Morally injurious combat events as an indirect risk factor for postconcussive symptoms among veterans: The mediating role of posttraumatic stress.

OBJECTIVE: Psychosocial factors, including combat-related distress (e.g., posttraumatic stress disorder [PTSD]), contribute to postconcussive symptoms (PCS) among veterans with mild traumatic brain injury (mTBI). However, research on risk factors for PCS has focused solely on life-threatening combat experiences, neglecting the morally injurious dimension of combat-related trauma and associated implications for treatment. Morally injurious events (MIEs) are associated with PTSD symptoms among veterans, a robust risk factor of PCS. Nonetheless, the interplay between MIEs, PTSD symptoms, and PCS remains poorly understood. We sought to investigate MIEs as an indirect risk factor for PCS among Veterans with mTBI. METHOD: This cross-sectional study of 145 veterans with mTBI used path analysis to investigate whether PTSD symptoms mediated the relationship between MIEs (transgressions and betrayals) and PCS (mood-behavioral, vestibular-sensory, and cognitive domains) among 145 veterans with mTBI. We used the Moral Injury Event Scale, PTSD Checklist-Civilian Version, and Neurobehavioral Symptom Inventory to measure MIEs, PTSD, and PCS, respectively. RESULTS: Perceived transgressions were indirectly associated with mood-behavioral (ß = .21, p = .005), vestibular-sensory (ß = .17, p = .005), and cognitive PCS (ß = .20, p = .005), as mediated by PTSD. Greater transgressions were associated with more severe PTSD (ß = .27, p = .003), and greater PTSD was associated with more severe mood-behavioral (ß = .79, p < .001), vestibular-sensory (ß = .64, p < .001), and cognitive PCS (ß = .73, p < .001). Betrayals were not indirectly associated with PCS. CONCLUSIONS: Findings offer preliminary support for responses to MIEs being a modifiable risk factor for PCS among veterans. Interventions designed to foster veterans' recovery by targeting the unique emotions and beliefs associated with MIEs may be indicated. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Participation Mediates the Relationship Between Postconcussive Symptoms and Suicidal Ideation Among Veterans.

IMPORTANCE: Veterans with mild traumatic brain injury (mTBI) and associated symptoms are at risk for suicide. Postconcussive symptoms (PCS) may heighten risk for suicidal thoughts by limiting veterans' participation. OBJECTIVE: To investigate whether participation mediates the relationship between PCS and suicidal ideation. DESIGN: Cross-sectional, exploratory design. Structural equation models were used to investigate whether participation mediated the relationship between PCS and suicidal ideation. SETTING: Community. PARTICIPANTS: Veterans with mTBI (N = 145). OUTCOMES AND MEASURES: The Ohio State University TBI Identification Method was used to establish mTBI diagnosis. We identified latent variables for PCS and participation using the Neurobehavioral Symptom Inventory and select domains of the Medical Outcomes Study Short Form-36, respectively. We used the Beck Scale for Suicide Ideation to measure the presence of suicidal ideation. RESULTS: Participation mediated the relationship between PCS and the presence of suicidal ideation (odds ratio [OR] = 1.09, p = .011). More severe PCS were associated with lesser participation (ß = -.86, p < .001); greater participation was associated with lower odds of suicidal ideation (OR = 0.92, p = .007). CONCLUSIONS AND RELEVANCE: PCS may heighten risk for suicidal thoughts among veterans by limiting successful participation, a primary target of occupational therapy intervention. Thus, the results suggest that occupational therapy practitioners can play a substantial role in suicide prevention services for veterans with mTBI. Preventive services could mitigate suicide risk among veterans with mTBI by enabling sustained engagement in meaningful and health-promoting activity (e.g., reasons for living) and targeting PCS. What This Article Adds: Researchers have proposed that occupational therapy practitioners can help prevent veteran suicide by supporting their engagement in meaningful, health-promoting activity and by targeting suicide risk factors within their scope of practice. To the best of our knowledge, this is the first study to offer empirical support for such proposed suicide prevention efforts. Although additional research is needed, these results are promising and highlight a distinct role for occupational therapy in suicide prevention.

Behavior-Change Intervention Targeting Physical Function, Walking, and Disability After Dysvascular Amputation: A Randomized Controlled Pilot Trial.

OBJECTIVE: To determine preliminary efficacy of a home-based behavior-change intervention designed to promote exercise, walking activity, and disease self-management. DESIGN: A single-blind, randomized controlled pilot trial. SETTING: One Veterans Administration and 2 regional medical centers. PARTICIPANTS: A total of 38 participants randomized to behavior-change intervention (n=19) or attention control (CTL; n=19) group. INTERVENTIONS: Weekly 30-minute telephone sessions for 12 weeks with intervention group sessions focused on health behavior change and CTL group sessions focused on health status monitoring. MAIN OUTCOME MEASURES: Physical function, walking activity (steps/d averaged over 10d), and disability were measured at baseline, 12 weeks (intervention end), and 24 weeks after baseline with the Timed Up and Go (TUG) test as the primary outcome measure. RESULTS: The TUG test was not changed from baseline in either group and was not different between groups after 12 or 24 weeks. Several exploratory outcomes were assessed, including daily step count, which increased 1135 steps per day in the intervention group compared to 144 steps per day in the CTL group after 12 weeks (P=.03). Only the intervention group had within-group increase in steps per day from baseline to 12 (P<.001) and 24 (P=.03) weeks and spent significantly less time in sedentary activity (4.8% decrease) than the CTL group (0.2% decrease) at 24 weeks (P=.04). There were no other between-group differences in physical function or disability change over time. CONCLUSION: The behavior-change intervention demonstrates promise for increasing walking activity for people with dysvascular transtibial amputation (TTA). The efficacy of implementing such intervention in the scope of conventional TTA rehabilitation should be further studied.

Explaining modified 2-min walk test outcomes in male Veterans with traumatic or nontraumatic lower-limb amputation.

Little evidence exists to support the presence of differences in spatiotemporal gait parameters and ambulation ability between those individuals with traumatic and nontraumatic lower-limb amputation (LLA). We conducted an exploratory study of 81 male Veterans with unilateral amputation to quantify differences in spatiotemporal gait parameters and ambulatory mobility between Veterans with traumatic and nontraumatic LLA. Furthermore, we identified variables that significantly contributed to the explanation of variability in modified 2-min walk test distance. All participants completed the modified 2-min walk test and a spatiotemporal gait analysis using an instrumented walkway during a routine physical therapy visit. Veterans with nontraumatic LLA walked significantly shorter mean distances during a modified 2-min walk test than Veterans with traumatic LLA. Variables identified as significant contributors to modified 2-min walk test variability were amputated limb stance time, amputated limb step length, and percentage of the gait cycle spent in double support. These findings demonstrate that differences in spatiotemporal gait parameters and ambulatory mobility exist between Veterans with traumatic and nontraumatic LLA and identify important spatiotemporal parameters of gait contributing to this decline. These parameters should be considered as targets for intervention and future investigation.

Functional Outcomes After the Prosthetic Training Phase of Rehabilitation After Dysvascular Lower Extremity Amputation.

OBJECTIVE: To describe physical function outcomes and modes of physical therapy intervention for a cohort of patients with dysvascular lower extremity amputation (LEA) during the prosthetic training phase of rehabilitation. DESIGN: A retrospective cohort study. SETTING: Physical rehabilitation clinics at a Veterans Affairs medical center and a university hospital. PATIENTS: Forty-two patients (38 men, 4 women, age 60.2 ± 8.4 years) who completed outpatient physical therapy rehabilitation with prosthetic training after dysvascular LEA. METHODS: All patients underwent a prosthetic training phase of rehabilitation, with standardized outcome measures performed at initiation and discharge. MAIN OUTCOME MEASURES: Performance-based physical function measures included Two-Minute Walk (2 MW), Timed-Up and Go (TUG), and 5-meter gait speed. Self-report physical function measures included the Prosthesis Evaluation Questionnaire-Mobility Section (PEQ-MS) and the Patient-Specific Functional Scale. Rehabilitation dose was tracked as total number of clinic visits, rehabilitation duration, and specific intervention modes. RESULTS: There were significant improvements between initial and discharge values (mean ± SD) for the Two-Minute Walk (67.5 ± 29.9 m and 103.3 ± 45.8 m, respectively, P < .001), gait speed (0.58 ± 0.27 m/s and 0.88 ± 0.39 m/s, respectively, P < .001), TUG (34.8 ± 21.3 seconds and 18.6 ± 13.9 seconds, respectively, P < .001), PEQ-MS (2.2 ± 0.9 and 2.8 ± 0.8, respectively, P < .001), and Patient-Specific Functional Scale (3.2 ± 2.0 and 5.9 ± 2.3, respectively, P < .001). Performance-based (TUG) and self-report (PEQ-MS) changes in functional mobility from initial exam to discharge had low or no correlations with rehabilitation dose measures. The number of clinic visits was 12.7 ± 13.1 and rehabilitation duration was 13.7 ± 16.8 weeks. CONCLUSIONS: Significant improvements in performance-based and self-report measures of physical function occurred during the prosthetic training phase of physical rehabilitation after dysvascular major LEA. Despite improvements in function, gait speed, and TUG outcomes remained below clinically important thresholds, indicating patients were limited in community ambulation and at risk for falls. Lack of moderate or greater correlation between rehabilitation dose and outcome measures may indicate the need for more specific rehabilitation dose measures.

DNA polymerase III of Enterococcus faecalis: expression and characterization of recombinant enzymes encoded by the polC and dnaE genes.

Enterococcus faecalis (Ef) dnaE and polC, the respective genes encoding the DNA replication-specific DNA polymerase III E and DNA polymerase III C, were cloned and engineered for expression in Escherichia coli as hexahistidine (his6)-tagged recombinant proteins. Each gene expressed a catalytically active DNA polymerase of the expected molecular weight. The recombinant polymerases were purified and each was characterized with respect to catalytic properties, inhibitor sensitivity, and recognition by specific antibody raised against the corresponding DNA polymerase III of the model Gram-positive (Gr(+)) organism, Bacillus subtilis (Bs). In conclusion, the properties of each Enterococcus polymerase enzymes were similar to those of the respective B. subtilis enzymes.

Low frequencies of resistance among Staphylococcus and Enterococcus species to the bactericidal DNA polymerase inhibitor N(3)-hydroxybutyl 6-(3'-ethyl-4'-methylanilino) uracil.

The 6-anilinouracils (AUs) constitute a new class of bactericidal antibiotics selective against gram-positive (Gr(+)) organisms. The AU family of compounds specifically inhibits a novel target, replicative DNA polymerase Pol IIIC. Like other antibiotics, AUs can be expected to engender the development of resistant bacteria. We have used a representative AU and clinically relevant strains of Staphylococcus aureus and Enterococcus to determine the frequency and mechanism(s) of resistance development. The frequency of resistance was determined by using N(3)-hydroxybutyl 6-(3'-ethyl-4'-methylanilino) uracil (HBEMAU) and commercially available antibiotics at eight times the MICs. For all five Gr(+) organisms tested, the frequency of resistance to HBEMAU ranged from 1 x 10(-8) to 3 x 10(-10). The frequencies of resistance to the antibiotics tested, including rifampin, gentamicin, and ciprofloxacin, were either greater than or equal to those for HBEMAU. In order to understand the mechanism of resistance, HBEMAU-resistant organisms were isolated. MIC assays showed that the organisms had increased resistance to AU inhibitors but not to other families of antibiotics. Inhibition studies with DNA polymerases from HBEMAU-sensitive and -resistant strains demonstrated that the resistance was associated with Pol IIIC. DNA sequence analysis of the entire polC genes from both wild-type and resistant organisms revealed that the resistant organisms had a sequence change that mapped to a single amino acid codon in all strains examined.