We describe a rapid polarization fluoroimmunoassay for screening for the presence of barbiturates in urine. The single reagent is prepared by pre-mixing antiserum with a fluorescein-labeled barbiturate derivative as tracer. Use of a mixture of two sheep antisera, raised against different barbiturate immunogens, results in an assay with a broad cross-reactivity spectrum for most common barbitura...

The location of the postganglionic parasympathetic cell bodies projecting to cerebral arteries is unknown. Using axonal tracing techniques, we examined whether the sphenopalatine ganglia (associated with the seventh cranial nerve) and otic ganglia (associated with ninth cranial nerve) contain perikarya which send axons to the feline middle cerebral artery (MCA). The tracers horseradish peroxida...

Between-sample variation in tracer binding in the 125I-labeled digoxin radioimmunoassay was investigated with two tracers, 3-O-succinyl-digoxigenin-[125I]-labeled tyrosine and [125I]-labeled tyrosine-methyl-ester-digoxin. Digoxin-free serum samples having various concentrations of thyroxine were assayed with both tracers. The percentage of tracer bound when the samples were assayed with the fir...

When direct flow velocity measurements are not feasible, the use of tracers can be a valuable tool. In present study, both laboratory and field experiments were conducted to evaluate applicability quinine as fluorescent tracer for estimating mean sheet velocities in different ambient light surface morphology conditions. Quinine excels low-light conditions when exposed UVA light. This was compar...

This report describes studies of calcium kinetics in ten normal young men. Serum, urinary, and fecal radioactivity was measured from 1 minute to 20 days after intravenous tracer (47)Ca injection, and these results were analyzed jointly with data obtained from a simultaneous metabolic balance study, using digital computer techniques. Surface radioactivity measurements were also obtained to gain ...

At the request of the U.S. Department of Energy, the JASON group that provides independent technical advice to the U.S. Government studied Enhanced Geothermal Systems (EGS) with a focus on i) assessment of technologies and approaches for subsurface imaging and characterization; and ii) assessment of approaches toward creating sites for EGS, including science and engineering to enhance permeabil...

MOTIVATION Advances in techniques to sparsely label neurons unlock the potential to reconstruct connectivity from 3D image stacks acquired by light microscopy. We present an application for semi-automated tracing of neurons to quickly annotate noisy datasets and construct complex neuronal topologies, which we call the Simple Neurite Tracer. AVAILABILITY Simple Neurite Tracer is open source so...

Graphical analysis techniques are often applied to positron emission tomography (PET) images to estimate physiological parameters. Patlak analysis is primarily used to obtain the rate constant (Ki) that indicates the transfer of a tracer from plasma to the irreversible compartment and ultimately describes how the tracer binds to the targeted tissue. One of the most common issues associated with...

The art and science of the use of deposition markers for the estimation of blood flow distributions throughout the body and within organs is reviewed. Development of diffusible tracer techniques started 50 years ago. Twenty years later, radioactive 15 micron microspheres became the standard marker. Early studies on small animals, fetal sheep in 1967 and rats in 1976, provoked much of the techni...