Total hip arthroplasty in patients under 50 years old: Does cementless fixation have better results?

BACKGROUND

Cementless fixation for hip arthroplasties has increased in the last decades, particularly in younger patients. The purpose of this study was to compare the long-term results three different types of fixations in patients under 50years old.

METHODS

Cemented, hybrid and cementless fixations were assessed in patients under 50years old with a minimum follow-up of 8years. Loosening, demarcation, complications, and prosthesis survival were assessed. Functional analysis was performed with the modified Harris Hip Score and Visual analogue scale was collected.

RESULTS

Final series consisted in 222 patients. Significant improvement was observed regarding mHHS and VAS score in each group. We observed statistically significant difference regarding demarcation between the groups (P<.001). The higher rate of acetabular and femoral stem loosening was observed in the cemented (20.0%) and hybrid (18.9%) group. The lowest prosthesis survival rate after 16 years was observed in hybrid group (P<.001).

CONCLUSION

Total hip replacement has good long-term clinical and functional outcomes. The lowest rate of prosthesis survival was observed in hybrid group with 84.2% after 16years.

Multi-Modal Digital Impressions For Palatal Defects

INTRODUCTION

This in-vitro study investigated limitations of intra-oral scanners (IOS) in capturing palatal defects at decreased mouth openings. The trueness and precision of composite 3D-printed models from Cone-Beam Computed Tomography (CBCT) and IOS were measured.

METHODS

A partially dentate palatal defect model was scanned with IOS (3M™TrueDefinition) at various simulated mouth openings. Five silicone impressions were poured in gypsum. Scans were taken using 3M™TrueDefinition; Planmeca Planscan®, n=5 each. Model was scanned on two CBCT (PlanmecaProFace®; Accuitomo170®CBCT, n=5 each). Geomagic®Control2014™ was used to create composite-models merging CBCT with IOS. Thirty composite-models were 3D-printed. Trueness and precision were measured. Pearson Correlation Coefficients measured correlation between mouth opening and data capture. Data analysed using Kruskal-Wallis, Wilcoxon rank-sum, and ANOVA. Statistical significance inferred when p⟨0.05.

RESULTS

Mouth openings ⟨20mm, IOS didn't capture information of soft tissue. Increased mouth opening positively correlated with increased data capture(r=0.93, p=0.001). AccuitomoCBCT and TrueDefinition IOS composite-models had the highest (trueness) and [precision](median (IQR) 0.172 mm(0.062-0.426)); [mean [SD] 0.080 mm [0.008]]. Casts had the lowest results (median (IQR) 0.289 mm(0.119-1.565));[mean [SD] 0.338 mm [0.089]](p⟨0.001).

CONCLUSION

Mouth opening ⟨20mm resulted in insufficient data capture by IOS for clinical applications. Composite digital models showed promising trueness and precision results.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Memory deficit following resection of an intraventricular myxoid glioneuronal tumor impinging on the bilateral fornix: A case report

Background

Recently recognized as a distinct entity, a myxoid glioneuronal tumor (MGNT) is a rare, low-grade central nervous system tumor. MGNTs are commonly located at the septum pellucidum or in the third ventricle, increasing the likelihood of tumor or treatment-related damage to adjacent structures critical for memory, such as the fornix. Though there have been a handful of case reports of neurosurgical and oncological outcomes of MGNTs, memory outcomes following resection of MGNTs adjacent to the fornix have not been previously reported.

Methods

We present a case of a high functioning female for whom an MRI revealed an incidental finding of an intraventricular tumor adjacent to the fornix bilaterally. The patient underwent resection of the tumor followed by MRI surveillance without additional oncologic intervention. Due to reported cognitive problems, the patient was referred for serial neuropsychological evaluations.

Results

Post-operative MRI following resection revealed cytotoxic edema followed by selective, progressive atrophy of the bilateral anterior fornices. Post-surgically, the patient developed an isolated verbal memory impairment, which persisted one-year post resection with minimal improvement. The memory impairment impacted the patient's everyday functioning, including the ability to work in a cognitively demanding job.

Conclusion

This unique case demonstrates the critical role of the bilateral fornix in verbal memory and underscores the importance of a careful risk/benefit analysis when considering neurosurgical intervention to MGNTs and other intracranial lesions adjacent to this structure during neurosurgical planning.

The effect of fibre cell remodelling on the power and optical quality of the lens

Vertebrate eye lenses are uniquely adapted to form a refractive index gradient (GRIN) for improved acuity, and to grow slowly in size despite constant cell proliferation. The mechanisms behind these adaptations remain poorly understood. We hypothesize that cell compaction contributes to both. To test this notion, we examined the relationship between lens size and shape, refractive characteristics and the cross-sectional areas of constituent fibre cells in mice of different ages. We developed a block-face imaging method to visualize cellular cross sections and found that the cross-sectional areas of fibre cells rose and then decreased over time, with the most significant reduction occurring in denucleating cells in the adult lens cortex, followed by cells in the embryonic nucleus. These findings help reconcile differences between the predictions of lens growth models and empirical data. Biomechanical simulations suggested that compressive forces generated from continuous deposition of fibre cells could contribute to cellular compaction. However, optical measurements revealed that the GRIN did not mirror the pattern of cellular compaction, implying that compaction alone cannot account for GRIN formation and that additional mechanisms are likely to be involved.

Cost-Effectiveness Analysis of 68Ga-DOTATATE PET/MRI in Radiotherapy Planning in Patients with Intermediate-Risk Meningioma

BACKGROUND AND PURPOSE

While contrast-enhanced MR imaging is the criterion standard in meningioma diagnosis and treatment response assessment, gallium 68Ga-DOTATATE PET/MR imaging has increasingly demonstrated utility in meningioma diagnosis and management. Integrating 68Ga-DOTATATE PET/MR imaging in postsurgical radiation planning reduces the planning target volume and organ-at-risk dose. However, 68Ga-DOTATATE PET/MR imaging is not widely implemented in clinical practice due to higher perceived costs. Our study analyzes the cost-effectiveness of 68Ga-DOTATATE PET/MR imaging for postresection radiation therapy planning in patients with intermediate-risk meningioma.

MATERIALS AND METHODS

We developed a decision-analytical model based on both recommended guidelines on meningioma management and our institutional experience. Markov models were implemented to estimate quality-adjusted life-years (QALY). Cost-effectiveness analyses with willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were performed from a societal perspective. Sensitivity analyses were conducted to validate the results. Model input values were based on published literature.

RESULTS

The cost-effectiveness results demonstrated that 68Ga-DOTATATE PET/MR imaging yields higher QALY (5.47 versus 5.05) at a higher cost ($404,260 versus $395,535) compared with MR imaging alone. The incremental cost-effectiveness ratio analysis determined that 68Ga-DOTATATE PET/MR imaging is cost-effective at a willingness to pay of $50,000/QALY and $100,000/QALY. Furthermore, sensitivity analyses showed that 68Ga-DOTATATE PET/MR imaging is cost-effective at $50,000/QALY ($100,000/QALY) for specificity and sensitivity values above 76% (58%) and 53% (44%), respectively.

CONCLUSIONS

68Ga-DOTATATE PET/MR imaging as an adjunct imaging technique is cost-effective in postoperative treatment planning in patients with meningiomas. Most important, the model results show that the sensitivity and specificity cost-effective thresholds of 68Ga-DOTATATE PET/MR imaging could be attained in clinical practice.

Predictive nonlinear modeling of malignant myelopoiesis and tyrosine kinase inhibitor therapy

Chronic myeloid leukemia (CML) is a blood cancer characterized by dysregulated production of maturing myeloid cells driven by the product of the Philadelphia chromosome, the BCR-ABL1 tyrosine kinase. Tyrosine kinase inhibitors (TKIs) have proved effective in treating CML, but there is still a cohort of patients who do not respond to TKI therapy even in the absence of mutations in the BCR-ABL1 kinase domain that mediate drug resistance. To discover novel strategies to improve TKI therapy in CML, we developed a nonlinear mathematical model of CML hematopoiesis that incorporates feedback control and lineage branching. Cell-cell interactions were constrained using an automated model selection method together with previous observations and new in vivo data from a chimeric BCR-ABL1 transgenic mouse model of CML. The resulting quantitative model captures the dynamics of normal and CML cells at various stages of the disease and exhibits variable responses to TKI treatment, consistent with those of CML patients. The model predicts that an increase in the proportion of CML stem cells in the bone marrow would decrease the tendency of the disease to respond to TKI therapy, in concordance with clinical data and confirmed experimentally in mice. The model further suggests that, under our assumed similarities between normal and leukemic cells, a key predictor of refractory response to TKI treatment is an increased maximum probability of self-renewal of normal hematopoietic stem cells. We use these insights to develop a clinical prognostic criterion to predict the efficacy of TKI treatment and design strategies to improve treatment response. The model predicts that stimulating the differentiation of leukemic stem cells while applying TKI therapy can significantly improve treatment outcomes.

Bridging Big Data: Procedures for Combining Non-equivalent Cognitive Measures from the ENIGMA Consortium

Investigators in neuroscience have turned to Big Data to address replication and reliability issues by increasing sample sizes, statistical power, and representativeness of data. These efforts unveil new questions about integrating data arising from distinct sources and instruments. We focus on the most frequently assessed cognitive domain - memory testing - and demonstrate a process for reliable data harmonization across three common measures. We aggregated global raw data from 53 studies totaling N = 10,505 individuals. A mega-analysis was conducted using empirical bayes harmonization to remove site effects, followed by linear models adjusting for common covariates. A continuous item response theory (IRT) model estimated each individual's latent verbal learning ability while accounting for item difficulties. Harmonization significantly reduced inter-site variance while preserving covariate effects, and our conversion tool is freely available online. This demonstrates that large-scale data sharing and harmonization initiatives can address reproducibility and integration challenges across the behavioral sciences.

An Economic Low-profile Elliptical Microstrip Antenna-to-RWG Transition for Microwave Laboratory and X-Band Applications.. [DOI: 10.21203/rs.3.rs-2357185/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The work presents a low-cost compact microstrip line (MSL)-to-rectangular waveguide (RWG) transition for space communication, satellite communication, RADAR, amateur radio; microwave laboratory X-band applications. A 90˚ MSL-to-RWG transition comprises a MSL and a RWG (WR-90). An elliptical microstrip antenna is used as an RF energy launcher in RWG which is fabricated on a low-cost lossy FR4 epoxy substrate with a loss tangent of 0.02 and a permittivity of 4.4. An impedance mismatch between the 50 Ω MSL and 500 Ω RWG is a challenging task and it has been achieved by changes in the probe geometry, microstrip line (width and length) and by adjusting the dimensions (height, width, and length) of the waveguide slot cut at the bottom end. The impedance matching results in an improved -10dB return loss (RL) with insertion loss (IL) of 2.1 dB at 10.12 GHz and a relative bandwidth of approximately 27% (9.84 GHz-10.38 GHz). An extremely unidirectional with directivity (9.97 dBi) and high gain microstrip antenna (8.24 dBi) has been utilized for electromagnetic energy launch into the WR-90. Therefore the designed MSL-to-RWG transition is a suitable candidate for X-band applications such as microwave laboratory experiment purposes, front end in transmitter/receiver of Space and Satellite applications, RADAR, amateur radio, as a connector for MMIC/MIC circuits and devices. The transition-measured results are also presented.

A Survey on Quantitative Risk Estimation Approaches for Secure and Usable User Authentication on Smartphones

Mobile user authentication acts as the first line of defense, establishing confidence in the claimed identity of a mobile user, which it typically does as a precondition to allowing access to resources in a mobile device. NIST states that password schemes and/or biometrics comprise the most conventional user authentication mechanisms for mobile devices. Nevertheless, recent studies point out that nowadays password-based user authentication is imposing several limitations in terms of security and usability; thus, it is no longer considered secure and convenient for the mobile users. These limitations stress the need for the development and implementation of more secure and usable user authentication methods. Alternatively, biometric-based user authentication has gained attention as a promising solution for enhancing mobile security without sacrificing usability. This category encompasses methods that utilize human physical traits (physiological biometrics) or unconscious behaviors (behavioral biometrics). In particular, risk-based continuous user authentication, relying on behavioral biometrics, appears to have the potential to increase the reliability of authentication without sacrificing usability. In this context, we firstly present fundamentals on risk-based continuous user authentication, relying on behavioral biometrics on mobile devices. Additionally, we present an extensive overview of existing quantitative risk estimation approaches (QREA) found in the literature. We do so not only for risk-based user authentication on mobile devices, but also for other security applications such as user authentication in web/cloud services, intrusion detection systems, etc., that could be possibly adopted in risk-based continuous user authentication solutions for smartphones. The target of this study is to provide a foundation for organizing research efforts toward the design and development of proper quantitative risk estimation approaches for the development of risk-based continuous user authentication solutions for smartphones. The reviewed quantitative risk estimation approaches have been divided into the following five main categories: (i) probabilistic approaches, (ii) machine learning-based approaches, (iii) fuzzy logic models, (iv) non-graph-based models, and (v) Monte Carlo simulation models. Our main findings are summarized in the table in the end of the manuscript.

Risk factors for fixation failure in intertrochanteric fractures treated with cephalomedullary nailing: a retrospective study of 251 patients

This study aimed to identify the variables associated with fixation failure in intertrochanteric fractures treated with cephalomedullary nailing (CMN). We retrospectively analyzed 251 consecutive patients who underwent surgery between January 2016 and July 2019. In order to identify predictors of failure (cut-out, cut-through, and/or nonunion), we analyzed: gender, age, fracture stability (according to the AO/OTA Classification), femoral neck angle (FNA), FNA as compared to the contralateral hip, lag screw position, and tip-apex distance (TAD). The failure rate was 9.6%: there were 10 cut-outs (4%), 7 non-unions (2.8%), and 7 cut-throughs (2.8%). Univariate logistic regression analysis showed that the risk factors for fixation failure were: female sex (p= 0.018), FNA <125° (p= 0.003), a difference in FNA of 7.5° as compared to the contralateral hip on the lateral radiograph (p= <0.0001), superior (p= 0.0141) and anterior position (p= <0.0001) of the lag screw, and TAD >25mm (p= 0.016). According to the multivariate analysis, female gender (OR 12.92 ; p 0.0019), the difference in FNA on the lateral view (OR 1.36; p < 0.001), and the anterior position of the screw in the femoral head (OR14.01;p <0.001) were confirmed as independent predictors of failure. In order to avoid failures in intertrochanteric hip fractures treated with CMN, this study confirmed the importance of achieving an accurate reduction on the lateral plane and avoiding the anterior position of the screw on the femoral head.

Fine-scale evaluation of two standard 16S rRNA gene amplicon primer pairs for analysis of total prokaryotes and archaeal nitrifiers in differently managed soils

The advance of high-throughput molecular biology tools allows in-depth profiling of microbial communities in soils, which possess a high diversity of prokaryotic microorganisms. Amplicon-based sequencing of 16S rRNA genes is the most common approach to studying the richness and composition of soil prokaryotes. To reliably detect different taxonomic lineages of microorganisms in a single soil sample, an adequate pipeline including DNA isolation, primer selection, PCR amplification, library preparation, DNA sequencing, and bioinformatic post-processing is required. Besides DNA sequencing quality and depth, the selection of PCR primers and PCR amplification reactions arguably have the largest influence on the results. This study tested the performance and potential bias of two primer pairs, i.e., 515F (Parada)-806R (Apprill) and 515F (Parada)-926R (Quince) in the standard pipelines of 16S rRNA gene Illumina amplicon sequencing protocol developed by the Earth Microbiome Project (EMP), against shotgun metagenome-based 16S rRNA gene reads. The evaluation was conducted using five differently managed soils. We observed a higher richness of soil total prokaryotes by using reverse primer 806R compared to 926R, contradicting to in silico evaluation results. Both primer pairs revealed various degrees of taxon-specific bias compared to metagenome-derived 16S rRNA gene reads. Nonetheless, we found consistent patterns of microbial community variation associated with different land uses, irrespective of primers used. Total microbial communities, as well as ammonia oxidizing archaea (AOA), the predominant ammonia oxidizers in these soils, shifted along with increased soil pH due to agricultural management. In the unmanaged low pH plot abundance of AOA was dominated by the acid-tolerant NS-Gamma clade, whereas limed agricultural plots were dominated by neutral-alkaliphilic NS-Delta/NS-Alpha clades. This study stresses how primer selection influences community composition and highlights the importance of primer selection for comparative and integrative studies, and that conclusions must be drawn with caution if data from different sequencing pipelines are to be compared.

Profile and prognosis of patients with heart failure with recovered ejection fraction

Background

Patients with heart failure (HF) and reduced ejection fraction (rEF) have a poor prognosis. Nevertheless, in the subgroup of patients with recovered ejection fraction (recEF) prognosis is unknown.

Purpose

To analyze characteristics and prognosis in patients with HFrEF (initial EF and at one year &lt;40%) and HFrecEF (initial EF &lt;40% and at one year ≥40% with ≥10% absolute improvement from the initial value).

Methods

Retrospective observational study of outpatients referred to the HF unit within March/2006 and November/2021. Baseline characteristics, ecocardiographic data and follow-up were collected, discerning between patients with HFrEF and HFrecEF.

Results

A total of 346 patients (76.0% men) were analyzed with a mean of age 66.3 (IQR 57.8–74.4) years, of which 50.6% remained with rEF and 49.4% recEF. Median follow-up was 4.6 (2.8–7.9) years. Both groups had a similar risk profile albeit less prevalence of dyslipidemia in the group with recEF (43.5% vs 56.7%, p=0.015). Ischemic etiology predominated in those with rEF (41.7% vs 25.7%, p=0.002) and enolic in recEF (10.5% vs 3.4%, p=0.009). The incidence of combined event (readmission for HF or death) was lower in HFrecEF (33.6% vs 66.4%, p&lt;0.001), as well as death (33.9% vs 66.1%, p&lt;0.001) and readmission for HF (24.4% vs 75.6%, p&lt;0.001). Prevalence of cardiovascular death was lower in the group with recEF (37.8% vs 61.1%, p=0.021). In the multivariate analysis, rEF was an independent predictor for the combined event (HR 2.17; 95% IC [1.45–3.25], p&lt;0.001), as well as for global mortality and readmission for HF.

Conclusion

Patients with HFrecEF have a similar risk profile than patients with HFrEF although with better long-term prognosis.

Funding Acknowledgement

Type of funding sources: None.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Majority Vote Cascading: A Semi-Supervised Framework for Improving Protein Function Prediction

A method to improve protein function prediction for sparsely annotated PPI networks is introduced. The method extends the DSD majority vote algorithm introduced by Cao et al. to give confidence scores on predicted labels and to use predictions of high confidence to predict the labels of other nodes in subsequent rounds. We call this a majority vote cascade. Several cascade variants are tested in a stringent cross-validation experiment on PPI networks from S. cerevisiae and D. melanogaster, and we show that for many different settings with several alternative confidence functions, cascading improves the accuracy of the predictions. A list of the most confident new label predictions in the two networks is also reported. Code and networks for the cross-validation experiments appear at http://bcb.cs.tufts.edu/cascade.

Analysis of gyrobianisotropic media effect on the input impedance, field distribution and mutual coupling of a printed dipole antenna

In this paper, we present an analytical study for the investigation of the effects of the magnetoelectric elements of a reciprocal and nonreciprocal bianisotropic grounded substrate on the input impedance, resonant length of a dipole antenna as well as on the mutual coupling between two element printed dipole array in three configuration geometries: broadside, collinear and echelon printed on the same material. This study examines also the effect of the considered bianisotropic medium on the electric and magnetic field distributions that has been less addressed in the literature for antenna structures. Computations are based on the numerical resolution, using the spectral method of moments, of the integral equation developed through the mathematical derivation of the appropriate spectral Green's functions of the studied dipole configuration. Original results, for chiral, achiral, Tellegen and general bi-anisotropic media cases, are obtained and discussed with the electric and magnetic field distributions for a better understanding and interpretation. These interesting results can serve as a stepping stone for further works to attract more attention to the reciprocal and non-reciprocal Tellgen media in-depth studies.

Clinical Correlates of Cardiac Conduction in Bipolar Disorder

Introduction

Patients with bipolar disorder (BD) have an increased risk for cardiovascular morbimortality. Clinical risk factors, specifically for arrhythmias and sudden cardiac death remain understudied.

Objectives

This study was conducted to assess differences in cardiac conduction among BD patients.

Methods

We included patients with BD in a cross-sectional design, confirmed by structured interview, age 18 through 80. Clinical characteristics were obtained using a structured questionnaire or medical records review. ECG intervals duration and morphology were manually assessed by cardiologists and compared among clinical subgroups using Chi-square, Mann-Whitney, and Kruskall-Wallis tests. Exploratory multivariable linear and logistic regression models were fitted to adjust for potential confounders.

Results

We included 117 patients (60.7% women, 76.9% bipolar I, 50% history of psychosis, 22.6% suicide attempts). We found a significantly longer QTc interval in BD patients with hypertension (difference: 9.5 ms, p=0.006), obesity (difference: 25 ms, p=0.001), and metabolic syndrome (difference: 13 ms, p=0.007). Hypertension remained a significant predictor of longer QTc after adjusting for age, gender, and antipsychotic use (estimate 17.718, p=0.018). We observed a significantly shorter PR interval in women (difference: 6 ms, p=0.029), early age of onset (difference 6 ms, p=0.025), non-users of lithium (difference 4 ms, p=0.002), and early trauma (difference 4 ms, p=0.038). Finally, we identified significant correlations between symptom severity, blood glucose and PR interval (r=0.298, p=0.001; r=0.278, p=0.003; respectively).

Conclusions

Patients with BD and hypertension may have an increased risk for QTc prolongation. Careful cardiovascular monitoring may be warranted.

Disclosure

No significant relationships.

OP0223 DISTINGUISHING OSTEOARTHRITIS AND RHEUMATOID ARTHRITIS SYNOVIUM WITH MACHINE LEARNING USING AUTOMATED CELL DENSITY AND PATHOLOGIST SCORES

Background

Joint damage in the knee can be severe in both rheumatoid arthritis (RA) and osteoarthritis (OA) such that total knee replacement (TKR) is often the only management option. Pathological assessment of the extent or type of synovial tissue inflammation from joint explants or biopsies can be useful. However, an ongoing challenge in using semi-quantitative assessments of synovitis is the disagreement between human pathologist scores of the same sample. We previously developed and validated a computer vision algorithm to automatically count each cell nucleus in an H&E-stained synovial whole slide image and yield a value of cell density, defined as mean nuclei count per mm2 of tissue1.

Objectives

We sought to develop methods to distinguish OA from RA based on machine learning analysis of histologic features on H&E-stained synovial tissue samples.

Methods

We measured 14 pathologist-scored histology features (137 RA and 152 OA patients) and computer vision quantified cell density (60 RA and 147 OA patients) in H&E stained synovial tissue samples from total knee replacement arthroplasty explants. A random forest model was trained using disease state (OA vs RA) as classifier and histology features and/or cell density as inputs, and feature importance scores for the model were calculated.

Results

Synovium from patients with RA exhibited increased lymphocytic inflammation, lining hyperplasia, neutrophils, detritus, plasma cells, Russell bodies, binucleate plasma cells, sub-lining giant cells, synovial lining giant cells, and fibrin (all p<0.001), while synovium from patients with OA had increased mast cells and fibrosis (both p<0.001). Fourteen pathologist-scored features allowed for discrimination between RA and OA samples, producing a macro-averaged area under the receiver operating curve (AUC) of 0.85. This discriminatory ability was comparable to that of the computer vision score of cell density alone (AUC = 0.88). Combining the pathologist scores with the cell density metric improved the discriminatory power of the model (AUC = 0.91). The three most important features in this combined model were mast cells followed by cell density and fibrosis (Figure 1). AUC values for each individual feature are provided in Table 1. The optimal cell density threshold to distinguish RA from OA synovium was 3,400 cells per mm2, which yielded a sensitivity of 0.82 and specificity of 0.82.

Table 1.

Area under receiver operating characteristic curves (AUC) of the synovial features in distinguishing RA and OA patients

FeatureAUCAutomated Cell Density0.88Fibrosis0.84Mast cells0.80Lining hyperplasia0.78Lymphocytic inflammation0.69Fibrin0.68Plasma cells0.66Detritus0.64Binucleate plasma cells0.60Neutrophils0.60Synovial giant cells0.58Sub-lining giant cells0.57Russell bodies0.56Germinal centers0.51Mucoid change0.50Figure 1.

Importance of synovial features in distinguishing RA and OA synovium

Feature importance scores for supervised machine learning model including all 14 pathology scores and the computer vision-generated cell density.

Conclusion

H&E-stained images of RA and OA TKR explant synovium are distinct. We identified cell density, mast cells and fibrosis as the three most important features for making this distinction, with RA being characterized by increased cell density, low mast cells, and low fibrosis. Cell density greater than 3400 per mm2 of tissue yields a sensitivity of 0.82 and a specificity of 0.82 for distinguishing RA from OA. In the future, this can have clinical and research applications as this technique removes the requirement for subjective selection of a certain field of interest, is reproducible, and is scalable as it does not require technical expertise of a pathologist.

References

[1]Guan S, Mehta B…Orange DE. Rheumatoid Arthritis Synovial Inflammation Quantification Using Computer Vision. ACR Open Rheumatology. 2022 Jan 10;acr2.11381.

Acknowledgements

This work was supported by the C. Ronald MacKenzie Young Scientist Endowment Award, the Leon Lowenstein Foundation, and the Kellen Scholar Award supported by the Anna Marie and Stephen Kellen Foundation Total Knee Improvement Program.

Disclosure of Interests

Bella Mehta Paid instructor for: Novartis, Susan Goodman Consultant of: UCB, Grant/research support from: Novartis, Edward DiCarlo: None declared, Deanna Jannat-Khah Shareholder of: AstraZeneca, Cytodyn, and Walgreens, J. Alex Gibbons: None declared, Miguel Otero Consultant of: Regeneron Pharmaceuticals, Grant/research support from: Tissue Genesis, Laura Donlin Speakers bureau: Stryker, Consultant of: Stryker, Grant/research support from: Karius, Inc, Tania Pannellini: None declared, William Robinson: None declared, Peter Sculco Consultant of: Intellijoint Surgical, DePuy Synthes, Lima Corporate, Zimmer Biomet, and EOS Imaging, Grant/research support from: Intellijoint Surgical and Zimmer Biomet, Mark Figgie Shareholder of: HS2, Mekanika, and Wishbone, Consultant of: Lima and Wishbone, Jose Rodriguez Consultant of: ConforMIS, Medacta, Exactech, Inc, and Smith & Nephew, Grant/research support from: DePuy, Exactech, Inc, and Smith & Nephew, Jessica Kirschmann: None declared, James Thompson: None declared, David Slater: None declared, Damon Frezza: None declared, Zhenxing Xu: None declared, Fei Wang: None declared, Dana Orange: None declared

Blockchain-Based Security Mechanisms for IoMT Edge Networks in IoMT-Based Healthcare Monitoring Systems

Despite the significant benefits that the rise of Internet of Medical Things (IoMT) can bring into citizens’ quality of life by enabling IoMT-based healthcare monitoring systems, there is an urgent need for novel security mechanisms to address the pressing security challenges of IoMT edge networks in an effective and efficient manner before they gain the trust of all involved stakeholders and reach their full potential in the market of next generation IoMT-based healthcare monitoring systems. In this context, blockchain technology has been foreseen by the industry and research community as a disruptive technology that can be integrated into novel security solutions for IoMT edge networks, as it can play a significant role in securing IoMT devices and resisting unauthorized access during data transmission (i.e., tamper-proof transmission of medical data). However, despite the fact that several blockchain-based security mechanisms have already been proposed in the literature for different types of IoT edge networks, there is a lack of blockchain-based security mechanisms for IoMT edge networks, and thus more effort is required to be put on the design and development of security mechanisms relying on blockchain technology for such networks. Towards this direction, the first step is the comprehensive understanding of the following two types of blockchain-based security mechanisms: (a) the very few existing ones specifically designed for IoMT edge networks, and (b) those designed for other types of IoT networks but could be possibly adopted in IoMT edge networks due to similar capabilities and technical characteristics. Therefore, in this paper, we review the state-of-the-art of the above two types of blockchain-based security mechanisms in order to provide a foundation for organizing research efforts towards the design and development of reliable blockchain-based countermeasures, addressing the pressing security challenges of IoMT edge networks in an effective and efficient manner.

Left atrial appendage perimeter ostium evaluation by cardiac CT utilizing 3mensio technology for watchman implantation

Background

Left atrial appendage occlusion (LAAO) with Watchman device traditionally relies on accurate left atrial appendage ostium diameter measurement by 2D or 3D transesophageal echocardiogram (TEE). Alternate methods of ostium measurement including area-derived diameter and perimeter-derived diameter using cardiac computed tomography (CT) have been proposed.

Methods

We performed a retrospective analysis of 92 patients with atrial fibrillation (Afib) who underwent LAAO with WATCHMAN implantation with pre-procedural TEE and CT between May 2015 and December 2018. LAA characteristics including ostial or landing zone perimeter, minimum and maximum diameters were acquired utilizing 3mensio Structural Heart Imaging Program. Proposed device size was estimated utilizing ostium perimeter by CT and compared to the current standard utilizing ostium diameter by 2D-TEE. Both measurements were then compared to actual final device size that satisfying release criteria.

Results

CT had a very high correlation with the actual implanted device size (Pearson coefficient r=0.94, p&lt;0.001), while TEE based sizing had a lower correlation (Pearson coefficient r=0.66, p&lt;0.001). CT predicted size had a significantly higher agreement compared to standard TEE based sizing (93.4% vs 47.8%), and higher interrater agreement (Cohen's kappa = 0.91 vs Cohen's kappa = 0.32, p&lt;0.001, p&lt;0.001 respectively). Bland-Altman analysis also showed better correlation with CT-based sizing. Procedural complications were 0, and 0 patients had a leak recorded at 45-days post implant.

Conclusion

CCT LAA perimeter sizing is superior to the current standard TEE based Watchman sizing. Larger, multi-center studies may be necessary to further validate results.

Funding Acknowledgement

Type of funding sources: None. 3mensio after CT upload

Cardiorespiratory Events in Children During Chemoembolization of Ophthalmic Artery for Retinoblastoma

Retinoblastoma (RB) is the most common eye neoplasm in childhood, accounting for 2.5% to 4% of all pediatric cancers. Recent approaches to treat RB include localized administration of chemotherapy, such as super-selective ophthalmic artery chemotherapy. Although localized chemotherapy aims that minimize systemic side effects, some adverse cardio-respiratory reactions have been described as associated with this therapy. Our case report describes the cardiorespiratory severe events presented secondary to super-selective chemotherapy of the ophthalmic artery, to which we must be prepared to avoid fatal outcomes

Ultra-Compact mm-Wave Monolithic IC Doherty Power Amplifier for Mobile Handsets

This work develops a novel dynamic load modulation Power Amplifier (PA) circuity that can provide an optimum compromise between linearity and efficiency while covering multiple cellular frequency bands. Exploiting monolithic microwave integrated circuits (MMIC) technology, a fully integrated 1W Doherty PA architecture is proposed based on 0.1 μm AlGaAs/InGaAs Depletion-Mode (D-Mode) technology provided by the WIN Semiconductors foundry. The proposed wideband DPA incorporates the harmonic tuning Class-J mode of operation, which aims to engineer the voltage waveform via second harmonic capacitive load termination. Moreover, the applied post-matching technique not only reduces the impedance transformation ratio of the conventional DPA, but also restores its proper load modulation. The simulation results indicate that the monolithic drive load modulation PA at 4 V operation voltage delivers 44% PAE at the maximum output power of 30 dBm at the 1 dB compression point, and 34% power-added efficiency (PAE) at 6 dB power back-off (PBO). A power gain flatness of around 14 ± 0.5 dB was achieved over the frequency band of 23 GHz to 27 GHz. The compact MMIC load modulation technique developed for the 5G mobile handset occupies the die area of 3.2 mm2.

Owners' Knowledge and Approaches to Colic in Working Equids in Honduras

In Honduras, many families are reliant on working equids in their daily life. The aim of this study was to evaluate knowledge about, and approaches to colic used by owners of working equids in Choluteca, Honduras using a phenomenological approach. Semi-structured, verbal questionnaires were conducted with ninety-three owners from eleven different communities in the Choluteca region on equid horse owners' knowledge of colic and treatments. Additional context was gained through observations and verbal questionnaires with three veterinary practitioners and eight agricultural pharmacy (agrovet) store owners. Working equids were commonly used for firewood collection 31% (40/126), transportation 24% (30/126), and carrying crops 13% (17/126). Thirty-eight percent of owners (35/92) said they did not know what colic was, 27% (24/89) could not name any clinical signs, and 46% (42/92) could not name any causes. Most owners with previous experience of colic had treated it themselves 79% (53/67), typically using herbal remedies. Colic was a major concern for owners of working equids who had prior experience or knowledge of the condition. Knowledge and understanding of colic varied, and access to evidence-based treatments was very limited. The findings will be used to inform the development of educational resources on colic in working equids.

Nutrient-Limited Enrichments of Nitrifiers From Soil Yield Consortia of Nitrosocosmicus-Affiliated AOA and Nitrospira-Affiliated NOB

The discovery of ammonia-oxidizing archaea (AOA) and complete ammonia-oxidizing (comammox) bacteria widespread in terrestrial ecosystems indicates an important role of these organisms in terrestrial nitrification. Recent evidence indicated a higher ammonia affinity of comammox bacteria than of terrestrial AOA and ammonia-oxidizing bacteria (AOB), suggesting that comammox bacteria could potentially represent the most low-nutrient adapted nitrifiers in terrestrial systems. We hypothesized that a nutrient-limited enrichment strategy could exploit the differences in cellular kinetic properties and yield enrichments dominated by high affinity and high yield comammox bacteria. Using soil with a mixed community of AOA, AOB, and comammox Nitrospira, we compared performance of nutrient-limited chemostat enrichment with or without batch culture pre-enrichment in two different growth media without inhibitors or antibiotics. Monitoring of microbial community composition via 16S rRNA and amoA gene sequencing showed that batch enrichments were dominated by AOB, accompanied by low numbers of AOA and comammox Nitrospira. In contrast, nutrient-limited enrichment directly from soil, and nutrient-limited sub-cultivation of batch enrichments consistently yielded high enrichments of Nitrosocosmicus-affiliated AOA associated with multiple canonical nitrite-oxidizing Nitrospira strains, whereas AOB numbers dropped below 0.1% and comammox Nitrospira were lost completely. Our results reveal competitiveness of Nitrosocosmicus sp. under nutrient limitation, and a likely more complex or demanding ecological niche of soil comammox Nitrospira than simulated in our nutrient-limited chemostat experiments.

Abstract 436: Whole body imaging of genetically labeled hematopoietic stem cells in human subjects

Background: Despite decades of experience with bone marrow transplantation, there has not been prior whole body visualization of the engraftment of hematopoietic stem cell (HSC) in bone marrow in humans. The herpes simplex virus type 1 sr39 thymidine kinase (sr39tk) gene is a positron emission tomography (PET) reporter/suicide gene that can be used to genetically label cells and track them in vivo based on the ability to retain the PET tracer [18F]FHBG, which is a penciclovir analogue.

Methods: Three patients with metastatic sarcoma were treated with gene-modified autologous CD34+ peripheral blood stem cells (PBSCs) transduced with a lentiviral vector encoding both a transgenic T-cell receptor against the tumor antigen NY-ESO-1 and the sr39tk reporter/suicide gene after a reduced intensity conditioning regimen of busulfan and fludarabine. These gene-modified stem cells were co-administered with gene-modified autologous T-cells also encoding the NY-ESO-1 T-cell receptor. The primary endpoint was safety and feasibility, while an exploratory endpoint was standardized uptake value of [18F]FHBG PET between post-transplant day +25 and day +120 scans to study the biodistribution of the gene-modified PBSCs and progeny T cells.

Results: Two patients (NYSCT-01 and NYSCT-03) demonstrated robust engraftment the gene-modified PBSCs in bone marrow niches by day +25-30, as demonstrated by whole body [18F]FHBG PET. PET signal was evident throughout the body in the bone marrow in the scalp, jaw, vertebrae, ribs, pelvis, femur and other bones with significant areas of bone marrow. The third patient (NYSCT-05), whose product had much lower transduction efficiency, did not display any engraftment signal at day +28. Patient NYSCT-01 demonstrated loss of [18F]FHBG signal at day +120, with no detectable T-cell progeny in peripheral circulation. Patient NYSCT-03 developed a post-transplant de novo multidrug-resistant cytomegalovirus (CMV) viremia at day +58 which ultimately required treatment with systemic ganciclovir, and passed away prior to her day +120 PET scan. Patient NYSCT-05 developed a post-transplant CMV reactivation viremia on day +45, which responded to oral valganciclovir treatment.

Conclusions: PET imaging allowed visualization of the successful engraftment of sr39tk reporter gene-labeled HSCs in bone marrow niches. Further studies are needed to determine mechanisms of loss of engraftment due to immunogenicity of the sr39tk gene, or insufficient transduction efficiency.

Citation Format: Theodore S. Nowicki, Beata Berent-Maoz, Cristina Puig-Saus, Paula Kaplan-Lefko, Ignacio Baselga Carretero, Ameya Champhekar, Giuseppe Carlucci, Mignonette Macabali, Ivan Perez Garcilazo, Agustin Vega-Crespo, Jonathan Rodriguez, Bartosz Chmielowski, Arun Singh, Martin Allen-Auerbach, Shaojun Zhu, Roger Slavik, Begonya Comin-Anduix, John Williams, Antoni Ribas. Whole body imaging of genetically labeled hematopoietic stem cells in human subjects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 436.

Latent-transforming growth factor beta-binding protein-2 (LTBP-2) is required for longevity but not for development of zonular fibers

Latent-transforming growth factor beta-binding protein 2 (LTBP-2) is a major component of arterial and lung tissue and of the ciliary zonule, the system of extracellular fibers that centers and suspends the lens in the eye. LTBP-2 has been implicated previously in the development of extracellular microfibrils, although its exact role remains unclear. Here, we analyzed the three-dimensional structure of the ciliary zonule in wild type mice and used a knockout model to test the contribution of LTBP-2 to zonule structure and mechanical properties. In wild types, zonular fibers had diameters of 0.5-1.0 micrometers, with an outer layer of fibrillin-1-rich microfibrils and a core of fibrillin-2-rich microfibrils. LTBP-2 was present in both layers. The absence of LTBP-2 did not affect the number of fibers, their diameters, nor their coaxial organization. However, by two months of age, LTBP-2-depleted fibers began to rupture, and by six months, a fully penetrant ectopia lentis phenotype was present, as confirmed by in vivo imaging. To determine whether the seemingly normal fibers of young mice were compromised mechanically, we compared zonule stress/strain relationships of wild type and LTBP-2-deficient mice and developed a quasi-linear viscoelastic engineering model to analyze the resulting data. In the absence of LTBP-2, the ultimate tensile strength of the zonule was reduced by about 50%, and the viscoelastic behavior of the fibers was altered significantly. We developed a harmonic oscillator model to calculate the forces generated during saccadic eye movement. Model simulations suggested that mutant fibers are prone to failure during rapid rotation of the eyeball. Together, these data indicate that LTBP-2 is necessary for the strength and longevity of zonular fibers, but not necessarily for their formation.