Disrupted ADP-ribose metabolism with nuclear Poly (ADP-ribose) accumulation leads to different cell death pathways in presence of hydrogen peroxide in procyclic Trypanosoma brucei

TbPARG in Trypanosoma brucei. A) TbPARG localization in untreated (control) and in procyclic cultures exposed to 500 μM H2O2 for 10 min. IFI was carried out as reported in our previous work [33]. TbPARG was identified with our home-made antibody against TcPARG [33]; and PAR was identified with a commercial antibody against PAR (BD). White bar represents 50 μm. B) Western blot analysis of 40 μg protein per lane revealed with a commercial anti-PARG antibody (Antibody Verify) in T. brucei procyclic (PC) and bloodstream (BST) forms. The arrow indicates the band with the expected molecular weight (approximately 60 kDa). The membrane stained with Red Ponceau was used as a loading control. (TIF 4272 kb

Bioavailability in soils

The consumption of locally-produced vegetables by humans may be an important exposure pathway for soil contaminants in many urban settings and for agricultural land use. Hence, prediction of metal and metalloid uptake by vegetables from contaminated soils is an important part of the Human Health Risk Assessment procedure. The behaviour of metals (cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and zinc) and metalloids (arsenic, boron and selenium) in contaminated soils depends to a large extent on the intrinsic charge, valence and speciation of the contaminant ion, and soil properties such as pH, redox status and contents of clay and/or organic matter. However, chemistry and behaviour of the contaminant in soil alone cannot predict soil-to-plant transfer. Root uptake, root selectivity, ion interactions, rhizosphere processes, leaf uptake from the atmosphere, and plant partitioning are important processes that ultimately govern the accumulation ofmetals and metalloids in edible vegetable tissues. Mechanistic models to accurately describe all these processes have not yet been developed, let alone validated under field conditions. Hence, to estimate risks by vegetable consumption, empirical models have been used to correlate concentrations of metals and metalloids in contaminated soils, soil physico-chemical characteristics, and concentrations of elements in vegetable tissues. These models should only be used within the bounds of their calibration, and often need to be re-calibrated or validated using local soil and environmental conditions on a regional or site-specific basis.Mike J. McLaughlin, Erik Smolders, Fien Degryse, and Rene Rietr

Residual effects of natural Zn chelates on navy bean response, Zn leaching and soil status

greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the aging and residual effects of three natural organic Zn chelates [Zn-ethylenediaminedisuccinate (Zn-EDDS), Zn-polyhydroxyphenylcarboxylate and Zn-aminelignosulfonate] each administered in a single application to a first navy bean (Phaseolus vulgaris L.) crop at several different Zn application rates. In a second navy bean crop, we determined the following parameters: the extent of Zn leaching, the amount of available Zn remaining in soils, the amount of easily leachable Zn, the size of Zn fractions in soils, the pH and redox potential, the dry matter yield, and the soluble and total Zn concentrations in plants. The residual effect after 2 years of Zn fertilization mainly depended on the aging effect of Zn chelates and losses due to Zn leaching. The data relating to the evolution from the first to the second crop showed that the aging effect was noticeable in the calcareous soil. In the latter soil, the Zn-S,S-EDDS treatments showed greater decreases in the Zn uptake by plants than the other Zn treatments and the greatest Zn uptake by plants occurred when Zn was applied as Zn-aminelignosulfonate (10 mg Zn kg−1 rate, 6.85 mg Zn per lysimeter; 5 mg Zn kg−1 rate, 3.36 mg Zn per lysimeter). In contrast, in the calcareous soil, the maximum amount of Zn uptake, for the three chelates was 0.82 mg Zn per lysimeter. Consequently, a further application of Zn would be needed to prevent Zn deficiencies in the plants of a subsequent crop. The behaviour of the pH and Eh parameters in the soils and leachates did not depend on the natural Zn sources applied. In this study, the easily leachable Zn estimated by BaCl2 extraction was not adequate to predict Zn leaching from the soils in subsequent crops

Neutron Reflection Study of Surface Adsorption of Fc, Fab, and the Whole mAb

Characterizing the influence of fragment crystallization (Fc) and antigen-binding fragment (Fab) on monoclonal antibody (mAb) adsorption at the air/water interface is an important step to understanding liquid mAb drug product stability during manufacture, shipping, and storage. Here, neutron reflection is used to study the air/water adsorption of a mAb and its Fc and Fab fragments. By varying the isotopic contrast, the adsorbed amount, thickness, orientation, and immersion of the adsorbed layers could be determined unambiguously. While Fc adsorption reached saturation within the hour, its surface adsorbed amount showed little variation with bulk concentration. In contrast, Fab adsorption was slower and the adsorbed amount was concentration dependent. The much higher Fc adsorption, as compared to Fab, was linked to its lower surface charge. Time and concentration dependence of mAb adsorption was dominated by Fab behavior, although both Fab and Fc behaviors contributed to the amount of mAb adsorbed. Changing the pH from 5.5 to 8.8 did not much perturb the adsorbed amount of Fc, Fab, or mAb. However, a small decrease in adsorption was observed for the Fc over pH 8-8.8 and vice versa for the Fab and mAb, consistent with a dominant Fab behavior. As bulk concentration increased from 5 to 50 ppm, the thicknesses of the Fc layers were almost constant at 40 Å, while Fab and mAb layers increased from 45 to 50 Å. These results imply that the adsorbed mAb, Fc, and Fab all retained their globular structures and were oriented with their short axial lengths perpendicular to the interface.</p

Stability indicating method development and validation for simultaneous estimation of atorvastatin calcium and celecoxib in bulk and niosomal formulation by RP-HPLC

The present work describes development and validation of a specific, sensitive, precise and stability-indicating high-performance liquid chromatographic method of analysis of atorvastatin calcium and celecoxib, both as a bulk drug and in niosomal formulation. The analysis has been performed by using Cosmosil-C18 column (4.6 mm´250 mm, 5 m) at 25 °C using acetonitrile: ammonium acetate buffer pH 5.0: methanol (50:25:25 v/v/v) as mobile phase. The detection was carried out at 277nm with a flow rate of 1.0mL/min. The retention times of Atorvastatin calcium and Celecoxib were 6.195 and 3.989min, respectively. The method was validated according to ICH guidelines, for specificity, precision, linearity, accuracy and robustness. Atorvastatin calcium and Celecoxib were subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. The degradation was observed in oxidation and acid hydrolysis. The linearity for atorvastatin calcium and celecoxib were in the range of 100-500 µg/mL. The recovery study of atorvastatin and celecoxib were found to be in the range of 98.96 - 99.92% and 98.90-100%, respectively. The proposed method was validated and successfully applied to the estimation of Atorvastatin calcium and Celecoxib in combined in-house niosomal formulation.O presente trabalho descreve o desenvolvimento e a validação de método de análise por cromatografia de alta eficiência específico, sensível, preciso e indicador de estabilidade de atorvastatina cálcica e celecoxibe, ambos como fármaco e como formulação niosômica. A análise foi realizada utilizando coluna Cosmosil-C18 (4,6 mm´250 mm, 5 m) a 25 °C, e acetonitrila: tampão acetato de amônio pH 5,0: metanol (50:25:25 v/v/v) como fase móvel. A detecção foi realizada a 277 nm, com fluxo de 1,0 mL/min. Os tempos de retenção de atorvastatina cálcica e de celecoxibe foram 6,195 e 3,989 min, respectivamente. O método foi validado de acordo com as regras da ICH para especificidade, precisão, exatidão e robustez. A atorvastatina cálcica e o celecoxibe foram submetidos a condições de estresse por hidrólise, oxidação, fotólise e degradação térmica. A degradação foi observada por oxidação e hidrólise ácida. Observou-se a linearidade da atorvastatina cálcica e do celecoxibe na faixa de 100-500 µg/mL. A recuperação da atorvastatina e do celecoxibe foi observada na faixa de 98,96-99,92% e 98,90-100%, respectivamente. O método proposto foi validado e aplicado com sucesso para a determinação de atorvastatina cálcica e celecoxibe em formulação niosômica caseira combinada

Systematic in vitro evolution in Plasmodium falciparum reveals key determinants of drug resistance

Surveillance of drug resistance and the discovery of novel targets-key objectives in the fight against malaria-rely on identifying resistance-conferring mutations in Plasmodium parasites. Current approaches, while successful, require laborious experimentation or large sample sizes. To elucidate shared determinants of antimalarial resistance that can empower in silico inference, we examined the genomes of 724 Plasmodium falciparum clones, each selected in vitro for resistance to one of 118 compounds. We identified 1448 variants in 128 recurrently mutated genes, including drivers of antimalarial multidrug resistance. In contrast to naturally occurring variants, those selected in vitro are more likely to be missense or frameshift, involve bulky substitutions, and occur in conserved, ordered protein domains. Collectively, our dataset reveals mutation features that predict drug resistance in eukaryotic pathogens.</p

Measurement of Angular Coefficients of Bˉ→D∗ℓνˉℓ\bar{B} \to D^* \ell \bar{\nu}_\ell: Implications for ∣Vcb∣|V_{cb}| and Tests of Lepton Flavor Universality

We measure the complete set of angular coefficients $J_i$ for exclusive $\bar{B} \to D^* \ell \bar{\nu}_\ell$ decays ($\ell = e, \mu$). Our analysis uses the full $711\,\mathrm{fb}^{-1}$ Belle data set with hadronic tag-side reconstruction. The results allow us to extract the form factors describing the $B \to D^*$ transition and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{\rm cb}|$. Using recent lattice QCD calculations for the hadronic form factors, we find $|V_{\rm cb}| = (41.0 \pm 0.7) \times 10^3$ using the BGL parameterization, compatible with determinations from inclusive semileptonic decays. We search for lepton flavor universality violation as a function of the hadronic recoil parameter $w$, and investigate the differences of the electron and muon angular distributions. We find no deviation from Standard Model expectations