Influence of Methionine and Vitamin E on Fluoride Concentration in Bones and Teeth of Rats Exposed to Sodium Fluoride in Drinking Water

Increased exposure to fluorine-containing compounds leads to accumulation of fluorides in hard tissues of bones and teeth, which may result in numerous skeletal and dental disorders. This study evaluates the influence of methionine and vitamin E on fluoride concentration in bones and teeth of rats subjected to long-term exposure to sodium fluoride in drinking water. The study was conducted in 30 3-month-old female Wistar FL rats. The animals were divided into five groups, six rats per group. The control group consisted of rats receiving only distilled water as drinking water. All other groups received NaF in the amount of 10 mg/kg of body mass/day in their drinking water. In addition, respective animal groups received: NaF + Met group—10 mg of methionine/kg of body mass/day, NaF + Met + E group—10 mg of methionine/kg of body mass/day and 3 mg of vitamin E (tocopheroli acetas)/rat/day and NaF + E group—3 mg of vitamin E/rat/day. Femoral bones and incisor teeth were collected for the study, and the fluoride concentration was determined using a fluoride ion-selective electrode. Fluoride concentration in both bones and teeth was found to be higher in the NaF and NaF + Met groups compared to the control group. In groups NaF + Met + E and NaF + E, the study material contained much lower fluoride concentration compared to the NaF group, while the effect was more prominent in the NaF + E group. The results of the studies indicate that methionine and vitamin E have opposite effects on accumulation of fluorides in hard tissue in rats. By stimulating fluoride accumulation, methionine reduces the adverse effect of fluorides on soft tissue, while vitamin E, which prevents excessive accumulation of fluorides in bones and teeth, protects these tissues from fluorosis. Therefore, it seems that combined application of both compounds would be optimal for the prevention of the adverse effects of chronic fluoride intoxication.     

兰州一个铝厂氟污染对植物的影响

木文是以兰州一个铝厂为中心,沿北面、西北面、东南面和南面四个方向设置十八个测点。采集空气样品235个,土壤样品127个,植物样品362个。这些样品的测定结果,说明空气和土壤的污染主要在2—4公里的半径范围内,下风向可能到达7.5公里。由于植物从空气中吸收氟,并加以积累,使叶片含量达数百ppm,最高达2534ppm,构成氟的伤害。这种伤害最早(5月间)出现在离铝厂最近测点的桃树(Prunus persica)、杏树(P．armeniaca)上,以后逐渐扩大到稍远的其他地方和别的植物,使葱、蒜失去食用价值,小麦发育不良,叶面积缩小,有效分蘖下降,穗长缩短,小穗数减少,千粒重从50.1克下降为37.6克,造成粮食减产。根据铝厂周围地区植物、土壤和空气氟的污染程度,可分为四种类型：清洁区、轻污染区、污染区和重污染区。     

草原及开垦后土壤有机质性质研究

从土壤有机无机复合状况、腐殖质结合形态和腐殖质组成等方面,研究了供试土壤(草原淡黑钙土、草原风沙土和已开垦的风沙土)有机质的性质．结果表明,不同土壤类型及利用方式对土壤有机质性质的影响有很大的差异．与风沙土相比,淡黑钙土的全土碳、生物量碳、重组碳、可提取腐殖物质(HE)、松结态腐殖质的含量和全土腐殖化度较高．风沙土种向日葵后其全土碳、生物量碳、重组碳和HE含量及各种结合形态腐殖质含量均下降,但腐殖化程度相差不大．     

Agroecosystem functioning on different types of soil contaminated with fluorides from aluminum production

The nitrogen cycles and functioning of agroecosystems planted with spring wheat were investigated on different types of soil contaminated with fluorides from aluminum production. The imbalance between the nitrogen fluxes directed toward the external and internal soil cycles was found to be higher in gray forest soil agroecosystems with low buffering capacity to fluoride pollution than in soddy-meadow soil. The stable functioning of agroecosystems on soddy-meadow soil (stress regime) is maintained by intense nitrogen recirculation.     

土壤保肥-供肥机理及其调节Ⅱ.棕壤型菜园土的腐殖质结合形态及其肥力学意义

采自辽宁省不同地区的１５对棕壤型菜园土肥、瘦地及其各粒级微团聚体的有机质储量和腐殖质结合形态的研究表明,肥地及其各粒级微团聚体的有机质和各结合形态腐殖质的含量与松结态腐殖质占有机质总量的比例均比瘦地及其各相应粒级微团聚体的高,稳结态腐殖质的比例较小,紧结态腐殖质的比例肥瘦地大体相当．无论肥地或瘦地,小粒级微团聚体的有机质和各结合形态腐殖质的含量及松、稳结态腐殖质占有机质总量的比例均较大粒级的高,而紧结态腐殖质则相反,表明大、小粒级微团聚体具有不同的肥力学意义     

Effect of temperature and fluorides on growth and development of Crepis tectorum L. seedlings from populations of polluted and nonpolluted habitats

The effect of temperature and soil contamination by fluorides on the early stages of the growth and development of narrowleaf hawksbeard plants from polluted and nonpolluted habitats has been studied. The character and degree of manifestation of the combined effects of pollution and temperature, as well as the variations in the direction of response depending on temperature, a measured parameters, and the origin of population are shown. In the populations of polluted habitats, the alteration of phenotypic plasticity in relation to temperature is revealed.     

Influence of Methionine upon the Activity of Antioxidative Enzymes in The Kidney of Rats Exposed to Sodium Fluoride

The intensified or uncontrolled formation of reactive oxygen species leads to disturbances of numerous biochemical processes. Among the factors inducing intensified free radical processes, fluoride ions are listed, among others. One of the organs most exposed to the toxic activity of fluorides is the kidney. In the study presented here, the influence of fluorine upon the activity of selected antioxidant enzymes in rat kidney has been examined, as well as antioxidant properties of methionine during intoxication with sodium fluoride. The experiment was carried out on Wistar FL rats (adult females) that for 35 days were administered water, NaF, NaF with methionine (doses: 10 mg NaF/kg bw/day, 10 mg Met/kg bw/day) . The influence of administered NaF and Met upon the antioxidative system in kidney was examined by analyzing the activity of the most important antioxidative enzymes (SOD, CAT, GPX, GR, GST). The studies carried out confirmed the disadvantageous effect of NaF upon the antioxidative system in rats (decrease in activity of antioxidative enzymes). Methionine increased the activity of antioxidative enzymes, most efficiently that of GPX, GR, and GST.     

Effects of Orthophosphates and Condensed Phosphates on Chemical and Spectral Properties of the Humus Derivatives of Phosphorus and Metals

Inorganic orthophosphates and condensed phosphates strongly affected the acidic-basic properties of soil humus substances, which was expressed by the degree of their hydrolyzability in alkaline, acidic, and neutral media. The humus substances modified by phosphates were characterized by increased electron donor (basic, after Lewis) properties, as compared to the native substances, due to accumulation of C=C-bonds. They exerted an especially strong dissolving effect on Fe- and Al-containing soil minerals and had a greater affinity to exogenous Zn. The pattern of distribution of phosphorus in ortho- and pyrophosphates among a fraction of humus substances was studied.     

Variation in the herb species response and the humus quality across a 200-year chronosequence of beech and oak plantations in Belgium

The present study aimed at exploring the long-term impact of pure and mixed beech Fagus sylvatica and oak Quercus robur stands on the forest floor by documenting changes in the herb species' behaviour and in humus index across a 200-yr chronosequence of forest stands. The research was conducted in central Belgium, in a 4383 ha beech-dominated forest. Analyses were carried out in stands which are replicated, of the same age, managed in the same way, and growing on the same soil type with the same land-use history. The results of this study indicate that stand aging is an important determinant of herb species occurrence in the studied area. Most of the species studied show a different response to stand age in pure compared to mixed stands. Our results clearly show a decrease of the humus quality with age in pure stands (beech as well as oak). On the other hand, we found that mixing beech and oak maintained or improved the humus status along the chronosequence according to the proportion of each tree. So the addition of some oak to the beech made it possible to keep a constant quality of the humus. We found that, even if the understory tree species is very scarce, it may be sufficient to maintain the humus status on the long term. In the present study, a cover of 1% oak in a beech stand was sufficient to show an effect of the minor species on these soils. This pattern contrasts with the widespread idea that substantial effects of the minor tree species on soils might not develop if the ratio of major/minor species is low.     

Influence of soil acidification and liming on selected enzymes of the carbohydrate metabolism and the contents of two major organic acids of mycorrhizal roots of Norway spruce (Picea abies [L.] Karst.)

Effects of soil acidification and liming on the activities of three enzymes of the carbohydrate metabolism and the quantities of two of the major organic acids of mycorrhizal roots of Norway spruce (Picea abies [L.) Karst.) were studied at Höglwald Forest in southern Germany. The enzymes investigated were glucosephosphate isomerase, pyruvate kinase and 6-phosphogluconate dehydrogenase. The organic acids studied were citric acid and malic acid.Annual mean activities of the three enzymes were equal in mycorrhizal roots of the humus and the upper mineral soil. But in autumn and winter the activities of each of the three enzymes were higher than in summer. Of the various soil treatments only soil acidification affected the activities of the three enzymes. It stimulated activities by a factor of 1.5 in mycorrhizal roots of the humus but had no effect on mycorrhizal roots from the upper mineral soil.Mycorrhizal roots in the humus contained approximately 10 times more citrate and two times more malate than mycorrhizal roots from the upper mineral soil (0–5 cm). In mycorrhizal roots from the humus citrate and malate were of similar concentrations. In mycorrhizal roots from the upper mineral soil malate was approximately four times more concentrated than citrate. In the humus the citric acid concentration of mycorrhizal roots decreased under soil acidification by a factor of 1.4 while it increased under liming and compensatory liming (acid irrigation after liming) by a factor of 1.5. Malic acid concentrations increased exclusively under liming in mycorrhizal roots of the humus by a factor of 1.3.     

Effects of Pinus sylvestris root growth and mycorrhizosphere development on bacterial carbon source utilization and hydrocarbon oxidation in forest and petroleum-contaminated soils

The hypothesis that Pinus sylvestris L. root and mycorrhizosphere development positively influences bacterial community-linked carbon source utilization, and drives a concomitant reduction in mineral oil levels in a petroleum hydrocarbon- (PHC-) contaminated soil was confirmed in a forest ecosystem-based phytoremediation simulation. Seedlings were grown for 9 months in large petri dish microcosms containing either forest humus or humus amended with cores of PHC-contaminated soil. Except for increased root biomass in the humus/PHC treatment, there were no other significant treatment-related differences in plant growth and needle C and N status. Total cell and culturable bacterial (CFU) densities significantly increased in both rhizospheres and mycorrhizospheres that actively developed in the humus and PHC-contaminated soil. Mycorrhizospheres (mycorrhizas and extramatrical mycelium) supported the highest numbers of bacteria. Multivariate analyses of bacterial community carbon source utilization profiles (Biolog GN microplate) from different rhizosphere, mycorrhizosphere, and bulk soil compartments, involving principal component and correspondence analysis, highlighted three main niche-related groupings. The respective clusters identified contained bacterial communities from (i) unplanted bulk soils, (ii) planted bulk PHC and rhizospheres in PHC-contaminated soils, and (iii) planted bulk humus and rhizosphere/mycorrhizosphere-influenced humus, and mycorrhizosphere-influenced PHC contaminated soil. Correspondence analysis allowed further identification of amino acid preferences and increased carboxylic/organic acid preferences in rhizosphere and mycorrhizosphere compartments. Decreased levels of mineral oil (non-polar hydrocarbons) were detected in the PHC-contaminated soil colonized by pine roots and mycorrhizal fungi. These data further support our view that mycorrhizosphere development and function plays a central role in controlling associated bacterial communities and their degradative activities in lignin-rich forest humus and PHC-contaminated soils.     

Effect of artificial soil acidification and liming on growth and nutrient status of mycorrhizal roots of Norway spruce (Picea abies [L.] Karst.)

Effects of soil acidification and liming on biomass responses and free Al, Ca, K, Mg, Mn and P contents of mycorrhizal roots of mature Norway spruce (Picea abies [L.] Karst.) were studied at Höglwald Forest in Southern Germany.At the untreated site, mycorrhizal root biomass was lower in the acid humus (pH = 3.3) than in the less acid upper (0–5 cm) mineral soil (pH 4.1). Mycorrhizal roots from the humus contained 10% of the level free Al in mycorrhizal roots from the upper mineral soil. During seven years of soil acidification the quantity of mycorrhizal roots remained unaffected in the humus and the upper mineral soil, perhaps due to the high buffering capacity of the humus which prevented a significant alteration of the nutrient status of the roots. However, two years after soil acidification had been terminated, the percentage of mycorrhizal roots in the humus decreased, possibly because the free root concentrations of K had decreased.On the other hand, six years after liming, there was a two-fold increase of the annual mean quantity of mycorrhizal roots in the humus. Compensatory liming (acid irrigation after liming) had a similar effect on mycorrhizal root production in the humus. However, two years after acid irrigation had been terminated a decrease of mycorrhizal roots in the upper mineral soil (0–5 cm) was observed. Since the total amount of mycorrhizal roots in the humus and upper mineral soil remained constant, compensatory liming produced a shift in fine roots to the humus layer.The higher mass of living mycorrhizal roots in the upper mineral soil (0–5 cm) as compared to the humus of the untreated plot as well as the increased mass of mycorrhizal roots in the humus after liming or compensatory liming are both attributed to an increase in pH to 4.5 rather than alleviation of Al toxicity.     

Behavior of Cu and Zn under combined pollution of 2,4-dichlorophenol in the planted soil

Behavior of heavy metals under combined pollution of 2,4-dichlorophenol (2,4-DCP) was investigated using metal contaminated soil which was sampled from the heavily industrialized areas, Fuyang county, Zhejiang Province, P.R. China and pretreated with 100 μg g^?1 2,4-DCP for 1 month. Metal complexes were the predominant species for Cu and Zn in the soil solution. The treatment of 2,4-DCP had limited effect on the dissolution of Cu and Zn in the soil without plant root growth. But the metal species might be changed due to the addition of organic pollutant. Planting with rye grass for 1 month, greatly increased both water soluble Cu and Zn. The increase of water soluble Cu and Zn in the presence of 2,4-DCP was much more than that in the absence of 2,4-DCP, which suggested more attention should be paid to the behavior of heavy metals under combined pollution of organic pollutants in the planted soil. The results also indicated that in comparison to Cu, soil planted with ryegrass was more effective in activating Zn from soils, which was consistent with its relative weak chemisorptions on clays, oxides and humus of soils.     

Changed Soil Properties after Pollution by Oilfield Brine at the Tuimazy Oilfield (Republic of Bashkortostan)

Changes in the main soil properties under the influence of oilfield brines were studied at the Tuimazy Oilfield. High salinization was observed in the cinnamonic forest soil one year after pollution. Progressing alkalinization deteriorated the main soil properties. The chemical composition of the aqueous extract and the ionic composition of the soil absorption complex changed, the base exchange capacity decreased, the humus state deteriorated, and enzyme activity was suppressed. In the meadow calcareous chernozem polluted 12 years ago, desalinization processes increased alkalinization and thus further degraded the soil.     

稻田免耕和稻草还田对土壤腐殖质和微生物活性的影响

为了阐明免耕和稻草还田土壤固碳机制,研究了无稻草还田免耕（NT）、无稻草还田常耕（CT）、稻草还田免耕（NTS）和稻草还田常耕（CTS）对水稻不同生育期不同土层（0—5,5—12,12—20cm）土壤腐殖质形态、含量及微生物活性的影响。结果表明,免耕（NT和NTS）处理显著增加0—5 cm土层土壤游离松结态、联结态和稳紧结态腐殖质含量和游离松结态腐殖质占总腐殖质的比例,且免耕对土壤各结合态腐殖质含量的影响程度有随生育期的推后而增加的趋势;5—12cm和12—20cm土层土壤各结合态腐殖质含量和0—20cm各土层微生物活性有减少趋势;在水稻分蘖期免耕对微生物活性影响很弱,在水稻拔节—灌浆期免耕处理显著降低5—12 cm土层土壤微生物活性,相反,免耕却增加水稻成熟期0—5 cm土层的微生物活性;另一方面,稻草还田（CTS和NTS）显著提高土壤各结合态腐殖质含量,尤其是0—5 cm土层、游离松结态腐殖质及水稻生育后期;CTS处理显著增加分蘖期—孕穗期0—20 cm土层的呼吸强度,而稻草还田显著增加孕穗期—成熟期0—5cm土层的纤维素分解强度。可见,通过增加土壤腐殖质含量和各结合态腐殖质含量并改变微生物活性免耕有利于表土层碳的固定作用,而免耕与稻草还田相结合更有利于土壤碳的积累。     

Fate of lead in the soil and its effects onPinus halepensis

Summary Chemical analysis of samples of needles of Aleppo pine (Pinus halepensis), humus and mineral soil collected in the vicinity of the Pb-smelter in Lavrion, Attica, showed that an area of about 2 km around the smelter is heavily polluted primarily with Pb and also with Zn, S and F^–. Most of the Pb was found accumulated in the humus and the top layer of the mineral soil.About 50% of the Pb found in the samples of Aleppo pine needles could be removed by washing them in a dilute detergent solution. One and 15% of the total Pb from Pb-polluted soil and humus samples, respectively, was extracted with normal ammonium acetate solution. No Pb or a very small amount was extracted with distilled H₂O from humus and soil samples treated with concentrations of Pb as high as 3000 ppm and incubated in the laboratory for 30 days.Humus samples treated with up to 1500 ppm Pb or Pb-polluted humus samples collected from points leeward of the smelter had no adverse effects on the germination of Aleppo pine seeds. When the germination experiment was conducted on Pb-polluted humus samples from points windward of the smelter, where a temporary pine needle death had been observed, the percentage seed germination, for two years, was found reduced and negatively correlated to the distance of the humus sampling point from the Pb-smelter.In nursery experiments Pb concentrations of up to 2000 ppm, added to a calcareous soil, had no adverse effect on height increase of Aleppo pine seedlings. Very little Pb was transported from the roots to the needles after seven months growth of the seedlings on either Pb-amended soil or on Pb-polluted soil from Lavrion. Concentrations of Pb in the roots of the seedlings, however, were found high in both cases and almost proportional to concentrations of Pb in the soil.     

Carbon stock evaluation from topsoil of forest stands in NE Italy

Gas emissions from anthropic activities, particularly CO2, are responsible for global warming. Soil is a major carbon sink on a planetary level, thereby contributing to mitigate greenhouse effect. In the present work, the objectives were: 1) to evaluate the topsoil carbon stock of different forest stands in NE Italy, and 2) to outline the relationships among humus forms, soil organic matter dynamics, and actual carbon stock under different vegetation coverage, with reference to climate change. Five forest stands and the related topsoils, were selected in the Dolomites area. The humus forms were examined in the field and samples were carried to the lab for further physical-chemical analyses. The carbon stock for each soil was calculated by means of pedotransfer functions. The less developed humus forms, as the Dysmull and the Hemimoder, presented the highest carbon storage capacity (168 t/y and 129 t/y), followed by Lithoamphimus (123 t/y) and Eu-amphimus (96 t/y), and by Oligomull (86 t/y). Organic horizons proved to recover 36% of the total carbon stocked along the soil profile, and this points to humus layers as a fundamental tool in carbon stock evaluation. Positive correlations between elevation, humus forms and soil carbon pools were found.     

A novel magnesium-dependent mechanism for the activation of transducin by fluoride

Activation of transducin-GDP by NaF is mainly mediated by aluminofluorde or beryllofluoride complexes acting as GTP gamma-phosphate analogs. In millimolar magnesium, NaF at concentrations above 3 mM is active even in the absence of aluminium or beryllium. This activation has a Hill coefficient of 3 with respect to F-, and its rate is linear with respect to Mg2+ concentrations above 2 mM. Upon fluoride dilution, inactivation rate is hundreds of times faster than for aluminofluoride-activated T alpha GDP. We propose that at high NaF concentrations, 3 hydrogen-bonded fluorides in the gamma-phosphate site of T alpha GDP entrap a magnesium counterion and this induces the transconformation to the T alpha GTP form.     

Meat‐eating enhances larval development of Anthracophora rusticola Burmeister (Coleoptera: Scarabaeidae), which breeds in bird nests

The scarab beetle Anthracophora rusticola Burmeister breeds in the nests of carnivorous birds including the honey buzzard Pernis apivorus (Linnaeus), Chinese goshawk Accipiter soloensis (Horsfield), oriental stork Ciconia boyciana Swinhoe and great cormorant Phalacrocorax carbo (Linnaeus). Although larvae of the beetle probably feed on animal matter (e.g. remnants of birds' food) in the nests of these birds, the effect of eating flesh on the growth of larvae has not been investigated. Laboratory experiments clearly showed that the development was faster, survival rate higher and body heavier just before pupation in larvae fed dried chicken meat with humus soil than in those fed only humus soil. We also investigated feeding behaviors of larvae of the beetle. A piece of chicken meat placed on the surface of humus soil was pulled under the soil by the larva, mostly at night. Video recordings made during the night showed that larvae came to the humus soil surface and ate the dried chicken meat or tried to take the meat under the soil. Our laboratory observations suggest that larvae in nature stay under the humus accumulated in bird nests during the daytime, and then come up to the surface mostly at night to actively seek and eat remnants of the birds' food.     

腐解6个月后杉木枯枝落叶及腐殖土中的化感成分对杉木种子的化感效应

对腐解6个月后杉木[Cunninghamia lanceolata（Lamb．）Hook．]枯枝落叶及腐殖土中的化感成分进行了提取分离及生物检测。结果表明,枯枝落叶及腐殖土中的极性和弱极性化感成分对杉木种子的绝对发芽率、绝对发芽势、胚根长和胚轴长均有一定的抑制作用。随浓度的提高,枯枝落叶中的弱极性化感成分对绝对发芽率、胚轴长及幼苗干质量的抑制作用及极性化感成分对绝对发芽势、胚轴长的抑制作用均逐渐增强;腐殖土中的弱极性化感成分对绝对发芽率、绝对发芽势、胚根长及胚轴长的抑制作用及极性化感成分对胚轴长的抑制作用也逐渐增强。枯枝落叶中的化感成分对绝对发芽率、绝对发芽势及幼苗干质量的抑制效应高于腐殖土中的化感成分。