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1.
Hum Brain Mapp ; 45(1): e26544, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38041476

RESUMEN

Neuromelanin-sensitive magnetic resonance imaging quantitative analysis methods have provided promising biomarkers that can noninvasively quantify degeneration of the substantia nigra in patients with Parkinson's disease. However, there is a need to systematically evaluate the performance of manual and automated quantification approaches. We evaluate whether spatial, signal-intensity, or subject specific abnormality measures using either atlas based or manually traced identification of the substantia nigra better differentiate patients with Parkinson's disease from healthy controls using logistic regression models and receiver operating characteristics. Inference was performed using bootstrap analyses to calculate 95% confidence interval bounds. Pairwise comparisons were performed by generating 10,000 permutations, refitting the models, and calculating a paired difference between metrics. Thirty-one patients with Parkinson's disease and 22 healthy controls were included in the analyses. Signal intensity measures significantly outperformed spatial and subject specific abnormality measures, with the top performers exhibiting excellent ability to differentiate patients with Parkinson's disease and healthy controls (balanced accuracy = 0.89; area under the curve = 0.81; sensitivity =0.86; and specificity = 0.83). Atlas identified substantia nigra metrics performed significantly better than manual tracing metrics. These results provide clear support for the use of automated signal intensity metrics and additional recommendations. Future work is necessary to evaluate whether the same metrics can best differentiate atypical parkinsonism, perform similarly in de novo and mid-stage cohorts, and serve as longitudinal monitoring biomarkers.


Asunto(s)
Melaninas , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/patología , Sensibilidad y Especificidad , Imagen por Resonancia Magnética/métodos , Biomarcadores/metabolismo , Sustancia Negra/metabolismo
2.
Hum Brain Mapp ; 45(7): e26699, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38726907

RESUMEN

With the steadily increasing abundance of longitudinal neuroimaging studies with large sample sizes and multiple repeated measures, questions arise regarding the appropriate modeling of variance and covariance. The current study examined the influence of standard classes of variance-covariance structures in linear mixed effects (LME) modeling of fMRI data from patients with pediatric mild traumatic brain injury (pmTBI; N = 181) and healthy controls (N = 162). During two visits, participants performed a cognitive control fMRI paradigm that compared congruent and incongruent stimuli. The hemodynamic response function was parsed into peak and late peak phases. Data were analyzed with a 4-way (GROUP×VISIT×CONGRUENCY×PHASE) LME using AFNI's 3dLME and compound symmetry (CS), autoregressive process of order 1 (AR1), and unstructured (UN) variance-covariance matrices. Voxel-wise results dramatically varied both within the cognitive control network (UN>CS for CONGRUENCY effect) and broader brain regions (CS>UN for GROUP:VISIT) depending on the variance-covariance matrix that was selected. Additional testing indicated that both model fit and estimated standard error were superior for the UN matrix, likely as a result of the modeling of individual terms. In summary, current findings suggest that the interpretation of results from complex designs is highly dependent on the selection of the variance-covariance structure using LME modeling.


Asunto(s)
Imagen por Resonancia Magnética , Humanos , Masculino , Femenino , Adolescente , Niño , Conmoción Encefálica/diagnóstico por imagen , Conmoción Encefálica/fisiopatología , Modelos Lineales , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Mapeo Encefálico/métodos , Función Ejecutiva/fisiología
3.
J Gen Intern Med ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38980465

RESUMEN

BACKGROUND: Despite clinical practice guidelines prioritizing cardiorenal risk reduction, national trends in diabetes outcomes, particularly in rural communities, do not mirror the benefits seen in clinical trials with emerging therapeutics and technologies. OBJECTIVE: Project ECHO supports implementation of guidelines in under-resourced areas through virtual communities of practice, sharing of best practices, and case-based learning. We hypothesized that diabetes outcomes of patients treated by ECHO-trained primary care providers (PCPs) would be similar to those of patients treated by specialists at an academic medical center. DESIGN: Specialists from the University of New Mexico (UNM) launched a weekly diabetes ECHO program to mentor dyads consisting of a PCP and community health worker at ten rural clinics. PARTICIPANTS: We compared cardiorenal risk factor changes in patients with diabetes treated by ECHO-trained dyads to patients treated by specialists at the UNM Diabetes Comprehensive Care Center (DCCC). Eligible participants included adults with type 1 diabetes, type 2 diabetes on insulin, or diabetes of either type with A1c > 9%. MAIN MEASURES: The primary outcome was change from baseline in A1c in the ECHO and DCCC cohorts. Secondary outcomes included changes in body mass index (BMI), blood pressure, cholesterol, and urine albumin to creatinine ratio (UACR). KEY RESULTS: Compared to the DCCC cohort (n = 151), patients in the ECHO cohort (n = 856) experienced greater A1c reduction (-1.2% vs -0.6%; p = 0.02 for difference in difference). BMI decreased in the Endo ECHO cohort and increased in the DCCC cohort (-0.2 vs. +1.3 kg/m2; p = 0.003 for difference in difference). Diastolic blood pressure declined in the Endo ECHO cohort only. Improvements of similar magnitude were observed in low-density lipoprotein cholesterol in both groups. UACR remained stable in both groups. CONCLUSIONS: ECHO may be a suitable intervention for improving diabetes outcomes in rural, under-resourced communities with limited access to a specialist.

4.
Brain Behav Immun ; 122: 345-352, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39163909

RESUMEN

Neuroinflammation is a key component underlying multiple neurological disorders, yet non-invasive and cost-effective assessment of in vivo neuroinflammatory processes in the central nervous system remains challenging. Diffusion weighted magnetic resonance spectroscopy (dMRS) has shown promise in addressing these challenges by measuring diffusivity properties of different neurometabolites, which can reflect cell-specific morphologies. Prior work has demonstrated dMRS utility in capturing microglial reactivity in the context of lipopolysaccharide (LPS) challenges and serious neurological disorders, detected as changes of microglial metabolite diffusivity properties. However, the extent to which such dMRS metrics are capable of detecting subtler and more nuanced levels of neuroinflammation in populations without overt neuropathology is unknown. Here we examined the relationship between intrinsic, gut-derived levels of systemic LPS and dMRS-based apparent diffusion coefficients (ADC) of choline, creatine, and N-acetylaspartate (NAA) in two brain regions: the thalamus and the corona radiata. Higher plasma LPS concentrations were significantly associated with increased ADC of choline and NAA in the thalamic region, with no such relationships observed in the corona radiata for any of the metabolites examined. As such, dMRS may have the sensitivity to measure microglial reactivity across populations with highly variable levels of neuroinflammation, and holds promising potential for widespread applications in both research and clinical settings.


Asunto(s)
Colina , Lipopolisacáridos , Espectroscopía de Resonancia Magnética , Microglía , Lipopolisacáridos/farmacología , Microglía/metabolismo , Animales , Colina/metabolismo , Masculino , Espectroscopía de Resonancia Magnética/métodos , Enfermedades Neuroinflamatorias/metabolismo , Creatina/metabolismo , Ácido Aspártico/metabolismo , Ácido Aspártico/análogos & derivados , Encéfalo/metabolismo , Imagen de Difusión por Resonancia Magnética/métodos , Tálamo/metabolismo , Femenino
5.
Pediatr Blood Cancer ; 71(3): e30822, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38146016

RESUMEN

BACKGROUND: Non-chromosomal birth defects are an important risk factor for several childhood cancers. However, these associations are less clear for Hodgkin lymphoma (HL). Therefore, we sought to more fully elucidate the association between non-chromosomal birth defects and HL risk. PROCEDURE: Information on cases (n = 517) diagnosed with HL (ages of 0-14) at Children's Oncology Group Institutions for the period of 1989-2003 was obtained. Control children without a history of cancer (n = 784) were identified using random digit dialing and individually matched to cases on sex, race/ethnicity, age, and geographic location. Parents completed comprehensive interviews and answered questions including whether their child had been born with a non-chromosomal birth defect. To test the association between birth defects and HL risk, conditional logistic regression was applied to generate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). RESULTS: Children born with any non-chromosomal birth defect were not more likely to be diagnosed with HL at 0-14 years of age (aOR: 0.91; 95% CI: 0.69-1.21). No associations were detected between major or minor birth defects and HL (aOR: 1.34; 95% CI: 0.67-2.67 and aOR: 0.88; 95% CI: 0.57-1.34, respectively). Similarly, no association was observed for children born with any birth defect and EBV-positive HL (aOR: 0.57; 95% CI: 0.25-1.26). CONCLUSIONS: Previous assessments of HL in children with non-chromosomal birth defects have been limited. Using data from the largest case-control study of HL in those <15 years of age, we did not observe strong associations between being born with a birth defect and HL risk.


Asunto(s)
Enfermedad de Hodgkin , Niño , Humanos , Estudios de Casos y Controles , Etnicidad , Extremidades , Enfermedad de Hodgkin/epidemiología , Enfermedad de Hodgkin/etiología , Factores de Riesgo , Masculino , Femenino
6.
Hum Brain Mapp ; 44(17): 6173-6184, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37800467

RESUMEN

There is a growing body of research showing that cerebral pathophysiological processes triggered by pediatric mild traumatic brain injury (pmTBI) may extend beyond the usual clinical recovery timeline. It is paramount to further unravel these processes, because the possible long-term cognitive effects resulting from ongoing secondary injury in the developing brain are not known. In the current fMRI study, neural processes related to cognitive control were studied in 181 patients with pmTBI at sub-acute (SA; ~1 week) and early chronic (EC; ~4 months) stages post-injury. Additionally, a group of 162 age- and sex-matched healthy controls (HC) were recruited at equivalent time points. Proactive (post-cue) and reactive (post-probe) cognitive control were examined using a multimodal attention fMRI paradigm for either congruent or incongruent stimuli. To study brain network function, the triple-network model was used, consisting of the executive and salience networks (collectively known as the cognitive control network), and the default mode network. Additionally, whole-brain voxel-wise analyses were performed. Decreased deactivation was found within the default mode network at the EC stage following pmTBI during both proactive and reactive control. Voxel-wise analyses revealed sub-acute hypoactivation of a frontal area of the cognitive control network (left pre-supplementary motor area) during proactive control, with a reversed effect at the EC stage after pmTBI. Similar effects were observed in areas outside of the triple-network during reactive control. Group differences in activation during proactive control were limited to the visual domain, whereas for reactive control findings were more pronounced during the attendance of auditory stimuli. No significant correlations were present between task-related activations and (persistent) post-concussive symptoms. In aggregate, current results show alterations in neural functioning during cognitive control in pmTBI up to 4 months post-injury, regardless of clinical recovery. We propose that subacute decreases in activity reflect a general state of hypo-excitability due to the injury, while early chronic hyperactivation represents a compensatory mechanism to prevent default mode interference and to retain cognitive control.


Asunto(s)
Conmoción Encefálica , Trastornos del Conocimiento , Disfunción Cognitiva , Humanos , Niño , Conmoción Encefálica/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Trastornos del Conocimiento/etiología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/complicaciones , Imagen por Resonancia Magnética , Cognición
7.
Mov Disord ; 38(7): 1262-1272, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37157056

RESUMEN

BACKGROUND: Cerebrovascular dysfunction in Parkinson's disease (PD) is heterogeneous and may contribute to disease pathophysiology or progression. There is a need to understand the mechanisms by which cerebrovascular dysfunction is altered in participants with PD. OBJECTIVES: The objective of this study is to test the hypothesis that participants with PD exhibit a significant reduction in the ability of the cerebral vessels to dilate in response to vasoactive challenges relative to healthy controls (HC). METHODS: The current study uses a vasodilatory challenge while participants undergo functional magnetic resonance imaging to quantify the amplitude and delay of cerebrovascular reactivity in participants with PD relative to age and sex-matched HC. An analysis of covariance was used to evaluate differences in cerebrovascular reactivity amplitude and latency between PD participants and HC. RESULTS: A significant main effect of group was observed for whole-brain cerebrovascular reactivity amplitude (F(1, 28) = 4.38, p = 0.046, Hedge's g = 0.73) and latency (F(1, 28) = 16.35, p < 0.001, Hedge's g = 1.42). Participants with PD exhibited reduced whole-brain amplitude and increased latencies in cerebrovascular reactivity relative to HC. The evaluation of regional effects indicates that the largest effects were observed in the cuneus, precuneus, and parietal regions. CONCLUSIONS: PD participants exhibited reduced and delayed cerebrovascular reactivity. This dysfunction may play an important role in chronic hypoxia, neuroinflammation, and protein aggregation, mechanisms that could lead to disease progression. Cerebrovascular reactivity may serve as an important biomarker and target for future interventions. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Enfermedad de Parkinson , Humanos , Encéfalo/patología , Imagen por Resonancia Magnética/métodos , Lóbulo Occipital , Lóbulo Parietal
8.
Mol Psychiatry ; 27(3): 1676-1682, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34853404

RESUMEN

Electroconvulsive therapy (ECT) remains the gold-standard treatment for patients with depressive episodes, but the underlying mechanisms for antidepressant response and procedure-induced cognitive side effects have yet to be elucidated. Such mechanisms may be complex and involve certain ECT parameters and brain regions. Regarding parameters, the electrode placement (right unilateral or bitemporal) determines the geometric shape of the electric field (E-field), and amplitude determines the E-field magnitude in select brain regions (e.g., hippocampus). Here, we aim to determine the relationships between hippocampal E-field strength, hippocampal neuroplasticity, and antidepressant and cognitive outcomes. We used hippocampal E-fields and volumes generated from a randomized clinical trial that compared right unilateral electrode placement with different pulse amplitudes (600, 700, and 800 mA). Hippocampal E-field strength was variable but increased with each amplitude arm. We demonstrated a linear relationship between right hippocampal E-field and right hippocampal neuroplasticity. Right hippocampal neuroplasticity mediated right hippocampal E-field and antidepressant outcomes. In contrast, right hippocampal E-field was directly related to cognitive outcomes as measured by phonemic fluency. We used receiver operating characteristic curves to determine that the maximal right hippocampal E-field associated with cognitive safety was 112.5 V/m. Right hippocampal E-field strength was related to the whole-brain ratio of E-field strength per unit of stimulation current, but this whole-brain ratio was unrelated to antidepressant or cognitive outcomes. We discuss the implications of optimal hippocampal E-field dosing to maximize antidepressant outcomes and cognitive safety with individualized amplitudes.


Asunto(s)
Terapia Electroconvulsiva , Antidepresivos , Encéfalo/fisiología , Terapia Electroconvulsiva/efectos adversos , Hipocampo , Humanos , Plasticidad Neuronal , Resultado del Tratamiento
9.
Brain ; 145(11): 4124-4137, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-35727944

RESUMEN

The underlying pathophysiology of paediatric mild traumatic brain injury and the time-course for biological recovery remains widely debated, with clinical care principally informed by subjective self-report. Similarly, clinical evidence indicates that adolescence is a risk factor for prolonged recovery, but the impact of age-at-injury on biomarkers has not been determined in large, homogeneous samples. The current study collected diffusion MRI data in consecutively recruited patients (n = 203; 8-18 years old) and age and sex-matched healthy controls (n = 170) in a prospective cohort design. Patients were evaluated subacutely (1-11 days post-injury) as well as at 4 months post-injury (early chronic phase). Healthy participants were evaluated at similar times to control for neurodevelopment and practice effects. Clinical findings indicated persistent symptoms at 4 months for a significant minority of patients (22%), along with residual executive dysfunction and verbal memory deficits. Results indicated increased fractional anisotropy and reduced mean diffusivity for patients, with abnormalities persisting up to 4 months post-injury. Multicompartmental geometric models indicated that estimates of intracellular volume fractions were increased in patients, whereas estimates of free water fractions were decreased. Critically, unique areas of white matter pathology (increased free water fractions or increased neurite dispersion) were observed when standard assumptions regarding parallel diffusivity were altered in multicompartmental models to be more biologically plausible. Cross-validation analyses indicated that some diffusion findings were more reproducible when ∼70% of the total sample (142 patients, 119 controls) were used in analyses, highlighting the need for large-sample sizes to detect abnormalities. Supervised machine learning approaches (random forests) indicated that diffusion abnormalities increased overall diagnostic accuracy (patients versus controls) by ∼10% after controlling for current clinical gold standards, with each diffusion metric accounting for only a few unique percentage points. In summary, current results suggest that novel multicompartmental models are more sensitive to paediatric mild traumatic brain injury pathology, and that this sensitivity is increased when using parameters that more accurately reflect diffusion in healthy tissue. Results also indicate that diffusion data may be insufficient to achieve a high degree of objective diagnostic accuracy in patients when used in isolation, which is to be expected given known heterogeneities in pathophysiology, mechanism of injury and even criteria for diagnoses. Finally, current results indicate ongoing clinical and physiological recovery at 4 months post-injury.


Asunto(s)
Conmoción Encefálica , Sustancia Blanca , Adolescente , Humanos , Niño , Conmoción Encefálica/patología , Estudios Prospectivos , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Imagen de Difusión por Resonancia Magnética/métodos , Agua , Encéfalo/patología
10.
South Med J ; 115(10): 734-739, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36191908

RESUMEN

OBJECTIVES: Primary health care (PHC) is essential for a well-functioning health system. Although PHC has been shown to have adverse effects on health outcomes, many barriers prevent adequate access, including a shortage of primary care physicians. In New Mexico, 32 of 33 counties are designed as primary care health professional shortage areas, and the state has a lower-than-average primary care provider density compared with other states. This study explored the predictors of job placement among New Mexican Family Medicine residents. METHODS: A retrospective cohort study design was used, which included a subset of data from The University of New Mexico (UNM) Family Medicine Residency Alumni Database and hard copy personnel files. The study's population consisted of the 260 graduates from the UNM Family Medicine Residency Program between 1998 and 2019. Analysis included simple and multiple logistic regression. RESULTS: Results indicated that, consistently, approximately two-thirds of first practices are in New Mexico, whereas the percentage with a current practice in New Mexico decreases over time. Those born in New Mexico or who attended the UNM School of Medicine were more likely to have their first and current practice in New Mexico. CONCLUSIONS: The results of this study provide further evidence that the relationship between place of birth and place of medical training are determining factors for both place of first and current practice. These results can inform practice, policy, and future research to address the pressing need for PHC in underserved and rural communities.


Asunto(s)
Medicina Familiar y Comunitaria , Internado y Residencia , Selección de Profesión , Medicina Familiar y Comunitaria/educación , Humanos , New Mexico , Ubicación de la Práctica Profesional , Estudios Retrospectivos
11.
Am J Geriatr Psychiatry ; 29(2): 166-178, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32651051

RESUMEN

INTRODUCTION: Electroconvulsive therapy (ECT) pulse amplitude, which determines the induced electric field magnitude in the brain, is currently set at 800-900 milliamperes (mA) on modern ECT devices without any clinical or scientific rationale. The present study assessed differences in depression and cognitive outcomes for three different pulse amplitudes during an acute ECT series. We hypothesized that the lower amplitudes would maintain the antidepressant efficacy of the standard treatment and reduce the risk of neurocognitive impairment. METHODS: This double-blind investigation randomized subjects to three treatment arms: 600, 700, and 800 mA (active comparator). Clinical, cognitive, and imaging assessments were conducted pre-, mid- and post-ECT. Subjects had a diagnosis of major depressive disorder, age range between 50 and 80 years, and met clinical indication for ECT. RESULTS: The 700 and 800 mA arms had improvement in depression outcomes relative to the 600 mA arm. The amplitude groups showed no differences in the primary cognitive outcome variable, the Hopkins Verbal Learning Test-Revised (HVLT-R) retention raw score. However, secondary cognitive outcomes such as the Delis Kaplan Executive Function System Letter and Category Fluency measures demonstrated cognitive impairment in the 800 mA arm. DISCUSSION: The results demonstrated a dissociation of depression (higher amplitudes better) and cognitive (lower amplitudes better) related outcomes. Future work is warranted to elucidate the relationship between amplitude, electric field, neuroplasticity, and clinical outcomes.


Asunto(s)
Trastorno Depresivo Mayor/terapia , Terapia Electroconvulsiva , Anciano , Anciano de 80 o más Años , Antidepresivos/uso terapéutico , Encéfalo , Trastorno Depresivo Mayor/tratamiento farmacológico , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Resultado del Tratamiento
12.
Crit Care ; 25(1): 428, 2021 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-34915927

RESUMEN

BACKGROUND: Traumatic brain injury (TBI) and severe blood loss resulting in hemorrhagic shock (HS) represent leading causes of trauma-induced mortality, especially when co-occurring in pre-hospital settings where standard therapies are not readily available. The primary objective of this study was to determine if 17α-ethinyl estradiol-3-sulfate (EE-3-SO4) increases survival, promotes more rapid cardiovascular recovery, or confers neuroprotection relative to Placebo following TBI + HS. METHODS: All methods were approved by required regulatory agencies prior to study initiation. In this fully randomized, blinded preclinical study, eighty (50% females) sexually mature (190.64 ± 21.04 days old; 28.18 ± 2.72 kg) Yucatan swine were used. Sixty-eight animals received a closed-head, accelerative TBI followed by removal of approximately 40% of circulating blood volume. Animals were then intravenously administered EE-3-SO4 formulated in the vehicle at 5.0 mg/mL (dosed at 0.2 mL/kg) or Placebo (0.45% sodium chloride solution) via a continuous pump (0.2 mL/kg over 5 min). Twelve swine were included as uninjured Shams to further characterize model pathology and replicate previous findings. All animals were monitored for up to 5 h in the absence of any other life-saving measures (e.g., mechanical ventilation, fluid resuscitation). RESULTS: A comparison of Placebo-treated relative to Sham animals indicated evidence of acidosis, decreased arterial pressure, increased heart rate, diffuse axonal injury and blood-brain barrier breach. The percentage of animals surviving to 295 min post-injury was significantly higher for the EE-3-SO4 (28/31; 90.3%) relative to Placebo (24/33; 72.7%) cohort. EE-3-SO4 also restored pulse pressure more rapidly post-drug administration, but did not confer any benefits in terms of shock index. Primary blood-based measurements of neuroinflammation and blood brain breach were also null, whereas secondary measurements of diffuse axonal injury suggested a more rapid return to baseline for the EE-3-SO4 group. Survival status was associated with biological sex (female > male), as well as evidence of increased acidosis and neurotrauma independent of EE-3-SO4 or Placebo administration. CONCLUSIONS: EE-3-SO4 is efficacious in promoting survival and more rapidly restoring cardiovascular homeostasis following polytraumatic injuries in pre-hospital environments (rural and military) in the absence of standard therapies. Poly-therapeutic approaches targeting additional mechanisms (increased hemostasis, oxygen-carrying capacity, etc.) should be considered in future studies.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Choque Hemorrágico , Animales , Lesiones Traumáticas del Encéfalo/complicaciones , Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Modelos Animales de Enfermedad , Estradiol/análogos & derivados , Femenino , Hemodinámica , Masculino , Enfermedades Neuroinflamatorias , Resucitación , Choque Hemorrágico/tratamiento farmacológico , Porcinos
13.
Neurobiol Dis ; 126: 124-136, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30010004

RESUMEN

BACKGROUND: Hypertension-induced microvascular brain injury is a major vascular contributor to cognitive impairment and dementia. We hypothesized that chronic hypoxia promotes the hyperphosphorylation of tau and cell death in an accelerated spontaneously hypertensive stroke prone rat model of vascular cognitive impairment. METHODS: Hypertensive male rats (n = 13) were fed a high salt, low protein Japanese permissive diet and were compared to Wistar Kyoto control rats (n = 5). RESULTS: Using electron paramagnetic resonance oximetry to measure in vivo tissue oxygen levels and magnetic resonance imaging to assess structural brain damage, we found compromised gray (dorsolateral cortex: p = .018) and white matter (corpus callosum: p = .016; external capsule: p = .049) structural integrity, reduced cerebral blood flow (dorsolateral cortex: p = .005; hippocampus: p < .001; corpus callosum: p = .001; external capsule: p < .001) and a significant drop in cortical oxygen levels (p < .05). Consistently, we found reduced oxygen carrying neuronal neuroglobin (p = .008), suggestive of chronic cerebral hypoperfusion in high salt-fed rats. We also observed a corresponding increase in free radicals (NADPH oxidase: p = .013), p-Tau (pThr231) in dorsolateral cortex (p = .011) and hippocampus (p = .003), active interleukin-1ß (p < .001) and neurodegeneration (dorsolateral cortex: p = .043, hippocampus: p = .044). Human patients with subcortical ischemic vascular disease, a type of vascular dementia (n = 38; mean age = 68; male/female ratio = 23/15) showed reduced hippocampal volumes and cortical shrinking (p < .05) consistent with the neuronal cell death observed in our hypertensive rat model as compared to healthy controls (n = 47; mean age = 63; male/female ratio = 18/29). CONCLUSIONS: Our data support an association between hypertension-induced vascular dysfunction and the sporadic occurrence of phosphorylated tau and cell death in the rat model, correlating with patient brain atrophy, which is relevant to vascular disease.


Asunto(s)
Encéfalo/patología , Hipoxia de la Célula/fisiología , Demencia Vascular/patología , Proteínas tau/metabolismo , Anciano , Animales , Demencia Vascular/metabolismo , Femenino , Humanos , Hipertensión/complicaciones , Hipertensión/patología , Masculino , Persona de Mediana Edad , Fosforilación , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY
14.
Hum Brain Mapp ; 40(10): 3058-3077, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30884018

RESUMEN

The brain is highly dynamic, reorganizing its activity at different interacting spatial and temporal scales, including variation within and between brain networks. The chronnectome is a model of the brain in which nodal activity and connectivity patterns change in fundamental and recurring ways over time. Most literature assumes fixed spatial nodes/networks, ignoring the possibility that spatial nodes/networks may vary in time. Here, we introduce an approach to calculate a spatially fluid chronnectome (called the spatial chronnectome for clarity), which focuses on the variations of networks coupling at the voxel level, and identify a novel set of spatially dynamic features. Results reveal transient spatially fluid interactions between intra- and internetwork relationships in which brain networks transiently merge and separate, emphasizing dynamic segregation and integration. Brain networks also exhibit distinct spatial patterns with unique temporal characteristics, potentially explaining a broad spectrum of inconsistencies in previous studies that assumed static networks. Moreover, we show anticorrelative connections to brain networks are transient as opposed to constant across the entire scan. Preliminary assessments using a multi-site dataset reveal the ability of the approach to obtain new information and nuanced alterations that remain undetected during static analysis. Patients with schizophrenia (SZ) display transient decreases in voxel-wise network coupling within visual and auditory networks, and higher intradomain coupling variability. In summary, the spatial chronnectome represents a new direction of research enabling the study of functional networks which are transient at the voxel level, and the identification of mechanisms for within- and between-subject spatial variability.


Asunto(s)
Encéfalo/fisiología , Conectoma/métodos , Modelos Neurológicos , Vías Nerviosas/fisiología , Esquizofrenia/fisiopatología , Adulto , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Adulto Joven
16.
Hum Brain Mapp ; 39(8): 3127-3142, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29602272

RESUMEN

Recent advances in neuroimaging techniques have provided significant insights into developmental trajectories of human brain function. Characterizations of typical neurodevelopment provide a framework for understanding altered neurodevelopment, including differences in brain function related to developmental disorders and psychopathology. Historically, most functional connectivity studies of typical and atypical development operate under the assumption that connectivity remains static over time. We hypothesized that relaxing stationarity assumptions would reveal novel features of both typical brain development related to children on the autism spectrum. We employed a "chronnectomic" (recurring, time-varying patterns of connectivity) approach to evaluate transient states of connectivity using resting-state functional MRI in a population-based sample of 774 6- to 10-year-old children. Dynamic connectivity was evaluated using a sliding-window approach, and revealed four transient states. Internetwork connectivity increased with age in modularized dynamic states, illustrating an important pattern of connectivity in the developing brain. Furthermore, we demonstrated that higher levels of autistic traits and ASD diagnosis were associated with longer dwell times in a globally disconnected state. These results provide a roadmap to the chronnectomic organization of the developing brain and suggest that characteristics of functional brain connectivity are related to children on the autism spectrum.


Asunto(s)
Trastorno del Espectro Autista/fisiopatología , Trastorno del Espectro Autista/psicología , Encéfalo/crecimiento & desarrollo , Encéfalo/fisiopatología , Trastorno del Espectro Autista/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Niño , Conectoma , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/fisiopatología , Descanso
17.
Proc Biol Sci ; 284(1861)2017 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-28855364

RESUMEN

Persistence and extinction are key processes in infectious disease dynamics that, owing to incomplete reporting, are seldom directly observable. For fully immunizing diseases, reporting probabilities can be readily estimated from demographic records and case reports. Yet reporting probabilities are not sufficient to unambiguously reconstruct disease incidence from case reports. Here, we focus on disease presence (i.e. marginal probability of non-zero incidence), which provides an upper bound on the marginal probability of disease extinction. We examine measles and pertussis in pre-vaccine era United States (US) cities, and describe a conserved scaling relationship between population size, reporting probability and observed presence (i.e. non-zero case reports). We use this relationship to estimate disease presence given perfect reporting, and define cryptic presence as the difference between estimated and observed presence. We estimate that, in early twentieth century US cities, pertussis presence was higher than measles presence across a range of population sizes, and that cryptic presence was common in small cities with imperfect reporting. While the methods employed here are specific to fully immunizing diseases, our results suggest that cryptic incidence deserves careful attention, particularly in diseases with low case counts, poor reporting and longer infectious periods.


Asunto(s)
Sarampión/epidemiología , Tos Ferina/epidemiología , Ciudades , Humanos , Incidencia , Densidad de Población , Estados Unidos
18.
BMC Endocr Disord ; 17(1): 46, 2017 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-28738902

RESUMEN

BACKGROUND: Diabetes risk is extremely high for Latinos from low-income households. Health guidelines recommend that individuals learn strategies to self-manage their diabetes, but getting people to adopt required lifestyle changes is challenging and many people are not able to prevent their pre-diabetes from escalating or effectively control their diabetes. Systematic reviews show that culturally competent self-management programs can significantly improve diabetes outcomes and different models for culturally competent programming have been developed. METHODS: This patient-engaged study will compare the effectiveness of two distinct evidence-based models for culturally competent diabetes health promotion at two sites that serve a large Latino patient population from low-income households: 1) The Diabetes Self-Management Support Empowerment Model, an educational session approach, and 2) The Chronic Care Model, a holistic community-based program. Data collection will involve interviews, focus groups, surveys and assessments of each program; and testing of patient participants for A1c, depression, Body Mass Index (BMI), and chronic stress with hair cortisol levels. We will recruit a total of 240 patient-social support pairs: Patients will be adults (men and women over the age of 18) who: 1.) Enter one of the two diabetes programs during the study; 2.) Self-identify as "Latino;" 3.) Are able to identify a social support person or key member of their social network who also agrees to participate with them; 4.) Are not pregnant (participants who become pregnant during the study will be excluded); and 5.) Have household income 250% of the Federal Poverty Level (FPL) or below. Social supports will be adults who are identified by the patient participants. PRIMARY OUTCOME: Improved capacity for diabetes self-management measured through improvements in diabetes knowledge and diabetes-related patient activation. SECONDARY OUTCOME: Successful diabetes self-management as measured by improvements in A1c, depression scale scores, BMI, and circulating levels of cortisol to determine chronic stress. DISCUSSION: Our hypothesis is that the program model that interfaces most synergistically with patients' culture and everyday life circumstances will have the best diabetes health outcomes. TRIAL REGISTRATION: This study was registered with ClinicalTrials.gov on December 16, 2016 (Registration # NCT03004664 ).


Asunto(s)
Diabetes Mellitus Tipo 2/etnología , Diabetes Mellitus Tipo 2/prevención & control , Promoción de la Salud , Hispánicos o Latinos/psicología , Modelos Estadísticos , Autocuidado , Automanejo/psicología , Glucemia/análisis , Índice de Masa Corporal , Estudios de Seguimiento , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/uso terapéutico , Pobreza , Pronóstico , Proyectos de Investigación , Apoyo Social
19.
J Neurosci ; 35(36): 12446-64, 2015 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-26354913

RESUMEN

A multifunctional microRNA, miR-155, has been recently recognized as an important modulator of numerous biological processes. In our previous in vitro studies, miR-155 was identified as a potential regulator of the endothelial morphogenesis. The present study demonstrates that in vivo inhibition of miR-155 supports cerebral vasculature after experimental stroke. Intravenous injections of a specific miR-155 inhibitor were initiated at 48 h after mouse distal middle cerebral artery occlusion (dMCAO). Microvasculature in peri-infarct area, infarct size, and animal functional recovery were assessed at 1, 2, and 3 weeks after dMCAO. Using in vivo two-photon microscopy, we detected improved blood flow and microvascular integrity in the peri-infarct area of miR-155 inhibitor-injected mice. Electron microscopy revealed that, in contrast to the control group, these animals demonstrated well preserved capillary tight junctions (TJs). Western blot analysis data indicate that improved TJ integrity in the inhibitor-injected animals could be associated with stabilization of the TJ protein ZO-1 and mediated by the miR-155 target protein Rheb. MRI analysis showed significant (34%) reduction of infarct size in miR-155 inhibitor-injected animals at 21 d after dMCAO. Reduced brain injury was confirmed by electron microscopy demonstrating decreased neuronal damage in the peri-infarct area of stroke. Preservation of brain tissue was reflected in efficient functional recovery of inhibitor-injected animals. Based on our findings, we propose that in vivo miR-155 inhibition after ischemia supports brain microvasculature, reduces brain tissue damage, and improves the animal functional recovery. Significance statement: In the present study, we investigated an effect of the in vivo inhibition of a microRNA, miR-155, on brain recovery after experimental cerebral ischemia. To our knowledge, this is the first report describing the efficiency of intravenous anti-miRNA injections in a mouse model of ischemic stroke. The role of miRNAs in poststroke revascularization has been unexplored and in vivo regulation of miRNAs during the subacute phase of stroke has not yet been proposed. Our investigation introduces a new and unexplored approach to cerebral regeneration: regulation of poststroke angiogenesis and recovery through direct modulation of specific miRNA activity. We expect that our findings will lead to the development of novel strategies for regulating neurorestorative processes in the postischemic brain.


Asunto(s)
Infarto de la Arteria Cerebral Media/terapia , MicroARNs/genética , Tratamiento con ARN de Interferencia , Animales , Inyecciones Intravenosas , Ratones , Ratones Endogámicos C57BL , Microvasos/metabolismo , Microvasos/patología , Oligonucleótidos Antisentido/administración & dosificación , Oligonucleótidos Antisentido/uso terapéutico , Proteínas de Uniones Estrechas/metabolismo , Uniones Estrechas/metabolismo , Uniones Estrechas/ultraestructura
20.
Pediatr Blood Cancer ; 63(9): 1557-62, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27198935

RESUMEN

BACKGROUND: Rhabdomyosarcoma (RMS) is a rare, highly malignant tumor arising from primitive mesenchymal cells that differentiate into skeletal muscle. Relatively little is known about RMS susceptibility. Based on growing evidence regarding the role of early immunologic challenges on RMS development, we evaluated the role of infections and immunizations on this clinically significant pediatric malignancy. PROCEDURE: RMS cases (n = 322) were enrolled from the third trial coordinated by the Intergroup Rhabdomyosarcoma Study Group. Population-based controls (n = 322) were pair matched to cases on race, sex, and age. The following immunizations were assessed: diphtheria, pertussis, and tetanus (DPT); measles, mumps, and rubella; and oral polio vaccine. We also evaluated if immunizations were complete versus incomplete. We examined selected infections including chickenpox, mumps, pneumonia, scarlet fever, rubella, rubeola, pertussis, mononucleosis, and lung infections. Conditional logistic regression models were used to calculate an odds ratio (OR) and 95% confidence interval (CI) for each exposure, adjusted for maternal education and total annual income. RESULTS: Incomplete immunization schedules (OR = 5.30, 95% CI: 2.47-11.33) and incomplete DPT immunization (OR = 1.56, 95% CI: 1.06-2.29) were positively associated with childhood RMS. However, infections did not appear to be associated with childhood RMS. CONCLUSIONS: This is the largest study of RMS to date demonstrating a possible protective effect of immunizations against the development of childhood RMS. Further studies are needed to validate our findings. Our findings add to the growing body of literature, suggesting a protective role of routine vaccinations in childhood cancer and specifically in childhood RMS.


Asunto(s)
Infecciones/complicaciones , Rabdomiosarcoma/prevención & control , Vacunación , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Rabdomiosarcoma/etiología
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