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614 result(s) for "Clare, Kevin"
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Chronic cocaine induces HIF-VEGF pathway activation along with angiogenesis in the brain
Cocaine induces vasoconstriction in cerebral vessels, which with repeated use can result in transient ischemic attacks and cerebral strokes. However, the neuroadaptations that follow cocaine's vasoconstricting effects are not well understood. Here, we investigated the effects of chronic cocaine exposure (2 and 4 weeks) on markers of vascular function and morphology in the rat brain. For this purpose we measured nitric oxide (NO) concentration in plasma, brain neuronal nitric oxide synthase (nNOS or NOS1), HIF-1α, and VEGF expression in different brain regions, i.e., middle prefrontal cortex, somatosensory cortex, nucleus accumbens, and dorsal striatum, using ELISA or Western blot. Additionally, microvascular density in these brain regions was measured using immunofluorescence microscopy. We showed that chronic cocaine significantly affected NOS1, HIF-1α and VEGF expression, in a region- and cocaine treatment-time- dependent manner. Cerebral microvascular density increased significantly in parallel to these neurochemical changes. Furthermore, significant correlations were detected between VEGF expression and microvascular density in cortical regions (middle prefrontal cortex and somatosensory cortex), but not in striatal regions (nucleus accumbens and dorsal striatum). These results suggest that following chronic cocaine use, as cerebral ischemia developed, NOS1, the regulatory protein to counteract blood vessel constriction, was upregulated; meanwhile, the HIF-VEGF pathway was activated to increase microvascular density (i.e., angiogenesis) and thus restore local blood flow and oxygen supply. These physiological responses were triggered presumably as an adaptation to minimize ischemic injury caused by cocaine. Therefore, effectively promoting such physiological responses may provide novel and effective therapeutic solutions to treat cocaine-induced cerebral ischemia and stroke.
Systematic elucidation of neuron-astrocyte interaction in models of amyotrophic lateral sclerosis using multi-modal integrated bioinformatics workflow
Cell-to-cell communications are critical determinants of pathophysiological phenotypes, but methodologies for their systematic elucidation are lacking. Herein, we propose an approach for the Systematic Elucidation and Assessment of Regulatory Cell-to-cell Interaction Networks (SEARCHIN) to identify ligand-mediated interactions between distinct cellular compartments. To test this approach, we selected a model of amyotrophic lateral sclerosis (ALS), in which astrocytes expressing mutant superoxide dismutase-1 (mutSOD1) kill wild-type motor neurons (MNs) by an unknown mechanism. Our integrative analysis that combines proteomics and regulatory network analysis infers the interaction between astrocyte-released amyloid precursor protein (APP) and death receptor-6 (DR6) on MNs as the top predicted ligand-receptor pair. The inferred deleterious role of APP and DR6 is confirmed in vitro in models of ALS. Moreover, the DR6 knockdown in MNs of transgenic mutSOD1 mice attenuates the ALS-like phenotype. Our results support the usefulness of integrative, systems biology approach to gain insights into complex neurobiological disease processes as in ALS and posit that the proposed methodology is not restricted to this biological context and could be used in a variety of other non-cell-autonomous communication mechanisms. Neuron-astrocyte communication plays a key role in pathophysiology, however systematic approaches to unveil it are limited. Here, the authors propose SEARCHIN, a multi-modal integrated workflow, as a tool to identify cross-compartment ligand-receptor interactions, applied to ALS models.
Safety and efficacy of a novel robotic transcranial doppler system in subarachnoid hemorrhage
Delayed cerebral ischemia (DCI) secondary to vasospasm is a determinate of outcomes following non-traumatic subarachnoid hemorrhage (SAH). SAH patients are monitored using transcranial doppler (TCD) to measure cerebral blood flow velocities (CBFv). However, the accuracy and precision of manually acquired TCD can be operator dependent. The NovaGuide robotic TCD system attempts to standardize acquisition. This investigation evaluated the safety and efficacy of the NovaGuide system in SAH patients in a Neuro ICU. We retrospectively identified 48 NovaGuide scans conducted on SAH patients. Mean and maximum middle cerebral artery (MCA) CBFv were obtained from the NovaGuide and the level of agreement between CBFv and computed tomography angiography (CTA) for vasospasm was determined. Safety of NovaGuide acquisition of CBFv was evaluated based on number of complications with central venous lines (CVL) and external ventricular drains (EVD). There was significant agreement between the NovaGuide and CTA (Cohen’s Kappa = 0.74) when maximum MCA CBFv ≥ 120 cm/s was the threshold for vasospasm. 27/48 scans were carried out with CVLs and EVDs present without negative outcomes. The lack of adverse events associated with EVDs/CVLs and the strong congruence between maximal MCA CBFv and CTA illustrates the diagnostic utility of the NovaGuide.
Predictors of Outcomes and a Weighted Mortality Score for Moderate to Severe Subdural Hematoma
As the incidence of subdural hematoma is increasing, it is important to understand symptomatology and clinical variables associated with treatment outcomes and mortality in this population; patients with subdural hematoma were selected from the National Inpatient Sample (NIS) Database between 2016 and 2020 using International Classification of Disease 10th Edition (ICD10) codes. Moderate-to-severe subdural hematoma patients were identified using the Glasgow Coma Scale (GCS). Multivariate regression was first used to identify predictors of in-hospital mortality and then beta coefficients were used to create a weighted mortality score. Of 29,915 patients admitted with moderate-to-severe subdural hematomas, 12,135 (40.6%) died within the same hospital admission. In a multivariate model of relevant demographic and clinical covariates, age greater than 70, diabetes mellitus, mechanical ventilation, hydrocephalus, and herniation were independent predictors of mortality (p < 0.001 for all). Age greater than 70, diabetes mellitus, mechanical ventilation, hydrocephalus, and herniation were assigned a “1” in a weighted mortality score. The ROC curve for our model showed an area under the curve of 0.64. Age greater than 70, diabetes mellitus, mechanical ventilation, hydrocephalus, and herniation were predictive of mortality. We created the first clinically relevant weighted mortality score that can be used to stratify risk, guide prognosis, and inform family discussions.
Incidence, Characteristics, and Outcomes of Stroke in Pediatric Patients with Celiac Disease
(1) Background: Celiac disease (CD) can cause long-term inflammation and endothelial dysfunction and has been cited as a risk factor for acute ischemic stroke (AIS) in pediatric patients. However, the rate and outcomes of AIS in pediatric patients with CD has not been explored in a large population. Our objective is to explore the rate, severity, and outcomes of CD amongst pediatric AIS patients on a nationwide level. (2) Methods: The National Inpatient Sample (NIS) database was queried from 2016 to 2020 for pediatric patients with a principal diagnosis of AIS. Patients with a concurrent diagnosis of CD (AIS-CD) were compared to those without (AIS). Baseline demographics and comorbidities, clinical variables of severity, hospital complications, and the rates of tissue plasminogen activator (tPA) and mechanical thrombectomy were compared between the two groups. The main outcomes studied were mortality, discharge disposition, length of stay (LOS), and total hospital charges. (3) Results: Of 12,755 pediatric patients with a principal diagnosis of AIS, 75 (0.6%) had concurrent CD. There were no differences in the severity, discharge disposition, or mortality between the AIS-CD and AIS patients. Patients with AIS-CD were more likely to receive tPA at an outside hospital within 24 h of admission (p < 0.01) and more likely to undergo mechanical thrombectomy (p < 0.01) compared to the AIS patients. (4) Conclusions: CD patients made up only 0.6% of all pediatric AIS patients. No differences in the severity, mortality, or discharge disposition suggests a minimal to absent role of CD in the etiology of stroke. The CD-AIS patients were more likely to receive a tPA or undergo a mechanical thrombectomy; studies are needed to confirm the safety and efficacy of these interventions in pediatric patients.
A double-hit: End-stage renal disease patients suffer worse outcomes in intracerebral hemorrhage
Abstract BACKGROUND: Intracerebral hemorrhage (ICH) carries significant morbidity and mortality. Previous single-center retrospective analysis suggests that end-stage renal disease (ESRD) is a risk factor for severe ICH and worse outcomes. This investigation aims to examine the impact of ESRD on ICH severity, complications, and outcomes using a multicenter national database. METHODS: The International Classification of Disease, Ninth and Tenth Revision Clinical Modification codes were used to query the National Inpatient Sample for patients with ICH and ESRD between 2010 and 2019. Primary endpoints were the functional outcome, length of stay (LOS), and in-hospital mortality. Multivariate variable regression models and a propensity-score matched analysis were established to analyze patient outcomes associated with baseline patient characteristics. RESULTS: We identified 211,266 patients with ICH, and among them, 7,864 (3.77%) patients had a concurrent diagnosis of ESRD. Patients with ESRD were younger (60.85 vs. 67.64, P < 0.01) and demonstrated increased ICH severity (0.78 vs. 0.77, P < 0.01). ESRD patients experienced higher rates of sepsis (15.9% vs. 6.15%, P < 0.01), acute myocardial infarction (8.05% vs. 3.65%, P < 0.01), and cardiac arrest (5.94% vs. 2.4%, P < 0.01). In addition, ESRD predicted poor discharge disposition (odds ratio [OR]: 2.385, 95% confidence interval [CI]: 2.227-2.555, P < 0.01), longer hospital LOS (OR: 1.629, 95% CI: 1.553-1.709, P < 0.01), and in-hospital mortality (OR: 2.786, 95% CI: 2.647-2.932, P < 0.01). CONCLUSIONS: This study utilizes a multicenter database to analyze the effect of ESRD on ICH outcomes. ESRD is a significant predictor of poor functional outcomes, in-hospital mortality, and prolonged stay in the ICH population.
Spatial proteomic differences in chronic traumatic encephalopathy, Alzheimer's disease, and primary age‐related tauopathy hippocampi
INTRODUCTION Alzheimer's disease (AD), primary age‐related tauopathy (PART), and chronic traumatic encephalopathy (CTE) all feature hyperphosphorylated tau (p‐tau)–immunoreactive neurofibrillary degeneration, but differ in neuroanatomical distribution and progression of neurofibrillary degeneration and amyloid beta (Aβ) deposition. METHODS We used Nanostring GeoMx Digital Spatial Profiling to compare the expression of 70 proteins in neurofibrillary tangle (NFT)‐bearing and non–NFT‐bearing neurons in hippocampal CA1, CA2, and CA4 subregions and entorhinal cortex of cases with autopsy‐confirmed AD (n = 8), PART (n = 7), and CTE (n = 5). RESULTS There were numerous subregion‐specific differences related to Aβ processing, autophagy/proteostasis, inflammation, gliosis, oxidative stress, neuronal/synaptic integrity, and p‐tau epitopes among these different disorders. DISCUSSION These results suggest that there are subregion‐specific proteomic differences among the neurons of these disorders, which appear to be influenced to a large degree by the presence of hippocampal Aβ. These proteomic differences may play a role in the differing hippocampal p‐tau distribution and pathogenesis of these disorders. Highlights Alzheimer's disease neuropathologic change (ADNC), possible primary age‐related tauopathy (PART), definite PART, and chronic traumatic encephalopathy (CTE) can be differentiated based on the proteomic composition of their neurofibrillary tangle (NFT)‐ and non–NFT‐bearing neurons. The proteome of these NFT‐ and non–NFT‐bearing neurons is largely correlated with the presence or absence of amyloid beta (Aβ). Neurons in CTE and definite PART (Aβ‐independent pathologies) share numerous proteomic similarities that distinguish them from ADNC and possible PART (Aβ‐positive pathologies).
Early tracheostomy in patients undergoing mechanical thrombectomy for acute ischemic stroke
Respiratory failure following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is a known complication, and requirement of tracheostomy is associated with worse outcomes. Our objective is to evaluate characteristics associated with tracheostomy timing in AIS patients treated with MT. The National Inpatient Sample was queried for adult patients treated with MT for AIS from 2016 to 2019. Baseline demographic characteristics, comorbidities, and inpatient outcomes were analyzed for associations in patients who received tracheostomy. Timing of early tracheostomy (ETR) was defined as placement before day 8 of hospital stay. Of 3505 AIS-MT patients who received tracheostomy, 915 (26.1%) underwent ETR. Patients who underwent ETR had shorter length of stay (LOS) (25.39 days vs 32.43 days, p < 0.001) and lower total hospital charges ($483,472.07 vs $612,362.86, p < 0.001). ETR did not confer a mortality benefit but was associated with less acute kidney injury (OR, 0.697; p = 0.013), pneumonia (OR, 0.449; p < 0.001), and sepsis (OR, 0.536; p = 0.002). An expected increase in complications and healthcare resource utilization is seen in AIS-MT patients receiving tracheostomy, likely reflecting the severity of patients' post-stroke neurologic injury. Among these high-risk patients, ETR was predictive of shorter LOS and fewer complications. •Early tracheostomy in stroke patients was predictive of shorter hospital stays.•There was no difference in mortality for patients receiving early tracheostomy.•These patients also had lower rates of systemic complications.
Cognitive and neuropsychological trajectories in patients with mixed neurodegenerative pathologies
INTRODUCTION The presence and interaction of multiple comorbid neuropathologies are a major contributor to the worldwide dementia burden. METHODS We analyzed 1183 subjects from the National Alzheimer's Coordinating Center dataset with various combinations of isolated and mixed neurodegenerative pathologies and conducted mixed‐effects multiple linear regression modeling to comprehensively compare the neurocognitive and neuropsychological trajectories between groups over time. RESULTS In combination with Alzheimer's disease neuropathologic change, various combinations of limbic‐predominant age‐related transactive response DNA‐binding protein 43 encephalopathy, Lewy body dementia, and cerebrovascular disease further impair global cognition and specific neurocognitive domains; however, they do not appear to extensively affect the rate of decline with time across these domains, suggesting an additive but not synergistic effect. DISCUSSION These findings corroborate the known cumulative effects of mixed pathologies on cognition and add nuance to our understanding of their specific interactions, which is crucial for the development of biomarkers and effective therapeutics. Highlights Mixed neurodegenerative pathologies are common in the elderly population. The most common neurodegenerative pathologies were Alzheimer's disease neuropathologic change (ADNC), cerebrovascular disease (CVD), Lewy body dementia (LBD), and limbic‐predominant age‐related transactive response DNA‐binding protein 43 encephalopathy (LATE). The addition of various combinations of comorbid CVD, LBD, and LATE to ADNC worsened overall performance on cognitive and neuropsychological testing across time. In general, the addition of multiple comorbid neurodegenerative pathologies did not influence the rate of decline across the evaluated time period.