Determination of cardamonin using a chemiluminescent flow-injection method

A sensitive and selective flow injection chemiluminescence method for the determination of cardamonin over the range 1.0 x 10(-8) to 8.0 x 10(-6) g/mL is described. The method is based on the enhancement by cardamonin of the chemiluminescence of the reaction between cerium (IV) and rhodamine 6G in sulphuric acid medium. The optimised flow injection procedure yielded a detection limit for cardamonin of 8.8 x 10(-9) g/mL, whilst the relative standard deviations of intraday and inter-day precision were below 2.5%. The method has the advantages of high sensitivity and a wide linear range. It was successfully applied to the determination of cardamonin in Alpinia katsumadai Hayata. The mechanism of the chemiluminescence reaction is proposed.     

Carnivorous pitcher plant uses free radicals in the digestion of prey

A study of the involvement of free oxygen radicals in trapping and digestion of insects by carnivorous plants was the main goal of the present investigation. We showed that the generation of oxygen free radicals by pitcher fluid of Nepenthes is the first step of the digestion process, as seen by EPR spin trapping assay and gel-electrophoresis. The EPR spectrum of N. gracilis fluid in the presence of DMPO spin trap showed the superposition of the hydroxyl radical spin adduct signal and of the ascorbyl radical signal. Catalase addition decreased the generation of hydroxyl radicals showing that hydroxyl radicals are generated from hydrogen peroxide, which can be derived from superoxide radicals. Gel-electrophoresis data showed that myosin, an abundant protein component of insects, can be rapidly broken down by free radicals and protease inhibitors do not inhibit this process. Addition of myoglobin to the pitcher plant fluid decreased the concentration of detectable radicals. Based on these observations, we conclude that oxygen free radicals produced by the pitcher plant aid in the digestion of the insect prey.     

Isolation of Butyl 2,3‐Dihydroxybenzoate From Paenibacillus elgii HOA73 Against Fusarium oxysporum f.sp. Lycopersici

Here we report for the first time the isolation of butyl 2,3‐dihydroxybenzoate (B2,3DB) from the novel antagonistic bacterium Paenibacillus elgii HOA73 and its activity against Fusarium oxysporum f.sp. lycopersici (FOL). In this study, the bacterial strain P. elgii HOA73 was isolated from soil and identified via 16S rRNA gene sequence analysis. The isolate demonstrated significant antagonism towards several plant pathogens including FOL. Our results showed the bacterial culture filtrate of P. elgii HOA73 to be highly active, inhibiting 86.1% of the growth of FOL at 50% concentration. Similarly, the bacterial crude extract of P. elgii HOA73 at 2 mg significantly inhibited FOL growth by 72.5%. An antifungal compound was purified from the bacterial crude extract of P. elgii HOA73 through different chromatographic techniques and was identif‐ied as butyl 2,3‐dihydroxybenzoate (B2,3DB) based on nuclear magnetic resonance and liquid chromatography‐mass spectrometry analyses. B2,3DB displayed potent antifungal properties, inhibiting FOL growth by 83.2% when used at 0.6 mg. The minimum inhibitory concentration of B2,3DB to inhibit any visible mycelial growth of FOL was 32 μg ml^?1. All FOL conidia displayed an absence of germination or degradation when treated with 32 μg ml^?1 B2,3DB after 8 or 24 h, respectively. Therefore, our results clearly demonstrated B2,3DB, as well as P. elgii HOA73, as potential biological control agents for the management of FOL.     

In vitro induction of tetraploids in an interspecific hybrid of Calanthe (Calanthe discolor × Calanthe sieboldii) through colchicine and oryzalin treatments

Tetraploids were successfully produced from diploid seeds obtained through interspecific crossing between Calanthe discolor and Calanthe sieboldii by treating with colchicine or oryzalin. Colchicine was tested at concentrations of 0.05 and 0.1 % for 0, 3, or 7 days and oryzalin was tested at a concentration of 0.003 % for 1, 2, 4, and 7 days, and the ploidy of the seedlings was determined by flow cytometry. Tetraploids (4×) were obtained from the interspecific hybrid seeds treated with all colchicine and oryzalin concentrations. The most efficient condition for inducing tetraploids seemed to be treated with 0.003 % oryzalin for 1 or 2 days. Cytological and morphological evidence confirmed the results of flow cytometric analysis. The stomatal density and sizes of the tetraploid plants were significantly higher and larger than those of the diploid plants. Differences in leaf shape were found between the tetraploid and diploid plants under the same growing conditions: the leaves of the diploids were elongated and those of the tetraploids were round.     

Monochloramine Inhibits the Expression of E-selectin and Intercellular Adhesion Molecule-1 Induced by TNF-α Through the Suppression of NF-κB Activation in Human Endothelial Cells

Reactive oxygen species have various effects on the expression of cell adhesion molecules induced by pro-inflammatory cytokines, such as tumor necrosis factor &#102 (TNF- &#102 ). We studied the effects of monochloramine (NH 2 Cl), a physiological oxidant derived from activated neutrophils, on the TNF- &#102 -induced expression of e-selectin and intercellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells (HUVEC). HUVEC were pretreated with or without NH 2 Cl (20-90 &#119 M for 20 min), then stimulated with TNF- &#102 (10 ng/ml), and the expression of e-selectin and ICAM-1 was measured. Without NH 2 Cl, TNF- &#102 induced marked expression of e-selectin and ICAM-1. Pretreatment with NH 2 Cl resulted in a significant, but transient inhibition of the expression of adhesion molecules. Higher dose of NH 2 Cl showed more pronounced inhibition, and the inhibitory effect lasted for 8 h when 70 &#119 M of NH 2 Cl was added. TNF- &#102 stimulation also induced marked activation of nuclear factor &#115 B (NF- &#115 B). Notably, NH 2 Cl also inhibited this NF- &#115 B activation in a dose- and time-dependent manner, which was similar to the inhibition of e-selectin and ICAM-1 expression. In addition, I &#115 B- &#102 phosphorylation and degradation were also inhibited by NH 2 Cl pretreatment. These observations indicated that NH 2 Cl inhibited TNF- &#102 -induced expression of e-selectin and ICAM-1 through the inhibition of NF- &#115 B activation. We speculate that neutrophil-derived chloramines may have a regulatory role in the recruitment of leukocytes.     

Male voice pitch mediates the relationship between objective and perceived formidability

Acoustic signals function in intrasexual mating competition in a wide variety of species, including humans. The low voice pitch of human males has been proposed to represent an honest signal of formidability. Although voice pitch in men affects perceptions of size and dominance, it is relatively weakly associated with objective measures of formidability such as body size and strength. As a result, some authors have argued that low male voice pitch is not a valid signal of formidability but is deceptive and salient only because it hijacks a tendency to perceive lower frequency sounds as emanating from larger sources. In this paper, we consider theoretical and empirical issues associated with this perceptual exploitation hypothesis and ask whether male voice pitch transmits information about formidability. We utilize mediation models to investigate whether male voice pitch is an honest signal of formidability in data collected from university students in the U.S. (n = 231 male speakers, 565 male raters) and Canada (n = 74 male speakers, 108 female raters, 65 male raters). In both data sets, male voice pitch mediated the relationship between objective (measured by height) and perceived formidability. Collectively, these results indicate that men’s voice pitch transmits information about formidability from signaler to receiver.     

The Arabidopsis tail-anchored protein PEROXISOMAL AND MITOCHONDRIAL DIVISION FACTOR1 is involved in the morphogenesis and proliferation of peroxisomes and mitochondria

Peroxisomes and mitochondria are multifunctional eukaryotic organelles that are not only interconnected metabolically but also share proteins in division. Two evolutionarily conserved division factors, dynamin-related protein (DRP) and its organelle anchor FISSION1 (FIS1), mediate the fission of both peroxisomes and mitochondria. Here, we identified and characterized a plant-specific protein shared by these two types of organelles. The Arabidopsis thaliana PEROXISOMAL and MITOCHONDRIAL DIVISION FACTOR1 (PMD1) is a coiled-coil protein tethered to the membranes of peroxisomes and mitochondria by its C terminus. Null mutants of PMD1 contain enlarged peroxisomes and elongated mitochondria, and plants overexpressing PMD1 have an increased number of these organelles that are smaller in size and often aggregated. PMD1 lacks physical interaction with the known division proteins DRP3 and FIS1; it is also not required for DRP3's organelle targeting. Affinity purifications pulled down PMD1's homolog, PMD2, which exclusively targets to mitochondria and plays a specific role in mitochondrial morphogenesis. PMD1 and PMD2 can form homo- and heterocomplexes. Organelle targeting signals reside in the C termini of these proteins. Our results suggest that PMD1 facilitates peroxisomal and mitochondrial proliferation in a FIS1/DRP3-independent manner and that the homologous proteins PMD1 and PMD2 perform nonredundant functions in organelle morphogenesis.     

Three-dimensional culture and bioreactors for cellular therapies

A bioreactor is defined as a specifically designed vessel to facilitate the growth of organisms and cells through application of physical and/or electrical stimulus. When cells with therapeutic potential were first discovered, they were initially cultured and expanded in two-dimensional (2-D) culture vessels such as plates or T-flasks. However, it was soon discovered that bioreactors could be used to expand and maintain cultures more easily and efficiently. Since then, bioreactors have come to be accepted as an indispensable tool to advance cell and tissue culture further. A wide array of bioreactors has been developed to date, and in recent years businesses have started supplying bioreactors commercially. Bioreactors in the research arena range from stirred tank bioreactors for suspension culture to those with various mechanical actuators that can apply different fluidic and mechanical stresses to tissues and three-dimensional (3-D) scaffolds. As regenerative medicine gains more traction in the clinic, bioreactors for use with cellular therapies are being developed and marketed. While many of the simpler bioreactors are fit for purpose, others fail to satisfy the complex requirements of tissues in culture. We have examined the use of different types of bioreactors in regenerative medicine and evaluated the application of bioreactors in the realization of emerging cellular therapies.