EThcD as a Unique Tool for the Top-Down De Novo Sequencing of Intact Natural Ranid Amphibian Peptides.

De novo sequencing of any novel peptide/protein is a difficult task. Full sequence coverage, isomeric amino acid residues, inter- and intramolecular S-S bonds, and numerous other post-translational modifications make the investigators employ various chemical modifications, providing a variety of specific fragmentation MSn patterns. The chemical processes are time-consuming, and their yields never reach 100%, while the subsequent purification often leads to the loss of minor components of the initial peptide mixture. Here, we present the advantages of the EThcD method that enables establishing the full sequence of natural intact peptides of ranid frogs in de novo top-down mode without any chemical modifications. The method provides complete sequence coverage, including the cyclic disulfide section, and reliable identification of isomeric leucine/isoleucine residues. The proposed approach demonstrated its efficiency in the analysis of peptidomes of ranid frogs from several populations of Rana arvalis, Rana temporaria, and Pelophylax esculentus complexes.

Direct anterior compared to posterior approach for hip hemiarthroplasty following femoral neck fractures.

The differences in complication rates between the direct anterior and posterior approaches for hemiarthroplasty in elderly patients with femoral neck fractures are not yet fully understood. Dislocation, a severe complication associated with increased mortality and often requiring additional surgery, may occur less frequently with the direct anterior approach compared to the posterior approach. Careful consideration of patient demographics is essential when planning the surgical approach. Future research in this area should focus on robust randomized controlled trials involving elderly patients recovering from femoral neck fractures.

Evaluation of the Efficacy of a Novel Dermatotomy Device for Central Venous Cannulation.

OBJECTIVE: To test the effectiveness of a novel wire-guided scalpel (Guideblade) to create a precise dermatotomy incision for central venous catheter (CVC) insertion. DESIGN: Prospective, nonrandomized interventional study. SETTING: Stanford University, single-center teaching hospital. PARTICIPANTS: Cardiac and vascular surgical patients (n = 100) with planned CVC insertion for operation. INTERVENTIONS: A wire-guided scalpel was used during CVC insertion. RESULTS: A total of 188 CVCs were performed successfully with a wire-guided scalpel without the need for additional equipment in 100 patients, and 94% of CVCs were accomplished with only a single dermatotomy attempt. "No bleeding" or "minimal bleeding" at the insertion site was observed in 90% of patients 30 minutes after insertion and 80.7% at the conclusion of surgery. CONCLUSION: The wire-guided scalpel was effective in performing dermatotomy for CVC with a 100% success rate and a very high first-attempt rate. The wire-guided scalpel may decrease bleeding at the CVC insertion site.

Twelve-Year Progression of Osteochondral Lesions of the Talus Observed Using Magnetic Resonance Imaging.

Osteochondral lesions of the talus are common injuries that are most often the result of trauma. The natural progression of osteochondral lesions is not well understood. It is still unclear which lesions eventually lead to joint degeneration and osteoarthritic changes and if the treatment method affects the progression. The existing literature surrounding this topic is sparse, with inconsistent findings. The presented images are taken from a 72-year-old man with bilateral osteochondral lesions of the talus. To our knowledge, this is the first published series of images illustrating the natural progression of a patient with bilateral osteochondral lesions of the talus over a 12-year time period.

Arthroscopic management of pediatric ankle fractures: a systematic review.

Background: Arthroscopic-assisted treatment of ankle fractures has proven useful in the adult population, but little evidence exists for the utilization of arthroscopic-assisted ankle fracture fixation in the pediatric population. The purpose of this systematic review is to examine the management of pediatric ankle fractures using arthroscopy. Methods: A systematic review was performed using PubMed, Web of Science, CINAHL, and MEDLINE from database inception to February 22nd, 2023. Inclusion criteria for this systematic review was pediatric population less than age 18, arthroscopic surgery management, and ankle fracture. Results: A total of 19 articles (n=30 patients) out of 176 articles met final inclusion criteria with all articles consisting of case reports or case series. The average patient age was 13.8±1.6 years. Sixteen of the patients (53%) had arthroscopic surgery along with an adjunct surgery as indicated, whereas 14 patients (47%) had arthroscopic surgery with or without percutaneous fixation. A high majority of patients demonstrated full range-of-motion and large improvements in function. Conclusions: Arthroscopy is used with percutaneous fixation or in adjunct to open approaches for pediatric ankle fracture management with good results. More research is needed to determine the utility of arthroscopy in the management of pediatric ankle fractures.

An AAV capsid reprogrammed to bind human transferrin receptor mediates brain-wide gene delivery.

Developing vehicles that efficiently deliver genes throughout the human central nervous system (CNS) will broaden the range of treatable genetic diseases. We engineered an adeno-associated virus (AAV) capsid, BI-hTFR1, that binds human transferrin receptor (TfR1), a protein expressed on the blood-brain barrier. BI-hTFR1 was actively transported across human brain endothelial cells and, relative to AAV9, provided 40 to 50 times greater reporter expression in the CNS of human TFRC knockin mice. The enhanced tropism was CNS-specific and absent in wild-type mice. When used to deliver GBA1, mutations of which cause Gaucher disease and are linked to Parkinson's disease, BI-hTFR1 substantially increased brain and cerebrospinal fluid glucocerebrosidase activity compared with AAV9. These findings establish BI-hTFR1 as a potential vector for human CNS gene therapy.

Ankle Osteoarthritis.

Ankle osteoarthritis (OA) is less common than knee and hip OA, and 75% to 80% of all presentations are posttraumatic in nature, resulting from either ligamentous or bony injury to the ankle. While the ankle joint cartilage demonstrates capacity for self-restoration, the ankle joint is sensitive to aberrancies in biomechanics and the inflammatory milieu after an injury is thought to contribute to the onset of posttraumatic ankle OA. Conservative care for ankle OA is currently centered on pain reduction, and derivatives that may delay the progression of ankle OA are the subject of ongoing investigation. Surgical management for end-stage ankle OA currently focuses on ankle arthrodesis and total ankle arthroplasty. Specific indication for one procedure over the other is the topic of much debate. While total ankle arthroplasty has become more frequently used with the advent of newer generation systems, ankle arthrodesis may still be favored in younger patients with high-demand occupations.

Mucolytic Drugs Ambroxol and Bromhexine: Transformation under Aqueous Chlorination Conditions.

Bromhexine and ambroxol are among the mucolytic drugs most widely used to treat acute and chronic respiratory diseases. Entering the municipal wastewater and undergoing transformations during disinfection with active chlorine, these compounds can produce nitrogen- and bromine-containing disinfection by-products (DBPs) that are dangerous for aquatic ecosystems. In the present study, primary and deep degradation products of ambroxol and bromhexine obtained in model aquatic chlorination experiments were studied via the combination of high-performance liquid and gas chromatography with high-resolution mass spectrometry. It was shown that at the initial stages, the reactions of cyclization, hydroxylation, chlorination, electrophilic ipso-substitution of bromine atoms with chlorine, and oxidative N-dealkylation occur. Along with known metabolites, a number of novel primary DBPs were tentatively identified based on their elemental compositions and tandem mass spectra. Deep degradation of bromhexine and ambroxol gives twenty-four identified volatile and semi-volatile compounds of six classes, among which trihalomethanes account for more than 50%. The specific class of bromhexine- and ambroxol-related DBPs are bromine-containing haloanilines. Seven of them, including methoxy derivatives, were first discovered in the present study. One more novel class of DBPs associated with bromhexine and ambroxol is represented by halogenated indazoles formed through dealkylation of the primary transformation products containing pyrazoline or tetrahydropyrimidine cycle in their structure.

Examining the Evidence Regarding Smoking and Patient Outcomes for Isolated Meniscus Pathology: A Comprehensive Systematic Review and Meta-Analysis.

Smoking is a well-known cause of impairment in wound healing and postoperative outcomes; however, its effects on treating meniscus issues remain unclear. This study assesses the relationship between smoking and meniscus treatment outcomes. PubMed, Scopus, Cochrane, and CINAHL were searched from inception to 24 December 2023. Inclusion criteria encompassed studies examining smoking's impact on patient outcomes regarding meniscus pathology. A secondary PubMed search targeted randomized controlled trials (RCTs) in the top ten orthopedic journals focusing on meniscus pathology and smoking as a demographic variable. Meta-analysis of six studies (n = 528) assessed meniscus failure rate based on smoking status. Eighteen observational studies (n = 8353 patients; 53.25% male; mean age: 51.35 ± 11.53 years; follow-up: 184.11 ± 117.34 months) were analyzed, covering meniscus repair, meniscectomy, allograft transplant, conservative care, and arthroscopy. Results showed four studies (36.36%) linked smoking with worse meniscus repair outcomes, while seven studies (63.64%) did not find significant associations. Meta-analysis from six studies showed no significant impact of smoking on repair failure (p = 0.118). Regarding meniscectomy, one study (33.33%) identified a significant association with smoking, but two did not. Only one (3.8%) of the RCTs in leading orthopedic journals included smoking as a factor. The evidence on smoking's effect on meniscus treatment is mixed, necessitating further investigation.

Association of Radiographic Soft Tissue Thickness With Revision Total Ankle Arthroplasty Following Primary Total Ankle Arthroplasty: A Minimum of 5-year Follow-up.

Background: The incidence of primary total ankle arthroplasty (TAA) is rising, with a corresponding increase in revision surgeries. Despite this, research on risk factors for revision TAA following primary TAA remains limited. Radiographic soft tissue thickness has been explored as a potential predictor for outcomes in hip, knee, and shoulder arthroplasty, but its role in TAA has not been assessed. This study aimed to assess the predictive value of radiographic soft tissue thickness for identifying patients at risk of requiring revision surgery following primary TAA. Methods: A retrospective study was conducted on 323 patients who underwent primary TAA between 2003 and 2019. Radiographic measurements of soft tissue thickness were obtained from preoperative radiographs. Two novel radiographic measures of soft tissue thickness were developed and assessed (tibial tissue thickness and talus tissue thickness). Clinical variables including age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, diabetes, smoking status, primary diagnosis, and implant type were recorded. Logistic regression analysis was used to assess the predictive value of soft tissue thickness and BMI for revision TAA. Results: The rate of revision surgery was 4.3% (14 of 323 patients). Patients requiring revision had significantly greater tibial tissue (3.54 vs 2.48 cm; P = .02) and talus tissue (2.79 vs 2.42 cm; P = .02) thickness compared with those not requiring revision. Both the tibial tissue thickness (odds ratio 1.16 [1.12-1.20]; P < .01) and the talus tissue thickness (odds ratio: 1.10 [1.05-1.15]; P < .01) measurements were significant predictors of revision TAA in multivariable logistic regression models. However, BMI was not a significant predictor of revision TAA. The two metrics demonstrated excellent interrater reliability. Conclusion: Greater soft tissue thickness was a better predictor of revision TAA compared with BMI. These findings suggest that radiographic soft tissue thickness may be a valuable tool for assessing the risk of the need for revision TAA following primary TAA. Further research is needed to validate and explore the potential impact on clinical practice. Level of Evidence: Level III, comparative study.

Mechanism of Injury for Traumatic Mid-Foot Lisfranc Injuries: Impact of the COVID-19 Pandemic.

Background During the COVID-19 pandemic, Americans transitioned away from their normal routines, drove in motor vehicles less, and reduced their physical activity, ultimately influencing the incidence and nature of orthopedic injuries that were operatively managed. The purpose of this study was to evaluate the effect of the COVID-19 pandemic lockdown and subsequent deconditioning on the mechanism of injury and severity of Lisfranc injury. Methods This retrospective study included patients with a traumatic Lisfranc injury who were surgically treated by a foot and ankle fellowship-trained orthopedic surgeon between 2015 and 2021. Electronic health records were queried for patient demographics, mechanism of injury, physical exam findings, and pain scores. Preoperative radiographs were reviewed to grade Lisfranc injuries using the previously described Nunley-Vertullo classification system. Descriptive and univariate statistics were performed to compare 15 patients in the pre-COVID-19 cohort and 15 patients in the post-COVID-19 cohort. Results In the pre-COVID-19 cohort, 80% (n=12/15) of the patients were female, the mean age was 46±15 years, the mean BMI was 29.7±7 kg/m2, and the mean follow-up period was 18.1±12 months. In the post-COVID-19 cohort, 53% (n=8/15) of the patients were female, the mean age was 48.5±17 years, the mean BMI was 31.4±7 kg/m2, and the mean follow-up period was 9.5±4 months. Significantly higher proportions of plantar ecchymosis (n=8/15, 53%), neuropathic pain (n=7/15, 47%), and swelling (n=12/15, 80%) were present in the post-COVID-19 cohort. A low-energy mechanism of injury was sustained by 73% (n=11/15) of the pre-COVID-19 cohort and 80% (n=12/15) of the post-COVID-19 cohort. Lisfranc injuries for the pre-COVID-19 cohort and the post-COVID-19 cohort demonstrated the following classifications: Grade 1 (33%, n=5/15 vs. 40%, n=6/15), Grade 2 (60%, n=9/15 vs. 53%, n=8/15), and Grade 3 (7%, n=1/15 vs. 7%, n=1/15). Conclusion Although a higher proportion of plantar ecchymosis, neuropathic pain, and swelling was observed, there was no association between a low mechanism of injury and a higher grade of Lisfranc injury following the COVID-19 pandemic.

Polyvinyl Alcohol Hydrogel Hemiarthroplasty of First Metatarsophalangeal Joint Hallux Rigidus.

Background Hallux rigidus (HR) is the most common arthritic condition of the foot. Although first metatarsophalangeal joint (MTPJ) arthrodesis has been the historical gold-standard treatment, polyvinyl alcohol (PVA) hydrogel implants have gained popularity as a joint-sparing technique. However, recent studies have shown variable failure rates of PVA hydrogel implants. The purpose of this study was to report the five-year experience with PVA hydrogel implants performed by a single surgeon. Methodology Health records were queried from August 2016 to 2021 for patients who underwent primary PVA hydrogel implant hemiarthroplasty for symptomatic late-stage HR. Patient demographics and postoperative outcomes variables were evaluated. Kaplan-Meier analysis was used to evaluate implant survival. A total of 146 PVA hydrogel implant procedures were performed with a minimum six-month follow-up. Results The majority of patients were female (n = 103, 70.5%), with a mean age of 58.1 (±10.1) years, body mass index of 27.3 (±5.2) kg/m2, and American Society of Anesthesiologists score <3 (n = 131, 89.7%). The majority had stage II or III disease (n = 115, 78.8%). Patients experienced significant improvement in visual analog scale score (p < 0.0001) and hallux dorsiflexion (p = 0.0005). There were 22 (15.1%) complications, including implant subsidence (n = 15, 10.3%), deep infection (n = 6, 4.1%), and hypertrophic ossification (n = 1, 0.7%). Revision surgeries were required in 12.3% (n = 18) of patients at an average of 9.4 (±9.2) months postoperatively. This included nine (6.2%) revision PVA hydrogel implant procedures and nine (6.2%) first MTJP arthrodesis. The one- and two-year survival rates for MTPJ arthrodesis (n = 9) were 95.9% and 86.3%, respectively. Conclusions In the largest single-surgeon series reported, first MTPJ hemiarthroplasty with a PVA hydrogel implant significantly improved pain and hallux dorsiflexion at an average of 14.5 months postoperatively. There was a high two-year survivorship of 86.3% until failure which required first MTPJ arthrodesis. Future studies should be performed to refine the indications for PVA hydrogel implants and identify risk factors.

Reliable detection of stochastic epigenetic mutations and associations with cardiovascular aging.

Stochastic epigenetic mutations (SEMs) have been proposed as novel aging biomarkers to capture heterogeneity in age-related DNA methylation changes. SEMs are defined as outlier methylation patterns at cytosine-guanine dinucleotide sites, categorized as hypermethylated (hyperSEM) or hypomethylated (hypoSEM) relative to a reference. Because SEMs are defined by their outlier status, it is critical to differentiate extreme values due to technical noise or data artifacts from those due to real biology. Using technical replicate data, we found SEM detection is not reliable: across 3 datasets, 24 to 39% of hypoSEM and 46 to 67% of hyperSEM are not shared between replicates. We identified factors influencing SEM reliability-including blood cell type composition, probe beta-value statistics, genomic location, and presence of SNPs. We used these factors in a training dataset to build a machine learning-based filter that removes unreliable SEMs, and found this filter enhances reliability in two independent validation datasets. We assessed associations between SEM loads and aging phenotypes in the Framingham Heart Study and discovered that associations with aging outcomes were in large part driven by hypoSEMs at baseline methylated probes and hyperSEMs at baseline unmethylated probes, which are the same subsets that demonstrate highest technical reliability. These aging associations were preserved after filtering out unreliable SEMs and were enhanced after adjusting for blood cell composition. Finally, we utilized these insights to formulate best practices for SEM detection and introduce a novel R package, SEMdetectR, which uses parallel programming for efficient SEM detection with comprehensive options for detection, filtering, and analysis.

Age-Invariant Genes: Multi-Tissue Identification and Characterization of Murine Reference Genes.

Studies of the aging transcriptome focus on genes that change with age. But what can we learn from age-invariant genes-those that remain unchanged throughout the aging process? These genes also have a practical application: they serve as reference genes (often called housekeeping genes) in expression studies. Reference genes have mostly been identified and validated in young organisms, and no systematic investigation has been done across the lifespan. Here, we build upon a common pipeline for identifying reference genes in RNA-seq datasets to identify age-invariant genes across seventeen C57BL/6 mouse tissues (brain, lung, bone marrow, muscle, white blood cells, heart, small intestine, kidney, liver, pancreas, skin, brown, gonadal, marrow, and subcutaneous adipose tissue) spanning 1 to 21+ months of age. We identify 9 pan-tissue age-invariant genes and many tissue-specific age-invariant genes. These genes are stable across the lifespan and are validated in independent bulk RNA-seq datasets and RT-qPCR. We find age-invariant genes have shorter transcripts on average and are enriched for CpG islands. Interestingly, pathway enrichment analysis for age-invariant genes identifies an overrepresentation of molecular functions associated with some, but not all, hallmarks of aging. Thus, though hallmarks of aging typically involve changes in cell maintenance mechanisms, select genes associated with these hallmarks resist fluctuations in expression with age. Finally, our analysis concludes no classical reference gene is appropriate for aging studies in all tissues. Instead, we provide tissue-specific and pan-tissue genes for assays utilizing reference gene normalization (i.e., RT-qPCR) that can be applied to animals across the lifespan.

Cartilage Injuries: Basic Science Update.

The last several decades have brought about substantial development in our understanding of the biomolecular pathways associated with chondral disease and progression to arthritis. Within domains relevant to foot and ankle, genetic modification of stem cells, augmentation of bone marrow stimulation techniques, and improvement on existing scaffolds for delivery of orthobiologic agents hold promise in improving treatment of chondral injuries. This review summarizes novel developments in the understanding of the molecular pathways underlying chondral damage and some of the recent advancements within related therapeutics.

Fabrication of a Novel 3D Extrusion Bioink Containing Processed Human Articular Cartilage Matrix for Cartilage Tissue Engineering.

Cartilage damage presents a significant clinical challenge due to its intrinsic avascular nature which limits self-repair. Addressing this, our study focuses on an alginate-based bioink, integrating human articular cartilage, for cartilage tissue engineering. This novel bioink was formulated by encapsulating C20A4 human articular chondrocytes in sodium alginate, polyvinyl alcohol, gum arabic, and cartilage extracellular matrix powder sourced from allograft femoral condyle shavings. Using a 3D bioprinter, constructs were biofabricated and cross-linked, followed by culture in standard medium. Evaluations were conducted on cellular viability and gene expression at various stages. Results indicated that the printed constructs maintained a porous structure conducive to cell growth. Cellular viability was 87% post printing, which decreased to 76% after seven days, and significantly recovered to 86% by day 14. There was also a notable upregulation of chondrogenic genes, COL2A1 (p = 0.008) and SOX9 (p = 0.021), suggesting an enhancement in cartilage formation. This study concludes that the innovative bioink shows promise for cartilage regeneration, demonstrating substantial viability and gene expression conducive to repair and suggesting its potential for future therapeutic applications in cartilage repair.

Understanding Breast Cancer Surgery Through Tiktok: an Analysis of Video Content and Viewer Engagement.

BACKGROUND: Breast cancer is the most common cancer in adolescents and young adults. Social media, particularly TikTok, has emerged as a crucial platform for sharing health information in this population. This study aims to characterize breast cancer surgery information on TikTok, focusing on content reliability, viewer reception, and areas for improvement. METHODS: We queried the search terms "breast cancer surgery," "mastectomy," and "lumpectomy" on TikTok, evaluating the top 50 videos for each. After watching each video, characteristics were recorded including: creator characteristics, video metrics, viewer reception, and video content. Statistical analysis was performed using Spearman's rank correlations and t-tests. RESULTS: A total of 138 videos were analyzed (excluding 12 duplicates from the initial 150). These videos received 4,895,373 likes and 109,705 comments. The most common content types were storytelling (57%) and education (20%), and the most common creator types were patients (77.3%) and physicians (10.3%). Videos with educational content by physicians were rare (6.5%). Engagement varied on the basis of video length, search terms, and creator characteristics. Overall, viewer comments predominantly expressed support and interest. CONCLUSIONS: Our study reveals that information on breast cancer surgery is widely shared on TikTok and has high viewer engagement. Factors influencing impact include video length, creator background, and search terms. While social media has democratized information sharing, there is a relative lack of physician creators providing objective and educational content. We highlight opportunities for health professionals to engage in social media as a tool for health education and ensure diverse and reliable healthcare content on these platforms.

Diabetic management and infection risk in total ankle arthroplasty.

BACKGROUND: As total ankle arthroplasty (TAA) increases in popularity nationwide for the management of end-stage arthritis, it is essential to understand ways to mitigate the risk of infection. Diabetes increases the risk of infection due to compromised immunity and impaired wound-healing mechanisms. However, there is limited research on how diabetic management, inclusive of medications and glucose control, may impact infection risks post-TAA. This study aims to demonstrate the impact of diabetic management on the occurrence of periprosthetic joint infection (PJI) following TAA. METHODS: This was a retrospective study of patients who underwent a TAA at a single academic institution from March 2002 to May 2022. Patients with diabetes who developed an intraarticular infection following TAA were propensity score matched (1:3) to diabetic patients who did not. Data collection included demographics, implant types, diabetic medications, and preoperative hemoglobin A1c. PJI was diagnosed based on Musculoskeletal Infection Society (MSIS) criteria. Statistical analyses assessed differences in medication use, glucose control, and infection rates between groups. RESULTS: Of the 1863 patients who underwent TAA, 177 patients had a diagnosis of diabetes. The infection rate in patients with diabetes (2.8%) was higher than the total cohort rate (0.8%). Five patients with diabetes developed a PJI at an average of 2.2 months postoperatively. This cohort (n = 5) was compared to propensity score-matched controls (n = 15). There was no significant difference in diabetic medication use. Patients who developed PJI had higher rates of uncontrolled diabetes (60.0% vs. 6.7%) and average A1c levels (7.02% vs. 6.29%) compared to controls. CONCLUSION: Our findings suggest that the elevated risk of PJI observed in individuals with diabetes subsequent to TAA may be attributed not solely to the presence of diabetes, but to inadequate glycemic control. Effectively managing blood glucose levels is imperative for achieving favorable outcomes following TAA. LEVEL OF EVIDENCE: III.

Osteochondral Lesions of the Talus: Etiology, Clinical Presentation, Treatment Options, and Outcomes.

This article reviews the etiology, clinical presentation, classification schemes, and treatment options for osteochondral lesions of the talus. These lesions typically occur after a traumatic injury and are best diagnosed on MRI. Asymptomatic lesions and incidentally found lesions are best treated conservatively; however, acute displaced osteochondral fragments may require surgical treatment. Lesion characteristics may dictate surgical technique. Outcomes following surgical treatment may be impacted by patient age, BMI, and lesion characteristics.