ABSTRACT
The accumulation and release of uranium and some uranium decay chain radionuclides were measured in the bones of rats that had been chronically exposed to inhaled uranium ore dust during the first half (approximately) of their natural adult lifespan. Endochondral bone (femur, tibia, humerus, radius, and ulna), membrane bone (skull roofing bones) and muscle of Sprague-Dawley rats (n = 55) that died at various times up to 65 weeks after the end of chronic inhalation of uranium ore dust aerosol (4.2 h d(-1) for 65 wk) and from age matched controls (n = 10), were analyzed for uranium, 230Th, 226Ra, 210Pb, and 210Po. Overall, during the period of dust inhalation, the nuclides accumulated in the above order of decreasing concentration in dry bone. However, the results demonstrate that there was some differential accumulation of uranium and uranium decay series radionuclides in muscle and two bone types of rats during the chronic inhalation period. The data also show that the bone levels of some, but not all, radionuclides decreased significantly with time after inhalation ceased. Lung uranium concentration at the time of death was a highly significant covariant for temporal changes in the levels of some radionuclides in both endochondral bone and membrane bone, indicating that lung remained a major source of these isotopes for accumulation in these bone types after ore dust inhalation had ceased. For some isotopes, the two bone types behaved differently during the dust inhalation period, and differently again after the dust inhalation ceased. The relative behavior of one bone type compared to the other for a particular isotope during the dust inhalation period did not predict the relative behavior after dust inhalation ceased. However, a faster accumulation of one bone type compared to the other for a particular isotope during the dust inhalation period predicted a faster decrease after dust inhalation ended.
Subject(s)
Bone and Bones/metabolism , Uranium/pharmacokinetics , Administration, Inhalation , Animals , Dust , Lead Radioisotopes/pharmacokinetics , Lung/metabolism , Male , Polonium/pharmacokinetics , Radium/pharmacokinetics , Rats , Rats, Sprague-Dawley , Thorium/pharmacokinetics , Uranium/administration & dosageABSTRACT
We report here the cloning of kinetoplast DNA (kDNA) sequences from Leishmania aethiopica in order to develop a specific and sensitive method for the identification of the parasite. Analysis of the cloned kDNA sequences showed different taxonomic specificities demonstrating sequence diversity within the kinetoplast DNA. Cloned whole minicircle hybridized with all Old World Leishmania species tested. Some cloned fragments of minicircle kDNA hybridized with Leishmania species causing cutaneous leishmaniasis in the Old World, but not with the viscerotropic species. Two L. aethiopica-specific clones were found. These clones hybridized with all L. aethiopica isolates tested, but did not react with other Leishmania species. The nucleotide sequence of the L. aethiopica-specific R3 clone is presented. Clones hybridizing with only some of the L. aethiopica isolates were also identified, although none of them showed specificity only for isolates causing localized (LCL) or diffuse (DCL) form of cutaneous leishmaniasis in Ethiopia.
