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Background and aims: Cereals can be made safer and more nutritious by reducing cadmium (Cd) and enhancing zinc (Zn) levels. To respectively regulate the accumulation of these chemically similar elements in grains, it is essential to understand the differences between Cd and Zn allocation to grains. Methods: In durum wheat (Triticum durum), dual-isotope (111Cd and 67Zn) labeling was used to trace the post-anthesis uptake fluxes separately from the remobilization of pre-anthesis vegetative pools. Laser ablation inductively coupled mass spectrometry was used to investigate the spatial distribution of Cd and Zn in the uppermost node. Results: Among the shoot organs, both pre- and post-anthesis derived Cd was more allocated to the high-transpiring organs (i.e., bracts and flag leaves) whereas Zn was more to the grain. Cadmium was likely less efficiently transferred from the xylem to the phloem as suggested by the elemental maps which showed that Cd was more abundant than Zn in the xylem of the uppermost node. Furthermore, unlike Zn, Cd was not significantly remobilized from the high-transpiring organs, which further limited the allocation of Cd to the grain. Conclusion: High-transpiring organs are sources of grain Zn but irreversible sinks of Cd. Agronomic strategies that enhance Cd sequestration and Zn remobilization in high-transpiring organs could contribute to producing grains with low Cd and high Zn concentrations. [ABSTRACT FROM AUTHOR]

Simple Summary: Efficient photosensitizers for photodyanmic therapy (PDT) need to be soluble in physiologic media. This requirement often complicates significantly the chemical access to such compounds, resulting in lower availability and higher production costs for the best representatives. Given that their screening and selection is often initially conducted in organic media from series of hydrophobic model compounds, the possibility to use directly such hydrophobic photosensitizers in real PDT studies was highly desirable to speed up their definitive identification but also to alleviate their cost. In this respect, PMLABe polymeric nanoparticles (NPs) were presently probed as nanocarriers to water-solubilize hydophobic star-shaped porphyrin-based which turned out to be promising oxygen photosensitizers for theranostic approaches. We show here that PDT conducted using such NPs loaded with these compounds is as efficient than when functional hydrosoluble analogues of these photosensitiers are tested alone and that tracking of the photosensitizer by fluorescence imaging is even easier. Star-shaped hydrophobic porphyrins, acting as powerful fluorescent two-photon photosensitizers for oxygen in organic solvents, can easily be loaded into PMLABe polymeric nanoparticles at various concentrations. In this contribution, the performance of these porphyrin-containing nanoparticles in terms of photodynamic therapy (PDT) is compared to those of the corresponding water-soluble porphyrin analogues when irradiated in MCF-7 cancer cells. While quite promising results are obtained for performing PDT with these nanoparticles, validating this approach as a mean for using more easily accessible and less expensive photosensitizers, from a synthetic perspective, we also show that their luminescence can still be used for bioimaging purposes in spite of their confinement in the nanoparticles, validating also the use of these nano-objects for theranostic purposes. [ABSTRACT FROM AUTHOR]

Phthalocyanines have been described as effective photosensitizers for photodynamic therapy and are therefore, being studied for their biomedical applications. The metalation of photosensitizers can improve their photodynamic therapy potential. Here, we focus on the biological properties of [1,4-Bis(3,6,9,12-Tetraoxatridec-1-yloxy)phthalocyaninato]zinc(II) (ZnPc(αEG 4) 2) and demonstrate its exceptional anticancer activity upon light stimulation to kill preferentially cancer cells with a start of efficiency at 10 pM. Indeed, in this work we highlighted the high selectivity of ZnPc(αEG 4) 2 for cancer cells compared with healthy ones and we establish its mechanism of action, enabling us to conclude that ZnPc(αEG 4) 2 could be a powerful tool for cancer therapy. [Display omitted] • Phthalocyanines are efficient photosensitisers for photodynamic therapy. • Here we have studied ZnPc(αEG 4) 2. • ZnPc(αEG 4) 2 demonstrates exceptional anticancer activity upon laser stimulation (10 pM). • ZnPc(αEG 4) 2 is 1000 fold less phototoxic on healthy cells. • ZnPc(αEG 4) 2 is 100 fold less phototoxic on cancer cells when excited by sunlight for 4 h instead of laser for 20 min. [ABSTRACT FROM AUTHOR]

The discovery of novel anticancer chemotherapeutics is fundamental to treat cancer more efficiently. Towards this goal, two dyads consisting of a gold porphyrin appended to organotin(IV) entities were synthesized and their physicochemical and biological properties were characterized. One dyad contains a gold porphyrin connected to a tin(IV) cation via a malonate and two phenyl ligands (AuP-SnPh2), while the other contains two tin(IV) cations each chelated to one carboxylic acid group of the malonate and three phenyl ligands (AuP-Sn2Ph6). The mode of chelation of Sn(IV) to the malonate was elucidated by IR spectroscopy and 119Sn NMR. In the solid state, the complexes exist as coordination polymers in which the tin is penta-coordinated and bridged to two different malonate units. In solution the chemical shifts of 119Sn signals indicate that the tin complexes are in the form of monomeric species associated with a tetra-coordinated tin cation. The therapeutic potential of these new compounds was assessed by determining their cytotoxic activities on human breast cancer cells (MCF-7) and on healthy human fibroblasts (FS 20-68). The study reveals that the dyads are more potent anticancer drugs than the mixture of their individual components (gold porphyrin and reference tin complexes). Therefore, the covalent link of organotin complexes to a gold porphyrin induces a synergistic cytotoxic effect. The dyad AuP-SnPh2 shows high cytotoxicity (0.13 μM) against MCF-7 along with good selectivity for cancer cells versus healthy cells. Finally, it was also shown that the dyad AuP-Sn2Ph6 exhibits a very high anticancer activity (LC50 = 0.024 μM), but the presence of two tin units induces strong cytotoxicity on healthy cells too (LC50 = 0.032 μM). This study underscores, thus, the potential of the association of gold porphyrin and organotin complexes to develop anticancer metallo-drugs. [ABSTRACT FROM AUTHOR]

The photophysical properties of a new series of fluorenyl porphyrins bearing water-solubilising oligoethyleneglycol chains are described. These biocompatible compounds present very good two-photon absorption and singlet oxygen generation properties, while retaining some fluorescence in water. After testing in vitro on breast cancer cells, some of them were shown to be efficient non-toxic two-photon photosensitisers allowing for fluorescence imaging, thus demonstrating their theranostic potential. [ABSTRACT FROM AUTHOR]

Mesoporous organosilica nanoparticles (PHT-PMO) have been prepared from an octa-triethoxysilylated Zn phthalocyanine precursor. These PHT-PMO nanoparticles had no dark toxicity but high phototoxicity when irradiated at 650 nm, and remarkable near-infrared phototoxicity when excited at 760 and 810 nm. The PHT-PMO were then aminated to promote electrostatic complexation with siRNA. Transfection experiments were performed upon NIR irradiation and photochemical internalization was very efficient, leading to 65% luciferase extinction in MCF-7 cancer cells expressing stable luciferase. [ABSTRACT FROM AUTHOR]

The synthesis and the optical properties of a family of new fluorenyl phthalocyanines substituted with water-solubilizing triethyleneglycol chains is described. These biocompatible molecules exhibit strong one- and two-photon absorptions, together with fluorescence and photosensitization properties similar to those of their lipophilic analogues, thus outperforming unsubstituted zinc phthalocyanine in terms of brightness and singlet oxygen production. They were subsequently probed in vitro on cancer cells under one and two-photon excitation in both fluorescence imaging and photodynamic therapy experiments. The metal-free compound was shown to be more biocompatible and thus more promising than the zinc complex for theranostic applications. • Synthesis of two water-soluble phthalocyanines: free base & Zn(II) complex. • New photosensitizers for theranostics. • Tested in vitro on breast cancer cells (MCF-7). • Allow fluorescence bioimaging and photodynamic therapy (PDT). • The free-base was shown to be more biocompatible than the Zn(II) complex. [ABSTRACT FROM AUTHOR]

Abstract: The fate of fertilizer sulphur (S) in soil is important to S availability to plants and consequently, the crop growth and quality of the harvested products. In a pot experiment, we studied the partitioning of 35S-labelled Na2SO4 in soil compartments (35S in CaCl2 extract, labile and non-labile 35S determined by hot water extraction) and in plant biomass. Rape (Brassica napus) and barley (Hordeum vulgare) were chosen for their contrasting S requirements. They were cultivated 28, 42 and 63 days in two contrasting soils: a calcareous soil (Rendzic Leptosol, pH 8.2, 2.3% organic C) and an acid brown soil (Fluvic Cambisol, pH 5.3, 1.0% organic C). Microbial activity was stimulated by the addition of glucose alone or glucose with N and P. Rape took up 2–3 times more S than barley. For both species, S accumulation in shoots was an exponential function of shoot biomass: S in shoots= α(shoot biomass)1−β , which suggests that the content of S in the shoot might be used as an index of plant S nutrition. In the calcareous soil, CaCl2-35S dominated whereas in the acid brown soil, labile 35S extracted by hot water (HW-35S) and CaCl2-35S were equally important. In both soils, CaCl2-35S was decreased by plant cultivation and when C was added whilst 35S in non-labile forms increased in parallel. In case of rape, the effect of the plant on 35S transformations in soil was of the same order of magnitude as the effect of the soil type. [Copyright &y& Elsevier]

The aim of this study was to evaluate if a model describing the efflux and the influx of C through the root surface could be fitted to experimental short-term kinetics of carbon (C) exudation by individual apical root segments in maize (Zea mays L.). The efflux of C was set constant or modelled by a power function of the distance from the apex to simulate the greater release of C around the root tip commonly reported in the literature. The influx was proportional to the C concentration in the external solution to simulate the active re-uptake of exudates by the root. Plants were exposed to full light or to shade to manipulate C allocation to roots. The model with a constant efflux gave satisfactory fits to the kinetics of exudation (average R2=0.66). The average gross efflux was then 2.1 μg C cm−2 root surface h−1. The model was improved if exudation was set more intense towards the root apex (average R2=0.74). The estimated gross efflux decreased then from 5.2 μg C cm−2 h−1 at the apex to 1.8 μg C cm−2 h−1 for the region located 5–25 cm from the root tip. The decrease in net exudation of individual roots due to the shading of plants was weak, which may indicate that the import of C by the primary roots studied was not reduced significantly. By describing the exudation of an apical root segment of variable length and diameter, the model is a first step in linking exudation to root system architecture models and to whole plant functioning. [ABSTRACT FROM PUBLISHER]

Abstract: The organic compounds released from roots (rhizodeposits) stimulate the growth of the rhizosphere microbial community. They may be responsible for the differences in the structure of the microbial communities commonly observed between the rhizosphere and the bulk soil. Rhizodeposits consists of a broad range of compounds including root mucilage. The aim of this study was to investigate if additions of maize root mucilage, at a rate of 70μgCg−1 day−1 for 15 days, to an agricultural soil could affect the structure of the bacterial community. Mucilage additions moderately increased microbial C (+23% increase relative to control), which suggests that the turnover rate of microorganisms consuming this substrate was high. Consistent with this, the number of cultivable bacteria was enhanced by +450%. Catabolic (Biolog® GN2) and 16S–23S intergenic spacer fingerprints exhibited significant differences between control and mucilage treatments. These data indicate that mucilage can affect both the metabolic and genetic structure of the bacterial community as shown by a greater catabolic potential for carbohydrates. We concluded that mucilage is likely to significantly contribute to differences in the structure of the bacterial communities present in the rhizosphere compared to the bulk soil. [Copyright &y& Elsevier]

The article focuses on the radio-frequency ablation (RFA) of primary lung cancer. A research study was conducted to evaluate the safety of performing RFA in patients with primary non-small cell lung cancer and to characterize the histologic changes in tumor tissue following such ablation. Conventional treatment strategies for patients with malignant lung tumors include surgery, chemotherapy, and radiation. Alternative forms of local therapy include stereotactic radiation therapy, cryoablation, RFA, and chemical ablation.

The objective of this work was to determine if the impact of nitrogen (N) on the release of organic carbon (C) into the soil by roots (rhizodeposition) correlated with the effect of this nutrient on some variables of plant growth.Lolium multiflorumLam. was grown at two levels of N supply, either in sterile sand percolated with nutrient solution or in non-sterile soil. The axenic sand systems allowed continuous quantification of rhizodeposition and accurate analysis of root morphology whilst the soil microcosms allowed the study of14C labelled C flows in physico-chemical and biological conditions relevant to natural soils. In the axenic sand cultures, enhanced N supply strongly increased the plant biomass, the plant N content and the shoot to root ratio. N supply altered the root morphology by increasing the root surface area and the density of apices, both being significantly positively correlated with the rate of organic C release by plant roots before sampling. This observation is consistent with the production of mucilage by root tips and with mechanisms of root exudation reported previously in the literature, i.e. the passive diffusion of roots solutes along the root with increased rate behind the root apex. We proposed a model of root net exudation, based on the number of root apices and on root soluble C that explained 60% of the variability in the rate of C release from roots at harvest. The effects of N on plant growth were less marked in soil, probably related to the relatively high supply of N from non-fertiliser soil-sources. N fertilization increased the shoot N concentration of the plants and the shoot to root ratio. Increased N supply decreased the partitioning of14C to roots. In parallel, N fertilisation increased the root soluble14C and the14C recovered in the soil per unit of root biomass, suggesting a stimulation of root exudation by N supply. However, due to the high concentration of N in our unfertilised plants, this stimulation was assumed to be very weak because no significant effect of N was observed on the microbial C and on the bacterial abundance in the rhizosphere. Considering the difficulties in evaluating rhizodeposition in non sterile soil, it is suggested that the root soluble C, the root surface area and the root apex density are additional relevant variables that should be useful to measure along with the variables that are commonly determined when investigating how plant functioning impacts on the release of C by roots (i.e soil C, C of the microbial biomass, rhizosphere respiration). [ABSTRACT FROM AUTHOR]

Systemic interleukin-2 (IL-2) therapy has been shown to enhance the clinical efficacy of peptide-based cancer vaccines. However, the mechanisms involved in this complex response remain poorly defined. IL-2 is known to be a potent T cell growth factor, but recent studies suggest that IL-2 is also involved in the regulation of T cell immune responses by increasing the susceptibility of proliferating T cells to apoptosis. Using an adoptive transfer model, we demonstrate that the administration of systemic IL-2 significantly enhances the primary and memory immune responses following peptide-based vaccination. In order to define the mechanisms of IL-2 therapy on the antigen-specific T cell response, the kinetics of T cell proliferation, apoptosis, and trafficking were explored. Systemic IL-2 therapy did not appear to alter the kinetics of T cell proliferation immediately following vaccination, but did prolong the proliferative response. Furthermore, IL-2 therapy did not significantly influence apoptosis of proliferating T cells. Such therapy did, however, potentiate l-selectin (CD62L) downregulation on activated antigen-specific T cells, and altered their trafficking confirming their potential therapeutic value. Our findings support the use of systemic IL-2 following peptide-based vaccination, and suggest that IL-2 therapy enhances the primary and memory immune responses by prolonging the proliferative response and altering the trafficking of antigen-specific T cells. [Copyright &y& Elsevier]

The combination of photodynamic therapy and chemotherapy is a promising strategy to enhance cancer therapeutic efficacy and reduce drug resistance. In this study two zinc(II) phthalocyanine-tin(IV) conjugates linked by a triethylene glycol chain were synthesized and characterized. In these complexes, the zinc(II) phthalocyanine was used as a potential photosensitizer for PDT and the tin complex was selected as cytostatic moiety. The two dyads composed of zinc(II) phthalocyanine and tin complexes exhibited high cytotoxicity, in absence of light stimulation, against MCF-7 human breast cancer cells with low LC50 values in the range of 0.016–0.453 µM. In addition, these complexes showed superior cytotoxicity than their mixture of equimolar component, accompanied with a higher activity towards cancer cells compared to human healthy fibroblasts. However, under irradiation of the zinc phthalocyanine unit (at 650 nm) no photodynamic activity could be detected, due to the most likely quenching of zinc(II) phthalocyanine singlet excited state by the nearby tin complex according to a photoinduced electron transfer process. This study demonstrates the potential of heterometallic anticancer chemotherapeutics composed of a zinc phthalocyanine and tin complex, and it highlights that the development of such conjugates requires that the sensitizer preserves its photophysical properties and in particular its singlet oxygen sensitization ability in the conjugate in order to combine the PDT activity with the cytotoxicity of the anticancer drug. [ABSTRACT FROM AUTHOR]

• Models were built to predict the compliance of durum wheat grain Cd content to regulatory thresholds. • Logistic regression and random forest were compared to multiple regression. • The models detected around 82% of the non-conformity cases with a reliability at around 75%. • Models were used to identify risky soil conditions for the phytoavailability of Cd. • Models and field trials showed a significant between-cultivar variability for the grain Cd content. Contamination of durum wheat grain by cadmium (Cd) threatens food safety and is of increasing concern because regulations concerning Cd are becoming stricter due to its toxicity. This work aimed at using soil variables and cultivar types to build models to predict whether durum wheat grain Cd will conform with current and possibly lower regulatory thresholds. We combined multiple Gaussian and logistic regressions and the random forest algorithm to take advantage of their strength. Models tested using cross-validation produced excellent performances including for the lowest regulatory threshold of 0.1 mg Cd/kg, half of the current one: 79–85% of the non-conformity cases were detected and the reliability of predictions was 69–82%. The models enabled identification of a x1.4 variability in grain Cd content between cultivars that do not have the low Cd accumulation allele of the Cdu1 gene. The models confirmed that for the grain Cd content, the between-cultivar variability had much less influence than the phytoavailability of Cd in soil, the critical contexts of which were characterized by the models. For farmers, these models are valuable tools to predict whether durum wheat production will conform with existing and future Cd regulation in foodstuffs. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and study of optical properties of innovative tetrafunctionalized zinc(II) porphyrins with carbonic anhydrase (CA) inhibitors in sulfonamide and coumarin series are described. The synthetic methodology relies on the preparation of the porphyrin core by condensation of azido triethyleneglycol functionalized benzaldehyde derivative with pyrrole followed by its metalation and inhibitors coupling via Huisgen click‐reaction. The tetrafunctionalized zinc(II) porphyrin with coumarin moieties showed selective inhibition against tumour‐associated hCA IX and hCA XII versus the cytosolic off‐targets hCA I and hCA II. This compound was able to accumulate on cell membrane and to impair pancreas cancer cells (Capan‐1) proliferation in normoxic conditions with LC50 of 4.5 μM. Moreover, its optical properties revealed efficient photosensitizing properties, leading to cancer cells death under light irradiation, making this compound a suitable candidate for photodynamic therapy. [ABSTRACT FROM AUTHOR]

Many experiments showed that exogenous ligands could enhance cadmium (Cd) phytoextraction efficiency in soils. Previous studies suggested that the dissociation and the apoplastic uptake of Cd complex could not fully explain the increase of root Cd uptake. Two hypotheses are evaluated to explain enhanced Cd uptake in the presence of ligand: i) enhanced apoplastic uptake of complex due to reduced apoplastic resistance and ii) complex internalization by membrane transporters. show that the ligand affinity for Cd is a key characteristic determining the potential mechanism for enhanced Cd uptake. When low molecular weight organic acids are applied, the complex dissociation could generally be fast (> 10−3.3 s−1) and result in the increased Cd uptake. When hydrophilic aminopolycarboxylic acids (APCAs) are applied in experiments without water or temperature stresses to the plant, the root water uptake flux could very likely be high (> 10−7.8 dm s−1), and the strong apoplastic complex uptake could enhance the root Cd uptake. When lipophilic APCAs are applied, the strong internalization of the complex by membrane transporters could result in the increased Cd uptake if the maximum internalization rate is high (> 10−12 mol dm−2 s−1). However, the complex internalization by membrane transporters must be experimentally confirmed. [Display omitted] • Mechanism for increased Cd uptake is mainly governed by ligand affinity for Cd. • LMWOAs can enhance Cd uptake by complex dissociation. • Hydrophilic APCAs can enhance Cd uptake under non-stress condition to plant. • Lipophilic APCAs could enhance Cd uptake if complex internalization rate is high. [ABSTRACT FROM AUTHOR]

In French Guiana, the malaria, a parasitic infection transmitted by Anopheline mosquitoes, remains a disease of public health importance. To prevent malaria transmission, the main effective way remains Anopheles control. For an effective control, accurate Anopheles species identification is indispensable to distinguish malaria vectors from non-vectors. Although, morphological and molecular methods are largely used, an innovative tool, based on protein pattern comparisons, the Matrix Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) profiling, emerged this last decade for arthropod identification. However, the limited mosquito fauna diversity of reference MS spectra remains one of the main drawback for its large usage. The aim of the present study was then to create and to share reference MS spectra for the identification of French Guiana Anopheline species. A total of eight distinct Anopheles species, among which four are malaria vectors, were collected in 6 areas. To improve Anopheles identification, two body parts, legs and thoraxes, were independently submitted to MS for the creation of respective reference MS spectra database (DB). This study underlined that double checking by MS enhanced the Anopheles identification confidence and rate of reliable classification. The sharing of this reference MS spectra DB should make easier Anopheles species monitoring in endemic malaria area to help malaria vector control or elimination programs. [ABSTRACT FROM AUTHOR]

A letter tot the editor is presented related to the successful treatment of longstanding vasospastic central retinal artery occlusion.

Background: In addition to their great optical properties, nanodiamonds (NDs) have recently proved useful for two-photon-excited photodynamic therapy (TPE-PDT) applications. Indeed, they are able to produce reactive oxygen species (ROS) directly upon two-photon excitation but not with one-photon excitation; Methods: Fluorescent NDs (FNDs) with a 100 nm diameter and detonation NDs (DNDs) of 30 nm were compared. In order to use the gems for cancer-cell theranostics, they were encapsulated in a bis(triethoxysilyl)ethylene-based (ENE) periodic mesoporous organosilica (PMO) shell, and the surface of the formed nanoparticles (NPs) was modified by the direct grafting of polyethylene glycol (PEG) and amino groups using PEG-hexyltriethoxysilane and aminoundecyltriethoxysilane during the sol–gel process. The NPs' phototoxicity and interaction with MDA-MB-231 breast cancer cells were evaluated afterwards; Results: Transmission electronic microscopy images showed the formation of core–shell NPs. Infrared spectra and zeta-potential measurements confirmed the grafting of PEG and NH2 groups. The encapsulation of the NDs allowed for the imaging of cancer cells with NDs and for the performance of TPE-PDT of MDA-MB-231 cancer cells with significant mortality. Conclusions: Multifunctional ND@PMO core–shell nanosystems were successfully prepared. The NPs demonstrated high biocompatibility and TPE-PDT efficiency in vitro in the cancer cell model. Such systems hold good potential for two-photon-excited PDT applications. [ABSTRACT FROM AUTHOR]

Sentinel lymph node biopsy (SLNB) is used to detect axillary lymph node metastases in breast cancer. Preoperative radiocolloid injection with lymphoscintigraphy (PL) is performed before SLNB. Few comparisons between 1- and 2-day PL protocols exist. Opponents of a 2-day protocol have expressed concerns of radiotracer washout to nonsentinel nodes. Proponents cite lack of scheduling conflicts between PL and surgery. A total of 387 consecutive patients with clinically node-negative breast cancer underwent SLNB with PL. Lymphoscintigraphy images were obtained within 30 minutes of radio-colloid injection. Axillary lymph node dissection was performed if the sentinel lymph node (SLN) could not be identified. Data were collected regarding PL technique and results. In all, 212 patients were included in the 2-day PL group and 175 patients in the 1-day PL group. Lymphoscintigraphy identified an axillary sentinel node in 143/212 (67.5%) of patients in the 2-day group and 127/175 (72.5%) in the 1-day group (P = 0.28). SLN was identified at surgery in 209/212 (98.6%) patients in the 2-day group and 174/175 (99.4%) in the 1-day group (P = 0.41). An average of 3 SLN was found at surgery in the 2-day group compared with 3.15 in the 1-day group (P = 0.43). SLN was positive for metastatic disease in 54/212 (25.5%) patients in the 2-day group compared with 40/175 (22.9%) in the 1-day group (P = 0.55). A 2-day lymphoscintigraphy protocol allows reliable detection of the SLN, of positive SLN and equivalent SLN harvest compared with a 1-day protocol. The timing of radiocolloid injection before SLNB can be left at the discretion of the surgeon. [ABSTRACT FROM AUTHOR]

ELISA and RIFI are currently used for serodiagnosis of canine visceral leishmaniasis (CVL). The accuracy of these tests is controversial in endemic areas where canine infections by Trypanosoma cruzi may occur. We evaluated the usefulness of synthetic peptides that were selected through phage display technique in the serodiagnosis of CVL. Peptides were chosen based on their ability to bind to IgGs purified from infected dogs pooled sera. We selected three phage clones that reacted only with those IgGs. Peptides were synthesized, polymerized with glutaraldehyde, and used as antigens in ELISA assays. Each individual peptide or a mix of them was reactive with infected dogs serum. The assay was highly sensitive and specific when compared to soluble Leishmania antigen that showed cross-reactivity with anti-T. cruzi IgGs. Our results demonstrate that phage display technique is useful for selection of peptides that may represent valuable synthetic antigens for an improved serodiagnosis of CVL. [ABSTRACT FROM AUTHOR]

Background: Malaria remains a major global health concern. The development of novel therapeutic strategies is critical to overcome the selection of multiresistant parasites. The subtilisin-like protease (SUB1) involved in the egress of daughter Plasmodium parasites from infected erythrocytes and in their subsequent invasion into fresh erythrocytes has emerged as an interesting new drug target. Findings: Using a computational approach based on homology modeling, protein–protein docking and mutation scoring, we designed protein–based inhibitors of Plasmodium vivax SUB1 (PvSUB1) and experimentally evaluated their inhibitory activity. The small peptidic trypsin inhibitor EETI-II was used as scaffold. We mutated residues at specific positions (P4 and P1) and calculated the change in free-energy of binding with PvSUB1. In agreement with our predictions, we identified a mutant of EETI-II (EETI-II-P4LP1W) with a Ki in the medium micromolar range. Conclusions: Despite the challenges related to the lack of an experimental structure of PvSUB1, the computational protocol we developed in this study led to the design of protein-based inhibitors of PvSUB1. The approach we describe in this paper, together with other examples, demonstrates the capabilities of computational procedures to accelerate and guide the design of novel proteins with interesting therapeutic applications. [ABSTRACT FROM AUTHOR]

Background: Psalmopeotoxin I (PcFK1), a protein of 33 aminoacids derived from the venom of the spider Psalmopoeus Cambridgei, is able to inhibit the growth of Plasmodium falciparum malaria parasites with an IC50 in the low micromolar range. PcFK1 was proposed to act as an ion channel inhibitor, although experimental validation of this mechanism is lacking. The surface loops of PcFK1 have some sequence similarity with the parasite protein sequences cleaved by PfSUB1, a subtilisin-like protease essential for egress of Plasmodium falciparum merozoites and invasion into erythrocytes. As PfSUB1 has emerged as an interesting drug target, we explored the hypothesis that PcFK1 targeted PfSUB1 enzymatic activity. Findings: Molecular modeling and docking calculations showed that one loop could interact with the binding site of PfSUB1. The calculated free energy of binding averaged 25.01 kcal/mol, corresponding to a predicted low-medium micromolar constant of inhibition. PcFK1 inhibited the enzymatic activity of the recombinant PfSUB1 enzyme and the in vitro P.falciparum culture in a range compatible with our bioinformatics analysis. Using contact analysis and free energy decomposition we propose that residues A14 and Q15 are important in the interaction with PfSUB1. Conclusions: Our computational reverse engineering supported the hypothesis that PcFK1 targeted PfSUB1, and this was confirmed by experimental evidence showing that PcFK1 inhibits PfSUB1 enzymatic activity. This outlines the usefulness of advanced bioinformatics tools to predict the function of a protein structure. The structural features of PcFK1 represent an interesting protein scaffold for future protein engineering. [ABSTRACT FROM AUTHOR]

This study tested the hypothesis that Cd uptake is correlated with the shoot or root growth of Arabidopsis thaliana ecotype Columbia cultivated hydroponically at environmentally relevant Cd concentrations: 20, 100 and 350 nmol L−1. Growth of both roots and shoots were delayed at 350 nmol L−1. The rate of Cd uptake determined by spiking the nutrient solution with 109Cd for 24 h, was significantly correlated with the root growth rate. The fraction of Cd absorbed that was allocated to shoots was constant with time but decreased with increasing exposure to Cd. Autoradiography and gamma counting showed that Cd was preferentially allocated to developing leaves. Hence, the quantity of Cd in shoots depended both on the root growth, which probably governed the uptake, and on the maturity of the leaves, which may have determined the Cd allocated to shoots through changes in the transpiration stream. [ABSTRACT FROM AUTHOR]

One alternative to mineral fertilization is to use organic fertilizers. Our aim was to compare the impacts of 7-year applications of composted pig manure and ammonium nitrate on the structure and activity of the denitrifying community. Mineralization and organization of N, denitrification rates and N2O/N2 ratio were also investigated. Fourteen months after the last application, the potential denitrifying activity (+319%), N mineralization (+110%) and organization (+112%) were higher under pig compost than under ammonium nitrate fertilization. On the other hand, the N2O/(N2O+N2) ratio was lower ( P<0.05, n=5) under organic fertilization. These effects of organic fertilization were in accordance with its higher total carbon content and microbial biomass. Fingerprints and clone library analyses showed that the structure of the denitrifying community was affected by the fertilization regime. Our results reveal that organic or mineral fertilizer applications could affect both structure and activity of the denitrifying community, with a possible influence on in situ N2O fluxes. These effects of the fertilization regime persisted for at least 14 months after the last application. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented about female patients with breast cancer who underwent skin sparing mastectomy with no immediate implant reconstruction.

Partitioning of metals between the soil solid phase and the solution is an important topic in environmental sciences because it determines the metal transfers to aquifers and biological organisms. Complexation of metals with ligands in the soil solution strongly influences the sorption/desorption (SD) of metals, in particular that of the free ion. Because the latter is the metal species principally absorbed by biological organisms, the bioavailability of a metal is better reflected by the soil-solution distribution coefficients of the free ion as compared to that of the total metal (sum of the free ion and of the complexes). The present work proposes a modeling approach to determine the distribution coefficients for the free ion and for the metal complexes from SD experiments. The method does not require estimating the mobile pool of the metal sorbed onto the solid phase by any chemical extraction as the modeling relies on the variation of the sorbed metal, which is experimentally exactly estimated from the variation of the amount of metal in solution during the SD experiment. Tested for cadmium (Cd), the model reproduced very well the SD curves observed for the total metal. For any solution:soil ratio including that at field soil moisture, the model gives estimates of important variables including the distribution coefficient for the free ion, the complex, the ligands and the total metal, the concentration of these species in the soil solution and onto the solid phase. The model can be applied as long as the range of the concentration investigated allows to assume a linear sorption of the metal. [ABSTRACT FROM AUTHOR]

Two trispicolinate 1,4,7‐triazacyclonane (TACN)‐based ligands bearing three picolinate biphotonic antennae were synthetized and their Yb3+ and Gd3+ complexes isolated. One series differs from the other by the absence (L1)/presence (L2) of bromine atoms on the antenna backbone, offering respectively improved optical and singlet‐oxygen generation properties. Photophysical properties of the ligands, complexes and micellar Pluronic suspensions were investigated. Complexes exhibit high two‐photon absorption cross‐section combined either with NIR emission (Yb) or excellent 1O2 generation (Gd). The very large intersystem crossing efficiency induced by the combination of bromine atom and heavy rare‐earth element was corroborated with theoretical calculations. The 1O2 generation properties of L2Gd micellar suspension under two‐photon activation leads to tumour cell death, suggesting the potential of such structures for theranostic applications. [ABSTRACT FROM AUTHOR]

Diazachlorin and diazabacteriochlorin have been prepared through reduction of diazaporphyrin and their in vitro and in vivo activity in photodynamic therapy has been investigated. [ABSTRACT FROM AUTHOR]

The sol‐gel synthesis of hollow organosilica nanoparticles incorporating amino groups with uniform size are described. These nanoparticles were successfully prepared via a microemulsion method. Then, the hollow nanoparticles were loaded with gemcitabine hydrochloride or methotrexate and studied in MCF‐7 breast cancer cells. Hollow Organosilica Nanoparticles (HONPs) with uniform size and incorporating amino groups were achieved via a microemulsion method. These hollow nanoparticles displayed a large cavity, enabling drug loading and release. In particular, the hydrophilic gemcitabine was loaded without early release and no chemical coupling was required. HONPs loaded with gemcitabine were very efficient to be internalized by cancer cells and to induce MCF‐7 cell killing. [ABSTRACT FROM AUTHOR]

We report the synthesis of new graftable three-branched octupolar fluorophores (F and F2), based on a triphenylamine core connected to electron-withdrawing sulfone-based peripheral groups through one or two π-conjugated phenylene-vinylene linkers. Their two-photon absorption (TPA), solvatochromism and photoluminescence properties were investigated to derive structure-property relationships. Notably, the chromophores presented TPA bands in the biological window (700–900 nm) and high TPA cross-sections at peak of 810 GM for F and F2. Then, after silylation, fluorophore F was further covalently integrated within the sol-gel synthesis of different periodic mesoporous organosilica nanoparticles (PMO NPs). Transmission electronic microscopy imaging revealed the formation of spherical NPs with good monodispersity in size, as confirmed by dynamic light scattering measurements. The obtained fluorophore-based nanoplatforms were shown to be biocompatible in vitro and demonstrated a good potential for two-photon imaging in cancer cells using two-photon excited fluorescence microscopy. [Display omitted] [ABSTRACT FROM AUTHOR]

The dissociation of metal complexes in the soil solution can increase the availability of metals for root uptake. When it is accounted for in models of bioavailability of soil metals, the number of partial differential equations (PDEs) increases and the computation time to numerically solve these equations may be problematic when a large number of simulations are required, for example for sensitivity analyses or when considering root architecture. This work presents analytical solutions for the set of PDEs describing the bioavailability of soil metals including the kinetics of complexation for three scenarios where the metal complex in solution was fully inert, fully labile, or partially labile. The analytical solutions are only valid i) at steady-state when the PDEs become ordinary differential equations, the transient phase being not covered, ii) when diffusion is the major mechanism of transport and therefore, when convection is negligible, iii) when there is no between-root competition. The formulation of the analytical solutions is for cylindrical geometry but the solutions rely on the spread of the depletion profile around the root, which was modelled assuming a planar geometry. The analytical solutions were evaluated by comparison with the corresponding PDEs for cadmium in the case of the French agricultural soils. Provided that convection was much lower than diffusion (Péclet's number < 0.02), the cumulative uptakes calculated from the analytic solutions were in very good agreement with those calculated from the PDEs, even in the case of a partially labile complex. The analytic solutions can be used instead of the PDEs to predict root uptake of metals. The analytic solutions were also used to build an indicator of the contribution of a complex to the uptake of the metal by roots, which can be helpful to predict the effect of soluble organic matter on the bioavailability of soil metals. [ABSTRACT FROM AUTHOR]

Aims: This study investigated the possible source organs delivering several trace elements to seeds (root uptake versus net remobilization), by studying changes in biomass and element contents in the plant organs.Methods: Sunflowers were grown in a greenhouse using a nutrient solution enriched with Cd. Four samplings were performed from the early flowering to the seeds physiological maturity.Results: The low grain Ca indicated that phloem was likely the main route for transporting the elements to seeds. Excluding roots, the mass balance of the elements indicated the following contribution of the net remobilization to the total quantities in seeds at maturity: Mg = 50%, Cd = 14%, Cu = 35%, Fe = 29%, Mn = 19%, Zn = 12%. Source organs were mainly the receptacle and the stem. No significant net remobilization was observed for Ca, K and Mo.Conclusions: The amount of trace elements accumulated in vegetative parts can be redistributed to seeds in an extent that depended on the element. Due to the important contribution of root uptake to the content in seeds at maturity, the availability of elements in soil during the reproductive stages is an important point to consider. [ABSTRACT FROM AUTHOR]

The measurement of colour has been frequently used as an alternative to chemical analysis in a wide range of applications. Colorimetry and spectrophotometry are the reference techniques nowadays to measure colour. Practical problems arise, however, when granular, powdery, rough, curved or non-regular surfaces are processed. A standard digital camera, in combination with image analysis, can be used as an inexpensive, portable, non-destructive and fast analytical tool to measure colour but, surprisingly, this approach has not been fully exploited up to date. In this work, we have used this technique to measure tomato colour at different ripening stages. Spectrophotometric analysis of the extracts of the tomatoes allowed us to record the characteristic spectrum of each sample and correlate them with the chromaticity parameters by non-linear regression analysis of the whole data set. The resulting mathematical model showed a high power to discriminate between tomatoes, and was further used to produce a relative scale from zero to ten that enabled us to sort naturally matured tomatoes according to their ripening stage. In addition, the proposed model also allowed a fast estimation of the lycopene content in the samples, avoiding long and tedious extraction procedures, with a significant saving of time and reagents. [ABSTRACT FROM AUTHOR]

The uptake of metals by plants and their partitioning between different organs is an important issue in fields like plant ecology, phytochemistry, phytoremediation and, in the case of plants with edible parts, food quality. In this work a five-month field experiment was carried out to investigate the uptake and partitioning of 20 elements (Mg, K, Ca, Na, Mn, Fe, Co, Cu, Zn, Mo, Sr, Ba, Al, Ti, V, Cr, As, Cd, Tl and Pb) by Swiss chards ( Beta vulgaris ). The effect of the harvesting time on the accumulation of these elements in roots, stalks and leaf blades was studied using plants cultivated in two different but adjacent air-open plots subjected to conventional or organic farming techniques. Plants were collected at six growth stages during their production cycle and samples were analysed by ICP-MS after microwave assisted acid digestion. Toxic elements (except Cd) were mainly immobilised in roots, whereas essential elements were translocated to aboveground organs. In general, the element concentrations in plant organs decreased with time. The use of organic fertilisers promoted the presence of nutrients in blades and stalks. Pb and Cd concentrations in the edible parts were always below the maximum levels set by the European Union. [ABSTRACT FROM AUTHOR]

Aims: This work concentrated on understanding the allocation of Cd recently taken up between the organs of sunflower at early and middle reproductive growth stages. The roles of transpiration and allometry were investigated. Methods: Sunflowers were grown hydroponically in greenhouse, being exposed to low concentrations of Cd (pCd = 11.03). At flower bud and grain filling stages, plants were exposed for three days to Cd and at the same time, subjected or not to fans to increase the transpiration. The partitioning of Cd between plant organs measured by high resolution ICP-MS was then modelled. Results: Although the use of fans increased the plant water uptake and transpiration by about 20%, there were no significant effects on the partitioning of recent Cd. Most of the recent Cd was recovered in roots (60%) and only 2.8% were found in seeds (0.8% for the husk and 2.0% for the almonds). The sequestration of recent Cd in a plant organ was successfully explained by its biomass and except for leaves, by the biomass of other organs acting as competitive sinks. Conclusions: This work proposes a modelling approach for the partitioning of the labelled Cd between plant organs in sunflower. [ABSTRACT FROM AUTHOR]

To assess the prevalence of malaria among illegal gold miners in the French Guiana rainforest, we screened 205 miners during May-June 2014. Malaria prevalence was 48.3%; 48.5% of cases were asymptomatic. Patients reported self-medication with artemisinin-based combination therapy. Risk for emergence and spread of artemisinin resistance among gold miners in the rainforest is high. [ABSTRACT FROM AUTHOR]

Aims: The objective of this study was to rank the mechanisms influencing the phytoavailability of cadmium (Cd) in agricultural soils. Methods: We developed a model that simulates the transport by diffusion and convection, the kinetics of sorption and complexation in solution and the root uptake of Cd. The ranking of mechanisms was performed by simulating the Cd uptake by 1 cm root for 30 days for French agricultural soil characteristics. Results: The initial Cd concentration was the most influential parameter followed by the soil buffer power for Cd and by the soil water content and impedance factor. The Cd was generally strongly depleted at the root surface and the convection was almost negligible. In general, the Cd complex dissociation contributed little to the uptake due to a strong kinetics limitation. Conversely, the kinetics of sorption was little influential. Conclusions: The initial concentration and diffusion of Cd were the dominant processes governing the phytoavailability in non-polluted soils. A model considering only the transport and sorption of Cd without kinetics would be adequate to predict the phytoavailability. The particular situations where these simplifications do not hold (relative error >10 %) corresponded to a high supply of labile Cd complex toward plant roots. [ABSTRACT FROM AUTHOR]

Aims: To rank the contributions of roots and shoots to Cd uptake by the hyperaccumulator Noccaea caerulescens, two hypotheses were tested: Shoots control the uptake through detoxification reactions; alternatively, roots do this through absorption and translocation. Methods: In a first experiment, plants with the same final age were exposed for 1, 2 or 3 weeks to 0.5 μM Cd in hydroponics. In another experiment, either roots or shoots or both were pruned before the plants were exposed for 1 week to Cd at 0.5 μM in the nutrient solution. Results: The first experiment showed that the Cd accumulation was driven by the root absorption combined with xylem loading, keeping the root Cd concentration constant. After root or/and shoot pruning, all the plants accumulated the same total quantity of Cd. After root pruning, the remaining roots increased their Cd absorption influx. Shoot pruning alone did not affect absorption or storage in roots and the pruned shoots accumulated as much Cd as the unpruned ones. Similar results were obtained for all major and minor nutrients. Conclusions: Root absorption and xylem loading are the major processes controlling Cd hyperaccumulation in N. caerulescens, the shoot being a compartment in which the metal exported by the roots is stored. [ABSTRACT FROM AUTHOR]

Background: Leishmania parasites can cause visceral or cutaneous disease and are found in subtropical and tropical regions of the Old and New World. The pathology of the infection is determined by both host immune factors and species/strain differences of the parasite. Dogs represent the major reservoir of Leishmania infantum (syn. L. chagasi) and vaccines are considered the most cost-effective control tools for canine disease. Methods: Selection of immunodominant peptides was performed by Phage Display to identify sequences recognized by L. infantum naturally infected animals. Sera from Leishmania infected animals were used in the biopanning to selection of specific peptides. Serum samples from T. cruzi infected and healthy animals were used as control. After selection, synthetic peptides were produced in membrane (spot-synthesis) in soluble form and blotting and ELISA were performed for validation of serum reactivity. Selected peptide was formulated with aluminum hydroxide and liposomes and immunization was performed in BALB/c mice. Protection was determined by qPCR after challenge infection with virulent L. infantum. Results: We reported the selection of Peptide 5 through Phage Display technique and demonstrate its ability to promote a state of immunity against L. infantum infection in murine model after immunization using liposomes as vaccine carrier. Our results demonstrate that immunization with Peptide 5 when formulated with aluminum hydroxide and liposomes is immunogenic and elicited significant protection associated with the induction of mixed Th1/Th2 immune response against L. infantum infection. Conclusion: Peptide 5 is a promising vaccine candidate and the findings obtained in the present study encourage canine trials to confirm the effectiveness of a vaccine against CVL. [ABSTRACT FROM AUTHOR]

Aims Cadmium (Cd) is a very toxic metal in soils, contaminating agricultural crops due to its absorption by roots. Among crops, sunflower ( Helianthus annuus L.) accumulates relatively high amounts of Cd. This work examined the variability of Cd and zinc (Zn) in shoots of sunflower cultivars and investigated if the variability was linked to the shoot growth, to the metal uptake and to the metal partitioning aboveground. Methods Fourteen cultivars of sunflower were cultivated in a nutrient solution containing 20 nM of Cd(NO 3 ) 2 and 760 nM ZnSO 4 . The between-cultivar variability for the total Cd and Zn content in root and shoot biomass was determined at the 6–8 leaf stage and possible correlations with the biomass and root architecture were investigated. Results Cd and Zn concentrations in shoots differed between cultivars by a factor of 2.3 and 2.2, respectively. Metal uptake was more positively correlated with shoot biomass than with root biomass and was not correlated with root architecture. The between cultivar differences for metal concentration in shoots was explained by differences in uptake relative to shoot growth and for Cd, by the partitioning of the metal between roots and shoots. Conclusions This study suggests that Cd root uptake relative to shoot growth and Cd partitioning to shoots could be targets for selecting cultivars having a low (for crop quality) or a high (for phytoextraction) Cd content aboveground. [ABSTRACT FROM AUTHOR]

Aims: In a previous work, we observed a longitudinal decrease in Cd influx starting from the root tip in first order lateral roots of sunflower ( Helianthus annuus L.) grown in hydroponics. This variable influx was expected to impact the total Cd uptake depending on the root system architecture and on how steep was the decrease of the influx. Here, we examined the influence of the culture substrate, of the age and order of lateral roots on the longitudinal variation of Cd influx. Methods: By using short-term exposures to Cd-labelled solution (5 to 200 nM), we compared the longitudinal variations in Cd roots influx depending on the growth substrate (hydroponics or sand), on the root age and order. Results: In second order laterals, Cd influx decreased from the apex to the root base, as for first order laterals. For sand cultures compared to hydroponics, the mean Cd influx was lower and decreased more steeply with the distance from the apex. The influx also decreased with increasing root age and order, markedly in hydroponics but less for sand cultures. Conclusion: Results suggested that for a given root surface area, the Cd uptake by a root system should increase with increasing number of root tips and decreasing individual root length. [ABSTRACT FROM AUTHOR]

Background: The snake Bothrops atrox is responsible for the majority of envenomings in the northern region of South America. Severe local effects, including hemorrhage, which are mainly caused by snake venom metalloproteinases (SVMPs), are not fully neutralized by conventional serum therapy. Little is known about the immunochemistry of the P-I SVMPs since few monoclonal antibodies (mAbs) against these molecules have been obtained. In addition, producing toxin-neutralizing mAbs remains very challenging. Methodology/Principal Findings: Here, we report on the set-up of a functional screening based on a synthetic peptide used as a biosensor to select neutralizing mAbs against SVMPs and the successful production of neutralizing mAbs against Atroxlysin-I (Atr-I), a P-I SVMP from B. atrox. Hybridomas producing supernatants with inhibitory effect against the proteolytic activity of Atr-I towards the FRET peptide Abz-LVEALYQ-EDDnp were selected. Six IgG1 Mabs were obtained (named mAbatr1 to mAbatr6) and also two IgM. mAbatrs1, 2, 3 and 6 were purified. All showed a high specific reactivity, recognizing only Atr-I and B. atrox venom in ELISA and a high affinity, showing equilibrium constants in the nM range for Atr-I. These mAbatrs were not able to bind to Atr-I overlapping peptides, suggesting that they recognize conformational epitopes. Conclusions/Significance: For the first time a functional screening based on a synthetic biosensor was successfully used for the selection of neutralizing mAbs against SVMPs. Author Summary: In this work, we propose a new screening strategy to produce monoclonal antibodies against Atr-I, a P-I class SVMP from Bothrops atrox, which is the snake responsible for the majority of the accidents in South America. SVMPs are the main toxic factors in Bothrops venom causing systemic and local hemorrhage, which may evolve to inflammation and/or necrosis. Since the toxic effects of SVMPs are related to their proteolytic activity, we have produced a peptide which was used as a biosensor for Atr-I hydrolysis. Hydrolysis of this substrate was monitored and the clones possessing inhibitory activity against the proteolytic activity of Atr-I upon the peptide were selected. Using our new approach, we have obtained four monoclonal antibodies highly specific and with neutralizing capacity against the hemorrhagic activity of either Atr-I alone or Bothrops atrox whole venom. To the best of the authors' knowledge, this is the first time where a functional screening is used for the selection of neutralizing mAbs against SVMPs. It is also the first description of mAbs anti-Atr-I, with inhibitory potential against its toxic activities which may be useful for diagnosis and treatment in the future. [ABSTRACT FROM AUTHOR]

Background: The snake Bothrops atrox is responsible for the majority of envenomings in the northern region of South America. Severe local effects, including hemorrhage, which are mainly caused by snake venom metalloproteinases (SVMPs), are not fully neutralized by conventional serum therapy. Little is known about the immunochemistry of the P-I SVMPs since few monoclonal antibodies (mAbs) against these molecules have been obtained. In addition, producing toxin-neutralizing mAbs remains very challenging. Methodology/Principal Findings: Here, we report on the set-up of a functional screening based on a synthetic peptide used as a biosensor to select neutralizing mAbs against SVMPs and the successful production of neutralizing mAbs against Atroxlysin-I (Atr-I), a P-I SVMP from B. atrox. Hybridomas producing supernatants with inhibitory effect against the proteolytic activity of Atr-I towards the FRET peptide Abz-LVEALYQ-EDDnp were selected. Six IgG1 Mabs were obtained (named mAbatr1 to mAbatr6) and also two IgM. mAbatrs1, 2, 3 and 6 were purified. All showed a high specific reactivity, recognizing only Atr-I and B. atrox venom in ELISA and a high affinity, showing equilibrium constants in the nM range for Atr-I. These mAbatrs were not able to bind to Atr-I overlapping peptides, suggesting that they recognize conformational epitopes. Conclusions/Significance: For the first time a functional screening based on a synthetic biosensor was successfully used for the selection of neutralizing mAbs against SVMPs. [ABSTRACT FROM AUTHOR]

Aims: Contamination of sunflower ( Helianthus annuus L.) by cadmium (Cd) is a concern for food and feed safety as this species accumulates Cd to a greater extent than other crops. We examined the relationships between root architecture and Cd uptake by roots. Methods: We determined and mathematically modelled the longitudinal variation of Cd influx in first order roots of sunflower grown in hydroponics by using short-term exposure to Cd-labelled solutions (0.8 to 500 nM). Thereafter, by taking into account the longitudinal variation of the influx, we simulated the uptake of Cd for 24 h by cohorts of roots characterised by various architectural characteristics. Results: Cd influx at the root tip was on average 2.9 times that of the basal region close to the taproot. The simulations indicated that the total Cd uptake by root cohorts mainly depends on 1/ the root diameter and the number of roots, 2/ the value of the Cd influx at the basal region 3/ the stronger influx at the root tip. Conclusion: Considering a higher Cd influx at the root tip may be important to understand the relationship between root architecture and Cd uptake by the root system. [ABSTRACT FROM AUTHOR]

Abstract: An important step in the development of therapeutic antivenoms is the pre-clinical testing using in vivo methods to assess their neutralizing potency. For spider antivenoms (Loxosceles species), horse serum potency against the necrotizing activities of Loxosceles intermedia crude venom is currently tested in rabbits. These procedures are time consuming and involve a large number of animals. The aim of this study was to develop an in vitro method to assess the neutralizing potency of anti-Loxosceles sera. We first demonstrated that it was not possible to establish a correlation between the ELISA antibody reactivity of horse anti-Loxosceles serum and their neutralizing potency. We then showed that the antivenoms recognized several peptide epitopes from different regions of SMase-D proteins, which are toxic antigens from Loxosceles venoms. The recognition of some peptides was observed only when high neutralizing potency sera was used. Based on these results, three peptides (peptide 1, DNRRPIWNLAHMVNA and peptide 3, DFSGPYLPSLPTLDA corresponding to residues 2–16 and 164–178, respectively, of SMase-1 protein from Loxosceles laeta, and peptide 2, EFVNLGANSIETDVS corresponding to residues 22–36 of A1H – LoxGa protein from Loxosceles gaucho and LiD1 protein from L. intermedia) were selected. The peptides were synthesized, coupled to bovine serum albumin (BSA), and used as antigens in indirect ELISA to test their reactivity with horse anti-Loxosceles serum of varying neutralizing potencies. We found certain assay conditions that discriminated between the high and low neutralizing potency sera. This study introduced an in vitro and peptide-based neutralization assay for anti-Loxosceles antivenoms. [Copyright &y& Elsevier]