Laser-Induced Axotomy of Human iPSC-Derived and Murine Primary Neurons Decreases Somatic Tau and AT8 Tau Phosphorylation: A Single-Cell Approach to Study Effects of Acute Axonal Damage

The microtubule-associated protein Tau is highly enriched in axons of brain neurons where it regulates axonal outgrowth, plasticity, and transport. Efficient axonal Tau sorting is critical since somatodendritic Tau missorting is a major hallmark of Alzheimer's disease and other tauopathies. However, the molecular mechanisms of axonal Tau sorting are still not fully understood. In this study, we aimed to unravel to which extent anterograde protein transport contributes to axonal Tau sorting. We developed a laser-based axotomy approach with single-cell resolution and combined it with spinning disk confocal microscopy enabling multi live-cell monitoring. We cultivated human iPSC-derived cortical neurons and mouse primary forebrain neurons in specialized chambers allowing reliable post-fixation identification and Tau analysis. Using this approach, we achieved high post-axotomy survival rates and observed axonal regrowth in a subset of neurons. When we assessed somatic missorting and phosphorylation levels of endogenous human or murine Tau at different time points after axotomy, we surprisingly did not observe somatic Tau accumulation or hyperphosphorylation, regardless of their regrowing activity, consistent for both models. These results indicate that impairment of anterograde transit of Tau protein and acute axonal damage may not play a role for the development of somatic Tau pathology. In sum, we developed a laser-based axotomy model suitable for studying the impact of different Tau sorting mechanisms in a highly controllable and reproducible setting, and we provide evidence that acute axon loss does not induce somatic Tau accumulation and AT8 Tau phosphorylation. UV laser-induced axotomy of human iPSC-derived and mouse primary neurons results in decreased somatic levels of endogenous Tau and AT8 Tau phosphorylation.

Understanding the relationship between patient language and outcomes in internet-enabled cognitive behavioural therapy: A deep learning approach to automatic coding of session transcripts

Objective: Understanding patient responses to psychotherapy is important in developing effective interventions. However, coding patient language is a resource-intensive exercise and difficult to perform at scale. Our aim was to develop a deep learning model to automatically identify patient utterances during text-based internet-enabled Cognitive Behavioural Therapy and to determine the association between utterances and clinical outcomes. Method: Using 340 manually annotated transcripts we trained a deep learning model to categorize patient utterances into one or more of five categories. The model was used to automatically code patient utterances from our entire data set of transcripts (∼34,000 patients), and logistic regression analyses used to determine the association between both reliable improvement and engagement, and patient responses. Results: Our model reached human-level agreement on three of the five patient categories. Regression analyses revealed that increased counter change-talk (movement away from change) was associated with lower odds of both reliable improvement and engagement, while increased change-talk (movement towards change or self-exploration) was associated with increased odds of improvement and engagement. Conclusions: Deep learning provides an effective means of automatically coding patient utterances at scale. This approach enables the development of a data-driven understanding of the relationship between therapist and patient during therapy.

Development of AC2 for the simulation of advanced reactor design of Generation 3/3+ and light water cooled SMRs

The transition from Generation 2 to Generation 3/3+ and 4 reactors, as well as the development of small modular reactors (SMR), place new demands on computational programs designed to simulate conditions of normal operation, operational occurrences, design basis accidents and severe accidents. On the one hand, most passive safety systems of advanced and innovative plants operate at low pressures even down to vacuum conditions and the driving forces are low compared to active systems. On the other hand, the containment is no longer just a barrier to retain radioactive material in the event of leakage of the cooling system, but it is an important link in the passive cooling chain. This requires an expansion and improvement of the existing simulation programs for the cooling circuit and containment, as well as the realization of a coupling between these simulation programs. The new AC2 program package combines the proven simulation codes ATHLET/ATHLET-CD and COCOSYS in one software suite to hit this target. The individual components of the suite are continuously extended and validated for their application to novel safety systems. This makes it possible to simulate the entire spectrum of accidents for Generation 3/3+, 4 and light water cooled SMR systems with just one program package. This publication gives an overview of the current state of development of AC2 and its individual modules.

Validation of the AC2 Codes ATHLET and ATHLET-CD

Verification and validation are basic quality assurance elements in code development and essential for code release. Therefore, the codes of AC2 (ATHLET – ATHLET-CD – COCOSYS) are tested on separate effect tests, integral tests as well as plant scenarios to verify and validate the models after new implementation or updates. The verification assures that the models are implemented and working correctly while the validation checks if the models predict the right phenomena and combined with other models and modules. The selected experiments are summarized in GRS's validation matrices, which in turn are based on the CSNI validation matrices derived from OECD/WGAMA task groups as well as current activities on experimental test campaigns. For ATHLET several test series are used to cover a wide range of phenomena which can occur in PWR, BWR and VVER. Additionally, plant transients are considered for German LWR. The ATHLET-CD validation matrix contains experiments covering most phenomena which can occur during a severe accident. But due to the interaction of several effects even in small scale experiments mainly integral experimental campaigns are used for the validation. Over the last decades the validation of the AC2 codeds ATHLET and ATHLET-CD has reached a high degree of fulfilment of GRS's validation matrices over all code versions. Innovative and advanced reactor concepts come with new or newly relevant phenomena, which AC2 needs to provide models for. Extending the validation base of AC2 for these models is one challenge for further code validation efforts besides the on-going update of the validation basis to recent code versions.

Necessary improvements of the GRS simulation chain for the simulation of light-water-cooled SMRs

Small modular reactors (SMRs) are one interesting option for new builds in almost all countries worldwide continuing to use nuclear energy for commercial power generation. For asserting of legitimate nuclear safety and/or security interests German authorities require in this context own and independent expertise for the safety assessments. The Gesellschaft für Anlagen und Reaktorsicherheit (GRS) mbH, which is the main technical support organization in nuclear safety for the German federal government, has among others performed a study on Safety and International development of Small Modular Reactors (GRS-376) to identify essential issues of SMR safety as well as needs for adaption, improvement and validation of nuclear evidence tools developed and applied by GRS. For the light-water-cooled SMRs, which have (at least according to GRS) the best prospects for realization, selected results of this study will be presented.

Abstract GS4-03: Randomized comparison of adjuvant tamoxifen (T) plus ovarian function suppression (OFS) versus tamoxifen in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): Update of the SOFT trial

Background: The primary results of SOFT at 5.6 years median follow-up found adding OFS to T did not provide a significant benefit in the overall study population of premenopausal women with HR+ BC (Francis et al, NEJM 2015). For those women at sufficient risk for recurrence to warrant adjuvant chemotherapy (CT) and who remained premenopausal, the addition of OFS improved disease outcomes. Follow-up was immature for overall survival (OS). We report a planned update with visit cut-off of 31Dec16 after 8 yrs median follow-up.

Methods: SOFT randomized premenopausal women with HR+ BC from Nov 2003 to Jan 2011 to 5 yrs of T vs T+OFS vs Exemestane(E)+OFS. OFS was by choice of GnRH agonist triptorelin, oophorectomy or ovarian irradiation. SOFT was stratified by the use of prior CT; 47% received no CT and 53% remained premenopausal after prior CT, determined by premenopausal estradiol level within 8 months of CT completion. The primary endpoint was invasive disease-free survival (DFS; randomization until invasive local, regional, distant recurrence or contralateral breast; invasive second malignancy; death). Secondary endpoints included invasive breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI) and OS. NCT00066690.

Results: DFS for patients assigned T+OFS (n=1015) was significantly improved over T (n=1018; HR=0.76 [95%CI 0.62-0.93]) and 8yr DFS was 83.2% vs 78.9%, respectively; BCFI and DRFI results were supportive (see Table). Hazard ratios for these 3 endpoints showed no heterogeneity by use of prior CT. For patients with prior CT, 8yr DFS was 76.7% with T+OFS vs 71.4% with T (Δ=5.3%); in those without CT, 8yr DFS was 90.6% vs 87.4% (Δ=3.2%). E+OFS (n=1014) improved outcomes relative to T (Table); 8yr DFS for E+OFS was 85.9% (80.4% with use of prior CT and 92.5% for those without CT). OS was improved with T+OFS vs T (8yr OS 93.3% vs 91.5%). 8yr OS was 92.1% with E+OFS. 201/225 deaths occurred in women with prior CT. For women without CT there have been 10, 5 and 9 deaths in the T+OFS, T and E+OFS groups (total n=1419), respectively, only half of these deaths after breast cancer event.

N. EventsHazard Ratio (95% CI)Endpoint(3 arms)T+OFS vs TE+OFS vs TDFS5180.76 (0.62-0.93) P=0.0090.65 (0.53-0.81)BCFI4370.76 (0.61-0.95)0.64 (0.51-0.81)DRFI3060.86 (0.66-1.13)0.73 (0.55-0.96)OS2250.67 (0.48-0.92)0.85 (0.62-1.15)

Overall toxicity was worse with T+ OFS than with T, including 32% vs 25% grade 3+ targeted AEs. Early cessation of tamoxifen occurred for 19% assigned T+OFS and 22% of women assigned T; the cumulative incidence of early cessation of triptorelin on the T+OFS arm was 23% by 4yrs. Early cessation of exemestane occurred for 28% and of triptorelin for 21% by 4yrs on the E+OFS arm.

Conclusions: With additional follow-up to a median of 8yrs, SOFT further supports the value of OFS for some premenopausal women. Follow-up continues, which will further clarify the safety and the benefit of OFS for late recurrence and overall survival. Oncologists appear to be able to select a low risk group (no chemotherapy) for whom treatment escalation is unlikely to improve survival.

Citation Format: Fleming G, Francis PA, Láng I, Ciruelos EM, Bellet M, Bonnefoi HR, Climent MA, Pavesi L, Burstein HJ, Martino S, Davidson NE, Geyer Jr CE, Walley BA, Coleman RE, Kerbrat P, Buchholz S, Ingle JN, Rabaglio-Poretti M, Colleoni M, Regan MM. Randomized comparison of adjuvant tamoxifen (T) plus ovarian function suppression (OFS) versus tamoxifen in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): Update of the SOFT trial [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 GS4-03.

System code improvements for modelling passive safety systems and their validation

GRS has been developing the system code ATHLET over many years. Because ATHLET, among other codes, is widely used in nuclear licensing and supervisory procedures, it has to represent the current state of science and technology. New reactor concepts such as Generation III+ and IV reactors and SMR are using passive safety systems intensively. The simulation of passive safety systems with the GRS system code ATHLET is still a big challenge, because of non-defined operation points and self-setting operation conditions. Additionally, the driving forces of passive safety systems are smaller and uncertainties of parameters have a larger impact than for active systems. This paper addresses the code validation and qualification work of ATHLET on the example of slightly inclined horizontal heat exchangers, which are e. g. used as emergency condensers (e. g. in the KERENA and the CAREM) or as heat exchanger in the passive auxiliary feed water systems (PAFS) of the APR+.

Effects of morcellation on long-term outcomes in patients with uterine leiomyosarcoma

OBJECTIVES

Clinical long-term outcomes of women with uterine leiomyosarcoma (ULMS) with different types of hysterectomy (open abdominal, vaginal, laparoscopic and switch from laparoscopic to open abdominal) were compared according to morcellation and other factors.

MATERIALS

The clinical cancer registry Regensburg (Germany) registered 64 patients between 2004 and 2013 with ULMS. A retrospective cohort analysis was performed using the Kaplan-Meier method to estimate 5-year overall survival (OAS), recurrence-free survival (RFS) and recurrence rates. To compare surgery with or without morcellation log rank test was used. To adjust for age, FIGO stage, grading and other factors multivariable Cox regression models were applied to estimate hazard ratios (HR).

RESULTS

In the cohort of 64 patients 15 underwent morcellation, preferably during laparoscopic surgery. Although numbers were small we performed analysis for OAS and RFS. Median OAS for morcellation was 10.6 vs. 6.4 years for non morcellation. 5y-OAS was 76.0 % for morcellation compared to 54.8 % in patients without morcellation (p = 0.115). Cox regression models rendered an unadjusted (univariable) HR 0.428 for morcellation vs. non-morcellation (p = 0.125) and an adjusted (multivariable) HR 0.644 (p = 0.406). 5y-RFR was 64.0 % compared to 42.8 % in patients without morcellation (p = 0.104; unadjusted HR 0.484, p = 0.111; adjusted HR 0.607, p = 0.306).

CONCLUSION

In general, the prognosis of patients with ULMS is poor. In our cohort, women who underwent hysterectomy with morcellation had a better cumulative OAS and RFS than women without morcellation. Although we adjusted for differences between women with and without morcellation regarding age, grading and stage, there were no statistically significant differences between the groups.