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1.
Child Adolesc Psychiatr Clin N Am ; 33(2): 125-140, 2024 04.
Article in English | MEDLINE | ID: mdl-38395500

ABSTRACT

The United States has long been the leading destination for Latin Americans seeking refuge. However, in the last 7 years, many children from Mexico and northern Central America, composed of El Salvador, Honduras, and Guatemala, have joined this migratory flow. The experience of forced migration is intense, chronic, and complex for children in their home countries, during their journey, and on arrival in the United States. Their stories can inform clinical practices, such as Psychological First Aid and Trauma-Focused Cognitive Behavioral Therapy, to promote resilience in children in vulnerable conditions.


Subject(s)
Emigrants and Immigrants , Psychological Trauma , Child , Humans , United States , Emigrants and Immigrants/psychology , Cognitive Behavioral Therapy , Resilience, Psychological , Vulnerable Populations
2.
Int J Mol Sci ; 25(2)2024 Jan 17.
Article in English | MEDLINE | ID: mdl-38256223

ABSTRACT

Blast-induced neurotrauma has received much attention over the past decade. Vascular injury occurs early following blast exposure. Indeed, in animal models that approximate human mild traumatic brain injury or subclinical blast exposure, vascular pathology can occur in the presence of a normal neuropil, suggesting that the vasculature is particularly vulnerable. Brain endothelial cells and their supporting glial and neuronal elements constitute a neurovascular unit (NVU). Blast injury disrupts gliovascular and neurovascular connections in addition to damaging endothelial cells, basal laminae, smooth muscle cells, and pericytes as well as causing extracellular matrix reorganization. Perivascular pathology becomes associated with phospho-tau accumulation and chronic perivascular inflammation. Disruption of the NVU should impact activity-dependent regulation of cerebral blood flow, blood-brain barrier permeability, and glymphatic flow. Here, we review work in an animal model of low-level blast injury that we have been studying for over a decade. We review work supporting the NVU as a locus of low-level blast injury. We integrate our findings with those from other laboratories studying similar models that collectively suggest that damage to astrocytes and other perivascular cells as well as chronic immune activation play a role in the persistent neurobehavioral changes that follow blast injury.


Subject(s)
Blast Injuries , Brain Concussion , Vascular System Injuries , Animals , Humans , Endothelial Cells , Astrocytes , Inflammation
3.
J Neurotrauma ; 41(5-6): 685-704, 2024 03.
Article in English | MEDLINE | ID: mdl-38183627

ABSTRACT

The long-term effects of exposure to blast overpressure are an important health concern in military personnel. Increase in amyloid beta (Aß) has been documented after non-blast traumatic brain injury (TBI) and may contribute to neuropathology and an increased risk for Alzheimer's disease. We have shown that Aß levels decrease following exposure to a low-intensity blast overpressure event. To further explore this observation, we examined the effects of a single 37 kPa (5.4 psi) blast exposure on brain Aß levels, production, and clearance mechanisms in the acute (24 h) and delayed (28 days) phases post-blast exposure in an experimental rat model. Aß and, notably, the highly neurotoxic detergent soluble Aß42 form, was reduced at 24 h but not 28 days after blast exposure. This reduction was not associated with changes in the levels of Aß oligomers, expression levels of amyloid precursor protein (APP), or increase in enzymes involved in the amyloidogenic cleavage of APP, the ß- and ϒ-secretases BACE1 and presenilin-1, respectively. The levels of ADAM17 α-secretase (also known as tumor necrosis factor α-converting enzyme) decreased, concomitant with the reduction in brain Aß. Additionally, significant increases in brain levels of the endothelial transporter, low-density related protein 1 (LRP1), and enhancement in co-localization of aquaporin-4 (AQP4) to perivascular astrocytic end-feet were observed 24 h after blast exposure. These findings suggest that exposure to low-intensity blast may enhance endothelial clearance of Aß by LRP1-mediated transcytosis and alter AQP4-aided glymphatic clearance. Collectively, the data demonstrate that low-intensity blast alters enzymatic, transvascular, and perivascular clearance of Aß.


Subject(s)
Amyloid Precursor Protein Secretases , Amyloid beta-Peptides , Animals , Rats , Aspartic Acid Endopeptidases , Brain , Amyloid beta-Protein Precursor , Aquaporin 4
4.
J Neurotrauma ; 41(5-6): 714-733, 2024 03.
Article in English | MEDLINE | ID: mdl-37917117

ABSTRACT

Many military veterans who experienced blast-related traumatic brain injuries in the conflicts in Iraq and Afghanistan currently suffer from chronic cognitive and mental health problems that include depression and post-traumatic stress disorder (PTSD). Male rats exposed to repetitive low-level blast develop cognitive and PTSD-related behavioral traits that are present for more than 1 year after exposure. We previously reported that a group II metabotropic receptor (mGluR2/3) antagonist reversed blast-induced behavioral traits. In this report, we explored mGluR2/3 expression following blast exposure in male rats. Western blotting revealed that mGluR2 protein (but not mGluR3) was increased in all brain regions studied (anterior cortex, hippocampus, and amygdala) at 43 or 52 weeks after blast exposure but not at 2 weeks or 6 weeks. mGluR2 RNA was elevated at 52 weeks while mGluR3 was not. Immunohistochemical staining revealed no changes in the principally presynaptic localization of mGluR2 by blast exposure. Administering the mGluR2/3 antagonist LY341495 after behavioral traits had emerged rapidly reversed blast-induced effects on novel object recognition and cued fear responses 10 months following blast exposure. These studies support alterations in mGluR2 receptors as a key pathophysiological event following blast exposure and provide further support for group II metabotropic receptors as therapeutic targets in the neurobehavioral effects that follow blast injury.


Subject(s)
Blast Injuries , Receptors, Metabotropic Glutamate , Stress Disorders, Post-Traumatic , Male , Animals , Rats , Anxiety , Blast Injuries/complications , Amygdala
5.
Acta Neuropathol Commun ; 11(1): 81, 2023 05 12.
Article in English | MEDLINE | ID: mdl-37173747

ABSTRACT

In the course of military operations in modern war theaters, blast exposures are associated with the development of a variety of mental health disorders associated with a post-traumatic stress disorder-related features, including anxiety, impulsivity, insomnia, suicidality, depression, and cognitive decline. Several lines of evidence indicate that acute and chronic cerebral vascular alterations are involved in the development of these blast-induced neuropsychiatric changes. In the present study, we investigated late occurring neuropathological events associated with cerebrovascular alterations in a rat model of repetitive low-level blast-exposures (3 × 74.5 kPa). The observed events included hippocampal hypoperfusion associated with late-onset inflammation, vascular extracellular matrix degeneration, synaptic structural changes and neuronal loss. We also demonstrate that arteriovenous malformations in exposed animals are a direct consequence of blast-induced tissue tears. Overall, our results further identify the cerebral vasculature as a main target for blast-induced damage and support the urgent need to develop early therapeutic approaches for the prevention of blast-induced late-onset neurovascular degenerative processes.


Subject(s)
Arteriovenous Malformations , Blast Injuries , Rats , Male , Animals , Vascular Remodeling , Blast Injuries/complications , Blast Injuries/pathology , Brain/pathology , Inflammation/pathology , Arteriovenous Malformations/complications , Arteriovenous Malformations/pathology , Disease Models, Animal
6.
Neurotrauma Rep ; 4(1): 197-217, 2023.
Article in English | MEDLINE | ID: mdl-37020715

ABSTRACT

Many military veterans who experienced blast-related traumatic brain injuries (TBIs) in the conflicts in Iraq and Afghanistan suffer from chronic cognitive and mental health problems, including post-traumatic stress disorder (PTSD). Male rats subjected to repetitive low-level blast exposure develop chronic cognitive and PTSD-related traits that develop in a delayed manner. Ketamine has received attention as a treatment for refractory depression and PTSD. (2R,6R)-hydroxynorketamine [(2R,6R)-HNK] is a ketamine metabolite that exerts rapid antidepressant actions. (2R,6R)-HNK has become of clinical interest because of its favorable side-effect profile, low abuse potential, and oral route of administration. We treated three cohorts of blast-exposed rats with (2R,6R)-HNK, beginning 7-11 months after blast exposure, a time when the behavioral phenotype is established. Each cohort consisted of groups (n = 10-13/group) as follows: 1) Sham-exposed treated with saline, 2) blast-exposed treated with saline, and 3) blast-exposed treated with a single dose of 20 mg/kg of (2R,6R)-HNK. (2R,6R)-HNK rescued blast-induced deficits in novel object recognition (NOR) and anxiety-related features in the elevated zero maze (EZM) in all three cohorts. Exaggerated acoustic startle was reversed in cohort 1, but not in cohort 3. (2R,6R)-HNK effects were still present in the EZM 12 days after administration in cohort 1 and 27 days after administration in NOR testing of cohorts 2 and 3. (2R,6R)-HNK may be beneficial for the neurobehavioral syndromes that follow blast exposure in military veterans. Additional studies will be needed to determine whether higher doses or more extended treatment regimens may be more effective.

7.
Neurosci Lett ; 797: 137080, 2023 02 16.
Article in English | MEDLINE | ID: mdl-36657633

ABSTRACT

Tauopathies are a heterogeneous group of neurodegenerative disorders that are clinically and pathologically distinct from Alzheimer's disease (AD) having tau inclusions in neurons and/or glia as their most prominent neuropathological feature. BCI-838 (MGS00210) is a group II metabotropic glutamate receptor (mGluR2/3) antagonist pro-drug. Previously, we reported that orally administered BCI-838 improved learning behavior and reduced anxiety in Dutch (APPE693Q) transgenic mice, a model of the pathological accumulation of Aß oligomers found in AD. Herein, we investigated effects of BCI-838 on PS19 male mice that express the tauopathy mutation MAPTP301S associated with human frontotemporal lobar degeneration (FTLD). These mice develop an aging-related tauopathy without amyloid accumulation. Mice were divided into three experimental groups: (1) non-transgenic wild type mice treated with vehicle, (2) PS19 mice treated with vehicle and (3) PS19 mice treated with 5 mg/kg BCI-838. Groups of 10-13 mice were utilized. Vehicle or BCI-838 was administered by oral gavage for 4 weeks. Behavioral testing consisting of a novel object recognition task was conducted after drug administration. Two studies were performed beginning treatment of mice at 3 or 7 months of age. One month of BCI-838 treatment rescued deficits in recognition memory in PS19 mice whether treatment was begun at 3 or 7 months of age. These studies extend the potential utility of BCI-838 to neurodegenerative conditions that have tauopathy as their underlying basis. They also suggest an mGluR2/3 dependent mechanism as a basis for the behavioral deficits in PS19 mice.


Subject(s)
Alzheimer Disease , Prodrugs , Receptors, Metabotropic Glutamate , Tauopathies , Male , Mice , Humans , Animals , Prodrugs/therapeutic use , Tauopathies/pathology , tau Proteins/genetics , Alzheimer Disease/pathology , Mice, Transgenic , Disease Models, Animal
8.
J Neurotrauma ; 40(5-6): 561-577, 2023 03.
Article in English | MEDLINE | ID: mdl-36262047

ABSTRACT

Chronic mental health problems are common among military veterans who sustained blast-related traumatic brain injuries. The reasons for this association remain unexplained. Male rats exposed to repetitive low-level blast overpressure (BOP) exposures exhibit chronic cognitive and post-traumatic stress disorder (PTSD)-related traits that develop in a delayed fashion. We examined blast-induced alterations on the transcriptome in four brain areas (anterior cortex, hippocampus, amygdala, and cerebellum) across the time frame over which the PTSD-related behavioral phenotype develops. When analyzed at 6 weeks or 12 months after blast exposure, relatively few differentially expressed genes (DEGs) were found. However, longitudinal analysis of amygdala, hippocampus, and anterior cortex between 6 weeks and 12 months revealed blast-specific DEG patterns. Six DEGs (hyaluronan and proteoglycan link protein 1 [Hapln1], glutamate metabotropic receptor 2 [Grm2], purinergic receptor P2y12 [P2ry12], C-C chemokine receptor type 5 [Ccr5], phenazine biosynthesis-like protein domain containing 1 [Pbld1], and cadherin related 23 [Cdh23]) were found altered in all three brain regions in blast-exposed animals. Pathway enrichment analysis using all DEGs or those uniquely changed revealed different transcription patterns in blast versus sham. In particular, the amygdala in blast-exposed animals had a unique set of enriched pathways related to stress responses, oxidative phosphorylation, and mitochondrial dysfunction. Upstream analysis implicated tumor necrosis factor (TNF)α signaling in blast-related effects in amygdala and anterior cortex. Eukaryotic initiating factor eIF4E (EIF4e), an upstream regulator of P2ry12 and Ccr5, was predicted to be activated in the amygdala. Quantitative polymerase chain reaction (qPCR) validated longitudinal changes in two TNFα regulated genes (cathepsin B [Ctsb], Hapln1), P2ry12, and Grm2. These studies have implications for understanding how blast injury damages the brain and implicates inflammation as a potential therapeutic target.


Subject(s)
Blast Injuries , Brain Injuries, Traumatic , Rats , Male , Animals , Neuroinflammatory Diseases , Eukaryotic Initiation Factor-4E/metabolism , Explosions , Brain Injuries, Traumatic/metabolism , Blast Injuries/pathology , Amygdala/metabolism , Tumor Necrosis Factor-alpha/metabolism
9.
Neurotrauma Rep ; 2(1): 548-563, 2021.
Article in English | MEDLINE | ID: mdl-34901948

ABSTRACT

Many military veterans who experienced blast-related traumatic brain injuries (TBIs) in the conflicts in Iraq and Afghanistan suffer from chronic cognitive and mental health problems, including post-traumatic stress disorder (PTSD). Transcranial laser therapy (TLT) uses low-power lasers emitting light in the far- to near-infrared ranges. Beneficial effects of TLT have been reported in neurological and mental-health-related disorders in humans and animal models, including TBI. Rats exposed to repetitive low-level blast develop chronic cognitive and PTSD-related behavioral traits. We tested whether TLT treatment could reverse these traits. Rats received a 74.5-kPa blast or sham exposures delivered one per day for 3 consecutive days. Beginning at 34 weeks after blast exposure, the following groups of rats were treated with active or sham TLT: 1) Sham-exposed rats (n = 12) were treated with sham TLT; 2) blast-exposed rats (n = 13) were treated with sham TLT; and 3) blast-exposed rats (n = 14) were treated with active TLT. Rats received 5 min of TLT five times per week for 6 weeks (wavelength, 808 nm; power of irradiance, 240 mW). At the end of treatment, rats were tested in tasks found previously to be most informative (novel object recognition, novel object localization, contextual/cued fear conditioning, elevated zero maze, and light/dark emergence). TLT did not improve blast-related effects in any of these tests, and blast-exposed rats were worse after TLT in some anxiety-related measures. Based on these findings, TLT does not appear to be a promising treatment for the chronic cognitive and mental health problems that follow blast injury.

10.
Rev. latinoam. psicol ; 53: 104-113, jul.-dic. 2021. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1361044

ABSTRACT

Resumen Introducción: Uno de los instrumentos más usados internacionalmente para medir la conciencia plena es el Kentucky Inventory of Mindfulness Skills. Debido a que esta escala no ha sido traducida ni adaptada a la lengua española, la investigación examinó la validez del constructo, su consistencia interna y validez de criterio, en una muestra mexicana. Método: La muestra estuvo conformada por 485 participantes (145 hombres y 340 mujeres). Resultados: Los resultados revelan una buena fiabilidad de la escala general, Asimismo, confirman que las cuatro dimensiones del inventario son factores sustantivos de la conciencia plena. Un análisis factorial confirmatorio muestra que los datos se ajustan de manera adecuada al modelo de cuatro factores. Conclusiones: Se concluye que este inventario es un instrumento válido y fiable para evaluar la conciencia plena en población general mexicana.


Abstract Introduction: One of the most common instruments used in the world to measure mindfulness is the Kentucky Inventory of Mindfulness Skills. Due to this scale has not been translated and adapted to Spanish, the purpose of this research was to examine the construct validity, internal consistency, and criterion validity in a Mexican sample. Method: The sample included 485 participants (145 men and 350 women). Results: Results found in this research revealed a good reliability of the general scale It was confirmed that the four dimensions of this inventory are significant factors of indfulness. Regarding the confirmatory factor analysis, results showed that data fitted properly to the four factors model. Conclusions: Inconclusion, this inventory is a valid and reliable instrument to measure mindfulness in general Mexican population.

11.
Acta Neuropathol Commun ; 9(1): 167, 2021 10 15.
Article in English | MEDLINE | ID: mdl-34654480

ABSTRACT

Cerebral vascular injury as a consequence of blast-induced traumatic brain injury is primarily the result of blast wave-induced mechanical disruptions within the neurovascular unit. In rodent models of blast-induced traumatic brain injury, chronic vascular degenerative processes are associated with the development of an age-dependent post-traumatic stress disorder-like phenotype. To investigate the evolution of blast-induced chronic vascular degenerative changes, Long-Evans rats were blast-exposed (3 × 74.5 kPa) and their brains analyzed at different times post-exposure by X-ray microcomputed tomography, immunohistochemistry and electron microscopy. On microcomputed tomography scans, regional cerebral vascular attenuation or occlusion was observed as early as 48 h post-blast, and cerebral vascular disorganization was visible at 6 weeks and more accentuated at 13 months post-blast. Progression of the late-onset pathology was characterized by detachment of the endothelial and smooth muscle cellular elements from the neuropil due to degeneration and loss of arteriolar perivascular astrocytes. Development of this pathology was associated with vascular remodeling and neuroinflammation as increased levels of matrix metalloproteinases (MMP-2 and MMP-9), collagen type IV loss, and microglial activation were observed in the affected vasculature. Blast-induced chronic alterations within the neurovascular unit should affect cerebral blood circulation, glymphatic flow and intramural periarterial drainage, all of which may contribute to development of the blast-induced behavioral phenotype. Our results also identify astrocytic degeneration as a potential target for the development of therapies to treat blast-induced brain injury.


Subject(s)
Astrocytes/pathology , Blast Injuries/pathology , Blood-Brain Barrier/pathology , Brain Injuries, Traumatic/pathology , Neuroinflammatory Diseases/pathology , Animals , Blast Injuries/complications , Brain Injuries, Traumatic/etiology , Endothelial Cells/pathology , Neuroinflammatory Diseases/etiology , Pericytes/pathology , Rats , Rats, Long-Evans , Vascular Remodeling/physiology
12.
J Neurotrauma ; 38(22): 3146-3173, 2021 11 15.
Article in English | MEDLINE | ID: mdl-34353119

ABSTRACT

Public awareness of traumatic brain injury (TBI) in the military increased recently because of the conflicts in Iraq and Afghanistan where blast injury was the most common mechanism of injury. Besides overt injuries, concerns also exist over the potential adverse consequences of subclinical blast exposures, which are common for many service members. A TBI is a risk factor for the later development of neurodegenerative diseases, including Alzheimer disease (AD)-like disorders. Studies of acute TBI in humans and animals have suggested that increased processing of the amyloid precursor protein (APP) toward the amyloid beta protein (Aß) may explain the epidemiological associations with AD. In a previous study, however, we found in both rat and mouse models of blast overpressure exposure that rather than increasing, rodent brain Aß42 levels were decreased after acute blast exposure. Here we subjected APP/presenilin 1 transgenic mice (APP/PS1 Tg) to an extended sequence of repetitive low-level blast exposures (34.5 kPa) administered three times per week over eight weeks. If initiated at 20 weeks of age, these repetitive exposures, which were designed to mimic human subclinical blast exposures, reduced anxiety and improved cognition as well as social interactions in APP/PS1 Tg mice, returning many behavioral parameters in APP/PS1 Tg mice to levels of non-transgenic wild type mice. Repetitive low-level blast exposure was less effective at improving behavioral deficits in APP/PS1 Tg mice when begun at 36 weeks of age. While amyloid plaque loads were unchanged, Aß 42 levels and Aß oligomers were reduced in the brain of mice exposed to repetitive low-level blast exposures initiated at 20 weeks of age, although levels did not directly correlate with behavioral parameters in individual animals. These results have implications for understanding the nature of blast effects on the brain and their relationship to human neurodegenerative diseases.


Subject(s)
Alzheimer Disease/metabolism , Alzheimer Disease/psychology , Amyloid beta-Peptides/metabolism , Behavior, Animal/physiology , Blast Injuries/complications , Brain Injuries, Traumatic/complications , Peptide Fragments/metabolism , Alzheimer Disease/etiology , Animals , Blast Injuries/psychology , Brain Injuries, Traumatic/psychology , Disease Models, Animal , Mice , Mice, Inbred C57BL , Mice, Transgenic
13.
Acta Neuropathol Commun ; 9(1): 33, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33648608

ABSTRACT

Military veterans who experience blast-related traumatic brain injuries often suffer from chronic cognitive and neurobehavioral syndromes. Reports of abnormal tau processing following blast injury have raised concerns that some cases may have a neurodegenerative basis. Rats exposed to repetitive low-level blast exhibit chronic neurobehavioral traits and accumulate tau phosphorylated at threonine 181 (Thr181). Using data previously reported in separate studies we tested the hypothesis that region-specific patterns of Thr181 phosphorylation correlate with behavioral measures also previously determined and reported in the same animals. Elevated p-tau Thr181 in anterior neocortical regions and right hippocampus correlated with anxiety as well as fear learning and novel object localization. There were no correlations with levels in amygdala or posterior neocortical regions. Particularly striking were asymmetrical effects on the right and left hippocampus. No systematic variation in head orientation toward the blast wave seems to explain the laterality. Levels did not correlate with behavioral measures of hyperarousal. Results were specific to Thr181 in that no correlations were observed for three other phospho-acceptor sites (threonine 231, serine 396, and serine 404). No consistent correlations were linked with total tau. These correlations are significant in suggesting that p-tau accumulation in anterior neocortical regions and the hippocampus may lead to disinhibited amygdala function without p-tau elevation in the amygdala itself. They also suggest an association linking blast injury with tauopathy, which has implications for understanding the relationship of chronic blast-related neurobehavioral syndromes in humans to neurodegenerative diseases.


Subject(s)
Blast Injuries/pathology , Blast Injuries/psychology , Functional Laterality , Stress Disorders, Post-Traumatic/pathology , Stress Disorders, Post-Traumatic/psychology , tau Proteins/metabolism , Animals , Anxiety/pathology , Anxiety/psychology , Behavior, Animal , Blast Injuries/complications , Brain Injuries, Traumatic/complications , Brain Injuries, Traumatic/pathology , Brain Injuries, Traumatic/psychology , Disease Models, Animal , Fear , Hippocampus/metabolism , Hippocampus/pathology , Male , Phosphorylation , Rats , Rats, Long-Evans , Stress Disorders, Post-Traumatic/complications
14.
Mol Psychiatry ; 26(10): 5940-5954, 2021 10.
Article in English | MEDLINE | ID: mdl-32094584

ABSTRACT

Traumatic brain injury (TBI) is a risk factor for the later development of neurodegenerative diseases that may have various underlying pathologies. Chronic traumatic encephalopathy (CTE) in particular is associated with repetitive mild TBI (mTBI) and is characterized pathologically by aggregation of hyperphosphorylated tau into neurofibrillary tangles (NFTs). CTE may be suspected when behavior, cognition, and/or memory deteriorate following repetitive mTBI. Exposure to blast overpressure from improvised explosive devices (IEDs) has been implicated as a potential antecedent for CTE amongst Iraq and Afghanistan Warfighters. In this study, we identified biomarker signatures in rats exposed to repetitive low-level blast that develop chronic anxiety-related traits and in human veterans exposed to IED blasts in theater with behavioral, cognitive, and/or memory complaints. Rats exposed to repetitive low-level blasts accumulated abnormal hyperphosphorylated tau in neuronal perikarya and perivascular astroglial processes. Using positron emission tomography (PET) and the [18F]AV1451 (flortaucipir) tau ligand, we found that five of 10 veterans exhibited excessive retention of [18F]AV1451 at the white/gray matter junction in frontal, parietal, and temporal brain regions, a typical localization of CTE tauopathy. We also observed elevated levels of neurofilament light (NfL) chain protein in the plasma of veterans displaying excess [18F]AV1451 retention. These findings suggest an association linking blast injury, tauopathy, and neuronal injury. Further study is required to determine whether clinical, neuroimaging, and/or fluid biomarker signatures can improve the diagnosis of long-term neuropsychiatric sequelae of mTBI.


Subject(s)
Chronic Traumatic Encephalopathy , Tauopathies , Animals , Biomarkers , Brain , Humans , Rats , Syndrome
15.
J Neurotrauma ; 38(14): 2030-2045, 2021 07 15.
Article in English | MEDLINE | ID: mdl-33115338

ABSTRACT

Many military veterans who experienced blast-related traumatic brain injuries (TBI) in the conflicts in Iraq and Afghanistan currently have chronic cognitive and mental health problems including post-traumatic stress disorder (PTSD). Besides static symptoms, new symptoms may emerge or existing symptoms may worsen. TBI is also a risk factor for later development of neurodegenerative diseases. In rats exposed to repetitive low-level blast overpressure (BOP), robust and enduring cognitive and PTSD-related behavioral traits develop that are present for at least one year after blast exposure. Here we determined the time-course of the appearance of these traits by testing rats in the immediate post-blast period. Three cohorts of rats examined within the first eight weeks exhibited no behavioral phenotype or, in one cohort, features of anxiety. None showed the altered cued fear responses or impaired novel object recognition characteristic of the fully developed phenotype. Two cohorts retested 36 to 42 weeks after blast exposure exhibited the expanded behavioral phenotype including anxiety as well as altered cued fear learning and impaired novel object recognition. Combined with previous work, the chronic behavioral phenotype has been observed in six cohorts of blast-exposed rats studied at 3-4 months or longer after blast injury, and the three cohorts studied here document the progressive nature of the cognitive/behavioral phenotype. These studies suggest the existence of a latent, delayed emerging and progressive blast-induced cognitive and behavioral phenotype. The delayed onset has implications for the evolution of post-blast neurobehavioral syndromes in military veterans and its modeling in experimental animals.


Subject(s)
Blast Injuries/psychology , Brain Injuries, Traumatic/psychology , Cognition Disorders/etiology , Stress Disorders, Post-Traumatic/etiology , Animals , Behavior, Animal , Disease Models, Animal , Fear , Male , Rats , Rats, Long-Evans , Time Factors
16.
Rev. cuba. med. gen. integr ; 35(1): e814, ene.-mar. 2019. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1093480

ABSTRACT

Introducción: El incremento de la multirresistencia bacteriana constituye un problema de salud pública a nivel internacional. Objetivos: Determinar la susceptibilidad antimicrobiana y los patrones de multirresistencia en cepas de Escherichia coli y Klebsiella pneumoniae aisladas de urocultivos. Métodos: Se realizó un estudio descriptivo retrospectivo en el Centro Municipal de Higiene, Epidemiología y Microbiología, municipio Güines, provincia Mayabeque, Cuba, en el periodo comprendido de enero a diciembre de 2017. El estudio incluyó 250 cepas de Escherichia coli y 62 de Klebsiella pneumoniae aisladas e identificadas de muestras de orina de pacientes con infección del tracto urinario adquirida en la comunidad. La susceptibilidad antimicrobiana fue evaluada con el método de difusión en agar empleado la técnica de Kirby Bauer. Resultados: En Escherichia coli se observó niveles de resistencia superiores al 60 por ciento a los antimicrobianos ácido nalidíxico, cefotaxima, trimetoprim - sulfametoxazol y ceftazidima. La nitrofurantoína y la amikacina presentaron 88,8 por ciento y 83,8 por ciento de efectividad, respectivamente. Se apreció en Klebsiella pneumoniae altos valores de resistencia a ceftazidima, trimetoprim - sulfametoxazol y ácido nalidíxico. Amikacina, presentó niveles de sensibilidad de un 71 por ciento. La resistencia a las cefalosporinas de tercera generación se detectó en 78 (31,2 por ciento) de Escherichia coli y 26 (41,9 por ciento) de Klebsiella pneumoniae. De los aislados de Escherichia coli 143 (57,2 por ciento) y Klebsiella pneumoniae 35 (56,4 por ciento) presentaron multidrogoresistencia. Conclusiones: Existe la circulación de cepas resistentes a cefalosporinas de tercera generación y multidrogorresistentes causantes de infecciones de las vías urinarias adquiridas en la comunidad y se informa sobre los antibióticos (nitrofurantoína y amikacina) que podrían ser utilizados para combatirlas de forma empírica en esta área geográfica(AU)


Introduction: The increase of bacterial multiresistance constitutes a public health problem at the international level. Objectives: To determine antimicrobial sensitivity and multiresistance patterns in strains of Escherichia coli and Klebsiellapneumoniae isolated from urine cultures. Methods: A retrospective, descriptive study was conducted at the Municipal Center for Hygiene, Epidemiology and Microbiology, Güines municipality, Mayabeque Province, Cuba, in the period from January to December, 2017. The study included 250 Escherichia coli and 62 Klebsiellapneumoniae strains isolated and identified from urine samples from patients with urinary tract infection acquired in the community. Antimicrobial sensitivity was evaluated with the method of diffusion in agar using Kirby Bauer´s technique. Results: In Escherichia coli, resistance levels higher than the 60% were observed in antimicrobial nalidixic acid, cefotaxime, trimethoprim-sulfamethoxazole and ceftazidime. Nitrofurantoin and amikacin presented 88.8 percent and 83.8 percent of effectiveness, respectively. High values of resistance to ceftazidime, trimethoprim-sulfamethoxazole and nalidixic acid were present in Klebsiellapneumoniae. Amikacin presented sensitivity levels of 71 percent. Resistance to third-generation cephalosporins was detected in 78 (31.2 percent) of Escherichia coli and 26 (41.9 percent) Klebsiellapneumoniae. From the Escherichia coli and Klebsiellapneumoniae isolates, 143 (57.2 percent) and 35 (56.4 percent),respectively, presented multidrug resistance. Conclusions: There is circulation of strains which are resistant to third generation cephalosporins and multidrug resistants that cause urinary tract infections acquired in the community and there are reports on antibiotics (nitrofurantoin and amikacin) that might be used to combat them empirically in this geographical area(AU)


Subject(s)
Humans , Male , Female , Klebsiella Infections/epidemiology , Drug Resistance, Microbial , Amikacin/therapeutic use , Cephalosporin Resistance , Escherichia coli Infections/epidemiology , Nitrofurantoin/therapeutic use , Epidemiology, Descriptive , Retrospective Studies
17.
Acta Neuropathol Commun ; 7(1): 6, 2019 01 09.
Article in English | MEDLINE | ID: mdl-30626447

ABSTRACT

Much concern exists over the role of blast-induced traumatic brain injury (TBI) in the chronic cognitive and mental health problems that develop in veterans and active duty military personnel. The brain vasculature is particularly sensitive to blast injury. The aim of this study was to characterize the evolving molecular and histologic alterations in the neurovascular unit induced by three repetitive low-energy blast exposures (3 × 74.5 kPa) in a rat model mimicking human mild TBI or subclinical blast exposure. High-resolution two-dimensional differential gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry of purified brain vascular fractions from blast-exposed animals 6 weeks post-exposure showed decreased levels of vascular-associated glial fibrillary acidic protein (GFAP) and several neuronal intermediate filament proteins (α-internexin and the low, middle, and high molecular weight neurofilament subunits). Loss of these proteins suggested that blast exposure disrupts gliovascular and neurovascular interactions. Electron microscopy confirmed blast-induced effects on perivascular astrocytes including swelling and degeneration of astrocytic endfeet in the brain cortical vasculature. Because the astrocyte is a major sensor of neuronal activity and regulator of cerebral blood flow, structural disruption of gliovascular integrity within the neurovascular unit should impair cerebral autoregulation. Disrupted neurovascular connections to pial and parenchymal blood vessels might also affect brain circulation. Blast exposures also induced structural and functional alterations in the arterial smooth muscle layer. Interestingly, by 8 months after blast exposure, GFAP and neuronal intermediate filament expression had recovered to control levels in isolated brain vascular fractions. However, despite this recovery, a widespread vascular pathology was still apparent at 10 months after blast exposure histologically and on micro-computed tomography scanning. Thus, low-level blast exposure disrupts gliovascular and neurovascular connections while inducing a chronic vascular pathology.


Subject(s)
Astrocytes/pathology , Brain Concussion/pathology , Brain/blood supply , Brain/pathology , Neurons/pathology , Animals , Astrocytes/metabolism , Brain/metabolism , Brain Concussion/metabolism , Disease Models, Animal , Male , Neurons/metabolism , Rats, Long-Evans
18.
Neuropharmacology ; 145(Pt B): 220-229, 2019 02.
Article in English | MEDLINE | ID: mdl-30227150

ABSTRACT

A striking observation among veterans returning from the recent conflicts in Iraq and Afghanistan has been the co-occurrence of blast-related mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD). PTSD and mTBI might coexist due to additive effects of independent psychological and physical traumas experienced in a war zone. Alternatively blast injury might induce PTSD-related traits or damage brain structures that mediate responses to psychological stressors, increasing the likelihood that PTSD will develop following a subsequent psychological stressor. Rats exposed to repetitive low-level blasts consisting of three 74.5 kPa exposures delivered once daily for three consecutive days develop a variety of anxiety and PTSD-related behavioral traits that are present for at least 9 months after blast exposure. A single predator scent challenge delivered 8 months after the last blast exposure induces additional anxiety-related changes that are still present 45 days later. Because the blast injuries occur under general anesthesia, it appears that blast exposure in the absence of a psychological stressor can induce chronic PTSD-related traits. The reaction to a predator scent challenge delivered many months after blast exposure suggests that blast exposure in addition sensitizes the brain to react abnormally to subsequent psychological stressors. The development of PTSD-related behavioral traits in the absence of a psychological stressor suggests the existence of blast-induced "PTSD". Findings that PTSD-related behavioral traits can be reversed by BCI-838, a group II metabotropic glutamate receptor antagonist offers insight into pathogenesis and possible treatment options for blast-related brain injury. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".


Subject(s)
Blast Injuries/complications , Brain Injuries, Traumatic/etiology , Stress Disorders, Post-Traumatic/etiology , Animals , Blast Injuries/drug therapy , Brain Injuries, Traumatic/drug therapy , Humans , Stress Disorders, Post-Traumatic/drug therapy
20.
eNeuro ; 5(1)2018.
Article in English | MEDLINE | ID: mdl-29387781

ABSTRACT

Battlefield blast exposure related to improvised explosive devices (IEDs) has become the most common cause of traumatic brain injury (TBI) in the recent conflicts in Iraq and Afghanistan. Mental health problems are common after TBI. A striking feature in the most recent veterans has been the frequency with which mild TBI (mTBI) and posttraumatic stress disorder (PTSD) have appeared together, in contrast to the classical situations in which the presence of mTBI has excluded the diagnosis of PTSD. However, treatment of PTSD-related symptoms that follow blast injury has become a significant problem. BCI-838 (MGS0210) is a Group II metabotropic glutamate receptor (mGluR2/3) antagonist prodrug, and its active metabolite BCI-632 (MGS0039) has proneurogenic, procognitive, and antidepressant activities in animal models. In humans, BCI-838 is currently in clinical trials for refractory depression and suicidality. The aim of the current study was to determine whether BCI-838 could modify the anxiety response and reverse PTSD-related behaviors in rats exposed to a series of low-level blast exposures designed to mimic a human mTBI or subclinical blast exposure. BCI-838 treatment reversed PTSD-related behavioral traits improving anxiety and fear-related behaviors as well as long-term recognition memory. Treatment with BCI-838 also increased neurogenesis in the dentate gyrus (DG) of blast-exposed rats. The safety profile of BCI-838 together with the therapeutic activities reported here, make BCI-838 a promising drug for the treatment of former battlefield Warfighters suffering from PTSD-related symptoms following blast-induced mTBI.


Subject(s)
Blast Injuries/complications , Brain Concussion/complications , Bridged Bicyclo Compounds/pharmacology , Psychotropic Drugs/pharmacology , Stress Disorders, Post-Traumatic/drug therapy , Stress Disorders, Post-Traumatic/psychology , Animals , Anxiety/drug therapy , Anxiety/metabolism , Blast Injuries/drug therapy , Blast Injuries/psychology , Brain Concussion/drug therapy , Brain Concussion/psychology , Dentate Gyrus/drug effects , Dentate Gyrus/metabolism , Dentate Gyrus/pathology , Disease Models, Animal , Excitatory Amino Acid Antagonists/pharmacology , Fear/drug effects , Fear/physiology , Male , Memory, Long-Term/drug effects , Memory, Long-Term/physiology , Neurogenesis/drug effects , Neurogenesis/physiology , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Rats, Long-Evans , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Receptors, Metabotropic Glutamate/metabolism , Recognition, Psychology/drug effects , Recognition, Psychology/physiology , Stress Disorders, Post-Traumatic/metabolism , Stress Disorders, Post-Traumatic/pathology
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