Systems toxicology meta-analysis of in vitro assessment studies: biological impact of a candidate modified-risk tobacco product aerosol compared with cigarette smoke on human organotypic cultures of the aerodigestive tract

Systems biology combines comprehensive molecular analyses with quantitative modeling to understand the characteristics of a biological system as a whole. Leveraging a similar approach, systems toxicology aims to decipher complex biological responses following exposures. This work reports a systems toxicology meta-analysis in the context of in vitro assessment of a candidate modified-risk tobacco product (MRTP) using three human organotypic cultures of the aerodigestive tract (buccal, bronchial, and nasal epithelia). Complementing a series of functional measures, a causal network enrichment analysis of transcriptomic data was used to compare quantitatively the biological impact of aerosol from the Tobacco Heating System (THS) 2.2, a candidate MRTP, with 3R4F cigarette smoke (CS) at similar nicotine concentrations. Lower toxicity was observed in all cultures following exposure to THS2.2 aerosol compared with 3R4F CS. Because of their morphological differences, a smaller exposure impact was observed in the buccal (stratified epithelium) compared with the bronchial and nasal (pseudostratified epithelium). However, the causal network enrichment approach supported a similar mechanistic impact of CS across the three cultures, including the impact on xenobiotic, oxidative stress, and inflammatory responses. At comparable nicotine concentrations, THS2.2 aerosol elicited reduced and more transient effects on these processes. To demonstrate the benefits of additional data modalities, we employed a newly established targeted mass-spectrometry marker panel to further confirm the reduced cellular stress responses elicited by THS2.2 aerosol compared with 3R4F CS in the nasal culture. Overall, this work demonstrates the applicability and robustness of the systems toxicology approach for in vitro inhalation toxicity assessment.

Spin caloritronic nano-oscillator

Energy loss due to ohmic heating is a major bottleneck limiting down-scaling and speed of nano-electronic devices, and harvesting ohmic heat for signal processing is a major challenge in modern electronics. Here, we demonstrate that thermal gradients arising from ohmic heating can be utilized for excitation of coherent auto-oscillations of magnetization and for generation of tunable microwave signals. The heat-driven dynamics is observed in Y₃Fe₅O₁₂/Pt bilayer nanowires where ohmic heating of the Pt layer results in injection of pure spin current into the Y₃Fe₅O₁₂ layer. This leads to excitation of auto-oscillations of the Y₃Fe₅O₁₂ magnetization and generation of coherent microwave radiation. Our work paves the way towards spin caloritronic devices for microwave and magnonic applications.

Harvesting ohmic heat for signal processing is one of major challenges in modern electronics and spin caloritronics, but not yet well accomplished. Here the authors demonstrate a spin torque oscillator device driven by pure spin current arising from thermal gradient across an Y₃Fe₅O₁₂/Pt interface.

Pretreatment ADC Values Predict Response to Radiosurgery in Vestibular Schwannomas

BACKGROUND AND PURPOSE

The response rate of vestibular schwannomas to radiation therapy is variable, and there are surgical options available in the event of treatment failure. The aim of this study was to determine whether pre- and posttreatment ADC values can predict the tumor response to radiation therapy.

MATERIALS AND METHODS

From a data base of 162 patients with vestibular schwannomas who underwent radiation therapy with gamma knife, CyberKnife, or fractionated stereotactic radiation therapy as the first-line therapy between January 2003 and December 2013, we found 20 patients who had pretreatment ADC values. There were 108 patients (including these 20) had serial MR images that included DWI allowing calculated ADC values from 2-132 months after radiation therapy. Two reviewers measured the mean, minimum, and maximum ADC values from elliptical ROIs that included tumor tissue only. Treatment responders were defined as those with a tumor total volume shrinkage of 20% or more after radiation therapy.

RESULTS

The pretreatment mean minimum ADC for nonresponders was 986.7 × 10^-6 mm²/s (range, 844-1230 × 10^-6 mm²/s) and it was 669.2 × 10^-6 mm²/s (range, 345-883 × 10^-6 mm²/s) for responders. This difference was statistically significant (P < .001). Using a minimum ADC value of 800 × 10^-6 mm²/s led to the correct classification of 18/20 patients based on pretreatment ADC values. The intraclass correlation between reviewers was 0.61. No posttreatment ADC values predicted response.

CONCLUSIONS

Pretreatment ADC values of vestibular schwannomas are lower in responders than nonresponders. Using a minimum ADC value of 800 × 10^-6 mm²/s correctly classified 90% of cases.

Stereotactic body radiotherapy for oligo-metastatic liver disease - Influence of pre-treatment chemotherapy and histology on local tumor control

INTRODUCTION

Stereotactic body radiation therapy (SBRT) is applied in the oligometastatic setting to treat liver metastases. However, factors influencing tumor control probability (TCP) other than radiation dose have not been thoroughly investigated. Here we set out to investigate such factors with a focus on the influence of histology and chemotherapy prior to SBRT using a large multi-center database from the German Society of Radiation Oncology.

METHODS

452 SBRT treatments in 363 patients were analyzed after collection of patient, tumor and treatment data in a multi-center database. Histology was considered through random effects in semi-parametric and parametric frailty models. Dose prescriptions were parametrized by conversion to the maximum biologically effective dose using alpha/beta of 10Gy (BED_max).

RESULTS

After adjusting for histology, BED_max was the strongest predictor of TCP. Larger PTV volumes, chemotherapy prior to SBRT and simple motion management techniques predicted significantly lower TCP. The model predicted a BED of 209±67Gy₁₀ necessary for 90% TCP at 2years with no prior chemotherapy, but 286±78Gy₁₀ when chemotherapy had been given. Breast cancer metastases were significantly more responsive to SBRT compared to other histologies with 90% TCP at 2years achievable with BED_max of 157±80Gy₁₀ or 80±62Gy₁₀ with and without prior chemotherapy, respectively.

CONCLUSIONS

Besides dose, histology and pretreatment chemotherapy were important factors influencing local TCP in this large cohort of liver metastases. After adjusting for prior chemotherapy, our data add to the emerging evidence that breast cancer metastases do respond better to hypofractionated SBRT compared to other histologies.

[Quality of life of patients with prostate cancer under androgen deprivation with GnRH analogues: Results of the noninterventional study TRIPTOSIX]

BACKGROUND

In Germany, data on the quality of life (QoL) of patients with advanced prostate cancer (PCa) under therapy with gonadotropin-releasing hormone (GnRH) analogues are limited.

OBJECTIVES

Androgen deprivation (ADT) is a palliative therapy for patients with advanced PCa, which is given over long periods and usually continued in combination with other therapies even after progression of the disease. The present study aimed to assess prospectively (over 1 year) different aspects of patients' QoL therapy with triptorelin in daily practice.

PATIENTS AND METHODS

This prospective, noninterventional study at 129 centers in Germany included 608 patients with advanced PCa treated with triptorelin. Quality of life was assessed at baseline and after 6 and 12 months, using validated EORTC QLQ-C30 and QLQ-PR25 questionnaires. Predefined subgroup analyses were performed to assess the impact of demographics, anamnestic and clinical parameters on QoL.

RESULTS AND DISCUSSION

The majority of patients with PCa under therapy with triptorelin showed generally stable global QoL over 1 year; approximately one-quarters of the patients had a clinically relevant improvement of their global QoL. In patients without previous PCa therapy and GnRH analogue treatment, significant improvements in global QoL were seen. At the same time, these patients also reported increased treatment-related symptoms. These data indicate that the perception of global QoL is not only influenced by subjective impairment through ADT-related side effects.

Lessons learnt by IRSN about the involvement of experts towards the population in contaminated areas in Fukushima Prefecture

Since November 2011, Institut de radioprotection et de sûreté nucléaire (IRSN) experts have participated in the International Commission on Radiological Protection's (ICRP) dialogue initiative for the rehabilitation of living conditions after the Fukushima accident. In 2013, IRSN and Centre d'étude sur l'Evaluation de la Protection dans le domaine Nucléaire (CEPN) launched a study to identify the main lessons that can be learned from these dialogues, and benefit French IRSN experts in the event of a postaccident situation. The main lesson is that in order to protect the inhabitants of contaminated areas efficiently, experts must work in cooperation with local actors to develop a co-expertise process. The availability of measurement devices for inhabitants is crucial to allow them to assess their own radiological situation. Measuring radioactivity makes it visible, and allows individuals to discuss the results in their communities and develop local projects to improve their daily life. Eventually, inhabitants create a practical radiological protection culture to manage their situation. However, helping people to protect themselves does not mean that authorities and experts have no responsibilities, and this calls for strong ethical principles such as not making decisions for people about their future. To be helpful, scientists need to understand that, as necessary as radiation protection is, it is not the only problem that inhabitants are facing and it cannot control people's lives. Radiation protection experts must commit themselves to be at the service of individuals and the community, and the issues they want to address.

Focal role of tolerability and reasonableness in the radiological protection system

The concepts of tolerability and reasonableness are at the core of the International Commission on Radiological Protection (ICRP) system of radiological protection. Tolerability allows the definition of boundaries for implementing ICRP principles, while reasonableness contributes to decisions regarding adequate levels of protection, taking into account the prevailing circumstances. In the 1970s and 1980s, attempts to find theoretical foundations in risk comparisons for tolerability and cost-benefit analysis for reasonableness failed. In practice, the search for a rational basis for these concepts will never end. Making a wise decision will always remain a matter of judgement and will depend on the circumstances as well as the current knowledge and past experience. This paper discusses the constituents of tolerability and reasonableness at the heart of the radiological protection system. It also emphasises the increasing role of stakeholder engagement in the quest for tolerability and reasonableness since Publication 103.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.