Publications by authors named "Lee E Goldstein"

46 Publications

Life-long brain compensatory responses to galactic cosmic radiation exposure.

Sci Rep 2021 Feb 22;11(1):4292. Epub 2021 Feb 22.

Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY, USA.

Galactic cosmic radiation (GCR) composed of high-energy, heavy particles (HZE) poses potentially serious hazards to long-duration crewed missions in deep space beyond earth's magnetosphere, including planned missions to Mars. Chronic effects of GCR exposure on brain structure and cognitive function are poorly understood, thereby limiting risk reduction and mitigation strategies to protect against sequelae from exposure during and after deep-space travel. Given the selective vulnerability of the hippocampus to neurotoxic insult and the importance of this brain region to learning and memory, we hypothesized that GCR-relevant HZE exposure may induce long-term alterations in adult hippocampal neurogenesis, synaptic plasticity, and hippocampal-dependent learning and memory. To test this hypothesis, we irradiated 3-month-old male and female mice with a single, whole-body dose of 10, 50, or 100 cGy Fe ions (600 MeV, 181 keV/μm) at Brookhaven National Laboratory. Our data reveal complex, dynamic, time-dependent effects of HZE exposure on the hippocampus. Two months post exposure, neurogenesis, synaptic plasticity and learning were impaired compared to sham-irradiated, age-matched controls. By six months post-exposure, deficits in spatial learning were absent in irradiated mice, and synaptic potentiation was enhanced. Enhanced performance in spatial learning and facilitation of synaptic plasticity in irradiated mice persisted 12 months post-exposure, concomitant with a dramatic rebound in adult-born neurons. Synaptic plasticity and spatial learning remained enhanced 20 months post-exposure, indicating a life-long influence on plasticity and cognition from a single exposure to HZE in young adulthood. These findings suggest that GCR-exposure can persistently alter brain health and cognitive function during and after long-duration travel in deep space.
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http://dx.doi.org/10.1038/s41598-021-83447-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7900210PMC
February 2021

Assessing the Severity of Traumatic Brain Injury-Time for a Change?

J Clin Med 2021 Jan 4;10(1). Epub 2021 Jan 4.

Concussion Care Centre of Virginia and Tree of Life, Richmond, VA 23233, USA.

Traumatic brain injury (TBI) has been described to be man's most complex disease, in man's most complex organ. Despite this vast complexity, variability, and individuality, we still classify the severity of TBI based on non-specific, often unreliable, and pathophysiologically poorly understood measures. Current classifications are primarily based on clinical evaluations, which are non-specific and poorly predictive of long-term disability. Brain imaging results have also been used, yet there are multiple ways of doing brain imaging, at different timepoints in this very dynamic injury. Severity itself is a vague concept. All prediction models based on combining variables that can be assessed during the acute phase have reached only modest predictive values for later outcome. Yet, these early labels of severity often determine how the patient is treated by the healthcare system at large. This opinion paper examines the problems and provides caveats regarding the use of current severity labels and the many practical and scientific issues that arise from doing so. The objective of this paper is to show the causes and consequences of current practice and propose a new approach based on risk classification. A new approach based on multimodal quantifiable data (including imaging and biomarkers) and risk-labels would be of benefit both for the patients and for TBI clinical research and should be a priority for international efforts in the field.
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http://dx.doi.org/10.3390/jcm10010148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7795933PMC
January 2021

Association of probable REM sleep behavior disorder with pathology and years of contact sports play in chronic traumatic encephalopathy.

Acta Neuropathol 2020 12 17;140(6):851-862. Epub 2020 Sep 17.

Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, MA, USA.

Probable rapid eye movement (REM) sleep behavior disorder (pRBD) is a synucleinopathy-associated parasomnia in which loss of REM sleep muscle atonia results in motor behavior during REM sleep, including dream enactment. Traumatic brain injury is independently associated with increased risk of pRBD and Lewy body disease, and both pRBD and Lewy body disease are often observed in chronic traumatic encephalopathy (CTE). However, the frequency and pathological substrate of pRBD in CTE have not been formally studied and remain unknown. Of the total sample of 247 men, age at death of 63.1 ± 18.8 years (mean ± SD), 80 [32%] were determined by informant report to have symptoms of pRBD. These participants had played more years of contact sports (18.3 ± 11.4) than those without pRBD (15.1 ± 6.5; P = 0.02) and had an increased frequency of Lewy body disease (26/80 [33%] vs 28/167 [17%], P = 0.005). Of the 80 participants with pRBD, 54 [68%] did not have Lewy body disease; these participants were more likely to have neurofibrillary tangles and pretangles in the dorsal and median raphe (41 of 49 [84%] non-LBD participants with pRBD symptoms vs 90 of 136 [66%] non-LBD participants without pRBD symptoms, P = 0.02), brainstem nuclei with sleep regulatory function. Binary logistic regression modeling in the total study sample showed that pRBD in CTE was associated with dorsal and median raphe nuclei neurofibrillary tangles (OR = 3.96, 95% CI [1.43, 10.96], P = 0.008), Lewy body pathology (OR = 2.36, 95% CI [1.18, 4.72], P = 0.02), and years of contact sports participation (OR = 1.04, 95% CI [1.00, 1.08], P = 0.04). Overall, pRBD in CTE is associated with increased years of contact sports participation and may be attributable to Lewy body and brainstem tau pathologies.
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http://dx.doi.org/10.1007/s00401-020-02206-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7669574PMC
December 2020

Characterizing tau deposition in chronic traumatic encephalopathy (CTE): utility of the McKee CTE staging scheme.

Acta Neuropathol 2020 10 11;140(4):495-512. Epub 2020 Aug 11.

Department of Neurology, Boston University Alzheimer's Disease and CTE Centers, Boston University School of Medicine, Boston, USA.

Chronic traumatic encephalopathy (CTE) is a tauopathy associated with repetitive head impacts (RHI) that has been neuropathologically diagnosed in American football players and other contact sport athletes. In 2013, McKee and colleagues proposed a staging scheme for characterizing the severity of the hyperphosphorylated tau (p-tau) pathology, the McKee CTE staging scheme. The staging scheme defined four pathological stages of CTE, stages I(mild)-IV(severe), based on the density and regional deposition of p-tau. The objective of this study was to test the utility of the McKee CTE staging scheme, and provide a detailed examination of the regional distribution of p-tau in CTE. We examined the relationship between the McKee CTE staging scheme and semi-quantitative and quantitative assessments of regional p-tau pathology, age at death, dementia, and years of American football play among 366 male brain donors neuropathologically diagnosed with CTE (mean age 61.86, SD 18.90). Spearman's rho correlations showed that higher CTE stage was associated with higher scores on all semi-quantitative and quantitative assessments of p-tau severity and density (p's < 0.001). The severity and distribution of CTE p-tau followed an age-dependent progression: older age was associated with increased odds for having a higher CTE stage (p < 0.001). CTE stage was independently associated with increased odds for dementia (p < 0.001). K-medoids cluster analysis of the semi-quantitative scales of p-tau across 14 regions identified 5 clusters of p-tau that conformed to increasing CTE stage (stage IV had 2 slightly different clusters), age at death, dementia, and years of American football play. There was a predilection for p-tau pathology in five regions: dorsolateral frontal cortex (DLF), superior temporal cortex, entorhinal cortex, amygdala, and locus coeruleus (LC), with CTE in the youngest brain donors and lowest CTE stage restricted to DLF and LC. These findings support the usefulness of the McKee CTE staging scheme and demonstrate the regional distribution of p-tau in CTE.
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http://dx.doi.org/10.1007/s00401-020-02197-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914059PMC
October 2020

Repetitive Head Trauma Induces Chronic Traumatic Encephalopathy by Multiple Mechanisms.

Semin Neurol 2020 08 16;40(4):430-438. Epub 2020 Jul 16.

Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, Massachusetts.

Exposure to repetitive neurotrauma increases lifetime risk for developing progressive cognitive deficits, neurobehavioral abnormalities, and chronic traumatic encephalopathy (CTE). CTE is a tau protein neurodegenerative disease first identified in boxers and recently described in athletes participating in other contact sports (notably American football, ice hockey, rugby, and wrestling) and in military veterans with blast exposure. Currently, CTE can only be diagnosed by neuropathological examination of the brain after death. The defining diagnostic lesion of CTE consists of patchy perivascular accumulations of hyperphosphorylated tau protein that localize in the sulcal depths of the cerebral cortex. Neuronal abnormalities, axonopathy, neurovascular dysfunction, and neuroinflammation are triggered by repetitive head impacts (RHIs) and likely act as catalysts for CTE pathogenesis and progression. However, the specific mechanisms that link RHI to CTE are unknown. This review will explore two important areas of CTE pathobiology. First, we will review what is known about the biomechanical properties of RHI that initiate CTE-related pathologies. Second, we will provide an overview of key features of CTE neuropathology and how these contribute to abnormal tau hyperphosphorylation, accumulation, and spread.
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http://dx.doi.org/10.1055/s-0040-1713620DOI Listing
August 2020

A longitudinal examination of plasma neurofilament light and total tau for the clinical detection and monitoring of Alzheimer's disease.

Neurobiol Aging 2020 10 29;94:60-70. Epub 2020 May 29.

Boston University Alzheimer's Disease Center and CTE Center, Boston University School of Medicine, Boston, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA. Electronic address:

We examined baseline and longitudinal associations between plasma neurofilament light (NfL) and total tau (t-tau), and the clinical presentation of Alzheimer's disease (AD). A total of 579 participants (238, normal cognition [NC]; 185, mild cognitive impairment [MCI]; 156, AD dementia) had baseline blood draws; 82% had follow-up evaluations. Plasma samples were analyzed for NfL and t-tau using Simoa technology. Baseline plasma NfL was higher in AD dementia than MCI (standardized mean difference = 0.55, 95% CI: 0.37-0.73) and NC (standardized mean difference = 0.68, 95% CI: 0.49-0.88), corresponded to Clinical Dementia Rating scores (OR = 1.94, 95% CI: 1.35-2.79]), and correlated with all neuropsychological tests (r's = 0.13-0.42). Longitudinally, NfL did not predict diagnostic conversion but predicted decline on 3/10 neuropsychological tests. Baseline plasma t-tau was higher in AD dementia than NC with a small effect (standardized mean difference = 0.33, 95% CI: 0.10-0.57) but not MCI. t-tau did not statistically significant predict any longitudinal outcomes. Plasma NfL may be useful for the detection of AD dementia and monitoring of disease progression. In contrast, there was minimal evidence in support of plasma t-tau.
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http://dx.doi.org/10.1016/j.neurobiolaging.2020.05.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7484086PMC
October 2020

In Vivo Quasi-Elastic Light Scattering Eye Scanner Detects Molecular Aging in Humans.

J Gerontol A Biol Sci Med Sci 2020 09;75(9):e53-e62

Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.

The absence of clinical tools to evaluate individual variation in the pace of aging represents a major impediment to understanding aging and maximizing health throughout life. The human lens is an ideal tissue for quantitative assessment of molecular aging in vivo. Long-lived proteins in lens fiber cells are expressed during fetal life, do not undergo turnover, accumulate molecular alterations throughout life, and are optically accessible in vivo. We used quasi-elastic light scattering (QLS) to measure age-dependent signals in lenses of healthy human subjects. Age-dependent QLS signal changes detected in vivo recapitulated time-dependent changes in hydrodynamic radius, protein polydispersity, and supramolecular order of human lens proteins during long-term incubation (~1 year) and in response to sustained oxidation (~2.5 months) in vitro. Our findings demonstrate that QLS analysis of human lens proteins provides a practical technique for noninvasive assessment of molecular aging in vivo.
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http://dx.doi.org/10.1093/gerona/glaa121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7494032PMC
September 2020

Slow blood-to-brain transport underlies enduring barrier dysfunction in American football players.

Brain 2020 06;143(6):1826-1842

Departments of Physiology and Cell Biology, Brain and Cognitive Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.

Repetitive mild traumatic brain injury in American football players has garnered increasing public attention following reports of chronic traumatic encephalopathy, a progressive tauopathy. While the mechanisms underlying repetitive mild traumatic brain injury-induced neurodegeneration are unknown and antemortem diagnostic tests are not available, neuropathology studies suggest a pathogenic role for microvascular injury, specifically blood-brain barrier dysfunction. Thus, our main objective was to demonstrate the effectiveness of a modified dynamic contrast-enhanced MRI approach we have developed to detect impairments in brain microvascular function. To this end, we scanned 42 adult male amateur American football players and a control group comprising 27 athletes practicing a non-contact sport and 26 non-athletes. MRI scans were also performed in 51 patients with brain pathologies involving the blood-brain barrier, namely malignant brain tumours, ischaemic stroke and haemorrhagic traumatic contusion. Based on data from prolonged scans, we generated maps that visualized the permeability value for each brain voxel. Our permeability maps revealed an increase in slow blood-to-brain transport in a subset of amateur American football players, but not in sex- and age-matched controls. The increase in permeability was region specific (white matter, midbrain peduncles, red nucleus, temporal cortex) and correlated with changes in white matter, which were confirmed by diffusion tensor imaging. Additionally, increased permeability persisted for months, as seen in players who were scanned both on- and off-season. Examination of patients with brain pathologies revealed that slow tracer accumulation characterizes areas surrounding the core of injury, which frequently shows fast blood-to-brain transport. Next, we verified our method in two rodent models: rats and mice subjected to repeated mild closed-head impact injury, and rats with vascular injury inflicted by photothrombosis. In both models, slow blood-to-brain transport was observed, which correlated with neuropathological changes. Lastly, computational simulations and direct imaging of the transport of Evans blue-albumin complex in brains of rats subjected to recurrent seizures or focal cerebrovascular injury suggest that increased cellular transport underlies the observed slow blood-to-brain transport. Taken together, our findings suggest dynamic contrast-enhanced-MRI can be used to diagnose specific microvascular pathology after traumatic brain injury and other brain pathologies.
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http://dx.doi.org/10.1093/brain/awaa140DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7297017PMC
June 2020

Beneficial association of angiotensin-converting enzyme inhibitors and statins on the occurrence of possible Alzheimer's disease after traumatic brain injury.

Alzheimers Res Ther 2020 03 27;12(1):33. Epub 2020 Mar 27.

Geriatric Research Education Clinical Center, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, 01730, USA.

Background: Pathological analysis of brain tissue from animals and humans with a history of traumatic brain injury (TBI) suggests that TBI could be one of the risk factors facilitating onset of dementia with possible Alzheimer's disease (AD), but medications to prevent or delay AD onset are not yet available.

Methods: This study explores four medication classes (angiotensin-converting enzyme inhibitors (ACEI), beta blockers, metformin, and statins) approved by the Food and Drug Administration (FDA) for other indications and evaluates their influence when used in combination on the risk of possible AD development for patients with a history of TBI. We identified patients with history of TBI from an existing Department of Veterans Affairs (VA) national database. Among 1,660,151 veterans who used VA services between the ages of 50 to 89 years old, we analyzed 733,920 patients, including 15,450 patients with a history of TBI and 718,470 non-TBI patients. The TBI patients were followed for up to 18.5 years, with an average of 7.7 ± 4.7 years, and onset of dementia with possible AD was recorded based on International Statistical Classification of Diseases (ICD) 9 or 10 codes. The effect of TBI on possible AD development was evaluated by multivariable logistic regression models adjusted by age, gender, race, and other comorbidities. The association of ACEI, beta blockers, metformin, statins, and combinations of these agents over time from the first occurrence of TBI to possible AD onset was assessed using Cox proportional hazard models adjusted for demographics and comorbidities.

Results: Veterans with at least two TBI occurrences by claims data were 25% (odds ratio (OR) = 1.25, 95% confidence intervals (CI) (1.13, 1.37)) more likely to develop dementia with possible AD, compared to those with no record of TBI. In multivariable logistic regression models (propensity score weighted or adjusted), veterans taking a combination of ACEI and statins had reduced risk in developing possible AD after suffering TBI, and use of this medication class combination was associated with a longer period between TBI occurring and dementia with possible AD onset, compared to patients who took statins alone or did not take any of the four target drugs after TBI.

Conclusions: The combination of ACEI and statins significantly lowered the risk of development of dementia with possible AD in a national cohort of people with a history of TBI, thus supporting a clinical approach to lowering the risk of dementia with possible AD.
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http://dx.doi.org/10.1186/s13195-020-00589-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102441PMC
March 2020

Nonhomogeneous Gadolinium Retention in the Cerebral Cortex after Intravenous Administration of Gadolinium-based Contrast Agent in Rats and Humans.

Radiology 2020 02 26;294(2):377-385. Epub 2019 Nov 26.

From the Departments of Radiology (O.M., N.H., N.L., A.Z.M., C.W.F., X.L., J.A.M., H.J., A.G., J.A.S., S.W.A., L.E.G.), Neurology (A.C.M., L.E.G.), Pathology and Laboratory Medicine (V.E.A., B.R.H., A.C.M., L.E.G.), Behavioral Neuroscience (S.E.C.), and Anatomy and Neurobiology (K.J.B.), Boston University School of Medicine, 670 Albany St, Boston, MA 02118; Boston University Alzheimer's Disease Center, Boston, Mass (O.M., N.H., P.T.K., L.E.E., S.E.C., J.A.M., V.E.A., B.R.H., A.C.M., L.E.G.); VA Boston Healthcare System, Jamaica Plain, Mass (A.M.H., V.E.A., B.R.H., A.C.M.); Stroke Branch, National Institute of Neurologic Diseases and Stroke, National Institutes of Health, Bethesda, Md (A.D.G., L.L.L.); Center for Neuroscience and Regenerative Medicine, Uniformed Services University, Bethesda, Md (A.D.G., L.L.L.); and Center for Biometals and Metallomics (O.M., N.L., J.A.M., L.E.G.), College of Engineering (E.S.F., A.C.M., S.W.A., L.E.G.), and Photonics Center (O.M., J.A.M., S.W.A., L.E.G.), Boston University, Boston, Mass.

Background Gadolinium retention after repeated gadolinium-based contrast agent (GBCA) exposure has been reported in subcortical gray matter. However, gadolinium retention in the cerebral cortex has not been systematically investigated. Purpose To determine whether and where gadolinium is retained in rat and human cerebral cortex. Materials and Methods The cerebral cortex in Sprague-Dawley rats treated with gadopentetate dimeglumine (three doses over 4 weeks; cumulative gadolinium dose, 7.2 mmol per kilogram of body weight; = 6) or saline ( = 6) was examined with antemortem MRI. Two human donors with repeated GBCA exposure (three and 15 doses; 1 and 5 months after exposure), including gadopentetate dimeglumine, and two GBCA-naive donors were also evaluated. Elemental brain maps (gadolinium, phosphorus, zinc, copper, iron) for rat and human brains were constructed by using laser ablation inductively coupled plasma mass spectrometry. Results Gadopentetate dimeglumine-treated rats showed region-, subregion-, and layer-specific gadolinium retention in the neocortex (anterior cingulate cortex: mean gadolinium concentration, 0.28 µg ∙ g ± 0.04 [standard error of the mean]) that was comparable ( > .05) to retention in the allocortex (mean gadolinium concentration, 0.33 µg ∙ g ± 0.04 in piriform cortex, 0.24 µg ∙ g ± 0.04 in dentate gyrus, 0.17 µg ∙ g ± 0.04 in hippocampus) and subcortical structures (0.47 µg ∙ g ± 0.10 in facial nucleus, 0.39 µg ∙ g ± 0.10 in choroid plexus, 0.29 µg ∙ g ± 0.05 in caudate-putamen, 0.26 µg ∙ g ± 0.05 in reticular nucleus of the thalamus, 0.24 µg ∙ g ± 0.04 in vestibular nucleus) and significantly greater than that in the cerebellum (0.17 µg ∙ g ± 0.03, = .01) and white matter tracts (anterior commissure: 0.05 µg ∙ g ± 0.01, = .002; corpus callosum: 0.05 µg ∙ g ± 0.02, = .001; cranial nerve: 0.02 µg ∙ g ± 0.01, = .004). Retained gadolinium colocalized with parenchymal iron. T1-weighted MRI signal intensification was not observed. Gadolinium retention was detected in the cerebral cortex, pia mater, and pia-ensheathed leptomeningeal vessels in two GBCA-exposed human brains but not in two GBCA-naive human brains. Conclusion Repeated gadopentetate dimeglumine exposure is associated with gadolinium retention in specific regions, subregions, and layers of cerebral cortex that are critical for higher cognition, affect, and behavior regulation, sensorimotor coordination, and executive function. © RSNA, 2019 See also the editorial by Kanal in this issue.
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http://dx.doi.org/10.1148/radiol.2019190461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6996690PMC
February 2020

Duration of American Football Play and Chronic Traumatic Encephalopathy.

Ann Neurol 2020 01 23;87(1):116-131. Epub 2019 Nov 23.

Boston University Alzheimer's Disease and Chronic Traumatic Encephalopathy Center, Boston University School of Medicine, Boston, MA.

Objective: Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to contact and collision sports, including American football. We hypothesized a dose-response relationship between duration of football played and CTE risk and severity.

Methods: In a convenience sample of 266 deceased American football players from the Veterans Affairs-Boston University-Concussion Legacy Foundation and Framingham Heart Study Brain Banks, we estimated the association of years of football played with CTE pathological status and severity. We evaluated the ability of years played to classify CTE status using receiver operating characteristic curve analysis. Simulation analyses quantified conditions that might lead to selection bias.

Results: In total, 223 of 266 participants met neuropathological diagnostic criteria for CTE. More years of football played were associated with having CTE (odds ratio [OR] = 1.30 per year played, 95% confidence interval [CI] = 1.19-1.41; p = 3.8 × 10 ) and with CTE severity (severe vs mild; OR = 1.14 per year played, 95% CI = 1.07-1.22; p = 3.1 × 10 ). Participants with CTE were 1/10th as likely to have played <4.5 years (negative likelihood ratio [LR] = 0.102, 95% CI = 0.100-0.105) and were 10 times as likely to have played >14.5 years (positive LR = 10.2, 95% CI = 9.8-10.7) compared with participants without CTE. Sensitivity and specificity were maximized at 11 years played. Simulation demonstrated that years played remained adversely associated with CTE status when years played and CTE status were both related to brain bank selection across widely ranging scenarios.

Interpretation: The odds of CTE double every 2.6 years of football played. After accounting for brain bank selection, the magnitude of the relationship between years played and CTE status remained consistent. ANN NEUROL 2020;87:116-131.
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http://dx.doi.org/10.1002/ana.25611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6973077PMC
January 2020

Association of White Matter Rarefaction, Arteriolosclerosis, and Tau With Dementia in Chronic Traumatic Encephalopathy.

JAMA Neurol 2019 Aug 5. Epub 2019 Aug 5.

Boston University Alzheimer's Disease Center and CTE Center, Department of Neurology, Boston University School of Medicine, Boston, Massachusetts.

Importance: Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive head impacts, including those from US football, that presents with cognitive and neuropsychiatric disturbances that can progress to dementia. Pathways to dementia in CTE are unclear and likely involve tau and nontau pathologic conditions.

Objective: To investigate the association of white matter rarefaction and cerebrovascular disease with dementia in deceased men older than 40 years who played football and had CTE.

Design, Setting, And Participants: This cross-sectional study involves analyses of data from the ongoing Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) Study, which is conducted via and included brain donors from the Veterans Affairs-Boston University-Concussion Legacy Foundation brain bank between 2008 and 2017. An original sample of 224 men who had played football and were neuropathologically diagnosed with CTE was reduced after exclusion of those younger than 40 years and those missing data.

Exposures: The number of years of football play as a proxy for repetitive head impacts.

Main Outcomes And Measures: Neuropathological assessment of white matter rarefaction and arteriolosclerosis severity (on a scale of 0-3, where 3 is severe); number of infarcts, microinfarcts, and microbleeds; and phosphorylated tau accumulation determined by CTE stage and semiquantitative rating of dorsolateral frontal cortex (DLFC) neurofibrillary tangles (NFTs) (none or mild vs moderate or severe). Informant-based retrospective clinical interviews determined dementia diagnoses via diagnostic consensus conferences.

Results: A total of 180 men were included. The mean (SD) age of the sample at death was 67.9 (12.7) years. Of 180, 120 [66.7%]) were found to have had dementia prior to death. Moderate to severe white matter rarefaction (84 of 180 [46.6%]) and arteriolosclerosis (85 of 180 [47.2%]) were common; infarcts, microinfarcts, and microbleeds were not. A simultaneous equations regression model controlling for age and race showed that more years of play was associated with more severe white matter rarefaction (β, 0.16 [95% CI, 0.02-0.29]; P = .03) and greater phosphorylated tau accumulation (DLFC NFTs: β, 0.15 [95% CI, 0.004-0.30]; P = .04; CTE stage: β, 0.27 [95% CI, 0.14-0.41]; P < .001). White matter rarefaction (β, 0.16 [95% CI, 0.02-0.29]; P = .03) and DLFC NFTs (β, 0.16 [95% CI, 0.03-0.28]; P = .01) were associated with dementia. Arteriolosclerosis and years of play were not associated, but arteriolosclerosis was independently associated with dementia (β, 0.21 [95% CI, 0.07-0.35]; P = .003).

Conclusions And Relevance: Among older men who had played football and had CTE, more years of football play were associated with more severe white matter rarefaction and greater DLFC NFT burden. White matter rarefaction, arteriolosclerosis, and DLFC NFTs were independently associated with dementia. Dementia in CTE is likely a result of neuropathologic changes, including white matter rarefaction and phosphorylated tau, associated with repetitive head impact and pathologic changes not associated with head trauma, such as arteriolosclerosis.
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http://dx.doi.org/10.1001/jamaneurol.2019.2244DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6686769PMC
August 2019

Pathophysiology of Concussion.

Semin Pediatr Neurol 2019 07 23;30:14-25. Epub 2019 Mar 23.

Molecular Aging & Development Laboratory, Boston University School of Medicine, Boston, MA; Boston University College of Engineering, Boston, MA; Department of Radiology, Boston University School of Medicine, Boston, MA; Boston University School of Medicine, Boston, MA; Alzheimer's Disease Center, CTE Program, Boston University School of Medicine, Boston, MA. Electronic address:

Although concussion has been a subject of interest for centuries, this condition remains poorly understood. The mechanistic underpinnings and accepted definition of concussion remain elusive. To make sense of these issues, this article presents a brief history of concussion studies, detailing the evolution of motivations and experimental conclusions over time. Interest in concussion as a subject of scientific inquiry has increased with growing concern about the long-term consequences of mild traumatic brain injury (TBI). Although concussion is often associated with mild TBI, these conditions-the former a neurological syndrome, the latter a neurological event-are distinct, both mechanistically and pathobiologically. Modern research primarily focuses on the study of the biomechanics, pathophysiology, potential biomarkers and neuroimaging to distinguish concussion from mild TBI. In addition, mild TBI and concussion outcomes are influenced by age, sex, and genetic differences in people. With converging experimental objectives and methodologies, future concussion research has the potential to improve clinical assessment, treatment, and preventative measures.
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http://dx.doi.org/10.1016/j.spen.2019.03.004DOI Listing
July 2019

Contact sport participation and chronic traumatic encephalopathy are associated with altered severity and distribution of cerebral amyloid angiopathy.

Acta Neuropathol 2019 09 10;138(3):401-413. Epub 2019 Jun 10.

Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston University, Boston, MA, 02118, USA.

Cerebral amyloid angiopathy (CAA) consists of beta-amyloid deposition in the walls of the cerebrovasculature and is commonly associated with Alzheimer's disease (AD). However, the association of CAA with repetitive head impacts (RHI) and with chronic traumatic encephalopathy (CTE) is unknown. We evaluated the relationship between RHI from contact sport participation, CTE, and CAA within a group of deceased contact sport athletes (n = 357), a community-based cohort (n = 209), and an AD cohort from Boston University AD Center (n = 241). Unsupervised hierarchal cluster analysis demonstrated a unique cluster (n = 11) with increased CAA in the leptomeningeal vessels compared to the intracortical vessels (p < 0.001) comprised of participants with significantly greater frequencies of CTE (7/11) and history of RHI. Overall, participants with CTE (n = 251) had more prevalent (p < 0.001) and severe (p = 0.010) CAA within the frontal leptomeningeal vessels compared to intracortical vessels. Compared to those with AD, participants with CTE had more severe CAA in frontal than parietal lobes (p < 0.001) and more severe CAA in leptomeningeal than intracortical vessels (p = 0.002). The overall frequency of CAA in participants with CTE was low, and there was no significant association between contact sport participation and the presence of CAA. However, in those with CAA, a history of contact sports was associated with increased CAA severity in the frontal leptomeningeal vessels (OR = 4.01, 95% CI 2.52-6.38, p < 0.001) adjusting for AD, APOE ε4 status, and age. Participants with CAA had increased levels of sulcal tau pathology and decreased levels of the synaptic marker PSD-95 (p's < 0.05), and CAA was a predictor of dementia (OR = 1.75, 95% CI 1.02-2.99, p = 0.043) adjusting for age, sex, and comorbid pathology. Overall, contact sport participation and CTE were associated with more severe frontal and leptomeningeal CAA, and CAA was independently associated with worse pathological and clinical outcomes.
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http://dx.doi.org/10.1007/s00401-019-02031-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6689453PMC
September 2019

Variation in TMEM106B in chronic traumatic encephalopathy.

Acta Neuropathol Commun 2018 11 4;6(1):115. Epub 2018 Nov 4.

Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, 72 E Concord Street, B7800, Boston, MA, 02118, USA.

The genetic basis of chronic traumatic encephalopathy (CTE) is poorly understood. Variation in transmembrane protein 106B (TMEM106B) has been associated with enhanced neuroinflammation during aging and with TDP-43-related neurodegenerative disease, and rs3173615, a missense coding SNP in TMEM106B, has been implicated as a functional variant in these processes. Neuroinflammation and TDP-43 pathology are prominent features in CTE. The purpose of this study was to determine whether genetic variation in TMEM106B is associated with CTE risk, pathological features, and ante-mortem dementia. Eighty-six deceased male athletes with a history of participation in American football, informant-reported Caucasian, and a positive postmortem diagnosis of CTE without comorbid neurodegenerative disease were genotyped for rs3173615. The minor allele frequency (MAF = 0.42) in participants with CTE did not differ from previously reported neurologically normal controls (MAF = 0.43). However, in a case-only analysis among CTE cases, the minor allele was associated with reduced phosphorylated tau (ptau) pathology in the dorsolateral frontal cortex (DLFC) (AT8 density, odds ratio [OR] of increasing one quartile = 0.42, 95% confidence interval [CI] 0.22-0.79, p = 0.008), reduced neuroinflammation in the DLFC (CD68 density, OR of increasing one quartile = 0.53, 95% CI 0.29-0.98, p = 0.043), and increased synaptic protein density (β = 0.306, 95% CI 0.065-0.546, p = 0.014). Among CTE cases, TMEM106B minor allele was also associated with reduced ante-mortem dementia (OR = 0.40, 95% CI 0.16-0.99, p = 0.048), but was not associated with TDP-43 pathology. All case-only models were adjusted for age at death and duration of football play. Taken together, variation in TMEM106B may have a protective effect on CTE-related outcomes.
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http://dx.doi.org/10.1186/s40478-018-0619-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6215686PMC
November 2018

Lewy Body Pathology and Chronic Traumatic Encephalopathy Associated With Contact Sports.

J Neuropathol Exp Neurol 2018 09;77(9):757-768

Boston University Alzheimer's Disease and CTE Center.

Traumatic brain injury has been associated with increased risk of Parkinson disease and parkinsonism, and parkinsonism and Lewy body disease (LBD) can occur with chronic traumatic encephalopathy (CTE). To test whether contact sports and CTE are associated with LBD, we compared deceased contact sports athletes (n = 269) to cohorts from the community (n = 164) and the Boston University Alzheimer disease (AD) Center (n = 261). Participants with CTE and LBD were more likely to have β-amyloid deposition, dementia, and parkinsonism than CTE alone (p < 0.05). Traditional and hierarchical clustering showed a similar pattern of LBD distribution in CTE compared to LBD alone that was most frequently neocortical, limbic, or brainstem. In the community-based cohort, years of contact sports play were associated with neocortical LBD (OR = 1.30 per year, p = 0.012), and in a pooled analysis a threshold of >8 years of play best predicted neocortical LBD (ROC analysis, OR = 6.24, 95% CI = 1.5-25, p = 0.011), adjusting for age, sex, and APOE ɛ4 allele status. Clinically, dementia was significantly associated with neocortical LBD, CTE stage, and AD; parkinsonism was associated with LBD pathology but not CTE stage. Contact sports participation may increase risk of developing neocortical LBD, and increased LBD frequency may partially explain extrapyramidal motor symptoms sometimes observed in CTE.
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http://dx.doi.org/10.1093/jnen/nly065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097837PMC
September 2018

Neurofilament relates to white matter microstructure in older adults.

Neurobiol Aging 2018 10 28;70:233-241. Epub 2018 Jun 28.

Department of Neurology, Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA. Electronic address:

Cerebrospinal fluid (CSF) neurofilament light (NFL) is a protein biomarker of axonal injury. To study whether NFL is associated with diffusion tensor imaging (DTI) measurements of white matter (WM) microstructure, Vanderbilt Memory & Aging Project participants with normal cognition (n = 77), early mild cognitive impairment (n = 15), and MCI (n = 55) underwent lumbar puncture to obtain CSF and 3T brain MRI. Voxel-wise analyses cross-sectionally related NFL to DTI metrics, adjusting for demographic and vascular risk factors. Increased NFL correlated with multiple DTI metrics (p-values < 0.05). An NFL × diagnosis interaction (excluding early mild cognitive impairment) on WM microstructure (p-values < 0.05) was detected, with associations strongest among MCI. Multiple NFL × CSF biomarker interactions were detected. Associations between NFL and worse WM metrics were strongest among amyloid-β-negative, tau-positive, and suspected nonamyloid pathology participants. Findings suggest increased NFL, a biomarker of axonal injury, is correlated with compromised WM microstructure. Results highlight the role of elevated NFL in predicting WM damage in cognitively impaired older adults who are amyloid-negative, tau-positive, or meet suspected nonamyloid pathology criteria.
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http://dx.doi.org/10.1016/j.neurobiolaging.2018.06.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6119102PMC
October 2018

Age of first exposure to tackle football and chronic traumatic encephalopathy.

Ann Neurol 2018 05;83(5):886-901

Boston University Alzheimer's Disease and CTE Center, Department of Neurology, Boston University School of Medicine, Boston, MA.

Objective: To examine the effect of age of first exposure to tackle football on chronic traumatic encephalopathy (CTE) pathological severity and age of neurobehavioral symptom onset in tackle football players with neuropathologically confirmed CTE.

Methods: The sample included 246 tackle football players who donated their brains for neuropathological examination. Two hundred eleven were diagnosed with CTE (126 of 211 were without comorbid neurodegenerative diseases), and 35 were without CTE. Informant interviews ascertained age of first exposure and age of cognitive and behavioral/mood symptom onset.

Results: Analyses accounted for decade and duration of play. Age of exposure was not associated with CTE pathological severity, or Alzheimer's disease or Lewy body pathology. In the 211 participants with CTE, every 1 year younger participants began to play tackle football predicted earlier reported cognitive symptom onset by 2.44 years (p < 0.0001) and behavioral/mood symptoms by 2.50 years (p < 0.0001). Age of exposure before 12 predicted earlier cognitive (p < 0.0001) and behavioral/mood (p < 0.0001) symptom onset by 13.39 and 13.28 years, respectively. In participants with dementia, younger age of exposure corresponded to earlier functional impairment onset. Similar effects were observed in the 126 CTE-only participants. Effect sizes were comparable in participants without CTE.

Interpretation: In this sample of deceased tackle football players, younger age of exposure to tackle football was not associated with CTE pathological severity, but predicted earlier neurobehavioral symptom onset. Youth exposure to tackle football may reduce resiliency to late-life neuropathology. These findings may not generalize to the broader tackle football population, and informant-report may have affected the accuracy of the estimated effects. Ann Neurol 2018;83:886-901.
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http://dx.doi.org/10.1002/ana.25245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6367933PMC
May 2018

Concussion, microvascular injury, and early tauopathy in young athletes after impact head injury and an impact concussion mouse model.

Brain 2018 02;141(2):422-458

Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA 02118, USA.

The mechanisms underpinning concussion, traumatic brain injury, and chronic traumatic encephalopathy, and the relationships between these disorders, are poorly understood. We examined post-mortem brains from teenage athletes in the acute-subacute period after mild closed-head impact injury and found astrocytosis, myelinated axonopathy, microvascular injury, perivascular neuroinflammation, and phosphorylated tau protein pathology. To investigate causal mechanisms, we developed a mouse model of lateral closed-head impact injury that uses momentum transfer to induce traumatic head acceleration. Unanaesthetized mice subjected to unilateral impact exhibited abrupt onset, transient course, and rapid resolution of a concussion-like syndrome characterized by altered arousal, contralateral hemiparesis, truncal ataxia, locomotor and balance impairments, and neurobehavioural deficits. Experimental impact injury was associated with axonopathy, blood-brain barrier disruption, astrocytosis, microgliosis (with activation of triggering receptor expressed on myeloid cells, TREM2), monocyte infiltration, and phosphorylated tauopathy in cerebral cortex ipsilateral and subjacent to impact. Phosphorylated tauopathy was detected in ipsilateral axons by 24 h, bilateral axons and soma by 2 weeks, and distant cortex bilaterally at 5.5 months post-injury. Impact pathologies co-localized with serum albumin extravasation in the brain that was diagnostically detectable in living mice by dynamic contrast-enhanced MRI. These pathologies were also accompanied by early, persistent, and bilateral impairment in axonal conduction velocity in the hippocampus and defective long-term potentiation of synaptic neurotransmission in the medial prefrontal cortex, brain regions distant from acute brain injury. Surprisingly, acute neurobehavioural deficits at the time of injury did not correlate with blood-brain barrier disruption, microgliosis, neuroinflammation, phosphorylated tauopathy, or electrophysiological dysfunction. Furthermore, concussion-like deficits were observed after impact injury, but not after blast exposure under experimental conditions matched for head kinematics. Computational modelling showed that impact injury generated focal point loading on the head and seven-fold greater peak shear stress in the brain compared to blast exposure. Moreover, intracerebral shear stress peaked before onset of gross head motion. By comparison, blast induced distributed force loading on the head and diffuse, lower magnitude shear stress in the brain. We conclude that force loading mechanics at the time of injury shape acute neurobehavioural responses, structural brain damage, and neuropathological sequelae triggered by neurotrauma. These results indicate that closed-head impact injuries, independent of concussive signs, can induce traumatic brain injury as well as early pathologies and functional sequelae associated with chronic traumatic encephalopathy. These results also shed light on the origins of concussion and relationship to traumatic brain injury and its aftermath.awx350media15713427811001.
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http://dx.doi.org/10.1093/brain/awx350DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837414PMC
February 2018

Clinicopathological Evaluation of Chronic Traumatic Encephalopathy in Players of American Football.

JAMA 2017 07;318(4):360-370

Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston, Massachusetts2Department of Neurology, Boston University School of Medicine, Boston, Massachusetts4VA Boston Healthcare System, US Department of Veteran Affairs, Boston, Massachusetts5Department of Veterans Affairs Medical Center, Bedford, Massachusetts12Department of Pathology, Boston University School of Medicine, Boston, Massachusetts23Boston University School of Medicine, Boston, Massachusetts.

Importance: Players of American football may be at increased risk of long-term neurological conditions, particularly chronic traumatic encephalopathy (CTE).

Objective: To determine the neuropathological and clinical features of deceased football players with CTE.

Design, Setting, And Participants: Case series of 202 football players whose brains were donated for research. Neuropathological evaluations and retrospective telephone clinical assessments (including head trauma history) with informants were performed blinded. Online questionnaires ascertained athletic and military history.

Exposures: Participation in American football at any level of play.

Main Outcomes And Measures: Neuropathological diagnoses of neurodegenerative diseases, including CTE, based on defined diagnostic criteria; CTE neuropathological severity (stages I to IV or dichotomized into mild [stages I and II] and severe [stages III and IV]); informant-reported athletic history and, for players who died in 2014 or later, clinical presentation, including behavior, mood, and cognitive symptoms and dementia.

Results: Among 202 deceased former football players (median age at death, 66 years [interquartile range, 47-76 years]), CTE was neuropathologically diagnosed in 177 players (87%; median age at death, 67 years [interquartile range, 52-77 years]; mean years of football participation, 15.1 [SD, 5.2]), including 0 of 2 pre-high school, 3 of 14 high school (21%), 48 of 53 college (91%), 9 of 14 semiprofessional (64%), 7 of 8 Canadian Football League (88%), and 110 of 111 National Football League (99%) players. Neuropathological severity of CTE was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college (27 [56%]), semiprofessional (5 [56%]), and professional (101 [86%]) players having severe pathology. Among 27 participants with mild CTE pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had cognitive symptoms, and 9 (33%) had signs of dementia. Among 84 participants with severe CTE pathology, 75 (89%) had behavioral or mood symptoms or both, 80 (95%) had cognitive symptoms, and 71 (85%) had signs of dementia.

Conclusions And Relevance: In a convenience sample of deceased football players who donated their brains for research, a high proportion had neuropathological evidence of CTE, suggesting that CTE may be related to prior participation in football.
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http://dx.doi.org/10.1001/jama.2017.8334DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807097PMC
July 2017

Shining (Laser) Light on Traumatic Brain Injury Blood Biomarkers.

JAMA Neurol 2017 09;74(9):1045-1047

Boston University Alzheimer's Disease & Chronic Traumatic Encephalopathy Center, Boston, Massachusetts.

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http://dx.doi.org/10.1001/jamaneurol.2017.0800DOI Listing
September 2017

Considerations for Experimental Animal Models of Concussion, Traumatic Brain Injury, and Chronic Traumatic Encephalopathy-These Matters Matter.

Front Neurol 2017 1;8:240. Epub 2017 Jun 1.

Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, United States.

Animal models of concussion, traumatic brain injury (TBI), and chronic traumatic encephalopathy (CTE) are widely available and routinely deployed in laboratories around the world. Effective animal modeling requires careful consideration of four basic principles. First, animal model use must be guided by clarity of definitions regarding the human disease or condition being modeled. Concussion, TBI, and CTE represent distinct clinical entities that require clear differentiation: concussion is a , TBI is a , and CTE is a . While these conditions are all associated with head injury, the pathophysiology, clinical course, and medical management of each are distinct. Investigators who use animal models of these conditions must take into account these clinical distinctions to avoid misinterpretation of results and . Second, model selection must be grounded by clarity of purpose with respect to experimental questions and frame of reference of the investigation. Distinguishing ("inputs") from ("outputs") may be helpful during animal model selection, experimental design and execution, and interpretation of results. Vigilance is required to rout out, or rigorously control for, model artifacts with potential to interfere with primary endpoints. The widespread use of anesthetics in many animal models illustrates the many ways that model artifacts can confound preclinical results. Third, concordance between key features of the animal model and the human disease or condition being modeled is required to confirm model biofidelity. Fourth, experimental results observed in animals must be confirmed in human subjects for model validation. Adherence to these principles serves as a bulwark against flawed interpretation of results, study replication failure, and confusion in the field. Implementing these principles will advance basic science discovery and accelerate clinical translation to benefit people affected by concussion, TBI, and CTE.
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http://dx.doi.org/10.3389/fneur.2017.00240DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5451508PMC
June 2017

Guidance on radiation dose limits for the lens of the eye: overview of the recommendations in NCRP Commentary No. 26.

Int J Radiat Biol 2017 10 3;93(10):1015-1023. Epub 2017 Apr 3.

o Life Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , CA , USA.

Purpose: This review summarizes the conclusions and recommendations of the new National Council on Radiation Protection and Measurements (NCRP) Commentary No. 26 guidance on radiation dose limits for the lens of the eye. The NCRP addressed radiation protection principles in respect to the lens of the eye, discussed the current understanding of eye biology and lens effects, reviewed and evaluated epidemiology, and assessed exposed populations with the potential for significant radiation exposures to the lens while suggesting monitoring and protection practices.

Conclusions: Radiation-induced damage to the lens of the eye can include the loss of clarity resulting in opacification or clouding several years after exposure. The impact is highly dependent on the type of radiation, how the exposure of the lens was delivered, the genetic susceptibilities of the individual exposed, and the location of the opacity relative to the visual axis of the individual. The preponderance of epidemiological evidence suggests that lens damage could occur at lower doses than previously considered and the NCRP has determined that it is prudent to reduce the recommended annual lens of the eye occupational dose limit from an equivalent dose of 150 mSv to an absorbed dose of 50 mGy. Significant additional research is still needed in the following areas: comprehensive evaluation of the overall effects of ionizing radiation on the eye, dosimetry methodology and dose-sparing optimization techniques, additional high quality epidemiology studies, and a basic understanding of the mechanisms of cataract development.
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http://dx.doi.org/10.1080/09553002.2017.1304669DOI Listing
October 2017

Detection and removal of impurities in nitric oxide generated from air by pulsed electrical discharge.

Nitric Oxide 2016 11 31;60:16-23. Epub 2016 Aug 31.

Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA. Electronic address:

Inhalation of nitric oxide (NO) produces selective pulmonary vasodilation without dilating the systemic circulation. However, the current NO/N cylinder delivery system is cumbersome and expensive. We developed a lightweight, portable, and economical device to generate NO from air by pulsed electrical discharge. The objective of this study was to investigate and optimize the purity and safety of NO generated by this device. By using low temperature streamer discharges in the plasma generator, we produced therapeutic levels of NO with very low levels of nitrogen dioxide (NO) and ozone. Despite the low temperature, spark generation eroded the surface of the electrodes, contaminating the gas stream with metal particles. During prolonged NO generation there was gradual loss of the iridium high-voltage tip (-90 μg/day) and the platinum-nickel ground electrode (-55 μg/day). Metal particles released from the electrodes were trapped by a high-efficiency particulate air (HEPA) filter. Quadrupole mass spectroscopy measurements of effluent gas during plasma NO generation showed that a single HEPA filter removed all of the metal particles. Mice were exposed to breathing 50 parts per million of electrically generated NO in air for 28 days with only a scavenger and no HEPA filter; the mice did not develop pulmonary inflammation or structural changes and iridium and platinum particles were not detected in the lungs of these mice. In conclusion, an electric plasma generator produced therapeutic levels of NO from air; scavenging and filtration effectively eliminated metallic impurities from the effluent gas.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5079831PMC
http://dx.doi.org/10.1016/j.niox.2016.08.005DOI Listing
November 2016

Cognitive Reserve as a Modifier of Clinical Expression in Chronic Traumatic Encephalopathy: A Preliminary Examination.

J Neuropsychiatry Clin Neurosci 2017 19;29(1):6-12. Epub 2016 Aug 19.

From Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, Boston (MLA, JM, NWK, TDS, LEG, RCC, TMS, PTK, LM, BA, DD, PHM, CJN, RAS, ACM); the Department of Neurology, Boston University School of Medicine, Boston (MLA, JM, NWK, TDS, LEG, DIK, TMS, PTK, LM, BA, DD, PHM, RAS, ACM); Internal Medicine Department, North Shore Medical Center (DD); the VA Boston Healthcare System, U.S. Department of Veteran Affairs, Boston (NWK, TDS, ACM); the Departments of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston (NWK, TDS, ACM); the Department of Veterans Affairs Medical Center, Bedford, Mass. (TDS, ACM); the Departments of Psychiatry and Ophthalmology, Boston University School of Medicine, Boston (LEG); the Departments of Biomedical, Electrical & Computer Engineering, Boston University College of Engineering, Boston (LEG); the Concussion Legacy Foundation (RCC, CJN); the Department of Neurosurgery, Boston University School of Medicine, Boston (RAS); the Department of Neurosurgery, Emerson Hospital, Concord, Mass. (RCC); Braintree Rehabilitation Hospital, Braintree, Mass. (DIK); and the Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston (PHM, RAS).

This study conducted a preliminary examination on cognitive reserve (CR) as a modifier of symptom expression in subjects with autopsy-confirmed chronic traumatic encephalopathy (CTE). The sample included 25 former professional football players neuropathologically diagnosed with CTE stage III or IV. Next of kin interviews ascertained age at cognitive and behavioral/mood symptom onset and demographic/athletic characteristics. Years of education and occupational attainment defined CR. High occupational achievement predicted later age at cognitive (p=0.02) and behavioral/mood (p=0.02) onset. Education was not an individual predictor. These preliminary findings suggest that CR may forestall the clinical manifestation of CTE.
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http://dx.doi.org/10.1176/appi.neuropsych.16030043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5288278PMC
April 2017

Amyloid-β peptide protects against microbial infection in mouse and worm models of Alzheimer's disease.

Sci Transl Med 2016 05;8(340):340ra72

Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.

The amyloid-β peptide (Aβ) is a key protein in Alzheimer's disease (AD) pathology. We previously reported in vitro evidence suggesting that Aβ is an antimicrobial peptide. We present in vivo data showing that Aβ expression protects against fungal and bacterial infections in mouse, nematode, and cell culture models of AD. We show that Aβ oligomerization, a behavior traditionally viewed as intrinsically pathological, may be necessary for the antimicrobial activities of the peptide. Collectively, our data are consistent with a model in which soluble Aβ oligomers first bind to microbial cell wall carbohydrates via a heparin-binding domain. Developing protofibrils inhibited pathogen adhesion to host cells. Propagating β-amyloid fibrils mediate agglutination and eventual entrapment of unatttached microbes. Consistent with our model, Salmonella Typhimurium bacterial infection of the brains of transgenic 5XFAD mice resulted in rapid seeding and accelerated β-amyloid deposition, which closely colocalized with the invading bacteria. Our findings raise the intriguing possibility that β-amyloid may play a protective role in innate immunity and infectious or sterile inflammatory stimuli may drive amyloidosis. These data suggest a dual protective/damaging role for Aβ, as has been described for other antimicrobial peptides.
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http://dx.doi.org/10.1126/scitranslmed.aaf1059DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5505565PMC
May 2016

Status of NCRP Scientific Committee 1-23 Commentary on Guidance on Radiation Dose Limits for the Lens of the Eye.

Health Phys 2016 Feb;110(2):182-4

*Memorial Sloan Kettering Cancer Center, New York, NY; †Public Health England, Oxford, United Kingdom; ‡Indiana University School of Medicine, Indianapolis, IN; §Medical University of South Carolina, Charleston, SC; **University of Wisconsin-Madison, Madison, WI; ††Indian Point Energy Center, Buchanan, NY; ‡‡Johns Hopkins Medicine, Bel Air, MD; §§Complutense University, Madrid, Spain; ***Northwestern University, Chicago, IL; †††U.S. Nuclear Regulatory Commission, Rockville, MD; ‡‡‡Boston University, Boston, MA; §§§Central Research Institute of Electric Power Industry, Tokyo, Japan; ****Electric Power Research Institute, Palo Alto, CA; ††††National Council on Radiation Protection and Measurements, Bethesda, MD; ‡‡‡‡Lawrence Berkeley National Laboratory, Berkeley, CA.

Previous National Council on Radiation Protection and Measurements (NCRP) publications have addressed the issues of risk and dose limitation in radiation protection and included guidance on specific organs and the lens of the eye. NCRP decided to prepare an updated commentary intended to enhance the previous recommendations provided in earlier reports. The NCRP Scientific Committee 1-23 (SC 1-23) is charged with preparing a commentary that will evaluate recent studies on the radiation dose response for the development of cataracts and also consider the type and severity of the cataracts as well as the dose rate; provide guidance on whether existing dose limits to the lens of the eye should be changed in the United States; and suggest research needs regarding radiation effects on and dose limits to the lens of the eye. A status of the ongoing work of SC 1-23 was presented at the Annual Meeting, "Changing Regulations and Radiation Guidance: What Does the Future Hold?" The following represents a synopsis of a few main points in the current draft commentary. It is likely that several changes will be forthcoming as SC 1-23 responds to subject matter expert review and develops a final document, expected by mid 2016.
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http://dx.doi.org/10.1097/HP.0000000000000412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4697269PMC
February 2016

Assessing clinicopathological correlation in chronic traumatic encephalopathy: rationale and methods for the UNITE study.

Alzheimers Res Ther 2015 Oct 12;7(1):62. Epub 2015 Oct 12.

Alzheimer's Disease Center, Boston University School of Medicine, 72 East Concord Street, B-7800, Boston, MA, 02118, USA.

Introduction: Chronic traumatic encephalopathy (CTE) is a progressive neurodegeneration associated with repetitive head impacts. Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) is a U01 project recently funded by the National Institute of Neurological Disorders and Stroke and the National Institute of Biomedical Imaging and Bioengineering. The goal of the UNITE project is to examine the neuropathology and clinical presentation of brain donors designated as "at risk" for the development of CTE based on prior athletic or military exposure. Here, we present the rationale and methodology for UNITE.

Methods: Over the course of 4 years, we will analyze the brains and spinal cords of 300 deceased subjects who had a history of repetitive head impacts sustained during participation in contact sports at the professional or collegiate level or during military service. Clinical data are collected through medical record review and retrospective structured and unstructured family interviews conducted by a behavioral neurologist or neuropsychologist. Blinded to the clinical data, a neuropathologist conducts a comprehensive assessment for neurodegenerative disease, including CTE, using published criteria. At a clinicopathological conference, a panel of physicians and neuropsychologists, blinded to the neuropathological data, reaches a clinical consensus diagnosis using published criteria, including proposed clinical research criteria for CTE.

Results: We will investigate the validity of these clinical criteria and sources of error by using recently validated neuropathological criteria as a gold standard for CTE diagnosis. We also will use statistical modeling to identify diagnostic features that best predict CTE pathology.

Conclusions: The UNITE study is a novel and methodologically rigorous means of assessing clinicopathological correlation in CTE. Our findings will be critical for developing future iterations of CTE clinical diagnostic criteria.
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http://dx.doi.org/10.1186/s13195-015-0148-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4601147PMC
October 2015

Antibody against early driver of neurodegeneration cis P-tau blocks brain injury and tauopathy.

Nature 2015 Jul 15;523(7561):431-436. Epub 2015 Jul 15.

Division of Translational Therapeutics, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.

Traumatic brain injury (TBI), characterized by acute neurological dysfunction, is one of the best known environmental risk factors for chronic traumatic encephalopathy and Alzheimer's disease, the defining pathologic features of which include tauopathy made of phosphorylated tau protein (P-tau). However, tauopathy has not been detected in the early stages after TBI, and how TBI leads to tauopathy is unknown. Here we find robust cis P-tau pathology after TBI in humans and mice. After TBI in mice and stress in vitro, neurons acutely produce cis P-tau, which disrupts axonal microtubule networks and mitochondrial transport, spreads to other neurons, and leads to apoptosis. This process, which we term 'cistauosis', appears long before other tauopathy. Treating TBI mice with cis antibody blocks cistauosis, prevents tauopathy development and spread, and restores many TBI-related structural and functional sequelae. Thus, cis P-tau is a major early driver of disease after TBI and leads to tauopathy in chronic traumatic encephalopathy and Alzheimer's disease. The cis antibody may be further developed to detect and treat TBI, and prevent progressive neurodegeneration after injury.
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http://dx.doi.org/10.1038/nature14658DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4718588PMC
July 2015

Post-traumatic neurodegeneration and chronic traumatic encephalopathy.

Mol Cell Neurosci 2015 May 7;66(Pt B):81-90. Epub 2015 Mar 7.

Boston University Chronic Traumatic Encephalopathy Program, Boston University School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; Boston University Alzheimer's Disease Center, Boston University School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; Department of Neurology, Boston University School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; Department of Pathology and Laboratory Medicine, Boston University School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; VA Boston Healthcare System, 150 South Huntington Avenue, Jamaica Plain, MA 02130, USA.

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity around the world. Concussive and subconcussive forms of closed-head injury due to impact or blast neurotrauma represent the most common types of TBI in civilian and military settings. It is becoming increasingly evident that TBI can lead to persistent, long-term debilitating effects, and in some cases, progressive neurodegeneration and chronic traumatic encephalopathy (CTE). The epidemiological literature suggests that a single moderate-to-severe TBI may be associated with accelerated neurodegeneration and increased risk of Alzheimer's disease, Parkinson's disease, or motor neuron disease. However, the pathologic phenotype of these post-traumatic neurodegenerations is largely unknown and there may be pathobiological differences between post-traumatic disease and the corresponding sporadic disorder. By contrast, the pathology of CTE is increasingly well known and is characterized by a distinctive pattern of progressive brain atrophy and accumulation of hyperphosphorylated tau neurofibrillary and glial tangles, dystrophic neurites, 43 kDa TAR DNA-binding protein (TDP-43) neuronal and glial aggregates, microvasculopathy, myelinated axonopathy, neuroinflammation, and white matter degeneration. Clinically, CTE is associated with behavioral changes, executive dysfunction, memory deficits, and cognitive impairments that begin insidiously and most often progress slowly over decades. Although research on the long-term effects of TBI is advancing quickly, the incidence and prevalence of post-traumatic neurodegeneration and CTE are unknown. Critical knowledge gaps include elucidation of pathogenic mechanisms, identification of genetic risk factors, and clarification of relevant variables-including age at exposure to trauma, history of prior and subsequent head trauma, substance use, gender, stress, and comorbidities-all of which may contribute to risk profiles and the development of post-traumatic neurodegeneration and CTE. This article is part of a Special Issue entitled 'Traumatic Brain Injury'.
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http://dx.doi.org/10.1016/j.mcn.2015.03.007DOI Listing
May 2015