Metagenomics analysis of sewage for surveillance of antimicrobial resistance in South Africa.

Our 24-month study used metagenomics to investigate antimicrobial resistance (AMR) abundance in raw sewage from wastewater treatment works (WWTWs) in two municipalities in Gauteng Province, South Africa. At the AMR class level, data showed similar trends at all WWTWs, showing that aminoglycoside, beta-lactam, sulfonamide and tetracycline resistance was most abundant. AMR abundance differences were shown between municipalities, where Tshwane Metropolitan Municipality (TMM) WWTWs showed overall higher abundance of AMR compared to Ekurhuleni Metropolitan Municipality (EMM) WWTWs. Also, within each municipality, there were differing trends in AMR abundance. Notably, within TMM, certain AMR classes (macrolides and macrolides_streptogramin B) were in higher abundance at a WWTW serving an urban high-income area, while other AMR classes (aminoglycosides) were in higher abundance at a WWTW serving a semi-urban low income area. At the AMR gene level, all WWTWs samples showed the most abundance for the sul1 gene (encoding sulfonamide resistance). Following this, the next 14 most abundant genes encoded resistance to sulfonamides, aminoglycosides, macrolides, tetracyclines and beta-lactams. Notably, within TMM, some macrolide-encoding resistance genes (mefC, msrE, mphG and mphE) were in highest abundance at a WWTW serving an urban high-income area; while sul1, sul2 and tetC genes were in highest abundance at a WWTW serving a semi-urban low income area. Differential abundance analysis of AMR genes at WWTWs, following stratification of data by season, showed some notable variance in six AMR genes, of which blaKPC-2 and blaKPC-34 genes showed the highest prevalence of seasonal abundance differences when comparing data within a WWTW. The general trend was to see higher abundances of AMR genes in colder seasons, when comparing seasonal data within a WWTW. Our study investigated wastewater samples in only one province of South Africa, from WWTWs located within close proximity to one another. We would require a more widespread investigation at WWTWs distributed across all regions/provinces of South Africa, in order to describe a more comprehensive profile of AMR abundance across the country.

Utility of Diffusion Tensor Imaging in Preterm Infants with Germinal Matrix Hemorrhage and Intraventricular Hemorrhage: A Systematic Review.

INTRODUCTION: Intraventricular hemorrhage (IVH) and germinal matrix hemorrhage (GMH) are the most common brain injuries in preterm infants. Neonates with these injuries are at greater risk of impaired neurodevelopmental outcome. Current guidelines recommend screening infants with cranial ultrasound (CUS), although this is prone to missing subtle injury patterns, particularly within the posterior fossa. The present report sought to discuss the utility of diffusion tensor imaging (DTI) in preterm infants. METHODS: A systematic review of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included manuscripts were methodically scrutinized for quality; DTI use; neurologic outcome. RESULTS: Twenty studies with 1574 infants who underwent DTI were included. There were 574 preterm infants with GMH-IVH on DTI. Twelve studies documented decreased fractional anisotropy (FA) while six demonstrated structural segregation and asymmetrical white matter myelination in these infants. Seven studies documented concurrent CUS use with two studies comparing DTI findings to CUS findings. In both studies, DTI more accurately detected presence of GMH, especially within the cerebellum. Among GMH-IVH preterm infants, 58.5% demonstrated cognitive, intellectual, and language delays at follow-up (mean: 32.4 months). Additionally, lower FA values on initial DTI were associated with cognitive, language, and motor delays. CONCLUSION: Although DTI is more sensitive for picking up subtle injury patterns, CUS remains the standard of care when screening for injuries that would necessitate surgical intervention. DTI offers a refined understanding of the sequelae of GMH-IVH with microstructural changes found on DTI being associated with childhood motor and cognitive outcomes.

Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study.

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as "PLIF/TLIF," is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD). METHODS: Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement-based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed. RESULTS: Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1-61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement-based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97-1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99-1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21-1.15), and the cost per QALY gained was $80,580. CONCLUSIONS: PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.

Implementation of a Standardized Protocol for Recurrent Laryngeal Nerve Monitoring Reduces False Negative Results During Neck Surgery: A Quality Control Case Study.

Recurrent laryngeal nerve (RLN) injury during neck surgery can cause significant morbidity related to vocal cord (VC) dysfunction. VC electromyography (EMG) is used to aid in the identification of the RLN and can reduce the probability of inadvertent surgical injury. Errors in the placement of specialized EMG endotracheal tubes (ETT) can result in unreliable signals, false-negative responses, or no response when stimulating the RLN. We describe a novel educational protocol developed to optimize uniformity in the placement of ETTs to improve the reliability of RLN monitoring. An intraoperative neuromonitoring database was queried for all neck surgeries requiring RLN monitoring. Data points extracted for all cases requiring EMG monitoring for neck procedures. Free running and stimulated EMG were monitored and continuously recorded by a certified technologist. Alerts were compared between 2013-14 and 2015-18 using a two-sample test of proportions. Significant reductions in alerts were demonstrated after protocol implementation (7.5% pre-implementation to 2.1% post). Alerts were compared between 2013-14 (overall alert rate of 1.8%, pre-implementation period) and 2015-18 (overall alert rate of 2.8%, post-implementation period). Protocolization for placement of EMG-ETT improved accuracy in EMG monitoring. In the follow-up cohort of 1,080 patients, use of this protocol continued to reduce the rate of alerts related to ETT malposition, confirming the sustainability of this intervention through routine education. The risk of nerve injury is reduced when the rate of alerts is minimized. Scheduled or continuous protocol education of anesthesia personnel should continue to ensure compliance with protocol.

Inhibition of NK cell cytotoxicity by tubular epithelial cell expression of Clr-b and Clr-f.

NK cells participate in ischemia reperfusion injury (IRI) and transplant rejection. Endogenous regulatory systems may exist to attenuate NK cell activation and cytotoxicity in IRI associated with kidney transplantation. A greater understanding of NK regulation will provide insights in transplant outcomes and could direct new therapeutic strategies. Kidney tubular epithelial cells (TECs) may negatively regulate NK cell activation by their surface expression of a complex family of C-type lectin-related proteins (Clrs). We have found that Clr-b and Clr-f were expressed by TECs. Clr-b was upregulated by inflammatory cytokines TNFα and IFNγ in vitro. Silencing of both Clr-b and Clr-f expression using siRNA resulted in increased NK cell killing of TECs compared to silencing of either Clr-b or Clr-f alone (p < 0.01) and when compared to control TECs (p < 0.001). NK cells treated in vitro with soluble Clr-b and Clr-f proteins reduced their capacity to kill TECs (p < 0.05). Hence, NK cell cytotoxicity can be inhibited by Clr proteins on the surface of TECs. Our study suggests a synergistic effect of Clr molecules in regulating NK cell function in renal cells and this may represent an important endogenous regulatory system to limit NK cell-mediated organ injury during inflammation.

Mapping the Course of Recovery Following Limb-Salvage Surgery for Soft-Tissue Sarcoma of the Extremities.

BACKGROUND: Despite the goal of an acceptable functional result, the surgical treatment of soft-tissue sarcoma can portend a prolonged course of recovery. More comprehensive data on the expected course of recovery following extremity sarcoma surgery are needed to help to inform physicians and patients. The purpose of the present study was to describe the typical course of functional recovery following limb-salvage resection of a soft-tissue sarcoma and to identify factors associated with a delayed postoperative course of recovery. METHODS: A retrospective review of a prospectively maintained institutional database was performed for all patients undergoing surgical treatment with limb salvage of a soft-tissue sarcoma of the extremities or pelvis with at least 1 year of follow-up after the definitive surgical procedure. All patients were required to have preoperative functional outcomes recorded for either the Toronto Extremity Salvage Score (TESS) or the Musculoskeletal Tumor Society (MSTS) score and functional outcome measures at 1 year postoperatively. The primary outcome measures were time to recovery and maximal functional improvement. RESULTS: In this study, 916 patients met inclusion criteria following surgical resection of a soft-tissue sarcoma of the extremities. The median follow-up was 74 months. Patients typically achieved a return to their baseline preoperative level of function for all functional outcome measures by 1 to 2 years and achieved maximal functional recovery by 2 years postoperatively. Older age, female sex, deep tumor location, larger tumor size, pelvic location, osseous resection, motor nerve resection, free and/or rotational soft-tissue coverage, and postoperative complications were independently associated with worse TESS and/or MSTS scores (p ≤ 0.05). Tumor recurrence was associated with worse functional outcomes scores. An analysis was performed to determine which patients had a prolonged course of recovery (i.e., were considered to still be recovering). Older age, female sex, larger tumor size, osseous resection, and motor nerve resection were associated with a delayed course of recovery (p ≤ 0.04). Complications and tumor recurrence were associated with delayed functional recovery across all domains. CONCLUSIONS: Most patients will achieve maximal recovery by 2 to 3 years following surgical resection for soft-tissue sarcoma of the extremities. Older age, female sex, larger tumor size, osseous resection, motor nerve resection, postoperative complications, and tumor recurrence portend poorer functional outcomes and a delayed course of recovery. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Genomics, the diversification of mammals, and the evolution of placentation.

When and why did variations in placental structure and function evolve? Such questions cannot be addressed without a reliable version of mammalian phylogeny. Twenty-five years ago, the mammalian tree was reshaped by molecular phylogenetics. Soon it was shown, in contrast to prevailing theories, that the common ancestor of placental mammals had invasive placentation. Subsequently, evolution of many other features of extraembryonic membranes was addressed. This endeavour stimulated research to fill gaps in our knowledge of placental morphology. Last year the mammalian tree was again revised based on a large set of genomic data. With that in mind, this review provides an update on placentation in the nineteen orders of placental mammals, incorporating much recent data. The principal features such as shape, interdigitation, the interhaemal barrier and the yolk sac are summarized in synoptic tables. The evolution of placental traits and its timing is then explored by reference to the revised mammalian tree. Examples are the early appearance of epitheliochorial placentation in the common ancestor of artiodactyls, perissodactyls, pangolins and carnivores (with reversion to invasive forms in the latter) and later refinements such as the binucleate trophoblast cells and placentomes of ruminants. In primates, the intervillous space gradually evolved from the more basic labyrinth whereas trophoblast invasion of the decidua was a late development in humans and great apes. Only seldom can we glimpse the "why" of placental evolution. The best examples concern placental hormones, including some striking examples of convergent evolution such as the chorionic gonadotropins of primates and equids. In concluding, I review current ideas about what drives placental evolution and identify significant gaps in our knowledge of placentation, including several relevant to the evolution of placentation in primates.

U-rich elements drive pervasive cryptic splicing in 3' UTR massively parallel reporter assays.

Non-coding RNA sequences play essential roles in orchestrating gene expression. However, the sequence codes and mechanisms underpinning post-transcriptional regulation remain incompletely understood. Here, we revisit the finding from a prior massively parallel reporter assay (MPRA) that AU-rich (U-rich) elements in 3' untranslated regions (3' UTRs) can drive upregulation or downregulation of mRNA expression depending on 3' UTR context. We unexpectedly discover that this variable regulation arises from widespread cryptic splicing, predominately from an unannotated splice donor in the coding sequence of GFP to diverse acceptor sites in reporter 3' UTRs. Splicing is activated by U-rich sequences, which function as potent position-dependent regulators of 5' and 3' splice site choice and overall splicing efficiency. Splicing has diverse impacts on reporter expression, causing both increases and decreases in reporter expression via multiple mechanisms. We further provide evidence that cryptic splicing impacts between 10 to 50% of measurements made by other published 3' UTR MPRAs. Overall, our work emphasizes U-rich sequences as principal drivers of splicing and provides strategies to minimize cryptic splicing artifacts in reporter assays.

Intra- and Inter-Rater Reliability of Linear and Nonlinear Measures of Short-Term Heart Rate Variability Following Combat-Related Traumatic Injury.

BACKGROUND: Heart rate variability (HRV) is a marker of autonomic function. However, the reliability of short-term HRV measurement in individuals with combat-related traumatic injury (CRTI) remains undetermined. METHODS: An intra- and inter-rater reliability study was conducted using a subsample (n = 35) of British servicemen with CRTI enrolled in the ongoing ADVANCE study. A five-minute epoch of single-lead electrocardiogram data collected during spontaneous breathing was used to measure HRV. HRV analyses were independently performed by two examiners using Kubios. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimum detectable change (MDC), and coefficient of variance were calculated for linear [root mean square of successive difference (RMSSD), standard deviation of NN interval, low-frequency, high-frequency, total power] and nonlinear (SD1-2, acceleration and deceleration capacities, sample entropy) measures. Bland-Altman %plots were used to assess bias in intra- and inter-rater HRV data. RESULTS: The mean age of participants was 39.3 ± 6.3 years. An excellent ICC score of 0.9998 (95% CI 0.9997, 0.9999) was observed for intra-rater analyses of RMSSD, and similar excellent ICC scores were seen for all other HRV measures. The inter-rater reliability analyses produced an excellent ICC score (range 0.97-1.00). Comparatively, frequency-domain measures produced higher MDC% and SEM% scores than time-domain and nonlinear measures in both inter- and intra-rater analyses. The Bland-Altman plots revealed relatively higher bias for frequency-domain and nonlinear measures than time-domain measures. CONCLUSION: ECG-related short-term HRV measures were reliable in injured servicemen under spontaneous breathing. However, the reliability appeared better with the time-domain measure than frequency-domain and nonlinear measures in this sample.

Association between childhood abuse and risk of post-COVID-19 conditions: Results from three large prospective cohort studies.

BACKGROUND: Significant early life adversities, such as childhood sexual and physical/emotional abuse, are associated with risk of poor health outcomes but are understudied risk factors for post-COVID-19 conditions. In this prospective study, we examined the associations between combined exposure to sexual and physical/emotional abuse during childhood with risk of post-COVID-19 conditions in adulthood. Additionally, we explored the extent to which lifestyle, health-related and psychological factors explain this association. METHODS: We used data from three large, ongoing cohorts: Nurses' Health Study (NHS)-II, NHS3, and the Growing Up Today Study. Between April 2020 and November 2021, participants responded to periodic COVID-19 surveys. Participants were included if they responded to a questionnaire about childhood abuse, subsequently tested positive for SARS-CoV-2 infection and responded to questions about post-COVID-19 conditions. Childhood sexual abuse was measured before the COVID-19 pandemic with the Sexual Maltreatment Scale of the Parent-Child Conflict Tactics Scale, and physical/emotional abuse was measured with the Physical and Emotional Abuse Subscale of the Childhood Trauma Questionnaire. Post-COVID-19 conditions, defined as COVID-19-related symptoms lasting 4 weeks or longer (e.g., fatigue, dyspnea), were self-reported in the final COVID-19 questionnaire in November 2021. Sexual abuse and physical/emotional abuse were examined separately and jointly in relation to post-COVID-19 conditions. Data on key lifestyle (e.g., cigarette smoking), health-related (e.g., asthma, diabetes), and psychological factors (e.g., depression and anxiety) were obtained. RESULTS: Of 2851 participants, the mean age (range) was 55.8 (22.0-75.0) years; 2789 (97.8 %) were females, and 2750 (96.5 %) were whites. We observed a dose-dependent relationship between severity of childhood abuse and post-COVID conditions (p-trend:<0.0001); participants with severe versus no childhood abuse had a 42 % higher subsequent risk of post-COVID conditions [relative risk (95 % confidence interval): 1.42 (1.25 to 1.61)]. Key lifestyle, health-related, and psychological factors mediated 25.5 % of this association. Both sexual and physical/emotional abuse, were independently associated with post-COVID conditions. CONCLUSIONS: In this prospective study of 2851 participants, childhood abuse was significantly associated with increased risk of post-COVID conditions. Biological pathways connecting childhood abuse with subsequent risk of post-COVID conditions should be investigated.

Association of serum biomarkers with radiographic knee osteoarthritis, knee pain and function in a young, male, trauma-exposed population - Findings from the ADVANCE study.

OBJECTIVE: The ArmeD SerVices TrAuma RehabilitatioN OutComE (ADVANCE) study is investigating long-term combat-injury outcomes; this sub-study aims to understand the association of osteoarthritis (OA) biomarkers with knee radiographic OA (rOA), pain and function in this high-risk population for post-traumatic OA. DESIGN: ADVANCE compares combat-injured participants with age, rank, deployment and job-role frequency-matched uninjured participants. Post-injury immunoassay-measured serum biomarkers, knee radiographs, Knee Injury and Osteoarthritis Outcome Scale, and six-minute walk tests are reported. The primary analysis, adjusted for age, body mass, socioeconomic status, and ethnicity, was to determine any differences in biomarkers between those with/without combat injury, rOA and pain. Secondary analyses were performed to compare post-traumatic/idiopathic OA, painful/painfree rOA and injury patterns. RESULTS: A total of 1145 male participants were recruited, aged 34.1 ± 5.4, 8.9 ± 2.2 years post-injury (n = 579 trauma-exposed, of which, traumatic-amputation n = 161) or deployment (n = 566 matched). Cartilage oligomeric matrix protein (COMP) was significantly higher in the combat-injured group compared to uninjured (p = 0.01). Notably, COMP was significantly lower in the traumatic-amputation group compared to non-amputees (p < 0.001), decreasing relative to number of amputations (p < 0.001). Leptin was higher (p = 0.005) and adiponectin lower (p = 0.017) in those with v without knee pain, associated with an increased risk of 22% and 17% for pain, and 46% and 34% for painful rOA, respectively. There were no significant differences between trauma-exposed and unexposed participants with rOA. CONCLUSIONS: The most notable findings of this large, unique study are the similarities between those with rOA regardless of trauma-exposure, the injury-pattern and traumatic-amputation-associated differences in COMP, and the relationship between adipokines and pain.

Epidemiology and antimicrobial resistance profiles of pathogenic Escherichia coli from commercial swine and poultry abattoirs and farms in South Africa: A One Health approach.

Pathogenic Escherichia coli (PEC) are important foodborne bacteria that can cause severe illness in humans. The PECs thrive within the intestines of humans as well as animals and may contaminate multiple ecosystems, including food and water, via faecal transmission. Abattoir and farm employees are at high risk of PEC exposure, which could translate to community risk through person-to-person contact. To determine the epidemiology and resistome of PECs in Gauteng and Limpopo provinces of South Africa, 198 swine faecal samples, 220 poultry cloacal swabs, 108 human hand swabs, 11 run-off water samples from abattoirs and farms were collected from four swine and five poultry commercial abattoirs and two swine farms. One effluent sample each was collected from four wastewater treatment plants (WWTP) and a tertiary hospital setting. Phenotypic and genotypic techniques were used including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Results showed EHEC and EPEC prevalence was 4.1 % (22/542) and 20.8 % (113/542), respectively, with the O26 serogroup detected the most in PEC isolates. According to the PFGE dendrogram, isolates from poultry, human hand swabs and run-off water clustered together. Diverse virulence factors such as the novel stx2k subtype and eae genes were detected among the 36 representative PEC isolates according to WGS. The results showed that 66.7 % (24/36) of sequenced PECs presented with multi-drug resistance (MDR) to ß-lactamase 13.9 % (5/36), aminoglycoside 61.1 % (22/36), tetracycline 41.7 % (15/36) and quinolones 38.9 % (14/36). No colistin nor carbapenem resistance was detected. Sequence types (STs) associated with MDR in this study were: ST752, ST189, ST206, ST10, ST48 and ST38. The findings highlight the threat of zoonotic pathogens to close human contacts and the need for enhanced surveillance to mitigate the spread of MDR foodborne PECs.

Incarcerated Gravid Uterus: A New Treatment Using the Transvaginal Ultrasound Probe and Narrative Literature Review.

BACKGROUND: 'Incarcerated gravid uterus' is a morbid complication that occurs in 1 in 3000 pregnancies. It is characterized by failure of a retropositioned uterus to become an abdominal organ between 12-14 weeks of gestation. If maternal symptoms develop or gestational age surpasses 14-16 weeks, replacement of a retropositioned uterus is recommended to reduce adverse outcomes. Previously described techniques for management include passive reduction, digital replacement, or more invasive methods such as laparoscopy, laparotomy, or sigmoidoscopy. These methods are either minimally effective, painful, or risky. OBJECTIVE: The objective of this report is to describe our clinical experience with a new minimally-invasive technique that uses the transvaginal ultrasound probe for uterine replacement in cases of incarceration, to conduct a narrative literature review on 'incarcerated gravid uterus,' and to propose an algorithm for management of this condition. STUDY DESIGN: This is a case series of eight patients with an incarcerated gravid uterus who were managed with the transvaginal ultrasound probe technique at one academic medical institution between March 2020 and July 2023, as well as a narrative review of the literature on 'incarcerated gravid uterus.' PubMed, Google Scholar, and Ovid MEDLINE databases were searched for the terms "incarcerated gravid uterus," "uterine incarceration," "uterine sacculation," and "retroverted uterus" up to April 2024. RESULTS: The transvaginal ultrasound probe technique resulted in successful uterine replacement, with resolution of symptoms, in all eight patients. All pregnancies resulted in live births with good neonatal outcomes-seven out of eight patients delivered at term, and one delivered in the late preterm period. CONCLUSION: Our proposed technique for treatment of an incarcerated gravid uterus with the transvaginal ultrasound probe is simple, minimally-invasive and effective. Based on our experience and the narrative literature review, an algorithm for the management of an incarcerated gravid uterus is proposed.

The American Board of Orthodontics: A brief history and update of the orthodontic certification process.

The American Board of Orthodontics (ABO) has updated its clinical examination process to remove barriers to the case-based examination and to distinguish board-certified orthodontists from uncertified dental practitioners who provide orthodontic care. In 2017, the ABO took the bold step of adopting a new clinical examination format (a scenario-based examination), thereby, addressing the challenges that were inherent in the former case-based examination format. The coronavirus disease 2019 pandemic forced the scenario-based clinical examination scheduled for July 2020 to be canceled. This caused the ABO to regroup and adapt the scenario-based clinical examination to a format that could be administered worldwide in a testing center environment, eliminating the need to travel to St Louis, Missouri. The ABO-written examination remained unaltered. Since the scenario-based format was adopted, 63% of the AAO members are now board-certified, and the trend is upward. In support of our mission to elevate the quality of orthodontics through certification, education, and professional collaboration, the ABO is responsible for certifying orthodontists in a fair, reliable, and valid manner. This requires continuous evaluation and review of our certification process to ensure that our examination reliably evaluates the ability of orthodontists to provide the highest level of patient care.

Utility of 64Cu-Sarcophagine-Bombesin PET/CT in Men with Biochemically Recurrent Prostate Cancer and Negative or Equivocal Findings on 68Ga-PSMA-11 PET/CT.

Despite a high detection rate of 68Ga-prostate-specific membrane antigen (PSMA) PET/CT in biochemical recurrence (BCR) of prostate cancer, a significant proportion of men have negative 68Ga-PSMA-11 PET/CT results. Gastrin-releasing peptide receptor, targeted by the copper-chelated bombesin analog 64Cu-sarcophagine-bombesin (SAR-BBN) PET/CT, is also overexpressed in prostate cancer. In this prospective imaging study, we investigate the detection rate of 64Cu-SAR-BBN PET/CT in patients with BCR and negative or equivocal 68Ga-PSMA-11 PET/CT results. Methods: Men with confirmed adenocarcinoma of the prostate, prior definitive therapy, and BCR (defined as a prostate-specific antigen [PSA] level > 0.2 ng/mL) with negative or equivocal 68Ga-PSMA-11 PET/CT results within 3 mo were eligible for enrollment. 64Cu-SAR-BBN PET/CT scans were acquired at 1 and 3 h after administration of 200 MBq of 64Cu-SAR-BBN, with further delayed imaging undertaken optionally at 24 h. PSA (ng/mL) was determined at baseline. All PET (PSMA and bombesin) scans were assessed visually. Images were read with masking of the clinical results by 2 experienced nuclear medicine specialists, with a third reader in cases of discordance. Accuracy was defined using a standard of truth that included biopsy confirmation, confirmatory imaging, or response to targeted treatment. Results: Twenty-five patients were enrolled. Prior definitive therapy was radical prostatectomy (n = 24, 96%) or radiotherapy (n = 1, 4%). The median time since definitive therapy was 7 y (interquartile range [IQR], 4-11 y), and the Gleason score was 7 or less (n = 15, 60%), 8 (n = 3, 12%), or 9 (n = 7, 28%). The median PSA was 0.69 ng/mL (IQR, 0.28-2.45 ng/mL). Baseline PSMA PET scans were negative in 19 patients (76%) and equivocal in 6 (24%). 64Cu-SAR-BBN PET-avid disease was identified in 44% (11/25): 12% (3/25) with local recurrence, 20% (5/25) with pelvic node metastases, and 12% (3/25) with distant metastases. The κ-score between readers was 0.49 (95% CI, 0.16-0.82). Patients were followed up for a median of 10 mo (IQR, 9-12 mo). Bombesin PET/CT results were true-positive in 5 of 25 patients (20%), false-positive in 2 of 25 (8%), false-negative in 7 of 25 (28%), and unverified in 11 of 25 (44%). Conclusion: 64Cu-SAR-BBN PET/CT demonstrated sites of disease recurrence in 44% of BCR cases with negative or equivocal 68Ga-PSMA-11 PET/CT results. Further evaluation to confirm diagnostic benefit is warranted.

Detection of the epidemic Pseudomonas aeruginosa AUST-03 (ST242) strain in people with cystic fibrosis in South Africa.

INTRODUCTION: Pseudomonas aeruginosa AUST-03 (ST242) has been reported to cause epidemics in people with CF (pwCF) from Australia and has been associated with multidrug resistance and increased morbidity and mortality. Here, we report an epidemic P. aeruginosa (AUST-03) strain in South African pwCF detected at a public hospital and characterize the genomic antibiotic resistance determinants. METHODS: The P. aeruginosa AUST-03 (ST242) study isolates were analysed with whole genome sequencing using the Illumina NextSeq2000 platform. Raw sequencing reads were processed using the Jekesa pipeline and multilocus sequence typing and genomic antibiotic resistance characterization was performed using public databases. Genetic relatedness between the study isolates and global P. aeruginosa ST242 from public databases was determined using a maximum-likelihood phylogenetic tree. Antibiotic susceptibility testing was performed using the disk diffusion and broth microdilution techniques. RESULTS: A total of 11 P. aeruginosa AUST-03 isolates were isolated from two children with CF. The majority (8/11) of these isolates were multidrug-resistant (MDR) or extensively drug resistant; and the multidrug efflux pumps MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM were the most clinically relevant antibiotic resistance determinants and were detected in all of the isolates. The study isolates were the most closely related to a 2020 P. aeruginosa AUST-03 (ST242) CF isolate from Russia. CONCLUSION: Epidemic MDR P. aeruginosa strains are present at South African public CF clinics and need to be considered when implementing segregation and infection control strategies to prevent possible spread and outbreaks.

Clinical Effectiveness of Anterior Cervical Discectomy and Fusion Using Tritanium C Anterior Cervical Cage vs. PEEK Cage.

Introduction: Anterior cervical discectomy and fusion (ACDF) has proven to be a clinically efficient and cost-effective method for treating patients with degenerative cervical spine conditions. New intervertebral implant products are being developed to improve fusion and stability while decreasing complications. This study assesses the effectiveness of Tritanium C (Tri-C) Anterior Cervical Cage (Stryker) in the treatment of degenerative disk disease (DDD) of the cervical spine compared with polyetheretherketone (PEEK) cages. Methods: A retrospective cohort analysis was conducted using data prospectively collected from two institutions. Patients who underwent ACDFs for DDD using either the Tri-C cage or PEEK cage were identified. The patients' demographics, comorbidities, operative variables, and baseline patient-reported outcomes (PROs) were collected. PROs included the Neck Disability Index (NDI) and numeric rating scale (NRS) for neck and arm pain. The primary outcomes included 3- and 12-month PROs as well as the rates of 90-day readmission, 90-day reoperation, and perioperative complication. The radiographic outcomes included rates of subsidence, cage movement, and successful fusion within 12 months. Multivariate linear regression models were run to identify variables predictive of 12-month PROs. Results: A total of 275 patients who underwent ACDF were included in this study and were divided into two groups: PEEK (n=213) and Tri-C (n=62). Both groups showed improvement in neck and arm pain and NDI postoperatively. When Tri-C and PEEK were compared, no significant differences were observed in the 3- or 12-month changes in neck or arm pain or NDI. Furthermore, there were no differences in the rates of 90-day readmission, 90-day reoperation, and perioperative complication. Regression analysis revealed that Tri-C vs. PEEK was not a significant predictor of any outcome. Conclusions: Our results indicate that the use of porous titanium Tri-C cage during ACDFs is an effective method for managing cervical DDD in terms of PROs, perioperative morbidity, and radiologic parameters. No significant difference was observed in any clinical outcome between patients undergoing ACDF using the Tri-C cage and those in whom the PEEK cage was used. Level of Evidence: III.

A synoptic literature review of animal models for investigating the biomechanics of knee osteoarthritis.

Osteoarthritis (OA) is a common chronic disease largely driven by mechanical factors, causing significant health and economic burdens worldwide. Early detection is challenging, making animal models a key tool for studying its onset and mechanically-relevant pathogenesis. This review evaluate current use of preclinical in vivo models and progressive measurement techniques for analysing biomechanical factors in the specific context of the clinical OA phenotypes. It categorizes preclinical in vivo models into naturally occurring, genetically modified, chemically-induced, surgically-induced, and non-invasive types, linking each to clinical phenotypes like chronic pain, inflammation, and mechanical overload. Specifically, we discriminate between mechanical and biological factors, give a new explanation of the mechanical overload OA phenotype and propose that it should be further subcategorized into two subtypes, post-traumatic and chronic overloading OA. This review then summarises the representative models and tools in biomechanical studies of OA. We highlight and identify how to develop a mechanical model without inflammatory sequelae and how to induce OA without significant experimental trauma and so enable the detection of changes indicative of early-stage OA in the absence of such sequelae. We propose that the most popular post-traumatic OA biomechanical models are not representative of all types of mechanical overloading OA and, in particular, identify a deficiency of current rodent models to represent the chronic overloading OA phenotype without requiring intraarticular surgery. We therefore pinpoint well standardized and reproducible chronic overloading models that are being developed to enable the study of early OA changes in non-trauma related, slowly-progressive OA. In particular, non-invasive models (repetitive small compression loading model and exercise model) and an extra-articular surgical model (osteotomy) are attractive ways to present the chronic natural course of primary OA. Use of these models and quantitative mechanical behaviour tools such as gait analysis and non-invasive imaging techniques show great promise in understanding the mechanical aspects of the onset and progression of OA in the context of chronic knee joint overloading. Further development of these models and the advanced characterisation tools will enable better replication of the human chronic overloading OA phenotype and thus facilitate mechanically-driven clinical questions to be answered.

Regulating interparticle proximity in plasmonic nanosphere aggregates to enhance photoacoustic response and photothermal stability.

Designing plasmonic nanoparticles for biomedical photoacoustic (PA) imaging involves tailoring material properties at the nanometer scale. A key in developing plasmonic PA contrast nanoagents is to engineer their enhanced optical responses in the near-infrared wavelength range, as well as heat transfer properties and photostability. This study introduces anisotropic plasmonic nanosphere aggregates with close interparticle proximity as photostable and efficient contrast agent for PA imaging. Silver (Ag), among plasmonic metals, is particularly attractive due to its strongest optical response and highest heat conductivity. Our results demonstrate that close interparticle proximity in silver nanoaggregates (AgNAs), spatially confined within a polymer shell layer, leads to blackbody-like optical absorption, resulting in robust PA signals through efficient pulsed heat generation and transfer. Additionally, our AgNAs exhibit a high photodamage threshold highlighting their potential to outperform conventional plasmonic contrast agents for high-contrast PA imaging over multiple imaging sessions. Furthermore, we demonstrate the capability of the AgNAs for molecular PA cancer imaging in vivo by incorporating a tumor-targeting peptide moiety.