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1.
J Physiol ; 602(12): 2985-2998, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38766932

RESUMO

Prolonged bed rest impairs standing balance but the underlying mechanisms are uncertain. Previous research suggests strength loss is not the cause, leaving impaired sensorimotor control as an alternative. Here we examine vestibular control of posture in 18 male volunteers before and after 60 days of bed rest. Stochastic vestibular stimulation (SVS) was used to evoke sway responses before, 1 and 6 days after bed rest under different head yaw orientations. The directional accuracy and precision of these responses were calculated from ground reaction force vectors. Bed rest caused up to 63% increases in spontaneous standing sway and 31% reductions in leg strength, changes which were uncorrelated. The increase in sway was exacerbated when the eyes were closed. Mean directions of SVS-evoked sway responses were unaffected, being directed towards the anodal ear and rotating in line with head orientation in the same way before and after bed rest. However, individual trial analysis revealed 25%-30% increases in directional variability, which were significantly correlated with the increase in spontaneous sway (r = 0.48-0.71; P ≤ 0.044) and were still elevated on day 6 post-bed rest. This reveals that individual sway responses may be inappropriately oriented, a finding masked by the averaging process. Our results confirm that impaired balance following prolonged bedrest is not related to loss of strength. Rather, they demonstrate that the sensorimotor transformation process which converts vestibular feedback into appropriately directed balance responses is impaired. KEY POINTS: Prolonged inactivity impairs balance but previous research suggests this is not caused by loss of strength. Here we investigated vestibular control of balance before and after 60 days of bed rest using electrical vestibular stimulation (EVS) to evoke sway responses. Spontaneous sway significantly increased and muscle strength reduced following bed rest, but, in keeping with previous research, these two effects were not correlated. While the overall accuracy of EVS-evoked sway responses was unaffected, their directional variability significantly increased following bed rest, and this was correlated with the increases in spontaneous sway. We have shown that the ability to transform head-centred vestibular feedback into an appropriately directed body sway response is negatively affected by prolonged inactivity; this may contribute to the impaired balance commonly observed following bed rest.


Assuntos
Repouso em Cama , Equilíbrio Postural , Vestíbulo do Labirinto , Humanos , Masculino , Equilíbrio Postural/fisiologia , Adulto , Vestíbulo do Labirinto/fisiologia , Adulto Jovem
2.
J Pharmacol Exp Ther ; 388(2): 358-366, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-37652711

RESUMO

Reactive oxygen species have an emerging role in the pathologic consequences of status epilepticus. We have previously demonstrated the efficacy of a water-for-injection formulation of the meso-porphyrin catalytic antioxidant, manganese (III) meso-tetrakis (N-N-diethylimidazole) porphyrin (AEOL10150) against oxidative stress, neuroinflammation, and neuronal death initiated by kainic acid, pilocarpine, diisopropylflurophosphate (DFP), and soman. This previous dose and dosing strategy of AEOL10150 required smaller multiple daily injections, precluding our ability to test its efficacy against delayed consequences of nerve agent exposure such as neurodegeneration and cognitive dysfunction. Therefore, we developed formulations of AEOL10150 designed to deliver a larger dose once daily with improved brain pharmacodynamics. We examined four new formulations of AEOL10150 that resulted in 8 times higher subcutaneous dose with lower acute toxicity, slower absorption, longer half-life, and higher maximal plasma concentrations compared with our previous strategy. AEOL10150 brain levels exhibited improved pharmacodynamics over 24 hours with all four formulations. We tested a subcutaneous dose of 40 mg/kg AEOL10150 in two formulations (2% carboxymethyl cellulose and 4% polyethylene glycol-4000) in the DFP rat model, and both formulations exhibited significant protection against DFP-induced oxidative stress. Additionally, and in one formulation (4% polyethylene glycol-4000), AEOL10150 significantly protected against DFP-induced neuronal death, microglial activation, delayed memory impairment, and mortality. These results suggest that reformulation of AEOL10150 can attenuate acute and delayed outcomes of organophosphate neurotoxicity. SIGNIFICANCE STATEMENT: Reformulation of manganese (III) meso-tetrakis (N-N-diethylimidazole) porphyrin allowed higher tolerated doses of the compound with improved pharmacodynamics. Specifically, one new formulation allowed fewer daily doses and improvement in acute and delayed outcomes of organophosphate toxicity.


Assuntos
Disfunção Cognitiva , Metaloporfirinas , Agentes Neurotóxicos , Ratos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Ratos Sprague-Dawley , Agentes Neurotóxicos/toxicidade , Doenças Neuroinflamatórias , Manganês , Estresse Oxidativo , Metaloporfirinas/farmacologia , Metaloporfirinas/uso terapêutico , Organofosfatos , Polietilenoglicóis
3.
Perception ; 52(7): 484-501, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37229751

RESUMO

We performed four experiments to investigate whether people can perceive the length of a target object (a "fish") that is attached to a freely wielded object (the "fishing pole") by a length of string, and if so, whether this ability is grounded in the sensitivity of the touch system to invariant mechanical parameters that describe the forces and torques required to move the target object. In particular, we investigated sensitivity to mass, static moment, and rotational inertia-the forces required to keep an object from falling due to gravity, the torque required to keep an object from rotating due to gravity, and the torques required to actively rotate an object in different directions, respectively. We manipulated the length of the target object (Experiment 1), the mass of the target object (Experiment 2), and the mass distribution of the target object (Experiments 3 and 4). Overall, the results of the four experiments showed that participants can perform this task. Moreover, when the task is configured such that it more closely approximates a wielding at a distance task, the ability to do so is grounded in sensitivity to such forces and torques.


Assuntos
Percepção de Tamanho , Percepção do Tato , Humanos , Tato
4.
Int J Mol Sci ; 24(5)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36901724

RESUMO

The use of electronic nicotine dispensing systems (ENDS), also known as electronic cigarettes (ECs), is common among adolescents and young adults with limited knowledge about the detrimental effects on lung health such as respiratory viral infections and underlying mechanisms. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), a protein of the TNF family involved in cell apoptosis, is upregulated in COPD patients and during influenza A virus (IAV) infections, but its role in viral infection during EC exposures remains unclear. This study was aimed to investigate the effect of ECs on viral infection and TRAIL release in a human lung precision-cut lung slices (PCLS) model, and the role of TRAIL in regulating IAV infection. PCLS prepared from lungs of nonsmoker healthy human donors were exposed to EC juice (E-juice) and IAV for up to 3 days during which viral load, TRAIL, lactate dehydrogenase (LDH), and TNF-α in the tissue and supernatants were determined. TRAIL neutralizing antibody and recombinant TRAIL were utilized to determine the contribution of TRAIL to viral infection during EC exposures. E-juice increased viral load, TRAIL, TNF-α release and cytotoxicity in IAV-infected PCLS. TRAIL neutralizing antibody increased tissue viral load but reduced viral release into supernatants. Conversely, recombinant TRAIL decreased tissue viral load but increased viral release into supernatants. Further, recombinant TRAIL enhanced the expression of interferon-ß and interferon-λ induced by E-juice exposure in IAV-infected PCLS. Our results suggest that EC exposure in human distal lungs amplifies viral infection and TRAIL release, and that TRAIL may serve as a mechanism to regulate viral infection. Appropriate levels of TRAIL may be important to control IAV infection in EC users.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Vírus da Influenza A , Influenza Humana , Adolescente , Humanos , Adulto Jovem , Anticorpos Neutralizantes/metabolismo , Vírus da Influenza A/fisiologia , Pulmão/patologia , Fator de Necrose Tumoral alfa/metabolismo
5.
J Physiol ; 600(2): 373-391, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34841531

RESUMO

There is increasing theoretical and empirical support for the brain combining multisensory information to determine the direction of gravity and hence uprightness. A fundamental part of the process is the spatial transformation of sensory signals between reference frames: eye-centred, head-centred, body-centred, etc. The question 'Am I the right way up?' posed by a patient with posterior cortical atrophy (PCA) suggests disturbances in upright perception, subsequently investigated in PCA and typical Alzheimer's disease (tAD) based on what looks or feels upright. Participants repeatedly aligned to vertical a rod presented either visually (visual-vertical) or haptically (haptic-vertical). Visual-vertical involved orienting a projected rod presented without or with a visual orientation cue (circle, tilted square (±18°)). Haptic-vertical involved orientating a grasped rod with eyes closed using a combination of side (left, right) and hand (unimanual, bimanual) configurations. Intraindividual uncertainty and bias defined verticality perception. Uncertainty was consistently greater in both patient groups than in control groups, and greater in PCA than tAD. Bias in the frontal plane was strongly directionally affected by visual cue tilt (visual-vertical) and grip side (haptic-vertical). A model was developed that assumed verticality information from multiple sources is combined in a statistically optimal way to produce observed uncertainties and biases. Model results suggest the mechanism that spatially transforms graviceptive information between body parts is disturbed in both patient groups. Despite visual dysfunction being typically considered the primary feature of PCA, disturbances were greater in PCA than tAD particularly for haptic-vertical, and are considered in light of posterior parietal vulnerability. KEY POINTS: The perception of upright requires accurate and precise estimates of orientation based on multiple noisy sensory signals. The question 'Am I the right way up?' posed by a patient with posterior cortical atrophy (PCA; purported 'visual variant Alzheimer's') suggests disturbances in the perception of upright. What looks or feels upright in PCA and typical Alzheimer's disease (tAD) was investigated by asking participants to repeatedly align to vertical a rod presented visually (visual-vertical) or haptically (haptic-vertical). PCA and tAD groups exhibited not only greater perceptual uncertainty than controls, but also exaggerated bias induced by tilted visual orientation cues (visual-vertical) and grip side (haptic-vertical). When modelled, these abnormalities, which were particularly evident in PCA haptic-vertical performance, were compatible with disruption of a mechanism that spatially transforms verticality information between body parts. The findings suggest an important role of posterior parietal cortex in verticality perception, and have implications for understanding spatial disorientation in dementia.


Assuntos
Doença de Alzheimer , Atrofia , Tecnologia Háptica , Humanos , Postura , Percepção Espacial , Percepção Visual
6.
Arch Toxicol ; 96(8): 2319-2328, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35672461

RESUMO

Electronic cigarettes or vaping products have been marketed as a safer alternative to smoking, but very little is known about the health effects in the human lung, particularly in the distal airways, a key site of airway obstruction and destruction in chronic obstructive pulmonary disease that is often exacerbated by viral infections. The aim of this study was to investigate the effects of electronic cigarette vapor (e-vapor) on human distal airway epithelial responses to influenza A virus (IAV) infection. We isolated primary small airway epithelial cells (SAECs) from donor lungs free of lung disease, and cultured them at air-liquid interface (ALI). To measure markers of epithelial injury such as integrity of epithelial barrier structure and function, we selected a regimen of non-toxic, barrier preserving e-vapor exposure of cultured cells to 15 puffs of e-vapor from a commercially available e-cigarette once per day for 3 days, prior to IAV infection. After 72 h of infection, media and cell lysates were collected to measure cytokines involved in inflammatory and antiviral responses. Pre-exposure to e-vapor with IAV infection, compared to IAV infection alone, significantly increased inflammatory and antiviral mediators including IL-8, CXCL10, IFN-beta, and MX1. Our results suggest that e-vapor exposure amplifies human distal airway pro-inflammatory response to IAV infection, independently of the severity of cell injury during viral infection.


Assuntos
Vapor do Cigarro Eletrônico , Sistemas Eletrônicos de Liberação de Nicotina , Vírus da Influenza A , Influenza Humana , Viroses , Antivirais/farmacologia , Células Epiteliais , Epitélio , Humanos , Pulmão
7.
J Am Chem Soc ; 143(21): 8022-8033, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34003001

RESUMO

Traditional chemical sensing methodologies have typically relied on the specific chemistry of the analyte for detection. Modifications to the local environment surrounding the sensor represent an alternative pathway to impart selective differentiation. Here, we present the hybridization of a 2-D metal organic framework (Cu3(HHTP)2) with single-walled carbon nanotubes (SWCNTs) as a methodology for size discrimination of carbohydrates. Synthesis and the resulting conductive performance are modulated by both mass loading of SWCNTs and their relative oxidation. Liquid gated field-effect transistor (FET) devices demonstrate improved on/off characteristics and differentiation of carbohydrates based on molecular size. Glucose molecule detection is limited to the single micromolar concentration range. Molecular Dynamics (MD) calculations on model systems revealed decreases in ion diffusivity in the presence of different sugars as well as packing differences based on the size of a given carbohydrate molecule. The proposed sensing mechanism is a reduction in gate capacitance initiated by the filling of the pores with carbohydrate molecules. Restricting diffusion around a sensor in combination with FET measurements represents a new type of sensing mechanism for chemically similar analytes.

8.
J Pharmacol Exp Ther ; 377(1): 1-10, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33500265

RESUMO

Oxidative stress plays a crucial role in the pathogenesis of Parkinson disease (PD), and one strategy for neuroprotective therapy for PD is to scavenge reactive species using a catalytic antioxidant. Previous studies in our laboratory revealed that pretreatment of lipophilic metalloporphyrins showed protective effects in a mouse PD model. In this study, we optimized the formulations of these metalloporphyrins to deliver them orally and tested their efficacy on disease outcomes in a second species after initiation of an insult (i.e., disease modification). In this study, a pharmaceutical formulation of two metalloporphyrin catalytic antioxidants, AEOL11207 and AEOL11114, was tested for oral drug delivery. Both compounds showed gastrointestinal absorption, achieved high plasma concentrations, and readily penetrated the blood-brain barrier after intravenous or oral delivery. AEOL11207 and AEOL11114 bioavailabilities were calculated to be 24% and 25%, respectively, at a dose of 10 mg/kg via the oral route. In addition, both compounds significantly attenuated 6-hydroxydopamine (6-OHDA)-induced neurotoxic damage, including dopamine depletion, cytokine production, and microglial activation in the striata; dopaminergic neuronal loss in the substantia nigra; oxidative/nitrative stress indices (glutathione disulfide and 3-nitrotyrosine) in the ventral midbrain; and rotation behavioral abnormality in rats. These results indicate that AEOL11207 and AEOL11114 are orally active metalloporphyrins and protect against 6-OHDA neurotoxicity 1-3 days postlesioning, suggesting disease-modifying properties and translational potential for PD. SIGNIFICANCE STATEMENT: Two catalytic antioxidants showed gastrointestinal absorption, achieved high plasma concentrations, and readily penetrated the blood-brain barrier. Both compounds significantly attenuated dopamine depletion, cytokine production, microglial activation, dopaminergic neuronal loss, oxidative/nitrative stress indices, and behavioral abnormality in a Parkinson disease rat model. The results suggest that both metalloporphyrins possess disease-modifying properties that may be useful in treating Parkinson disease.


Assuntos
Antioxidantes/farmacocinética , Metaloporfirinas/farmacocinética , Fármacos Neuroprotetores/farmacocinética , Transtornos Parkinsonianos/tratamento farmacológico , Administração Oral , Animais , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Barreira Hematoencefálica/metabolismo , Masculino , Metaloporfirinas/administração & dosagem , Metaloporfirinas/uso terapêutico , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/uso terapêutico , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
9.
Chem Res Toxicol ; 34(12): 2408-2423, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34808040

RESUMO

Approximately 3 million United States military personnel and contractors were deployed to Southwest Asia and Afghanistan over the past two decades. After returning to the United States, many developed persistent respiratory symptoms, including those due to asthma, rhinosinusitis, bronchiolitis, and others, which we collectively refer to as deployment-related lung diseases (DRLD). The mechanisms of different DRLD have not been well defined. Limited studies from us and others suggest that multiple factors and biological signaling pathways contribute to the onset of DRLD. These include, but are not limited to, exposures to high levels of particulate matter (PM) from sandstorms, burn pit combustion products, improvised explosive devices, and diesel exhaust particles. Once inhaled, these hazardous substances can activate lung immune and structural cells to initiate numerous cell-signaling pathways such as oxidative stress, Toll-like receptors, and cytokine-driven cell injury (e.g., interleukin-33). These biological events may lead to a pro-inflammatory response and airway hyperresponsiveness. Additionally, exposures to PM and other environmental hazards may predispose military personnel and contractors to more severe disease due to the interactions of those hazardous materials with subsequent exposures to allergens and cigarette smoke. Understanding how airborne exposures during deployment contribute to DRLD may identify effective targets to alleviate respiratory diseases and improve quality of life in veterans and active duty military personnel.


Assuntos
Pneumopatias/induzido quimicamente , Material Particulado/efeitos adversos , Afeganistão , Humanos , Iraque , Militares
10.
AJR Am J Roentgenol ; 216(3): 759-768, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33474983

RESUMO

OBJECTIVE. The purpose of this article is to summarize the role of molecular imaging of the brain by use of SPECT, FDG PET, and non-FDG PET radiotracers in epilepsy. CONCLUSION. Quantitative image analysis with PET and SPECT has increased the diagnostic utility of these modalities in localizing epileptogenic onset zones. A multi-modal platform approach integrating the functional imaging of PET and SPECT with the morphologic information from MRI in presurgical evaluation of epilepsy can greatly improve outcomes.


Assuntos
Encéfalo/diagnóstico por imagem , Epilepsia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Criança , Pré-Escolar , Cisteína/análogos & derivados , Cisteína/farmacocinética , Feminino , Fluordesoxiglucose F18/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Compostos de Organotecnécio/farmacocinética , Oximas/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética
11.
Stereotact Funct Neurosurg ; 99(4): 287-294, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33279909

RESUMO

BACKGROUND: Deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) has been investigated for the treatment of levodopa-refractory gait dysfunction in parkinsonian disorders, with equivocal results so far. OBJECTIVES: To summarize the clinical outcomes of PPN-DBS-treated patients at our centre and elicit any patterns that may guide future research. MATERIALS AND METHODS: Pre- and post-operative objective overall motor and gait subsection scores as well as patient-reported outcomes were recorded for 6 PPN-DBS-treated patients, 3 with Parkinson's disease (PD), and 3 with progressive supranuclear palsy (PSP). Electrodes were implanted unilaterally in the first 3 patients and bilaterally in the latter 3, using an MRI-guided MRI-verified technique. Stimulation was initiated at 20-30 Hz and optimized in an iterative manner. RESULTS: Unilaterally treated patients did not demonstrate significant improvements in gait questionnaires, UPDRS-III or PSPRS scores or their respective gait subsections. This contrasted with at least an initial response in bilaterally treated patients. Diurnal cycling of stimulation in a PD patient with habituation to the initial benefit reproduced substantial improvements in freezing of gait (FOG) 3 years post-operatively. Among the PSP patients, 1 with a parkinsonian subtype had a sustained improvement in FOG while another with Richardson syndrome (PSP-RS) did not benefit. CONCLUSIONS: PPN-DBS remains an investigational treatment for levodopa-refractory FOG. This series corroborates some previously reported findings: bilateral stimulation may be more effective than unilateral stimulation; the response in PSP patients may depend on the disease subtype; and diurnal cycling of stimulation to overcome habituation merits further investigation.


Assuntos
Estimulação Encefálica Profunda , Transtornos Neurológicos da Marcha , Doença de Parkinson , Núcleo Tegmental Pedunculopontino , Transtornos Neurológicos da Marcha/etiologia , Transtornos Neurológicos da Marcha/terapia , Humanos , Levodopa , Doença de Parkinson/terapia
12.
J Physiol ; 598(10): 1929-1941, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32108335

RESUMO

KEY POINTS: It is unclear whether the visual input that accompanies a perturbation of a standing person can affect whether a recovery step is taken. Visual motion speeds were manipulated during unexpected forward and backward shoulder pulls. Visual motion that appeared slower than actual body motion reduced the initial in-place resistance to the perturbation. As a result of the modulation of the in-place response, less pull force was needed to trigger a step when visual velocity appeared slower than normal. The visuomotor postural response occurred earlier and was larger when the full-field visual input was paired with a mechanical perturbation. ABSTRACT: The present study aimed to determine how visual motion evoked by an upper body perturbation during standing affects compensatory postural responses. This was investigated by rotating the visual field forwards or backwards about the ankle, time-locked to a forwards or backwards shoulder pull. Kinematic, kinetic and electromyographic responses were recorded to a range of pull forces over 160 trials in 12 healthy adults (mean ± SD = 31 ± 5.8 years). Stepping threshold forces and in-place postural responses were compared between conditions. When the visual field moved in the same direction as the pull, so that the apparent velocity of the body was reduced (SLOW condition), the pull-force required to induce a step was less than when the visual field either rotated in the opposite direction (FAST) or was unaltered (NATURAL). For in-place responses, the body was displaced further in the direction of the pull in the SLOW condition. This was the result of a reduction in the resistive force from lower leg muscles 130 ms after the visual motion onset. In trials with no pull, the visual motion induced postural responses that were later (290 ms) and had smaller amplitudes compared to when visual motion is paired with an unexpected perturbation of the body. The results suggest that the apparent speed of the visual environment during a perturbation does influence whether a compensatory step is taken, not via a direct effect on the decision to step but by modulating the initial in-place response.


Assuntos
Perna (Membro) , Campos Visuais , Adulto , Fenômenos Biomecânicos , Humanos , Movimento (Física) , Movimento , Músculo Esquelético , Equilíbrio Postural
13.
J Physiol ; 598(11): 2125-2136, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32133628

RESUMO

KEY POINTS: While it has been well described that prolonged rotational stepping will adapt the podokinetic sense of rotation, the mechanisms involved are not clearly understood. By studying podokinetic after-rotations following conditioning rotations not previously reported we have shown that slower rotational velocities are more readily adapted than faster velocities and adaptation occurs more quickly than previously thought. We propose a dynamic feedback model of vestibular and podokinetic adaptation that can fit rotation trajectories across multiple conditions and data sets. Two adaptation processes were identified that may reflect central and peripheral processes and the discussion unifies prior findings in the podokinetic literature under this new framework. The findings show the technique is feasible for people with locomotor turning problems. ABSTRACT: After a prolonged period stepping in circles, people walk with a curved trajectory when attempting to walk in a straight line without vision. Podokinetic adaptation shows promise in clinical populations to improve locomotor turning; however, the adaptive mechanisms involved are poorly understood. The first phase of this study asks: how does the podokinetic conditioning velocity affect the response velocity and how quickly can adaptation occur? The second phase of the study asks: can a mathematical feedback model account for the rotation trajectories across different conditioning parameters and different datasets? Twelve healthy participants stepped in place on the axis of a rotating surface ranging from 4 to 20 deg s-1 for durations of 1-10 min, while using visual cues to maintain a constant heading direction. Afterward on solid ground, participants were blindfolded and attempted to step without rotating. Participants unknowingly stepped in circles opposite to the direction of the prior platform rotation for all conditions. The angular velocity of this response peaked within 1 min and the ratio of the stimulus-to-response peak velocity fitted a decreasing power function. The response then decayed exponentially. The feedback model of podokinetic and vestibular adaptive processes had a good fit with the data and suggested that podokinetic adaptation is explained by a short (141 s) and a long (27 min) time constant. The podokinetic system adapts more quickly than previously thought and subjects adapt more readily to slower rotation than to faster rotation. These findings will have implications for clinical applications of the technique.


Assuntos
Adaptação Fisiológica , Vestíbulo do Labirinto , Sinais (Psicologia) , Humanos , Caminhada
14.
Toxicol Appl Pharmacol ; 404: 115186, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777237

RESUMO

Increased symptoms of asthma-like respiratory illnesses have been reported in soldiers returning from tours of duty in Afghanistan. Inhalation of desert particulate matter (PM) may contribute to this deployment-related lung disease (DRLD), but little is known about disease mechanisms. The IL-33 signaling pathway, including its receptor ST2, has been implicated in the pathogenesis of lung diseases including asthma, but its role in PM-mediated airway dysfunction has not been studied. The goal of this study was to investigate whether IL-33/ST2 signaling contributes to airway dysfunction in preclinical models of lung exposure to Afghanistan PM (APM). Wild-type (WT) and ST2 knockout (KO) mice on the BALB/C background were oropharyngeally instilled with a single dose of saline or 50 µg of APM in saline. Airway hyperresponsiveness (AHR) and inflammation were assessed after 24 h. In WT mice, a single APM exposure induced AHR and neutrophilic inflammation. Unlike the WT mice, ST2 KO mice that lack the receptor for IL-33 did not demonstrate AHR although airway neutrophilic inflammation was comparable to the WT mice. Oropharyngeal delivery of a soluble ST2 decoy receptor in APM-exposed WT mice significantly blocked AHR. Additional data in mouse tracheal epithelial cell and lung macrophage cultures demonstrated a role of APM-induced IL-33/ST2 signaling in suppression of regulator of G protein signaling 2 (RGS2), a gene known to protect against bronchoconstriction. We present for the first time that APM may increase AHR, one of the features of asthma, in part through the IL-33/ST2/RGS2 pathway.


Assuntos
Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/metabolismo , Pneumopatias/induzido quimicamente , Material Particulado/toxicidade , Afeganistão , Animais , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Interleucina-33/genética , Macrófagos/efeitos dos fármacos , Camundongos , Neutrófilos/efeitos dos fármacos , Neutrófilos/fisiologia , Tamanho da Partícula , Alvéolos Pulmonares/citologia , Transdução de Sinais/efeitos dos fármacos
15.
Sensors (Basel) ; 20(3)2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32050552

RESUMO

Gas sensor arrays, also known as electronic noses, leverage a diverse set of materials to identify the components of complex gas mixtures. Metal-organic frameworks (MOFs) have emerged as promising materials for electronic noses due to their high-surface areas and chemical as well as structural tunability. Using our recently reported genetic algorithm design approach, we examined a set of 50 MOFs and searched through over 1.125 × 1015 unique array combinations to identify optimal arrays for the detection of CO2 in air. We found that despite individual MOFs having lower selectivity for O2 or N2 relative to CO2, intelligently selecting the right combinations of MOFs enables accurate prediction of the concentrations of all components in the mixture (i.e., CO2, O2, N2). We also analyzed the physical properties of the elements in the arrays to develop an intuition for improving array design. Notably, we found that an array whose MOFs have diversity in their volumetric surface areas has improved sensing. Consistent with this observation, we found that the best arrays consistently had greater structural diversity (e.g., pore sizes, void fractions, and surface areas) than the worst arrays.

16.
J Biol Chem ; 292(13): 5532-5545, 2017 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-28202547

RESUMO

Neuroinflammation and oxidative stress are hallmarks of various neurological diseases. However, whether and how the redox processes control neuroinflammation is incompletely understood. We hypothesized that increasing cellular glutathione (GSH) levels would inhibit neuroinflammation. A series of thiol compounds were identified to elevate cellular GSH levels by a novel approach (i.e. post-translational activation of glutamate cysteine ligase (GCL), the rate-limiting enzyme in GSH biosynthesis). These small thiol-containing compounds were examined for their ability to increase intracellular GSH levels in a murine microglial cell line (BV2), of which dimercaprol (2,3-dimercapto-1-propanol (DMP)) was found to be the most effective compound. DMP increased GCL activity and decreased LPS-induced production of pro-inflammatory cytokines and inducible nitric-oxide synthase induction in BV2 cells in a concentration-dependent manner. The ability of DMP to elevate GSH levels and attenuate LPS-induced pro-inflammatory cytokine production was inhibited by buthionine sulfoximine, an inhibitor of GCL. DMP increased the expression of GCL holoenzyme without altering the expression of its subunits or Nrf2 target proteins (NQO1 and HO-1), suggesting a post-translational mechanism. DMP attenuated LPS-induced MAPK activation in BV2 cells, suggesting the MAPK pathway as the signaling mechanism underlying the effect of DMP. Finally, the ability of DMP to increase GSH via GCL activation was observed in mixed cerebrocortical cultures and N27 dopaminergic cells. Together, the data demonstrate a novel mechanism of GSH elevation by post-translational activation of GCL. Post-translational activation of GCL offers a novel targeted approach to control inflammation in chronic neuronal disorders associated with impaired adaptive responses.


Assuntos
Dimercaprol/farmacologia , Glutamato-Cisteína Ligase/metabolismo , Inflamação/prevenção & controle , Animais , Linhagem Celular , Citocinas/antagonistas & inibidores , Ativação Enzimática/efeitos dos fármacos , Glutamato-Cisteína Ligase/efeitos dos fármacos , Glutationa/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos , Sistema Nervoso/patologia , Oxirredução , Ratos , Compostos de Sulfidrila/metabolismo
17.
Lung ; 196(1): 103-114, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29080069

RESUMO

INTRODUCTION: Chronic beryllium disease (CBD) is characterized by accumulation of macrophages and beryllium-specific CD4+ T cells that proliferate and produce Th1 cytokines. 5-Amino salicylic acid (5-ASA) is currently used to treat inflammatory bowel disease and has both antioxidant and anti-inflammatory actions. We hypothesized that 5-ASA may be a beneficial therapeutic in CBD. METHODS: Seventeen CBD patients were randomized 3:1 to receive 5-ASA 500-mg capsules or placebo four times daily for 6 weeks orally. Primary study endpoints included changes in beryllium lymphocyte proliferation (BeLPT). Secondary endpoints included changes in bronchoalveolar lavage (BAL) fluid, cells, serum, and blood cell glutathione (GSH) levels, BAL cell TNF-α levels, lung function, and quality of life measures. RESULTS: 5-ASA decreased BAL cell BeLPT by 20% within the 5-ASA treatment group. No significant changes were observed in serum, PBMCs, BALF, or BAL cell GSH levels in either the 5-ASA or placebo treatment group. 5-ASA treatment decreased ex vivo Be-stimulated BAL cell TNF-α levels within the 5-ASA group and when compared to placebo. Significant improvements were noted in quality of life measurements with 5-ASA treatment. CONCLUSIONS: 5-ASA's ability to decrease BAL cell BeLPT and Be-stimulated BAL cell TNF-α levels suggests that 5-ASA may impact the beryllium-specific immune response in CBD. 5-ASA use in other non-infectious granulomatous lung diseases, such as sarcoidosis, may prove to be a useful alternative treatment to corticosteroids for those with mild to moderate disease.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Beriliose/tratamento farmacológico , Beriliose/imunologia , Imunidade Celular/efeitos dos fármacos , Mesalamina/uso terapêutico , Idoso , Beriliose/metabolismo , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/imunologia , Proliferação de Células/efeitos dos fármacos , Doença Crônica , Método Duplo-Cego , Feminino , Glutationa/metabolismo , Humanos , Leucócitos Mononucleares , Linfócitos/fisiologia , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Fator de Necrose Tumoral alfa/metabolismo
18.
Arthroscopy ; 34(8): 2511-2513, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30077276

RESUMO

Personalized (based on a percentage of a patient's limb occlusion pressure) blood flow restriction is emerging as a potential advancement in orthopaedic surgery. Safe application of the technology requires the use of medical devices capable of customizing the pressures applied to individual patients. In those circumstances, it is a low risk and noninvasive technique. By limiting muscle atrophy and aiding in the recovery of strength and function, it has the potential to significantly reduce the morbidity from limb trauma and surgery, and aid in achieving a substantially earlier return to full activity.


Assuntos
Terapia por Exercício/métodos , Músculo Esquelético/irrigação sanguínea , Procedimentos Ortopédicos/reabilitação , Cuidados Pós-Operatórios/métodos , Fluxo Sanguíneo Regional/fisiologia , Humanos , Pressão
19.
Toxicol Appl Pharmacol ; 326: 34-42, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28400118

RESUMO

Reactive oxygen species are a well-defined therapeutic target for Parkinson's disease (PD) and pharmacological agents that catalytically scavenge reactive species are promising neuroprotective strategies for treatment. Metalloporphyrins are synthetic catalytic antioxidants that mimic the body's own antioxidant enzymes i.e. superoxide dismutases and catalase. The goal of this study was to determine if newly designed metalloporphyrins have enhanced pharmacodynamics including oral bioavailability, longer plasma elimination half-lives, penetrate the blood brain barrier, and show promise for PD treatment. Three metalloporphyrins (AEOL 11216, AEOL 11203 and AEOL 11114) were identified in this study as potential candidates for further pre-clinical development. Each of these compounds demonstrated blood brain barrier permeability by the i.p. route and two of three compounds (AEOL 11203 and AEOL 11114) were orally bioavailable. All of these compounds protected against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity, including dopamine depletion in the striatum, dopaminergic neuronal loss in the substantial nigra, and increased oxidative/nitrative stress indices (glutathione disulfide and 3-nitrotyrosine) in the ventral midbrain of the mice without inhibiting MPTP metabolism. Daily therapeutic dosing of these metalloporphyrins were well tolerated without accumulation of brain manganese levels or behavioral alterations assessed by open field and rotarod tests. The study identified two orally active metalloporphyrins and one injectable metalloporphyrin as clinical candidates for further development in PD.


Assuntos
Antioxidantes/farmacologia , Antiparkinsonianos/farmacologia , Encéfalo/efeitos dos fármacos , Intoxicação por MPTP/prevenção & controle , Metaloporfirinas/farmacologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Administração Oral , Animais , Antioxidantes/administração & dosagem , Antioxidantes/farmacocinética , Antiparkinsonianos/administração & dosagem , Antiparkinsonianos/farmacocinética , Comportamento Animal/efeitos dos fármacos , Disponibilidade Biológica , Biomarcadores/metabolismo , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Permeabilidade Capilar , Modelos Animais de Doenças , Dopamina/metabolismo , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Meia-Vida , Injeções Intraperitoneais , Intoxicação por MPTP/etiologia , Intoxicação por MPTP/metabolismo , Intoxicação por MPTP/fisiopatologia , Masculino , Metaloporfirinas/administração & dosagem , Metaloporfirinas/farmacocinética , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacocinética , Teste de Desempenho do Rota-Rod
20.
Epilepsia ; 58(11): 1842-1851, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28776646

RESUMO

OBJECTIVES: Specific changes in the functional connectivity of brain networks occur in patients with epilepsy. Yet whether such changes reflect a stable disease effect or one that is a function of active seizure burden remains unclear. Here, we longitudinally assessed the connectivity of canonical cognitive functional networks in patients with intractable temporal lobe epilepsy (TLE), both before and after patients underwent epilepsy surgery and achieved seizure freedom. METHODS: Seventeen patients with intractable TLE who underwent epilepsy surgery with Engel class I outcome and 17 matched healthy controls took part in the study. The functional connectivity of a set of cognitive functional networks derived from typical cognitive tasks was assessed in patients, preoperatively and postoperatively, as well as in controls, using stringent methods of artifact reduction. RESULTS: Preoperatively, functional networks in TLE patients differed significantly from healthy controls, with differences that largely, but not exclusively, involved the default mode and temporal/auditory subnetworks. However, undergoing epilepsy surgery and achieving seizure freedom did not lead to significant changes in network connectivity, with postoperative functional network abnormalities closely mirroring the preoperative state. SIGNIFICANCE: This result argues for a stable chronic effect of the disease on brain connectivity, with changes that are largely "burned in" by the time a patient with intractable TLE undergoes epilepsy surgery, which typically occurs years after the initial diagnosis. The result has potential implications for the treatment of intractable epilepsy, suggesting that delaying surgical intervention that may achieve seizure freedom may lead to functional network changes that are no longer reversible by the time of epilepsy surgery.


Assuntos
Epilepsia do Lobo Temporal/fisiopatologia , Epilepsia do Lobo Temporal/cirurgia , Rede Nervosa/fisiopatologia , Cuidados Pós-Operatórios/tendências , Convulsões/fisiopatologia , Convulsões/cirurgia , Adulto , Eletroencefalografia/tendências , Epilepsia do Lobo Temporal/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética/tendências , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Convulsões/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Lobo Temporal/cirurgia , Adulto Jovem
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