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.

Mutations Causing X-Linked Amelogenesis Imperfecta Alter miRNA Formation from Amelogenin Exon4

Amelogenin plays a crucial role in tooth enamel formation, and mutations on X-chromosomal amelogenin cause X-linked amelogenesis imperfecta (AI). Amelogenin pre-messenger RNA (mRNA) is highly alternatively spliced, and during alternative splicing, exon4 is mostly skipped, leading to the formation of a microRNA (miR-exon4) that has been suggested to function in enamel and bone formation. While delivering the functional variation of amelogenin proteins, alternative splicing of exon4 is the decisive first step to producing miR-exon4. However, the factors that regulate the splicing of exon4 are not well understood. This study aimed to investigate the association between known mutations in exon4 and exon5 of X chromosome amelogenin that causes X-linked AI, the splicing of exon4, and miR-exon4 formation. Our results showed mutations in exon4 and exon5 of the amelogenin gene, including c.120T>C, c.152C>T, c.155C>G, and c.155delC, significantly affected the splicing of exon4 and subsequent miR-exon4 production. Using an amelogenin minigene transfected in HEK-293 cells, we observed increased inclusion of exon4 in amelogenin mRNA and reduced miR-exon4 production with these mutations. In silico analysis predicted that Ser/Arg-rich RNA splicing factor (SRSF) 2 and SRSF5 were the regulatory factors for exon4 and exon5 splicing, respectively. Electrophoretic mobility shift assay confirmed that SRSF2 binds to exon4 and SRSF5 binds to exon5, and mutations in each exon can alter SRSF binding. Transfection of the amelogenin minigene to LS8 ameloblastic cells suppressed expression of the known miR-exon4 direct targets, Nfia and Prkch, related to multiple pathways. Given the mutations on the minigene, the expression of Prkch has been significantly upregulated with c.155C>G and c.155delC mutations. Together, we confirmed that exon4 splicing is critical for miR-exon4 production, and mutations causing X-linked AI in exon4 and exon5 significantly affect exon4 splicing and following miR-exon4 production. The change in miR-exon4 would be an additional etiology of enamel defects seen in some X-linked AI.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Factors Involved in the Choice Between Thoracic and Abdominal Deep Inspiration Breath Holds During Left Breast Cancer Radiotherapy

PURPOSE

Deep inspiration breath hold (DIBH) is used with adjuvant radiation therapy after left breast cancer surgery to reduce radiation dose to the heart. In this study we determined whether thoracic DIBH (T-DIBH) or abdominal DIBH (A-DIBH) should be selected based on patient background.

METHODS

Three-dimensional conformal radiation therapy plans were created under the same conditions using free breathing (FB), T-DIBH, and A-DIBH CT scans of patients who had previously undergone treatment at our hospital.

RESULTS

A-DIBH decreased the left lung dose compared to FB. In comparing T-DIBH and A-DIBH, the heart maximum and left lung doses were significantly lower in A-DIBH. The differences in the heart mean dose (Dmean) between FB, and T-DIBH and A-DIBH were correlated with the cardiothoracic ratio, heart volume, and left lung volume. The difference in the heart Dmean and the left lung dose of T-DIBH and A-DIBH correlated with the forced vital capacity (FVC).

CONCLUSIONS

A-DIBH is preferable over T-DIBH with respect to the heart and left lung doses; however, with respect to the heart Dmean, T-DIBH was more effective in reducing the dose in some cases, and the FVC was a relevant factor in this study.

Effect on Heart and Lung Doses Reduction of Abdominal and Thoracic Deep Inspiratory Breath-hold Assuming Involved-field Radiation Therapy in Patients with Simulated Esophageal Cancer

PURPOSE

The purpose of this study was to evaluate the lung and heart doses in volumetric-modulated arc therapy (VMAT) using involved-field irradiation in patients with middle-to-lower thoracic esophageal cancer during free breathing (FB), abdominal deep inspiratory breath-hold (A-DIBH), and thoracic DIBH (T-DIBH) images.

METHODS

Computed tomography images of A-DIBH, T-DIBH, and FB from 25 patients with breast cancer were used to simulate patients with esophageal cancer. The irradiation field was set at an involved-field, and target and risk organs were outlined according to uniform criteria. VMAT optimization was performed, and lung and heart doses were evaluated.

RESULTS

A-DIBH had a lower lung V20 Gy than FB and a lower lung V40 Gy, V30 Gy, V20 Gy than T-DIBH. The heart all dose indices were lower in T-DIBH than FB, and the heart V10 Gy was lower in A-DIBH than FB. However, the heart D_mean was comparable with A-DIBH and T-DIBH.

CONCLUSIONS

A-DIBH had significant dose advantages for lungs compared to FB and T-DIBH, and the heart D_mean was comparable to T-DIBH. Therefore, when performing DIBH, A-DIBH is suggested for radiotherapy in patients with middle-to-lower thoracic esophageal cancer, excluding irradiation of the prophylactic area.

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}.

Dose and organ displacement comparisons with breast conservative radiotherapy using abdominal and thoracic deep-inspiration breath-holds: A comparative dosimetric study

Deep-inspiration breath-hold (DIBH) reduces the radiation dose to the heart and lungs during breast radiotherapy in cancer. However, there is not enough discussion about suitable breathing methods for DIBH. Therefore, we investigated the radiation doses and organ and body surface displacement in abdominal DIBH (A-DIBH) and thoracic DIBH (T-DIBH). Free-breathing, A-DIBH, and T-DIBH computed tomography images of 100 patients were used. After contouring the targets, heart, and lungs, radiotherapy plans were created. We investigated the heart and lung doses, the associations between the heart and left lung displacements, and the thorax and abdominal surface displacements. No significant differences were observed in the target dose indices. However, the heart and lung doses were significantly lower in A-DIBH than in T-DIBH for all the indices; the mean heart and lung doses were 1.69 and 3.48 Gy, and 1.91 and 3.55 Gy in A-DIBH and T-DIBH, respectively. The inferior displacement of the heart and the left lung was more significant in A-DIBH. Therefore, inferior expansion of the heart and lungs may be responsible for the respective dose reductions. The abdominal surface displaced more than the thoracic surface in both A-DIBH and T-DIBH, and thoracic surface displacement was greater in T-DIBH than in A-DIBH. Moreover, A-DIBH can be identified because abdominal surface displacement was greater in A-DIBH than in T-DIBH. In conclusion, A-DIBH and T-DIBH could be distinguished by comparing the abdominal and thoracic surfaces of A-DIBH and T-DIBH, thereby ensuring the implementation of A-DIBH and reducing the heart and lung doses.

Cardiopulmonary arrest and in-hospital outcomes in young patients with acute myocardial infarction: insights from the Japanese nationwide registry

Background

Cardiopulmonary arrest (CPA) is the most serious presentation of acute myocardial infarction (AMI). However, the frequency and prognostic impact of CPA in young patients with AMI have been still unclear.

Objectives

This study aimed to characterize AMI in young patients who underwent primary percutaneous coronary intervention using large-scale nationwide all-comer registry data in Japan (J-PCI registry).

Methods

Data on risk factor profiles, clinical features, post-procedural complications, and in-hospital outcomes were reviewed within the J-PCI registry between 2014 and 2018.

Results

Among 213,297 patients with AMI, 23,985 (11.2%) were young (age, 20–49 years). Compared with the older group (age, 50–79 years; n=189,312), the young group included a higher number of men, smokers, patients with dyslipidemia, and patients with single-vessel disease, and a lower number of patients with hypertension and diabetes. Despite favorable clinical profiles, younger age was associated with a higher rate of presentation with CPA (Figure 1). Further, concomitant CPA was strongly associated with in-hospital mortality in the young group (Table 1).

Conclusions

Young patients with AMI presented a higher risk of CPA than older patients, which was strongly associated with in-hospital mortality.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI

Comparing the toxicity and disease control rate of radiotherapy for prostate cancer between salvage settings after high-intensity focused ultrasound therapy and initial settings

The purpose of this retrospective study was to compare the toxicity and disease control rate of radiotherapy for prostate cancer in salvage settings after high-intensity focused ultrasound (HIFU) therapy (HIFU cohort) with those in radical settings (non-HIFU cohort). From 2012 to 2020, 215 patients were identified for this study and 17 were treated in the salvage settings after HIFU. The median follow-up time was 34.5 months (range: 7-102 months, inter-quartile range [IQR]: 16-64 months). Genitourinary (GU) and gastrointestinal (GI) adverse events were evaluated in acute and late periods with Common Terminology Criteria for Adverse Events version 5, and the rates of biochemical-clinical failure free survival (BCFS) and overall survival (OS) were estimated. The cumulative incidence of late GU Grade 2 or greater toxicity after five years was significantly different between the non-HIFU and HIFU cohorts with rates of 7.3% and 26.2%, respectively (P = 0.03). Regarding GI Grade 2 or greater toxicity, there was no significant difference between the two cohorts. The 5y-BCFS was 84.2% in the non-HIFU cohort and 69.5% in the HIFU cohort with no significant difference (P = 0.10) and the 5y-OS was 95.9% and 92.3%, respectively (P = 0.47). We concluded that the possibility of increased late GU Grade 2 or greater should be considered when applying salvage radiotherapy for local recurrence after HIFU.

Expressions of PD-L1 and Nectin-4 in urothelial cancer patients treated with pembrolizumab

OBJECTIVES

Recently, the standard of care for advanced urothelial cancer (UC) has been changed by developing immune-checkpoint inhibitors (ICIs). However, its response rate is limited to 20-30%. The identification of biomarkers to predict the therapeutic effects of ICIs is urgently needed. The present study explored the association between immunohistochemical biomarkers and clinical outcomes in UC patients treated with pembrolizumab.

PATIENTS AND METHODS

A total of 85 patients with UC who received pembrolizumab after chemotherapy from January 2018 to May 2020 were retrospectively reviewed. Tumor tissues were obtained for immunohistochemical study from 47 out of 85 patients. The protein expressions of PD-L1, WT1, Nectin-4, CD4, CD8, Foxp3, and CD68 in tumor cells and/or tumor infiltrating lymphocytes were immunohistochemically examined. The associations between protein expressions and overall survival (OS), progression-free survival (PFS), and disease control rate (DCR) were statistically analyzed.

RESULTS

Patients with positive PD-L1 in tumor cells showed significantly worse OS (Log-rank test: HR 5.146, p = 0.001, Cox regression analysis: HR 4.331, p = 0.014) and PFS (Log-rank test: HR 3.31. p = 0.022), along with significantly lower DCR (14.3%) compared to the PD-L1 negative patients (67.5%). In addition, patients with strong expression of Nectin-4 in tumor cells showed significantly higher DCR (100%) than the other patients (50%).

CONCLUSION

PD-L1 expression in tumor cells was associated with poor prognosis (OS and PFS) and low DCR. Interestingly, the strong expression of Nectin-4 was correlated with high DCR. PD-L1 and Nectin-4 expression in tumor cells could be prognostic biomarkers useful for pembrolizumab in patients with advanced UC.

Differential impact of renal function on the diagnostic performance of resting full-cycle ratio as non-hyperemic physiological assessment

Background

Fractional flow reserve (FFR) is a gold standard method to evaluate functional lesion severity in daily clinical practice. Recently, the resting full-cycle ratio (RFR) was Previous studies showed the better diagnostic performance of RFR comparing with FFR. It is well known that patients with chronic kidney disease (CKD) have poor prognosis. Therefore, we should carefully assess the functional lesion severity in CKD patients. However, it is unclear whether the diagnostic performance of RFR for detecting functional ischemia is similar regardless of the degree of renal function. The aim of this study is to compare the diagnostic performance of RFR based on renal function.

Method

This study was a prospectively enrolled observational study. A total of 265 consecutive patients with 373 intermediate lesions were enrolled in this study. There were classified into three groups according to renal function (Group 1: eGFR ≥60 mL/min/1.73m2; Group 2: 30 mL/min/1.73m2 ≤eGFR <60 mL/min/1.73m2; Group 3: eGFR <30mL/min/1.73m2). The RFR was measured after adequately waiting for stable condition, while FFR was measured after intravenous administration of ATP (180mcg/kg/min). The discordance between FFR and RFR were assessed the data using known cutoffs for FFR (≤0.80) and RFR (≤0.89).

Results

Of 373 lesions, the median age was 70.1±11.0 years. Functional significance was observed in 153 lesions (41.0%) of all lesions. RFR showed a significant correlation with FFR in each group (Group 1; r2=0.63 [p<0.001], Group 2: r2=0.67 [p<0.001], Group 3: r2=0.51 [p<0.001], respectively). The ROC curve analysis of RFR showed differential results for predicting functional significance (Group 1: AUC 0.88, cut-off value 0.91; Group 2: AUC 0.88, cut-off value 0.89; Group 3: AUC 0.81, cut-off value 0.83; respectively) in each group. The prevalence of discordant between RFR and FFR was significantly different among 3 groups (Group 1: 16.5%, Group 2: 19.4%, Group 3: 25.0%, respectively, p<0.05 for among 3 groups).

Conclusion

The diagnostic performance of RFR was different based on renal function. During RFR acquisition, the degree of renal function could influence concordance with FFR, and should be taken into account when interpreting RFR.

Funding Acknowledgement

Type of funding sources: None.

Association of common carotid artery measurements with the incidence of hypertension: a retrospective cohort study

Background

Diameter, intima–media thickness (IMT), and flow parameters, including resistance index (RI) and pulsatility index (PI), in the common carotid artery (CCA) are markers of arterial remodeling, atherosclerosis, and vascular resistance, respectively. These CCA parameters have usually been evaluated as markers of target organ damage. Little is known about whether these parameters predict a new onset of hypertension.

Purpose

In this study, we investigated the association of CCA parameters including IMT, diameter, RI, and PI with the incidence of hypertension.

Methods

This is an observational study involving 1249 participants (656 women, mean age 69.6 years) without hypertension, who underwent carotid artery ultrasonography at baseline. The participants were divided into elderly group (defined as age ≥70 years) and a middle-aged group. We defined obesity as BMI ≥25 kg/m2. CCA diameter was defined as the distance between the adventitia–media interface on the near wall and the media–adventitia interface on the far wall. IMT was defined as the distance between the lumen–intima and media–adventitia interfaces. RI was calculated as [peak systolic velocity (PSV)- end-diastolic velocity (EDV)]/PSV. PI was calculated as (PSV-EDV)/Vmean. Larger CCA diameter, increased IMT, high RI, and high PI were determined based on the optimal cutoff values from ROC curve analysis.

Results

Over a mean 5.1-year follow-up period, 524 participants developed hypertension. Multivariate logistic regression analyses showed that larger CCA diameter and increased IMT were significant predicators for incident hypertension in elderly group, but not in middle-aged group. High RI, and high PI were significant predicators for incident hypertension in both the two groups. CCA diameter, IMT, and RI predicted the incidence of hypertension only in nonobesity group, whereas PI predicted it in both obesity and nonobesity groups (Table).

Conclusion

CCA parameters assessed by ultrasonography are useful markers to estimate the risk of hypertension. In particular, PI is a better predictor for the incidence of hypertension.

Funding Acknowledgement

Type of funding sources: None.

Association of adipose tissue insulin resistance and serum free fatty acid levels with the incidence of type 2 diabetes: a retrospective cohort study

Background

Insulin resistance in adipose tissue attenuates the suppression of lipolysis, leading to increased free fatty acid (FFA) release. The excess FFA may be involved in the development of type 2 diabetes.

Purpose

In this study, we investigated the association of adipose tissue insulin resistance and serum free fatty acid levels with the incidence of type 2 diabetes.

Methods

This is an observational study involving 6800 participants (3451 women, mean age 69.2 years) without diabetes who underwent 75-g oral glucose tolerance test (OGTT) at baseline. The participants were divided into the obesity and nonobesity groups on the basis of body mass index of ≥25 and <25 kg/m2, respectively. Serum FFA levels were assessed before and 30, 60, and 120 min after glucose ingestion, and the total area under the FFA curve (AUCFFA) was calculated. Adipose tissue insulin resistance was assessed using adipose insulin resistance index (adipo-IR) calculated based on fasting FFA and insulin concentrations. The homeostasis model assessment of insulin resistance (HOMA-IR), and the Matsuda index were evaluated as measures of insulin resistance in the liver and whole-body, respectively. High adipo-IR, high fasting FFA, great AUCFFA high HOMA-IR, and low Matsuda index were determined based on the optimal cutoff values from ROC curve analysis.

Results

Over a mean 5.3-year follow-up period, 485 participants developed type 2 diabetes. Multivariate logistic regression analyses showed that high adipo-IR was a significant predicator for incident type 2 diabetes in the obesity group, but not in nonobesity group. AUCFFA, HOMA-IR, and Matsuda index were significantly associated with incident type 2 diabetes in both the two groups (Table).

Conclusion

Serum FFA levels after glucose loading predict the incidence of type 2 diabetes. Adipose tissue insulin resistance was associated with the risk of type 2 diabetes in individuals with obesity, but not in individuals without obesity.

Funding Acknowledgement

Type of funding sources: None.

Delayed Enhancement of Ascites after Iodine Contrast Administration Assessed with Dual-energy Computed Tomography: A Case Report

We report a case of 71-year-old woman with lung cancer and high-attenuation ascites (HAA) due to iodine contrast material (ICM). The patient underwent two sequential CT scans at interval of 4 h between examinations by using ICM. The second scan was obtained by dual-energy CT (DE-CT), yielding the virtual non-contrast (VNC) image and iodine map, which were used to evaluate HAA. The VNC image revealed ascites with water density, and HAA was thought to contain iodine because the attenuation of ascites around the liver was similar to that of the spleen on the iodine map. The VNC image and iodine map using DE-CT were useful in differentiating HAA due to iodine (delayed enhancement of ascites) from hemorrhagic ascites in this patient.

Clinical impact of triglyceride deposit cardiomyovasculopathy, coronary atherosclerosis with triglyceride deposition, on vascular failure after drug-eluting stent implantation

Background

Triglyceride deposit cardiomyovasculopathy (TGCV) is a novel cardiovascular disorder, encoded as orphan disease in Europe in 2019, characterized by excessive accumulation of triglyceride in vascular smooth muscle cells, leading to coronary artery disease (CAD). However, there is no data about impact of TGCV on vascular failure after coronary stent implantation.

Purpose

To assess impact of TGCV on the outcome following coronary stent implantation in CAD patients with diabetes mellitus (DM) as Study 1, and chronic hemodialysis as Study 2.

Methods

This is multicenter retrospective estimation consisting of two studies.

Study 1) Among 526 consecutive patients suspected of having CAD who underwent coronary angiography (CAG) and iodine-123-β-methyliodophenyl-pentadecanoic acid (BMIPP) scintigraphy, a tracer for the diagnosis of TGCV, data from 81 patients with DM were analyzed.

The patients were divided into two groups; TGCV (n=7) or non-TGCV (n=74). All patients were implanted with a second-generation DES and underwent follow-up CAG. Binary restenosis (ISR), defined as angiographic luminal diameter >50% by quantitative coronary angiography, in-stent late loss were assessed in 15 stents of TGCV patients and 111 stents of non-TGCV patients.

Study 2) Similarly, among 88 chronic hemodialysis patients, ISR and in-stent late loss were assessed in 12 stents of 9 TGCV patients and 21 stents of 17 non-TGCV patients.

Results

Study 1) There were no significant differences in baseline characteristics between the two groups. In-stent late loss was greater in TGCV group than in non-TGCV group (0.91mm [0.27, 2.39] vs. 0.15mm [0.03, 0.35]; p<0.001), resulting in greater incidence of ISR in TGCV group than in non-TGCV group (46.7% vs. 9.0%; p<0.001). Multivariable logistic analysis revealed TGCV to be an independent predictor for vascular failure after DES implantation in patients with DM.

Study 2) Similarly, in-stent late loss and incidence of ISR were greater in TGCV group than in non-TGCV group (1.20±0.99mm vs. 0.50±0.70, p=0.02; 58.3% vs. 9.5%, p=0.002, respectively). TGCV was an independent predictor for vascular failure after DES implantation in chronic hemodialysis patients.

Conclusion

Apart from existing risk factors such as DM and hemodialysis, TGCV could contribute to a novel risk factor for vascular failure, even in the second-generation DES era.

Figure 1

Funding Acknowledgement

Type of funding source: None

Differential impact of target vessel on the diagnostic performance of resting full-cycle ratio as non-hyperemic physiological assessment

Background

Recently, wire-based resting indices have been recognized as gold standard for evaluating physiological lesion assessment. The resting full-cycle ratio (RFR) is a unique resting index which is calculated as the point of absolutely lowest distal pressure to aortic pressure during entire cardiac cycle. It is unclear whether the diagnostic performance of RFR for detecting functional coronary artery stenosis is similar in each coronary artery. The aim of this study is to compare the diagnostic performance of RFR based on target coronary vessel.

Method

This study was a prospectively enrolled observational study. A total of 156 consecutive patients with 220 intermediate lesions were enrolled in this study. The RFR was measured after adequately waiting for stable condition, while FFR was measured after intravenous administration of ATP (180mcg/kg/min). Lesions with FFR ≤0.80 were considered functionally significant coronary artery stenosis.

Results

In all lesions, reference diameter, diameter stenosis, lesion length, RFR, and FFR were 3.0±0.7mm, 45±13%, 13.0±8.8mm, 0.90±0.09, and 0.82±0.10, respectively. Functional significance was observed in 88 lesions (40%) of all lesions. RFR showed a significant correlation with FFR in overall lesions (r=0.774, p<0.001). The ROC curve analysis of RFR showed good accuracy for predicting functional significance (AUC 0.87, diagnostic accuracy 81%) in all subjects. Regarding each target vessel, there were similar and significant positive correlation between RFR and FFR (LAD; r=0.733, p<0.001, LCX; r=0.771, p<0.001, RCA; r=0.769, p<0.001, respectively). The prevalence of discordant between RFR and FFR was significantly different among 3 vessels (LAD 26%, LCX 12%, RCA 13%, respectively, p<0.05 for among 3 groups). Regarding the comparison of ROC curves according to lesion location, AUC was significantly lower in LAD than in LCX and RCA (LAD 0.780, LCX 0.947, RCA 0.926, p<0.01 for LAD compared to LCX, p<0.01 for LAD compared to RCA, respectively). Furthermore, the diagnostic accuracy was significantly different according to target vessel (LAD 74%, LCX 88%, RCA 87%, respectively, p<0.05 for among 3 vessels).

Conclusion

RFR demonstrated better diagnostic accuracy for evaluating functional lesion severity. The diagnostic performance of RFR was different based on target vessel. RFR is a unique and useful resting index, and it may detect functionally significant coronary stenosis that cannot be detected with other resting indices in daily practice.

Funding Acknowledgement

Type of funding source: None

Impact of higher detection rate of residual pulmonary thromboemboli one-year after acute pulmonary embolism: modified CT scan imaging method with modified CT obstruction index

Background

Recently, post pulmonary embolism (PE) syndrome or chronic thromboembolic disease after acute PE, has been recognized as important long-term complications. Furthermore, patients may develop with chronic thromboembolic pulmonary hypertension.

Purpose

We aimed to evaluate the frequency of residual pulmonary thromboemboli after acute PE by using our “higher”-resolution CT scan imaging method to detect residual thromboemboli down to sub-segmental pulmonary arteries.

Methods

This study was a prospective multi-center observational study. We enrolled consecutive 34 patients with acute symptomatic PE whose informed consent was obtained, and followed up for one year. One year after the onset of acute PE, patients were referred to our hospital and multiple examination including CT scan, 6-minute walk test (6MWT), questionnaire of SF-36, echocardiography and laboratory testing were performed. Additionally, we have modified the CT obstruction index (CTOI) to quantitatively evaluate the thromboemboli down to sub-segmental pulmonary arteries.

Results

Mean age was 60.5±15.8 years, and 56% were male. No patient was categorized as low recurrent VTE risk which was caused by transient factors, one patient was associated with active cancer, and 12% had known thrombophilia. In 85% of the patients, this onset was the first obvious episode of PE. At diagnosis, elevated B-type natriuretic peptide (BNP) (≥100 pg/ml) or N-terminal (NT)-proBNP (≥500 pg/ml) was observed in 45% of the patients. Median tricuspid regurgitation peak gradient (TRPG) by echocardiography was 30.9 (19.3–50.1) mmHg. Among all, 35% of the patients received single-drug approach with DOACs. At discharge, all of the patients except two were treated with DOACs.

One year after the onset, 21% of the patient were in NYHA II and others were in NYHA I. It was notable that pulmonary thromboemboli was detected by our CT scan in 76% of the patients. Modified CTOI was median 11.9 (1.8–24.4) % as shown in the figure.

In multiple regression analysis, TRPG at diagnosis and BNP at one month were significantly associated with mCTOI (β=0.536, p=0.002 and β=−0.482, p=0.003, respectively). Additionally, lowest SpO2 during 6MWT after one year from the onset, tended to inversely associate with mCTOI (β=−0.341, p=0.052).

Conclusions

Using our modified CT scan imaging method and modified CTOI, residual pulmonary thromboemboli was able to be detected more frequently than the previous studies. Residual pulmonary thromboemboli could be one of the cause of the post PE syndrome and lead to exercise-induced desaturation.

Figures

Funding Acknowledgement

Type of funding source: None

Clinical course of pulmonary embolism patients treated with DOACs: comparing prognosis, recurrent thromboembolism, and major bleeding between patients with and without cancer

Background

Venous thromboembolism (VTE) is the third frequent acute cardiovascular syndrome in the Europe and Japan. Since direct oral anticoagulants (DOACs) are widely used now, the morbidity and mortality of pulmonary embolism (PE) patients especially associated with cancer needs to be re-evaluated.

Purpose

We evaluated the clinical course of patients with PE mainly treated with DOACs.

Methods

This retrospective observational study was conducted in a single center. The data were collected from the medical record of consecutive patients who received inpatient treatment of PE. In this study, we have compared PE patients with cancer (cancer PE) to those without cancer (non-cancer PE) and evaluated the mortality, recurrent of VTE and major bleedings.

Results

In total, 140 patients were enrolled: 94 patients were cancer-related, and 46 patients were without cancer (Table). The type of the tumor in cancer PE patients were as follows: gastric 8 (9%), esophageal 5 (5%), pancreatic 12 (13%), lung 14 (15%), lymphoma 2 (2%), gynecologic 17 (18%), renal 2 (2%), bile duct 8 (9%), colon 12 (13%), and others 17 (18%).

Kaplan-Meier curve showed that the cumulative all-cause mortality was significantly higher in the cancer PE group (35/94 (37%) vs. 2/46 (4%), P<0.001 (log rank), HR 10.3 [95% CI:2.5–43.3]). The cumulative incidence of recurrent VTE was significantly higher in the cancer PE group (7/94 (7%) vs. 0/46, P=0.03 (log rank)). There was no significant difference in the cumulative incidence of major bleeding between the cancer PE group and the non-cancer PE group (8/94 (9%) vs. 5/46 (11%)).

Conclusions

The risk of recurrent VTE was still higher in cancer PE patients compared to non-cancer PE patients, although DOACs were used. Meanwhile the incidence of major bleeding was comparable in both groups, the risk of bleeding might be acceptable with using DOACs especially in cancer PE patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

Discordance predictor between fractional flow reserve and resting full-cycle ratio in clinical characteristics

Introduction

Fractional flow reserve (FFR) is a gold standard method to evaluate functional lesion severity in daily clinical practice. Recently, the resting full-cycle ratio (RFR) which was newly developed resting indices was launched. Unlike other resting indices evaluated in diastolic phase, RFR is evaluated during entire cardiac phase. Previous studies showed discordance predictors between FFR and instantaneous wave-free ratio. However, it is previously unreported what predictor cause discordant outcome between FFR and RFR.

Purpose

The purpose of this study was to evaluate clinical predictors of discordance between FFR and RFR.

Methods

A total of 156 patients with 220 lesions were prospectively enrolled in this study. RFR was evaluated before inducing hyperemia. FFR was measured after intravenous adenosine triphosphate administration (180 mcg/kg/min). According to FFR and RFR values, the patients and lesions were classified into 4 groups: Concordant negative (Group-1 [n=114]: FFR >0.80, RFR >0.89); negative FFR and positive RFR (Group-2 [n=18]: FFR >0.80, RFR ≤0.89); positive FFR and negative RFR (Group-3 [n=25]: FFR ≤0.80, RFR >0.89); Concordant positive (Group-4 [n=63]: FFR ≤0.80, RFR ≤0.89). Among them, discordance predictors with clinical characteristics between RFR and FFR were compared using by two separate logistic regression analyses. (Group-1 vs. Group-2, Group-3 vs. Group-4, respectively). Age, sex and those predictors with a p value ≤0.10 were included in a multivariate regression analysis using by forward stepwise selection to identify independent predictors of discordance.

Results

On multiple regression analysis, hemodialysis (HD) (OR:6.072 [1.090–33.836]), peripheral artery disease (PAD) (OR:9.053 [1.776–46.162]) and left anterior descending artery (LAD) (OR:9.264 [2.092–41.031]) were significantly associated with positive RFR among negative FFR groups (Groupe 2 discordance). Conversely, diabetes mellitus (DM) (OR:0.212 [0.062–0.721]) and Hb (OR:1.480 [1.102–1.987]) were significantly associated with negative RFR among positive FFR groups (Groupe 3 discordance)

Conclusions

Since the clinical characteristics with HD, PAD, LAD, DM and Hb may influence concordant with FFR during RFR evaluation, it should be considered when interpreting RFR.

Distribution and independent predictors

Funding Acknowledgement

Type of funding source: None

Diagnostic feasibility of resting full-cycle ratio between systole and diastole to assess functional lesion severity of intermediate coronary artery stenosis

Background

Recently, non-hyperemic physiologic indices have become widespread for evaluating physiological lesion assessment. The resting full-cycle ratio (RFR) is a unique non-hyperemic index which is calculated as the point of absolutely lowest distal pressure to aortic pressure during entire cardiac cycle. It is unclear whether RFR may detect functionally significant coronary stenosis that cannot be detected with other resting indices due to differences in the cardiac cycle. The aim of this study is to compare the diagnostic performance of RFR based on cardiac cycle.

Method

This study was a prospectively enrolled observational study. A total of 156 consecutive patients with 220 intermediate lesions were enrolled in this study. The RFR was measured after adequately waiting for stable condition, while FFR was measured after intravenous administration of ATP (180mcg/kg/min). Lesions with FFR ≤0.80 were considered functionally significant coronary artery stenosis.

Results

In all lesions, reference diameter, diameter stenosis, lesion length, RFR, and FFR were 3.0±0.7mm, 45±13%, 13.0±8.8mm, 0.90±0.09, and 0.82±0.10, respectively. Functional significance was observed in 88 lesions (40%) of all lesions. RFR systole was observed in 24 lesions (10.9%). Regarding to the coronary lesions, RFR systole was more frequent in non-LAD (LAD; 4.2%, left circumflex artery (LCX); 9.8%, and right coronary artery (RCA); 30.4%, respectively, p<0.018). RFR showed a significant correlation with FFR in both systole and diastole (R = 0.918, p<0.001, R = 0.733, p<0.001, respectively). The ROC curve analysis showed similar agreement in both systole and diastole (AUC: 0.881, p<0.001, AUC: 0.864, p<0.001, respectively). RFR provided a good diagnostic accuracy and no difference in both systole and diastole (79.6% and 87.5%, respectively, p=0.58).

Conclusion

RFR is feasible and reliable non-hyperemic index regardless of the difference of cardiac cycle to evaluate physiological lesion severity in daily practice.

Funding Acknowledgement

Type of funding source: None

Correction to: Comprehensive genetic analyses using targeted next-generation sequencing and genotype-phenotype correlations in 53 Japanese patients with osteogenesis imperfecta

The original article has been corrected.

Electrochemical reduction of CO2 using Germanium-Sulfide-Indium amorphous glass structures

The research in electrochemical reduction of CO₂ is shifting towards the discovery of new and novel materials. This study shows a new class of material, that of Ge-S-In chalcogenide glass, to be active for reduction of CO₂ in aqueous solutions. Experiments were conducted with bulk and particle form of the material, yielding different product for each structural form. Faradaic efficiency of upto 15% was observed in bulk form for CO production while formic acid with up to 26.1 % faradaic efficiency was measured in powder form. Chalcogenide studies have focused primarily on the photoelectrochemical reduction however these results provide a strong merit for introducing metal in chalcogenide glass structures for electrochemical reduction of CO₂. The activity for CO₂ reduction and the change in product selectivity reflects that further efforts to improve the glass structures can be undertaken in order to increase the faradaic efficiency and selectivity of the products.

Comprehensive genetic analyses using targeted next-generation sequencing and genotype-phenotype correlations in 53 Japanese patients with osteogenesis imperfecta

To elucidate mutation spectrum and genotype-phenotype correlations in Japanese patients with OI, we conducted comprehensive genetic analyses using NGS, as this had not been analyzed comprehensively in this patient population. Most mutations were located on COL1A1 and COL1A2. Glycine substitutions in COL1A1 resulted in the severe phenotype.

INTRODUCTION

Most cases of osteogenesis imperfecta (OI) are caused by mutations in COL1A1 or COL1A2, which encode α chains of type I collagen. However, mutations in at least 16 other genes also cause OI. The mutation spectrum in Japanese patients with OI has not been comprehensively analyzed, as it is difficult to identify using classical Sanger sequencing. In this study, we aimed to reveal the mutation spectrum and genotype-phenotype correlations in Japanese patients with OI using next-generation sequencing (NGS).

METHODS

We designed a capture panel for sequencing 15 candidate OI genes and 19 candidate genes that are associated with bone fragility or Wnt signaling. Using NGS, we examined 53 Japanese patients with OI from unrelated families.

RESULTS

Pathogenic mutations were detected in 43 out of 53 individuals. All mutations were heterozygous. Among the 43 individuals, 40 variants were identified including 15 novel mutations. We found these mutations in COL1A1 (n = 30, 69.8%), COL1A2 (n = 12, 27.9%), and IFITM5 (n = 1, 2.3%). Patients with glycine substitution on COL1A1 had a higher frequency of fractures and were more severely short-statured. Although no significant genotype-phenotype correlation was observed for bone mineral density, the trabecular bone score was significantly lower in patients with glycine substitutions.

CONCLUSION

We identified pathogenic mutations in 81% of our Japanese patients with OI. Most mutations were located on COL1A1 and COL1A2. This study revealed that glycine substitutions on COL1A1 resulted in the severe phenotype among Japanese patients with OI.

P3638Triglyceride deposite cardiomyovasculopathy latency in population with coronary artery disease

Background

Triglyceride deposit cardiomyovasculopathy (TGCV) is a novel clinical concept found among Japanese cardiac transplant recipients in 2008 that the abnormal intracellular triglyceride (TG) metabolism results in the ectopic accumulation of TG in vascular smooth muscle cells and cardiomyocytes, leading to diffuse narrowing coronary artery disease (CAD) and heart failure. TGCV is estimated to affect almost forty to fifty-thousand people in Japan, but there is no real-world date about the prevalence or latency.

Purpose

To evaluate TGCV latency in population with CAD, especially requiring urgent coronary angiography as Study 1, and chronic hemodialysis as Study 2.

Methods

This is multicenter retrospective estimation consisting of two studies.

Study 1) From 2012 to 2017, consecutive 400 patients of unstable angina or acute myocardial infarction who underwent urgent coronary angiography (CAG) and following iodine-123-β-methyliodophenyl-pentadecanoic acid (BMIPP) scintigraphy, a tracer for the diagnosis of TGCV, were enrolled.

Study 2) From 2011 to 2017, 88 chronic hemodialysis patients who underwent planed CAG and BMIPP scintigraphy for detection of ischemic heart disease were enrolled.

TGCV was diagnosed based on the latest diagnostic criteria for TGCV. The criteria include two major items (2 points each: BMIPP scintigraphy Wash-Out Rare <10%, Diffuse narrowing coronary arteries) and two minor items (1 point each: Jordans' anomaly in peripheral blood smear, Diabetes). Four points or more and three points indicated definite and probable TGCV, respectively. Only Items other than Jordans' anomaly were available for the diagnosis of TGCV because of retrospective nature. We evaluated the latent rate of definite and probable TGCV.

Results

Study 1) Figure (left) demonstrates the result of Study 1. Definitive TGCV patients were 14 patients, accounting for 3.5% of total 400 patients, and probable TGCV patients were 39 patients, accounting for 9.8% of all. Total 53 definitive and probable TGCV patients accounted for 13.3% of all. Annual average latency were 3.6±1.7% as definitive, 10.0±5.5% as probable and 13.6±6.6% as definitive and probable TGCV, respectively.

Study 2) Figure (right) demonstrates the result of Study 2. Definitive TGCV patients were 17 patients, accounting for 19.3% of total 88 hemodialysis patients, and probable TGCV patients were 22 patients, accounting for 25.0% of all. Total 39 definitive and probable TGCV patients accounted for 44.3% of all. Annual average latency of definitive TGCV was 19.3±13.4%. Of the 17 definitive TGCV patients, 9 patients were hemodialysis patients with diabetes.

Figure 1

Conclusions

TGCV might be latent with a probability of 3.6±1.7% per year in patients with unstable angina or acute myocardial infarction, and with a probability of 19.3±13.4% per year in chronic hemodialysis patients suspected of ischemic heart disease.

P2688A novel risk factor of stent restenosis after drug-eluting stent implantation; Involvement of triglyceride deposit cardiomyovasculopathy, coronary atherosclerosis with triglyceride deposition

Background

Triglyceride deposit cardiomyovasculopathy (TGCV) is a novel disease concept characterized by the excessive accumulation of triglyceride in cardiomyocytes and vascular smooth muscle cells, leading to coronary artery disease (CAD), heart failure, and arrhythmia. However, it is rarely known whether TGCV contributes to the increased risk of vascular failure after drug eluting stent (DES) implantation.

Purpose

The aim of this study was to evaluate vascular failure after 2nd generation DES implantation in patients with TGCV.

Methods

Among 637 consecutive patients suspected of having CAD who underwent both coronary angiography and iodine-123-β-methyliodophenyl-pentadecanoic acid (BMIPP) scintigraphy between 2010 and 2018, we analyzed the data from 92 patients who met the inclusion criteria (shown in Table and Figure). Ninety-two patients were allocated to the presence (TGCV group, 11 patients) or absence (control group, 81 patients) of TGCV. All of 92 patients were implanted 2nd generation DES and underwent planned follow up coronary angiography. Control patients were diagnosed of diabetes mellitus. Binary restenosis (ISR), defined as angiographic luminal diameter ≥50% by quantitative coronary angiography, target lesion revascularization (TLR), In-stent late loss and restenosis morphology were assessed in 23 stents of TGCV group and 120 stents of control group.

Results

There were no significant differences in baseline characteristics between the two groups except for the prevalence of hypertension. In-stent late loss was greater in TGCV than in control (0.45 (−0.04 to 3.33) vs. 0.15 (−0.18 to 2.75), p=0.ehz748.10067), resulting in greater incidence of ISR and TLR in TGCV than in control (34.8% vs. 10.0%, p=0.0017; 21.7% vs. 6.7%, p=0.021, respectively). On multivariable logistic regression analysis, TGCV was found to be a significant and independent predictor for ISR after 2nd generation DES implantation. Regarding restenosis morphology, diffuse and occlusive pattern of ISR, were more frequently observed in TGCV than control (87.5% and 33.3%, Fisher's exact test p=0.028).

Table 1.The 4th edition diagnostic criteria for TGCV Items Clinical findings 2 points I) BMIPP scintigraphy Wash-Out Rare <10% II) Diffuse narrowng coronary arteries 1 point III) Jordans anomaly in peripheral blood smear IV) Diabetes Decision 4 points or more → Definite TGCV

Figure 1

Conclusion

Patients with TGCV showed the greater incidence of vascular failure even after 2nd generation DES implantation, contributing to the novel risk factor for coronary intervention even in the 2nd DES era.

P5633Diagnostic impact of resting full-cycle ratio as newly developed non-hyperemic indices for physiological lesion assessment

Background

Although fractional flow reserve (FFR) is a gold standard method to evaluate functional lesion severity in the catheterization laboratory, the need of hyperemic condition limits the widespread adoption of FFR. Recently, the resting full-cycle ratio (RFR) which was newly developed resting indices was launched. It is unclear whether RFR as resting condition could assess physiological lesion severity of coronary artery stenosis. The aim of this study was to evaluate the diagnostic impact of RFR compared to FFR in entire range of coronary artery stenosis.

Method

A total of 53 patients with 70 lesions were enrolled in this study. The RFR was measured after adequately waiting for stable condition, while FFR was measured after intravenous administration of ATP (180mcg/kg/min). Lesions with FFR ≤0.80 were considered functionally significant coronary artery stenosis.

Results

In all lesions, reference diameter, diameter stenosis, lesion length, RFR, and FFR were 3.3±0.8mm, 44±12%, 14.6±7.2mm, 0.90±0.11, and 0.83±0.11, respectively. Functional significance was observed in 24 lesions (34%) of all lesions. The RFR showed a significant correlation with FFR (y = 0.800x + 0.239, R = 0.817, p<0.001). The Bland-Altman plot demonstrated a good agreement with a mean difference of 0.07 and a standard deviation of 0.06 between RFR and FFR across entire range of coronary artery stenosis. ROC curve analysis showed an excellent accuracy of RFR cut-off of ≤0.90 in predicting FFR ≤0.80 which had 78% sensitivity and 87% specificity (AUC 0.87, diagnostic accuracy 84%).

Conclusion

The RFR as newly resting indices is reliable to the assessment of functional lesion severity. This physiology-based approach may be a possible alternative method for FFR measurements in daily practice.

Polarization-diversity Stokes-analyzer-based coherent receiver

Since the conventional coherent transceiver is costly to be deployed in short-reach networks due to its complicated receiver structure, it is desired to simplify the structure itself. In this paper, we propose a simple polarization-diversity coherent receiver structure by exploiting the concept of the Stokes analyzer. Compared to the conventional architecture, the number of the photodiodes (PDs) is reduced from eight to six without relying on complicated analog circuits. In addition, splitters and combiners for dual-polarization (DP) signals can be replaced with only one polarization beam splitter or combiner (PBS/C). For evaluation of the proof-of-concept (PoC), we developed a prototype of the receiver using free-space optical components. We demonstrate the transmission of 120-Gb/s DP quadrature phase-shift keying (QPSK) and DP 8-ary quadrature-amplitude modulation (8QAM) signals over a 100-km single-mode fiber (SMF). We believe that the demonstrated architecture could potentially be integrated monolithically on silicon-photonic or InP platforms to realize compact and low-cost coherent transceivers for short-reach applications.

Abstract P1-03-02: ASCO/CAP human epidermal growth factor receptor-2 (HER2) in situ hybridization (ISH) categories evaluated by quantitative HER2 protein diagnostic methodologies: A comparative analysis

Background: In 2013, the ASCO/CAP consensus panel published updated guidelines for HER2 testing in breast cancer that modified the definition of HER2 amplification by in situ hybridization (ISH), creating five new prognostic categories (group 1: classic amplified, group 2: monosomy, group 3: co-amplified (polysomy), group 4: equivocal, and group 5: classic non-amplified). Patients determined to be ISH amplified, were considered eligible for HER2-directed therapy. Concern over whether patients from non-classic groups 2-4 would benefit from treatment has led to the recent publication of the 2018 HER2 focused update. This update has modified the criteria for interpreting these ISH categories, recommending that the final diagnosis take into consideration a combination of HER2 immunohistochemistry (IHC) and ISH results. With increased emphasis on the HER2 protein assessment, it has prompted us to quantitatively examine HER2 protein expression in the ISH categories, using two different novel technologies. Materials & Methods: A cohort of 170 cases (URMC) and 102 cases (PSHMC) of invasive breast cancers, which had previously undergone HER2 IHC and ISH testing, were selected for this study. Cases were sorted and categorized into the HER2 ISH categories defined by ASCO/CAP. HER2 protein expression was quantitatively measured in the URMC and PSHMC cohorts using a novel immunodetection methodology (streptavidin-coated Phosphor-Integrated Dot (PID) fluorescent nanoparticles), and a novel dual-antibody, proximity-binding immunoassay (HERmark® Breast Cancer Assay, Monogram Biosciences, South San Francisco, California), respectively. HER2 protein expression was compared to the HER2 FISH and IHC results by ASCO/CAP category. Results: Cases in group 1 had a significantly (p &lt; 0.01) higher average PID/cell and HERmark compared to cases in groups 2-5 (Table 1). Cases in groups 2-4 showed lower quantitative levels of HER2 protein expression, similar to the classic non-amplified cases (group 5). Group 1 was further divided into three subgroups (Table 2): Group A - ISH high-level amplified (ratio &gt; 2, HER2 &gt; 6, CEP17 &lt; 2.7), Group B - amplified with elevated CEP17 (ratio &gt; 2, CEP17 &gt; 2.7), and Group C - low-level amplified (ratio &gt; 2, HER2 &gt; 4 and &lt; 6). Group A and B had a significantly (p &lt; 0.01) higher average PID/cell and HERmark compared to Group C. Group C was more comparable to cases in groups 2-5 (Table 1). Conclusion: Our results suggest that quantitative assessment of HER2 protein expression may help to further classify cases for HER2 status for targeted therapy, supporting the 2018 ASCO/CAP recommendation that non-classic ISH results might be resolved by evaluating protein expression. Follow up studies with a larger patient cohort and dual quantitative assessment are warranted.

Average PID/cell and HERmark in ASCO category groupsASCO category groupN (URMC)PID/cell (URMC)*N (PSHMC)HERmark (PSHMC)*18888.07761.521011.20N/A32016.0213.84238.5315.95296.3208.3*averageTable 2:Average PID/cell and HERmark in subgroups of Group 1SubgroupN (URMC)PID/cell (URMC)*N (PSHMC)HERmark (PSHMC)*A24157.66465.7B34101.61044.1C3016.9329.8*average

Citation Format: Buscaglia B, Turner B, Goda H, Huang W, Leitzel K, Natori T, Nakano Y, Okada H, Sperinde J, Ali S, Vasekar M, D'Aguiar M, McMahon L, Henry J, Lipton A, Hicks D. ASCO/CAP human epidermal growth factor receptor-2 (HER2) in situ hybridization (ISH) categories evaluated by quantitative HER2 protein diagnostic methodologies: A comparative analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-03-02.

A cryogenic linear ion trap beamline for providing keV ion bunches

A new cryogenic linear ion trap beamline has been constructed and commissioned, which serves to inject cold molecular and cluster ions into the RIKEN cryogenic electrostatic ring (RICE). Ions are created with an electrospray ion source, and a quadrupole mass filter is used for mass-selection prior to trap injection. The radio frequency octupole ion trap can be continuously loaded with ions and features a fast ion extraction mode to create short ion bunches with tens of μs duration. We report here on the simulations and development of the ion trap beamline and validate performance with the moderately heavy molecular cation methylene blue. Characterization of the novel trap design with additional wedge-shaped electrodes was carried out, which includes the determination of the temporal and spatial shape of the ion bunch and the total number of ions after extraction. Finally, these ion bunches are synchronized with the switching of a pulsed high-voltage acceleration device downstream of the trap, where the ions obtain a kinetic energy of up to 20 keV. The preparation and control of the keV ion beam are demonstrated for the ion injection into RICE.

The Plasmin Heavy Chain - Urokinase Conjugate: A Specific Thrombolytic Agent

Low molecular weight urokinase (LMW-UK) was coupled to the heavy chain of plasmin to make it able to bind to fibrin. The purified conjugate (PHC-UK conjugate), which consisted of equimolar concentrations of each starting material had a molecular weight of 93,600, bound tightly to fibrin-monomer-Sepharose and was not washed off with 1 M NaCl, but was eluted specifically with s-amino caproic acid. The conjugate showed higher fibrinolytic activity than HMW-UK. A control conjugate prepared by coupling human serum albumin to LMW-UK (HSA-UK conjugate) showed the same fibrinolytic activity as HMW-UK. The half-lives of these two conjugates in rabbits were about 3 times that of HMW-UK. In an experimental pulmonary embolism model in rabbits, the PHC-UK conjugate showed about 10 times higher thrombolytic activity than HMW-UK, while the HSA-UK conjugate showed similar thrombolytic activity as HMW-UK, and moreover caused severe systemic fibrinogen breakdown. Thus the significant increase in thrombolytic activity after injection of PHC-UK conjugate into rabbits may be due to its newly acquired fibrin binding activity, and not to increase in its half-life. It is concluded that the PHC-UK conjugate may be useful in treatment of thrombosis.

Search for Boosted Dark Matter Interacting with Electrons in Super-Kamiokande

A search for boosted dark matter using 161.9 kt yr of Super-Kamiokande IV data is presented. We search for an excess of elastically scattered electrons above the atmospheric neutrino background, with a visible energy between 100 MeV and 1 TeV, pointing back to the Galactic center or the Sun. No such excess is observed. Limits on boosted dark matter event rates in multiple angular cones around the Galactic center and Sun are calculated. Limits are also calculated for a baseline model of boosted dark matter produced from cold dark matter annihilation or decay. This is the first experimental search for boosted dark matter from the Galactic center or the Sun interacting in a terrestrial detector.