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1.
Proc Natl Acad Sci U S A ; 121(19): e2313568121, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38648470

RESUMO

United States (US) Special Operations Forces (SOF) are frequently exposed to explosive blasts in training and combat, but the effects of repeated blast exposure (RBE) on SOF brain health are incompletely understood. Furthermore, there is no diagnostic test to detect brain injury from RBE. As a result, SOF personnel may experience cognitive, physical, and psychological symptoms for which the cause is never identified, and they may return to training or combat during a period of brain vulnerability. In 30 active-duty US SOF, we assessed the relationship between cumulative blast exposure and cognitive performance, psychological health, physical symptoms, blood proteomics, and neuroimaging measures (Connectome structural and diffusion MRI, 7 Tesla functional MRI, [11C]PBR28 translocator protein [TSPO] positron emission tomography [PET]-MRI, and [18F]MK6240 tau PET-MRI), adjusting for age, combat exposure, and blunt head trauma. Higher blast exposure was associated with increased cortical thickness in the left rostral anterior cingulate cortex (rACC), a finding that remained significant after multiple comparison correction. In uncorrected analyses, higher blast exposure was associated with worse health-related quality of life, decreased functional connectivity in the executive control network, decreased TSPO signal in the right rACC, and increased cortical thickness in the right rACC, right insula, and right medial orbitofrontal cortex-nodes of the executive control, salience, and default mode networks. These observations suggest that the rACC may be susceptible to blast overpressure and that a multimodal, network-based diagnostic approach has the potential to detect brain injury associated with RBE in active-duty SOF.


Assuntos
Traumatismos por Explosões , Militares , Humanos , Traumatismos por Explosões/diagnóstico por imagem , Adulto , Masculino , Estados Unidos , Imageamento por Ressonância Magnética , Feminino , Tomografia por Emissão de Pósitrons , Cognição/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Adulto Jovem
2.
Folia Morphol (Warsz) ; 83(1): 83-91, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-36811140

RESUMO

BACKGROUND: Thiel-fixed body donors are highly valued for surgical training courses. The pronounced flexibility of Thiel-fixed tissue has been postulated to be caused by histologically visible fragmentation of striated muscle. The aim of this study was to analyse whether a specific ingredient, pH, decay, or autolysis could cause this fragmentation in order to modulate the Thiel solution to adapt specimen flexibility specifically to the needs of different courses. MATERIALS AND METHODS: Striated muscle of the mouse was fixed for different time periods in formalin, Thiel solution, and its individual ingredients, and analysed by light microscopy. Further, pH-values of Thiel solution and its ingredients were measured. In addition, unfixed muscle tissue was histologically analysed including Gram staining to investigate a relationship between autolysis, decomposition, and fragmentation. RESULTS: Muscle fixed with Thiel solution for 3 months was slightly more fragmentated than muscle fixed for 1 day. Fragmentation was more pronounced after 1 year of immersion. Three individual salt ingredients showed slight fragmentation. Decay and autolysis had no effect on fragmentation, which occurred regardless of the pH of all solutions. CONCLUSIONS: Fragmentation of Thiel-fixed muscle is dependent on fixation time and most likely occurs due to salts present in the Thiel solution. Adjustment of the salt composition in the Thiel solution with verification of the influence on the fixation effect, fragmentation and flexibility of the cadavers could be performed in further studies.


Assuntos
Embalsamamento , Formaldeído , Animais , Camundongos , Embalsamamento/métodos , Formaldeído/química , Músculo Esquelético , Cadáver , Violeta Genciana
3.
J Spec Oper Med ; 23(4): 47-56, 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-37851859

RESUMO

United States Special Operations Forces (SOF) personnel are frequently exposed to explosive blasts in training and combat. However, the effects of repeated blast exposure on the human brain are incompletely understood. Moreover, there is currently no diagnostic test to detect repeated blast brain injury (rBBI). In this "Human Performance Optimization" article, we discuss how the development and implementation of a reliable diagnostic test for rBBI has the potential to promote SOF brain health, combat readiness, and quality of life.


Assuntos
Traumatismos por Explosões , Militares , Humanos , Estados Unidos , Qualidade de Vida , Encéfalo/diagnóstico por imagem , Traumatismos por Explosões/diagnóstico , Traumatismos por Explosões/terapia , Explosões
4.
Clin Neuropsychol ; 36(8): 2300-2312, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-34157935

RESUMO

Objective: The Automated Neuropsychological Assessment Metrics (ANAM) has long been used to assess cognition in military samples before deployment and following injury. The purpose of this study was to explore the effects of various demographic factors on the ANAM4 Military Expanded (ANAM4 ME) performance of Special Operations Forces (SOF) and to provide regression-based normative data for clinicians working with SOF personnel. Method: The sample was a large active duty military sample of SOF and support personnel (n = 24,072) who were tested under a new baseline policy. Results: Performance differences based on demographic variables were generally small. In general, increasing age was associated with significantly worse performance, except on mathematical processing. Higher education level was associated with better performance on most subtests, as expected, but was associated with worse performance on spatial processing. Conclusion: This paper provides regression formulas for calculating adjusted scores based on the most relevant demographic variables, as well as base rates of obtaining one or more clearly above or below average scores across the entire ANAM4 ME battery.


Assuntos
Transtornos Cognitivos , Militares , Humanos , Militares/psicologia , Testes Neuropsicológicos , Benchmarking , Cognição
5.
J Neurotrauma ; 39(19-20): 1391-1407, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35620901

RESUMO

Emerging evidence suggests that repeated blast exposure (RBE) is associated with brain injury in military personnel. United States (U.S.) Special Operations Forces (SOF) personnel experience high rates of blast exposure during training and combat, but the effects of low-level RBE on brain structure and function in SOF have not been comprehensively characterized. Further, the pathophysiological link between RBE-related brain injuries and cognitive, behavioral, and physical symptoms has not been fully elucidated. We present a protocol for an observational pilot study, Long-Term Effects of Repeated Blast Exposure in U.S. SOF Personnel (ReBlast). In this exploratory study, 30 active-duty SOF personnel with RBE will participate in a comprehensive evaluation of: 1) brain network structure and function using Connectome magnetic resonance imaging (MRI) and 7 Tesla MRI; 2) neuroinflammation and tau deposition using positron emission tomography; 3) blood proteomics and metabolomics; 4) behavioral and physical symptoms using self-report measures; and 5) cognition using a battery of conventional and digitized assessments designed to detect subtle deficits in otherwise high-performing individuals. We will identify clinical, neuroimaging, and blood-based phenotypes that are associated with level of RBE, as measured by the Generalized Blast Exposure Value. Candidate biomarkers of RBE-related brain injury will inform the design of a subsequent study that will test a diagnostic assessment battery for detecting RBE-related brain injury. Ultimately, we anticipate that the ReBlast study will facilitate the development of interventions to optimize the brain health, quality of life, and battle readiness of U.S. SOF personnel.


Assuntos
Traumatismos por Explosões , Concussão Encefálica , Lesões Encefálicas , Militares , Biomarcadores , Traumatismos por Explosões/complicações , Humanos , Militares/psicologia , Estudos Observacionais como Assunto , Projetos Piloto , Qualidade de Vida , Estados Unidos/epidemiologia
6.
PLoS One ; 16(11): e0257349, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34748555

RESUMO

Pulmonary acini represent the functional gas-exchanging units of the lung. Due to technical limitations, individual acini cannot be identified on microscopic lung sections. To overcome these limitations, we imaged the right lower lobes of instillation-fixed rat lungs from postnatal days P4, P10, P21, and P60 at the TOMCAT beamline of the Swiss Light Source synchrotron facility at a voxel size of 1.48 µm. Individual acini were segmented from the three-dimensional data by closing the airways at the transition from conducting to gas exchanging airways. For a subset of acini (N = 268), we followed the acinar development by stereologically assessing their volume and their number of alveoli. We found that the mean volume of the acini increases 23 times during the observed time-frame. The coefficients of variation dropped from 1.26 to 0.49 and the difference between the mean volumes of the fraction of the 20% smallest to the 20% largest acini decreased from a factor of 27.26 (day 4) to a factor of 4.07 (day 60), i.e. shows a smaller dispersion at later time points. The acinar volumes show a large variation early in lung development and homogenize during maturation of the lung by reducing their size distribution by a factor of 7 until adulthood. The homogenization of the acinar sizes hints at an optimization of the gas-exchange region in the lungs of adult animals and that acini of different size are not evenly distributed in the lungs. This likely leads to more homogeneous ventilation at later stages in lung development.


Assuntos
Pulmão/ultraestrutura , Alvéolos Pulmonares/ultraestrutura , Troca Gasosa Pulmonar/fisiologia , Respiração , Células Acinares/fisiologia , Células Acinares/ultraestrutura , Animais , Animais Recém-Nascidos/fisiologia , Humanos , Pulmão/fisiologia , Alvéolos Pulmonares/fisiologia , Ratos
7.
Front Physiol ; 12: 749776, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777012

RESUMO

Lung aging is characterized by lung function impairment, ECM remodeling and airspace enlargement. Tenascin-C (TNC) is a large extracellular matrix (ECM) protein with paracrine and autocrine regulatory functions on cell migration, proliferation and differentiation. This matricellular protein is highly expressed during organogenesis and morphogenetic events like injury repair, inflammation or cancer. We previously showed that TNC deficiency affected lung development and pulmonary function, but little is known about its role during pulmonary aging. In order to answer this question, we characterized lung structure and physiology in 18 months old TNC-deficient and wild-type (WT) mice. Mice were mechanically ventilated with a basal and high tidal volume (HTV) ventilation protocol for functional analyses. Additional animals were used for histological, stereological and molecular biological analyses. We observed that old TNC-deficient mice exhibited larger lung volume, parenchymal volume, total airspace volume and septal surface area than WT, but similar mean linear intercept. This was accompanied by an increase in proliferation, but not apoptosis or autophagy markers expression throughout the lung parenchyma. Senescent cells were observed in epithelial cells of the conducting airways and in alveolar macrophages, but equally in both genotypes. Total collagen content was doubled in TNC KO lungs. However, basal and HTV ventilation revealed similar respiratory physiological parameters in both genotypes. Smooth muscle actin (α-SMA) analysis showed a faint increase in α-SMA positive cells in TNC-deficient lungs, but a marked increase in non-proliferative α-SMA + desmin + cells. Major TNC-related molecular pathways were not up- or down-regulated in TNC-deficient lungs as compared to WT; only minor changes in TLR4 and TGFßR3 mRNA expression were observed. In conclusion, TNC-deficient lungs at 18 months of age showed exaggerated features of the normal structural lung aging described to occur in mice between 12 and 18 months of age. Correlated to the increased pulmonary function parameters previously observed in young adult TNC-deficient lungs and described to occur in normal lung aging between 3 and 6 months of age, TNC might be an advantage in lung aging.

8.
J Spec Oper Med ; 20(1): 87-93, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32203612

RESUMO

There is growing concern that military breaching and training and firing artillery and mortars, grenades, and shoulder-fired weapons may have some type of cumulative deleterious effects. There are anecdotal reports of those with repetitive exposure to low-level blast complaining of various symptoms, as well as increasing empirical evidence. The purpose of this report is to provide a systematic review of the literature on repetitive lowlevel blast as it pertains to military and police training protocols. An extensive literature search was conducted, resulting in detailed review of 18 studies. Results suggest few consistent findings, likely due to the heterogeneity of methods, high risk of bias, and lack of reliance on objective blast-exposure data. Adverse effects, when present, dissipated over time. All studies that used blast gauges found significant associations, though only a subset actually reported using the blast-gauge data (to correlate objective exposure with outcomes). When comparing studies within an outcome domain (e.g., cognitive), findings were largely inconsistent. Research with larger sample sizes, followed longitudinally, is needed.


Assuntos
Traumatismos por Explosões/epidemiologia , Explosões , Humanos , Militares/educação , Polícia/educação
9.
Aviat Space Environ Med ; 79(2): 147-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18309914

RESUMO

Hypertrophic cardiomyopathy (HCM) is a cardiac disorder affecting 1 in 500 persons. The cardinal feature is (inappropriate) left ventricular hypertrophy in the absence of another identifiable cause. Sudden cardiac death (SCD) is the most devastating and feared complication and may be the presenting manifestation. The striking heterogeneity and unpredictability of HCM make risk stratification problematic and imprecise. Cases must be deferred to the FAA for third- or limited second-class special issuance consideration. In general, first-class and full second-class medical certification is not permitted.


Assuntos
Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/terapia , Insuficiência da Valva Mitral/etiologia , Síncope/etiologia , Adulto , Medicina Aeroespacial , Cateterismo Cardíaco/métodos , Cardiomiopatia Hipertrófica/complicações , Avaliação da Deficiência , Ecocardiografia , Etanol/administração & dosagem , Tolerância ao Exercício , Humanos , Masculino
10.
J Appl Physiol (1985) ; 115(9): 1379-87, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23970533

RESUMO

The small trees of gas-exchanging pulmonary airways, which are fed by the most distal purely conducting airways, are called acini and represent the functional gas-exchanging units. The three-dimensional architecture of the acini has a strong influence on ventilation and particle deposition. Due to the difficulty in identifying individual acini on microscopic lung sections, the knowledge about the number of acini and their biological parameters, like volume, surface area, and number of alveoli per acinus, are limited. We developed a method to extract individual acini from lungs imaged by high-resolution synchrotron radiation-based X-ray tomographic microscopy and estimated their volume, surface area, and number of alveoli. Rat acini were isolated by semiautomatically closing the airways at the transition from conducting to gas-exchanging airways. We estimated a mean internal acinar volume of 1.148 mm(3), a mean acinar surface area of 73.9 mm(2), and a mean of 8,470 alveoli/acinus. Assuming that the acini are similarly sized throughout different regions of the lung, we calculated that a rat lung contains 5,470 ± 833 acini. We conclude that our novel approach is well suited for the fast and reliable characterization of a large number of individual acini in healthy, diseased, or transgenic lungs of different species, including humans.


Assuntos
Células Acinares/diagnóstico por imagem , Células Acinares/ultraestrutura , Pulmão/diagnóstico por imagem , Pulmão/ultraestrutura , Animais , Microscopia/métodos , Troca Gasosa Pulmonar/fisiologia , Ratos , Ratos Sprague-Dawley , Tomografia Computadorizada por Raios X/métodos
11.
J Am Osteopath Assoc ; 107(12): 547-53, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18178764

RESUMO

CONTEXT: President George W. Bush announced a national smallpox vaccination program (SVP) on December 13, 2002, for military personnel, civilian healthcare workers, and "first responders." The program was intended to protect these individuals against exposure to weaponized smallpox. The US Air Force (USAF) began implementation of the SVP on January 7, 2003. OBJECTIVES: To determine if the SVP affected USAF personnel readiness, and, based on these results, to determine the overall safety of a large-scale SVP. METHODS: A retrospective cohort study of duty-restriction rates measured by duties not to include flying (DNIFs) of C-17 aircrews in the USAF Air Mobility Command (AMC). Data from January 2002 to May 2002 (prevaccination) and January 2003 to May 2003 (vaccination) were compiled by month from three of the 11 AMC bases. Total DNIFs associated with or attributed to the smallpox vaccine were recorded. In addition, total 2003 DNIFs in 1662 study subjects (678 [40.8%] of whom received smallpox vaccination) were recorded and compared with total 2002 DNIFs in 1602 control subjects before SVP implementation. Differences in monthly DNIF rates were calculated using the one-tailed paired t test. RESULTS: In the 678 subjects who received smallpox vaccination, 13 vaccine-related DNIFs (1.9%) occurred. Differences in DNIF rates were statistically significant (P<.05) during 2 months at one AMC base. However, the SVP did not increase overall DNIF rates in the SVP study period. CONCLUSIONS: With DNIF status as a health marker, the SVP did not impose operational constraints or adversely affect aircrew preparedness in the USAF AMC. The authors suggest that a similar SVP with comparable screening measures would indicate the overall safety of the vaccine.


Assuntos
Medicina Aeroespacial , Programas de Imunização , Medicina Militar , Vacina Antivariólica , Varíola/prevenção & controle , Análise e Desempenho de Tarefas , Adulto , Humanos , Programas de Imunização/organização & administração , Saúde Ocupacional , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Vacina Antivariólica/efeitos adversos , Estados Unidos
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