chiniofon and pyrithione

Dithiocarbamates, thiuram sulphides, xanthates, pyridinethiones and halogenated 8-hydroxyquinolines are groups of compounds which can form lipophilic complexes with Ni2+. These compounds are widely used as drugs and pesticides, and in industry. We have exposed rodents (mice, rats) and fish (brown trout) to substances belonging to these groups of compounds together with 63Ni2+ (as 63NiCl2) and then examined the uptake of the 63Ni2+ in the tissues of the animals. One dithiocarbamate--sodium diethyldithiocarbamate, which is used clinically in nickel carbonyl intoxications--was also examined with regard to effects on the tissue disposition of the metal in mice exposed to 63Ni(CO)4. The studies with 63Ni2+ showed that some of the complexing substances examined caused highly increased tissue levels of the metal in the animals. However, the enhancing effect varied with different complexing compounds. A facilitated penetration of the lipophilic 63Ni2+ complexes across the cellular membranes may underlie the increments in the tissue levels of the metal, but the effects on the disposition of the 63Ni2+ may vary depending on the lipophilicity and the stability of the complexes. In mice exposed to 63Ni(CO)4 by inhalation, sodium diethyldithiocarbamate decreased the levels of the metal in tissues such as the lung, brain and heart. These tissues are targets in nickel carbonyl intoxications and will attain high levels of the metal following inhalation of the compound. The nickel is present in nickel carbonyl as Ni0, but will be oxidized to Ni2+ in the tissues. The experiments presented here indicate that the diethyldithiocarbamate is able to reach and bind the intracellular Ni2+ in the critical target tissues and this property may underlie the ability of the compound to act as an antidote in nickel carbonyl intoxications. However, the ability of diethyldithiocarbamate to act as a nickel antidote may be limited to nickel carbonyl. Generally, the increased uptake of nickel induced by the compounds forming lipophilic complexes with the metal may imply risks of noxious combination effects.

Topics: Animals; Chelating Agents; Fishes; Hydroxyquinolines; Mice; Nickel; Organometallic Compounds; Pyridines; Rats; Thiocarbamates; Thiones; Thiram; Tissue Distribution

We studied the effects of various 111In-water soluble chelates and incubation media on labeling efficiency of platelets and in vitro platelet aggregability. High labeling efficiency of platelets in ACD-saline was achieved with 111In-oxine sulfate, 111In-tropolone and 111In-MPO (2-mercaptopyridine-N-oxide). In the condition with 4.8 x 10(6)/mm3 platelets in ACD-plasma, 111In-oxine-sulfate had low labeling efficiency and inconsistent labeling, while 111In-tropolone and 111In-MPO had high labeling efficiency. In vitro platelet aggregability (ADP 2 microM) was reduced when platelets were labeled in the absence of plasma. However, there was no significant difference in platelet aggregability among 111In-platelets labeled by three different chelates. In conclusion, to maintain aggregation activity of the platelets with relatively high labeling efficiency, the best result was obtained by using MPO or tropolone chelate in plasma at 4.8 x 10(6)/microliters platelet concentration.

Topics: Adult; Blood Platelets; Citric Acid; Culture Media; Cycloheptanes; Glucose; Humans; Hydroxyquinolines; Indium Radioisotopes; Ligands; Male; Oxyquinoline; Plasma; Platelet Aggregation; Pyridines; Thiones; Tropolone

Indium-111 leukocyte scanning has evolved into a practical and highly accurate method for the identification of infectious and inflammatory processes. The most commonly used agent for labeling leukocytes has been [111In]oxine. We have investigated a newer agent, 2-mercaptopyridine-N-oxide (Merc) at our institution which unlike oxine, allows us to label leukocytes in plasma, using a simple kit procedure. Of the 92 consecutive patients referred for detection or localization of an infectious process, autologous leukocytes of 55 patients were labeled with [111In]Merc, while those of the remaining 37 patients were labeled with [111In]oxine. The sensitivities for Merc and oxine procedures were 87% and 92%, respectively, while the respective specificities were 100% and 92%. We conclude that the [111In]Merc-labeled leukocytes are equally effective as [111In]oxine-labeled leukocytes in detecting infectious processes. The use of [111In]Merc is advantageous over [111In]oxine for white blood cell labeling because of its easier preparation.

Topics: Abscess; Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Female; Humans; Hydroxyquinolines; Indium; Isotope Labeling; Leukocytes; Male; Middle Aged; Organometallic Compounds; Oxyquinoline; Pyridines; Radioisotopes; Radionuclide Imaging; Statistics as Topic; Thiones

Generator produced 68Ga-labeled platelets could be useful for positron emission tomographic (PET) studies of thrombosis or atherosclerosis. To label platelets with 68Ga, we have studied the effects of trace metals in elutions of 68Ga from 68Ge. Studies were conducted on the formation of lipophilic 68Ga complexes 8-hydroxyquinoline, tropolone, and mercaptopyridine-N-oxide (MPO). Parameters such as pH, buffers, concentration of ligand, and stability with time were investigated. High performance liquid chromatography and instant thin layer chromatography were used to quantitate formation of the 68Ga complex. Platelets from human, dog, and rabbit plasma were incubated with the 68Ga complexes and the percent labeling determined. Accumulation of platelets in the catheter scraped aorta of the rabbit was determined by PET imaging, tissue counting, and autoradiography. Gallium-68 MPO gave 40-60% labeling of rabbit platelets with higher accumulation in the scraped aorta compared to the normal.

Topics: Animals; Aorta; Blood Platelets; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Cycloheptanes; Dogs; Gallium Radioisotopes; Germanium; Humans; Hydroxyquinolines; Isotope Labeling; Oxyquinoline; Pyridines; Rabbits; Radioisotopes; Thiones; Tomography, Emission-Computed; Trace Elements; Tropolone

Topics: Antimalarials; Chelating Agents; Cyclic N-Oxides; Erythrocytes; Humans; Hydroxyquinolines; In Vitro Techniques; Oxyquinoline; Plasmodium falciparum; Pyridines; Thiones