Reaction Analysis Research Articles

Detection of chicken DNA in commercial dog foods

BackgroundThese days the number of potential food allergens is very large, but chicken is one of the most common allergens in dogs. Elimination diet is one of the clinical tools for the diagnosis of allergies and allergy tests are not very reliable. The restriction diet is most commonly carried out by feeding pet foods, relying on the ingredients on the label to select an elimination diet not containing previously eaten foods. Unfortunately, mislabeling of pet food is quite common. The purpose of this study was to determine the absence or presence of chicken DNA using both qualitative and quantitative polymerase chain reaction (PCR) analysis methods in dry and wet maintenance complete pet foods for adult dogs. Results were used to verify the declared composition on the labels.ResultsEleven out of fifteen (73%) dog foods were produced as declared by the manufacturer, two of which showed the presence of chicken protein as stated on the label. The remaining nine foods contained amounts of chicken DNA below 1%, consistent with declarations that no chicken was added in the composition. Four of tested dog foods (27%) were not produced consistently with the declaration on the packaging. Two dog foods (one dry and one wet) did not contain the claimed chicken protein. In two foods the addition of chicken DNA was detected at the level of over 2% and almost 6%, respectively.ConclusionsIn this study, we focused on one of the most commonly undeclared animal species on the label—chicken protein—and performed DNA analyzes to investigate possible contamination and mislabeling. The results showed some inaccuracies. However, most of them are trace amounts below 1%, which proves compliance with the label. Our results showed that undeclared animal species can be as common as missing an animal protein declared on the label. The conducted research indicates that both dry and wet analyzed foods should not be recommended as a diagnostic tool in elimination tests, because it may result in false negative results. Over-the-counter maintenance foods for dogs should not be recommended for the diagnosis and treatment of food hypersensitivity.

Free-Energy Profile Analysis of the Catalytic Reaction of Glycinamide Ribonucleotide Synthetase.

The second step in the de novo biosynthetic pathway of purine is catalyzed by PurD, which consumes an ATP molecule to produce glycinamide ribonucleotide (GAR) from glycine and phosphoribosylamine (PRA). PurD initially reacts with ATP to produce an intermediate, glycyl-phosphate, which then reacts with PRA to produce GAR. The structure of the glycyl-phosphate intermediate bound to PurD has not been determined. Therefore, the detailed reaction mechanism at the molecular level is unclear. Here, we developed a computational protocol to analyze the free-energy profile for the glycine phosphorylation process catalyzed by PurD, which examines the free-energy change along a minimum energy path based on a perturbation method combined with the quantum mechanics and molecular mechanics hybrid model. Further analysis revealed that during the formation of glycyl-phosphate, the partial atomic charge distribution within the substrate molecules was not localized according to the formal charges, but was delocalized overall, which contributed significantly to the interaction with the charged amino acid residues in the ATP-grasp domain of PurD.

Molecular Fingerprinting by Single Cell Clone Analysis in Adverse Drug Reaction (ADR) Assessment.

Causality assessment for idiosyncratic ADRs mainly relies on epidemiology, signal detection and less often on proven or plausible mechanistic evidence of the drug at a cellular or organ level. Distinct clones of cells can exist within organs of individual patients, some conferring susceptibility to well-recognised Adverse Drug Reactions (ADRs). Recent advances in molecular biology have allowed the development of single-cell clonal techniques, including single-cell RNA sequencing (scRNA-seq) to molecularly fingerprint ADRs and distinguish between distinct clones of cells within organs in individuals, which may confer differing susceptibilities to ADRs. ScRNA- seq permits molecular fingerprinting of some serious ADRs, mainly in the skin, through the identification of Directly Expressed Genes (DEG) of interest within specific clones. Overexpressed DEGs provide an opportunity for targeted treatment strategies to be developed. scRN A-seq could be applied to a number of other ADRs involving tissues that can be biopsied/sampled (including skin, liver, kidney, blood, stem cells) as well as providing a molecular basis for rapid screening of potential therapeutic candidates, which may not otherwise be predictable from a class of toxicity/organ involvement. A framework for putative assessment for ADRs using scRNA-seq is proposed as well as speculating on potential regulatory implications for pharmacovigilance and drug development. Molecular fingerprinting of ADRs using scRNA-seq may allow better targeting for enhanced pharmacovigilance and risk minimisation measures for medicines with appropriate benefit-risk profiles, although cost-effectiveness and other factors, such as frequency/severity of individual ADRs and population differences, will still be relevant.

Trypanosoma evansi infection in a captive Indian Wolf Canis lupus pallipes – molecular diagnosis and therapy

A five-year old, apparently healthy male Indian Wolf Canis lupus pallipes of Nandankanan Zoological Park, Odisha became ill with acute signs of anorexia, lethargy, staggering gait, and was non-responsive to external stimuli. Microscopic examination of Giemsa stained blood smear revealed presence of extracellular flagellates having morphological similarity to Trypanosoma spp. Haematological parameters showed anaemia (Hb 6.0 g%), mild leucopenia (total leukocyte count 5 × 103 / mm3) and thrombocytopenia (180 x 103 / µl). Serum biochemistry revealed high aspartate aminotransferase (AST) (830 IU/L), blood urea nitrogen (BUN) (178.2 mg/dl), creatinine (4.44 mg/dl), and low glucose (25.7 mg/dl) levels. Polymerase chain reaction (PCR) analysis targeting internal transcribed spacer (ITS1) region followed by National Centre for Biotechnology Information blast confirmed Trypanosoma evansi infection in the captive Indian Wolf. The animal showed clinical recovery with the administration of single dose of quinapyramine sulphate and quinapyramine chloride @ 4.0 mg/kg b wt subcutaneously. The wolf started taking meat from the very next day with improved activity. No trypanosomes could be detected in the stained blood smears as well as through PCR carried 25 days post treatment. The occurrence became an eye opener for the zoo and henceforth, all canids were included under chemoprophylaxis protocol against trypanosomosis.

First application of the dispersive optical model to (p,2p) reaction analysis within the distorted-wave impulse approximation framework

Both ($e$,$e'p$) and ($p$,$2p$) reactions have been performed to study the proton single-particle character of nuclear states with its related spectroscopic factor. Recently, the dispersive optical model (DOM) was applied to the ($e$,$e'p$) analysis revealing that the traditional treatment of the single-particle overlap function, distorted waves, and nonlocality must be further improved to achieve quantitative nuclear spectroscopy. We apply the DOM wave functions to the traditional ($p$,$2p$) analysis and investigate the consistency of the DOM spectroscopic factor that describes the ($e$,$e'p$) cross section with the result of the ($p$,$2p$) analysis. Additionally, we make a comparison with a phenomenological single-particle wave function and optical potential. Uncertainty arising from a choice of $p$-$p$ interaction is also investigated. We implement the DOM wave functions to the distorted wave impulse approximation (DWIA) framework for ($p$,$2p$) reactions. DOM + DWIA analysis on $^{40}$Ca($p$,$2p$)$^{39}$K data generates a proton $0d_{3/2}$ spectroscopic factor of 0.560, which is meaningfully smaller than the DOM value of 0.71 shown to be consistent with the ($e$,$e'p$) analysis. Uncertainties arising from choices of single-particle wave function, optical potential, and $p$-$p$ interaction do not explain this inconsistency. The inconsistency in the spectroscopic factor suggests there is urgent need for improving the description of $p$-$p$ scattering in a nucleus and the resulting in-medium interaction with corresponding implications for the analysis of this reaction in inverse kinematics.

Classical Thermodynamic Analysis of Deuterium-Based Fusion Reactions

The fusion reactions involving deuterium are of great interest for the exploitation of the fusion energy via magnetic-confinement devices. In classical thermodynamics, the spontaneity of a process is established through the assessment of the change in Gibbs free energy. So far, the feasibility of nuclear reactions has been characterized in terms of cross section and Q-value while the entropic term (T ΔS) has been neglected. Such an assumption is always justified for fission reactions where the term ΔS is positive. In the case of fusion reactions that operate at very high temperatures (106–107 K) and where ΔS is negative, the change in Gibbs free energy may be positive, making the reaction non-spontaneous. This paper proposes a classical thermodynamic analysis of D-based reactions of interest for the magnetic-confinement fusion applications. The entropy contribution was evaluated via the Sackur–Tetrode equation while the change in enthalpy was considered constant and as corresponding to the Q-value of the fusion reaction. The results of the thermodynamic analysis are compared with nuclear reaction feasibility criteria based on the reaction reactivity. The DT and D3He reactions show a high degree of spontaneity although the second one presents a lower reactivity. An increase in temperature could enhance the reactivity of the D3He reaction at the cost of decreasing its thermodynamic spontaneity. Both branches of the DD reaction are characterized by a much lower thermodynamic spontaneity than that of the DT and D3He reactions. Furthermore, at the temperature of their maximum cross section, the DD reactions exhibit a largely positive change in Gibbs free energy and, therefore, are not spontaneous. At the temperature of magnetic-confinement fusion machines (1.5 × 108 K), among the D-based reactions studied, the DT one exhibits the highest degrees of spontaneity and reactivity.

Hsa_circ_0020850 promotes the malignant behaviors of lung adenocarcinoma by regulating miR-326/BECN1 axis

BackgroundCircular RNAs (circRNAs) are a novel type of endogenous RNAs and play vital roles in lung adenocarcinoma. However, the function and underlying mechanism of circ_0020850 in lung adenocarcinoma remain unknown.MethodsThe levels of circ_0020850, microRNA-326 (miR-326), and Beclin1 (BECN1) were analyzed by real-time quantitative polymerase chain reaction and western blot analyses. The migration and invasion were determined by wound healing and transwell assays, respectively. Colony formation assay was used to assess cell proliferation ability. The angiogenic ability was analyzed by Matrigel angiogenesis assay. The apoptosis rate was calculated by flow cytometry assay. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were conducted to confirm the interaction relationship among circ_0020850, miR-326, and BECN1. A xenograft mice model was established to assess the role of circ_0020850 in vivo.ResultsWe found that circ_0020850 was obviously overexpressed in lung adenocarcinoma tissues and cells. Knockdown of circ_0020850 inhibited migration, invasion, proliferation, and angiogenesis but induced apoptosis in lung adenocarcinoma cells in vitro, as well as curbed tumor growth in vivo. MiR-326 was a target of circ_0020850, and knockdown of miR-326 abolished the suppression effect of circ_0020850 on the malignant behaviors of lung adenocarcinoma cells. Additionally, miR-326 could negatively regulate BECN1 expression, thereby regulating lung adenocarcinoma cell phenotypes. Importantly, circ_0020850 could directly bind to miR-326 and thus relieve miR-326-mediated inhibition on BECN1.ConclusionCirc_0020850 promoted the malignant development of lung adenocarcinoma by regulating miR-326/BECN1 axis, indicating that circ_0020850 might serve as a promising target for the diagnosis and treatment of lung adenocarcinoma patients.

The lolB gene in Xanthomonas campestris pv. campestris is required for bacterial attachment, stress tolerance, and virulence

BackgroundXanthomonas campestris pv. campestris (Xcc) is a Gram-negative bacterium that can cause black rot disease in crucifers. The lipoprotein outer membrane localization (Lol) system is involved in the lipoprotein sorting to the outer membrane. Although Xcc has a set of annotated lol genes, there is still little known about the physiological role in this phytopathogen. In this study, we aimed to characterize the role of LolB of Xcc in bacterial attachment, stress tolerance, and virulence.ResultsTo characterize the role of LolB, lolB mutant was constructed and phenotypic evaluation was performed. The lolB mutant revealed reductions in bacterial attachment, extracellular enzyme production, and virulence. Mutation of lolB also resulted in reduced tolerance to a myriad of stresses, including heat and a range of membrane-perturbing agents. Trans-complementation of lolB mutant with intact lolB gene reverted these altered phenotypes to the wild-type levels. From subsequent reporter assay and reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis, the expression of genes that encode the major extracellular enzymes and the stress-related proteins was reduced after lolB mutation.ConclusionsThe results in this work contribute to the functional understanding of lolB in Xanthomonas for the first time, and provide new insights into the function of lolB in bacteria.

Ozone treatment alleviates brain injury in cerebral ischemic rats by inhibiting the NF-κB signaling pathway and autophagy

ABSTRACT Stroke is the most frequent cause of disability in developed countries. A common phenomenon of stroke, cerebral ischemia, is threatening many lives worldwide. In addition, ozone treatment was previously reported to exert functions in relieving brain injury. In the current study, the therapeutic effects of ozone on cerebral ischemia are investigated. A rat model of middle cerebral artery occlusion (MCAO) was established. The brain water content was calculated by weighing brain tissues, and the 2, 3, 5-triphenyltetrazolium chloride staining was performed to measure brain infarction volume in rats. A colorimetric assay was conducted to examine expression levels of malondialdehyde, superoxide dismutase, catalase, and glutathione in the rat hippocampus. Reverse transcription quantitative polymerase-chain reaction and Western blot analyses were employed to evaluate expression levels of Beclin1, LC3B, p62, and critical factors implicated in the NF-κB signaling pathway. We found that ozone significantly improved the survival rate of MCAO model rats, reduced the cerebral water content, and decreased the neurological scores of ischemic rats. Ozone markedly reduced cerebral ischemia-induced infarction in ischemic rats. Ozone decreased MDA levels and increased SOD, catalase, and GSH levels in the hippocampus of rats. Ozone significantly inhibited autophagy by decreasing Beclin1 and LC3B expression and increasing p62 expression. The ozone inactivated the NF-κB signaling pathway by decreasing the protein levels of TLR4, p-IKKβ, p-IKBα, and p-p65. We conclude that ozone treatment alleviates the brain injury in ischemic rats by suppressing autophagy and inactivating the NF-κB signaling pathway.

Adiponectin triggers breast cancer cell death via fatty acid metabolic reprogramming

BackgroundAdiponectin, the most abundant adipokine derived from adipose tissue, exhibits a potent suppressive effect on the growth of breast cancer cells; however, the underlying molecular mechanisms for this effect are not completely understood. Fatty acid metabolic reprogramming has recently been recognized as a crucial driver of cancer progression. Adiponectin demonstrates a wide range of metabolic activities for the modulation of lipid metabolism under physiological conditions. However, the biological actions of adiponectin in cancer-specific lipid metabolism and its role in the regulation of cancer cell growth remain elusive.MethodsThe effects of adiponectin on fatty acid metabolism were evaluated by measuring the cellular neutral lipid pool, free fatty acid level, and fatty acid oxidation (FAO). Colocalization between fluorescent-labeled lipid droplets and LC3/lysosomes was employed to detect lipophagy activation. Cell viability and apoptosis were examined by MTS assay, caspase-3/7 activity measurement, TUNEL assay, and Annexin V binding assay. Gene expression was determined by real time-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The transcriptional activity of SREBP-1 was examined by a specific dsDNA binding assay. The modulatory roles of SIRT-1 and adiponectin-activated mediators were confirmed by gene silencing and/or using their pharmacological inhibitors. Observations from in vitro assays were further validated in an MDA-MB-231 orthotopic breast tumor model.ResultsGlobular adiponectin (gAcrp) prominently decreased the cellular lipid pool in different breast cancer cells. The cellular lipid deficiency promoted apoptosis by causing disruption of lipid rafts and blocking raft-associated signal transduction. Mechanistically, dysregulated cellular lipid homeostasis by adiponectin was induced by two concerted actions: 1) suppression of fatty acid synthesis (FAS) through downregulation of SREBP-1 and FAS-related enzymes, and 2) stimulation of lipophagy-mediated lipolysis and FAO. Notably, SIRT-1 induction critically contributed to the adiponectin-induced metabolic alterations. Finally, fatty acid metabolic remodeling by adiponectin and the key role of SIRT-1 were confirmed in nude mice bearing breast tumor xenografts.ConclusionThis study elucidates the multifaceted role of adiponectin in tumor fatty acid metabolic reprogramming and provides evidence for the connection between its metabolic actions and suppression of breast cancer.

Bio-electron transfer modulated localized surface plasmon resonance biosensing with charge density monitoring

The analysis of reactant at different regions of the bioreaction interface is significant for the study on the influence of interface condition on bioreaction. In this study, we proposed a localized surface plasmon resonance (LSPR) biosensing platform for local charge density monitoring and corresponding analytes detection based on the bio-electron transfer modulation of plasmon resonance. Core-shell nanocomposites of polyaniline coated gold nanoparticles were synthesized for the enhanced sensitivity of plasmon resonance to applied electric potential. Tin-doped indium oxide (ITO) substrates modified with the nanocomposites were used as LSPR chip for optical and electrochemical measurements simultaneously. The charge sensitivity of LSPR was verified with external electric potential modulation theoretically and experimentally. Through layer-by-layer self-assembly immobilization of glucose oxidase (GOD) on the LSPR chips, the charge transfer monitoring during the bioreaction of glucose catalysis was further demonstrated based on the bio-electron transfer modulation of LSPR. By equivalent circuit method, the charge density of the LSPR chip were detected with optical extinction peak shifts, and the limit of detection was about 0.51 μC/cm2. This bio-electron transfer modulated LSPR provides a promising approach for the detection of spatial charge densities and the evaluation of bioreaction substances at different region of single chip.

Этнокультурные и гендерные стереотипные представления об интеллекте: китайцы и русские

The article presents the results of a cross-group sociolinguistic experiment aimed at analyzing the features of the expression of Chinese and Russian stereotypes about intelligence, as well as at identifying the influence of ethnic and gender factors on the stereotypical perceptions of Chinese and Russian women and men about the intelligence of the same social groups (the experiment involved four groups of informants – Chinese women, Chinese men, Russian women, and Russian men – 30 people in each group). During the experiment, the informants were asked to name five words characterizing the intelligence of the social groups under study. As a result, there were received 1,050 responses from the Chinese informants and 845 responses from the Russians. For the processing and analysis of reactions, semantic as well as quantitative analyses were used: all the reactions obtained were combined into semantic groups, the volume of which was considered as an indicator of the stereotyping of a particular feature. The study showed that the structures of stereotypes regarding the intelligence of different social groups differ depending on the ethnic group and gender of the evaluating and assessed groups. The core of the stereotype among Chinese is formed by three features – ‘Mind’, ‘Quick-wittedness’, and ‘Talent’, while the core of the stereotype among the Russians is formed by five features: ‘Quick-wittedness’, ‘Mind’, ‘Sanity’, ‘Education’, and ‘Evaluation’. Thus, the stereotype structure among Chinese is more compact than that among the Russians. At the same time, Chinese give higher marks to their intellect than to the intellect of the Russians; for the Russians, the ethnic factor does not have a significant impact on the assessment of a group. Ideas about intelligence in women do not depend on the gender factor of the group being assessed, while in men auto and hetero stereotypes differ to a greater extent. Analysis of the interaction between ethnic and gender factors shows that in-group favoritism is characteristic of only one of the considered groups – Chinese men, with the gender factor being more important for them than the ethnic one.

SnO deposition via water based ALD employing tin(II) formamidinate: precursor characterization and process development.

Tin monoxide (SnO) is a promising oxide semiconductor which is appealing for a wide range of applications from channel materials in p-type field effect transistors (FET) to electrode materials searched for next-generation batteries. For the controlled growth of SnO films at low temperatures, atomic layer deposition (ALD) is employed in this study, where the choice of the precursor plays a significant role. A comparative thermal evaluation of four different amidinate-based tin(II) precursors and the influence of the ligand sphere on their physicochemical properties revealed that bis(N,N'-diisopropylformamidinato tin(II) (1) possesses the required volatility, good thermal stability and sufficient reactivity towards water, to be implemented as the ALD precursor. The water-assisted ALD process resulted in crystalline SnO films on Si substrates with a growth per cycle (GPC) of 0.82 Å at temperatures as low as 140 °C. By employing complementary analytical tools, namely, X-ray diffraction (XRD), atomic force microscopy (AFM), X-ray reflectivity (XRR), Rutherford backscattering spectrometry/nuclear reaction analysis (RBS/NRA) and X-ray photoelectron spectroscopy (XPS), the formation of tin monoxide was confirmed. Finally, the optical properties of the as-deposited films were analyzed via UV-Vis spectroscopy, exhibiting a band gap of 2.74 eV, which further confirms the formation of the targeted SnO phase.

Comparative Analysis of Key Transcription Factors Involved in Development in Sea Lamprey (Petromyzon marinus) through Systematic Mining of Lamprey Gene Expression Dataset.

Transcription factors (TFs), key regulators for gene expression, play varied yet crucial roles throughout cellular polarization, migration, proliferation, differentiation and apoptosis. An important function of TFs is acting in embryogenesis and organogenesis. To identify the candidate TFs in the progression of lamprey early embryogenesis, datasetGSE76037 was downloaded from the Gene Expression Omnibus (GEO) database and an integrated bioinformatic analysis was performed. Our findings revealed a total of 152 TFs in the dataset. The function enrichment analysis showed that these genes were mainly enriched in transcription from RNA polymerase II promoter, cell differentiation, embryonic digestive tract morphogenesis and so on. Hierarchical clustering analysis suggested the expression of TFs was significantly different during early embryogenesis. Moreover, volcano plots and Venn diagrams analysis identified 36 key TFs, which were considered to play an important role during embryogenesis. The weighted correlation network analysis (WGCNA) was constructed and the Pearson correlation coefficient was performed, indicating these TFs might involve in early development of lamprey germline by synergistically regulating each other. The result was confirmed by real-time polymerase chain reaction and Western blotting analysis. In conclusion, differentially expressed genes identified in the present study help us understand the molecular mechanisms underlying the lamprey embryogenesis and provide candidate TFs for further study of vertebrate embryonic development.

Analysis and Comparison of Adverse Reactions of Erythromycin and Azithromycin

Analysis and Comparison of Adverse Reactions of Erythromycin and Azithromycin

GADD45B induced the enhancing of cell viability and proliferation in radiotherapy and increased the radioresistance of HONE1 cells

AbstractThis study aimed to investigate the key role and mechanism of GADD45B in the radiation resistance of nasopharyngeal carcinoma (NPC) cell lines. Radiotherapy-resistant HONE1 (HONE1-R) cells with stable genetic radioresistance were cultured under continuous radiation stimulation. CCK-8 and clone formation assays were used to verify the radioresistance of the cell line. Transcriptome sequencing was used to identify the most important differential signaling pathway in the cell line. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis were used to verify the sequencing results. GADD45B-siRNA was used to knock down the key gene so as to verify the downstream gene expression and analyze its mechanism. The transcriptome analysis showed that 702 genes were upregulated and 772 genes were downregulated in the HONE1-R cell lines. The core differential signaling pathway was mitogen-activated protein kinase (MAPK) signaling pathway, and the core differential gene was GADD45B. After GADD45B was knocked down, the cell viability and proliferation ability of HONE1-R cell lines significantly decreased under radiation, and the expression of cyclin B1 and p-CDK1 decreased significantly. MAPK is the core signaling pathway in radioresistance of NPC. GADD45B plays an important role by affecting cell viability and proliferation in NPC radioresistance. GADD45B is a potential target of radioresistance in NPC.

Morphological and molecular markers based assessment of genetic diversity of a valuable endemic plant Lasiurus sindicus Henr. in the arid region of Rajasthan, India

Morphological and molecular markers are useful in genetic diversity assessment and improvement of plants. In the present study, five morphological traits, random amplified polymorphic DNA (RAPD) and Start codon targeted (SCoT) markers were used for genetic diversity evaluation of Sewan grass (Lasiurus sindicus Henr.), a valuable endemic plant of Indian Thar desert. Accessions collected from 14 different sites were used for measuring morphological traits, namely plant height (PH), number of tillers (NT), number of nodes (NN), leaf length (LL) and spike length (SL) which showed large variations among populations; particularly PH, NT and LL. Ward’s linkage hierarchical cluster analysis exhibited two major clusters and Cluster I contained two minor clusters. The percentage polymorphic bands (PPB) produced were 89.64% and 64.51% for RAPD and SCoT respectively. RAPD markers based dendrogram revealed three clades while there was no clear clade formation with SCoT markers. Single primer amplification reaction (SPAR) analysis with combined data of RAPD + SCoT showed more similarity with SCoT than with RAPD clusters. AMOVA revealed higher variation within population (90%) than among populations (10%) of L. sindicus. The Principal coordinate analysis (PCoA) also supported this result. There was no correlation between morphological and molecular data confirming environmental impact on morphological variation. SCoT and SPAR markers have clearly identified a novel genotype (LS JS 3) which has high values of PH, NN and LL. This study suggests that morphological data combined with molecular data can alone help in the identification of novel genotypes of L. sindicus among its populations.

1H NMR Analysis of the Metathesis Reaction between 1-Hexene and (E)-Anethole Using Grubbs 2nd Generation Catalyst: Effect of Reaction Conditions on (E)-1-(4-Methoxyphenyl)-1-hexene Formation and Decomposition

The metathesis of 1-hexene and (E)-anethole in the presence of Grubbs 2nd generation catalyst was monitored by in situ 1H NMR spectroscopy at different temperatures (15 °C, 25 °C, and 45 °C) and anethole mol fractions (XAnethole ≈ 0.17, 0.29, 0.5, 0.71, 0.83). Time traces confirmed the instantaneous formation of (E)-1-(4-methoxyphenyl)-1-hexene, the cross-metathesis product. A maximum concentration of (E)-1-(4-methoxyphenyl)-1-hexene is reached fairly fast (the time depending on the reaction conditions), and this is followed by a decrease in the concentration of (E)-1-(4-methoxyphenyl)-1-hexene due to secondary metathesis. The maximum concentration of (E)-1-(4-methoxyphenyl)-1-hexene was more dependent on the XAnethole than the temperature. The highest TOF (3.46 min−1) was obtained for the reaction where XAnethole was 0.16 at 45 °C. The highest concentration of the cross-metathesis product was however achieved after 6 min with an anethole mol fraction of 0.84 at 25 °C. A preliminary kinetic study indicated that the secondary metathesis reaction followed first order kinetics.

Intrathecal IGF2 siRNA injection provides long-lasting anti-allodynic effect in a spared nerve injury rat model of neuropathic pain.

Previous studies have shown an increase of insulin-like growth factor-2 (IGF2) in animal models of neuropathic pain. We aimed to examine the hypothesis that reducing the expression of IGF2 using intrathecal IGF2 small-interfering RNA (siRNA) would attenuate the development of neuropathic pain in rats after spared nerve injury (SNI). Male Wistar rats were divided into three groups: sham-operated group, in which surgery was performed to cut the muscles without injuring the nerves; SNI group, in which SNI surgery was performed to sever the nerves; and SNI + siRNA IGF2 group, in which SNI surgery was performed, and IGF2-siRNA was administered intrathecally 1 day after SNI. The rats were assessed for mechanical allodynia and cold allodynia 1 day before surgery (baseline), and at 2, 4, 6, 8, and 10 days after siRNA treatment. The rat spinal cord was collected for quantitative polymerase chain reaction and western blot analysis. Compared with the SNI group, rats that received IGF2 siRNA showed a significantly increased SNI-induced paw-withdrawal threshold to metal filament stimulation from Day 4 to Day 10 after SNI surgery. IGF2 siRNA significantly decreased the response duration from the acetone test from Day 2 to Day 10 following SNI surgery. SNI increased IGF2 mRNA expression on Day 2 and increased IGF2 protein expression on Day 8 and Day 10 in the spinal cord of the SNI rats. However, the above-mentioned effects of IGF2 mRNA and protein expression were significantly inhibited in the SNI + IGF2 siRNA group. We demonstrated that intrathecal administration of IGF2 siRNA provided significant inhibition of SNI-induced neuropathic pain via inhibition of IGF2 expression in the spinal cord. The analgesic effect lasted for 10 days. Further exploration of intrathecal IGF2 siRNA administration as a potential therapeutic strategy for neuropathic pain is warranted.

Impacts of anthropogenic contaminants and elevated temperature on prevalence and proliferation of Escherichia coli in the wild-caught American oyster, Crassostrea virginica in the southern Gulf of Mexico coast

ABSTRACT Escherichia coli is one of the most common indicators of environmental contamination and health risk to aquatic organisms including shellfish. E. coli can adapt to various stress conditions (e.g. heat, pollution, acidification, etc.). American oyster, Crassostrea virginica, a marine bivalve mollusc, is a seafood popular due to its delicacy and high nutritional value. Based on increasing concern about global warming, coastal pollution and microbial contamination in live or raw seafood, the present study focused on the detection and enumeration of the bacterial pathogen E. coli in the American oyster in south Texas waters, and in controlled laboratory heat-exposure conditions. Immunohistochemical, reverse transcription-polymerase chain reaction (RT-PCR) and quantitative real-time PCR (qRT-PCR) analyses showed substantial bacterial pathogen presence in the gills and digestive glands of oysters collected from polluted sites in San Martin Lake and South Padre Island on the southern Gulf coast of Texas. Laboratory heat-exposure studies showed an increasing trend of E. coli protein and mRNA expression in gills and digestive glands in elevated temperatures (28°C and 32°C) compared with control (24°C) and reduced integrated protein density of E. coli in gills at high temperature. Biochemical analyses were also performed to examine the extrapallial fluid (EPF, an integral body fluid) conditions in oysters. EPF glucose levels, pH and protein concentration varied at high temperatures and appeared to be pertinent to pathogen intensity in oysters. Collectively, these results suggest that American oyster is prone to waterborne pathogen contamination in the southern Gulf of Mexico coast, and E. coli proliferation escalates at rising sea surface temperatures.