Bacterial and Chemical Evidence of Coastal Water Pollution from the Tijuana River in Sea Spray Aerosol.

Roughly half of the human population lives near the coast, and coastal water pollution (CWP) is widespread. Coastal waters along Tijuana, Mexico, and Imperial Beach (IB), USA, are frequently polluted by millions of gallons of untreated sewage and stormwater runoff. Entering coastal waters causes over 100 million global annual illnesses, but CWP has the potential to reach many more people on land via transfer in sea spray aerosol (SSA). Using 16S rRNA gene amplicon sequencing, we found sewage-associated bacteria in the polluted Tijuana River flowing into coastal waters and returning to land in marine aerosol. Tentative chemical identification from non-targeted tandem mass spectrometry identified anthropogenic compounds as chemical indicators of aerosolized CWP, but they were ubiquitous and present at highest concentrations in continental aerosol. Bacteria were better tracers of airborne CWP, and 40 tracer bacteria comprised up to 76% of the bacteria community in IB air. These findings confirm that CWP transfers in SSA and exposes many people along the coast. Climate change may exacerbate CWP with more extreme storms, and our findings call for minimizing CWP and investigating the health effects of airborne exposure.

Long-Term Outcomes in Female Patients With Carpometacarpal Arthroplasty and Metacarpophalangeal Fusion Compared With the Unoperated Side or Carpometacarpal Arthroplasty.

PURPOSE: Patients with carpometacarpal (CMC) osteoarthritis (OA) often present with metacarpophalangeal (MP) hyperextension and/or thenar atrophy. This study hypothesizes that MP fusion (MPF) performed at the time of CMC arthroplasty (CMCA) for patients who have moderate-to-severe thenar atrophy, MP hyperextension >30°, or MP arthritis will have greater long-term pinch strength and improvements in the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score from preoperative values when compared with the unoperated side or those who had CMCA only. METHODS: This study involved a retrospective review of long-term results from patients who underwent either CMCA or CMCA/MPF. The QuickDASH score, the pain visual analog scale (VAS), and an average of three pinch readings from each thumb were measured on the Baseline pinch gauge and recorded with a correction for hand dominance in right-handed patients. RESULTS: Fifty-three female patients with 70 operated thumbs were included in the study. The mean age was 67.2 years. There were 29 CMCAs and 41CMCA/MPFs. The mean follow-up was 6.3 years (range 2-16.9 years). At the latest follow-up, the mean CMCA/MPF pinch strength (11.3 lbs) was significantly stronger than that of CMCA (8.0 lbs) and carpometacarpal osteoarthritis thumbs (8.9 lbs). There was no significant difference in pinch strength between patients who underwent a CMCA and CMCOA thumbs (8.0 lbs vs 8.9 lbs, respectively). Preoperative QuickDASH demonstrated worse function in the CMCA/MPF group (55.8 vs 36.5). At the latest follow-up, QuickDASH and VAS revealed similar values in both the CMCA/MPF (10.5 and 0.66) and CMCA (18.5 and 0.52) groups. CONCLUSION: Long-term results demonstrate stronger pinch and greater improvement in QuickDASH scores in patients who underwent CMCA/MPF compared with those who underwent a CMCA or untreated carpometacarpal osteoarthritis thumbs. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Isotopic Insights into Organic Composition Differences between Supermicron and Submicron Sea Spray Aerosol.

To elucidate the seawater biological and physicochemical factors driving differences in organic composition between supermicron and submicron sea spray aerosol (SSAsuper and SSAsub), carbon isotopic composition (δ13C) measurements were performed on size-segregated, nascent SSA collected during a phytoplankton bloom mesocosm experiment. The δ13C measurements indicate that SSAsuper contains a mixture of particulate and dissolved organic material in the bulk seawater. After phytoplankton growth, a greater amount of freshly produced carbon was observed in SSAsuper with the proportional contribution being modulated by bacterial activity, emphasizing the importance of the microbial loop in controlling the organic composition of SSAsuper. Conversely, SSAsub exhibited no apparent relationship with biological activity but tracked closely with surface tension measurements probing the topmost ∼0.2-1.5 µm of the sea surface microlayer. This probing depth is similar to a bubble's film thickness at the ocean surface, suggesting that SSAsub organic composition may be influenced by the presence of surfactants at the air-sea interface that are transferred into SSAsub by bubble bursting. Our findings illustrate the substantial impact of seawater dynamics on the pronounced organic compositional differences between SSAsuper and SSAsub and demonstrate that these two SSA populations should be considered separately when assessing their contribution to marine aerosols and climate.

Biceps Tenodesis Combined With Arthroscopic Posterior Labral Repair for Type VIII SLAP Lesions in Active-Duty Military Patients Yields Excellent Return to Military Duty.

PURPOSE: To report short-term outcomes following biceps tenodesis combined with arthroscopic posterior labral repair of type VIII SLAP lesions in active-duty military patients. METHODS: All consecutive patients from January 2012 through December 2018 who underwent biceps tenodesis combined with arthroscopic posterior labral repair of type VIII SLAP tears performed by the senior surgeon with complete outcome scores and minimum 2.5 years follow-up were identified. Exclusion criteria included concomitant glenoid microfracture, rotator cuff repair, or other capsulolabral repair. Outcome measures were completed by patients within 7 days before surgery and at latest follow-up. Biceps tenodesis performed was a mini-open, through a subpectoral approach, using a double-loaded 2.9mm suture-anchor. RESULTS: Thirty-two patients met the inclusion criteria for the study. All patients were active-duty military at time of surgery. Average follow-up was 73.53 ± 22.37 months. Thirty-one patients achieved the minimal clinically important difference, 30 of 32 reached the substantial clinical benefit, and 31 of 32 met the patient acceptable symptomatic state, as defined for the American Shoulder and Elbow Surgeons Shoulder Score. Similarly, 30 of 32 patients reached the minimal clinically important difference, 29 of 32 achieved the substantial clinical benefit, and 32 of 32 met the patient acceptable symptomatic state for the Single Assessment Numeric Evaluation. There were no significant changes in forward flexion, external rotation, or internal rotation between pre- and postoperative measurements. Three patients reported postoperative complications and 1 patient progressed to further surgery. Thirty (93.75%) patients remained on active-duty military service and were able to return to preinjury levels of activity. CONCLUSIONS: Active-duty military patients with type VIII SLAP tears had statistically and clinically significant increases in outcome scores, marked improvement in pain, and high rates of return to unrestricted active-duty following mini-open subpectoral biceps tenodesis combined with posterior labral repair. LEVEL OF EVIDENCE: IV, retrospective case series.

The Association of H-index and Academic Rank Among Full-time Academic Foot and Ankle Surgeons Affiliated with Fellowship Programs.

The purpose of this study is to investigate the association between Hirsch index (h-index) and academic rank among foot and ankle surgeons affiliated with American Orthopaedic Foot and Ankle Society (AOFAS) fellowship programs. The total number of publications, academic rank, years in practice, fellowship training pedigree, and h-indices of 176 foot and ankle surgeons from 48 AOFAS fellowship programs were recorded, and statistical analysis was performed. We found a strong association between total number of publications and h-index. Number of publications, h-index and training program affiliation were associated with higher academic rank, except at the chair/director position. Overall, h-index is a stronger predictor of academic rank than number of publications. The results of this study suggest that h-index and total number of publications are associated with a higher academic rank for full-time foot and ankle fellowship affiliated surgeons. (Journal of Surgical Orthopaedic Advances 31(4):263-267, 2022).

A review of clinical trials of advance care planning interventions adapted for limited health literacy.

OBJECTIVES: Advance care planning is vital for ensuring individuals receive end-of-life care that is consistent with their care preferences and improves patient quality of life and satisfaction with care; however, only 11% of Americans have discussed advance care planning with a healthcare provider. Individuals with limited health literacy are even less likely to participate in advance care planning due to difficulty comprehending complex health information. The purpose of this review was to identify randomized controlled trials designed to address the effects of limited health literacy on advance care planning, evaluate the quality of these studies, and summarize evaluation data to inform future studies. METHODS: This systematic review examined randomized controlled trials published from January 1997 to July 2020 using the PubMed, CINAHL, PsycINFO, and Scopus databases. Data were extracted and two reviewers independently evaluated the quality of studies using the Joanna Briggs Institute Critical Appraisal Tool. RESULTS: The database search yielded 253 studies and five studies were included in the final review. Studies were conducted in mostly White patients in outpatient clinics in the United States. Researchers wrote text at lower reading levels, added images to materials, and created videos to enhance communication. Health literacy interventions increased participant knowledge, preference for comfort care, engagement, and care documentation; however, several methodological issues were identified, including baseline differences in treatment and control groups, issues with blinding, lack of valid and reliable outcome measures, and inappropriate statistical analyses. SIGNIFICANCE OF RESULTS: More high-quality intervention studies that address the effects of limited health literacy on advance care planning in diverse populations and settings are needed. Future intervention studies should use reliable and valid instruments to measure advance care planning outcomes. Clinicians should use materials appropriate for their patients' health literacy levels to address their advance care planning needs.

Applying ASTM Standards to Tensile Tests of Musculoskeletal Soft Tissue: Methods to Reduce Grip Failures and Promote Reproducibility.

Tensile testing is an essential experiment to assess the mechanical integrity of musculoskeletal soft tissues, yet standard test methods have not been developed to ensure the quality and reproducibility of these experiments. The ASTM International standards organization has created tensile test standards for common industry materials that specify geometric dimensions of test specimens (coupons) that promote valid failures within the gage section (midsubstance), away from the grips. This study examined whether ASTM test standards for plastics, elastomers, and fiber-reinforced composites are suitable for tensile testing of bovine meniscus along the circumferential fiber direction. We found that dumbbell (DB) shaped coupons based on ASTM standards for elastomers and plastics had an 80% and 60% rate of midsubstance failures, respectively. The rate of midsubstance failures dropped to 20% when using straight (ST) coupons based on ASTM standards for fiber-reinforced composites. The mechanical properties of dumbbell shaped coupons were also significantly greater than straight coupons. Finite element models of the test coupons revealed stress distributions that supported our experimental findings. In addition, we found that a commercial deli-slicer was able to slice meniscus to uniform layer thicknesses that were within ASTM dimensional tolerances. This study provides methods, recommendations, and insights that can advance the standardization of tensile testing in meniscus and other soft fibrous tissues.

Cardiovascular Risk Screening and Pregnancy Complications: A Comparison of Two Canadian Maternal Health Clinic Populations.

OBJECTIVE: This study compared pregnancy-related cardiovascular disease risk indicators between women who attended 2 different postpartum screening and education clinics: 1 at an urban tertiary care centre and 1 at a northern, rural community hospital. Risk differences associated with ethnicity were also examined. METHODS: We conducted a retrospective record review that compared data from an urban clinic in Kingston, Ontario (n = 675) with those from a rural clinic in Prince Rupert, British Columbia (n = 65). Patients who had a hypertensive disorder of pregnancy, gestational diabetes, intrauterine growth restriction, idiopathic preterm birth, or placental abruption attended the clinics at 6 months postpartum. Demographic information, personal and family history, physical examination findings, and laboratory results were collected and used to generate cardiovascular risk estimates using validated scoring systems. These estimates were compared between clinic populations and between ethnic subsets. RESULTS: Fifty-five percent of the Prince Rupert cohort were Indigenous, while 87% of the Kingston cohort were White (P < 0.001). A greater proportion of the Kingston cohort had experienced hypertensive disorders of pregnancy (P = 0.002), while a greater proportion of the Prince Rupert cohort had developed gestational diabetes (P=0.010). The Prince Rupert population had higher lifetime and 30-year cardiovascular disease risk scores (P = 0.008 and P = 0.005, respectively). Indigenous patients had more major cardiovascular risk factors as well as higher lifetime and 30-year cardiovascular risk scores (P = 0.001 and P = 0.008, respectively) than White and Asian patients. CONCLUSION: The increased cardiovascular disease risk in both rural and Indigenous women supports the need for better postpartum care, long-term follow-up, and early promotion of cardiovascular health in these populations.

Variation in state and federal reimbursement in the United States in the treatment of upper extremity fractures.

BACKGROUND: Medicare and Medicaid are 2 of the largest government-run health care programs in the United States. Although Medicare reimbursement is determined at the federal level by the Centers for Medicare & Medicaid Services, Medicaid reimbursement rates are set by each individual state. The purpose of this study is to compare Medicaid reimbursement rates with regional Medicare reimbursement rates for 12 orthopedic procedures performed to treat common fractures of the upper extremity. METHODS: Twelve orthopedic procedures were selected and their Medicare reimbursement rates were collected from the 2020 Medicare Physician Fee Schedule. Medicaid reimbursement rates were obtained from each state's physician fee schedule. Reimbursement rates were then compared by assessing the ratio of Medicaid to Medicare, the dollar difference in Medicaid to Medicare reimbursement, and the difference per relative value unit. The range of variation in Medicaid reimbursement and Medicare wage index-adjusted Medicaid reimbursement was calculated. Comparisons in reimbursement were calculated using coefficient of variation and Student t tests to evaluate the differences between the mean Medicaid and Medicare reimbursements. Two-sample coefficient of variation testing was used to determine whether dispersion in Medicare and Medicaid reimbursement rates differed significantly. RESULTS: There was significant difference in reimbursement rates between Medicare and Medicaid for all 12 procedures, with Medicare reimbursing on average 46.5% more than Medicaid. In 40 states, Medicaid reimbursed less than Medicare for all 12 procedures. Regarding the dollar difference per relative value unit, Medicaid reimbursed on average $18.03 less per relative value unit than Medicare. The coefficient of variation for Medicaid reimbursement rates ranged from 0.26-0.33. This is in stark contrast with the significantly lower variability observed in Medicare reimbursement, which ranged from 0.06-0.07. CONCLUSION: Our findings highlight the variation in reimbursement that exists among state Medicaid programs for 12 orthopedic procedures commonly used to treat fractures of the upper extremity. Furthermore, average Medicaid reimbursement rates were significantly lower than Medicare rates for all 12 procedures. Such discrepancies in reimbursement may act as a barrier, impeding many Medicaid patients from accessing timely orthopedic care.

Fluorescence-Detected Conformational Changes in Duplex DNA in Open Complex Formation by Escherichia coli RNA Polymerase: Upstream Wrapping and Downstream Bending Precede Clamp Opening and Insertion of the Downstream Duplex.

FRET (fluorescence resonance energy transfer) between far-upstream (-100) and downstream (+14) cyanine dyes (Cy3, Cy5) showed extensive bending and wrapping of λPR promoter DNA on Escherichia coli RNA polymerase (RNAP) in closed and open complexes (CC and OC, respectively). Here we determine the kinetics and mechanism of DNA bending and wrapping by FRET and of formation of RNAP contacts with -100 and +14 DNA by single-dye protein-induced fluorescence enhancement (PIFE). FRET and PIFE kinetics exhibit two phases: rapidly reversible steps forming a CC ensemble ({CC}) of four intermediates [initial (RPC), early (I1E), mid (I1M), and late (I1L)], followed by conversion of {CC} to OC via I1L. FRET and PIFE are first observed for I1E, not RPc. FRET and PIFE together reveal large-scale bending and wrapping of upstream and downstream DNA as RPC advances to I1E, decreasing the Cy3-Cy5 distance to ∼75 Å and making RNAP-DNA contacts at -100 and +14. We propose that far-upstream DNA wraps on the upper ß'-clamp while downstream DNA contacts the top of the ß-pincer in I1E. Converting I1E to I1M (∼1 s time scale) reduces FRET efficiency with little change in -100 or +14 PIFE, interpreted as clamp opening that moves far-upstream DNA (on ß') away from downstream DNA (on ß) to increase the Cy3-Cy5 distance by ∼14 Å. FRET increases greatly in converting I1M to I1L, indicating bending of downstream duplex DNA into the clamp and clamp closing to reduce the Cy3-Cy5 distance by ∼21 Å. In the subsequent rate-determining DNA-opening step, in which the clamp may also open, I1L is converted to the initial unstable OC (I2). Implications for facilitation of CC-to-OC isomerization by upstream DNA and upstream binding, DNA-bending transcription activators are discussed.

Emerging Gene-Editing Modalities for Osteoarthritis.

Osteoarthritis (OA) is a pathological degenerative condition of the joints that is widely prevalent worldwide, resulting in significant pain, disability, and impaired quality of life. The diverse etiology and pathogenesis of OA can explain the paucity of viable preventive and disease-modifying strategies to counter it. Advances in genome-editing techniques may improve disease-modifying solutions by addressing inherited predisposing risk factors and the activity of inflammatory modulators. Recent progress on technologies such as CRISPR/Cas9 and cell-based genome-editing therapies targeting the genetic and epigenetic alternations in OA offer promising avenues for early diagnosis and the development of personalized therapies. The purpose of this literature review was to concisely summarize the genome-editing options against chronic degenerative joint conditions such as OA with a focus on the more recently emerging modalities, especially CRISPR/Cas9. Future advancements in novel genome-editing therapies may improve the efficacy of such targeted treatments.

Center of Biomedical Research Excellence in Matrix Biology: Building Research Infrastructure, Supporting Young Researchers, and Fostering Collaboration.

The Center of Biomedical Research Excellence in Matrix Biology strives to improve our understanding of extracellular matrix at molecular, cellular, tissue, and organismal levels to generate new knowledge about pathophysiology, normal development, and regenerative medicine. The primary goals of the Center are to i) support junior investigators, ii) enhance the productivity of established scientists, iii) facilitate collaboration between both junior and established researchers, and iv) build biomedical research infrastructure that will support research relevant to cell-matrix interactions in disease progression, tissue repair and regeneration, and v) provide access to instrumentation and technical support. A Pilot Project program provides funding to investigators who propose applying their expertise to matrix biology questions. Support from the National Institute of General Medical Sciences at the National Institutes of Health that established the Center of Biomedical Research Excellence in Matrix Biology has significantly enhanced the infrastructure and the capabilities of researchers at Boise State University, leading to new approaches that address disease diagnosis, prevention, and treatment. New multidisciplinary collaborations have been formed with investigators who may not have previously considered how their biomedical research programs addressed fundamental and applied questions involving the extracellular matrix. Collaborations with the broader matrix biology community are encouraged.

Inhibition of motor neuron death in vitro and in vivo by a p75 neurotrophin receptor intracellular domain fragment.

The p75 neurotrophin receptor (p75(NTR); also known as NGFR) can mediate neuronal apoptosis in disease or following trauma, and facilitate survival through interactions with Trk receptors. Here we tested the ability of a p75(NTR)-derived trophic cell-permeable peptide, c29, to inhibit p75(NTR)-mediated motor neuron death. Acute c29 application to axotomized motor neuron axons decreased cell death, and systemic c29 treatment of SOD1(G93A) mice, a common model of amyotrophic lateral sclerosis, resulted in increased spinal motor neuron survival mid-disease as well as delayed disease onset. Coincident with this, c29 treatment of these mice reduced the production of p75(NTR) cleavage products. Although c29 treatment inhibited mature- and pro-nerve-growth-factor-induced death of cultured motor neurons, and these ligands induced the cleavage of p75(NTR) in motor-neuron-like NSC-34 cells, there was no direct effect of c29 on p75(NTR) cleavage. Rather, c29 promoted motor neuron survival in vitro by enhancing the activation of TrkB-dependent signaling pathways, provided that low levels of brain-derived neurotrophic factor (BDNF) were present, an effect that was replicated in vivo in SOD1(G93A) mice. We conclude that the c29 peptide facilitates BDNF-dependent survival of motor neurons in vitro and in vivo.

Clinical Outcomes of Metformin Use in Populations With Chronic Kidney Disease, Congestive Heart Failure, or Chronic Liver Disease: A Systematic Review.

BACKGROUND: Recent changes to the U.S. Food and Drug Administration boxed warning for metformin will increase its use in persons with historical contraindications or precautions. Prescribers must understand the clinical outcomes of metformin use in these populations. PURPOSE: To synthesize data addressing outcomes of metformin use in populations with type 2 diabetes and moderate to severe chronic kidney disease (CKD), congestive heart failure (CHF), or chronic liver disease (CLD) with hepatic impairment. DATA SOURCES: MEDLINE (via PubMed) from January 1994 to September 2016, and Cochrane Library, EMBASE, and International Pharmaceutical Abstracts from January 1994 to November 2015. STUDY SELECTION: English-language studies that: 1) examined adults with type 2 diabetes and CKD (with estimated glomerular filtration rate less than 60 mL/min/1.73 m2), CHF, or CLD with hepatic impairment; 2) compared diabetes regimens that included metformin with those that did not; and 3) reported all-cause mortality, major adverse cardiovascular events, and other outcomes of interest. DATA EXTRACTION: 2 reviewers abstracted data and independently rated study quality and strength of evidence. DATA SYNTHESIS: On the basis of quantitative and qualitative syntheses involving 17 observational studies, metformin use is associated with reduced all-cause mortality in patients with CKD, CHF, or CLD with hepatic impairment, and with fewer heart failure readmissions in patients with CKD or CHF. LIMITATIONS: Strength of evidence was low, and data on multiple outcomes of interest were sparse. Available studies were observational and varied in follow-up duration. CONCLUSION: Metformin use in patients with moderate CKD, CHF, or CLD with hepatic impairment is associated with improvements in key clinical outcomes. Our findings support the recent changes in metformin labeling. PRIMARY FUNDING SOURCE: U.S. Department of Veterans Affairs. (PROSPERO: CRD42016027708).

A Combined Experimental and Computational Approach to Subject-Specific Analysis of Knee Joint Laxity.

Modeling complex knee biomechanics is a continual challenge, which has resulted in many models of varying levels of quality, complexity, and validation. Beyond modeling healthy knees, accurately mimicking pathologic knee mechanics, such as after cruciate rupture or meniscectomy, is difficult. Experimental tests of knee laxity can provide important information about ligament engagement and overall contributions to knee stability for development of subject-specific models to accurately simulate knee motion and loading. Our objective was to provide combined experimental tests and finite-element (FE) models of natural knee laxity that are subject-specific, have one-to-one experiment to model calibration, simulate ligament engagement in agreement with literature, and are adaptable for a variety of biomechanical investigations (e.g., cartilage contact, ligament strain, in vivo kinematics). Calibration involved perturbing ligament stiffness, initial ligament strain, and attachment location until model-predicted kinematics and ligament engagement matched experimental reports. Errors between model-predicted and experimental kinematics averaged <2 deg during varus-valgus (VV) rotations, <6 deg during internal-external (IE) rotations, and <3 mm of translation during anterior-posterior (AP) displacements. Engagement of the individual ligaments agreed with literature descriptions. These results demonstrate the ability of our constraint models to be customized for multiple individuals and simultaneously call attention to the need to verify that ligament engagement is in good general agreement with literature. To facilitate further investigations of subject-specific or population based knee joint biomechanics, data collected during the experimental and modeling phases of this study are available for download by the research community.

Computational Lower Limb Simulator Boundary Conditions to Reproduce Measured TKA Loading in a Cohort of Telemetric Implant Patients.

Recent advancements in computational modeling offer opportunities to refine total knee arthroplasty (TKA) design and treatment strategies. This study developed patient-specific simulator external boundary conditions (EBCs) using a PID-controlled lower limb finite element (FE) model. Calibration of the external actuation required to achieve measured patient-specific joint loading and motion was completed for nine patients with telemetric implants during gait, stair descent, and deep knee bend. The study also compared two EBC scenarios: activity-specific hip AP motion and pelvic rotation (that was averaged across all patients for an activity) and patient-specific hip AP motion and pelvic rotation. Including patient-specific data significantly improved reproduction of joint-level loading, reducing root mean squared error between the target and achieved loading by 28.7% and highlighting the importance of detailed patient data in replicating joint kinematics and kinetics. The principal component analysis (PCA) of the EBCs for the patient dataset showed that one component represented 77.8% of the overall variation, while the first three components represented 97.8%. Given the significant loading variability within the patient cohort, this group of patient-specific models can be run individually to provide insight into expected TKA mechanics variability, and the PCA can be utilized to further create reasonable EBCs that expand the variability evaluated.

Bacterial metallothionein, PmtA, a novel stress protein found on the bacterial surface of Pseudomonas aeruginosa and involved in management of oxidative stress and phagocytosis.

Metallothioneins (MTs) are small cysteine-rich proteins that play important roles in homeostasis and protection against heavy metal toxicity and oxidative stress. The opportunistic pathogen, Pseudomonas aeruginosa, expresses a bacterial MT known as PmtA. Utilizing genetically modified P. aeruginosa PAO1 strains (a human clinical wound isolate), we show that inducing pmtA increases levels of pyocyanin and biofilm compared to other PAO1 isogenic strains, supporting previous results that pmtA is important for pyocyanin and biofilm production. We also show that overexpression of pmtA in vitro provides protection for cells exposed to oxidants, which is a characteristic of inflammation, indicating a role for PmtA as an antioxidant in inflammation. We found that a pmtA clean deletion mutant is phagocytized faster than other PAO1 isogenic strains in THP-1 human macrophage cells, indicating that PmtA provides protection from the phagocytic attack. Interestingly, we observed that monoclonal anti-PmtA antibody binds to PmtA, which is accessible on the surface of PAO1 strains using both flow cytometry and enzyme-linked immunosorbent assay techniques. Finally, we investigated intracellular persistence of these PAO1 strains within THP-1 macrophages cells and found that the phagocytic endurance of PAO1 strains is affected by pmtA expression. These data show for the first time that a bacterial MT (pmtA) can play a role in the phagocytic process and can be found on the outer surface of PAO1. Our results suggest that PmtA plays a role both in protection from oxidative stress and in the resistance to the host's innate immune response, identifying PmtA as a potential therapeutic target in P. aeruginosa infection. IMPORTANCE: The pathogen Pseudomonas aeruginosa is a highly problematic multidrug-resistant (MDR) pathogen with complex virulence networks. MDR P. aeruginosa infections have been associated with increased clinical visits, very poor healthcare outcomes, and these infections are ranked as critical on priority lists of both the Centers for Disease Control and Prevention and the World Health Organization. Known P. aeruginosa virulence factors have been extensively studied and are implicated in counteracting host defenses, causing direct damage to the host tissues, and increased microbial competitiveness. Targeting virulence factors has emerged as a new line of defense in the battle against MDR P. aeruginosa strains. Bacterial metallothionein is a newly recognized virulence factor that enables evasion of the host immune response. The studies described here identify mechanisms in which bacterial metallothionein (PmtA) plays a part in P. aeruginosa pathogenicity and identifies PmtA as a potential therapeutic target.

Subacromial Balloon Placement Demonstrates No Advantage Over Debridement in the Treatment of Massive Irreparable Rotator Cuff Tears: A Dual-Armed Systematic Review and Meta-analysis of Over 1000 Patients.

BACKGROUND: In recent years, the placement of a subacromial balloon (SAB) spacer has emerged as a treatment option for massive irreparable rotator cuff tears (MIRCTs); however, there is significant controversy regarding its utility in comparison with other surgical interventions. PURPOSE: To compare outcomes after SAB spacer placement versus arthroscopic debridement for MIRCTs. STUDY DESIGN: Dual-armed systematic review and meta-analysis (level IV evidence). METHODS: A literature search of PubMed (MEDLINE), Scopus, and CINAHL Complete databases for articles published before May 7, 2022, was conducted to identify patients with MIRCTs undergoing the 2 procedures. For the SAB arm, 14 of 449 studies were considered eligible for inclusion, while 14 of 272 studies were considered eligible for inclusion in the debridement arm. RESULTS: In total, 528 patients were eligible for inclusion in the SAB arm and 479 patients in the debridement arm, and 69.9% of patients undergoing SAB placement also underwent concomitant debridement. Decreases in the visual analog scale (VAS) pain score and increases in the Constant score were found to be significantly larger after debridement (-0.7 points [P < .001] and +5.5 points [P < .001], respectively), although the Patient Acceptable Symptom State for the VAS was not achieved after either procedure. Both SAB placement and debridement significantly improved range of motion in forward flexion/forward elevation, internal and external rotation, and abduction (P < .001). Rates of general complication were higher after debridement versus SAB placement (5.2% ± 5.6% vs 3.5% ± 6.3%, respectively; P < .001); however, there were no significant differences between SAB placement and debridement in rates of persistent symptoms requiring a reintervention (3.3% ± 6.2% vs 3.8% ± 7.3%, respectively; P = .252) or reoperation rates (5.1% ± 7.6% vs 4.8% ± 8.4%, respectively; P = .552). The mean time to conversion to reverse total shoulder arthroplasty was 11.0 versus 25.4 months, respectively, for the SAB versus debridement arm. CONCLUSION: While SAB placement was associated with acceptable postoperative outcomes in the treatment of MIRCTs, there was no clear benefit over debridement alone. Shorter operative times coupled with better postoperative outcomes and longer times to conversion to reverse total shoulder arthroplasty rendered debridement a more attractive option. While there may be a role for SAB placement in poor surgical candidates, there is burgeoning evidence to support debridement alone without SAB placement for the treatment of MIRCTs.

Effect of age on ankle biomechanics and tibial compression during stair descent.

BACKGROUND: Stress fracture is a concern among older adults, as age-related decrements in ankle neuromuscular function may impair their ability to attenuate tibial compressive forces experienced during daily locomotor tasks, such as stair descent. Yet, it is unknown if older adults exhibit greater tibial compression than their younger counterparts when descending stairs. RESEARCH QUESTION: Do older adults exhibit differences in ankle biomechanics that alter their tibial compression during stair descent compared to young adults, and is there a relation between tibial compression and specific changes in ankle biomechanics? METHODS: Thirteen young (18-25 years) and 13 older (> 65 years) adults had ankle joint biomechanics and tibial compression quantified during a stair descent. Discrete ankle biomechanics (peak joint angle and moment, and joint stiffness) and tibial compression (maximum and impulse) measures were submitted to an independent t-test, while ankle joint angle and moment, and tibial compression waveforms were submitted to an independent statistical parametric mapping t-test to determine group differences. Pearson correlation coefficients (r) determined the relation between discrete ankle biomechanics and tibial compression measures for all participants, and each group. RESULTS: Older adults exhibited smaller maximum tibial compression (p = 0.004) from decreases in peak ankle joint angle and moment between 17 % and 34 % (p = 0.035), and 20-31 % of stance (p < 0.001) than young adults. Ankle biomechanics exhibited a negligible to weak correlation with tibial compression for all participants, with peak ankle joint moment and maximum tibial compression (r = -0.48 ±â€¯0.32) relation the strongest. Older adults typically exhibited a stronger relation between ankle biomechanics and tibial compression (e.g., r = -0.48 ±â€¯0.47 vs r = -0.27 ±â€¯0.52 between peak ankle joint moment and maximum tibial compression). SIGNIFICANCE: Older adults altered ankle biomechanics and decreased maximum tibial compression to safely execute the stair descent. Yet, specific alterations in ankle biomechanics could not be identified as a predictor of changes in tibial compression.

Outcomes of Concomitant Glenohumeral Stabilization After Arthroscopic Rotator Cuff Repair in Military Patients Younger Than 40 Years.

Background: While concomitant rotator cuff and inferior labral tears are relatively uncommon in young civilians, military populations represent a unique opportunity to study this injury pattern. Purpose: To (1) evaluate the long-term outcomes after combined arthroscopic rotator cuff and inferior labral repair in military patients <40 years and (2) compare functional outcomes with those after isolated arthroscopic rotator cuff repair. Study Design: Cohort study; Level of evidence, 3. Methods: Military patients who underwent arthroscopic rotator cuff repair between January 2011 and December 2016 and had a minimum of 5-year follow-up data were included in this study. The patients were categorized into those who had undergone combined arthroscopic rotator cuff and inferior labral repair (RCIL cohort) and those who had isolated arthroscopic rotator cuff repair (ARCR cohort). Pre- and postoperative outcome measures-visual analog scale for pain, Single Assessment Numeric Evaluation, American Shoulder and Elbow Surgeons shoulder score, Rowe Instability Score, and range of motion-were compared between the groups. Results: A total of 50 shoulders (27 in the RCIL cohort and 23 in the ARCR cohort) were assessed. The RCIL and ARCR groups were similar in terms of age (mean, 33.19 years [range, 21-39 years] vs 35.39 years [range, 26-39 years], respectively) and sex (% male, 88.46% vs 82.61%, respectively). All patients were active-duty military at the time of surgery. The mean final follow-up was at 106.93 ± 16.66 months for the RCIL group and 105.70 ± 7.52 months for the ARCR group (P = .75). There were no differences in preoperative outcome scores between groups. Postoperatively, both groups experienced statistically significant improvements in all outcome scores (P < .0001 for all), and there were no significant group differences in any final postoperative outcome measures. At the final follow-up, 26 (96.30%) patients in the RCIL cohort and 20 (86.96%) in the ARCR cohort had returned to unrestricted active-duty military service (P = .3223). Conclusion: The study findings indicate that concomitant glenohumeral stabilization does not prevent worse outcomes after arthroscopic rotator cuff repair in this military cohort. Combined repair produced statistically and clinically significant improvements in outcome scores at the long-term follow-up, indicating that simultaneous repair of combined lesions was an appropriate treatment option in this patient population.