Utility of remnant liver volume for predicting posthepatectomy liver failure after hepatectomy with extrahepatic bile duct resection

BACKGROUND

Hepatectomy with extrahepatic bile duct resection is associated with a high risk of posthepatectomy liver failure (PHLF). However, the utility of the remnant liver volume (RLV) in cholangiocarcinoma has not been studied intensively.

METHODS

Patients who underwent major hepatectomy with extrahepatic bile duct resection between 2002 and 2018 were reviewed. The RLV was divided by body surface area (BSA) to normalize individual physical differences. Risk factors for clinically relevant PHLF were evaluated with special reference to the RLV/BSA.

RESULTS

A total of 289 patients were included. The optimal cut-off value for RLV/BSA was determined to be 300 ml/m2. Thirty-two patients (11.1 per cent) developed PHLF. PHLF was more frequent in patients with an RLV/BSA below 300 ml/m2 than in those with a value of 300 ml/m2 or greater: 19 of 87 (22 per cent) versus 13 of 202 (6.4 per cent) (P < 0.001). In multivariable analysis, RLV/BSA below 300 ml/m2 (P = 0.013), future liver remnant plasma clearance rate of indocyanine green less than 0.075 (P = 0.031), and serum albumin level below 3.5 g/dl (P = 0.015) were identified as independent risk factors for PHLF. Based on these risk factors, patients were classified into three subgroups with low (no factors), moderate (1-2 factors), and high (3 factors) risk of PHLF, with PHLF rates of 1.8, 14.8 and 63 per cent respectively (P < 0.001).

CONCLUSION

An RLV/BSA of 300 ml/m2 is a simple predictor of PHLF in patients undergoing hepatectomy with extrahepatic bile duct resection.

Long-term outcomes and recurrence-free interval after the treatment of keloids with a standardized protocol

BACKGROUND

Recurrence rates of keloids have generally been reported at one time point. However, the longer the duration after treatment, the greater the likelihood that such lesions will recur. In this study, we analysed the time to recurrence during long-term follow-up.

MATERIAL AND METHODS

We retrospectively reviewed recurrence-free interval in 52 patients with keloid (age 8-79 years) who had been treated between June 2006 and January 2011 using a standardised protocol developed by our group.

RESULTS

Mean duration of follow-up was 37.5 (range, 7-120) months in patients with keloid. Kaplan-Meier survival curves revealed a statistically significant difference in recurrence-free interval between ear keloids and keloids excluding ear keloids. Recurrence rate for keloids was high in the first 2 years after treatment.

CONCLUSIONS

Kaplan-Meier analysis was useful for understanding the tendency of recurrence of keloids after treatment using a standardised protocol.

CD49d and CD49e induce cell adhesion-mediated drug resistance through the nuclear factor-κB pathway in Burkitt lymphoma

Burkitt lymphoma (BL) is a highly aggressive form of non-Hodgkin's B-cell lymphoma. Currently, multi-agent chemotherapy regimens are being used to significantly improve cure rates and achieve complete remissions in BL patients. However, drug resistance can often occur within 6 months in BL patients, contributing to poor prognosis. Mounting evidence suggests that cell adhesion-mediated drug resistance (CAM-DR), caused by the interaction between the bone marrow microenvironment and tumour cells may play an important role in drug resistance to chemotherapy. However, the molecular mechanism underlying CAM-DR in BL has not been identified yet. In this study, we investigated the molecular mechanism responsible for CAM-DR in BL cells. We also examined the therapeutic targets of CAM-DR in BL cells and found CD49d and CD49e to be the important adhesion molecules involved. However, CD49a, CD49b, CD11a, CD29, CD18, and CD61 were not found to be associated with CAM-DR in BL cells. Furthermore, we clarified that CD49d- and CD49e-mediated CAM-DR could be attributed to an increase in the expression of B cell leukemia-xL (Bcl-xL) and survivin proteins, and a decrease in the expression of Bcl-2 associated X (Bax), Bcl-2 interacting mediator (Bim) and p53 upregulated modulator of apoptosis (PUMA) proteins via nuclear factor kappaB (NF-κB) activation. In addition, bortezomib was found to overcome CAM-DR in BL cells by inhibiting NF-κB. Thus, bortezomib may have potential clinical applications in the treatment of CD49d- and CD49e-mediated CAM-DR in BL patients.

Preclinical proof-of-concept study: antisense-mediated knockdown of CALM as a therapeutic strategy for calmodulinopathy

Background

Calmodulin (CaM) is a ubiquitous Ca2+ sensor molecule encoded by three distinct calmodulin genes, CALM1–3, and has an important role for cardiac ion channel function. Recently, heterozygous missense mutations in CALM genes were reported to cause a new category of life-threatening genetic arrhythmias such as long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT), which is called as “calmodulinopathy”. The patients with calmodulinopathy show poor prognosis and there is no effective treatment for them.

Purpose

Considering the dominant-negative effect of mutant calmodulin proteins produced by heterozygous missense mutations in CALMs, we aimed to prove the concept of antisense-based therapy to treat calmodulinopathy using human iPS cell-derived cardiomyocyte (hiPSC-CM) model.

Methods

We designed multiple locked nucleic acid (LNA) gapmer-antisense oligonucleotides (ASOs) targeting CALM2 and analyzed the silencing efficiency and toxicity in cultured cells to select the most potent ASO. Using CMs differentiated from hiPSCs which were generated form a 12-year-old boy with LQTS carrying a heterozygous CALM2-N98S mutation, CALM2 expression and action potentials (APs) were analyzed to evaluate the efficacy of ASOs.

Results

We identified several ASOs which reduced CALM2 expression without affecting cell viability in human cultured cells (HepG2) (ASO 50 nM, n=2; Figure 1A). Considering further experiments in vivo mouse model, we investigated the CALM2 silencing activity in mouse cultured cells (3T3-L1) without transfection (free-uptake) (ASO 1 μM, n=2; †ASOs have homologous sequence between human and mouse; Figure B). After free-uptake CALM2 silencing analysis in 3T3-L1 cells, we identified that ASO #2 has the most potent CALM2 silencing activity and low cytotoxicity (Figure 1B). ASO #2 effectively reduced CALM2 expression even in hiPSC-CMs (ASO(−): n=3, lipofection: n=4, free-uptake: n=3; P&lt;0.05; Figure 1C). In action potential recordings, we demonstrated that ASO #2 ameliorated prolonged AP durations (APD90) in N98S-hiPSC-CMs at 0.5 Hz pacing (ASO(−): 666±123 ms (n=7), lipofection: 329±21 ms (n=8), free-uptake: 388±34 ms (n=12); P&lt;0.05; Figure 1D).

Conclusion

Our results using patient-derived hiPSC-CM model suggest that ASO-based therapy might be a promising strategy for the treatment of calmodulinopathy.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Nissan Chemical Corporation

Clinical aspects of pediatric Brugada syndrome

Introduction

Brugada syndrome (BrS) is an inherited arrhythmia characterized by a coved-type ST elevation and sudden death, especially in middle-aged males and more common in Asia. Mutations in SCN5A are detected in 15–20% and reported to be associated with poor prognosis. Among children, BrS is rare and the risk factors in pediatric BrS are unknown, especially in Asian population.

Purpose

The purpose of this study is to elucidate the risk factors for fatal arrhythmic events in Japanese pediatric patients with BrS.

Methods

We enrolled 52 Japanese children with BrS younger than 20 years, and performed genetic analysis and collected the clinical information.

Results

The mean age of initial symptoms was 10.7±5.5 years, and the mean follow-up period was 3.9±5.5 years. Ninety percent of patients were probands. No subjective symptom was confirmed in 28 of the patients, but aborted cardiac arrest (ACA) in 4, ventricular tachycardia in 4, ventricular fibrillation in 1, and syncope in 11. We identified mutations in SCN5A in 63%. There was no significant gender difference in ≤10 years, but a significant male predominance appeared in &gt;10 years. And no gender difference was confirmed in the incidence of severe cardiac events in ≤10 years.

Conclusion

No gender difference was confirmed in ≤10 years in this study about Asian children. And being girls did not reduce the risk in ≤10 years. The frequency of SCN5A mutations was higher than adults, but decreased from childhood (68%) to adolescence (59%). In BrS, genetical and environmental factors may be more effective in childhood and adulthood, respectively.

Funding Acknowledgement

Type of funding source: None

Usefulness of collaboration between mathematical models and cell engineering for elucidating complex disease mechanisms and discover effective drugs

Background

A missense mutation, CACNA1C-E1115K, located in the cardiac L-type calcium channel (LTCC), was recently reported to be associated with diverse arrhythmias. Several studies reported in-vivo and in-vitro modeling of this mutation, but actual mechanism and target drug of this disease has not been clarified due to its complex ion-mechanisms.

Objective

To reveal the mechanism of this diverse arrhythmogenic phenotype using combination of in-vitro and in-silico model.

Methods and results

Cell-Engineering Phase: We generated human induced pluripotent stem cell (hiPSC) from a patient carrying heterozygous CACNA1C-E1115K and differentiated into cardiomyocytes. Spontaneous APs were recorded from spontaneously beating single cardiomyocytes by using the perforated patch-clamp technique.

Mathematical-Modeling Phase: We newly developed ICaL-mutation mathematical model, fitted into experimental data, including its impaired ion selectivity. Furthermore, we installed this mathematical model into hiPSC-CM simulation model.

Collaboration Phase: Mutant in-silico model showed APD prolongation and frequent early afterdepolarization (EAD), which are same as in-vitro model. In-silico model revealed this EAD was mostly related to robust late-mode of sodium current occurred by Na+ overload and suggested that mexiletine is capable of reducing arrhythmia. Afterward, we applicated mexiletine onto hiPSC-CMs mutant model and found mexiletine suppress EADs.

Conclusions

Precise in-silico disease model can elucidate complicated ion currents and contribute predicting result of drug-testing.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists

SAT0011 COMBINED INHIBITION OF AUTOPHAGY AND GLUTAMINE METABOLISM SUPPRESSES CELL GROWTH OF RA SYNOVIOCYTES AND AMELIORATES ARTHRITIS IN SKG MICE

Background:

Immunometabolism is now recognaized to be crucial in the pathogenesis of rheumatoid arthritis (RA). We have recently shown that the expression of glutaminase 1 (GLS1), a key enzyme in glutaminolysis, is upregulated in fibroblast-like synoviocytes from RA patients (RA-FLS) and that GLS1 inhibition suppresses RA-FLS proliferation (1). However, glutaminolysis has been known to suppress autophagy by activating mTORC1 or counteracting ROS production (2). Given the possibility of autophagy upregulation following glutamiolysis inhibition, therapies targeting both autophagy and glutaminolysis may be more effective in suppressing cell growth of RA-FLS, yet the relation between glutaminolysis and autophagy in RA-FLS has not been investigated.

Objectives:

To examine the effects of inhibiting both glutaminolysis and autophagy on RA-FLS and autoimmune arthritis in SKG mice.

Methods:

GLS1 inhibitor, compound 968 (C968), was used to suppress glutaminolysis, and Chloroquine (CQ) was used to inhibit autophagy. To detect autophagy, the expression of ATG5 and LC3B was measured by real-time PCR and the production of LC3-II was analyzed by Western blotting. The formation of autophagic vacuoles was identified by immunfluorescense. Cell growth was evaluated by BrdU assay. Apoptosis was analyzed by flow cytometry staining with Annexin V-FITC and PI. C968 and CQ were administered subcutaneously to Zymosan A-injected SKG mice.

Results:

C968 upregulated the expression of ATG5 and LC3B, and increased the protein level of LC3-II in RA-FLS. C968 also facilitated autophagosome formation. These results suggested that inhibition of glutaminolysis promoted autophagy in RA-FLS. The combined treatment with C968 and CQ significantly suppressed cell proliferation of RA-FLS more strongly than did C968 or CQ alone. In addition, C968 combined with CQ increased the apoptosis rate, whereas either C968 or CQ alone did not. Furthermore, combination of C968 and CQ significantly attenuated the degree of arthritis in SKG mice, while C968 or CQ monotherapy did not (Figure).

Conclusion:

The GLS1 inhibitor C968 promotes autophagy in RA-FLS. C968 in combination with CQ reduces proliferation and enhances apoptosis in RA-FLS, and ameliorates the arthritis in SKG mice. Suppressing C968-induced autophagy may be a promising therapy for arthritis.

References:

[1] Takahashi S., et al. Arthritis Res Ther. 2017 Apr 11;19(1):76.

[2] Villar VH., et al. Autophagy. 2015;11(8):1198-208.

Acknowledgments :

None

Disclosure of Interests:

None declared

SAT0235 THE EFFECT OF ANTIPHOSPHOLIPID ANTIBODIES ON APTT WAVEFORM PATTERNS

Background:

Patients with antiphospholipid antibody (aPL) are said to be at increased risk for thrombosis, however it is difficult to predict whether they will develop thrombosis. In recent years, it has been revealed that the characteristics of the second derivative curve of APTT waveform with aPL positive patient is biphasic changes1,2. As first step in predicting the risk of thrombosis, we sought to understand the effect of aPL on APTT waveform patterns.

Objectives:

To analyze the characteristics of APTT waveforms according to the background diseases and the presence of aPL

Methods:

Patients who underwent coagulation function tests from 2017 to 2019 were analyzed. A coagulation waveform (Clot waveform: CW) was drawn using a fully automatic coagulation time measuring device manufactured by Instrumentation Laboratory From the APTT waveform, the 1st derivative curve (DC) indicating the coagulation speed and the 2nd DC indicating the coagulation acceleration were depicted to measure the 1st DC height, 2nd DC peak 1 time, and 2nd DC peak 1 height (Figure12). Patients were devided into CTD with aPL-negative patients (group A), aPL-positive patients with no prior thrombosis (group B), and antiphospholipid antibody syndrome (APS) (group C). Patients characteristics and aPL (anti-cardiolipin [CL] antibody IgM, anti-CL antibody IgG, anti-CLβ2GP1 complex antibody, LA-APTT, and LA- DRVVT) status were examind. A further analysis was performed according to the numbers of positive aPL. Comparison between the three groups were made by the one-way ANOVA method, with significant differences set as p-values <0.1. Factors with significant differences were analyzed by Steel-Dwass test. APTT waveforms was analyzed according to the numbers of positive aPL by least squares methods. Furthermore, to determine the cut off value of APTT, 1st DC height, 2nd DC peak 1 time, and 2nd DC peak 1 height for each case with 2 or more positive aPLs and 3 positive aPLs, area under the curve (AUC) of the receiver operating characteristic (ROC) curve, sensitivity and specificity were caliculated.

Figure 1.

Results:

The APTT waveform was analyzed in 61 patients (51 women, 83.6%) with average age of 54.1 ± 17.1 years. Group A was 26 cases, Group B was 18 cases, and Group C was 17 cases. APTT, 2nd DC peak1 time, 2nd DC peak1 height, 1st DC peak time were significantly different among A, B, and C groups (p <0.01). APTT, 1st DC peak height, 2nd DC peak 1 time, and 2nd DC peak 1 height differed among the number of aPL (p < 0.01, respectively). APTT and 2nd DC peak1 time prolonged by 9.43 (seconds) and 16.3 (seconds) respectively according to the number of aPLs increased, and 1st DC peak height (mabs/s) and 2nd DC peak1 height (mabs/s2) decreased by 56.4 (mabs/s) and 223.9 (mabs/s2) respectively according to the number of aPLs decreased (Table 1). APTT> 35.2 (seconds) (sensitivity 80%, specificity 80.4%), 2nd DC peak1 height> 302 (mabs/s2) (sensitivity 80%, specificity 91.3%) were relevant to the presence of two or more aPLs and APTT> 35.2 (seconds) (sensitivity 100%, specificity 80%), 2nd DC peak1 height> 302 (mabs/s2) (sensitivity 100%, specificity 90%) were relevant to the presence of three aPLs.

Table 1.The number of positive aPL0123p valueThe number of cases2719411APTT(seconds)28.9[26.8, 31.4]30.9[29.1, 38.2]31.1[27.3, 54.2]60.7[45.9, 73.7]0.00012nd DC peak time (seconds)29.2[26.8, 30.7]33.7[31, 41.7]36.1[31.5, 99]75.8[50.5, 102.4]0.00012nd DC peak height (mabs/s2)839.9[666.1, 962.2]669.6[346.4, 946]608.4[137.8, 956.7]119.3[30.6, 196]0.00011st DC peak height (mabs/s)309.6[260.6, 355.1]271.5[168, 353]241.8[96.3, 364.0]135.6[76.8, 163]0.0001

Conclusion:

The presence of aPL was more related to the 2nd DC peak1 height of APTT waveform than APTT. A detailed review of the APTT waveform may further predict future thrombosis risk.

References:

[1]Tokunaga N, et al. Blood Coagul Fibrinolysis. 2016;27:474-476.

[2]Matsumoto T, et al. Int J Hematol. 2017;105:174-183.

Disclosure of Interests:

YASUO SUZUKI: None declared, Asako Mitsui: None declared, Yoshiki Yamamoto: None declared, Kentaro Noda: None declared, Ayako Nakajima Grant/research support from: AN has received research grants from Chugai Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Consultant of: AN has consultant fee from Nippon Kayaku Co. Ltd., Speakers bureau: AN has received speaker’s fee from AbbVie Japan GK, Actelion Pharmaceuticals Japan LTD., Asahi Kasei Pharma Co., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Hisamitsu Pharmaceutical Co. Inc., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Co., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., and Teijin Pharma Ltd.

0746 Dynamics of Sleep Stage Transitions in Patients with Narcolepsy and Other Hypersomnias

Introduction

Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness and abnormal REM sleep phenomena. Narcolepsy can be distinguished into type 1 (NT1; with cataplexy) and type 2 (NT2; without cataplexy). It has been reported that sleep stage sequences at sleep-onset as well as sleep-wake dynamics across the night may be useful in the differential diagnosis of hypersomnia. Here we studied dynamic features of sleep stage transitions during whole night sleep in patients with NT1, NT2, and other types of hypersomnia (o-HS).

Methods

Twenty patients with NT1, 14 patients with NT2, and 35 patients with o-HS underwent overnight PSG. Transition probabilities between sleep stages (wake, N1, N2, N3, and REM) and survival curves of continuous runs of each sleep stage were compared between groups. Transition-specific survival curves of continuous runs of each sleep stage, dependent on the subsequent stage of the transition, were also compared.

Results

The probability of transitions from N1-to-wake was significantly greater in NT1 than in NT2 and o-HS while that from N1-to-N2 was significantly smaller in NT1 than in NT2 and o-HS. The probability of transitions from N2-to-REM was significantly smaller in NT1 than in o-HS. Wake and N1 were significantly more continuous in NT1 than in NT2; specifically, N1 followed by N2 was significantly more continuous in NT1 than in NT2 and o-HS. N2 was significantly less continuous in NT1 and NT2 than in o-HS; this was specifically confirmed for N2 followed by N1/wake. REM sleep was significantly less continuous in NT1 than in NT2 and o-HS; specifically, REM sleep followed by wake was significantly less continuous in NT1 than in o-HS. Continuity of N3 did not differ significantly between groups.

Conclusion

Dynamics of sleep stage transitions differed between NT1, NT2, and o-HS. Dynamic features of sleep such as sleep instability, persistency of wake/N1, and REM fragmentation may differentiate NT1 from NT2, while N2 continuity may differentiate narcolepsy from o-HS. The results suggest that sleep transition analysis may be of clinical utility and provide insights into the underlying pathophysiology of hypersomnia and narcolepsy.

Support

JSPS KAKENHI (18K17891 to AK).

The efficacy of eribulin mesylate for patients with cutaneous angiosarcoma previously treated with taxane: a multicentre prospective observational study

BACKGROUND

Taxanes are the current first-line treatment for advanced cutaneous angiosarcoma (CAS) for patients who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. However, no effective second-line therapy for such patients has been established.

METHODS

We designed a single-arm prospective observational study of eribulin mesylate (ERB) administered at a dose of 1·4 mg m^-2 on days 1 and 8 in a 21-day cycle. Patients with advanced CAS who were previously treated with a taxane and were scheduled to begin ERB treatment were enrolled. The primary endpoint was overall survival (OS) and the secondary endpoints were response rate (RR), progression-free survival (PFS) and toxicity assessment.

RESULTS

We enrolled a total of 25 patients. The median OS and PFS were 8·6 months and 3·0 months, respectively. The best overall RR was 20% (five of 25). In total, 16 grade 3/4 severe adverse events (SAEs) occurred; however, all patients recovered. Patients who achieved partial response or stable disease as best response had longer OS than those with progressive disease (median OS not reached and 3·3 months, respectively; P < 0·001). Patients who did not experience SAEs showed longer OS than those who did (median OS 18·8 months and 7·5 months, respectively; P < 0·05). Patients with distant metastasis had shorter median OS than those with locoregional disease, but without statistically significant difference.

CONCLUSIONS

ERB showed a promising RR and is a potential candidate for second-line treatment for patients with CAS, after treatment with taxanes. However, owing to the occurrence of SAEs in over half of the participants, caution should be exercised regarding ERB use in elderly patients. What is already known about this topic? Taxanes are the current first-line treatment for patients with advanced cutaneous angiosarcoma (CAS) who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. No effective therapy for taxane-resistant CAS has been established thus far. Eribulin suppresses microtubule polymerization and elicits an antitumour effect similar to that of taxanes. What does this study add? In our single-arm prospective observational study to evaluate the efficacy of eribulin for treating patients with advanced CAS who previously received taxanes, the median overall survival and progression-free survival were 8·6 and 3·0 months, respectively. Response rates at weeks 7, 13 and 25 were 20%, 17% and 14%, respectively. Although 16 grade 3/4 severe adverse events occurred, all patients recovered. Eribulin showed a promising response rate and is a potential candidate for second-line treatment in CAS after taxane treatment. Linked Comment: Smrke and Benson. Br J Dermatol 2020; 183:797-798.

Characteristic brain hypoperfusion by 99mTc-ECD single photon emission computed tomography (SPECT) in patients with the first-episode schizophrenia

Objective

In this study, we evaluated brain perfusion in patients with first-episode medicated schizophrenia using the new analytical method, statistical parametric mapping (SPM) applied to single photon emission computed tomography (SPECT).

Method

We performed SPECT with 99-Tc-ethyl cysteinate dimer (99mTc-ECD) of the brain and magnetic resonance imaging (MRI) in patients with schizophrenia (n = 30) and control subjects matched for age and gender (n = 37). A voxel-by-voxel group analysis was performed using SPM2 (Z > 3.0, P < 0.001, uncorrected for multiple comparisons).

Result

In comparison with control subjects, the volumes of the bilateral frontal areas were found to be decreased on MRI. Blood flow was found to be reduced in the bilateral temporal areas in the patients with schizophrenia on SPECT.

Conclusion

In this study, patients with first-episode schizophrenia appeared to have significant bilateral temporal hypoperfusion, although temporal volumes were not significantly decreased in comparison with control subjects. Abnormality of temporal lobe blood flow in schizophrenia may show that functional changes occur earlier than structural changes, and may assist in the diagnosis of schizophrenia.

Evaluation of an amplicon-based custom gene panel for the diagnosis of hereditary tumors

Genetic testing based on next-generation sequencing (NGS) analysis has recently been used to diagnose hereditary diseases. In this study, we explored the usefulness of our custom amplicon panel that targeted 23 genes related to hereditary tumors given in the American College of Medical Genetics and Genomics recommendations. We applied our custom NGS panel to samples from 12 patients previously diagnosed by Sanger sequencing as having the diseases or diagnosed clinically by meeting the diagnostic criteria in this study. Our gene panel not only successfully identified all variants detected by Sanger sequencing but also identified previously unrecognized variants that resulted in confirmation of the disease, or even in the revision of the diagnosis. For instance, a patient identified with an SDHD gene mutation actually had von Hippel-Lindau (VHL) syndrome, as determined by the presence of a pathogenic VHL gene variant. We also identified false-positive results that were generated by amplification of genome regions that are not intended to be investigated. In conclusion, NGS-based amplicon sequencing is a highly effective method to detect germline variants, as long as they are also carefully reviewed by manual inspection.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

Possible Lightest Ξ Hypernucleus with Modern ΞN Interactions

Experimental evidence exists that the Ξ-nucleus interaction is attractive. We search for NNΞ and NNNΞ bound systems on the basis of the AV8 NN potential combined with either a phenomenological Nijmegen ΞN potential or a first principles HAL QCD ΞN potential. The binding energies of the three-body and four-body systems (below the d+Ξ and ^{3}H/^{3}He+Ξ thresholds, respectively) are calculated by a high precision variational approach, the Gaussian expansion method. Although the two ΞN potentials have significantly different isospin (T) and spin (S) dependence, the NNNΞ system with quantum numbers (T=0, J^{π}=1^{+}) appears to be bound (one deep for Nijmegen and one shallow for HAL QCD) below the ^{3}H/^{3}He+Ξ threshold. Experimental implications for such a state are discussed.