Contact Sport Athletes Research Articles

Sensitivity of staphylococcus microflora of wrestlers’ skin to bacteriophages

The purpose of this study was to identify the characteristics of bacteriocenosis of wrestlers’ skin and to determine the sensitivity of staphylococcal microflora to bacteriophages. Methods and organization of the research. The experiment involved 15 athletes aged 17-21 years engaged in national wrestling and belt wrestling. Qualifications ranged from 1st adult rank to the master of sports. We used the method of microbiological seeding on yolk-salt agar (JSA) to analyze the washes from the intact skin of the medial part of forearms of wrestlers before and immediately after training. We identified the grown colonies of microorganisms using MALDI Microflex Biotyper mass-spectrometer (Bruker, Germany). In addition to the total microbial abundance, the frequency of occurrence of hemolytic forms of bacteria on wrestlers’ skin was determined before and after training. We determined the sensitivity of Staphylococcus aureus bacteria to staphylococcal bacteriophage and polyvalent pyobacteriophage by the diameter of the bacteria lysis zone. Results and discussion. The research revealed the following facts. 1) S. aureus appears more often than other staphylococci on the skin of the medial part of wrestlers’ forearms both before and after training. 2) We detected high frequency of occurrence of hemolytic forms of Staphylococcus bacteria, which indicates the dysbiosis of wrestlers’ skin. 3) It is more efficient to use a staphylococcal bacteriophage than polyvalent pyobacteriophage for the prevention and treatment of infectious diseases of wrestlers’ skin caused by S. aureus. Conclusion. Athletes of contact sports demonstrate an increased risk of skin infectious diseases, and they need effective means of protection and prevention.

Association of Concussion Symptoms With Testosterone Levels and Erectile Dysfunction in Former Professional US-Style Football Players

Small studies suggest that head trauma in men may be associated with low testosterone levels and sexual dysfunction through mechanisms that likely include hypopituitarism secondary to ischemic injury and pituitary axonal tract damage. Athletes in contact sports may be at risk for pituitary insufficiencies or erectile dysfunction (ED) because of the high number of head traumas experienced during their careers. Whether multiple symptomatic concussive events are associated with later indicators of low testosterone levels and ED is unknown. To explore the associations between concussion symptom history and participant-reported indicators of low testosterone levels and ED. This cross-sectional study of former professional US-style football players was conducted in Boston, Massachusetts, from January 2015 to March 2017. Surveys on past football exposures, demographic factors, and current health conditions were sent via electronic and postal mail to participants within and outside of the United States. Analyses were conducted in Boston, Massachusetts; the data analysis began in March 2018 and additional analyses were performed through June 2019. Of the 13 720 male former players eligible to enroll who were contacted, 3506 (25.6%) responded. Concussion symptom score was calculated by summing the frequency with which participants reported 10 symptoms, such as loss of consciousness, disorientation, nausea, memory problems, and dizziness, at the time of football-related head injury. Self-reported recommendations or prescriptions for low testosterone or ED medication served as indicators for testosterone insufficiency and ED. In 3409 former players (mean [SD] age, 52.5 [14.1] years), the prevalence of indicators of low testosterone levels and ED was 18.3% and 22.7%, respectively. The odds of reporting low testosterone levels or ED indicators were elevated for previously established risk factors (eg, diabetes, sleep apnea, and mood disorders). Models adjusted for demographic characteristics, football exposures, and current health factors showed a significant monotonically increasing association of concussion symptom score with the odds of reporting the low testosterone indicator (highest vs lowest quartile, odds ratio, 2.39; 95% CI, 1.79-3.19; P < .001). The ED indicator showed a similar association (highest quartile vs lowest, odds ratio, 1.72; 95% CI, 1.30-2.27; P < .001). Concussion symptoms at the time of injury among former football players were associated with current participant-reported low testosterone levels and ED indicators. These findings suggest that men with a history of head injury may benefit from discussions with their health care clinicians regarding testosterone deficiency and sexual dysfunction.

Repetitive Head Impact Exposure in College Football Following an NCAA Rule Change to Eliminate Two-A-Day Preseason Practices: A Study from the NCAA-DoD CARE Consortium

Repetitive head impact exposure sustained by athletes of contact sports has been hypothesized to be a mechanism for concussion and a possible explanation for the high degree of variability in sport-related concussion biomechanics. In an attempt to limit repetitive head impact exposure during the football preseason, the NCAA eliminated two-a-day practices in 2017, while maintaining the total number of team practice sessions. The objective of this study was to quantify head impact exposure during the preseason and regular season in Division I college football athletes to determine whether the 2017 NCAA ruling decreased head impact exposure. 342 unique athletes from five NCAA Division I Football Bowl Subdivision (FBS) programs were consented and enrolled. Head impacts were recorded using the Head Impact Telemetry (HIT) System during the entire fall preseasons and regular seasons in 2016 and 2017. Despite the elimination of two-a-day practices, the number of preseason contact days increased in 2017, with an increase in average hourly impact exposure (i.e., contact intensity), resulting in a significant increase in total head impact burden (+ 26%) for the 2017 preseason. This finding would indicate that the 2017 NCAA ruling was not effective at reducing the head impact burden during the football preseason. Additionally, athletes sustained a significantly higher number of recorded head impacts per week (+ 40%) during the preseason than the regular season, implicating the preseason as a time of elevated repetitive head impact burden. With increased recognition of a possible association between repetitive head impact exposure and concussion, increased preseason exposure may predispose certain athletes to a higher risk of concussion during the preseason and regular season. Accordingly, efforts at reducing concussion incidence in contact sports should include a reduction in overall head impact exposure.

Multi-Modal Signatures of Tau Pathology, Neuronal Fiber Integrity, and Functional Connectivity in Traumatic Brain Injury.

[18F]AV-1451 (aka 18F-Flortaucipir, [18F]T807) was developed for positron-emission tomography (PET) imaging of paired helical filaments of hyperphosphorylated tau, which are of interest in a range of neuropathologies, including traumatic brain injury (TBI). Magnetic resonance imaging (MRI) techniques like diffusion tensor imaging (DTI) and resting state functional connectivity assess structural and functional characteristics of the brain, complementing the molecular information that can be obtained by PET. The goal herein was to explore the utility of such multi-modal imaging in a case series based on a population of TBI subjects. This study probes the interrelationship between tau deposition, white matter integrity, and gray matter functional connectivity across the spectrum of TBI. Nineteen subjects (11 controls, five former contact sports athletes, one automotive accident, and two with military-related injury) underwent [18F]AV-1451 PET and magnetic resonance scanning procedures. [18F]AV-1451 distribution volume ratio (DVR) was estimated using the Logan method and the cerebellum as a reference region. Diffusion tractography images and fractional anisotropy (FA) images were generated using diffusion toolkit and FSL. Resting-state functional MRI (fMRI) analysis was based on a graph theory metric, namely weighted degree centrality. TBI subjects showed greater heterogeneity in [18F]AV-1451 DVR when compared with control subjects. In a subset of TBI subjects, areas with high [18F]AV-1451 binding corresponded with increased FA and diminished white matter tract density in DTI. Functional MRI results exhibited an increase in functional connectivity, particularly among local connections, in the areas where tau aggregates were more prevalent. In a case series of a diverse group of TBI subjects, brain regions with elevated tau burden exhibited increased functional connectivity as well as decreased white matter integrity. These findings portray molecular, microstructural, and functional corollaries of TBI that spatially coincide and can be measured in the living human brain using noninvasive neuroimaging techniques.

Engaging Athletic Trainers in Concussion Detection: Overview of the National Football League ATC Spotter Program, 2011-2017.

To assist sideline medical staff and to augment detection of concussion in National Football League (NFL) players during preseason and regular season games via the use of certified athletic trainer (ATC) spotters. Detecting concussive injuries in contact-sport athletes can be a challenging task for health care providers on the sideline. Over the past 8 years, professional sport leagues have begun to use additional sets of eyes (medical spotters along with video review) to help identify athletes with possible concussive injuries. The NFL first began a program using spotters in 2011, and the ATC Spotter Program has undergone systematic enhancements each year. This article describes the evolution of the ATC Spotter Program, the requirements and training of its participants, and the program data available to date. Directions for future improvement and research are addressed. The use of ATC spotters stationed in the broadcast booth has enhanced the real-time detection of concussed players in the NFL.

Abstracts from The 37th Annual National Neurotrauma Symposium June 29–July 3, 2019 Pittsburgh, Pennsylvania

Abstracts from The 37^th Annual National Neurotrauma Symposium June 29–July 3, 2019 Pittsburgh, Pennsylvania

Diffusion Tensor Imaging in Athletes Sustaining Repetitive Head Impacts: A Systematic Review of Prospective Studies.

Competitive sport participation, in contact and collision sports, exposes athletes to repetitive head impacts. Although these impacts do not always result in overt symptomology or a diagnosed "concussion," evidence indicates that cumulative repetitive impacts affect brain pathophysiology. The purpose of this study was to perform a systematic review of prospective, longitudinal trials evaluating repetitive head impact exposure on white matter (WM) microstructure in collision and contact sport athletes to inform clinical care and treatment strategies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to determine studies that met predetermined inclusion and exclusion criteria. Initially, 2498 abstracts were identified, and 20 studies were critically evaluated herein. The majority of studies demonstrated significant longitudinal changes in anisotropy and/or diffusivity metrics that were associated with the quantity and/or the magnitude of head impact exposure, highlighting the utility of diffusion tensor imaging (DTI) for measuring changes in WM microstructure. Our review also comments on study methodology and describes how age, sex, sport, and time between sport cessation and DTI measures contribute to divergent findings within the literature. Suggestions for future research are also provided to overcome previous study limitations and maximize our understanding of the role of repetitive head impact exposure on WM integrity and long-term neurological sequela.

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

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

Frequency and Magnitude of Game-Related Head Impacts in Male Contact Sports Athletes: A Systematic Review and Meta-Analysis

Sensor devices have enabled estimations of head impact kinematics across contact sports. To quantitatively report the magnitude (linear and rotational acceleration) and frequency of game-related head impacts recorded in male contact sports athletes. A systematic review was conducted in June 2017. Inclusion criteria were English-language in vivo studies published after 1990 with a study population of male athletes aged ≥ 16years, in any sport, where athletes were instrumented with an accelerometer device for measuring head impacts. Study populations were not limited to players with a clinical diagnosis of concussion. Twenty-one studies met the inclusion criteria with 12 conducted on American Football athletes. Six of these studies were included for meta-analysis. At a threshold of 10g, amateur rugby players sustained the most impacts per player per game (mean = 77, SD = 42), followed by amateur Australian Football (mean = 29, SD = 37) and collegiate lacrosse athletes (mean = 11.5, SD = 3.6). At thresholds of greater than 14.4g, high school American Football athletes sustained between 19 (SD = 19.1) and 24.4 (SD = 22.4) impacts per player per game. Statistically significant heterogeneity was observed among the included studies, and meta-analysis of impact magnitude was limited. The frequency of "headacceleration events" was quantified and demonstrated substantial variation in methodology and reporting of results. Future research with standardised reporting of head impacts and inclusion of non-helmeted sports is warranted to enable more robust comparisons across sports. CRD42017070065.

Chronic traumatic encephalopathy is a common co-morbidity, but less frequent primary dementia in former soccer and rugby players

Chronic traumatic encephalopathy (CTE) is reported at high prevalence in selected autopsy case series of former contact sports athletes. Nevertheless, the contribution of CTE pathology to clinical presentation and its interaction with co-morbid neurodegenerative pathologies remain unclear. To address these issues, we performed comprehensive neuropathology assessments on the brains of former athletes with dementia and considered these findings together with detailed clinical histories to derive an integrated clinicopathological diagnosis for each case. Consecutive, autopsy-acquired brains from former soccer and rugby players with dementia were assessed for neurodegenerative pathologies using established and preliminary consensus protocols. Thereafter, next of kin interviews were conducted to obtain detailed accounts of the patient’s clinical presentation and course of disease to inform a final, integrated clinicopathological diagnosis. Neuropathologic change consistent with CTE (CTE-NC) was confirmed in five of seven former soccer and three of four former rugby players’ brains, invariably in combination with mixed, often multiple neurodegenerative pathologies. However, in just three cases was the integrated dementia diagnosis consistent with CTE, the remainder having alternate diagnoses, with the most frequent integrated diagnosis Alzheimer’s disease (AD) (four cases; one as mixed AD and vascular dementia). This consecutive autopsy series identifies neuropathologic change consistent with preliminary diagnostic criteria for CTE (CTE-NC) in a high proportion of former soccer and rugby players dying with dementia. However, in the majority, CTE-NC appears as a co-morbidity rather than the primary, dementia causing pathology. As such, we suggest that while CTE-NC might be common in former athletes with dementia, in many cases its clinical significance remains uncertain.

Prevalence of Staphylococcus aureus carriage and pattern of antibiotic resistance, including methicillin resistance, among contact sport athletes in Italy.

Background and purpose: Athletes participating in contact or collision sports have a great chance of acquiring Staphylococcus aureus infections. The risk factors for colonization and infections include frequent antibiotic use, close contact situations, skin trauma, sharing of sports equipment, and poor hygiene. Therefore, our specific goals were to determine (1) prevalence of S. aureus among different types of contact sport athletes which were barely studied in the European region, (2) antimicrobial resistance of S. aureus isolates, and (3) association of carriage with particular risk factors of spor t practices.Patients and methods: A cross-sectional study was conducted among contact or collision sport athletes in Italy. A questionnaire was used to gather information about sociodemographic characteristics, specific sport activities, and participants’ health conditions. Swabs were collected from the nares, oropharynx, and fingers and tested for S. aureus isolation and antimicrobial susceptibility.Results: S. aureus was carried by 42% of 238 enrolled athletes. Colonization was associated with number of weekly training days, sharing of sports equipment, not taking a shower immediately after training, and a previous history of pharyngitis or sinusitis and skin manifestations. Isolates were resistant to clindamycin (24.8%) and erythromycin (15.8%). Of all athletes, 1.3% carried methicillin-resistant S. aureus (MRSA); MRSA were 3% of all S. aureus isolates. No strains were resistant to sulfamethoxazole/trimethoprim.Conclusion: Our results have shown a high prevalence of S. aureus carriage and a relevant resistance to antimicrobials used for the treatment of S. aureus infections. Prevention efforts aimed at reducing S. aureus colonization, and thus potentially reducing infections, should be improved.

Anterior Cruciate Ligament Injury Risk in Sport: A Systematic Review and Meta-Analysis of Injury Incidence by Sex and Sport Classification.

To evaluate sex differences in incidence rates (IRs) of anterior cruciate ligament (ACL) injury by sport type (collision, contact, limited contact, and noncontact). A systematic review was performed using the electronic databases PubMed (1969-January 20, 2017) and EBSCOhost (CINAHL, SPORTDiscus; 1969-January 20, 2017) and the search terms anterior cruciate ligament AND injury AND (incidence OR prevalence OR epidemiology). Studies were included if they provided the number of ACL injuries and the number of athlete-exposures (AEs) by sex or enough information to allow the number of ACL injuries by sex to be calculated. Studies were excluded if they were analyses of previously reported data or were not written in English. Data on sport classification, number of ACL injuries by sex, person-time in AEs for each sex, year of publication, sport, sport type, and level of play were extracted for analysis. We conducted IR and IR ratio (IRR) meta-analyses, weighted for study size and calculated. Female and male athletes had similar ACL injury IRs for the following sport types: collision (2.10/10 000 versus 1.12/10 000 AEs, IRR = 1.14, P = .63), limited contact (0.71/10 000 versus 0.29/10 000 AEs, IRR = 1.21, P = .77), and noncontact (0.36/10 000 versus 0.21/10 000 AEs, IRR = 1.49, P = .22) sports. For contact sports, female athletes had a greater risk of injury than male athletes did (1.88/10 000 versus 0.87/10 000 AEs, IRR = 3.00, P < .001). Gymnastics and obstacle-course races were outliers with respect to IR, so we created a sport category of fixed-object, high-impact rotational landing (HIRL). For this sport type, female athletes had a greater risk of ACL injury than male athletes did (4.80/10 000 versus 1.75/10 000 AEs, IRR = 5.51, P < .001), and the overall IRs of ACL injury were greater than all IRs in all other sport categories. Fixed-object HIRL sports had the highest IRs of ACL injury for both sexes. Female athletes were at greater risk of ACL injury than male athletes in contact and fixed-object HIRL sports.

The Effect of Repetitive Head Impact Exposure on Response Inhibition in Contact Sport Athletes (P2.9-058)

The Effect of Repetitive Head Impact Exposure on Response Inhibition in Contact Sport Athletes (P2.9-058)

An Evidence-Based Objective Study Protocol for Evaluating Cardiovascular and Cerebrovascular Indices Following Concussion: The Neary Protocol.

Introduction: The prevalence and incidence of sport-related concussion have continued to increase over the past decade, and researchers from various backgrounds strive for evidenced-based clinical assessment and management. When diagnosing and managing a concussion, a battery of tests from several domains (e.g., symptom reporting, neurocognitive, physiology) must be used. In this study, we propose and develop an objective, evidence-based protocol to assess the pathophysiology of the brain by using non-invasive methods. Methods: Contact sport athletes (n = 300) will be assessed at the beginning of the season in a healthy state to establish baseline values, and then prospectively followed if a mild traumatic brain injury (mTBI) occurs on approximately days 1–2, 3–5, 7–10, 21, 30, and subsequently thereafter, depending on the severity of injury. The protocol includes spontaneous measurements at rest, during head postural change, controlled breathing maneuvers for cerebrovascular reactivity, a neurovascular coupling stimuli, and a baroreflex/autoregulation maneuver. Physiological data collection will include cerebral blood flow velocity, cerebral oxygenation, respiratory gases for end-tidal oxygen and carbon dioxide, finger photoplethysmography for blood pressure, seismocardiography for cardiac mechanics, and electrocardiography. Conclusion, Limitations, and Ethics: The protocol will provide an objective, physiological evidence-based approach in an attempt to better diagnose concussion to aid in return-to-play or -learn. Ethics approval has been granted by the University Research Ethics Board.

Long-standing groin pain in contact sports: a prospective case–control and MRI study

ObjectivesWe aimed to prospectively evaluate the prevalence of long-standing groin pain and related MRI findings in contact sports.MethodsThis case–control study followed three male elite-level soccer, ice-hockey and bandy teams (102...

Prevalence of Potentially Clinically Significant Magnetic Resonance Imaging Findings in Athletes with and without Sport-Related Concussion.

Previous studies have shown that mild traumatic brain injury (mTBI) can cause abnormalities in clinically relevant magnetic resonance imaging (MRI) sequences. No large-scale study, however, has prospectively assessed this in athletes with sport-related concussion (SRC). The aim of the current study was to characterize and compare the prevalence of acute, trauma-related MRI findings and clinically significant, non-specific MRI findings in athletes with and without SRC. College and high-school athletes were prospectively enrolled and participated in scanning sessions between January 2015 through August 2017. Concussed contact sport athletes (n = 138; 14 female [F]; 19.5 ± 1.6 years) completed up to four scanning sessions after SRC. Non-concussed contact (n = 135; 15 F; 19.7 ± 1.6) and non-contact athletes (n = 96; 15 F; 20.0 ± 1.7) completed similar scanning sessions and served as controls. Board-certified neuroradiologists, blinded to SRC status, reviewed T1-weighted and T2-weighted fluid-attenuated inversion recovery and T2*-weighted and T2-weighted images for acute (i.e., injury-related) or non-acute findings that prompted recommendation for clinical follow-up. Concussed athletes were more likely to have MRI findings relative to contact (30.4% vs. 15.6%; odds ratio [OR] = 2.32; p = 0.01) and non-contact control athletes (19.8%; OR = 2.11; p = 0.04). Female athletes were more likely to have MRI findings than males (43.2% vs. 19.4%; OR = 2.62; p = 0.01). One athlete with SRC had an acute, injury-related finding; group differences were largely driven by increased rate of non-specific white matter hyperintensities in concussed athletes. This prospective, large-scale study demonstrates that <1% of SRCs are associated with acute injury findings on qualitative structural MRI, providing empirical support for clinical guidelines that do not recommend use of MRI after SRC.

Arthroscopic anterior shoulder stabilisation in overhead sport athletes: 5-year follow-up.

Shoulder instability following traumatic glenohumeral dislocation is a common injury sustained by athletes particularly in contact and collision sports. Overhead contact sports such as gaelic football and hurling pose a unique hazard to the glenohumeral joint, increasing the risk of dislocation. To assess return to sport, level of play, recurrence and functional outcomes in gaelic football and hurling athletes in comparison with players of other sports. A retrospective cohort study was carried out from 2007 to 2016. Follow-up was conducted via telephone interview using the Western Ontario Shoulder Instability Index (WOSI) score used to assess functional outcomes as well as return to sport, level of return and recurrence. Ninety patients were included with follow-up which was obtained on 61 patients (68%) with a mean follow-up of 5.04years. 91.8% played sport at the time of injury, 55.4% of those (31 patients) played a gaelic sport with 44.6% (25 patients) playing other sports. 76.8% returned to their sport, 80.4% of these able to return at their pre-injury level. Recurrence occurred in 10 patients (16.4%). WOSI scores were not significantly different between groups (p = 0.77). No significance in recurrence between groups was noted (p = 0.78). Favourable outcomes can be expected for overhead contact sport athletes undergoing anterior arthroscopic stabilisation for recurrent instability. Players from these groups returned to sport sooner than those from other sports and no difference in recurrence was noted. The level at which they can expect to return to is favourable with most athletes reaching their pre-injury level.

CHIMERA repetitive mild traumatic brain injury induces chronic behavioural and neuropathological phenotypes in wild-type and APP/PS1 mice

BackgroundThe annual incidence of traumatic brain injury (TBI) in the United States is over 2.5 million, with approximately 3–5 million people living with chronic sequelae. Compared with moderate-severe TBI, the long-term effects of mild TBI (mTBI) are less understood but important to address, particularly for contact sport athletes and military personnel who have high mTBI exposure. The purpose of this study was to determine the behavioural and neuropathological phenotypes induced by the Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) model of mTBI in both wild-type (WT) and APP/PS1 mice up to 8 months post-injury.MethodsMale WT and APP/PS1 littermates were randomized to sham or repetitive mild TBI (rmTBI; 2 × 0.5 J impacts 24 h apart) groups at 5.7 months of age. Animals were assessed up to 8 months post-injury for acute neurological deficits using the loss of righting reflex (LRR) and Neurological Severity Score (NSS) tasks, and chronic behavioural changes using the passive avoidance (PA), Barnes maze (BM), elevated plus maze (EPM) and rotarod (RR) tasks. Neuropathological assessments included white matter damage; grey matter inflammation; and measures of Aβ levels, deposition, and aducanumab binding activity.ResultsThe very mild CHIMERA rmTBI conditions used here produced no significant acute neurological or motor deficits in WT and APP/PS1 mice, but they profoundly inhibited extinction of fear memory specifically in APP/PS1 mice over the 8-month assessment period. Spatial learning and memory were affected by both injury and genotype. Anxiety and risk-taking behaviour were affected by injury but not genotype. CHIMERA rmTBI induced chronic white matter microgliosis, axonal injury and astrogliosis independent of genotype in the optic tract but not the corpus callosum, and it altered microgliosis in APP/PS1 amygdala and hippocampus. Finally, rmTBI did not alter long-term tau, Aβ or amyloid levels, but it increased aducanumab binding activity.ConclusionsCHIMERA is a useful model to investigate the chronic consequences of rmTBI, including behavioural abnormalities consistent with features of post-traumatic stress disorder and inflammation of both white and grey matter. The presence of human Aβ greatly modified extinction of fear memory after rmTBI.

Skin Microbiota in Contact Sports Athletes and Selection of Antiseptics for Professional Hygiene.

Background The aim of this study was to assess changes in skin microbiota of wrestlers during training sessions and to determine the sensitivity of hemolytic bacterial isolates to antiseptics. Methods The main skin bacterial isolates obtained from the skin of 15 wrestlers were identified by cultivation method, with the following MALDI Biotyper and 16S rRNA gene sequencing methods. The sensitivity of hemolytic isolates to antiseptics (Veltosept-2, Cutasept F, Chlorhexidine, Miramistin, and Hydrogen Peroxide) was evaluated by measuring the size of bacterial growth inhibition zone on agar plates. Results Opportunistic bacteria of the species Bacillus cereus, Staphylococcus aureus, S. epidermidis, and S. saprophyticus were the most commonly found species in skin microbiota of wrestlers before and after training sessions. Representatives of all these species mostly had a hemolytic activity. An alcohol-containing antiseptic Veltosept-2 showed the strongest inhibitory effect on the bacterial isolates of athletes' skin microbiota most frequently detected in this study. Conclusions The general increase in the bacterial colonization of wrestlers' skin, as well as the presence of hemolytic forms of opportunistic bacteria in cutaneous microbiota, indicates dysbiotic changes and a decrease in the protective features of the host organism. Veltosept-2 application can reduce the incidence of skin infections in contact sports athletes with the highest efficiency.

Acromioclavicular and Coracoclavicular Ligament Reconstruction for Acromioclavicular Joint Instability.

Numerous operative techniques have been described for acromioclavicular and coracoclavicular ligament reconstruction for the treatment of acromioclavicular joint instability. Injuries of this nature are commonly sustained by contact-sport athletes in high-impact collisions or falls. Traumatic injury to the acromioclavicular joint and ligamentous structures can range in severity, as can the degree of subsequent joint instability. Injuries classified between Type I and Type III are generally treated nonoperatively, whereas Type-IV injuries may be treated similarly to the treatment described in this article for Type-V injuries. The use of free tendon grafts in conjunction with suspensory devices has demonstrated reliable postoperative outcomes and low rates of unplanned reoperation. We present a surgical technique involving harvest of a semitendinosus autograft from the hamstrings, in addition to allograft augmentation. These free tendon grafts reestablish acromioclavicular joint stability following Rockwood Type-V or VI injuries to the joint. Note that there are differences in the outcomes of free tendon graft, suspensory devices, and modified Weaver-Dunn techniques commonly used to treat acromioclavicular joint instability. Although comparable outcomes have been reported for these modalities, treatment with hook plates and Kirschner wires has demonstrated the highest complication rates when used with this procedure. The Weaver-Dunn technique has been found to yield the lowest postoperative American Shoulder and Elbow Surgeons scores among the aforementioned techniques. Additionally, although other procedures may be less invasive, this technique is beneficial because it reinforces horizontal stability in addition to the vertical stability provided by other procedures, resulting in optimal overall shoulder stability. The procedure is performed as follows: (1) harvest the semitendinosus hamstring autograft, (2) dissect the acromioclavicular joint and prepare the acromion by passing sutures through a drilled tunnel, (3) prepare the coracoid in a fashion similar to that of the acromion, (4) prepare the clavicle and establish the trapezoid-clavicular attachment using an AC TightRope (Arthrex), (5) reduce the clavicle via contraction of the AC TightRope, (6) pass grafts and perform fixation of the trapezoid, (7) perform fixation of the acromioclavicular and conoid ligaments, and (8) skin closure with sutures. We acknowledge the inherent potential for complications when performing this procedure, and this is addressed at the appropriate points of concern throughout the video.