Sterilization of Plants for Phytoremediation Studies by Bleach Treatment

Bleach treatment of plants was studied as a simple alternative to axenic tissue cultures for demonstrating phytodegradation of aqueous and gas-phase environmental contaminants. Parrotfeather (Myriophyllum aquaticum), spinach (Spinacia oleracea), and wheat (Triticum aestivum) were exposed to 0.525% NaC10 solutions for 15 s, then rinsed in deionized water. Plate counts indicated that 97 to 100% of viable bacteria were removed from parrotfeather and spinach. Transformation rates for 2,4,6-trinitrotoluene (TNT) by bleached and untreated parrotfeather were virtually identical. Similarly, treated and untreated spinach, wheat heads, and wheat leaves removed methyl bromide (MeBr) from air at the same rates. However, wheat root with attendant adhering soil was rendered inactive by bleach treatment. Parrotfeather roots examined by dissecting microscope and by electron microscope showed no significant damage caused by bleach treatment.     

Clonal populations of the mouse mammary cell line,COMMA-D,which retain capability of morphogenesis in vivo

Summary Clonal populations were isolated from the mouse mammary cell line, COMMA-D, by transfection with a dominant-selectable gene, pSV2Neo, which confers resistance to the antibiotic, G418. Seven of twenty-four clones isolated retained the ability of the parental line to repopulate cleared mammary fat pads in vivo as ductal-alveolar hyperplasias. Two sublines designated CDNR2 and CDNR4 retained hyperplastic growth potential after multiple passages in vitro with low incidence of tumor formation. A third subpopulation, CDNR1, contained a single integration site for the pSV2Neo plasmid indicating a bonafide clonal origin for this subline. CDNR1 cells displayed heterogeneous growth phenotypes in vivo including hyperplasia, adenocarcinoma, and bone formation. Functional differentiation of CDNR1 cells organized as alveolarlike structures in vivo or on floating collagen gels in vitro was observed as determined by immunoperoxidase staining for the milk-specific protein, casein. Overall, the results indicate that a subset of cells from the COMMA-D cell line may be functionally analogous to stem cells existing in the mammary gland. Supported by NCI research grants CA-38650, CA-33369, CA-39017, and CA-25215.     

Toxicity of Fipronil to the Predatory Lacewing Chrysoperla carnea (Neuroptera: Chrysopidae)

All the developmental stages of Chrysoperla carnea (Stephens) were treated with fipronil using different modes of exposure under laboratory conditions. Eggs were dipped in an aqueous range of concentrations and no effects were recorded, except at the highest concentration. Pupae treated topically on the silk cocoon moulted to healthy adults, without any deleterious effects on their reproduction. In contrast, larvae and adults were killed by the compound, irrespective of the mode of treatment, even at rates below the maximum field recommended rate in Spain (30 g c.p./ha). Sublethal concentrations of fipronil did not affect the fecundity or fertility of survivors. We conclude that fipronil is very toxic under laboratory conditions to this predatory lacewing.     

Enterobacteriaceae, coliforms, faecal coliforms and salmonellas in raw ewes' milk

Thirty-nine samples of freshly drawn ewes' milk collected at 13 farms, and 120 samples of raw ewes' milk collected on arrival at a dairy were examined. Farm samples had geometric mean counts of 4.4 X 10(2) Enterobacteriaceae/ml, 3.9 X 10(2) coliforms/ml and 2.0 X 10(2) faecal coliforms/ml, whereas the respective mean counts were 6.2 X 10(3)/ml, 5.4 X 10(3)/ml and 1.3 X 10(3)/ml for dairy samples. Salmonellas were not detected by enrichment procedures in any of the 159 samples examined. Escherichia coli (47.5% strains), Enterobacter cloacae (17.7%), Ent. agglomerans (11.3%), Hafnia alvei (6.5%) and Klebsiella oxytoca (6.0%) were the predominant species in 434 Enterobacteriaceae strains isolated from farm samples. Levels and species of Enterobacteriaceae found in the present work in raw ewes' milk imply a considerable risk of early blowing in cheese-making from unpasteurized milk.     

Cytochemical localization of calcium in renal sac nephrocytes of Helix aspersa

In renal sac nephrocytes of Helix aspersa, intracellular calcium has been localized using the oxalate-pyroantimonate (OPA) and phosphate-pyroantimonate (PPA) methods. Pyroantimonate precipitates are preferentially localized in the excretory spherule and in vesicles located in the basal and lateral regions of the nephrocyte. Such vesicles appear to release their content into the excretory vacuole. Calcium may interact with diverse types of molecules present in the excretory vacuole, thus favouring stabilization and packaging of the excretory spherule.     

Acetyl-cholinesterase and fluoride-resistant acid phosphatase activities in dorsal root ganglia in the rat

Acetylcholinesterase and fluoride-resistant acid phosphatase activities were contrasted in alternative serial sections of rat dorsal root ganglia. The morphometric analysis demonstrated no correlation between cellular size and enzymatic activity. Differences with previous works in this area are discussed.     

Identification by flow cytometry of two distinct rhodamine-123-stained mitochondrial populations in rat liver

Isolated rat liver mitochondria were split into three fractions of increasing density when applied to a Percoll gradient. NADH-ubiquinone oxidoreductase, succinate dehydrogenase and cytochrome-c oxidase but not F1-ATPase activities increased with density as well as respiratory rate in state 3 and the respiratory control index. Flow cytometry of mitochondrial density fractions stained with rhodamine-123 revealed the occurrence in each density fraction of two distinct mitochondrial populations with different fluorescence intensity. The high fluorescence population was minor and its proportion decreased with density. The extent of high fluorescence population staining depended on the deenergized state of the mitochondria suggesting that this population represents an immature form of the mitochondria which may develop into a fully functional organelle by the incorporation of structural and/or functional proteins.     

Nitrogen metabolism in tumor bearing mice

In experiments with whole animals infested with a highly malignant strain of Ehrlich ascites tumor cells, serial concentrations of amino acids were determined for host plasma, ascitic fluid, and tumor cells, throughout tumor development. Concentration gradients of glutamine, asparagine, valine, leucine, isoleucine, phenylalanine, tyrosine, histidine, tryptophan, arginine, serine, methionine, and taurine from the host plasma toward the ascitic liquid were established; while on the other hand, concentration gradients from the ascitic liquid toward the plasma were established for glutamate, aspartate, glycine, alanine, proline, and threonine. With the exception of aspartate the concentrations of these amino acids were highest inside the cells. Arginine was the only amino acid not detected in tumor cells. In vitro incubations of tumor cells in the presence of glutamine and/or glucose, as the energy and nitrogen sources, confirmed the amino acid fluxes previously deduced from the observed relative concentrations of amino acids in plasma, ascitic liquid, and tumor cells, suggesting that glutamate, alanine, aspartate, glycine, and serine can be produced by tumors. These findings support that changes in amino acid patterns occurring in the host system are related to tumor development.