Interaction between hydrogen peroxide and sodium nitroprusside following chemical priming of Ocimum basilicum L. against salt stress

Sodium nitroprusside (SNP) and hydrogen peroxide (H₂O₂)_, as priming agents, have the well-recorded property to increase plant tolerance against a range of different abiotic stresses such as salinity. In this regard, the present study was conducted to evaluate the effect of different levels of SNP (100 and 200 µM) and H₂O₂ (2.5 and 5 mM) as well as their combinations under salt stress (0 and 50 mM NaCl) on key physiological and biochemical attributes of the economically important aromatic plant basil (Ocimum basilicum L.) grown under hydroponic culture. Results revealed that morphological parameters such as plant height, root length, leaf fresh and dry weights (FW and DW) were significantly decreased by salinity stress, while SNP and H₂O₂ treatments, alone or combined, increased FW and DW thus enhancing plant tolerance to salt stress. Furthermore, 200 µM SNP + 2.5 mM H₂O₂ appeared to be the most effective treatment by causing significant increase in chlorophyll a and b, anthocyanin content and guaiacol peroxidase and ascorbate peroxidase enzymes activities under saline condition. In addition, analytical measurements showed that essential oil profile (concentration of main components) under salt stress was mostly affected by SNP and H₂O₂ treatments. The highest increase was observed for methyl chavicol (43.09–69.91%), linalool (4.8–17.9%), cadinol (1.5–3.2%) and epi-α-cadinol (0.18–10.75%) compounds. In conclusion, current findings demonstrated a positive crosstalk between SNP and H₂O₂ toward improved basil plant tolerance to salt stress, linked with regulation of essential oil composition.     

Understanding sensitivity to BH3 mimetics: ABT-737 as a case study to foresee the complexities of personalized medicine

ABSTRACT: BH3 mimetics such as ABT-737 and navitoclax bind to the BCL-2 family of proteins and induce apoptosis through the intrinsic apoptosis pathway. There is considerable variability in the sensitivity of different cells to these drugs. Understanding the molecular basis of this variability will help to determine which patients will benefit from these drugs. Furthermore, this understanding aids in the design of rational strategies to increase the sensitivity of cells which are otherwise resistant to BH3 mimetics. We discuss how the expression of BCL-2 family proteins regulates the sensitivity to ABT-737. One of these, MCL-1, has been widely described as contributing to resistance to ABT-737 which might suggest a poor response in patients with cancers that express levels of MCL-1. In some cases, resistance to ABT-737 conferred by MCL-1 is overcome by the expression of pro-apoptotic proteins that bind to apoptosis inhibitors such as MCL-1. However, the distribution of the pro-apoptotic proteins amongst the various apoptosis inhibitors also influences sensitivity to ABT-737. Furthermore, the expression of both pro- and anti-apoptotic proteins can change dynamically in response to exposure to ABT-737. Thus, there is significant complexity associated with predicting response to ABT-737. This provides a paradigm for the multiplicity of intricate factors that determine drug sensitivity which must be considered for the full implementation of personalized medicine.     

Ion exchange chromatographic conditions for obtaining individual subunits of soybean β-conglycinin

Soybean β-conglycinin is a complex protein possessing health-promoting properties. β-Conglycinin is a trimeric glycoprotein. Little information related to methods for separation of the individual chains forming β-conglycinin has been so far published and it is of great interest. As a consequence, less data on the bioactivities of α, α′ and β subunits of this glycoprotein have been published. The present research aimed to find out new alternative chromatographic conditions to obtain β-conglycinin subunits that are free of contaminating proteins. In the present short communication, we propose the use of a two-step ion exchange chromatographic protocol to achieve this goal. Firstly, β subunit was separated by means of anionic exchange fast protein liquid chromatography. Secondly, α and α′ chains were separated from each other by cationic exchange. Our data indicated the feasibility of proposed fractionation protocol to separate soybean β-conglycinin α and α′ subunits from other contaminating proteins and to obtain enough amounts of the three individual chains forming this glycoprotein for further characterization and application. The procedure may be easily up-scaled.     

Synthesis of galacto-oligosaccharide from lactose using beta-galactosidase from Kluyveromyces lactis: Studies on batch and continuous UF membrane-fitted bioreactors

A study of galacto-oligosaccharides (GOS) synthesis from lactose with beta-galactosidase from Kluyveromyces lactis (Maxilact L2000) was carried out. The synthesis was performed using various initial lactose concentrations ranging from 220 to 400 mg/mL and enzyme concentrations ranging from 3 to 9 U/mL, and was investigated at 40 degrees C and pH 7, in a stirred-tank reactor. In the experimental range examined, the results showed the amount of GOS formed depended on lactose concentration but not on enzyme concentration. Galactose was a competitive inhibitor, while glucose was a non-competitive inhibitor. In a further study, a laboratory-scale reactor system, fitted with a 10-kDa NMWCO composite regenerated cellulose membrane, was used in a continuous process. The reactor was operated in cross-flow mode. The effect of operating pressures on flux and productivity was investigated by applying different transmembrane pressures to the system. The continuous process showed better production performance compared to the batch synthesis with the same lactose and enzyme concentrations at 40 degrees C, pH 7. Comparison of product structures from batch and continuous processes, analyzed by HPAE-PAD and methylation analysis, showed similarities but differed from the structures found in a commercial GOS product (Vivinal GOS).     

Computer quantification of airway collapse on forced expiration to predict the presence of emphysema

Background

Spirometric parameters are the mainstay for diagnosis of COPD, but cannot distinguish airway obstruction from emphysema. We aimed to develop a computer model that quantifies airway collapse on forced expiratory flow–volume loops. We then explored and validated the relationship of airway collapse with computed tomography (CT) diagnosed emphysema in two large independent cohorts.

Methods

A computer model was developed in 513 Caucasian individuals with ≥15 pack-years who performed spirometry, diffusion capacity and CT scans to quantify emphysema presence. The model computed the two best fitting regression lines on the expiratory phase of the flow-volume loop and calculated the angle between them. The collapse was expressed as an Angle of collapse (AC) which was then correlated with the presence of emphysema. Findings were validated in an independent group of 340 individuals.

Results

AC in emphysema subjects (N = 251) was significantly lower (131° ± 14°) compared to AC in subjects without emphysema (N = 223), (152° ± 10°) (p < 0.0001). Multivariate regression analysis revealed AC as best indicator of visually scored emphysema (R² = 0.505, p < 0.0001) with little significant contribution of K_CO, %predicted and FEV_1, %predicted to the total model (total R² = 0.626, p < 0.0001). Similar associations were obtained when using CT-automated density scores for emphysema assessment. Receiver operating characteristic (ROC) curves pointed to 131° as the best cut-off for emphysema (95.5% positive predictive value, 97% specificity and 51% sensitivity). Validation in a second group confirmed the significant difference in mean AC between emphysema and non-emphysema subjects. When applying the 131° cut-off, a positive predictive value of 95.6%, a specificity of 96% and a sensitivity of 59% were demonstrated.

Conclusions

Airway collapse on forced expiration quantified by a computer model correlates with emphysema. An AC below 131° can be considered as a specific cut-off for predicting the presence of emphysema in heavy smokers.     

Disease activity and low physical activity associate with number of hospital admissions and length of hospitalisation in patients with rheumatoid arthritis

Introduction  

Substantial effort has been devoted for devising effective and safe interventions to reduce preventable hospital admissions in chronic disease patients. In rheumatoid arthritis (RA), identifying risk factors for admission has important health policy implications, but knowledge of which factors cause or prevent hospital admissions is currently lacking. We hypothesised that disease activity/severity and physical activity are major predictors for the need of hospitalisation in patients with RA.     

Cell-based therapy for prevention and reversal of myocardial remodeling

Although pharmacological and interventional advances have reduced the morbidity and mortality of ischemic heart disease, there is an ongoing need for novel therapeutic strategies that prevent or reverse progressive ventricular remodeling following myocardial infarction, the process that forms the substrate for ventricular failure. The development of cell-based therapy as a strategy to repair or regenerate injured tissue offers extraordinary promise for a powerful anti-remodeling therapy. In this regard, the field of cell therapy has made major advancements in the past decade. Accumulating data from preclinical studies have provided novel insights into stem cell engraftment, differentiation, and interactions with host cellular elements, as well as the effectiveness of various methods of cell delivery and accuracy of diverse imaging modalities to assess therapeutic efficacy. These findings have in turn guided rationally designed translational clinical investigations. Collectively, there is a growing understanding of the parameters that underlie successful cell-based approaches for improving heart structure and function in ischemic and other cardiomyopathies.