Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 236
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-39287762

RESUMEN

The Deep South is the epicenter of the HIV-epidemic in the United States, with rural AAs bearing the greatest burden. Traditional efforts to improve testing efforts have been largely unsuccessful due to their failure to recognize and leverage the sociopolitical and cultural factors that affect the uptake of HIV-screening interventions at the community level. The purpose of this study was to gain a deeper understanding of the socio-cultural contexts impacting HIV-testing in the rural South, and to assess strategies to increase testing in rural, Southern communities. Focus groups (n = 8) and semi-structured interviews (n = 31) were conducted among community and faith-based leaders in Alabama and Mississippi, to inform our understanding of local perceptions of HIV infection, barriers and facilitators impacting HIV-testing, and best strategies for improving testing efforts at the local level. Interviews and focus groups were audio-recorded, transcribed verbatim, and analyzed to extract major themes. While both faith-based and community leaders reported at least some stigmatizing attitudes towards HIV infection, faith-based leaders were more likely to report discomfort being around someone with HIV and were more likely to link the spread of HIV to immoral behaviors. The combination of the cultural importance of the Church, deep-seated religiosity among community members, and faith-based messages associating HIV infection with immorality directly impacted HIV stigma within the community-in turn, decreasing willingness to participate in HIV-testing, disclose positive HIV serostatus, or openly discuss transmission protection behaviors. The Church was identified as crucial to include to improve HIV-testing efforts in the rural South, due to their prominent sociopolitical roles within communities and ability to influence community members' perceptions of HIV stigma. Faith-based leaderships should be included in initiatives to increase improve HIV-testing and awareness of status and reduce HIV disparities in the Deep South.

2.
Microbiol Mol Biol Rev ; 88(3): e0014423, 2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39158275

RESUMEN

SUMMARYUnderstanding the dynamic adaptive plasticity of microorganisms has been advanced by studying their responses to extreme environments. Spaceflight research platforms provide a unique opportunity to study microbial characteristics in new extreme adaptational modes, including sustained exposure to reduced forces of gravity and associated low fluid shear force conditions. Under these conditions, unexpected microbial responses occur, including alterations in virulence, antibiotic and stress resistance, biofilm formation, metabolism, motility, and gene expression, which are not observed using conventional experimental approaches. Here, we review biological and physical mechanisms that regulate microbial responses to spaceflight and spaceflight analog environments from both the microbe and host-microbe perspective that are relevant to human health and habitat sustainability. We highlight instrumentation and technology used in spaceflight microbiology experiments, their limitations, and advances necessary to enable next-generation research. As spaceflight experiments are relatively rare, we discuss ground-based analogs that mimic aspects of microbial responses to reduced gravity in spaceflight, including those that reduce mechanical forces of fluid flow over cell surfaces which also simulate conditions encountered by microorganisms during their terrestrial lifecycles. As spaceflight mission durations increase with traditional astronauts and commercial space programs send civilian crews with underlying health conditions, microorganisms will continue to play increasingly critical roles in health and habitat sustainability, thus defining a new dimension of occupational health. The ability of microorganisms to adapt, survive, and evolve in the spaceflight environment is important for future human space endeavors and provides opportunities for innovative biological and technological advances to benefit life on Earth.


Asunto(s)
Ecosistema , Vuelo Espacial , Humanos , Ingravidez , Biopelículas/crecimiento & desarrollo , Bacterias/metabolismo , Adaptación Fisiológica
3.
Gut Microbes ; 16(1): 2357767, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38783686

RESUMEN

The ability of bacteria to sense and respond to mechanical forces has important implications for pathogens during infection, as they experience wide fluid shear fluctuations in the host. However, little is known about how mechanical forces encountered in the infected host drive microbial pathogenesis. Herein, we combined mathematical modeling with hydrodynamic bacterial culture to profile transcriptomic and pathogenesis-related phenotypes of multidrug resistant S. Typhimurium (ST313 D23580) under different fluid shear conditions relevant to its transition from the intestinal tract to the bloodstream. We report that D23580 exhibited incremental changes in transcriptomic profiles that correlated with its pathogenic phenotypes in response to these progressive increases in fluid shear. This is the first demonstration that incremental changes in fluid shear forces alter stress responses and gene expression in any ST313 strain and offers mechanistic insight into how forces encountered by bacteria during infection might impact their disease-causing ability in unexpected ways.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple , Fenotipo , Salmonella typhimurium , Salmonella typhimurium/genética , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Salmonella/microbiología , Infecciones por Salmonella/genética , Regulación Bacteriana de la Expresión Génica , Humanos , Hidrodinámica , Transcriptoma , Estrés Mecánico
4.
mSphere ; 7(4): e0021022, 2022 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-35913142

RESUMEN

The discovery that biomechanical forces regulate microbial virulence was established with the finding that physiological low fluid shear (LFS) forces altered gene expression, stress responses, and virulence of the enteric pathogen Salmonella enterica serovar Typhimurium during the log phase. These log phase LFS-induced phenotypes were independent of the master stress response regulator, RpoS (σS). Given the central importance of RpoS in regulating stationary-phase stress responses of S. Typhimurium cultured under conventional shake flask and static conditions, we examined its role in stationary-phase cultures grown under physiological LFS. We constructed an isogenic rpoS mutant derivative of wild-type S. Typhimurium and compared the ability of these strains to survive in vitro pathogenesis-related stresses that mimic those encountered in the infected host and environment. We also compared the ability of these strains to colonize (adhere, invade, and survive within) human intestinal epithelial cell cultures. Unexpectedly, LFS-induced resistance of stationary-phase S. Typhimurium cultures to acid and bile salts stresses did not rely on RpoS. Likewise, RpoS was dispensable for stationary-phase LFS cultures to adhere to and survive within intestinal epithelial cells. In contrast, the resistance of these cultures to challenges of oxidative and thermal stresses, and their invasion into intestinal epithelial cells was influenced by RpoS. These findings expand our mechanistic understanding of how physiological fluid shear forces modulate stationary-phase S. Typhimurium physiology in unexpected ways and provide clues into microbial mechanobiology and nuances of Salmonella responses to microenvironmental niches in the infected host. IMPORTANCE Bacterial pathogens respond dynamically to a variety of stresses in the infected host, including physical forces of fluid flow (fluid shear) across their surfaces. While pathogens experience wide fluctuations in fluid shear during infection, little is known about how these forces regulate microbial pathogenesis. This is especially important for stationary-phase bacterial growth, which is a critical period to understand microbial resistance, survival, and infection potential, and is regulated in many bacteria by the general stationary-phase stress response protein RpoS. Here, we showed that, unlike conventional culture conditions, several stationary-phase Salmonella pathogenic stress responses were not impacted by RpoS when bacteria were cultured under fluid shear conditions relevant to those encountered in the intestine of the infected host. These findings offer new insight into how physiological fluid shear forces encountered by Salmonella during infection might impact pathogenic responses in unexpected ways that are relevant to their disease-causing ability.


Asunto(s)
Salmonella typhimurium , Factor sigma , Ácidos/metabolismo , Proteínas Bacterianas/metabolismo , Humanos , Salmonella typhimurium/metabolismo , Factor sigma/genética , Factor sigma/metabolismo , Virulencia/genética
5.
Front Cell Infect Microbiol ; 12: 705647, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35711662

RESUMEN

Physical forces associated with spaceflight and spaceflight analogue culture regulate a wide range of physiological responses by both bacterial and mammalian cells that can impact infection. However, our mechanistic understanding of how these environments regulate host-pathogen interactions in humans is poorly understood. Using a spaceflight analogue low fluid shear culture system, we investigated the effect of Low Shear Modeled Microgravity (LSMMG) culture on the colonization of Salmonella Typhimurium in a 3-D biomimetic model of human colonic epithelium containing macrophages. RNA-seq profiling of stationary phase wild type and Δhfq mutant bacteria alone indicated that LSMMG culture induced global changes in gene expression in both strains and that the RNA binding protein Hfq played a significant role in regulating the transcriptional response of the pathogen to LSMMG culture. However, a core set of genes important for adhesion, invasion, and motility were commonly induced in both strains. LSMMG culture enhanced the colonization (adherence, invasion and intracellular survival) of Salmonella in this advanced model of intestinal epithelium using a mechanism that was independent of Hfq. Although S. Typhimurium Δhfq mutants are normally defective for invasion when grown as conventional shaking cultures, LSMMG conditions unexpectedly enabled high levels of colonization by an isogenic Δhfq mutant. In response to infection with either the wild type or mutant, host cells upregulated transcripts involved in inflammation, tissue remodeling, and wound healing during intracellular survival. Interestingly, infection by the Δhfq mutant led to fewer transcriptional differences between LSMMG- and control-infected host cells relative to infection with the wild type strain. This is the first study to investigate the effect of LSMMG culture on the interaction between S. Typhimurium and a 3-D model of human intestinal tissue. These findings advance our understanding of how physical forces can impact the early stages of human enteric salmonellosis.


Asunto(s)
Biomimética , Vuelo Espacial , Animales , Técnicas de Cocultivo , Interacciones Huésped-Patógeno , Humanos , Mamíferos , Salmonella typhimurium/genética
7.
Eur Neuropsychopharmacol ; 56: 50-59, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34933219

RESUMEN

Cognitive impairment is an emerging treatment target in patients with bipolar disorder (BD) but so far, no evidence-based treatment options are available. Recent studies indicate promising effects of Cognitive Remediation (CR) interventions, but it is unclear who responds most to these interventions. This report aimed to investigate whether pre-treatment dorsal prefrontal cortex (dPFC) thickness predicts improvement of executive function in response to Action-Based Cognitive Remediation (ABCR) in patients with BD. Complete baseline magnetic resonance imaging (MRI) data were available from 45 partially or fully remitted patients with BD from our randomized controlled ABCR trial (ABCR: n = 25, control group: n = 20). We performed cortical reconstruction and volumetric segmentation using FreeSurfer. Multiple linear regression analysis was conducted to assess the influence of dPFC thickness on ABCR-related executive function improvement, reflected by change in the One Touch Stocking of Cambridge performance from baseline to post-treatment. We also conducted whole brain vertex wise analysis for exploratory purposes. Groups were well-matched for demographic and clinical variables. Less pre-treatment dPFC thickness was associated with greater effect of ABCR on executive function (p = 0.02). Further, whole-brain vertex analysis revealed an association between smaller pre-treatment superior temporal gyrus volume and greater ABCR-related executive function improvement. The observed associations suggest that structural abnormalities in dPFC and superior temporal gyrus are key neurocircuitry treatment targets for CR interventions that target impaired executive function in BD.


Asunto(s)
Trastorno Bipolar , Remediación Cognitiva , Trastorno Bipolar/complicaciones , Trastorno Bipolar/diagnóstico por imagen , Trastorno Bipolar/terapia , Encéfalo/diagnóstico por imagen , Remediación Cognitiva/métodos , Función Ejecutiva , Humanos , Imagen por Resonancia Magnética
8.
Cardiovasc Diabetol ; 20(1): 219, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34753480

RESUMEN

BACKGROUND: Recent studies indicated that sodium glucose cotransporter (SGLT)2 inhibition increases levels of ketone bodies in the blood in patients with type 1 and 2 diabetes. Other studies suggested that in patients with chronic heart failure (CHF), increased myocardial oxygen demand can be provided by ketone bodies as a fuel substrate. Experimental studies reported that ketone bodies, specifically beta-hydroxybutyrate (ß-OHB) may increase blood pressure (BP) by impairing endothelium-dependant relaxation, thereby leading to increased vascular stiffness. In our study we assessed whether the SGLT 2 inhibition with empagliflozin increases ketone bodies in patients with stable CHF and whether such an increase impairs BP and vascular function. METHODS: In a prospective, double blind, placebo controlled, parallel-group single centre study 75 patients with CHF (left ventricular ejection fraction 39.0 ± 8.2%) were randomised (2:1) to the SGLT-2 inhibitor empagliflozin 10 mg orally once daily or to placebo, 72 patients completed the study. After a run-in phase we evaluated at baseline BP by 24 h ambulatory blood pressure (ABP) monitoring, vascular stiffness parameters by the SphygmoCor system (AtCor Medical, Sydney, NSW, Australia) and fasting metabolic parameters, including ß-OHB by an enzymatic assay (Beckman Coulter DxC 700 AU). The same measurements were repeated 12 weeks after treatment. In 19 of the 72 patients serum levels of ß-OHB were beneath the lower border of our assay (< 0.05 mmol/l) therefore being excluded from the subsequent analysis. RESULTS: In patients with stable CHF, treatment with empagliflozin (n = 36) was followed by an increase of ß-OHB by 33.39% (p = 0.017), reduction in 24 h systolic (p = 0.038) and diastolic (p = 0.085) ABP, weight loss (p = 0.003) and decrease of central systolic BP (p = 0.008) and central pulse pressure (p = 0.008). The increase in ß-OHB was related to an attenuated decrease of empagliflozin-induced 24 h systolic (r = 0.321, p = 0.069) and diastolic (r = 0.516, p = 0.002) ABP and less reduction of central systolic BP (r = 0.470, p = 0.009) and central pulse pressure (r = 0.391, p = 0.033). No significant changes were seen in any of these parameters after 12 weeks of treatment in the placebo group (n = 17). CONCLUSION: In patients with stable CHF ketone bodies as assessed by ß-OHB increased after treatment with empagliflozin. This increase led to an attenuation of the beneficial effects of empagliflozin on BP and vascular parameters. Trial registration The study was registered at http://www.clinicaltrials.gov (NCT03128528).


Asunto(s)
Ácido 3-Hidroxibutírico/sangre , Compuestos de Bencidrilo/uso terapéutico , Glucósidos/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Anciano , Compuestos de Bencidrilo/efectos adversos , Biomarcadores/sangre , Presión Sanguínea/efectos de los fármacos , Enfermedad Crónica , Método Doble Ciego , Femenino , Alemania , Glucósidos/efectos adversos , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Inhibidores del Cotransportador de Sodio-Glucosa 2/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Regulación hacia Arriba , Rigidez Vascular/efectos de los fármacos
9.
NPJ Biofilms Microbiomes ; 7(1): 70, 2021 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-34489467

RESUMEN

While sequencing technologies have revolutionized our knowledge of microbial diversity, little is known about the dynamic emergent phenotypes that arise within the context of mixed-species populations, which are not fully predicted using sequencing technologies alone. The International Space Station (ISS) is an isolated, closed human habitat that can be harnessed for cross-sectional and longitudinal functional microbiome studies. Using NASA-archived microbial isolates collected from the ISS potable water system over several years, we profiled five phenotypes: antibiotic resistance, metabolism, hemolysis, and biofilm structure/composition of individual or multispecies communities, which represent characteristics that could negatively impact astronaut health and life-support systems. Data revealed a temporal dependence on interactive behaviors, suggesting possible microbial adaptation over time within the ecosystem. This study represents one of the most extensive phenotypic characterization of ISS potable water microbiota with implications for microbial risk assessments of water systems in built environments in space and on Earth.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Agua Potable/microbiología , Microbiota , Vuelo Espacial , Antiinfecciosos , Astronautas , Bacterias/clasificación , Bacterias/aislamiento & purificación , Estudios Transversales , Humanos , Propiedades de Superficie
10.
NPJ Microgravity ; 7(1): 9, 2021 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-33750813

RESUMEN

Spaceflight uniquely alters the physiology of both human cells and microbial pathogens, stimulating cellular and molecular changes directly relevant to infectious disease. However, the influence of this environment on host-pathogen interactions remains poorly understood. Here we report our results from the STL-IMMUNE study flown aboard Space Shuttle mission STS-131, which investigated multi-omic responses (transcriptomic, proteomic) of human intestinal epithelial cells to infection with Salmonella Typhimurium when both host and pathogen were simultaneously exposed to spaceflight. To our knowledge, this was the first in-flight infection and dual RNA-seq analysis using human cells.

12.
Sci Rep ; 9(1): 9911, 2019 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-31289321

RESUMEN

Over the course of a mission to the International Space Station (ISS) crew members are exposed to a number of stressors that can potentially alter the composition of their microbiomes and may have a negative impact on astronauts' health. Here we investigated the impact of long-term space exploration on the microbiome of nine astronauts that spent six to twelve months in the ISS. We present evidence showing that the microbial communities of the gastrointestinal tract, skin, nose and tongue change during the space mission. The composition of the intestinal microbiota became more similar across astronauts in space, mostly due to a drop in the abundance of a few bacterial taxa, some of which were also correlated with changes in the cytokine profile of crewmembers. Alterations in the skin microbiome that might contribute to the high frequency of skin rashes/hypersensitivity episodes experienced by astronauts in space were also observed. The results from this study demonstrate that the composition of the astronauts' microbiome is altered during space travel. The impact of those changes on crew health warrants further investigation before humans embark on long-duration voyages into outer space.


Asunto(s)
Astronautas , Bacterias/clasificación , Bacterias/aislamiento & purificación , Citocinas/sangre , ADN Bacteriano/análisis , Microbiota , Saliva/microbiología , Bacterias/genética , Monitoreo del Ambiente , Humanos , Estudios Longitudinales , Vuelo Espacial/instrumentación , Factores de Tiempo
13.
J Affect Disord ; 257: 382-389, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31302528

RESUMEN

BACKGROUND: Trials targeting cognition in bipolar disorder (BD) are advised to include a measure of functional capacity as key secondary or co-primary outcome to assess whether treatment efficacy on cognition translates into enhanced functional capacity. However, it is unclear which measure of functional capacity shows the strongest association with objectively-measured cognition and may thus be best suited for inclusion in cognition trials. METHODS: Participants (N = 58) with BD in partial or full remission with objective cognitive impairment and healthy controls (N = 37) were assessed with mood ratings and were given a comprehensive battery of neuropsychological tests and a questionnaire assessing subjective cognitive function, respectively. They were also assessed with performance-based, interview-based and self-reported measures of functional capacity. Associations between objective and subjective cognition and measures of functional capacity were assessed with correlation analyses. For significant correlations, multiple regression analyses were conducted to assess if the associations remained significant after adjustment for clinical and demographic variables. RESULTS: Objectively-measured cognition was directly associated with performance-based functional capacity (ß = 0.37, p < 0.01) also after adjustment for clinical and demographic variables, but not with self-reported or interview-based functional capacity (ps ≥0 .20). In contrast, subjective cognitive complaints were associated with self-reported (ß = 0.59, p < 0.01) and interview-based functional capacity (ß = 0.47, p < 0.01), but not performance-based functional capacity (ps ≥ 0.28). LIMITATIONS: The cross-sectional design and modest sample size. CONCLUSIONS: A performance-based measure of functional capacity seems most feasible for inclusion as a secondary outcome in cognition trials to capture improved functional capacity following treatment-related improvements in cognition.


Asunto(s)
Trastorno Bipolar/psicología , Ensayos Clínicos como Asunto/estadística & datos numéricos , Disfunción Cognitiva/psicología , Calidad de Vida , Adulto , Trastorno Bipolar/complicaciones , Disfunción Cognitiva/complicaciones , Estudios Transversales , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Autoinforme , Adulto Joven
14.
mBio ; 10(1)2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30647159

RESUMEN

The long-term response of microbial communities to the microgravity environment of space is not yet fully understood. Of special interest is the possibility that members of these communities may acquire antibiotic resistance. In this study, Escherichia coli cells were grown under low-shear modeled microgravity (LSMMG) conditions for over 1,000 generations (1000G) using chloramphenicol treatment between cycles to prevent contamination. The results were compared with data from an earlier control study done under identical conditions using steam sterilization between cycles rather than chloramphenicol. The sensitivity of the final 1000G-adapted strain to a variety of antibiotics was determined using Vitek analysis. In addition to resistance to chloramphenicol, the adapted strain acquired resistance to cefalotin, cefuroxime, cefuroxime axetil, cefoxitin, and tetracycline. In fact, the resistance to chloramphenicol and cefalotin persisted for over 110 generations despite the removal of both LSMMG conditions and trace antibiotic exposure. Genome sequencing of the adapted strain revealed 22 major changes, including 3 transposon-mediated rearrangements (TMRs). Two TMRs disrupted coding genes (involved in bacterial adhesion), while the third resulted in the deletion of an entire segment (14,314 bp) of the genome, which includes 14 genes involved with motility and chemotaxis. These results are in stark contrast with data from our earlier control study in which cells grown under the identical conditions without antibiotic exposure never acquired antibiotic resistance. Overall, LSMMG does not appear to alter the antibiotic stress resistance seen in microbial ecosystems not exposed to microgravity.IMPORTANCE Stress factors experienced during space include microgravity, sleep deprivation, radiation, isolation, and microbial contamination, all of which can promote immune suppression (1, 2). Under these conditions, the risk of infection from opportunistic pathogens increases significantly, particularly during long-term missions (3). If infection occurs, it is important that the infectious agent should not be antibiotic resistant. Minimizing the occurrence of antibiotic resistance is, therefore, highly desirable. To facilitate this, it is important to better understand the long-term response of bacteria to the microgravity environment. This study demonstrated that the use of antibiotics as a preventive measure could be counterproductive and would likely result in persistent resistance to that antibiotic. In addition, unintended resistance to other antimicrobials might also occur as well as permanent genome changes that might have other unanticipated and undesirable consequences.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Estrés Mecánico , Ingravidez , Adaptación Biológica , Cloranfenicol/farmacología , Elementos Transponibles de ADN , Reordenamiento Génico , Tetraciclina/farmacología , Secuenciación Completa del Genoma , beta-Lactamas/farmacología
15.
Phys Rev Lett ; 121(17): 173005, 2018 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-30411962

RESUMEN

The reconstruction of the full temporal dipole response of a strongly driven time-dependent system from a single absorption spectrum is demonstrated, only requiring that a sufficiently short pulse is employed to initialize the coherent excitation of the system. We apply this finding to the time-domain observation of Rabi cycling between doubly excited atomic states in the few-femtosecond regime. This allows us to pinpoint the breakdown of few-level quantum dynamics at the critical laser intensity near 2 TW/cm^{2} in doubly excited helium. The present approach unlocks single-shot real-time-resolved signal reconstruction across timescales down to attoseconds for nonequilibrium states of matter. In contrast to conventional pump-probe schemes, there is no need for scanning time delays in order to access real-time information. The potential future applications of this technique range from testing fundamental quantum dynamics in strong fields to measuring and controlling ultrafast chemical and biological reaction processes when applied to traditional transient-absorption spectroscopy.

16.
Infect Immun ; 86(11)2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30181350

RESUMEN

Tissues and organs provide the structural and biochemical landscapes upon which microbial pathogens and commensals function to regulate health and disease. While flat two-dimensional (2-D) monolayers composed of a single cell type have provided important insight into understanding host-pathogen interactions and infectious disease mechanisms, these reductionist models lack many essential features present in the native host microenvironment that are known to regulate infection, including three-dimensional (3-D) architecture, multicellular complexity, commensal microbiota, gas exchange and nutrient gradients, and physiologically relevant biomechanical forces (e.g., fluid shear, stretch, compression). A major challenge in tissue engineering for infectious disease research is recreating this dynamic 3-D microenvironment (biological, chemical, and physical/mechanical) to more accurately model the initiation and progression of host-pathogen interactions in the laboratory. Here we review selected 3-D models of human intestinal mucosa, which represent a major portal of entry for infectious pathogens and an important niche for commensal microbiota. We highlight seminal studies that have used these models to interrogate host-pathogen interactions and infectious disease mechanisms, and we present this literature in the appropriate historical context. Models discussed include 3-D organotypic cultures engineered in the rotating wall vessel (RWV) bioreactor, extracellular matrix (ECM)-embedded/organoid models, and organ-on-a-chip (OAC) models. Collectively, these technologies provide a more physiologically relevant and predictive framework for investigating infectious disease mechanisms and antimicrobial therapies at the intersection of the host, microbe, and their local microenvironments.


Asunto(s)
Microambiente Celular , Interacciones Huésped-Patógeno , Mucosa Intestinal/fisiología , Técnicas de Cultivo de Órganos/métodos , Organoides , Ingeniería de Tejidos/métodos , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Modelos Biológicos , Técnicas de Cultivo de Órganos/historia , Ingeniería de Tejidos/historia
17.
Front Immunol ; 9: 1437, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30018614

RESUMEN

Recent studies have established that dysregulation of the human immune system and the reactivation of latent herpesviruses persists for the duration of a 6-month orbital spaceflight. It appears certain aspects of adaptive immunity are dysregulated during flight, yet some aspects of innate immunity are heightened. Interaction between adaptive and innate immunity also seems to be altered. Some crews experience persistent hypersensitivity reactions during flight. This phenomenon may, in synergy with extended duration and galactic radiation exposure, increase specific crew clinical risks during deep space exploration missions. The clinical challenge is based upon both the frequency of these phenomena in multiple crewmembers during low earth orbit missions and the inability to predict which specific individual crewmembers will experience these changes. Thus, a general countermeasure approach that offers the broadest possible coverage is needed. The vehicles, architecture, and mission profiles to enable such voyages are now under development. These include deployment and use of a cis-Lunar station (mid 2020s) with possible Moon surface operations, to be followed by multiple Mars flyby missions, and eventual human Mars surface exploration. Current ISS studies will continue to characterize physiological dysregulation associated with prolonged orbital spaceflight. However, sufficient information exists to begin consideration of both the need for, and nature of, specific immune countermeasures to ensure astronaut health. This article will review relevant in-place operational countermeasures onboard ISS and discuss a myriad of potential immune countermeasures for exploration missions. Discussion points include nutritional supplementation and functional foods, exercise and immunity, pharmacological options, the relationship between bone and immune countermeasures, and vaccination to mitigate herpes (and possibly other) virus risks. As the immune system has sentinel connectivity within every other physiological system, translational effects must be considered for all potential immune countermeasures. Finally, we shall discuss immune countermeasures in the context of their individualized implementation or precision medicine, based on crewmember specific immunological biases.

18.
Eur Neuropsychopharmacol ; 28(8): 915-924, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29891215

RESUMEN

Electroconvulsive therapy (ECT) is the most effective treatment for severe depression but its neurocognitive mechanisms are unclear. This randomized, sham-controlled functional magnetic resonance imaging (fMRI) study explored the effects of a single ECT on neural response to affective pictures. Twenty-seven patients with major depressive disorder were randomized to a single active ECT (N = 15) or sham (N = 12) session in a double-blind, parallel-group design. On the following day, patients underwent fMRI during which they viewed pleasant, unpleasant and neutral pictures and performed a free recall test after the scan. Mood symptoms were assessed before ECT/sham and at the time of fMRI. Subsequently, all patients continued active ECT as usual. Mood symptoms were reassessed after six active ECT sessions. A single ECT vs. sham session reduced neural response to unpleasant vs. pleasant pictures in the medial prefrontal cortex, a region showing greater response in the more depressed patients. This effect occurred in the absence of between-group differences in picture recall, mood symptoms or concomitant medication. In conclusion, modulation of medial prefrontal hyper-activity during encoding of negative affective information may be a common mechanism of distinct biological depression treatments.


Asunto(s)
Afecto/fisiología , Encéfalo/fisiopatología , Trastorno Depresivo Mayor/fisiopatología , Trastorno Depresivo Mayor/terapia , Terapia Electroconvulsiva , Percepción Visual/fisiología , Adulto , Antidepresivos/uso terapéutico , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Estudios Transversales , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/psicología , Método Doble Ciego , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Recuerdo Mental/fisiología , Estimulación Luminosa , Resultado del Tratamiento
19.
Poult Sci ; 97(8): 2713-2721, 2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-29897525

RESUMEN

Coccidiosis is a costly parasitic disease to the poultry industry with multiple prevention methods being explored to control its impact. This study evaluated the feeding effects of ß-glucans on performance and responses of chickens during a coccidiosis challenge. Cobb 500 male broilers (n = 1280) were assigned to 1 of 8 treatment groups (8 replicate pens; 20 birds/pen) in a 2 × 4 factorial arrangement, including non-infected and Eimeria-infected birds fed for 28 d a control diet, control + BG (150 g/MT Algamune 50), control + BGZn (100 g/MT Algamune 50 Zn), and control + 0.01% Salinomycin (Sal). On d15, birds in the challenge groups received a mixed Eimeria inoculum. Birds and feed were weighed weekly on a per pen basis to evaluate body weight gain (BWG), feed intake (FI), and feed conversion ratios (FCR). Lesion scores were assessed 6 d post infection (d21) on 3 birds per pen. Performance data were subjected to ANOVA and differences were established using the LS-MEANS statement with significance reported at P ≤ 0.05. There were minor differences in lesion scores among the dietary treatments in the infected groups with reduced duodenal and cecal scores in the Sal group compared to the BGZn and BG groups, respectively. The coccidiosis challenge main effect resulted in a significant reduction in 0-28 d BW and FI. Dietary treatment resulted in non-significant effect on BWG, but Sal addition resulted in increased FI. A significant diet X challenge interaction resulted in higher FCR in the Eimeria-challenged birds supplemented with Sal and BGZn in comparison to the other challenged groups, likely due to reduced mortality in the challenged Sal and BGZn groups. Body composition analysis at d28 revealed that the Eimeria challenge reduced both fat and lean tissue contents, where the ß-glucans and Sal birds had lower fat percent than control birds.


Asunto(s)
Pollos/inmunología , Coccidiosis/inmunología , Coccidiosis/veterinaria , Factores Inmunológicos/farmacología , Enfermedades de las Aves de Corral/inmunología , Prebióticos , beta-Glucanos/farmacología , Alimentación Animal/análisis , Animales , Pollos/crecimiento & desarrollo , Pollos/metabolismo , Dieta/veterinaria , Eimeria/fisiología , Metabolismo Energético , Masculino , Aumento de Peso , Zinc/administración & dosificación
20.
Cardiovasc Diabetol ; 17(1): 5, 2018 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-29301520

RESUMEN

BACKGROUND AND AIMS: Sodium tissue content by 23Na magnetic resonance imaging (Na-MRI) has been validated in experimental and human studies. SGLT-2 inhibition blocks the reabsorption of glucose and of sodium in the proximal tubular cells in a 1:1 fashion. We hypothesized that SGLT-2 inhibition in patients with type 2 diabetes characterized by sodium retention leads to decreased tissue sodium content due to its pharmacological action. MATERIALS AND METHODS: In a prospective double blind, placebo controlled, cross-over trial 59 patients (61 ± 7.6 years) with type 2 diabetes were randomized to either dapagliflozin 10 mg or placebo once daily for 6 weeks each. In addition to metabolic parameters and ambulatory blood pressure (BP) we analysed the sodium content in the skin and muscles of the lower leg by Na-MRI. RESULTS: Compared to baseline 6 weeks treatment with the SGLT-2 inhibitor dapagliflozin decreased fasting (132 ± 28 vs. 114 ± 19 mg/dl, p < 0.001), postprandial blood glucose (178 ± 66 mg/dl vs. 153 ± 46 mg/dl, p < 0.001), body weight (87.6 vs. 86.6 kg, p < 0.001) and systolic (129 ± 12 vs. 126 ± 11 mmHg, p = 0.010), and diastolic (77.4 ± 9 vs. 75.6 ± 8 mmHg, p = 0.024), 24-h ambulatory BP. Tissue sodium content in the skin was reduced after 6 weeks treatment with dapagliflozin compared to baseline [24.1 ± 6.6 vs. 22.7 ± 6.4 A.U.(arbitrary unit) p = 0.013]. No significant reduction of tissue sodium content was observed in the muscle (M. triceps surae: 20.5 ± 3.5 vs. 20.4 ± 3.7 A.U. p = 0.801). No clear significant difference in tissue water content of muscle and skin was observed after 6 weeks of treatment with dapagliflozin, compared to baseline. CONCLUSION: SGLT-2 inhibition with dapagliflozin resulted in a significant decrease in tissue sodium content of the skin after 6 weeks. This observation point to a decrease of total sodium content in patients with type 2 diabetes prone to cardiovascular complications, that might be mitigated by SGLT-2 inhibition. Trial registration The study was registered at http://www.clinicaltrials.gov (NCT02383238) retrospectively registered.


Asunto(s)
Compuestos de Bencidrilo/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Glucósidos/uso terapéutico , Músculo Esquelético/efectos de los fármacos , Piel/efectos de los fármacos , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Transportador 2 de Sodio-Glucosa/efectos de los fármacos , Sodio/metabolismo , Anciano , Compuestos de Bencidrilo/efectos adversos , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Estudios Cruzados , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatología , Método Doble Ciego , Femenino , Alemania , Glucósidos/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/metabolismo , Estudios Prospectivos , Piel/metabolismo , Transportador 2 de Sodio-Glucosa/metabolismo , Inhibidores del Cotransportador de Sodio-Glucosa 2/efectos adversos , Factores de Tiempo , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA