Major and trace elements in the twig axes of Norway spruce and the relationship between twig axis and needles

Summary The concentrations of 23 elements have been determined by instrumental neutron activation analysis in the needles and axes of 1-year-old spruce twigs from 12 different sites. Although the twigs had been washed with toluene and tetrahydrofuran prior to analysis, it was found that the amounts of eight elements (Al, Cr, Eu, Fe, La, Sc, Th and V) present were predominantly due to aerosol particles still being retained on the surface of the axes. The results of the remaining 15 elements (Ba, Br, Ca, Cl, Co, Cs, Hg, K, Mg, Mn, Na, P, Rb, Sr and Zn) were not or only slightly influenced by this effect and are considered to represent their inherent concentrations within the axes. With most of these latter 15 elements there are highly significant and linear correlations between the concentrations in the needles and in the axis, which testify to the great similarity of needles and axis of a twig. The axis/needles ratios are constant for every element (except K), but the individual elements show considerable differentiation, as evidenced by their ratios, which have values between 0.5 and 2.8. Inter-element correlations in the axes are mainly found within two groups of elements. With Na, Cl and Br these correlations are probably due to different pollution levels of the different sites, whereas with Mn, Co, Rb and Cs they are due to the pH of the soil. The activity of ¹³⁷Cs from the Chernobyl fallout represents independent confirmation of the results obtained with the stable elements. With twigs sprouted before the deposition of the fallout, ¹³⁷Cs acts as a tracer for aerosol particles, whereas it forms a tracer for the stable Cs inherent to the plant with twigs sprouted after the deposition.     

The interaction of cadmium with calcium and cisplatin with chloride

Changes in the locomotor rate of the ciliateTetrahymena pyriformis were used to quantitatively evaluate chemical interactions produced by: cadmium in combination with varying amounts of calcium, andcis-dichlorodiammineplatinum (II) (cisplatin) with varying amounts of sodium chloride. Cadmium (as CdCl₂) produces a measurable decline in the locomotor rate of the cells. Cadmium's detrimental effect can be reduced by the addition of calcium (as CaCl₂) in combination with cadmium. At a ratio of 30∶1 (calcium: cadmium), cadmium's negative effect upon motility is essentially nullified. It is suggested that the “protective” action afforded by calcium stems from the chemical similarity of the two cations and their involvement/competition for molecular sites responsible for the energy release and/or delivery of ciliary activity. Cisplatin will also effect a reduction in ciliary activity. However, the interaction between cisplatin, sodium chloride, and the cell appears more complex than that found with cadmium-calcium. At the lower range of chloride (as NaCl) used in this study, increased chloride concentration produces an increase in cisplatin's action against ciliary activity. At the higher levels, the chloride reduced cisplatin's negative effects. It is suggested that the increases in cisplatin's effects are caused by mass chemical action of increased chloride, which increases the concentration of the nonpolar cisplatin. The reduced effects found with the higher concentrations of sodium chloride may be because of the presence and action of elevated NaCl in/on the cell. This study clearly demonstrates differences in biologically relevant chemical interactions occurring with the two sets: cadmium-calcium and cisplatin-chloride.     

Concentrations of nutritional and trace elements in needles of Norway spruce (Picea abies [L.] Karst.) as functions of the needle age class

The endogenous concentrations of the essential elements Ca, Cl, Cu, Fe, K, Mg, Mn, N, P and Zn, and of the nonessential elements Al, As, Ba, Br, Co, Cr, Cs, Hg, I, La, Na, Rb, Sb, Sc, Si and Sr were determined in 5 successive needle age classes. 40 mature spruce trees from 6 different sites were investigated individually. A given element usually shows smooth changes with the needle age class t. Trees on a given site usually have a similar dynamic behaviour. The same holds for the different site means. The concentrations can be approximated by functions c=f(t). Three different types of functions are required to describe the dynamic behaviour of 3 groups of elements that increase with t, and one for the elements that decrease with t. A given element usually can be described by the same type of function at all sites, even if its concentration differs widely. Exceptions are Mn, Co and Zn, which change from a decreasing function at low concentrations to an increasing function at high concentrations. Further irregulatities are found at some sites with Ca, Sr and Ba. These findings are corroborated by a multivariate statistical analysis.     

Huntingtin inclusion bodies are iron-dependent centers of oxidative events

Recently, we reported that the transient expression of huntingtin exon1 polypeptide containing polyglutamine tracts of various sizes (httEx1-polyQ) in cell models of Huntington disease generated an oxidative stress whose intensity was CAG repeat expansion-dependent. Here, we have analyzed the intracellular localization of the oxidative events generated by the httEx1-polyQ polypeptides. Analysis of live COS-7 cells as well as neuronal SK-N-SH and PC12 cells incubated with hydroethidine or dichlorofluorescein diacetate revealed oxidation of these probes at the level of the inclusion bodies formed by httEx1-polyQ polypeptides. The intensity and frequency of the oxidative events among the inclusions were CAG repeat expansion-dependent. Electron microscopic analysis of cell sections revealed the presence of oxidation-dependent morphologic alterations in the vicinity of httEx1-polyQ inclusion bodies. Moreover, a high level of oxidized proteins was recovered in partially purified inclusions. We also report that the iron chelator deferroxamine altered the structure, localization and oxidative potential of httEx1-polyQ inclusion bodies. Hence, despite the fact that the formation of inclusion bodies may represent a defense reaction of the cell to eliminate httEx1 mutant polypeptide, this phenomenon appears inherent to the generation of iron-dependent oxidative events that can be deleterious to the cell.     

Analysis of oxidative events induced by expanded polyglutamine huntingtin exon 1 that are differentially restored by expression of heat shock proteins or treatment with an antioxidant

We recently reported that the transient expression of polyglutamine tracts of various size in exon 1 of the huntingtin polypeptide (httEx1) generated abnormally high levels of intracellular reactive oxygen species that directly contributed to cell death. Here, we compared the protection generated by heat shock proteins to that provided by the antioxidant agent N-acetyl-L-cysteine. In cells expressing httEx1 with 72 glutamine repeats (httEx1-72Q), the overexpression of Hsp27 or Hsp70 plus Hdj-1(Hsp40) or treatment of the cells with N-acetyl-L-cysteine inhibited not only mitochondrial membrane potential disruption but also the increase in reactive oxygen species, nitric oxide and protein oxidation. However, only heat shock proteins and not N-acetyl-L-cysteine reduced the size of the inclusion bodies formed by httEx1-72Q. In cells expressing httEx1 polypeptide with 103 glutamine repeats (httEx1-103Q), heat shock proteins neither decreased oxidative damage nor reduced the size of the inclusions. In contrast, N-acetyl-L-cysteine still efficiently decreased the oxidative damage induced by httEx1-103Q polypeptide without altering the inclusions. N-Acetyl-L-cysteine was inactive with regard to proteasome inhibition, whereas heat shock proteins partially restored the caspase-like activity of this protease. These observations suggest some relationships between the presence of inclusion bodies and the oxidative damage induced by httEx1-polyQ.     

The effects of the organophosphate insecticide malathion on very young chick embryos: malformations detected by histological examination

This histological study sought to determine the nature and incidence of developmental abnormalities induced by one of the reportedly least teratogenic of insecticides injected into very young chick embryos. Using techniques to assure rapid contact between injectant and embryo, eggs incubated for 24, 48, or 72 hr were injected with corn oil or 125 micrograms-4.0 mg malathion. The embryos were recovered 48 hr later, paraffin-embedded, serially cross-sectioned, and examined in detail. Structures affected (and the nature of the defects) were as follows: wing level notochord and spinal cord (folded or undulated); trunk/leg level spinal cord (variously, neural folds unfused, roof infolded, canal partitioned, etc.); eye (lens misshapen or severely thinned, optic cup incompletely invaginated); diencephalon (epiphysis bifurcated or off-center, supernumerary outgrowths); cardiovascular structures (atrium and major blood vessels enlarged); and tailbud (curled into hindgut: ourentery). Overall incidence was both dose- and age-related, doubling for each doubling of dose and tripling for each 24 hr less age at exposure. For most (not all) individual structures, incidence was greatest when exposed at 24 hr and nil at 72 hr. Severity of effect was not consistently dose- or age-dependent. We conclude that contrary to previous reports, 24- to 72-hr embryos are highly vulnerable to insecticide exposure, with the youngest the most vulnerable, and many of the defects detected may be attributed to either of two mechanisms: failure in formation of the supportive sheath, or factors that cause epithelial morphogenesis (e.g., microtubules, microfilaments, extracellular material, cell-to-cell adhesion mechanisms). Previous observations that 1- to 3-day embryos are relatively unresponsive to insecticides are probably artifactual owing to imprecise techniques.     

GENETICS OF PHYTOPATHOGENIC FUNGI. V. HETEROCARYONS INVOLVING FORMAE OF FUSARIUM OXYSPORUM

Garber , E. D., Ellen G. Wyttenbach , and T. S. Dhillon . (U. Chicago, Chicago, Ill.) Genetics of phytopathogenic fungi. V. Heterocaryons involving formae of Fusarium oxysporum. Amer. Jour. Bot. 48(4): 325–329. 1961.—Heterocaryons involving mutant strains of 4 formae of Fusarium oxysporum were studied; the strains differed in nutritional requirements, resistance to acriflavine, and colonial morphology and color. Spores from the heterocaryons gave colonies on minimal medium which resembled one component strain in morphology and color; spores from heterocaryons involving f. pisi yielded colonies on complete medium containing a concentration of acriflavine inhibitory to the other component strain.