Physiology and Genetics of Drought Tolerance in Cowpea and Winter Wheat

In the wake of rising temperatures, erratic rainfall, and declining ground water table, breeding for drought tolerance in food crops has become a top priority throughout the world. Phenotyping a large population of breeding lines for drought tolerance is time-consuming and often unreliable due to multiple possible mechanisms involved. In cowpea (Vigna unguiculata L. Walp), a box-screening method has been used to partition the confounding effects that shoot and root traits have on drought tolerance by restricting root growth and providing a homogeneous soil moisture environment across genotypes. Nonetheless, multiple mechanisms of shoot drought tolerance have been reported which further complicate phenotyping. In winter wheat (Triticum aestivum L.), canopy temperature depression (CTD) has been proposed as a good indicator of drought tolerance. The recent development of low-cost thermal imaging devices could enable high-throughput phenotyping of canopy temperature. While CTD can be an indicator of overall plant water status, it can be confounded by high stomatal resistance, which is another seemingly contradictory mechanism of drought tolerance. The objectives of this study were to explore the physiological basis and genetics of the two mechanisms of shoot drought tolerance previously reported in cowpea and to develop and evaluate a method of high-throughput phenotyping of drought tolerance in winter wheat using thermal imaging. In cowpea, a legume well known for its tight stomatal control, no differences in gas exchange between drought tolerant and susceptible genotypes were observed. A unifoliate stay-green trait was discovered that segregates as a single recessive gene. However, it did not correlate with trifoliate necrosis or overall drought tolerance. In winter wheat, CTD did not always correlate with yield under rainfed conditions. One drought-tolerant cultivar, in particular, had the hottest canopy temperature, possibly because it was able to conserve moisture by closing its stomata whereas another closely related drought-tolerant cultivar had the coolest canopy temperature. Therefore, it appears that no single method of phenotyping for drought tolerance can be broadly applied across all genotypes of a given species due to possible contrasting mechanisms of drought-tolerance and environmental differences

The Role of Maternal Smoking in Effect of Fetal Growth Restriction on Poor Scholastic Achievement in Elementary School

Fetal growth restriction and maternal smoking during pregnancy are independently implicated in lowering intellectual attainment in children. We hypothesized that only reduction of fetal growth that is attributable to extrinsic causes (e.g., maternal smoking) affects intellectual development of a child. Cross-sectional survey of 3,739 students in Nova Scotia (Canada) in 2003 was linked with the perinatal database, parental interviews on socio-demographic factors and the performance on standardized tests when primarily 11–12 years of age, thereby forming a retrospective cohort. Data was analyzed using hierarchical logistic regression with correction for clustering of children within schools. The risk of poor test result among children born small-for-gestational-age (SGA) to mothers who smoked was 29.4%, higher than in any other strata of maternal smoking and fetal growth. The adjusted odds ratio among SGA children born to mothers who smoked was the only one elevated compared to children who were not growth restricted and born to mothers who did not smoke (17.0%, OR = 1.46, 95% CI 1.02, 2.09). Other perinatal, maternal and socio-demographic factors did not alter this pattern of effect modification. Heterogeneity of etiology of fetal growth restriction should be consider in studies that address examine its impact on health over life course

Epileptogenic potential of mefloquine chemoprophylaxis: a pathogenic hypothesis

<p>Abstract</p> <p>Background</p> <p>Mefloquine has historically been considered safe and well-tolerated for long-term malaria chemoprophylaxis, but prescribing it requires careful attention in order to rule out contraindications to its use. Contraindications include a history of certain neurological conditions that might increase the risk of seizure and other adverse events. The precise pathophysiological mechanism by which mefloquine might predispose those with such a history to seizure remains unclear.</p> <p>Presentation of the hypothesis</p> <p>Studies have demonstrated that mefloquine at doses consistent with chemoprophylaxis accumulates at high levels in brain tissue, which results in altered neuronal calcium homeostasis, altered gap-junction functioning, and contributes to neuronal cell death. This paper reviews the scientific evidence associating mefloquine with alterations in neuronal function, and it suggests the novel hypothesis that among those with the prevalent EPM1 mutation, inherited and mefloquine-induced impairments in neuronal physiologic safeguards might increase risk of GABAergic seizure during mefloquine chemoprophylaxis.</p> <p>Testing and implications of the hypothesis</p> <p>Consistent with case reports of tonic-clonic seizures occurring during mefloquine chemoprophylaxis among those with family histories of epilepsy, it is proposed here that a new contraindication to mefloquine use be recognized for people with EPM1 mutation and for those with a personal history of myoclonus or ataxia, or a family history of degenerative neurologic disorder consistent with EPM1. Recommendations and directions for future research are presented.</p

The position of mefloquine as a 21st century malaria chemoprophylaxis

BACKGROUND: Malaria chemoprophylaxis prevents the occurrence of the symptoms of malaria. Travellers to high-risk Plasmodium falciparum endemic areas need an effective chemoprophylaxis. METHODS: A literature search to update the status of mefloquine as a malaria chemoprophylaxis. RESULTS: Except for clearly defined regions with multi-drug resistance, mefloquine is effective against the blood stages of all human malaria species, including the recently recognized fifth species, Plasmodium knowlesi. New data were found in the literature on the tolerarability of mefloquine and the use of this medication by groups at high risk of malaria. DISCUSSION: Use of mefloquine for pregnant women in the second and third trimester is sanctioned by the WHO and some authorities (CDC) allow the use of mefloquine even in the first trimester. Inadvertent pregnancy while using mefloquine is not considered grounds for pregnancy termination. Mefloquine chemoprophylaxis is allowed during breast-feeding. Studies show that mefloquine is a good option for other high-risk groups, such as long-term travellers, VFR travellers and families with small children. Despite a negative media perception, large pharmaco-epidemiological studies have shown that serious adverse events are rare. A recent US evaluation of serious events (hospitalization data) found no association between mefloquine prescriptions and serious adverse events across a wide range of outcomes including mental disorders and diseases of the nervous system. As part of an in-depth analysis of mefloquine tolerability, a potential trend for increased propensity for neuropsychiatric adverse events in women was identified in a number of published clinical studies. This trend is corroborated by several cohort studies that identified female sex and low body weight as risk factors. CONCLUSION: The choice of anti-malarial drug should be an evidence-based decision that considers the profile of the individual traveller and the risk of malaria. Mefloquine is an important, first-line anti-malarial drug but it is crucial for prescribers to screen medical histories and inform mefloquine users of potential adverse events. Careful prescribing and observance of contraindications are essential. For some indications, there is currently no replacement for mefloquine available or in the pipeline

Non-conventional sources of peptides presented by MHC class I

Effectiveness of immune surveillance of intracellular viruses and bacteria depends upon a functioning antigen presentation pathway that allows infected cells to reveal the presence of an intracellular pathogen. The antigen presentation pathway uses virtually all endogenous polypeptides as a source to produce antigenic peptides that are eventually chaperoned to the cell surface by MHC class I molecules. Intriguingly, MHC I molecules present peptides encoded not only in the primary open reading frames but also those encoded in alternate reading frames. Here, we review recent studies on the generation of cryptic pMHC I. We focus on the immunological significance of cryptic pMHC I, and the novel translational mechanisms that allow production of these antigenic peptides from unconventional sources

The HELLP syndrome: Clinical issues and management. A Review

<p>Abstract</p> <p>Background</p> <p>The HELLP syndrome is a serious complication in pregnancy characterized by haemolysis, elevated liver enzymes and low platelet count occurring in 0.5 to 0.9% of all pregnancies and in 10–20% of cases with severe preeclampsia. The present review highlights occurrence, diagnosis, complications, surveillance, corticosteroid treatment, mode of delivery and risk of recurrence.</p> <p>Methods</p> <p>Clinical reports and reviews published between 2000 and 2008 were screened using Pub Med and Cochrane databases.</p> <p>Results and conclusion</p> <p>About 70% of the cases develop before delivery, the majority between the 27th and 37th gestational weeks; the remainder within 48 hours after delivery. The HELLP syndrome may be complete or incomplete. In the Tennessee Classification System diagnostic criteria for HELLP are haemolysis with increased LDH (> 600 U/L), AST (≥ 70 U/L), and platelets < 100·10⁹/L. The Mississippi Triple-class HELLP System further classifies the disorder by the nadir platelet counts. The syndrome is a progressive condition and serious complications are frequent. Conservative treatment (≥ 48 hours) is controversial but may be considered in selected cases < 34 weeks' gestation. Delivery is indicated if the HELLP syndrome occurs after the 34th gestational week or the foetal and/or maternal conditions deteriorate. Vaginal delivery is preferable. If the cervix is unfavourable, it is reasonable to induce cervical ripening and then labour. In gestational ages between 24 and 34 weeks most authors prefer a single course of corticosteroid therapy for foetal lung maturation, either 2 doses of 12 mg betamethasone 24 hours apart or 6 mg or dexamethasone 12 hours apart before delivery. Standard corticosteroid treatment is, however, of uncertain clinical value in the maternal HELLP syndrome. High-dose treatment and repeated doses should be avoided for fear of long-term adverse effects on the foetal brain. Before 34 weeks' gestation, delivery should be performed if the maternal condition worsens or signs of intrauterine foetal distress occur. Blood pressure should be kept below 155/105 mmHg. Close surveillance of the mother should be continued for at least 48 hours after delivery.</p

Assessment of a panel of interleukin-8 reporter lung epithelial cell lines to monitor the pro-inflammatory response following zinc oxide nanoparticle exposure under different cell culture conditions

Stably transfected lung epithelial reporter cell lines pose an advantageous alternative to replace complex experimental techniques to monitor the pro-inflammatory response following nanoparticle (NP) exposure. Previously, reporter cell lines have been used under submerged culture conditions, however, their potential usefulness in combination with air-liquid interface (ALI) exposures is currently unknown. Therefore, the aim of the present study was to compare a panel of interleukin-8 promoter (pIL8)-reporter cell lines (i.e. green or red fluorescent protein (GFP, RFP), and luciferase (Luc)), originating from A549 lung epithelial type II-like cells cells, following NPs exposure under both submerged and ALI conditions. All cell lines were exposed to zinc oxide (ZnO) NPs at 0.6 and 6.2 μg/cm 2 for 3 and 16 hours under both submerged and ALI conditions. Following physicochemical characterization, the cytotoxic profile of the ZnO-NPs was determined for each exposure scenario. Expression of IL-8 from all cell types was analyzed at the promoter level and compared to the mRNA (qRT-PCR) and protein level (ELISA). In summary, each reporter cell line detected acute pro-inflammatory effects following ZnO exposure under each condition tested. The pIL8-Luc cell line was the most sensitive in terms of reporter signal strength and onset velocity following TNF-α treatment. Both pIL8-GFP and pIL8-RFP also showed a marked signal induction in response to TNF-α, although only after 16 hrs. In terms of ZnO-NP-induced cytotoxicity pIL8-RFP cells were the most affected, whilst the pIL8-Luc were found the least responsive. In conclusion, the use of fluorescence-based reporter cell lines can provide a useful tool in screening the pro-inflammatory response following NP exposure in both submerged and ALI cell cultures. The online version of this article (doi:10.1186/s12989-015-0104-6) contains supplementary material, which is available to authorized users