scispace - formally typeset
Search or ask a question
Author

Ronald J. Voll

Bio: Ronald J. Voll is an academic researcher from Emory University. The author has contributed to research in topics: Dopamine transporter & Radioligand. The author has an hindex of 19, co-authored 68 publications receiving 1115 citations. Previous affiliations of Ronald J. Voll include Yerkes National Primate Research Center.


Papers
More filters
Journal ArticleDOI
02 Apr 2012-PLOS ONE
TL;DR: A novel small molecule, MSX-122, is developed that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for long-term blockade of metastasis than other reported CX CR4 antagonists.
Abstract: Background Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4) and its ligand stromal cell-derived factor-1 (CXCL12) interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites.

122 citations

Journal ArticleDOI
TL;DR: An improved synthesis of the precursor of anti-[18F]FACBC has been devised which demonstrates high stereoselectivity and suitability for large-scale preparations, and the major non-radioactive species present in doses of anti- 1-amino-3-hydroxycyclobutane-1-carboxylic acid has been identified.

106 citations

Journal Article
TL;DR: In this article, an initial assessment of the usefulness of 2β-carbomethoxy-3β-(4-chlorophenyl)-8-(2-18F-fluoroethyl)nortropane (18F -FECNT) PET scanning in determining in vivo brain dopamine transporter (DAT) density in healthy humans and subjects with Parkinson's disease (PD).
Abstract: The aim of this study was to do an initial assessment of the usefulness of 2β-carbomethoxy-3β-(4-chlorophenyl)-8-(2-18F-fluoroethyl)nortropane (18F-FECNT) PET scanning in determining in vivo brain dopamine transporter (DAT) density in healthy humans and subjects with Parkinson’s disease (PD). Methods: We investigated 6 neurologically healthy subjects and 5 PD patients: 2 with mild unilateral disease, 1 with mild-to-moderate bilateral disease, and 2 with moderately severe bilateral disease. The healthy subjects underwent a 3-h PET scan (26 frames) and the PD subjects underwent a 2-h PET scan (23 frames) while 18F-FECNT was being injected over the first 5 min of the scan. Arterial blood samples were taken throughout scanning for well-counter and metabolite analysis to determine the presence of possible active metabolites. The scans were reconstructed; then we placed spheric regions of interest in the caudate nuclei, putamena, thalami, brain stem, cerebellum, and occipital cortex of each subject. The radioactivity level in each region was calculated for each frame of a subject’s PET scan. Then we calculated target tissue-to-cerebellum ratios for each time frame. Results: The analysis of arterial blood samples revealed that metabolism of the tracer was rapid. The ether-extractable component of the arterial input was >98% pure 18F-FECNT. The caudate nucleus and putamen exhibited the highest uptake and prolonged retention of the radioligand. They both attained maximum uptake at ∼90 min, with the healthy subjects’ average caudate- and putamen-to-cerebellum ratios (±SD) at that time being 9.0 ± 1.2 and 7.8 ± 0.7, respectively. The maximal caudate-to-cerebellum ratios for the healthy subjects ranged from 7.6 to 10.5 and their maximal putamen-to-cerebellum ratios ranged from 7.1 to 9.3. The 2 early-stage, unilateral PD patients had, at 90 min, an average right caudate-to-cerebellum ratio of 5.3 ± 1.1 and a left ratio of 5.9 ± 0.7 and an average right putamen-to cerebellum ratio of 2.8 ± 0.1 and a left ratio of 3.0 ± 0.6. The late-stage PD patients had, at 90 min, an average right caudate-to-cerebellum ratio of 3.7 ± 0.4 and a left ratio of 3.9 ± 0 and an average right putamen-to cerebellum ratio of 1.8 ± 0.1 and a left ratio of 1.8 ± 0. Conclusion: These results indicate that 18F-FECNT is an excellent candidate radioligand for in vivo imaging of the DAT system in humans. It has a much higher affinity for DAT than for the serotonin transporter and yields the highest peak striatum-to-cerebellum ratios and has among the most favorable kinetics of 18F-radiolabeled DAT ligands. Having picked up presymptomatic changes in the hemisphere opposite the unaffected side of the body in our early-stage (unilateral) PD patients, it appears that, like other DAT radioligands, it may be able to identify presymptomatic PD.

72 citations

Journal ArticleDOI
TL;DR: In vitro experiments indicate that DAT is trafficked into the cell by isoflurane without changing the total amount of DAT in the striatum, and the PET data are consistent with this finding, provided that intracellular DAT acquires a conformation that has low affinity for [18F]FECNT.
Abstract: BackgroundIsoflurane administration is known to increase extracellular dopamine (DA) concentration Because the dopamine transporter (DAT) is a key regulator of DA, it is likely affected by isoflurane This study investigates the hypothesis that isoflurane inhibits DA reuptake by causing DAT to be t

60 citations

Journal ArticleDOI
TL;DR: Two new fluorinated imidazo[1,2-a]pyridine derivatives, 6-(2'-fluoroethyl)-2-(4'-dimethylamino)phenylimidazo(FEPIP) and FPPIP, were synthesized and their binding affinity to amyloid plaques in human AD cortical tissues was determined.

54 citations


Cited by
More filters
Book ChapterDOI
TL;DR: An overview of the 13 Carbon-Nuclear magnetic resonance (13 C-NMR) spectroscopy of monosaccharides can be found in this paper, where an almost complete collection of 13 C- NMR chemical shifts of polysaccharides, their methyl glycosides, and acetates is presented.
Abstract: Publisher Summary This chapter provides an overview of the 13 Carbon-nuclear magnetic resonance ( 13 C-NMR) spectroscopy of monosaccharides. The 13 C-NMR spectroscopy has become increasingly important as a tool for the characterization and structural elucidation of sugars and their derivatives. Although 13 C-NMR is closely related to 1 H-NMR spectroscopy, especially when both types of spectra are recorded with Fourier-transform instruments, the two techniques are sufficiently different to be valuable complements to each other. In many cases, in particular when dealing with complex molecules such as polysaccharides, the amount of information obtainable from 1 H-NMR spectra is limited as compared to that revealed by 13 C- NMR spectra. This chapter provides an almost complete collection of 13 C- NMR chemical shifts of monosaccharides, their methyl glycosides, and acetates, along with the examples of shift data for as many different types of monosaccharide derivative as possible. It also provides details on sampling techniques and assignment techniques, and discusses the identity of monosaccharides, their structure determination, and conformational analysis .

1,273 citations

Journal ArticleDOI

990 citations

Journal ArticleDOI
TL;DR: A wide range of new lead finding and lead optimization opportunities result from novel screening methods by NMR, which are the topic of this review article.
Abstract: In recent years, tools for the development of new drugs have been dramatically improved. These include genomic and proteomic research, numerous biophysical methods, combinatorial chemistry and screening technologies. In addition, early ADMET studies are employed in order to significantly reduce the failure rate in the development of drug candidates. As a consequence, the lead finding, lead optimization and development process has gained marked enhancement in speed and efficiency. In parallel to this development, major pharma companies are increasingly outsourcing many components of drug discovery research to biotech companies. All these measures are designed to address the need for a faster time to market. New screening methodologies have contributed significantly to the efficiency of the drug discovery process. The conventional screening of single compounds or compound libraries has been dramatically accelerated by high throughput screening methods. In addition, in silico screening methods allow the evaluation of virtual compounds. A wide range of new lead finding and lead optimization opportunities result from novel screening methods by NMR, which are the topic of this review article.

803 citations

Journal ArticleDOI
TL;DR: The mechanisms of OXT expression and release, expression and binding of the OXTR in brain and periphery, OX TR-coupled signaling cascades, and their involvement in behavioral outcomes are discussed to assemble a comprehensive picture of the central and peripheral OXT system.
Abstract: The many facets of the oxytocin (OXT) system of the brain and periphery elicited nearly 25,000 publications since 1930 (see FIGURE 1, as listed in PubMed), which revealed central roles for OXT and ...

510 citations