessments. On the basis of our reviews, we have arbitrarily outlined five general source terms. These are fallout, fuel cycle waste, accidents, disposal sites and resuspension. Resuspension of the transuranic radionuclides is a unique source term, in that the radionuclides can originate from any of the other source terms. If these transuranic radionuclides become resuspended into the air, they then become important as a source of inhaled radionuclides.

Novel Aflatoxin Derivatives and Protein Conjugates

Directory of Open Access Journals (Sweden)

Reinhard Niessner

2007-03-01

Full Text Available Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities.

Dynamic enzyme docking to the ribosome coordinates N-terminal processing with polypeptide folding.

Science.gov (United States)

Sandikci, Arzu; Gloge, Felix; Martinez, Michael; Mayer, Matthias P; Wade, Rebecca; Bukau, Bernd; Kramer, Günter

2013-07-01

Newly synthesized polypeptides undergo various cotranslational maturation steps, including N-terminal enzymatic processing, chaperone-assisted folding and membrane targeting, but the spatial and temporal coordination of these steps is unclear. We show that Escherichia coli methionine aminopeptidase (MAP) associates with ribosomes through a charged loop that is crucial for nascent-chain processing and cell viability. MAP competes with peptide deformylase (PDF), the first enzyme to act on nascent chains, for binding sites at the ribosomal tunnel exit. PDF has extremely fast association and dissociation kinetics, which allows it to frequently sample ribosomes and ensure the processing of nascent chains after their emergence. Premature recruitment of the chaperone trigger factor, or polypeptide folding, negatively affect processing efficiency. Thus, the fast ribosome association kinetics of PDF and MAP are crucial for the temporal separation of nascent-chain processing from later maturation events, including chaperone recruitment and folding.

Radionuclide characterization of environmental air around nuclear facilities

International Nuclear Information System (INIS)

Gede Sutresna Wijaya; Anung Muharini

2015-01-01

Air is an important environmental component in human life. Presence of air pollutants or contaminants will have a negative impact on human health. According to the existence of a nuclear facility in Yogyakarta, the characterization of radionuclides in the air is absolutely necessary to ensure the safety of people and the environment and also to supervise the safe operation of the facility. In this research the characterization of radionuclides in the air was carried through the air sampling by using High Volume Air Sampler equipped with filter TFA 2133, followed by analysis using combination of a gamma and alpha spectrometers. The concentration of radioactivity in the air fluctuates depending on the time and duration of sampling. Characterization of gamma emitting radionuclides in the air is dominated by radon progeny radionuclides such as 214 Pb, 214 Bi with activity 20.09 ± 1.23 until 32.91 ± 4.87 Bq/m 3 and 31.22 ± 1.76 until 44.25 ± 4.91 Bq/m 3 . Alpha emitter radionuclide was dominated by 214 Po (7.69 MeV) which is also radon progeny and a primordial radionuclides. It can be concluded that the presence of radionuclides in the environmental air not as a product resulting from the operation of nuclear facilities in Yogyakarta. (author)

An overview of BORIS: Bioavailability of Radionuclides in Soils

International Nuclear Information System (INIS)

Tamponnet, C.; Martin-Garin, A.; Gonze, M.-A.; Parekh, N.; Vallejo, R.; Sauras-Yera, T.; Casadesus, J.; Plassard, C.; Staunton, S.; Norden, M.; Avila, R.; Shaw, G.

2008-01-01

The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K d for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance its

An overview of BORIS: Bioavailability of Radionuclides in Soils

Energy Technology Data Exchange (ETDEWEB)

Tamponnet, C. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France)], E-mail: christian.tamponnet@irsn.fr; Martin-Garin, A.; Gonze, M.-A. [Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, B.P. 1, 13108 Saint-Paul-lez-Durance, Cedex (France); Parekh, N. [Center for Ecology and Hydrology, Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Vallejo, R.; Sauras-Yera, T.; Casadesus, J. [Department of Plant Biology, University of Barcelona, 08028 Barcelona (Spain); Plassard, C.; Staunton, S. [INRA, UMR Rhizosphere and Symbiosis, Place Viala, 34060 Montpellier (France); Norden, M. [Swedish Radiation Protection Institute, 171 16 Stockholm (Sweden); Avila, R. [Facilia AB, Valsgaerdevaegen 12, 168 53 Bromma, Stockholm (Sweden); Shaw, G. [Division of Agricultural and Environmental Sciences University Park, Nottingham NG7 2RD (United Kingdom)

2008-05-15

The ability to predict the consequences of an accidental release of radionuclides relies mainly on the level of understanding of the mechanisms involved in radionuclide interactions with different components of agricultural and natural ecosystems and their formalisation into predictive models. Numerous studies and databases on contaminated agricultural and natural areas have been obtained, but their use to enhance our prediction ability has been largely limited by their unresolved variability. Such variability seems to stem from incomplete knowledge about radionuclide interactions with the soil matrix, soil moisture, and biological elements in the soil and additional pollutants, which may be found in such soils. In the 5th European Framework Programme entitled Bioavailability of Radionuclides in Soils (BORIS), we investigated the role of the abiotic (soil components and soil structure) and biological elements (organic compounds, plants, mycorrhiza, and microbes) in radionuclide sorption/desorption in soils and radionuclide uptake/release by plants. Because of the importance of their radioisotopes, the bioavailability of three elements, caesium, strontium, and technetium has been followed. The role of one additional non-radioactive pollutant (copper) has been scrutinised in some cases. Role of microorganisms (e.g., K{sub d} for caesium and strontium in organic soils is much greater in the presence of microorganisms than in their absence), plant physiology (e.g., changes in plant physiology affect radionuclide uptake by plants), and the presence of mycorrhizal fungi (e.g., interferes with the uptake of radionuclides by plants) have been demonstrated. Knowledge acquired from these experiments has been incorporated into two mechanistic models CHEMFAST and BIORUR, specifically modelling radionuclide sorption/desorption from soil matrices and radionuclide uptake by/release from plants. These mechanistic models have been incorporated into an assessment model to enhance

Structure Property Relationships in Organic Conjugated Systems

OpenAIRE

O'Neill, Luke

2008-01-01

A series of pi(п) conjugated oligomers containing 1 to 6 monomer units were studied by absorption and photoluminescence spectroscopies. The results are discussed and examined with regard to the variation of the optical properties with the increase of effective conjugation length. It was found that there was a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length. The relationships are in good agreement with the si...

A basic toxicity classification of radionuclides

International Nuclear Information System (INIS)

1963-01-01

In the course of its work in the field of health and safety the International Atomic Energy Agency has often met the practical requirement for grading radionuclides in order of their relative radiotoxicities. This need was particularly evident when the Agency's Basic Safety Standards for the protection of health against ionizing radiation were in preparation, when it was necessary to exempt quantities of radionuclides from inclusion in the norms. A basic toxicity grading might be of help to laboratories in meeting some of their requirements in problems related to waste management as well as for the design of experimental facilities. It should also serve as a basis for the development of safety criteria for laboratory equipment and procedures for handling and transporting various quantities and kinds of radionuclides. The purpose of the present Report is to make a toxicity grading of the radionuclides according to the risk of biological injury which they may cause when they have become incorporated in the human body. 4 refs, 4 tabs

A basic toxicity classification of radionuclides

Energy Technology Data Exchange (ETDEWEB)

1963-04-01

In the course of its work in the field of health and safety the International Atomic Energy Agency has often met the practical requirement for grading radionuclides in order of their relative radiotoxicities. This need was particularly evident when the Agency's Basic Safety Standards for the protection of health against ionizing radiation were in preparation, when it was necessary to exempt quantities of radionuclides from inclusion in the norms. A basic toxicity grading might be of help to laboratories in meeting some of their requirements in problems related to waste management as well as for the design of experimental facilities. It should also serve as a basis for the development of safety criteria for laboratory equipment and procedures for handling and transporting various quantities and kinds of radionuclides. The purpose of the present Report is to make a toxicity grading of the radionuclides according to the risk of biological injury which they may cause when they have become incorporated in the human body. 4 refs, 4 tabs.

Method of preparing radionuclide doses

International Nuclear Information System (INIS)

Kuperus, J.H.

1987-01-01

A method is described of preparing aliquot dosea of a tracer material useful in diagnostic nuclear medicine comprising: storing discrete quantities of a lyophilized radionuclide carrier in separate tubular containers from which air and moisture is excluded, selecting from the tubular containers a container in which is stored a carrier appropriate for a nuclear diagnostic test to be performed, interposing the selected container between the needle and the barrel of a hypodermic syringe, and drawing a predetermined amount of a liquid containing a radionuclide tracer in known concentration into the hypodermic syringe barrel through the hypodermic needle and through the selected container to dissolve the discrete quantity of lyophilized carrier therein to combine the carrier with the radionuclide tracer to form an aliquot dose of nuclear diagnostic tracer material, as needed

Transfer parameters of radionuclides in the marine environment

International Nuclear Information System (INIS)

1996-03-01

To increase the accuracy of estimation of exposure dose by radionuclides in the marine, the informations of environmental parameter data in the marine were collected, arranged and discussed. The informations were discussed by 'a sectional committee of marine suspended solids and sediment'. The following problems were investigated and the studies were recorded in this report, clear explanation about the distribution factor (kd), the estimation method of kd, the fluctuating factor of kd data (properties of suspension and sediment, differences among the experimental methods), the physical and chemical behavior of radionuclides, sediment of radionuclides by means of sorption to the suspended particles in the marine, sorption of radionuclides into the marine soil (sediment), re-eluent of radionuclides sorpted in the marine soil (sediment), and relation between marine organism and marine suspended materials and sediment. (S.Y.)

Sources and Bioactive Properties of Conjugated Dietary Fatty Acids.

Science.gov (United States)

Hennessy, Alan A; Ross, Paul R; Fitzgerald, Gerald F; Stanton, Catherine

2016-04-01

The group of conjugated fatty acids known as conjugated linoleic acid (CLA) isomers have been extensively studied with regard to their bioactive potential in treating some of the most prominent human health malignancies. However, CLA isomers are not the only group of potentially bioactive conjugated fatty acids currently undergoing study. In this regard, isomers of conjugated α-linolenic acid, conjugated nonadecadienoic acid and conjugated eicosapentaenoic acid, to name but a few, have undergone experimental assessment. These studies have indicated many of these conjugated fatty acid isomers commonly possess anti-carcinogenic, anti-adipogenic, anti-inflammatory and immune modulating properties, a number of which will be discussed in this review. The mechanisms through which these bioactivities are mediated have not yet been fully elucidated. However, existing evidence indicates that these fatty acids may play a role in modulating the expression of several oncogenes, cell cycle regulators, and genes associated with energy metabolism. Despite such bioactive potential, interest in these conjugated fatty acids has remained low relative to the CLA isomers. This may be partly attributed to the relatively recent emergence of these fatty acids as bioactives, but also due to a lack of awareness regarding sources from which they can be produced. In this review, we will also highlight the common sources of these conjugated fatty acids, including plants, algae, microbes and chemosynthesis.

Preparation and immunological properties of procaine-protein conjugates

International Nuclear Information System (INIS)

Liakopoulou, A.

1981-01-01

Procaine was conjugated to BSA and rat and rabbit Gf using the carbodiimide method and 14 C-procaine as tracer. The composition of the conjugates could be varied depending on the time of incubation and the concentration of procaine in the reaction mixtures. Procaine-BSA conjugates were soluble in water or saline. However, procaine conjugates to rat or rabbit Gf were not readily soluble in saline. These conjugates were good for immunization purposes, but it was cumbersome to work with them when clear solutions were needed, as in the immunochemical procedures used in this study. The immunological properties of the conjugates were studied in rats and rabbits. Rats responded with production of IgGa and precipitating antibodies to the procaine group, but IgE antibodies to the immunogen could not be detected. Furthermore, precipitating antibodies towards the procaine group were raised in rabbits. When BSA was the protein carrier, antibodies to the carrier molecule were also detected in both rats and rabbits. The conjugates of procaine to rat or rabbit Gf did not elicit antibody response to the carrier molecule when used in the homologous species. Hapten inhibition studies suggested that, in the rabbit, antibodies were also produced with specificity directed towards the molecular configuration of the hapten-carrier bond. (author)

IRDye78 Conjugates for Near-Infrared Fluorescence Imaging

Directory of Open Access Journals (Sweden)

Atif Zaheer

2002-10-01

Full Text Available The detection of human malignancies by near-infrared (NIR fluorescence will require the conjugation of cancer-specific ligands to NIR fluorophores that have optimal photoproperties and pharmacokinetics. IRDye78, a tetra-sulfonated heptamethine indocyanine NIR fluorophore, meets most of the criteria for an in vivo imaging agent, and is available as an N-hydroxysuccinimide ester for conjugation to low-molecular-weight ligands. However, IRDye78 has a high charge-to-mass ratio, complicating purification of conjugates. It also has a potentially labile linkage between fluorophore and ligand. We have developed an ion-pairing purification strategy for IRDye78 that can be performed with a standard C18 column under neutral conditions, thus preserving the stability of fluorophore, ligand, and conjugate. By employing parallel evaporative light scatter and absorbance detectors, all reactants and products are identified, and conjugate purity is maximized. We describe reversible and irreversible conversions of IRDye78 that can occur during sample purification, and describe methods for preserving conjugate stability. Using seven ligands, spanning several classes of small molecules and peptides (neutral, charged, and/or hydrophobic, we illustrate the robustness of these methods, and confirm that IRDye78 conjugates so purified retain bioactivity and permit NIR fluorescence imaging of specific targets.

Production of medical short-lived radionuclides in Canada

International Nuclear Information System (INIS)

Wiebe, L.I.

1985-01-01

The production of radionuclides for medical and biomedical research in Canada has been reviewed with respect to the national geographic and demographic characteristics which influence their use. The types of facilities available for the production of short-lived radionuclides have been summarized, and a tabulation of the radionuclides that are produced has been presented. In broad terms production facilities can be classified as belonging to one of two groups, nuclear reactor or charged-particle accelerators. The charged-particle accelerators produce the more neutron-deficient and (because of the resultant decay properties) the more useful radionuclides for medical application. The nuclear reactor facilities for radionuclide production range in size and capacity from the high-flux research reactors of AECL to the six SLOWPOKE reactors, five of which are located on university campuses across the country. The McMaster University reactor is used to produce curie quantities of fluorine-18 weekly. Millicurie amounts of a large number of radionuclides, most of which have half-lives ranging from 2 to 50 hr, are produced in the low-flux reactors, in support of basic medical research

Simulation of radionuclide transport in U.S. agriculture

International Nuclear Information System (INIS)

Sharp, R.D.; Baes, C.F. III.

1982-01-01

Because of the recent concern about the impact of energy technologies on man and related health effects, there has emerged a need for models to calculate or predict the effects of radionuclides on man. A general overview is presented of a model that calculates the ingrowth of radionuclides into man's food chain. The FORTRAN IV computer program TERRA, Transport of Environmentally Released Radionuclides in Agriculture, simulates the build-up of radionuclides in soil, four plant food compartments, in meat and milk from beef, and in the livestock food compartments that cause radionuclide build-up in milk and meat from beef. A large data set of spatially oriented parameters has been developed in conjunction with TERRA. This direct-access data set is called SITE, Specific Information on the Terrestrial Environment, and contains 35 parameters for each of 3525 half-degree longitude-latitude cells which define the lower 48 states. TERRA and SITE are used together as a package for determining radionuclide concentrations in man's food anywhere within the conterminous 48 states due to atmospheric releases

Assessment of the important radionuclides in nuclear waste

International Nuclear Information System (INIS)

Kerrisk, J.F.

1985-10-01

The relative importance of the various radionuclides contained in nuclear waste has been assessed by consideration of (1) the quantity of each radionuclide present, (2) the Environmental Protection Agency's release limits for radionuclides, (3) how retardation processes such as solubility and sorption affect radionuclie transport, and (4) the physical and chemical forms of radionuclides in the waste. Three types of waste were reviewed: spent fuel, high-level waste, and defense high-level waste. Conditions specific to the Nevada Nuclear Waste Storage Investigations project potential site at Yucca Mountain were used to describe radionuclide transport. The actinides Am, Pu, Np, and U were identified as the waste elements for which solubility and sorption data were most urgently needed. Other important waste elements were identified as Sr, Cs, C, Ni, Zr, Tc, Th, Ra, and Sn. Under some conditions, radionuclides of three elements (C, Tc, and I) may have high solubility and negligible sorption. The potential for transport of some waste elements (C and I) in the gas phase must also be evaluated for the Yucca Mountain Site. 12 refs., 17 tabs

Radionuclide Retention in Concrete Wasteforms - FY13

Energy Technology Data Exchange (ETDEWEB)

Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

2013-10-15

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

International Nuclear Information System (INIS)

Franzi, J.J.

1985-01-01

Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal

Induction of a M/sub r/ 21,000 polypeptide in an Arthrobacter Sp. by dye-sensitized photooxidation

Energy Technology Data Exchange (ETDEWEB)

Franzi, J.J.

1985-01-01

Irradiation of aerobic cultures of an Arthrobacter species with near-UV light and oxygen induced synthesis of a cell surface protein, M/sub r/ 21,000 polypeptide. Visible light, oxygen and a sensitizing dye were also effective in induction. Far-UV light, bleomycin and nalidixic acid, all inducers of the recA protein in Escherichia coli, were ineffective inducers of this protein. Furthermore, X-irradiation and radical-generating oxidants failed to induce synthesis of the M/sub r/ 21,000 polypeptide. DNA binding dyes proved to be capable of inducing synthesis of this protein or inhibiting dye-mediated stimulation of synthesis of this protein. For example, dGdC-specific dyes (e.g. methylene blue, neutral red, acridine orange or ethidium bromide) were efficient inducers of the M/sub r/ 21,000 polypeptide. Also methylene blue and neutral red were more efficient inducers than were acridine orange or ethidium bromide, which could be explained by the greater dGdC specificity and, possibly by the greater photoreactivity of methylene blue and neutral red. dAdT-specific dyes such as methyl green or daunomycin effectively inhibited dye-mediated induction. Rose bengal is an anionic dye which does not bind to DNA but does mediate the photooxidation of deoxyguanosine residues in DNA. It is an efficient inducer of the M/sub r/ 21,000 polypeptide. Induction with this dye is nearly eliminated when novobiocin, an inhibitor of DNA gyrase (topoisomerase II) which mediates relaxation, is added in conjunction with rose bengal.

21 CFR 892.1390 - Radionuclide rebreathing system.

Science.gov (United States)

2010-04-01

... gaseous or volatile radionuclide or a radionuclide-labeled aerosol and permit it to be respired by the patient during nuclear medicine ventilatory tests (testing process of exchange between the lungs and the...

Naturally occurring radionuclides in agricultural products: An overview

International Nuclear Information System (INIS)

Hanlon, E.A.

1994-01-01

Low levels of naturally occurring radionuclides exist in phosphatic clays, a by-product of phosphatic mining and beneficiation processes. Concerns about these radionuclides entering the human food chain were an immediate research priority before the phosphate clays could be reclaimed for intensive agricultural purposes. Efforts included the assembly of a large body of data from both sons and plants, part of which were produced by the Polk County (Florida) Mined Lands Agricultural Research/Demonstration Project MLAR/DP. Additional detailed studies involving dairy and beef cattle (Bos taurus) were conducted by researchers working with the MLAR/DP. A national symposium was conducted in which data concerning the MLAR/DP work and other research projects also dealing with naturally occurring radionuclides in agriculture could be discussed. The symposium included invited review papers dealing with the identification of radionuclide geological origins, the geochemistry and movement of radionuclides within the environment, mechanisms of plant uptake, entry points into the food chain, and evaluation of dose and risk assessment to the consumer of low levels of radionuclides. The risk to human health of an individual obtaining 0.1 of his or her dietary intake from crops produced on phosphatic clays increased by 1 in 5 x 10 6 /yr above a control individual consuming no food grown on phosphatic clays. Leaf tissues were found to be generally higher than fruit, grain, or root tissues. The natural range in radionuclide content among various food types was greater than the difference in radionuclides content between the same food produced on phosphatic clays vs. natural soils. 19 refs

Internal radiotherapy and dosimetric study for 111In/177Lu-pegylated liposomes conjugates in tumor-bearing mice

International Nuclear Information System (INIS)

Wang, H.-E.; Yu, H.-M.; Lu, Y.-C.; Heish, N.-N.; Tseng, Yun-Long; Huang, K.-L.; Chuang, K.-T.; Chen, Chin-Hsiung; Hwang, J.-J.; Lin, W.-J.; Wang, Shyh-Jen; Ting, G.; Whang-Peng, Jacqueline; Deng, W.-P.

2006-01-01

In vivo characterization and dosimetric analysis has been performed to evaluate the potential of pegylated liposomes as carriers of radionuclides in tumor internal radiotherapy. Methods: The DTPA/PEG-liposomes were synthesized with a medium size of 110 nm, conjugated with 111 In/ 177 Lu-(oxine) 3 to afford 111 In/ 177 Lu-liposome. The stability of 111 In/ 177 Lu-liposome in serum was investigated. The biodistribution, scintigraphic imaging and pharmacokinetics of 111 In/ 177 Lu-liposomes after intravenous(i.v.) injection into C-26 tumor-bearing BALB/cByJ mice were studied. Radiation dose was estimated by MIRD-III program. Results: The incorporation efficiency of 111 In/ 177 Lu into liposomes was 95%. After incubation at 37 o C for 72 h in serum, more than 83% of radioactivity was still retained in the intact 111 In/ 177 Lu-liposomes. The biodistribution of 111 In-liposomes showed that the radioactivity in the blood decreased from 23.14±8.16%ID/g at 1 h to 0.02±0.00%ID/g at 72 h post-injection (p.i.), while reaching its maximum accumulation in tumors at 48 h p.i., with half-life in blood of 10.2 h. The results were supported by that of 177 Lu-liposomes. Scintigraphic imaging with 111 In-liposomes showed unambiguous tumor images at 48 h p.i. Dose estimation showed that the absorbed dose in tumor from 177 Lu-liposomes was 5.74x10 -5 Gy/MBq. Conclusions: This study provides an in vivo characterization and dosimetric evaluation for the use of liposome systems as carriers in targeted radionuclide therapy. The results suggest that adequate tumor targeting as well as dose delivered to tumors could be achieved by the use of radionuclide targeted liposomes

Migration of radionuclides through a river system

Energy Technology Data Exchange (ETDEWEB)

Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1999-03-01

Migration behavior of several atmospherically-derived radionuclides in a river watershed was studied. A main interest was in their relocation from the ground soil of the watershed to a downstream region through a river. Studied radionuclides are: {sup 137}Cs generated by weapon tests in the atmosphere; {sup 210}Pb and {sup 7}Be of naturally occurring radionuclides; {sup 137}Cs, {sup 90}Sr, {sup 239,240}Pu and {sup 241}Am released by the Chernobyl nuclear power plant accident. Dominance of the form in suspended solid in river water (particulate form) was qualified for the radionuclides in the Kuji river watershed. An importance of discharge in flooding was also confirmed. A historical budget analysis for weapon test derived {sup 137}Cs was presented for the Hi-i river watershed and its accompanied lake sediment (Lake Shinji). The work afforded a scheme of a fate of {sup 137}Cs after falling on the ground soil and on the lake surface. Several controlling factors, which can influence on the chemical form of radionuclides discharged to a river, were also investigated in the vicinity of the Chernobyl nuclear power plant. A special attention was paid on the association of the radionuclides with dissolved species in water. Preferential association of Pu and Am isotopes to a large molecular size of dissolved matrices, probably of humic substances, was suggested. (author)

Preconditioning the modified conjugate gradient method ...

African Journals Online (AJOL)

In this paper, the convergence analysis of the conventional conjugate Gradient method was reviewed. And the convergence analysis of the modified conjugate Gradient method was analysed with our extension on preconditioning the algorithm. Convergence of the algorithm is a function of the condition number of M-1A.

Mathematical simulation of sediment and radionuclide transport in estuaries

International Nuclear Information System (INIS)

Onishi, Y.; Trent, D.S.

1982-11-01

The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions

Online estimation of radionuclide transportation in water environment

International Nuclear Information System (INIS)

Yi-Jing Zhang; Li-Sheng Hu

2017-01-01

Transportation evaluation of the radionuclide waste discharged from nuclear power plants is an essential licensing issue, especially for inland sites. Basically, the dynamics of radionuclide transportation are nonlinear and time-varying. Motivated by its time-consuming computation, the work proposed an online estimation method for the radionuclide waste in water surface. After extracting the nonlinearity of factors influencing radionuclide transportation, the method utilizes transfer function and generalized autoregressive conditional heteroskedasticity models to perform deterministic and probabilistic estimations. It turns out that, the resulting predictions show high accuracy and can optimize the online discharge management of radioactive waste for nuclear power plants. (author)

Radionuclide examinations

International Nuclear Information System (INIS)

Lentle, B.C.

1989-01-01

This paper reports on radionuclide examinations of the pancreas. The pancreas, situated retroperitonally high in the epigastrium, was a particularly difficult organ to image noninvasively before ultrasonography and computed tomography (CT) became available. Indeed the organ still remains difficult to examine in some patients, a fact reflected in the variety of methods available to evaluate pancreatic morphology. It is something of a paradox that the pancreas is metabolically active and physiologically important but that its examination by radionuclide methods has virtually ceased to have any role in day-to-day clinical practice. To some extent this is caused by the tendency of the pancreas's commonest gross diseases emdash carcinoma and pancreatitis, for example emdash to result in nonfunction of the entire organ. Disorders of pancreatic endocrine function have generally not required imaging methods for diagnosis, although an understanding of diabetes mellitus and its nosology has been advanced by radioimmunoassay of plasma insulin concentrations

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Howard, B.J.; Kennedy, V.H.; Nelson, A.

1983-06-01

A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)

Quantitative assessments of the distinct contributions of polypeptide backbone amides versus sidechain groups to chain expansion via chemical denaturation

Science.gov (United States)

Holehouse, Alex S.; Garai, Kanchan; Lyle, Nicholas; Vitalis, Andreas; Pappu, Rohit V.

2015-01-01

In aqueous solutions with high concentrations of chemical denaturants such as urea and guanidinium chloride (GdmCl) proteins expand to populate heterogeneous conformational ensembles. These denaturing environments are thought to be good solvents for generic protein sequences because properties of conformational distributions align with those of canonical random coils. Previous studies showed that water is a poor solvent for polypeptide backbones and therefore backbones form collapsed globular structures in aqueous solvents. Here, we ask if polypeptide backbones can intrinsically undergo the requisite chain expansion in aqueous solutions with high concentrations of urea and GdmCl. We answer this question using a combination of molecular dynamics simulations and fluorescence correlation spectroscopy. We find that the degree of backbone expansion is minimal in aqueous solutions with high concentrations denaturants. Instead, polypeptide backbones sample conformations that are denaturant-specific mixtures of coils and globules, with a persistent preference for globules. Therefore, typical denaturing environments cannot be classified as good solvents for polypeptide backbones. How then do generic protein sequences expand in denaturing environments? To answer this question, we investigated the effects of sidechains using simulations of two archetypal sequences with amino acid compositions that are mixtures of charged, hydrophobic, and polar groups. We find that sidechains lower the effective concentration of backbone amides in water leading to an intrinsic expansion of polypeptide backbones in the absence of denaturants. Additional dilution of the effective concentration of backbone amides is achieved through preferential interactions with denaturants. These effects lead to conformational statistics in denaturing environments that are congruent with those of canonical random coils. Our results highlight the role of sidechain-mediated interactions as determinants of the

Status report on radionuclide transfer

International Nuclear Information System (INIS)

1980-01-01

At the suggestion of the Federal Minstry of the Interior, in June 1978, a group of scientists from several institutions who are active in the field of radionuclide transfer or are interested in these problems got together. During the discussions of the work team, especially the transfer soil/plants was emphasized. Then the work team set up a status report on the transfer of the radionuclides relevant in the sense of the radiation protection act. The nuclides H 3 and C14, the isotopes of the Sr, J, and Cs, Tc99, the so-called corrosion nuclides Mn54, Fe59, co-isotopes and Zn65, and isotopes of Pu, Am, and Cm were regarded as important for a possible radiation exposition. Recent investigations revealed that also the natural radionuclides Ra226, Po210, and Pb210 should be covered by the investigations. The goal of this status report is to present the level of knowledge on the transfer of these radionuclides to man in a brief form, giving hints at the most important literature. It was requested by the Federal Ministry of the Interior, as fas as possible, to indicate transfer factors which are necessary for the radio-occology act to be decreed according to Para. 45 of the radiation protection act. Another goal of the report was to show the gap in the knowledge on the radio nuclide transfer. This was thought to help to create a basis for the decisions of the Federal Ministry concerning the support of other investigation projects in the field of transfer of radionuclides. (orig./MG) [de

The fate and importance of radionuclides produced in nuclear events

Energy Technology Data Exchange (ETDEWEB)

Shore, B; Anspaugh, L; Chertok, R; Gofman, J; Harrison, F; Heft, R; Koranda, J; Ng, Y; Phelps, P; Potter, G; Tamplin, A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1969-07-01

Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

The fate and importance of radionuclides produced in nuclear events

International Nuclear Information System (INIS)

Shore, B.; Anspaugh, L.; Chertok, R.; Gofman, J.; Harrison, F.; Heft, R.; Koranda, J.; Ng, Y.; Phelps, P.; Potter, G.; Tamplin, A.

1969-01-01

Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

99mTC-dextran-antibody conjugates. Labelling procedures

International Nuclear Information System (INIS)

Marquez, M.; Westlin, J.E.; Nilsson, S.; Holmberg, A.R.

1996-01-01

Dextran forms stable chelates with 99m Tc, a radionuclide with ideal properties for planar scintigraphic and tomographic imaging. This study investigates some of the factors of importance to the formation of 99m Tc-dextran. The complex was used for the technetium labelling of a monoclonal antibody. Two radiolabelling methods were studied: Direct dextran labelling with the reductant dissolved in HCl and labelling via a weak 'transfer' chelator (tartaric acid) with the reductant dissolved in ethanol. Different conditions during the labelling reaction were studied. Finally, dextran was coupled to a monoclonal anticytokeratin antibody and the conjugate was subsequently radiolabelled with 99m Tc. Gel filtration (GFR) and thin layer chromatography (TLC) were compared as methods for estimation of the labelling efficiency. When using 10-500 μM of ligand, 5-100 μM SnC1 2 with 10-500 MBq of technetium at pH7 incubated for 10-15 min, the radiolabelling seemed optimal (70-75% labelling efficiency). It was found that 100 μM tartaric acid used as a weak intermediate chelator with SnCl 2 dissolved in ethanol improved the reproducibility of the labelling. The labelling efficiency was not affected by either the presence of oxygen or the addition of an oxygen scavenger during the labelling incubation. In general, TLC showed higher labelling efficiencies than GFR, indicating inadequate separation of the different moieties. (orig.)

Migration of radionuclides in geologic media: Fundamental research needs

International Nuclear Information System (INIS)

Reed, D.T.; Zachara, J.M.; Wildung, R.E.; Wobber, F.J.

1990-01-01

An assessment of the fundamental research needs in understanding and predicting the migration of radionuclides in the subsurface is provided. Emphasis is on the following three technical areas: (1) aqueous speciation of radionuclides, (2) the interaction of radionuclides with substrates, and (3) intermediate-scale interaction studies. This research relates to important issues associated with environmental restoration and remediation of DOE sites contaminated with mixed radionuclide-organic wastes. 64 refs., 1 fig., 1 tab

Radiopharmaceuticals and other compounds labelled with short-lived radionuclides

CERN Document Server

Welch, Michael J

2013-01-01

Radiopharmaceuticals and Other Compounds Labelled with Short-Lived Radionuclides covers through both review and contributed articles the potential applications and developments in labeling with short-lived radionuclides whose use is restricted to institutions with accelerators. The book discusses the current and potential use of generator-produced radionuclides as well as other short-lived radionuclides, and the problems of quality control of such labeled compounds. The book is useful to nuclear medicine physicians.

Radionuclides incorporation in activated natural nanotubes

International Nuclear Information System (INIS)

Silva, Jose Parra

2016-01-01

Natural palygorskite nanotubes show suitable physical and chemical properties and characteristics to be use as potential nanosorbent and immobilization matrix for the concentration and solidification of radionuclides present in nuclear wastes. In the development process of materials with sorption properties for the incorporation and subsequent immobilization of radionuclides, the most important steps are related with the generation of active sites simultaneously to the increase of the specific surface area and suitable heat treatment to producing the structural folding. This study evaluated the determining parameters and conditions for the activation process of the natural palygorskite nanotubes aiming at the sorption of radionuclides in the nanotubes structure and subsequent evaluation of the parameters involve in the structural folding by heat treatments. The optimized results about the maximum sorption capacity of nickel in activated natural nanotubes show that these structures are apt and suitable for incorporation of radionuclides similar to nickel. By this study is verified that the optimization of the acid activation process is fundamental to improve the sorption capacities for specifics radionuclides by activated natural nanotubes. Acid activation condition optimized maintaining structural integrity was able to remove around 33.3 wt.% of magnesium cations, equivalent to 6.30·10 -4 g·mol -1 , increasing in 42.8% the specific surface area and incorporating the same molar concentration of nickel present in the liquid radioactive waste at 80 min. (author)

100 Years of radionuclide metrology

International Nuclear Information System (INIS)

Judge, S.M.; Arnold, D.; Chauvenet, B.; Collé, R.; De Felice, P.; García-Toraño, E.; Wätjen, U.

2014-01-01

The discipline of radionuclide metrology at national standards institutes started in 1913 with the certification by Curie, Rutherford and Meyer of the first primary standards of radium. In early years, radium was a valuable commodity and the aim of the standards was largely to facilitate trade. The focus later changed to providing standards for the new wide range of radionuclides, so that radioactivity could be used for healthcare and industrial applications while minimising the risk to patients, workers and the environment. National measurement institutes responded to the changing demands by developing new techniques for realising primary standards of radioactivity. Looking ahead, there are likely to be demands for standards for new radionuclides used in nuclear medicine, an expansion of the scope of the field into quantitative imaging to facilitate accurate patient dosimetry for nuclear medicine, and an increasing need for accurate standards for radioactive waste management and nuclear forensics. - Highlights: • The driving forces for the development of radionuclide metrology. • Radium standards to facilitate trade of this valuable commodity in the early years. • After 1950, focus changes to healthcare and industrial applications. • National Measurement Institutes develop new techniques, standards, and disseminate the best practice in measurement. • Challenges in nuclear medicine, radioactive waste management and nuclear forensics

Underground radionuclide migration at the Nevada Test Site

International Nuclear Information System (INIS)

Nimz, G.J.; Thompson, J.L.

1992-01-01

This document reviews results from a number of studies concerning underground migration of radionuclides from nuclear test cavities at the Nevada Test Site (NTS). Discussed are all cases known to the Department of Energy's Hydrology and Radionuclide Migration Program where radionuclides have been detected outside of the immediate vicinity of nuclear test cavities that are identifiable as the-source of the nuclides, as well as cases where radionuclides might have been expected and were intentionally sought but not fixed. There are nine locations where source-identifiable radionuclide migration has been detected, one where migration was purposely induced by pumping, and three where migration might be expected but was not found. In five of the nine cases of non-induced migration, the inferred migration mechanism is prompt fracture injection during detonation. In the other four cases, the inferred migration mechanism is water movement. In only a few of the reviewed cases can the actual migration mechanism be stated with confidence, and the attempt has been made to indicate the level of confidence for each case. References are cited where more information may be obtained. As an aid to future study, this document concludes with a brief discussion of the aspects of radionuclide migration that, as the present review indicates, are not yet understood. A course of action is suggested that would produce a better understanding of the phenomenon of radionuclide migration

Doxorubicin conjugated to D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS): conjugation chemistry, characterization, in vitro and in vivo evaluation.

Science.gov (United States)

Cao, Na; Feng, Si-Shen

2008-10-01

To develop a polymer-anticancer drug conjugate, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was employed as a carrier of doxorubicin (DOX) to enhance its therapeutic effects and reduce its side effects. Doxorubicin was chemically conjugated to TPGS. The molecular structure, drug loading efficiency, drug release kinetics and stability of the conjugate were characterized. The cellular uptake, intracellular distribution, and cytotoxicity were accessed by using MCF-7 breast cancer cells and C6 glioma cells as in vitro cell model. The conjugate showed higher cellular uptake efficiency and broader distribution within the cells. Judged by IC(50), the conjugate was found 31.8, 69.6, 84.1% more effective with MCF-7 cells and 43.9, 87.7, 42.2% more effective with C6 cells than the parent drug after 24, 48, 72 h culture, respectively. The in vivo pharmacokinetics and biodistribution were investigated after an i.v. administration at 5 mg DOX/kg body weight in rats. Promisingly, 4.5-fold increase in the half-life and 24-fold increase in the area-under-the-curve (AUC) of DOX were achieved for the TPGS-DOX conjugate compared with the free DOX. The drug level in heart, gastric and intestine was significantly reduced, which is an indication of reduced side effects. Our TPGS-DOX conjugate showed great potential to be a prodrug of higher therapeutic effects and fewer side effects than DOX itself.

Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

Science.gov (United States)

Liu, Ying; Liu, Xiaoheng; Wang, Xin

2011-12-01

Herein, the generation of gold, silver, and silver-gold (Ag-Au) bimetallic nanoparticles was carried out in collagen (gelatin) solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV-visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure) into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device.

Effect of Sequence Blockiness on the Morphologies of Surface-grafted Elastin-like Polypeptides

Science.gov (United States)

Albert, Julie; Sintavanon, Kornkanok; Mays, Robin; MacEwan, Sarah; Chilkoti, Ashutosh; Genzer, Jan

2014-03-01

The inter- and intra- molecular interactions among monomeric units of copolymers and polypeptides depend strongly on monomer sequence distribution and dictate the phase behavior of these species both in solution and on surfaces. To study the relationship between sequence and phase behavior, we have designed a series of elastin-like polypeptides (ELPs) with controlled monomer sequences that mimic copolymers with various co-monomer sequence distributions and attached them covalently to silicon substrates from buffer solutions at temperatures below and above the bulk ELPs' lower critical solution temperatures (LCSTs). The dependence of ELP grafting density on solution temperature was examined by ellipsometry and the resultant surface morphologies were examined in air and under water with atomic force microscopy. Depositions performed above the LCST resulted in higher grafting densities and greater surface roughness of ELPs relative to depositions carried out below the LCST. In addition, we are using gradient substrates to examine the effect of ELP grafting density on temperature responsiveness.

21 CFR 892.5700 - Remote controlled radionuclide applicator system.

Science.gov (United States)

2010-04-01

... radionuclide applicator system. (a) Identification. A remote controlled radionuclide applicator system is an... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Remote controlled radionuclide applicator system... include patient and equipment supports, component parts, treatment planning computer programs, and...

Serological Reactivity and Identification of Immunoglobulin E-Binding Polypeptides of Ganoderma applanatum Crude Spore Cytoplasmic Extract in Puerto Rican Subjects.

Science.gov (United States)

Vilá-Héreter, Frances; Rivera-Mariani, Félix E; Bolaños-Rosero, Benjamín

2017-01-01

The allergenic potential of Ganoderma applanatum basidiospores has been demonstrated previously in Puerto Rico. However, basidiomycete allergens are not available for inclusion in allergy diagnostic panels. Therefore, we sought to confirm allergic sensitization to G. applanatum crude spore cytoplasmic extract through reactivity in serological assays and detection of immunoglobulin E (IgE)-binding polypeptides. Via an indirect ELISA, serological reactivity was compared between groups of individuals with different allergic profiles. Group 1 (n = 51) consisted of individuals with sIgE to the allergens included in the diagnostic panels; group 2 (n = 14) comprised individuals with no sIgE to the allergens tested; and group 3 (n = 22) included individuals with no allergic history. To visualize IgE-binding polypeptides, group 1 sera were examined via Western blotting (WB). Polypeptide bands with the highest reactivity were analyzed by mass spectrometry (MS) for putative identification. The serological reactivity of group 1 was significantly higher than that of group 3 in an indirect ELISA (p = 0.03). Sixty-five percent of group 1 individuals showed reactivity to polypeptide bands in WB. Bands of 81 and 56 kDa had the highest reactivity proportions among the reactive sera, followed by a 45-kDa band. MS analysis of these 3 polypeptides suggests that they are basidiomycete-derived enzymes with aconitate hydratase, catalase, and enolase functions. G. applanatum spores have allergenic components recognized by Puerto Rican individuals, which could eventually be considered as markers in cases of fungal allergy and be included in diagnostic allergen panels in Puerto Rico and tropical regions. © 2017 S. Karger AG, Basel.

Accelerated evolution of the pituitary adenylate cyclase-activating polypeptide precursor gene during human origin

DEFF Research Database (Denmark)

Wang, Yin-Qiu; Qian, Ya-Ping; Yang, Su

2005-01-01

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide abundantly expressed in the central nervous system and involved in regulating neurogenesis and neuronal signal transduction. The amino acid sequence of PACAP is extremely conserved across vertebrate species, indicating a...

The contamination of the oceans by anthropogenic radionuclides

International Nuclear Information System (INIS)

Figueira, Rubens C.L.; Cunha, Ieda I.L.

1998-01-01

Several hundreds of artificial of artificial radionuclides are produced as the result of human activities, such as the applications of nuclear reactors and particle accelerators, testing of nuclear weapons and nuclear accidents. Many of these radionuclides are short-lived and decay quickly after their production, but some of them are longer-lived and are released into the environment. From the radiological point of view the most important radionuclides are cesium-137, strontium-90 and plutonium-239, due to their chemical and nuclear characteristics. The two first radioisotopes present long half life (30 and 28 years), high fission yields and chemical behaviour similar to potassium and calcium, respectively. No stable element exists for plutonium-239, that presents high radiotoxity, longh half-life (24000 years) and some marine organisms accumulate plutonium at high levels. The radionuclides introduced into marine environment undergo various physical, chemical and biological processes taking place in the sea. These processes may be due to physical, dispersion or complicated chemical and biological interactions of the radionuclides with inorganic and organic suspend matter, variety of living organism, bottom sediments, etc. The behaviour of radionuclides in the sea depends primarily on their chemical properties, but it may also be influenced by properties of interacting matrices and other environmental factors. The major route of radiation exposure of man to artificial radionuclides occuring in the marine environment is through ingestion of radiologically contamined marine organisms. This paper summarizes the main sources of contamination in the marine environment and presents an overview covering the oceanic distribution of anthropogenic radionuclides in the FAO regions. A great number of measurements of artificial radioclides have been carried out on various marine environmental samples in different oceans over the world, being cesium-137 the most widely measured

Radionuclide examination in rheumatology

International Nuclear Information System (INIS)

Streda, A.; Kolar, J.; Valesova, M.

1984-01-01

On the basis of twenty years of experience with the use of radionuclides in bone and articular rheumatic diseases indications for such examinations are summed up. The main advantage of the use of radionuclide methods is that they bring forward early diagnosis of tissue reconstruction which can thus be detected at the stage of microstructural changes. They also provide earlier and more reliable detection of the degree of the pathological process than is provided by X-ray examination. In some cases scintiscan may also be found useful as a method for following up the results of treatment of rheumatic diseases. (author)

Solubility limited radionuclide transport through geologic media

International Nuclear Information System (INIS)

Muraoka, Susumu; Iwamoto, Fumio; Pigford, T.H.

1980-11-01

Prior analyses for the migration of radionuclides neglect solubility limits of resolved radionuclide in geologic media. But actually some of the actinides may appear in chemical forms of very low solubility. In the present report we have proposed the migration model with no decay parents in which concentration of radionuclide is limited in concentration of solubility in ground water. In addition, the analytical solutions of the space-time-dependent concentration are presented in the case of step release, band release and exponential release. (author)

Radionuclide determination of right and left ventricular stroke volumes

Energy Technology Data Exchange (ETDEWEB)

Shen, Wei Feng; Roubin, G S; Choong, C Y.P.; Harris, P J; Flether, P J; Kelly, D T; Uren, R F; Hutton, B F

1985-03-01

The relationship between radionuclide and thermodilution measurement of stroke volumes (SV) was investigated in 30 patients without valvular regurgitation or intracardiac shunt (group A) at rest and during exercise. Both attenuated radionuclide right ventricular (RV) and left ventricular (LV) SV measurements correlated well with the SV determined by the thermodilution method (r = 0.87 and r = 0.93, all P < 0.001). The reliability of the radionuclide method to estimate SV was evaluated prospectively in two additional groups of patients. In 11 patients without valvular regurgitation or intracardiac shunt (group B) the radionuclide RVSV and LVSV closely approximated to thermodilution SV at rest and during exercise. In 15 patients with aortic regurgitation (group C) the radionuclide stroke volume ratio correlated well with the angiographic regurgitant fraction. Thus, both RVSV and LVSV and the severity of aortic regurgitation can be reliably measured with gated radionuclide ventriculography.

Methods for determining radionuclide retardation factors: status report

International Nuclear Information System (INIS)

Relyea, J.F.; Serne, R.J.; Rai, D.

1980-04-01

This report identifies a number of mechanisms that retard radionuclide migration, and describes the static and dynamic methods that are used to study such retardation phenomena. Both static and dynamic methods are needed for reliable safety assessments of underground nuclear-waste repositories. This report also evaluates the extent to which the two methods may be used to diagnose radionuclide migration through various types of geologic media, among them unconsolidated, crushed, intact, and fractured rocks. Adsorption is one mechanism that can control radionuclide concentrations in solution and therefore impede radionuclide migration. Other mechanisms that control a solution's radionuclide concentration and radionuclide migration are precipitation of hydroxides and oxides, oxidation-reduction reactions, and the formation of minerals that might include the radionuclide as a structural element. The retardation mechanisms mentioned above are controlled by such factors as surface area, cation exchange capacity, solution pH, chemical composition of the rock and of the solution, oxidation-reduction potential, and radionuclide concentration. Rocks and ground waters used in determining retardation factors should represent the expected equilibrium conditions in the geologic system under investigation. Static test methods can be used to rapidly screen the effects of the factors mentioned above. Dynamic (or column) testing, is needed to assess the effects of hydrodynamics and the interaction of hydrodynamics with the other important parameters. This paper proposes both a standard method for conducting batch Kd determinations, and a standard format for organizing and reporting data. Dynamic testing methods are not presently developed to the point that a standard methodology can be proposed. Normal procedures are outlined for column experimentation and the data that are needed to analyze a column experiment are identified

Bis-polymer lipid-peptide conjugates and nanoparticles thereof

Energy Technology Data Exchange (ETDEWEB)

Xu, Ting; Dong, He; Shu, Jessica; Dube, Nikhil

2018-04-24

The present invention provides bis-polymer lipid-peptide conjugates containing a hydrophobic block and headgroup containing a helical peptide and two polymer blocks. The conjugates can self-assemble to form helix bundle subunits, which in turn assemble to provide micellar nanocarriers for drug cargos and other agents. Particles containing the conjugates and methods for forming the particles are also disclosed.

Research progess on treatment of cancer with targeted radionuclide therapy

International Nuclear Information System (INIS)

Luo Jiawen; Zhang Caixia

2008-01-01

The new development and situation of targeted radionuclide therapy in oncology is described, which include radioimmunotherapy, peptide receptor radionuclide therapy, gene therapy and radionuclide labled chemotherapeutics therapy. The application research on labled carrier of those therapy is emphasized. Meanwhile, the research progess of indomethacin and its combined with targeted radionuclide therapy is also described. (authors)

Radionuclide cisternographic findings in patients with spontaneous intracranial hypotension

International Nuclear Information System (INIS)

Jung, Dong Jin; Kim, Jae Seung; Ryu, Jin Sook; Shin, Jung Woo; Im, Joo Hyuk; Lee, Myoung Chong; Jung, Sung Joo; Moon, Dae Hyuk; Lee, Hee Kyung

1998-01-01

Radionuclide cisternography may be helpful in understanding pathophysiology of postural headache and low CSF pressure in patients with spontaneous intracranial hypotension. The purpose of this study was to characterize radionuclide cisternogrpahic findings of spontaneous intracranial hypotension. The study population consists of 15 patients with spontaneous intracranial hypotension. Diagnosis was based on their clinical symptoms and results of lumbar puncture. All patients underwent radionuclide cisternography following injection of 111 to 222 MBq of Tc-99m DTPA into the lumbar subarachnoid space. Sequential images were obtained between 1/2 hour and 24 hour after the injection of Tc-99m DTPA. Radioactivity of the bladder, soft tissue uptake, migration of radionuclide in the subarachnoid space, and extradural leakage of radionuclide were evaluated according to the scan time. Radionuclide cisternogram showed delayed migration of radionuclide into the cerebral convexity (14/15), increased soft tissue uptake (11/15), and early visualization of bladder activity at 30 min (6/10) and 2 hr (13/13). Cisternography also demonstrated leakage site of CSF in 4 cases and 2 of these were depicted at 30min. Epidural blood patch was done in 11 patients and headache was improved in all cases. The characteristics findings of spontaneous intracranial hypotension were delayed migration of radionuclide and early visualization of the soft tissue and bladder activity. These scintigraphic findings suggest that CSF leakage rather than increased CSF absorption or decreased production may be the main pathophysiology of spontaneous intracranial hypotension. Early and multiple imaging including the bladder and soft tissue is required to observe the entire dynamics of radionuclide migration

Fire fighting in a radionuclide laboratory

International Nuclear Information System (INIS)

Wenzel, H.

1991-01-01

A fire-brigade was called to a laboratory which held a handling licence for the radionuclides C-14, T, P-32, Se-75, Mo-99, and S-35. The fire-brigade was unaware of a release of radionuclides. Therefore they used respiratory equipment, and all persons present were subsequently examined for contamination. (DG) [de

Membrane polypeptide in rabbit erythrocytes associated with the inhibition of L-lactate transport by a synthetic anhydride of lactic acid

International Nuclear Information System (INIS)

Donovan, J.A.; Jennings, M.L.

1985-01-01

The synthetic lactyl anhydride isobutylcarbonyl lactyl anhydride (iBCLA), a selective and potent inhibitor of L-(+)-lactate transport in rabbit erythrocytes, reduces the chemical labeling of a 40-50-kdalton polypeptide by tritiated 4,4'-diisothiocyanato-2,2'-dihydrostilbenedisulfonate ([ 3 H]H 2 DIDS). iBCLA does so in a dose-dependent manner at concentrations that strongly inhibit lactate-lactate exchange but not chloride-phosphate exchange. These labeling experiments and inhibition reversal studies using iBCLA, p-(chloro-mercuri)benzenesulfonic acid (pCMBS), and dithiothreitol (DDT) suggest that iBCLA does not act at sulfhydryl groups but at or near an amino group that is near a disulfide linkage in the polypeptide which catalyzes lactate transport. These experiments support the association between specific monocarboxylate transport and a 40-50-kdalton membrane-bound polypeptide of the rabbit erythrocyte

Characterization of cell surface polypeptides of unfertilized, fertilized, and protease-treated zona-free mouse eggs

International Nuclear Information System (INIS)

Boldt, J.; Gunter, L.E.; Howe, A.M.

1989-01-01

The polypeptide composition of unfertilized, fertilized, and protease-treated zona-free mouse eggs was evaluated in this study. Zona-free eggs were radioiodinated by an Iodogen-catalyzed reaction. Light microscopic autoradiography of egg sections revealed that labeling was restricted to the cell surface. Labeled eggs were solubilized, and cell surface polypeptides were identified by one-dimensional SDS polyacrylamide gel electrophoresis and autoradiography. The unfertilized egg demonstrated 8-10 peptides that incorporated 125 I, with major bands observed at approximately 145-150, 94, and 23 kilodaltons (kD). Zona-free eggs fertilized in vitro and then radiolabeled demonstrated several new bands in comparison to unfertilized eggs, with a major band appearing at approximately 36 kD. Treatment of radiolabeled unfertilized eggs with either trypsin or chymotrypsin (1 mg/ml for 5-20 min) caused enzyme-specific modifications in labeled polypeptides. Trypsin (T) treatment resulted in time-dependant modification of the three major peptides at 145-150, 94, and 23 kD. Chymotrypsin (CT) treatment, in contrast, was associated with loss or modification of the 94 kD band, with no apparent effect on either the 145-150 or 23 kD band. Taken together with previous data indicating that T or CT egg treatment interferes with sperm-egg attachment and fusion, these results suggest a possible role for the 94 kD protein in sperm-egg interaction

Permissible annual depositions and radionuclide concentrations in air

International Nuclear Information System (INIS)

Belyaev, V.A.; Golovko, M.Yu.

1993-01-01

It is established that it necessary to take into account the other ways of radionuclide intake apart from the inhalation one when determining the standards for radionuclide contamination of the atmospheric air. Whereby it is proposed to standardize annual depositions rather than permissible concentration in the atmospheric air for the ways related to radionuclide releases on the ground surface, which is explained by ambiguity of their dry deposition rate from the air. Formulae and results of calculation of standard characteristics are presented. The permissible radionuclide depositions, related to the intake through food chains are calculated with account for diet diversity, agroclimatic and phenological parameters in different regions of the country

Understanding Radionuclide Interactions with Layered Materials

Science.gov (United States)

Wang, Y.

2015-12-01

Layered materials play an important role in nuclear waste management and environmental cleanup. Better understanding of radionuclide interactions with those materials is critical for engineering high-performance materials for various applications. This presentation will provide an overview on radionuclide interactions with two general categories of layered materials - cationic clays and anionic clays - from a perspective of nanopore confinement. Nanopores are widely present in layered materials, either as the interlayers or as inter-particle space. Nanopore confinement can significantly modify chemical reactions in those materials. This effect may cause the preferential enrichment of radionuclides in nanopores and therefore directly impact the mobility of the radionuclides. This effect also implies that conventional sorption measurements using disaggregated samples may not represent chemical conditions in actual systems. The control of material structures on ion exchange, surface complexation, and diffusion in layered materials will be systematically examined, and the related modeling approaches will be discussed. This work was performed at Sandia National Laboratories, which is a multiprogram laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the DOE under contract DE-AC04-94AL8500.

Radionuclide transport in a single fissure

International Nuclear Information System (INIS)

Eriksen, T.E.

1988-12-01

The study of radionuclide migration through rock is currently of great interest due to its relevance to the possible escape paths into the biosphere of radionuclides released from high level radioactive wastes burried in deep geological repositories. While water will provide the vehicle for transportation, interaction with geological material may greatly influence the radionuclide movement relative that of water. A flow system for laboratory studies of radionuclide transport in natural fissures in granitic rock under reducing conditions is described. The system based on the use of synthetic ground water equilibrated with granitic rock in a well sealed system, allow experiments to be carried out at -240 mV reduction potential. In flow experiments with technetium the retardation was found to be dependent on the method used for reducing TcO 4 - . The preparation of the tracer solutions is crucial, as some of the redox-reactions may be very slow. The dynamics of the Tc(VII) reduction and also speciation need to be carried out in separate experiments. (4 illustrations, 5 tables)

Radionuclide therapy practice and facilities in Europe

International Nuclear Information System (INIS)

Hoefnagel, C.A.; Clarke, S.E.M.; Fischer, M.; Chatal, J.F.; Lewington, V.J.; Nilsson, S.; Troncone, L.; Vieira, M.R.

1999-01-01

Using a questionnaire the EANM Task Group Radionuclide Therapy in 1993 collected data on the current practice of radionuclide therapy in European countries. Subsequently, at the request of the EANM Executive Committee, the EANM Radionuclide Therapy Committee has made an inventory of the distribution of facilities for radionuclide therapy and undertaken an assessment of the total number of patients treated throughout Europe and of the types of treatment provides, with the aim of supporting the development of policy to adjust the available capacity to the needs by the year 2000. For this purpose, a second, more detailed questionnaire was sent out the members and national advisors of the Committee (see below), who gathered the data for each country that was a member of the EANM at the time. It is concluded that a wide bariation in therapy practice exists across Europe, particularly in the utilisation of radionuclide therapy, the requirement and availability of proper isolation facilities and the background training of those undertaking therapy. More uniform guidelines and legislation are required, although changes in legislation may have a significant impact in some countries. Although there is wide variation in the therapies used in each country, one the whole it appears that there is an underutilisation of nuclear medicine as a therapeutic modality. A rapidly increasing role may be expected, in particular for oncological indications requiring high-dose radionuclide treatment. Therefore there is an urgent need for a greater number of isolation beds in dedicated centers throughout Europe

Pituitary adenylate cyclase-activating polypeptide stimulates renin secretion via activation of PAC1 receptors

DEFF Research Database (Denmark)

Hautmann, Matthias; Friis, Ulla G; Desch, Michael

2007-01-01

Besides of its functional role in the nervous system, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is involved in the regulation of cardiovascular function. Therefore, PACAP is a potent vasodilator in several vascular beds, including the renal vasculature. Because...

Conjugated polymer nanoparticles, methods of using, and methods of making

KAUST Repository

Habuchi, Satoshi; Piwonski, Hubert Marek; Michinobu, Tsuyoshi

2017-01-01

Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

Conjugated polymer nanoparticles, methods of using, and methods of making

KAUST Repository

Habuchi, Satoshi

2017-03-16

Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

Surface diffusion of sorbed radionuclides

International Nuclear Information System (INIS)

Berry, J.A.; Bond, K.A.

1991-01-01

Surface diffusion has in the past been invoked to explain rates of radionuclide migration which were greater than those predicted. Results were generally open to interpretation but the possible existence of surface diffusion, whereby sorbed radionuclides could potentially migrate at much enhanced rates, necessitated investigation. In this work through-diffusion experiments have shown that although surface diffusion does exist for some nuclides, the magnitude of the phenomenon is not sufficient to affect repository safety assessment modelling. (author)

DNA damage induced by radionuclide internal irradiation

International Nuclear Information System (INIS)

Cui Fengmei; Zhao Jingyong; Hong Chengjiao; Lao Qinhua; Wang Liuyi; Yang Shuqin

2004-01-01

Objective: To study the DNA damage of peripheral blood mononuclear cell (PBMC) in rats exposed to radionuclide internal irradiation. Methods: The radionuclides were injected into the rats and single cell get electrophoresis (SCGE) was performed to detect the length of DNA migration in the rat PBMC. Results: DNA migration in the rat PBMC increased with accumulative dose or dose-rate. It showed good relationship of dose vs. response and of dose-rate vs. response, both relationship could be described as linear models. Conclusion: Radionuclide internal irradiation could cause DNA damage in rat PBMC. (authors)

Radionuclide Basics: Iodine

Science.gov (United States)

... Centers Radiation Protection Contact Us Share Radionuclide Basics: Iodine Iodine (chemical symbol I) is a chemical element. ... in the environment Iodine sources Iodine and health Iodine in the Environment All 37 isotopes of iodine ...

40 CFR 141.66 - Maximum contaminant levels for radionuclides.

Science.gov (United States)

2010-07-01

... beta particle and photon radioactivity from man-made radionuclides in drinking water must not produce.../year). (2) Except for the radionuclides listed in table A, the concentration of man-made radionuclides... may make this technology too complex for small surface water systems. e Removal efficiencies can vary...

Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

Directory of Open Access Journals (Sweden)

Shinya Yano

2015-01-01

Full Text Available Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO. First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC, a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

Nonlinear conjugate gradient methods in micromagnetics

Directory of Open Access Journals (Sweden)

J. Fischbacher

2017-04-01

Full Text Available Conjugate gradient methods for energy minimization in micromagnetics are compared. The comparison of analytic results with numerical simulation shows that standard conjugate gradient method may fail to produce correct results. A method that restricts the step length in the line search is introduced, in order to avoid this problem. When the step length in the line search is controlled, conjugate gradient techniques are a fast and reliable way to compute the hysteresis properties of permanent magnets. The method is applied to investigate demagnetizing effects in NdFe12 based permanent magnets. The reduction of the coercive field by demagnetizing effects is μ0ΔH = 1.4 T at 450 K.

Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in Caco-2 cells

NARCIS (Netherlands)

Usta, M.; Wortelboer, H.M.; Vervoort, J.J.M.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, van P.J.; Cnubben, N.H.P.

2007-01-01

Curcumin, an alpha,beta-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional H-1 NMR

Wall-associated kinase-like polypeptide mediates nutritional status perception and response

Science.gov (United States)

Yang, Zhenbiao; Karr, Stephen

2014-02-11

The disclosure relates to methods for modulating plant growth and organogenesis using dominant-negative receptor-like kinases. The disclosure further provides a method for increasing plant yield relative to corresponding wild type plants comprising modulating the expression in a plant of a nucleic acid encoding a Wall-Associated Kinase-like 14 polypeptide or a homolog thereof, and selecting for plants having increased yield or growth on a nutrient deficient substrate.

Sustained Release of Antibiotics from Injectable and Thermally Responsive Polypeptide Depots

OpenAIRE

Adams, Samuel B.; Shamji, Mohammed F.; Nettles, Dana L.; Hwang, Priscilla; Setton, Lori A.

2009-01-01

Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to u...

Selective Covalent Conjugation of Phosphorothioate DNA Oligonucleotides with Streptavidin

Directory of Open Access Journals (Sweden)

Christof M. Niemeyer

2011-08-01

Full Text Available Protein-DNA conjugates have found numerous applications in the field of diagnostics and nanobiotechnology, however, their intrinsic susceptibility to DNA degradation by nucleases represents a major obstacle for many applications. We here report the selective covalent conjugation of the protein streptavidin (STV with phosphorothioate oligonucleotides (psDNA containing a terminal alkylthiolgroup as the chemically addressable linking unit, using a heterobifunctional NHS-/maleimide crosslinker. The psDNA-STV conjugates were synthesized in about 10% isolated yields. We demonstrate that the terminal alkylthiol group selectively reacts with the maleimide while the backbone sulfur atoms are not engaged in chemical conjugation. The novel psDNA-STV conjugates retain their binding capabilities for both biotinylated macromolecules and the complementary nucleic acid. Moreover, the psDNA-STV conjugate retained its binding capacity for complementary oligomers even after a nuclease digestion step, which effectively degrades deoxyribonucleotide oligomers and thus the binding capability of regular DNA-STV conjugates. The psDNA-STV therefore hold particular promise for applications e.g. in proteome research and novel biosensing devices, where interfering endogenous nucleic acids need to be removed from analytes by nuclease digestion.

Dye linked conjugated homopolymers: using conjugated polymer electroluminescence to optically pump porphyrin-dye emission

DEFF Research Database (Denmark)

Nielsen, K.T.; Spanggaard, H.; Krebs, Frederik C

2004-01-01

. Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue......Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were...

Lipid-peptide-polymer conjugates and nanoparticles thereof

Science.gov (United States)

Xu, Ting; Dong, He; Shu, Jessica

2015-06-02

The present invention provides a conjugate having a peptide with from about 10 to about 100 amino acids, wherein the peptide adopts a helical structure. The conjugate also includes a first polymer covalently linked to the peptide, and a hydrophobic moiety covalently linked to the N-terminus of the peptide, wherein the hydrophobic moiety comprises a second polymer or a lipid moiety. The present invention also provides helix bundles form by self-assembling the conjugates, and particles formed by self-assembling the helix bundles. Methods of preparing the helix bundles and particles are also provided.

Novel β-cyclodextrin-eosin conjugates.

Science.gov (United States)

Benkovics, Gábor; Afonso, Damien; Darcsi, András; Béni, Szabolcs; Conoci, Sabrina; Fenyvesi, Éva; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

2017-01-01

Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

Novel β-cyclodextrin–eosin conjugates

Directory of Open Access Journals (Sweden)

Gábor Benkovics

2017-03-01

Full Text Available Eosin B (EoB and eosin Y (EoY, two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

Prohormone convertase 1/3 is essential for processing of the glucose-dependent insulinotropic polypeptide precursor

DEFF Research Database (Denmark)

Ugleholdt, Randi; Poulsen, Marie-Louise H; Holst, Peter J

2006-01-01

The physiology of the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and their role in type 2 diabetes currently attract great interest. Recently we reported an essential role for prohormone convertase (PC) 1/3 in the cleavage of intesti......The physiology of the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and their role in type 2 diabetes currently attract great interest. Recently we reported an essential role for prohormone convertase (PC) 1/3 in the cleavage....../3 is essential and sufficient for the production of the intestinal incretin hormone GIP, whereas PC2, although capable of cleaving proGIP, does not participate in intestinal proGIP processing and is not found in intestinal GIP-expressing cells....

Choice of radionuclide for antibody labelling: new perspectives

International Nuclear Information System (INIS)

Hazra, D.K.; Dass, S.

1983-01-01

The expanding horizons of labelled antibody techniques in diagnostic imaging or assay, therapy and research and the availabilities of monoclonal antibodies is resulting in a demand for suitable radionuclides as antibody labels. An outline is given of the different criteria for choosing an appropriate radionuclide for labelling an antibody depending on its particular field of use. The requirements of procedures for firmly linking radionuclides to antibodies are also given. (U.K.)

Emissions of the corrosion radionuclides in an atmosphere

International Nuclear Information System (INIS)

Vardanyan, M.

2010-01-01

In area of Armenian nuclear power plant location, in atmospheric air in majority of cases log two technogenic radionuclides: l 37 C s and 9 0 S r. Presence of these radionuclides basically is caused by global fall out (consequences of tests of the nuclear weapon and Chernobyl NPP accident), whose contribution to the contents of these radionuclides in atmosphere is incomparably greater, than emissions from the NPP. However there are some cases when in an atmosphere are registered the technogenic radionuclides, caused by emissions from NPP. In the present work such case is considered. Gas-aerosol releases of NPP in the atmosphere are carefully purified by means of various high-efficiency filters and gas-cleaning systems. Nevertheless, one should forecast and measure, the possible impact of these releases on the environment in the regions surrounding the NPP. Radioactive releases of the Armenian NPP (ANPP) contain the set of radionuclides characteristic for NPPs of this type. They may be divided into three groups: 1 31 I , 1 37 C s, 1 34 C s, 9 0 S r and 8 9 S r fission fragments, isotopes of noble gases krypton and xenon and other radionuclides; corrosion originated radionuclides: 6 0 C o, 1 10m A g, 5 4 M n, 5 l C r and others; activation products of the heat-transfer agent itself. It should be noted that the amount of radioactive materials released in the environment by the ANPP during the whole period of its operation was much lower than the admissible quantities specified in the corresponding legal documents (RSN, NPPSP) acting in Armenia, which are practically identical to the internationally accepted norms. The amounts of releases and their radionuclides composition for the ANPP are given

Radiopharmaceutical labeling research

International Nuclear Information System (INIS)

Anon.

1985-01-01

The objective of this research is to develop methods of attaching radionuclides to monoclonal antibodies and antibody fragments for use in tumor imaging and internal radiation therapy. Monoclonal antibodies and their fragments are of interest because they enable the selective targeting of tumors. The labeled antibodies could be employed as carriers to transport radioisotopes to tumors, thus minimizing total-body radiation dose and radiation damage to normal tissue. Because the time required for labeled antibodies to find the tumor antigen and deliver the dose to the tumor is estimated to be about 1-3 days, radionuclides with a l- to 3-day half-life would be optimum for this purpose. Two of the radionuclides produced at LAMPF, 67 Cu and 77 Br, have the suitable half-life and nuclear-decay properties for use in tumor imaging or therapy with radiolabeled antibodies. These radionuclides and the efforts to prepare radiolabeled antibodies with them are described. We have used three different approaches to meet this objective of labeling antibodies: (1) labeling chelating agents with metal radionuclides, then conjugating the labeled chelating agents to antibodies; (2) conjugating activated chelating agents to antibodies, followed by metalation with metal radionuclides; and (3) radiobrominating small molecules that can be conjugated to antibodies

Photodynamic tissue adhesion with chlorin(e6) protein conjugates.

Science.gov (United States)

Khadem, J; Veloso, A A; Tolentino, F; Hasan, T; Hamblin, M R

1999-12-01

To test the hypothesis that a photodynamic laser-activated tissue solder would perform better in sealing scleral incisions when the photosensitizer was covalently linked to the protein than when it was noncovalently mixed. Conjugates and mixtures were prepared between the photosensitizer chlorin(e6) and various proteins (albumin, fibrinogen, and gelatin) in different ratios and used to weld penetrating scleral incisions made in human cadaveric eyes. A blue-green (488-514 nm) argon laser activated the adhesive, and the strength of the closure was measured by increasing the intraocular pressure until the wound showed leakage. Both covalent conjugates and noncovalent mixtures showed a light dose-dependent increase in leaking pressure. A preparation of albumin chlorin(e6) conjugate with additional albumin added (2.5 protein to chlorin(e6) molar ratio) showed significantly higher weld strength than other protein conjugates and mixtures. This is the first report of dye-protein conjugates as tissue solders. These conjugates may have applications in ophthalmology.

Human glutathione S-transferase-mediated glutathione conjugation of curcumin and efflux of these conjugates in caco-2 cells

NARCIS (Netherlands)

Usta, M.; Wortelboer, H.M.; Vervoort, J.; Boersma, M.G.; Rietjens, I.M.C.M.; Bladeren, P.J. van; Cnubben, N.H.P.

2007-01-01

Curcumin, an α,β-unsaturated carbonyl compound, reacts with glutathione, leading to the formation of two monoglutathionyl curcumin conjugates. In the present study, the structures of both glutathione conjugates of curcumin were identified by LC-MS and one- and two-dimensional 1H NMR analysis, and

DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

DEFF Research Database (Denmark)

2004-01-01

Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

Stochastic analysis of radionuclide migration in saturated-unsaturated soils

International Nuclear Information System (INIS)

Kawanishi, Moto

1988-01-01

In Japan, LLRW (low level radioactive wastes) generated from nuclear power plants shall be started to store concentrically in the Shimokita site from 1990, and those could be transformed into land disposal if the positive safety is confirmed. Therefore, it is hoped that the safety assessment method shall be successed for the land disposal of LLRW. In this study, a stochastic model to analyze the radionuclide migration in saturated-unsaturated soils was constructed. The principal results are summarized as follows. 1) We presented a generalized idea for the modeling of the radionuclide migration in saturated-unsaturated soils as an advective-dispersion phenomena followed by the decay of radionuclides and those adsorption/desorption in soils. 2) Based on the radionuclide migration model mentioned above, we developed a stochastic analysis model on radionuclide migration in saturated-unsaturated soils. 3) From the comparison between the simulated results and the exact solution on a few simple one-dimensional advective-dispersion problems of radionuclides, the good validity of this model was confirmed. 4) From the comparison between the simulated results by this model and the experimental results of radionuclide migration in a one-dimensional unsaturated soil column with rainfall, the good applicability was shown. 5) As the stochastic model such as this has several advantages that it is easily able to represent the image of physical phenomena and has basically no numerical dissipation, this model should be more applicable to the analysis of the complicated radionuclide migration in saturated-unsaturated soils. (author)

Preparation of Radiopharmaceuticals Labeled with Metal Radionuclides

Energy Technology Data Exchange (ETDEWEB)

Welch, M.J.

2012-02-16

The overall goal of this project was to develop methods for the production of metal-based radionuclides, to develop metal-based radiopharmaceuticals and in a limited number of cases, to translate these agents to the clinical situation. Initial work concentrated on the application of the radionuclides of Cu, Cu-60, Cu-61 and Cu-64, as well as application of Ga-68 radiopharmaceuticals. Initially Cu-64 was produced at the Missouri University Research Reactor and experiments carried out at Washington University. A limited number of studies were carried out utilizing Cu-62, a generator produced radionuclide produced by Mallinckrodt Inc. (now Covidien). In these studies, copper-62-labeled pyruvaldehyde Bis(N{sup 4}-methylthiosemicarbazonato)-copper(II) was studied as an agent for cerebral myocardial perfusion. A remote system for the production of this radiopharmaceutical was developed and a limited number of patient studies carried out with this agent. Various other copper radiopharmaceuticals were investigated, these included copper labeled blood imaging agents as well as Cu-64 labeled antibodies. Cu-64 labeled antibodies targeting colon cancer were translated to the human situation. Cu-64 was also used to label peptides (Cu-64 octriatide) and this is one of the first applications of a peptide radiolabeled with a positron emitting metal radionuclide. Investigations were then pursued on the preparation of the copper radionuclides on a small biomedical cyclotron. A system for the production of high specific activity Cu-64 was developed and initially the Cu-64 was utilized to study the hypoxic imaging agent Cu-64 ATSM. Utilizing the same target system, other positron emitting metal radionuclides were produced, these were Y-86 and Ga-66. Radiopharmaceuticals were labeled utilizing both of these radionuclides. Many studies were carried out in animal models on the uptake of Cu-ATSM in hypoxic tissue. The hypothesis is that Cu-ATSM retention in vivo is dependent upon the

Radionuclide transfer onto ground surface in surface water flow, 1

International Nuclear Information System (INIS)

Mukai, Masayuki; Takebe, Shinichi; Komiya, Tomokazu; Kamiyama, Hideo

1991-07-01

Radionuclides migration in ground surface water flow is considered to be one of the important path way in the scenario for environmental migration of radionuclides leaked from low level radioactive waste repository. Simulating the slightly sloped surface on which contaminated solution is flowing downward, testing for radionuclide migration on ground surface had been started. As it's first step, an experiment was carried out under the condition of restricted infiltration in order to elucidate the adsorption behavior of radionuclides onto the loamy soil surface in related with hydraulic conditions. Radionuclides concentration change in effluent solution with time and a concentration distribution of radionuclides adsorbed on the ground surface were obtained from several experimental conditions combining the rate and the duration time of the water flow. The radionuclides concentration in the effluent solution was nearly constant during each experimental period, and was reduced under the condition of lower flow rate. The surface distribution of radionuclides concentration showed two distinctive regions. The one was near the inlet vessel where the concentration was promptly reducing, and the other was following the former where the concentration was nearly constant. The characteristic surface distribution of radionuclides concentration can be explained by a two dimensional diffusion model with a first order adsorption reaction, based on the advection of flow rate distribution in perpendicular direction. (author)

Extreme radionuclide accumulation on alpine glaciers in cryoconites

International Nuclear Information System (INIS)

Lettner, H.; Wilflinger, T.; Hubmer, A.K.; Bossew, P.

2008-01-01

Full text: Under environmental conditions when radionuclide fallout will not be diluted by media like soil or water, radionuclides deposited may accumulate to unusual high activities. On glacier surfaces conditions as such exist for aerosols and airborne dust deposited with anthropogenic and natural radionuclides attached on their surfaces. In the course of agglomeration processes initiated by melting and redistribution, these particles may concentrate in small depressions, ice pockets, ablation edges etc. and form substances called cryoconites ('ice dust'). As there is no other matrix than the original aerosol particles, cryoconites are a sink for radionuclides and airborne pollutants and their activity levels are among the highest produced by natural processes observed in environmental media. 137 Cs activities found on glaciers in the Austrian alps are between 255 and 136.000 Bq/kg and predominantly derived from Chernobyl, but also from global fallout. Further anthropogenic radionuclides detected are 134 Cs, 90 Sr, 238,239+240 Pu, 241 Am, 125 Sb, 154 Eu, 60 Co and 207 Bi. In combination with the naturally occurring radionuclides 7 Be and 210 Pb and isotopic ratios such as 134 Cs/ 137 Cs, identification and discrimination of the sources, the nuclear weapon tests and the Chernobyl fallout, can be carried out. (author)

Radionuclide X-ray fluorescence analysis

International Nuclear Information System (INIS)

Cechak, T.

1994-01-01

The author's achievements in the title field are summarized and discussed. The following topics are dealt with: (i) principles of radionuclide X-ray fluorescence analysis; (ii) mathematical methods in X-ray fluorescence analysis; (iii) Ross differential filters; (iv) application of radionuclide X-ray fluorescence analysis in the coal industry (with emphasis on the determination of the ash content, sulfur content, and arsenic content of coal); and (v) evaluation of the X-ray fluorescence analyzer from the radiological safety point of view. (P.A.)

Radionuclide generators for biomedical applications

International Nuclear Information System (INIS)

Finn, R.D.; Molinski, V.J.; Hupf, H.B.; Kramer, H.

1983-10-01

This document reviews the chemical literature of those radionuclide generators that have gained or appear to possess utility in medical imaging. The text represents a conscientious effort to peruse the scientific literature through 1980. The intent of this work is to provide a reference point for the investigator who is interested in the development of a particular generator system and the refinements which have been reported. Moreover, the incorporation of the particular daughter radionuclide into a suitable radiodiagnostic agent is presented

A conserved helicase processivity factor is needed for conjugation and replication of an integrative and conjugative element.

Directory of Open Access Journals (Sweden)

Jacob Thomas

Full Text Available Integrative and conjugative elements (ICEs are agents of horizontal gene transfer and have major roles in evolution and acquisition of new traits, including antibiotic resistances. ICEs are found integrated in a host chromosome and can excise and transfer to recipient bacteria via conjugation. Conjugation involves nicking of the ICE origin of transfer (oriT by the ICE-encoded relaxase and transfer of the nicked single strand of ICE DNA. For ICEBs1 of Bacillus subtilis, nicking of oriT by the ICEBs1 relaxase NicK also initiates rolling circle replication. This autonomous replication of ICEBs1 is critical for stability of the excised element in growing cells. We found a conserved and previously uncharacterized ICE gene that is required for conjugation and replication of ICEBs1. Our results indicate that this gene, helP (formerly ydcP, encodes a helicase processivity factor that enables the host-encoded helicase PcrA to unwind the double-stranded ICEBs1 DNA. HelP was required for both conjugation and replication of ICEBs1, and HelP and NicK were the only ICEBs1 proteins needed for replication from ICEBs1 oriT. Using chromatin immunoprecipitation, we measured association of HelP, NicK, PcrA, and the host-encoded single-strand DNA binding protein Ssb with ICEBs1. We found that NicK was required for association of HelP and PcrA with ICEBs1 DNA. HelP was required for association of PcrA and Ssb with ICEBs1 regions distal, but not proximal, to oriT, indicating that PcrA needs HelP to progress beyond nicked oriT and unwind ICEBs1. In vitro, HelP directly stimulated the helicase activity of the PcrA homologue UvrD. Our findings demonstrate that HelP is a helicase processivity factor needed for efficient unwinding of ICEBs1 for conjugation and replication. Homologues of HelP and PcrA-type helicases are encoded on many known and putative ICEs. We propose that these factors are essential for ICE conjugation, replication, and genetic stability.

2014 LANL Radionuclide Air Emissions Report

Energy Technology Data Exchange (ETDEWEB)

Fuehne, David Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-07-21

This report describes the emissions of airborne radionuclides from operations at Los Alamos National Laboratory (LANL) for calendar year 2014, and the resulting off-site dose from these emissions. This document fulfills the requirements established by the National Emissions Standards for Hazardous Air Pollutants in 40 CFR 61, Subpart H – Emissions of Radionuclides other than Radon from Department of Energy Facilities, commonly referred to as the Radionuclide NESHAP or Rad-NESHAP. Compliance with this regulation and preparation of this document is the responsibility of LANL’s RadNESHAP compliance program, which is part of the Environmental Protection Division. The information in this report is required under the Clean Air Act and is being submitted to the U.S. Environmental Protection Agency (EPA) Region 6.

Conjugate Gaze Palsies

Science.gov (United States)

... version Home Brain, Spinal Cord, and Nerve Disorders Cranial Nerve Disorders Conjugate Gaze Palsies Horizontal gaze palsy Vertical ... Version. DOCTORS: Click here for the Professional Version Cranial Nerve Disorders Overview of the Cranial Nerves Internuclear Ophthalmoplegia ...

N-terminal and C-terminal heparin-binding domain polypeptides derived from fibronectin reduce adhesion and invasion of liver cancer cells

International Nuclear Information System (INIS)

Tang, Nan-Hong; Chen, Yan-Lin; Wang, Xiao-Qian; Li, Xiu-Jin; Wu, Yong; Zou, Qi-Lian; Chen, Yuan-Zhong

2010-01-01

Fibronectin (FN) is known to be a large multifunction glycoprotein with binding sites for many substances, including N-terminal and C-terminal heparin-binding domains. We investigated the effects of highly purified rhFNHN29 and rhFNHC36 polypeptides originally cloned from the two heparin-binding domains on the adhesion and invasion of highly metastatic human hepatocellular carcinoma cells (MHCC97H) and analyzed the underlying mechanism involved. The MHCC97H cells that adhered to FN in the presence of various concentrations of rhFNHN29 and rhFNHC36 polypeptides were stained with crystal violet and measured, and the effects of rhFNHN29 and rhFNHC36 on the invasion of the MHCC97H cells were then detected using the Matrigel invasion assay as well as a lung-metastasis mouse model. The expression level of integrins and focal adhesion kinase (FAK) phosphotyrosyl protein was examined by Western blot, and the activity of matrix metalloproteinases (MMPs) and activator protein 1 (AP-1) was analyzed by gelatin zymography and the electrophoretic mobility band-shift assay (EMSA), respectively. Both of the polypeptides rhFNHN29 and rhFNHC36 inhibited adhesion and invasion of MHCC97H cells; however, rhFNHC36 exhibited inhibition at a lower dose than rhFNHN29. These inhibitory effects were mediated by integrin αvβ3 and reversed by a protein tyrosine phosphatase inhibitor. Polypeptides rhFNHN29 and rhFNHC36 abrogated the tyrosine phosphorylation of focal adhesion kinase (p-FAK) and activation of activator protein 1 (AP-1), resulting in the decrease of integrin αv, β3 and β1 expression as well as the reduction of MMP-9 activity. Polypeptides rhFNHN29 and rhFNHC36 could potentially be applicable to human liver cancer as anti-adhesive and anti-invasive agents

Inventories of selected radionuclides in the oceans

International Nuclear Information System (INIS)

1988-10-01

In March 1984 an ad hoc Review Committee composed of senior experts in the marine radioactivity field made recommendations that ''the Monaco Laboratory should be engaged in compiling and evaluating the input of radionuclides into the marine environment''. The Committee recommended that work should commence on selected radionuclides, viz., 14 C, caesium isotopes, plutonium isotopes, 210 Po and 210 Pb followed by 226 Ra. Depending on the radionuclides involved the assistance of competent experts from outside as well as inside the IAEA was sought. The present document is a product of the work carried out within the framework of the above-mentioned task and contains reports on 14 C, 90 Sr, 137 Cs, 238 Pu, 239+240 Pu, 210 Pb, 210 Po and 226 Ra. Although the estimation of the inventory in the marine environment and related input and output fluxes, is the same for all radionuclides concerned, different approaches were followed to achieve this objective. These approaches depended on the geochemical characteristics of the radionuclides and the availability of data for different times and locations. For regions where data were lacking, extrapolation on the basis of specific assumptions has often been necessary. As the work was initiated during the pre-Chernobyl period, the radionuclides derived from the Chernobyl incident were not, in general, considered. Since the work for preparing the forthcoming report of the UNSCEAR is scheduled to be completed by 1991, it is hoped that the information contained in this volume will be beneficial. Refs, figs and tabs

New radionuclide generator systems for use in nuclear medicine

International Nuclear Information System (INIS)

Atcher, R.W.

1979-01-01

A current emphasis in nuclear medicine is to better match the physical lifetime of the radionuclides used in vivo for diagnosis and treatment to the biological lifetime of the diagnostic procedure or to minimize radiation dose to areas other than those to be treated. In many cases the biological lifetime is on the order of minutes. Since the direct production of radionuclides with half lives of minutes requires the user to be near a suitable reactor or accelerator, this study was undertaken to produce short-lived radionuclides indirectly. If a long-lived radionuclide decays into a short-lived radionuclide, quick separation of the daughter activity from the parent enables the user to have a short-lived daughter while freeing him from the constraint of proximity to a cyclotron. Systems where a short-lived daughter is separated from a long-lived parent are called radionuclide generators. Two generator systems were developed for use in nuclear medicine, one in diagnostic work and the other for therapeutic work. The yield and breakthrough characteristics were within the limits required to minimize unnecessary radiation exposure in patients. Two parent radionuclides were produced using 4 He beams available from medium energy cyclotrons. The yield was high enough to produce generators that would be useful in clinical applications

Development of a transportable system for radionuclide analysis

International Nuclear Information System (INIS)

Cunningham, W.C.; Anderson, D.L.; Lamont, W.H.; South, P.K.; Rury, M.A.; Beachley, G.M.; Ondov, J.M.

2008-01-01

Transportable radioanalytical systems were assembled and tested for quantitative determination of γ-emitting radionuclides and screening of β- emitting radionuclides. Standard operating procedures (SOPs), including instructions for assembly, disassembly, operation, sample collection and analysis, and all other procedures needed, were developed. Foods, as well as National Institute of Standards and Technology, International Atomic Energy Agency, and in-house Reference Materials were analyzed. An SOP for γ-emitting radionuclides was successfully tested at 3 locations. (author)

Hydrology/Radionuclide Migration Program and related research activities

International Nuclear Information System (INIS)

Jones, M.A.

1992-02-01

This report presents the results of technical studies conducted under the Hydrology/Radionuclide Migration Program (HRMP) at the Nevada Test Site (NTS) for the period of October 1, 1985 through September 30, 1986. The HRMP was initiated in 1973 as the Radionuclide Migration Program to study and better understand the hydrologic systems of the NTS and potential movement and rates of movement of radionuclides and other contaminants injected into these systems by underground nuclear testing

Synthesis of Mikto-Arm Star Peptide Conjugates.

Science.gov (United States)

Koo, Jin Mo; Su, Hao; Lin, Yi-An; Cui, Honggang

2018-01-01

Mikto-arm star peptide conjugates are an emerging class of self-assembling peptide-based structural units that contain three or more auxiliary segments of different chemical compositions and/or functionalities. This group of molecules exhibit interesting self-assembly behavior in solution due to their chemically asymmetric topology. Here we describe the detailed procedure for synthesis of an ABC Mikto-arm star peptide conjugate in which two immiscible entities (a saturated hydrocarbon and a hydrophobic and lipophobic fluorocarbon) are conjugated onto a short β-sheet forming peptide sequence, GNNQQNY, derived from the Sup35 prion, through a lysine junction. Automated and manual Fmoc-solid phase synthesis techniques are used to synthesize the Mikto-arm star peptide conjugates, followed by HPLC purification. We envision that this set of protocols can afford a versatile platform to synthesize a new class of peptidic building units for diverse applications.

Fullerene-biomolecule conjugates and their biomedicinal applications.

Science.gov (United States)

Yang, Xinlin; Ebrahimi, Ali; Li, Jie; Cui, Quanjun

2014-01-01

Fullerenes are among the strongest antioxidants and are characterized as "radical sponges." The research on biomedicinal applications of fullerenes has achieved significant progress since the landmark publication by Friedman et al in 1993. Fullerene-biomolecule conjugates have become an important area of research during the past 2 decades. By a thorough literature search, we attempt to update the information about the synthesis of different types of fullerene-biomolecule conjugates, including fullerene-containing amino acids and peptides, oligonucleotides, sugars, and esters. Moreover, we also discuss in this review recently reported data on the biological and pharmaceutical utilities of these compounds and some other fullerene derivatives of biomedical importance. While within the fullerene-biomolecule conjugates, in which fullerene may act as both an antioxidant and a carrier, specific targeting biomolecules conjugated to fullerene will undoubtedly strengthen the delivery of functional fullerenes to sites of clinical interest.

Gold Nanoparticle Conjugation Enhances the Antiacanthamoebic Effects of Chlorhexidine

Science.gov (United States)

Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Anwar, Ayaz; Shah, Muhammad Raza

2015-01-01

Acanthamoeba keratitis is a serious infection with blinding consequences and often associated with contact lens wear. Early diagnosis, followed by aggressive topical application of drugs, is a prerequisite in successful treatment, but even then prognosis remains poor. Several drugs have shown promise, including chlorhexidine gluconate; however, host cell toxicity at physiologically relevant concentrations remains a challenge. Nanoparticles, subcolloidal structures ranging in size from 10 to 100 nm, are effective drug carriers for enhancing drug potency. The overall aim of the present study was to determine whether conjugation with gold nanoparticles enhances the antiacanthamoebic potential of chlorhexidine. Gold-conjugated chlorhexidine nanoparticles were synthesized. Briefly, gold solution was mixed with chlorhexidine and reduced by adding sodium borohydride, resulting in an intense deep red color, indicative of colloidal gold-conjugated chlorhexidine nanoparticles. The synthesis was confirmed using UV-visible spectrophotometry that shows a plasmon resonance peak of 500 to 550 nm, indicative of gold nanoparticles. Further characterization using matrix-assisted laser desorption ionization-mass spectrometry showed a gold-conjugated chlorhexidine complex at m/z 699 ranging in size from 20 to 100 nm, as determined using atomic force microscopy. To determine the amoebicidal and amoebistatic effects, amoebae were incubated with gold-conjugated chlorhexidine nanoparticles. For controls, amoebae also were incubated with gold and silver nanoparticles alone, chlorhexidine alone, neomycin-conjugated nanoparticles, and neomycin alone. The findings showed that gold-conjugated chlorhexidine nanoparticles exhibited significant amoebicidal and amoebistatic effects at 5 μM. Amoebicidal effects were observed by parasite viability testing using a Trypan blue exclusion assay and flow-cytometric analysis using propidium iodide, while amoebistatic effects were observed using growth

Analytical characterization of polymer-drug conjugates

International Nuclear Information System (INIS)

Rizzo, V.; Gigli, M.; Pinciroli, V.

1998-01-01

A few polymeric conjugates of antitumor drugs have been recently developed in view of possible therapeutic advantages: solubilization of sparingly soluble drugs in water, improvement of therapeutic index, organ targeting through a second chemical species bound to the same polymeric chain. In this article it's described the analytical approach used in the characterization of the conjugates for chemical identity, purity and strength of the contained active ingredient. The techniques are: high field NMR and size exclusion chromatography with non-aqueous mobile phase for identity; selective hydrolysis and HPLC for strength and purity. A complete and reliable picture is thus obtained both for qualitative and for quantitative aspects. This is an important step forward in the direction of further development and marketing of polymer-drug conjugates [it

Conjugate gradient algorithms using multiple recursions

Energy Technology Data Exchange (ETDEWEB)

Barth, T.; Manteuffel, T.

1996-12-31

Much is already known about when a conjugate gradient method can be implemented with short recursions for the direction vectors. The work done in 1984 by Faber and Manteuffel gave necessary and sufficient conditions on the iteration matrix A, in order for a conjugate gradient method to be implemented with a single recursion of a certain form. However, this form does not take into account all possible recursions. This became evident when Jagels and Reichel used an algorithm of Gragg for unitary matrices to demonstrate that the class of matrices for which a practical conjugate gradient algorithm exists can be extended to include unitary and shifted unitary matrices. The implementation uses short double recursions for the direction vectors. This motivates the study of multiple recursion algorithms.

TISSUE POLYPEPTIDE-SPECIFIC ANTIGEN - A DISCRIMINATIVE PARAMETER BETWEEN PROSTATE-CANCER AND BENIGN PROSTATIC HYPERTROPHY

NARCIS (Netherlands)

MARRINK, J; OOSTEROM, R; BONFRER, HMG; SCHRODER, FH; MENSINK, HJA

1993-01-01

The serum concentration of the cell proliferation marker TPS (tissue polypeptide-specific antigen) was compared with the tumour marker PSA (prostate specific antigen). PSA was found elevated in 50% of the benign prostatic hypertrophy (BPH) patients, in 88% of the patients with active prostate cancer

EBS Radionuclide Transport Abstraction

International Nuclear Information System (INIS)

J.D. Schreiber

2005-01-01

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers

EBS Radionuclide Transport Abstraction

Energy Technology Data Exchange (ETDEWEB)

J.D. Schreiber

2005-08-25

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport

EBS Radionuclide Transport Abstraction

Energy Technology Data Exchange (ETDEWEB)

J. Prouty

2006-07-14

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

EBS Radionuclide Transport Abstraction

International Nuclear Information System (INIS)

J. Prouty

2006-01-01

The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

Four-wave mixing and phase conjugation in plasmas

International Nuclear Information System (INIS)

Federici, J.F.

1989-01-01

Nonlinear optical effects such as Stimulated Brillouin Scattering, Stimulated Raman Scattering, self-focusing, wave-mixing, parametric mixing, etc., have a long history in plasma physics. Recently, four-wave mixing in plasmas and its applications to phase conjugation has been extensively studied. Although four-wave mixing (FWM), using various nonlinear mediums, has many practical applications in the visible regime, no successful attempt has been made to study or demonstrate FWM for wavelengths longer than 10μm. Plasmas as phase conjugate mirrors have received considerable attention since they become more efficient at longer wavelengths (far-infrared to microwave). The purpose of this thesis is to study various fundamental issues which concern the suitability of plasmas for four-wave mixing and phase conjugation. The major contributions of this thesis are the identification and study of thermal and ionization nonlinearities as potential four-wave mixing and phase conjugation mechanisms and the study of the affect of density inhomogeneities on the FWM process. Using a fluid description for the plasma, this thesis demonstrates that collisional heating generates a thermal force which substantially enhances the phase conjugate reflectivity. The prospect of using a novel ionization nonlinearity in weakly ionized plasmas for wave-mixing and phase conjugation is discussed. The ionization nonlinearity arises from localized heating of the plasma by the beat-wave. Wherever, the local temperature is increased, a plasma density grating is produced due to increased electron-impact ionization. Numerical estimates of the phase conjugate reflectivity indicate reflectivities in the range of 10 -4 -10 -3 are possible in a weakly ionized steady-state gas discharge plasma

Improving global laboratory capabilities for emergency radionuclide bioassay

International Nuclear Information System (INIS)

Li, C.; Jourdain, J.; Kramer, G. H.

2012-01-01

During a radiological or nuclear emergency, first-responders and the general public may be internally contaminated with the radionuclide(s) involved. A timely radionuclide bioassay provides important information about contamination, for subsequent dose assessment and medical management. Both technical and operational gaps are discussed in this paper. As many people may need to be assessed in a short period of time, any single laboratory may find its capabilities insufficient. Laboratories from other regions or other countries may be called upon for assistance. This paper proposes a road-map to improve global capabilities in emergency radionuclide bioassay, suggesting a phased approach for establishing a global laboratory network. Existing international collaboration platforms could provide the base on which to build such a network. (authors)

Conjugation of the CRM197-inulin conjugate significantly increases the immunogenicity of Mycobacterium tuberculosis CFP10-TB10.4 fusion protein.

Science.gov (United States)

Hu, Shun; Yu, Weili; Hu, Chunyang; Wei, Dong; Shen, Lijuan; Hu, Tao; Yi, Youjin

2017-11-01

Mycobacterium tuberculosis (Mtb) is a serious fatal pathogen that causes tuberculosis (TB). Effective vaccination is urgently needed to deal with the serious threat from TB. Mtb-secreted protein antigens are important virulence determinants of Mtb with poor immunogenicity. Adjuvants and antigen delivery systems are thus highly desired to improve the immunogenicity of protein antigens. Inulin is a biocompatible polysaccharide (PS) adjuvant that can stimulate a strong cellular and humoral immunity. Bacterial capsular PS and haptens have been conjugated with cross-reacting material 197 (CRM 197 ) to improve their immunogenicity. CFP10 and TB10.4 were two Mtb-secreted immunodominant protein antigens. A CFP10-TB10.4 fusion protein (CT) was used as the antigen for covalent conjugation with the CRM 197 -inulin conjugate (CRM-inu). The resultant conjugate (CT-CRM-inu) elicited high CT-specific IgG titers, stimulated splenocyte proliferation and provoked the secretion of Th1-type and Th2-type cytokines. Conjugation with CRM-inu significantly prolonged the systemic circulation of CT and exposure to the immune system. Moreover, CT-CRM-inu showed no apparent toxicity to cardiac, hepatic and renal functions. Thus, conjugation of CT with CRM-inu provided an effective strategy for development of protein-based vaccines against Mtb infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Primary structure, gene organization and polypeptide expression of poliovirus RNA

Energy Technology Data Exchange (ETDEWEB)

Kitamura, N. (State Univ. of New York, Stony Brook); Semler, B.L.; Rothberg, P.G.

1981-06-18

The primary structure of the poliovirus genome has been determined. The RNA molecule is 7433 nucleotides long, polyadenylated at the 3' terminus, and covalently linked to a small protein (VPg) at the 5' terminus. An open reading frame of 2207 consecutive triplets spans over 89% of the nucleotide sequence and codes for the viral polyprotein NCVPOO. Twelve viral polypeptides have been mapped by amino acid sequence analysis and were found to be proteolytic cleavage products of the polyprotein, cleavages occurring predominantly at Gln-Gly pairs.

Radionuclide techniques for brain imaging

International Nuclear Information System (INIS)

Cowan, R.J.; Moody, D.M.

1984-01-01

Over the past decade, many of the prime indications for radionuclide brain scanning have become instead indications for CCT, and nuclear medicine studies of the brain have assumed more of a complementary, supportive role. However, there is great promise for improvement in central nervous system radionuclide applications with advances anticipated in both radiopharmaceuticals and instrumentation. Nuclear medicine is continuing to function as a powerful research tool and, in the relatively near future, may regain its role as a major clinical test of the central nervous system

Relating β+ radionuclides' properties by order theory

International Nuclear Information System (INIS)

Quintero, N.Y.; Guillermo Restrepo; Cohen, I.M.; Universidad Tecnologica Nacional, Buenos Aires

2013-01-01

We studied 27 β + radionuclides taking into account some of their variants encoding information of their production, such as integral yield, threshold energy and energy of projectiles used to generate them; these radionuclides are of current use in clinical diagnostic imaging by positron emission tomography (PET). The study was conducted based on physical, physico-chemical, nuclear, dosimetric and quantum properties, which characterise the β + radionuclides selected, with the aim of finding meaningful relationships among them. In order to accomplish this objective the mathematical methodology known as formal concept analysis was employed. We obtained a set of logical assertions (rules) classified as implications and associations, for the set of β + radionuclides considered. Some of them show that low mass defect is related to high and medium values of maximum β + energy, and with even parity and low mean lives; all these parameters are associated to the dose received by a patient subjected to a PET analysis. (author)

Metabolic transformation of radionuclides in marine organisms

International Nuclear Information System (INIS)

Koyanagi, Taku

1987-01-01

Physico-chemical form of radionuclides is one of the important factors governing the concentration by marine organisms, whereas biological activities affect the existing states of radionuclides especially in coastal waters. Radioiodine in the form of iodate which is predominant species in seawater is reduced to iodide ion by biological activities and concentration factor of iodide is an order of magnitude higher than those of iodate. Extremely high accumulation of transition elements, actinides, or natural radionuclides in branchial heart of octopus is explained by the fuction of adenochrome, a glandular pigment in the organ as a natural complexing agent, and similar metal-binding proteins with relatively low molecular weight have been found in various marine invertebrates. High accumulation of some elements also found in mollusk kidney is considered to be caused by the intracellular concretions composed of calcium phosphate. All these biological processes suggest the significance of further investigations on metabolic transformation of radionuclides in marine organisms. (author)

High-resolution polypeptide structure and dynamics in anisotropic environments: The gramicidin channel

Energy Technology Data Exchange (ETDEWEB)

Cross, T.A.; Lee, K.C.; Ketchem, R.R.; Hu, W.; Lazo, N.D.; Huo, S. [Florida State Univ., Tallahassee, FL (United States)

1994-12-01

To understand the details of macromolecular function, high-resolution structural and dynamic detail is essential. The polypeptide fold of the gramicidin channel has been effectively modeled for the past 20 years, yet the functional changes in conductance and channel lifetime associated with amino acid substitutions cannot be predicted. To accomplish this goal, high-resolution electrostatic modeling and the precise orientation of all dipoles are required. Furthermore, an enhanced knowledge of the complex molecular environment of this membrane-bound peptide is needed. An aqueous environment is relatively uniform and achiral. The membrane environment is very heterogenous and chiral. A knowledge of the interactions, specific and nonspecific, between peptide and lipid will aid in developing a better understanding of this environment. To accomplish this goal, it is necessary to study the peptide in an extended lipid bilayer, rather than in a vesicular or micellar form. These latter environments are likely to possess increased dynamics, increased water penetration, and distorted interactions between the polypeptide and membrane surface. To perform NMR studies on bilayer bound peptides, solid state NMR methods are required, and for specific site information, isotopic labels are incorporated using solid phase peptide synthesis.

Specific photoaffinity labeling of two plasma membrane polypeptides with an azido auxin

International Nuclear Information System (INIS)

Hicks, G.R.; Rayle, D.L.; Jones, A.M.; Lomax, T.L.

1989-01-01

Plasma membrane vesicles were isolated from zucchini (Cucurbita pepo) hypocotyl tissue by aqueous phase partitioning and assessed for homogeneity by the use of membrane-specific enzyme assays. The highly pure plasma membrane vesicles maintained a pH differential across the membrane and accumulated a tritiated azido analogue of 3-indoleacetic acid (IAA), 5-azido-[7- 3 H]IAA([ 3 H]N 3 IAA), in a manner similar to the accumulation of [ 3 H]IAA. The association of the [ 3 H]N 3 IAA with membrane vesicles was saturable and subject to competition by IAA and auxin analogues. Auxin-binding proteins were photoaffinity labeled by addition of [ 3 H]N 3 IAA to plasma membrane vesicles prior to exposure to UV light and detected by subsequent NaDodSO 4 /PAGE and fluorography. When the reaction temperature was lowered to -196 degree C, high-specific-activity labeling of a 40-kDa and a 42-kDa polypeptide was observed. Collectively, these results suggest that the radiolabeled polypeptides are auxin receptors. The covalent nature of the label should facilitate purification and further characterization of the receptors

O:2-CRM(197) conjugates against Salmonella Paratyphi A.

Science.gov (United States)

Micoli, Francesca; Rondini, Simona; Gavini, Massimiliano; Lanzilao, Luisa; Medaglini, Donata; Saul, Allan; Martin, Laura B

2012-01-01

Enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. Salmonella enterica serovar Typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of S. Paratyphi A, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against S. Paratyphi A. The O-specific polysaccharide (O:2) of S. Paratyphi A is a protective antigen and clinical data have previously demonstrated the potential of using O:2 conjugate vaccines. Here we describe a new conjugation chemistry to link O:2 and the carrier protein CRM(197), using the terminus 3-deoxy-D-manno-octulosonic acid (KDO), thus leaving the O:2 chain unmodified. The new conjugates were tested in mice and compared with other O:2-antigen conjugates, synthesized adopting previously described methods that use CRM(197) as carrier protein. The newly developed conjugation chemistry yielded immunogenic conjugates with strong serum bactericidal activity against S. Paratyphi A.

O:2-CRM(197 conjugates against Salmonella Paratyphi A.

Directory of Open Access Journals (Sweden)

Francesca Micoli

Full Text Available Enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. Salmonella enterica serovar Typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of S. Paratyphi A, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against S. Paratyphi A. The O-specific polysaccharide (O:2 of S. Paratyphi A is a protective antigen and clinical data have previously demonstrated the potential of using O:2 conjugate vaccines. Here we describe a new conjugation chemistry to link O:2 and the carrier protein CRM(197, using the terminus 3-deoxy-D-manno-octulosonic acid (KDO, thus leaving the O:2 chain unmodified. The new conjugates were tested in mice and compared with other O:2-antigen conjugates, synthesized adopting previously described methods that use CRM(197 as carrier protein. The newly developed conjugation chemistry yielded immunogenic conjugates with strong serum bactericidal activity against S. Paratyphi A.

The main trends in clinical use of radionuclides in oncology

International Nuclear Information System (INIS)

Agranat, V.Z.

1979-01-01

The main trends of using radionuclide methods in clinical oncology are shown. Two main aspects of using radionuclide methods are pointed out: radionuclide investigation of the primary tumour as ''local'' manifestation of the cancer disease, radionuclide investigation of the body ''response'' to the tumour process. Each of the aspects of the problem is briefly considered on some examples. Examples of positive scintigraphy of tumours are given. It is shown that tumorotropic properties of some radionuclides make possible using visualization methods realizing the differential diagnosis of some tumours. Considered are direct and indirect signs which allow determining the presence of metastases and testifying to the tumour process spread

Comparison of the pharmacological and biological properties of HPMA copolymer-pirarubicin conjugates: A single-chain copolymer conjugate and its biodegradable tandem-diblock copolymer conjugate

Czech Academy of Sciences Publication Activity Database

Etrych, Tomáš; Tsukigawa, K.; Nakamura, H.; Chytil, Petr; Fang, J.; Ulbrich, Karel; Otagiri, M.; Maeda, H.

2017-01-01

Roč. 106, 30 August (2017), s. 10-19 ISSN 0928-0987 R&D Projects: GA ČR(CZ) GA15-02986S; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Grant - others:AV ČR,Japan Society for the Promotion of Science(CZ) JSPS-16-05 Program:Bilaterální spolupráce Institutional support: RVO:61389013 Keywords : pirarubicin * PHPMA conjugate * tandem-diblock PHPMA conjugate Subject RIV: FR - Pharmacology ; Medidal Chemistry OBOR OECD: Pharmacology and pharmacy Impact factor: 3.756, year: 2016

The generalized model of polypeptide chain describing the helix-coil transition in biopolymers

International Nuclear Information System (INIS)

Mamasakhlisov, E.S.; Badasyan, A.V.; Tsarukyan, A.V.; Grigoryan, A.V.; Morozov, V.F.

2005-07-01

In this paper we summarize some results of our theoretical investigations of helix-coil transition both in single-strand (polypeptides) and two-strand (polynucleotides) macromolecules. The Hamiltonian of the Generalized Model of Polypeptide Chain (GMPC) is introduced to describe the system in which the conformations are correlated over some dimensional range Δ (it equals 3 for polypeptide, because one H-bond fixes three pairs of rotation, for double strand DNA it equals to one chain rigidity because of impossibility of loop formation on the scale less than Δ). The Hamiltonian does not contain any parameter designed especially for helix-coil transition and uses pure molecular microscopic parameters (the energy of hydrogen bond formation, reduced partition function of repeated unit, the number of repeated units fixed by one hydrogen bond, the energies of interaction between the repeated units and the solvent molecules). To calculate averages we evaluate the partition function using the transfer-matrix approach. The GMPC allowed to describe the influence of a number of factors, affecting the transition, basing on a unified microscopic approach. Thus we obtained, that solvents change transition temperature and interval in different ways, depending on type of solvent and on energy of solvent- macromolecule interaction; stacking on the background of H-bonding increases stability and decreases cooperativity of melting. For heterogeneous DNA we could analytically derive well known formulae for transition temperature and interval. In the framework of GMPC we calculate and show the difference of two order parameters of helix-coil transition - the helicity degree, and the average fraction of repeated units in helical conformation. Given article has the aim to review the results obtained during twenty years in the context of GMPC. (author)

Radionuclide concentrations in white sturgeon from the Columbia River

International Nuclear Information System (INIS)

Dauble, D.D.; Price, K.R.; Poston, T.M.

1993-11-01

The objectives of this study were to (1) review and summarize historical data on radionuclide concentrations in white sturgeon from the Columbia River, (2) determine present-day radionuclide tissue burdens from different locations in the Columbia River, and (3) compare historical data with current data. We first reviewed and summarized the historical literature on radionuclide concentrations in white sturgeon from the Hanford Reach. Field studies were then conducted to evaluate the relationship among sample locations, age/length of white sturgeon, and present radionuclide tissue burdens. Results and comparisons are discussed in the remainder of this report

Radionuclide Therapies in Molecular Imaging and Precision Medicine.

Science.gov (United States)

Kendi, A Tuba; Moncayo, Valeria M; Nye, Jonathon A; Galt, James R; Halkar, Raghuveer; Schuster, David M

2017-01-01

This article reviews recent advances and applications of radionuclide therapy. Individualized precision medicine, new treatments, and the evolving role of radionuclide therapy are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Natural and anthropogenic radionuclide activity concentrations in the New Zealand diet.

Science.gov (United States)

Pearson, Andrew J; Gaw, Sally; Hermanspahn, Nikolaus; Glover, Chris N

2016-01-01

To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for (137)Caesium, (90)Strontium and (131)Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide (210)Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand diet contains activity concentrations of anthropogenic radionuclides far below the Codex Alimentarius guideline levels. Activity concentrations obtained for milk support its continued use as a sentinel for monitoring fallout radionuclides in terrestrial agriculture. The significant levels of natural and anthropogenic radionuclide activity concentrations detected in finfish and molluscs support undertaking further research to identify a suitable sentinel for New Zealand seafood monitoring. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

CRRIS, Health Risk Assessment from Atmospheric Releases of Radionuclides

International Nuclear Information System (INIS)

1999-01-01

1 - Description of program or function: CRRIS consists of eight fully integrated computer codes which calculate environmental transport of atmospheric releases of radionuclides and resulting doses and health risks to individuals or populations. Each code may be used alone for various assessment applications. Because of its modular structure, CRRIS allows assessments to be tailored to the user's needs. Radionuclides are handled by CRRIS either in terms of the released radionuclides or the exposure radionuclides which consist of both the released nuclides and decay products that build up during environmental transport. Atmospheric dispersion calculations are performed by the ANEMOS computer code for distances less than 100 km and the RETADD-II computer code regional-scale distances. Both codes estimate annual-average air concentrations and ground deposition rates by location. SUMIT will translate and scale multiple ANEMOS runs onto a master grid. TERRA reads radionuclide air concentrations and deposition rates to estimate concentrations of radionuclides in food and surface soil. Radiologic decay and ingrowth, soil leaching, and transport through the food chain are included in the calculations. MLSOIL computes an effective radionuclide ground-surface concentration to be used in computing external health effects. The five-layer model of radionuclide transport through soil in MLSOIL provides an alternative to the single-layer model used in TERRA. DFSOIL computes dose factors used in MLSOIL to compute doses from the five soil layers and from the ground surface. ANDROS reads environmental concentrations of radionuclides computed by the other CRRIS codes and produces tables of doses and risks to individuals or populations from atmospheric releases of radionuclides. 2 - Method of solution: SUMIT performs geometric interpolation. TERRA and MLSOIL are terrestrial transport compartment models. DFSOIL computes soil-layer-specific dose factors based on the point-kernel method

Integrated circuits based on conjugated polymer monolayer.

Science.gov (United States)

Li, Mengmeng; Mangalore, Deepthi Kamath; Zhao, Jingbo; Carpenter, Joshua H; Yan, Hongping; Ade, Harald; Yan, He; Müllen, Klaus; Blom, Paul W M; Pisula, Wojciech; de Leeuw, Dago M; Asadi, Kamal

2018-01-31

It is still a great challenge to fabricate conjugated polymer monolayer field-effect transistors (PoM-FETs) due to intricate crystallization and film formation of conjugated polymers. Here we demonstrate PoM-FETs based on a single monolayer of a conjugated polymer. The resulting PoM-FETs are highly reproducible and exhibit charge carrier mobilities reaching 3 cm 2  V -1  s -1 . The high performance is attributed to the strong interactions of the polymer chains present already in solution leading to pronounced edge-on packing and well-defined microstructure in the monolayer. The high reproducibility enables the integration of discrete unipolar PoM-FETs into inverters and ring oscillators. Real logic functionality has been demonstrated by constructing a 15-bit code generator in which hundreds of self-assembled PoM-FETs are addressed simultaneously. Our results provide the state-of-the-art example of integrated circuits based on a conjugated polymer monolayer, opening prospective pathways for bottom-up organic electronics.

The behaviour of radionuclides in soil

International Nuclear Information System (INIS)

Bunzl, K.

1987-01-01

Radionuclides in soil are of natural as well as of artificial origin. Their migration in the soil and their availability for ecological processes depend considerably on the extent at which they are sorbed. The methods for the determination of the vertical rate of migration are described. For most radionuclides this transport is very slow (a few cm per year). Cs-137 is of especial interest. It is sorbed strongly by most soils and, as a consequence, its root uptake is small. However, as a result of the sorption, this radionuclide is eluted from the root zone only very slowly and its thus available for the root uptake for many years. The Cs-137 concentrations in plants to be expected in the coming years as a result of the fallout from Chernobyl are small. (orig.) [de

Transport of radionuclides in the biosphere

International Nuclear Information System (INIS)

Bundi, A.

1983-10-01

The dispersion of radionuclides in the biosphere and their uptake by man via various nutritional pathways is studied using a compartment model. The sample environment is the area of the lower Limmat and Aare valleys. General considerations of the compartmental description of the biosphere are made. The problem of the description of surface features, in particular soil, sediment and water, is studied in detail using the code BIOPATH. This study is intended to be an example of how a model of the biosphere could be constructed. It is shown that this is a reasonable model to calculate the spreading of radionuclides in the biosphere and that it indicates the relative significance of individual compartments, pathways and radionuclides. Calculated values of dose committment, however, should not be used as reference data for safety analyses. (Auth.)

Bone stress: a radionuclide imaging perspective

International Nuclear Information System (INIS)

Roub, L.W.; Gumerman, L.W.; Hanley, E.N. Jr.; Clark, M.W.; Goodman, M.; Herbert, D.L.

1979-01-01

Thirty-five college athletes with lower leg pain underwent radiography and radionuclide studies to rule out a stress fracture. Their asymptomatic extremities and 13 pain-free athletes served as controls. Four main patterns were observed: (a) sharply marginated scintigraphic abnormalities and positive radiographs; (b) sharply marginated scintigraphic abnormalities and negatives radiographs; (c) ill-defined scintigraphic abnormalities and negative radiographs; and (d) negative radionuclide images and negative radiographs. Since the patients with the first two patterns were otherwise identical medically, the authors feel that this scintigraphic appearance is characterisic of bone stress in the appropriate clinical setting, regardless of the radiographic findings. A schema is proposed to explain the occurrence of positive radionuclide images and negative radiographs in the same patient, using a broad conceptual approach to the problem of bone stress

In vivo evaluation of an anti-PSMA antibody conjugated with varying numbers of biotin molecules in a pretargeting protocol

International Nuclear Information System (INIS)

Wilbur, D.S.; Hamlin, D.K.; Quinn, J.; Vessella, R.L.

2003-01-01

An investigation has been conducted to determine the effect of varying the number of biotin molecules conjugated with an anti-PSMA antibody (mAb) as part of our studies to optimize biotinylated antibodies and radiolabeled streptavidin in pretargeting protocols for Targeted Radionuclide Therapy of prostate cancer. In the investigation, the anti-PSMA antibody 107-1A4 was biotinylated with varying amounts of biotinamidocaproate N-hydroxysuccinimide ester. This procedure resulted in obtaining 107-1A4 with 2.3, 4.5, and 6.8 biotin conjugated as measured by the standard HABA assay. The biotinylated 107-1A4 was radioiodinated and was evaluated in a pretargeting protocol in athymic mice bearing LNCaP human tumor xenografts. In the protocol, 50 μg biotinylated [ 125 I]107-1A4 was injected, followed 48h later by 25 μg of avidin for blood clearance, and 1h after that 20 μg of radiolabeled succinylated recombinant streptavidin ([ 13 1I]sSAv) was administered. The tumor localization and tissue distribution was evaluated at 24, 48, and 72h post [ 131 I]sSAv injection. With 2.3 biotin/mAb, an approximate 1:1 molar ratio (4-5 pmol/g) of sSAv/mAb was obtained at all three time points. With 4.5 biotin/mAb, a 1:1 ratio was observed at 24h, but approx. 2: 1 was observed at 48 and 72h pi. With 6.8 biotin/mAb, sSAv/mAb ratios of approximately 1.5:1; 2:1; and 3:1 were obtained at 24, 48, and 72h pi respectively. The amount of sSAv localized in the tumor was nearly the same (4-5 pmol/g) when 107-1A4 had 2.3 or 4.5 biotin conjugated, but decreased to 3-4.5 pmol/g with 6.8 biotin conjugated. Because the highest levels of co-localized sSAv was found with the lowest number of biotin conjugates, the observed differences in ratios of sSAv/mAb may be best explained as differences in internalization, and degradation of mAb and protease resistant sSAv. In duplicate experiments, similar results were obtained with biotinylated 107-1A4 F(ab') 2 , but not with an mAb to a non-internalizing antigen

Radionuclide migration in groundwater. Annual progress report for 1982

International Nuclear Information System (INIS)

Robertson, D.E.; Toste, A.P.; Abel, K.H.; Brodzinski, R.L.

1984-01-01

Research has continued at a low-level waste disposal facility to characterize the physicochemical species of radionuclides migrating in groundwater. This facility consists of an unlined basin and connecting trench which receives effluent water containing low levels of a wide variety of fission and activation products and trace amounts of transuranic radionuclides. The effluent water percolates through the soil and a small fraction of it emerges at seepage springs located some 260 meters from the trench. The disposal basin and trench are very efficient in retaining most of the radionuclides, but trace amounts of a number of radionuclides existing in mobile chemical forms migrate in the groundwater from the trench to the springs. This facility provides the opportunity for characterizing the rates and mechanisms of radionuclide migration in groundwaters, identifying retardation processes, and validating geochemical models. 13 references, 25 figures, 23 tables

METHOD OF CONJUGATED CIRCULAR ARCS TRACING

Directory of Open Access Journals (Sweden)

N. Ageyev Vladimir

2017-01-01

Full Text Available The geometric properties of conjugated circular arcs connecting two points on the plane with set directions of tan- gent vectors are studied in the work. It is shown that pairs of conjugated circular arcs with the same conditions in frontier points create one-parameter set of smooth curves tightly filling all the plane. One of the basic properties of this set is the fact that all coupling points of circular arcs are on the circular curve going through the initially given points. The circle radius depends on the direction of tangent vectors. Any point of the circle curve, named auxiliary in this work, determines a pair of conjugated arcs with given boundary conditions. One more condition of the auxiliary circle curve is that it divides the plane into two parts. The arcs going from the initial point are out of the circle limited by this circle curve and the arcs coming to the final point are inside it. These properties are the basis for the method of conjugated circular arcs tracing pro- posed in this article. The algorithm is rather simple and allows to fulfill all the needed plottings using only the divider and ruler. Two concrete examples are considered. The first one is related to the problem of tracing of a pair of conjugated arcs with the minimal curve jump when going through the coupling point. The second one demonstrates the possibility of trac- ing of the smooth curve going through any three points on the plane under condition that in the initial and final points the directions of tangent vectors are given. The proposed methods of conjugated circular arcs tracing can be applied in solving of a wide variety of problems connected with the tracing of cam contours, for example pattern curves in textile industry or in computer-aided-design systems when programming of looms with numeric control.

Field surveying of radionuclide contamination in forests

International Nuclear Information System (INIS)

Turunen, J.; Rantavaara, A.; Ammann, M.

2009-01-01

Field measurements of radionuclides after an accidental contamination of forests assume the capacity for identification of a number of nuclides in varying source geometries. The continuous redistribution of radionuclides in forests through natural processes implies a decrease of prevailing surface contamination of trees and an increase in activity density on the ground. Portable gamma spectrometers have long been based on Na(I) detectors which, due to their low energy resolution, are not the tool for analysis of contamination from accidental releases of fission and activation products in the first days or weeks after a deposition. Data of airborne radionuclides from the Chernobyl accident in April 1986 were used for demonstration of initial and later distribution of radionuclides as sources of air Kerma in forests. Forest model (FDMF, PV. 6.0) of the RODOS system was used for the assessment of time-dependent Kerma rate from different forest compartments. The results show the fast reduction of activities of short-lived nuclides and their contributions to the Kerma rate in the first weeks and months. The results also give an estimate for the time needed until a gamma spectrometer with a low energy resolution would give useful information about long-lived radioactivity on the forest floor. An example is given on a portable high resolution semiconductor spectrometer that has suitable characteristics for field surveying also during occurrence of a great number of radionuclides contributing to the gamma spectrum. The needs for further research of a recently deposited radionuclide contamination on forest vegetation and soil, and the efforts for improvement of portable radiation meters and their use in management planning and radioecological research on contaminated forests are discussed. (au)

Exchange of certain radionuclides between environment and freshwater algae

International Nuclear Information System (INIS)

Marchyulenene, E. D.P.

1978-01-01

Data on the dynamics and levels of accumulation of strontium, cesium, cerium and ruthenium radionuclides by Charophyta and Cladophora fresh-water algae are presented. An attempt has been made to investigate some processes that accompany the accumulation of radionuclides by plants. Under experimental conditions, the intensity and levels of radionuclide accumulation can be presented in the following order: 144 Ce> 106 Ru> 90 Sr> 137 Cs. The dynamics of radionuclide accumulation varied greatly with the radionuclide and the algae species studied. The 144 Ce accumulation coefficients (AC) in the course of experiment (from 3 hours to 16 days) increased 8-, 9-, 23.4-, 27-, 14.3- and 20.4-fold for Cladophora glomerata, Nitella syncarpa, Nitellopsis obtusa, Chara vulgaris, Ch. rudis, and Ch. aspera, respectively. In the case of 106 Ru, AC for C.glomerata, N. syncarapa, Ch. vulgaris and Ch. rudis increased 34-, 18-,24- and 23-fold, respectively. In all algae species studied the equilibrium of radionuclide accumulation was attained after 2-4 days of experiment. Levels of accumulated 90 Sr and 137 Cs in most species depended on the season while that of 144 Cs and 106 Ru remained constant throughout the vegetation period. The levels of radionuclide elimination, like the accumulation levels, are shown to depend on both isotopes and algae species

Peptide-Carrier Conjugation

DEFF Research Database (Denmark)

Hansen, Paul Robert

2015-01-01

To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

Exposure to radionuclides in smoke from vegetation fires

International Nuclear Information System (INIS)

Carvalho, Fernando P.; Oliveira, João M.; Malta, Margarida

2014-01-01

Naturally occurring radionuclides of uranium, thorium, radium, lead and polonium were determined in bushes and trees and in the smoke from summer forest fires. Activity concentrations of radionuclides in smoke particles were much enriched when compared to original vegetation. Polonium-210 ( 210 Po) in smoke was measured in concentrations much higher than all other radionuclides, reaching 7255 ± 285 Bq kg −1 , mostly associated with the smaller size smoke particles ( 210 Po in surface air near forest fires displayed volume concentrations up to 70 mBq m −3 , while in smoke-free air 210 Po concentration was about 30 μBq m −3 . The estimated absorbed radiation dose to an adult member of the public or a firefighter exposed for 24 h to inhalation of smoke near forest fires could exceed 5 μSv per day, i.e, more than 2000 times above the radiation dose from background radioactivity in surface air, and also higher than the radiation dose from 210 Po inhalation in a chronic cigarette smoker. It is concluded that prolonged exposure to smoke allows for enhanced inhalation of radionuclides associated with smoke particles. Due to high radiotoxicity of alpha emitting radionuclides, and in particular of 210 Po, the protection of respiratory tract of fire fighters is strongly recommended. - Highlights: • Natural radionuclides in vegetation are in low concentrations. • Forest fires release natural radionuclides from vegetation and concentrate them in inhalable ash particles. • Prolonged inhalation of smoke from forest fires gives rise enhanced radiation exposure of lungs especially due to polonium. • Respiratory protection of fire fighters and members of public is highly recommended for radioprotection reasons

Recombinant DNA specifying the human amyloid. beta. precursor protein (ABPP) encodes a 95-kDa polypeptide

Energy Technology Data Exchange (ETDEWEB)

Mita, S; Sadlock, J; Herbert, J; Schon, E A

1988-10-11

Although the ABPP gene give rise to multiple mRNAs, the primary translation product of this gene is unknown. The longest published cDNA sequences predict a 770-aa polypeptide of 87 kDa. However, in immunoblots, ABPP migrated as a single species of >92 kDa in rat brain, and in human, as a species of 95-100 kDa in non-membrane bound form, as multiple species of 110-135 kDa in membrane-associated form and as a 130-kDa species in fibroblasts. The sizes of these larger species relative to the MW of ABPP predicted from the cDNA sequences have been attributed to postranslational modification. However, the authors have isolated a cDNA (lambdaHAP2) from a human fetal muscle lambdagt11 cDNA library encoding an 843-aa polypeptide with a deduced MW of 94,642. This cDNA contains both exons encoding an 843-aa polypeptide with a deduced MW of 94.642. This cDNA contains both exons encoding the protease inhibitor domains. Primer extension analysis indicates that the 5' terminus of this cDNA is 14 nt from a transcriptional start site. This cDNA, encoding the longest ABPP described to date, may explain some of the observations on the sizes of tissue-derived ABPP.