Characterization of human breast cancer tissues by infrared imaging.

Fourier Transform InfraRed (FTIR) spectroscopy coupled to microscopy (IR imaging) has shown unique advantages in detecting morphological and molecular pathologic alterations in biological tissues. The aim of this study was to evaluate the potential of IR imaging as a diagnostic tool to identify characteristics of breast epithelial cells and the stroma. In this study a total of 19 breast tissue samples were obtained from 13 patients. For 6 of the patients, we also obtained Non-Adjacent Non-Tumor tissue samples. Infrared images were recorded on the main cell/tissue types identified in all breast tissue samples. Unsupervised Principal Component Analyses and supervised Partial Least Square Discriminant Analyses (PLS-DA) were used to discriminate spectra. Leave-one-out cross-validation was used to evaluate the performance of PLS-DA models. Our results show that IR imaging coupled with PLS-DA can efficiently identify the main cell types present in FFPE breast tissue sections, i.e. epithelial cells, lymphocytes, connective tissue, vascular tissue and erythrocytes. A second PLS-DA model could distinguish normal and tumor breast epithelial cells in the breast tissue sections. A patient-specific model reached particularly high sensitivity, specificity and MCC rates. Finally, we showed that the stroma located close or at distance from the tumor exhibits distinct spectral characteristics. In conclusion FTIR imaging combined with computational algorithms could be an accurate, rapid and objective tool to identify/quantify breast epithelial cells and differentiate tumor from normal breast tissue as well as normal from tumor-associated stroma, paving the way to the establishment of a potential complementary tool to ensure safe tumor margins.

Silicon Reduces Black Sigatoka Development in Banana.

The effect of silicon (Si) uptake on the susceptibility of Musa acuminata to Mycosphaerella fijiensis was investigated in three experiments conducted under controlled conditions. Plants were grown in the presence of Si or not, in pots adapted for a hydroponic culture system or in pots filled with compost. The banana leaves were inoculated after 4 or 6 months of plant growth by spraying conidial suspensions or by brushing mycelia fragments. The disease progress over time was assessed using quantitative and qualitative scales. At the end of each experiment, disease severity was also analyzed using the image analysis software ASSESS. The Si concentration in the leaves of plants supplied with Si reached 10 to 28 g/kg of dry matter. The first symptoms appeared 18 days after inoculation. The disease developed more rapidly and more severely on banana plants grown without Si than on plants supplied with Si. The areas under the disease progress curve (AUDPCs) calculated for plants grown with Si were significantly lower than the AUDPCs for plants not supplied with Si, regardless of inoculation method. Thus, Si supply could be a valuable tool in integrated pest management against M. fijiensis by reducing the disease pressure on banana.

Impact of arbuscular mycorrhizal fungi on uranium accumulation by plants.

Contamination by uranium (U) occurs principally at U mining and processing sites. Uranium can have tremendous environmental consequences, as it is highly toxic to a broad range of organisms and can be dispersed in both terrestrial and aquatic environments. Remediation strategies of U-contaminated soils have included physical and chemical procedures, which may be beneficial, but are costly and can lead to further environmental damage. Phytoremediation has been proposed as a promising alternative, which relies on the capacity of plants and their associated microorganisms to stabilize or extract contaminants from soils. In this paper, we review the role of a group of plant symbiotic fungi, i.e. arbuscular mycorrhizal fungi, which constitute an essential link between the soil and the roots. These fungi participate in U immobilization in soils and within plant roots and they can reduce root-to-shoot translocation of U. However, there is a need to evaluate these observations in terms of their importance for phytostabilization strategies.

Role and influence of mycorrhizal fungi on radiocesium accumulation by plants.

This review summarizes current knowledge on the contribution of mycorrhizal fungi to radiocesium immobilization and plant accumulation. These root symbionts develop extended hyphae in soils and readily contribute to the soil-to-plant transfer of some nutrients. Available data show that ecto-mycorrhizal (ECM) fungi can accumulate high concentration of radiocesium in their extraradical phase while radiocesium uptake and accumulation by arbuscular mycorrhizal (AM) fungi is limited. Yet, both ECM and AM fungi can transport radiocesium to their host plants, but this transport is low. In addition, mycorrhizal fungi could thus either store radiocesium in their intraradical phase or limit its root-to-shoot translocation. The review discusses the impact of soil characteristics, and fungal and plant transporters on radiocesium uptake and accumulation in plants, as well as the potential role of mycorrhizal fungi in phytoremediation strategies.

Long-lasting potentiation of a single-dose of rocuronium by amikacin: case report.

We report for the first time to our knowledge long-lasting (4 hours) potentiation of single intubating dose of rocuronium by a single bolus of amikacin given 55 minutes later in a woman having no precipitating factor (renal failure, hepatic failure, ionic disorder, other drugs influencing neuromuscular function). This patient had received the same rocuronium dose one month sooner in similar circumstances (without aminoglycoside antibiotic drug) and had not presented any prolonged neuromuscular blockade at this time. Neuromuscular blockade should be monitored in every patient receiving aminoglycoside antibiotic with even a single intubating dose of neuromuscular blocking drug.

Echocardiography for management of low cardiac output state after axillary block in a dehydrated patient with aortic stenosis: case report.

We report an episode of transient low cardiac output in a dehydrated elderly woman having an undetected clinically significant aortic stenosis, after an axillary blockade. Cardiac echography was determinant for management of this patient. Events were considered to be from hemodynamic origin.

Rhizospheric mobilization and plant uptake of radiocesium from weathered micas: I. Influence of potassium depletion.

Potassium depletion in the soil solution around plant roots promotes the root uptake of radiocesium. However, it can also induce the transformation of mica through the release of interlayer K. In bulk soil, the formation of frayed edge sites (FES) with a high selectivity for Cs adsorption is usually related with mica weathering. We studied the effect of K level in the nutrient solution on the root-induced weathering of phlogopite as well as on the root uptake of radiocesium by willow (Salix viminalis L. var. Orm). The willows were grown for 7 wk in column lysimeters filled with a quartz-phlogopite mixed substrate continuously irrigated with nutrient solutions differing in K concentration (0-2 mM). From a potassium supply of 0.4 mM downward, we observed a decrease in root uptake of potassium as well as an increase in (i) potassium release from phlogopite, (ii) degree of transformation of phlogopite into vermiculite, and (iii) root uptake of radiocesium. Increasing K depletion had thus two effects: a decrease of the root uptake of potassium and an increase of phlogopite weathering in the rhizosphere, both of which promoted the root uptake of radiocesium.

Mobility of radiocesium in three distinct forest floors.

The degree of mixing of organic matter with minerals in organic and hemi-organic horizons of forest soils largely differs between humus types. As clay minerals might control the mobility of radiocesium in these forest floor horizons, plant contamination could greatly vary with the kind of humus. We measured the mobility of radiocesium in the upper O, OAh and Ah horizons of three acid forest soils with three distinct humus types: eumoder, dysmoder and fibrimor. We used two different approaches: a physico-chemical test quantifying the radiocesium interception potential (RIP) and a biological assay simulating an experimental rhizosphere. The results show that the (137)Cs horizon-to-plant transfer is directly governed by RIP, and thus by frayed edge sites born by weathered micaceous minerals. The inverse relationship between RIP and organic matter content indicates that in the three sites investigated the mixing of organic residues with Cs-fixing minerals is a key process in 137Cs mobility. These Cs-fixing clay minerals indeed decrease in the sequence eumoder > dysmoder > fibrimor because they are more diluted in forest floor with less bioturbation. Our results suggest that humus type might be an important parameter in classifying forest soils with respect to their ability to transfer radiocesium to the above standing vegetation.