In Situ Labeling of the Aqueous Compartment of Extracellular Vesicles with Luminescent Gold Nanoclusters

Extracellular vesicles (EVs) are well-known membrane-limited particles secreted by both healthy and cancerous cells. They are considered as biomarkers for early cancer diagnosis and are involved in many pathologies and physiological pathways. They could serve as diagnostic tools in liquid biopsies, as therapeutics in regenerative medicine, or as drug delivery vehicles. Our aim is here to encapsulate luminescent nanoprobes in the aqueous compartment of human EVs extracted from reproductive fluids. The analysis and labeling of the EVs content with easily detectable luminescent nanoparticles could enable a powerful tool for early diagnosis of specific diseases and also for the design of new therapeutics. In this view, gold nanoclusters (AuNCs) appear as an attractive alternative as nontoxic fluorophore probes because of their luminescence properties, large window of fluorescence lifetimes (1 ns-1 μs), ultrasmall size (<2 nm), good biocompatibility, and specific ability as X-ray photosensitizers. Here, we investigated an attractive method that uses fusogenic liposomes to deliver gold nanoclusters into EVs. This approach guarantees the preservation of the EVs membrane without any breakage, thus maintaining compartmental integrity. Different lipid compositions of liposomes preloaded with AuNCs were selected to interact electrostatically with human EVs and compared in terms of fusion efficiency. The mixture of liposomes and EVs results in membrane mixing as demonstrated by FRET experiments and fusion revealed by flux cytometry and cryo-TEM. The resulting fused EVs exhibit typical fluorescence of the AuNCs together with an increased size in agreement with fusion. Moreover, the fusion events in mixtures of EVs and AuNCs preloaded liposomes were analyzed by using cryo-electron microscopy. Finally, the ratio of released AuNCs during the fusion between the fusogenic liposomes and the EVs was estimated to be less than 20 mol % by Au titration using ICP spectroscopy.

scRNAseq and High-Throughput Spatial Analysis of Tumor and Normal Microenvironment in Solid Tumors Reveal a Possible Origin of Circulating Tumor Hybrid Cells

Metastatic cancer is a leading cause of death in cancer patients worldwide. While circulating hybrid cells (CHCs) are implicated in metastatic spread, studies documenting their tissue origin remain sparse, with limited candidate approaches using one-two markers. Utilizing high-throughput single-cell and spatial transcriptomics, we identified tumor hybrid cells (THCs) co-expressing epithelial and macrophage markers and expressing a distinct transcriptome. Rarely, normal tissue showed these cells (NHCs), but their transcriptome was easily distinguishable from THCs. THCs with unique transcriptomes were observed in breast and colon cancers, suggesting this to be a generalizable phenomenon across cancer types. This study establishes a framework for HC identification in large datasets, providing compelling evidence for their tissue residence and offering comprehensive transcriptomic characterization. Furthermore, it sheds light on their differential function and identifies pathways that could explain their newly acquired invasive capabilities. THCs should be considered as potential therapeutic targets.

Resection of intradural spinal lesions with concomitant instrumented fusion in children: a systematic review and representative cases

OBJECTIVE

More than one-third of pediatric patients who undergo resection of intradural spine lesions develop progressive postoperative deformity, with as many as half of these patients subsequently requiring surgical fusion. Intradural spinal procedures with simultaneous instrumented fusion in children, however, are infrequently performed. Moreover, the rationale for patient selection, outcomes, and safety of this single-stage surgery in children has not been systematically investigated. In this study, the authors review the practice of simultaneous intradural spinal resection and instrumented fusion in pediatric patients and provide two representative case examples from their institution.

METHODS

The authors searched the PubMed and Embase databases and performed a systematic review following the PRISMA protocol. Original articles of pediatric patients (age ≤ 18 years) who underwent intradural spine surgery, regardless of pathology, with concomitant instrumented fusion and reported outcomes were included. An institutional database of all spinal operations with instrumented fusion performed in patients aged ≤ 18 years over a 3-year period was screened to identify those who underwent intradural spine surgery with concomitant fusion.

RESULTS

Nine patients (median age 12 years) from 6 studies who underwent intradural lesion resection and concomitant fusion met inclusion criteria. Among all 11 patients included, primary rationales for concomitant fusion were extensive bone removal (i.e., corpectomy or total facetectomy, 73%), concerns for deformity in the setting of multilevel laminectomy/laminoplasty (18%), and severe baseline deformity (9%). The most represented pathology was neurenteric cyst (55%) followed by schwannoma (18%). Myxopapillary ependymoma, granular cell tumor, and pilocytic astrocytoma each were seen in 1 case. Seven patients (64%) underwent an anterior-approach corpectomy, tumor resection, and fusion, while the remaining 4 patients (36%) underwent a posterior approach. All patients with at least 1 year of follow-up cases achieved bony fusion. CSF leak and new-onset neurological deficit each occurred in 9% (1/11).

CONCLUSIONS

The rationales for performing single-stage intradural resection and fusion in pediatric patients in studies to date include the presence of severe baseline deformity, large extent of bone resection, and multilevel laminectomy/laminoplasty across cervicothoracic or thoracolumbar junctions. As current literature involving this cohort is limited, more data are needed to determine when concomitant fusion in intradural resections is appropriate in pediatric patients and whether its routine implementation is safe or beneficial.

Evaluating the Readability of Patient Education Materials for Anterior Vertebral Body Tethering, Distraction-Based Methods, and Posterior Spinal Fusion for the Treatment of Pediatric Spinal Deformity

BACKGROUND

The Internet is an important source of information for patients, but its effectiveness relies on the readability of its content. Patient education materials (PEMs) should be written at or below a sixth-grade reading level as outlined by agencies such as the American Medical Association. This study assessed PEMs' readability for the novel anterior vertebral body tethering (AVBT), distraction-based methods, and posterior spinal fusion (PSF) in treating pediatric spinal deformity.

METHODS

An online search identified PEMs using the terms "anterior vertebral body tethering," "growing rods scoliosis," and "posterior spinal fusion pediatric scoliosis." We selected the first 20 general medical websites (GMWs) and 10 academic health institution websites (AHIWs) discussing each treatment (90 websites total). Readability tests for each webpage were conducted using Readability Studio software. Reading grade levels (RGLs), which correspond to the US grade at which one is expected to comprehend the text, were calculated for sources and independent t tests compared with RGLs between treatment types.

RESULTS

The mean RGL was 12.1 ± 2.0. No articles were below a sixth-grade reading level, with only 2.2% at the sixth-grade reading level. AVBT articles had a higher RGL than distraction-based methods (12.7 ± 1.6 vs 11.9 ± 1.9, P = 0.082) and PSF (12.7 ± 1.6 vs 11.6 ± 2.3, P = 0.032). Materials for distraction-based methods and PSF were comparable (11.9 ± 1.9 vs 11.6 ± 2.3, P = 0.566). Among GMWs, AVBT materials had a higher RGL than distraction-based methods (12.9 ± 1.4 vs 12.1 ± 1.8, P = 0.133) and PSF (12.9 ± 1.4 vs 11.4 ± 2.4, P = 0.016).

CLINICAL RELEVANCE

Patients' health literacy is important for shared decision-making. Assessing the readability of scoliosis treatment PEMs guides physicians when sharing resources and discussing treatment with patients.

CONCLUSION

Both GMWs and AHIWs exceed recommended RGLs, which may limit patient and parent understanding. Within GMWs, AVBT materials are written at a higher RGL than other treatments, which may hinder informed decision-making and patient outcomes. Efforts should be made to create online resources at the appropriate RGL. At the very least, patients and parents may be directed toward AHIWs; RGLs are more consistent.

LEVEL OF EVIDENCE: 3

Does Bone Morphogenetic Protein Use Reduce Pseudarthrosis Rates in Single-Level Transforaminal Lumbar Interbody Fusion Surgeries?

BACKGROUND

Recombinant human bone morphogenetic protein 2 (rhBMP-2, or BMP for short) is a popular biological product used in spine surgeries to promote fusion and avoid the morbidity associated with iliac crest autograft. BMP's effect on pseudarthrosis in transforaminal lumbar interbody fusion (TLIF) remains unknown.

OBJECTIVE

To assess the rates of pseudarthrosis in single-level TLIF with and without concurrent use of BMP.

METHODS

This was a retrospective cohort study conducted at a single academic institution. Adults undergoing primary single-level TLIF with a minimum of 1 year of clinical and radiographic follow-up were included. BMP use was determined by operative notes at index surgery. Non-BMP cases with iliac crest bone graft were excluded. Pseudarthrosis was determined using radiographic and clinical evaluation. Bivariate differences between groups were assessed by independent t test and χ 2 analyses, and perioperative characteristics were analyzed by multiple logistic regression.

RESULTS

One hundred forty-eight single-level TLIF patients were included. The mean age was 59.3 years, and 52.0% were women. There were no demographic differences between patients who received BMP and those who did not. Pseudarthrosis rates in patients treated with BMP were 6.2% vs 7.5% in the no BMP group (P = 0.756). There was no difference in reoperation for pseudarthrosis between patients who received BMP (3.7%) vs those who did not receive BMP (7.5%, P = 0.314). Patients who underwent revision surgery for pseudarthrosis more commonly had diabetes with end-organ damage (revised 37.5% vs not revised 1.4%, P < 0.001). Multiple logistic regression analysis demonstrated no reduction in reoperation for pseudarthrosis related to BMP use (OR 0.2, 95% CI 0.1-3.7, P = 0.269). Diabetes with end-organ damage (OR 112.6,95% CI 5.7-2225.8, P = 0.002) increased the risk of reoperation for pseudarthrosis.

CONCLUSIONS

BMP use did not reduce the rate of pseudarthrosis or the number of reoperations for pseudarthrosis in single-level TLIFs. Diabetes with end-organ damage was a significant risk factor for pseudarthrosis.

CLINICAL RELEVANCE

BMP is frequently used "off-label" in transforaminal lumbar interbody fusion; however, little data exists to demonstrate its safety and efficacy in this procedure.

LEVEL OF EVIDENCE: 3

Diagnostic impact of RNA-based next-generation sequencing fusion panel for solid tumors: A single-institution experience

OBJECTIVES

Gene rearrangements frequently act as oncogenic driver mutations and determine the onset and progression of cancer. RNA-based next-generation sequencing (NGS) is being used with increasing frequency for solid tumors. The purpose of our study is to investigate the feasibility and utility of an RNA-based NGS fusion panel for solid tumors.

METHODS

We conducted a retrospective, single-institution review of fusion panels requested between May 2022 and March 2023. Demographic, clinical, pathologic, and molecular findings of the patients were reviewed. The utility of the RNA-based NGS fusion panel for the pathologic diagnosis of solid tumors was assessed.

RESULTS

Our study included 345 cases, and a fusion event was identified in 24.3% (78/321) of cases. Among the 110 cases submitted for diagnostic purposes, a fusion event was detected in 42.7% (47/110) of cases. The results led to refinement or clarification of the initial diagnosis in 31.9% (15/47) of cases and agreement or support for the initial diagnosis in 59.6% (28/47) of cases. Furthermore, our study indicated that the overall cellularity (tumor and normal tissue) of the tested specimen influences the success of the testing process.

CONCLUSIONS

In summary, this study demonstrated the feasibility and utility of an RNA-based NGS fusion panel for a wide variety of solid tumors in the appropriate clinicopathologic context. These findings warrant further validation in larger studies involving multiple institutional patient cohorts.

Impact of depression and anxiety on patient reported outcomes measures after lumbar fusion

INTRODUCTION

Depression and anxiety are common in patients undergoing spinal surgery and might negatively impact outcomes. This study investigates the possible effect of these diagnoses on patient reported outcomes following lumbar fusion.

METHODS

Retrospective review of a registry containing prospectively collected data of lumbar fusion procedures at a single institution was performed from 5/23/2012 to 6/15/2022. Patients with a minimum of two year follow up were included. Demographic information, diagnoses,medications, patient-reported outcomes measures (PROMs), and complications data at preoperative, three months, six months, one year, and two years postoperative were collected. Statistical analysis was performed using Student's T-tests, χ2, binomial correlation, odds ratios, logistic regression, and Mean Clinically Important Difference (MCID).

RESULTS

A total of 156 patients were included (60 male, 96 female) with mean age 62.6±11.1 years at surgery. Thirty-nine (25%) had depression and/or anxiety (DA). Baseline Oswestry Disability Index (ODI) and EQ5D scores were significantly worse in the DA cohort compared to controls (ODI 51.1±18.3 vs. 42.9±15.8; p=0.010, EQ5D 0.46±0.21 vs. 0.57±0.21; p=0.005). Both cohorts experienced similar relative improvement at two years (delta ODI -18.2±27.9 vs. -17.8±22.1; p=0.924, EQ5D 6.8±33.8 vs 8.1±32.9; p=0.830). Absolute outcome scores were worse in the DA cohort at all intervals. DA were not independently predictive of changes in PROMs (delta ODI mean difference 4.49, r2=0.36, p=0.924).

CONCLUSION

The present study showed similar improvement in PROMs following lumbar fusion for patients with anxiety and depression compared to healthy controls. These data suggest these patients are no less likely to benefit from appropriately planned lumbar fusion.

Can Discharge Radiographs Predict Junctional Complications? A Decision Tree Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To determine if standing pre-discharge radiographs can predict the development of junctional complications.

MATERIALS AND METHODS

Adult spinal deformity patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) were included. All patients underwent full-length standing radiographs before hospital discharge. Outcomes of interest included 2-year radiographic PJK and proximal junctional failure (PJF). Patients were stratified into 3 exclusive groups: No PJK, PJK, and PJF. Chi-square automatic interaction detection (CHAID) decision tree analysis was utilized to identify pre-discharge proximal junctional angle (PJA) thresholds associated with increased risk of PJK or PJF.

RESULTS

The 117 study patients had a mean age 65.8 ± 8.5, BMI 27.2 ± 4.9, PI-LL 23.3 ± 17.4, TPA 27.2 ± 11.5. Sample was stratified into 64 (54.7%) No PJK, 39 (33.3%) PJK, 14 (12.0%) PJF. No differences were detected between cohorts in discharge alignment, preop-discharge change, or offset from age-adjusted alignment targets (P > .005). Decision tree analysis showed that the first branch point depended on the UIV, as most patients with an UT UIV did not develop PJK or PJF (no PJK, 67.4%). For patients with an LT UIV, a second branch point occurred based on the ΔPJA. 89.5% of LT patients with a ΔPJA < 4.3° were free of radiographic PJK and PJF. The third branch point occurred based on the PJA at discharge. Thus, the highest risk group was comprised of ΔPJA ≥4.3° and PJA > 15.5°, as 57.1% of developed PJF and 28.6% PJK.

CONCLUSION

Most patients with a lower thoracic UIV, preop-discharge ΔPJA ≥4.3°, and discharge PJA > 15.5° develop PJF.

Reduced Monocular Luminance Promotes Fusion But Not Mixed Perception in Amblyopia

Purpose

The purpose of this study was to understand how monocular luminance reduction affects binocular balance and examine whether it differentially influences fusion and mixed perception in amblyopia.

Methods

Twenty-three normally sighted observers and 12 adults with amblyopia participated in this study. A novel binocular rivalry task was used to measure the phase duration of four perceptual responses (right- and left-tilts, fusion, and mixed perception) before and after a neutral density (ND) filter was applied at various levels to the dominant eye (DE) of controls and the fellow eye (FE) of patients with amblyopia. Phase durations were analyzed to assess whether the duration of fusion or mixed perception shifted after monocular luminance reduction. Moreover, we quantified ocular dominance and adjusted monocular contrast and luminance separately to investigate the relationship between changes in ocular dominance induced by the two manipulations.

Results

In line with previous studies, binocular balance shifted in favor of the brighter eye in both normal adults and patients with amblyopia. As a function of the ND filter's density, the duration of fusion and mixed perception decreased in normal controls, whereas that of fusion but not mixed perception increased significantly in patients with amblyopia. In addition, changes in binocular balance from luminance reduction were more significant in more balanced amblyopes or normal observers. Furthermore, shifts in binocular balance after contrast and luminance modulation were correlated in both normal and amblyopic observers.

Conclusions

The duration of fusion but not mixed perception increased in amblyopia after monocular luminance reduction in the FE. Moreover, our findings demonstrate that changes in ocular dominance from contrast-modulation and luminance-modulation are correlated in both normal and amblyopic observers.

Rapid quantitative detection system for measles virus-neutralizing antibodies using HiBiT-tagged virus-like particles

Immunological testing to detect neutralizing antibodies (NAbs) is important in measles (MV) infection control. Currently, the plaque reduction neutralization test is the only credible method for measuring actual virus NAbs; however, its feasibility is hampered by drawbacks, such as long turnaround times, low throughput, and the need for laboratory biosafety equipment. To solve these problems, we developed a simple and rapid MV-NAb detection system using lentivirus-based virus-like particles incorporated with the NanoLuc fragment peptide HiBiT comprising the MV fusion protein and hemagglutinin on their exterior surface. Overall, this simple, safe, and rapid method could be used to detect MV NAbs.

Why care for humanity?

Some of the most pressing challenges facing our planet-such as climate change, biodiversity loss, warfare and extreme poverty-require social cohesion and prosocial action on a global scale. How can this be achieved? Previous research suggests that identity fusion-a strong form of group cohesion motivating prosocial action-results from perceptions of shared personally transformative experiences or of common biological essence. Here, we present results from two studies with United States samples exploring each pathway to identity fusion on a global scale. Study 1 focused on globally shared motherhood experiences and found that US mothers were more fused with women around the world if they shared motherhood experiences with them, which was also reflected in money allocation behaviour. Study 2 showed that exposure to a talk about globally shared biology increased fusion with humanity at large, Americans and the extended family suggesting that fusion with humanity does not need to weaken fusion with nation or extended family. We discuss implications of our results for future research on bonding with humanity at large and for addressing collective action problems on a global scale.

Biportal endoscopic transforaminal lumbar interbody fusion using a large cage for degenerative spondylolisthesis with stenosis

Recently, biportal endoscopic transforaminal lumbar interbody fusion (TLIF) has been used to treat lumbar degenerative diseases, such as lumbar instability and spondylolisthesis. Biportal endoscopic TLIF may have the advantages of endoscopic spine approaches and minimally invasive lumbar fusion surgeries. In this biportal endoscopic TLIF, large cages similar to oblique lumbar interbody fusion (OLIF) cages have been used. Biportal endoscopic TLIF using a large cage can be successfully performed in the lower lumbar area. The author presents the surgical technique of biportal endoscopic TLIF using a large cage. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23231.

FGFR1 fusions as a novel molecular driver in rhabdomyosarcoma

The wide application of RNA sequencing in clinical practice has allowed the discovery of novel fusion genes, which have contributed to a refined molecular classification of rhabdomyosarcoma (RMS). Most fusions in RMS result in aberrant transcription factors, such as PAX3/7::FOXO1 in alveolar RMS (ARMS) and fusions involving VGLL2 or NCOA2 in infantile spindle cell RMS. However, recurrent fusions driving oncogenic kinase activation have not been reported in RMS. Triggered by an index case of an unclassified RMS (overlapping features between ARMS and sclerosing RMS) with a novel FGFR1::ANK1 fusion, we reviewed our molecular files for cases harboring FGFR1-related fusions. One additional case with an FGFR1::TACC1 fusion was identified in a tumor resembling embryonal RMS (ERMS) with anaplasia, but with no pathogenic variants in TP53 or DICER1 on germline testing. Both cases occurred in males, aged 7 and 24, and in the pelvis. The 2nd case also harbored additional alterations, including somatic TP53 and TET2 mutations. Two additional RMS cases (one unclassified, one ERMS) with FGFR1 overexpression but lacking FGFR1 fusions were identified by RNA sequencing. These two cases and the FGFR1::TACC1-positive case clustered together with the ERMS group by RNAseq. This is the first report of RMS harboring recurrent FGFR1 fusions. However, it remains unclear if FGFR1 fusions define a novel subset of RMS or alternatively, whether this alteration can sporadically drive the pathogenesis of known RMS subtypes, such as ERMS. Additional larger series with integrated genomic and epigenetic datasets are needed for better subclassification, as the resulting oncogenic kinase activation underscores the potential for targeted therapy.

Three-dimensional imaging studies in mice identify cellular dynamics of skeletal muscle regeneration

The function of many organs, including skeletal muscle, depends on their three-dimensional structure. Muscle regeneration therefore requires not only reestablishment of myofibers but also restoration of tissue architecture. Resident muscle stem cells (SCs) are essential for regeneration, but how SCs regenerate muscle architecture is largely unknown. We address this problem using genetic labeling of mouse SCs and whole-mount imaging to reconstruct, in three dimensions, muscle regeneration. Unexpectedly, we found that myofibers form via two distinct phases of fusion and the residual basement membrane of necrotic myofibers is critical for promoting fusion and orienting regenerated myofibers. Furthermore, the centralized myonuclei characteristic of regenerated myofibers are associated with myofibrillogenesis and endure months post injury. Finally, we elucidate two cellular mechanisms for the formation of branched myofibers, a pathology characteristic of diseased muscle. We provide a synthesis of the cellular events of regeneration and show that these differ from those used during development.

Functional properties of measles virus proteins derived from a subacute sclerosing panencephalitis patient who received repeated remdesivir treatments

Subacute sclerosing panencephalitis (SSPE) is a rare but fatal late neurological complication of measles, caused by persistent measles virus (MeV) infection of the central nervous system. There are no drugs approved for the treatment of SSPE. Here, we followed the clinical progression of a 5-year-old SSPE patient after treatment with the nucleoside analog remdesivir, conducted a post-mortem evaluation of the patient's brain, and characterized the MeV detected in the brain. The quality of life of the patient transiently improved after the first two courses of remdesivir, but a third course had no further clinical effect, and the patient eventually succumbed to his condition. Post-mortem evaluation of the brain displayed histopathological changes including loss of neurons and demyelination paired with abundant presence of MeV RNA-positive cells throughout the brain. Next-generation sequencing of RNA isolated from the brain revealed a complete MeV genome with mutations that are typically detected in SSPE, characterized by a hypermutated M gene. Additional mutations were detected in the polymerase (L) gene, which were not associated with resistance to remdesivir. Functional characterization showed that mutations in the F gene led to a hyperfusogenic phenotype predominantly mediated by N465I. Additionally, recombinant wild-type-based MeV with the SSPE-F gene or the F gene with the N465I mutation was no longer lymphotropic but instead efficiently disseminated in neural cultures. Altogether, this case encourages further investigation of remdesivir as a potential treatment of SSPE and highlights the necessity to functionally understand SSPE-causing MeV.IMPORTANCEMeasles virus (MeV) causes acute, systemic disease and remains an important cause of morbidity and mortality in humans. Despite the lack of known entry receptors in the brain, MeV can persistently infect the brain causing the rare but fatal neurological disorder subacute sclerosing panencephalitis (SSPE). SSPE-causing MeVs are characterized by a hypermutated genome and a hyperfusogenic F protein that facilitates the rapid spread of MeV throughout the brain. No treatment against SSPE is available, but the nucleoside analog remdesivir was recently demonstrated to be effective against MeV in vitro. We show that treatment of an SSPE patient with remdesivir led to transient clinical improvement and did not induce viral escape mutants, encouraging the future use of remdesivir in SSPE patients. Functional characterization of the viral proteins sheds light on the shared properties of SSPE-causing MeVs and further contributes to understanding how those viruses cause disease.

Steroidogenesis Upregulation through Mitochondria-Associated Endoplasmic Reticulum Membranes and Mitochondrial Dynamics in Rat Testes: The Role of D-Aspartate

Mitochondria-Associated Endoplasmic Reticulum Membranes (MAMs) mediate the communication between the Endoplasmic Reticulum (ER) and the mitochondria, playing a fundamental role in steroidogenesis. This study aimed to understand how D-aspartate (D-Asp), a well-known stimulator of testosterone biosynthesis and spermatogenesis, affects the mechanism of steroidogenesis in rat testes. Our results suggested that D-Asp exerts this function through MAMs, affecting lipid trafficking, calcium signaling, ER stress, and mitochondrial dynamics. After 15 days of oral administration of D-Asp to rats, there was an increase in both antioxidant enzymes (SOD and Catalase) and in the protein expression levels of ATAD3A, FACL4, and SOAT1, which are markers of lipid transfer, as well as VDAC and GRP75, which are markers of calcium signaling. Additionally, there was a decrease in protein expression levels of GRP78, a marker of aging that counteracts ER stress. The effects of D-Asp on mitochondrial dynamics strongly suggested its active role as well. It induced the expression levels of proteins involved in fusion (MFN1, MFN2, and OPA1) and in biogenesis (NRF1 and TFAM), as well as in mitochondrial mass (TOMM20), and decreased the expression level of DRP1, a crucial mitochondrial fission marker. These findings suggested D-Asp involvement in the functional improvement of mitochondria during steroidogenesis. Immunofluorescent signals of ATAD3A, MFN1/2, TFAM, and TOMM20 confirmed their localization in Leydig cells showing an intensity upgrade in D-Asp-treated rat testes. Taken together, our results demonstrate the involvement of D-Asp in the steroidogenesis of rat testes, acting at multiple stages of both MAMs and mitochondrial dynamics, opening new opportunities for future investigation in other steroidogenic tissues.

Predictive Factors of Postoperative Pain in Patients With Tibiotalocalcaneal Arthrodesis With an Intramedullary Nail: A Retrospective Review

Tibiotalocalcaneal arthrodesis has been shown in literature to have good results in regards to low complication rates and deformity correction. While previous studies have investigated functional outcomes and complication rates, no large-scale studies have looked at pain outcomes. The present study performed a retrospective review of 154 extremities to analyze how a patient's comorbidities and characteristics influence pain outcomes following a tibiotalocalcaneal arthrodesis. The present study found an average change of pain from 7.1 to 3.0 in at least a 6 month follow up. We found that a diagnosis of chronic pain and tobacco use had statistically significant less pain improvement compared to patients without chronic pain or current tobacco use. We determined no statistically significant difference in pain outcomes for patients with or without Charcot deformity. Lastly, we found that with older patients there was more pain improvement observed. We physicians can educate current tobacco users of the improved pain outcomes with tobacco cessation prior to surgery. We recommend a multidisciplinary approach for pain in patients with a pre-operative diagnosis of chronic pain and to educate patients on realistic postoperative pain outcomes.

Single-Position Prone Lateral Lumbar Interbody Fusion Technique Guide: Surgical Tips and Tricks

Lateral lumbar interbody fusion (LLIF) is a popular technique as it allows for the placement of a large interbody implant through a retroperitoneal, transpsoas working corridor. Historically, the interbody is placed with the patient in lateral decubitus and then repositioned to prone for the posterior instrumentation. While this has been an effective and successful technique, removing the interoperative flip would improve the efficiency of these cases. This has led to modified LLIF approaches including single-position prone LLIF (pLLIF). This modification has shown to be an efficient and powerful technique; however, learning to navigate the LLIF approach in the prone position has its own challenges. The purpose of this article is to provide a detailed description of our pLLIF technique while simultaneously introducing surgical tips to overcome the challenges of the approach and optimize the implantation of the interbody device.

Lumbar Decompression versus Decompression and Fusion in Octogenarians: Complications and Clinical Course With 3-Year Follow-Up

STUDY DESIGN

Retrospective review.

OBJECTIVES

This study aimed to assess and compare the clinical course and complications between surgical decompression and decompression with fusion in lumbar spine patients aged ≥80 years.

METHODS

A retrospective review of electronic medical records at a single institution was conducted between September 2005 and December 2021. Logistic regression was used to identify potential risk factors for the occurrence of complications.

RESULTS

Over a 16-year period, 327 patients were allocated to the decompression only group and 89 patients were allocated to the decompression and instrumented fusion group. The study had a mean follow-up duration of 36.7 ± 12.4 months. When assessing the CCI, patients of the instrumentation group had fewer comorbidities (8.9 ± .5 points vs 6.2 ± 1.5 points; P < .001), significantly longer surgical duration (290 ± 106 minutes vs 145 ±50.2 minutes; P < .001), significantly higher volume of intraoperative blood loss (791 ± 319.3 ml vs 336.1 ± 150.8 ml; P < .001), more frequent intraoperative blood transfusion (7 ± 2.1% vs 16± 18.0%; P < .001), and extended stays in the intensive care unit and hospitalization rates. Logistic regression analysis revealed that surgical duration and extent of surgery were unique risk factors for the occurrence of complications.

CONCLUSIONS

Lumbar decompression and additional fusion in octogenarians are considerable treatment techniques; albeit associated with increased complication risks. Prolonged operative time and extent of surgery are critical confounding factors associated with higher rates of postoperative complications. Surgery should only be performed after careful outweighing of potential benefits and risks.

Growth Patterns of Prostate Cancers Undetected by Prostate 3T Multiparametric MRI

BACKGROUND/AIM

The multiparametric magnetic resonance imaging (mpMRI)-ultrasound (US) fusion targeted biopsy (TB) is a useful diagnostic device for men with suspected prostate cancer (PC) and can increase the detection rate for clinically significant PCs (csPC). However, few studies have shown pathological findings of undetectable csPCs on the prostate mpMRI.

PATIENTS AND METHODS

This study investigated the growth patterns of csPC undetected in prostate mpMRI. The study enrolled 248 patients with suspected PCs and ≥PI-RADS 2 lesions, who then underwent mpMRI-US fusion TB and nearly prostate-mapping systematic biopsies (SB). A total 248 biopsies included 404 regions of interest in TB and 2976 mapping-regions in SB.

RESULTS

The detection rates of csPC, defined as PC grade group (GG) ≥2, were 42% in TB and 44% in SB, and the highest detection rate was 50%, using both TB and SB. Approximately 79% of PI-RADS 3/4/5 with any PC showed csPC. A total 201 PI-RADS 3/4/5 lesions showed benign prostatic hyperplasia, lymphocytic prostatitis, or fibromuscular stroma only in the core tissues. Notably, 22 csPCs detected in SB but undetected in prostate mpMRI preferentially showed a pattern of mixed well-formed and fused PC glands. The other patterns including cribriform glands and poorly formed glands with intracytoplasmic vacuoles were also seen. Approximately 85% of the 22 csPCs showed tumor volume less than 50% of core tissues.

CONCLUSION

Changes in prostatic stroma amounts, inflammation severity, tumor volume and growth patterns of PC glands affected the detectability of prostate mpMRI.

Filamentous-Actin-Mimicking Nanoplatform for Enhanced Cytosolic Protein Delivery

Despite the potential of protein therapeutics, the cytosolic delivery of proteins with high efficiency and bioactivity remains a significant challenge owing to exocytosis and lysosomal degradation after endocytosis. Therefore, it is important to develop a safe and efficient strategy to bypass endocytosis. Inspired by the extraordinary capability of filamentous-actin (F-actin) to promote cell membrane fusion, a cyanine dye assembly-containing nanoplatform mimicking the structure of natural F-actin is developed. The nanoplatform exhibits fast membrane fusion to cell membrane mimics and thus enters live cells through membrane fusion and bypasses endocytosis. Moreover, it is found to efficiently deliver protein cargos into live cells and quickly release them into the cytosol, leading to high protein cargo transfection efficiency and bioactivity. The nanoplatform also results in the superior inhibition of tumor cells when loaded with anti-tumor proteins. These results demonstrate that this fusogenic nanoplatform can be valuable for cytosolic protein delivery and tumor treatment.

Is single-level cervical disc arthroplasty associated with a lower reoperation rate than anterior cervical discectomy and fusion?

OBJECTIVE

Long-term meta-analysis of cervical disc arthroplasty (CDA) trials report lower rates of subsequent cervical spine surgical procedures with CDA compared with anterior cervical discectomy and fusion (ACDF). The objective of this study was to compare the rate of subsequent cervical spine surgery in single-level CDA-treated patients to that of a matched cohort of single-level ACDF-treated patients by using records from 2010 to 2021 included in a large national administrative claims database (PearlDiver).

METHODS

This retrospective matched-cohort study used a large national insurance claims database; 525,510 patients who had undergone a single-level ACDF or CDA between 2010 and 2021 were identified. Patients with other same-day spine procedures, as well as those for trauma, infection, or tumor, were excluded, yielding 148,531 patients. ACDF patients were matched 2:1 to CDA patients on the basis of clinical and demographic characteristics. The primary outcome was the overall incidence of all-cause cervical reoperation after index surgery. Secondary outcomes included readmission, any adverse event within 90 days, and overall reintervention after index surgery. Multivariable logistic regression analyses were adjusted for covariates and were employed to estimate the effect of the index ACDF or CDA procedure on patient outcomes. Survival was assessed using Kaplan-Meier estimation, and differences between ACDF- and CDA-treated patients were compared using log-rank tests.

RESULTS

After the patients were matched, 28,795 ACDF patients to 14,504 CDA patients were included. ACDF patients had higher rates of 90-day adverse events (18.4% vs 14.6%, adjusted odds ratio [aOR] 0.77, 95% CI 0.73-0.82, p < 0.001) and readmission (11.5% vs 9.7%, aOR 0.87, 95% CI 0.81-0.93, p < 0.001). Over a mean 4.3 years of follow-up, 5.0% of ACDF patients and 5.4% of CDA patients underwent reoperation (aOR 1.09, 95% CI 1.00-1.19, p = 0.059). The rate of aggregate reintervention was higher in CDA patients than in ACDF patients (11.7% vs 10.7%, aOR 1.10, p = 0.002). The Kaplan-Meier 10-year reoperation-free survival rate was worse for CDA than ACDF (91.0% vs 92.0%, p = 0.05), as was the rate of reintervention-free survival (81.2% vs 82.0%, p = 0.003).

CONCLUSIONS

Single-level CDA was associated with a similar rate of reoperation and higher rate of subsequent injections when compared with a matched cohort that underwent single-level ACDF. CDA was associated with lower rates of 90-day adverse events and readmissions.

Differences in microorganisms causing infection after cranial and spinal surgeries

OBJECTIVE

The primary aim of this retrospective study was to assess differences in the pathogens causing surgical site infections (SSIs) following craniectomies/craniotomies and open spinal surgery. The secondary aim was to assess differences in rates of SSI among these operative procedures.

METHODS

ANOVA tests with Bonferroni correction and incidence risk ratios (RRs) were used to identify differences in pathogens by surgical site and procedure using retrospective, de-identified records of 19,993 postneurosurgical patients treated between 2007 and 2020.

RESULTS

The overall infection rates for craniotomy/craniectomy, laminectomy, and fusion were 2.1%, 1.1%, and 1.5%, respectively, and overall infection rates for cervical, thoracic, and lumbar spine surgery were 0.3%, 1.6%, and 1.9%, respectively. Craniotomy/craniectomy was more likely to result in an SSI than spine surgery (RR 1.8, 95% CI 1.4-2.2, p < 0.0001). Cutibacterium acnes (RR 24.2, 95% CI 7.3-80.0, p < 0.0001); coagulase-negative staphylococci (CoNS) (methicillin-susceptible CoNS: RR 2.9, 95% CI 1.6-5.4, p = 0.0006; methicillin-resistant CoNS: RR 5.6, 95% CI 1.4-22.3, p = 0.02); Klebsiella aerogenes (RR 6.5, 95% CI 1.7-25.1, p = 0.0003); Serratia marcescens (RR 2.4, 95% CI 1.1-7.1, p = 0.01); Enterobacter cloacae (RR 3.1, 95% CI 1.2-8.1, p = 0.02); and Candida albicans (RR 3.9, 95% CI 1.2-12.3, p = 0.02) were more commonly associated with craniotomy/craniectomy cases than fusion or laminectomy SSIs. Pseudomonas aeruginosa was more commonly associated with fusion SSIs than craniotomy SSIs (RR 4.4, 95% CI 1.3-14.8, p = 0.02), whereas Escherichia coli was nonsignificantly associated with fusion SSIs compared to craniotomy SSIs (RR 4.1, 95% CI 0.9-18.1, p = 0.06). Infections with E. coli and P. aeruginosa occurred primarily in the lumbar spine (p = 0.0003 and p = 0.0001, respectively).

CONCLUSIONS

SSIs due to typical gastrointestinal or genitourinary gram-negative bacteria occur most commonly following lumbar surgery, particularly fusion, and are likely to be due to contamination of the surgical bed with microbial flora in the perianal area and genitourinary tract. Cutibacterium acnes in the skin flora of the head and neck increases risk of infection due to this microbe following surgical interventions in these body sites. The types of gram-negative bacteria associated with craniotomy/craniectomy SSIs suggest potential environmental sources of these pathogens. Based on the authors' findings, neurosurgeons should consider using a two-step skin preparation with benzoyl peroxide, in addition to a standard antiseptic such as alcoholic chlorhexidine for cranial, cervical, and upper thoracic surgeries. Additionally, broader gram-negative bacterial coverage, such as use of a third-generation cephalosporin, should be considered for lumbar/lumbosacral fusion surgical antibiotic prophylaxis.

Comparison of Loss of Bone Height Following Total Ankle Arthroplasty Versus Tibiotalocalcaneal Arthrodesis

Ankle arthrodesis and total ankle arthroplasty are both well-accepted surgical treatment options for end-stage ankle arthrosis. However, total ankle arthroplasty has gained popularity as the survivability of implants is improving. It is understood that there is loss of bone height following tibiotalocalcaneal arthrodesis, but to our knowledge, this has not been investigated in the setting of total ankle arthroplasty. A retrospective radiographic review was conducted over a 5-year period. We investigated all patients who underwent a tibiotalocalcaneal arthrodesis or total ankle arthroplasty for treatment of ankle arthritis by a single fellowship-trained orthopedic surgeon. The anterior and posterior height measurements were measured on preoperative and postoperative lateral radiographs. Differences between preoperative and postoperative heights were analyzed through a series of analyses of covariance. One hundred and thirty-three patients and 143 operative extremities were included: 71 operative extremities in the tibiotalocalcaneal arthrodesis group (mean age 55.5 ± 13.3 years, BMI 32.2 ± 7.9) and 72 in the total ankle arthroplasty group (mean age 65.4 ± 9.5 years, BMI 30.7 ± 6.4). Statistical analysis demonstrated a loss of height in the tibiotalocalcaneal arthrodesis group, and an increased anterior and posterior height in the total ankle arthroplasty group. However, when comparing the arthroplasty group and arthrodesis group only the anterior height measurement reached statistical significance when stratified by gender (p < .001). The potential change in height is an important factor to consider during surgical planning as a limb length discrepancy may result.

A Highly Sensitive XNA-Based RT-qPCR Assay for the Identification of ALK, RET, and ROS1 Fusions in Lung Cancer

Lung cancer is often triggered by genetic alterations that result in the expression of oncogenic tyrosine kinases. Specifically, ALK, RET, and ROS1 chimeric receptor tyrosine kinases are observed in approximately 5-7%, 1-2%, and 1-2% of NSCLC patients, respectively. The presence of these fusion genes determines the response to tyrosine kinase inhibitors. Thus, accurate detection of these gene fusions is essential in cancer research and precision oncology. To address this need, we have developed a multiplexed RT-qPCR assay using xeno nucleic acid (XNA) molecular clamping technology to detect lung cancer fusions. This assay can quantitatively detect thirteen ALK, seven ROS1, and seven RET gene fusions in FFPE samples. The sensitivity of the assay was established at a limit of detection of 50 copies of the synthetic template. Our assay has successfully identified all fusion transcripts using 50 ng of RNA from both reference FFPE samples and cell lines. After validation, a total of 77 lung cancer patient FFPE samples were tested, demonstrating the effectiveness of the XNA-based fusion gene assay with clinical samples. Importantly, this assay is adaptable to highly degraded RNA samples with low input amounts. Future steps involve expanding the testing to include a broader range of clinical samples as well as cell-free RNAs to further validate its applicability and reliability.

Normal and malaligned talonavicular fusion alters cadaveric foot pressure and kinematics

Talonavicular (TN) fusion is a common treatment for TN arthritis or deformity correction. There is incongruous evidence regarding remaining motion at the talocalcaneal and calcaneocuboid joints after TN fusion. Additionally, the effects of a malaligned TN fusion are not well understood and alignment of the fusion may be important for overall foot integrity. This project assessed the kinematic and kinetic effects of neutral and malaligned TN fusions. Ten cadaveric feet were tested on a gait simulator in four conditions: unfused, fused in neutral, fused in varus, and fused in valgus. The fusions were simulated with external fixation hardware. An eight-camera motion analysis system and a 10-segment foot model generated kinematic data, and a pressure mat captured pressure data. Simulated TN fusion was achieved in eight feet. From unfused to fused-neutral, range of motion (ROM) was not eliminated in the adjacent joints, but the positions of the joints changed significantly throughout stance phase. Furthermore, the ROM increased at the tibiotalar joint. Plantar pressure and center of pressure shifted laterally with neutral fusion. The malalignments marginally affected the ROM but changed joint positions throughout stance phase. Pressure patterns were shifted laterally in varus malalignment and medially in valgus malalignment. The residual motion and the altered kinematics at the joints in the triple joint complex after TN fusion may subsequently increase the incidence of arthritis. Clinical significance: This study quantifies the effects of talonavicular fusion and malalignment on the other joints of the triple joint complex.

A novel fusion framework of deep bottleneck residual convolutional neural network for breast cancer classification from mammogram images

With over 2.1 million new cases of breast cancer diagnosed annually, the incidence and mortality rate of this disease pose severe global health issues for women. Identifying the disease's influence is the only practical way to lessen it immediately. Numerous research works have developed automated methods using different medical imaging to identify BC. Still, the precision of each strategy differs based on the available resources, the issue's nature, and the dataset being used. We proposed a novel deep bottleneck convolutional neural network with a quantum optimization algorithm for breast cancer classification and diagnosis from mammogram images. Two novel deep architectures named three-residual blocks bottleneck and four-residual blocks bottle have been proposed with parallel and single paths. Bayesian Optimization (BO) has been employed to initialize hyperparameter values and train the architectures on the selected dataset. Deep features are extracted from the global average pool layer of both models. After that, a kernel-based canonical correlation analysis and entropy technique is proposed for the extracted deep features fusion. The fused feature set is further refined using an optimization technique named quantum generalized normal distribution optimization. The selected features are finally classified using several neural network classifiers, such as bi-layered and wide-neural networks. The experimental process was conducted on a publicly available mammogram imaging dataset named INbreast, and a maximum accuracy of 96.5% was obtained. Moreover, for the proposed method, the sensitivity rate is 96.45, the precision rate is 96.5, the F1 score value is 96.64, the MCC value is 92.97%, and the Kappa value is 92.97%, respectively. The proposed architectures are further utilized for the diagnosis process of infected regions. In addition, a detailed comparison has been conducted with a few recent techniques showing the proposed framework's higher accuracy and precision rate.

Two SEPALLATA MADS-Box Genes, SlMBP21 and SlMADS1, Have Cooperative Functions Required for Sepal Development in Tomato

MADS-box transcription factors have crucial functions in numerous physiological and biochemical processes during plant growth and development. Previous studies have reported that two MADS-box genes, SlMBP21 and SlMADS1, play important regulatory roles in the sepal development of tomato, respectively. However, the functional relationships between these two genes are still unknown. In order to investigate this, we simultaneously studied these two genes in tomato. Phylogenetic analysis showed that they were classified into the same branch of the SEPALLATA (SEP) clade. qRT-PCR displayed that both SlMBP21 and SlMADS1 transcripts are preferentially accumulated in sepals, and are increased with flower development. During sepal development, SlMBP21 is increased but SlMADS1 is decreased. Using the RNAi, tomato plants with reduced SlMBP21 mRNA generated enlarged and fused sepals, while simultaneous inhibition of SlMBP21 and SlMADS1 led to larger (longer and wider) and fused sepals than that in SlMBP21-RNAi lines. qRT-PCR results exhibited that the transcripts of genes relating to sepal development, ethylene, auxin and cell expansion were dramatically changed in SlMBP21-RNAi sepals, especially in SlMBP21-SlMADS1-RNAi sepals. Yeast two-hybrid assay displayed that SlMBP21 can interact with SlMBP21, SlAP2a, TAGL1 and RIN, and SlMADS1 can interact with SlAP2a and RIN, respectively. In conclusion, SlMBP21 and SlMADS1 cooperatively regulate sepal development in tomato by impacting the expression or activities of other related regulators or via interactions with other regulatory proteins.

Fusion genes in pancreatic tumors

Gene fusions and rearrangements play a crucial role in tumor biology. They are rare events typically detected in KRAS wild-type (WT) pancreatic tumors. Their identification can inform clinical management by enabling precision oncology, as fusions involving BRAF, FGFR2, RET, NTRK, NRG1, and ALK represent actionable targets in KRAS-WT cancers, and serve diagnostic purposes since fusions involving PRKACA/B represent the diagnostic hallmark of intraductal oncocytic papillary neoplasms (IOPNs). Although they are rare, the therapeutic and diagnostic importance of these genomic events should not be underestimated, highlighting the need for quality-ensured molecular diagnostics in the management of cancer. Herein we review the existing literature on the role of fusion genes in pancreatic tumors and their clinical potential as effective biomarkers and therapeutic targets.

The failed adult traumatic brachial plexus reconstruction

Traumatic adult brachial plexus injuries typically cause immediate loss of upper limb function. Timely multidisciplinary treatment in specialized centres often results in a useful helper arm. Both the patient and the surgical team can benefit from an open discussion to set realistic expectations. Surgical reconstruction is customized for each patient, considering their injury factors and functional objectives. Optimizing pain control, adherence to procedure indications and using meticulous surgical techniques help minimize the risk of failing to meet the patient's goals. The need for potential alternative treatment(s) if the desired result is not achieved should be detailed before the initial reconstruction. This review discusses late treatment options, including tendon transfers, joint fusions, free functioning muscle transfers and prosthetics, for managing the failed primary reconstruction of the traumatic adult brachial plexus.

Advancing Prone-Transpsoas Spine Surgery: A Narrative Review and Evolution of Indications with Representative Cases

The Prone Transpsoas (PTP) approach to lumbar spine surgery, emerging as an evolution of lateral lumbar interbody fusion (LLIF), offers significant advantages over traditional methods. PTP has demonstrated increased lumbar lordosis gains compared to LLIF, owing to the natural increase in lordosis afforded by prone positioning. Additionally, the prone position offers anatomical advantages, with shifts in the psoas muscle and lumbar plexus, reducing the likelihood of postoperative femoral plexopathy and moving critical peritoneal contents away from the approach. Furthermore, operative efficiency is a notable benefit of PTP. By eliminating the need for intraoperative position changes, PTP reduces surgical time, which in turn decreases the risk of complications and operative costs. Finally, its versatility extends to various lumbar pathologies, including degeneration, adjacent segment disease, and deformities. The growing body of evidence indicates that PTP is at least as safe as traditional approaches, with a potentially better complication profile. In this narrative review, we review the historical evolution of lateral interbody fusion, culminating in the prone transpsoas approach. We also describe several adjuncts of PTP, including robotics and radiation-reduction methods. Finally, we illustrate the versatility of PTP and its uses, ranging from 'simple' degenerative cases to complex deformity surgeries.

Mechanistic Insights into the Bacterial Luciferase-based Bioluminescence Resonance Energy Transfer Luminescence: The Role of Protein Complex Dimer

Bacterial bioluminescence holds significant potential in the realm of optical imaging due to the inherent advantages of bioluminescence and ease of operation. However, its practical utility is hindered by its low light intensity. The fusion of bacterial luciferase with a highly fluorescent protein has been demonstrated to significantly enhance autonomous luminescence. Nevertheless, the underlying mechanism behind this enhancement remains unclear, and there is a dearth of research investigating the mechanistic aspects of bioluminescence resonance energy transfer (BRET) luminescence, whether it occurs naturally or can be achieved through experimental means. In this study, we investigated the phenomenon of bacterial luciferase-based BRET luminescence employing a range of computational techniques, including structural modeling, molecular docking, molecular dynamics simulations, as well as combined quantum mechanics and molecular mechanics calculations. The theoretical findings suggest that the BRET luminescence occurs through resonance energy transfer between the excited bioluminophore and the ground chromophore within the protein complex dimer. The proposed mechanism of the protein complex dimer offers a microscopic understanding of the intriguing BRET phenomenon and has the potential to inspire further practical applications in the field of optical imaging.

A Hybrid System for Defect Detection on Rail Lines through the Fusion of Object and Context Information

Defect detection on rail lines is essential for ensuring safe and efficient transportation. Current image analysis methods with deep neural networks (DNNs) for defect detection often focus on the defects themselves while ignoring the related context. In this work, we propose a fusion model that combines both a targeted defect search and a context analysis, which is seen as a multimodal fusion task. Our model performs rule-based decision-level fusion, merging the confidence scores of multiple individual models to classify rail-line defects. We call the model "hybrid" in the sense that it is composed of supervised learning components and rule-based fusion. We first propose an improvement to existing vision-based defect detection methods by incorporating a convolutional block attention module (CBAM) in the you only look once (YOLO) versions 5 (YOLOv5) and 8 (YOLOv8) architectures for the detection of defects and contextual image elements. This attention module is applied at different detection scales. The domain-knowledge rules are applied to fuse the detection results. Our method demonstrates improvements over baseline models in vision-based defect detection. The model is open for the integration of modalities other than an image, e.g., sound and accelerometer data.

Nonunion Rate Following Primary Arthrodesis for Acute Lisfranc Injuries

Injury to the tarsometatarsal joint (TMT) results in instability throughout the midfoot that does not often improve with conservative management. If instability is identified, surgical intervention is frequently recommended, either open reduction and internal fixation (ORIF) or primary arthrodesis (PA). These 2 treatment options have been compared in the literature multiple times, often reporting similar outcomes. Due to this, as well as the need for subsequent hardware removal after ORIF has led many surgeons towards PA at the index surgery. Concern for nonunion is a leading concern with surgeons who advocate instead for ORIF. The purpose of this study is to review patients who underwent PA and observe nonunion rates. Nonunion at the TMT has been previously studied, but only in the chronic setting. We performed a retrospective study of 34 patients who had PA in the management of an acute Lisfranc injury. The average age in our study was 43.9 years old (range 19-72, SD 17.4) with an average follow-up of 9.4 months (range 4-33, SD 6.2). Radiographs were evaluated for signs of nonunion at regular postoperative intervals. Within the patients included in the study, a total of 71 TMT joints were fused. Overall successful fusion rate was 95.8% at an average of 7.9 weeks (range 6-12, SD 1.4) postoperatively. Individual nonunion rates at the first, second, and third TMT were 0%, 1.4% and 2.8% respectively. Our study demonstrates that primary arthrodesis provides a predictable outcome with low nonunion rates in the management of acute Lisfranc injury.

A Mechanistic Understanding of the Modes of Ca2+ Ion Binding to the SARS-CoV-1 Fusion Peptide and Their Role in the Dynamics of Host Membrane Penetration

The SARS-CoV-1 spike glycoprotein contains a fusion peptide (FP) segment that mediates the fusion of the viral and host cell membranes. Calcium ions are thought to position the FP optimally for membrane insertion by interacting with negatively charged residues in this segment (E801, D802, D812, E821, D825, and D830); however, which residues bind to calcium and in what combinations supportive of membrane insertion are unknown. Using biological assays and molecular dynamics studies, we have determined the functional configurations of FP-Ca2+ binding that likely promote membrane insertion. We first individually mutated the negatively charged residues in the SARS CoV-1 FP to assay their roles in cell entry and syncytia formation, finding that charge loss in the D802A or D830A mutants greatly reduced syncytia formation and pseudoparticle transduction of VeroE6 cells. Interestingly, one mutation (D812A) led to a modest increase in cell transduction, further indicating that FP function likely depends on calcium binding at specific residues and in specific combinations. To interpret these results mechanistically and identify specific modes of FP-Ca2+ binding that modulate membrane insertion, we performed molecular dynamics simulations of the SARS-CoV-1 FP and Ca2+ions. The preferred residue pairs for Ca2+ binding we identified (E801/D802, E801/D830, and D812/E821) include the two residues found to be essential for S function in our biological studies (D802 and D830). The three preferred Ca2+ binding pairs were also predicted to promote FP membrane insertion. We also identified a Ca2+ binding pair (E821/D825) predicted to inhibit FP membrane insertion. We then carried out simulations in the presence of membranes and found that binding of Ca2+ to SARS-CoV-1 FP residue pairs E801/D802 and D812/E821 facilitates membrane insertion by enabling the peptide to adopt conformations that shield the negative charges of the FP to reduce repulsion by the membrane phospholipid headgroups. This calcium binding mode also optimally positions the hydrophobic LLF region of the FP for membrane penetration. Conversely, Ca2+ binding to the FP E801/D802 and D821/D825 pairs eliminates the negative charge screening and instead creates a repulsive negative charge that hinders membrane penetration of the LLF motif. These computational results, taken together with our biological studies, provide an improved and nuanced mechanistic understanding of the dymanics of SARS-CoV-1 calcium binding and their potential effects on host cell entry.

Resolution of Radiculopathy Following Indirect Versus Direct Decompression in Single Level Lumbar Fusion

STUDY DESIGN

Retrospective analysis.

OBJECTIVES

To evaluate resolution of radiculopathy in one-level lumbar fusion with indirect or direct decompression techniques.

METHODS

Patients ≥18 years of age with preoperative radiculopathy undergoing single-level lumbar fusion with up to 2-year follow-up were grouped by indirect and direct decompression. Direct decompression (DD) group included ALIF and LLIF with posterior DD procedure as well as all TLIF. Indirect decompression (ID) group included ALIF and LLIF without posterior DD procedure. Propensity score matching was used to control for intergroup differences in age. Intergroup outcomes were compared using means comparison tests. Logistic regressions were used to correlate decompression type with symptom resolution over time. Significance set at P < .05.

RESULTS

116 patients were included: 58 direct decompression (DD) (mean 53.9y, 67.2% female) and 58 indirect decompression (ID) (mean 54.6y, 61.4% female). DD patients experienced greater blood loss than ID. Additionally, DD patients were 4.7 times more likely than ID patients to experience full resolution of radiculopathy at 3 months post-op. By 6 months, DD patients demonstrated larger reductions in VAS score. With regard to motor function, DD patients had improved motor score associated with the L5 dermatome at 6 months relative to ID patients.

CONCLUSIONS

Direct decompression was associated with greater resolution of radiculopathy in the near post-operative term, with no differences at long term follow-up when compared with indirect decompression. In particularly debilitated patients, these findings may influence surgeons to perform a direct decompression to achieve more rapid resolution of radiculopathy symptoms.

Craniocervical fusion in the paediatric population - case series of 21 patients

PURPOSE

Craniocervical junction instability in a paediatric population presents a formidable challenge to the neurosurgeon. With a variety of anatomical variations, diminutive bony and ligamentous structures, possible superimposed syndromic abnormalities, the craniocervical junction is a technically challenging region to operate within. We aimed to review our series of patients to identify the common pathologies necessitating craniocervical fusion along with the use of intraoperative image guidance.

METHODS

We performed a retrospective review of twenty-one patients, with a mean age of 8.1 years, undergoing craniocervical fixations, involving either occipitocervical fusion or atlantoaxial fixation, from a single institution over a twelve-year period. The presentation, preoperative investigations, indication for surgery, surgical procedure, use of intraoperative navigation and clinical and radiological results were examined.

RESULTS

Twelve patients underwent primary C1-2 fixation, with the remaining 9 undergoing occipitocervical fusion. Five patients underwent surgery for traumatic instability, seven for os odontoideum, six for congenital anomalies and three for post-infectious instability. Follow up for 20 patients averaged 34 months (range 2-93 months). Five patients had Trisomy 21 and all underwent C1-2 fixation. Frameless stereotactic image guidance was utilised in five patients. No patients suffered immediate complications resulting from craniocervical junction fusion. Patients were observed to either neurologically improve (n = 6), or arrest their neurological deterioration following surgical intervention (n = 14), with concomitant radiological evidence of osseous fusion at follow up in 18 of 20 patients (90%). Two patients (10%) had radiological evidence of screw lucency, but neither required intervention because of being asymptomatic.

CONCLUSIONS

Craniocervical fixation in a paediatric population is a viable and safe treatment modality for the management of disorders requiring stabilisation at the craniocervical junction. Our experience of utilising frameless stereotaxy in the setting of grossly distorted anatomical landmarks is also reported.

SARS-CoV-2 BA.2.86 enters lung cells and evades neutralizing antibodies with high efficiency

BA.2.86, a recently identified descendant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.2 sublineage, contains ∼35 mutations in the spike (S) protein and spreads in multiple countries. Here, we investigated whether the virus exhibits altered biological traits, focusing on S protein-driven viral entry. Employing pseudotyped particles, we show that BA.2.86, unlike other Omicron sublineages, enters Calu-3 lung cells with high efficiency and in a serine- but not cysteine-protease-dependent manner. Robust lung cell infection was confirmed with authentic BA.2.86, but the virus exhibited low specific infectivity. Further, BA.2.86 was highly resistant against all therapeutic antibodies tested, efficiently evading neutralization by antibodies induced by non-adapted vaccines. In contrast, BA.2.86 and the currently circulating EG.5.1 sublineage were appreciably neutralized by antibodies induced by the XBB.1.5-adapted vaccine. Collectively, BA.2.86 has regained a trait characteristic of early SARS-CoV-2 lineages, robust lung cell entry, and evades neutralizing antibodies. However, BA.2.86 exhibits low specific infectivity, which might limit transmissibility.

Incidence of Nonunion of the First Metatarsophalangeal Joint Arthrodesis After Failed Implant Arthroplasty: A Systematic Review

Joint arthroplasty of the first metatarsophalangeal (MTP) joint is an accepted surgical option for patients with hallux rigidus. However, this procedure has been reported to have a high complication rate and unpredictable survivorship. Implant arthroplasty failure is a devastating complication that results in significant osseous defect with altered biomechanics of the foot. Commonly, salvage options are limited to arthrodesis with bone grafting. However, outcomes are rarely reported. The purpose of this study is to investigate the fusion rates of first metatarsophalangeal joint arthrodesis after conversion from failed implant arthroplasty. A systematic review of electronic databases to find reports of conversion arthrodesis after failed implant arthroplasty was performed. Six studies involving a total of 76 patients with a weighted mean age of 54.9 met the inclusion criteria. Out of the 6 included articles, the nonunion rate was 16.5% at a weighted mean follow-up of 48.1 months. The nonunion rate in the current report is higher than reported nonunion rates of primary arthrodesis. More prospective studies with consistent and standard outcome measures are needed to further determine the success rate of this salvage procedure.Levels of Evidence: 4, Systematic Review of Level 4 Studies.

Class key feature extraction and fusion for 2D medical image segmentation

BACKGROUND

The size variation, complex semantic environment and high similarity in medical images often prevent deep learning models from achieving good performance.

PURPOSE

To overcome these problems and improve the model segmentation performance and generalizability.

METHODS

We propose the key class feature reconstruction module (KCRM), which ranks channel weights and selects key features (KFs) that contribute more to the segmentation results for each class. Meanwhile, KCRM reconstructs all local features to establish the dependence relationship from local features to KFs. In addition, we propose the spatial gating module (SGM), which employs KFs to generate two spatial maps to suppress irrelevant regions, strengthening the ability to locate semantic objects. Finally, we enable the model to adapt to size variations by diversifying the receptive field.

RESULTS

We integrate these modules into class key feature extraction and fusion network (CKFFNet) and validate its performance on three public medical datasets: CHAOS, UW-Madison, and ISIC2017. The experimental results show that our method achieves better segmentation results and generalizability than those of mainstream methods.

CONCLUSION

Through quantitative and qualitative research, the proposed module improves the segmentation results and enhances the model generalizability, making it suitable for application and expansion.

Management of recurrent lumbar disc herniation: a comparative analysis of posterior lumbar interbody fusion and repeat discectomy

Background

For recurrent lumbar disc herniation, many experts suggest a repeat discectomy without stabilization due to its minimal tissue manipulation, lower blood loss, shorter hospital stay, and lower cost, recent research on the role of instability in disc herniation has made fusion techniques popular among spinal surgeons. The authors compare the postoperative outcomes of posterior lumbar interbody fusion (PLIF) and repeat discectomy for same-level recurrent disc herniation.

Methods

The patients included had previously undergone discectomy and presented with a same-level recurrent lumbar disc herniation. The patients were placed into two groups: 1) discectomy only, 2) PLIF based on the absence or presence of segmental instability. Preoperative and postoperative Oswestry disability index scores, duration of surgery, blood loss, duration of hospitalization, and complications were analyzed.

Results

The repeat discectomy and fusion groups had 40 and 34 patients, respectively. The patients were followed up for 2.68 (1-4) years. There was no difference in the duration of hospitalization (3.73 vs. 3.29 days P=0.581) and operative time (101.25 vs. 108.82 mins, P=0.48). Repeat discectomy had lower intraoperative blood loss, 88.75 ml (50-150) versus 111.47 ml (30-250) in PLIF (P=0.289). PLIF had better ODI pain score 4.21 (0-10) versus 9.27 (0-20) (P-value of 0.018). Recurrence was 22.5% in repeat discectomy versus 0 in PLIF.

Conclusion

PLIF and repeat discectomy for recurrent lumbar disc herniation have comparable intraoperative blood loss, duration of surgery, and hospital stay. PLIF is associated with lower durotomy rates and better long-term pain control than discectomy. This is due to recurrence and progression of degenerative process in discectomy patients, which are eliminated and slowed, respectively, by PLIF.

Comparison of Different Osteobiologics in Terms of Imaging Modalities and Time Frames for Fusion Assessment in Anterior Cervical Discectomy and Fusion: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The study's primary objective was to determine how osteobiologic choice affects fusion rates in patients undergoing anterior cervical discectomy and fusion (ACDF). The study's secondary objectives were to 1) determine the optimal timing of fusion assessment following ACDF and 2) determine if osteobiologic type affects the timing and optimal modality of fusion assessment.

METHODS

A systematic search of PubMed/MEDLINE was conducted for literature published from 2000 through October 2020 comparing anterior fusion in the cervical spine with various osteobiologics. Both comparative studies and case series of ≥10 patients were included.

RESULTS

A total of 74 studies met the inclusion criteria. Seventeen studies evaluated the efficacy of autograft on fusion outcomes, and 23 studies assessed the efficacy of allograft on fusion outcomes. 3 studies evaluated the efficacy of demineralized bone matrix, and seven assessed the efficacy of rhBMP-2 on fusion outcomes. Other limited studies evaluated the efficacy of ceramics and bioactive glasses on fusion outcomes, and 4 assessed the efficacy of stem cell products. Most studies utilized dynamic radiographs for the assessment of fusion. Overall, there was a general lack of supportive data to determine the optimal timing of fusion assessment meaningfully or if osteobiologic type influenced fusion timing.

CONCLUSIONS

Achieving fusion following ACDF appears to remain an intricate interplay between host biology and various surgical factors, including the selection of osteobiologics. While alternative osteobiologics to autograft exist and may produce acceptable fusion rates, limitations in study methodology prevent any definitive conclusions from existing literature.

What factors influence surgical decision-making in anterior versus posterior surgery for cervical myelopathy? A QOD analysis

OBJECTIVE

The aim of this study was to explore the preoperative patient characteristics that affect surgical decision-making when selecting an anterior or posterior operative approach in patients diagnosed with cervical spondylotic myelopathy (CSM).

METHODS

This was a multi-institutional, retrospective study of the prospective Quality Outcomes Database (QOD) Cervical Spondylotic Myelopathy module. Patients aged 18 years or older diagnosed with primary CSM who underwent multilevel (≥ 2-level) elective surgery were included. Demographics and baseline clinical characteristics were collected.

RESULTS

Of the 841 patients with CSM in the database, 492 (58.5%) underwent multilevel anterior surgery and 349 (41.5%) underwent multilevel posterior surgery. Surgeons more often performed a posterior surgical approach in older patients (mean 64.8 ± 10.6 vs 58.5 ± 11.1 years, p < 0.001) and those with a higher American Society of Anesthesiologists class (class III or IV: 52.4% vs 46.3%, p = 0.003), a higher rate of motor deficit (67.0% vs 58.7%, p = 0.014), worse myelopathy (mean modified Japanese Orthopaedic Association score 11.4 ± 3.1 vs 12.4 ± 2.6, p < 0.001), and more levels treated (4.3 ± 1.3 vs 2.4 ± 0.6, p < 0.001). On the other hand, surgeons more frequently performed an anterior surgical approach when patients were employed (47.2% vs 23.2%, p < 0.001) and had intervertebral disc herniation as an underlying pathology (30.7% vs 9.2%, p < 0.001).

CONCLUSIONS

The selection of approach for patients with CSM depends on patient demographics and symptomology. Posterior surgery was performed in patients who were older and had worse systemic disease, increased myelopathy, and greater levels of stenosis. Anterior surgery was more often performed in patients who were employed and had intervertebral disc herniation.

Sarcomas With RAD51B Fusions Are Associated With a Heterogeneous Phenotype

RAD51B-rearranged sarcomas are rare neoplasms that exhibit a heterogeneous morphology. To date, 6 cases have been reported, all involving the uterus, including 4 perivascular epithelioid cell tumors (PEComas) and 2 leiomyosarcomas (LMS). In this study, we describe the morphologic, immunohistochemical, and molecular features of 8 additional sarcomas with RAD51B rearrangement, including the first extrauterine example. All patients were women with a median age of 57 years at presentation. Seven tumors originated in the uterus, and one in the lower extremity soft tissue, with a median tumor size of 12 cm. Histologically, 4 tumors showed predominantly spindle cell morphology with eosinophilic fibrillary cytoplasm, with or without nuclear pleomorphism, whereas 2 tumors exhibited pleomorphic epithelioid cells, featuring clear to eosinophilic, granular cytoplasm. Two neoplasms exhibited undifferentiated cytomorphology, including one with uniform small blue round cells. All tumors showed high-grade cytologic atypia and high mitotic activity (median: 30/10 high-power fields), whereas coagulative necrosis was noted in 6 cases and lymphovascular invasion in 2. By immunohistochemistry, 2 showed myoid and melanocytic markers in keeping with PEComa, whereas 4 cases were only positive for smooth muscle markers consistent with LMS (including 3 myxoid). The remaining 2 cases had a nonspecific immunoprofile. Five cases tested by targeted RNA sequencing (Archer FusionPlex, Illumina TruSight) showed different fusion partners (HMGA2, PDDC1, and CEP170). RAD51B rearrangements were identified by FISH in the remaining 3 cases. Targeted DNA sequencing in 2 cases was negative for TSC gene alterations. Clinical outcome, available in 5 patients (median follow-up, 19 months), revealed 3 local recurrences, 2 lung metastases, and 4 deaths due to disease. Our results expand the spectrum of sarcomas with RAD51B fusions, demonstrating variable clinical presentations, morphologic spectrum, and fusion partners. These tumors have a predilection for a uterine location, with either LMS, PEComa, or undifferentiated phenotypes, and are associated with an aggressive clinical course.

PEComa with ASPSCR1::TFE3 fusion: expanding the molecular genetic spectrum of TFE3-rearranged PEComa with an emphasis on overlap with alveolar soft part sarcoma

AIMS

Mesenchymal neoplasms involving TFE3 gene fusions are diverse, mainly include alveolar soft part sarcoma (ASPS) that is characterised by ASPSCR1::TFE3 fusion, and a small subset of perivascular epithelioid cell tumours (PEComas) referred to as TFE3-rearranged PEComa, that most frequently harbours SFPQ::TFE3 fusion. Historically, ASPS and TFE3-rearranged PEComa are considered two distinctive entities despite their known morphological overlap. However, recent studies have suggested a potential histogenetic relationship between them, and several neoplasms that showed morphological features more closely fit PEComa rather than ASPS but harboured ASPSCR1::TFE3 fusion have been documented. In this study, we report three cases of PEComa with ASPSCR1::TFE3 fusion.

METHODS AND RESULTS

Clinicopathological features were assessed and partner agnostic targeted next-generation sequencing on clinically validated platforms were performed. The patients are two females and one male with age at presentation ranging from 21 to 51 years. All three tumours were located in the viscera (rectum, kidney and cervix). On a relatively limited follow-up period (range = 9-15 months), all patients are alive without evidence of recurrent or metastatic disease. The neoplasms were composed of tight nested architecture of epithelioid clear cells separated by a delicate vascular network, two of which were associated with sheets of plump spindle cells, and none showed significant discohesive tumour morphology. Immunohistochemically, in addition to TFE3 protein, all three neoplasms demonstrated co-expression of melan-A and smooth muscle actin. RNA-sequencing identified ASPSCR1::TFE3 fusion in all three cases that were confirmed by subsequent fluorescence in-situ hybridisation analyses.

CONCLUSIONS

Our study expands the molecular genetic spectrum of TFE3-rearranged PEComa and further indicates its close relationship to ASPS.

Do Osteobiologics Augment Fusion in Anterior Cervical Discectomy and Fusion Surgery Performed With Mechanical Interbody Devices (Polyether ether ketone, Carbon Fiber, Metal Cages) and is the Fusion Rate Comparable to that With Autograft? A Systematic Review

STUDY DESIGN

Systematic Review of the Literature.

OBJECTIVE

The purpose of this study was to perform a systematic review describing fusion rates for anterior cervical discectomy and fusion (ACDF) using autograft vs various interbody devices augmented with different osteobiologic materials.

METHODS

A systematic review limited to the English language was performed in Medline, Embase and Cochrane library using Medical Subject Heading (MeSH) terms. Studies that evaluated fusion after ACDF using autografts and osteobiologics combined with PEEK, carbon fibre, or metal cages were searched for. Articles in full text that met the criteria were included in the review. The main outcomes evaluated were the time taken to merge, the definition of the fusion assessment, and the modality of the fusion assessment. The risk of bias of each article was assessed by the MINORS score or ROB 2.0 depending on the randomisation process.

RESULTS

The total number of references reviewed was six hundred and eighty-two. After applying the inclusion criteria, 54 were selected for the retrieval of the full text. Eight studies were selected and included for final analysis in this study. Fusion rates were reported between 83.3% and 100% for autograft groups compared to 46.5% and 100% for various interbody device/osteobiological combinations. The overall quality of the evidence in all radiographic fusion studies was considered insufficient due to a serious risk of bias.

CONCLUSION

Mechanical interbody devices augmented with osteobiologics performed similarly to autografts in terms of reliability and efficacy. Their time to fusion and fusion rate were comparable to autografts at the end of the final follow-up.

A Systematic Literature Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To assess the available evidence related to dose-dependent effectiveness (i.e., bone fusion) and morbidity of osteobiologics used in anterior cervical discectomy and fusion (ACDF).

METHODS

Studies with more than 9 adult patients with degenerated/herniated cervical discs operated for one-to four-levels ACDF reporting used osteobiologics doses, fusion rates at six months or later, and related comorbidities were included. PubMed, EMBASE, ClinicalTrials, and Cochrane were searched through September 2021. Data extracted in spread sheet and risk of bias assessed using MINORS and Rob-2.

RESULTS

Sixteen studies were selected and sub-grouped into BMP and non-BMP osteobiologics. For the 10 BMP studies, doses varied from 0.26 to 2.1 mg in 649 patients with fusion rates of 95.3 to 100% at 12 months. For other osteobiologics, each of six studies reported one type of osteobiologic in certain dose/concentration/volume in a total of 580 patients with fusion rates of 6.8 to 96.9% at 12 months. Risk of bias was low in three of the 13 non-randomized (18.75%) and in all the three randomized studies (100%).

CONCLUSIONS

Taking into account the inconsistent reporting within available literature, for BMP usage in ACDF, doses lower than 0.7 mg per level can achieve equal successful fusion rates as higher doses, and there is no complication-free dose proved yet. It seems that the lower the dose the lower the incidence of serious complications. As for non-BMP osteobiologics the studies are very limited for each osteobiologic and thus conclusions must be drawn individually and with caution.