An improved instrument for the fluorescence excitation measurement of concentrations of lead in bone has been developed. This is based on a large area high purity germanium detector and a point source of 109Cd. The source is positioned in a tungsten shield at the centre of the detector face such that 88keV photons cannot enter the detector directly. In vivo measurements are calibrated with plas...

High Cd content in durum wheat (Triticum turgidum L. var durum) grain grown in the United States and Canada presents potential health and economic problems for consumers and growers. In an effort to understand the biological processes that result in excess Cd accumulation, root Cd uptake and xylem translocation to shoots in seedlings of bread wheat (Triticum aestivum L.) and durum wheat cultiva...

Elevated blood lead levels, a risk factor for cardiovascular disease, have been reported among patients with end-stage renal disease. We evaluated whether these higher levels are due to release of lead from the skeleton because of uremic bone disease. Fifty-one African-American patients with end-stage renal disease were recruited from 3 Tulane University dialysis programs between January and Ju...

Introduction We would like to present the use of another natural radionuclide chain, that of 232Th. It is suggested to be used as a relative energy calibrator, while absolute calibration will be done by a standard source of 137Cs which, due to its long half-life, requires a change of the calibrated standard only in about 30 to 50 years. Most Ge detector/MCA set-ups are calibrated for energy and...

In rats injected with 5 micron mole CdCl2/kg, 5 days/week, metallothionein was detected in plasma by gel filtration chromatography as early as four weeks. The mean renal concentration of cadmium was 80 microgram/g. The excretion of cadmium in urine at this time was rather low and amounted to 0.01% of the total dose. The amount of metallothionein in plasma, as determined by 109Cd-binding to the ...

Measurements of lead in bone have recently become the focus of research because a) bone lead levels serve as a cumulative dosimeter of lead exposure over many years (because of lead's long residence time in bone), and cumulative exposure may be more predictive of chronic toxicity than recent exposure, which is what blood lead levels mostly reflect; b) there is suspicion that heightened bone tur...

Placental transfer rates of cadmium were investigated in rats in relation to dose (0.1, 0.4, and 1.6 mg Cd/kg) and the gestational age (12, 15, and 20 days) when rats were treated. Pregnant rats were injected intravenously with a single dose of 109CdCl2 (approximately 20 muCi/animal), and animals were sacrificed after 24 hr. 109Cd concentrations were measured in the fetus, placenta, maternal li...

Metallothioneins take part in the homeostasis of the ions of the metals which are necessary for the proper metabolism of the organism (zinc, copper), in biosynthesis regulation of the zinc-containing proteins and also in the detoxication of metals from the tissues. They also protect the tissue from the effects of free radicals, radiation, electrophilic pharmacological agents used in the cancer ...

The uptake and release of 109Cd, 51Cr, 60Co, 59Fe, 54Mn, and 65Zn were studied using end-member waters and particles from Port Jackson estuary, Australia. The kinetics of adsorption and desorption were studied as a function of suspended particulate matter (SPM) loading and salinity. Batch experiments showed that the position and slope of the pH edges are dependent on the metal and on the salini...

A flow-dialysis apparatus suitable for the study of high-affinity metal-binding proteins has been utilized to study calmodulin-metal exchange as a measure of relative calmodulin-metal association constants. Calmodulin labelled with radioactive 153Gd was dialysed against buffer containing various competing metal ions. The rate of label exchange was monitored by a gamma-ray scintillation detector...