scholarly journals Synthesis and Initial In Vivo Evaluation of [11C]AZ683 – a Novel PET Radiotracer for Colony Stimulating Factor 1 Receptor (CSF1R)

2018 ◽  
Author(s):  
Sean S. Tanzey ◽  
Xia Shao ◽  
Jenelle Stauff ◽  
Janna Arteaga ◽  
Phillip Sherman ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Colony Stimulating Factor ◽  
Positron Emission ◽  
New Strategy ◽  
Activity Yield ◽  
Stimulating Factor

Positron emission tomography (PET) imaging of Colony Stimulating Factor 1 Receptor (CSF1R) is a new strategy for quantifying both neuroinflammation and inflammation in the periphery since CSF1R is expressed on microglia. AZ683 has high affinity for CSF1R (Ki = 8 nM; IC50 = 6 nM) and >250-fold selectivity over 95 other kinases and, in this paper, we report the radiosynthesis of [11C]AZ683 and initial evaluation of its use in CSF1R PET. [11C]AZ683 was synthesized by 11C-methylation of the desmethyl precursor with [11C]MeOTf in 3.0% non-corrected activity yield (based upon [11C]MeOTf), >99% radiochemical purity and high specific activity. Preliminary PET imaging with [11C]AZ683 revealed no brain uptake in rodents and nonhuman primates suggesting that [11C]AZ683 is a poor candidate for imaging neuroinflammation, but that it could still be useful for peripheral imaging of inflammation.

scholarly journals Synthesis and Initial In Vivo Evaluation of [11C]AZ683—A Novel PET Radiotracer for Colony Stimulating Factor 1 Receptor (CSF1R)

2018 ◽  
Vol 11 (4) ◽  
pp. 136 ◽  
Author(s):  
Sean Tanzey ◽  
Xia Shao ◽  
Jenelle Stauff ◽  
Janna Arteaga ◽  
Phillip Sherman ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Radiochemical Purity ◽  
Colony Stimulating Factor ◽  
In Vivo Evaluation ◽  
Molar Activity ◽  
Positron Emission ◽  
New Strategy ◽  
Activity Yield ◽  
Stimulating Factor

Positron emission tomography (PET) imaging of Colony Stimulating Factor 1 Receptor (CSF1R) is a new strategy for quantifying both neuroinflammation and inflammation in the periphery since CSF1R is expressed on microglia and macrophages. AZ683 has high affinity for CSF1R (Ki = 8 nM; IC50 = 6 nM) and >250-fold selectivity over 95 other kinases. In this paper, we report the radiosynthesis of [11C]AZ683 and initial evaluation of its use in CSF1R PET. [11C]AZ683 was synthesized by 11C-methylation of the desmethyl precursor with [11C]MeOTf in 3.0% non-corrected activity yield (based upon [11C]MeOTf), >99% radiochemical purity and high molar activity. Preliminary PET imaging with [11C]AZ683 revealed low brain uptake in rodents and nonhuman primates, suggesting that imaging neuroinflammation could be challenging but that the radiopharmaceutical could still be useful for peripheral imaging of inflammation.

scholarly journals In vitro and in vivo hematopoietic effect of mutant human granulocyte colony-stimulating factor [see comments]

Blood ◽  
1990 ◽  
Vol 75 (9) ◽  
pp. 1788-1793 ◽  
Author(s):  
M Okabe ◽  
M Asano ◽  
T Kuga ◽  
Y Komatsu ◽  
M Yamasaki ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Intravenous Injection ◽  
Specific Activity ◽  
High Specific Activity ◽  
Daily Injection ◽  
Total Leukocyte Count ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Stimulating Factor

About 100 derivatives of human recombinant granulocyte colony- stimulating factor (rhG-CSF) were created by various gene-mutagenic techniques, and KW-2228, in which amino acids were replaced at five positions of N-terminal region of intact rhG-CSF, was picked up and evaluated for its biologic and physicochemical properties in comparison with intact rhG-CSF. KW-2228 showed two to four times higher specific activity than that of intact rhG-CSF in mouse and/or human bone marrow progenitor cells by colony-forming unit assay in soft agar, and by cell- proliferation assay in liquid culture. KW-2228 showed a potency to increase peripheral neutrophil counts when it was administered to normal C3H/He mice by single intravenous injection. Increase of total leukocyte count and neutrophils was observed, with peak level at 8 to 12 hours at low doses (0.5 to 1.0 micrograms/mouse), and the highest level was maintained for 24 to 30 hours at high doses (5 to 10 micrograms/mouse). The granulopoietic effect of KW-2228 was examined by several doses of single course (once daily for 10 days) or multiple courses (twice daily injection for 5 days followed by cessation for 9 days on one cycle, 3 cycles in total) of treatment. KW-2228 showed higher activity than that of rhG-CSF, especially at sub-optimal doses of multiple courses of treatment. Furthermore, KW-2228 was found to be more stable physicochemically and biologically than intact rhG-CSF, especially under thermal conditions at 56 degrees C and in the human plasma at 37 degrees C, suggesting a protease resistancy. Pharmacokinetic study showed that plasma concentration of KW-2228 assayed for its bioactivity maintained a higher level than that of intact rhG-CSF for 60 minutes after intravenous injection of this protein to normal mice. Those results suggest that KW-2228 might show a superior in vivo hematopoietic effect to intact rhG-CSF due to its high specific activity to progenitor cells, and also due to its improved physicochemical, biologic, and pharmacokinetic stability in host animals.

scholarly journals In vitro and in vivo hematopoietic effect of mutant human granulocyte colony-stimulating factor [see comments]

Blood ◽  
1990 ◽  
Vol 75 (9) ◽  
pp. 1788-1793 ◽  
Author(s):  
M Okabe ◽  
M Asano ◽  
T Kuga ◽  
Y Komatsu ◽  
M Yamasaki ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Intravenous Injection ◽  
Specific Activity ◽  
High Specific Activity ◽  
Daily Injection ◽  
Total Leukocyte Count ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Stimulating Factor

Abstract About 100 derivatives of human recombinant granulocyte colony- stimulating factor (rhG-CSF) were created by various gene-mutagenic techniques, and KW-2228, in which amino acids were replaced at five positions of N-terminal region of intact rhG-CSF, was picked up and evaluated for its biologic and physicochemical properties in comparison with intact rhG-CSF. KW-2228 showed two to four times higher specific activity than that of intact rhG-CSF in mouse and/or human bone marrow progenitor cells by colony-forming unit assay in soft agar, and by cell- proliferation assay in liquid culture. KW-2228 showed a potency to increase peripheral neutrophil counts when it was administered to normal C3H/He mice by single intravenous injection. Increase of total leukocyte count and neutrophils was observed, with peak level at 8 to 12 hours at low doses (0.5 to 1.0 micrograms/mouse), and the highest level was maintained for 24 to 30 hours at high doses (5 to 10 micrograms/mouse). The granulopoietic effect of KW-2228 was examined by several doses of single course (once daily for 10 days) or multiple courses (twice daily injection for 5 days followed by cessation for 9 days on one cycle, 3 cycles in total) of treatment. KW-2228 showed higher activity than that of rhG-CSF, especially at sub-optimal doses of multiple courses of treatment. Furthermore, KW-2228 was found to be more stable physicochemically and biologically than intact rhG-CSF, especially under thermal conditions at 56 degrees C and in the human plasma at 37 degrees C, suggesting a protease resistancy. Pharmacokinetic study showed that plasma concentration of KW-2228 assayed for its bioactivity maintained a higher level than that of intact rhG-CSF for 60 minutes after intravenous injection of this protein to normal mice. Those results suggest that KW-2228 might show a superior in vivo hematopoietic effect to intact rhG-CSF due to its high specific activity to progenitor cells, and also due to its improved physicochemical, biologic, and pharmacokinetic stability in host animals.

In vivo preparation of [32P]cAMP and thin-layer chromatography of cAMP-related compounds

1979 ◽  
Vol 57 (11) ◽  
pp. 1281-1283
Author(s):  
Hiroshi Yamazaki ◽  
Kwok-Luen Leung ◽  
Ann D. E. Feaser
Keyword(s):  
Wild Type Strain ◽  
Radiochemical Purity ◽  
Specific Activity ◽  
High Specific Activity ◽  
Alumina Column ◽  
Alumina Column Chromatography ◽  
Camp Metabolism ◽  
Layer Chromatography ◽  
Related Compounds

A simple and rapid method for preparing [32P]adenosine 3′,5′-cyclic monophosphate (cAMP) is described. A culture of an Escherichia coli mutant which excretes cAMP about 150 times faster than does a wild-type strain was incubated overnight with [82P]orthophosphate of high specific activity (e.g., 4000 Ci/mol (1 Ci = 37 GBq)). The [32P]cAMP which accumulated extracellularly was then purified to 99.9% radiochemical purity in less than 4 h by adsorption to charcoal and alumina column chromatography. A two-dimensional chromatography system using a PEI-cellulose plate is also described which should prove useful for studying cAMP metabolism with 32P- or 3H-labeled cAMP or ATP.

Interaction of Colony-Stimulating Factors and Fluorodeoxyglucose F18 Positron Emission Tomography

2002 ◽  
Vol 36 (11) ◽  
pp. 1796-1799 ◽  
Author(s):  
Dmitri Mayer ◽  
Edward M Bednarczyk
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Fdg Pet ◽  
Emission Tomography ◽  
Colony Stimulating Factor ◽  
Colony Stimulating Factors ◽  
Positron Emission ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

OBJECTIVE: To evaluate reports of altered diagnostic images with fluorodeoxyglucose F18 (FDG) positron emission tomography (PET) after treatment with colony-stimulating factors (CSFs). DATA SOURCES: Literature was identified by a MEDLINE search (1966–December 2001). Key search terms included granulocyte colony-stimulating factor, granulocyte—macrophage colony-stimulating factor, macrophage colony-stimulating factor, fluorodeoxyglucose, and emission-computed tomography. English language literature was reviewed. DATA SYNTHESIS: Reports have suggested altered FDG PET images following CSF treatment. Studies that assessed the effect of CSF administration on FDG PET imaging of the bone and bone marrow were reviewed. CONCLUSIONS: Administration of CSFs may interfere with accurate FDG PET imaging. Separating FDG PET imaging from CSF therapy by ≥5 days may diminish this interference.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

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.

scholarly journals Development of a blood sample detector for multi-tracer positron emission tomography using gamma spectroscopy

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Carlos Velasco ◽  
Adriana Mota-Cobián ◽  
Jesús Mateo ◽  
Samuel España
Keyword(s):  
Positron Emission Tomography ◽  
Blood Sample ◽  
Pet Imaging ◽  
Spectroscopic Analysis ◽  
Gamma Spectroscopy ◽  
Emission Tomography ◽  
Blood Samples ◽  
Positron Emission

Abstract Background Multi-tracer positron emission tomography (PET) imaging can be accomplished by applying multi-tracer compartment modeling. Recently, a method has been proposed in which the arterial input functions (AIFs) of the multi-tracer PET scan are explicitly derived. For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter. Alternatively, these blood samples required for the spectroscopic analysis may be obtained and analyzed on site by an automated detection device, thus minimizing analysis time and radiation exposure of the operating personnel. In this work, a new automated blood sample detector based on silicon photomultipliers (SiPMs) for single- and multi-tracer PET imaging is presented, characterized, and tested in vitro and in vivo. Results The detector presented in this work stores and analyzes on-the-fly single and coincidence detected events. A sensitivity of 22.6 cps/(kBq/mL) and 1.7 cps/(kBq/mL) was obtained for single and coincidence events respectively. An energy resolution of 35% full-width-half-maximum (FWHM) at 511 keV and a minimum detectable activity of 0.30 ± 0.08 kBq/mL in single mode were obtained. The in vivo AIFs obtained with the detector show an excellent Pearson’s correlation (r = 0.996, p < 0.0001) with the ones obtained from well counter analysis of discrete blood samples. Moreover, in vitro experiments demonstrate the capability of the detector to apply the gamma spectroscopic analysis on a mixture of 68Ga and 18F and separate the individual signal emitted from each one. Conclusions Characterization and in vivo evaluation under realistic experimental conditions showed that the detector proposed in this work offers excellent sensibility and stability. The device also showed to successfully separate individual signals emitted from a mixture of radioisotopes. Therefore, the blood sample detector presented in this study allows fully automatic AIFs measurements during single- and multi-tracer PET studies.

Sign in / Sign up

Export Citation Format

Share Document