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PubMed2005

Stabilization of metals in acidic mine spoil with amendments and red fescue (Festuca rubra L.) growth.

Stabilization of metals with amendments and red fescue (Festuca rubra, cv. Keszthelyi 2) growth was studied on an acidic and phytotoxic mine spoil (pH(KCl) 3.20-3.26; Cd 7.1 mg kg(-1), Cu 120 mg kg(-1), Pb 2154 mg kg(-1) and Zn 605 mg kg(-1)) from Gyöngyösoroszi, Hungary in a pot experiment. Raising the pH above 5.0 by lime (CaCO(3)), and supplementing with 40 mg kg(-1)nitrogen (NH(4)NO(3)) made this material suitable for plant growth. All cultures were limed with 0.5% (m/m) CaCO(3) (treatment 1), which was combined with 5% (m/m) municipal sewage sludge compost (treatment 2), 5% (m/m) peat (treatment 3), 7.5% (m/m) natural zeolite (clinoptilolite) (treatment 4), and 0.5 (m/m) KH(2)PO(4) (treatment 5). Treatments 1-5 were combined with each other (treatment 6). After 60 days of red fescue growth, pH of the limed mine spoil decreased in all cultures units. Application of peat caused the highest pH decrease (1.15), while decrease of pH was less than 0.23 in treatments 2, 5 or 6. Application of lime significantly reduced concentrations of metals in the 'plant available' fraction of mine spoil compared to non-limed mine spoil. Amendments added to limed mine spoil changed variously the ratio of Cd, Cu, Pb and Zn in exchangeable or 'plant available' fractions, differently influencing the phytoavailability of these metals. Most of the metals were captured in the roots of test plants. Treatment 2 caused the appearance of less Cd in shoots (<0.1 microg g(-1)) or roots (3.11 microg g(-1)), while treatment 5 resulted in the highest Cd concentration (2.13 microg g(-1)) in shoots. Treatments did not influence significantly the Cu accumulation in shoots. The Pb accumulation of roots (44.7 microg g(-1)) was most effectively inhibited by combined treatment, while the highest value (136 microg g(-1)) was found in the culture treated with potassium phosphate. Pb concentration in shoots was below the detection limit, except for treatments 5 and 6. Peat application resulted in higher Zn concentration (448 microg g(-1)) in shoots than other amendments, where these values were around 100 microg g(-1). All amendments influenced positively the dry matter yield of red fescue grown in limed mine spoil, however the application of 0.5 phosphate was less favourable. Liming, application of amendments and growth of red fescue can stabilize metals in acidic and phytotoxic mine spoil, and by phytostabilization they can reduce the risk of metal contamination of the food chain.

Biodegradation, Environmental↗
PubMed2003

Role of viticultural factors on stilbene concentrations of grapes and wine.

Stilbenes are phenolics that can be found in different grapevine organs, such as berries, leaves, canes and roots. Stilbenes act as antifungal compounds since they are synthesized by the plant in response to pathogen attack. Other abiotic elicitors, such as ultraviolet rays and heavy metals, can trigger stilbene production. Many stilbenic compounds have been detected in grapes and wine (resveratrol, piceid, viniferins, astringin, etc.). The latest stilbene to be analyzed is piceatannol (or astringinin). Stilbene synthesis in grapes depends on different viticultural factors such as the grape variety, the environment and cultural practices. Concerning grape variety, red berry-grapes have higher stilbene levels than white berry-grapes. With regard to climate, preliminary results suggest a positive correlation between vineyard elevation and stilbene grape concentrations. Quality-oriented cultural practices produce grapes with high levels of stilbenes.

Agriculture↗
PubMedDate not supplied

Responses of oral 2,4,6-trinitrotoluene (TNT) exposure to the common pigeon (Columba livia): a phylogenic and methodological comparison.

Considerable concentrations of the explosive, 2,4,6-trinitrotoluene (TNT) have been found in the soil at many installations where explosives have been used, manufactured, assembled, or destroyed. To evaluate risk to avian receptors, measures of exposure are compared with a threshold level of sublethal toxicity. To date, a single feeding study has evaluated the responses of oral TNT exposure to birds with equivocal results regarding sublethal effects. The present study followed a controlled dosing regime comprising four dose groups and a control (200, 120, 70, 20, and 0 mg TNT/kg body weight [bw]-day) in the common pigeon (Columba livia) for 60 days. Overt signs of toxicity occurred with both sexes between 2 and 3 weeks of exposure. Signs included weight loss, neuromuscular effects (e.g., ataxia, tremors, etc.), and scant red feces (chromaturia). Emetic events following dosing were common and proportional to dose; however, attempts to quantify vomitus compound concentration suggests that birds were marginally successful at removing TNT following administration. Eight of 12 and 2 of 12 males and females died or were moribund in the 200 and 120 mg/kg-day groups, respectively. Changes in hematological parameters, liver, kidney, and ovary weights were related to treatment. Dose-related changes in plasma albumin and sodium concentrations were also observed. These results suggest that subchronic exposure to TNT can adversely affect the central nervous system and hematological parameters in birds. Chemical analysis of blood detected concentrations of the two primary reduction metabolites, but not parent compound, suggesting that toxicity may be due to the bioaccumulation of a toxic intermediate.

Administration, Oral↗
PubMed2002

Plant water uptake by hard red winter wheat (Triticum aestivum L.) genotypes at 2 degrees C and low light intensity.

BACKGROUND: Hard red winter wheat (HRWW; Triticum aestivm L.) plants from genotypes selected in the Northern Great Plains of the U.S. have less tissue water after exposure to cool autumn temperatures than plants from the Southern Great Plains. It is generally assumed that the reduced tissue water content of northern compared to southern cultivars is due to an impedance to water uptake by northern plants as a result of the low autumn temperatures. We hypothesize that if low temperature impedes water uptake then less soil water would be removed by northern than by southern-selected cultivars. This hypothesis was tested by comparing plant water uptake of a northern (FR) and a southern (FS) cultivar in relation to their foliage water content at 2 degrees C. RESULTS: At 2 degrees C foliage water content of FR plants decreased more rapidly than that of FS plants, similar to field results in the fall. During 6 wk, foliage water content of FR plants decreased 20 to 25% of the pre-treatment value, compared to only 5 to 10% by FS plants. Plant water uptake was about 60 g H2O*g FDW(-1) by FS plants, while FR plants maintained plant water uptake in excess of 100 g H2O*g FDW(-1) during the 6 wk period at 2 degrees C. When four other northern genotypes of equal freeze resistance were studied, foliage water content and plant water uptake change were similar to FR plants. CONCLUSION: In these northern-selected HRWW cultivars foliage water content reduction resulting from cold acclimation is not due to impedance to plant water uptake.

Algorithms↗
PubMed2004

A case of trauma related Acanthamoeba keratitis.

Acanthamoeba is an uncommon cause of keratitis but one of the most severe because of the prolonged and painful course of the disease and poor visual outcome. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Two cases of Acanthamoeba keratitis involving women contact lens wearers have previously been reported in Malaysia but this is the first time, a non contact lens related Acanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye during work. His eye was struck by sand and dust particles after which he quickly washed with water from an open tank at the construction site. He experienced pain, redness, glaring and blurring of vision of the right eye three days later. The diagnosis was missed at initial presentation but culture of the corneal scraping had proven Acanthamoeba as the aetiological agent. The history and clinical findings of this trauma related Acanthamoeba keratitis are briefly discussed.

Journal Article↗
PubMed2004

The relationship between lysosomal biomarker and organismal responses in an acute toxicity test with Eisenia Fetida (Oligochaeta) exposed to the fungicide copper oxychloride.

The LC50 of copper oxychloride for Eisenia fetida was determined, and its effects on biomass change and lysosomal damage using neutral red retention times (NRRT) of coelomocytes were measured. The aim was to establish whether a lysosomal subcellular response, measured as NRRT, could be linked to the LC50 and biomass changes. Further, we attempted to establish the ecological relevance of the LC50 by comparing it to studies previously carried out on the effects of copper oxychloride on field earthworm populations. The experiment was conducted over a period of 28 days, during which the earthworms were exposed to different concentrations of copper oxychloride in artificial soil. The calculated LC50 was 883 microg g(-1) for copper oxychloride and 519 microg g(-1) for copper. Results indicated that changes in coelomocyte membrane stability manifested earlier than effects on biomass. Since the NRRT assay was very sensitive and generated an early response before changes in biomass or mortality could be measured, it may have predictive value and may contribute information during acute toxicity tests, which could be of greater ecological relevance than mortality data alone.

Animals↗
PubMed2003

Food habit of the juvenile of the Japanese newt Cynops pyrrhogaster.

The previous study showed that the red coloration of the ventral skin of the Japanese newt Cynops pyrrhogaster was associated with the number of carotenoid vesicles and the content of carotenoid in the pigment cell of the skin. To elucidate the mechanism for the red coloration of the skin of the newt, we studied the food habit of the juvenile from the Japanese newt Cynops pyrrhogaster. Sixty-two juveniles were collected in Fukue Island in Nagasaki Prefecture from November 2000 to May 2002 and divided into 2 groups according to the snout-vent length (SVL). Over 400 prey animals were obtained from the juveniles by stomach flushing. In the larger group (SVL>30.0mm), Collembola (45.4%) and Acari (12.6%), which are very common species of soil animals, were the prey animals dominant in number. In the group with the smaller SVL (<29.9mm), Collembola (30.4%) and Acari (25.4%) were in number as well. We also studied the food habit of the Japanese clouded salamander, Hynobius nebulosus. In the salamander, Doratodesmidae (56.5%) and Amphipoda (13%) were the prey animals dominant in number. Our results, taken together, suggest that the Japanese juvenile C. pyrrhogaster does not change its food habit as it grows, and that it eats soil animals common in its habitat. Moreover, the food habit of juvenile C. pyrrhogaster differs from that of H. nebulosus, although the juveniles of both species live in the same area.

Animals↗
PubMed2004

Genetically modified bacterial strains and novel bacterial artificial chromosome shuttle vectors for constructing environmental libraries and detecting heterologous natural products in multiple expression hosts.

The enormous diversity of uncultured microorganisms in soil and other environments provides a potentially rich source of novel natural products, which is critically important for drug discovery efforts. Our investigators reported previously on the creation and screening of an Escherichia coli library containing soil DNA cloned and expressed in a bacterial artificial chromosome (BAC) vector. In that initial study, our group identified novel enzyme activities and a family of antibacterial small molecules encoded by soil DNA cloned and expressed in E. coli. To continue our pilot study of the utility and feasibility of this approach to natural product drug discovery, we have expanded our technology to include Streptomyces lividans and Pseudomonas putida as additional hosts with different expression capabilities, and herein we describe the tools we developed for transferring environmental libraries into all three expression hosts and screening for novel activities. These tools include derivatives of S. lividans that contain complete and unmarked deletions of the act and red endogenous pigment gene clusters, a derivative of P. putida that can accept environmental DNA vectors and integrate the heterologous DNA into the chromosome, and new BAC shuttle vectors for transferring large fragments of environmental DNA from E. coli to both S. lividans and P. putida by high-throughput conjugation. Finally, we used these tools to confirm that the three hosts have different expression capabilities for some known gene clusters.

Anti-Bacterial Agents↗
PubMed2004

An experimental test of the adaptive evolution of phototropins: blue-light photoreceptors controlling phototropism in Arabidopsis thaliana.

Phototropins are blue-light photoreceptor molecules mediating the capacity for phototropism or bending toward or away from directional light. Like the red-light sensing phytochromes that control shade avoidance, phototropins modulate developmental plasticity in plant architecture. Yet, unlike phytochromes, the adaptive significance of phototropins has been largely a topic of conjecture. In Arabidopsis thaliana, phototropism of seedling and plant stems is under the control of two paralogous genes, PHOT1 and PHOT2, that encode different phototropins with partially redundant light response qualities. The PHOT1 gene product interacts with the NPH3 gene product to cause phototropic bending over a broad range of light intensity, from very weak light in the soil to stronger light in the aerial environment. The PHOT2 gene product modulates shoot bending in response to light of higher intensity only. We compared the fitness of wild-type, phot1, phot2, and nph3 genotypes over a range of light conditions in the field. Seeds were sown in the field on the soil surface and left bare or covered with either gravel or bark mulch chips. Plantings were made under full sun and dense canopy cover. Rates of seedling emergence, survival to flowering, and total seed set were measured. All mutant genotypes had significantly reduced lifetime fitness compared to wild-type. Consistent with their different fluence rate sensitivities, phot1 and phot2 signaling pathways affected fitness at discrete life-cycle stages. Fitness costs of phot1 and nph3 were expressed mainly during seedling emergence from the soil whereas that of phot2 was expressed solely after emergence. Surprisingly, the only significant genotype-by-environment interaction for fitness occurred during emergence: genotypes blind to dim blue light (phot1 and nph3) had poor emergence in the open, but not in the shade. Possibly, the loss of negative phototropism in seedling roots of mutant genotypes reduced establishment success in open (dry soil) conditions. Results show that phototropin-modulated pathways are adaptive and that their evolution has involved functional specialization. However, mechanism(s) of selection on these pathways remain a mystery.

Adaptation, Physiological↗
PubMed2003

Histological analysis on the medieval mummy in Korea.

Recently, there have been some reports on the mummies from the medieval tombs in Korea, which were not made on purpose. Although these mummies could be an invaluable source for the studies on the physical state of medieval Koreans, there were not any reports on this subject until now. In this study, we first tried to investigate the various tissues using light- and electron-microscopic techniques. In the organs we have examined, even though the collagen fibers were profusely found within all of them, some types of cells, such as red blood cells, chondrocytes, hepatocyte and muscle cells, were also visible in various tissues. The histological characteristics of the current case seemed to be well matched with the previous study in general even though there were also somewhat different findings from the previous reports on the mummies. Although the cause of the mummification in Korea was not completely explained, we think that the cause in this case could be correlated with cultural aspects--not with natural conditions--because the mummies were only found in cases where the lime-soil barrier was maintained until their discovery, and which separated the inner space of the coffins from the outer space. As similar cases are frequently reported nowadays, invaluable data on the physical status of the medieval Koreans could be attainable if systemic investigation could be performed on similar cases which are found in the future.

Bayes Theorem↗
PubMed2002

Influence of dietary 2,4,6-trinitrotoluene exposure in the northern bobwhite (Colinus virginianus).

The risk to wildlife from exposure to the explosive, 2,4,6-trinitrotoluene (TNT) has been a concern at numerous military installations where it has been found in the soil. To date, no published data are available describing effects of TNT exposure in an avian species. Subchronic dietary exposure to TNT was therefore evaluated in a species of management concern at military installations, the northern bobwhite (Colinus virginianus). Adult male and female quail (n = 5/sex/dose) were given commercial feed containing 3,000, 1,500, 750, and 100 mg/kg TNT for 90 d following the determination of an acute lethal dose and a 14-d range finding study. Dietary TNT intake caused a dose-dependent decrease in total red blood cell counts, packed cell volume, total plasma protein, blood prolymphocytes, and blood lymphocytes. An increased trend in late apoptotic/necrotic blood leukocytic cells was also observed in TNT-exposed birds, as was hemosiderosis in the liver. With the exception of hemosiderosis, these trends were statistically significant yet of questionable biological significance. Since treatment-related responses in this preliminary study were variable, a conservative interpretation is suggested. However, since these treatments had concentrations that were a log-fold or more than doses in similar studies using mammals, these data suggest that northern bobwhite are less sensitive to oral exposures of TNT than mammals.

Animal Feed↗
PubMed1999

Elemental content of Vietnamese rice. Part 2. Multivariate data analysis.

Rice samples were obtained from the Red River region and some other parts of Vietnam as well as from Yanco, Australia. These samples were analysed for 14 elements (P, K, Mg, Ca, Mn, Zn, Fe, Cu, Al, Na, Ni, As, Mo and Cd) by ICP-AES, ICP-MS and FAAS as described in Part 1. This data matrix was then submitted to multivariate data analysis by principal component analysis to investigate the influences of environmental and crop cultivation variables on the elemental content of rice. Results revealed that geographical location, grain variety, seasons and soil conditions are the most likely significant factors causing changes in the elemental content between the rice samples. To assess rice quality according to its elemental content and physio-biological properties, a multicriteria decision making method (PROMETHEE) was applied. With the Vietnamese rice, the sticky rice appeared to contain somewhat higher levels of nutritionally significant elements such as P, K and Mg than the non-sticky rice. Also, rice samples grown during the wet season have better levels of nutritionally significant mineral elements than those of the dry season, but in general, the wet season seemed to provide better overall elemental and physio-biological rice quality.

Environment↗
PubMed2005

Phytochrome-mediated long-term memory of seeds.

The question is how long phytochrome, stored within the cytoplasm of plant diaspores, may stimulate their germination. This question arose from the observation that soil cultivations in darkness for weed control gave inconsistent results. Namely, after a single nighttime or daytime cultivation during spring and summer, differences in weed emergence became hardly detectable after a period of six weeks. However, after nighttime and daytime cultivations in late autumn, emergence differences persisted for up to nine months. To examine whether this differing memory effect is phytochrome-mediated, seeds of Chenopodium album and Stellaria media were sown in pots with wet peat, either in daylight or after sunset. In the latter, seeds were irradiated with far-red light for one day prior to being covered and buried. For more than two years the far-red irradiated seeds produced significantly reduced emergence, indicating that germination and emergence of weeds in the field may be supported by maternal far-red absorbing seed phytochrome B(fr) over several months or even years. This conclusion allows refining of the strategy of lightless tillage.

Chenopodium album↗
PubMed2005

Studies of selenium in environmental samples and synthetic mixtures by spectrophotometry.

A rapid, highly sensitive and selective spectrophotometric method for the determination of traces of selenium(IV) is described. The method is based on oxidation of p-nitroaniline by selenium(IV) followed by coupling reaction with N-(1-naphthalene-1-yl)ethane-1,2-diamine dihydrochloride (NEDA) in neutral medium to give red colored derivative with lambda(max) 515 nm and is stable for more than 10 days at 35 degrees C. Beer's law is obeyed for selenium(IV) in the concentration range of 0.02-3.2 microg ml(-1) at the wavelength of maximum absorption. The optimum reaction conditions and other analytical parameters were investigated to enhance the sensitivity of the present method. The detailed study of various interferences made the method more selective. The proposed method was successfully applied to the analysis of selenium in polluted water, natural water samples, plant material, soil samples, and synthetic mixtures. The results obtained were agreed with the reported methods at the 95% confidence level. The performance of proposed method was evaluated in terms of Student's t-test and Variance ratio f-test which indicates the significance of proposed method over reported method.

Aniline Compounds↗
PubMed2002

Phytochrome from Agrobacterium tumefaciens has unusual spectral properties and reveals an N-terminal chromophore attachment site.

Phytochromes are photochromic photoreceptors with a bilin chromophore that are found in plants and bacteria. The soil bacterium Agrobacterium tumefaciens contains two genes that code for phytochrome-homologous proteins, termed Agrobacterium phytochrome 1 and 2 (Agp1 and Agp2). To analyze its biochemical and spectral properties, Agp1 was purified from the clone of an E. coli overexpressor. The protein was assembled with the chromophores phycocyanobilin and biliverdin, which is the putative natural chromophore, to photoactive holoprotein species. Like other bacterial phytochromes, Agp1 acts as light-regulated His kinase. The biliverdin adduct of Agp1 represents a previously uncharacterized type of phytochrome photoreceptor, because photoreversion from the far-red absorbing form to the red-absorbing form is very inefficient, a feature that is combined with a rapid dark reversion. Biliverdin bound covalently to the protein; blocking experiments and site-directed mutagenesis identified a Cys at position 20 as the binding site. This particular position is outside the region where plant and some cyanobacterial phytochromes attach their chromophore and thus represents a previously uncharacterized binding site. Sequence comparisons imply that the region around Cys-20 is a ring D binding motif in phytochromes.

Agrobacterium tumefaciens↗
PubMed1992

Changes in selected enzyme activities during growth of pure and mixed cultures of the white-rot decay fungus Trametes versicolor and the potential biocontrol fungus Trichoderma harzianum.

Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organism Trichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase, and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and peroxidase activities were enhanced, while laccase activities were reduced. Most importantly, laccase activities of Trametes versicolor, and to a smaller extent, cellobiase activities of both fungi, were significantly induced in mixed cultures of Trametes versicolor and Trichoderma harzianum.

Cellulase↗
PubMedDate not supplied

Environmental uranium and human health.

Uranium from the environment enters the human body by ingestion with food and drink and by inhalation of respirable airborne uranium-containing dust particles or aerosols. Daily intake of uranium in food and water varies from approximately 1 to approximately 5 micrograms U/d daily in uncontaminated regions to 13-18 micrograms/d or more in uranium mining areas. A 70 kg, non-occupationally exposed 'Reference Man' living in Europe or in the United States has an estimated total body uranium content of about 22 micrograms. Uranium is absorbed from the intestine or the lungs, enters the bloodstream, and is rapidly deposited in the tissues, predominantly kidney and bone, or excreted in the urine. In the bloodstream, uranium is associated with red cells, and its clearance is relatively rapid. Renal toxicity is a major adverse effect of uranium, but the metal has toxic effects on the cardiovascular system, liver, muscle, and nervous system as well. Any possible direct risk of cancer or other chemical- or radiation-induced health detriments from uranium deposited in the human body is probably less than 0.005% in contrast to an expected indirect risk of 0.2% to 3% through inhaling the radioactive inert gas radon, which is produced by the decay of environmental uranium-238 in rocks and soil and is present in materials that are used to build dwellings and buildings where people live and work.

Air Pollution, Radioactive↗