scholarly journals Influence of the Generator in-Growth Time on the Final Radiochemical Purity and Stability of Radiopharmaceuticals

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
L. Uccelli ◽  
A. Boschi ◽  
M. Pasquali ◽  
A. Duatti ◽  
G. Di Domenico ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Growth Time ◽  
Direct Production ◽  
Theoretical Investigations ◽  
Standard Quality ◽  
Control Procedures ◽  
Italian National Institute ◽  
Preliminary Irradiation

At Legnaro laboratories of the Italian National Institute for Nuclear Physics (INFN), a feasibility study has started since 2011 related to accelerated-based direct production of by the100Mo(p,2n) reaction. Both theoretical investigations and some recent preliminary irradiation tests on100Mo-enriched samples have pointed out that both the / ratio and the specific activity will be basically different in the final accelerator-produced Tc with respect to generator-produced one, which might affect the radiopharmaceutical procedures. The aim of this work was to evaluate the possible impact of different / isomeric ratios on the preparation of different Tc-labeled pharmaceutical kits. A set of measurements with , eluted from a standard99Mo/ generator, was performed, and results on both radiochemical purity and stability studies (following the standard quality control procedures) are reported for a set of widely used pharmaceuticals (i.e., -Sestamibi, -ECD, -MAG3, -DTPA, -MDP, -HMDP, -nanocolloids, and -DMSA). These pharmaceuticals have been all reconstituted with either the first [O4]−eluate obtained from a99Mo/ generator (coming from two different companies) or eluates after 24, 36, 48, and 72 hours from last elution. Results show that the radiochemical purity and stability of these radiopharmaceuticals were not affected up to the value of 11.84 for the / ratio.

scholarly journals A likelihood ratio approach for identifying three-quarter siblings in genetic databases

Heredity ◽  
2021 ◽  
Author(s):  
Iván Galván-Femenía ◽  
Carles Barceló-Vidal ◽  
Lauro Sumoy ◽  
Victor Moreno ◽  
Rafael de Cid ◽  
...  
Keyword(s):  
Likelihood Ratio ◽  
Family Relationships ◽  
Genetic Research ◽  
Data Set ◽  
Scientific Disciplines ◽  
Genome Wide ◽  
Standard Quality ◽  
Control Procedures ◽  
Identity By State ◽  
Second Degree

AbstractThe detection of family relationships in genetic databases is of interest in various scientific disciplines such as genetic epidemiology, population and conservation genetics, forensic science, and genealogical research. Nowadays, screening genetic databases for related individuals forms an important aspect of standard quality control procedures. Relatedness research is usually based on an allele sharing analysis of identity by state (IBS) or identity by descent (IBD) alleles. Existing IBS/IBD methods mainly aim to identify first-degree relationships (parent–offspring or full siblings) and second degree (half-siblings, avuncular, or grandparent–grandchild) pairs. Little attention has been paid to the detection of in-between first and second-degree relationships such as three-quarter siblings (3/4S) who share fewer alleles than first-degree relationships but more alleles than second-degree relationships. With the progressively increasing sample sizes used in genetic research, it becomes more likely that such relationships are present in the database under study. In this paper, we extend existing likelihood ratio (LR) methodology to accurately infer the existence of 3/4S, distinguishing them from full siblings and second-degree relatives. We use bootstrap confidence intervals to express uncertainty in the LRs. Our proposal accounts for linkage disequilibrium (LD) by using marker pruning, and we validate our methodology with a pedigree-based simulation study accounting for both LD and recombination. An empirical genome-wide array data set from the GCAT Genomes for Life cohort project is used to illustrate the method.

scholarly journals Early Evaluation of Copper Radioisotope Production at ISOLPHARM

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2437 ◽  
Author(s):  
Francesca Borgna ◽  
Michele Ballan ◽  
Chiara Favaretto ◽  
Marco Verona ◽  
Marianna Tosato ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Specific Activity ◽  
Isotope Separation ◽  
Pure Copper ◽  
Mass Separation ◽  
Monte Carlo Code ◽  
Early Evaluation ◽  
On Line ◽  
Isol Facility

The ISOLPHARM (ISOL technique for radioPHARMaceuticals) project is dedicated to the development of high purity radiopharmaceuticals exploiting the radionuclides producible with the future Selective Production of Exotic Species (SPES) Isotope Separation On-Line (ISOL) facility at the Legnaro National Laboratories of the Italian National Institute for Nuclear Physics (INFN-LNL). At SPES, a proton beam (up to 70 MeV) extracted from a cyclotron will directly impinge a primary target, where the produced isotopes are released thanks to the high working temperatures (2000 °C), ionized, extracted and accelerated, and finally, after mass separation, only the desired nuclei are collected on a secondary target, free from isotopic contaminants that decrease their specific activity. A case study for such project is the evaluation of the feasibility of the ISOL production of 64Cu and 67Cu using a zirconium germanide target, currently under development. The producible activities of 64Cu and 67Cu were calculated by means of the Monte Carlo code FLUKA, whereas dedicated off-line tests with stable beams were performed at LNL to evaluate the capability to ionize and recover isotopically pure copper.

Self-radiation induced exchange between tritiated water and organic compounds. The labelling of L-chiro-inositol, myo-inositol and Hexa-O-methyl-L-chiro-inositol

1975 ◽  
Vol 28 (9) ◽  
pp. 1981 ◽  
Author(s):  
DHT Fong ◽  
CL Bodkin ◽  
MA Long ◽  
JL Garnett
Keyword(s):  
Organic Compounds ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Tritiated Water ◽  
High Specific Activity ◽  
Methyl Derivative ◽  
Radiation Induced ◽  
By Products ◽  
Gas Exposure

The stereochemistry of the tritiation of L-chiro-inositol, myo-inositol and hexa-O-methyl-L-chiro-inositol by self-radiation induced exchange with tritiated water of high specific activity has been investigated. Predominance of configurational retention was found to accompany tritium labelling in the two inositols, while substantial configurational inversion occurred in the hexa-O-methyl derivative. Tritiation occurred predominantly at C 1 in L-chiro-inositol, with slight inversion at this position alone accompanying the labelling. Comparison with Wilzbach T2 gas exposure results indicates the HTO method yields less by-products, myo-inositol having a radiochemical purity of 97%.

Radiosynthesis of a Novel PET Fluoronicotinamide for Melanoma Tumour PET Imaging; [18F]MEL050

2011 ◽  
Vol 64 (7) ◽  
pp. 873 ◽  
Author(s):  
Ivan Greguric ◽  
Stephen Taylor ◽  
Tien Pham ◽  
Naomi Wyatt ◽  
Cathy D. Jiang ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Large Scale ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
Phase 1 ◽  
Radiochemical Yield ◽  
Synthesis Time ◽  
Clinical Phase ◽  
One Step ◽  
No Carrier Added

[18F]6-Fluoro-N-[2-(diethylamino)ethyl]nicotinamide [18F]MEL050 is a novel nicotinamide-based radiotracer, designed to target random metastatic dissemination of melanoma tumours by targeting melanin. Preclinical studies suggest that [18F]MEL050 has an excellent potential to improve diagnosis and staging of melanoma. Here we report the radiochemical optimization conditions of [18F]MEL050 and its large scale automated synthesis using a GE FXFN automated radiosynthesis module for clinical, phase-1 investigation. [18F]MEL050 was prepared via a one-step synthesis using no-carrier added K[18F]F-Krytpofix® 222 (DMSO, 170°C, 5 min) followed by HPLC purification. Using 6-chloro-N-[2-(diethylamino)ethyl]nicotinamide as precursor, [18F]MEL050 was obtained in 40–46% radiochemical yield (non-decay corrected), in greater than 99.9% radiochemical purity and specific activity ranging from 240 to 325 GBq μmol–1. Total synthesis time including formulation was 40 min and [18F]MEL050 was stable (99.8%) in PBS for 6 h.

An improved ultrafiltration method for free thyroxine and triiodothyronine in serum.

1980 ◽  
Vol 26 (1) ◽  
pp. 159-162 ◽  
Author(s):  
J Sophianopoulos ◽  
I Jerkunica ◽  
C N Lee ◽  
D Sgoutas
Keyword(s):  
Radiochemical Purity ◽  
Specific Activity ◽  
Equilibrium Dialysis ◽  
Free Ligand ◽  
High Specific Activity ◽  
Free Thyroxine ◽  
Free Triiodothyronine ◽  
Men And Women ◽  
Adult Men ◽  
Hyperthyroid Patients

Abstract We describe an ultrafiltration technique for rapidly and directly determining free triiodothyronine or free thyroxine, or both. After equilibrating serum at 37 degrees C with purified tracer of high specific activity, we placed 0.15 mL of serum in 2.8 mL of phosphate buffer (0.1 mol/L, pH 7.4) in the ultrafiltration cell and obtained successive 0.2- and 0.6-mL fractions of protein-free ultrafiltrate. Under our conditions free ligand concentration was independent of flow rate. After purifying the second fraction with protein-coated charcoal, we could determine the proportion of free triiodothyronine or free thyroxine. Samples from normal adult men and women, including women who were taking oral contraceptives or were pregnant, and from hypo- and hyperthyroid patients gave results that agreed with those obtained by equilibrium dialysis. Speed is the main advantage of the method: one technologist can complete the procedure in 2 h and, using a multi-micro-ultrafiltration system, can process many samples in one day. For laboratories where index-type reactions are performed routinely and direct free triiodothyronine or free thyroxine is determined only on selected specimens, this method is superior to dialysis. It is also very convenient for rapidly purifying tracers, to at least 97% radiochemical purity, with 94% recovery and no dilution.

Synthesis of 18F-labelled 2-fluoroethyl-nitrosoureas

1984 ◽  
Vol 62 (11) ◽  
pp. 2107-2112 ◽  
Author(s):  
Simin Farrokhzad ◽  
Mirko Diksic ◽  
Lucas Y. Yamamoto ◽  
William Feindel
Keyword(s):  
Radiochemical Purity ◽  
Specific Activity ◽  
Radiochemical Yield ◽  
Nucleophilic Attack ◽  
Aziridine Ring ◽  
Geometrical Isomers ◽  
Isomeric Mixture

18F-labelled 1,3-bis-(2-fluoroethyl) nitrosourea (18F-BFNU) (9) and 1-(2-chloroethyl)-3-(2-fluoroethyl) nitrosourea (18F-CFNU) (isomeric mixture, 11,12) were synthesized by nucleophilic attack of 18F-labelled tetra-n-butylammonium fluoride on the aziridine ring of 1,3-substituted ureas. Diethyleneurea (DEU) (5), 1-(2-fluoroethyl)-3-ethyleneurea (FEU) (7), and 1-(2-chloroethyl)-3-ethyleneurea (CEU) (14) were used as starting materials in the synthesis. Nitrosation of 18F-labelled 1,3-bis-(2-fluoroethyl) urea (18F-BFU) (6) produced 18F-BFNU with a radiochemical yield of 5–10%. Nitrosation of 18F-labelled 1-(2-chloroethyl)-3-(2-fluoroethyl) urea (18F-CFU) (15) gave 18F-CFNU as a mixture of two isomers. Geometrical isomers of CFNU were separated by hplc, and the radiochemical yield of the two isomers ranged from 8% to 15%, with a radiochemical purity exceeding 96%. Syntheses, which took about 60 min, yielded products with specific activity of 680 mCi/mmol when n-Bu4N+F− was used, or 300 mCi/mmol when HF was used to complete the opening of the aziridine ring.

scholarly journals Implementation of a quality control for Radio Occultation observations in the presence of large gradients of atmospheric refractivity

2014 ◽  
Vol 7 (10) ◽  
pp. 10487-10511
Author(s):  
L. Cucurull
Keyword(s):  
Quality Control ◽  
Radio Occultation ◽  
Model Simulation ◽  
Retrieval Process ◽  
Current Standard ◽  
Quality Controls ◽  
Standard Quality ◽  
Control Procedures ◽  
Tropical Troposphere ◽  
Environmental Prediction

Abstract. In preparation for the launch of the first six satellites of the COSMIC-2 mission in equatorial orbit, and the larger number of observations that such a mission will provide in the lower tropical troposphere, work is underway at the National Oceanic and Atmospheric Administration (NOAA) to improve the assimilation of Radio Occultation (RO) observations, particularly in the lower tropical troposphere. As part of the improvement of the bending angle forward operator at the National Centers for Environmental Prediction (NCEP), additional quality controls aimed to detect and reject observations that might have been affected by super-refraction conditions have been implemented and tested. The updated quality control procedures also address the situation where the model detects atmospheric super-refraction conditions. This paper describes the limitations of the current standard quality controls and discusses the implementation of additional quality control procedures to address the limitations of assimilating observations likely affected by the super-refraction conditions, either in the model simulation or in the retrieval process.

scholarly journals Implementation of a quality control for radio occultation observations in the presence of large gradients of atmospheric refractivity

2015 ◽  
Vol 8 (3) ◽  
pp. 1275-1285 ◽  
Author(s):  
L. Cucurull
Keyword(s):  
Quality Control ◽  
Radio Occultation ◽  
Model Simulation ◽  
Retrieval Process ◽  
Current Standard ◽  
Quality Controls ◽  
Standard Quality ◽  
Control Procedures ◽  
Tropical Troposphere ◽  
Environmental Prediction

Abstract. In preparation for the launch of the first six satellites of the COSMIC-2 mission in equatorial orbit, and the larger number of observations that such a mission will provide in the lower tropical troposphere, work is underway at the National Oceanic and Atmospheric Administration (NOAA) to improve the assimilation of radio occultation (RO) observations, particularly in the lower tropical troposphere. As part of the improvement of the bending angle forward operator at the National Centers for Environmental Prediction (NCEP), additional quality controls aimed to detect and reject observations that might have been affected by super-refraction conditions have been implemented and tested. The updated quality control procedures also address the situation where the model detects atmospheric super-refraction conditions. This paper describes the limitations of the current standard quality controls and discusses the implementation of additional quality control procedures to address the limitations of assimilating observations likely affected by the super-refraction conditions, either in the model simulation or in the retrieval process.

scholarly journals KARAKTERISASI FISIKO-KIMIA RADIOISOTOP 149Pm HASIL IRADIASI BAHAN SASARAN 148Nd ALAM

2015 ◽  
Vol 16 (1) ◽  
pp. 29
Author(s):  
Azmairit Aziz ◽  
Nana Suherman
Keyword(s):  
Cancer Therapy ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Chemical Characterization ◽  
Irradiation Position ◽  
Radionuclide Purity ◽  
Physico Chemical ◽  
Carrier Free

ABSTRAK KARAKTERISASI FISIKO-KIMIA RADIOISOTOP 149Pm HASIL IRADIASI BAHAN SASARAN 148Nd ALAM. Penyakit kanker merupakan salah satu masalah utama yang dihadapi Indonesia di bidang kesehatan. Radioisotop pemancar-β- dengan aktivitas jenis tinggi dapat digunakan untuk penandaan biomolekul sebagai radiofarmaka spesifik target untuk terapi sel kanker. Promesium-149 (149Pm) merupakan salah satu radiolantanida pemancar-β- yang me-miliki energi beta (Eβ-)maksimum sebesar 1,07 MeV (95,9 %) dan dapat dipertimbangkan untuk digunakan pada terapi kanker berdasarkan sifat nuklir yang dimilikinya. Radioisotop 149Pm dapat dibuat dengan cara tidak langsung melalui reaksi inti (n,γ) di reaktor nuklir menggunakan bahan sasaran isotop 148Nd (neodymium-148) dan radioisotop 149Pm yang dihasilkan adalah bebas pengemban (carrier free) sehingga memiliki aktivitas jenis tinggi. Pada penelitian ini digunakan bahan sasaran Nd2O3 alam yang diiradiasi selama ± 4 hari di Central Irradiation Position (CIP) RSG-G.A.Siwabessy – Serpong pada fluks neutron termal ~1014 n.cm-2.det-1. Radioisotop 149Pm dipisahkan dari bahan sasaran Nd2O3 hasil iradiasi menggunakan metode kromatografi ekstraksi. Larutan radioisotop 149PmCl3 yang dihasilkan dikarakterisasi secara fisiko-kimia meliputi penentuan kemurnian radiokimia menggunakan metode kromatografi kertas dan elektroforesis kertas. Kemurnian radionuklida ditentukan menggunakan spektro-meter-γ dengan detektor HP-Ge yang dilengkapi multichannel analyzer (MCA). Larutan 149PmCl3 yang diperoleh berupa larutan jernih, memiliki pH 2 dan konsentrasi radioaktif 4,2 – 7,4 mCi/mL. Larutan 149PmCl3 memiliki kemurnian radiokimia 99,70 ± 0,23% dan kemurnian radionuklida setelah pendinginan selama 9 hari sebesar 98,58 ± 0,44%. Larutan 149PmCl3 stabil selama 2 minggu pada temperatur kamar. Larutan radioisotop 149PmCl3 memiliki karakteristik fisiko-kimia yang memenuhi persyaratan untuk digunakan dalam pembuatan radiofarmaka ABSTRACT  PHYSICO - CHEMICAL CHARACTERIZATION OF 149Pm RADIOISOTOPE FROM IRRADIATED NATURAL 148Nd TARGET. Cancer is one of the major problems encountered in the field of health in Indonesia. A beta-emitting radioisotope with high specific activity can be used for labeling of biomolecules as a targeted radiopharmaceutical for cancer therapy. Promethium-149 (149Pm) is one of beta-emitting radiolanthanides with beta energy (Eβ-) maximum of 1.07 MeV (95.9%) and can be considered to be used for cancer therapy based on its nuclear properties. Radioisotope of 149Pm can be produced by indirect methode through (n,γ) reaction in nuclear reactor using 148Nd (neodymium-148) target material and 149Pm was produced as a carrier free radioisotope, so that it has high specific activity. In this study, natural Nd2O3 target was irradiated for ± 4 days in central irradiation position (CIP) of RSG-G.A. Siwabessy – Serpong at a thermal neutron flux of ~ 1014 n.cm-2.sec-1. Radioisotope of 149Pm was separated from irradiated of Nd2O3 target using extraction chromatography method. The physico-chemical characterization of 149PmCl3 solution was studied involves the determination of its radiochemical purity using paper chromatography and paper electrophoresis methods. The radionuclide purity was determined using a γ-spectrometer with  HP-Ge detector and coupled with a multichannel analyzer (MCA). 149PmCl3 was obtained as a clear solution, has a pH of 2 and  radioactive concentration of 4.2 to 7.4 mCi/mL. 149PmCl3 solution has radiochemical purity of 99.70 ± 0.23% and radionuclide purity after cooling for 9 days of 98.58 ± 0.44%. 149PmCl3 solution was stable for 2 weeks at room temperature. 149PmCl3 solution has the physico-chemical characteristics that meet requirements for use in preparation of radiopharmaceuticals.

Sign in / Sign up

Export Citation Format

Share Document