[(18)F]FDG-PET Standard Uptake Value as a Metabolic Predictor of Bone Marrow Response to Radiation: Impact on Acute and Late Hematological Toxicity in Cervical Cancer Patients Treated With Chemoradiation Therapy.

PURPOSE: To quantify the relationship between bone marrow (BM) response to radiation and radiation dose by using (18)F-labeled fluorodeoxyglucose positron emission tomography [(18)F]FDG-PET standard uptake values (SUV) and to correlate these findings with hematological toxicity (HT) in cervical cancer (CC) patients treated with chemoradiation therapy (CRT). METHODS AND MATERIALS: Seventeen women with a diagnosis of CC were treated with standard doses of CRT. All patients underwent pre- and post-therapy [(18)F]FDG-PET/computed tomography (CT). Hemograms were obtained before and during treatment and 3 months after treatment and at last follow-up. Pelvic bone was autosegmented as total bone marrow (BMTOT). Active bone marrow (BMACT) was contoured based on SUV greater than the mean SUV of BMTOT. The volumes (V) of each region receiving 10, 20, 30, and 40 Gy (V10, V20, V30, and V40, respectively) were calculated. Metabolic volume histograms and voxel SUV map response graphs were created. Relative changes in SUV before and after therapy were calculated by separating SUV voxels into radiation therapy dose ranges of 5 Gy. The relationships among SUV decrease, radiation dose, and HT were investigated using multiple regression models. RESULTS: Mean relative pre-post-therapy SUV reductions in BMTOT and BMACT were 27% and 38%, respectively. BMACT volume was significantly reduced after treatment (from 651.5 to 231.6 cm(3), respectively; P<.0001). BMACT V30 was significantly correlated with a reduction in BMACT SUV (R(2), 0.14; P<.001). The reduction in BMACT SUV significantly correlated with reduction in white blood cells (WBCs) at 3 months post-treatment (R(2), 0.27; P=.04) and at last follow-up (R(2), 0.25; P=.04). Different dosimetric parameters of BMTOT and BMACT correlated with long-term hematological outcome. CONCLUSIONS: The volumes of BMTOT and BMACT that are exposed to even relatively low doses of radiation are associated with a decrease in WBC counts following CRT. The loss in proliferative BM SUV uptake translates into low WBC nadirs after treatment. These results suggest the potential of intensity modulated radiation therapy to spare BMTOT to reduce long-term hematological toxicity.

Manganese uptake and redistribution in soybean as affected by glyphosate

Detrimental effects of glyphosate on plant mineral nutrition have been reported in the literature, particularly on Mn uptake and redistribution. However, in most of the experiments conducted so far glyphosate-susceptible plants were used. Effects of glyphosate on Mn absorption kinetics, accumulation, and distribution within the plant, as well as soybean response to Mn as affected by glyphosate were studied in three experiments. In the first experiment, in nutrient solution, the effect of glyphosate on soybean Mn uptake kinetic parameters (Imax, Km and Cmin) was determined. In a second experiment, also in nutrient solution, differential Mn accumulation and distribution were studied for a conventional soybean cultivar and its near-isogenic glyphosate-resistant counterpart as affected by glyphosate. In a third experiment, response of glyphosate-resistant soybean cultivars to Mn application was studied in the presence of glyphosate, in pots with Mn-deficient soil. Maximum Mn influx (Imax) was higher in the herbicide-resistant (GR) cultivar than in its conventional counterpart. Glyphosate applied to nutrient solution at low rates decreased Km and Cmin. A few days after herbicide treatment, RR soybean plants developed yellowish leaves, a symptom which, in the field, could be misinterpreted as Mn deficiency, but herbicide application had no effect on Mn uptake or distribution within the plant. In the soil experiment, soybean Mn uptake was increased by Mn application, with no effect of glyphosate. Under greenhouse conditions, there was no evidence of deleterious effects of glyphosate on Mn absorption, accumulation and distribution in the plant and on soybean cultivars response to Mn application.

Biomass production and nutrient uptake of short-rotation plantations

Summary

Kinetic parameters of silicon uptake by rice cultivars

Silicon is considered an important chemical element for rice, because it can improve tolerance to biotic and abiotic stress. However, in many situations no positive effect of silicon was observed, probably due to genetic factors. The objective of this research was to monitor Si uptake kinetics and identify responses of rice cultivars in terms of Si uptake capacity and use. The experiment was carried out in a greenhouse of the São Paulo State University (UNESP), Brazil. The experiment was arranged in a completely randomized, factorial design with three replications. that consisted of two rice cultivars and two Si levels. Kinetic parameters (Vmax, Km, and Cmin), root morphology variables, dry matter yield, Si accumulation and levels in shoots and roots, uptake efficiency, utilization efficiency, and root/shoot ratio were evaluated. Higher Si concentrations in the nutrient solution did not increase rice dry matter. The development of the low-affinity silicon uptake system of the rice cultivar 'Caiapó' was better than of 'Maravilha'.

Deficiency symptoms and uptake of micronutrients by castor bean grown in nutrient solution

Castor bean is a nutrient-demanding species, but there is still little information on its micronutrient requirements. The objectives of this study were to evaluate the effects of levels of B (2.5, 12.5 and 25.0 µmol L-1), Cu (0.05, 0.25 and 0.50 µmol L-1), Mn (0.2, 1.0 and 2.0 µmol L-1) and Zn (0.2, 1.0 and 2.0 µmol L-1) in a nutrient solution on plant B, Cu, Mn and Zn concentrations and uptake, vegetative growth and fruit yield of castor bean "Iris", grown in greenhouse. The experiment was arranged in a completely randomized block design with three replicates. The first deficiency symptoms were observed for B, followed by Zn, Cu and Mn. The main changes in the cell ultrastructure due to lack of B were thickening of the cell walls and middle lamellae, distorted chloroplasts and tightly stacked thylakoids, besides the absence of starch grains. The Mn, Zn and Cu deficiencies led to disruption of chloroplasts, disintegration of thylakoids and absence of amyloplasts. The concentration and uptake of B, Cu, Mn, and Zn in castor bean plants increased with micronutrient supply in the solution. Fruit yield was drastically reduced by B and Mn deficiencies. On the other hand, the dry matter yield of the shoot and root of castor bean plants was not. In the treatment with full nutrient solution, the leaves accumulated 56 and 48 % of the total B and Mn taken up by the plants, respectively, and the seeds and roots 85 and 61 % of the total Cu and Zn taken up, respectively. This shows the high demand of castor bean Iris for B and Mn for fruit yield.

Evaluation of uptake and transport of cationic and anionic ultrasmall iron oxide nanoparticles by human colon cells.

Nanoparticles (NPs) are in clinical use or under development for therapeutic imaging and drug delivery. However, relatively little information exists concerning the uptake and transport of NPs across human colon cell layers, or their potential to invade three-dimensional models of human colon cells that better mimic the tissue structures of normal and tumoral colon. In order to gain such information, the interactions of biocompatible ultrasmall superparamagnetic iron oxide nanoparticles (USPIO NPs) (iron oxide core 9-10 nm) coated with either cationic polyvinylamine (aminoPVA) or anionic oleic acid with human HT-29 and Caco-2 colon cells was determined. The uptake of the cationic USPIO NPs was much higher than the uptake of the anionic USPIO NPs. The intracellular localization of aminoPVA USPIO NPs was confirmed in HT-29 cells by transmission electron microscopy that detected the iron oxide core. AminoPVA USPIO NPs invaded three-dimensional spheroids of both HT-29 and Caco-2 cells, whereas oleic acid-coated USPIO NPs could only invade Caco-2 spheroids. Neither cationic aminoPVA USPIO NPs nor anionic oleic acid-coated USPIO NPs were transported at detectable levels across the tight CacoReady? intestinal barrier model or the more permeable mucus-secreting CacoGoblet? model.

Compared boron uptake and translocation in cotton cultivars

The mobility of boron (B), a commonly deficient micronutrient in cotton, has been shown to be low in the plant phloem. Nevertheless, studies have indicated that cotton cultivars can respond differently to B application. A greenhouse experiment was conducted to compare B absorption and mobility in cotton cultivars grown in nutrient solution. Treatments consisted of three cotton cultivars (FMT 701, DP 604BG and FMX 993), and five B rates (0.0, 2.5, 5.0, 10.0, and 20.0 µmol L-1). Plant growth and development were monitored for four weeks from the appearance of the first square. The time of onset and severity of B deficiency symptoms varied among cotton cultivars. Initial B uptake of cv. DP 604BG was lower than of the other cultivars, but a greater amount of available B in the nutrient solution was required to prevent deficiency symptoms in this cultivar. Boron deficiency impairs cotton growth, with no differences among cultivars, regardless of the time of appearance and intensity of B deficiency symptoms.

Reversible and irreversible pollutant-induced bacterial cellular stress effects measured by ethidium bromide uptake and efflux.

Chemical pollution is known to affect microbial community composition but it is poorly understood how toxic compounds influence physiology of single cells that may lay at the basis of loss of reproductive fitness. Here we analyze physiological disturbances of a variety of chemical pollutants at single cell level using the bacterium Pseudomonas fluorescens in an oligotrophic growth assay. As a proxy for physiological disturbance we measured changes in geometric mean ethidium bromide (EB) fluorescence intensities in subpopulations of live and dividing cells exposed or not exposed to different dosages of tetradecane, 4-chlorophenol, 2-chlorobiphenyl, naphthalene, benzene, mercury chloride, or water-dissolved oil fractions. Because ethidium bromide efflux is an energy-dependent process any disturbance in cellular energy generation is visible as an increased cytoplasmic fluorescence. Interestingly, all pollutants even at the lowest dosage of 1 nmol/mL culture produced significantly increased ethidium bromide fluorescence compared to nonexposed controls. Ethidium bromide fluorescence intensities increased upon pollutant exposure dosage up to a saturation level, and were weakly (r(2) = 0.3905) inversely correlated to the proportion of live cells at that time point in culture. Temporal increase in EB fluorescence of growing cells is indicative for toxic but reversible effects. Cells displaying high continued EB fluorescence levels experience constant and permanent damage, and no longer contribute to population growth. The procedure developed here using bacterial ethidium bromide efflux pump activity may be a useful complement to screen sublethal toxicity effects of chemicals.

Uptake of heavy metals by plants from airborne deposition and polluted soils

Selostus: Kasvien raskasmetallien otto ilmasta ja saastuneesta maasta

Active uptake of dendritic cell-derived exovesicles by epithelial cells induces the release of inflammatory mediators through a TNF-alpha-mediated pathway.

Dendritic cells (DCs) can release hundreds of membrane vesicles, called exovesicles, which are able to activate resting DCs and distribute antigen. Here, we examined the role of mature DC-derived exovesicles in innate and adaptive immunity, in particular their capacity to activate epithelial cells. Our analysis of exovesicle contents showed that exovesicles contain major histocompatibility complex-II, CD40, and CD83 molecules in addition to tumor necrosis factor (TNF) receptors, TNFRI and TNFRII, and are important carriers of TNF-alpha. These exovesicles are rapidly internalized by epithelial cells, inducing the release of cytokines and chemokines, but do not transfer an alloantigen-presenting capacity to epithelial cells. Part of this activation appears to involve the TNF-alpha-mediated pathway, highlighting the key role of DC-derived exovesicles, not only in adaptive immunity, but also in innate immunity by triggering innate immune responses and activating neighboring epithelial cells to release cytokines and chemokines, thereby amplifying the magnitude of the innate immune response.

Macronutrient uptake, accumulation and export by the irrigated 'vitória' pineapple plant

The nutritional state of the pineapple plant has a large effect on plant growth, on fruit production, and fruit quality. The aim of this study was to assess the uptake, accumulation, and export of nutrients by the irrigated 'Vitória' pineapple plant during and at the end of its development. A randomized block statistical design with four replications was used. The treatments were defined by different times of plant collection: at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The collected plants were separated into the following components: leaves, stem, roots, fruit, and slips for determination of fresh and dry matter weight at 65 ºC. After drying, the plant components were ground for characterization of the composition and content of nutrients taken up and exported by the pineapple plant. The results were subjected to analysis of variance, and non-linear regression models were fitted for the significant differences identified by the F test (p<0.01). The leaves and the stem were the plant components that showed the greatest accumulation of nutrients. For production of 72 t ha-1 of fruit, the macronutrient accumulation in the 'Vitória' pineapple exhibited the following decreasing order: K > N > S > Ca > Mg > P, which corresponded to 898, 452, 134, 129, 126, and 107 kg ha-1, respectively, of total accumulation. The export of macronutrients by the pineapple fruit was in the following decreasing order: K > N > S > Ca > P > Mg, which was equivalent to 18, 17, 11, 8, 8, and 5 %, respectively, of the total accumulated by the pineapple. The 'Vitória' pineapple plant exported 78 kg ha-1 of N, 8 kg ha-1 of P, 164 kg ha-1 of K, 14 kg ha-1 of S, 10 kg ha-1 of Ca, and 6 kg ha-1 of Mg by the fruit. The nutrient content exported by the fruits represent important components of nutrient extraction from the soil, which need to be restored, while the nutrients contained in the leaves, stems and roots can be incorporated in the soil within a program of recycling of crop residues.

Impaired uptake of glutathione by hepatic mitochondria from chronic ethanol-fed rats. Tracer kinetic studies in vitro and in vivo and susceptibility to oxidant stress.

Isolated hepatocytes incubated with [35S]-methionine were examined for the time-dependent accumulation of [35S]-glutathione (GSH) in cytosol and mitochondria, the latter confirmed by density gradient purification. In GSH-depleted and -repleted hepatocytes, the increase of specific activity of mitochondrial GSH lagged behind cytosol, reaching nearly the same specific activity by 1-2 h. However, in hepatocytes from ethanol-fed rats, the rate of increase of total GSH specific radioactivity in mitochondria was markedly suppressed. In in vivo steady-state experiments, the mass transport of GSH from cytosol to mitochondria and vice versa was 18 nmol/min per g liver, indicating that the half-life of mitochondrial GSH was approximately 18 min in controls. The fractional transport rate of GSH from cytosol to mitochondria, but not mitochondria to cytosol, was significantly reduced in the livers of ethanol-fed rats. Thus, ethanol-fed rats exhibit a decreased mitochondrial GSH pool size due to an impaired entry of cytosol GSH into mitochondria. Hepatocytes from ethanol-fed rats exhibited a greater susceptibility to the oxidant stress-induced cell death from tert-butylhydroperoxide. Incubation with glutathione monoethyl ester normalized the mitochondrial GSH and protected against the increased susceptibility to t-butylhydroperoxide, which was directly related to the lowered mitochondrial GSH pool size in ethanol-fed cells.

Evaluation of uptake and transport of ultrasmall superparamagnetic iron oxide nanoparticles by human brain-derived endothelial cells.

Aim: Ultrasmall superparamagnetic iron oxide nanoparticles (USPIO-NPs) are under development for imaging and drug delivery; however, their interaction with human blood-brain barrier models is not known. Materials & Methods: The uptake, reactive oxygen species production and transport of USPIO-NPs across human brain-derived endothelial cells as models of the blood-brain tumor barrier were evaluated for either uncoated, oleic acid-coated or polyvinylamine-coated USPIO-NPs. Results: Reactive oxygen species production was observed for oleic acid-coated and polyvinylamine-coated USPIO-NPs. The uptake and intracellular localization of the iron oxide core of the USPIO-NPs was confirmed by transmission electron microscopy. However, while the uptake of these USPIO-NPs by cells was observed, they were neither released by nor transported across these cells even in the presence of an external dynamic magnetic field. Conclusion: USPIO-NP-loaded filopodia were observed to invade the polyester membrane, suggesting that they can be transported by migrating angiogenic brain-derived endothelial cells.