Tumor Necrosis Factor -α, Interleukin-10, Intercellular and Vascular Adhesion Molecules Are Possible Biomarkers of Disease Severity in Complicated Plasmodium vivax Isolates from Pakistan

Background

Cytokine-mediated endothelial activation pathway is a known mechanism of pathogenesis employed by Plasmodium falciparum to induce severe disease symptoms in human host. Though considered benign, complicated cases of Plasmodium vivax are being reported worldwide and from Pakistan. It has been hypothesized that P.vivax utilizes similar mechanism of pathogenesis, as that of P.falciparum for manifestations of severe malaria. Therefore, the main objective of this study was to characterize the role of cytokines and endothelial activation markers in complicated Plasmodium vivax isolates from Pakistan.

Methods and Principle Findings

A case control study using plasma samples from well-characterized groups suffering from P.vivax infection including uncomplicated cases (n=100), complicated cases (n=82) and healthy controls (n=100) were investigated. Base line levels of Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-10 (IL-10), Intercellular adhesion molecule-1 (ICAM-1), Vascular adhesion molecule-1(VCAM-1) and E-selectin were measured by ELISA. Correlation of cytokines and endothelial activation markers was done using Spearman’s correlation analysis. Furthermore, significance of these biomarkers as indicators of disease severity was also analyzed. The results showed that TNF-α, IL-10, ICAM-1and VCAM-1 were 3-fold, 3.7 fold and 2 fold increased between uncomplicated and complicated cases. Comparison of healthy controls with uncomplicated cases showed no significant difference in TNF-α concentrations while IL-6, IL-10, ICAM-1, VCAM-1 and E-selectin were found to be elevated respectively. In addition, significant positive correlation was observed between TNF-α and IL-10/ ICAM-1, IL-6 and IL-10, ICAM-1 and VCAM-1.A Receiver operating curve (ROC) was generated which showed that TNF-α, IL-10, ICAM-1 and VCAM-1 were the best individual predictors of complicated P.vivax malaria.

Conclusion

The results suggest that though endothelial adhesion molecules are inducible by pro-inflammatory cytokine TNF-α, however, cytokine-mediated endothelial activation pathway is not clearly demonstrated as a mechanism of pathogenesis in complicated P.vivax malaria cases from Pakistan.     

A new assembly and technique for testing insecticides

A new design of insecticide testing assembly has been devised that is highly versatile in testing the efficacy, potency and interaction of insecticides and other test chemicals. The merits of the assembly and technique have been explained.     

Impact of control for air pollution and respiratory epidemics on the estimated associations of temperature and daily mortality

We assessed the influence of control for air pollution and respiratory epidemics on associations between apparent temperature (AT) and daily mortality in Mexico City and Monterrey. Poisson regressions were fit to mortality among all ages, children (ages 0–14 years) and the elderly (ages 65 years). Predictors included mean daily AT, season, day of week and public holidays for the base model. Respiratory epidemics and air pollution (particulate matter <10 m in aerodynamic diameter and O₃) were added singly and then jointly for a fully adjusted model. Percent changes in mortality were calculated for days of relatively extreme temperatures [cold (10–11°C) for both cities and heat (35–36°C) for Monterrey], compared to days at the overall mean temperature in each city (15°C in Mexico City, 25°C in Monterrey). In Mexico City, total mortality increased 12.4% [95% confidence interval (CI) 10.5%, 14.5%] on cold days (fully adjusted). Among children, the adjusted association was similar [10.9% (95% CI: 5.4%, 16.7%)], but without control for pollution and epidemics, was nearly twice as large [19.7% (95% CI: 13.9%, 25.9)]. In Monterrey, the fully adjusted heat effect for all deaths was 18.7% (95% CI: 11.7%, 26.1%), a third lower than the unadjusted estimate; the heat effect was lower among children [5.5% (95% CI: –10.1%, 23.8%)]. Cold had a similar effect on all-age mortality as in Mexico City [11.7% (95% CI: 3.7%, 20.3%)]. Responses of the elderly differed little from all-ages responses in both cities. Associations between weather and health persisted even with control for air pollution and respiratory epidemics in two Mexican cities, but risk assessments and climate change adaptation programs are best informed by analyses that account for these potential confounders.     

Complete inhibition of anisomycin and UV radiation but not cytokine induced JNK and p38 activation by an aryl-substituted dihydropyrrolopyrazole quinoline and mixed lineage kinase 7 small interfering RNA

Mixed lineage kinase 7 (MLK7) is a mitogen-activated protein kinase kinase kinase (MAPKKK) that activates the pro-apoptotic signaling pathways p38 and JNK. A library of potential kinase inhibitors was screened, and a series of dihydropyrrolopyrazole quinolines was identified as highly potent inhibitors of MLK7 in vitro catalytic activity. Of this series, an aryl-substituted dihydropyrrolopyrazole quinoline (DHP-2) demonstrated an IC50 of 70 nM for inhibition of pJNK formation in COS-7 cell MLK7/JNK co-transfection assays. In stimulated cells, DHP-2 at 200 nM or MLK7 small interfering RNA completely blocked anisomycin and UV induced but had no effect on interleukin-1beta or tumor necrosis factor-alpha-induced p38 and JNK activation. Additionally, the compound blocked anisomycin and UV-induced apoptosis in COS-7 cells. Heart tissue homogenates from MLK7 transgenic mice treated with DHP-2 at 30 mg/kg had reduced JNK and p38 activation with no apparent effect on ERK activation, demonstrating that this compound can be used to block MLK7-driven MAPK pathway activation in vivo. Taken together, these data demonstrate that MLK7 is the MAPKKK required for modulation of the stress-activated MAPKs downstream of anisomycin and UV stimulation and that DHP-2 can be used to block MLK7 pathway activation in cells as well as in vivo.     

Assessment of Titanium Dioxide Nanoparticles (TiO<Subscript>2</Subscript>-NPs) Induced Hepatotoxicity and Ameliorative Effects of <Emphasis Type="Italic">Cinnamomum cassia</Emphasis> in Sprague-Dawley Rats

This study assessed the protective effects of Cinnamomum cassia (cinnamon) bark extract in rats exposed to titanium dioxide nanoparticles or titanium dioxide bulk salt. For in vivo evaluation of the ameliorative role of the cinnamon extract, the experimental groups were orally administered with the cinnamon extract at different dose levels (50 or 100 or 150 mg/kg bodyweight) along with the subcutaneous injections of 150 mg/kg bodyweight titanium dioxide nanoparticles or titanium dioxide bulk salt. The extract showed significant ameliorative role on the antioxidant system in response to elevated levels of titanium dioxide nanoparticles or titanium dioxide bulk salt-induced oxidative stress. It aided in the recovery of the antioxidant system as well as protective role in histological damages and some haematological parameters in the rat liver treated with titanium dioxide nanoparticles or titanium dioxide bulk salt.     

Association of sugar content QTL and PQL with physiological traits relevant to frost damage resistance in pea under field and controlled conditions

To increase yield in pea (Pisum sativum L.), autumn sowing would be preferable. Hence, frost tolerance of pea became a major trait of interest for breeders. In order to better understand the cold acclimation in pea, Champagne a frost tolerant line and Terese, a frost sensitive line, and their recombinant inbred lines (RIL) were studied. RIL frost tolerance was evaluated by a frost damage scale under field as well as controlled conditions. A quantitative trait loci (QTL) approach was used to identify chromosomal regions linked to frost tolerance. The detected QTL explained from 6.5 to 46.5% of the phenotypic variance. Amongst them, those located on linkage groups 5 and 6 were consistent with over all experiments, in field as well as in controlled environments. In order to improve the understanding of the frost tolerance mechanisms, several cold acclimation key characters such as concentration of sugars, electrolyte leakage, osmotic pressure, and activity of RuBisCO were assessed. Some of these physiological QTL colocalised with QTL for frost damage, in particular two raffinose QTL on LG5 and LG6 and one RuBisCO activity QTL on LG6, explaining 8.8 to 27.0% of the phenotypic variance. In addition, protein quantitative loci were mapped; some of them colocalised with frost damage and physiological QTL on LG5 and LG6, explaining 16.0–43.6% of the phenotypic variance. Raffinose metabolism and RuBisCO activity and its effect on photosynthesis might play a major role in cold acclimation of pea. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Integration of Experiments across Diverse Environments Identifies the Genetic Determinants of Variation in Sorghum bicolor Seed Element Composition

Seedling establishment and seed nutritional quality require the sequestration of sufficient element nutrients. The identification of genes and alleles that modify element content in the grains of cereals, including sorghum (Sorghum bicolor), is fundamental to developing breeding and selection methods aimed at increasing bioavailable element content and improving crop growth. We have developed a high-throughput work flow for the simultaneous measurement of multiple elements in sorghum seeds. We measured seed element levels in the genotyped Sorghum Association Panel, representing all major cultivated sorghum races from diverse geographic and climatic regions, and mapped alleles contributing to seed element variation across three environments by genome-wide association. We observed significant phenotypic and genetic correlation between several elements across multiple years and diverse environments. The power of combining high-precision measurements with genome-wide association was demonstrated by implementing rank transformation and a multilocus mixed model to map alleles controlling 20 element traits, identifying 255 loci affecting the sorghum seed ionome. Sequence similarity to genes characterized in previous studies identified likely causative genes for the accumulation of zinc, manganese, nickel, calcium, and cadmium in sorghum seeds. In addition to strong candidates for these five elements, we provide a list of candidate loci for several other elements. Our approach enabled the identification of single-nucleotide polymorphisms in strong linkage disequilibrium with causative polymorphisms that can be evaluated in targeted selection strategies for plant breeding and improvement.Sorghum (Sorghum bicolor) is a globally cultivated source of food, feed, and fiber. Contrasting needs for elemental nutrient accumulation limit crop yield and quality for sorghum marketed to different sectors. The seed-bearing reproductive organs, or panicles, in sorghum represent up to 30% of the total dry matter yield (Amaducci et al., 2004). Plant-based diets, in which grains compose the major food source, require the accumulation of bioavailable essential elements in the plant seeds. Currently, iron (Fe) and zinc (Zn) deficiencies negatively affect the health of over two billion people worldwide (World Health Organization, 2002). Increased bioavailable elemental nutrient content in the edible portions of sorghum for human and animal nutrition could ameliorate this nutritional crisis (Graham et al., 1999; World Health Organization, 2002). Additional global health benefits could be achieved by increasing magnesium (Mg), selenium (Se), calcium (Ca), and copper (Cu; White and Broadley, 2005) while reducing the concentration of toxic elements, including arsenic (As) and cadmium (Cd; Ma et al., 2008).Seed element accumulation results from interconnected biological processes, including element uptake by the roots, translocation and remobilization within the plant, and ultimately import, deposition, and assimilation/storage in the seeds. Element availability is further affected by the accumulation of metabolites in seeds (Vreugdenhil et al., 2004). High-throughput ionomic analysis, or concurrent measurement of multiple elements, allows for the quantitative and simultaneous measurement of an organism’s elemental composition, providing a snapshot of the functional state of an organism under different experimental conditions (Salt et al., 2008). Most studies of the plant ionome utilize inductively coupled plasma mass spectroscopy (ICP-MS). Briefly, inductively coupled plasma (ICP) functions to ionize the analyte into atoms, which are then detected by mass spectroscopy. Reference standards are used to identify and quantitate each element of interest in the sample. ICP-MS analysis can be accomplished in as little as 1 min per sample, which allows for high-throughput processing of thousands of samples (Salt et al., 2008). Previous studies have demonstrated that several elements, including Fe, manganese (Mn), Zn, cobalt (Co), and Cd, share mechanisms of accumulation (Yi and Guerinot, 1996; Vert et al., 2002; Connolly et al., 2003). Ionomic signatures derived from multiple elements also have been shown to better predict plant physiological status for some elements than the measure of the element’s concentration, including essential nutrients like Fe (Baxter et al., 2008). Holistically examining the ionome provides significant insights into the networks underlying ion homeostasis beyond single-element studies (Baxter and Dilkes, 2012).There are over 45,000 catalogued lines of sorghum at the U.S. Department of Agriculture Germplasm Resource Information Network. This diverse collection of sorghum germplasm contains genetic variation with undiscovered impact on seed element composition (Das et al., 1997). Mapping quantitative trait loci for seed element concentration has been successful in a number of species, including Arabidopsis (Arabidopsis thaliana; Vreugdenhil et al., 2004; Waters and Grusak, 2008; Buescher et al., 2010), rice (Oryza sativa; Norton et al., 2010; Zhang et al., 2014), wheat (Triticum aestivum; Shi et al., 2008; Peleg et al., 2009), and maize (Zea mays; Simić et al., 2012; Baxter et al., 2013, 2014). Genome-wide association (GWA) mapping is well suited for uncovering the genetic basis for complex traits, including seed element accumulation. One of the key strengths of association mapping is that a priori knowledge is not necessary to identify new loci associated with the trait of interest. Furthermore, a GWA mapping population is composed of lines that have undergone numerous recombination events, allowing for a narrower mapping interval. Previous GWA studies in maize (Tian et al., 2011), rice (Huang et al., 2010), and sorghum (Morris et al., 2013) have been successful in identifying the genetic basis for various agronomic traits. Here, we analyzed the seed ionome from a community-generated association panel to identify potential loci underlying seed element accumulation in sorghum.     

Natural variation in priming of basal resistance: from evolutionary origin to agricultural exploitation

Biotic stress has a major impact on the process of natural selection in plants. As plants have evolved under variable environmental conditions, they have acquired a diverse spectrum of defensive strategies against pathogens and herbivores. Genetic variation in the expression of plant defence offers valuable insights into the evolution of these strategies. The 'zigzag' model, which describes an ongoing arms race between inducible plant defences and their suppression by pathogens, is now a commonly accepted model of plant defence evolution. This review explores additional strategies by which plants have evolved to cope with biotic stress under different selective circumstances. Apart from interactions with plant-beneficial micro-organisms that can antagonize pathogens directly, plants have the ability to prime their immune system in response to selected environmental signals. This defence priming offers disease protection that is effective against a broad spectrum of virulent pathogens, as long as the augmented defence reaction is expressed before the invading pathogen has the opportunity to suppress host defences. Furthermore, priming has been shown to be a cost-efficient defence strategy under relatively hostile environmental conditions. Accordingly, it is possible that selected plant varieties have evolved a constitutively primed immune system to adapt to levels of disease pressure. Here, we examine this hypothesis further by evaluating the evidence for natural variation in the responsiveness of basal defence mechanisms, and discuss how this genetic variation can be exploited in breeding programmes to provide sustainable crop protection against pests and diseases.     

Influence of aluminium on neurotoxicity of lead in adult male albino rats

Influence of aluminium on neurotoxicity of lead was studied in male albino rats. Aluminium enhanced the net deposition of lead in brain. This was further substantiated by higher levels of malondialdehyde (MDA), and lower activities of acetylcholinesterase enzyme in the brain homogenates of the rats treated with both lead and aluminium as compared to those of rats treated with lead only. In lead plus aluminium treated animals, a significant neurological deficit was observed when the animals were subjected to rota-rod, traction performance (TP) and tail immersion tests.