An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of liquid chromatography – tandem mass spectrometry (LC-MS/MS) assays used ...for the determination of serum total 25-hydroxyvitamin D (25(OH)D), which is the sum of 25-hydroxyvitamin D
2
(25(OH)D
2
) and 25-hydroxyvitamin D
3
(25(OH)D
3
). A set of 50 single-donor samples was assigned target values for concentrations of 25(OH)D
2
, 25(OH)D
3
, 3-epi-25-hydroxyvitamin D
3
(3-epi-25(OH)D
3
), and 24R,25-dihydroxyvitamin D
3
(24R,25(OH)
2
D
3
) using isotope dilution liquid chromatography – tandem mass spectrometry (ID LC-MS/MS). VDSP Intercomparison Study 2 Part 1 includes results from 14 laboratories using 14 custom LC-MS/MS assays. Assay performance was evaluated using mean % bias compared to the assigned target values and using linear regression analysis of the test assay mean results and the target values. Only 53% of the LC-MS/MS assays met the VDSP criterion of mean % bias ≤ |±5%|. For the LC-MS/MS assays not meeting the ≤ |±5%| criterion, four assays had mean % bias of between 12 and 21%. Based on multivariable regression analysis using the concentrations of the four individual vitamin D metabolites in the 50 single-donor samples, the performance of several LC-MS/MS assays was found to be influenced by the presence of 3-epi-25(OH)D
3
. The results of this interlaboratory study represent the most comprehensive comparison of LC-MS/MS assay performance for serum total 25(OH)D and document the significant impact of the lack of separation of 3-epi-25(OH)D
3
and 25(OH)D
3
on assay performance, particularly with regard to mean % bias.
Graphical abstract
In order to understand photosynthetic responses of pomegranate plants (Punica granatum L.) to salinity, an experiment was conducted with three varieties, 'Mollar de Elche', 'Valenciana', and ...'Wonderful', irrigated with seven salt concentrations (0, 40, 60, 80, 100, 120, and 140 mM NaCl). At the end of the experiment, parameters of gas exchange, chlorophyll fluorescence, water relations, and sugar and chloride concentrations were measured in leaves. As the concentration of NaCl increased, the concentration of Cl- in leaves was elevated, and the CO2 assimilation rate, stomatal conductance, variable fluorescence/maximum fluorescence ratio, PSII quantum yield, and total soluble sugars decreased. In 'Valenciana', the decrease of the net assimilation of CO2 could occur due to the closure of stomata, while in 'Mollar' and 'Wonderful', this was due to damage caused by Cl- toxicity. The study of carbohydrates also suggests a different behavior of carbon metabolism in the three varieties.
The kelch 13 (K13) propeller gene is associated with artemisinin resistance. In a previous work, there were no mutations found in 138 Plasmodium falciparum isolates collected in 2012 and 2013 from ...patients residing in Dakar, Senegal (M. Torrentino-Madamet et al., Malar J 13:472, 2014, http://dx.doi.org/10.1186/1475-2875-13-472). However, the N554H, Q613H, and V637I mutations were identified in the propeller region of K13 in 92 (5.5%) isolates in 2013 and 2014. There were five polymorphisms identified in the Plasmodium/Apicomplexa-specific domain (K123R, N137S, N142NN/NNN, T149S, and K189T/N).
Inflammation contributes to the pathogenesis of chronic kidney disease (CKD). Molecules released by the inflamed injured tissue can activate toll-like receptors (TLRs), thereby modulating macrophage ...and CD4(+) T-cell activity. We propose that in renal fibrogenesis, M2 macrophages are recruited and activated in a T helper subset 2 cell (T(H)2)-prone inflammatory milieu in a MyD88-dependent manner. Mice submitted to unilateral ureteral ligation (UUO) demonstrated an increase in macrophage infiltration with collagen deposition after 7 d. Conversely, TLR2, TLR4 and MyD88 knockout (KO) mice had an improved renal function together with diminished T(H)2 cytokine production and decreased fibrosis formation. Moreover, TLR2, TLR4 and MyD88 KO animals exhibited less M2 macrophage infiltration, namely interleukin (IL)-10(+) and CD206(+) CD11b(high) cells, at 7 d after surgery. We evaluated the role of a T(H)2 cytokine in this context, and observed that the absence of IL-4 was associated with better renal function, decreased IL-13 and TGF-β levels, reduced arginase activity and a decrease in fibrosis formation when compared with IL-12 KO and wild-type (WT) animals. Indeed, the better renal outcomes and the decreased fibrosis formation were restricted to the deficiency of IL-4 in the hematopoietic compartment. Finally, macrophage depletion, rather than the absence of T cells, led to reduced lesions of the glomerular filtration barrier and decreased collagen deposition. These results provide evidence that future therapeutic strategies against renal fibrosis should be accompanied by the modulation of the M1:M2 and T(H)1:T(H)2 balance, as T(H)2 and M2 cells are predictive of fibrosis toward mechanisms that are sensed by innate immune response and triggered in a MyD88-dependent pathway.
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•Boron stress, toxicity or deficiency, occurs frequently in plants worldwide.•This stress decreases plant production and fruit quality.•Boron stresses occur simultaneously with other ...as salinity, drought, light, etc.•This ms studies the plants response under combination stresses including Boron.
Boron (B), an essential nutrient for plants, participates in many physiological processes, with emphasis its role in the formation of the plant’s cell wall. In soil, the range between deficiency and toxicity of B is very narrow as compared to other nutrients, which makes its management in agriculture very difficult, as it depends on the soil and environmental conditions. B stress simultaneously acts with others (extreme temperatures, excess of light, high concentration of CO2, drought, salinity or heavy metal contamination, etc.). The effects of these other stresses could increase the sensitivity of plants to B toxicity or deficiency. The simultaneous combination (B stress × other abiotic stresses) is a complex interaction that should be analyzed in detail if the resistance of crops to climate change is needed. This article reviews the response of plants when facing a combination of B stress with other stresses, and compares this response with the individual stresses. Also, in the last few years, the role of B has been described in multiple plant functions that can improve its resilience to specific stresses. Thus, this article also analyses in what conditions the application of B can be efficient for the improvement of the plant’s response to other stresses.
The emergence of Plasmodium falciparum resistance to artemisinin and its derivatives, manifested as delayed parasite clearance following the treatment, has developed in Southeast Asia. The spread of ...resistance to artemisinin from Asia to Africa may be catastrophic for malaria control and elimination worldwide. Recently, mutations in the propeller domain of the Kelch 13 (k13) gene (PF3D71343700) were associated with in vitro resistance to artemisinin and with delayed clearance after artemisinin treatment in southern Asia. The aim of the study was to characterize the genetic variability of k13 and to evaluate the molecular resistance to artemisinin for the first time in Senegal.
Plasmodium falciparum isolates were collected from 138 malaria patients in Dakar and its districts during the rainy season of October 2012 to January 2013 at the Hôpital Principal de Dakar. The k13 gene was amplified using nested PCR and sequenced.
A very limited variability within the k13 gene in Senegalese P. falciparum isolates was identified. No polymorphism was detected in the six k13-propeller blades. Only two mutations, T149S (6.3%) and K189T (42.2%), and one (N) or two (NN) asparagine insertion at the codon 142 (4.7 and 6.3%, respectively) were detected in the Plasmodium/Apicomplexa-specific domain. None of the polymorphisms associated with artemisinin resistance in Southeast Asia was detected in the 138 P. falciparum from Dakar.
The present data do not suggest widespread artemisinin resistance in Dakar in 2012-2013. Notably, the C580Y, R539T or Y493H substitutions that were associated with in vitro resistance or delayed parasite clearance in Southeast Asia were not observed in Dakar, nor were any of the polymorphisms observed in parasites from Southeast Asia, nor the M476I mutation that was selected in vitro with artemisinin pressure in a African parasite line.
Results of measurements on the thermoelectric power of 45 nm diameter interconnected nanowire networks consisting of pure Fe, dilute FeCu and FeCr alloys and Fe/Cu multilayers are presented. The ...thermopower values of Fe nanowires are very close to those found in bulk materials, at all temperatures studied between 70 and 320 K. For pure Fe, the diffusion thermopower at room temperature, estimated to be around - 15 Formula: see textV/K from our data, is largely supplanted by the estimated positive magnon-drag contribution, close to 30 Formula: see textV/K. In dilute FeCu and FeCr alloys, the magnon-drag thermopower is found to decrease with increasing impurity concentration to about 10 Formula: see textV/K at 10Formula: see text impurity content. While the diffusion thermopower is almost unchanged in FeCu nanowire networks compared to pure Fe, it is strongly reduced in FeCr nanowires due to pronounced changes in the density of states of the majority spin electrons. Measurements performed on Fe(7 nm)/Cu(10 nm) multilayer nanowires indicate a dominant contribution of charge carrier diffusion to the thermopower, as previously found in other magnetic multilayers, and a cancellation of the magnon-drag effect. The magneto-resistance and magneto-Seebeck effects measured on Fe/Cu multilayer nanowires allow the estimation of the spin-dependent Seebeck coefficient in Fe, which is about - 7.6 Formula: see textV/K at ambient temperature.
Cadmium is absorbed by plants rapidly and without control through the same channels as other essential metals, interfering with their transport and utilization. Many studies have shown that selenium ...could be utilized as a way to avoid this unwanted transport and other negative effects of Cd. For this reason, the present research study was conducted with four treatments (−Cd/−Se, +Cd/−Se, +Cd/+SeF, and +Cd/+SeR) to determine the type of application of Se that is best (foliarly and/or via the root) as regards the reduction of the toxic effects of Cd on plants. Our results showed that the Cd excess in the nutrient solution resulted in a decrease in the total dry biomass of the plants grown under these conditions, and this decrease was due to the reduction of the growth of the shoot (48% +Cd/−Se, 45% +Cd/+SeF, and 38% +Cd/+SeR, relative to −Cd/−Se). This reduction in growth was due to: (i) the toxicity of Cd itself and (ii) the nutritional disequilibrium suffered by the plants. It seems that under hydroponic conditions, the addition of Se to the nutrient solution, and therefore its absorption through the roots (lower antioxidant activity, superoxide dismutase, H2O2 concentration and higher catalase activity), greatly delayed and reduced the toxic effects of Cd on the pepper plants, as opposed to the foliar application of this element.
The ATLAS programme aims to promote and implement HIV self-testing (HIVST) in three West African countries: Côte d'Ivoire, Mali, and Senegal. During 2019-2021, in close collaboration with the ...national AIDS implementing partners and communities, ATLAS plans to distribute 500,000 HIVST kits through eight delivery channels, combining facility-based, community-based strategies, primary and secondary distribution of HIVST. Considering the characteristics of West African HIV epidemics, the targets of the ATLAS programme are hard-to-reach populations: key populations (female sex workers, men who have sex with men, and drug users), their clients or sexual partners, partners of people living with HIV and patients diagnosed with sexually transmitted infections and their partners. The ATLAS programme includes research support implementation to generate evidence for HIVST scale-up in West Africa. The main objective is to describe, analyse and understand the social, health, epidemiological effects and cost-effectiveness of HIVST introduction in Côte d'Ivoire, Mali and Senegal to improve the overall HIV testing strategy (accessibility, efficacy, ethics).
ATLAS research is organised into five multidisciplinary workpackages (WPs): Key Populations WP: qualitative surveys (individual in-depth interviews, focus group discussions) conducted with key actors, key populations, and HIVST users. Index testing WP: ethnographic observation of three HIV care services introducing HIVST for partner testing. Coupons survey WP: an anonymous telephone survey of HIVST users. Cost study WP: incremental economic cost analysis of each delivery model using a top-down costing with programmatic data, complemented by a bottom-up costing of a representative sample of HIVST distribution sites, and a time-motion study for health professionals providing HIVST. Modelling WP: Adaptation, parameterisation and calibration of a dynamic compartmental model that considers the varied populations targeted by the ATLAS programme and the different testing modalities and strategies.
ATLAS is the first comprehensive study on HIV self-testing in West Africa. The ATLAS programme focuses particularly on the secondary distribution of HIVST. This protocol was approved by three national ethic committees and the WHO's Ethical Research Committee.
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