Modification of the 137Cs, 90Sr, and 60Co transfer to wheat plantlets by NH4+ fertilizers.

Inorganic fertilizers are used as agricultural countermeasures intended to inhibit the soil to plant transfer of radionuclides after a radioactive fallout. Two NH4+ fertilizers, diammonium phosphate (DAP) and NPK, were applied to soil contaminated with a mixture of radionuclides to analyze whether they modify the transfer of 137Cs, 90Sr, and 60Co and stable elements (K, Na, Ca, and Mg) to wheat plantlets grown under controlled laboratory conditions. DAP introduced NH4+ in the soil, which can increase 137Cs transfer, while NPK also introduced K+, which can decrease it. The application of DAP increased the accumulation of 137Cs in wheat plantlets with increasing application rate, so did the 137Cs/K in plantlets. Regarding the NPK application, the 137Cs increased in all treatments, but at maximum rate, the available K introduced by the fertilizer was probably able to partially satisfy the nutritional requirements of the wheat plantlet and the 137Cs decreased relative to the recommended rate. The 137Cs/K ratio in plantlet decreased with increasing NPK rates. The transfer of 90Sr increased with increasing DAP rate and only at the maximum NPK rate. The 60Co transfer only increased at the maximum application rates for DAP and NPK. These modifications should be considered when using these fertilizers as agricultural countermeasures.

Fine needle aspiration in myxoid tumors of the soft tissues.

Myxoid tumors of soft tissues constitute a histogenetically heterogeneous group of lesions, both benign and malignant, that show an overproduction of mucopolysaccharide substances. A correlative fine needle aspiration (FNA) cytologic and histologic study was performed on 16 such cases (3 intramuscular myxomas, 2 lipoblastomas, 6 myxoid liposarcomas, 4 myxoid malignant fibrous histocytomas [MFHs] and 1 extraskeletal myxoid chondrosarcoma), with electron microscopic examination of the aspirate in 4 cases. FNA of all tumors produced a gelatinous material. Smears from all but one of the tumors had a granular myxoid background substance that stained blue to blue-red with the Diff-Quik stain; the exception was the extraskeletal myxoid chondrosarcoma, whose smears stained intensely blue-red to red. On light microscopy, only lipomatous tumors had distinctive cells with diagnostic value: the lipoblasts. Although the arrangement of lipoblasts in lipoblastomas differed somewhat from that found in myxoid liposarcomas, clinical data were important for making a definitive diagnosis. Intramuscular myxomas generally showed a low cellularity composed of fibroblastlike cells with no cytologic atypia. Myxoid MFHs were composed of fibroblastlike cells and macrophagelike cells; the elongated cells with slight-to-moderate nuclear atypia predominated in tumors of low-grade malignancy, while polygonal or round cells with one or more nuclei and marked nuclear atypia predominated in high-grade tumors. Although extraskeletal myxoid chondrosarcoma was mainly differentiated from low-grade myxoid MFH by its metachromatic matrix, ultrastructural studies showed the distinctive distended cisternae with microtubular aggregates in the extraskeletal myxoid chondrosarcoma, thus contributing to the definitive diagnosis.