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1.
Mol Psychiatry ; 28(5): 2136-2147, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36973347

RESUMO

Maternal immune dysregulation is a prenatal risk factor for autism spectrum disorder (ASD). Importantly, a clinically relevant connection exists between inflammation and metabolic stress that can result in aberrant cytokine signaling and autoimmunity. In this study we examined the potential for maternal autoantibodies (aAbs) to disrupt metabolic signaling and induce neuroanatomical changes in the brains of exposed offspring. To accomplish this, we developed a model of maternal aAb exposure in rats based on the clinical phenomenon of maternal autoantibody-related ASD (MAR-ASD). Following confirmation of aAb production in rat dams and antigen-specific immunoglobulin G (IgG) transfer to offspring, we assessed offspring behavior and brain structure longitudinally. MAR-ASD rat offspring displayed a reduction in pup ultrasonic vocalizations and a pronounced deficit in social play behavior when allowed to freely interact with a novel partner. Additionally, longitudinal in vivo structural magnetic resonance imaging (sMRI) at postnatal day 30 (PND30) and PND70, conducted in a separate cohort of animals, revealed sex-specific differences in total and regional brain volume. Treatment-specific effects by region appeared to converge on midbrain and cerebellar structures in MAR-ASD offspring. Simultaneously, in vivo 1H magnetic resonance spectroscopy (1H-MRS) data were collected to examine brain metabolite levels in the medial prefrontal cortex. Results showed that MAR-ASD offspring displayed decreased levels of choline-containing compounds and glutathione, accompanied by increased taurine compared to control animals. Overall, we found that rats exposed to MAR-ASD aAbs present with alterations in behavior, brain structure, and neurometabolites; reminiscent of findings observed in clinical ASD.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Efeitos Tardios da Exposição Pré-Natal , Humanos , Masculino , Gravidez , Feminino , Ratos , Animais , Transtorno Autístico/metabolismo , Transtorno do Espectro Autista/metabolismo , Autoanticorpos , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Encéfalo/metabolismo , Exposição Materna
3.
J Neurosci ; 41(48): 9971-9987, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34607967

RESUMO

Human epidemiological studies implicate exposure to infection during gestation in the etiology of neurodevelopmental disorders. Animal models of maternal immune activation (MIA) have identified the maternal immune response as the critical link between maternal infection and aberrant offspring brain and behavior development. Here we evaluate neurodevelopment of male rhesus monkeys (Macaca mulatta) born to MIA-treated dams (n = 14) injected with a modified form of the viral mimic polyinosinic:polycytidylic acid at the end of the first trimester. Control dams received saline injections at the same gestational time points (n = 10) or were untreated (n = 4). MIA-treated dams exhibited a strong immune response as indexed by transient increases in sickness behavior, temperature, and inflammatory cytokines. Although offspring born to control or MIA-treated dams did not differ on measures of physical growth and early developmental milestones, the MIA-treated animals exhibited subtle changes in cognitive development and deviated from species-typical brain growth trajectories. Longitudinal MRI revealed significant gray matter volume reductions in the prefrontal and frontal cortices of MIA-treated offspring at 6 months that persisted through the final time point at 45 months along with smaller frontal white matter volumes in MIA-treated animals at 36 and 45 months. These findings provide the first evidence of early postnatal changes in brain development in MIA-exposed nonhuman primates and establish a translationally relevant model system to explore the neurodevelopmental trajectory of risk associated with prenatal immune challenge from birth through late adolescence.SIGNIFICANCE STATEMENT Women exposed to infection during pregnancy have an increased risk of giving birth to a child who will later be diagnosed with a neurodevelopmental disorder. Preclinical maternal immune activation (MIA) models have demonstrated that the effects of maternal infection on fetal brain development are mediated by maternal immune response. Since the majority of MIA models are conducted in rodents, the nonhuman primate provides a unique system to evaluate the MIA hypothesis in a species closely related to humans. Here we report the first longitudinal study conducted in a nonhuman primate MIA model. MIA-exposed offspring demonstrate subtle changes in cognitive development paired with marked reductions in frontal gray and white matter, further supporting the association between prenatal immune challenge and alterations in offspring neurodevelopment.


Assuntos
Encéfalo/patologia , Modelos Animais de Doenças , Transtornos do Neurodesenvolvimento/etiologia , Complicações Infecciosas na Gravidez , Efeitos Tardios da Exposição Pré-Natal/patologia , Animais , Feminino , Indutores de Interferon/toxicidade , Macaca mulatta , Masculino , Transtornos do Neurodesenvolvimento/patologia , Neurogênese/fisiologia , Poli I-C/toxicidade , Gravidez , Complicações Infecciosas na Gravidez/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente
4.
Nature ; 537(7621): 508-514, 2016 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-27626380

RESUMO

Approximately one-third of all mammalian genes are essential for life. Phenotypes resulting from knockouts of these genes in mice have provided tremendous insight into gene function and congenital disorders. As part of the International Mouse Phenotyping Consortium effort to generate and phenotypically characterize 5,000 knockout mouse lines, here we identify 410 lethal genes during the production of the first 1,751 unique gene knockouts. Using a standardized phenotyping platform that incorporates high-resolution 3D imaging, we identify phenotypes at multiple time points for previously uncharacterized genes and additional phenotypes for genes with previously reported mutant phenotypes. Unexpectedly, our analysis reveals that incomplete penetrance and variable expressivity are common even on a defined genetic background. In addition, we show that human disease genes are enriched for essential genes, thus providing a dataset that facilitates the prioritization and validation of mutations identified in clinical sequencing efforts.


Assuntos
Embrião de Mamíferos/embriologia , Embrião de Mamíferos/metabolismo , Genes Essenciais/genética , Genes Letais/genética , Mutação/genética , Fenótipo , Animais , Sequência Conservada/genética , Doença , Estudo de Associação Genômica Ampla , Ensaios de Triagem em Larga Escala , Humanos , Imageamento Tridimensional , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Penetrância , Polimorfismo de Nucleotídeo Único/genética , Homologia de Sequência
5.
Geophys Res Lett ; 48(15)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34690382

RESUMO

We report for the first time the day-to-day variation of the longitudinal structure in height of the F2 layer (hmF2) in the equatorial ionosphere using multi-satellite observations of electron density profiles by the Constellation Observing System for Meteorology, Ionosphere and Climate-2 (COSMIC-2). These observations reveal a ~3-day modulation of the hmF2 wavenumber-4 structure viewed in a fixed local time frame during January 30-February 14, 2021. Simultaneously, ~3-day planetary wave activity is discerned from zonal wind observations at ~100 km by the Ionospheric Connection Explorer (ICON) Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI). This signature is not observed at ~180-250 km altitudes, suggesting the dissipation of this wave below the F-region. We propose that the 3-day variation identified in h mF2 is likely caused by the planetary wave-tide interaction through the E-region dynamo.

6.
Arch Toxicol ; 94(6): 2149-2162, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32303805

RESUMO

Organophosphate (OP) threat agents can trigger seizures that progress to status epilepticus, resulting in persistent neuropathology and cognitive deficits in humans and preclinical models. However, it remains unclear whether patients who do not show overt seizure behavior develop neurological consequences. Therefore, this study compared two subpopulations of rats with a low versus high seizure response to diisopropylfluorophosphate (DFP) to evaluate whether acute OP intoxication causes persistent neuropathology in non-seizing individuals. Adult male Sprague Dawley rats administered DFP (4 mg/kg, sc), atropine sulfate (2 mg/kg, im), and pralidoxime (25 mg/kg, im) were monitored for seizure activity for 4 h post-exposure. Animals were separated into groups with low versus high seizure response based on behavioral criteria and electroencephalogram (EEG) recordings. Cholinesterase activity was evaluated by Ellman assay, and neuropathology was evaluated at 1, 2, 4, and 60 days post-exposure by Fluoro-Jade C (FJC) staining and micro-CT imaging. DFP significantly inhibited cholinesterase activity in the cortex, hippocampus, and amygdala to the same extent in low and high responders. FJC staining revealed significant neurodegeneration in DFP low responders albeit this response was delayed, less persistent, and decreased in magnitude compared to DFP high responders. Micro-CT scans at 60 days revealed extensive mineralization that was not significantly different between low versus high DFP responders. These findings highlight the importance of considering non-seizing patients for medical care in the event of acute OP intoxication. They also suggest that OP intoxication may induce neurological damage via seizure-independent mechanisms, which if identified, might provide insight into novel therapeutic targets.


Assuntos
Ondas Encefálicas/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Inibidores da Colinesterase/toxicidade , Convulsivantes/toxicidade , Isoflurofato/toxicidade , Degeneração Neural , Síndromes Neurotóxicas/etiologia , Convulsões/induzido quimicamente , Acetilcolinesterase/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/diagnóstico por imagem , Encéfalo/enzimologia , Encéfalo/fisiopatologia , Proteínas Ligadas por GPI/metabolismo , Masculino , Síndromes Neurotóxicas/diagnóstico por imagem , Síndromes Neurotóxicas/enzimologia , Síndromes Neurotóxicas/fisiopatologia , Ratos Sprague-Dawley , Convulsões/diagnóstico por imagem , Convulsões/enzimologia , Convulsões/fisiopatologia , Fatores de Tempo , Microtomografia por Raio-X
7.
Meteorit Planet Sci ; 55(11): 2341-2359, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33510569

RESUMO

The Hamburg meteorite fell on January 16, 2018, near Hamburg, Michigan, after a fireball event widely observed in the U.S. Midwest and in Ontario, Canada. Several fragments fell onto frozen surfaces of lakes and, thanks to weather radar data, were recovered days after the fall. The studied rock fragments show no or little signs of terrestrial weathering. Here, we present the initial results from an international consortium study to describe the fall, characterize the meteorite, and probe the collision history of Hamburg. About 1 kg of recovered meteorites was initially reported. Petrology, mineral chemistry, trace element and organic chemistry, and O and Cr isotopic compositions are characteristic of H4 chondrites. Cosmic ray exposure ages based on cosmogenic 3He, 21Ne, and 38Ar are ~12 Ma, and roughly agree with each other. Noble gas data as well as the cosmogenic 10Be concentration point to a small 40-60 cm diameter meteoroid. An 40Ar-39Ar age of 4532 ± 24 Ma indicates no major impact event occurring later in its evolutionary history, consistent with data of other H4 chondrites. Microanalyses of phosphates with LA-ICPMS give an average Pb-Pb age of 4549 ± 36 Ma. This is in good agreement with the average SIMS Pb-Pb phosphate age of 4535.3 ± 9.5 Ma and U-Pb Concordia age of 4535 ± 10 Ma. The weighted average age of 4541.6 ± 9.5 Ma reflects the metamorphic phosphate crystallization age after parent body formation in the early solar system.

8.
Fetal Diagn Ther ; 46(6): 376-384, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30970373

RESUMO

INTRODUCTION: The surgically induced fetal lamb model is the most commonly used large animal model of myelomeningocele (MMC) but is subject to variation due to surgical technique during defect creation. MATERIAL AND METHODS: Thirty-one fetal lambs underwent creation of the MMC defect, followed by defect repair with either an extracellular matrix (ECM) patch (n = 10) or ECM seeded with placental mesenchymal stromal cells (n = 21). Postnatal hindlimb function was assessed using the Sheep Locomotor Rating (SLR) scale. Postmortem magnetic resonance imaging of the lumbar spine was used to measure the level and degree of spinal angulation, as well as cross-sectional area of remaining vertebral bone. RESULTS: Median level of angulation was between the 2nd and 3rd lumbar vertebrae, with a median angle of 24.3 degrees (interquartile range 16.2-35.3). There was a negative correlation between angulation degree and SLR (r = -0.44, p = 0.013). Degree of angulation also negatively correlated with the normalized cross-sectional area of remaining vertebral bone (r = -0.75, p < 0.0001). DISCUSSION: Surgical creation of fetal MMC leads to varying severity of spinal angulation in the ovine model, which affects postnatal functional outcomes. Postnatal assessment of spinal angulation aids in standardization of the surgical model of fetal MMC repair.


Assuntos
Membro Posterior/inervação , Vértebras Lombares/cirurgia , Meningomielocele/cirurgia , Transplante de Células-Tronco Mesenquimais , Animais , Modelos Animais de Doenças , Feminino , Idade Gestacional , Humanos , Locomoção , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiopatologia , Imageamento por Ressonância Magnética , Meningomielocele/diagnóstico por imagem , Meningomielocele/etiologia , Meningomielocele/fisiopatologia , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Placenta/citologia , Valor Preditivo dos Testes , Gravidez , Diagnóstico Pré-Natal , Carneiro Doméstico
9.
Am J Physiol Renal Physiol ; 313(2): F351-F360, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28424208

RESUMO

Among solid organs, the kidney's vascular network stands out, because each nephron has two distinct capillary structures in series and because tubuloglomerular feedback, one of the mechanisms responsible for blood flow autoregulation, is specific to renal tubules. Tubuloglomerular feedback and the myogenic mechanism, acting jointly, autoregulate single-nephron blood flow. Each generates a self-sustained periodic oscillation and an oscillating electrical signal that propagates upstream along arterioles. Similar electrical signals from other nephrons interact, allowing nephron synchronization. Experimental measurements show synchronization over fields of a few nephrons; simulations based on a simplified network structure that could obscure complex interactions predict more widespread synchronization. To permit more realistic simulations, we made a cast of blood vessels in a rat kidney, performed micro-computed tomography at 2.5-µm resolution, and recorded three-dimensional coordinates of arteries, afferent arterioles, and glomeruli. Nonterminal branches of arcuate arteries form treelike structures requiring two to six bifurcations to reach terminal branches at the tree tops. Terminal arterial structures were either paired branches at the tops of the arterial trees, from which 52.6% of all afferent arterioles originated, or unpaired arteries not at the tree tops, yielding the other 22.9%; the other 24.5% originated directly from nonterminal arteries. Afferent arterioles near the corticomedullary boundary were longer than those farther away, suggesting that juxtamedullary nephrons have longer afferent arterioles. The distance separating origins of pairs of afferent arterioles varied randomly. The results suggest an irregular-network tree structure with vascular nodes, where arteriolar activity and local blood pressure interact.


Assuntos
Arteríolas/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Néfrons/irrigação sanguínea , Artéria Renal/diagnóstico por imagem , Microtomografia por Raio-X , Animais , Arteríolas/anatomia & histologia , Masculino , Modelos Anatômicos , Modelos Cardiovasculares , Ratos Sprague-Dawley , Artéria Renal/anatomia & histologia , Técnicas de Réplica
10.
Am J Primatol ; 79(3): 1-9, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27757971

RESUMO

Pair bonding leads to increases in dopamine D1 receptor (D1R) binding in the nucleus accumbens of monogamous prairie voles. In the current study, we hypothesized that there is similar up-regulation of D1R in a monogamous primate, the titi monkey (Callicebus cupreus). Receptor binding of the D1R antagonist [11 C]-SCH23390 was measured in male titi monkeys using PET scans before and after pairing with a female. We found that within-subject analyses of pairing show significant increases in D1R binding in the lateral septum, but not the nucleus accumbens, caudate, putamen, or ventral pallidum. The lateral septum is involved in a number of processes that may contribute to social behavior, including motivation, affect, reward, and reinforcement. This region also plays a role in pair bonding and paternal behavior in voles. Our observations of changes in D1R in the lateral septum, but not the nucleus accumbens, suggest that there may be broadly similar dopaminergic mechanisms underlying pair bonding across mammalian species, but that the specific changes to neural circuitry differ. This study is the first research to demonstrate neuroplasticity of the dopamine system following pair bonding in a non-human primate; however, substantial variability in the response to pairing suggests the utility of further research on the topic.


Assuntos
Ligação do Par , Pitheciidae , Receptores de Dopamina D1 , Comportamento Social , Animais , Feminino , Masculino , Apego ao Objeto
11.
PLoS Genet ; 10(4): e1004257, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24699068

RESUMO

Cleft palate (CP) is one of the most commonly occurring craniofacial birth defects in humans. In order to study cleft palate in a naturally occurring model system, we utilized the Nova Scotia Duck Tolling Retriever (NSDTR) dog breed. Micro-computed tomography analysis of CP NSDTR craniofacial structures revealed that these dogs exhibit defects similar to those observed in a recognizable subgroup of humans with CP: Pierre Robin Sequence (PRS). We refer to this phenotype in NSDTRs as CP1. Individuals with PRS have a triad of birth defects: shortened mandible, posteriorly placed tongue, and cleft palate. A genome-wide association study in 14 CP NSDTRs and 72 unaffected NSDTRs identified a significantly associated region on canine chromosome 14 (24.2 Mb-29.3 Mb; p(raw )= 4.64 × 10(-15)). Sequencing of two regional candidate homeobox genes in NSDTRs, distal-less homeobox 5 (DLX5) and distal-less homeobox 6 (DLX6), identified a 2.1 kb LINE-1 insertion within DLX6 in CP1 NSDTRs. The LINE-1 insertion is predicted to insert a premature stop codon within the homeodomain of DLX6. This prompted the sequencing of DLX5 and DLX6 in a human cohort with CP, where a missense mutation within the highly conserved DLX5 homeobox of a patient with PRS was identified. This suggests the involvement of DLX5 in the development of PRS. These results demonstrate the power of the canine animal model as a genetically tractable approach to understanding naturally occurring craniofacial birth defects in humans.


Assuntos
Fissura Palatina/genética , Genes Homeobox/genética , Proteínas de Homeodomínio/genética , Elementos Nucleotídeos Longos e Dispersos/genética , Síndrome de Pierre Robin/genética , Animais , Cães , Frequência do Gene/genética , Estudo de Associação Genômica Ampla/métodos , Humanos , Mandíbula/metabolismo , Mutação de Sentido Incorreto/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
12.
J Foot Ankle Surg ; 56(3): 484-491, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28341493

RESUMO

Inflammatory markers are essential tools in the decision-making process for lower extremity infections. When coupled with objective findings, clinicians can more accurately diagnose and treat these entities. Typically, markers such as the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are used to initially assess these patients or monitor the progression of medical or surgical therapy. Procalcitonin is a newer inflammatory marker that is specific for an infectious process. Originally, procalcitonin was used to monitor antibiotic therapy and sepsis for patients in the intensive care setting, but it has now been expanded to other facets of medicine. The utility of procalcitonin has been described for diagnosing infection or osteomyelitis in diabetic foot ulcers. However, limited research has compared inflammatory marker levels and the level of amputation. A retrospective inpatient medical record review was performed of 156 consecutive patient occurrences during 25 months in which surgical intervention was required for a lower extremity infection and an initial procalcitonin level had been obtained. This initial procalcitonin value was then compared with the level of amputation at the final surgical intervention. A highly statistically significant difference was found when comparing those who underwent a below-the-knee or above-the-knee amputation (median procalcitonin 1.72 ng/mL) and those who did not (median procalcitonin 0.105 ng/mL; p < .001). Therefore, patients with higher initial procalcitonin values were more likely to undergo below-the-knee or above-the-knee amputation or require aggressive surgical intervention. Thus, the procalcitonin level can provide valuable initial information to the clinician.


Assuntos
Amputação Cirúrgica , Infecções Bacterianas/sangue , Calcitonina/sangue , Pé Diabético/sangue , Gangrena Gasosa/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Bacterianas/etiologia , Infecções Bacterianas/cirurgia , Biomarcadores/sangue , Pé Diabético/complicações , Pé Diabético/diagnóstico por imagem , Feminino , Pé/diagnóstico por imagem , Gangrena/etiologia , Gangrena/cirurgia , Gangrena Gasosa/diagnóstico por imagem , Gangrena Gasosa/etiologia , Humanos , Extremidade Inferior/patologia , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Adulto Jovem
13.
J Neuroinflammation ; 13(1): 267, 2016 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-27733171

RESUMO

BACKGROUND: Acute intoxication with organophosphorus (OP) cholinesterase inhibitors can trigger convulsions that progress to life-threatening status epilepticus. Survivors face long-term morbidity including mild-to-severe decline in memory. It is posited that neuroinflammation plays a key role in the pathogenesis of OP-induced neuropsychiatric deficits. Rigorous testing of this hypothesis requires preclinical models that recapitulate relevant phenotypic outcomes. Here, we describe a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) that exhibits persistent neuroinflammation and cognitive impairment. METHODS: Neuroinflammation, neurodegeneration, and cognitive function were compared in adult male Sprague Dawley rats injected with an acutely toxic dose of DFP vs. vehicle controls at multiple time points up to 36 days post-exposure. Neuroinflammation was quantified using immunohistochemical biomarkers of microglia (ionized calcium-binding adapter molecule 1, IBA1) and activated astrocytes (glial fibrillary acidic protein, GFAP) and positron emission tomography (PET) imaging of [11C]-(R)-PK11195, a ligand for the 18-kDa mitochondrial membrane translocator protein (TSPO). FluoroJade-B staining was used to assess neurodegeneration; Pavlovian conditioning, to assess cognitive function. RESULTS: Animals exhibited moderate-to-severe seizures within minutes of DFP injection that continued for up to 6 h post-injection. As indicated by IBA1 and GFAP immunoreactivity and by PET imaging of TSPO, acute DFP intoxication triggered neuroinflammation in the hippocampus and cortex during the first 3 days that peaked at 7 days and persisted to 21 days post-exposure in most animals. Neurodegeneration was detected in multiple brain regions from 1 to 14 days post-exposure. All DFP-intoxicated animals exhibited significant deficits in contextual fear conditioning at 9 and 20 days post-exposure compared to vehicle controls. Whole-brain TSPO labeling positively correlated with seizure severity score, but did not correlate with performance in the contextual fear-conditioning task. CONCLUSIONS: We describe a preclinical model in which acute DFP intoxication causes seizures, persistent neuroinflammation, neurodegeneration, and memory impairment. The extent of the neuroinflammatory response is influenced by seizure severity. However, the observation that a subset of animals with moderate seizures and minimal TSPO labeling exhibited cognitive deficits comparable to those of animals with severe seizures and significant TSPO labeling suggests that DFP may impair learning and memory circuitry via mechanisms independent of seizures or neuroinflammation.


Assuntos
Inibidores da Colinesterase/toxicidade , Disfunção Cognitiva/induzido quimicamente , Encefalite/induzido quimicamente , Isoflurofato/toxicidade , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Condicionamento Clássico/efeitos dos fármacos , Encefalite/diagnóstico por imagem , Comportamento Exploratório/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Imageamento por Ressonância Magnética , Masculino , Proteínas dos Microfilamentos/metabolismo , Tomografia por Emissão de Pósitrons , Ratos , Ratos Sprague-Dawley , Receptores de GABA-A/metabolismo , Análise de Regressão , Fatores de Tempo
15.
Neuropharmacology ; 251: 109918, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38527652

RESUMO

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.


Assuntos
Lesões Encefálicas , Estado Epiléptico , Ratos , Animais , Diazepam/farmacologia , Midazolam/farmacologia , Midazolam/uso terapêutico , Isoflurofato/farmacologia , Organofosfatos , Doenças Neuroinflamatórias , Neuroproteção , Ratos Sprague-Dawley , Encéfalo/metabolismo , Benzodiazepinas/farmacologia , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/diagnóstico por imagem , Estado Epiléptico/tratamento farmacológico , Tomografia por Emissão de Pósitrons , Proteínas de Transporte/metabolismo , Imageamento por Ressonância Magnética , Lesões Encefálicas/metabolismo , Atrofia/patologia
16.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38065138

RESUMO

When incorporated into a top-hat electrostatic analyzer, a gate electrode enables the separation of ions by their mass-per-charge with modest mass resolution (M/∆M ∼ 10). Gated-time-of-flight (TOF) instruments avoid the energy straggling and angular scattering effects prevalent in foil-based detection systems, providing more pristine measurements of three-dimensional distribution functions of incident ions. Gated-TOF implementations are ideal for measuring the properties of low-energy (i.e., <100 eV) thermal ions in various space environments. We present an instrument prototype capable of separating H+, He+, O+, and O2+ in Earth's ionosphere and demonstrate that in addition to providing species determination, precise operation of the gate electrode provides an electronically adjustable geometric factor that can extend a single instrument's dynamic range by several orders of magnitude.

17.
Mol Metab ; 69: 101679, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36708951

RESUMO

OBJECTIVE: Cold stimuli trigger the conversion of white adipose tissue into beige adipose tissue, which is capable of non-shivering thermogenesis. However, what process drives this activation of thermogenesis in beige fat is not well understood. Here, we examine the ER protein NNAT as a regulator of thermogenesis in adipose tissue. METHODS: We investigated the regulation of adipose tissue NNAT expression in response to changes in ambient temperature. We also evaluated the functional role of NNAT in thermogenic regulation using Nnat null mice and primary adipocytes that lack or overexpress NNAT. RESULTS: Cold exposure or treatment with a ß3-adrenergic agonist reduces the expression of adipose tissue NNAT in mice. Genetic disruption of Nnat in mice enhances inguinal adipose tissue thermogenesis. Nnat null mice exhibit improved cold tolerance both in the presence and absence of UCP1. Gain-of-function studies indicate that ectopic expression of Nnat abolishes adrenergic receptor-mediated respiration in beige adipocytes. NNAT physically interacts with the ER Ca2+-ATPase (SERCA) in adipocytes and inhibits its activity, impairing Ca2+ transport and heat dissipation. We further demonstrate that NHLRC1, an E3 ubiquitin protein ligase implicated in proteasomal degradation of NNAT, is induced by cold exposure or ß3-adrenergic stimulation, thus providing regulatory control at the protein level. This serves to link cold stimuli to NNAT degradation in adipose tissue, which in turn leads to enhanced SERCA activity. CONCLUSIONS: Our study implicates NNAT in the regulation of adipocyte thermogenesis.


Assuntos
Adipócitos Bege , Animais , Camundongos , Adipócitos/metabolismo , Adipócitos Bege/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo Branco/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Termogênese/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Retículo Endoplasmático/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-36805246

RESUMO

BACKGROUND: Epidemiological studies suggest that maternal immune activation (MIA) is a significant risk factor for future neurodevelopmental disorders, including schizophrenia (SZ), in offspring. Consistent with findings in SZ research and work in rodent systems, preliminary cross-sectional findings in nonhuman primates suggest that MIA is associated with dopaminergic hyperfunction in young adult offspring. METHODS: In this unique prospective longitudinal study, we used [18F]fluoro-l-m-tyrosine positron emission tomography to examine the developmental time course of striatal presynaptic dopamine synthesis in male rhesus monkeys born to dams (n = 13) injected with a modified form of the inflammatory viral mimic, polyinosinic:polycytidylic acid [poly(I:C)], in the late first trimester. Striatal (caudate, putamen, and nucleus accumbens) dopamine from these animals was compared with that of control offspring born to dams that received saline (n = 10) or no injection (n = 4). Dopamine was measured at 15, 26, 38, and 48 months of age. Prior work with this cohort found decreased prefrontal gray matter volume in MIA offspring versus controls between 6 and 45 months of age. Based on theories of the etiology and development of SZ-related pathology, we hypothesized that there would be a delayed (relative to the gray matter decrease) increase in striatal fluoro-l-m-tyrosine signal in the MIA group versus controls. RESULTS: [18F]fluoro-l-m-tyrosine signal showed developmental increases in both groups in the caudate and putamen. Group comparisons revealed significantly greater caudate dopaminergic signal in the MIA group at 26 months. CONCLUSIONS: These findings are highly relevant to the known pathophysiology of SZ and highlight the translational relevance of the MIA model in understanding mechanisms by which MIA during pregnancy increases risk for later illness in offspring.


Assuntos
Efeitos Tardios da Exposição Pré-Natal , Esquizofrenia , Gravidez , Animais , Feminino , Humanos , Masculino , Esquizofrenia/diagnóstico por imagem , Dopamina , Estudos Transversais , Estudos Longitudinais , Estudos Prospectivos , Tomografia por Emissão de Pósitrons , Primatas
19.
Am Heart J ; 163(2): 260-7.e3, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22305845

RESUMO

BACKGROUND: Cardiac resynchronization therapy (CRT) is effective in reducing clinical events in systolic heart failure patients with a wide QRS. Previous retrospective studies suggest only patients with QRS prolongation due to a left bundle-branch block (LBBB) benefit from CRT. Our objective was to examine this by performing a meta-analysis of all randomized controlled trials of CRT. METHODS: Systematic searches of MEDLINE and the Food and Drug Administration official website were conducted for randomized controlled CRT trials. Trials reporting adverse clinical events (eg, all-cause mortality, heart failure hospitalizations) according to QRS morphology were included in the meta-analysis. RESULTS: Four randomized trials totaling 5,356 patients met the inclusion criteria. In patients with LBBB at baseline, there was a highly significant reduction in composite adverse clinical events with CRT (RR = 0.64 [95% CI (0.52-0.77)], P = .00001). However no such benefit was observed for patients with non-LBBB conduction abnormalities (RR = 0.97 [95% CI (0.82-1.15)], P = .75). When examined separately, there was no benefit in patients with right-bundle branch block (RR = 0.91 [95% CI (0.69-1.20)], P = .49) or non-specific intraventricular conduction delay (RR = 1.19 [95% CI (0.87-1.63)], P = .28). There was no heterogeneity among the clinical trials with regards to the lack of benefit in non-LBBB patients (I(2) = 0%). When directly compared, the difference in effect of CRT between LBBB versus non-LBBB patients was highly statistically significant (P = .0001 by heterogeneity analysis). CONCLUSIONS: While CRT was very effective in reducing clinical events in patients with LBBB, it did not reduce such events in patients with wide QRS due to other conduction abnormalities.


Assuntos
Terapia de Ressincronização Cardíaca/métodos , Eletrocardiografia , Insuficiência Cardíaca/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Insuficiência Cardíaca/fisiopatologia , Humanos , Resultado do Tratamento
20.
J Pain Res ; 15: 71-91, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35046718

RESUMO

PURPOSE: To investigate the feasibility, acceptability, and preliminary efficacy of a 6-session music therapy protocol on self-efficacy, quality of life, and coping skills in adults with sickle cell disease (SCD). PATIENTS AND METHODS: Using a mixed-methods intervention design, adults with SCD (ages 21-57; mean age 32.33) were randomized (1:1) to either 1) a 6-session music therapy (MT) intervention (n = 12) or 2) waitlist control (WLC) (n = 12) using stratified randomization where factors were age in years (≤30 vs >30), and sex (male, female). All participants completed two weeks of daily electronic pain diary entries and self-efficacy, quality of life, and coping skills measures before and after their assigned study condition to explore preliminary efficacy. MT participants were taught music exercises accessed via smartphone and subsequently interviewed to determine feasibility and acceptability. RESULTS: The enrollment rate was 89%. All study measures were completed, with high rates of electronic pain diary completion at baseline (70%) and 2-week follow-up (66%). Interviews revealed two overall themes related to MT participants' experience: 1) participants learned new self-management skills and 2) MT improved participants' ability to cope with pain. MT participants demonstrated 100% attendance. In preliminary analyses, MT participants demonstrated significant improvements (means ± SD) in self-efficacy (5.42 ± 5.43, p = 0.008, d = 1.20), PROMIS sleep disturbance (-1.49 ± 6.68, p = 0.023, d = -0.99), PROMIS pain interference (-2.10 ± 4.68, p = 0.016, d = -1.06), and ASCQ-Me social functioning impact scores (2.97 ± 6.91, p = 0.018, d = 1.05) compared to WLC participants. CONCLUSION: Preliminary findings support the feasibility and acceptability of music therapy for home use in adults with SCD. While music therapy may assist adults with SCD in improving self-efficacy and quality of life, subsequent, fully-powered clinical research is needed to determine its efficacy.

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