Automation of etch pit analyses on solid-state nuclear track detectors with machine learning for laser-driven ion acceleration

Solid-state nuclear track detectors (SSNTDs) are often used as ion detectors in laser-driven ion acceleration experiments and are considered to be the most reliable ion diagnostics since they are sensitive only to ions and measure ions one by one. However, ion pit analyses require tremendous time and effort in chemical etching, microscope scanning, and ion pit identification by eyes. From a laser-driven ion acceleration experiment, there are typically millions of microscopic images, and it is practically impossible to analyze all of them by hand. This research aims to improve the efficiency and automation of SSNTD analyses for laser-driven ion acceleration. We use two sets of data obtained from calibration experiments with a conventional accelerator where ions with known nuclides and energies are generated and from actual laser experiments using SSNTDs. After chemical etching and scanning the SSNTDs with an optical microscope, we use machine learning to distinguish the ion etch pits from noises. From the results of the calibration experiment, we confirm highly accurate etch-pit detection with machine learning. We are also able to detect etch pits with machine learning from the laser-driven ion acceleration experiment, which is much noisier than calibration experiments. By using machine learning, we successfully identify ion etch pits ∼105 from more than 10 000 microscopic images with a precision of ≳95%. A million microscopic images can be examined with a recent entry-level computer within a day with high precision. Machine learning tremendously reduces the time consumption on ion etch pit analyses detected on SSNTDs.

Mass-resolved ion measurement by particle counting analysis for characterizing relativistic ion beams driven by lasers

Particle counting analysis is a possible way to characterize GeV-scale, multi-species ions produced in laser-driven experiments. We present a multi-layered scintillation detector to differentiate multi-species ions of different masses and energies. The proposed detector concept offers potential advantages over conventional diagnostics in terms of (1) high sensitivity to GeV ions, (2) realtime analysis, and (3) the ability to differentiate ions with the same charge-to-mass ratio. A novel choice of multiple scintillators with different ion stopping powers results in a significant difference in energy deposition between the scintillators, allowing accurate particle identification in the GeV range. Here, we report a successful demonstration of particle identification for heavy ions, performed at the Heavy Ion Medical Accelerator in Chiba. In the experiment, the proposed detector setup showed the ability to differentiate particles with similar atomic numbers, such as C⁶⁺ and O⁸⁺ ions, and provided an excellent energy resolution of 0.41%-1.2% (including relativistic effect, 0.51%--1.6%).

A multi-stage scintillation counter for GeV-scale multi-species ion spectroscopy in laser-driven particle acceleration experiments

Particle counting analysis (PCA) with a multi-stage scintillation detector shows a new perspective on angularly resolved spectral characterization of GeV-scale, multi-species ion beams produced by high-power lasers. The diagnosis provides a mass-dependent ion energy spectrum based on time-of-flight and pulse-height analysis of single particle events detected through repetitive experiments. With a novel arrangement of multiple scintillators with different ions stopping powers, PCA offers potential advantages over commonly used diagnostic instruments (CR-39, radiochromic films, Thomson parabola, etc.) in terms of coverage solid angle, detection efficiency for GeV-ions, and real-time analysis during the experiment. The basic detector unit was tested using 230-MeV proton beam from a synchrotron facility, where we demonstrated its potential ability to discriminate major ion species accelerated in laser-plasma experiments (i.e., protons, deuterons, carbon, and oxygen ions) with excellent energy and mass resolution. The proposed diagnostic concept would be essential for a better understanding of laser-driven particle acceleration, which paves the way toward all-optical compact accelerators for a range of applications.

Surface nanostructures on Nb-doped SrTiO3irradiated with swift heavy ions at grazing incidence

A single crystal of SrTiO₃doped with 0.5 wt% niobium (Nb-STO) was irradiated with 200 MeV Au³²⁺ions at grazing incidence to characterize the irradiation-induced hillock chains. Exactly the same hillock chains are observed by using atomic force microscopy (AFM) and scanning electron microscopy (SEM) to study the relation between irradiation-induced change of surface topography and corresponding material property changes. As expected, multiple hillocks as high as 5-6 nm are imaged by AFM observation in tapping mode. It is also found that the regions in between the adjacent hillocks are not depressed, and in many cases they are slightly elevated. Line-like contrasts along the ion paths are found in both AFM phase images and SEM images, indicating the formation of continuous ion tracks in addition to multiple hillocks. Validity of preexisting models for explaining the hillock chain formation is discussed based on the present results. In order to obtain new insights related to the ion track formation, cross-sectional transmission electron microscopy (TEM) observation was performed. The ion tracks in the near-surface region are found to be relatively large, whereas buried ion tracks in the deeper region are relatively small. The results suggest that recrystallization plays an important role in the formation of small ion tracks in the deep region, whereas formation of large ion tracks in the near-surface region is likely due to the absence of recrystallization. TEM images also show shape deformation of ion tracks in the near-surface region, suggesting that material transport towards the surface is the reason for the absence of recrystallization.

Predictors of the usefulness of mirogabalin for neuropathic pain: a single-institution retrospective study

Mirogabalin is a novel, preferentially selective α2δ-1 ligand to treat neuropathic pain. However, this agent is not always effective for patients with neuropathic pain. We therefore attempted to identify factors that could predict the efficacy of mirogabalin. The study comprised 133 patients given mirogabalin for alleviation of neuropathic pain between April and November 2019 at our hospital. Variables were extracted from medical records for regression analysis of factors associated to alleviation of neuropathic pain. We evaluated the effect of mirogabalin at two weeks after administration. Groups were categorized according to degree of improvement: poor, effective, or very effective. Multivariate ordered logistic regression analysis was conducted to identify predictors for the usefulness of mirogabalin. Threshold measures were analysed using receiver operating characteristic (ROC) curves. Maintenance dose [odds ratio (OR) = 0.90; 95% confidence interval (CI) = 0.84-0.98; P = 0.01], concomitant use of opioids (OR = 0.26, 95% CI = 0.08-0.83; P = 0.023) and Neurotropin^® (NTP) (OR = 4.78, 95% CI =1.04-21.93; P = 0.044) were factors significantly correlated to the effect of mirogabalin. ROC curve analysis of the effective group indicated a threshold maintenance dose of≤ 20 mg/day (area under the curve [AUC] = 0.53). In conclusion, maintenance dose (≤ 20 mg), concomitant use of opioids and NTP were identified as predictors for the utility of mirogabalin.

Effect of voluntary participation on an alternating and a simultaneous prisoner's dilemma

We studied the evolution of cooperation in the framework of evolutionary game theory, implementing voluntary participation in the prisoner's dilemma. Although previous studies have tried to overcome the dilemma by introducing voluntary participation called a "loner," the question of which strategies among various strategies including voluntary participation are adaptive under competitive circumstances is still an unsolved puzzle. Here we have developed a model that consists of all possible strategies using a one-period memory of past actions. This model enables us to analyze a "melting pot" of strategies, wherein several strategies interact and compete with each other. Our results revealed that one strategy, in which one escapes if a partner defects or cooperates if a partner becomes a loner, dominates and maintains cooperation in an alternating prisoner's dilemma game. However, the so-called "win-stay, lose-shift" strategy dominates in a simultaneous prisoner's dilemma game. Our simulations clearly show that voluntary participation in the prisoner's dilemma game works in the alternating situation rather than the simultaneous one.

Safety and efficacy of PD-1/PD-L1 blockade in patients with preexisting antinuclear antibodies

PURPOSE

Immune checkpoint inhibitors (ICIs) show promising clinical activity in advanced cancers. However, the safety and efficacy of PD-1/PD-L1 blockade in patients with preexisting antinuclear antibodies (ANA) are unclear.

METHODS

191 patients treated with nivolumab, pembrolizumab, atezolizumab, or durvalumab for unresectable advanced cancers between September 2014 and December 2018 were identified retrospectively. Patients were divided into positive (ANA titers ≥ 1:160) and negative ANA groups (ANA titers < 1:160). Development of immune-related adverse events (irAEs), the overall response rate (ORR), and disease control rate (DCR) were monitored.

RESULTS

Positive ANA titers were seen in 9 out of 191 patients. Four patients in the positive ANA group and 69 patients in the negative group developed irAEs of any grade without a significant difference between the groups. The development of endocrine, pulmonary, and cutaneous irAEs was not significant, whereas positive ANA was significantly higher in patients who developed colitis (2/9) than in patients who did not (3/182, P = 0.0002). DCR in the positive and negative ANA group was 37.5% and 67.5%, respectively, and was not statistically significant, but had better efficacy in patients without ANA (P = 0.08). ANA-related autoimmune diseases such as SLE, Sjögren's syndrome, MCTD, scleroderma, dermatomyositis, and polymyositis was not induced in either group. However, one patient with preexisting dermatomyositis had a flare up after initiation of atezolizumab.

CONCLUSION

Further studies to identify predictive factors for the development of irAEs are required to provide relevant patient care and maximize the therapeutic benefits of ICIs.

Abstract P1-11-07: Risk analysis for chemotherapy induced nausea and vomiting (CINV) in patients receiving FEC100 treatment

BACKGROUND:

Anthracycline-containing regimens are standard treatment options in adjuvant and neoadjuvant chemotherapy in breast cancer. Chemotherapy-induced nausea and vomiting (CINV) is experienced frequently in patients receiving these regimens, but the risk factors for CINV are unknown.

OBJECTIVE:

The aim of this study was to investigate risk factors for CINV in anthracycline-containing regimens retrospectively.

METHODS:

Data were collected from the JONIE study, which was conducted in order to estimate the efficacy of zoledronic acid in a neoadjuvant setting from March 2010 to June 2012 (UMIN000003261). A total of 180 patients were recruited, and we used CINV data from the first cycle of FEC100 treatment and patient backgrounds. As the protocol regulation allowed the use of antiemetic drugs,in the first cycle of the FEC100 regimen, patients received various types of antiemetic agents, which we classified into four groups: Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3)+neurokinin-1 receptor antagonist (NK1) (DEX+5-HT3+NK1) group; Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3) (DEX+5HT3) group; Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3)+dopamine receptor antagonist (DRA) (DEX+5HT3+DRA) group; and Dexamethasone (DEX)+5-HT3 receptor antagonist (5-HT3)+neurokinin-1 receptor antagonist (NK1)+ dopamine receptor antagonist (DRA) (DEX+5-HT3+NK1+DRA) group. Risk factors were selected from patient backgrounds and the combinations of antiemetic drugs. In patient backgrounds, the body mass index (BMI) was stratified into 3 categories: Less than 18.5 (underweight group); equal to or more than 18.5 but less than 25 (standard BMI group); and equal to or more than 25 (overweight group). The risks for CINV were analyzed by univariate and multivariate analyses. P values of less than 0.05 were defined as significant.

RESULTS:

In a univariate analysis of nausea, the body mass index (BMI) was the only significant factor (P&lt;0.05). On the other hand, BMI and the combination of antiemetic drugs were significant factors in vomiting. (P&lt;0.05 and 0.005, respectively). In a multivariate analysis of nausea, the P value for BMI was 0.02. The odds ratio for the underweight group was 7.745 (confidence interval: 2.171 to 27.634) compared with the standard BMI group. In a multivariate analysis of vomiting, BMI and the combination of antiemetic drugs were significant risk factors (P=0.025 and 0.023, respectively). The odds ratio for the underweight group was 3.481 (confidence interval: 1.183 to 10.241)compared with the standard BMI group. Furthermore, the odds ratios in the DEX+5-HT3+DRA and DEX+5HT3 groups were 5.005 (confidence interval: 1.543 to 16.239) and 4.178 (confidence interval: 1.428 to 12.222), respectively, compared with the DEX+5-HT3+NK1 group, which was consistent with the CINV guidelines in 2011.

CONCLUSIONS:

This study revealed that BMI was the most important risk factor for nausea, and that BMI and the combination of antiemetic drugs were risk factors for vomiting. Underweight-patients tend to have CINV in anthracycline-containing regimen. The DEX+5-HT3+NK1 group was the best antiemetic drug combination. These result show that following the CINV guideline treatment is mandatory in order to prevent CINV.

Citation Format: Hayashi M, Nakazawa K, Hasegawa Y, Horiguchi J, Miura D, Ishikawa T, Takao S, Kim SJ, Yamagami K, Miyashita M, Konishi M, Shigeoka Y, Suzuki M, Taguchi T, Kubota T, Tanino Y, Yamada K, Kimura K, Akazawa K, Kohno N. Risk analysis for chemotherapy induced nausea and vomiting (CINV) in patients receiving FEC100 treatment [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 P1-11-07.

A multichannel gated neutron detector with reduced afterpulse for low-yield neutron measurements in intense hard X-ray backgrounds

A design of multichannel gated photomultiplier tube (PMT) is presented for the 960-channel neutron time-of-flight detector at the Institute of Laser Engineering of Osaka University. This is important for the fusion science and the nuclear photonics where intense hard X-rays are generated from the interaction of ultra-short laser pulse of petawatt power density with matter. The hard X-rays often overload PMTs and cause signal-induced background noises called afterpulses, making the detection of subsequent neutrons impossible. For this reason, the PMTs are coupled with an electrical time-gating (ETG) system to avoid overloading. The ETG system disables the PMT by modulating the dynode potential during the primary X-ray flash. An after-pulsing suppression technique is demonstrated by applying a reverse bias voltage between the photocathode and the first dynode. The presented multichannel scheme provides a gate response time of 80 ns, a signal cutoff ratio of 2.5 × 10², and requires reasonably low power consumption.

Phenotypic and functional analysis of bovine peripheral blood dendritic cells before parturition by a novel purification method

Dendritic cells (DCs) are specialized antigen presenting cells specializing in antigen uptake and processing, and play an important role in the innate and adaptive immune response. A subset of bovine peripheral blood DCs was identified as CD172a⁺/CD11c⁺/MHC (major histocompatibility complex) class II⁺ cells. Although DCs are identified at 0.1%–0.7% of peripheral blood mononuclear cells (PBMC), the phenotype and function of DCs remain poorly understood with regard to maintaining tolerance during the pregnancy. All cattle used in this study were 1 month before parturition. We have established a novel method for the purification of DCs from PBMC using magnetic‐activated cell sorting, and purified the CD172a⁺/CD11c⁺DCs, with high expression of MHC class II and CD40, at 84.8% purity. There were individual differences in the expressions of CD205 and co‐stimulatory molecules CD80 and CD86 on DCs. There were positive correlations between expression of cytokine and co‐stimulatory molecules in DCs, and the DCs maintained their immune tolerance, evidenced by their low expressions of the co‐stimulatory molecules and cytokine production. These results suggest that before parturition a half of DCs may be immature and tend to maintain tolerance based on the low cytokine production, and the other DCs with high co‐stimulatory molecules may already have the ability of modulating the T‐cell linage.

Abstract OT2-01-01: Observational study of axilla treatment for breast cancer patients with 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes

[Background] Axilla surgery in node-positive breast cancer is dramatically changing from axillary lymph node dissection (ALND) to sentinel node biopsy (SNB). From the results of ACOSOG Z0011, IBCSG23-01 and AMAROS trials, adjuvant therapy and regional node irradiation could reduce regional lymph node recurrence for sentinel node-positive breast cancer patients. However, optimal indication of SNB alone remains uncertain. Trial design: To evaluate the outcome of sentinel node-positive breast cancer patients, the Japanese Society for Sentinel Node Navigation Surgery (SNNS) conducted a prospective cohort study in 2013 (UMIN000011782, Jpn J Clin Oncol, p.876-9, 2014). [Eligibility criteria] For eligible patients, SNB was performed or scheduled after 1 January 2012. Then 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes are confirmed by histological or molecular diagnosis. Primary chemotherapy before or after SNB is also acceptable for registration. [Specific aims] The primary endpoint is the 5-year recurrence rate of regional lymph node in patients treated with SNB alone. The secondary endpoint is the 5-year overall survival rate of this cohort. Patients treated with SNB followed by ALND are also registered simultaneously to compare the prognosis. The propensity score matching (PSM) is used to make the distributions of baseline risk factors comparable. [Statistical method] Based on an estimated recurrence rate of 5% at 5 years among patients treated with SNB alone, 240 patients are needed to give a 80% power to reject the null hypothesis that the recurrence rate is 10% with a one-sided type I error rate of 2.5%. If we consider that some patients will be lost to follow-up or become ineligible, a total of 250 patients will be needed to comprise the sample. [Present accrual] Eight hundred and eighty patients who underwent SNB alone or SNB followed by ALND were registered from 27 participating institutes between 2013 and 2016. Data cleaning is being performed. Patient's background and PSM will be reported.

Citation Format: Imoto S, Saito Oba M, Masuda N, Nagashima T, Wada N, Takashima T, Kitada M, Kawada M, Hayashida T, Taguchi T, Aihara T, Miura D, Toh U, Yoshida M, Sugae S, Yoneyama K, Matsumoto H, Jinno H, Sakamoto J. Observational study of axilla treatment for breast cancer patients with 1 to 3 positive micrometastases or macrometastases in sentinel lymph nodes [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 OT2-01-01.

Hillocks created for amorphizable and non-amorphizable ceramics irradiated with swift heavy ions: TEM study

In a previous study, we found that hillocks (i.e. surface ion tracks) can be imaged using transmission electron microscopy (TEM) by irradiating thin CeO₂ samples with swift heavy ions (SHI) at oblique incidence. In the present study, the same TEM method is applied to Y₃Fe₅O₁₂ (YIG) and three fluorides (CaF₂, SrF₂ and BaF₂) for observing hillocks. For YIG, which is one of the amorphizable materials, hillocks are found to have amorphous features consistent with amorphous features of ion tracks. For the fluorides, it is found that the hillocks do not exhibit amorphous features, and they are composed of nanocrystallites. Although hillocks for YIG and CaF₂ exhibit different crystallographic features, hillock diameter agrees with the molten region diameter predicted by the thermal spike model for both materials. It is found that for YIG the hillock diameter is comparable to the ion track diameter, whereas for the fluorides it is always larger than the ion track diameter. The present result shows the existence of the velocity effect for ion track diameter in CaF₂. It is also found that for fluorides both hillock and ion track diameters vary in the order of cation mass (i.e. CaF₂ < SrF₂ < BaF₂). The above results of hillocks and ion tracks for SHI-irradiated fluorides can be consistently interpreted within the framework of the thermal spike model, if melting and successive recrystallization are assumed.

Abstract P5-16-10: Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial

BACKGROUND and AIM:

Findings from a randomized phase 2 JONIE1 trial in women with HER2-negative early breast cancer have shown that the addition of zoledronic acid (ZOL) to neoadjuvant chemotherapy (CT) has potential anticancer benefits in postmenopausal and triple-negative breast cancer patients. We report the data for the prespecified secondary endpoint of disease-free survival (DFS).

METHODS:

We enrolled women with HER2-negative early breast cancer and randomly assigned them to receive CT or CT+ZOL (CTZ). All patients received 4 cycles of FEC100 (fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 500 mg/m2), followed by 12 cycles of paclitaxel at 80 mg/m2 weekly. ZOL (4 mg) was administered 3-4 times weekly for 7 weeks to the CTZ group patients. Definitive surgery was performed 3-4 weeks after the last paclitaxel dose. The primary endpoint was pathological complete response (pCR). The secondary endpoints were the clinical response rates, rate of breast-conserving surgery, safety, and DFS (defined as the time from randomization to disease occurrence or death). The trial is registered as UMIN000003261 (www.umin.ac.jp/english/) with ongoing follow-up.

FINDINGS:

Of the 188 patients enrolled, 95 were assigned to the CT group and 93 to the CTZ group. The mean (95% CI) DFS time of the CT group was 5.15 years (4.83-5.47) and that of the CTZ group was 5.38 years (5.11-5.66). The 3-year DFS rate was 84.6% (95% CI 77.2-92.0) in the CT group and 90.7% (84.6-96.8) in the CTZ group with no significant difference (p = 0.120). The particular benefit from ZOL for the neoadjuvant CT seen as improvement of the pCR rate was indicated in the 3-year DFS period for triple-negative cancer cases (CT vs CTZ: 70.6% vs 94.1%), but not for postmenopausal cases.

CONCLUSIONS:

ZOL slightly improved DFS when combined with CT. Although a significant difference was not found in this study, plans are underway for conducting a combined analysis of 3 neoadjuvant CT trials together with ZOL. The improvement of the pCR rate may be associated with DFS in triple-negative cases. Previous studies have shown that ZOL was more efficacious in an estrogen-suppressed condition. However, the short-term application of ZOL in this study may not be sufficient to improve the outcome in postmenopausal patients.

Citation Format: Ishikawa T, Akazawa K, Hasegawa Y, Tanino H, Horiguchi J, Miura D, Hayashi M, Takao S, Kim SJ, Yamagami K, Miyashita M, Konishi M, Shigeoka Y, Suzuki M, Taguchi T, Kubota T, Kohno N. Zoledronic acid combined with neoadjuvant chemotherapy for HER2-negative early breast cancer (JONIE 1 trial): Survival outcomes of a randomized multicenter phase 2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-10.

Prediction of time to delivery by transperineal ultrasound in second stage of labor

OBJECTIVE

To investigate whether the transperineal sonographic (TPS) parameters angle of progression (AoP) and midline angle (MLA) can predict the time remaining in the second stage of labor.

METHODS

We evaluated prospectively women with a singleton pregnancy in cephalic presentation at term between October 2013 and September 2014. TPS volumes were obtained immediately after confirmation by digital vaginal examination of a fully dilated cervix. AoP and MLA were measured offline by analyzing the ultrasound volumes. Progression of labor was evaluated every hour during the second stage. The associations of AoP and MLA with the interval between TPS assessment and delivery were evaluated using multivariable Cox proportional hazards analyses in nulliparous and parous women separately.

RESULTS

A total of 557 women were evaluated. An AoP ≥ 160° (adjusted hazard ratio (aHR), 2.52 (95% CI, 1.98-3.19)) and MLA ≤ 10° (aHR, 1.79 (95% CI, 1.35-2.34)) in nulliparous women and an AoP ≥ 150° (aHR, 1.86 (95% CI, 1.34-2.57)) and MLA ≤ 20° (aHR, 1.69 (95% CI, 1.21-2.34)) in parous women were significantly associated with the remaining time in labor. The positive/negative likelihood ratios of AoP, MLA, clinical station (fetal head descent as observed by digital examination) and clinical rotation (fetal head rotation as observed by digital examination) at these cut-off points were 3.6/0.6, 2.0/0.6, 1.6/0.6 and 1.6/0.8, respectively, in nulliparous women, and 2.4/0.6, 1.3/0.7, 7.6/0.5 and 5.2/0.7, respectively, in parous women.

CONCLUSION

TPS assessment of AoP and MLA in the second stage of labor was useful for predicting the time remaining in labor and had higher predictive value than did digital vaginal examination in nulliparous women. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

The prevalence and impact of chronic neuropathic pain on daily and social life: A nationwide study in a Japanese population

BACKGROUND

This study marks the first epidemiological evaluation of the prevalence and burden of chronic neuropathic pain (NeP) in an Asian population. The objective of this nationwide cross-sectional study was to identify the characteristics of individuals with NeP, detect the NeP features that affect their quality of life (QOL), and demonstrate the negative effects of NeP on social and daily living as well as comorbidities including depression, anxiety and sleep disorders.

METHODS

We mailed a cross-sectional, population-based epidemiological survey to a random nationwide sample of 10,000 Japanese adults over 20 years old.

RESULTS

The response rate was 54.4% (2445 men, 2992 women; mean age, 53.4 years). Prevalence of chronic pain was 16.6%, and prevalence of NeP was 3.2% as detected by the PainDETECT. Participants with NeP showed significantly lower quality of life according to scores on the EuroQol-5 Dimensions scale (p < 0.001), higher levels of psychological distress on the Kessler 6-item psychological distress scale (p < 0.001), poorer sleep quality (p < 0.001), and more workdays lost (p < 0.001) than did participants without NeP. Linear regression modelling showed that widespread pain, thermal hyperalgesia and pressure-induced pain had strong associations with lower QOL, with regression coefficients of -0.046 (p < 0.001), -0.038 (p < 0.001), and -0.040 (p < 0.001), respectively.

CONCLUSIONS

This study is the first to report the prevalence of NeP in an Asian population using a validated questionnaire. This study provides compelling evidence that chronic NeP is more strongly associated with poorer QOL, mental health and social well-being than CP without a neuropathic component.

SIGNIFICANCE

This population-based nationwide epidemiological study revealed the prevalence, characteristics, and negative effects of chronic pain with neuropathic components in Asian society. The prevalence of neuropathic pain was 3.2% with PainDETECT.

Enhanced sealing strength of a hydrophobically-modified Alaska pollock gelatin-based sealant

A novel tissue sealant composed of hydrophobically-modified Alaska pollock gelatin and polyethylene glycol-based crosslinker showed higher sealing effect than commercially available tissue sealant.

Local recurrence risk after previous salvage mastectomy

INTRODUCTION

Breast-conserving surgery is a standard treatment for early breast cancer. For ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery, salvage mastectomy is the current standard surgical procedure. However, it is not rare for patients with IBTR who have received salvage mastectomy to develop local recurrence. In this study, we examined the risk factors of local recurrence after salvage mastectomy for IBTR.

PATIENTS AND METHODS

A total of 118 consecutive patients who had histologically confirmed IBTR without distant metastases and underwent salvage mastectomy without irradiation for IBTR between 1989 and 2008 were included from eight institutions in Japan. The risk factors of local recurrence were assessed.

RESULTS

The median follow-up period from salvage mastectomy for IBTR was 4.6 years. Patients with pN2 or higher on diagnosis of the primary tumor showed significantly poorer local recurrence-free survival than those with pN0 or pN1 at primary tumor (p < 0.001). Multivariate analysis showed that the lymph node status of the primary tumor was a significantly independent predictive factor of local recurrence-free survival (p = 0.02).

CONCLUSION

The lymph node status of the primary tumor might be a predictive factor of local recurrence-free survival after salvage mastectomy for IBTR. Further research and validation studies are needed. (UMIN-CTR number UMIN000008136).

Abstract P3-07-50: Early and accurate prediction of pathological response by magnetic resonance imaging and ultrasonography in patients undergoing neoadjuvant chemotherapy for operable breast cancer

Background: Neoadjuvant chemotherapy (NAC) reduces tumor size, and increases the frequency of breast-conserving surgery in operable breast cancers. Response predictions to NAC are made based on diagnostic imaging.

Although various studies have reported the optimal timing for diagnostic imaging, this still remains unclear.

Purpose: To identify the optimal timing of diagnostic imaging for the response prediction to NAC, and to evaluate the accuracy of response prediction.

Methods: We evaluated 146 cases enrolled in the JONIE-1 study (a randomized controlled trial comparing zoledronic acid plus chemotherapy with chemotherapy alone as a NAC in patients with HER2-negative primary breast cancer). The chemotherapy regimen was FEC100×4 courses followed by weekly paclitaxel 80×12 courses (± zoledronic acid). Statistical analysis of the association between the tumor reduction ratio and the histopathological response and the prediction of pathological complete response (pCR) was performed using JMP software. The maximum tumor diameter was evaluated using magnetic resonance imaging and ultrasound on each patient 3 times (before NAC, after FEC treatment, after NAC) and tumor reduction ratios were calculated.

Results: The average age of the patients was 49.8 years old. The menopause status was pre-menopause in 84 patients, and post-menopause in 58 patients. Regarding the subtype classification, 116 patients were of the luminal type (Lum) and 26 patients were triple negative (TN), and the Ki-67 labeling index had a median of 25% (1%-93%).

Pathological examination demonstrated that 16 patients had pCR(11.3%, Lum, 9;TN: 7), and 126 patients had non-pCR (88.7%, Lum:107; TN:19). Seven patients had clinical-CR (4.8%, Lum: 4; TN: 3) at post-FEC, and 26 patients (17.8%, Lum: 20; TN: 6) at post-NAC. The prediction of pCR at post-FEC and post-NAC was evaluated by single variable analysis, resulting in an AUC (0.75645) p=0.0017 at post-FEC, and AUC (0.76563) p=0.0001 at post-NAC. The sensitivity / specificity / positive predictive value / negative predictive value were 0.625 / 0.873 / 0.385 / 0.948 at post-FEC, 0.250 / 0.976 / 0.571 / 0.911 at post-NAC, respectively. In TN cases, the values were 0.714 / 0.947 / 0.833 / 0.900 in post-FEC, and 0.429 / 1.000 / 1.000 / 0.826 in post-NAC.

Conclusions: Diagnostic imaging evaluation performed after FEC treatment was useful for the prediction of pCR. Furthermore, the reliability was high in Triple Negative Sub type, but is affected by the existence of residual tumors in Luminal type.

Citation Format: Kaise H, Ishikawa T, Miura D, Hasegawa Y, Horiguchi J, Hayashi M, Takao S, Kim SJ, Tanino H, Miyashita M, Konishi M, Shigeoka Y, Yamagami K, Suzuki M, Taguchi T, Akazawa K, Kohno N. Early and accurate prediction of pathological response by magnetic resonance imaging and ultrasonography in patients undergoing neoadjuvant chemotherapy for operable breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-50.

Characteristics of C6-7 myelopathy: assessment of clinical symptoms and electrophysiological findings

STUDY DESIGN

This is a single-center retrospective study.

OBJECTIVES

The objective of this study was to study the clinical symptoms and electrophysiological features of C6-7 myelopathy.

SETTING

This study was conducted at the Department of Orthopedic surgery, Yamaguchi University Graduate school of medicine, Japan.

METHODS

A total of 20 patients with cervical compressive myelopathy were determined by spinal cord-evoked potentials or a single level of obvious magnetic resonance imaging (MRI)-documented cervical spinal cord compression. Neurological examinations included manual muscle testing and investigation of deep tendon reflex, including Hoffmann sign, and of sensory disturbance areas. Motor-evoked potentials (MEPs), compound muscle action potentials (CMAPs) and F-wave were recorded from bilateral abductor digit minim and abductor halluces muscles. Central motor conduction time was calculated as follows: MEPs latency-(CMAPs latency+F latency-1)/2 (ms).

RESULTS

Eighteen patients (90%) had negative Hoffmann sign. Eight patients (40%) had no sensory disturbance in the upper limbs and 8 patients (40%) had no muscle weakness in the upper limbs. We determined that patients had cervical myelopathy when their central motor conduction time measured in abductor digit minim was longer than 6.76 ms (+2 s.d.). Using this definition, the sensitivity for myelopathy was 42.8%.

CONCLUSION

Patients with C6-7 myelopathy may lack clinical symptoms in their hands and central motor conduction time measured in abductor digit minim tended to be less prolonged, and it only showed symptoms in their lower limbs as gait disturbance. Surgeons should bear in mind the possibility of disorders of caudal C6-7 when they encounter patients with no or few symptoms in their hands and with leg weakness or numbness.

Experimental evidence of crystalline hillocks created by irradiation of CeO₂ with swift heavy ions: TEM study

In this study, CeO2 was irradiated with 200 MeV Au ions at oblique incidence. Observation of as-irradiated samples by transmission electron microscopy (TEM) shows that hillocks are created not only at the wide surfaces, but also at the crack faces of the thin samples. Since the hillocks created at the crack faces can be imaged by TEM, their shape and crystallographic features can be revealed. From the images of hillocks created at the crack faces, many of the hillocks are found to be spherical. We present the first experimental evidence that hillocks created for CeO2 irradiated with swift heavy ions have a crystal structure whose lattice spacing and orientation coincide with those of the matrix. The mechanism of spherical crystalline hillock formation is discussed based on the present results.

Aggravating factor in lupus nephritis; electron microscopic observation

47 renal biopsies from 36 patients with SLE were examined in detail to compare with clinical courses and ultrastructural findings. Of 36 patients, 8 cases were free from renal involvement. The severity of electron dense deposits in glomeruli with lupus nephritis were generally well correlated with each clinical feature obtained. Moreover, mesangiocapillary cell proliferation was considered to be the main morphological promoting factor in poor prognosis of the lupus nephritis. Prominent circumferential subendothelial dense deposits were suggested to enhance to enhance the proliferation of mesangial cells, mostly with a mode of circumferential interposition. In each deposit with lapse of time and/or treatments, subepithelial deposits were gradually degraded to granular material but not lucent, though most subendothelial deposits rapidly disappeared without any remnant structure or with only a few flocculent materials. Mesangial deposits were mostly stabilized and rarely turned membranous.

A high incidence of WT1 abnormality in bilateral Wilms tumours in Japan, and the penetrance rates in children with WT1 germline mutation

Background:

Bilateral Wilms tumours (BWTs) occur by germline mutation of various predisposing genes; one of which is WT1 whose abnormality was reported in 17–38% of BWTs in Caucasians, whereas no such studies have been conducted in East-Asians. Carriers with WT1 mutations are increasing because of improved survival.

Methods:

Statuses of WT1 and IGF2 were examined in 45 BWTs from 31 patients with WT1 sequencing and SNP array-based genomic analyses. The penetrance rates were estimated in WT1-mutant familial Wilms tumours collected from the present and previous studies.

Results:

We detected WT1 abnormalities in 25 (81%) of 31 patients and two families, which were included in the penetrance rate analysis of familial Wilms tumour. Of 35 BWTs from the 25 patients, 31 had small homozygous WT1 mutations and uniparental disomy of IGF2, while 4 had large 11p13 deletions with the retention of 11p heterozygosity. The penetrance rate was 100% if children inherited small WT1 mutations from their fathers, and 67% if inherited the mutations from their mothers, or inherited or had de novo 11p13 deletions irrespective of parental origin (P=0.057).

Conclusions:

The high incidence of WT1 abnormalities in Japanese BWTs sharply contrasts with the lower incidence in Caucasian counterparts, and the penetrance rates should be clarified for genetic counselling of survivors with WT1 mutations.

Change in estrogen receptor, HER2, and Ki-67 status between primary breast cancer and ipsilateral breast cancer tumor recurrence

INTRODUCTION

Changes in the biological marker status between primary and recurrent tumors are observed in breast cancer. However, their clinical significance is still uncertain, especially for patients with ipsilateral breast tumor recurrence (IBTR) after breast-conserving surgery.

PATIENTS AND METHODS

A total of 117 patients with IBTR without distant metastases were enrolled in this study. All patients were examined for estrogen receptor (ER), HER2, and Ki-67 in both the primary tumors and paired IBTR. We evaluated the impact of changes in these biomarkers between primary tumors and IBTR on the prognosis after IBTR.

RESULTS

There were no associations of changes in the ER, HER2 status with distant disease-free survival (DDFS) after surgical resection of IBTR, whereas the change in the Ki-67 status between the primary tumors and IBTR was significantly correlated with DDFS (unadjusted: p = 0.0094; adjusted: p = 0.013). Patients in the "increased or remained high" Ki-67 group had a significantly shorter DDFS than those in the "decreased or remained low" Ki-67 group (5-year DDFS: 55.5 vs. 79.3%, respectively, p = 0.0084 by log-rank test).

CONCLUSION

An increased or persistently high Ki-67 status in the IBTR was significantly correlated with a poorer prognosis after IBTR.

Clinical characteristics of monochorionic twins with large hemoglobin level discordance at birth

OBJECTIVES

To evaluate neonatal outcomes and clinical characteristics of monochorionic diamniotic (MCDA) twins with a large intertwin hemoglobin (Hb) difference at birth.

METHODS

This was a retrospective cohort study of MCDA twin gestations delivered at Osaka Medical Center and Research Institute for Maternal and Child Health between 2003 and 2012. Cases of pregnancy termination, acardiac twins or intrauterine death were excluded. A large intertwin Hb difference at birth was defined as > 8.0 g/dL according to the postnatal criteria for twin anemia-polycythemia sequence (TAPS). The intertwin reticulocyte count ratio (RCR) was calculated by dividing the reticulocyte count of the anemic twin by that of the polycythemic twin. Cases with Hb differences were divided into two groups according to the RCR, TAPS when the RCR was > 1.7 and acute fetofetal hemorrhage (AFFH) when the RCR was ≤ 1.7. Neonatal outcomes were compared between the TAPS and AFFH groups.

RESULTS

During the study period, 432 MCDA twin pregnancies of a total of 532 born at our hospital were analyzed. There were 12 (2.8%) cases of a large intertwin Hb difference. The median gestational age at birth of these cases was 34 (range, 23-38) weeks, and all were delivered by Cesarean section. There were seven (1.6%) cases of TAPS and five (1.2%) of AFFH. The neonatal survival rate was 91.7%; in one pair of twins with TAPS neonatal death occurred. All (100%) cases with TAPS and two (40%) with AFFH required blood transfusion or partial-exchange transfusion for at least one infant.

CONCLUSIONS

Although the incidence of TAPS and AFFH may be low in MCDA twins, many affected neonates required treatment for hematological abnormalities. Delivery of MCDA twins via Cesarean section does not appear to prevent AFFH, despite the absence of labor.

Utilizing stomach content and faecal DNA analysis techniques to assess the feeding behaviour of largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus

In this study, the feeding behaviour of the non-native invasive predatory fishes largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus was studied in the Ezura River, a northern tributary of Lake Biwa, Japan. Prey composition was estimated based on visual examination of stomach contents and faecal DNA analysis to determine feeding habits of these predatory fishes. Stomach content analysis showed that native fishes (e.g. ayu Plecoglossus altivelis and gobies Rhinogobius spp.) and shrimps (e.g. Palaemon paucidens) were the major prey items for M. salmoides, while snails, larval Chironomidae and submerged macrophytes were the dominant prey items of L. macrochirus. Micropterus salmoides tended to select larger fish in the case of crucian carp Carassius spp., but smaller fishes in the case of P. altivelis and Rhinogobius spp. Faecal DNA analyses revealed prey compositions similar to those identified in predator stomach contents, and identified additional prey species not detected in stomach content inspection. This study demonstrated that both stomach content inspection and DNA-based analysis bear several inherent shortcomings and advantages. The former method is straightforward, although identification of species can be inaccurate or impossible, whereas the latter method allows for accurate species identification, but cannot distinguish prey size or stage. Hence, integration of morphology-based and DNA-based methods can provide more reliable estimates of foraging habits of predatory fishes.