Gut–organ axis: a microbial outreach and networking

Human gut microbiota (GM) includes a complex and dynamic population of microorganisms that are crucial for well-being and survival of the organism. It has been reported as diverse and relatively stable with shared core microbiota, including Bacteroidetes and Firmicutes as the major dominants. They are the key regulators of body homeostasis, involving both intestinal and extra-intestinal effects by influencing many physiological functions such as metabolism, maintenance of barrier homeostasis, inflammation and hematopoiesis. Any alteration in GM community structures not only trigger gut disorders but also influence other organs and cause associated diseases. In recent past, the GM has been defined as a ‘vital organ’ with its involvement with other organs; thus, establishing a link or a bi- or multidirectional communication axis between the organs via neural, endocrine, immune, humoral and metabolic pathways. Alterations in GM have been linked to several diseases known to humans; although the exact interaction mechanism between the gut and the organs is yet to be defined. In this review, the bidirectional relationship between the gut and the vital human organs was envisaged and discussed under several headings. Furthermore, several disease symptoms were also revisited to redefine the communication network between the gut microbes and the associated organs.     

Variation in essential oil composition of Leonotis leonurus,an important medicinal plant in South Africa

Leonotis leonurus widely used by traditional healers in southern Africa for treatment of various ailments, is well known for its reported psychoactive properties. The present study was undertaken to investigate the variation in essential oil composition between geographically distinct populations of L. leonurus in South Africa using gas chromatography. Plant material (n = 50) was collected from three provinces of South Africa. Essential oils of the aerial parts were obtained by hydrodistillation and analysed using one and two dimensional gas chromatography. Twenty-six compounds accounted for more than 80% of the total composition of the oil. Eight major constituents in the oil, representing about 50% of the total oil composition, were identified by both GC–MS–FID and GCxGC–ToF–MS. These major compounds were trans-β-ocimene (0.1–5.0%), cis-β-ocimene (0.1–31.5%), β-caryophyllene (0.3–15.0%), caryophyllene oxide (0.1–5.0%), α-humulene (0.4–18.2%), γ-elemene (0.4–10.6%), α-cubebene (0.2–12.0%) and germacrene D (0.1–22.1%). Marked similarities exist in the essential oil composition between populations; differences are mostly quantitative when determined by GC–MS–FID, while GCxGC–ToF–MS data reveals both quantitative and qualitative differences.Untargeted multivariate analysis was performed using SIMCA-P + 14.0 PCA and OPLS-DA methods, identifying two distinct clusters, inland and coastal populations.     

Determination of a peptide-doxorubicin,prostate-specific antigen activated prodrug,and its active metabolites in human plasma using high-performance liquid chromatography with fluorescence detection. Stabilization of the peptide prodrug with EDTA

A method for the determination of I, a peptide-doxorubicin conjugate that was evaluated for the treatment of prostate cancer, and two of its active metabolites, doxorubicin and leucine-doxorubicin is described. Blood samples were chilled immediately after being drawn in order to prevent ex vivo entry of the metabolites into red blood cells. EDTA (10 mg/ml final concentration) was used to prevent plasma-mediated degradation of the peptide portion of the prodrug. After the addition of internal standard, plasma was prepared for analysis using a C-8 solid-phase extraction column. In order to overcome secondary ionic interactions with the silica-based extraction column, the analytes were eluted with ammonium hydroxide in methanol. The extracts were evaporated to dryness, reconstituted, and assayed by step change, gradient, reverse phase HPLC with fluorescence detection. Two interfering metabolites found in post dose plasma were chromatographically separated by an adjustment of the mobile phase pH. The within-day reproducibility of the doxorubicin and leucine-doxorubicin chromatographic retention times was improved by a brief washing of the analytical column with 90% acetonitrile after each injection. The range of the standard curve was 12.5-1250 ng/ml for doxorubicin and 25-2500 ng/ml for I and leucine-doxorubicin.     

Asymmetric reduction of (4S)-(+)-carvone catalyzed by baker's yeast: A green method for monitoring the conversion based on liquid–liquid–liquid microextraction with polypropylene hollow fiber membranes

The α,β-unsaturated carbonyl compound (4S)-(+)-carvone was selectively reduced to (1R,2R,4S)-iso-dihydrocarveol using baker's yeasts. The conversion of the bioreduction reaction was monitored using a green hollow-fiber liquid–liquid–liquid microextraction (HF-LLLME) technique. Several parameters which may affect the bioreduction of (4S)-(+)-carvone, such as temperature, time, substrate/enzyme ratio, pH and buffer concentration, were evaluated. The effect of some additives, such as trehalose, DMSO and the ionic liquid [BMIm][PF₆], was also studied. The (1R,2R,4S)-iso-dihydrocarveol was recovered with 52.7% conversion and diastereoisomeric excess >99% after 48 h of reaction at 40 °C in an aqueous monophasic system, with 0.1 mol L^?1 buffer concentration (pH 7.5) and a substrate/yeast cell mass ratio of 8.0 mg g^?1. The HF-LLLME microextraction technique allowed the optimization of the reaction with a reduction of over 99.5% in relation to the use of organic solvents.     

Biological pest control by investing crops in pests

We propose a biological pest control system that invests part of a crop in feeding a pest in a cage. The fed pest maintains a predator that attacks the pest in the target area (i.e., the area for storing or growing crops). The fed pest cannot leave the cage nor the target pest cannot enter the cage. The predator, however, can freely attack both the fed and target pests in the target area. By introducing a refuge in the cage against the predator for the fed pest, the fed pest and predator may be stably sustained. In this study, we analyzed the potential performance of this system by modeling the population dynamics of the target pest, fed pest, and predator as differential equations. First, we show analytically that the target pest can be suppressed at extremely low abundance by adjusting both refuge efficiency and crop investment. Second, we show numerically that crop damage by the pest may be effectively suppressed by investing only small amounts of the crop. Third, we show numerically that the magnitude of required crop investment can be estimated by an index comprising of the predator's searching cost for prey and the relative growth efficiency of the predator with respect to the pest. Even if the system structure is changed or its population dynamics is modeled based on host–parasitoid interactions, crop damage can be suppressed effectively by small amounts of crop investment.     

Nonorthogonal tight-binding model with H–C–N–O parameterisation

A parametric nonorthogonal tight-binding model (NTBM1) with the set of parameters for H–C–N–O systems is presented. This model compares well with widely used semi-empirical AM1 and PM3/PM7 models but contains less fitting parameters per atom. All NTBM1 parameters are derived based on a criterion of the best agreement between the calculated and experimental values of bond lengths, valence angles and binding energies for various H–C–N–O molecules. Results for more than 200 chemical compounds are reported. Parameters are currently available for hydrogen, carbon, nitrogen, oxygen atoms and corresponding interatomic interactions. The model has a good transferability and can be used for both relaxation of large molecular systems (e.g., high-molecular compounds or covalent cluster complexes) and long-timescale molecular dynamics simulation (e.g., modelling of thermal decomposition processes). The program package based on this model is available for download at no cost from http://ntbm.info.     

Synthesis of Arg–Gly–Asp (RGD) Sequence Conjugated Thermo-Reversible Gel via the PEG Spacer Arm as an Extracellular Matrix for a Pheochromocytoma Cell (PC12) Culture

Adhesion molecules composed of Gly–Arg–Gly–Asp–Ser (GRGDS) peptides and cell recognition ligands were inculcated into thermo-reversible hydrogel composed of N-isopropylacrylamide, with a small amount of succinyl poly(ethylene glycol) (PEG) acrylate (MW 3400) used as a biomimetic extracellular matrix (ECM). The GRGDS-containing p(NiPAAm-co-PEG) copolymer gel was studied in vitro for its ability to promote cell spreading and to increase the viability of cells by introducing PEG spacers. Hydrogel lacking the adhesion molecules proved to be a poor ECM for adhesion, permitting only a 20% spread of the seeded cells after 10 days. When PEG spacer arms, immobilized by a peptide linkage, had been integrated into the hydrogel, conjugation of RGD promoted cell spread by 600% in a 10-day trial. In addition, in a serum-free medium, only GRGDS peptides conjugated with the spacer arm were able to promote cell spread. In terms of the cell viability, GRGDS peptides conjugated with the PEG-carrying copolymer gel specifically mediated cell spread. This result supports the theory that specific recognition is the result of interaction between the integrin families on the fibroblast, and the RGD sequence on the p(NiPAAm-co-PEG) copolymer gel.     

Discovery of new low-molecular-weight p53–Mdmx disruptors and their anti-cancer activities

Although several p53–Mdm2-binding disruptors have been identified to date, few studies have been published on p53–Mdmx-interaction inhibitors. In the present study, we demonstrated that o-aminothiophenol derivatives with molecular weights of 200–300 selectively inhibited the p53–Mdmx interaction. S-2-Isobutyramidophenyl 2-methylpropanethioate (K-178) (1c) activated p53, up-regulated the expression of its downstream genes such as p21 and Mdm2, and preferentially inhibited the growth of cancer cells with wild-type p53 over those with mutant p53. Furthermore, we found that the S-isobutyryl-deprotected forms 1b and 3b of 1c and S-2-benzamidophenyl 2-methylpropanethioate (K-181) (3c) preferentially inhibited the p53–Mdmx interaction over the p53–Mdm2 interaction, respectively, by using a Flag-p53 and glutathione S-transferase (GST)-fused protein complex (Mdm2, Mdmx, DAPK1, or PPID). In addition, the interaction of p53 with Mdmx was lost by replacing a sulfur atom with an oxygen atom in 1b and 1c. These results suggest that sulfides such as 1b, 3b, 4b, and 5b interfere with the binding of p53–Mdmx, resulting in the dissociation of the two proteins. Furthermore, the results of oral administration experiments using xenografts in nude mice indicated that 1c reduced the volume of tumor masses to 49.0% and 36.6% that of the control at 100 mg/kg and 150 mg/kg, respectively, in 40 days.     

Identification of a radical formed in the reaction mixtures of oxidized phosphatidylcholine with ferrous ions using HPLC–ESR and HPLC–ESR–MS

Identification of free radicals was performed for the reaction mixtures of autoxidized 1,2-dilinoleoylphosphatidylcholine (DLPC) with ferrous ions (or DLPC hydroperoxide with ferrous ions) and of DLPC with soybean lipoxygenase using electron spin resonance (ESR), high performance liquid chromatography (HPLC)–ESR and HPLC–ESR–mass spectrometry (MS) combined use of spin trapping technique. ESR measurements of the reaction mixtures showed prominent signals with hyperfine coupling constants (a^N=1.58?mT and a^Hβ=0.26?mT). Outstanding peaks with almost same retention times (autoxidized DLPC, 36.9?min; DLPC hydroperoxide, 35.0?min; DLPC with soybean lipoxygenase, 37.1?min) were observed on the elution profile of the HPLC–ESR analyses of the reaction mixtures. HPLC–ESR–MS analyses of the reaction mixtures gave two ions at m/z 266 and 179, suggesting that 4-POBN/pentyl radical adduct forms in these reaction mixtures.     

Tsetse flies,trypanosomes, humans and animals: what is proteomics revealing about their crosstalks?

Human and animal African trypanosomoses, or sleeping sickness and Nagana, are neglected vector-borne parasitic diseases caused by protozoa belonging to the Trypanosoma genus. Advances in proteomics offer new tools to better understand host–vector–parasite crosstalks occurring during the complex parasitic developmental cycle, and to determine the outcome of both transmission and infection. In this review, we summarize proteomics studies performed on African trypanosomes and on the interactions with their vector and mammalian hosts. We discuss the contributions and pitfalls of using diverse proteomics tools, and argue about the interest of pathogenoproteomics, both to generate advances in basic research on the best knowledge and understanding of host–vector–pathogen interactions, and to lead to the concrete development of new tools to improve diagnosis and treatment management of trypanosomoses in the near future.     

An acetylcholinesterase biosensor based on graphene–gold nanocomposite and calcined layered double hydroxide

In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu–Mg–Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene–gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene–gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150 μg/L. The detection limit for chlorpyrifos was 0.05 μg/L.     

Centrally administered N-terminal fragments of ACTH (1-10, 4-10, 4-9) display convulsant properties in rabbits

Electroencephalographic and behavioral effects of the following ACTH fragments: 1-4, 4-9, 4-11, 1-10, 4-10, 1-13, 1-17 and 1-24 were studied in rabbits. Sequences 4-9, 1-10 and 4-10 displayed some epileptic properties, i.e., they induced epileptic seizures (only electrographic or also behavioral) or increased hippocampal spiking. The 4-9 sequence seemed to be the common sequence responsible for these proconvulsant effects. The possible involvement of the enkephalinergic system is discussed.     

Protective effect of Zizyphus lotus jujube fruits against cypermethrin-induced oxidative stress and neurotoxicity in mice

Context: Cypermethrin (CYP) is a synthetic pyrethroid insecticide used worldwide in agriculture, home pest control. The toxicity of CYP is well studied in many organisms.

Objective: The aim of present study was to investigate the protective effect of Zizyphus lotus (Zizyp) fruit against neurotoxicity and oxidative stress induced by CYP in mice.

Materials and methods: Mice were divided into four groups of six each: groups I and II were used as control and CYP control (20?mg/kg body weight). While, groups III was orally treated with Zizyphus lotus fruit (5?g/kg body weight) plus CYP (20?mg/kg body weight) for 18?days. Furthermore, HPLC–ESI–MS–MS (Q-Tof) and GC–MS were used to identify the compounds fraction.

Results: Antioxidant enzyme catalase (CAT), neurotoxicity enzyme acetylcholinesterase (AChE) activities and hydrogen peroxide (H₂O₂)_, malondialdehyde (MDA) levels were determined in the liver, kidney and heart. CYP caused decreased CAT activity, inhibition of AChE activity and increased the levels of H₂O₂ and MDA in heart, liver and kidney.

Conclusion: Our results indicate that Zizyp fruit is markedly effective in protecting mice against CYP-induced biochemical changes. This protection may be due to its antioxidant property and scavenging ability against active free radicals.     

Sequence,Packing and Nanometer Scale Structure in STM Images of Nucleic Acids Under Water

Abstract

Scanning tunneling microscope (STM) images of random-sequence nucleic acid polymers under water show internal structure which depends strongly on the packing density of the polymer. Images of dense aggregates have a semicrystalline order with the individual polymers adopting simple periodic structures. Loose aggregates (or isolated molecules) show structural variability with considerable local bending and curving on a nanometer scale. It is not clear to what extent this structure is induced by the operation of the microscope. In order to investigate the possibility that the structure is sequence directed, we have imaged various DNA and RNA polymers at low packing densities. We present results here for random sequence DNA, poly(dAT) · poly(dAT), poly(dA) · poly(dT), poly(dCG) · poly(dCG) and for random sequence RNA and poly(U). In contrast to loose aggregates of the random sequence material, the homopolymers show few sharp bends. Furthermore, the homopolymers appear to yield characteristic backbone patterns, usually at resolutions in excess of that obtained with random sequence polymers. The random sequence polymers show much more evidence of image distortion due to tip-molecule interactions, suggesting that they are, on average, mechanically less stable in the STM tunnel-gap than the homopolymers. Thus, while some of the structure observed in STM images is a consequence of tip-molecule interactions, it is related to sequence-directed properties of the polymer.     

Reliability and validity of the Korean version of Morningness–Eveningness Questionnaire in adults aged 20–39 years

Morningness–Eveningness (ME) can be defined by the difference in individual diurnal preference observed from general behavioral patterns including sleep habits. The Horne & Östberg Morningness–Eveningness Questionnaire (MEQ) has been used for classifying ME types. We examined the reliability of a Korean version of the MEQ (Korean MEQ) and verified its validity by comparing responses on the Korean MEQ to objectively-recorded sleep–wake rhythms. After translating and back translating the MEQ from English into Korean, we examined the internal consistency of 19 items of the Korean MEQ in 91 subjects, and the test–retest reliability in 21 subjects who took the Korean MEQ twice, 4 weeks apart. The Korean MEQ was then administered to 1022 young adult subjects. A subset of 46 morning, neither, and evening type subjects took part in a validation study in which their rest-activity timing was collected by actigraphy for 7 days. Cosinor analyses on these data were done to obtain the acrophase and amplitude of the sleep–wake rhythm. Cronbach’s alpha of the total scores from the Korean MEQ was 0.77, and the test–retest reliability intra-class correlation coefficient was 0.90 (p?<?0.0001). There was a significant negative correlation between Korean MEQ score and reported sleep–wake timing among the entire cohort (p?<?0.0001). There was a significant difference in bedtime and wake time (on both work and free days), and in the mean sleep–wake rhythm acrophase, between ME types (p?<?0.01). In this study, the validity of the Korean MEQ was verified by illustrating the difference in acrophases of the sleep–wake rhythm between the ME types in young adults.     

A sensitive liquid chromatography-tandem mass spectrometry method for the quantification of mometasone furoate in human plasma

A robust, rapid, selective and sensitive liquid chromatography-negative atmospheric pressure chemical ionization (LC-(APCI(-))-MS-MS) method has been developed for the quantification of mometasone furoate (MF) in human plasma utilizing a solid-phase extraction clean-up step and 13C-fluticasone propionate as internal standard. The intra- and inter-day coefficients of variation were < or = 15% and the lower limit of quantification (LLOQ) was 15 pg/ml. This method is ideally suited for pharmacokinetic investigations of low MF levels following inhalation of MF.     

Modulation of the EMT/MET process by pyrrole–imidazole polyamide targeting human transforming growth factor-β1

Transforming growth factor-β1 (TGF-β1) is a potent induction factor for epithelial–mesenchymal transition (EMT). Mesenchymal–epithelial transition (MET), as the inverse process of EMT, has recently been reported to promote the induction of induced pluripotent stem cells (iPSCs). We have developed pyrrole–imidazole (PI) polyamide, a novel gene regulator that targets human TGF-β1, and investigated its effects on the EMT/MET process. PI polyamide targeted to TGF-β1 significantly inhibited the mRNA expression of TGF-β1 and SNAI1 as an EMT marker and increased mRNA and protein expression of E-cadherin in human epithelial cells. To enhance the induction of iPSCs by the MET process, PI polyamide targeted to TGF-β1 was applied to human fibroblasts transfected with exogenous reprogramming factors by Sendai virus vector and grown in human iPSCs. The PI polyamide significantly increased the number of alkaline phosphatase-positive colonies. The expression of undifferentiated markers was also observed in these colonies. These results suggest that PI polyamide targeted to human TGF-β is a novel compound that can control the EMT/MET process of human epithelial cells and enhance the induction of human fibroblasts to iPSCs.     

Susceptibility of male reproductive system to bisphenol A,an endocrine disruptor: Updates from epidemiological and experimental evidence

Bisphenol A (BPA) is an omnipresent environmental pollutant. Despite being restrictions in-force for its utilization, it is widely being used in the production of polycarbonate plastics and epoxy resins. Direct, low-dose, and long-term exposure to BPA is expected when they are used in the packaging of food products and are used as containers for food consumption. Occupationally, workers are typically exposed to BPA at higher levels and for longer periods during the manufacturing process. BPA is a known endocrine disruptor chemical (EDC), that causes male infertility, which has a negative impact on human life from emotional, physical, and societal standpoints. To minimize the use of BPA in numerous consumer products, efforts and regulations are being made. Despite legislative limits in numerous nations, BPA is still found in consumer products. This paper examines BPA's overall male reproductive toxicity, including its impact on the hypothalamic-pituitary-testicular (HPT) axis, hormonal homeostasis, testicular steroidogenesis, sperm parameters, reproductive organs, and antioxidant defense system. Furthermore, this paper highlighted the role of non-monotonic dose–response (NMDR) in BPA exposure, which will help to improve the overall understanding of the harmful effects of BPA on the male reproductive system.