Artifact reduction in low and ultra-low dose chest computed tomography for patients with pacemaker: A phantom study

INTRODUCTION

Implanted pacemakers (PM) would decrease the detection of lung nodules in chest computed tomography (CT) due to the metal artifact. This study aimed to explore the computer-aided diagnosis (CAD) detectability of pulmonary nodules for the patients implanted with PMs in low- and ultra-low-dose chest CT screening.

METHODS

Four different sizes of artificial nodules were placed in an anthropomorphic chest phantom with two alternative diameters utilized. A commercially available PM was placed on the surface of the left chest wall of the phantom. The image acquisitions were performed with 120 kV and 150 kV with a dedicated selective photon shield made of tin filter (Sn150 kV) at low- and ultra-low- radiation doses (1.0 and 0.5 mGy of volume CT dose index), and reconstructed with and without Iterative Metal Artifact Reduction (iMAR, Siemens Healthineers, Erlangen, Germany). The relative artifact index (AIr) was calculated as an index of metal artifacts, and the nodule detectability was evaluated with a CAD system.

RESULTS

Sn150 kV reduced AIr in all acquisitions when comparing 120 kV and Sn150 kV. Although PM reduced the detectability of nodules, Sn150 kV showed higher detectability compared to 120 kV. The use of iMAR showed inconsistent results in nodule detectability.

CONCLUSION

Sn150 kV reduced PM-induced metal artifacts and improved nodule detectability with CAD compared to 120 kV acquisition in many conditions including low and ultra-low doses and large phantoms, but iMAR did not improve the detectability.

IMPLICATIONS FOR PRACTICE

Based on the results of the current phantom study, low and ultra-low dose with Sn150 kV acquisition reduced PM-induced metal artifacts and improved nodule detectability.

Risk factors for early-onset adjacent segment degeneration after one-segment posterior lumbar interbody fusion

Adjacent segment degeneration (ASD) is a major postoperative complication associated with posterior lumbar interbody fusion (PLIF). Early-onset ASD may differ pathologically from late-onset ASD. The aim of this study was to identify risk factors for early-onset ASD at the cranial segment occurring within 2 years after surgery. A retrospective study was performed for 170 patients with L4 degenerative spondylolisthesis who underwent one-segment PLIF. Of these patients, 20.6% had early-onset ASD at L3-4. In multivariate logistic regression analysis, preoperative larger % slip, vertebral bone marrow edema at the cranial segment on preoperative MRI (odds ratio 16.8), and surgical disc space distraction (cut-off 4.0 mm) were significant independent risk factors for early-onset ASD. Patients with preoperative imaging findings of bone marrow edema at the cranial segment had a 57.1% rate of early-onset ASD. A vacuum phenomenon and/or concomitant decompression at the cranial segment, the degree of surgical reduction of slippage, and lumbosacral spinal alignment were not risk factors for early-onset ASD. The need for fusion surgery requires careful consideration if vertebral bone marrow edema at the cranial segment adjacent to the fusion segment is detected on preoperative MRI, due to the negative impact of this edema on the incidence of early-onset ASD.

Association between skin toxicity and efficacy of necitumumab in squamous non-small-cell lung cancer: a pooled analysis of two randomized clinical trials-SQUIRE and JFCM

BACKGROUND

Efficacy of necitumumab [recombinant human monoclonal antibody that blocks the ligand binding epidermal growth factor receptor (EGFR)] in patients with squamous (SQ) non-small-cell lung cancer (NSCLC) has been confirmed in two randomized clinical trials (SQUIRE and JFCM). This study evaluated the association between efficacy and initial skin toxicity with necitumumab treatment by analyzing pooled data from two clinical trials (SQUIRE and JFCM).

MATERIALS AND METHODS

Data of 635 patients with SQ-NSCLC (intent-to-treat population) treated with necitumumab plus gemcitabine and cisplatin (N + GC) were pooled from two clinical trials (SQUIRE and JFCM). The relationship between skin toxicities developed by the end of the second cycle and efficacy was evaluated. Efficacy endpoints included overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). Univariate and multivariate analyses were carried out for these endpoints.

RESULTS

OS and ORR were associated with skin toxicity, whereas PFS was not. Patients with grade ≥2 or grade 1 skin toxicity had significantly longer OS compared to patients without skin toxicity (grade 0) in the N + GC group [median = 15.0 (grade ≥2); 12.7 (grade 1); 9.4 (grade 0) months; hazard ratio (HR) = 0.51 (grade ≥2 to grade 0); 95% confidence interval (CI) 0.40-0.64, P < 0.001 and HR = 0.64 (grade 1 to grade 0); 95% CI 0.52-0.80, P < 0.001]. In multivariate analysis, OS was significantly associated with skin toxicity.

CONCLUSIONS

A significant association was found between necitumumab-induced skin toxicity and efficacy. These results are consistent with the previously reported association between other EGFR inhibitors-induced skin toxicity and efficacy.

Comparing Various Resin Luting Cement Systems in Different Etching Modes Through Bond Durability and Morphological Features

OBJECTIVES

This study aimed to investigate bond performance of various resin luting cement (RLC) systems on enamel and dentin in different etching modes and to compare the RLC-tooth interface morphology using scanning electron microscopy (SEM).

METHODS AND MATERIALS

The self-adhesive RLC systems used in combination with universal adhesives were as follows: Scotchbond Universal Adhesive Plus + RelyX Universal (3M Oral Care) and Clearfil Universal Bond Quick ER + SA Luting Multi (Kuraray Noritake Dental). These RLC systems were also used alone as self-adhesive RLC systems without universal adhesives (self-adhesive mode). The conventional RLC systems for comparison materials were as follows: BeautiBond Xtream + ResiCem EX (Shofu) and Tooth Primer + Panavia V5 (Kuraray Noritake Dental). Twelve specimens were prepared for each group to measure shear bond strength (SBS) in different etching modes. A stainless-steel rod was used as a substitute for indirect restorations. Bonded specimens were allocated to baseline (stored for 24 hours) and artificially aged (thermocycling [TC] for 10,000 cycles) groups. Representative treated tooth surfaces and RLC-tooth interfaces were observed using SEM.

RESULTS

Three-way analysis of variance (ANOVA) revealed that all the factors (etching mode, storage period, and RLC system) had a significant influence on the enamel SBS values (p<0.05). Enamel SBS was significantly higher in etch-&-rinse (ER) mode than in self-etch (SE) mode, regardless of RLC system or storage period. Three-way ANOVA showed that all the factors had a significant influence on the dentin SBS values (p<0.001). Most RLC systems showed significantly higher dentin SBS in SE mode than in ER mode, regardless of storage period. However, the combination with Scotchbond Universal Adhesive Plus and RelyX Universal showed no significant difference in SBS values between etching modes at the baseline and showed a significantly higher SBS value in ER mode than in SE mode after TC.

CONCLUSIONS

The self-adhesive RLC systems with universal adhesives tended to show higher enamel and dentin bond performance than the self-adhesive RLC systems alone. The morphology of treated tooth surfaces and resin cement-tooth interfaces were dependent on the RLC system and etching mode used. The RLC systems with primer application showed a thin, high-density layer above the intact dentin in both etching modes, suggesting chemical interaction.

Demonstration of nuclear gamma-ray polarimetry based on a multi-layer CdTe Compton camera

To detect and track structural changes in atomic nuclei, the systematic study of nuclear levels with firm spin-parity assignments is important. While linear polarization measurements have been applied to determine the electromagnetic character of gamma-ray transitions, the applicable range is strongly limited due to the low efficiency of the detection system. The multi-layer Cadmium-Telluride (CdTe) Compton camera can be a state-of-the-art gamma-ray polarimeter for nuclear spectroscopy with the high position sensitivity and the detection efficiency. We demonstrated the capability to operate this detector as a reliable gamma-ray polarimeter by using polarized 847-keV gamma rays produced by the [Formula: see text]([Formula: see text]) reaction. By combining the experimental data and simulated calculations, the modulation curve for the gamma ray was successfully obtained. A remarkably high polarization sensitivity was achieved, compatible with a reasonable detection efficiency. Based on the obtained results, a possible future gamma-ray polarimetery is discussed.

Impact of the lateral skeletal stability following bilateral sagittal split ramus osteotomy for mandibular asymmetry

This study evaluated the stability of bilateral sagittal split ramus osteotomy (BSSRO) associated with positional plagiocephaly and temporal and masseter muscles using posteroanterior cephalogram analysis and three-dimensional computed tomography (3D-CT). This retrospective cohort study included 31 patients who underwent BSSRO for mandibular asymmetry. The cranial vault asymmetry index (CVAI) and the cephalic index were used as indicators of positional plagiocephaly. The distance from the vertical reference line to the menton (Me) was measured on posteroanterior cephalograms immediately and 1 year after surgery, and postoperative stability was assessed. Temporal and masseter muscles were constructed from 3D-CT data and their volumes were measured. Simple regression analysis showed a significant correlation between postoperative changes in the vertical reference line to the Me and the CVAI (R = 0.56, p = 0.001), the amount of surgical movement in the vertical reference line to the Me (R = 0.41, p = 0.023), and the variable temporal muscle volume (R = 0.27, p = 0.028). There was no significant correlation between postoperative changes in the vertical reference line to the Me and the cephalic index (R = 0.093, p = 0.62) and variable masseter muscle volume (R = 0.16, p = 0.38). According to multivariate analysis, CVAI (p = 0.003) and amount of surgical movement in the vertical reference line to the Me (p = 0.014) were significant predictors of postoperative change in the vertical reference line to the Me. Positional plagiocephaly and amount of surgical movement influence lateral skeletal stability following BSSRO for mandibular asymmetry.

Management of Cervical Spinal Cord Injury without Major Bone Injury in Adults

The incidence of cervical spinal cord injury (CSCI) without major bone injury is increasing, possibly because older people typically have pre-existing cervical spinal canal stenosis. The demographics, neurological injury, treatment, and prognosis of this type of CSCI differ from those of CSCI with bone or central cord injury. Spine surgeons worldwide are debating on the optimal management of CSCI without major bone injury. Therefore, this narrative review aimed to address unresolved clinical questions related to CSCI without major bone injury and discuss treatment strategies based on current findings. The greatest divide among spine surgeons worldwide hinges on whether surgery is necessary for patients with CSCI without major bone injury. Certain studies have recommended early surgery within 24 h after injury; however, evidence regarding its superiority over conservative treatment remains limited. Delayed MRI may be beneficial; nevertheless, reliable factors and imaging findings that predict functional prognosis during the acute phase and ascertain the necessity of surgery should be identified to determine whether surgery/early surgery is better than conservative therapy/delayed surgery. Quality-of-life assessments, including neuropathic pain, spasticity, manual dexterity, and motor function, should be performed to examine the superiority of surgery/early surgery to conservative therapy/delayed surgery.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Dosimetric Evaluation of Targets and Organs at Risk in Dose Escalation Study for Total Marrow and Lymphoid Irradiation

PURPOSE/OBJECTIVE(S)

Total marrow and lymphoid irradiation (TMLI) delivers radiation dose to the bone marrow and lymph nodal region while reducing the dose to non-target organs. We conducted a dose-escalation study of TMLI to improve treatment outcomes while reducing OAR doses using intensity-modulated radiation therapy. However, this dose escalation strategy may cause increasing risk of recurrence and adverse events because of dose uniformity compromises of the target. We hypothesized that the homogeneity index (HI) could become worse with increased target's dose while maintaining reduced OAR doses for the nine patients enrolled in the TMLI phase Ⅰ clinical trial.

MATERIALS/METHODS

Nine patients treated with TMLI using a treatment delivery system from September 2019 to August 2021 were included. The prescribed doses were 14 Gy/6 fr, 16 Gy/6 fr, and 18 Gy/6 fr twice daily for 3 days, with three patients allocated each prescription. Bone marrow, lymph nodal region, spleen, testis, brain, and liver were designated as targets. The bone marrow was divided into eight parts (see Table); an individual PTV margin was added to each structure. We intended to deliver the D80% prescription dose for PTV. For the brain and liver, the prescribed dose was 12 Gy in consideration of function preservation. Lenses, oral cavity, parotid glands, lungs, heart, esophagus, stomach, kidneys, intestines, and breasts were defined as OAR. Targets were evaluated with HI that was calculated using the formula HI = (D2%-D98%)/D50%, based on ICRU report 83. For OARs, Dmax, D2%, D10%, and mean dose constraint were evaluated.

RESULTS

The table lists HI for the PTV_ALL and each target. The HI of PTV_ALL rose with increasing prescription dose and was highest at 18 Gy. The highest HI was 0.632 for PTV_Rib at 18 Gy, and the lowest HI was 0.045 for PTV_testis at 14 Gy. OAR Dose constraints were achieved in all patients. The average OAR doses in all cases for lenses, oral cavity, parotid glands, lungs, heart, esophagus, intestines, kidneys, and breast were 4.7±0.80, 4.4±0.51, 6.7±0.48, 7.6±0.22, 7.8±0.19, 6.7±0.18, 7.4±1.12, 6.9±0.96, and 14.7 Gy, respectively. The Dmax of the lenes, D2% of the esophagus, and D10% of the stomach were 7.2 ± 1.09, 11.5 ± 0.47, and 10.9 ± 0.98 Gy, respectively.

CONCLUSION

In the TMLI phase I clinical trial, we evaluated the dose uniformity to the targets and the OAR dose constraints. Although the HI for PTV_ALL worsened with increasing prescription dose, compliance with OAR dose constraints was achieved in all patients.

Artificial placenta technology: History, potential and perception

As presently conceptualised, the artificial placenta (AP) is an experimental life support platform for extremely preterm infants (i.e. 400-600 g; 21-23+6 weeks of gestation) born at the border of viability. It is based around the oxygenation of the periviable fetus using gas-exchangers connected to the fetal vasculature. In this system, the lung remains fluid-filled and the fetus remains in a quiescent state. The AP has been in development for some sixty years. Over this time, animal experimental models have evolved iteratively from employing external pump-driven systems used to support comparatively mature fetuses (generally goats or sheep) to platforms driven by the fetal heart and used successfully to maintain extremely premature fetuses weighing around 600 g. Simultaneously, sizable advances in neonatal and obstetric care mean that the nature of a potential candidate patient for this therapy, and thus the threshold success level for justifying its adoption, have both changed markedly since this approach was first conceived. Five landmark breakthroughs have occurred over the developmental history of the AP: i) the first human studies reported in the 1950's; ii) foundation animal studies reported in the 1960's; iii) the first extended use of AP technology combined with fetal pulmonary resuscitation reported in the 1990s; iv) the development of AP systems powered by the fetal heart reported in the 2000's; and v) the adaption of this technology to maintain extremely preterm fetuses (i.e. 500-600 g body weight) reported in the 2010's. Using this framework, the present paper will provide a review of the developmental history of this long-running experimental system and up-to-date assessment of the published field today. With the apparent acceleration of AP technology towards clinical application, there has been an increase in the attention paid to the field, along with some inaccurate commentary regarding its potential application and merits. Additionally, this paper will address several misrepresentations regarding the potential application of AP technology that serve to distract from the significant potential of this approach to greatly improve outcomes for extremely preterm infants born at or close to the present border of viability.

A two-color dual-comb system for time-resolved measurements of ultrafast magnetization dynamics using triggerless asynchronous optical sampling

We report on an Er-doped fiber (EDF)-laser-based dual-comb system that allows us to perform triggerless asynchronous optical sampling pump-probe measurements of ultrafast demagnetization and spin precession in magnetic materials. Because the oscillation frequencies of the two frequency-comb light sources are highly stabilized, the pulse-to-pulse timing jitter is sufficiently suppressed, and data accumulation without any trigger signals is possible. To effectively induce spin precession in ferromagnetic thin films, the spectral bandwidth of the output of one of the EDF frequency comb sources is broadened by a highly nonlinear fiber and then amplified at a wavelength of about 1030 nm by a Yb-doped fiber amplifier. The output of the other frequency comb source is converted to about 775 nm by second harmonic generation. We used this system to observe ultrafast demagnetization and spin precession dynamics on the picosecond and nanosecond time scales in a permalloy thin film. This time-domain spectroscopy system is promising for the rapid characterization of spin-wave generation and propagation dynamics in magnetic materials.

Adipose-Derived Mesenchymal Stromal Cell Transplantation for Severe Spinal Cord Injury: Functional Improvement Supported by Angiogenesis and Neuroprotection

Mesenchymal stromal cell transplantation alone is insufficient when motor dysfunction is severe; combination therapy with rehabilitation could improve motor function. Here, we aimed to analyze the characteristics of adipose-derived MSCs (AD-MSCs) and determine their effectiveness in severe spinal cord injury (SCI) treatment. A severe SCI model was created and motor function were compared. The rats were divided into AD-MSC-transplanted treadmill exercise-combined (AD-Ex), AD-MSC-transplanted non-exercise (AD-noEx), PBS-injected exercise (PBS-Ex), and no PBS-injected exercise (PBS-noEx) groups. In cultured cell experiments, AD-MSCs were subjected to oxidative stress, and the effects on the extracellular secretion of AD-MSCs were investigated using multiplex flow cytometry. We assessed angiogenesis and macrophage accumulation in the acute phase. Spinal cavity or scar size and axonal preservation were assessed histologically in the subacute phase. Significant motor function improvement was observed in the AD-Ex group. Vascular endothelial growth factor and C-C motif chemokine 2 expression in AD-MSC culture supernatants increased under oxidative stress. Enhanced angiogenesis and decreased macrophage accumulation were observed at 2 weeks post-transplantation, whereas spinal cord cavity or scar size and axonal preservation were observed at 4 weeks. Overall, AD-MSC transplantation combined with treadmill exercise training improved motor function in severe SCI. AD-MSC transplantation promoted angiogenesis and neuroprotection.

Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst)  eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

The effect of Daikenchuto on blood flow of the superior mesenteric artery and portal vein in ELBW: A prospective study

BACKGROUND

Focal intestinal perforation (FIP) is a devastating complication of premature birth, and extremely low birth weight (ELBW) infants are at highest risk. This study aimed to evaluate the relationship of the superior mesenteric artery (SMA) and portal vein (PV) blood flow velocities to investigate the association between intestinal blood flow and FIP. In addition, the herbal formula Daikenchuto (TJ-100) is expected to improve intestinal blood flow disorders; therefore, we evaluated its effect.

METHODS

We conducted a prospective cohort study of 15 ELBW infants from January 2020 to August 2021. Measured variables included birth weight, 5-minute Apgar score, time of oral feeding initiation, ductus arteriosus (PDA) closure (percent), diastolic and systolic blood pressure, SMA and PV blood flow velocity, and FIP onset data. Fifteen infants were divided into three groups: a non-surgery group (Group I; 6), a surgery group with FIP (Group II; 4), and a TJ-100 administration group (Group III; 5). The main outcome parameters included SMA and PV blood flow velocities with TJ-100.

RESULTS

SMA and PV blood flow differed significantly for the SMA of Group I and the SMA and PV of Group III (P < 0.01, P = 0.01, and P = 0.04, respectively). There was a correlation between SMA and PV in Group III (P = 0.03).

CONCLUSION

TJ-100 may increase SMA and PV blood flow and improve intestinal blood flow in ELBW infants at risk of FIP. Therefore, the effects of TJ-100 should undergo further study.

Clinical impact of short limited lumbar fusion for adult spinal deformity with postural and radiological abnormalities

Extensive surgical spinopelvic fusion for patients with adult spinal deformity (ASD) to achieve optimal radiological parameters should be avoided. The aim of this study was to review clinical and imaging findings in patients with ASD with postural and radiological abnormalities who underwent a novel three-level limited lumbar fusion as two-stage surgery in an attempt to propose a better tolerated alternative to spinopelvic long fusion to the pelvis. The subjects were 26 patients with a minimum follow-up period of 2 years. Cobb angle, C7 sagittal vertical axis, and pelvic incidence (PI) minus lumbar lordosis (LL) were significantly improved after surgery and maintained at follow-up. Most radiological parameters were corrected with lateral interbody fusion (LIF) as the initial surgery, and few with posterior fusion. PI-LL remained high after limited lumbar fusion, but scores on patient-based questionnaires and sagittal and coronal tilt in gait analysis improved. In cases with postoperative progression of proximal junctional kyphosis (11.5%), residual L1-L2 local kyphosis after LIF was the most significant radiological feature. In some cases of ASD with postural abnormalities, short limited lumbar fusion gives sufficient postoperative clinical improvement with preservation of spinal mobility and activities of daily living. The range of fixation should be determined based on radiological parameters after LIF to avoid postoperative complications.

Symptom-based characteristics and treatment efficacy of neuropathic pain related to spinal disorders

BACKGROUND

Symptom-based therapeutic management is required for neuropathic pain (NeP) to achieve higher treatment efficacy. In spinal disorders, which have a high prevalence of NeP, neurological symptoms are classified into myelopathy, radiculopathy, and cauda equina syndrome. The characteristics of pain and the treatment efficacy for each of these symptoms require clarification.

METHODS

A retrospective patient-based outcome study was conducted in 265 outpatients with chronic NeP (≥3 months) related to spinal disorders. The patients were classified into three groups according to their neurological symptoms: spinal cord-related pain, radicular pain, and cauda equina syndrome. Data were obtained from patient-based questionnaires using the Neuropathic Pain Symptom Inventory (NPSI) and the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP), and from clinical information.

RESULTS

Most of the patients with NeP had a NPSI score >10 (moderate to severe pain) and 40% had psychiatric problems. The common subtype of NeP was spontaneous pain and paresthesia/dysesthesia in patients with radicular pain and cauda equina syndrome, whereas more severe paresthesia/dysesthesia was particularly prominent in patients with spinal cord-related pain. The pain reduction rate was significantly lower in these latter patients, especially in association with residual paresthesia/dysesthesia.

CONCLUSIONS

The characteristics and treatment efficacy of NeP in patients with spinal disorders varied according to neurological symptoms. Effective treatment was difficult, especially for paresthesia/dysesthesia in patients with spinal cord-related pain. These findings enhance the understanding of the underlying mechanisms of pain and could help in design of symptom-based therapeutic management.

Prognosis after Palliative Surgery for Patients with Spinal Metastasis: Comparison of Predicted and Actual Survival

Simple Summary

Increased options for cancer treatment have made the prediction of prognosis an important factor in therapeutic decision making. The aim of this study was to assess the clinical significance of prognosis–scoring systems and to identify predictors for 6–month mortality after palliative surgery. The median actual survival period was longer than the predicted life expectancy based on the revised Tokuhashi score and new Katagiri score. However, 21.3% of patients died of cancers within 6 months after palliative surgery. A statistical analysis showed that a higher CRP/albumin ratio (odds ratio: 0.39; cut–off 0.409) and absence of postoperative adjuvant therapy (odds ratio: 7.15) were independent risk factors for poor survival. Our findings suggest the need for careful consideration to determine if palliative surgery is the best option for a patient with these negative prognostic factors, regardless of life expectancy predicted based on a prognosis score.

Abstract

Prediction of prognosis is a key factor in therapeutic decision making due to recent the development of therapeutic options for spinal metastases. The aim of the study was to examine predictive scoring systems and identify prognostic factors for 6–month mortality after palliative surgery. The participants were 75 patients with spinal metastases who underwent palliative surgery and had a minimum follow–up period of 1 year. Associations of actual survival with categories based on the revised Tokuhashi score and new Katagiri score were evaluated. Univariate and multivariate analyses were performed to identify prognostic factors for 6–month mortality after palliative surgery. The median actual survival period was longer than those predicted using the scoring systems. However, 21.3% of patients died of cancers within 6 months after surgery. A higher CRP/albumin ratio (odds ratio: 0.39; cut–off 0.409) and absence of postoperative adjuvant therapy (odds ratio: 7.15) were independent risk factors for 6–month mortality. There was no association of mortality with primary site, severity of sarcopenia, or other biomarkers. These results suggest that careful consideration is needed to determine whether palliative surgery is the best option for patients with a high preoperative CRP/albumin ratio and/or absence of postoperative adjuvant therapy, regardless of predictions made from scoring systems.

P-131 The fate of irregularly divided blastomeres: why does “Direct cleavage” reduce blastocyst development rate but not blastocyst euploid rate?

Study question

How do the blastomeres formed by direct cleavage (dynamics of one cell dividing into three or more cells) subsequently develop?

Summary answer

About half of the blastomeres by direct cleavage did not form blastocysts.

What is known already

There are many reports that embryos with direct cleavage in the early development have a lower blastocyst development rate because direct cleavage produces chromosomal abnormal cells. However, when such embryos develop into blastocysts, there have been some reports that the transfer pregnancy rate and euploid rate did not decrease, but the reasons for this have not been clarified.

Study design, size, duration

This is a retrospective study of 89 blastocysts obtained during 2013-18. These embryos were those that patients requested to be discarded and consented to be used in this study. All target embryos were time-lapse monitored by EmbryoScope (Vitrolife, Sweden), and several trophectoderms were biopsied and examined for euploidy.

Participants/materials, setting, methods

The target embryos were classified into three groups: embryos with normal first and second cleavage (NC group), embryos with irregular division (one cell dividing into three or more cells) called direct cleavage at the first cleavage (DC1 group), and embryos with direct cleavage of one blastomere at the second cleavage (DC2 group). It was recorded whether the blastomeres of the embryos subsequently developed into blastocysts or not. NGS analysis was performed on the embryos.

Main results and the role of chance

The target embryos were classified as 48 in the NC group, 32 in the DC1 group, and 9 in the DC2 group. Whether the blastomeres in the target embryos subsequently formed blastocysts or not was recorded one by one by time-lapse images, resulting in the blastomeres’ blastocyst formation rate was 95.1% in the NC group and 55.9% in the DC1 group, which was significantly lower in the DC1 group (P &lt; 0.01). In the DC2 group, blastomeres formed by normal division and those by direct cleavage at the second cleavage were recorded separately, and the blastocyst formation rate was 90.8% for normal cleavage blastomeres and 46.0% for direct cleavage blastomeres, with significantly lower rates for direct cleavage blastomeres (P &lt; 0.01). Therefore, about half of the blastomeres generated by direct cleavage at the first or second cleavage did not form blastocysts. The results of NGS analysis were as follows: NC group: 35.4% euploid, 45.8% aneuploid, and 18.8% mosaic; DC1 group: 37.5%, 53.1%, and 9.4%, respectively; and DC2 group: 55.6%, 33.3%, and 11.1%, respectively. There was no significant difference in any of the items, suggesting that direct cleavage does not affect the euploidy of blastocysts.

Limitations, reasons for caution

For the purpose of NGS analysis, all the target embryos in this study were blastocysts, but if all the cultured embryos were included, arrested embryos would be included, which would probably result in more blastomeres formed by direct cleavage not developing into blastocysts.

Wider implications of the findings

The blastomeres generated by direct cleavage were often excluded from blastocyst formation. This may be an exclusion of chromosomally abnormal cells and may be one of the reasons why direct cleavage decreases blastocyst development rate but does not decrease blastocyst euploid rate.

Trial registration number

not applicable

O-289 Effects of Taxol on the developmental potency of human and mouse GV oocytes

Study question

Is it possible to improve the quality of oocytes with delayed maturation or aging?

Summary answer

Yes, modification of oocyte microtubules at the germinal vesicle (GV) stage inhibits abnormal chromosome separation in in-vitro maturation and enhances early cleavage.

What is known already

Oocyte aging is characterized by an increase of aneuploidy and a decrease of the developmental potency with maternal ages, which will results in low frequencies of the blastocyte formation and implantation. In addition to the 1st meiotic division, it has become clear that the 2nd meiotic division also significantly contributes to aneuploidy production which is followed by pre-implantation embryo loss. However, no method for overcoming the oocyte aging has been established.

Study design, size, duration

Human GV oocytes with delayed maturation obtained from consented female patients were used. Mouse GV oocytes collected from 9-15 month old ICR mice were also used. After exposure to Taxol for 1hr, the oocytes were matured in vitro and examined cytogenetically and cytologically at the GV stage, the MII stage and pronuclear stage.

Participants/materials, setting, methods

RNA transcripts of the GV stage oocytes were compared before and after Taxol exposure with microarray in both species. Chromosome aberrations at the MII stage and blastocyst formation rate were examined in human IVM oocytes. Mouse IVM oocytes were evaluated on 2nd polar body (PB) extrusion and O2 consumption (CRAS3.0, Crino Co Inc.) at the pronuclear stage after parthenogenetic activation with electro-stimulation.

Main results and the role of chance

After Taxol treatment, premature chromosome separation was significantly reduced from 96% to 7% and the blastocyst formation rate increased from 3% to 16% in human. In mice, normal PB extrusion rate increased from 29% to 92%, and oxygen consumption was higher in some pronuclear oocytes. In human GV oocytes, taxol treatment altered gene expression only in a few factors related to chromosome attachment and segregation. On the other hand, in mouse GV oocytes, gene expression was significantly altered by oocyte aging and Taxol treatment.

Limitations, reasons for caution

The present results were obtained in human GV oocytes with delayed maturation which were collected after PMS and HCG administrations. It is not clear whether Taxol is effective on the GV oocytes collected before HCG administration.

Wider implications of the findings

Our results indicate that the combination of biochemical modification and IVM in the GV stage may be able to restore the aging of human oocytes.

Trial registration number

not applicable

Another operator-theoretical proof for the second-order phase transition in the BCS-Bogoliubov model of superconductivity

In the preceding papers, imposing certain complicated and strong conditions, the present author showed that the solution to the BCS-Bogoliubov gap equation in superconductivity is twice differentiable only on the neighborhoods of absolute zero temperature and the transition temperature so as to show that the phase transition is of the second order from the viewpoint of operator theory. Instead, we impose a certain simple and weak condition in this paper, and show that there is a unique nonnegative solution and that the solution is indeed twice differentiable on a closed interval from a certain positive temperature to the transition temperature as well as pointing out several properties of the solution. We then give another operator-theoretical proof for the second-order phase transition in the BCS-Bogoliubov model. Since the thermodynamic potential has the squared solution in its form, we deal with the squared BCS-Bogoliubov gap equation. Here, the potential in the BCS-Bogoliubov gap equation is a function and need not be a constant.

Prognostic Factors for the Postoperative Improvement of Spinal Cord-Related Neuropathic Pain in Patients with Degenerative Cervical Myelopathy

Introduction

The number of patients with degenerative cervical myelopathy (DCM) requiring surgical treatment has markedly increased in today's aging society. Such patients often exhibit impaired activities of daily living because of motor dysfunction as well as neuropathic pain (NeP). Although many studies have demonstrated the safety and efficacy of surgical treatment for DCM, residual postoperative NeP has not been well described. Therefore, this study aimed to identify the predictors of postoperative NeP improvement in patients with DCM.

Methods

This retrospective study included 92 outpatients with postoperative chronic NeP (≥3 months) related to DCM. Data were obtained from clinical information, magnetic resonance imaging (MRI) findings, and patient-based questionnaires using the Neuropathic Pain Symptom Inventory (NPSI) and the Brief Scale for Psychiatric Problems in Orthopaedic Patients. Univariate and multivariate analyses were performed for patients with NPSI improvement rates <30% and ≥30% to identify prognostic factors.

Results

Among 92 patients, 61 (66.3%) had residual NeP, with a low improvement rate even after surgery. The independent negative prognostic factors for NeP improvement after surgery were older age at operation (odds ratio (OR): 0.932), longer symptom duration before surgery (OR: 0.589), and higher preoperative NPSI score (OR: 0.932). The cut-off value of symptom duration before surgery for postoperative NeP improvement was 1 year. By contrast, the preoperative Japanese Orthopaedic Association score and MRI findings, including signal intensity change and the degree of spinal cord compression, were not associated with postoperative NeP improvement. Moreover, even in patients with an NPSI improvement rate ≥30%, the NPSI subscores for deep pain and paresthesia/dysesthesia remained high.

Conclusions

Discrepancies between physician- and image-based assessments and patient-based assessments were identified as factors associated with improvement in postoperative NeP. Our findings are important for both spine surgeons and patients to manage patient expectations with respect to recovery during the postoperative course.

Combining transcranial direct current stimulation and peripheral electrical stimulation to improve upper limb function in a patient with acute central cord syndrome: a case report

We report the immediate improvement of weakened muscles after combined treatment with transcranial direct current stimulation (tDCS) and peripheral electrical stimulation (PES) in a patient with acute central cord syndrome (CCS) who presented with severe upper limb motor dysfunction. A 70-year-old man sustained CCS with severe motor deficits in the left upper limb, which did not improve with conventional training until 6 days after injury. On the seventh day after the injury, the left upper limb was targeted with combined tDCS (1 mA for 20 minutes/day, anode on the right, cathode on the left) and PES (deltoid and wrist extensors, 20 minutes/day at the motor threshold), and his performance score immediately improved from 0 to 6 on the Box and Block test. After four sessions, the left upper limb function improved to 32 on the Box and Block test, and manual muscle test scores of the stimulated deltoid and wrist extensors improved from 1 to 2. This improvement of the left upper limb led to improved self-care activities such as eating and changing clothes. Exercise combined with tDCS and PES may be a novel treatment for upper limb movement deficits after acute CCS.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Distribution and Polarization of Hematogenous Macrophages Associated with the Progression of Intervertebral Disc Degeneration

STUDY DESIGN

In vivo study using immunostaining and immunoblot analysis.

OBJECTIVE

To determine the distribution of bone marrow-derived macrophages (BMDMs), macrophage polarization and cytokine expression in the process of intervertebral disc (IVD) degeneration.

SUMMARY OF BACKGROUND DATA

Knowledge of the detailed distribution of exogeneous macrophages in the disc degeneration process is important for understanding the pathomechanisms and establishing novel therapeutic targets.

METHODS

To distinguish BMDMs, GFP-labeled bone marrow chimeric rats (n = 12) were generated. The degenerative process of the intervertebral disc was reproduced in a rat caudal disc puncture model (n = 49). Immunofluorescence staining was performed to observe the distribution of BMDMs, Iba-1 and GFP double-positive cells, and Iba-1 and iNOS (M1 macrophage) or arginase-1 (M2 macrophage) double-positive cells. Immunoblot analysis was used to evaluate differences in cytokines (TNF-α, IL-1β, IL-6, TGF-β, IL-4, and IL-10) depending on the distribution of BMDMs.

RESULTS

BMDMs infiltrated into the outer annulus fibrosus and endplate, while increasing tissue-resident macrophage was observed inside the annulus fibrosus/nucleus pulposus. The ratio of BMDMs and the polarity change differed among the regions. Especially in the endplate, BMDMs increased gradually and the macrophage phenotype was M2 dominant. Expression of IL-1β decreased gradually at endplate, and that of IL-4 increased early after disc puncture at inside of the annulus fibrosus.

CONCLUSION

During the disc degeneration process, BMDMs were observed mainly around the endplate and outside area of the annulus fibrosus, with few in the inside area of annulus fibrosus and nucleus pulposus. Compared to other IVD area, macrophage polarity and cytokine expression is concomitantly M2-dominant in endplate. Increased hematogenous M2-phenotype macrophages in endplate with progression of IVD degeneration could enhance our understanding of the underlying mechanisms of disc degeneration.Level of Evidence: N/A.

Risk Factors and Prevention of C5 Palsy After Anterior Cervical Decompression and Fusion: Similarity of the Pathomechanism With That After a Posterior Approach

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

The objective of this study was to review clinical and imaging findings after anterior cervical decompression and fusion, as a basis for prevention of C5 palsy.

SUMMARY OF BACKGROUND DATA

C5 palsy is a common postoperative complication in spine surgery, but the mechanistic basis for this condition is unknown.

MATERIALS AND METHODS

The subjects were 239 patients with cervical myelopathy who underwent anterior cervical decompression and fusion including at C4-C5 disk level at our hospital from 2001 to 2018. Twelve of these patients (5.0%) had C5 palsy postoperatively. Clinical features and imaging findings were compared in patients with and without C5 palsy.

RESULTS

In patients with C5 palsy, the sagittal alignment of the cervical spine was kyphotic, the width of the C5 intervertebral foramen was narrower, and the lateral decompressed line was wider beyond the medial part of the Luschka joint. Age, sex, disease, the number of fused segments, decompression width, and anterior shift of the spinal cord did not differ significantly between patients with and without C5 palsy.

CONCLUSIONS

These results indicate that the pathomechanism of C5 palsy may be dependent on the location of the lateral decompression line, especially in patients with cervical kyphosis and a narrow C5 intervertebral foramen. Excessive lateral decompression beyond the Luchka joint might lead to C5 root kinking between the intervertebral foramen and posterior edge of vertebra. This pathomechanism may be similar in anterior and posterior approaches. To prevent C5 palsy, the medial line of the Luschka joint should be confirmed intraoperatively and decompression should be performed within the Luschka joints. Alternatively, medial foraminotomy should be used in cases needing wide decompression, such as those with massive ossification of the posterior longitudinal ligament, lateral osteophytes, and symptomatic foraminal stenosis.

LEVEL OF EVIDENCE

Level III.

Prognostic Factors for Cervical Spinal Cord Injury Without Major Bone Injury in Elderly Patients

In the current aging society, there has been a marked increase in the incidence of cervical spinal cord injury (CSCI) without major bone injury. This multi-center study aimed to identify predictors of neurological improvement in elderly patients with CSCI without major bone injury. The participants were 591 patients aged ≥65 years with CSCI without major bone injury and a minimum follow-up period of three months. Neurologic status was defined using the American Spinal Injury Association (ASIA) impairment scale (AIS). Univariate and multi-variate analyses were performed to identify prognostic factors for walking recovery in AIS A–C cases and full upper extremity motor recovery in AIS D cases. In AIS A–C cases, body mass index (odds ratio (OR): 1.112), magnetic resonance imaging signal change (OR: 0.240), AIS on admission (OR: 3.497), comorbidity of dementia/delirium (OR: 0.365), and post-injury pneumonia (OR: 0.194) were identified as independent prognostic factors for walking recovery. The prevalence of ossification of the posterior longitudinal ligament (OR: 0.494) was also found to be an independent prognostic factor in AIS B and C cases only. In AIS D cases, age (OR: 0.937), upper extremity ASIA motor score on admission (OR: 1.230 [per 5 scores]), and operation (OR: 0.519) were independent prognostic factors for full motor recovery. The severity of AIS at admission was the strongest predictor of functional outcomes. Promoting rehabilitation, however, through measures to reduce cognitive changes, post-injury pneumonia, and unhealthy body weight changes can contribute to greater neurological improvement in AIS A–C cases.

Cutaneous ischemia-reperfusion injury is exacerbated by IL-36 receptor antagonist deficiency

BACKGROUND

Loss-of-function homozygous or compound heterozygous mutations in IL36RN, which encodes interleukin-36 receptor antagonist (IL-36Ra), has been implicated in the pathogenesis of skin disorders. However, the pathogenic role of IL-36Ra in cutaneous ischemia-reperfusion (I/R) injury remains unclear.

OBJECTIVES

We investigated the role of IL36Ra in cutaneous I/R injury.

METHODS

We examined I/R injury in Il36rn^-/- mice. The area of wounds, numbers of infiltrated cells, apoptotic cells and neutrophil extracellular trap (NET) formation were assessed. The expression levels of various genes were analysed using real-time RT-PCR. The expression of high mobility group box 1 (HMGB1), an endogenous toll-like receptor (TLR) 4 ligand, was confirmed using immunohistology, and serum HMGB1 levels were measured by ELISA. Cytokine production by stimulated cultured J774A.1 and HaCaT cells was examined.

RESULTS

IL-36Ra deficiency resulted in significantly delayed wound healing and increased neutrophil and macrophage infiltration into the wound tissues. Il36rn^-/- mice had increased mRNA expression levels of CXCL1, CXCL2, CCL4, TNF-α, TGF-β, IL-1β, IL-6 and IL-36γ relative to wild-type mice. Apoptosis was identified in keratinocytes by TUNEL assay. HMGB1 expression in the I/R site was decreased in both keratinocytes and adnexal cells, while serum HMGB1 levels were significantly elevated after reperfusion. The mRNA levels of various cytokines, including IL-1β, were elevated in J774A.1 cells through TLR4 signalling by HMGB1 stimulation. In addition, HaCaT cells stimulated with IL-1β showed significantly increased CXCL1, TNF-α, IL-6, IL-36β and IL-36γ mRNA expression. Furthermore, NET formation was increased by IL-36Ra deficiency. Finally, either the blockade of TLR4 signalling by TAK-242 or inhibition of NET formation by Cl-amidine normalized exacerbated I/R injury in Il36rn^-/- mice.

CONCLUSIONS

This study indicated that IL-36Ra deficiency exacerbates cutaneous I/R injury due to excessive inflammatory cell recruitment, NET formation, and excessive cytokine and chemokine production via the TLR4 pathway by HMGB1 released from epidermal apoptotic cells.

Negative impact of short-level posterior lumbar interbody fusion in patients with diffuse idiopathic skeletal hyperostosis extending to the lumbar segment

OBJECTIVE

The development of diffuse idiopathic skeletal hyperostosis (DISH) often requires further surgery after posterior decompression without fusion because of postoperative intervertebral instability. However, there is no information on whether fusion surgery is recommended for these patients as the standard surgery. The aim of this study was to review the clinical and imaging findings in lumbar spinal canal stenosis (LSS) patients with DISH affecting the lumbar segment (L-DISH) and to assess the indication for fusion surgery in patients with DISH.

METHODS

A total of 237 patients with LSS underwent 1- or 2-level posterior lumbar interbody fusion (PLIF) at the authors' hospital and had a minimum follow-up period of 2 years. Patients with L-DISH were classified as such (n = 27, 11.4%), whereas those without were classified as controls (non-L-DISH; n = 210, 88.6%). The success rates of short-level PLIF were compared in patients with and those without L-DISH. The rates of adjacent segment disease (ASD), pseudarthrosis, postoperative symptoms, and revision surgery were examined in the two groups.

RESULTS

L-DISH from L2 to L4 correlated significantly with early-onset ASD, pseudarthrosis, and the appearance of postsurgical symptoms, especially at a lower segment and one distance from the segment adjacent to L-DISH, which were associated with the worst clinical outcome. Significantly higher percentages of L-DISH patients developed ASD and pseudarthrosis than those in the non-L-DISH group (40.7% vs 4.8% and 29.6% vs 2.4%, respectively). Of those patients with ASD and/or pseudarthrosis, 69.2% were symptomatic and 11.1% underwent revision surgery.

CONCLUSIONS

The results highlighted the negative impact of short-level PLIF surgery for patients with L-DISH. Increased mechanical stress below the fused segment was considered the reason for the poor clinical outcome.

Low serum chloride level gives renin-angiotensin system inhibitor a prognostic impact in heart failure patients with preserved ejection fraction

Background

Hypochloremia is associated with a poor prognosis of heart failure (HF) patients. This phenomenon is sustained even in HF with preserved ejection fraction (HFpEF). Serum chloride level is known to be affected by serum renin secretion; however, this relationship is one of the least investigated field in HF patients. Renin-angiotensin system (RAS) inhibitor is recommended as a first-line medication for HF patients with reduced left ventricular ejection fraction, but no prior studies of RAS inhibitors have achieved to improve the prognosis of HFpEF patients.

Purpose

We investigated the relationship between baseline serum chloride level and the prognostic impact of RAS inhibitor in HFpEF patients.

Methods

This is an observational study including 1,913 consecutive patients who admitted to hospital due to worsening of HF and discharged alive in a single university hospital. After excluding patients who received regular hemodialysis and whose left ventricular ejection fraction were under 50%, 506 HFpEF patients were ultimately analyzed. They were categorized into tertiles by serum chloride levels at discharge (T1: −100 mEq/L, T2: 101–104 mEq/L, T3: 105- mEq/L), and patients in each category were further divided into subgroups depending on the prescription of RAS inhibitor at discharge (RAS inhibitor group and Non-RAS inhibitor group). The primary endpoint of this study was death from any cause.

Results

During the observation period with 479 days of median follow-up, 77 (15.2%) died. Patients in the RAS inhibitor group had significantly better prognosis than those in the Non-RAS inhibitor group in T1 category (Log-rank: p=0.003, Figure). In contrast, there was no statistical difference in the mortality between the RAS inhibitor group and Non-RAS inhibitor group in T2 and T3 categories (Log-rank: p=0.15, p=0.81, respectively, Figure). Multivariate Cox regression analysis in T1 category revealed that taking RAS inhibitor at discharge was independently associated with a lower mortality rate, even after the adjustment of diverse covariates (hazard ratio: 0.40, 95% confidence interval: 0.20–0.80).

Conclusion

In this observational study, the administration of RAS inhibitor was associated with an improved prognosis of HFpEF patients only in low serum chloride level at discharge. Therapeutic strategy focusing on the chloride level may be one of the promising options to find the light on a unintervenable prognosis of HFpEF.

Funding Acknowledgement

Type of funding sources: None.

Impact of catheter ablation on functional tricuspid regurgitation in patients with atrial fibrillation

Background

Since atrial functional tricuspid regurgitation (AF-TR) is associated with increased heart failure and mortality, the management of AF-TR is clinically important. Atrial fibrillation (AF) plays the main role in AF-TR. However, the effectiveness of catheter ablation (CA) and mechanism of improvement of AF-TR haven't been fully evaluated.

Purpose

We sought to investigate the impact of CA for AF on AF-TR in patients with moderate or more TR.

Methods

We retrospectively investigated consecutive 2685 patients with AF who received CA from February 2004 to December 2019 in Japan. The current study population consisted of 102 patients with moderate or greater TR who underwent CA for AF. The echocardiographic parameters were compared between pre-ablation and post-ablation transthoracic echocardiography (TTE), and the recurrence rate of AF/ atrial tachycardia (AT) was measured.

Results

The mean age was 73.2 years, 53% were women. TR severity and TR jet area significantly improved after CA for AF (TR jet area: 5.8 [3.9–7.6] cm2 to 2.0 [1.1–3.0] cm2, p&lt;0.001). In addition, mitral regurgitation (MR) jet area, left atrial (LA) area, mitral valve diameter, right ventricular (RV) end-diastolic area, right atrial (RA) area, tricuspid valve (TV) diameter decreased after CA (p&lt;0.001, &lt;0.001, &lt;0.001, = 0.02, &lt;0.001, and &lt;0.001, respectively). There was no significant difference between one-year recurrence of AF/AT and TR severity at pre-ablation TTE (moderate 28.6%, moderate to severe 37.2%, and severe 31.6%, p=0.72).

Conclusions

TR severity and jet area improved after CA in patients with AF and moderate or more TR. RV size, RA size, TV diameter also decreased after CA, which may be associated with TR improvement. There was no significant difference between one-year recurrence of AF/AT and TR severity at pre-ablation TTE.

Funding Acknowledgement

Type of funding sources: None.

Prognostic advantage of optimal medical therapy is not cancelled in hospitalized heart failure patients receiving regular hemodialysis

Background

As the first-line medications, renin-angiotensin-aldosterone system inhibitor (RAASi) and β-blocker provide prognostic benefits in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF). However, the negative inotropic effect of these drugs may destabilize the hemodynamics during hemodialysis (HD) and become prognostically controversial in patients receiving regular HD. Indeed, prior studies have reported the cancellation of the favorable prognostic effects of RAASi and β-blocker in patients with HD. However, it is totally unknown whether the guideline-directed medical therapy affects the prognosis in HF patients receiving regular HD.

Purpose

We aimed to evaluate the prognostic impact of RAASi and β-blocker on the cardiovascular (CV) events in HF patients on regular HD.

Methods

This observational study initially included 1,930 consecutive patients who were hospitalized due to HF and discharged alive. Of these, 151 patients who received regular HD were ultimately analyzed. They were classified into 3 groups depending on the prescribing medications at discharge; patients who received none of RAASi or β-blocker (None group: N=19), either RAASi or β-blocker (Either group: N=56), and both RAASi and β-blocker (Both group: N=76). The primary endpoint was a composite of CV death and readmission due to HF.

Results

During the observation period of median 501 (interquartile range: 197–954) days, the primary endpoint occurred in 61 patients (40%). Kaplan-Meier analysis showed the highest rate of composite endpoint in the None group (log-rank for trend: p&lt;0.001, Figure). After adjusting for covariates of age, sex, LVEF, and systolic blood pressure and heart rate at discharge, the hazard ratio (HR) for a composite endpoint was significantly lower in the Either group or Both group than that in the None group [HR: 0.19, 95% confidence interval (CI): 0.08–0.45; HR: 0.16, 95% CI: 0.06–0.42, respectively].

Conclusions

The prescription of RAASi or β-blocker at discharge was associated with lower adverse CV event rates in patients on regular HD who were hospitalized for HF. In order to improve long-term prognosis of HF patients on HD, we should consider the prescription of RAASi or β-blocker for them if hemodynamics during HD is affordable.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Heart failure re-hospitalization differently affects the following mortality in patients with reduced, mid-range and preserved LVEF

Introduction

The recent advances in the treatment for heart failure with reduced ejection fraction (HFrEF) have been remarkable, while no therapy has convincingly improved the prognosis in HF patients with preserved (HFpEF) and mid-range (HFmrEF) ejection fraction. Frequent decompensations of HF lead to progressive deterioration of cardiac and renal function, and quality of life. Hence, prior studies have reported that the mortality of HFrEF patients increases as hospitalization for HF repeats. However, it is still unclear whether this trend applies for HFpEF and HFmrEF patients.

Purpose

We aimed to compare the prognostic impact of re-hospitalization due to HF on cardiovascular death (CVD) among HFrEF, HFmrEF and HFpEF patients.

Methods

This observational study included 1,930 consecutive patients who were hospitalized for worsening of HF and discharged alive. Of them, patients who have never or have not been hospitalized for HF at least last 2 years, were finally analyzed. Patients were consisted of the population with HFrEF (EF&lt;40%, n=421), HFmrEF (EF 40–49%, n=202) and HFpEF (EF&gt;50%, n=291). Patients in each EF-classified population were divide into 2 subgroups based on whether patients were re-hospitalized for HF during the observational period, respectively. The primary endpoint of this study was CVD.

Results

During the observation period, Kaplan-Meier analysis showed that patients who were re-hospitalized for HF had higher event rate of CVD in HFrEF group (Log-rank p=0.008, Figure). Even after adjusting with multivariate covariates including age, sex, EF, brain natriuretic peptide and estimated glomerular filtration rate, re-hospitalization for HF was an independent predictor for CVD in HFrEF group (HR: 1.95, 95% CI: 1.11–2.86, p=0.029). However, in HFmrEF group and HFpEF group, there was no significant difference in the rates of CVD between 2 subgroups divided whether patients were re-hospitalized for HF or not (p=0.91, p=0.34, respectively).

Conclusion

Re-hospitalization for HF affected the CVD rate in HFrEF group, but not in HFmrEF and HFpEF groups. The prevention of re-hospitalization for HF is important particularly in HFrEF patients in order to improve cardiovascular mortality.

Funding Acknowledgement

Type of funding sources: None.

Influence of renal dysfunction on clinical outcomes in elderly patients with atrial fibrillation: a subanalysis of the phase 3, randomized, placebo-controlled ELDERCARE-AF trial

Background

Renal dysfunction is common in elderly patients with atrial fibrillation (AF) and is thought to be associated with increased risk of thromboembolic and bleeding events. Once-daily low-dose (15 mg) edoxaban was superior to placebo in preventing stroke or systemic embolic events (S/SEE) without significantly increasing major bleeding events in very elderly (≥80 years) non-valvular AF (NVAF) patients in whom standard oral anticoagulant therapy at approved doses was inappropriate (ELDERCARE-AF trial). Little is known about how renal dysfunction affects the effects of low-dose edoxaban in these patients.

Purpose

We used prespecified subgroup analysis to investigate the relation between renal function (assessed by creatinine clearance, CrCl) and the efficacy and safety of edoxaban in elderly NVAF patients.

Methods

ELDERCARE-AF patients were divided into 3 subgroups according to baseline CrCl: normal renal function/mild dysfunction (CrCl &gt;50 mL/min), moderate renal dysfunction (CrCl ≥30 to ≤50 [“30–50”] mL/min) and severe renal dysfunction (CrCl ≥15 to &lt;30 [“15–30”] mL/min). Primary efficacy and safety endpoints were annualized incidence of S/SEE and ISTH-defined major bleeding, respectively.

Results

Of 984 patients randomized to edoxaban 15 mg or placebo (each group N=492), 681 completed the trial. The 303 discontinuations were due to withdrawal of consent (n=158), death (n=135), or other causes (n=10). Discontinuation rate was the same in the edoxaban and placebo groups. S/SEE incidence in patients with CrCl &gt;50, 30–50 and 15–30 mL/min was 2.0%, 1.3% and 3.5%, respectively, in edoxaban, and 4.4%, 4.6% and 9.7%, respectively, in placebo. In those with CrCl 30–50 and 15–30 mL/min, it was significantly lower in edoxaban than in placebo (adjusted hazard ratio [HR], 0.30 [95% CI, 0.10–0.91], p=0.03; and 0.33 [95% CI, 0.16–0.71], p&lt;0.01, respectively). Incidence of major bleeding in patients with CrCl &gt;50, 30–50 and 15–30 mL/min was 1.0%, 1.8% and 6.2%, respectively, in edoxaban, and 0.9%, 1.5% and 2.4%, respectively, in placebo. Incidence of major bleeding in those with CrCl 15–30 mL/min was higher in edoxaban but not significantly (adjusted HR, 2.53 [95% CI, 0.96–6.72], p=0.062). Incidence of gastrointestinal bleeding in patients with CrCl 15–30 mL/min was 4.3% in edoxaban and 1.6% in placebo (adjusted HR, 2.61 [95% CI, 0.79–8.68], p=0.12). Incidence of all-cause death in patients with CrCl &gt;50, 30–50 and 15–30 mL/min was 5.8%, 6.8% and 15.2%, respectively, in edoxaban, and 7.0%, 6.3% and 15.5%, respectively, in placebo (no significant intergroup differences).

Conclusions

Incidence of S/SEE, major bleeding and all-cause death increased with declining renal function in elderly NVAF patients. Edoxaban 15 mg remained superior to placebo in preventing S/SEE, even in those with moderate to severe renal dysfunction. Incidence of major bleeding in patients with severe renal dysfunction was higher (non-significantly) with edoxaban than with placebo.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi-Sankyo Co., Ltd.

Short-Term Outcome and Predictors of Therapeutic Effects of Intradiscal Condoliase Injection for Patients with Lumbar Disc Herniation

Introduction

Intradiscal chondroitin sulfate ABC endolyase (condoliase) injection for lumbar disc herniation (LDH) is an intermediate between conservative treatment and surgery. This approach can only be performed once in a lifetime; therefore, understanding the factors that determine the indication for the use of condoliase and predict outcomes is important. The aim of this study was to review clinical and imaging findings in patients after intradiscal condoliase injection, and to assess the short-term outcomes and factors associated with therapeutic effects.

Methods

The subjects were 42 patients with LDH who underwent intradiscal condoliase injection. Patients with and without a ≥50% improvement from baseline of leg pain at 3 months after injection were defined as responders and non-responders, respectively. Clinical features and radiological findings were compared between these groups.

Results

Of the 42 patients, 32 (76.2%) were responders and 10 (23.8%) were non-responders. Of 8 patients with a history of discectomy at the same level as LDH, 6 (75.0%) were responders. Non-responders had a significantly longer time from onset to treatment, smaller herniated volume before treatment, lower percentage reduction of herniated mass, and less intervertebral disc degeneration before treatment. There were no significant differences in LDH types (subligamentous extrusion or transligamentous extrusion types), high-intensity area within the herniation, changes in disc height, and region of condoliase injection between the two groups.

Conclusions

Intradiscal condoliase injection had a good short-term therapeutic effect in patients with LDH, including in transligamentous extrusion-type and revision cases as well as subligamentous extrusion-type cases. Administration of intradiscal condoliase injection may be most effective in patients with a larger herniated mass volume before treatment, and least effective in cases with a longer time and less intervertebral disc degeneration before treatment.

P–131 Significance of the phenomenon of blastomere exclusion from compaction: Its relation to irregular cleavage, blastocyst development rate, and pregnancy rate

Study question

When does blastomere exclusion from compaction increase and what effect does it have on the embryo?

Summary answer

More blastomere were excluded from compaction in embryos with irregular cleavage, resulting in lower blastocyst development rates, but no decrease in pregnancy rates at transfer.

What is known already

It has been reported that many of the chromosome analysis results of blastomere excluded from compaction were aneuploid, and pointed out that this exclusion may be related to the repair of blastocyst euploidy, but the effect of the number of excluded blastomere has not been reported.

Study design, size, duration

This is a retrospective study of 578 embryos that developed into morula with time-lapse monitoring by EmbryoScope (Vitrolife) in 2018–2019.

Participants/materials, setting, methods

The target embryos were classified into two groups: embryos with normal first and second cleavage (normal cleavage group) and embryos with irregular cleavage (dynamics of one cell dividing into three or more cells), called “direct cleavage”, at either cleavage (DC group), and the number of blastomere excluded from compaction during morula formation was recorded and compared. The blastocyst development rate and single blastocyst transfer pregnancy rates of the two groups were compared.

Main results and the role of chance

There are 286 in the normal cleavage group and 292 in the DC group. The mean number of excluded blastomere was 0.76 and 3.55, respectively, which was significantly higher in the DC group (P &lt; 0.01). Good blastocyst (Gardner classification 4 or higher) development rate was 84.5% (239/283) and 65.8% (181/275), respectively, and high grade blastocyst (Gardner classification BB or higher) development rate was 43.9% (105/239) and 14.9% (27/181) of them, both significantly higher in the normal cleavage group (P &lt; 0.01). The single blastocyst transfer pregnancy rates were 31.6% (25/79) and 32.4% (11/34), and the miscarriage rates were 24.0% (6/25) and 27.3% (3/11), respectively, neither was there a significant difference between the two groups. So, direct cleavage increased the number of blastomere excluded from compaction, decreased the rate of morula to good blastocyst development and reduced blastocyst grade, but did not affect blastocyst transfer pregnancy rate and miscarriage rate.

Limitations, reasons for caution

Please note that all target embryos must have developed into morula or larger (embryos that did not develop into morula will not be included in the study).

Wider implications of the findings: Severe chromosomal aberrant blastomeres formed by direct cleavage were excluded from compaction, and the blastocyst development rate decreased due to a decrease in the amount of viable cells, but it is suggested that this blastomere exclusion mechanism is not related to euploidy after blastocyst development.

Trial registration number

Not applicable

An operator-theoretical study on the BCS-Bogoliubov model of superconductivity near absolute zero temperature

In the preceding papers the present author gave another proof of the existence and uniqueness of the solution to the BCS-Bogoliubov gap equation for superconductivity from the viewpoint of operator theory, and showed that the solution is partially differentiable with respect to the temperature twice. Thanks to these results, we can indeed partially differentiate the solution and the thermodynamic potential with respect to the temperature twice so as to obtain the entropy and the specific heat at constant volume of a superconductor. In this paper we show the behavior near absolute zero temperature of the thus-obtained entropy, the specific heat, the solution and the critical magnetic field from the viewpoint of operator theory since we did not study it in the preceding papers. Here, the potential in the BCS-Bogoliubov gap equation is an arbitrary, positive continuous function and need not be a constant.

Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kβ x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

Clinical and imaging features of surgically treated low lumbar osteoporotic vertebral collapse in patients with Parkinson's disease

Osteoporosis and Parkinson's disease (PD) are age-related diseases, and surgery for osteoporotic vertebral collapse (OVC) in PD patients become more common. OVC commonly affects the thoracolumbar spine, but low lumbar OVC is frequent in patients with lower bone mineral density (BMD). The aim of this study was to identify differences in clinical and imaging features of low lumbar OVC with or without PD and to discuss the appropriate treatment. The subjects were 43 patients with low lumbar OVC below L3 who were treated surgically, including 11 patients with PD. The main clinical symptoms were radicular pain in non-PD cases and a cauda equina sign in PD cases. Rapid progression and destructive changes of OVC were seen in patients with PD. The morphological features of OVC were flat-type in non-PD cases with old compression fracture, and destruction-type in PD cases without old compression fracture. Progression of PD was associated with decreased lumbar lordosis, lower lumbar BMD, and severe sarcopenia. High postoperative complication rates were associated with vertebral fragility and longer fusion surgery. Progression of postural instability as a natural course of PD may lead to mechanical stress and instrumentation failure. Invasive long-fusion surgery should be avoided for single low lumbar OVC.

Strongly correlated superconductivity in a copper-based metal-organic framework with a perfect kagome lattice

Metal-organic frameworks (MOFs), which are self-assemblies of metal ions and organic ligands, provide a tunable platform to search a new state of matter. A two-dimensional (2D) perfect kagome lattice, whose geometrical frustration is a key to realizing quantum spin liquids, has been formed in the π - d conjugated 2D MOF [Cu₃(C₆S₆)] _n (Cu-BHT). The recent discovery of its superconductivity with a critical temperature T _c of 0.25 kelvin raises fundamental questions about the nature of electron pairing. Here, we show that Cu-BHT is a strongly correlated unconventional superconductor with extremely low superfluid density. A nonexponential temperature dependence of superfluid density is observed, indicating the possible presence of superconducting gap nodes. The magnitude of superfluid density is much smaller than those in conventional superconductors and follows the Uemura's relation of strongly correlated superconductors. These results imply that the unconventional superconductivity in Cu-BHT originates from electron correlations related to spin fluctuations of kagome lattice.

The utility of a novel approach to quantify dyssynchrony by multidetector computed tomography

Funding Acknowledgements

Type of funding sources: None.

Background

Quantification of left ventricular (LV) dyssynchrony is of great interest for resynchronization therapy (CRT). Recently, cardiac computed tomography (CCT) is feasible for evaluation of dyssynchrony. Our aim was to assess a novel simplified approach using CCT to quantify LV dyssynchrony.

Methods

We studied 346 consecutive patients with a wide range of QRS width and ejection fractions (EF). Electrocardiogram-gated contrast-enhanced 256-slice multidetector CT (Brilliance 256 iCT, Philips Medical Systems) was performed before CRT. After CCT scan, the LV endocardial boundaries from short-axis images reconstructed at 5% increments of cardiac cycle were automatically detected, and a time from R-wave to maximal wall motion was calculated for each of the 16 standardized segments for all slices using software "Myocardial Contraction Map" (Argus, Inc Ehime, Japan). The standard deviation of all segments modified by mean heart rate (%SD) was respectively calculated as the global parameter of dyssynchrony. LVEF was also measured using MDCT.

Results

%SD was feasible in all patients, respectably. %SD was significantly different between the different QRS duration groups; narrow QRS (&lt;120ms): 9 ± 5%, relatively wide QRS (120-150 ms): 11 ± 6%, and significantly wide QRS (&gt;150 ms): 14 ± 7% (p &lt;0.001). Moreover, there was significantly difference in %SD between the different morphology groups; normal: 9 ± 7%, Non-left bundle branch block (Non-LBBB): 10 ± 6%, LBBB: 17 ± 7% (p &lt;0.001).

Conclusion

This novel simplified approach by CCT can quantify dyssynchrony in different QRS duration and morphology groups. This method has promise for clinical applications to the evaluation of patients for CRT.

Abstract Figure.