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1.
J Cancer Educ ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730103

RESUMO

Recent treatment advances have resulted in significantly increased survival times following metastatic breast cancer (MBC) diagnosis. Novel treatment approaches-and their related side effects-have changed the landscape of MBC treatment decision-making. We developed a prototype of an online educational tool to prepare patients with MBC for shared decision-making with their oncologists. We describe the five phases of tool development: (1) in-depth, semi-structured qualitative interviews and (2) feedback on storyboards of initial content with patients with MBC and oncology providers. This was followed by three phases of iterative feedback with patients in which they responded to (3) initial, non-navigable website content and (4) a beta version of the full website. In the final phase (5), patients newly diagnosed with MBC (N = 6) used the website prototype for 1 week and completed surveys assessing acceptability, feasibility, treatment knowledge, preparation for decision-making, and self-efficacy for decision-making. Participants in Phase 1 characterized a cyclical process of MBC treatment decision-making and identified key information needs. Website content and structure was iteratively developed in Phases 2-4. Most participants in Phase 5 (n = 4) accessed the website 2-5 times. All participants who accessed the website at least once (n = 5) felt they learned new information from the website prototype and would recommend it to others newly-diagnosed with MBC. After using the website prototype, participants reported high preparation and self-efficacy for decision-making. This multiphase, iterative process resulted in a prototype intervention designed to support decision-making for MBC patients.

2.
Brain Commun ; 6(2): fcad314, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38560515

RESUMO

Repeated head trauma acquired through sports injuries has been associated with the development of long-term disabling symptoms that negatively impact the quality of life. In this retrospective case series, 52 male former professional athletes involved in contact sports and with a history of multiple concussions were evaluated for chronic clinical symptoms and post-mortem neuropathological diagnoses. The clinical symptoms of 19 cases were examined in greater detail for symptom type, severity and duration. Information on neurological, psychiatric and physical symptoms, substance use profiles and concussion histories was obtained from the athletes' next of kin and assessed in relation to post-mortem neuropathological diagnoses. Cases were categorized into three different neuropathological groups: no major neuropathological findings, the presence of only chronic traumatic encephalopathy (CTE) and the diagnosis(es) of other neurodegenerative diseases. Age at death and the presence of DNA damage in the post-mortem brains were analysed for correlation with the clinical symptoms. In this case series, 14/52 (26.9%) cases (mean age 48.2 ± 11.4) had neuropathological evidence of low-stage/low-burden CTE. A total of 11/52 (21.2%) cases (mean age 38.7 ± 12.7) presented a similar profile and severity of behavioural symptoms to those with CTE, despite the lack of significant post-mortem neuropathological findings. A total of 27/52 (51.9%) cases (mean age 75.5 ± 8.7) presented with complex post-mortem neurodegenerative diagnoses, including Alzheimer's disease and other mixed pathologies, and clinical symptoms associated with language, memory and sensory dysfunction. The presence of DNA damage in the brain was found in all neuropathological groups, predominantly in the ependymal lining of ventricles, and phosphorylated histone H2AX staining was correlated with higher age at death (r = 0.59) and symptoms of language dysfunction (r = 0.56). Findings from our case series suggest that post-concussive symptoms are not driven by CTE. Our findings show that proteinopathies alone may not account for the complexity of the clinical manifestations and suggest the possibility of other drivers, such as DNA damage, as potentially useful markers of brain trauma. Broadening the search for biological markers that reflect the effects of brain injury, even when proteinopathy is not observed, and taking a symptom-driven approach are therefore advised.

3.
Front Neurosci ; 17: 1225226, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37638313

RESUMO

Emerging evidence suggests cellular senescence, as a consequence of excess DNA damage and deficient repair, to be a driver of brain dysfunction following repeated mild traumatic brain injury (rmTBI). This study aimed to further investigate the role of deficient DNA repair, specifically BRCA1-related repair, on DNA damage-induced senescence. BRCA1, a repair protein involved in maintaining genomic integrity with multiple roles in the central nervous system, was previously reported to be significantly downregulated in post-mortem brains with a history of rmTBI. Here we examined the effects of impaired BRCA1-related repair on DNA damage-induced senescence and outcomes 1-week post-rmTBI using mice with a heterozygous knockout for BRCA1 in a sex-segregated manner. Altered BRCA1 repair with rmTBI resulted in altered anxiety-related behaviours in males and females using elevated zero maze and contextual fear conditioning. Evaluating molecular markers associated with DNA damage signalling and senescence-related pathways revealed sex-specific differences attributed to BRCA1, where females exhibited elevated DNA damage, impaired DNA damage signalling, and dampened senescence onset compared to males. Overall, the results from this study highlight sex-specific consequences of aberrant DNA repair on outcomes post-injury, and further support a need to develop sex-specific treatments following rmTBI.

4.
Front Neurosci ; 16: 1027116, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408415

RESUMO

Mild traumatic brain injury (mTBI) is an important public health issue, as it can lead to long-term neurological symptoms and risk of neurodegenerative disease. The pathophysiological mechanisms driving this remain unclear, and currently there are no effective therapies for mTBI. In this study on repeated mTBI (rmTBI), we have induced three mild closed-skull injuries or sham procedures, separated by 24 h, in C57BL/6 mice. We show that rmTBI mice have prolonged righting reflexes and astrogliosis, with neurological impairment in the Morris water maze (MWM) and the light dark test. Cortical and hippocampal tissue analysis revealed DNA damage in the form of double-strand breaks, oxidative damage, and R-loops, markers of cellular senescence including p16 and p21, and signaling mediated by the cGAS-STING pathway. This study identified novel sex differences after rmTBI in mice. Although these markers were all increased by rmTBI in both sexes, females had higher levels of DNA damage, lower levels of the senescence protein p16, and lower levels of cGAS-STING signaling proteins compared to their male counterparts. Single-cell RNA sequencing of the male rmTBI mouse brain revealed activation of the DNA damage response, evidence of cellular senescence, and pro-inflammatory markers reminiscent of the senescence-associated secretory phenotype (SASP) in neurons and glial cells. Cell-type specific changes were also present with evidence of brain immune activation, neurotransmission alterations in both excitatory and inhibitory neurons, and vascular dysfunction. Treatment of injured mice with the senolytic drug ABT263 significantly reduced markers of senescence only in males, but was not therapeutic in females. The reduction of senescence by ABT263 in male mice was accompanied by significantly improved performance in the MWM. This study provides compelling evidence that senescence contributes to brain dysfunction after rmTBI, but may do so in a sex-dependent manner.

5.
Acta Neuropathol Commun ; 9(1): 197, 2021 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-34924026

RESUMO

Mild traumatic brain injuries (mTBIs) are a prevalent form of injury that can result in persistent neurological impairments. Microglial activation has become increasingly recognized as a key process regulating the pathology of white matter in a wide range of brain injury and disease contexts. As white matter damage is known to be a major contributor to the impairments that follow mTBI, microglia have rightfully become a common target of investigation for the development of mTBI therapies and biomarkers. Recent work has demonstrated that the efficacy of microglial manipulation as a therapeutic intervention following injury or disease is highly time-sensitive, emphasizing the importance of advancing our understanding of the dynamics of post-mTBI microglial activation from onset to resolution. Current reporting of microglial activation in experimental studies of mTBI is non-standardized, which has limited our ability to identify concrete patterns of post-mTBI microglial activation over time. In this review, we examine preclinical studies of mTBI that report on microglial activation in white matter regions to summarize our current understanding of these patterns. Specifically, we summarize timecourses of post-mTBI microglial activation in white matter regions of the brain, identify factors that influence this activation, examine the temporal relationship between microglial activation and other post-mTBI assessments, and compare the relative sensitivities of various methods for detecting microglial activation. While the lack of replicated experimental conditions has limited the extent of conclusions that can confidently be drawn, we find that microglia are activated over a wide range of timecourses following mTBI and that microglial activation is a long-lasting outcome of mTBI that may resolve after most typical post-mTBI assessments, with the exception of those measuring oligodendrocyte lineage cell integrity. We identify several understudied parameters of post-mTBI microglial activation in white matter, such as the inclusion of female subjects. This review summarizes our current understanding of the progression of microglial activation in white matter structures following experimental mTBI and offers suggestions for important future research directions.


Assuntos
Concussão Encefálica/imunologia , Microglia/imunologia , Substância Branca/imunologia , Animais , Fatores de Tempo
6.
Front Aging Neurosci ; 13: 742632, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34650425

RESUMO

Mild traumatic brain injury (mTBI) can lead to long-term neurological dysfunction and increase one's risk of neurodegenerative disease. Several repercussions of mTBI have been identified and well-studied, including neuroinflammation, gliosis, microgliosis, excitotoxicity, and proteinopathy - however the pathophysiological mechanisms activating these pathways after mTBI remains controversial and unclear. Emerging research suggests DNA damage-induced cellular senescence as a possible driver of mTBI-related sequalae. Cellular senescence is a state of chronic cell-cycle arrest and inflammation associated with physiological aging, mood disorders, dementia, and various neurodegenerative pathologies. This narrative review evaluates the existing studies which identify DNA damage or cellular senescence after TBI (including mild, moderate, and severe TBI) in both experimental animal models and human studies, and outlines how cellular senescence may functionally explain both the molecular and clinical manifestations of TBI. Studies on this subject clearly show accumulation of various forms of DNA damage (including oxidative damage, single-strand breaks, and double-strand breaks) and senescent cells after TBI, and indicate that cellular senescence may be an early event after TBI. Further studies are required to understand the role of sex, cell-type specific mechanisms, and temporal patterns, as senescence may be a pathway of interest to target for therapeutic purposes including prognosis and treatment.

9.
Acta Neuropathol Commun ; 9(1): 82, 2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-33964983

RESUMO

Mild traumatic brain injury (mTBI) results in broad neurological symptoms and an increased risk of being diagnosed with a neurodegenerative disease later in life. While the immediate oxidative stress response and post-mortem pathology of the injured brain has been well studied, it remains unclear how early pathogenic changes may drive persistent symptoms and confer susceptibility to neurodegeneration. In this study we have used a mouse model of repeated mTBI (rmTBI) to identify early gene expression changes at 24 h or 7 days post-injury (7 dpi). At 24 h post-injury, gene expression of rmTBI mice shows activation of the DNA damage response (DDR) towards double strand DNA breaks, altered calcium and cell-cell signalling, and inhibition of cell death pathways. By 7 dpi, rmTBI mice had a gene expression signature consistent with induction of cellular senescence, activation of neurodegenerative processes, and inhibition of the DDR. At both timepoints gliosis, microgliosis, and axonal damage were evident in the absence of any gross lesion, and by 7 dpi rmTBI also mice had elevated levels of IL1ß, p21, 53BP1, DNA2, and p53, supportive of DNA damage-induced cellular senescence. These gene expression changes reflect establishment of processes usually linked to brain aging and suggests that cellular senescence occurs early and most likely prior to the accumulation of toxic proteins. These molecular changes were accompanied by spatial learning and memory deficits in the Morris water maze. To conclude, we have identified DNA damage-induced cellular senescence as a repercussion of repeated mild traumatic brain injury which correlates with cognitive impairment. Pathways involved in senescence may represent viable treatment targets of post-concussive syndrome. Senescence has been proposed to promote neurodegeneration and appears as an effective target to prevent long-term complications of mTBI, such as chronic traumatic encephalopathy and other related neurodegenerative pathologies.


Assuntos
Envelhecimento/patologia , Concussão Encefálica/patologia , Disfunção Cognitiva/patologia , Dano ao DNA/fisiologia , Modelos Animais de Doenças , Idade de Início , Envelhecimento/genética , Envelhecimento/psicologia , Animais , Concussão Encefálica/genética , Concussão Encefálica/psicologia , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL
11.
Neurology ; 96(14): e1835-e1843, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33627496

RESUMO

OBJECTIVE: To determine whether an association exists between career duration or position played and the presence of chronic traumatic encephalopathy (CTE) at autopsy in a series of elite football and hockey players. METHODS: This retrospective cohort study analyzed postmortem brains of 35 former football or hockey players (29 professional, 6 university varsity/major junior), with the presence of CTE at autopsy as the primary outcome. Position played (highest level), age at retirement (indicator of lifetime exposure to sport), and hockey fighting/penalization histories (surrogate marker for role/style of play) were collected. A blinded neuropathologic evaluation of each participant was performed, providing an assessment for neurodegenerative diseases including CTE, based on the 2015 National Institute of Neurological Disorders and Stroke/National Institute of Biomedical Imaging and Bioengineeringconsensus paper. RESULTS: In total, 17 of 35 former players (48.6%) showed pathologic evidence of CTE. There was no correlation found between position played and CTE presence, nor between hockey fighting/penalization histories and CTE, in either the football or hockey groups (p > 0.75, Mann-Whitney-Wilcoxon). Similarly, there was no association between age at retirement and CTE presence (p > 0.5, Mann-Whitney-Wilcoxon). In 24 of 35 cases (68.6%), other neuropathologies were present, 13 of 24 (54.2%) of which were coexistent with CTE. CONCLUSION: In this cohort of 35 former collision sports athletes, no significant associations were found between career duration, position or role played, and CTE presence at autopsy. Although limited by the small and nonrepresentative sample studied, these findings suggest that nonsport factors may be important to understand differing susceptibilities among athletes to CTE.


Assuntos
Encefalopatia Traumática Crônica/etiologia , Futebol Americano/lesões , Hóquei/lesões , Idoso , Atletas , Autopsia , Canadá , Encefalopatia Traumática Crônica/patologia , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo
12.
Blood Adv ; 4(5): 953-968, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32150612

RESUMO

Values and preferences relate to the importance that patients place on health outcomes (eg, bleeding, having a deep venous thrombosis) and are essential when weighing benefits and harms in guideline recommendations. To inform the American Society of Hematology guidelines for management of venous thromboembolism (VTE) disease, we conducted a systematic review of patients' values and preferences related to VTE. We searched Medline, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, and the Cumulative Index to Nursing and Allied Health Literature from inception to April of 2018 (PROSPERO-CRD42018094003). We included quantitative and qualitative studies. We followed Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidance for rating the certainty and presenting findings for quantitative research about the relative importance of health outcomes and a grounded theory approach for qualitative thematic synthesis. We identified 14 quantitative studies (2465 participants) describing the relative importance of VTE-related health states in a widely diverse population of patients, showing overall small to important impact on patients' lives (certainty of the evidence from low to moderate). Additionally, evidence from 34 quantitative studies (6424 participants) and 15 qualitative studies (570 participants) revealed that patients put higher value on VTE risk reduction than on the potential harms of the treatment (certainty of evidence from low to moderate). Studies also suggested a clear preference for oral medication over subcutaneous medication (moderate certainty). The observed variability in health state values may be a result of differences in the approaches used to elicit them and the diversity of included populations rather than true variability in values. This finding highlights the necessity to explore the variability induced by different approaches to ascertain values.


Assuntos
Hematologia , Neoplasias , Tromboembolia Venosa , Anticoagulantes/uso terapêutico , Heparina de Baixo Peso Molecular , Humanos , Estados Unidos , Tromboembolia Venosa/tratamento farmacológico
13.
Acta Neuropathol Commun ; 7(1): 182, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727161

RESUMO

Mild traumatic brain injury (mTBI) leads to diverse symptoms including mood disorders, cognitive decline, and behavioral changes. In some individuals, these symptoms become chronic and persist in the long-term and can confer an increased risk of neurodegenerative disease and dementia diagnosis later in life. Despite the severity of its consequences, the pathophysiological mechanism of mTBI remains unknown. In this post-mortem case series, we assessed DNA damage-induced cellular senescence pathways in 38 professional athletes with a history of repeated mTBI and ten controls with no mTBI history. We assessed clinical presentation, neuropathological changes, load of DNA damage, morphological markers of cellular senescence, and expression of genes involved in DNA damage signaling, DNA repair, and cellular senescence including the senescence-associated secretory phenotype (SASP). Twenty-eight brains with past history of repeated mTBI history had DNA damage within ependymal cells, astrocytes, and oligodendrocytes. DNA damage burden was increased in brains with proteinopathy compared to those without. Cases also showed hallmark features of cellular senescence in glial cells including astrocytic swelling, beading of glial cell processes, loss of H3K27Me3 (trimethylation at lysine 27 of histone H3) and lamin B1 expression, and increased expression of cellular senescence and SASP pathways. Neurons showed a spectrum of changes including loss of emerin nuclear membrane expression, loss of Brahma-related gene-1 (BRG1 or SMARCA4) expression, loss of myelin basic protein (MBP) axonal expression, and translocation of intranuclear tau to the cytoplasm. Expression of DNA repair proteins was decreased in mTBI brains. mTBI brains showed substantial evidence of DNA damage and cellular senescence. Decreased expression of DNA repair genes suggests inefficient DNA repair pathways in this cohort, conferring susceptibly to cellular senescence and subsequent brain dysfunction after mTBI. We therefore suggest that brains of contact-sports athletes are characterized by deficient DNA repair and DNA damage-induced cellular senescence and propose that this may affect neurons and be the driver of brain dysfunction in mTBI, predisposing the progression to neurodegenerative diseases. This study provides novel targets for diagnostic and prognostic biomarkers, and represents viable targets for future treatments.


Assuntos
Traumatismos em Atletas/patologia , Concussão Encefálica/patologia , Senescência Celular/fisiologia , Dano ao DNA/fisiologia , Distúrbios no Reparo do DNA/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atletas , Traumatismos em Atletas/genética , Concussão Encefálica/genética , Distúrbios no Reparo do DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esportes/fisiologia , Esportes/tendências , Adulto Jovem
14.
Lab Invest ; 99(7): 1008-1018, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30760862

RESUMO

Mild traumatic brain injury (mTBI) is common in many populations, including athletes, veterans, and domestic abuse victims. mTBI can cause chronic symptoms, including depression, irritability, memory problems, and attention deficits. A history of repetitive mTBI has been epidemiologically associated with developing early-onset dementia and neurodegenerative diseases and, in particular, is thought to be the underlying cause of chronic traumatic encephalopathy (CTE)-a progressive tauopathy diagnosed by the presence of perivascular hyperphosphorylated tau protein (p-tau) in the depths of cortical sulci. However, the scarce and focal pathology often seen in CTE does not correlate with the severity of symptoms experienced by patients. This paper proposes accumulation of γH2AX, a marker of double-stranded DNA damage, as a novel pathological marker to identify brain damage post-mTBI. We present two cases of men with history of mTBI. Immunohistochemistry revealed extensive DNA damage throughout the frontal cortex, hippocampus, and brainstem areas. Furthermore, gene expression profiling showed increases of ataxia telangiectasia mutated (ATM) and checkpoint kinase 2 (CHEK2), two serine/threonine kinases recruited in response to double-strand breaks in the DNA damage response pathway. These cases highlight the complex pathophysiology of head trauma, and suggest DNA damage as the molecular mechanism behind mTBI-induced pathology and symptoms.


Assuntos
Concussão Encefálica/patologia , Encéfalo/patologia , Encefalopatia Traumática Crônica/patologia , Dano ao DNA , Adulto , Idoso de 80 Anos ou mais , Biomarcadores , Humanos , Masculino
15.
Blood Adv ; 2(22): 3292-3316, 2018 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-30482766

RESUMO

BACKGROUND: Despite an increasing incidence of venous thromboembolism (VTE) in pediatric patients in tertiary care settings, relatively few pediatric physicians have experience with antithrombotic interventions. OBJECTIVE: These guidelines of the American Society of Hematology (ASH), based on the best available evidence, are intended to support patients, clinicians, and other health care professionals in their decisions about management of pediatric VTE. METHODS: ASH formed a multidisciplinary guideline panel that included 2 patient representatives and was balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including updating or performing systematic evidence reviews (up to April of 2017). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, including GRADE Evidence-to-Decision frameworks, to assess evidence and make recommendations, which were subject to public comment. RESULTS: The panel agreed on 30 recommendations, covering symptomatic and asymptomatic deep vein thrombosis, with specific focus on management of central venous access device-associated VTE. The panel also addressed renal and portal vein thrombosis, cerebral sino venous thrombosis, and homozygous protein C deficiency. CONCLUSIONS: Although the panel offered many recommendations, additional research is required. Priorities include understanding the natural history of asymptomatic thrombosis, determining subgroup boundaries that enable risk stratification of children for escalation of treatment, and appropriate study of newer anticoagulant agents in children.


Assuntos
Anticoagulantes/uso terapêutico , Tromboembolia Venosa/tratamento farmacológico , Antitrombinas/uso terapêutico , Cateteres Venosos Centrais/efeitos adversos , Criança , Medicina Baseada em Evidências , Humanos , Veia Porta/patologia , Embolia Pulmonar/tratamento farmacológico , Púrpura Fulminante/patologia , Veias Renais/patologia , Fatores de Risco , Trombose Venosa/tratamento farmacológico
16.
Blood Adv ; 2(22): 3317-3359, 2018 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-30482767

RESUMO

BACKGROUND: Venous thromboembolism (VTE) complicates ∼1.2 of every 1000 deliveries. Despite these low absolute risks, pregnancy-associated VTE is a leading cause of maternal morbidity and mortality. OBJECTIVE: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and others in decisions about the prevention and management of pregnancy-associated VTE. METHODS: ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations. RESULTS: The panel agreed on 31 recommendations related to the treatment of VTE and superficial vein thrombosis, diagnosis of VTE, and thrombosis prophylaxis. CONCLUSIONS: There was a strong recommendation for low-molecular-weight heparin (LWMH) over unfractionated heparin for acute VTE. Most recommendations were conditional, including those for either twice-per-day or once-per-day LMWH dosing for the treatment of acute VTE and initial outpatient therapy over hospital admission with low-risk acute VTE, as well as against routine anti-factor Xa (FXa) monitoring to guide dosing with LMWH for VTE treatment. There was a strong recommendation (low certainty in evidence) for antepartum anticoagulant prophylaxis with a history of unprovoked or hormonally associated VTE and a conditional recommendation against antepartum anticoagulant prophylaxis with prior VTE associated with a resolved nonhormonal provoking risk factor.


Assuntos
Anticoagulantes/uso terapêutico , Tromboembolia Venosa/tratamento farmacológico , Administração Oral , Aleitamento Materno , Medicina Baseada em Evidências , Feminino , Fibrinolíticos/uso terapêutico , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Lactente , Recém-Nascido , Gravidez , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/prevenção & controle
17.
J Alzheimers Dis ; 64(4): 1067-1076, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30010133

RESUMO

Chronic traumatic encephalopathy (CTE) is considered to be a progressive neurodegenerative disease caused by mild traumatic brain injury (mTBI). Recently there has been a significant amount of media attention surrounding the commonness of CTE in professional athletes, particularly American football, based on several postmortem case series. However, despite the persuasive claims made by the media about CTE, research on the disease and the effects of mTBI in general remain in its infancy. Commonly cited case series studying CTE are limited by methodological biases, pathological inconsistencies, insufficient clinical data, and a reliance on inherently biased postmortem data. These case series do not allow for the collection of any epidemiological data and are not representative of the general population. The exaggerated assumptions and assertions taken from these studies run the risk of creating a self-fulfilling prophecy for individuals who believe they are at risk and have the potential to negatively influence sports-related policymaking. This review outlines the status and limitations of recent CTE case series and calls for future prospective, longitudinal studies to further characterize the pathological and clinical hallmarks of CTE.


Assuntos
Viés , Encefalopatia Traumática Crônica/diagnóstico , Encefalopatia Traumática Crônica/etiologia , Adolescente , Adulto , Encéfalo/metabolismo , Encéfalo/patologia , Encefalopatia Traumática Crônica/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índices de Gravidade do Trauma , Adulto Jovem
18.
Anal Bioanal Chem ; 406(9-10): 2325-32, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24553666

RESUMO

Ethyl glucuronide (EtG), a minor metabolite of ethanol, is used as a marker of alcohol consumption in a variety of clinical and forensic settings. At present there are very few studies of UDP-glucuronosyltransferases (UGT), responsible for catalyzing EtG formation, and the possible effect of nutritional components, e.g. flavonoids, which are extensively glucuronidated, on EtG formation has not been addressed at all. The following incubation conditions were optimized with regard to previously published conditions: buffer, substrate concentration, and incubation time. Isolation of EtG from the incubation mixture was also optimized. Recombinant UGT enzymes (UGT1A1, 1A3, 1A4, 1A6, 1A9, 2B7, 2B10, 2B15) were screened for their activity towards ethanol, and kinetic data were then established for all enzymes. It was decided to study the effect of the flavonoids quercetin and kaempferol on glucuronidation of ethanol. Isolation was by solid-phase extraction (SPE) to minimize matrix effects. Analysis was performed by liquid chromatography-tandem mass spectrometry (LC-MS-MS), with EtG-d5 as the internal standard. SPE was vital to avoid severe ion suppression after direct injection of the incubation solution. EtG formation was observed for all enzymes under investigation; their kinetics followed the Michaelis-Menten model, meaning the maximum reaction rate achieved at saturating substrate concentrations (V(max)) and the substrate concentration at which the reaction rate is half of V(max) (Michaelis-Menten constant, K(m)) could be calculated. The highest rate of glucuronidation was observed with UGT1A9 and 2B7. After co-incubation with both flavonoids, formation of EtG was significantly reduced for all enzymes except for UGT2B15, whose activity did not seem to be affected. Results reveal that multiple UGT isoforms are capable of catalyzing glucuronidation of ethanol; nevertheless, the effect of UGT polymorphism on glucuronidation of ethanol needs further study. Formation of EtG is inhibited by the flavonoids under investigation. Obviously, nutritional components affect conversion of ethanol to EtG. This observation may serve as a partial explanation of its variable formation in man.


Assuntos
Glucuronatos/metabolismo , Glucuronosiltransferase/química , Glucuronosiltransferase/metabolismo , Biocatálise , Etanol/metabolismo , Glucuronatos/química , Humanos , Isoenzimas/química , Isoenzimas/metabolismo , Cinética
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