Sport-related concussions in baseball and softball: do mechanisms of injury affect recovery?

OBJECTIVE: Baseball and softball pose unique risks for sport-related concussion (SRC). Although these are not collision sports, concussions in baseball and softball can nonetheless involve high-speed impacts. In a regional, single-institution cohort of baseball and softball athletes who sustained an SRC, the current study sought to 1) describe the mechanisms of injury that led to SRC, and 2) compare initial symptom burden and recovery metrics across mechanisms, including time to return to learn (RTL), time to symptom resolution, and time to return to play (RTP) by mechanism of injury. METHODS: A retrospective cohort study was performed of baseball and softball athletes 12 to 23 years old who sustained an SRC between November 2017 and April 2022. Mechanisms of injury were divided into two categories: 1) contact mechanism (i.e., what initiated contact with the injured player, such as head-to-ball), and 2) player mechanism (i.e., the action the injured player was performing at the time of injury, such as fielding). The recovery outcomes of time to RTL, symptom resolution, and RTP were compared between mechanisms using bivariate analysis and multivariable regression analysis, controlling for sex, age, time to present to concussion clinic, and initial total symptom score. RESULTS: The sample included 58 baseball and softball players (60.3% female, mean age 16.0 ± 1.9 years). Most SRCs (62.1%) occurred during competition. Head-to-ball (50.0%) was the most common contact mechanism, followed by head-to-head/body (31.0%) and head-to-wall/ground/equipment (17.2%). Fielding (63.8%) was the most common player mechanism, followed by drills (20.7%) and running (13.8%). SRCs sustained in practice had significantly longer RTL (median 10.0 [interquartile range (IQR) 3.3-16.3] vs 4.0 [IQR 2.0-8.0] days; U = 421.5, p = 0.031) and symptom resolution (37.0 [IQR 18.0-90.0] vs 14.0 [IQR 7.0-41.0] days; U = 406.5, p = 0.025) compared with SRCs sustained in competition. Multivariable regression analysis revealed that head-to-wall/ground/equipment contact mechanism was associated with longer RTL (ß = 0.30, 95% CI 0.07-0.54, p = 0.013). CONCLUSIONS: The current study found that SRCs in baseball and softball occurred more often in competition than in practice. Head-to-ball and fielding were the most common contact and player mechanisms, respectively. SRCs sustained in practice were associated with longer time to RTL and symptom resolution, and head-to-wall/ground/equipment was associated with longer RTL in multivariable regression analysis. These results provide empirical data to improve concussion safety in baseball/softball.

What are the Protocols and Resources for Sport-Related Concussion Among Top National Collegiate Athletic Association Football Programs? A Cross-Sectional Survey of A5 Schools.

OBJECTIVE: This study summarizes findings from a cross-sectional survey conducted among National Collegiate Athletic Association (NCAA) Division 1 football programs, focusing on sport-related concussion (SRC) protocols for the 2018 season. DESIGN: Cross-sectional survey study. SETTING: 65 football programs within the Autonomy Five (A5) NCAA conferences. PARTICIPANTS: Athletic trainers and team physicians who attended a football safety meeting at the NCAA offices June 17 to 18, 2019, representing their respective institutions. INTERVENTION: Electronic surveys were distributed on June 14, 2019, before the football safety meeting. MAIN OUTCOME MEASURES: Results for 16 unique questions involving SRC protocols and resources were summarized and evaluated. RESULTS: The survey garnered responses from 46 of 65 programs (response rate = 71%). For baseline testing, 98% measured baseline postural stability and balance, 87% used baseline neurocognitive testing, while only 61% assessed baseline vestibular and/or ocular function. Regarding concussion prevention, 51% did not recommend additional measures, while 4% and 24% recommended cervical compression collars and omega-3 supplementation, respectively. In postconcussion treatment, 26% initiated aerobic exercise 1 day postconcussion if symptoms were stable, 24% waited at least 48 hours, 4% waited for the athlete to return to baseline, 11% waited until the athlete became asymptomatic, and 35% determined procedures on a case-by-case basis. CONCLUSIONS: Most institutions assessed postural stability/balance and neurocognitive functioning at baseline and introduced light aerobic exercise within 48 h postconcussion. There was variation in baseline assessment methods and concussion prevention recommendations. These survey findings deepen our understanding of diverse SRC protocols in NCAA football programs.

Mouse Pancreatic Peptide Hormones Probed at the Sub-Single-Islet Level: The Effects of Acute Corticosterone Treatment.

We combine liquid chromatography coupled with ion mobility spectrometry-mass spectrometry to elucidate how short exposure to corticosterone (Cort) alters the output of mouse pancreatic islet hormones. The workflow enables the robust separation of mouse insulin 1 (Ins1) and insulin 2 (Ins2) and the detection of major islet hormones in a homogenate equivalent to 100-150 islet cells. We show that Ins2 has a unique structure and is degraded much faster than Ins1. Further investigation indicates that Ins2 may populate both T and R states, whereas Ins1 may not. The assemblies of Ins1's B-chain also introduce more structural heterogeneity than Ins2. Collectively, these features account for their unique degradation profiles, the diabetes risk associated with Ins1, and the protective effect of Ins2. In the same experiments, we observe that the ratio of amylin to Ins1 increased significantly in Cort-treated mice (15:1) compared to the control mice (42:1), correlating well with ß-cell proliferation observed in immunoassays on the same animal model. We observe no increase in intact full-length insulin levels but more of the truncated forms, indicating that enzymatic activity is accelerated. Our data provide a molecular basis for reduced insulin action induced by Cort and connections between insulin turnover and insulin resistance.

Isolation and characterization of canine placenta-derived mesenchymal stromal cells for the treatment of neurological disorders in dogs.

Spinal cord injury (SCI) is a devastating disorder that affects humans and dogs. The prognosis of SCI depends on the severity of the injury and can include varying levels of motor and sensory deficits including devastating paraplegia and quadriplegia. Placental mesenchymal stromal cells (PMSCs) have been shown to improve wound healing and possess neuroprotective and immunomodulatory capabilities, but have not yet been clinically tested for the treatment of SCI. This study established a protocol to isolate fetal PMSCs from canine placentas and characterized their paracrine secretion profile and ability to stimulate neurons in vitro to assess their potential as a treatment option for neurological disorders in dogs. Canine PMSCs (cPMSCs) were plastic adherent and capable of trilineage differentiation. cPMSCs expressed typical MSC markers and did not express hematopoietic or endothelial cell markers. Genotyping of cPMSCs revealed fetal rather than maternal origin of the cells. cPMSCs were viable and mitotically expansive in a collagen hydrogel delivery vehicle, and they secreted the immunomodulatory and neurotrophic paracrine factors interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), and vascular endothelial growth factor (VEGF). cPMSCs also stimulated the growth of complex neural networks when co-cultured with SH-SY5Y cells, a neuroblastoma cell line used to model neuron growth in vitro. cPMSCs are analogous to human PMSCs. They meet the criteria to be defined as MSCs and represent a potential regenerative therapy option for neurological disorders in dogs with their robust growth in collagen hydrogel, stimulation of neural network formation, and secretion of potent paracrine factors. © 2017 International Society for Advancement of Cytometry.

Manufacture and preparation of human placenta-derived mesenchymal stromal cells for local tissue delivery.

BACKGROUND: In this study we describe the development of a Current Good Manufacturing Practice (CGMP)-compliant process to isolate, expand and bank placenta-derived mesenchymal stromal cells (PMSCs) for use as stem cell therapy. We characterize the viability, proliferation and neuroprotective secretory profile of PMSCs seeded on clinical-grade porcine small intestine submucosa extracellular matrix (SIS-ECM; Cook Biotech). METHODS: PMSCs were isolated from early gestation placenta chorionic villus tissue via explant culture. Cells were expanded, banked and screened. Purity and expression of markers of pluripotency were determined using flow cytometry. Optimal loading density and viability of PMSCs on SIS-ECM were determined using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell proliferation and fluorescent live/dead assays, respectively. Growth factors secretion was analyzed using enzyme-linked immunosorbent assays (ELISA). RESULTS: PMSCs were rapidly expanded and banked. Viable Master and Working Cell Banks were stable with minimal decrease in viability at 6 months. All PMSCs were sterile, free from Mycoplasma species, karyotypically normal and had low endotoxin levels. PMSCs were homogeneous by immunophenotyping and expressed little to no pluripotency markers. Optimal loading density on SIS-ECM was 3-5 × 105 cells/cm2, and seeded cells were >95% viable. Neurotrophic factor secretion was detectable from PMSCs seeded on plastic and SIS-ECM with variability between donor lots. DISCUSSION: PMSCs from early gestation placental tissues can be rapidly expanded and banked in stable, viable cell banks that are free from contaminating agents, genetically normal and pure. PMSC delivery can be accomplished by using SIS-ECM, which maintains cell viability and protein secretion. Future work in vivo is necessary to optimize cell seeding and transplantation to maximize therapeutic capabilities.

Stopping at C2 Versus C3/4 in Elective Posterior Cervical Decompression and Fusion: A 5-Year Follow-up Study.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: In patients undergoing elective posterior cervical laminectomy and fusion (PCLF) with a minimum of 5-year follow-up, we sought to compare reoperation rates between patients with an upper instrumented vertebra (UIV) of C2 versus C3/4. SUMMARY OF BACKGROUND DATA: The long-term outcomes of choosing between C2 versus C3/4 as the UIV in PCLF remain unclear. METHODS: A single-institution, retrospective cohort study from a prospective registry was conducted of patients undergoing elective, degenerative PCLF from December 2010 to June 2018. The primary exposure was UIV of C2 versus C3/4. The primary outcome was reoperation. Multivariable logistic regression controlled for age, smoking, diabetes, and fusion to the thoracic spine. RESULTS: Of the 68 patients who underwent PCLF with 5-year follow-up, 27(39.7%) had a UIV of C2, and 41(60.3%) had a UIV of either C3/4. Groups had similar duration of symptoms (P=0.743), comorbidities (P>0.999), and rates of instrumentation to the thoracic spine (70.4% vs. 53.7%, P=0.210). The C2 group had significantly longer operative time (231.8±65.9 vs. 181.6±44.1 mins, P<0.001) and more fused segments (5.9±1.8 vs. 4.2±0.9, P<0.001). Reoperation rate was lower in the C2 group compared with C3/4 (7.4% vs. 19.5%), though this did not reach statistical significance (P=0.294). Multivariable logistic regression showed increased odds of reoperation for the C3/4 group compared with the C2 group (OR=3.29, 95%CI=0.59-18.11, P=0.170), though statistical significance was not reached. Similarly, the C2 group had a lower rate of instrumentation failure (7.4% vs. 12.2%, P=0.694) and adjacent segment disease/disk herniation (0% vs. 7.3%, P=0.271), though neither trend attained statistical significance. CONCLUSIONS: Patients with a UIV of C2 had less than half the number of reoperations and less adjacent segment disease, though neither trend was statistically significant. Despite a lack of statistical significance, whether a clinically meaningful difference exists between UIV of C2 versus C3/4 should be validated in larger samples with long-term follow-up. LEVEL OF EVIDENCE: Level-3.

Obstacles to receiving postoperative radiation therapy following separation surgery for metastatic spine disease.

OBJECTIVE: Obtaining timely postoperative radiotherapy (RT) following separation surgery is critical to avoid local recurrence of disease yet can be a challenge due to scheduling conflicts, insurance denials, and travel arrangements. In patients undergoing metastatic spine surgery for spinal cord compression, the authors sought to: 1) report the rate of postoperative RT, 2) describe reasons for patients not receiving postoperative RT, and 3) investigate factors that may predict whether a patient receives postoperative RT. METHODS: A single-center retrospective case series was undertaken of all patients who underwent metastatic spine surgery for extradural disease between January 2010 and January 2021. Inclusion criteria were patients with intermediate or radioresistant tumors with evidence of spinal cord compression who underwent surgery. The primary outcome was the occurrence of RT within 3 months following surgery. Multivariable logistic regression analysis was performed controlling for age, BMI, race, total number of decompressed levels, tumor size, other organ metastasis, and preoperative RT or chemotherapy to predict patients receiving postoperative RT. RESULTS: Of 239 patients undergoing spine surgery for metastatic disease, 113 (47.3%) received postoperative RT while 126 (52.7%) did not. In the postoperative RT group, 24 (21.2%) received stereotactic body radiation therapy while 89 (78.8%) received conventional external-beam radiation therapy. The most common reasons for patients not receiving postoperative RT included death or transfer to hospice (31.0%), RT not being recommended by radiation oncology (30.2%), and loss to follow-up (23.8%). On critical review with the radiation oncology department, the authors estimated that 101 of 126 (80.2%) patients who did not receive postoperative RT were potential candidates for postoperative RT. Patients who received postoperative RT had more documented inpatient (48.7% vs 32.5%, p < 0.001) and outpatient (100.0% vs 65.1%, p < 0.001) radiation oncology consultations than those who did not. Additionally, patients who received postoperative RT had a higher rate of postoperative chemotherapy (53.1% vs 25.4%, p < 0.001), while patients who did not receive postoperative RT had a higher rate of preoperative RT (7.1% vs 31.0%, p < 0.001). Multivariable analysis confirmed that patients who received preoperative RT had lower odds of undergoing postoperative RT (OR 0.14, 95% CI 0.06-0.34; p < 0.001), and patients who underwent postoperative chemotherapy had higher odds of undergoing postoperative RT (OR 3.83, 95% CI 2.05-7.17; p < 0.001). CONCLUSIONS: In the current study reflecting real-world care of patients with metastatic spine disease after undergoing separation surgery, 47% of patients did not receive postoperative RT, and 80% of those patients were potential candidates for postoperative RT. Radiation oncology consultation and postoperative chemotherapy were significantly associated with receiving postoperative RT, whereas preoperative RT was significantly associated with not receiving postoperative RT. The lack of timely postoperative RT highlights a potential gap in metastatic spine tumor care and underscores the necessity for prompt radiation oncology consultation and effective planning.

Nonenzymatic Posttranslational Modifications and Peptide Cleavages Observed in Peptide Epimers.

Posttranslational modifications (PTMs) play vital roles in cellular homeostasis and are implicated in various pathological conditions. This work uses two ion mobility spectrometry-mass spectrometry (IMS-MS) modalities, drift-tube IMS (DT-IMS) and trapped IMS (TIMS), to characterize three important nonenzymatic PTMs that induce no mass loss: l/d isomerization, aspartate/isoaspartate isomerization, and cis/trans proline isomerization. These PTMs are assessed in a single peptide system, the recently discovered pleurin peptides, Plrn2, from Aplysia californica. We determine that the DT-IMS-MS/MS can capture and locate asparagine deamidation into aspartate and its subsequent isomerization to isoaspartate, a key biomarker for age-related diseases. Additionally, nonenzymatic peptide cleavage via in-source fragmentation is evaluated for differences in the intensities and patterns of fragment peaks between these PTMs. Peptide fragments resulting from in-source fragmentation, preceded by peptide denaturation by liquid chromatography (LC) mobile phase, exhibited cis/trans proline isomerization. Finally, the effects of differing the fragmentation voltage at the source and solution-based denaturation conditions on in-source fragmentation profiles are evaluated, confirming that LC denaturation and in-source fragmentation profoundly impact N-terminal peptide bond cleavages of Plrn2 and the structures of their fragment ions. With that, LC-IMS-MS/MS coupled with in-source fragmentation could be a robust method to identify three important posttranslational modifications: l/d isomerization, Asn-deamidation leading to Asp/IsoAsp isomerization, and cis/trans proline isomerization.

Minimizing the risk of occupational Q fever exposure: A protocol for ensuring Coxiella burnetii-negative pregnant ewes are used for medical research.

Q fever is a worldwide zoonosis caused by Coxiella burnetii that can lead to abortion, endocarditis, and death in humans. Researchers utilizing parturient domestic ruminants, including sheep, have an increased risk of occupational exposure. This study evaluated the effectiveness of our screening protocol in eliminating C. burnetii-positive sheep from our facility. From August 2010 to May 2018, all ewes (N = 306) and select lambs (N = 272; ovis aries) were screened twice for C. burnetii utilizing a serum Phase I and Phase II antibody immunofluorescence assay (IFA). The first screen was performed by the vendor prior to breeding, and the second screen was performed on arrival to the research facility. Ewes that were positive on arrival screening were quarantined and retested using repeat IFA serology, enzyme-linked immunosorbent assay, buffy coat polymerase chain reaction (PCR), and amniotic fluid PCR. The overall individual seroprevalence of C. burnetii in the flocks tested by the vendor was 14.2%. Ewes with negative Phase I and Phase II IFA results were selected for transport to the research facility. Upon arrival to the facility, two (0.7%) ewes had positive Phase I IFA results. Repeat testing demonstrated seropositivity in one of these two ewes, though amniotic fluid PCR was negative in both. The repeat seropositive ewe was euthanized prior to use in a research protocol. No Q fever was reported among husbandry, laboratory or veterinary staff during the study period. Serologic testing for C. burnetii with IFA prior to transport and following arrival to a research facility limits potential exposure to research staff.

Early gestation chorionic villi-derived stromal cells for fetal tissue engineering.

AIM: To investigate the potential for early gestation placenta-derived mesenchymal stromal cells (PMSCs) for fetal tissue engineering. METHODS: PMSCs were isolated from early gestation chorionic villus tissue by explant culture. Chorionic villus sampling (CVS)-size tissue samples (mean = 35.93 mg) were used to test the feasibility of obtaining large cell numbers from CVS within a clinically relevant timeframe. We characterized PMSCs isolated from 6 donor placentas by flow cytometry immunophenotyping, multipotency assays, and through immunofluorescent staining. Protein secretion from PMSCs was examined using two cytokine array assays capable of probing for over 70 factors in total. Delivery vehicle compatibility of PMSCs was determined using three common scaffold systems: fibrin glue, collagen hydrogel, and biodegradable nanofibrous scaffolds made from a combination of polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA). Viral transduction of PMSCs was performed using a Luciferase-GFP-containing lentiviral vector and efficiency of transduction was tested by fluorescent microscopy and flow cytometry analysis. RESULTS: We determined that an average of 2.09 × 10(6) (SD ± 8.59 × 10(5)) PMSCs could be obtained from CVS-size tissue samples within 30 d (mean = 27 d, SD ± 2.28), indicating that therapeutic numbers of cells can be rapidly expanded from very limited masses of tissue. Immunophenotyping by flow cytometry demonstrated that PMSCs were positive for MSC markers CD105, CD90, CD73, CD44, and CD29, and were negative for hematopoietic and endothelial markers CD45, CD34, and CD31. PMSCs displayed trilineage differentiation capability, and were found to express developmental transcription factors Sox10 and Sox17 as well as neural-related structural proteins NFM, Nestin, and S100ß. Cytokine arrays revealed a robust and extensive profile of PMSC-secreted cytokines and growth factors, and detected 34 factors with spot density values exceeding 10(3). Detected factors had widely diverse functions that include modulation of angiogenesis and immune response, cell chemotaxis, cell proliferation, blood vessel maturation and homeostasis, modulation of insulin-like growth factor activity, neuroprotection, extracellular matrix degradation and even blood coagulation. Importantly, PMSCs were also determined to be compatible with both biological and synthetic material-based delivery vehicles such as collagen and fibrin hydrogels, and biodegradable nanofiber scaffolds made from a combination of PLA and PLGA. Finally, we demonstrated that PMSCs can be efficiently transduced (> 95%) with a Luciferase-GFP-containing lentiviral vector for future in vivo cell tracking after transplantation. CONCLUSION: Our findings indicate that PMSCs represent a unique source of cells that can be effectively utilized for in utero cell therapy and tissue engineering.