RESUMEN
Hepatitis E Virus (HEV) genotype 1 and 2 infect an estimated 20 million people each year, via the faecal-oral transmission route. An urban outbreak of HEV occurred in Am Timan, Chad, between September 2016 and April 2017. As part of the outbreak response, Médecins Sans Frontières and the Ministry of Health implemented water and hygiene interventions, including the chlorination of town water sources. We aimed to understand whether these water treatment activities had any impact on the number of HEV infections, using geospatial analysis of epidemiological and water treatment monitoring data. By conducting cluster analysis we investigated whether there were areas of particularly high and low infection risk during the outbreak and explored the reasons for this. We observed two high-risk spatial clusters of suspected cases and one high-risk cluster of confirmed cases. Our main finding was that confirmed HEV cases had a higher median number of days of exposure to unsafe water compared to suspected and non-confirmed cases (Kruskal-Wallis Chi Square: 15.5; p < 0.001). Our study confirms the mixed, but shifting, transmission routes during this outbreak. It also highlights the spatial and temporal analytical methods, which can be employed in future outbreaks to improve understanding of HEV transmission.
Asunto(s)
Virus de la Hepatitis E , Hepatitis E/epidemiología , Purificación del Agua/métodos , Chad/epidemiología , Ciudades , Brotes de Enfermedades , Halogenación , AguaRESUMEN
Bacteria can be motile and planktonic or, alternatively, sessile and participating in the biofilm mode of growth. The transition between these lifestyles can be regulated by a second messenger, cyclic dimeric GMP (c-di-GMP). High intracellular c-di-GMP concentration correlates with biofilm formation and motility inhibition in most bacteria, including Bordetella bronchiseptica, which causes respiratory tract infections in mammals and forms biofilms in infected mice. We previously described the diguanylate cyclase BdcA as involved in c-di-GMP synthesis and motility regulation in B. bronchiseptica; here, we further describe the mechanism whereby BdcA is able to regulate motility and biofilm formation. Amino acid replacement of GGDEF with GGAAF in BdcA is consistent with the conclusion that diguanylate cyclase activity is necessary for biofilm formation and motility regulation, although we were unable to confirm the stability of the mutant protein. In the absence of the bdcA gene, B. bronchiseptica showed enhanced motility, strengthening the hypothesis that BdcA regulates motility in B. bronchiseptica We showed that c-di-GMP-mediated motility inhibition involved regulation of flagellin expression, as high c-di-GMP levels achieved by expressing BdcA significantly reduced the level of flagellin protein. We also demonstrated that protein BB2109 is necessary for BdcA activity, motility inhibition, and biofilm formation. Finally, absence of the bdcA gene affected bacterial infection, implicating BdcA-regulated functions as important for bacterium-host interactions. This work supports the role of c-di-GMP in biofilm formation and motility regulation in B. bronchiseptica, as well as its impact on pathogenesis.IMPORTANCE Pathogenesis of Bordetella spp., like that of a number of other pathogens, involves biofilm formation. Biofilms increase tolerance to biotic and abiotic factors and are proposed as reservoirs of microbes for transmission to other organs (trachea, lungs) or other hosts. Bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) is a second messenger that regulates transition between biofilm and planktonic lifestyles. In Bordetella bronchiseptica, high c-di-GMP levels inhibit motility and favor biofilm formation. In the present work, we characterized a B. bronchiseptica diguanylate cyclase, BdcA, which regulates motility and biofilm formation and affects the ability of B. bronchiseptica to colonize the murine respiratory tract. These results provide us with a better understanding of how B. bronchiseptica can infect a host.
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Proteínas Bacterianas/metabolismo , Infecciones por Bordetella/metabolismo , Infecciones por Bordetella/microbiología , Bordetella bronchiseptica/enzimología , Proteínas de Escherichia coli/metabolismo , Liasas de Fósforo-Oxígeno/metabolismo , Infecciones del Sistema Respiratorio/microbiología , Animales , Proteínas Bacterianas/genética , Infecciones por Bordetella/genética , Bordetella bronchiseptica/genética , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Ratones , Ratones Endogámicos C57BL , Movimiento , Liasas de Fósforo-Oxígeno/genéticaRESUMEN
In September 2016, Médecins Sans Frontières responded to a hepatitis E (HEV) outbreak in Chad by implementing water treatment and hygiene interventions. To evaluate the coverage and use of these interventions, we conducted a cross-sectional study in the community. Our results showed that 99% of households interviewed had received a hygiene kit from us, aimed at improving water handling practice and personal hygiene and almost all respondents had heard messages about preventing jaundice and handwashing. Acceptance of chlorination of drinking water was also very high, although at the time of interview, we were only able to measure a safe free residual chlorine level (free chlorine residual (FRC) ≥0.2 mg/L) in 43% of households. Households which had refilled water containers within the last 18 hours, had sourced water from private wells or had poured water into a previously empty container, were all more likely to have a safe FRC level. In this open setting, we were able to achieve high coverage for chlorination, hygiene messaging and hygiene kit ownership; however, a review of our technical practice is needed in order to maintain safe FRC levels in drinking water in households, particularly when water is collected from multiple sources, stored and mixed with older water.
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Hepatitis E/epidemiología , Higiene/normas , Purificación del Agua/métodos , Chad/epidemiología , Estudios Transversales , Brotes de Enfermedades , Hepatitis E/prevención & control , Humanos , Purificación del Agua/estadística & datos numéricos , Abastecimiento de Agua/estadística & datos numéricosRESUMEN
Bordetella hinzii is known to cause respiratory disease in poultry and has been associated with a variety of infections in immunocompromised humans. In addition, there are several reports of B. hinzii infections in laboratory-raised mice. Here we sequenced and analysed the complete genome sequences of multiple B. hinzii-like isolates, obtained from vendor-supplied C57BL/6 mice in animal research facilities on different continents, and we determined their taxonomic relationship to other Bordetella species. The whole-genome based and 16S rRNA gene based phylogenies each identified two separate clades in B. hinzii, one was composed of strains isolated from poultry, humans and a rabbit whereas the other clade was restricted to isolates from mice. Distinctly different estimated DNA-DNA hybridization values, average nucleotide identity scores, gene content, metabolic profiles and host specificity all provide compelling evidence for delineation of the two species, B. hinzii - from poultry, humans and rabbit - and Bordetella pseudohinzii sp. nov. type strain 8-296-03T (=NRRL B-59942T=NCTC 13808T) that infect mice.
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Bordetella/clasificación , Ratones Endogámicos C57BL/microbiología , Filogenia , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , Bordetella/genética , Bordetella/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/análisis , Humanos , Ratones , Hibridación de Ácido Nucleico , Aves de Corral , ARN Ribosómico 16S/genética , Conejos , Análisis de Secuencia de ADNRESUMEN
UNLABELLED: Vibrio cholerae is an aquatic organism and facultative human pathogen that colonizes the small intestine. In the small intestine, V. cholerae is exposed to a variety of antimicrobial compounds, including bile. V. cholerae resistance to bile is multifactorial and includes alterations in the membrane permeability barrier that are mediated by ToxR, a membrane-associated transcription factor. ToxR has also been shown to be required for activation of the LysR family transcription factor leuO in response to cyclic dipeptides. LeuO has been implicated in the regulation of multiple V. cholerae phenotypes, including biofilm production and virulence. In this study, we investigated the effects of bile on leuO expression. We show that leuO transcription increased in response to bile and bile salts but not in response to other detergents. The bile-dependent increase in leuO expression was dependent on ToxR, which was found to bind directly to the leuO promoter. The periplasmic domain of ToxR was required for basal leuO expression and for the bile-dependent induction of both leuO and ompU transcription. V. cholerae mutants that did not express leuO exhibited increased bile susceptibility, suggesting that LeuO contributes to bile resistance. Our collective results demonstrate that ToxR activates leuO expression in response to bile and that LeuO is a component of the ToxR-dependent responses that contribute to bile resistance. IMPORTANCE: The success of Vibrio cholerae as a human pathogen is dependent upon its ability to rapidly adapt to changes in its growth environment. Growth in the human gastrointestinal tract requires the expression of genes that provide resistance to host antimicrobial compounds, including bile. In this work, we show for the first time that the LysR family regulator LeuO mediates responses in V. cholerae that contribute to bile resistance.
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Proteínas Bacterianas/metabolismo , Ácidos y Sales Biliares/farmacología , Proteínas de Unión al ADN/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Factores de Transcripción/metabolismo , Vibrio cholerae/efectos de los fármacos , Vibrio cholerae/metabolismo , Proteínas Bacterianas/genética , Proteínas de Unión al ADN/genética , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Regiones Promotoras Genéticas , Estructura Terciaria de Proteína , Factores de Transcripción/genética , Vibrio cholerae/genéticaRESUMEN
The Cpx two-component regulatory system has been shown in Escherichia coli to alleviate stress caused by misfolded cell envelope proteins. The Vibrio cholerae Cpx system was previously found to respond to cues distinct from those in the E. coli system, suggesting that this system fulfills a different physiological role in the cholera pathogen. Here, we used microarrays to identify genes that were regulated by the V. cholerae Cpx system. Our observations suggest that the activation of the V. cholerae Cpx system does not induce expression of genes involved in the mitigation of stress generated by misfolded cell envelope proteins but promotes expression of genes involved in antimicrobial resistance. In particular, activation of the Cpx system induced expression of the genes encoding the VexAB and VexGH resistance-nodulation-division (RND) efflux systems and their cognate outer membrane pore protein TolC. The promoters for these loci contained putative CpxR consensus binding sites, and ectopic cpxR expression activated transcription from the promoters for the RND efflux systems. CpxR was not required for intrinsic antimicrobial resistance, but CpxR activation enhanced resistance to antimicrobial substrates of VexAB and VexGH. Mutations that inactivated VexAB or VexGH efflux activity resulted in the activation of the Cpx response, suggesting that vexAB and vexGH and the cpxP-cpxRA system are reciprocally regulated. We speculate that the reciprocal regulation of the V. cholerae RND efflux systems and the Cpx two-component system is mediated by the intracellular accumulation of an endogenously produced metabolic by-product that is normally extruded from the cell by the RND efflux systems.
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Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Vibrio cholerae/metabolismo , Proteínas Bacterianas/genética , Secuencia de Bases , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Ligamiento Genético , Proteínas de Transporte de Membrana , Datos de Secuencia Molecular , Mutación , Vibrio cholerae/genéticaRESUMEN
BACKGROUND AND OBJECTIVES: Paralysis after spinal cord injury involves damage to pathways that connect neurons in the brain to peripheral nerves in the limbs. Re-establishing this communication using neural interfaces has the potential to bridge the gap and restore upper extremity function to people with high tetraplegia. We report a novel approach for restoring upper extremity function using selective peripheral nerve stimulation controlled by intracortical microelectrode recordings from sensorimotor networks, along with restoration of tactile sensation of the hand using intracortical microstimulation. METHODS: A 27-year-old right-handed man with AIS-B (motor-complete, sensory-incomplete) C3-C4 tetraplegia was enrolled into the clinical trial. Six 64-channel intracortical microelectrode arrays were implanted into left hemisphere regions involved in upper extremity function, including primary motor and sensory cortices, inferior frontal gyrus, and anterior intraparietal area. Nine 16-channel extraneural peripheral nerve electrodes were implanted to allow targeted stimulation of right median, ulnar (2), radial, axillary, musculocutaneous, suprascapular, lateral pectoral, and long thoracic nerves, to produce selective muscle contractions on demand. Proof-of-concept studies were performed to demonstrate feasibility of using a brain-machine interface to read from and write to the brain for restoring motor and sensory functions of the participant's own arm and hand. RESULTS: Multiunit neural activity that correlated with intended motor action was successfully recorded from intracortical arrays. Microstimulation of electrodes in somatosensory cortex produced repeatable sensory percepts of individual fingers for restoration of touch sensation. Selective electrical activation of peripheral nerves produced antigravity muscle contractions, resulting in functional movements that the participant was able to command under brain control to perform virtual and actual arm and hand movements. The system was well tolerated with no operative complications. CONCLUSION: The combination of implanted cortical electrodes and nerve cuff electrodes has the potential to create bidirectional restoration of motor and sensory functions of the arm and hand after neurological injury.
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Brazo , Interfaces Cerebro-Computador , Adulto , Humanos , Masculino , Brazo/inervación , Encéfalo , Electrodos Implantados , Mano/fisiología , Cuadriplejía , Extremidad Superior , Ensayos Clínicos como AsuntoRESUMEN
Stereoelectroencephalography (SEEG) is becoming more prevalent as a planning tool for surgical treatment of intractable epilepsy. Stereoelectroencephalography uses long, thin, cylindrical "depth" electrodes containing multiple recording contacts along each electrode's length. Each lead is inserted into the brain percutaneously. The advantage of SEEG is that the electrodes can easily target deeper brain structures that are inaccessible with subdural grid electrodes, and SEEG does not require a craniotomy. Brain-machine interface (BMI) research is also becoming more common in the Epilepsy Monitoring Unit. A brain-machine interface decodes a person's desired movement or action from the recorded brain activity and then uses the decoded brain activity to control an assistive device in real time. Although BMIs are primarily being developed for use by severely paralyzed individuals, epilepsy patients undergoing invasive brain monitoring provide an opportunity to test the effectiveness of different invasive recording electrodes for use in BMI systems. This study investigated the ability to use SEEG electrodes for control of 2D cursor velocity in a BMI. Two patients who were undergoing SEEG for intractable epilepsy participated in this study. Participants were instructed to wiggle or rest the hand contralateral to their SEEG electrodes to control the horizontal velocity of a cursor on a screen. Simultaneously they were instructed to wiggle or rest their feet to control the vertical component of cursor velocity. The BMI system was designed to detect power spectral changes associated with hand and foot activity and translate those spectral changes into horizontal and vertical cursor movements in real time. During testing, participants used their decoded SEEG signals to move the brain-controlled cursor to radial targets that appeared on the screen. Although power spectral information from 28 to 32 electrode contacts were used for cursor control during the experiment, post hoc analysis indicated that better control may have been possible using only a single SEEG depth electrode containing multiple recording contacts in both hand and foot cortical areas. These results suggest that the advantages of using SEEG for epilepsy monitoring may also apply to using SEEG electrodes in BMI systems. Specifically, SEEG electrodes can target deeper brain structures, such as foot motor cortex, and both hand and foot areas can be targeted with a single SEEG electrode implanted percutaneously. Therefore, SEEG electrodes may be an attractive option for simple BMI systems that use power spectral modulation in hand and foot cortex for independent control of 2 degrees of freedom.
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Interfaces Cerebro-Computador , Encéfalo/fisiopatología , Electroencefalografía , Epilepsia/patología , Electrodos , Epilepsia/fisiopatología , Humanos , Neuroimagen , Técnicas EstereotáxicasRESUMEN
BACKGROUND: Brain-computer interface (BCI) systems have been developed to provide paralyzed individuals the ability to command the movements of an assistive device using only their brain activity. BCI systems are typically tested in a controlled laboratory environment were the user is focused solely on the brain-control task. However, for practical use in everyday life people must be able to use their brain-controlled device while mentally engaged with the cognitive responsibilities of daily activities and while compensating for any inherent dynamics of the device itself. BCIs that use electroencephalography (EEG) for movement control are often assumed to require significant mental effort, thus preventing users from thinking about anything else while using their BCI. This study tested the impact of cognitive load as well as speaking on the ability to use an EEG-based BCI. FINDINGS: Six participants controlled the two-dimensional (2D) movements of a simulated neuroprosthesis-arm under three different levels of cognitive distraction. The two higher cognitive load conditions also required simultaneously speaking during BCI use. On average, movement performance declined during higher levels of cognitive distraction, but only by a limited amount. Movement completion time increased by 7.2%, the percentage of targets successfully acquired declined by 11%, and path efficiency declined by 8.6%. Only the decline in percentage of targets acquired and path efficiency were statistically significant (p < 0.05). CONCLUSION: People who have relatively good movement control of an EEG-based BCI may be able to speak and perform other cognitively engaging activities with only a minor drop in BCI-control performance.
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Atención/fisiología , Interfaces Cerebro-Computador , Encéfalo/fisiología , Prótesis e Implantes , Interfaz Usuario-Computador , Brazo , Electroencefalografía , HumanosRESUMEN
Health and social care professional practice needs to move with the times and to respond to the ever-changing combination of health needs, economic realities and health-policy imperatives. A clear understanding of the variety of forces at play and the ability to marshal these to good effect by working in partnership with multidisciplinary colleagues and children/families is a must, not least in this time of economic austerity and ever-rising health inequalities, when vulnerable children's lives and complex family relationships and behaviours so easily become increasingly strained and challenged. This sad reality calls out for relevant joined-up solutions by all participants--an agenda so often called into question by court judgement after court judgement. The multidisciplinary workshops to be discussed have developed and changed over the past decade and provide a safe but realistic learning environment for students from health and social care backgrounds to experience the difficulties and barriers to good multidisciplinary working, to better understand others' perspectives and activities and consider and develop new and better practical strategies for working with multidisciplinary professional colleagues, children and families. All of the workshops are underpinned by specific discipline-focused theoretical work.
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Protección a la Infancia , Enfermería en Salud Comunitaria/educación , Competencia Cultural/educación , Servicios de Enfermería Escolar/educación , Servicio Social/educación , Niño , Inglaterra , Humanos , Estudios Interdisciplinarios , Desarrollo de Programa , Enseñanza/métodosRESUMEN
Background: Paralysis after spinal cord injury involves damage to pathways that connect neurons in the brain to peripheral nerves in the limbs. Re-establishing this communication using neural interfaces has the potential to bridge the gap and restore upper extremity function to people with high tetraplegia. Objective: We report a novel approach for restoring upper extremity function using selective peripheral nerve stimulation controlled by intracortical microelectrode recordings from sensorimotor networks, along with restoration of tactile sensation of the hand using intracortical microstimulation. Methods: A right-handed man with motor-complete C3-C4 tetraplegia was enrolled into the clinical trial. Six 64-channel intracortical microelectrode arrays were implanted into left hemisphere regions involved in upper extremity function, including primary motor and sensory cortices, inferior frontal gyrus, and anterior intraparietal area. Nine 16-channel extraneural peripheral nerve electrodes were implanted to allow targeted stimulation of right median, ulnar (2), radial, axillary, musculocutaneous, suprascapular, lateral pectoral, and long thoracic nerves, to produce selective muscle contractions on demand. Proof-of-concept studies were performed to demonstrate feasibility of a bidirectional brain-machine interface to restore function of the participant's own arm and hand. Results: Multi-unit neural activity that correlated with intended motor action was successfully recorded from intracortical arrays. Microstimulation of electrodes in somatosensory cortex produced repeatable sensory percepts of individual fingers for restoration of touch sensation. Selective electrical activation of peripheral nerves produced antigravity muscle contractions. The system was well tolerated with no operative complications. Conclusion: The combination of implanted cortical electrodes and nerve cuff electrodes has the potential to allow restoration of motor and sensory functions of the arm and hand after neurological injury.
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OBJECTIVES: Previous studies have identified behavioral phenotypes that predispose genetically vulnerable youth to a later onset of bipolar I or II disorder, but few studies have examined whether early psychosocial intervention can reduce risk of syndromal conversion. In a one-year open trial, we tested a version of family-focused treatment adapted for youth at high risk for bipolar disorder (FFT-HR). METHODS: A referred sample of 13 children (mean 13.4±2.69 years; 4 boys, 9 girls) who had a parent with bipolar I or II disorder participated at one of two outpatient specialty clinics. Youth met DSM-IV criteria for major depressive disorder (n=8), cyclothymic disorder (n=1), or bipolar disorder not otherwise specified (n=4), with active mood symptoms in the past month. Participants were offered FFT-HR (12 sessions in four months) with their parents, plus psychotropic medications as needed. Independent evaluators assessed depressive symptoms, hypomanic symptoms, and global functioning at baseline and then every four months for one year, with retrospective severity and impairment ratings made for each week of the follow-up interval. RESULTS: Families were mostly adherent to the treatment protocol (85% retention), and therapists administered the FFT-HR manual with high levels of fidelity. Youth showed significant improvements in depression, hypomania, and psychosocial functioning scores on the Adolescent Longitudinal Interval Follow-up Evaluation. They also showed significant improvements in Young Mania Rating Scale and Children's Depression Rating Scale scores. CONCLUSIONS: FFT-HR is a promising intervention for youth at high risk for BD. Larger-scale randomized trials that follow youth into young adulthood will be necessary to determine whether early psychosocial intervention can reduce the probability of developing bipolar I or II disorder among genetically vulnerable youth.
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Trastorno Bipolar/terapia , Trastorno Depresivo/terapia , Terapia Familiar/métodos , Adolescente , Edad de Inicio , Trastorno Bipolar/diagnóstico , Trastorno Bipolar/genética , Niño , Comunicación , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/genética , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Cooperación del Paciente , Educación del Paciente como Asunto , Solución de Problemas , Psicotrópicos/uso terapéutico , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Objective.Intracortical recordings have now been combined with functional electrical stimulation (FES) of arm/hand muscles to demonstrate restoration of upper-limb function after spinal cord injury. However, for each desired limb position decoded from the brain, there are multiple combinations of muscle stimulation levels that can produce that position. The objective of this simulation study is to explore how modulating the amount of coactivation of antagonist muscles during FES can impact reaching performance and energy usage. Stiffening the limb by cocontracting antagonist muscles makes the limb more resistant to perturbation. Minimizing cocontraction saves energy and reduces fatigue.Approach.Prior demonstrations of reaching via FES used a fixed empirically-derived lookup table for each joint that defined the muscle stimulation levels that would position the limb at the desired joint angle decoded from the brain at each timestep. This study expands on that previous work by using simulations to: (a) test the feasibility of controlling arm reaching using asuiteof lookup tables with varying levels of cocontraction instead of a single fixed lookup table for each joint, (b) optimize a simple function for automatically switching between these different cocontraction tables using only the desired kinematic information already being decoded from the brain, and (c) compare energy savings and movement performance when using the optimized function to automatically modulate cocontraction during reaching versus using the best fixed level of cocontraction.Main results.Our data suggests energy usage and/or movement performance can be significantly improved by dynamically modulating limb stiffness using our multi-table method and a simple function that determines cocontraction level based on decoded endpoint speed and its derivative.Significance.By demonstrating how modulating cocontraction can reduce energy usage while maintaining or even improving movement performance, this study makes brain-controlled FES a more viable option for restoration of reaching after paralysis.
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Movimiento , Extremidad Superior , Estimulación Eléctrica , Mano , Músculo EsqueléticoRESUMEN
Obesity remains prevalent in the US. One potential treatment is vagus nerve stimulation (VNS), which activates the sensory afferents innervating the stomach that convey stomach volume and establish satiety. However, current VNS approaches and stimulus optimization could benefit from additional understanding of the underlying neural response to stomach distension. In this study, obesity-prone Sprague Dawley rats consumed a standard, high-carbohydrate, or high-fat diet for several months, leading to diet-induced obesity in the latter two groups. Under anesthesia, the neural activity in the vagus nerve was recorded with a penetrating microelectrode array while the stomach was distended with an implanted balloon. Vagal tone during distension was compared to baseline tone prior to distension. Responses were strongly correlated with stomach distension, but the sensitivity to distension was significantly lower in animals that had been fed the nonstandard diets. The results indicate that both high fat and high carbohydrate diets impair vagus activity.
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Carbohidratos/efectos adversos , Dieta Alta en Grasa/efectos adversos , Obesidad/fisiopatología , Nervio Vago/efectos de los fármacos , Potenciales de Acción/efectos de los fármacos , Anestesia , Animales , Peso Corporal/efectos de los fármacos , Carbohidratos/farmacología , Modelos Animales de Enfermedad , Humanos , Obesidad/inducido químicamente , Obesidad/metabolismo , Ratas , Estómago/inervación , Estómago/fisiopatología , Nervio Vago/fisiopatología , Estimulación del Nervio VagoRESUMEN
(1) Background: Intracortical microelectrodes (IMEs) are essential to basic brain research and clinical brain-machine interfacing applications. However, the foreign body response to IMEs results in chronic inflammation and an increase in levels of reactive oxygen and nitrogen species (ROS/RNS). The current study builds on our previous work, by testing a new delivery method of a promising antioxidant as a means of extending intracortical microelectrodes performance. While resveratrol has shown efficacy in improving tissue response, chronic delivery has proven difficult because of its low solubility in water and low bioavailability due to extensive first pass metabolism. (2) Methods: Investigation of an intraventricular delivery of resveratrol in rats was performed herein to circumvent bioavailability hurdles of resveratrol delivery to the brain. (3) Results: Intraventricular delivery of resveratrol in rats delivered resveratrol to the electrode interface. However, intraventricular delivery did not have a significant impact on electrophysiological recordings over the six-week study. Histological findings indicated that rats receiving intraventricular delivery of resveratrol had a decrease of oxidative stress, yet other biomarkers of inflammation were found to be not significantly different from control groups. However, investigation of the bioavailability of resveratrol indicated a decrease in resveratrol accumulation in the brain with time coupled with inconsistent drug elution from the cannulas. Further inspection showed that there may be tissue or cellular debris clogging the cannulas, resulting in variable elution, which may have impacted the results of the study. (4) Conclusions: These results indicate that the intraventricular delivery approach described herein needs further optimization, or may not be well suited for this application.
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Previously, we showed that human umbilical cord blood (UCB) regulatory T cells (Tregs) could be expanded approximately 100-fold using anti-CD3/28 monoclonal antibody (mAb)-coated beads to provide T-cell receptor and costimulatory signals. Because Treg numbers from a single UCB unit are limited, we explored the use of cell-based artificial antigen-presenting cells (aAPCs) preloaded with anti-CD3/28 mAbs to achieve higher levels of Treg expansion. Compared with beads, aAPCs had similar expansion properties while significantly increasing transforming growth factor beta (TGF-beta) secretion and the potency of Treg suppressor function. aAPCs modified to coexpress OX40L or 4-1BBL expanded UCB Tregs to a significantly greater extent than bead- or nonmodified aAPC cultures, reaching mean expansion levels exceeding 1250-fold. Despite the high expansion and in contrast to studies using other Treg sources, neither OX40 nor 4-1BB signaling of UCB Tregs reduced in vitro suppression. UCB Tregs expanded with 4-1BBL expressing aAPCs had decreased levels of proapoptotic bim. UCB Tregs expanded with nonmodified or modified aAPCs versus beads resulted in higher survival associated with increased Treg persistence in a xeno-geneic graft-versus-host disease lethality model. These data offer a novel approach for UCB Treg expansion using aAPCs, including those coexpressing OX40L or 4-1BBL.
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Células Presentadoras de Antígenos/inmunología , Sangre Fetal/citología , Receptores OX40/inmunología , Linfocitos T Reguladores/citología , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/inmunología , Ligando 4-1BB/metabolismo , Animales , Células Presentadoras de Antígenos/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteína 11 Similar a Bcl2 , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Sangre Fetal/efectos de los fármacos , Enfermedad Injerto contra Huésped/inmunología , Humanos , Proteínas de la Membrana/metabolismo , Ratones , Microesferas , Proteínas Proto-Oncogénicas/metabolismo , Sirolimus/farmacología , Análisis de Supervivencia , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/inmunologíaRESUMEN
An efficient two-step route to a broad range of aza- and diazaindoles was established, starting from chloroamino-N-heterocycles, without the need for protecting groups. The method involves an optimized Suzuki-Miyaura coupling with (2-ethoxyvinyl)borolane followed by acetic acid-catalyzed cyclization.
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Compuestos Aza/síntesis química , Compuestos de Boro/química , Cloraminas/química , Indoles/química , Indoles/síntesis química , Compuestos de Vinilo/química , Compuestos Aza/química , Catálisis , Espectroscopía de Resonancia Magnética , Modelos Químicos , Relación Estructura-ActividadRESUMEN
INTRODUCTION: Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes. METHODS: We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission. RESULTS: Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both. CONCLUSIONS: Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.
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Cólera/prevención & control , Brotes de Enfermedades/prevención & control , Epidemias/prevención & control , Composición Familiar , Guías como Asunto/normas , Saneamiento/métodos , Purificación del Agua/métodos , Cólera/microbiología , Cólera/transmisión , Humanos , Agencias Internacionales , Microbiología del AguaRESUMEN
Long-term reliability of intracortical microelectrodes remains a challenge for increased acceptance and deployment. There are conflicting reports comparing measurements associated with recording quality with postmortem histology, in attempts to better understand failure of intracortical microelectrodes (IMEs). Our group has recently introduced the assessment of motor behavior tasks as another metric to evaluate the effects of IME implantation. We hypothesized that adding the third dimension to our analysis, functional behavior testing, could provide substantial insight on the health of the tissue, success of surgery/implantation, and the long-term performance of the implanted device. Here we present our novel analysis scheme including: (1) the use of numerical formal concept analysis (nFCA) and (2) a regression analysis utilizing modern model/variable selection. The analyses found complimentary relationships between the variables. The histological variables for glial cell activation had associations between each other, as well as the neuronal density around the electrode interface. The neuronal density had associations to the electrophysiological recordings and some of the motor behavior metrics analyzed. The novel analyses presented herein describe a valuable tool that can be utilized to assess and understand relationships between diverse variables being investigated. These models can be applied to a wide range of ongoing investigations utilizing various devices and therapeutics.
RESUMEN
Progress has been made in the field of neural interfacing using both mouse and rat models, yet standardization of these models' interchangeability has yet to be established. The mouse model allows for transgenic, optogenetic, and advanced imaging modalities which can be used to examine the biological impact and failure mechanisms associated with the neural implant itself. The ability to directly compare electrophysiological data between mouse and rat models is crucial for the development and assessment of neural interfaces. The most obvious difference in the two rodent models is size, which raises concern for the role of device-induced tissue strain. Strain exerted on brain tissue by implanted microelectrode arrays is hypothesized to affect long-term recording performance. Therefore, understanding any potential differences in tissue strain caused by differences in the implant to tissue size ratio is crucial for validating the interchangeability of rat and mouse models. Hence, this study is aimed at investigating the electrophysiological variances and predictive device-induced tissue strain. Rat and mouse electrophysiological recordings were collected from implanted animals for eight weeks. A finite element model was utilized to assess the tissue strain from implanted intracortical microelectrodes, taking into account the differences in the depth within the cortex, implantation depth, and electrode geometry between the two models. The rat model demonstrated a larger percentage of channels recording single unit activity and number of units recorded per channel at acute but not chronic time points, relative to the mouse model Additionally, the finite element models also revealed no predictive differences in tissue strain between the two rodent models. Collectively our results show that these two models are comparable after taking into consideration some recommendations to maintain uniform conditions for future studies where direct comparisons of electrophysiological and tissue strain data between the two animal models will be required.