Evaluation of strategies to narrow the product chain-length distribution of microbially synthesized free fatty acids.

The dominant strategy for tailoring the chain-length distribution of free fatty acids (FFA) synthesized by heterologous hosts is expression of a selective acyl-acyl carrier protein (ACP) thioesterase. However, few of these enzymes can generate a precise (greater than 90% of a desired chain-length) product distribution when expressed in a microbial or plant host. The presence of alternative chain-lengths can complicate purification in situations where blends of fatty acids are not desired. We report the assessment of several strategies for improving the dodecanoyl-ACP thioesterase from the California bay laurel to exhibit more selective production of medium-chain free fatty acids to near exclusivity. We demonstrated that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) was an effective library screening technique for identification of thioesterase variants with favorable shifts in chain-length specificity. This strategy proved to be a more effective screening technique than several rational approaches discussed herein. With this data, we isolated four thioesterase variants which exhibited a more selective FFA distribution over wildtype when expressed in the fatty acid accumulating E. coli strain, RL08. We then combined mutations from the MALDI isolates to generate BTE-MMD19, a thioesterase variant capable of producing free fatty acids consisting of 90% of C12 products. Of the four mutations which conferred a specificity shift, we noted that three affected the shape of the binding pocket, while one occurred on the positively charged acyl carrier protein landing pad. Finally, we fused the maltose binding protein (MBP) from E. coli to the N - terminus of BTE-MMD19 to improve enzyme solubility and achieve a titer of 1.9 g per L of twelve-carbon fatty acids in a shake flask.

National Trends of Pediatric Aspirated/Ingested Foreign Bodies.

Foreign body (FB) aspiration/ingestion in children represents a major cause of hospital admission and mortality. Evaluating risk factors and identifying trends in specific FB products could improve targeted health literacy and policy changes. A cross-sectional study querying emergency department patients less than 18 years old with a diagnosis of aspirated/ingested FB was conducted using the National Electronic Injury Surveillance System database between 2010 and 2020. Incidence rates per 100 000 people-year were calculated and multivariate analyses were performed to identify risk factors for hospital admission and mortality. There has been a significantly decreasing rate of aspirated (-23.6%; P = .013) but not ingested FB (-9.4%; P = .066) within the study period. Within pediatric aspirated FB, black compared with white patients had decreased odds of same hospital admission (odds ratio [OR]: 0.8), but increased odds of transfer admission (OR: 1.6) and mortality (OR: 9.2) (all, P < .001).

Impact of Obesity, Smoking, and Age on 30-Day Postoperative Outcomes of Patients Undergoing Arthroscopic Meniscus Surgery.

BACKGROUND: The purpose of this study was to evaluate the impact that obesity, smoking, and older age have on 30-day postoperative complications, reoperations, and readmissions of patients undergoing arthroscopic meniscectomy or meniscus repair. MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried to identify meniscus surgeries and operative outcomes between 2008 and 2016. Controlled regression analysis was then performed to evaluate for an association between obesity, age, and smoking and these outcomes. RESULTS: While obesity showed no influence on adverse postoperative complications or reoperations, class I obesity was associated with a lower rate of readmission. Older age, smoking, and comorbidity burden were significant predictors of postoperative complications, reoperations, and/or readmissions. Age 80 years or older was particularly predictive of 30-day complications (odds ratio, 3.5; P<.001) and readmissions (odds ratio, 2.5; P=.004). CONCLUSION: Obesity is not a major risk factor for complications when undergoing meniscus surgery, while age older than 70 years predicts negative short-term postoperative outcomes. [Orthopedics. 20XX;4X(X):XXX-XXX.].

Discovery and characterization of dietary antigens in oral tolerance.

Food antigens elicit immune tolerance through the action of regulatory T cells (Tregs) in the intestine. Although antigens that trigger common food allergies are known, the epitopes that mediate tolerance to most foods have not been described. Here, we identified murine T cell receptors specific for maize, wheat, and soy, and used expression cloning to de-orphan their cognate epitopes. All of the epitopes derive from seed storage proteins that are resistant to degradation and abundant in the edible portion of the plant. Multiple unrelated T cell clones were specific for an epitope at the C-terminus of 19 kDa alpha-zein, a protein from maize kernel. An MHC tetramer loaded with this antigen revealed that zein-specific T cells are predominantly Tregs localized to the intestine. These cells, which develop concurrently with weaning, constitute up to 2% of the peripheral Treg pool. Bulk and single-cell RNA sequencing revealed that these cells express higher levels of immunosuppressive markers and chemokines compared to other Tregs. These data suggest that immune tolerance to plant-derived foods is focused on a specific class of antigens with common features, and they reveal the functional properties of naturally occurring food-specific Tregs.

Evaluating the impact of multiple sclerosis on 2 year postoperative outcomes following long fusion for adult spinal deformity: a propensity score-matched analysis.

STUDY DESIGN: Retrospective cohort study. PURPOSE: The impact of neuromuscular disorders such as multiple sclerosis (MS) on outcomes following long segment fusion is underreported. This study evaluates the impact of MS on two-year (2Y) postoperative complications and revisions following ≥ 4-level fusion for adult spinal deformity (ASD). METHODS: Patients undergoing ≥ 4-level fusion for ASD were identified from a statewide database. Patients with a baseline diagnosis of MS were also identified. Patients with infectious/traumatic/neoplastic indications were excluded. Subjects were 1:1 propensity score-matched (MS to no-MS) based on age, sex and race and compared for rates of 2Y postoperative complications and reoperations. Logistic regression models were utilized to determine risk factors for adverse outcomes at 2Y. RESULTS: 86 patients were included overall (n = 43 per group). Age, sex, and race were comparable between groups (p > 0.05). MS patients incurred higher charges for their surgical visit ($125,906 vs. $84,006, p = 0.007) with similar LOS (8.1 vs. 5.3 days, p > 0.05). MS patients experienced comparable rates of overall medical complications (30.1% vs. 25.6%) and surgical complications (34.9% vs. 30.2%); p > 0.05. MS patients had similar rates of 2Y revisions (16.3% vs. 9.3%, p = 0.333). MS was not associated with medical, surgical, or overall complications or revisions at minimum 2Y follow-up. CONCLUSION: Patients with MS experienced similar postoperative course compared to those without MS following ≥ 4-level fusion for ASD. This data supports the findings of multiple previously published case series' that long segment fusions for ASD can be performed relatively safely in patients with MS.

E-scooter use continues to rev up fracture diagnoses and hospital admissions compared to other modes of transportation.

Introduction: The COVID-19 pandemic was associated with an increase in popularity of e-scooter usage and a rise in e-scooter related injuries. Recent studies have elucidated trends within e-scooter injuries but there are few epidemiological studies that evaluate injury rates amongst multiple modes of transportation. This study seeks to investigate trends of e-scooter orthopedic fracture injuries compared to other traditional methods of transportation using a national database. Methods: The National Electronic Injury Surveillance System (NEISS) database was queried between 2014 and 2020 for patients who were injured after usage of e-scooters, bicycles, or all-terrain vehicles. Primary analysis included patients with a diagnosis of fracture and utilized univariate/multivariate models to evaluate risk of hospital admission. Secondary analysis included all isolated patients to evaluate the odds of fracture development amongst modes of transportation. Results: A total of 70,719 patients with injuries associated with e-scooter, bicycle, or all-terrain vehicle use were isolated. 15997 (22.6%) of these patients had a fracture diagnosis. Both e-scooters and all-terrain vehicles reported increased odds of fracture-related injury and direct hospitalization when compared to bicycles. E-scooter users reported a greater odds of both associated fracture (OR 1.25; 95%CI 1.03-1.51; p = 0.024) and hospital admission (OR: 2.01; 95%CI: 1.26-3.21; p = 0.003) in 2020 compared to 2014-2015. Discussion: E-scooter related orthopedic injuries and hospital admissions had the largest incidence rate increase compared to bicycle and all-terrain vehicles between 2014 and 2020. E-scooter fractures were most commonly located in the lower leg in 2014-2017, the wrist in 2018-2019, and the upper trunk in 2020. In comparison, bicycle and all-terrain vehicle fractures was most commonly shoulder and upper trunk within the study period. Further research will help to promote further understanding of the e-scooter health care burden and in prevention of these injuries. Level of evidence: 3.

Leaving No Stone Unturned: Factors Associated With Overturning Insurance Claim Denials for Urological Conditions in New York State.

INTRODUCTION: Denied health claims in New York State may be appealed by external review. After appeal, the denial can either be upheld or overturned. Regardless, an appeal process results in delays in care and can negatively impact patient health and practice efficiency. This study aimed to describe the epidemiology of New York State urological external appeals and assess factors associated with successful appeals. METHODS: The New York State External Appeals database was queried for 2019-2021 urological cases (N=408). Patient age, gender, decision year, appeal reason, diagnosis, treatment, and reference to American Urological Association were extracted. Annual appeal volume was analyzed by linear regression. Relationships between appeal outcomes and characteristics were analyzed by χ2 tests. Multivariate logistic regression analysis was used to identify factors related to overturns. RESULTS: Overall, 39.5% of denials in this data set were overturned. Appeal volume increased annually, with overturned cases increasing 244% (mean 29.5, P = .068). Of reviewers, 15.6% referenced American Urological Association guidelines in their decision. Appeals mostly involved ages 40-59 years (32.4%), inpatient stays (63.5%), and infections (32.4%). Female sex, age 80+, diagnosis of incontinence/lower urinary tract symptoms, treatment with home health care, medications, or surgical services, and not referencing American Urological Association guidelines were significantly associated with successful appeal. Referencing American Urological Association guidelines had 70% decreased odds of overturning denials. CONCLUSIONS: Our findings suggest that upon appeal of denied claims, practices may have a high chance of overturning an initial denial and this trend is rising. These findings will help serve as a reference for future external appeals research and urology policy and advocacy groups.

Epidemiology of Fragility Pubic Ramus Fractures in the United States.

Introduction: Previous studies illustrate significant increases in pelvic fracture incidence; however, there is a paucity of information on the incidence of osteoporotic pelvic ring injuries based on large-scale examinations of geographically and ethnically diverse populations. This study addresses the epidemiology of osteoporotic pubic ramus fractures in the United States and details differences in incidence rates with respect to age, gender, and race. Materials and Methods: National Electronic Injury Surveillance System (NEISS) data between 2002 and 2019 was gathered for individuals aged 60 and above presenting to U.S. emergency departments with ramus fractures. Incidence rates for ramus injuries were calculated using adjusted U.S. Census Bureau estimates of population. Fracture incidences were calculated for age, gender, and race strata. Results: The overall incidence rate of pubic ramus fractures in the United States between 2002 and 2019 was 13.47 per 1,000,000 people 60 years and older (95% confidence limit: 9.92-17.01). The incidence of pubic ramus fractures for females in the US was 21.71 (16.08-27.34). Rates of ramus fracture increased overall (P < .001) and for both genders between the ages of 60 and 100, though the rate increase was significantly greater in females than in males (P < .001). In terms of race, incidence was highest Asian females and lowest in Native American and Pacific Islander men. Discussion/Conclusion: : As the first national study addressing the epidemiology of ramus injuries in the United States, this work reveals these injuries comprise a significant fracture risk in the elderly. In addition, it highlights gender and ethnic strata that are more susceptible to these injuries.

Crohn's disease in total knee arthroplasty patients correlates with increased rates of 90-day and overall postoperative complications and readmissions.

BACKGROUND: Joint involvement is a common extraintestinal manifestation of Crohn's Disease (CD) that may require total knee arthroplasty (TKA). There is a paucity of evidence regarding the relationship between CD and postoperative outcomes after TKA surgery. This study seeks to evaluate the impact of CD on 90-day and ≥2-year follow-up postoperative outcomes of TKA patients. METHODS: We retrospectively analyzed the Statewide Planning and Research Cooperative System database (2009-2013) and isolated ICD-9 codes for TKA patients (8154), while excluding those with any revision of knee replacements (0080-0084) and split into 2 groups with or without CD (5550-5559). Patient demographics and postoperative outcomes were compared. Logistic regression analyses with covariates (sex, race, Deyo score, age, and insurance) were utilized to evaluate the association of CD with 90-day and overall postoperative outcomes. RESULTS: A total of 89,134 TKA patients were identified, 244 of whom had CD. Significant differences in age, race distribution, insurance, and Deyo score (all, p < 0.05) were found. Multivariable analysis demonstrated CD was an independent risk factor for 90-day and overall medical complications, surgical complications, and readmission. Univariate and multivariable analyses report CD had significant increased rates and was a predictor, respectively, of overall blood transfusions (OR 1.5 [95% CI 1.1-2.0] p < 0.01), acute renal failure (OR 1.7 [95% CI 1.1-2.6] p = 0.03), and pulmonary embolism (OR 2.5 [95% CI 1.3-4.6] p = 0.01). CONCLUSION: Patients with CD undergoing TKA have increased risk both 90-day and overall surgical and medication complications, as well as readmissions compared to patients without CD.

Racial Differences in Orthopedic Trauma Surgery.

Racial discrepancies among patients in the United States undergoing orthopedic trauma surgery have not been investigated. Issues relating to socioeconomic status and access to care have played a role in the health outcomes of racial groups. In orthopedic surgery, recent joint arthroplasty literature has shown significant racial differences in the use of elective joint arthroplasty. Furthermore, studies also suggest increased rates of early complication in racial minority groups. In general, little information exists on the postoperative outcomes of racial minority groups in orthopedic surgery. We retrospectively queried the National Surgical Quality Improvement Program database to identify patients undergoing orthopedic trauma surgery between 2008 and 2016. Patients of all ages who underwent orthopedic trauma surgery were identified using Current Procedural Terminology codes. Patients classified as either Black or White were included in the study. Demographic data, comorbidities, and basic surgical data were compared between the groups. Adverse outcomes in the initial 30 days postoperative were also examined. Higher frequencies of deep wound infection (0.5% vs 0.3%, P=.002) were noted among Black patients, with decreased mortality (0.3% vs 0.6%, P=.004) and postoperative transfusion (2.7% vs 3.8%, P<.001) rates, compared with White patients. Clear differences exist in the demographic, surgical, and outcome data between Black and White patients undergoing orthopedic trauma surgery. More epidemiological studies are required to further investigate racial differences in orthopedic trauma surgery. [Orthopedics. 2022;45(2):71-76.].

Comparison of Risk Factors and Postoperative Outcomes in Syndesmosis Injuries with Various Ankle Fracture Types.

There is a lack of understanding of risk factors and postoperative outcomes of syndesmotic injuries with singular versus multipart fractures. A retrospective analysis was done between 2008 and 2016, utilizing the American College of Surgeons National Surgical Improvement Program database. Patients with open reduction and internal fixation of isolated lateral malleolus fractures, bimalleolar fractures, or trimalleolar fractures were identified. A total of 2045 patients underwent syndesmotic fixation. Subjects with bimalleolar or trimalleolar fractures were more likely than those with unimalleolar fractures to be Caucasian (odds ratio [OR] = 1.5 and 1.9), female (OR = 1.8 and 2.9), aged > 65 years (OR = 1.6 and 1.9), or have American Society of Anesthesiologists (ASA) classification III (OR =1.5 and 1.4) (all, P ≤ 0.028). Patients with a unimalleolar fracture were more likely than those with a bimalleolar or trimalleolar fracture to be male (OR = 1.8 and 2.9), African American (OR = 1.5 and 1.8), aged < 30 years (OR = 1.4 and 1.8), or present with an ASA I classification (OR = 1.6 and 2.0) (all, P ≤ 0.004). Subjects with bimalleolar or trimalleolar fractures were more likely than those with unimalleolar fractures to have lengthier hospital stays (OR = 1.8 and 2.1), while patients with trimalleolar fractures were more likely than those with unimalleolar fractures to have hypoalbuminemia (OR = 2.3), develop a complication (OR = 2.2) or an open wound (OR = 1.9), or to be readmitted (OR = 2.2) (all, P ≤ 0.036). In this study, comorbidity rates and adverse postoperative outcomes significantly increased as the number-part fractures increased in syndesmotic fixation patients. Risk factors also varied across fracture severity.

Mindfulness Awareness Is Associated With a Lower Risk of Anxiety and Depressive Symptoms in Older Adults With Neurocognitive Disorders.

Background: Apart from depressive disorders, there are great interests in adopting mindfulness based interventions (MBIs) for other mental health conditions. Depression and anxiety are common in people with neurocognitive disorders (NCD). The potential of MBIs as an adjuvant treatment in this cognitively at-risk group should be further explored. Objectives: The current study explored the association between depression and anxiety symptoms with dispositional mindfulness in older adults, and if same association stays in the context of cognitive impairment. Methods: The Hong Kong Mental Morbidity Survey for Older People (MMSOP) is an ongoing epidemiology study of the prevalence of neurocognitive and mental disorders in adults aged 60 years or over in Hong Kong. MMSOP evaluated cognitive function, psychiatric symptoms (Clinical Interview Schedule-revised, CIS-R), chronic physical disease burden, psychosocial support, and resilience factors, including dispositional mindfulness as measured by the Mindful Attention Awareness Scale (MAAS). We analyzed the impact of MAAS on CIS-R and potential moderation effects of mindfulness. Results: In March 2021, 1,218 community dwelling participants completed assessments. The mean age of the sample is 69.0 (SD 6.9) years. Eight hundred and two participants (65.7%) were not demented (CDR 0) and 391 (32%) and 25 (2%) were categorized as having mild NCD (CDR 0.5) and major NCD (CDR 1 or more), respectively. One hundred forty-three (11.7%) satisfied ICD-10 criteria for anxiety or depressive disorder as measured by CIS-R. Linear regression analysis showed that female gender, CIRS, and MAAS scores were significant factors associated with CIS-R scores. MAAS scores moderated and attenuated the impact CIRS on CIS-R (adjusted R 2 = 0.447, p < 0.001). MAAS scores remained as significant moderator for CIRS in patients with NCD (CDR ≥ 0.5) (adjusted R 2 = 0.33, p < 0.001). Conclusion: Interim findings of the MMSOP suggested that dispositional mindfulness is associated with lower level of mood symptoms in community dwelling older adults in Hong Kong. The interaction effects further suggested that high mindful awareness may reduce the adverse effects of chronic physical morbidity on mental health. The observation stayed in the participants with cognitive impairment. We should further explore MBIs as a non-pharmacological treatment for in older adults at-risk of physical morbidity and cognitive decline.