Generation of Fabry cardiomyopathy model for drug screening using induced pluripotent stem cell-derived cardiomyocytes from a female Fabry patient

BACKGROUND

Fabry disease is an X-linked disease caused by mutations in α-galactosidase A (GLA); these mutations result in the accumulation of its substrates, mainly globotriaosylceramide (Gb3). The accumulation of glycosphingolipids induces pathogenic changes in various organs, including the heart, and Fabry cardiomyopathy is the most frequent cause of death in patients with Fabry disease. Existing therapies to treat Fabry disease have limited efficacy, and new approaches to improve the prognosis of patients with Fabry cardiomyopathy are required.

METHODS AND RESULTS

We generated induced pluripotent stem cell (iPSC) lines from a female patient and her son. Each iPSC clone from the female patient showed either deficient or normal GLA activity, which could be used as a Fabry disease model or its isogenic control, respectively. Erosion of the inactivated X chromosome developed heterogeneously among clones, and mono-allelic expression of the GLA gene was maintained for a substantial period in a subset of iPSC clones. Gb3 accumulation was observed in iPSC-derived cardiomyocytes (iPS-CMs) from GLA activity-deficient iPSCs by mass-spectrometry and immunofluorescent staining. The expression of ANP was increased, but the cell surface area was decreased in iPS-CMs from the Fabry model, suggesting that cardiomyopathic change is ongoing at the molecular level in Fabry iPS-CMs. We also established an algorithm for selecting proper Gb3 staining that could be used for high-content analysis-based drug screening.

CONCLUSIONS

We generated a Fabry cardiomyopathy model and a drug screening system by using iPS-CMs from a female Fabry patient. Drug screening using our system may help discover new drugs that would improve the prognosis of patients with Fabry cardiomyopathy.

SHORT CHAIN FATTY ACIDS UPREGULATE ADIPOKINE PRODUCTION IN TYPE 2 DIABETES-DERIVED HUMAN ADIPOCYTES

PURPOSE

Short chain fatty acids (SCFAs) play a major regulatory role in adipocyte function and metabolism. The aim of this study was to investigate the effects of SCFAs on adiponectin and leptin expression in adipocytes, and also to determine whether the effects of SCFA treatment in visceral adipocytes obtained from healthy subjects are different relative to the effects in adipocytes from patients with type 2 diabetes.

MATERIALS AND METHODS

Human pericardiac preadipocytes and human pericardiac preadipocytes type 2 diabetes were differentiated into adipocytes for 21 days in 48-well plates. After differentiation, two kinds of mature adipocytes, human pericardiac adipocytes (HPAd) and human pericardiac adipocytes-type 2 diabetes (HPAd-T2D) were incubated with or without 1 mM of acetic acid (AA), butyrate acid (BA), and propionic acid (PA). After 48 hours of incubation, intracellular lipid accumulation was measured using oil red staining. In addition, mRNA levels of adiponectin, leptin and Peroxisome Proliferator-Activated Receptor γ (PPARγ) were determined by Real-Time PCR system.

RESULTS

In HPAd, SCFA supplementation did not inhibit lipid accumulation. By contrast, both AA (p<0.01) and PA (p<0.01) significantly inhibited lipid accumulation in HPAd-T2D. Regarding mRNA levels of adiponectin, no significant changes were found in HPAd, while all three types of SCFAs significantly increased (p<0.05) adiponectin expression in HPAd-T2D. Leptin mRNA expression levels were significantly increased by treatment with all three types of SCFAs in both HPAd (p<0.05) and HPAd-T2D (p<0.05).

CONCLUSION

SCFAs inhibited lipid droplet accumulation and increased mRNA expression of adiponectin and leptin in T2D-derived adipocytes.

Bilirubin oxidation derived from oxidative stress is associated with disease severity of atopic dermatitis in adults

BACKGROUND

Bilirubin is an essential antioxidant. Its oxidative metabolites, biopyrrins, are sensitive urinary markers of oxidative stress. Multiple studies suggest that oxidative stress affects the pathogenesis of skin diseases such as atopic dermatitis (AD).

AIM

To examine oxidative stress-induced bilirubin oxidation and its association with AD pathogenesis in adults.

METHODS

In total, 11 patients with AD and 7 healthy controls (HCs) were enrolled. Bilirubin oxidation profiles in the combined urine of the patients and that of the HCs were examined using high-performance liquid chromatography (HPLC) and fast atom bombardment mass spectrometry. The concentrations of urinary biopyrrins and serum biomarkers for AD disease severity, such as IgE and thymus and activation-regulated chemokine (TARC)/CCL17, were measured by ELISA to determine correlations between urinary biopyrrins and serum biomarkers. Local bilirubin oxidation in AD skin lesions was assessed by immunohistochemical analyses using two antibodies against bilirubin.

RESULTS

Levels of dipyrrole-monopyrrole-aldehyde, a novel urinary biopyrrin, were higher in patients with AD than in HCs, and increased with disease severity based on the SCORing Atopic Dermatitis (SCORAD) objective scoring system. Additionally, urinary biopyrrin levels correlated significantly with serum IgE and TARC/CCL17 levels. Furthermore, immunohistochemical analyses revealed that biopyrrins were strongly expressed in both infiltrating and resident cells in AD lesions. However, bilirubin was expressed at low levels in the lesions, suggesting that bilirubin oxidation is augmented in AD lesions.

CONCLUSIONS

Bilirubin oxidation derived from oxidative stress in the skin lesions can be associated with disease severity of AD.

SurePath® LBC improves the diagnostic accuracy of intrahepatic and hilar cholangiocarcinoma

INTRODUCTION

The current study aimed to compare cytology using SurePath^® (SP)-LBC and biliary tissue histology (BTH) for the diagnosis of biliary disease.

METHODS

Between January 2014 and December 2016, 57 patients underwent endoscopic retrograde cholangiopancreatography for the diagnosis of biliary disease. Biliary cytological samples were processed using SP-LBC and subsequently BTH was performed. A final diagnosis was confirmed by surgery (23 malignant cases) and clinical follow-up (34 benign and malignant cases): 18 extrahepatic cholangiocarcinoma; 17 intrahepatic/hilar cholangiocarcinoma (intra/H-CC); eight other malignant disease; and 14 benign biliary disease. The diagnoses made using SP-LBC and BTH were classified into four categories: (1) benign; (2) indeterminate; (3) suspicious for malignancy/malignant; and (4) inadequate. In addition, diagnostic accuracy was compared between SP-LBC and BTH.

RESULTS

Although 23% (13/57) of BTH samples were classified as inadequate, all SP-LBC cases were classified as adequate. Among 43 malignant cases, 11 normal, four indeterminate and 28 suspicious for malignancy/malignant were found using SP-LBC (26%, 9% and 65%, respectively), in contrast to 10 inadequate, nine normal, 10 indeterminate and 14 suspicious for malignancy/malignant observed using BTH (23%, 21%, 23%, and 33%, respectively). The identification of malignant cells was strikingly different between SP-LBC and BTH. Furthermore, limited to intra/H-CC, accuracy was significantly higher using SP-LBC than using BTH (P < .001).

CONCLUSIONS

SP-LBC of the biliary tract is a useful and reliable method for diagnosing biliary malignant disease and has an advantage over BTH for detecting malignant cells and accurately diagnosing intra/H-CC.

Effects of a high-fat diet on superoxide anion generation and membrane fluidity in liver mitochondria in rats

Background

Obesity is a primary factor of lifestyle-related diseases, and the age of its onset has decreased. The reactive oxygen species (ROS), the superoxide anion, is generated in the mitochondrial electron transport chain and the damage it induces in cells may be a contributing factor to obesity-related lifestyle diseases. In the present study, the influence of the ingestion of a high-fat diet (HFD) on superoxide anion generation in rat liver mitochondria (Mt) and membrane fluidity was investigated.

Methods

Male Wistar rats were fed a normal diet (ND, n = 6) or HFD (n = 6). Liver Mt were isolated and oxygen consumption, superoxide anion production (the adrenaline method), and membrane fluidity (the spin label method) were measured.

Results

After 11 weeks, body weights and abdominal circumferences were higher in the HFD group than in the ND group. Mt oxygen consumption was higher in the HFD group than in the ND group. Superoxide anion production was significantly lower in the HFD group than in the ND group, while no significant changes were observed in membrane fluidity.

Conclusion

Although rats developed diet-induced obesity, it did not reach the level of disease development. The promotion of lipid metabolism appeared to reduce superoxide anion production, but did not influence membrane fluidity. While superoxide anion damages cells as an oxidative stress, ROS and superoxide dismutase are essential signaling molecules in the body. The present results suggest that the continuous ingestion of a HFD impairs Mt and induces disease development.

Genetic variants of DNA repair-related genes predict efficacy of TAS-102 in patients with refractory metastatic colorectal cancer

Background

Tri-phosphorylated trifluridine (FTD) incorporation into DNA is TAS-102's main anti-tumor action. We tested whether genetic polymorphisms in homologous recombination (HR) and cell cycle checkpoint pathway for DNA repair is associated with outcomes in refractory metastatic colorectal cancer (mCRC) patients treated with TAS-102.

Patients and methods

We analyzed genomic DNA extracted from 233 samples of three cohorts: an evaluation cohort of 52 patients receiving TAS-102, a validation cohort of 129 patients receiving TAS-102 and a control cohort of 52 patients receiving regorafenib. Single nucleotide polymorphisms of genes involved in HR (ATM, BRCA1, BRCA2, XRCC3, FANCD2, H2AX, RAD51) and cell cycle checkpoint (ATR, CHEK1, CHEK2, CDKN1A, TP53, CHE1, PIN1, PCNA) were analyzed by PCR-based direct sequencing.

Results

In univariate analysis for the evaluation cohort, patients with any G allele in ATM rs609429 had longer overall survival (OS) than those with the C/C variant (8.7 vs. 4.4 months, HR 0.37, 95% CI: 0.14-0.99, P = 0.022). Patients carrying any A allele in XRCC3 rs861539 had significantly longer progression-free survival (PFS) (3.8 vs. 2.3 months, HR 0.44, 95% CI: 0.21-0.92, P = 0.024) and OS (15.6 vs. 6.3 months, HR 0.25, 95% CI: 0.08-0.79, P = 0.012) than those with the G/G variant. In multivariable analysis, ATM rs609429 remained significant for OS (P = 0.020). In the validation cohort, patients having ATM rs609429 with any G allele showed longer OS and PFS; the G/A variant in XRCC3 rs861539 showed longer OS, though without statistical significance.

Conclusion

Genetic variants in the HR pathway may predict clinical outcome in mCRC patients receiving TAS-102.

Abstract P3-13-03: NEOS: A randomized, open label, phase 3 trial of adjuvant chemotherapy for postmenopausal breast cancer patients who responded to neoadjuvant letrozole: First report of long-term outcome and prognostic value of response to neoadjuvant endocrine therapy

Background: Whether adjuvant chemotherapy is required for patients (pts) with intermediate-risk endocrine-responsive postmenopausal breast cancer (BC) remains unknown. Sufficient data have not been available about the long-term prognosis of patients with neoadjuvant endocrine therapy (ET). NEOS is a randomized phase III study that assessed the long-term prognosis of estrogen receptor positive (ER+) primary breast cancer (PBC) pts who received neoadjuvant ET with/without adjuvant chemotherapy.

Methods: Postmenopausal BC pts with ER +/HER2 negative, T1c-2, clinically node negative, under 76 years old were enrolled at primary registration. Pts were treated by leterozole (LET) in weeks 24-28 after primary enrollment. Pts experienced progression (PD) during neoadjuvant phase were excluded at randomization and received any systemic therapy driven by investigators before or after surgery. The long-term prognosis was followed in all registered pts including PD pts. Response to neoadjuvant ET was evaluated as complete response (CR), partial response (PR) or stable disease (SD) using calipers, ultrasound and MRI (or CT) at the baseline and end of treatment before surgery. Pts who met eligibility criteria were randomized 1:1 to LET for 4.5-5 years after chemotherapy or LET alone for 4.5-5 years without chemotherapy after surgery. Pts excluded at second registration were treated any systemic therapies driven by investigators. The primary endpoint was disease-free survival (DFS) and secondary endpoints included overall survival (OS), clinical response rate in neoadjuvant phase, pathological response, and breast-conserving surgery rate. The randomization code have been blinded to the investigators.

Results: Between May 2008 and June 2013, 904 patients were enrolled at primary registration from 100 institutions in Japan (median follow-up: 4.0 years) and 24 pts were withdrawn during neoadjuvant phase. The median age was 63 years, T1c:37%, T2:63%, and PgR+:78%. Clinical response rates (CR, PR, SD and PD) were2% (16pts), 48% (421pts), 45% (400pts) and 5% (43pts), respectively and, in each response category, 0% (0/16), 5.5% (23/421), 7.8% (31/400), and 20.9% (9/43) experienced DFS events. DFS in PD pts to neoadjuvant ET were statistically significantly worse than CR, PR, SD pts (p&lt;0.0001, hazard ratio 4.7 (95% CI:2.3-9.5). The prognosis after surgery in 669 randomized pts was good regardless with/without chemotherapy, forty four pts (6.6%) experienced DFS events after surgery. The predictive markers of PD for neoadjuvant ET were yet unclear among evaluated clinical factors.

Conclusion: This is the first report of DFS in the largest neoadjuvant ET trial (NEOS). The DFS of postmenopausal, ER+/HER2-, PBC pts excluding PD pts to neoadjuvant ET is highly good regardless with/without chemotherapy. Neoadjuvant ET with utilization of PD response as a prognostic marker can be considered as a standard treatment option for these patients. Clinical trial information: UMIN000001090.

Citation Format: Iwata H, Masuda N, Fujisawa T, Toyama T, Ohtani S, Yamamoto Y, Kashiwaba M, Taira N, Sakai T, Hasegawa Y, Nakamura R, Akabane H, Shibahara Y, Sasano H, Yamaguchi T, Ohashi Y. NEOS: A randomized, open label, phase 3 trial of adjuvant chemotherapy for postmenopausal breast cancer patients who responded to neoadjuvant letrozole: First report of long-term outcome and prognostic value of response to neoadjuvant endocrine therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-13-03.

Abstract PD5-03: TransNEOS: Validation of the oncotype DX recurrence score (RS) testing core needle biopsy samples from NEOS as predictor of clinical response to neoadjuvant endocrine therapy for postmenopausal estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer patients

Background: Neoadjuvant therapy for locally advanced breast cancer has the potential to improve surgical therapeutic outcomes without sacrificing the survival advantages of adjuvant therapy. However, determining whether ER+ patients (pts) will respond to neoadjuvant (NA) chemotherapy (CT) or hormone therapy (HT) can be difficult. Not all ER+ pts respond to NACT, while response to NAHT can vary across ER+ pts. Thus, the ability to select pts more likely to benefit from NAHT would represent progress in clinical management of breast cancer. NEOS is a randomized phase III study assessinglong-term prognosis of ER+ primary breast cancer with/without adjuvant CT following NAHT (UMIN 000001090, http://www.umin.ac.jp/). We used archived core biopsy tumor samples from the NEOS study to validate the RS result as a predictor of clinical response and its association with successful breast conserving surgery (BCS) in pts treated with 6 months of NAHT.

Methods: NEOS enrolled 904 postmenopausal pts with ER+, HER2-, clinically node negative (cN0) breast cancer to evaluate whether adjuvant CT was necessary for pts who responded to NAHT. In this current study, we enrolled pts with tumors ≥2cm from the NEOS study. Biopsy samples of 333 pts were assessed for the Oncotype DX assay. Response to NAHT was recorded as complete/partial response (CR/PR), or stable/progressive disease (SD/PD).

Primary endpoint of this study was to evaluate clinical response (CR/PR) to NA letrozole between pts with low (&lt;18) and high (≥31) RS result. Secondary endpoints include evaluating the relationships between clinical response and continuous RS results, and other covariates including age, tumor size, grade, Ki67 by IHC, ER and PR single gene scores, and ER and proliferation gene group scores by RT-PCR.

Results: The analysis included 294 pts with median age of 63 yrs, median tumor size of 25mm, and 66% were nuclear grade 1. 156 (53.0%), 83 (28.6%) and 54(18.4%) cases were low, intermediate, and high RS groups by Oncotype DX, respectively. Six (2%), 126 (42.8%), 149 (50.3%), 13 (4.4%) cases experienced CR, PR, SD, PD as clinical response, respectively, similar to that of all NEOS pts. Clinical response rate was 54%, 42% and 22% in low, intermediate, and high RS groups, respectively. The proportion of pts with clinical response was significantly higher in the low RS group vs the high RS group (p&lt;0.001). In univariate analyses, continuous RS was significantly associated with clinical response (p&lt;0.001), along with ER (p=.02), PR (p&lt;0.001), and ER gene group score (p&lt;0.001). Other covariates were not associated with clinical response.

Conclusion: The Oncotype DX RS test in core biopsy samples is validated as a predictive assay for clinical response of NAHT in postmenopausal, ER+/HER2-, cN0, primary early breast cancer pts. Further results on the association of RS results with BCS outcomes following NAHT will be presented. These results when combined with previously published data on RS in NACT studies help guide pts with ER+, HER2- breast cancer with NAHT vs NACT treatment options to maximize clinical response.

Citation Format: Yamamoto Y, Iwata H, Masuda N, Fujisawa T, Toyama T, Kashiwaba M, Ohtani S, Taira N, Sakai T, Hasegawa Y, Nakamura R, Akabane H, Shibahara Y, Sasano H, Yamaguchi T, Sakamaki K, Chao C, McCullough D, Sugiyama N, Ohashi Y. TransNEOS: Validation of the oncotype DX recurrence score (RS) testing core needle biopsy samples from NEOS as predictor of clinical response to neoadjuvant endocrine therapy for postmenopausal estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD5-03.

Biodistribution of N-lsopropyl-p-lodoamphetamine in the Rat Brain

The biodistribution of N-isopropyl-p-iodoamphetamine (IMP) was studied in the rat brain.131 l-labelled IMP was injected intravenously in awake animals. Activities in the brain of Sprague-Dawley rats were 2.68–3.22 (% dose/g) in the cortex and 0.59–0.66 (% dose/g) in the white matter at 1 min p. i. Activities in the cortex were slightly increased at 60 min p. i., while activities in the white matter increased markedly at 60 min and 6 h p. i. Therefore, the cerebral cortex-to-white matter ratio decreased from 5 to 1 within 60 min after injection. Autoradiograms of the rat brain at 1–10 min p. i. showed high contrasts. Activities were high in the cortex and low in the white matter, but homogeneous at 60 min – 6 h. IMP seems to be a useful agent for cerebral perfusion imaging in the early phase after injection. Knowledge of biodistribution of this agent is considered to be indispensable for the interpretation of images.

Alert System for Inappropriate Prescriptions Relating to Patients’ Clinical Condition

Objectives: Because information of contraindication and careful indication of medication is vast, there have been numerous cases of prescribing medication inappropriately. Our goal is to have a clinical decision support system (CDSS) combined with a computerized physician order entry (CPOE) to aid physicians in prescribing medication appropriately. In this study we developed an alert system for evaluating renal function and checking doses of medication according to the patient’s renal function. In addition, we developed functions of extracting target problems from the raw data and verifying if contraindicated medication has being prescribed.

Methods: This system scrutinizes data handled in the CPOE system. It picks up the data needed to ascertain problems and the data of medication entered from the order entry system. First we made an alert system for renal dysfunction. Creatinine clearance (Ccr) of a patient was calculated by the estimate equation of Cockcroft and Gault. If a patient data fulfills the condition of impaired renal function, the alert message is sent to the database. The alert system also checks the dosage of each medication according to a patient’s renal function. When the dosage is over-prescribed, an alert is sent. Next, we made an alert system targeting contraindication for liver diseases, renal diseases and diabetes mellitus. The criteria of these problems were set in the knowledge base. If a patient’s data meets the criteria, that fact is stored in the problem database. The system also keeps a prescription check master and checks whether the patient has a problem which is a contraindication of the prescribed medication. If a problem exists, an alert is sent to the alert message database. The alert-presenting module is a web system. After accepting patients’ ID indicated by a user, the system searches the alerts concerning the patients from the database and constructs pages presenting the alert message.

Results: We compared the period during which the contraindicated medication was prescribed before and after the alert system was put into operation. Of the patients with renal dysfunction who were prescribed the contraindicated medication, 24% had their medication discontinued before the alert system was put into operation. In contrast, the rate significantly increased to 54% after the alert system began to function.

Conclusion: We developed an alert system for inappropriate prescriptions for each patient’s clinical condition. The alerts generated by this system were effective for discontinuing contraindicated medication.

In Vitro and In Vivo Behaviour of Four Different 99(m)Tc-HEDP Complexes

According to absorption spectra, at least four different 99Tc-HEDP complexes [complex I (colorless), complex II (yellow), complex III (pink-red) and complex IV (brown)] were observed under various labeling conditions. Both pH and Sn (II)-HEDP concentration greatly influenced the formation of these complexes. In acidic or neutral media, complex II was the main product while in alkaline media complex III and complex IV were formed below concentration levels of 1 x 10–3M of Sn (II) and of 3x 10–3M of HEDP. At high Sn (II)-HEDP concentrations complexes I and II were formed, while complexes III and IV were found at lower Sn (II)-HEDP concentrations in weak alkaline media. All four 99(m)Tc-HEDP complexes were stable against air oxidation until at least 6 hrs after preparation. Complexes I and II were stable against dilution by distilled water, while complexes III and IV were unstable and readily dissociated. In organ distribution studies high soft-tissue uptakes were observed with complexes III and IV, while complexes I and II had high bone-seeking properties.

Robotic-assisted multivisceral resection for rectal cancer: short-term outcomes at a single center

BACKGROUND

The safety and feasibility of robotic-assisted multivisceral resection for locally advanced rectal cancer remain unclear. The aim of this study was to assess the short-term outcomes of this procedure at our institution.

METHODS

From December 2011 to December 2016, patients who underwent robotic-assisted multivisceral resection for rectal cancer were investigated. Patient demographics, treatment characteristics, perioperative outcomes, and pathological results were evaluated retrospectively.

RESULTS

There were 31 patients; 17 men (54.8%) and 14 women (45.2%), with a median age of 65 years (range 40-82 years). Twenty-one patients (67.7%) had a cT4 tumor, 9 patients (29.0%) had a pT4b tumor, and all patients except one (96.8%) underwent complete resection of the primary tumor with negative resection margins. Eleven patients (35.5%) received neoadjuvant chemoradiation. The most commonly resected organ was the vaginal wall (n = 12, 38.7%), followed by the prostate (n = 10, 32.3%). Lateral lymph node dissection was performed in 20 patients (64.5%). The median operative time was 394 min (range 189-549 min), and the median blood loss was 41 mL (range 0-502 mL). None of the patients received intraoperative blood transfusions or required conversion to open. Overall, postoperative complications occurred in 11 patients (35.5%). The most frequent complication was urinary retention (n = 5, 16.1%), and none of the patients developed serious complications classified as Clavien-Dindo grades III-V.

CONCLUSIONS

Robotic-assisted multivisceral resection for rectal cancer is safe and technically feasible.

Monitoring of hemostatic abnormalities in major orthopedic surgery patients treated with edoxaban by APTT waveform

INTRODUCTION

An analysis of the activated partial thromboplastin time (APTT) in major orthopedic surgery patients receiving edoxaban for the prevention of venous thromboembolism (VTE) was carried out.

METHODS

The APTT waveform was analyzed in the above patients to monitor edoxaban administration.

RESULTS

Of these 99 patients, 12 exhibited deep vein thrombosis, and 25 had massive bleeding. An increased biphasic pattern of the APTT waveform was observed after the administration of edoxaban, but there were no significant differences between the patients with and without complications. The peak times of acceleration, velocity, and 1/2 fibrin formation were significantly prolonged after the administration of edoxaban, especially in patients with massive bleeding, and were moderately correlated with the anti-Xa activity. While the heights of velocity and acceleration peak 2 were lower in patients receiving warfarin treatment than in those receiving edoxaban, the widths of these parameters were significantly longer. The height of 1/2 fibrin formation and the width of acceleration peaks 1 and 2 and the velocity were significantly increased after the administration of edoxaban.

CONCLUSION

The peak time of the APTT waveform was significantly prolonged after the administration of edoxaban. The analysis of the APTT waveform may therefore be useful for the prediction of the risk of massive bleeding.

Hole-phonon coupling effect on the band dispersion of organic molecular semiconductors

The dynamic interaction between the traveling charges and the molecular vibrations is critical for the charge transport in organic semiconductors. However, a direct evidence of the expected impact of the charge-phonon coupling on the band dispersion of organic semiconductors is yet to be provided. Here, we report on the electronic properties of rubrene single crystal as investigated by angle resolved ultraviolet photoelectron spectroscopy. A gap opening and kink-like features in the rubrene electronic band dispersion are observed. In particular, the latter results in a large enhancement of the hole effective mass (> 1.4), well above the limit of the theoretical estimations. The results are consistent with the expected modifications of the band structures in organic semiconductors as introduced by hole-phonon coupling effects and represent an important experimental step toward the understanding of the charge localization phenomena in organic materials.The charge transport properties in organic semiconductors are affected by the impact of molecular vibrations, yet it has been challenging to quantify them to date. Here, Bussolotti et al. provide direct experimental evidence on the band dispersion modified by molecular vibrations in a rubrene single crystal.

Variability of treatment planning of seed implantation: A Japanese multicenter simulation study

PURPOSE

This multicenter study was conducted to evaluate the current variability of treatment planning of seed implantation in Japanese centers and the feasibility of two virtual trials.

METHODS AND MATERIALS

Two types of contour data were sent to 12 radiation oncologists with a request letter that asked them to make treatment plans on the data in the same manner as in their own practice. Five of the 12 radiation oncologists were asked to participate in the two virtual trials in which the D90 (dose to the hottest 90% of prostate volume) was 1) required to be set at just 180 Gy and 2) increased as much as possible without violating other limitations.

RESULTS

A relatively high dose with a small deviation was irradiated to the prostate in Japanese centers (mean D90 = 188 Gy; SD = 10 Gy). In the virtual trials, all five physicians could achieve 180 Gy for the D90 with a very small deviation, although the urethral dose showed relatively large deviations. Dose escalation without increase of urethral dose or V150 was difficult, although the rectum could be spared by most of the physicians.

CONCLUSION

Our study showed a relatively high dose with a small deviation was prescribed to the prostate in Japanese centers. Consolidated protocols such as D90 = 180 Gy could be available for future trials. Meanwhile, our study suggested that some cautions might be needed for urethral dose and the V150, even when a relatively low D90 was requested.

Control of tunnel barriers in multi-wall carbon nanotubes using focused ion beam irradiation

We have formed tunnel barriers in individual multi-wall carbon nanotubes using the Ga focused ion beam irradiation. The barrier height was estimated by the temperature dependence of the current (Arrhenius plot) and the current-voltage curves (Fowler-Nordheim plot). It is shown that the barrier height has a strong correlation with the barrier resistance that is controlled by the dose. Possible origins for the variation in observed barrier characteristics are discussed. Finally, the single electron transistor with two barriers is demonstrated.