Host-microbe interactions rewire metabolism in a C. elegans model of leucine breakdown deficiency.

In humans, defects in leucine catabolism cause a variety of inborn errors in metabolism. Here, we use Caenorhabditis elegans to investigate the impact of mutations in mccc-1, an enzyme that functions in leucine breakdown. Through untargeted metabolomic and transcriptomic analyses we find extensive metabolic rewiring that helps to detoxify leucine breakdown intermediates via conversion into previously undescribed metabolites and to synthesize mevalonate, an essential metabolite. We also find that the leucine breakdown product 3,3-hydroxymethylbutyrate (HMB), commonly used as a human muscle-building supplement, is toxic to C. elegans and that bacteria modulate this toxicity. Unbiased genetic screens revealed interactions between the host and microbe, where components of bacterial pyrimidine biosynthesis mitigate HMB toxicity. Finally, upregulated ketone body metabolism genes in mccc-1 mutants provide an alternative route for biosynthesis of the mevalonate precursor 3-hydroxy-3-methylglutaryl-CoA. Our work demonstrates that a complex host-bacteria interplay rewires metabolism to allow host survival when leucine catabolism is perturbed.

Mitochondrial inorganic polyphosphate is required to maintain proteostasis within the organelle.

The existing literature points towards the presence of robust mitochondrial mechanisms aimed at mitigating protein dyshomeostasis within the organelle. However, the precise molecular composition of these mechanisms remains unclear. Our data show that inorganic polyphosphate (polyP), a polymer well-conserved throughout evolution, is a component of these mechanisms. In mammals, mitochondria exhibit a significant abundance of polyP, and both our research and that of others have already highlighted its potent regulatory effect on bioenergetics. Given the intimate connection between energy metabolism and protein homeostasis, the involvement of polyP in proteostasis has also been demonstrated in several organisms. For example, polyP is a bacterial primordial chaperone, and its role in amyloidogenesis has already been established. Here, using mammalian models, our study reveals that the depletion of mitochondrial polyP leads to increased protein aggregation within the organelle, following stress exposure. Furthermore, mitochondrial polyP is able to bind to proteins, and these proteins differ under control and stress conditions. The depletion of mitochondrial polyP significantly affects the proteome under both control and stress conditions, while also exerting regulatory control over gene expression. Our findings suggest that mitochondrial polyP is a previously unrecognized, and potent component of mitochondrial proteostasis.

A combined radio-immunotherapy regimen eradicates late-stage tumors in mice.

Background: The majority of experimental approaches for cancer immunotherapy are tested against relatively small tumors in tumor-bearing mice, because in most cases advanced cancers are resistant to the treatments. In this study, we asked if even late-stage mouse tumors can be eradicated by a rationally designed combined radio-immunotherapy (CRI) regimen. Methods: CRI consisted of local radiotherapy, intratumoral IL-12, slow-release systemic IL-2 and anti- CTLA-4 antibody. Therapeutic effects of CRI against several weakly immunogenic and immunogenic mouse tumors including B78 melanoma, MC38 and CT26 colon carcinomas and 9464D neuroblastoma were evaluated. Immune cell depletion and flow cytometric analysis were performed to determine the mechanisms of the antitumor effects. Results: Tumors with volumes of 2,000 mm3 or larger were eradicated by CRI. Flow analyses of the tumors revealed reduction of T regulatory (Treg) cells and increase of CD8/Treg ratios following CRI. Rapid shrinkage of the treated tumors did not require T cells, whereas T cells were involved in the systemic effect against the distant tumors. Cured mice developed immunological memory. Conclusions: These findings underscore that rationally designed combination immunotherapy regimens can be effective even against large, late-stage tumors.

Phasing millions of samples achieves near perfect accuracy, enabling parent-of-origin classification of variants.

Haplotype phasing, the process of determining which genetic variants are physically located on the same chromosome, is crucial for various genetic analyses. In this study, we first benchmark SHAPEIT and Beagle, two state-of-the-art phasing methods, on two large datasets: > 8 million diverse, research-consented 23andMe, Inc. customers and the UK Biobank (UKB). We find that both perform exceptionally well. Beagle's median switch error rate (SER) (after excluding single SNP switches) in white British trios from UKB is 0.026% compared to 0.00% for European ancestry 23andMe research participants; 55.6% of European ancestry 23andMe research participants have zero non-single SNP switches, compared to 42.4% of white British trios. South Asian ancestry 23andMe research participants have the highest median SER amongst the 23andMe populations, but it is still remarkably low at 0.46%. We also investigate the relationship between identity-by-descent (IBD) and SER, finding that switch errors tend to occur in regions of little or no IBD segment coverage. SHAPEIT and Beagle excel at 'intra-chromosomal' phasing, but lack the ability to phase across chromosomes, motivating us to develop an inter-chromosomal phasing method, called HAPTIC ( HAP lotype TI ling and C lustering), that assigns paternal and maternal variants discretely genome-wide. Our approach uses identity-by-descent (IBD) segments to phase blocks of variants on different chromosomes. HAPTIC represents the segments a focal individual shares with their relatives as nodes in a signed graph and performs bipartite clustering on the signed graph using spectral clustering. We test HAPTIC on 1022 UKB trios, yielding a median phase error of 0.08% in regions covered by IBD segments (33.5% of sites). We also ran HAPTIC in the 23andMe database and found a median phase error rate (the rate of mismatching alleles between the inferred and true phase) of 0.92% in Europeans (93.8% of sites) and 0.09% in admixed Africans (92.7% of sites). HAPTIC's precision depends heavily on data from relatives, so will increase as datasets grow larger and more diverse. HAPTIC enables analyses that require the parent-of-origin of variants, such as association studies and ancestry inference of untyped parents.

Evaluation of a Combinatorial Immunotherapy Regimen That Can Cure Mice Bearing MYCN-Driven High-Risk Neuroblastoma That Resists Current Clinical Therapy.

Background: Incorporating GD2-targeting monoclonal antibody into post-consolidation maintenance therapy has improved survival for children with high-risk neuroblastoma. However, ~50% of patients do not respond to, or relapse following, initial treatment. Here, we evaluated additional anti-GD2-based immunotherapy to better treat high-risk neuroblastoma in mice to develop a regimen for patients with therapy-resistant neuroblastoma. Methods: We determined the components of a combined regimen needed to cure mice of established MYCN-amplified, GD2-expressing, murine 9464D-GD2 neuroblastomas. Results: First, we demonstrate that 9464D-GD2 is nonresponsive to a preferred salvage regimen: anti-GD2 with temozolomide and irinotecan. Second, we have previously shown that adding agonist anti-CD40 mAb and CpG to a regimen of radiotherapy, anti-GD2/IL2 immunocytokine and anti-CTLA-4, cured a substantial fraction of mice bearing small 9464D-GD2 tumors; here, we further characterize this regimen by showing that radiotherapy and hu14.18-IL2 are necessary components, while anti-CTLA-4, anti-CD40, or CpG can individually be removed, and CpG and anti-CTLA-4 can be removed together, while maintaining efficacy. Conclusions: We have developed and characterized a regimen that can cure mice of a high-risk neuroblastoma that is refractory to the current clinical regimen for relapsed/refractory disease. Ongoing preclinical work is directed towards ways to potentially translate these findings to a regimen appropriate for clinical testing.

Understanding Public Perception of Naloxone: A Study of FAQs and Answer Source Credibility.

PURPOSE: The most commonly used intervention for opioid overdoses is naloxone. With naloxone soon to be sold over-the-counter in the United States, the goal of this paper is to categorize frequently asked questions (FAQs) and answers about naloxone using internet sources in a cross-sectional fashion. METHODS: Terms "narcan" and "naloxone" were searched on a clean Google Chrome browser using the "People also asked" tab to find FAQs and their answer sources. We classified questions and sources and assessed each website's quality and credibility grading with JAMA benchmark criteria. The Kruskal-Wallis H test was used to determine variance of mean JAMA score by source type and Post-Hoc Dunn's test with Bonferroni corrected alpha of 0.005 used to compare source types. RESULTS: Of the 305 unique questions, 202 (66.2%) were classified as facts, 78 (25.6%) were policy, and 25 (8.2%) were value. Of the 144 unique answer sources, the two most common included 55 (38.2%) which were government entities and 47 (32.6%) which were commercial entities. Ninety-two (of 144, 63.9%) sources met three or more JAMA benchmark criteria. Statistical analysis showed a significant difference between the JAMA benchmark scores by source type H(4) = 12.75, p = 0.0126 and between the mean rank of academic and government sources (p = 0.0036). CONCLUSION: We identified FAQs and their citations about naloxone, highlighting potential lack of understanding and knowledge of this important intervention. We recommend updating websites to accurately reflect current and useful information for those that may require naloxone.

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.

Racial Disparities in Treatment and Outcomes of Patients With Hepatitis C Undergoing Elective Total Joint Arthroplasty.

BACKGROUND: African Americans have the highest prevalence of chronic Hepatitis C virus (HCV) infection. Racial disparities in outcome are observed after elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study sought to identify if disparities in treatments and outcomes exist between Black and White patients who have HCV prior to elective THA and TKA. METHODS: Patient demographics, comorbidities, HCV characteristics, perioperative variables, in-hospital outcomes, and postoperative complications at 1-year follow-up were collected and compared between the 2 races. Patients who have preoperative positive viral load (PVL) and undetectable viral load were identified. Chi-square and Fisher's exact tests were used to compare categorical variables, while 2-tailed Student's Kruskal-Wallis t-tests were used for continuous variables. A P value of less than .05 was statistically significant. RESULTS: The liver function parameters, including aspartate aminotransferase and model for end-stage liver disease scores, were all higher preoperatively in Black patients undergoing THA (P = .01; P < .001) and TKA (P = .03; P = .003), respectively. Black patients were more likely to undergo THA (65.8% versus 35.6%; P = .002) and TKA (72.1% versus 37.3%; 0.009) without receiving prior treatment for HCV. Consequently, Black patients had higher rates of preoperative PVL compared to White patients in both THA (66% versus 38%, P = .006) and TKA (72% versus 37%, P < .001) groups. Black patients had a longer length of stay for both THA (3.7 versus 3.3; P = .008) and TKA (4.1 versus 3.0; P = .02). CONCLUSIONS: The HCV treatment prior to THA and TKA with undetectable viral load has been shown to be a key factor in mitigating postoperative complications, including joint infection. We noted that Black patients were more likely to undergo joint arthroplasty who did not receive treatment and with a PVL. While PVL rates decreased over time for both races, a significant gap persists for Black patients.

Regulation of proteostasis and innate immunity via mitochondria-nuclear communication.

Mitochondria are perhaps best known as the "powerhouse of the cell" for their role in ATP production required for numerous cellular activities. Mitochondria have emerged as an important signaling organelle. Here, we first focus on signaling pathways mediated by mitochondria-nuclear communication that promote protein homeostasis (proteostasis). We examine the mitochondrial unfolded protein response (UPRmt) in C. elegans, which is regulated by a transcription factor harboring both a mitochondrial- and nuclear-targeting sequence, the integrated stress response in mammals, as well as the regulation of chromatin by mitochondrial metabolites. In the second section, we explore the role of mitochondria-to-nuclear communication in the regulation of innate immunity and inflammation. Perhaps related to their prokaryotic origin, mitochondria harbor molecules also found in viruses and bacteria. If these molecules accumulate in the cytosol, they elicit the same innate immune responses as viral or bacterial infection.

Efficient and sustained FOXP3 locus editing in hematopoietic stem cells as a therapeutic approach for IPEX syndrome.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a monogenic disorder caused by mutations in the FOXP3 gene, required for generation of regulatory T (Treg) cells. Loss of Treg cells leads to immune dysregulation characterized by multi-organ autoimmunity and early mortality. Hematopoietic stem cell (HSC) transplantation can be curative, but success is limited by autoimmune complications, donor availability and/or graft-vs.-host disease. Correction of FOXP3 in autologous HSC utilizing a homology-directed repair (HDR)-based platform may provide a safer alternative therapy. Here, we demonstrate efficient editing of FOXP3 utilizing co-delivery of Cas9 ribonucleoprotein complexes and adeno-associated viral vectors to achieve HDR rates of >40% in vitro using mobilized CD34+ cells from multiple donors. Using this approach to deliver either a GFP or a FOXP3 cDNA donor cassette, we demonstrate sustained bone marrow engraftment of approximately 10% of HDR-edited cells in immune-deficient recipient mice at 16 weeks post-transplant. Further, we show targeted integration of FOXP3 cDNA in CD34+ cells from an IPEX patient and expression of the introduced FOXP3 transcript in gene-edited primary T cells from both healthy individuals and IPEX patients. Our combined findings suggest that refinement of this approach is likely to provide future clinical benefit in IPEX.

Concomitant Biceps Tenodesis Does Not Portend Inferior Outcomes After Anterior Glenohumeral Stabilization.

BACKGROUND: Military patients are known to suffer disproportionately high rates of glenohumeral instability as well as superior labrum anterior to posterior (SLAP) tears. Additionally, a concomitant SLAP tear is frequently observed in patients with anterior shoulder instability. Even though biceps tenodesis has been demonstrated to produce superior outcomes to SLAP repair in military patients with isolated SLAP lesions, no existing studies have reported on outcomes after simultaneous tenodesis and anterior labral repair in patients with co-existing abnormalities. PURPOSE: To evaluate outcomes after simultaneous arthroscopic-assisted subpectoral biceps tenodesis and anterior labral repair in military patients younger than 40 years. We also sought to compare these outcomes with those after repair of an isolated anterior labral tear. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This study is a retrospective analysis of all military patients younger than 40 years from a single base who underwent arthroscopic anterior glenohumeral stabilization with or without concomitant biceps tenodesis between January 2010 and December 2019. Patients with glenoid bone loss of >13.5% were not eligible for inclusion. Outcome measures including the visual analog scale (VAS) for pain, the Single Assessment Numeric Evaluation (SANE), the American Shoulder and Elbow Surgeons (ASES) shoulder score, the Rowe instability score, and range of motion were administered preoperatively and postoperatively, and scores were compared between groups. RESULTS: A total of 82 patients met inclusion criteria for the study. All patients were active-duty service members at the time of surgery. The mean follow-up was 87.75 ± 27.05 months in the repair + tenodesis group and 94.07 ± 28.72 months in the isolated repair group (P = .3085). Patients who underwent repair + tenodesis had significantly worse preoperative VAS pain (6.85 ± 1.86 vs 5.02 ± 2.07, respectively; P < .001), ASES (51.78 ± 11.89 vs 62.43 ± 12.35, respectively; P = .0002), and Rowe (26.75 ± 7.81 vs 37.26 ± 14.91, respectively; P = .0002) scores than patients who underwent isolated repair. Both groups experienced significant improvements in outcome scores postoperatively (P < .0001 for all), and there were no statistically significant differences in postoperative outcome scores or range of motion between groups. There were no differences in the percentage of patients who achieved the minimal clinically important difference, substantial clinical benefit, and patient acceptable symptom state for the VAS pain, SANE, ASES, and Rowe scores between groups. Overall, 37 of the 40 (92.50%) patients in the repair + tenodesis group and 40 of the 42 (95.24%) patients in the isolated repair group returned to unrestricted active-duty military service (P = .6045). In addition, 38 (95.00%) patients in the repair + tenodesis group and 40 (95.24%) patients in the isolated repair group returned to preinjury levels of sporting activity (P = .9600). There were no significant differences in the number of failures, revision surgical procedures, or patients discharged from the military between groups (P = .9421, P = .9400, and P = .6045, respectively). CONCLUSION: The findings of this study indicate that simultaneous biceps tenodesis and labral repair was a viable treatment option for the management of concomitant SLAP and anterior labral lesions in young, active military patients younger than 40 years.

Epidemiology of shoulder dislocations presenting to United States emergency departments: An updated ten-year study.

BACKGROUND: Glenohumeral dislocation is a common injury that may predispose patients to chronic pain and instability. However, there is a paucity of current data available regarding the epidemiological trends of this injury. AIM: To provide an updated, comparative assessment of the epidemiology of shoulder dislocations presenting to emergency departments in the United States. We also sought to analyze patient demographic risk factors and consumer products associated with dislocation events. METHODS: Data were obtained from the national electronic injury surveillance system database for glenohumeral dislocations between 2012 and 2021. Incidence, age, sex, and injury characteristics were analyzed using weighted population statistics as well as incidence rates and 95% confidence intervals (CI). RESULTS: In total, an estimated 773039 shoulder dislocations (CI: 640598-905481) presented to emergency rooms across the United States during the study period. The annual incidence rate was 23.96 per 100000 persons and the average patient age at the time of injury was 37.1 years. Significantly more male patients sustained dislocations than female patients (537189, 69.5%, vs 235834, 30.5%, P < 0.001). With regard to associated consumer products, sports and recreation equipment were involved in the highest proportion of incidents (44.31%), followed by home structures and construction materials (21.22%), and home furnishings, fixtures, and accessories (21.21%). Regarding product sub-groups, stairs, ramps, landings, floors was cited in the greatest number of cases (131745). CONCLUSION: The national annual incidence rate of glenohumeral dislocations throughout the study period was approximately 23.92 per 100000 persons. Male adolescents sustained the highest proportion of dislocations, with a peak incidence in age group 15-20 years, predominantly secondary to participation in sporting and recreational activities. Conversely, women experienced a relatively consistent incidence of dislocation throughout their lifespan. After age 63, the incidence rate of dislocations in females was found to surpass that observed in males.

Tyrosinase Inhibitors: A Perspective.

Due to its integral role in the biosynthesis of melanin in all kingdoms of life, tyrosinase has become an extremely important target for inhibition in several sectors of research including agricultural and cosmetic research. Inhibitors of tyrosinase have made it to the market in the cosmetics industry, but their use has been limited due to conflicting efficacy and potential toxicity, which has led to several small molecules being removed from the market. Undaunted, researchers have continued to pursue tyrosinase inhibitors with varying degrees of success. These pursuits have built an impressive and rich library of research. This review is intended to provide a perspective of the past twenty years (2003-2023) of research on tyrosinase inhibitors by highlighting exemplar molecules and developments.

ATFS-1 counteracts mitochondrial DNA damage by promoting repair over transcription.

The ability to balance conflicting functional demands is critical for ensuring organismal survival. The transcription and repair of the mitochondrial genome (mtDNA) requires separate enzymatic activities that can sterically compete1, suggesting a life-long trade-off between these two processes. Here in Caenorhabditis elegans, we find that the bZIP transcription factor ATFS-1/Atf5 (refs. 2,3) regulates this balance in favour of mtDNA repair by localizing to mitochondria and interfering with the assembly of the mitochondrial pre-initiation transcription complex between HMG-5/TFAM and RPOM-1/mtRNAP. ATFS-1-mediated transcriptional inhibition decreases age-dependent mtDNA molecular damage through the DNA glycosylase NTH-1/NTH1, as well as the helicase TWNK-1/TWNK, resulting in an enhancement in the functional longevity of cells and protection against decline in animal behaviour caused by targeted and severe mtDNA damage. Together, our findings reveal that ATFS-1 acts as a molecular focal point for the control of balance between genome expression and maintenance in the mitochondria.

In vivo characterization of the maturation steps of a pigment dispersing factor neuropeptide precursor in the Drosophila circadian pacemaker neurons.

Pigment dispersing factor (PDF) is a key signaling molecule coordinating the neuronal network associated with the circadian rhythms in Drosophila. The precursor (proPDF) of the mature PDF (mPDF) consists of 2 motifs, a larger PDF-associated peptide (PAP) and PDF. Through cleavage and amidation, the proPDF is predicted to produce cleaved-PAP (cPAP) and mPDF. To delve into the in vivo mechanisms underlying proPDF maturation, we generated various mutations that eliminate putative processing sites and then analyzed the effect of each mutation on the production of cPAP and mPDF by 4 different antibodies in both ectopic and endogenous conditions. We also assessed the knockdown effects of processing enzymes on the proPDF maturation. At the functional level, circadian phenotypes were measured for all mutants and knockdown lines. As results, we confirm the roles of key enzymes and their target residues: Amontillado (Amon) for the cleavage at the consensus dibasic KR site, Silver (Svr) for the removal of C-terminal basic residues from the intermediates, PAP-KR and PDF-GK, derived from proPDF, and PHM (peptidylglycine-α-hydroxylating monooxygenase) for the amidation of PDF. Our results suggest that the C-terminal amidation occurs independently of proPDF cleavage. Moreover, the PAP domain is important for the proPDF trafficking into the secretory vesicles and a close association between cPAP and mPDF following cleavage seems required for their stability within the vesicles. These studies highlight the biological significance of individual processing steps and the roles of the PAP for the stability and function of mPDF which is essential for the circadian clockworks.

Radiographic Findings in Flexion Instability after Total Knee Arthroplasty.

Flexion instability (FI) is one of the leading causes of knee pain and revision surgery. Generally, the biomechanical etiology is considered to be a larger flexion than extension gap. This may be due to mismatch of components sizes to the bone or malalignment. Other factors such as muscle weakness may also play a role, and the diagnosis of FI after total knee arthroplasty (TKA) relies on a combination of patient's complaints during stair descent or walking and physical examination findings. Our study examines the role of implant positioning and sizes in the diagnosis of FI. A retrospective review of 20 subjects without perceived FI and 13 patients diagnosed with FI after TKA was conducted. Knee injury and osteoarthritis outcome scores (KOOS) were documented, and postoperative radiographs were examined. Measurements including included tibial slope, condylar offset, femoral joint line elevation along with surrogate soft-tissue measures for girth and were compared between groups. The FI group was found to have a significantly lower KOOS score compared with the non-FI group (55.6 vs. 73.5; p = 0.009) as well as smaller soft-tissue measurements over the pretubercle region (6.0 mm vs. 10.6 mm; p = 0.007). Tibial slope, condylar offset ratios, and femoral joint line elevation were not significantly different between the FI and non-FI groups. We noted a significant difference in tibial slope in posterior-stabilized implants in subjects with and without FI (6.4° vs. 1.5°; p = 0.003). Radiographic measurements consistent with malalignment were not indicative of FI. X-ray measurements alone are not sufficient to conclude FI as patient symptoms, and clinical examinations remain the key indicators for diagnosis. Radiographic findings may aid in surgeon determination of an underlying cause for an already identified FI situation and help in planning revision surgery.

Analysis of the Quality of Prospective Randomized Controlled Trials for Treatment of Boxer's Fractures.

BACKGROUND: This study aimed to review level I and II therapeutic studies on boxer's fractures to measure variation in quality among the highest level study designs. METHODS: We used quantitative measures of study quality to evaluate prospective randomized controlled trials (RCTs) of treatments of boxer's fractures. A search of PubMed, using terms "boxer's fracture" and "fifth metacarpal neck fracture" identified 164 articles from 1961 to 2019. From this list, we identified 6 RCTs. Two observers classified each trial according to 3 systems: the Oxford Levels of Evidence, the modified Coleman Methodology Score, and the revised Consolidated Standards of Reporting Trials (CONSORT) score. RESULTS: The 2 reviewers were consistent in their use of the Oxford Levels of Evidence (100% agreement). The differences between the average modified Coleman Methodology scores and the average CONSORT scores assigned by the 2 observers were not significant (46.2 vs 45.3 points, κ = 0) and (13.7 vs 14.3 points, κ = 0.33), respectively. Both observers rated all the studies as level I and as unsatisfactory according to the Coleman Methodology Score (100% and 100%), and less than half as unsatisfactory according to the CONSORT score (50% and 17%). Areas of deficiency included randomization, blinding, group comparability, clinical effect measurements, and allocation into treatment arms. CONCLUSION: Classifying orthopedic scientific reports according to the levels of evidence implies a degree of respect for level I and II studies that may not always be merited. Our data suggest that the quality of higher level studies, namely those involving boxer's fractures, varies and may often be unsatisfactory when critically evaluated.

Mitochondrial genome recovery by ATFS-1 is essential for development after starvation.

Nutrient availability regulates the C. elegans life cycle as well as mitochondrial physiology. Food deprivation significantly reduces mitochondrial genome (mtDNA) numbers and leads to aging-related phenotypes. Here we show that the bZIP (basic leucine zipper) protein ATFS-1, a mediator of the mitochondrial unfolded protein response (UPRmt), is required to promote growth and establish a functional germline after prolonged starvation. We find that recovery of mtDNA copy numbers and development after starvation requires mitochondrion-localized ATFS-1 but not its nuclear transcription activity. We also find that the insulin-like receptor DAF-2 functions upstream of ATFS-1 to modulate mtDNA content. We show that reducing DAF-2 activity represses ATFS-1 nuclear function while causing an increase in mtDNA content, partly mediated by mitochondrion-localized ATFS-1. Our data indicate the importance of the UPRmt in recovering mitochondrial mass and suggest that atfs-1-dependent mtDNA replication precedes mitochondrial network expansion after starvation.

The hepatic integrated stress response suppresses the somatotroph axis to control liver damage in nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) can be ameliorated by calorie restriction, which leads to the suppressed somatotroph axis. Paradoxically, the suppressed somatotroph axis is associated with patients with NAFLD and is correlated with the severity of fibrosis. How the somatotroph axis becomes dysregulated and whether the repressed somatotroph axis impacts liver damage during the progression of NAFLD are unclear. Here, we identify a regulatory branch of the hepatic integrated stress response (ISR), which represses the somatotroph axis in hepatocytes through ATF3, resulting in enhanced cell survival and reduced cell proliferation. In mouse models of NAFLD, the ISR represses the somatotroph axis, leading to reduced apoptosis and inflammation but decreased hepatocyte proliferation and exacerbated fibrosis in the liver. NAD+ repletion reduces the ISR, rescues the dysregulated somatotroph axis, and alleviates NAFLD. These results establish that the hepatic ISR suppresses the somatotroph axis to control cell fate decisions and liver damage in NAFLD.

Pediatric fractures following implant removal: A systematic review.

Objectives: To evaluate the available literature for postoperative fracture rates following implant removal in the pediatric population. Methods: A systematic review of articles in the PubMed and Embase computerized literature databases from January 2000 to June 2022 was performed using PRISMA guidelines. Randomized controlled trials, case-control studies, cohort studies (retrospective and prospective), and case series involving pediatric patients that included data on fracture rate following removal of orthopedic implants were eligible for review. Two authors independently extracted data from selected studies for predefined data fields for implant type, anatomic location of the implant, indication for implantation, fracture or refracture rate following implant removal, mean time to implant removal, and mean follow-up time. Results: Fifteen studies were included for qualitative synthesis. Reported fracture rates following implant removal vary based on several factors, with an overall reported incidence of 0%-14.9%. The available literature did not offer sufficient data for conduction of a meta-analysis. Conclusion: Our systematic review demonstrates that fracture following implant removal in pediatric patients is a relatively frequent complication. In children, the forearm and femur are the most commonly reported sites of fracture following removal of implants. Traumatic fractures treated definitively with external fixation have the highest reported aggregate rate of refracture. Knowledge of the incidence of this risk is important for orthopedic surgeons. There remains a need for well-designed studies and trials to further clarify the roles of the variables that contribute to this complication.