Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall

OBJECTIVE

The deviation of the power-weighted center of the echo signal from the geometric center within the velocity estimation window for calculating strain rate (SR) causes an estimation error. This study aimed to confirm whether an erroneous multilayer pattern in the SR distribution of the left ventricular wall could be corrected by considering the power-weighted center of the echo signal.

METHODS

The SR distributions were measured locally in the transmural direction around the pre-ejection and early diastolic phases in healthy volunteers. The estimation error related to the power-weighted center of the echo signal was corrected using a previously proposed method, and the effectiveness of the correction was confirmed based on the accuracy of the estimated myocardial displacement.

RESULTS

The SR distribution in early diastole was observed as multilayers of low- and high-amplitude negative SRs. However, this multilayer pattern disappeared after correction. In the pre-ejection phase, multilayers of positive and negative SRs were observed in the SR distributions with and without correction. This correction was sufficiently effective in accurately tracking the local peak of the echo signal.

CONCLUSION

The multilayer pattern of low- and high-amplitude positive or negative SRs is caused by estimation errors related to the power-weighted center of the echo signal. The multilayer pattern of positive and negative SRs might not be caused by these errors and might relate to the actual change in myocardial thickness because the estimation errors do not convert the negative (positive) SR to positive (negative) in a homogeneous negative (positive) SR distribution.

Compensatory expansion of the right middle lobe: volumetric and functional analysis of the changes after right upper or lower lobectomy

The right middle lobe often poorly expands after right upper lobectomy. Postoperative pulmonary function may be inferior after right upper lobectomy than after right lower lobectomy due to poor expansion of the middle lobe. This study examined the difference in the postoperative right middle lobe expansion and pulmonary function between right upper and right lower lobectomy. Patients who underwent right upper or right lower lobectomy through video-assisted thoracic surgery (n = 82) were enrolled in this retrospective study. Pulmonary function tests and computed tomography were performed preoperatively and at 1 year postoperatively. Using three-dimensional computed tomography volumetry, the preoperative and postoperative lung volumes were measured, and the predicted postoperative forced expiratory volume in 1 s was calculated. Middle lobe volume ratio (i.e., ratio of the postoperative to the preoperative middle lobe volume) and the postoperative forced expiratory volume in 1 s ratio (i.e., ratio of the measured to the predicted postoperative forced expiratory volume in 1 s) were compared between right upper and right lower lobectomy. Compared with the patients who underwent right upper lobectomy (n = 50), those who underwent right lower lobectomy (n = 32) had significantly higher middle lobe volume ratio (1.15 ± 0.32 vs. 1.63 ± 0.52, p < 0.001) and postoperative forced expiratory volume in 1 s ratio (1.12 ± 0.12 vs. 1.19 ± 0.13, p = 0.010). The right middle lobe showed more expansion and better recovery of postoperative pulmonary function after right lower lobectomy than after right upper lobectomy.

Pericardial effusion in oncological patients: current knowledge and principles of management

BACKGROUND

This article provides an up-to-date overview of pericardial effusion in oncological practice and a guidance on its management. Furthermore, it addresses the question of when malignancy should be suspected in case of newly diagnosed pericardial effusion.

MAIN BODY

Cancer-related pericardial effusion is commonly the result of localization of lung and breast cancer, melanoma, or lymphoma to the pericardium via direct invasion, lymphatic dissemination, or hematogenous spread. Several cancer therapies may also cause pericardial effusion, most often during or shortly after administration. Pericardial effusion following radiation therapy may instead develop after years. Other diseases, such as infections, and, rarely, primary tumors of the pericardium complete the spectrum of the possible etiologies of pericardial effusion in oncological patients. The diagnosis of cancer-related pericardial effusion is usually incidental, but cancer accounts for approximately one third of all cardiac tamponades. Drainage, which is mainly attained by pericardiocentesis, is needed when cancer or cancer treatment-related pericardial effusion leads to hemodynamic impairment. Placement of a pericardial catheter for 2-5 days is advised after pericardial fluid removal. In contrast, even a large pericardial effusion should be conservatively managed when the patient is stable, although the best frequency and timing of monitoring by echocardiography in this context are yet to be established. Pericardial effusion secondary to immune checkpoint inhibitors typically responds to corticosteroid therapy. Pericardiocentesis may also be considered to confirm the presence of neoplastic cells in the pericardial fluid, but the yield of cytological examination is low. In case of newly found pericardial effusion in individuals without active cancer and/or recent cancer treatment, a history of malignancy, unremitting or recurrent course, large effusion or presentation with cardiac tamponade, incomplete response to empirical therapy with nonsteroidal anti-inflammatory, and hemorrhagic fluid at pericardiocentesis suggest a neoplastic etiology.

A novel ultrasonic method for measuring minute sinusoidal displacement by network analyzer

We developed a method for generating continuous sinusoidal displacements of an object to estimate viscoelastic parameters. However, the amplitude of the displacement caused by the ultrasonic excitation force under safe guidelines was small (a few micrometers), and it was difficult to stably measure the displacement. Therefore, to stably measure the amplitude of sinusoidal displacement as small as the order of micrometers, we proposed a novel method using a network analyzer. Ultrasonic waves were irradiated using an ultrasonic transducer on an object vibrating sinusoidally. The S parameter of the first reflected wave received from the surface of the object was measured using a network analyzer. The S parameter and the inverse Fourier transform were formulated theoretically, and the amplitude of the sinusoidal displacement of the object was estimated from the amplitude characteristics of the inverse Fourier-transformed signal. The proposed method was applied to measure sinusoidal displacements on the order of micrometers from 10 to 300 Hz on an object using a water tank experiment. The obtained sinusoidal displacement agreed well with the reference values measured using a laser displacement meter. The proposed method can accurately measure minute sinusoidal displacements that occur on an object.

Reduction in drain-related adverse events using the barbed suture method for chest tube wound closure

OBJECTIVE

A chest tube is usually placed in patients undergoing general thoracic surgery. Although the barbed suture method has been introduced for chest tube wound closure, its superiority to the conventional suture methods for drain management remains unclear. The study aimed to determine whether the barbed suture method could reduce drain-related adverse events compared to the conventional method.

METHODS

We retrospectively reviewed the medical records of patients who underwent general thoracic surgery between January 2021 and December 2022, 1 year before and after the introduction of the barbed suture method at our institution. Patients who underwent the barbed suture or conventional method were included. Univariate and multivariate analyses of drain-related adverse events were performed.

RESULTS

Of the 250 participants, 110 and 140 underwent the barbed suture method and conventional suture method, respectively. The univariate analysis showed that a higher body mass index, preoperative malignant diagnosis, lobectomy, longer operative time, larger tube size, longer chest drainage duration, surgical complications, and conventional method were risk factors for drain-related adverse events. The multivariate analysis showed that the barbed suture method was a protective factor against drain-related adverse events (odds ratio 0.267; 95% confidence interval 0.103-0.691; P = 0.007).

CONCLUSIONS

The barbed suture method could reduce drain-related adverse events compared to the conventional method. Therefore, it might be a potential standard method for chest tube wound closure in patients undergoing general thoracic surgery.

Estimation error in speed of sound caused by rotation of measured cross-section from short-axis plane of blood vessels: a preliminary study

PURPOSE

Estimating the speed of sound (SoS) in ultrasound propagation media is important for improving the quality of B-mode images and for quantitative tissue characterization. We have been studying a method for estimating the SoS by measuring the reception time distribution of waves scattered from a scatterer at the elements in a probe. Previously, the measurement cross section was assumed to be perpendicular to the long axis of the blood vessel. In this study, we experimentally investigated the relationship between rotation angle [Formula: see text] of the probe relative to the short-axis plane of the blood vessel and the estimated SoS, [Formula: see text].

METHODS

Water tank and phantom experiments were conducted to investigate the characteristics of [Formula: see text] and element signals when the probe was rotated.

RESULTS

The received signal powers at the elements around both edges greatly decreased as [Formula: see text] increased. We introduced a parameter representing the decrease in power, [Formula: see text], in the received signal at the elements at both edges relative to the center element. [Formula: see text] was estimated to be larger as [Formula: see text] increased, especially for [Formula: see text]. [Formula: see text] also increased as [Formula: see text] increased. An approximately proportional relationship existed between the errors in [Formula: see text] and [Formula: see text].

CONCLUSION

Based on these results, we can distinguish between the presence and the absence of SoS misestimations using the difference in power among the elements in the received signal. In the absence of misestimation, we can obtain the true SoS, even if the target has a non-negligible size, by applying our previously proposed methods.

Modified multi-Rayleigh model-based statistical analysis of ultrasound envelope for quantification of liver steatosis and fibrosis

PURPOSE

Quantitative diagnosis of the degree of fibrosis progression is currently a focus of attention for fatty liver in nonalcoholic steatohepatitis (NASH). However, previous studies have focused on either lipid droplets or fibrotic tissue, and few have reported the evaluation of both in patients whose livers contain adipose and fibrous features. Our aim was to evaluate fibrosis tissue and lipid droplets in the liver.

METHODS

We used an analytical method combining the multi-Rayleigh (MRA) model and a healthy liver structure filter (HLSF) as a technique for statistical analysis of the amplitude envelope to estimate fat and fibrotic volumes in clinical datasets with different degrees of fat and fibrosis progression.

RESULTS

Fat mass was estimated based on the non-MRA fraction corresponding to the signal characteristics of aggregated lipid droplets. Non-MRA fraction has a positive correlation with fat mass and is effective for detecting moderate and severe fatty livers. Progression of fibrosis was estimated using MRA parameters in combination with the HLSF. The proposed method was used to extract non-healthy areas with characteristics of fibrotic tissue. Fibrosis in early fatty liver suggested the possibility of evaluation. On the other hand, fat was identified as a factor that reduced the accuracy of estimating fibrosis progression in moderate and severe fatty livers.

CONCLUSION

The proposed method was used to simultaneously evaluate fat mass and fibrosis progression in early fatty liver, suggesting the possibility of quantitative evaluation for discriminating between lipid droplets and fibrous tissue in the early fatty liver.

Optimizing irradiation conditions for low-intensity pulsed ultrasound to upregulate endothelial nitric oxide synthase

PURPOSE

Here we aimed to develop a minimally invasive treatment for ischemic heart disease and demonstrate that low-intensity pulsed ultrasound (LIPUS) therapy improves myocardial ischemia by promoting myocardial angiogenesis in a porcine model of chronic myocardial ischemia. Studies to date determined the optimal treatment conditions within the range of settings available with existing ultrasound equipment and did not investigate a wider range of conditions.

METHODS

We investigated a broad range of five parameters associated with ultrasound irradiation conditions that promote expression of endothelial nitric oxide synthase (eNOS), a key molecule that promotes angiogenesis in human coronary artery endothelial cells (HCAEC).

RESULTS

Suboptimal irradiation conditions included 1-MHz ultrasound frequency, 500-kPa sound pressure, 20-min total irradiation time, 32-48-[Formula: see text] pulse duration, and 320-[Formula: see text] pulse repetition time. Furthermore, a proposed index, [Formula: see text], calculated as the product of power and the total number of irradiation cycles applied to cells using LIPUS, uniformly revealed the experimental eNOS expression associated with the various values of five parameters under different irradiation conditions.

CONCLUSION

We determined the suboptimal ultrasound irradiation conditions for promoting eNOS expression in HCAEC.

Post-Synthetic Nucleobase Modification of Oligodeoxynucleotides by Sonogashira Coupling and Influence of Alkynyl Modifications on the Duplex-Forming Ability

Recently, it was reported that the alkynyl modification of nucleobases mitigates the toxicity of antisense oligonucleotides (ASO) while maintaining the efficacy. However, the general effect of alkynyl modifications on the duplex-forming ability of oligonucleotides (ONs) is unclear. In this study, post-synthetic nucleobase modification by Sonogashira coupling in aqueous medium was carried out to efficiently evaluate the physiological properties of various ONs with alkynyl-modified nucleobases. Although several undesired reactions, including nucleobase cyclization, were observed, various types of alkynyl-modified ONs were successfully obtained via Sonogashira coupling of ONs containing iodinated nucleobases. Evaluation of the stability of the duplex formed by the synthesized alkynyl-modified ONs showed that the alkynyl modification of pyrimidine was less tolerated than that of purine, although both the modifications occurred in the major groove of the duplex. These results can be attributed to the bond angle of the alkyne on the pyrimidine and the close proximity of the alkynyl substituents to the phosphodiester backbone. The synthetic method developed in this study may contribute to the screening of the optimal chemical modification of ASO because various alkynyl-modified ONs that are effective in reducing the toxicity of ASO can be easily synthesized by this method.

guitARhero: Interactive Augmented Reality Guitar Tutorials

This paper presents guitARhero, an Augmented Reality application for interactively teaching guitar playing to beginners through responsive visualizations overlaid on the guitar neck. We support two types of visual guidance, a highlighting of the frets that need to be pressed and a 3D hand overlay, as well as two display scenarios, one using a desktop magic mirror and one using a video see-through head-mounted display. We conducted a user study with 20 participants to evaluate how well users could follow instructions presented with different guidance and display combinations and compare these to a baseline where users had to follow video instructions. Our study highlights the trade-off between the provided information and visual clarity affecting the user's ability to interpret and follow instructions for fine-grained tasks. We show that the perceived usefulness of instruction integration into an HMD view highly depends on the hardware capabilities and instruction details.

Exemplar-Based Inpainting for 6DOF Virtual Reality Photos

Multi-layer images are currently the most prominent scene representation for viewing natural scenes under full-motion parallax in virtual reality. Layers ordered in diopter space contain color and transparency so that a complete image is formed when the layers are composited in a view-dependent manner. Once baked, the same limitations apply to multi-layer images as to conventional single-layer photography, making it challenging to remove obstructive objects or otherwise edit the content. Object removal before baking can benefit from filling disoccluded layers with pixels from background layers. However, if no such background pixels have been observed, an inpainting algorithm must fill the empty spots with fitting synthetic content. We present and study a multi-layer inpainting approach that addresses this problem in two stages: First, a volumetric area of interest specified by the user is classified with respect to whether the background pixels have been observed or not. Second, the unobserved pixels are filled with multi-layer inpainting. We report on experiments using multiple variants of multi-layer inpainting and compare our solution to conventional inpainting methods that consider each layer individually.

Multi-Layer Scene Representation from Composed Focal Stacks

Multi-layer images are a powerful scene representation for high-performance rendering in virtual/augmented reality (VR/AR). The major approach to generate such images is to use a deep neural network trained to encode colors and alpha values of depth certainty on each layer using registered multi-view images. A typical network is aimed at using a limited number of nearest views. Therefore, local noises in input images from a user-navigated camera deteriorate the final rendering quality and interfere with coherency over view transitions. We propose to use a focal stack composed of multi-view inputs to diminish such noises. We also provide theoretical analysis for ideal focal stacks to generate multi-layer images. Our results demonstrate the advantages of using focal stacks in coherent rendering, memory footprint, and AR-supported data capturing. We also show three applications of imaging for VR.

Speed-of-sound estimation in ultrasound propagation medium by considering size of target scatterer

PURPOSE

Accurate speed-of-sound (SoS) estimation in an ultrasound propagation medium improves imaging quality and contributes to better diagnosis of diseases. In conventional time-delay-based SoS estimation approaches studied by several groups, a received wave is assumed to be scattered from an ideal point scatterer. In these approaches, the SoS is overestimated when the target scatterer has a non-negligible size. In this paper, we propose the SoS estimation method that considers target size.

METHODS

In the proposed method, the error ratio of the estimated SoS using the conventional time-delay-based approach is determined from measurable parameters using the geometric relationship between the received elements and target. Subsequently, the SoS erroneously estimated using conventional estimation, assuming the ideal point scatterer as a target, is corrected by the determined estimation error ratio. To validate the proposed method, the SoS in water was estimated for several wire sizes.

RESULTS

The SoS in the water was overestimated using the conventional SoS estimation method, with a maximum positive error of 38 m/s. The proposed method corrected the SoS estimates, and the errors were suppressed to within 6 m/s, irrespective of the wire diameter.

CONCLUSION

The present results demonstrate that the proposed method can estimate the SoS by considering the target size without using information on the true SoS, true target depth, and true target size, which is applicable to in vivo measurements.

Lateral M-Mode: Ultrasound Visualization of Displacement Along Longitudinal Direction at Intima-Media Complex

Quantification of the dynamics of the carotid artery wall is useful in evaluating arteriosclerosis and atherosclerosis. As the carotid artery wall moves not only in the radial direction but also in the longitudinal direction, longitudinal movement should be considered in the analysis of the dynamic properties of the carotid artery wall. In this study, we propose a "lateral M-mode" method for visualizing the longitudinal movement of the intima-media complex (IMC). For the lateral M-mode, we set the target line in the longitudinal direction along the IMC and visualize the signals on the target line frame-by-frame by correcting the position of the target line along the radial displacement estimated by the phased tracking method. Differentiating the envelope signals between consecutive ultrasound beams was effective in visualizing the lateral movement of the IMC. The precision of the longitudinal displacement of the IMC estimated using the conventional block-matching method was validated by comparing it with the lateral M-mode. Because the conventional M-mode sequence plays an important role in evaluation of the dynamics of various tissues, the proposed "lateral M-mode" contributes to a detailed understanding of vascular dynamics and the development of diagnostic methods for vascular diseases.

Metabolically Stable Anomeric Linkages Containing GalNAc-siRNA Conjugates: An Interplay among ASGPR, Glycosidase, and RISC Pathways

Conjugation of synthetic triantennary N-acetyl-d-galactosamine (GalNAc) to small interfering RNA (siRNA) mediates binding to the asialoglycoprotein receptor (ASGPR) on the surface of hepatocytes, facilitating liver-specific uptake and siRNA-mediated gene silencing. The natural β-glycosidic bond of the GalNAc ligand is rapidly cleaved by glycosidases in vivo. Novel GalNAc ligands with S-, and C-glycosides with both α- and β-anomeric linkages, N-glycosides with β-anomeric linkage, and the O-glycoside with α-anomeric linkage were synthesized and conjugated to siRNA either on-column during siRNA synthesis or through a high-throughput, post-synthetic method. Unlike natural GalNAc, modified ligands were resistant to glycosidase activity. The siRNAs conjugated to newly designed ligands had similar affinities for ASGPR and similar silencing activity in mice as the parent GalNAc-siRNA conjugate. These data suggest that other factors, such as protein-nucleic acid interactions and loading of the antisense strand into the RNA-induced silencing complex (RISC), are more critical to the duration of action than the stereochemistry and stability of the anomeric linkage between the GalNAc moiety of the ligand conjugated to the sense strand of the siRNA.

Modified Egocentric Viewpoint for Softer Seated Experience in Virtual Reality

Users in a prolonged experience of virtual reality adopt a sitting position according to their task, as they do in the real world. However, inconsistencies in the haptic feedback from a chair they sit on in the real world and that which is expected in the virtual world decrease the feeling of presence. We aimed to change the perceived haptic features of a chair by shifting the position and angle of the users' viewpoints in the virtual reality environment. The targeted features in this study were seat softness and backrest flexibility. To enhance the seat softness, we shifted the virtual viewpoint using an exponential formula soon after a user's bottom contacted the seat surface. The flexibility of the backrest was manipulated by moving the viewpoint, which followed the tilt of the virtual backrest. These shifts make users feel as if their body moves along with the viewpoint; as a result, they would perceive pseudo-softness or flexibility consistently with the body movement. Based on subjective evaluations, we confirmed that the participants perceived the seat as being softer and the backrest as being more flexible than the actual ones. These results demonstrated that only shifting the viewpoint could change the participants' perceptions of the haptic features of their seats, although significant changes created strong discomfort.

Effect of resected lung lobe on the prediction of postoperative pulmonary function

OBJECTIVES

This study examined whether a resected lung lobe can affect the accuracy of postoperative forced expiratory volume in 1 second (FEV1) predicted using the subsegment counting method and three-dimensional computed tomography (3D-CT) volumetry.

METHODS

Overall, 125 patients who underwent lobectomy through video-assisted thoracic surgery (VATS) were enrolled in this retrospective study. Pulmonary function tests (PFTs) were performed preoperatively and postoperatively at 3 months. We defined the accuracy index as the ratio of predicted postoperative FEV1 to measured postoperative FEV1 and compared the accuracy index of the subsegment counting method and 3D-CT volumetry. Factors affecting the accuracy index were also examined.

RESULTS

The accuracy index of the subsegment counting method was 0.94 ± 0.12, versus 0.93 ± 0.11 for 3D-CT volumetry (p = 0.539). There was a significant difference among the resected lobes in the accuracy index of the subsegment counting method (p < 0.001) but not in that of 3D-CT volumetry (p = 0.370). The resected lobe, the number of staples used for interlobar dissection, and interstitial pneumonia (IP) were significantly associated with the accuracy index of the subsegment counting method (all p < 0.001). The number of staples and IP were significantly associated with the accuracy index of 3D-CT volumetry (p < 0.001, respectively), whereas the resected lobe was not a significant factor (p = 0.240).

CONCLUSIONS

The resected lobe affected the accuracy of the subsegment counting method but not that of 3D-CT volumetry. Further, 3D-CT volumetry predicted postoperative FEV1 independent of the resected lobe.

CLINICAL REGISTRATION NUMBER

This study was approved by the ethics committee of Jikei University School of Medicine [approval number: 33-259 (10877)].

Application of low-complexity generalized coherence factor to in vivo data

PURPOSE

Beamforming using the generalized coherence factor (GCF) reduces sidelobe artifacts and provides an excellent contrast-to-noise ratio. We previously proposed GCF_real, a method to calculate GCF without generating analytic signals, and GCF_bin, a method to calculate GCF by binarizing the received signals. In this study, we applied these methods to in vivo data and showed the effect of the computational complexity reduction on contrast performance.

METHODS

Channel RF data were acquired from the human liver and gallbladder. We set up several observation points in each data set and investigated the mechanism that causes the differences in contrast performance among the methods based on the signals and their power spectra in the channel direction.

RESULTS

For GCF and GCF_real, the obtained values were almost the same. However, there were large differences in GCF_bin from GCF when the signals from the focus point or from outside the focus point were received on different channels. This is because the amplitudes of the signals with high coherence and those with low coherence were changed by binarizing the signals.

CONCLUSION

While GCF_bin can significantly reduce the computational complexity, there are differences in the values of GCF_bin and GCF due to binarizing of the received signals. However, this difference resulted in GCF_bin being superior to GCF in terms of artifact reduction. This is owing to the elimination of amplitude information in GCF_bin, which makes it a new efficient coherence factor with different characteristics from GCF.

Role of a "Magic" Methyl: 2'-Deoxy-2'-α-F-2'-β-C-methyl Pyrimidine Nucleotides Modulate RNA Interference Activity through Synergy with 5'-Phosphate Mimics and Mitigation of Off-Target Effects

Although 2′-deoxy-2′-α-F-2′-β-C-methyl (2′-F/Me) uridine nucleoside derivatives are a successful class of antiviral drugs, this modification had not been studied in oligonucleotides. Herein, we demonstrate the facile synthesis of 2′-F/Me-modified pyrimidine phosphoramidites and their subsequent incorporation into oligonucleotides. Despite the C3′-endo preorganization of the parent nucleoside, a single incorporation into RNA or DNA resulted in significant thermal destabilization of a duplex due to unfavorable enthalpy, likely resulting from steric effects. When located at the terminus of an oligonucleotide, the 2′-F/Me modification imparted more resistance to degradation than the corresponding 2′-fluoro nucleotides. Small interfering RNAs (siRNAs) modified at certain positions with 2′-F/Me had similar or better silencing activity than the parent siRNAs when delivered via a lipid nanoparticle formulation or as a triantennary N-acetylgalactosamine conjugate in cells and in mice. Modification in the seed region of the antisense strand at position 6 or 7 resulted in an activity equivalent to the parent in mice. Additionally, placement of the antisense strand at position 7 mitigated seed-based off-target effects in cell-based assays. When the 2′-F/Me modification was combined with 5′-vinyl phosphonate, both E and Z isomers had silencing activity comparable to the parent. In combination with other 2′-modifications such as 2′-O-methyl, the Z isomer is detrimental to silencing activity. Presumably, the equivalence of 5′-vinyl phosphonate isomers in the context of 2′-F/Me is driven by the steric and conformational features of the C-methyl-containing sugar ring. These data indicate that 2′-F/Me nucleotides are promising tools for nucleic acid-based therapeutic applications to increase potency, duration, and safety.

Aminooxy Click Chemistry as a Tool for Bis-homo and Bis-hetero Ligand Conjugation to Nucleic Acids

An aminooxy click chemistry (AOCC) strategy was used to synthesize nucleoside building blocks for incorporation during solid-support synthesis of oligonucleotides to enable bis-homo and bis-hetero conjugation of various biologically relevant ligands. The bis-homo aminooxy conjugation leads to bivalent ligand presentation, whereas the bis-hetero conjugation allows the placement of different ligands with either the same or different chemical linkages. This facile synthetic methodology allows introduction of two different ligands with different biological functions simultaneously.

POS0670 EVALUATION OF UPADACITINIB IN RHEUMATOID ARTHRITIS PATIENTS WITH INADEQUATE RESPONSE TO FIRST-GENERATION JANUS KINASE INHIBITORS

Background

Janus kinase inhibitors (JAKi) are effective in the treatment of patients with difficult-to-treat rheumatoid arthritis (D2T RA), regardless of previous use of biological disease-modifying antirheumatic drugs (bDMARDs), and receive equal billing with biological therapies in the latest version of the EULAR recommendations for treatment of RA1. However, as with bDMARDs, cases of discontinuation due to intolerance or inadequate response have been observed in patients treated with the so-called first-generation JAKi, leading to the development of a new generation of JAKi that aims to maximize efficacy and improve safety by enhancing kinase selectivity. The results of randomized controlled trials and meta-analyses suggest that the efficacy and safety of Upadacitinib (UPA) treatment are favorable. Although there have been no head-to-head trials between JAKi, a matched-adjusted indirect comparative study has shown a difference in efficacy between JAKi2, suggesting that the new generation of JAKi may be effective in rheumatoid arthritis patients with intolerance or inadequate response to first-generation JAKi. It is already apparent that a clear need exists for a JAK-IR trial to give guidance in those difficult patients who are JAKi non-responders3.

Objectives

To evaluate real world efficacy of a second-generation JAK1-selective JAKi UPA in single-center cohort of RA patients who had discontinued first-generation JAKi.

Methods

Patients with RA who had discontinued tofacitinib and/or baricitinib due to inadequate response or intolerance, regardless of whether they had used bDMARDs or not, were eligible for the study if they had received UPA by October 2021 and had been followed up for at least 12 weeks. Endpoints were Kaplan-Meier survival rate with inadequate response or intolerance as reasons for discontinuation, various disease activity assessments (DAS28-ESR, SDAI, CDAI, etc.), and patient reported outcomes (visual analogue scales (VASs) such as pain and stiffness, HAQ-DI, FACIT-Fatigue Scale, etc.) at 12 weeks. In addition, the reasons for discontinuation were investigated.

Results

Fifty-one patients were included in the study, all of whom had D2T RA and had used at least one bDMARD as well as JAKi. The mean (median) age was 72.7 (77) years, disease duration 18.0 (17) years, number of bDMARDs used 3.34 (3), number of JAKi used 1.3(1), 5 patients with methotrexate, 6 patients with prednisolone, and DAS28-ESR 3.83 (3.9). At 12 weeks, the overall survival rate was 94% (94.6% in 37 cases used as 2nd JAKi and 92.9% in 14 cases used as 3rd JAKi). For reference, there was no significant difference from the 100% of the 15 cases used as the 1st JAKi (P=0.49). DAS28-ESR <3.2 and <2.6 were achieved in 60.8% and 29.4%, VASs for pain and stiffness decreased by a mean of 12.9 mm (9 mm) and 12.1 mm (7 mm), respectively, and FACIT-Fatigue scale improved by a mean of 3.0 (1). The reasons for discontinuation in the three patients were inadequate efficacy in two and leg cramps due to venous thromboembolism in one.

Conclusion

UPA is more selective for JAK1 than first generation JAKi, and is expected to reduce adverse reactions caused by inhibition of JAK family members other than JAK1. The present study suggests that UPA is effective and well tolerated, regardless of the number and type of first-generation JAKi used in the past, albeit for a short period of time. Limitations include the small number of cases and the short time frame for discussing adverse reactions.

References

[1]Smolen JS, Landewé BM, Bijlsma WJ et al., EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Ann Rheum Dis 2020;79:685–699.

[2]Christopher JE, Ruta S, Vishvas G et al. A Matching-Adjusted Indirect Comparison of Upadacitinib Versus Tofacitinib in Adults with Moderate-to-Severe Rheumatoid Arthritis. Rheumatol Ther 2021; 8:167–181.

[3]Peter Nash, Clinical use of Jak 1 inhibitors for rheumatoid arthritis. Rheumatology, Volume 60, Issue Supplement_2, May 2021, Pages ii31–ii38

Disclosure of Interests

None declared

Good Keyframes to Inpaint

Diminished Reality (DR) propagates pixels from a keyframe to subsequent frames for real-time inpainting. Keyframe selection has a significant impact on the inpainting quality, but untrained users struggle to identify good keyframes. Automatic selection is not straightforward either, since no previous work has formalized or verified what determines a good keyframe. We propose a novel metric to select good keyframes to inpaint. We examine the heuristics adopted in existing DR inpainting approaches and derive multiple simple criteria measurable from SLAM. To combine these criteria, we empirically analyze their effect on the quality using a novel representative test dataset. Our results demonstrate that the combined metric selects RGBD keyframes leading to high-quality inpainting results more often than a baseline approach in both color and depth domains. Also, we confirmed that our approach has a better ranking ability of distinguishing good and bad keyframes. Compared to random selections, our metric selects keyframes that would lead to higher-quality and more stably converging inpainting results. We present three DR examples, automatic keyframe selection, user navigation, and marker hiding.

Video See-Through Mixed Reality with Focus Cues

This work introduces the first approach to video see-through mixed reality with full support for focus cues. By combining the flexibility to adjust the focus distance found in varifocal designs with the robustness to eye-tracking error found in multifocal designs, our novel display architecture reliably delivers focus cues over a large workspace. In particular, we introduce gaze-contingent layered displays and mixed reality focal stacks, an efficient representation of mixed reality content that lends itself to fast processing for driving layered displays in real time. We thoroughly evaluate this approach by building a complete end-to-end pipeline for capture, render, and display of focus cues in video see-through displays that uses only off-the-shelf hardware and compute components.

Clinical significance of chest CT for the exclusion of COVID-19 in pre-admission screening: is it worthwhile using chest CT with reverse-transcription polymerase chain reaction test?

Background

A single reverse-transcription polymerase chain reaction (RT-PCR) test is not sufficient to exclude COVID-19 in hospital pre-admission screening. However, repeated RT-PCR tests are time-consuming. This study investigates the utility of chest computed tomography (CT) for COVID-19 screening in asymptomatic patients.

Methods

Between April 2020 and March 2021, RT-PCR testing and chest CT were performed to screen COVID-19 in 10 823 asymptomatic patients prior to admission. Chest CT findings were retrospectively evaluated using the reporting system of the Radiological Society of North America. Using RT-PCR results as a reference, we assessed the diagnostic efficacy of chest CT during both the low- and high-prevalence periods of the COVID-19 pandemic.

Results

Following a positive RT-PCR test, 20 asymptomatic patients (0.18%) were diagnosed with COVID-19; in the low-prevalence period, 5 of 6556 patients (0.076%) were positive; and in the high-prevalence period, 15 of 4267 patients (0.35%) were positive. Of the 20 asymptomatic COVID-19 positive patients, chest CT results were positive for COVID-19 pneumonia in 8 patients. Chest CT results were false-positive in 185 patients (1.7% false-positive rate, and 60% false-negative rate). Pneumonia that was classified as a “typical appearance” of COVID-19 reported as false-positives in 36 of 39 patients (92.3%). Across the study period, the diagnostic efficacy of “typical appearance” on chest CT were characterized by a sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of 15%, 99.7%, 99.7%, 7.7%, and 99.8%; 20%, 99.6%, 99.6%, 4%, and 99.9%; and 13.3%, 99.7%, 99.7%, 14.3%, and 99.7%, in the entire study, low-, and high-prevalence periods, respectively.

Conclusions

Addition of chest CT to RT-PCR testing provides no benefit to the detection of COVID-19 in asymptomatic patients.

Appropriate Window Function and Window Length in Multifrequency Velocity Estimator for Rapid Motion and Locality of Layered Myocardium

The heart wall has a multilayered structure and moves rapidly during ejection and rapid filling periods. Local strain rate (SR) measurements of each myocardial layer can contribute to accurate and sensitive evaluations of myocardial function. However, ultrasound-based velocity estimators using a single-frequency phase difference cannot realize these measurements owing to insufficient maximum detectable velocity, which is limited by a quadrature frequency. We previously proposed a velocity estimator using multifrequency phase differences to improve the maximum detectable velocity. However, the improvement is affected by a spatial discrete Fourier transform (DFT) window length that represents the locality of the velocity estimation. In this article, we theoretically describe that shortening the window increases the interference between different frequency components and decreases the maximum detectable velocity. The tradeoff between the maximum detectable velocity and the window length was confirmed through simulations and a water-tank experiment. Under the tradeoff, the Hanning window, which was used in previous studies, is not always appropriate for the local measurement of the velocity, which sometimes exceeds 100 mm [Formula: see text] depending on the subject, direction of the ultrasound beam to the heart wall, and cardiac periods. In the in vivo measurement with the short window, the Tukey window with a large flat part that has a high-frequency resolution and ameliorates the discontinuity at both edges of the windowed signal was appropriate to measure the maximum velocity. This study offers the potential for local measurements of each myocardial layer using the multifrequency velocity estimator with the appropriate window function and window length.

Superomedial pedicle skin-reducing mastectomy in ptotic and large-sized breasts with two-stage reconstruction through transaxillary video-assisted technique: An effective surgical and anesthetic approach

Introduction

Skin-reducing mastectomy has been applied to several surgical techniques in which subcutaneous mastectomy is associated with various types of skin reduction, with preservation of a lower dermal flap to reinforce the inferior lateral seat of an implant. The aim of the study is to present a case series of patients with pendulous/ptotic and/or large-sized breasts treated for breast cancer at the Breast Surgery Unit of Istituto Nazionale Tumori IRCCS Fondazione "G. Pascale", Naples, Italy, with the superomedial pedicle skin-reducing mastectomy technique, two-stage reconstruction, and transaxillary video-assisted technique, when a postoperative radiotherapy was indicated. We verified its effectiveness by discussing its results, especially in patients who are candidates for postmastectomy radiotherapy.

Materials and methods

A single-center retrospective study was performed between January 2020 and March 2021 on a prospectively filled database of conservative mastectomies. Of the 64 patients who underwent nipple/skin-sparing mastectomies in the mentioned period, 17 (mean age 46 years, range 30-62 years) were treated with superomedial pedicle skin-reducing mastectomy, with two-stage breast reconstruction through transaxillary video-assisted replacement expander with definitive prosthesis and contralateral symmetrization, selected for postmastectomy radiotherapy.

Results

We had only three minor complications. No flap necrosis, no infections, no breast seromas, and no reconstructive failures were observed. During follow-up of the patients treated with video-assisted reconstruction, there were no cases of infection, hematoma, implant rupture, or suture dehiscence in the reconstructed breast.

Discussion

Skin-reducing mastectomy with superomedial pedicle is a safe and reliable procedure to treat breast cancer in selected patients, i.e., those with pendulous/ptotic and or large-sized breasts. Particularly, in patients who undergo postmastectomy radiotherapy, the two-stage reconstruction with video-assisted transaxillary endoscopic approach can find its main indication, using incisions positioned far from the mammary region, offering numerous advantages.

[A Case of Synchronous Multiple Colorectal Cancer with Rectal Neuroendocrine Tumor and Ascending Colon Cancer]

A 43-year-old man who had no previous medical history or family history had positive fecal occult blood test in a local physician. Colonoscopy revealed a type 2 tumor of the ascending colon and a 10 mm submucosal tumor(SMT)of the lower rectum. Biopsy indicated moderately-differentiated adenocarcinoma of the ascending colon and neuroendocrine tumor (NET)of the lower rectum. No metastasis was detected by computed tomography. Therefore, the rectal SMT was resected first by endoscopic submucosal resection. Histopathologically, the lesion was localized in the submucosa and no lymphovascular invasion was found. Vertical margin was also negative. We decided not to perform additional intestinal resection for rectal NET. Thereafter, the patient underwent laparoscopic right hemicolectomy for ascending colon cancer. The histopathological findings were pT3, pN1, pM0, pStage Ⅲb. The patient received adjuvant chemotherapy. No relapse was found 18 months after surgery. We reported a rare case of a lower rectal NET with concomitant ascending colon cancer.

[A Case of Advanced Rectal Cancer with Left Hydronephrosis Treated with Left Ureter-Sparing Laparoscopic High Anterior Resection after Chemotherapy]

A 47-year-old woman with a complaint of weight loss for the past 5 months was referred to our hospital. Colonoscopy revealed advanced rectal cancer 20 cm from the anal verge. The patient had left hydronephrosis caused by ureteral invasion. Firstly, we performed transverse colostomy and left nephrostomy. After 8 courses of capecitabine, oxaliplatin plus bevacizumab( CAPOX plus Bmab)therapy, colonoscopy and computed tomography revealed shrinkage of both the primary and metastatic lesions. Laparoscopic high anterior resection was performed, and the left ureter was successfully preserved. The patient received chemotherapy after surgery. Neither local recurrence nor enlargement of metastases has been observed 8 months after surgery.

A randomized, controlled trial of once-weekly teriparatide injection versus alendronate in patients at high risk of osteoporotic fracture: primary results of the Japanese Osteoporosis Intervention Trial-05

In this randomized, controlled trial, treatment with once-weekly subcutaneous injection of teriparatide for 72 weeks was found to be associated with a significant reduction in the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

INTRODUCTION

To determine whether the anti-fracture efficacy of teriparatide is superior to that of alendronate, a prospective, randomized, open-label, blinded-endpoint trial was performed.

METHODS

Japanese women aged at least 75 years were eligible for the study if they had primary osteoporosis and were at high risk of fracture. Patients were randomly assigned in a 1:1 ratio to receive sequential therapy (once-weekly subcutaneous injection of teriparatide 56.5 μg for 72 weeks followed by alendronate for 48 weeks) or monotherapy with alendronate for 120 weeks. The primary endpoint was the incidence of morphometric vertebral fractures at 72 weeks (at the end of teriparatide treatment).

RESULTS

Between October 2014 and December 2017, 1011 patients (505 in the teriparatide group and 506 in the alendronate group) were enrolled. Of these, 778 patients (351 and 427, respectively) were included in the primary analysis. The incidence of morphometric vertebral fractures was significantly lower in the teriparatide group (56 per 419.9 person-years, annual incidence rate 0.1334) than in the alendronate group (96 per 553.6 person-years, annual incidence rate 0.1734), with a rate ratio of 0.78 (95% confidence interval 0.61 to 0.99, P = 0.04). In both groups, adverse events were most frequently reported in the following system organ classes: infections and infestations, gastrointestinal disorders, and musculoskeletal and connective tissue disorders.

CONCLUSION

Once-weekly subcutaneous injection of teriparatide significantly reduced the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

TRIAL REGISTRATION

jRCTs031180235 and UMIN000015573, March 12, 2019.

A successful case of complete surgical resection via left upper and right lower lobectomy for bilateral lung metastases of a perivascular epithelioid cell tumor in the colon: a case report

Background

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms with malignant potential. No effective treatment other than surgical resection has been established for lung metastases of PEComas. We describe a patient who underwent complete surgical resection via bilateral lobectomy involving a two-step procedure for lung metastases 8 years after undergoing radical surgery for a colonic PEComa.

Case presentation

A 53-year-old woman underwent partial colectomy for a PEComa in the transverse colon 8 years ago. She presented with an abnormal chest shadow during a health examination. Chest computed tomography (CT) revealed a solid nodule 2 cm in diameter located centrally in the right lower lobe and a solid nodule 3 cm in diameter located centrally in the left upper lobe. Positron emission tomography revealed 18F-fluorodeoxyglucose uptake in these nodules. These nodules were suspected to be metastatic tumors of the colonic PEComa and were considered for complete surgical resection. Segmentectomy could not be performed because of the anatomical location of the tumors straddling the segments; therefore, bilateral lobectomy was required for complete surgical resection. Therefore, we performed two-step lobectomy safely with the expectation of pulmonary function recovery. Microscopically, the tumors were diagnosed as lung metastases of the PEComa. One year after the last surgery, no recurrence was detected, and the patient’s pulmonary function improved.

Conclusions

This case indicates that even if multiple lung metastases of a PEComa require bilateral lobectomy, complete resection with a two-step surgery may be considered.

Strain Rate Distribution in Layered Myocardium Measured Using Local Velocity Estimator with Multifrequency Phase Differences

Measurement of the myocardial strain rate (SR), with high spatial resolution, is useful in evaluation of the transmurality of myocardial infarction. As the SR distribution is calculated using velocities observed at multiple positions in the heart wall, it is necessary to estimate the local velocity to measure SR distribution. In the present study, our previously proposed local velocity estimator, with multifrequency phase differences, was used to measure SR distribution in the heart wall. The SR distribution measured with the proposed local velocity estimator revealed alternate layers of contraction and relaxation, which were not measured with the conventional velocity estimator with spatial averaging. The reproducibility of the SR distributions was confirmed in three consecutive heartbeats with three subjects. High-spatial-resolution SR measurement with the proposed local velocity estimator will allow myocardial layer-specific analysis in the transmural direction.

Visualization Techniques in Augmented Reality: A Taxonomy, Methods and Patterns

In recent years, the development of Augmented Reality (AR) frameworks made AR application development widely accessible to developers without AR expert background. With this development, new application fields for AR are on the rise. This comes with an increased need for visualization techniques that are suitable for a wide range of application areas. It becomes more important for a wider audience to gain a better understanding of existing AR visualization techniques. In this article we provide a taxonomy of existing works on visualization techniques in AR. The taxonomy aims to give researchers and developers without an in-depth background in Augmented Reality the information to successively apply visualization techniques in Augmented Reality environments. We also describe required components and methods and analyze common patterns.

Impaired TRIM16-Mediated Lysophagy in Chronic Obstructive Pulmonary Disease Pathogenesis

Insufficient autophagic degradation has been implicated in accelerated cellular senescence during chronic obstructive pulmonary disease (COPD) pathogenesis. Aging-linked and cigarette smoke (CS)-induced functional deterioration of lysosomes may be associated with impaired autophagy. Lysosomal membrane permeabilization (LMP) is indicative of damaged lysosomes. Galectin-3 and tripartite motif protein (TRIM) 16 play a cooperative role in recognizing LMP and inducing lysophagy, a lysosome-selective autophagy, to maintain lysosome function. In this study, we sought to examine the role of TRIM16-mediated lysophagy in regulating CS-induced LMP and cellular senescence during COPD pathogenesis by using human bronchial epithelial cells and lung tissues. CS extract (CSE) induced lysosomal damage via LMP, as detected by galectin-3 accumulation. Autophagy was responsible for modulating LMP and lysosome function during CSE exposure. TRIM16 was involved in CSE-induced lysophagy, with impaired lysophagy associated with lysosomal dysfunction and accelerated cellular senescence. Airway epithelial cells in COPD lungs showed an increase in lipofuscin, aggresome and galectin-3 puncta, reflecting accumulation of lysosomal damage with concomitantly reduced TRIM16 expression levels. Human bronchial epithelial cells isolated from COPD patients showed reduced TRIM16 but increased galectin-3, and a negative correlation between TRIM16 and galectin-3 protein levels was demonstrated. Damaged lysosomes with LMP are accumulated in epithelial cells in COPD lungs, which can be at least partly attributed to impaired TRIM16-mediated lysophagy. Increased LMP in lung epithelial cells may be responsible for COPD pathogenesis through the enhancement of cellular senescence.

Measured versus predicted postoperative pulmonary function at repeated times up to 1 year after lobectomy

OBJECTIVES

Postoperative pulmonary function is difficult to predict accurately, because it changes from the time of the operation and is also affected by various factors. The objective of this study was to assess the accuracy of predicted postoperative forced expiratory volume in 1 s (FEV1) at different postoperative times after lobectomy.

METHODS

This retrospective study enrolled 104 patients who underwent lobectomy by video-assisted thoracic surgery. Pulmonary function tests were performed preoperatively and postoperatively at 3, 6 and 12 months. We investigated time-dependent changes in FEV1. In addition, the ratio of measured to predicted postoperative FEV1 calculated by the subsegmental method was evaluated to identify the factors associated with variations in postoperative FEV1.

RESULTS

Compared with the predicted postoperative FEV1, the measured postoperative FEV1 was 8% higher at 3 months, 11% higher at 6 months and 13% higher at 12 months. The measured postoperative FEV1 significantly increased from 3 to 6 months (P = 0.002) and from 6 to 12 months (P = 0.015) after lobectomy resected lobe, smoking history and body mass index were significant factors associated with the ratio of measured to predicted postoperative FEV1 at 12 months (P < 0.001, P = 0.036 and P = 0.025, respectively).

CONCLUSIONS

Postoperative FEV1 increased up to 12 months after lobectomy by video-assisted thoracic surgery. The predicted postoperative pulmonary function was underestimated after 3 months, particularly after lower lobectomy.

AB0252 EFFICACY OF A SECOND JANUS KINASE INHIBITOR THAT WAS SWITCHED FOR DIFFICULT-TO-TREAT RA IN CLINICAL PRACTICE

Background:

In clinical practice, when refractory rheumatoid arthritis (RA) is present, of which the definition implies previous use of at least two biologic disease-modifying antirheumatic drugs (bDMARDs) (generally tumour necrosis factor inhibitors (TNFis)), the next treatment choice often made is a bDMARD of another class (non-TNFis) [1]. However, patients who are inadequately responding to bDMARDs need new treatment options because subsequent bDMARDs treatment reduces their response [2]. Janus Kinase inhibitors (JAKis) are the first targeted synthetic DMARDs (tsDMARD) licensed for the treatment of RA with comparable efficacy to bDMARDs. Unlike the single cytokine targeting approach of bDMARDs, JAKis are specifically designed to inhibit intracellular signalling molecules common to the receptors of multiple inflammatory cytokines implicated in RA pathogenesis. The choice of therapeutic agents for refractory RA is increasing, and its efficacy is expected. On the other hand, it is also true that some patients discontinued JAKis at a rate that cannot be overlooked because of insufficient efficacy. Difficult-to-treat (D2T) RA is defined as refractory to two or more b/ts DMARDs with different mechanisms of action, with active and progressive disease, as published by Eular(3)

Objectives:

To evaluate real world efficacy of approved JAKis switching in patients with D2T RA who were unable to control their disease activity due to insufficient efficacy despite the sequential use of multiple bDMARDs and JAKis, focusing on the drug retention rate.

Methods:

In our hospital, RA was diagnosed according to the 1987 or 2010 classification criteria, and when two or more bDMARDs (including both TNFis and non-TNFis) were inadequately effective, it was defined as D2T RA. We retrospectively investigated patients who switched to JAKis for D2T RA. The drug retention rate was investigated by the Kaplan-Meier method, and the difference was tested by the Logrank test.

Results:

The 1-year retention rate of JAKis for D2T RA was 50.8% in TOF 38 cases [28 women, age average 70.2 years, disease duration average 12.4 years, past bDMARDs use average 3.5 drugs, MTX combination 9 cases, DAS28 ESR average 4.11] and 66.3% in BAR 35 cases [26 cases, 73.0 years old, 14.8 years, 4.17 agents, 9 cases, 3.68], and there was no significant difference (P = 0.30). Among them, there were 17 cases [11 cases, 70.6 years old, 13.5 years, 4.18 drugs, 2 cases, 3.65] of switching between JAKis, all of which were switching from TOF to BAR. The 1-year retention rate was 45.8% [reason for discontinuation: insufficient effect in 3 cases, adverse events in 6 cases], which was not significantly different but tended to be lower than 72.7% [reason for discontinuation: insufficient effect in 1 case, adverse event in 2 cases, patient’s convenience in 1 case] in 16 patients [13 cases, 76.3 years old, 17.1 years, 3.19 drugs, 7 cases, 3.69] who received BAR as the first JAKi for D2T RA patients (P = 0.089).

Conclusion:

Although the number of cases is small in the retrospective survey, it is suggested that the retention rate of BAR switched to D2T RA may be slightly lower in patients with a history of TOF discontinuation due to insufficient efficacy than in JAKi naive patients. It is expected that the number of new JAKi usage cases will increase in the future, and it is necessary to consider switching between other JAKis in addition to switching from BAR to TOF.

References:

[1]Smolen JS, Landewe R, Bijlsma J et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 update. Ann Rheum Dis 2017;76:960_77.

[2]Rendas-Baum R, Wallenstein GV, Koncz T et al. Evaluating the efficacy of sequential biologic therapies for rheumatoid arthritis patients with an inadequate response to tumor necrosis factor-α inhibitors. Arthritis Res Ther 2011;13:R25.

[3]Nagy G, et al. EULAR definition of difficult-to-treat rheumatoid arthritis. Ann Rheum Dis 2021;80:31–35. doi:10.1136/annrheumdis-2020-217344.

Disclosure of Interests:

None declared

POS0088 EFFICACY OF JANUS KINASE INHIBITORS FOR DIFFICULT-TO-TREAT RA IN CLINICAL PRACTICE

Background:

In 20-30% of rheumatoid arthritis (RA) patients, the first biologic disease-modifying antirheumatic drugs (bDMARDs) (generally tumour necrosis factor inhibitors (TNFis)) is ineffective, and among the patients who do respond to therapy, 20% is faced with secondary ineffectiveness within the first 2 years of treatment [1]. In practice, when refractory RA is present, of which the definition implies previous use of at least two bDMARDs (generally TNFis), the next treatment choice often made is a bDMARD of another class (non-TNFis) [2]. On the other hand, patients who are inadequately responding to bDMARDs need new treatment options because subsequent bDMARD treatment reduces their response [3]. Janus Kinase inhibitors (JAKis) are the first targeted synthetic DMARDs (tsDMARD) licensed for the treatment of RA with comparable efficacy to bDMARDs. Unlike the single cytokine targeting approach of bDMARDs, JAKis are specifically designed to inhibit intracellular signalling molecules common to the receptors of multiple inflammatory cytokines implicated in RA pathogenesis.

Objectives:

Difficult-to-treat (D2T) RA is defined as refractory to two or more b/ts DMARDs with different mechanisms of action, with active and progressive disease, as published by Eular(4). We evaluated real world efficacy of approved JAKis and factors that may help to continue them in patients with D2T RA.

Methods:

Patients who had inadequate response to two or more bDMARDs (including both TNFis and non-TNFis) at our hospital by December 2019 were defined as D2T RA, and patients who switched to JAKis were retrospectively investigated. The drug retention rate was determined by Kaplan-Meier method, and the difference was tested by Logrank test. Multiple regression analysis was used as the statistical method to predict continuation of JAKis for more than 1 year, with patient background (age, gender, during the disease, number of bDMARDs used, with or without methotrexate and/or glucocorticoids, disease activity score assessing 28 joints using erythrocyte sedimentation rate’ presence of rheumatoid factor/anti-CCP antibody, matrix metalloproteinase 3 value, Health Assessment Questionnaire disability index) at the time of initiation as an explanatory variable.

Results:

A total of 915 bDMARDs had been administered to 394 RA patients. The retention rate of bDMARDs and the number of bDMARDs used were 89.3% and 1.48 bDMARDs at 1 year, 67.7% and 2.27 bDMARDs at 5 years, and 52.0% and 3.15 bDMARDs at 10 years, respectively. The retention rate of JAKis at 1 year was 60.2% in 65 patients with tofacitinib (TOF) and 67.2% in 70 patients with baricitinib (BAR) (P=0.38). Among them, the drug retention rate in D2T RA patients was 50.8% in 38 TOF patients and 66.3% in 35 BAR patients with no significant difference (P=0.30). There were no patient background factors that significantly predicted continuation at 1 year for any JAKis.

Conclusion:

Despite the limited number of patients and the retrospective nature of the study, TOF and BAR were shown to be effective options for D2T RA, regardless of patient background such as disease activity or number of bDMARDs used. Other JAKis and switches between JAKis need to be investigated in the future.

References:

[1]Schaeverbeke T, Truchetet ME, Kostine M et al. Immunogenicity of biologic agents in rheumatoid arthritis patients: lessons for clinical practice. Rheumatology 2016;55:210_20.

[2]Smolen JS, Landewe R, Bijlsma J et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2016 update. Ann Rheum Dis 2017;76:960_77.

[3]Rendas-Baum R, Wallenstein GV, Koncz T et al. Evaluating the efficacy of sequential biologic therapies for rheumatoid arthritis patients with an inadequate response to tumor necrosis factor-α inhibitors. Arthritis Res Ther 2011;13:R25.

[4]Nagy G, et al. EULAR definition of difficult-to-treat rheumatoid arthritis. Ann Rheum Dis 2021;80:31–35. doi:10.1136/annrheumdis-2020-217344.

Disclosure of Interests:

None declared

Optimal timing of video-assisted thoracic surgery for acute pyothorax: a retrospective study

OBJECTIVE

Although the value of video-assisted thoracic surgery for acute pyothorax is becoming widely recognized, the optimal timing of surgery has not been established. Therefore, we aimed to determine the optimal timing of video-assisted thoracic surgery in acute pyothorax.

METHODS

We retrospectively reviewed 38 consecutive video-assisted thoracic surgeries performed for acute pyothorax between January 2013 and December 2017 at our institution. Data were analyzed using the independent samples t test and Mann-Whitney U test. A receiver-operating characteristic curve was used to identify the optimal time for intervention.

RESULTS

The average time from disease onset to surgery was 17.9 days, and the average preoperative drainage period was 8.3 days. The operation was completed in all patients with video-assisted thoracic surgery curettage and drainage under general anesthesia; single lung ventilation was administered, and one or two thoracic drains were placed. The average postoperative drainage period was 10.8 days. Intraoperative complications were observed in two cases; no perioperative death occurred. Additional surgery was performed in four cases because of poor treatment response. There was no recurrence of pyothorax over a mean postoperative follow-up period of 42.5 months. A receiver-operating characteristic curve showed that the cut-off time from disease onset to surgery was 21.0 days; complication rates were 14.3% and 25.0% for patients operated on before and after 21 days, respectively.

CONCLUSIONS

Thoracoscopic surgery for acute pyothorax is safe and curative, and should be performed within 21 days of disease onset to avoid postoperative complications.

Low-complexity generalized coherence factor estimated from binarized signals in ultrasound beamforming

PURPOSE

In coherence-based beamforming (CBB) using a generalized coherence factor (GCF), unnecessary signals caused by sidelobes are reduced, and an excellent contrast-to-noise ratio (CNR) is achieved in ultrasound imaging. However, the GCF computation is complex compared to the standard delay-and-sum (DAS) beamforming. In the present study, we propose a method that significantly reduces the number of GCF computations.

METHODS

In the previously proposed GCF_real, generation of the analytic signal for each element in the conventional GCF could be omitted. Furthermore, in GCF estimated from binarized signals (GCFB) proposed in the present study, the GCF value is calculated after the received signal of each element is binarized to reduce the computational complexity of the GCF.

RESULTS

The values of GCFB and GCF_real estimated from simulation and experimental data were compared. We also evaluated the image quality of B-mode images weighted by GCFB and GCF_real. Compared with GCF_real, GCFB was superior in reducing unnecessary signals but tended to reduce the brightness of the diffused scattering media. The CNR improvement was comparable for both methods.

CONCLUSION

Generalized coherence factor estimated from binarized signals exhibits excellent CNR improvement compared to DAS. CNR improvements yielded by GCFB and GCF_real may depend on the observation target; however, under the conditions of the present study, comparable performances were obtained. Because GCFB can significantly reduce the computational complexity, it is potentially applicable in clinical diagnostic equipment.

Fatty liver evaluation with double-Nakagami model under low-resolution conditions

In previous studies, the double-Nakagami (DN) model has been proposed for fatty liver assessment and applied to in vivo rat livers and clinical data sets. The healthy liver structure filter (HLSF) method, which extracts non-healthy areas using two DN parameters, has also been proposed. In this paper, we first verify the accuracy of the DN model and the HLSF method for acoustic fields at 15 and 5 MHz, which were reproduced using numerical simulation. We then apply the method to clinical data sets of livers observed using a frequency of 3 MHz and investigate the method’s clinical usefulness. A positive correlation ( r = 0.28 ) was found between the ratio of the non-healthy area and fat mass. Although the results were inferior to the results produced using 15 MHz ultrasound ( r = 0.96 ), we found that it was possible to detect the difference between a normal liver and a fatty liver even at a lower frequency.

Multifrequency Phased Tracking Method for Estimating Velocity in Heart Wall

Local high-accuracy velocity estimation is important for the ultrasound-based evaluation of regional myocardial function. The ultrasound phase difference at the center frequency of the transmitted signal has been conventionally used for velocity estimation. In the conventional method, spatial averaging is necessary owing to the frequency-dependent attenuation and interference of backscattered waves. Here, we propose a method for suppressing these effects using multifrequency phase differences. The resulting improvement in velocity estimation in the heart wall was validated by in vivo experiments. In the conventional method, the velocity waveform exhibits spike-like changes. The velocity waveform estimated using the proposed method did not exhibit such changes. Because the proposed method estimates myocardium velocity without spatial averaging, it can be used for measuring heart wall dynamics involving thickness changes.