The labeling of brassinosteroids by tritium

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

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Production of Sm-153 With Very High Specific Activity for Targeted Radionuclide Therapy

Frontiers in Medicine ◽

10.3389/fmed.2021.675221 ◽

2021 ◽

Vol 8 ◽

Author(s):

Michiel Van de Voorde ◽

Charlotte Duchemin ◽

Reinhard Heinke ◽

Laura Lambert ◽

Eric Chevallay ◽

...

Keyword(s):

Neutron Irradiation ◽

Radionuclide Therapy ◽

High Efficiency ◽

Separation Efficiency ◽

Specific Activity ◽

High Specific Activity ◽

Mass Separation ◽

Full Potential ◽

Targeted Radionuclide Therapy ◽

Very High

Samarium-153 (153Sm) is a highly interesting radionuclide within the field of targeted radionuclide therapy because of its favorable decay characteristics. 153Sm has a half-life of 1.93 d and decays into a stable daughter nuclide (153Eu) whereupon β− particles [E = 705 keV (30%), 635 keV (50%)] are emitted which are suitable for therapy. 153Sm also emits γ photons [103 keV (28%)] allowing for SPECT imaging, which is of value in theranostics. However, the full potential of 153Sm in nuclear medicine is currently not being exploited because of the radionuclide's limited specific activity due to its carrier added production route. In this work a new production method was developed to produce 153Sm with higher specific activity, allowing for its potential use in targeted radionuclide therapy. 153Sm was efficiently produced via neutron irradiation of a highly enriched 152Sm target (98.7% enriched, σth = 206 b) in the BR2 reactor at SCK CEN. Irradiated target materials were shipped to CERN-MEDICIS, where 153Sm was isolated from the 152Sm target via mass separation (MS) in combination with laser resonance enhanced ionization to drastically increase the specific activity. The specific activity obtained was 1.87 TBq/mg (≈ 265 times higher after the end of irradiation in BR2 + cooling). An overall mass separation efficiency of 4.5% was reached on average for all mass separations. Further radiochemical purification steps were developed at SCK CEN to recover the 153Sm from the MS target to yield a solution ready for radiolabeling. Each step of the radiochemical process was fully analyzed and characterized for further optimization resulting in a high efficiency (overall recovery: 84%). The obtained high specific activity (HSA) 153Sm was then used in radiolabeling experiments with different concentrations of 4-isothiocyanatobenzyl-1,4,7,10-tetraazacyclododecane tetraacetic acid (p-SCN-Bn-DOTA). Even at low concentrations of p-SCN-Bn-DOTA, radiolabeling of 0.5 MBq of HSA 153Sm was found to be efficient. In this proof-of-concept study, we demonstrated the potential to combine neutron irradiation with mass separation to supply high specific activity 153Sm. Using this process, 153SmCl3 suitable for radiolabeling, was produced with a very high specific activity allowing application of 153Sm in targeted radionuclide therapy. Further studies to incorporate 153Sm in radiopharmaceuticals for targeted radionuclide therapy are ongoing.

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Eine Methode zur qualitativen und quantitativen Bestimmung von drei Juvenilhormonen von Insekten

Zeitschrift für Naturforschung C ◽

10.1515/znc-1974-3-412 ◽

1974 ◽

Vol 29 (3-4) ◽

pp. 161-168 ◽

Cited By ~ 41

Author(s):

K. H. Trautmann ◽

A. Schuler ◽

M. Suchý ◽

H.-K. Wipf

Keyword(s):

Quantitative Determination ◽

Specific Activity ◽

High Specific Activity ◽

Ether Extract ◽

Qualitative And Quantitative ◽

Work Up ◽

First Time ◽

Very High ◽

Tenebrio Molitor Larvae

Abstract A method is presented permitting the qualitative and quantitative determination of all three presently known hormones (JH1-3). The determination is based on the method of radioactive isotope dilution, whereby a very small known amount of tritium-labelled JH-1 is added to the ether extract of the particular species. The addition of radioactive JH-1 permits the isolation of all three hormones, because of their similar behaviour during the chosen work up. The quantitative determination was carried out by gas chromatography and the identification was confirmed with the help of retention-times and GC-MS combination. The method was checked by using an extract of Hyalophora cecropia. For the first time methyl 10,11-epoxy-3,7,11-trimethyl-2-trans-6-trans-dodecadienoate (JH-3) could also be identified as the juvenile hormone of Melolontha melolontha. In Vanessa io larvae, Tenebrio molitor larvae and adults and in Musca domestica larvae none of the three known hormones could be detected. The preparation of JH-1 labelled with tritium in the methyl group of the ester was accomplished with very high specific activity (4.34 Ci/mmol) of the tritiated acid with diazomethane.

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Allele-Specific Hybridization Using Oligonucleotide Probes of Very High Specific Activity: Discrimination of the Human βA- and βS-Globin Genes

DNA ◽

10.1089/dna.1.1984.3.7 ◽

1984 ◽

Vol 3 (1) ◽

pp. 7-15 ◽

Cited By ~ 82

Author(s):

ANNA B. STUDENCKI ◽

R. BRUCE WALLACE

Keyword(s):

Specific Activity ◽

High Specific Activity ◽

Oligonucleotide Probes ◽

Globin Genes ◽

Specific Hybridization ◽

Allele Specific ◽

Very High

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Modified Method for the Preparation of Purified Bovine Prothrombin of High Specific Activity

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651194 ◽

1968 ◽

Vol 19 (01/02) ◽

pp. 178-185 ◽

Cited By ~ 8

Author(s):

O. P Malhotra ◽

J. R Carter

Keyword(s):

Moving Boundary ◽

Specific Activity ◽

High Specific Activity ◽

Disc Electrophoresis ◽

Factor Vii ◽

Voltage Gradient ◽

Factor V ◽

Isolation And Purification ◽

Modified Method ◽

Very High

SummaryA modified method for the isolation and purification of bovine prothrombin is described. The preparations have a very high specific activity, viz. 3,200 ± 200 u/mg of protein, show a single symmetrical peak in the analytical ultracentrifuge and by moving boundary electrophoresis at both pH 6.86 and 8.6. They do not undergo inactivation or dissociation during electrophoresis at high voltage gradient (7.5) at alkaline pH. Disc electrophoresis also shows essentially a single component. For optimal activation, prothrombin requires the presence of factor VII-X complex in addition to factor V.

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Discovery and molecular and biocatalytic properties of hydroxynitrile lyase from an invasive millipede,Chamberlinius hualienensis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1508311112 ◽

2015 ◽

Vol 112 (34) ◽

pp. 10605-10610 ◽

Cited By ~ 37

Author(s):

Mohammad Dadashipour ◽

Yuko Ishida ◽

Kazunori Yamamoto ◽

Yasuhisa Asano

Keyword(s):

Specific Activity ◽

Enantiomeric Excess ◽

High Specific Activity ◽

Potassium Cyanide ◽

Aromatic Aldehydes ◽

Building Blocks ◽

Industrial Biotechnology ◽

Hydroxynitrile Lyase ◽

Wide Range ◽

Very High

Hydroxynitrile lyase (HNL) catalyzes the degradation of cyanohydrins and causes the release of hydrogen cyanide (cyanogenesis). HNL can enantioselectively produce cyanohydrins, which are valuable building blocks for the synthesis of fine chemicals and pharmaceuticals, and is used as an important biocatalyst in industrial biotechnology. Currently, HNLs are isolated from plants and bacteria. Because industrial biotechnology requires more efficient and stable enzymes for sustainable development, we must continuously explore other potential enzyme sources for the desired HNLs. Despite the abundance of cyanogenic millipedes in the world, there has been no precise study of the HNLs from these arthropods. Here we report the isolation of HNL from the cyanide-emitting invasive millipedeChamberlinius hualienensis, along with its molecular properties and application in biocatalysis. The purified enzyme displays a very high specific activity in the synthesis of mandelonitrile. It is a glycosylated homodimer protein and shows no apparent sequence identity or homology with proteins in the known databases. It shows biocatalytic activity for the condensation of various aromatic aldehydes with potassium cyanide to produce cyanohydrins and has high stability over a wide range of temperatures and pH values. It catalyzes the synthesis of (R)-mandelonitrile from benzaldehyde with a 99% enantiomeric excess, without using any organic solvents. Arthropod fauna comprise 80% of terrestrial animals. We propose that these animals can be valuable resources for exploring not only HNLs but also diverse, efficient, and stable biocatalysts in industrial biotechnology.

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