Search results for "TRACER"
showing 10 items of 145 documents
The brainstem efferent acoustic chiasm in pigmented and albino rats
2015
Abstract The present study examined whether structural peculiarities in the brain-efferent pathway to the organ of Corti may underlie functional differences in hearing between pigmented and albino individuals of the same mammalian species. Pigmented Brown-Norway rats and albino Wistar rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani of the cochlea to identify olivocochlear neurons (OCN) in the brainstem superior olivary complex. After five days, brains were perfusion-fixed and brainstem sections were cut and analyzed with respect to retrogradely labeled neurons. Intrinsic neurons of the lateral system were lo…
Mercury concentration, speciation and budget in volcanic aquifers: Italy and Guadeloupe (Lesser Antilles)
2009
Abstract Quantifying the contribution of volcanism to global mercury (Hg) emissions is important to understand the pathways and the mechanisms of Hg cycling through the Earth's geochemical reservoirs and to assess its environmental impacts. While previous studies have suggested that degassing volcanoes might contribute importantly to the atmospheric budget of mercury, little is known about the amount and behaviour of Hg in volcanic aquifers. Here we report on detailed investigations of both the content and the speciation of mercury in aquifers of active volcanoes in Italy and Guadeloupe Island (Lesser Antilles). In the studied groundwaters, total Hg (THg) concentrations range from 10 to 500…
PET: Theoretical Background and Practical Aspects
2012
Positron emission tomography (PET) is a nuclear medicine imaging tool utilized for investigation of physiological processes in vivo. PET uses the decay characteristics of positron-emitting radionuclides which are produced in a cyclotron and then used to label compounds involved in physiological processes. Usually, the labeled compound—the tracer—is administered intravenously and distributed in the tissue. The radionuclide decays and the emitted photons are detected by the PET scanner. PET then offers the possibility to compute three-dimensional images of the biodistribution and kinetics of the regional radioactivity concentration. There are several options to analyze reconstructed PET image…
In vivo triglyceride synthesis in subcutaneous adipose tissue of humans correlates with plasma HDL parameters
2016
Backgrounds and aims: Low concentrations of plasma HDL-C are associated with the development of atherosclerotic cardiovascular diseases and type 2 diabetes. Here we aimed to explore the relationship between the in vivo fractional synthesis of triglycerides (fTG) in subcutaneous (s.q.) abdominal adipose tissue (AT), HDL-C concentrations and HDL particle size composition in non-diabetic humans. Methods: The fTG in s.q. abdominal AT was measured in 16 non-diabetic volunteers (7 women, 9 men; Age: 49 ± 20 years; BMI: 31 ± 5 kg/m; Fasting Plasma Glucose: 90 ± 10 mg/dl) after 2H2O labeling. HDL-C concentration and subclasses, large (L-HDL), intermediate (I-HDL) and small (S-HDL) were measured. Re…
Neuroprotective effect of erythropoietin and darbepoetin alfa after experimental intracerebral hemorrhage.
2009
OBJECTIVE: Intracerebral hemorrhage (ICH) is a devastating clinical syndrome for which no truly efficacious therapy has yet been identified. In preclinical studies, erythropoietin (EPO) and its long-lasting analog, darbepoetin alfa, have been demonstrated to be neuroprotective in several models of neuronal insult. The objectives of this study were to analyze whether the systemic administration of recombinant human EPO (rHuEPO) and its long-lasting derivative darbepoetin alfa expedited functional recovery and brain damage in a rat model of ICH. METHODS: Experimental ICH was induced in rats by injecting autologous blood into the right striatum under stereotactic guidance. Subsequently, animal…
Evaluating equilibrium and non-equilibrium transport of bromide and isoproturon in disturbed and undisturbed soil columns.
2007
19 pages; International audience; In this study, displacement experiments of isoproturon were conducted in disturbed and undisturbed columns of a silty clay loam soil under similar rainfall intensities. Solute transport occurred under saturated conditions in the undisturbed soil and under unsaturated conditions in the sieved soil because of a greater bulk density of the compacted undisturbed soil compared to the sieved soil. The objective of this work was to determine transport characteristics of isoproturon relative to bromide tracer. Triplicate column experiments were performed with sieved (structure partially destroyed to simulate conventional tillage) and undisturbed (structure preserve…
Reinvestigation of the synthesis and evaluation of [N-methyl-11C]vorozole, a radiotracer targeting cytochrome P450 aromatase
2009
Abstract Introduction We reinvestigated the synthesis of [ N -methyl- 11 C]vorozole, a radiotracer for aromatase, and discovered the presence of an N -methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [ N -methyl- 11 C]vorozole. Methods Norvorozole was alkylated with [ 11 C]methyl iodide as previously described and also with unlabeled methyl iodide. A high-performance liquid chromatography (HPLC) method was developed to separate the regioisomers. Nuclear magnetic resonance (NMR) spectroscopy ( 13 C and 2D-nuclear Overhauser effect spectroscopy NMR) was used to identify and assign s…
Dual-Time Point [68Ga]Ga-PSMA-11 PET/CT Hybrid Imaging for Staging and Restaging of Prostate Cancer
2020
Routine [68Ga]Ga-PSMA-11 PET/CT (one hour post-injection) has been shown to accurately detect prostate cancer (PCa) lesions. The goal of this study is to evaluate the benefit of a dual-time point imaging modality for the staging and restaging of PCa patients. Biphasic [68Ga]Ga-PSMA-11 PET/CT of 233 patients, who underwent early and late scans (one/three hours post-injection), were retrospectively studied. Tumor uptake and biphasic lesion detection for 215 biochemically recurrent patients previously treated for localized PCa (prostatectomized patients (P-P)/irradiated patients (P-I) and 18 patients suspected of having primary PCa (P-T) were separately evaluated. Late [68Ga]Ga-PSMA-11 PET/CT …
A quantitative analysis of stratospheric HCl, HNO3, and O3 in the tropopause region near the subtropical jet
2014
The effects of chemical two-way mixing on the Extratropical Transition Layer (ExTL) near the subtropical jet are investigated by stratospheric tracer-tracer correlations. To this end, in situ measurements were performed west of Africa (25-32 ◦ N) during the Transport and Composition of the Upper Troposphere Lower Stratosphere (UTLS)/Earth System Model Validation (TACTS/ESMVal) mission in August/September 2012. The Atmospheric chemical Ionization Mass Spectrometer sampling HCl and HNO3 was for the first time deployed on the new German High Altitude and Long range research aircraft (HALO). Measurements of O3, CO, European Centre for Medium-Range Weather Forecasts (ECMWF) analysis, and the tig…
Determination of metal inventory and current efficiency in commercial aluminum reduction cells
1971
A method for the determination of the metal inventory in commercial aluminum reduction cells, based on radioisotope dilution, has been developed, employing a198Au tracer. By taking a large number of samples from the cells, the current efficiency is evaluated from the slope of the cumulative metal inventory vs time data. The method allows a determination of the current efficiency over a period of 2 to 3 days with a relative precision of approximately 1 pct. The paper gives a thorough discussion of the sources of error inherent in the procedure suggested.