Occurrence of multiple metal-resistance in bacterial isolates associated with transgenic white poplars ( Populus alba L.)

The occurrence of multiple metal-resistance was assessed in two bacterial collections, named Herbicide Resistant Bacteria (HRB) and Nuclease-Producing Bacteria (NPB) respectively, consisting of 15 and 11 isolates obtained from a loamy sand cultivated with transgenic white poplars (Populus alba L., cv 'Vilafranca') engineered for herbicide resistance. A third collection of 11 bacterial isolates, named Leaf-Associated Bacteria (LAB), obtained from the leaves of transgenic white poplars expressing theStSy gene for resveratrol production and from untransformed plants was evaluated. Resistance to Cd, Co, Cu, Pb and Zn was tested. As for the HRB collection, nine different phenotypes were monitored, which included tetra-, tri- and double-resistance. Tri- and double-metal resistance occurred also within the NPB and LAB collections. In both cases five different phenotypes were recovered. An additional investigation was carried out on the HRB-1c isolate, resistant to Cd, Co, Pb and Zn, which was previously demonstrated to produce indoleacetic acid, a plant-growth-promoting trait. Colorimetric assays, performed on the cell-depleted medium of HRB-1c liquid cultures grown in presence of heavy metals, confirmed that this trait was not affected. A 19-kb plasmid, possibly involved in the maintenance of the multiple metal-resistant phenotype, was detected in the HRB-1c cells

Increased Resistance of Bt Aspens to Phratora vitellinae (Coleoptera) Leads to Increased Plant Growth under Experimental Conditions

One main aim with genetic modification (GM) of trees is to produce plants that are resistant to various types of pests. The effectiveness of GM-introduced toxins against specific pest species on trees has been shown in the laboratory. However, few attempts have been made to determine if the production of these toxins and reduced herbivory will translate into increased tree productivity. We established an experiment with two lines of potted aspens (Populus tremula×Populus tremuloides) which express Bt (Bacillus thuringiensis) toxins and the isogenic wildtype (Wt) in the lab. The goal was to explore how experimentally controlled levels of a targeted leaf beetle Phratora vitellinae (Coleoptera; Chrysomelidae) influenced leaf damage severity, leaf beetle performance and the growth of aspen. Four patterns emerged. Firstly, we found clear evidence that Bt toxins reduce leaf damage. The damage on the Bt lines was significantly lower than for the Wt line in high and low herbivory treatment, respectively. Secondly, Bt toxins had a significant negative effect on leaf beetle survival. Thirdly, the significant decrease in height of the Wt line with increasing herbivory and the relative increase in height of one of the Bt lines compared with the Wt line in the presence of herbivores suggest that this also might translate into increased biomass production of Bt trees. This realized benefit was context-dependent and is likely to be manifested only if herbivore pressure is sufficiently high. However, these herbivore induced patterns did not translate into significant affect on biomass, instead one Bt line overall produced less biomass than the Wt. Fourthly, compiled results suggest that the growth reduction in one Bt line as indicated here is likely due to events in the transformation process and that a hypothesized cost of producing Bt toxins is of subordinate significance

Vascular risk factors in glaucoma: the results of a national survey

Background The role of vascular risk factors in glaucoma is still being debated. To assess the importance of vascular risk factors in patients with primary open-angle glaucoma (POAG), data from the medical history of 2,879 POAG patients and 973 age-matched controls were collected and analyzed. Methods Design: observational survey. Setting: 35 Italian academic centers. Study population: POAG patients and age-matched controls. In order to reduce bias consecutive patients were included. Observation procedures: data concerning vascular risk factors were collected for all patients with a detailed questionnaire. A complete ophthalmological examination with assessment of intraocular pressure (IOP), visual field, optic disc, and systemic blood pressure was performed. Main outcome measures: the ESH-ESC (European Society of Hypertension-European Society of Cardiology) guidelines were used to calculate the level of cardiovascular risk. Crude and adjusted estimates of the odds ratios (OR) were calculated for all cardiovascular risk factors in POAG and controls. Results The study included 2,879 POAG patients and 973 controls. POAG cases had a significantly higher systolic and diastolic blood pressure (p=0.001) and systolic perfusion pressure (p=0.02) as compared with controls. Also mean IOP was significantly higher in the POAG group (p=0.01), while diastolic perfusion pressure was not significantly different in the two groups. Myopia was more prevalent in the POAG group (23 vs 18%, p=0.005) as well as a positive family history for glaucoma (26 vs 12%, p= 0.004). POAG patients tended to have a higher cardiovascular risk than controls: 63% of glaucoma cases vs 55% of controls (OR: 1.38, p=0.005) had a “high” or “very high” cardiovascular risk. Conclusions The level of cardiovascular risk was significantly higher in glaucoma patients than in controls

Effects of Heavy Metals and Arbuscular Mycorrhiza on the Leaf Proteome of a Selected Poplar Clone: A Time Course Analysis

Arbuscular mycorrhizal (AM) fungi establish a mutualistic symbiosis with the roots of most plant species. While receiving photosynthates, they improve the mineral nutrition of the plant and can also increase its tolerance towards some pollutants, like heavy metals. Although the fungal symbionts exclusively colonize the plant roots, some plant responses can be systemic. Therefore, in this work a clone of Populus alba L., previously selected for its tolerance to copper and zinc, was used to investigate the effects of the symbiosis with the AM fungus Glomus intraradices on the leaf protein expression. Poplar leaf samples were collected from plants maintained in a glasshouse on polluted (copper and zinc contaminated) or unpolluted soil, after four, six and sixteen months of growth. For each harvest, about 450 proteins were reproducibly separated on 2DE maps. At the first harvest the most relevant effect on protein modulation was exerted by the AM fungi, at the second one by the metals, and at the last one by both treatments. This work demonstrates how importantly the time of sampling affects the proteome responses in perennial plants. In addition, it underlines the ability of a proteomic approach, targeted on protein identification, to depict changes in a specific pattern of protein expression, while being still far from elucidating the biological function of each protein

Phytoremediation of heavy metal-contaminated sites: Eco-environmental concerns, field studies, sustainability issues and future prospects

Environmental contamination due to heavy metals (HMs) is of serious ecotoxicological concern worldwide because of their increasing use at industries. Due to non-biodegradable and persistent nature, HMs cause serious soil/water pollution and severe health hazards in living beings upon exposure. HMs can be genotoxic, carcinogenic, mutagenic, and teratogenic in nature even at low concentration. They may also act as endocrine disruptors and induce developmental as well as neurological disorders and thus, their removal from our natural environment is crucial for the rehabilitation of contaminated sites. To cope with HM pollution, phytoremediation has emerged as a low-cost and eco-sustainable solution to conventional physico-chemical cleanup methods that require high capital investment and labor alter soil properties and disturb soil microflora. Phytoremediation is a green technology wherein plants and associated microbes are used to remediate HM-contaminated sites to safeguard the environment and protect public health. Hence, in view of the above, the present paper aims to examine the feasibility of phytoremediation as a sustainable remediation technology for the management of metals-contaminated sites. Therefore, this paper provides an in-depth review on both the conventional and novel phytoremediation approaches, evaluate their efficacy to remove toxic metals from our natural environment, explore current scientific progresses, field experiences and sustainability issues and revise world over trends in phytoremediation research for its wider recognition and public acceptance as a sustainable remediation technology for the management of contaminated sites in 21st century

Deep lamellar keratoplasty with trypan blue intrastromal staining.

This technique was developed to facilitate removal of the deep stromal layers during deep lamellar keratoplasty. A trypan blue 0.02% solution is injected into the stromal fibers, enabling the surgeon to visualize and remove the posterior stromal layers. This decreases the risk of perforation of Descemet’s membrane and the endothelium

Escherichia coli endophthalmitis after trans-scleral resection of uveal melanoma.

PURPOSE: To report a case of Escherichia coli endophthalmitis after trans-scleral resection of an uveal melanoma. METHODS: A large ciliary body melanoma was treated by trans-scleral resection and full-thickness sclerectomy because of epibulbar tumor extrusion, followed by adjuvant ruthenium plaque therapy. RESULTS: Two months after treatment the patient developed wound dehiscence and consecutive endophthalmitis. Cultures of the involved sclera yielded Escherichia coil. The infection resolved after systemic intravenous ciprofloxacin and ceftriaxone, with aggressive topical ciprofloxacin and tobramycin. Final visual acuity was light perception. CONCLUSIONS: We assume that the ruthenium plaque placed over the scleral patch was responsible for the delay in scleral healing, with consequent wound dehiscence and E. coli endophthalmitis

Femtosecond laser-assisted in situ keratomileusis for the correction of residual ametropia after deep anterior lamellar keratoplasty: A pilot investigation

PurposeTo evaluate the refractive and visual results of one-stage laser-assisted in situ keratomileusis with femtosecond laser (Femto-LASIK) for the correction of residual ametropia after deep anterior lamellar keratoplasty (DALK).MethodsThis retrospective study included 13 eyes of 12 patients, who underwent corneal Femto-LASIK to correct refractive errors after DALK. IntraLase FS150 was used to create a lamellar flap and excimer laser ablation for refractive correction was performed using the Star S4 IR Excimer Laser in eight cases and the Technolas 217z Excimer Laser in Tissue Saving mode in five cases. Perioperative variables of interest included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction and corneal topography.ResultsThe mean spherical equivalent preoperatively was 4.85±2.82 (range, 9.5 to 0 D). At the last visit the mean postoperative spherical equivalent (SE) was 0.44±0.67 D (P<0.05). The mean postoperative UDVA was 0.12±0.12 logMAR. There was a statistically significant increase in CDVA 6 months after Femto-LASIK (P<0.05). Intraoperative and postoperative complications did not develop in this series of eyes.ConclusionsCorrecting the preoperative manifest refractive error with Femto-LASIK led to a significant improvement in the UDVA and CDVA without surgical complications. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved