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Inflammatory bowel diseases (IBD) are chronic inflammatory conditions of the gastrointestinal tract. IBD are associated with a high prevalence of cognitive, behavioural and emotional comorbidities, including anxiety and depression. The link between IBD and the development of behavioural comorbidities is poorly understood. As the intestinal microbiota profoundly influences host behaviour, we sought to determine whether the altered gut microbiota associated with intestinal inflammation contributes to the development of behavioural abnormalities. Using the dextran sulphate sodium (DSS) model of colitis, we characterized intestinal inflammation, behaviour (elevated plus maze and tail suspension test) and the composition of the microbiota in male mice. Cecal contents from colitic mice were transferred into germ-free (GF) or antibiotic (Abx)-treated mice, and behaviour was characterized in recipient mice. Gene expression was measured using qPCR. DSS colitis was characterized by a significant reduction in body weight and an increase in colonic inflammatory markers. These changes were accompanied by increased anxiety-like behaviour, an altered gut microbiota composition, and increased central Tnf expression. Transfer of the cecal matter from colitic mice induced similar behavioural changes in both GF and Abx-treated recipient mice, with no signs of colonic or neuroinflammation. Upon characterization of the microbiota in donor and recipient mice, specific taxa were found to be associated with behavioural changes, notably members of the Lachnospiraceae family. Behavioural abnormalities associated with intestinal inflammation are transmissible via transfer of cecal matter, suggesting that alterations in the composition of the gut microbiota play a key role in driving behavioural changes in colitis.

Propulsive gastrointestinal (GI) motility is critical for digestive physiology and host defense. GI motility is finely regulated by the intramural reflex pathways of the enteric nervous system (ENS). The ENS is in turn regulated by luminal factors: diet and the gut microbiota. The gut microbiota is a vast ecosystem of commensal bacteria, fungi, viruses, and other microbes. The gut microbiota not only regulates the motor programs of the ENS but also is critical for the normal structure and function of the ENS. In this chapter, we highlight recent research that has shed light on the microbial mechanisms of interaction with the ENS involved in the control of motility. Toll-like receptor signaling mechanisms have been shown to maintain the structural integrity of the ENS and the neurochemical phenotypes of enteric neurons, in part through the production of trophic factors including glia-derived neurotrophic factor. Microbiota-derived short-chain fatty acids and/or single-stranded RNA regulates the synthesis of serotonin in enterochromaffin cells, which are involved in the initiation of enteric reflexes, among other functions. Further evidence suggests a crucial role for microbial modulation of serotonin in maintaining the integrity of the ENS through enteric neurogenesis. Understanding the microbial pathways of enteric neural control sheds new light on digestive health and provides novel treatment strategies for GI motility disorders.

The outstanding electronic properties of carbon black (CB) and its economic advantages have fueled its application as nanostructured electrode material for the development of new electrochemical sensors and biosensors. CB-based electrochemical sensing devices have been found to exhibit high surface area, fast charge transfer kinetics, and excellent functionalization. In the present work, we set forth a comprehensive review of the recent advances made in the development and application of CB-based electrochemical devices for pharmaceutical and biomedical analyses - from quantitative monitoring of drug formulations to clinical diagnoses - and the underlying challenges and constraints that need to be overcome. We also present a thorough discussion about the strategies and techniques employed in the development of new electrochemical sensing platforms and in the enhancement of their analytical properties and biocompatibility for anchoring active biomolecules, as well as the combination of these sensing devices with other materials aiming at boosting the performance and efficiency of the sensors.

This paper reports the development and application of a low-cost multifunctional webcam spectrophotometer for the conduct of molecular absorption and fluorometric measurements. The equipment, which...

Background The intestinal microbiota plays an important role in regulating gastrointestinal (GI) physiology in part through interactions with the enteric nervous system (ENS). Alterations in the gut microbiome frequently occur together with disturbances in enteric neural control in pathophysiological conditions. However, the mechanisms by which the microbiota regulates GI function and the structure of the ENS are incompletely understood. Using a mouse model of antibiotic (Abx)-induced bacterial depletion, we sought to determine the molecular mechanisms of microbial regulation of intestinal function and the integrity of the ENS. Spontaneous reconstitution of the Abx-depleted microbiota was used to assess the plasticity of structure and function of the GI tract and ENS. Microbiota-dependent molecular mechanisms of ENS neuronal survival and neurogenesis were also assessed. Results Adult male and female Abx-treated mice exhibited alterations in GI structure and function, including a longer small intestine, slower transit time, increased carbachol-stimulated ion secretion, and increased intestinal permeability. These alterations were accompanied by the loss of enteric neurons in the ileum and proximal colon in both submucosal and myenteric plexuses. A reduction in the number of enteric glia was only observed in the ileal myenteric plexus. Recovery of the microbiota restored intestinal function and stimulated enteric neurogenesis leading to increases in the number of enteric glia and neurons. Lipopolysaccharide (LPS) supplementation enhanced neuronal survival alongside bacterial depletion, but had no effect on neuronal recovery once the Abx-induced neuronal loss was established. In contrast, short-chain fatty acids (SCFA) were able to restore neuronal numbers after Abx-induced neuronal loss, demonstrating that SCFA stimulate enteric neurogenesis in vivo. Conclusions Our results demonstrate a role for the gut microbiota in regulating the structure and function of the GI tract in a sex-independent manner. Moreover, the microbiota is essential for the maintenance of ENS integrity, by regulating enteric neuronal survival and promoting neurogenesis. Molecular determinants of the microbiota, LPS and SCFA, regulate enteric neuronal survival, while SCFA also stimulates neurogenesis. Our data reveal new insights into the role of the gut microbiota that could lead to therapeutic developments for the treatment of enteric neuropathies.

A simple, rapid and low-cost electroanalytical method is proposed for the determination of acetaminophen (ACP) and codeine (COD) at nanomolar levels in pharmaceutical and biological samples. The analytical procedure is based on a flow injection analysis system coupled to electrochemical detection, which was multiple pulse amperometry (FIA-MPA). Boron-doped diamond was used as the working electrode for electrochemical detection. The electrode was subjected to a cathodic pretreatment and was selected in this work due its good electrochemical performance. By applying the FIA-MPA method, after a number of optimization assays, the analgesics were simultaneously determined at excellent linear concentration ranges. The analytical curves ranged from 80 nmol L−1 to 100 µmol L−1 for ACP and from 50 nmol L−1 to 10 µmol L−1 for COD, and the obtained limits of detection were 30 nmol L−1 and 35 nmol L−1 for ACP and COD, respectively. The practical applicability of the electroanalytical method was evaluated from the ACP and COD determination in two sample matrices: commercial pharmaceutical samples and biological fluids. In the case of pharmaceutical formulation samples, the obtained results were statistically similar to those obtained using a reference chromatographic method. In addition, these drugs were simultaneously quantified in biological fluid samples of urine and human serum with excellent recovery percentages. Keywords: Paracetamol, Codeine, Flow injection analysis, Boron-doped diamond, Multiple pulse amperometry

Significance Isotopic analysis has the ability to detect changes in metal homeostasis in vivo. Using this advanced technique to investigate metal metabolism, we identified a significant change in copper processing in the gut of mice with depleted gut microbiota. In addition, we observed changes in the expression of copper transporters in the colon. The role of intestinal microbiota in copper processing in the gastrointestinal tract was previously unknown. Using the unique ability of isotopic analyses to detect changes in metal processing has enabled the identification of the intestinal microbiota as a significant influence on copper metabolism in the gut., Copper is a critical enzyme cofactor in the body but also a potent cellular toxin when intracellularly unbound. Thus, there is a delicate balance of intracellular copper, maintained by a series of complex interactions between the metal and specific copper transport and binding proteins. The gastrointestinal (GI) tract is the primary site of copper entry into the body and there has been considerable progress in understanding the intricacies of copper metabolism in this region. The GI tract is also host to diverse bacterial populations, and their role in copper metabolism is not well understood. In this study, we compared the isotopic fractionation of copper in the GI tract of mice with intestinal microbiota significantly depleted by antibiotic treatment to that in mice not receiving such treatment. We demonstrated variability in copper isotopic composition along the length of the gut. A significant difference, ∼1.0‰, in copper isotope abundances was measured in the proximal colon of antibiotic-treated mice. The changes in copper isotopic composition in the colon are accompanied by changes in copper transporters. Both CTR1, a copper importer, and ATP7A, a copper transporter across membranes, were significantly down-regulated in the colon of antibiotic-treated mice. This study demonstrated that isotope abundance measurements of metals can be used as an indicator of changes in metabolic processes in vivo. These measurements revealed a host–microbial interaction in the GI tract involved in the regulation of copper transport.

In this study, we report an electrochemical study based on nanocellulose (NC) and single-walled carbon nanohorns (SWCNH). SWCNH and NC ensure large surface area, good conductivity, high porosity and chemical stability, becoming attractive for electrodes. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Scanning Electron Micrograph (SEM), Transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential. Using XRD and FTIR it was possible to observe particular characteristics of NC and SWCNH. The presence of dahlia-like assemblies on the NC surface was observed by MEV and TEM. Then, we investigated the electrochemical behavior of NC-SWCNH, which showed the excellent results when it was used guanine and adenine, as proof of concept, by using cyclic and linear sweep voltammetry (LSV). LSV was also employed for simultaneous detection resulting in limits of detection of 1.7 × 10−7 mol L−1 and 1.4 × 10−6 mol L−1, for guanine and adenine, respectively. In addition, the proposed electrode was applied for determination of both bases in synthetic human serum and fish sperm. We demonstrate that it is possible to use NC, a renewable material, in conducting thin films with SWCNH, and due to simplicity in the preparation and high conductivity, this new thin film could be extended for others electrochemical purposes such as sensing and biosensing.

The intestinal microbiota plays an important role in regulating brain functions and behaviour. Microbiota-dependent changes in host physiology have been suggested to be key contributors to psychiatric conditions. However, specific host pathways modulated by the microbiota involved in behavioural control are lacking. Here, we assessed the role of the aryl hydrocarbon receptor (Ahr) in modulating microbiota-related alterations in behaviour in male and female mice after antibiotic (Abx) treatment. Mice of both sexes were treated with Abx to induce bacterial depletion. Mice were then tested in a battery of behavioural tests, including the elevated plus maze and open field tests (anxiety-like behaviour), 3 chamber test (social preference), and the tail suspension and forced swim tests (despair behaviour). Behavioural measurements in the tail suspension test were also performed after microbiota reconstitution and after administration of an Ahr agonist, β-naphthoflavone. Gene expression analyses were performed in the brain, liver, and colon by qPCR. Abx-induced bacterial depletion did not alter anxiety-like behaviour, locomotion, or social preference in either sex. A sex-dependent effect was observed in despair behaviour. Male mice had a reduction in despair behaviour after Abx treatment in both the tail suspension and forced swim tests. A similar alteration in despair behaviour was observed in Ahr knockout mice. Despair behaviour was normalized by either microbiota recolonization or Ahr activation in Abx-treated mice. Ahr activation by β-naphthoflavone was confirmed by increased expression of the Ahr-target genes Cyp1a1, Cyp1b1, and Ahrr. Our results demonstrate a role for Ahr in mediating the behaviours that are regulated by the crosstalk between the intestinal microbiota and the host. Ahr represents a novel potential modulator of behavioural conditions influenced by the intestinal microbiota.

Made available in DSpace on 2021-06-25T12:25:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-15 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The present study reports the development of graphite pencil electrode modified with palladium nanoparticles (PdNPs) and its application as an electrochemical sensor for the simultaneous detection of direct yellow 50, tryptophan, carbendazim and caffeine in river water and synthetic urine samples. The combination involving the conductive surface of the graphite pencil electrode (GPE) and the enlargement of the surface area caused by the use of palladium nanoparticles (PdNPs) led to the improvement of the analytical performance of the proposed device. The surface of the GPE-PdNPs was characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The charge transfer kinetics of the electrode was evaluated based on the elec-trochemical analysis of the potassium ferricyanide redox probe. Using square wave voltammetry (SWV), welldefined and fully resolved anodic peaks were detected for the analytes, with peak-to-peak potential separation not less than 200 mV. Under optimised conditions, the following linear range concentrations were obtained: 0.99-9.9 mu mol L-1 for direct yellow 50; 1.2-12 mu mol L-1 for tryptophan; 0.20-1.6 mu mol L-1 for carbendazim; and 25-190 mu mol L-1 for caffeine. The sensor showed good sensitivity, repeatability, and stability. The device was successfully applied for the determination of analytes in urine and river water samples, where recovery rates close to 100% were obtained. Due to its low cost and reusability by simple polishing, the sensor has strong potential to be used as an electrochemical sensor for the determination of different analytes. State Univ Sao Paulo, Inst Chem, Dept Analyt Chem, Araraquara, SP, Brazil Univ Fed Sao Carlos, Dept Chem, Rod Washington Luis Km 235, Sao Carlos, SP, Brazil Univ Fed Sao Carlos, Ctr Nat Sci, Rod Lauri Simoes Barros Km 12, Buri, SP, Brazil State Univ Sao Paulo, Inst Chem, Dept Analyt Chem, Araraquara, SP, Brazil CNPq: 150184/2019-0 CNPq: 405546/2018-1 CNPq: 408430/2016-8 FAPESP: 2014/50945-4 FAPESP: 2019/00677-7 FAPESP: 2020/01050-5 CAPES: 0674/2018

In this work, we present a computational investigation on the photoexcitation of indigo carmine (IC). Physical insights regarding IC photoexcitation and photolysis were obtained from a fundamental perspective through quantum chemistry computations. Density functional theory (DFT) was used to investigate the ground state while its time-dependent formalism (TD-DFT) was used for probing excited state properties, such as vertical excitation energies, generalized oscillator strengths (GOS), and structures. All the computations were undertaken using two different approaches: M06-2X/6-311+G(d,p) and CAM-B3LYP/6-311+G(d,p), in water. Results determined using both methods are in systematic agreement. For instance, the first singlet excited state was found at 2.28 eV (with GOS = 0.4730) and 2.19 eV (GOS = 0.4695) at the TD-DFT/CAM-B3LYP/6-311+G(d,p) and TD-DFT/M06-2X/6-311+G(d,p) levels of theory, respectively. Excellent agreement was observed between the computed and the corresponding experimental UV-Vis spectra. Moreover, results suggest IC undergoes photodecomposition through excited state chemical reaction rather than via a direct photolysis path. To the best of our knowledge, this work is the first to tackle the photoexcitation, and its potential connections to photodegradation, of IC from a fundamental chemical perspective, being presented with expectations to motivate further studies.

Patients with rheumatoid arthritis experience chronic pain, depression and fatigue, even when inflammation of the joints is well controlled. To study the relationship between arthritis, depression, and sustained pain when articular inflammation is no longer observed, we tested the hypothesis that brain TNF drives post-inflammation depression-like behavior and persistent pain in experimental arthritis. The murine model of antigen-induced arthritis (AIA) was used to evaluate the effects of knee inflammation on sustained pain and depression-like behavior. We measured joint pain using an automated dynamic plantar algesiometer and depression-like behavior with the tail suspension test. Cytokines were measured by Luminex assay and ELISA. TNF in the brain was blocked by intracerebroventricular injection of anti-TNF antibodies. Histological damage and elevated levels of cytokines were observed in the knee 24 h after antigen treatment, but not at 13 days. Reduced pain thresholds were seen 24 h and 13 days after treatment. Depression-like behavior was observed on day 13. Treatment with the antidepressant imipramine reduced both depression-like behavior and persistent pain. However, blocking joint pain with the analgesic dipyrone did not alter depression-like behavior. Elevated levels of TNF, CCL2, and CXCL-1 were observed in the hippocampus 24 h after treatment, with TNF remaining elevated at day 13. Intracerebroventricular infusion of an anti-TNF antibody blocked depression-like behavior and reduced persistent pain. We have demonstrated that depression-like behavior and pain is sustained in AIA mice after the resolution of inflammation. These changes are associated with elevated levels of TNF in the hippocampus and are dependent upon brain TNF. The findings reveal an important mechanistic link between the expression of chronic pain and depression in experimental arthritis. Furthermore, they suggest treating depression in rheumatoid arthritis may positively impact other debilitating features of this condition.

Beverages containing Trichilia catigua are commonly employed in folk medicine. T. catigua bark extracts possess antioxidant, anti-inflammatory, and bactericidal properties. These properties suggest T. catigua bark extracts as a potential treatment for inflammatory bowel diseases (IBD). Using the 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced model of colitis in rats we evaluated the effect of an ethyl-acetate fraction (EAF) of T. catigua (200 mg/kg) administered by daily oral gavage or intrarectally at different time points after TNBS challenge. TNBS treatment evoked severe colonic inflammation after 24 h that persisted for 7 days, characterized by weight loss, high levels of myeloperoxidase activity, histological and macroscopic damage, and elevated index of oxidative stress in the blood. T. catigua EAF treatment prevented the oxidative stress within 24 h and enhanced tissue recovery observed at day 7, returning histological and macroscopic damage levels to that of the control group. TNBS treatment led to loss of myenteric neurons after 28 days. T. catigua EAF was unable to prevent the neuronal loss. Oral delivery of T. catigua EAF was more effective than intrarectal administration of the extract. In conclusion, T. catigua EAF treatment normalized oxidative stress parameters in blood and reduced the degree of acute inflammation in TNBS colitis.

Background TNBS-induced colitis is an experimental immunopathology in rats that shares many features with human inflammatory bowel diseases. Copaiba oleoresin is extracted from plants of the genus Copaifera and is shown to reduce inflammation. Objective The aim of this study was to investigate the action of copaiba oil (C. reticulata Ducke) on inflammation and oxidative status in the distal colon of colitic rats. Methods Acute and subchronic colitis were induced in Wistar rats by an intracolonic enema with 2,4,6-trinitrobenzenesulfonic acid (TNBS). The colonic morphology was assessed by histological analysis and the oxidative stress parameters were measured in the intestinal homogenate. The liver damage markers were measured in the plasma. Control and colitic rats were orally treated either with one single dose (acute colitis) of copaiba oil (1.15 g Kg-1) or once a day during seven days (subchronic colitis). Results The intestinal morphology was severely modified by acute and subchronic colitis, as indicated by the intramural infiltration of polymorphonuclear cells and the increased thickness of all colon layers. The levels of TBARS, protein carbonyl groups and reactive oxygen species (ROS) were increased in the intestine of colitic rats. Copaiba oil did not attenuate the inflammatory damage in acute and subchronic colitis, but it decreased the activity of myeloperoxidase, leukocyte infiltration and oxidative stress in the colon. The level of plasma bilirubin and the activity of alkaline phosphatase were both increased in treated healthy and colitic rats. Conclusion Copaiba oil decreased oxidative stress and inflammation but did not prevent intestinal damage in the colon of colitic rats. The alterations of plasma markers of hepatic damage caused by the oil seem to be associated to its harmful action on the liver.

Abastract Levodopa analysis is important to monitor progress of patients in Parkinson's disease, as well as to determine the treatment directions. In this way, the development of an electrochemical sensor based on a glassy carbon electrode modified with gold nanoparticles supported in activated charcoal with an epichlorohydrin-reticulated chitosan film was carried out under the assistance of a Doehlert matrix design experiment. The resulting electrode was subjected to a series of characterization techniques, including scanning electron microscopy, transmission electron microscopy, and X-ray diffraction, for morphological analysis, as well as electrochemical impedance spectroscopy and cyclic voltammetry for electrochemical characterization. The active surface presented response for electrocatalytic oxidation of levodopa with high current response at reduced potential, which was applied, along with a square-wave adsorptive anodic stripping voltammetric methodology, for analysis of levodopa in different samples, presenting a three order of magnitude linear concentration range (50.0 nmol L−1 to 10.0 µmol L−1), low detection limit of 8.2 nmol L−1, good recovery analysis of spiked samples with low signal deviation under the presence of interfering species, and good accuracy front a comparative methodology.

Melatonin is a hormone that affects sleep-wake cycles and plays a role in the understanding of neuronal disorders and has excellent potential for therapeutical applications in infectious diseases, becoming an important target of chemical analysis. In this context, we report the development of an electrochemical device comprising a self-adhesive electrode based on a graphite-automotive varnish (Gr-AV) mixture as a conductive material to produce a printable ink applied over a paper adhesive easily transferred to a polyethylene terephthalate substrate. The Gr-AV electrode presented a high electrochemically active surface area which showed to be suitable for melatonin oxidation. The association of the device alongside a square-wave voltammetry method offered a linear behavior in the concentration range from 10.0 to 100.0 µmol L−1, a limit of detection of 0.49 µmol L−1, as well as presenting exciting recovery and relative standard deviation over samples analysis. The results showed the valid application of the device for the determination of melatonin in biological samples, pharmaceutical formulations, and its potential for point-of-care analysis.

Background and Purpose The pathogenesis of the inflammatory bowel diseases (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), involves aberrant interactions between a genetically susceptible individual, their microbiota and environmental factors. Alterations in xenobiotic receptor expression and function are associated with increased risk for IBD. Here, we have assessed the role of the constitutive androstane receptor (CAR), a xenobiotic receptor closely related to the pregnane X receptor, in the regulation of intestinal mucosal homeostasis. Experimental Approach CAR expression was assessed in intestinal mucosal biopsies obtained from CD and UC patients, and in C57/Bl6 mice exposed to dextran sulphate sodium (DSS; 3.5% w/v in drinking water) to evoke intestinal inflammation and tissue damage. CAR-deficient mice were exposed to DSS and mucosal healing assessed. Modulation of wound healing by CAR was assessed in vitro. The therapeutic potential of CAR activation was evaluated, using 3,3′,5,5′-tetrachloro-1,4-bis(pyridyloxy)benzene (TCPOBOP), a selective rodent CAR agonist. Key Results CAR expression was reduced in CD and UC samples, compared with expression in healthy controls. This was reproduced in our DSS studies, where CAR expression was reduced in colitic mice. CAR-deficient mice exhibited reduced healing following DSS exposure. In vitro, CAR activation accelerated intestinal epithelial wound healing by enhancing cell migration. Lastly, treating mice with TCPOBOP, following induction of colitis, enhanced mucosal healing. Conclusion and Implications Our results support the notion that xenobiotic sensing is altered during intestinal inflammation, and suggest that CAR activation may prove effective in enhancing mucosal healing in patients with IBD.

A new architecture for a sensor and a voltammetric procedure were proposed, using a glassy carbon electrode modified with nanodiamonds and dihexadecyl phosphate for determination of codeine (COD) in pharmaceutical and biological fluid samples. Square-wave voltammetry (SWV) was used and the relevant experimental parameters were optimized. Under optimal experimental conditions, the analytical curve presented a linear concentration range from 0.299 to 10.8 μmol L −1 , and a limit of detection of 54.5 nmol L − 1 . The proposed voltammetric method was used for COD determination in commercial pharmaceutical and biological fluid samples such as urine and human serum with satisfactory results.

Background The enteric microbiota has been recognized as an essential regulator of both gut and brain physiology, a complex interaction generally termed the microbiota-gut-brain axis. Disturbances to gastrointestinal physiology lead to alterations in the composition of the enteric microbiota, whereas dysbiosis can also contribute to pathophysiology. Inflammatory bowel diseases (IBD) are chronic, relapsing inflammatory conditions of the gastrointestinal tract, associated with microbial dysbiosis. Interestingly, IBD patients exhibit an increased incidence of mental illness (i.e. anxiety and depression), often termed “sickness behavior”, even during the remitting phase of their disease. Nevertheless, it is unclear if alterations in the enteric microbiota associated with IBD are responsible for the observed modification in brain function and behavior. Here, we hypothesized that sickness behavior is driven by alterations in microbial composition, which occur in the context of intestinal inflammation. Aims We sought to determine whether transfer of the microbiota from colitic mice, exhibiting sickness behaviour, into healthy counterparts would induce behavioral changes. Methods Male mice (C57Bl/6J; 8 weeks old) were used in all experiments. Colitis was induced by administration of 2.5% dextran sodium sulfate (DSS) in the drinking water for 5 days. Colonic inflammation was assessed by measuring fecal lipocalin-2 and the expression of pro-inflammatory mediators via qPCR. Cecal matter from donor mice (control or DSS treated) were collected for fecal microbiota transplant (FMT). FMT was performed via oral gavage in antibiotic-treated recipient mice. Gut bacteria were evaluated by 16S rRNA sequencing in cecal samples. Anxiety- and depression-like behavior were assessed by elevated plus maze and tail suspension test, respectively. Results DSS-treated mice exhibited clinical disease, reflected by body weight loss, increased fecal lipocalin-2 and elevated colonic pro-inflammatory cytokine transcripts. An increase in anxiety-like behavior was observed in mice with colitis, although no alterations in depression-like behavior were detected. Colitic mice exhibited a unique microbial community. Transferring cecal material from colitic mice into recipient, antibiotic-treated mice, recapitulated alterations in behavior seen in colitic donors, as shown by increased anxiety-like behavior and unexpectedly, increased depression-like behavior. These behavioral changes occurred in the absence of colonic or brain inflammation in the recipient mice, but were associated with changes in stress-related gene expression (i.e. Crh). Conclusions Colitis-associated sickness behavior can be transmitted to antibiotic-treated recipient mice via FMT, which occurs in the absence of overt intestinal or brain inflammation. Funding Agencies CIHRNational Council for Scientific and Technological Development (CNPq-Brazil)

The gut microbiome consists of a multi-kingdom microbial community. Whilst the role of bacteria as causal contributors governing host physiological development is well established, the role of fungi remains to be determined. Here, we use germ-free mice colonized with defined species of bacteria, fungi, or both to differentiate the causal role of fungi on microbiome assembly, immune development, susceptibility to colitis, and airway inflammation. Fungal colonization promotes major shifts in bacterial microbiome ecology, and has an independent effect on innate and adaptive immune development in young mice. While exclusive fungal colonization is insufficient to elicit overt dextran sulfate sodium-induced colitis, bacterial and fungal co-colonization increase colonic inflammation. Ovalbumin-induced airway inflammation reveals that bacterial, but not fungal colonization is necessary to decrease airway inflammation, yet fungi selectively promotes macrophage infiltration in the airway. Together, our findings demonstrate a causal role for fungi in microbial ecology and host immune functionality, and therefore prompt the inclusion of fungi in therapeutic approaches aimed at modulating early life microbiomes., The immunomodulatory role of commensal gut fungi and interactions with bacteria remain unclear. Here, using germ-free mice colonized with defined species of bacteria and fungi, the authors find that fungal colonization induces changes in bacterial microbiome ecology while having an independent effect on innate and adaptive immunity in mice.

Inflammatory bowel disease (IBD) is characterized by relapsing periods of gut inflammation, and is comorbid with depression, anxiety, and cognitive deficits. Animal models of IBD that explore the behavioral consequences almost exclusively use acute models of gut inflammation, which fails to recapitulate the cyclic, chronic nature of IBD. This study sought to identify behavioral differences in digging, memory, and stress-coping strategies in mice exposed to one (acute) or three (chronic) cycles of gut inflammation, using the dextran sodium sulfate (DSS) model of colitis. Similar levels of gut pathology were observed between acute and chronically exposed mice, although mice in the chronic treatment had significantly shorter colons, suggesting more severe disease. Behavioral measures revealed an unexpected pattern in which chronic treatment evoked fewer deficits than acute treatment. Specifically, acutely-treated mice showed alterations in measures of object burying, novel object recognition, object location memory, and stress-coping (forced swim task). Chronically-treated animals, however, showed similar alterations in object burying, but not the other measures. These data suggest an adaptive or tolerizing effect of repeated cycles of peripheral gut inflammation on mnemonic function and stress-coping, whereas some other behaviors continue to be affected by gut inflammation. We speculate that the normalization of some functions may involve the reversion to the baseline state of the hypothalamic-pituitary-adrenal axis and/or levels of neuroinflammation, which are both activated by the first exposure to the colitic agent.

Gut microbiomes make major contributions to the physiological and immunological development of the host, but the relative importance of their bacterial and fungal components, and how they interact, remain largely unknown. We applied carefully controlled experiments in gnotobiotic mice colonized with defined communities of bacteria, fungi, or both to differentiate the direct role of fungi on microbiome assembly, host development, and susceptibility to colitis and airway inflammation. Our results revealed that fungal colonization alone was insufficient to promote the intestinal anatomic and physiological changes seen in mice colonized by bacteria, and had limited impact on the fecal metabolome. However, fungal colonization promoted major shifts in bacterial microbiome ecology, and had an independent effect on the innate and adaptive immune development in young mice. Fungi further exacerbated some aspects of the inflammatory effects of the bacterial community during OVA-induced airway inflammation by promoting macrophage infiltration in the airway. Our results demonstrate a dominant ecological and physiological role of bacteria in gut microbiomes, but highlight fungi as an ecological factor shaping the assembly of the bacterial community and a direct capacity to impact immune system and modulate disease susceptibility. These findings demonstrate that studies focused on bacteria alone provide an incomplete portrayal on microbiome ecology and functionality, and prompt for the inclusion of fungi in human microbiome studies.

BACKGROUND: Recent studies suggest that the gut microbiota may contribute to the regulation of gastrointestinal (GI) motility. Alterations in motility are commonly associated with gastrointestinal disorders, which are linked to intestinal dysbiosis. However, the mechanisms through which the microbiota regulates GI motility remain to be fully characterized. It has recently been reported that the distribution of enteric glial cells (EGC) are altered in the context of changes in the microbiota. AIMS: Given the role that EGC play in contributing to modulation of gut motility, we hypothesized that alterations in the microbiota may trigger dysmotility through altering EGC distribution and/or function. METHODS: To test this hypothesis, we depleted the intestinal microbiota in adult C57Bl/6 mice (male and female) administering antibiotics (ABX) for three weeks, and subsequently assessed gut motility through assays including: quantifying fecal pellet output; measuring whole gut and small intestine transit time (Evan’s blue dye); and assessing colonic bead propulsion. Intestinal permeability was assessed using fluorescein sulfonic acid (FSA). Lastly, EGC morphology and distribution was assessed by immunohistochemistry using an anti-S100β antibody. RESULTS: We observed an increase in whole gut transit time in the ABX-treated male and female mice. Both male and female ABX-treated mice exhibited an increased small intestinal transit time, with no alterations in motility of the colon. The number of fecal pellets expelled per hour was not affected by ABX treatment, however, this regimen led to a greater water content in the fecal pellets. Intestinal permeability was equally increased in ABX-treated mice of both sexes. Finally, to our surprise we found no differences in the morphology or distribution of EGC in the mucosa or myenteric plexus of ABX-treated mice. CONCLUSIONS: In summary, depletion of gut microbiota led to alterations in motility in both male and female mice. The increased whole gut transit time in ABX-treated mice was associated with increased small intestinal transit time, however, we cannot rule out the contribution of changes in gastric emptying at this time. While the motility and permeability changes were striking in ABX-treated mice, we found no associated changes in the distribution of EGC. Further investigation is required to identify the underlying mechanisms through which the microbiota regulates intestinal motility and whether ABX treatment altered the function of EGC. FUNDING AGENCIES: CIHRNational Counsel of Technological and Scientific Development (CNPq – Brazil).

Bentazon (BTZ) is a post-emergence herbicide widely applied in different cultures. It is characterized by low adsorption and high solubility in water, which facilitates its penetration and contamination of aquatic environments. Human exposure to BTZ is responsible for numerous toxic effects and, therefore, it is of great importance to develop simple and efficient analytical methods capable of accurately detecting the presence of this herbicide in environmental samples. The present paper reports the development and application of a glassy carbon electrode modified with carbon nanosphere-based cross-linked chitosan film for the voltammetric determination of BTZ herbicide. The incorporation of cetyltrimethylammonium bromide surfactant into the supporting electrolyte solution helped enhance the voltammetric signal and the sensor repeatability. The use of chitosan film crosslinked with epicholorohydrin contributed toward improving the properties of the carbon nanospheres, including the electron transfer rate. A set of assays were conducted aiming optimizing the experimental parameters related to the supporting electrolyte composition (pH and surfactant concentration) and the square-wave voltammetry technique. Under optimized conditions and based on the application of the method proposed in the study, a linear concentration range of 1.99 to 65.4 μ mol L−1 was obtained, with limit of detection of 1.4 μ mol L−1 and sensitivity of 6.22 A mol−1 L cm−2. The modified electrode presented good intra- (2.8%, n = 10 ) and inter-day (1.4%, n = 5 ) repeatability and high selectivity for bentazon. The optimized electroanalytical technique was successfully applied for the quantification of bentazon in environmental water samples (recoveries close to 100%).

A novel flow injection spectrophotometric determination of ranitidine in pharmaceuticals is reported. The method is based on a compound formed in a reaction using ranitidine with and potassium permanganate in neutral media, which can be monitored at 430 nm. Under optimal conditions, an analytical curve was constructed, which was linear in the range between 5.0 × 10−5 and 1.0 × 10−3 mol L−1 with a detection limit of 1.0 × 10−5 mol L−1. In addition, the sample throughput was 60 h−1 and the obtained results for commercial formulation samples by applying the proposed method were in good agreement with labeled values and those obtained by a reference method at a 95% confidence level.

In this work, a biosensor using a glassy carbon electrode modified with gold nanoparticles (AuNPs) and tyrosinase (Tyr) within a dihexadecylphosphate film is proposed. Cystamine and glutaraldehyde crosslinking agents were used as a support for Tyr immobilization. The proposed biosensor was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and cyclic voltammetry in the presence of catechol. The determination of catechol was carried out by amperometry and presented a linear concentration range from 2.5×10(-6) to 9.5×10(-5)molL(-1) with a detection limit of 1.7×10(-7)molL(-1). The developed biosensor showed good repeatability and stability. Moreover, this novel amperometric method was successfully applied in the determination of catechol in natural water samples. The results were in agreement with a 95% confidence level for those obtained using the official spectrophotometric method.

A carbon paste electrode (CPE) was modified with graphite oxide (GrO) and β-cyclodextrin (CD) to obtain a sensor for simultaneous voltammetric determination of levodopa (LD), piroxicam (PRX), ofloxacin (OFX) and methocarbamol (MCB). The morphology, structure and electrochemical properties of the functionalized GrO were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, contact angle measurements and cyclic voltammetry. Under the optimal experimental conditions, the sensor is capable of detecting LD, PRX, OFX and MCB by square wave voltammetry (SWV) at working potentials of +0.40, +0.60, +1.03 and + 1.27 V (versus Ag/AgCl), respectively. Response is linear from 1.0 to 20 μM for LD, from 1.0 to 15 μM for PRX, from 1.0 to 20 μM for OFX, and from 1.0 to 50 μM for MCB. The respective limits of detection are 65, 105, 89 and 400 nM. The method was successfully applied to the simultaneous determination of LD, PRX, OFX and MCB in (spiked) real river water and synthetic urine samples, and the results were in agreement with those obtained using a spectrophotometric method, with recoveries close to 100%. Graphical abstract Schematic presentation of a novel electroanalytical method employing a carbon paste electrode modified with graphite oxide and β-cyclodextrin for the simultaneous determination of levodopa, piroxicam, ofloxacin and methocarbamol in urine and river water samples by square wave voltammetry.

Background Cholestatic liver disease is associated with immune-mediated inflammatory liver injury. This disorder is also associated with brain dysfunction and behavioural changes, notably fatigue, depression and social withdrawal. The mechanisms leading to these central nervous system abnormalities are unknown, however, they are associated with neuroinflammation. Microglia and astrocytes are two glial populations that play key roles in neuroinflammation. Activated glia display morphological changes, secrete cytokines, and mediate electrophysiological changes, altering the normal functioning of the brain. The aryl hydrocarbon receptor (AhR) is a transcription factor involved in the immune response. AhR is present on glia and its’ activation has been shown to reduce neuroinflammation. The role of the AhR in cholestatic liver disease has yet to be examined. Aims To study the function of the AhR in a model of cholestic liver disease. We will test the hypothesis that activation of AhR in the brain will reduce neuroinflammation and behavioral deficits observed in cholestatic mice. Methods Male C57Bl/6J mice had cholestasis induced by bile duct ligation (BDL); comparisons were made to sham-operated controls. Mice were tested for social interaction with a 4-week old juvenile in their home cage and the number of social interaction attempts quantified. Next, mice were euthanized, brains were removed and processed for immunohistochemistry. Brain sections were stained for markers of microglia (IBA-1) and astrocytes (GFAP). Microglia were counted and astrocyte activation was qualitatively assessed. PCR was used to quantify gene expression of AhR and its downstream gene targets (eg. CYP1A1) in mice that recived treatment with beta-napthoflavone (BNF), an AhR agonist, or in vehicle treated controls. Results BDL mice made significantly fewer attempts to interact with the juvenile as compared to controls (P Conclusions Cholestatic liver damage was associated with impaired social behavior. Further, glial activation, an indicator of neuroinflammation was increased in components of the limbic system associated with the response to stress, learning, and memory. Future experiments will address whether activation of the AhR will ameliorate neuroinflammation and behavioral changes observed in mice with cholestatic liver injury. Funding Agencies CCC, CIHR

A glassy carbon electrode (GCE) modified with carbon Printex 6L (Printex6L/GCE) as a novel sensor is proposed. A morphological study was carried out using scanning electron microscopy, and an electrochemical characterization of the proposed electrode was performed by cyclic voltammetry (CV) using [Fe(CN)6]4− as a redox probe. With the incorporation of the carbon Printex 6L film onto the GCE surface, the [Fe(CN)6]4− analytical signal was substantially increased and the difference between the oxidation and reduction potentials (ΔE p) decreased, a characteristic of the electrocatalytic effect. Furthermore, the use of carbon Printex 6L film resulted in an 84 % increase in the oxidation current and a 123 % increase in the reduction current. Faster charge transfer was observed at the proposed electrode/electrolyte interface during CV when compared with GCE. The Printex6L/GCE was tested for ranitidine (RNT) sensing and showed a decrease in the working potential and an increase in the analytical signal, when compared with GCE, again demonstrating an electrocatalytic effect. Under optimized experimental conditions, the developed square-wave adsorptive anodic stripping voltammetry (SWAdASV) method presented an analytical curve that was linear in RNT concentration range from 1.98 × 10−6 to 2.88 × 10−5 mol L−1 with a detection limit of 2.44 × 10−7 mol L−1. The developed Printex6L/GCE was successfully applied to the determination of RNT concentrations in human body fluid samples (urine and serum).

In this study, the performance of a glassy carbon electrode (GCE) modified with functionalized multi-walled carbon nanotubes (MWCNT) immobilized within a poly(allylamine hydrochloride) (PAH) film for the electrochemical determination of the catecholamines, levodopa (LD) and carbidopa (CD) is evaluated. The electrochemical behaviour of the MWCNT-PAH/GCE sensor was investigated via cyclic voltammetry. Under the optimum experimental conditions, the LD and CD analytes were determined by differential pulse voltammetry (DPV) using their oxidation redox processes at −24 mV and +490 mV (versus Ag/AgCl (3.0 mol L−1 KCl)), respectively. The obtained analytical curves were linear from 2.0 to 27 μmol L−1 for LD and from 2.0 to 23 μmol L−1 for CD, with limits of detection of 0.84 μmol L−1 for LD and 0.65 μmol L−1 for CD. The proposed DPV method was successfully employed for LD and CD determination in commercial pharmaceutical formulation samples, and the collected results were consistent with those obtained by the respective standard methods at a confidence level of 95%. In addition, the potentiality of the DPV method was tested for LD and CD quantification in human serum samples.

A new architecture for a biosensor is proposed using a glassy carbon electrode (GCE) modified with hemoglobin (Hb) and silver nanoparticles (AgNPs) encapsulated in poly(amidoamine) dendrimer (PAMAM). The biosensors were characterized using ultraviolet-visible spectroscopy, ζ-potential and cyclic voltammetry to investigate the interactions between Hb, AgNPs and the PAMAM film. The biosensor exhibited a well-defined cathodic peak attributed to reduction of the Fe(3+) present in the heme group in Hb, as revealed by cyclic voltammetry in the presence of O2. An apparent heterogeneous electron transfer rate of 4.1s(-1) was obtained. The Hb-AgNPs-PAMAM/GCE third generation biosensor was applied in the amperometric determination of hydrogen peroxide over the linear range from 6.0 × 10(-6) to 9.1 × 10(-5)mol L(-1) with a detection limit of 4.9 × 1 0(-6)mol L(-1). The proposed method can be extended to immobilize and evaluate the direct electron transfer of other redox enzymes.

An analytical procedure was developed for the simultaneous determination of acetaminophen (ACP) and tramadol (TRA) by flow injection analysis with multiple pulse amperometric detection (FIA–MPA) using a cathodically pretreated boron-doped diamond electrode (BDDE). The proposed method was applied to the simultaneous determination of ACP and TRA in pharmaceutical samples and synthetic biological fluids. The obtained results are in acceptable levels, the proposed method presents low RSD values (