John J, Strauss T, Szelc AM, Tagg N, Terao K, Thomson M, Toups M, Tsai YT, Tufanli S, Usher T, Van De Pontseele W, Van de Water RG, Viren B, Weber M, Wickremasinghe DA, Wolbers S, Wongjirad T, Woodruff K, Yang T, Yates L, Zeller GP, Zennamo J, Zhang C. The Pandora multi-algorithm approach to automated pattern recognition of cosmic-ray muon and neutrino events in the MicroBooNE detector

The development and operation of liquid-argon time-projection chambers for neutrino physics has created a need for new approaches to pattern recognition in order to fully exploit the imaging capabilities offered by this technology. Whereas the human brain can excel at identifying features in the recorded events, it is a significant challenge to develop an automated, algorithmic solution. The Pandora Software Development Kit provides functionality to aid the design and implementation of pattern-recognition algorithms. It promotes the use of a multi-algorithm approach to pattern recognition, in which individual algorithms each address a specific task in a particular topology. Many tens of algorithms then carefully build up a picture of the event and, together, provide a robust automated pattern-recognition solution. This paper describes details of the chain of over one hundred Pandora algorithms and tools used to reconstruct cosmic-ray muon and neutrino events in the MicroBooNE detector. Metrics that assess the current pattern-recognition performance are presented for simulated MicroBooNE events, using a selection of final-state event topologies.

The risk of cardiac failure following metal-on-metal hip arthroplasty

AIMS

The aim of this study was to determine whether patients with metal-on-metal (MoM) arthroplasties of the hip have an increased risk of cardiac failure compared with those with alternative types of arthroplasties (non-MoM).

PATIENTS AND METHODS

A linkage study between the National Joint Registry, Hospital Episodes Statistics and records of the Office for National Statistics on deaths was undertaken. Patients who underwent elective total hip arthroplasty between January 2003 and December 2014 with no past history of cardiac failure were included and stratified as having either a MoM (n = 53 529) or a non-MoM (n = 482 247) arthroplasty. The primary outcome measure was the time to an admission to hospital for cardiac failure or death. Analysis was carried out using data from all patients and from those matched by propensity score.

RESULTS

The risk of cardiac failure was lower in the MoM cohort compared with the non-MoM cohort (adjusted hazard ratio (aHR) 0.901; 95% confidence interval (CI) 0.853 to 0.953). The risk of cardiac failure was similar following matching (aHR 0.909; 95% CI 0.838 to 0.987) and the findings were consistent in subgroup analysis.

CONCLUSION

The risk of cardiac failure following total hip arthroplasty was not increased in those in whom MoM implants were used, compared with those in whom other types of prostheses were used, in the first seven years after surgery. Cite this article: Bone Joint J 2018;100-B:20-7.

Quantum-mechanical analysis of effect of alloying elements on ε-martensite start temperature of steels

With regard to the transformation mechanism of austenitic high manganese steel, the prediction of the ε-martensite start temperature is a critical consideration in alloy design. Evaluation of the ε-martensite start temperature makes it possible to predict the microstructure and to understand the phase transformation occurring during deformation. Here we use the quantum mechanical calculation of random alloys to understand the physics for ε-martensitic transformation in steels. We could find the linear relationship between the measured ε-martensite start temperatures and the crystal structure stability for various compositions. We also could estimate the effect of several alloying elements. It is expected that the effect of decreasing the temperatures for the same amount of alloying elements addition will be larger moving farther from Group VIII. By creating a free-energy model that reflects the temperature effect, we were able to calculate the average driving force required for the ε-martensitic transformations.

Risk Factor Analysis of Recanalization Timing in Coiled Aneurysms: Early versus Late Recanalization

BACKGROUND AND PURPOSE

Long-term documentation of anatomic and angiographic characteristics pertaining to the timing of recanalization in coiled aneurysms has been insufficient. Our intent was to analyze and compare early and late-phase recanalization after coiling, identifying respective risk factors.

MATERIALS AND METHODS

A total of 870 coiled saccular aneurysms were monitored for extended periods (mean, 30.8 ± 8.3 months). Medical records and radiologic data were also reviewed, stratifying patients as either early (n = 128) or late (n = 52) recanalization or as complete occlusion (n = 690). Early recanalization was equated with confirmed recanalization within 6 months after the procedure, whereas late recanalization was defined as verifiable recanalization after imaging confirmation of complete occlusion at 6 months. A multinomial regression model served to assess potential risk factors, the reference point being early recanalization.

RESULTS

Posterior circulation (P = .009), subarachnoid hemorrhage at presentation (P = .011), second attempt for recanalized aneurysm (P < .001), and aneurysm size >7 mm (P < .001) emerged as variables significantly linked with early recanalization (versus complete occlusion). Late (versus early) recanalization corresponded with aneurysms ≤7 mm (P = .013), and in a separate subanalysis of lesions ≤7 mm, aneurysms 4-7 mm showed a significant predilection for late recanalization (P = .008). However, the propensity for complete occlusion in smaller lesions (≤7 mm) increased as the size diminished.

CONCLUSIONS

Although long-term complete occlusion after coiling was more likely in aneurysms ≤7 mm, such lesions were more prone to late (versus early) recanalization, particularly those of 4-7 mm in size. Long-term follow-up imaging is thus appropriate in aneurysms >4 mm to detect late recanalization of those formerly demonstrating complete occlusion.

Abstract AP30: PHASE IB/II WITH EXPANSION OF PATIENTS AT THE MTD STUDY OF OLAPARIB PLUS WEEKLY (METRONOMIC) CARBOPLATIN AND PACLITAXEL IN RELAPSED OVARIAN CANCER PATIENTS

BACKGROUND: We established the olaparib tablet maximum tolerated dose (MTD) at 150 mg bid, dose limiting toxicities (DLT's) and response to therapy or carboplatin, paclitaxel and olaparib tablet given simultaneously, reported at ASCO 2014. This abstract will include data from both the phase 1b and the phase 2 expansion.

METHODS: A total of 54 subjects were evaluated in this trial, 14 in phase 1b and 40 in phase 2. Eligibility required measurable disease, adequate organ function and ECOG performance status of ~ 2. Subjects had to have failed first line platinum containing chemotherapy. BRCA testing was conducted as available. Subjects received the metronomic therapy of paclitaxel 60mg/m2 IV and carboplatin AUC 2 IV weekly, 3 weeks out of 4, and olaparib tablets at 150 mg bid administered orally for 3 consecutive days (D1-D3) every week for each cycle. Subjects were assessed for toxicity and response according to the protocol. Subjects that reached a confirmed complete remission were transitioned to olaparib tablets only, 300 mg bid until disease progression.

RESULTS: Median age was 58 and median number of prior regimens was 4. There have been no deaths due to the study regimen. One patient had grade 4 neutropenia and an allergic reaction to carboplatin. The common grade 3/4 toxicities were caused by the chemotherapy (neutropenia. anemia and thrombocytopenia). Two patients had mild GI toxicities. One patient had a skin rash. There was no evidence of cardiac, hepatic, or pulmonary toxicities in any of these patients. 25% of subjects had a complete remission (CR), 31% had PR, 23% had SD and 21% had

PD. Of the 13 CRs, 4 were BRCA negative. PFS median for BRCA positive subjects is 12.6 months vs 4.8 months for BRCA negative subjects. OS median for BRCA positive subjects is 24 months vs 16 months for BRCA negative subjects. All of the CR's are alive.

CONCLUSION: Olaparib tablet can be safely administered simultaneously with a weekly regimen of carboplatin and paclitaxel in heavily pretreated ovarian cancer patients. Olaparib appears to be highly effective in BRCA positive subjects. This is the first successful combination of olaparib tablets with carboplatin and paclitaxel that has been well tolerated.

Citation Format: Rivkin SE, Moon J, Iriarte D, Sloan H, Wiseman C, Klee M, Ference K, Drescher C, Veljovich D, Bondurant A, Peters W, Jiang P, Goodman G, Park M, Fer M, Shah C, Johnston E, Kaplan H, Wahl T, Ellis E. PHASE IB/II WITH EXPANSION OF PATIENTS AT THE MTD STUDY OF OLAPARIB PLUS WEEKLY (METRONOMIC) CARBOPLATIN AND PACLITAXEL IN RELAPSED OVARIAN CANCER PATIENTS [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP30.

29 POSITRON EMISSION TOMOGRAPHY IMAGING OF BRAIN METABOLISM AND DOPAMINERGIC NEURON DESTRUCTION IN PARKINSON&apos;S DISEASE MODEL PIG

Due to similarities between human and porcine, pigs have been proposed as an excellent experimental animal for human medical research. Especially in paediatric brain research, piglets share similarities with human infants in the extent of peak brain growth at the time of birth and the growth pattern of brain. Thus, these findings have supported the wider use of pigs rather than rodents in neuroscience research. Previously, we reported the production of porcine model of Parkinson's disease (PD) by nuclear transfer using donor cell that had been stably infected with lentivirus containing the human α-synuclein gene. The purpose of this study was to determine the alternation of brain metabolism and dopaminergic neuron destruction using noninvasive method in a 2-yr-old PD model and a control pig. The positron emission tomography (PET) scan was done using Biograph TruePoint40 with a TrueV (Siemens, Munich, Germany). The [18F]N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-iodophenyl) nortropane (FP-CIT) was administrated via the ear vein. Static images of the brain for 15 min were acquired from 2 h after injection. The 18F-fluorodeoxy-D-glucose PET (18F-FDG PET) images of the brain were obtained for 15 min at 45 min post-injection. Computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed at the same location of the brain. In both MRI and CT images, there was no difference in brain regions between PD model and control pigs. However, administration of [18F]FP-CIT was markedly decreased in the bilateral putamen of the PD model pig compared with the control pigs. Moreover, [18F]FP-CIT administration was asymmetrical in the PD model pig but it was symmetrical in control pigs. Regional brain metabolism was also assessed and there was no significant difference in cortical metabolism of PD model and control pigs. We demonstrated that PET imaging could provide a foundation for translational Parkinson neuroimaging in transgenic pigs. In the present study, a 2-yr-old PD model pig showed dopaminergic neuron destruction in brain regions. Therefore, PD model pig expressing human α-synuclein gene would be an efficient model for human PD patients. This study was supported by Korea IPET (#311011–05–5-SB010), Research Institute for Veterinary Science, TS Corporation and the BK21 plus program.