Complexation of cadmium in seeds and vegetative tissues of the cadmium hyperaccumulator Thlaspi praecox as studied by X-ray absorption spectroscopy

The cadmium hyperaccumulator Thlaspi praecox Wulfen (Brassicaceae) can accumulate unusually high amounts of Cd (>1,000 μg g^?1 dry weight) in its seeds without drastically affecting seed viability. As embryonic tissues are the most sensitive to Cd toxicity, the aim of this study was to investigate the Cd coordination and ligand environment in seeds of field collected T. praecox using extended X-ray absorption fine structure (EXAFS), and to compare the Cd ligand environment to that in the vegetative tissues of the plant. In intact seeds and isolated embryos, almost two thirds of the Cd ligands were thiol groups (Cd-S-C-). In addition, there was coordination to phosphate groups via bridging oxygens (Cd-O-P-), as for phytate, although this ligand was not observed in the vegetative organs and tissues. In roots and shoots up to 80% of the Cd ligands were oxygen ligands that are provided by the cell walls and by organic acids stored in vacuoles. In leaf epidermis only a slightly higher percentage of oxygen ligands was detected, as compared to the mesophyll, making vacuolar compartmentation and binding to the cell walls the main detoxification mechanisms in both of these leaf tissues.     

Tetrahydrophthalazine derivative "sodium nucleinate" exert its anti-inflammatory effects through inhibition of oxidative burst in human monocytes

We described the use of a new chemical substance Sodium nucleinate (SN) as an immunomodulatory substance exhibiting antiinflammatory properties. Sodium nucleinate (SN) registrated in Russian Federation as Tamerit, is 2-amino-1,2,3,4-tetrahydrophthalazine-1,4-dione sodium salt dihydrate, derivative of well known chemical substance luminol. To comprehend the mechanisms of SN immunomodulatory activity, we examined the SN modulation of the oxidative burst responses of whole blood human monocytes and polimorphonuclear cells (PMC) stimulated with phorbol 12-myristate 13-acetate (PMA) or E. coli suspension in vitro. SN did not inhibit the proportion of neutrophils and monocytes phagocytosing E. coli. Oxidative burst responses of monocytes stimulated with PMA were strongly inhibited at SN concentration ranging from 10-500 mg/ml, less efficient inhibitor was SN in E. coli stimulated monocytes (inhibition range was from 50-500 mg/ml SN). SN inhibited PMC oxidative burst only in range 100-500 mg/ml SN. In conclusion, we found SN as an efficient inhibitor of oxidative burst in monocytes. Since ROS generation in monocytes/macrophages has been found to be important for LPS-driven production of several proinflammatory cytokines, SN may exsert its antiinflammatory effects through monocyte/macrophage oxidative burst inhibition.     

HLA-DR expression on CD8 lymphocytes from gastric mucosa in urease-positive and urease-negative gastritis

Abstract We isolated lymphocytes from chronically inflamed gastric mucosa. We analysed the expression of IL-2 receptors (CD25), transferin receptors (CD71) and HLA-DR molecules on T lymphocytes by flow cytometric analysis in 16 patients with urease-positive and in 7 patients with urease-negative chronic gastritis. In G0, G1 and G2 histological type (Sydney classification) of gastritis the number of lymphocytes obtained from the gastric mucosa biopsies was too low for the flow cytometric analysis. However, in G3 histological type of chronic gastritis we obtained enough cells for the flow cytometric analysis in 75 %. We demonstrated a significant increase in HLA-DR expression on CD8 cells from patients with urease-positive gastritis compared to urease-negative gastritis. We also observed a statistically non-significant increase in HLA-DR expression on CD3 cells, and in CD71 expression on both CD3 and CD8 cells in urease-positive gastritis. However, no difference in CD25 expression was found between the two types of gastritis.     

Therapeutic electric stimulation does not affect immune status in healthy individuals – a preliminary report

Background

For the treatment of low back pain, the following three scenarios of posterior lumbar interbody fusion (PLIF) were usually used, i.e., PLIF procedure with autogenous iliac bone (PAIB model), PLIF with cages made of PEEK (PCP model) or titanium (Ti) (PCT model) materiel. But the benefits or adverse effects among the three surgical scenarios were still not fully understood.

Method

Finite element analysis (FEA), as an efficient tool for the analysis of lumbar diseases, was used to establish a three-dimensional nonlinear L1-S1 FE model (intact model) with the ligaments of solid elements. Then it was modified to simulate the three scenarios of PLIF. 10?Nm moments with 400?N preload were applied to the upper L1 vertebral body under the loading conditions of extension, flexion, lateral bending and torsion, respectively.

Results

Different mechanical parameters were calculated to evaluate the differences among the three surgical models. The lowest stresses on the bone grafts and the greatest stresses on endplate were found in the PCT model. The PCP model obtained considerable stresses on the bone grafts and less stresses on ligaments. But the changes of stresses on the adjacent discs and endplate were minimal in the PAIB model.

Conclusions

The PCT model was inferior to the other two models. Both the PCP and PAIB models had their own relative merits. The findings provide theoretical basis for the choice of a suitable surgical scenario for different patients.     

Effect of media components on the gynogenic regeneration of onion (Allium cepa L.) cultivars and analysis of regenerants

Summary Two separate experiments were performed to analyze the effects of different media on gynogenic regeneration in four onion cultivars. In a two step flower/ovary culture procedure, 2,4-dichlorophenoxyacetic acid added to the induction medium was superior to phenylacetic acid in the highly regenerating cultivar, while the effect of thidiazuron in the regeneration medium was generally optimal in higher (2 mg/l) rather than in lower (0.2 mg/l) concentrations. Gellan-gum was compared to agar solidified media. A higher number of regenerants was achieved on the former, but an undesirable hyperhydricity of regenerants formed on gellan-gum solidified media greatly reduced the final survival of formed embryos. Analysis of the time interval needed for regeneration showed high variability (from 46 to 152 days after inoculation), which was particularly pronounced in genotypes with lower regeneration capacity. Simpler isozyme patterns of regenerants showed that all analysed regenerants of the cultivar with a high regeneration capacity were homozygous, while in the other three cultivars, a considerable percentage (11.1 to 36.4%) of heterozygous regenerants were also detected. Ploidy analysis of the regenerants with simpler isozyme patterns revealed that the majority of lines remain haploid. Identification of 2 homozygous triploid regenerants demonstrated that as in androgenesis, nuclear fusions can occur during gynogenic haploid regeneration.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BA benzylaminopurine - PAA phenylacetic acid - TDZ thidiazuron - B5 Gamborg et al. (1968) medium - BDS Dunstan and Short (1977) medium     

Effect of two plant extracts and Lactobacillus fermentum on colonization of gastrointestinal tract by Salmonella enterica var. Düsseldorf in chicks

According to published data, it is well known that essential oils from plants possess antimicrobial activity against a wide range of pathogens, including Salmonella strains. The influence of the administration of essential oils from oregano (Origanum vulgare) and thyme (Thymus vulgaris) as well as Lactobacillus fermentum on crop, caecum, liver and spleen colonization by Salmonella enterica var. Düsseldorf in chicks was investigated in this study. For the experiment, one hundred 1-day old chicks were used, and they were divided into four groups: (i) untreated (C); (ii) treated with L. fermentum (L); (iii) treated with a mixture of oregano and thyme essential oils (OT); and (iv) treated with a combination of L. fermentum and a mixture of oregano and thyme essential oils (LOT). Essential oils from oregano and thyme were mixed with commercial poultry diet, which was offered ad libitum to chicks in appertaining groups. L. fermentum was added daily to drinking water. After 3 days all the chicks were challenged orally with S. enterica var. Düsseldorf. The crops, ceca, spleens and livers of the birds were examined for S. enterica var. Düsseldorf colonization 5 days after the challenge. Our results showed that a combined administration of L. fermentum and essential oils (oregano and thyme) in group with combined application of essential oils and lactobacillus strain reduced the percentage of colonized crops and ceca when compared to the control group without any treatment. Presented at the Second Probiotic Conference, Košice, 15–19 September 2004, Slovakia.     

HlyA knock out yields a safer Escherichia coli A0 34/86 variant with unaffected colonization capacity in piglets

Escherichia coli A0 34/86 (O83:K24:H31) has been successfully used for prophylactic and therapeutic intestinal colonization of premature and newborn infants, with the aim of preventing nosocomial infections. Although E. coli A0 34/86 was described as a nonpathogenic commensal, partial sequencing revealed that its genome harbours gene clusters highly homologous to virulence determinants of different types of E. coli, including closely linked genes of the alpha-haemolysin operon (hlyCABD) and for the cytotoxic necrotizing factor (cnf1). A haemolysin-deficient mutant (Delta hlyA) of E. coli A0 34/86 was generated and its colonization capacity was determined. The results show that a single dose of the A0 34/86 wild-type or Delta hlyA strains resulted in efficient intestinal colonization of newborn conventional piglets, and that this was still considerable after several weeks. No difference was observed between the wild-type and the mutant strains, showing that haemolysin expression does not contribute to intestinal colonization capacity of E. coli A0 34/86. Safety experiments revealed that survival of colostrum-deprived gnotobiotic newborn piglets was substantially higher upon colonization by the nonhaemolytic strain than following inoculation by its wild-type ancestor. We suggest that the E. coli A0 34/86 Delta hlyA mutant may represent a safer prophylactic and/or immunomodulatory tool with unaffected colonization capacity.     

Leaf traits in parental and hybrid species of Sorbus (Rosaceae)

? Premise of the study: Knowledge of functional leaf traits can provide important insights into the processes structuring plant communities. In the genus Sorbus, the generation of taxonomic novelty through reticulate evolution that gives rise to new microspecies is believed to be driven primarily by a series of interspecific hybridizations among closely related taxa. We tested hypotheses for dispersion of intermediacy across the leaf traits in Sorbus hybrids and for trait linkages with leaf area and specific leaf area. ? Methods: Here, we measured and compared the whole complex of growth, vascular, and ecophysiological leaf traits among parental (Sorbus aria, Sorbus aucuparia, Sorbus chamaemespilus) and natural hybrid (Sorbus montisalpae, Sorbus zuzanae) species growing under field conditions. A recently developed atomic force microscopy technique, PeakForce quantitative nanomechanical mapping, was used to characterize the topography of cell wall surfaces of tracheary elements and to map the reduced Young's modulus of elasticity. ? Key results: Intermediacy was associated predominantly with leaf growth traits, whereas vascular and ecophysiological traits were mainly parental-like and transgressive phenotypes. Larger-leaf species tended to have lower modulus of elasticity values for midrib tracheary element cell walls. Leaves with a biomass investment related to a higher specific leaf area had a lower density. Leaf area- and length-normalized theoretical hydraulic conductivity was related to leaf thickness. ? Conclusions: For the whole complex of examined leaf traits, hybrid microspecies were mosaics of parental-like, intermediate, and transgressive phenotypes. The high proportion of transgressive character expressions found in Sorbus hybrids implies that generation of extreme traits through transgressive segregation played a key role in the speciation process.     

The use of a food supplementation with D-phenylalanine, L-glutamine and L-5-hydroxytriptophan in the alleviation of alcohol withdrawal symptoms

We described the use of a food supplementation with D-phenylalanine, L-glutamine and L-5-hydroxytriptophan in the alleviation of alcohol withdrawal symptoms in patients starting a detoxification therapy. Since abstinence from ethanol causes a hypodopaminergic and a hypoopioidergic environment in the reword system circuits, manifesting with withdrawal symptoms, food supplements that contains D-phenylalanine a peptidase inhibitor (of opioide inactivation) and L-amino-acids (for dopamine synthesis) were used to replenish a lack in neurotransmitters and alleviate the symptoms of alcohol withdrawal. 20 patients suffering from alcohol addictions starting a detoxification therapy have been included in a prospective, randomized, double blind study. The patients have been randomly devided in two groups. One group recieved for a period of 40 days a food supplement containing D-phenylalanine, L-glutamine and L-5-hydroxytriptophan (investigation group), and the control (placebo) group. On the first day of hospitalization the patients performed a SCL-90-R test, and blood samples were taken for measuring liver enzymes, total bilirubin, unbound cortisol and lymphocyte populations. The same was done on the 40th day of hospitalization. During the therapy a significant decrease in SCL-90-R psychiatric symptoms scores and a significant increase in CD4 lymphocyte count was observed in the investigation group. The cortisol values were significantly, but equally decreased in both groups, the same was with the liver enzymes and the total bilirubin values. We conclude that abstinence causes a major stress for the patients. The use of food supplement containing D-phenylalanine, L-glutamine and L-5-hydroxytriptophan alleviates the withdrawal symptoms and causes a rise in CD4 lymphocyte population, but it dose not affect the serum cortisol levels, which are probably more affected by liver inflammation and the liver restitution.