Quantification of hydrogen peroxide in plant tissues using Amplex Red.

Reactive oxygen species (ROS) are by-products of photosynthesis and respiration in plant tissues. Abiotic and biotic stressors also induce the production and temporary accumulation of ROS in plants, including hydrogen peroxide (H2O2), whereby they can act as secondary messengers/chemical mediators in plant defense signaling and lead to programmed cell death. H2O2 acts as a hub for critical information flow in plants. Despite such key roles in fundamental cellular processes, reliable determination of H2O2 levels in plant tissues is hard to achieve. We optimized an Amplex Red-based quantitation method for H2O2 estimation from plant tissue lysate. The standard limit of detection and quantitation was determined as 6 and 18picomol respectively. In this study we also quantified constitutive and/or induced levels of H2O2 in three model plants, Pinus nigra (Austrian pine), Oryza sativa (rice), and Arabidopsis thaliana. Overall, assay sensitivity was in the nmolg-1 FW range. Commonly used additives for H2O2 extraction such as activated charcoal, ammonium sulfate, perchloric acid, polyvinylpolypyrrolidone, and trichloroacetic acid either degraded H2O2 directly or interfered with the Amplex Red assay. Finally, We measured stability of Amplex Red working solution over one month of storage at -80°C and found it to be significantly stable over time. With appropriate modifications, this optimized method should be applicable to any plant tissue.

Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability.

A situated practice of ethics for participatory visual and digital methods in public health research and practice: a focus on digital storytelling.

This article explores ethical considerations related to participatory visual and digital methods for public health research and practice, through the lens of an approach known as "digital storytelling." We begin by briefly describing the digital storytelling process and its applications to public health research and practice. Next, we explore 6 common challenges: fuzzy boundaries, recruitment and consent to participate, power of shaping, representation and harm, confidentiality, and release of materials. We discuss their complexities and offer some considerations for ethical practice. We hope this article serves as a catalyst for expanded dialogue about the need for high standards of integrity and a situated practice of ethics wherein researchers and practitioners reflexively consider ethical decision-making as part of the ongoing work of public health.

Pediatric combined heart-liver transplantation performed en bloc: a single-center experience.

Pediatric CHLT is rarely performed in transplant centers and even fewer are performed en bloc. In the hands of an experienced surgeon with the appropriate patient selection, CHLT performed en bloc may have several operative and immunologic benefits, thereby resulting in improved outcomes for the transplant recipient. A single-institutional, retrospective review from 1/1/06 to 12/31/10 was conducted. Three pediatric patients with end-stage heart and liver disease who were considered low immunologic risk were included. All were managed by the same surgeon with a herein-described CHLT donor and recipient operation. Data were collected on patient and graft survival, rejection episodes, infectious complications, operative time, intraoperative transfusion requirements, and immunosuppression regimens. One-yr patient and graft survival rates were 100%. No patients experienced antibody-mediated or cell-mediated rejection. No patients had postoperative infections, and all patients were free of opportunistic infections at one-yr post-transplant. All patients were maintained safely on steroid-free immunosuppression. There were no intraoperative complications. In pediatric end-stage heart and liver disease patients with low immunologic risk, it is reasonable to proceed with en bloc CHLT so long as there is an experienced surgeon to perform the case. This offers operative and immunologic advantages to the recipient while maintaining equivalent, if not improved, recipient and graft outcomes.

The Stamp-in-Safety programme, an intervention to promote better supervision of children on childcare centre playgrounds: an evaluation in an urban setting.

Using a non-equivalent control group design, this report evaluated a previously studied behavioural intervention, the Stamp-in-Safety programme, which is designed to reduce the injury risk for young children on playgrounds at childcare centres by increasing the quality of adult supervision and rewarding children for safe play. In an urban, commercial childcare centre, 71 children aged 3-5 years and 15 teachers participated. Primary outcome measures were teacher verbalisations (warnings, explanations, redirects), teacher location (core, outskirt, or fringe of playground), child risk-taking behaviours (using equipment appropriately) and the number of injuries on the playground. Analyses revealed that the intervention had a modest positive effect in promoting safer teacher and child playground behaviours. This study reaffirms previous results that the Stamp-in-Safety programme is an effective method to decrease the risk of playground injuries at childcare centres.

Characterization of protein changes associated with sugar beet (Beta vulgaris) resistance and susceptibility to Fusarium oxysporum.

Fusarium oxysporum (F-19) is a serious threat to sugar beet. Resistance exists, but the basis for resistance and disease is unknown. Protein extracts from sugar beet genotypes C1200.XH024 (resistant, R) and Fus7 (susceptible, S) were analyzed by multidimensional liquid chromatography at 2 and 5 days postinoculation (dpi) and compared to mock-inoculated controls. One hundred twenty-one (R) and 73 (S) protein peaks were induced/repressed by F-19, approximately 12 (R) and 8% (S) of the total proteome detected. Temporal protein regulation occurred within and between each genotype, indicating that the timing of expression may be important for resistance. Thirty-one (R) and 48 (S) of the differentially expressed peaks were identified using matrix-assisted laser desorption-ionization with tandem time-of-flight mass spectrometry; others were below detection level. Comparison between the two genotypes uncovered R- and S-specific proteins with potential roles in resistance and disease development, respectively. Use of these proteins to select for new sources of resistance and to develop novel disease control strategies is discussed.

Influence of glyphosate on Rhizoctonia and Fusarium root rot in sugar beet.

This study tests the effect of glyphosate application on disease severity in glyphosate-resistant sugar beet, and examines whether the increase in disease is fungal or plant mediated. In greenhouse studies of glyphosate-resistant sugar beet, increased disease severity was observed following glyphosate application and inoculation with certain isolates of Rhizoctonia solani Kuhn and Fusarium oxysporum Schlecht. f. sp. betae Snyd. & Hans. Significant increases in disease severity were noted for R. solani AG-2-2 isolate R-9 and moderately virulent F. oxysporum isolate FOB13 on both cultivars tested, regardless of the duration between glyphosate application and pathogen challenge, but not with highly virulent F. oxysporum isolate F-19 or an isolate of R. solani AG-4. The increase in disease does not appear to be fungal mediated, since in vitro studies showed no positive impact of glyphosate on fungal growth or overwintering structure production or germination for either pathogen. Studies of glyphosate impact on sugar beet physiology showed that shikimic acid accumulation is tissue specific and the rate of accumulation is greatly reduced in resistant cultivars when compared with a susceptible cultivar. The results indicate that precautions need to be taken when certain soil-borne diseases are present if weed management for sugar beet is to include post-emergence glyphosate treatments.

A single institution experience in compliance with universal screening for Lynch syndrome in colorectal cancer.

BACKGROUND: Detection of Lynch syndrome has the potential to reduce morbidity and mortality among patients and their family members due to beneficial screening and treatment options. Several institutions have begun to adopt universal rather than risk-stratified screening protocols, but the lack of 100 % compliance rates requires identification of system-level interventions to improve screening practices. OBJECTIVE: We aimed to identify patient, tumor, and system factors associated with lack of screening and identify system-based interventions to improve Lynch syndrome screening. DESIGN AND SETTINGS: This study is a retrospective analysis of Lynch syndrome screening among colorectal cancer patients undergoing surgery in a single healthcare system. PATIENTS: Two hundred and sixty-two patients who underwent surgery for colorectal cancer were studied. MAIN OUTCOME MEASURES: Rate of Lynch syndrome screening. RESULTS: We identified that 75 % of the total cohort was screened for Lynch syndrome. Of patients under the age of 50, 78 % percent were screened. Lower screening rates were found among patients with complete pathologic tumor response and lower pathologic stage of tumor. Higher screening rates were found at the academic hospital and with colorectal surgeons. In multivariable logistic regression analysis, lower screening rates were associated with community hospital location (OR, 0.22; 95 % CI, 0.08-0.56). LIMITATIONS: Results may not be generalizable to different hospital settings. CONCLUSIONS: Several potential system-level interventions were identified to improve screening rates including an emphasis on improved provider communication.

Playground safety and quality in chicago.

OBJECTIVES: To assess playground safety and quality in Chicago, Illinois, identify disparities in access, and use the data to inform collaborative improvement. METHODS: A cross-sectional survey of public park playgrounds in Chicago, Illinois, was conducted in 2009, 2010, and 2011 by using the National Program for Playground Safety Standardized Survey. All playgrounds were surveyed in 2009 and 2010; those that failed in 2010 were resurveyed in 2011. Playgrounds were assessed in 4 main categories: age-appropriate design, fall surfacing, equipment maintenance, and physical environment. Safety scores were generated from the assessment. Geographic information system mapping provided a visual description of the playground pass/fail rate based on neighborhood, child population, race/ethnicity, and poverty level. RESULTS: Of the ∼500 playgrounds, 467 were assessed in 2009, and 459 were assessed in 2010. In 2009, half of all playgrounds (55%) and in 2010, nearly two-thirds (61%) earned scores consistent with safe playgrounds (P < .001). Playgrounds scored poorest in fall surfacing and equipment maintenance. Geographic information system mapping showed neighborhoods with a higher percentage of children and impoverished families had fewer playgrounds and more failing playgrounds. In 2011, 154 (85%) of the playgrounds that failed in 2010 were surveyed. The mean playground score among failing playgrounds improved significantly between 2010 (61%) and 2011 (67%, P < .001). CONCLUSIONS: Since the playground improvement initiative began in 2009, considerable progress has been made in the safety scores, although access to high-quality playgrounds varies by neighborhood. Many failing playgrounds can be brought up to standard with improvement in fall surfacing and equipment maintenance.

Nutritional attributes of ash (Fraxinus spp.) outer bark and phloem and their relationships to resistance against the emerald ash borer.

The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an alien, invasive wood-boring insect that is responsible for killing millions of ash trees since its discovery in North America in 2002. All North American ash species (Fraxinus spp.) that EAB has encountered have shown various degrees of susceptibility, while Manchurian ash (Fraxinus mandshurica Ruprecht), which shares a co-evolutionary history with this insect, is resistant. Recent studies have looked into constitutive resistance mechanisms in Manchurian ash, concentrating on the secondary phloem, which is the feeding substrate for the insect. In addition to specialized metabolism and defense-related components, primary metabolites and nutritional summaries can also be important to understand the feeding behavior of insect herbivores. Here, we have compared the nutritional characteristics (water content, total protein, free amino acids, total soluble sugars and starch, percent carbon and nitrogen, and macro- and micronutrients) of outer bark and phloem from black, green, white and Manchurian ash to determine their relevance to resistance or susceptibility to EAB. Water content and concentrations of Al, Ba, Cu, Fe, K, Li, tryptophan and an unknown compound were found to separate black and Manchurian ash from green and white ash in a principal component analysis (PCA), confirming their phylogenetic placements into two distinct clades. The traits that distinguished Manchurian ash from black ash in the PCA were water content and concentrations of total soluble sugars, histidine, lysine, methionine, ornithine, proline, sarcosine, tyramine, tyrosol, Al, Fe, K, Na, V and an unknown compound. However, only proline, tyramine and tyrosol were significantly different, and higher, in Manchurian ash than in black ash.