Towards practical cadmium phytoextraction with Noccaea caerulescens.

A series of field trials were conducted to investigate the potential of Noccaea caerulescens F.K. Mey [syn. Thlaspi caerulescens J &C Presl. (see Koch and Al-Shehbaz 2004)] populations (genotypes) derived from southern France to phytoextract localized Cd/Zn contamination in Thailand. Soil treatments included pH variation and fertilization level and application of fungicide. N. caerulescens populations were transplanted to the field plots three months after germination and harvested in May, prior to the onset of seasonal rains. During this period growth was rapid with shoot biomass ranging from 0.93-2.2 g plant(-1) (280-650 kg ha(-1)) DW. Shoot Cd and Zn concentrations for the four populations evaluated ranged from 460-600 and 2600-2900 mg kg(-1) DW respectively. Cadmium and Zn Translocation Factors (shoot/root) for the populations tested ranged from 0.91-1.0 and 1.7-2.1 and Bioaccumulation Factors ranged from 12-15 and 1.2-1.3. We conclude that optimizing the use of fungicidal sprays, acidic soil pH, planting density and increasing the effective cropping period will increase rates of Cd and Zn removal enough to facilitate practical Cd phytoextraction from rice paddy soils in Thailand.

Hypotheses, mechanisms and trade-offs of tolerance and adaptation to serpentine soils: from species to ecosystem level.

Understanding the relative importance of the abiotic environment and species interactions in determining the distribution and abundance of organisms has been a challenge in ecological research. Serpentine substrata are stressful environments for plant growth due to multiple limitations, collectively called the "serpentine syndrome". In the present review, our aim is not only to describe recent work in serpentine ecology, but also to highlight specific mechanisms of species tolerance and adaptation to serpentine soils and their effects on community structure and ecosystem functioning. We present hypotheses of the development of serpentine endemism and a description of functional traits of serpentine plants together with a synthesis of species interactions in serpentine soils and their effects on community structure and ecosystem productivity. In addition, we propose hypotheses about the effects of the 'serpentine syndrome' on ecosystem processes including productivity and decomposition.

Evolutionary dynamics of nickel hyperaccumulation in Alyssum revealed by its nrDNA analysis.

• Molecular phylogeny based on ribosomal internal transcribed spacer (ITS) sequences was studied to investigate the phyletic relationships among some nickel (Ni)-hyperaccumulating and nonhyperaccumulating species of the genus Alyssum in relation to their geographic distribution and Ni-hyperaccumulating phenotype. • Thirty-seven samples belonging to 32 taxa were analysed by sequencing the polymerase chain reaction-amplified ITS region and performing neighbor joining, maximum parsimony and maximum likelihood phylogenetic analyses. • The ITS region in the sampled species varied from 221 to 307 bp of ITS1 and from 194 to 251 bp of ITS2. A total of 765 characters was used to infer the phylogeny and the average nucleotide variation detected was 15.15%. • Nickel-hyperaccumulation could have been lost or acquired independently more than once during the speciation of the genus. The geographical location of species could not be related to phylogenetic affinities.

Nickel-accumulating plants from the ancient serpentine soils of Cuba.

Extraordinary uptake of nickel (Ni), reaching concentrations of 0.1-5.0%, c. 1000 times greater than those usually found in flowering plants, has been observed previously in c, 190 species that grow on Ni-rich serpentine soils derived from ultramafic rocks in various parts of the world. These so-called hyperaccumulators of Ni include c. 50 species from the rich ultramafic flora of New Caledonia and c. 80 species from the Brassicaceae of Mediterranean Europe and Turkey. A study of a limited part (the families Buxaceae and Euphorbiaceae) of the very large ultramafic flora of Cuba has now identified this as the home of at least 80 hyperaccumulators, the largest number jet found in any one country. The more frequent incidence here of this unusual form of plant behaviour is linked to the very long period (r. 10-30 million years) during which some of the Cuban ultramafic substrata are believed to have been continuously available for colonization; the distribution of Ni hyperaccumulators between older and younger ultrarnafic soils in Cuba mirrors the overall incidence of endemic species in these areas.

Heavy metal accumulation and tolerance in British populations of the metallophyte Thlaspi caerulescens J. & C. Presl (Brassicaceae).

Heavy metai uptake, accumulation and tolerance were investigated in five British populations of the metallophyte Thlaspi caerulescens from metalliferous sites from the north and south Pennines orefields. Analysis of field samples showed mean shoot Zn, Pb and Cd concentrations of up to 21000, 660 and 164/zMug g-1 respectively. A solution culture experiment designed to investigate both tolerance and metal accumulation is reported. Indices of tolerance of five populations to 12 metals (Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Zn) showed few population differences but unexpectedly high tolerance to metals not present at elevated concentrations in the parent soils. This was paralleled by exceptionally high uptakes of all metals studied. Zn, Cd, Co, Mn and Ni were readily transported to the shoot whereas Al, Cr Cu, Fe and Pb were predominantly immobilized in the roots. The data suggest common mechanisms of absorption and transport of several metals in this species.

Soluble dietary fiber and cholesterol influence in vivo hepatic and intestinal cholesterol biosynthesis in rats.

Ninety-six male Sprague-Dawley rats were randomly assigned to eight dietary treatments. Rats were fed, with ad libitum access, diets containing 10% dietary fiber as cellulose (control), pectin, psyllium or oat bran with or without 0.3% added cholesterol for 3 wk. Among cholesterol-fed rats, liver total cholesterol was significantly lower in rats fed diets supplemented with either pectin or psyllium compared with those fed cellulose. In contrast, rats fed oat bran with cholesterol had significantly higher liver cholesterol concentrations compared with cellulose-fed animals. Liver total lipid concentrations were significantly lower in groups fed pectin and psyllium with or without dietary cholesterol compared with cellulose-fed controls. Pectin feeding with or without dietary cholesterol significantly lowered plasma total cholesterol compared with cellulose feeding. Oat bran had no effect on plasma total cholesterol compared with control diets. Hepatic sterol synthesis was significantly greater for animals fed soluble dietary fibers compared with those fed cellulose, but the effect on intestinal sterol synthesis was less pronounced.

Dietary soluble fiber and cholesterol affect serum cholesterol concentration, hepatic portal venous short-chain fatty acid concentrations and fecal sterol excretion in rats.

Sprague-Dawley rats were fed diets containing 7.5% dietary fiber as cellulose (control), pectin, psyllium or oat bran with or without 0.3% added cholesterol for 3 wk. Among rats fed cholesterol, liver total lipid and cholesterol concentrations were significantly lower in groups fed pectin, psyllium and oat bran compared with cellulose-fed controls. Cholesterol feeding resulted in significantly greater liver cholesterol in rats fed cellulose, psyllium and oat bran but not in those fed pectin. Among rats fed cholesterol, total serum cholesterol levels were significantly lower in those fed pectin than in those fed psyllium, oat bran or cellulose. When cholesterol was fed, the oat bran-fed group had significantly higher butyrate and the pectin-fed group had significantly higher propionate concentrations in the hepatic portal vein than did cellulose-fed controls. The groups fed psyllium, oat bran and pectin all had significantly higher fecal neutral sterols than did the cellulose-fed group when cholesterol was fed. Without dietary cholesterol only pectin-fed rats had significantly higher fecal excretion of neutral sterols than those fed cellulose. Dietary fiber did not influence fecal acidic sterol excretion. However, the addition of cholesterol to these fiber diets was accompanied by a significantly higher bile acid excretion than that of animals fed cellulose without cholesterol. The results of this study indicate that soluble dietary fibers may exert their hypocholesterolemic effect by increasing excretion of fecal neutral sterols.

Animal model of conjunctival primary acquired melanosis.

A condition clinically identical to human conjunctival primary acquired melanosis (PAM) was induced in 16 of 20 Dutch (pigmented) rabbits after weekly topical 60-microliters applications of a 1% solution of 7,12-dimethylbenz[a]anthracene (DMBA) in acetone. Pigment stippling appeared in the conjunctiva as early as 5 weeks after the initial carcinogen application. Confluent patches of flat pigmentation appeared over the palpebral conjunctiva 18 weeks after the onset of treatment and showed progressive lateral enlargement and darkening. Histologically, a spectrum of changes from increased melanin production and melanocytic hyperplasia without atypia (resembling the human condition of PAM without atypia) through atypical melanocytic hyperplasia (resembling human PAM with atypia) was identified. The development of this model permits further investigations to explore and explain the clinically observed phenomenon of waxing and waning of PAM and its promotion to conjunctival malignant melanoma.

Irradiation increases superoxide dismutase in rat intestinal smooth muscle.

We investigated whether X-irradiation could induce the enzyme superoxide dismutase (SOD) in intestinal muscle. Groups of rats received abdominal irradiation and the time course and dose response for SOD activity determined. Jejunal smooth muscle homogenates were analyzed for the activities of copper/zinc (CuZn) and manganese (Mn) SOD activity and for a mitochondrial marker enzyme, citrate synthase. A progressive rise in Mn SOD activity occurred at 20, 46, and 72 h after 1500 R. No significant changes in Cu-Zn SOD activity occurred at any time after 1500 R. At 20 h after 250 R of X-irradiation, Mn SOD activity increased but no further increase occurred at higher irradiation exposures. At the same time, CuZn SOD activity at 20 h after irradiation was greater than controls only at an exposure of 1000 R (p less than 0.05). Using Western blotting, we were able to clearly demonstrate an increase in immunoreactive Mn SOD protein in muscle samples 20 h after 1500 R. The rise in Mn SOD is not simply due to increase in mitochondrial numbers or increase in all mitochondrial enzyme activities because activity of the mitochondrial marker enzyme citrate synthase was decreased after X-irradiation. Transmission electron microscopic studies demonstrated damage to mitochondria after a dose of 3000 R. The data yield evidence that free radicals play a role in irradiation-induced intestinal smooth muscle injury.

Biogeochemical study of areas of sulphide mineralisation in eastern Thrace, Greece.

The uptake of copper, lead and zinc by plants in several areas of sulphide mineralisation in eastern Thrace, Greece, has been studied. Two indicator plants for sulphide deposits in central Macedonia,Rumex acetosella L. andMinuartia verna (L.) Hiern, have not been found on Thracian soils high in sulphides. However, the widespread speciesHypericum perforatum L. andScleranthus perennis L. are tolerant of the elevated metal levels in these soils. AlthoughH. perforatum is not useful as a biogeochemical indicator, the levels of Cu, Pb and Zn inS. perennis were found to be strongly correlated with the corresponding concentrations in the soil.

Ovine ceroid-lipofuscinosis. I: Lipopigment composition is indicative of a lysosomal proteinosis.

The ceroid-lipofuscinoses are inherited lysosomal storage diseases of children and animals characterised by a fluorescent lipopigment stored in a variety of tissues. Defects in lipid metabolism or the control of lipid peroxidation have been postulated to explain their pathogenesis but the underlying biochemical defect is still unknown. In the present study lipopigment was isolated from liver, kidney, pancreas and brain of sheep affected with ceroid-lipofuscinosis. Approximately two-thirds of the lipopigment mass was protein. Sodium dodecyl sulphate polyacrylamide gel electrophoresis showed a major polypeptide band of Mr 14,800, heterogeneous polypeptides between 5,000-9,000 Mr and a major band of Mr 3,500. These were not normal lysosomal proteins. I125 radiolabeling studies indicated that they were 47% of the pancreatic lipopigment mass, the 3,500 Mr polypeptides alone accounting for 26%. Lipopigment polypeptides were not subunits of a larger protein held together by disulphide bonds. The presence of the 3,500 Mr proteins in whole affected tissue homogenates distinguished them from homogenates of normal tissues. Lipopigment phospholipids were the same species as normal lysosomal phospholipids, including bis (monoacylglycero) phosphate, a lysosomal marker. Similarly the neutral lipids, notably dolichol, ubiquinone and dolichyl esters were typical of those in lysosomal membranes. Lipopigments contained 1-1.7% metals. Analyses of them indicated a functional lysosomal origin for the lipopigment. It was concluded that low Mr proteins are specifically stored in ovine ceroid-lipofuscinosis and that this disease is a lysosomal proteinosis.

Influence of zinc on growth, somatomedin, and glycosaminoglycan metabolism in rats.

Weanling male rats were fed control ad libitum, zinc-deficient (ZD, 1 ppm zinc) or pair-fed (PF) control diets for 13 days. Rats subsequently were refed control diets for up to 8 days and serially killed. ZD and PF diets significantly decreased growth rate, feed intake, and feed efficiency compared to controls. Body weight and feed efficiency, but not feed intake, were significantly less in ZD compared to PF. Bone zinc was 315, 286, and 109 micrograms/g (p less than 0.0001) for control, PF, and ZD at the end of depletion. 35SO4 uptake by glycosaminoglycans (GAG) was significantly less in ZD compared to either control ad libitum or PF rats. Xylosyltransferase activity was decreased significantly below PF and control by ZD, suggesting depressed enzyme activity and/or decreased GAG acceptor sites. Bioassayable somatomedin (Sm) activity was 0.81, 0.42 and 0.33 +/- 0.09 relative activity for control, PF and ZD at the end of depletion. Sm was statistically less in ZD compared to PF at day 2 and 5 of refeeding, but not at the end of depletion. Sm activity and GAG metabolism returned to normal after refeeding for 2-5 days in PF and for 5-8 days in ZD rats. Serum insulin but not glucose was significantly depressed by ZD and PF diets. Thus, zinc deficiency depressed growth and cartilage metabolism and was associated with decreased Sm activity and insulin levels. Some of these changes could be attributed to decreased feed intake as a result of ZD.

Effect of dietary fiber in insulin-dependent diabetics: insulin requirements and serum lipids.

Four young adult (18 to 26 years old), nonobese human subjects (two men and two women) with insulin-dependent diabetes mellitus volunteered to consume a series of three diets: baseline (normal daily intake), wheat bran (normal daily intake + 78 gm wheat bran per day), and cellulose (normal daily intake + 30 gm cellulose per day). Wheat bran and cellulose diets both contained 60 gm dietary fiber, with 50% of the dietary fiber from wheat bran or cellulose, respectively. Each patient served as his or her own control. Randomized diets were of 6 weeks' duration, separated by a 4-week "recovery" period. At the conclusion of each diet, subjects were hospitalized and underwent 12 hours of computer-controlled, insulin-glucose infusions. Significant decreases were seen in fasting cholesterol (p less than .05), but the decreases seemed to result largely from the significant reductions in high-density lipoprotein cholesterol. A large reduction in triglycerides was noted with cellulose feeding but not with wheat bran. The mean daily insulin dose decreased (p less than .05) in response to fiber addition (8% and 10% decrease for wheat bran and cellulose feeding, respectively). Mean biostator insulin requirements decreased 11% with wheat bran (p less than .05) but not with cellulose. During biostator monitoring, subjects experienced delayed postprandial blood glucose and insulin-infusion rate peaks with both wheat bran and cellulose feeding. The wheat bran diet reduced peak blood glucose concentration and peak insulin infusion rate in comparison with baseline and cellulose diets. The data suggest that high levels of cellulose or wheat bran are of marginal benefit to insulin-dependent diabetic subjects.

Influence of selected amino acid deficiencies on somatomedin, growth and glycosaminoglycan metabolism in weanling rats.

The effects of lysine-, methionine- or histidine-deficient diets compared to a control diet fed ad libitum or 15, 10 or 5 g/d were studied in weanling rats. Feed intake was 5-7 g/d for the amino acid-deficient animals. After 3 wk, all amino acid-deficient rats had lost more weight (P less than 0.01) than the controls fed at comparable energy levels. Serum somatomedin (Sm) activity was significantly decreased in lysine- (0.55 U/ml), methionine- (0.32 U/ml) and histidine-deficient (0.38 U/ml) rats compared to rats fed the control diet ad libitum (1.6 U/ml). Differences between amino acid-deficient and calorie-restricted animals were not significant. A similar response was observed in 35SO4 uptake by cartilage glycosaminoglycans (GAG). Caloric restriction and amino acid deficiency each resulted in lower 35SO4 uptake by cartilage GAG than occurred with ad libitum feeding, but there were no significant differences between the rats fed amino acid-deficient diets and those fed 5 or 10 g of the control diet. Compared to rats fed the control diet ad libitum, plasma growth hormone (GH) concentrations were lower in the rats fed 5 or 10 g of control diet per day and in those fed amino acid-deficient diets (P less than 0.05), but GH concentrations were not consistent with the growth retardation observed. The results confirm that Sm and GAG activities are reduced in protein-energy restriction independent of GH. However, changes could not be attributed to specific deficiencies of lysine, methionine and/or histidine.

Influence of manganese on growth, somatomedin and glycosaminoglycan metabolism.

Day-old chicks were fed control or manganese (Mn deficient diets ad libitum for 25 d. The chicks subsequently were refed control diet for up to 5 d. Mn deficiency significantly decreased growth rate and feed intake compared to controls. After 25 d of depletion, bone Mn concentration was 2% that of controls and 88% of the deficient chicks exhibited signs of perosis. Sulfate (35SO4) uptake into uronic acid was significantly depressed in cartilage from the Mn-depleted chicks and increased rapidly with refeeding, which may indicate increased glycosaminoglycan (GAG) biosynthesis or increased sulfation of the GAG molecule. In vitro activity of glycosyltransferases suggest that GAG synthesis may be interrupted by Mn deficiency. Somatomedin activity, serum insulin and glucose levels were not influenced significantly by Mn deficiency. Thus, while Mn deficiency decreased growth and GAG synthesis these effects were not mediated by somatomedin.

Elemental anomalies at the cretaceous-tertiary boundary, woodside creek, new zealand.

Iridium and 26 other elements were determined in shale from the Cretaceous-Tertiary boundary at the locus classicus (for iridium anomalies) at Woodside Creek, New Zealand. Iridium, gold, copper, cobalt, chromium, nickel, arsenic, molybdenum, and iron were enriched in the basal 2 millimeters of the 8-millimeter shale parting as compared with the rest of the stratigraphic column. No other shale partings in the column had anomalous concentrations of any element when the data were expressed on a carbonate-free basis. The boundary material showed striking compositional similarities with the Stevns Klint Danish boundary shale. Elemental concentrations were in general much higher in the New Zealand material than in nonboundary shales from elsewhere in the world. The high concentration of iridium (153 nanograms per gram) in the basal layer of the boundary, together with the enrichment of other siderophile elements supports the idea of an extraterrestrial source for much of the material. The iridium/gold ratio of 2.1 is also in accordance with such a source. The iridium content of the basal layer is higher than for any other marine boundary shale obtained on land. The integrated iridium value is 187 nanograms per square centimeter of boundary surface.

Ultrasonographic versus clinical evaluation of a pelvic mass.

Ultrasonography has become an essential tool in the practice of modern obstetrics. Its usefulness in the evaluation of a pelvic mass in gynecologic practice remains unclear. The present investigation is a comparison of pelvic examination findings and preoperative ultrasound findings in 72 patients who underwent exploratory laparotomy for a pelvic mass at the Nation Naval Medical Center. Of the 72 patients, 65 (90%) were correctly diagnosed as having a pelvic mass by both pelvic examination and ultrasonography. The ultrasound study had a 5.6% false-negative rate (4 patients), and 4.4% (3 patients) had false-positive pelvic examinations. There was no significant difference by chi 2 analysis in accuracy between ultrasonography and pelvic examination in detection, estimation of size, or determining the unilateral or bilateral position of the mass (P less than .05). Ultrasonography was significantly more accurate in determining the cystic or solid nature of the mass (P greater than .05). In no patient was the decision to perform exploratory laparotomy altered by the preoperative ultrasound study. It is concluded from this investigation that routine ultrasonography is not necessary in the preoperative evaluation of a pelvic mass unless the cystic or solid nature of the mass will modify the patient's treatment.

Nickel uptake by Flacourtiaceae of New Caledonia.

Herbarium and field specimens (over 300) of all of the Flacourtiaceae of New Caledonia were analysed for nickel in order to identify hyperaccumulators (greater than 1000 microgram/g dry mass) and to assess nickel accumulation in relation to the evolutionary status of 'nickel plants' of New Caledonia. One hyperaccumulator was identified in the genus Lasiochlamys, ten among Xylosoma, one among Casearia and seven among Homalium. Although these Homalium nickel plants had previously been recorded, fresh data for these and other Homalium are presented. The remarkable tolerance of Flacourticeae to ultrabasic rocks is shown by the fact that 75% of the species are found on such substrates. The number of hyperaccumulators was greatest in the genera Xylosoma and Homalium. The Flacourtiaceae are among the most primitive of all angiosperms and in common with other primitive hyperaccumulators, contain nickel as a complex with citric acid. The only advanced New Caledonian nickel plant (Psychotria douarrei) has most of its nickel bound with ligands other than citric acid, a feature of other advanced hyperaccumulators. It is postulated that nickel complexing with citric acid may be a primitive character. Most of the New Caledonian nickel plants belong to the order Violales of subclass Dilleniidae. It is suggested that hyperaccumulation of nickel is an evolutionary character which occurs in long-indisturbed floras such as that of New Caledonia.