Suspension cultures of castor bean (Ricinus communis L.) which have been treated with pectic fragment elicitor rapidly accumulate lignin as measured by derivatization with thioglycolic acid. The responsiveness of cultured cells to elicitor is dependent on the stage of culture growth. In 6-day (maximally responsive) cultures, increases in lignin are first evident 3 hours after addition of pectic fragment elicitor with maximal rates of lignin synthesis between 4 and 10 hours. The abundance of lignin in cultures after 12 hours of elicitor treatment is 10-to 20-fold higher than in untreated control cultures and can thereby account for as much as 2% of the dry cell weight. Only intermediate sizes of pectic oligomer are active as elicitors of lignin. Half-maximal accumulation of lignin occurs at 250 to 300 micrograms per milliliter of an optimal elicitor preparation with an average degree of polymerization of seven. We consider the synthesis of lignin in elicited cultures to be a mechanism of plant disease resistance which is induced by the elicitor. Plant peroxidases have been proposed to catalyze the last enzymatic steps in the biosynthesis of both lignin and hydrogen peroxide. Six extracellular isoenzymes of peroxidase (two anionic, designated Al and A2, and four cationic, designated C2, C3, C4, and C7) are detectable in healthy suspension cultures of castor bean by native gel electrophoresis. Treatment of cultures with elicitor causes substantial changes in the activity of four of these species (Al, C2, C3, and C7). Elicitor treatment also results in the appearance of three new peroxidase isoenzymes that are not readily detectable in healthy cultures (Cl, C5, and C6). Increases in the activities of these isoenzymes are concurrent with or slightly precede the accumulation of lignin in elicited 6-day cultures. By 12 hours after addition of elicitor, Cl becomes the most abundant extracellular isoperoxidase. The differential regulation of expression of peroxidase isoenzymes following elicitor treatment suggests that individual isoenzymes of peroxidase may have specific functional roles in the biosynthesis of disease-lignin.Resistance of plants to pathogens is frequently a result of the rapid establishment ofa localized 'hypersensitive response' by the plant at regions of attempted infection. There are

BackgroundSupport for early detection of lung cancer has emerged from the National Lung Screening Trial (NLST), in which low-dose computed tomography (LDCT) screening reduced lung cancer mortality by 20 % relative to chest x-ray. The US Preventive Services Task Force (USPSTF) recently recommended annual screening for the high-risk population, concluding that the benefits (life years gained) outweighed harms (false positive findings, abortive biopsy/surgery, radiation exposure). In making their recommendation, the USPSTF noted that the moderate net benefit of screening was dependent on the resolution of most false-positive results without invasive procedures. Circulating biomarkers may serve as a valuable adjunctive tool to imaging.ResultsWe developed a broad-based proteomics discovery program, integrating liquid chromatography/mass spectrometry (LC/MS) analyses of freshly resected lung tumor specimens (n = 13), lung cancer cell lines (n = 17), and conditioned media collected from tumor cell lines (n = 7). To enrich for biomarkers likely to be found at elevated levels in the peripheral circulation of lung cancer patients, proteins were prioritized based on predicted subcellular localization (secreted, cell-membrane associated) and differential expression in disease samples. 179 candidate biomarkers were identified. Several markers selected for further validation showed elevated levels in serum collected from subjects with stage I NSCLC (n = 94), relative to healthy smoker controls (n = 189). An 8-marker model was developed (TFPI, MDK, OPN, MMP2, TIMP1, CEA, CYFRA 21–1, SCC) which accurately distinguished subjects with lung cancer (n = 50) from high risk smokers (n = 50) in an independent validation study (AUC = 0.775).ConclusionsIntegrating biomarker discovery from multiple sample types (fresh tissue, cell lines and conditioned medium) has resulted in a diverse repertoire of candidate biomarkers. This unique collection of biomarkers may have clinical utility in lung cancer detection and diagnoses.Electronic supplementary materialThe online version of this article (doi:10.1186/s12014-015-9090-9) contains supplementary material, which is available to authorized users.

castor bean plant as a phytoalexin (18). A number of the biochemical characteristics of casbene biosynthesis have been elucidated (26).Substances which trigger the production of phytoalexins in higher plants are termed elicitors. A wide variety of fungal molecules, including polysaccharide wall components, polypeptides, glycoproteins and lipids, have been implicated as elicitors (25). Two lines of investigation have shown that fungal enzymes can also act as elicitors. Swinburne (22,23) has implicated a fungal proteinase as an elicitor of benzoic acid production in infected apple fruit. In addition, recent work in our laboratory (11,12) has shown that homogeneous a-1,4-endopolygalacturonase from culture filtrates of the fungus Rhizopus stolonifer elicits casbene synthetase activity in castor bean (R communis L.) seedlings. In both cases, heat-treatment of the enzyme preparations leads to equivalent losses of both enzymic activity and elicitor ability. This suggests that the elicitor abilities of these enzymes may be dependent on their catalytic activities.The work described in this paper demonstrates that pectic cell wall fragments released from particulate fractions of castor bean seedling homogenates through the action of R stolonifer endopolygalacturonase possess casbene synthetase elicitor activity and supports a model in which these elicitor fragments serve as obligate intermediates in the process of elicitation by the enzyme in vivo.Many species of higher plants have been shown to produce antifungal compounds known as phytoalexins (4,6,10). The presence of low or undetectable levels of phytoalexins in healthy plant tissues and the greatly increased accumulation of these substances in the region of fungal infection are distinctive features of phytoalexin production. Because of these characteristics and their general toxicities for a broad range of fungi, phytoalexins are believed to play a defensive role against invasion of the plant by fungal predators.Casbene is one of the five cyclic diterpene hydrocarbons produced from GGPP2 in cell-free extracts of young seedlings of the castor bean (Ricinus communis L.) (14,15 Figure 1. At the lower concentrations of elicitor, the amount of casbene synthetase activity follows a nearly linear relationship with the amount of elicitor tested. Higher levels of elicitor, however, saturate the response. The amount of EPGase tested in elicitor bioassays was usually between 0.2 and 0.3 units in order to produce responses which were in the approximately linear region of the dose response curve.Synthesis of Radiolabeled Geranylgeranyl Pyropbosphate. 4,4'-[3H]Geranylgeraniol (10.0 mCi/mmol) was synthesized from farnesylacetone in a manner similar to that described by Upper andWest (24) as later modified by Simcox (17). The tritium label was introduced into farnesylacetone by refluxing a solution of famesylacetone and tritiated water in dioxane for 40 h. A small amount of NaOH was added to the mixture prior to reflux to catalyze the exchange of hydrogens bound to carbons alpha to...

Scholars have long observed that presidential communication about a marginalized group can help shape that group's reality. Yet most analyses of such communication focus on a relatively small number of texts, making it difficult to identify important changes over time and analyze factors that might explain those changes. The present study proposes an analytic framework that specifies 4 measurable parameters of presidential communication about marginalized groups, as well as 4 explanatory factors. We use this framework to analyze the census of presidents' formal communications about the LGBT community. Results highlight presidents' limited communicative engagement with the LGBT community and the roles that political party, rhetorical context, public opinion, and sociocultural touchstones play in explaining presidential communication about this important group.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe pressure and temperature regime of the shallow sedimentary section in the Deepwater Gulf of Mexico is conducive for the accumulation of gas hydrates. However, public information is limited regarding observation of in-situ hydrates during deepwater drilling operations. This paper documents drilling observations of possible gas hydrate dissociation from a well in the Deepwater Gulf of Mexico and explains how gas risk associated with potential in-situ hydrate was assessed during planning of subsequent appraisal and development activities. The paper contributes to industry knowledge of how in-situ hydrates are recognized during drilling and presents techniques for predicting hydrate-related risks during shallow hazards assessment.