Metabolic profiling of murine radiation-induced lung injury with Raman spectroscopy and comparative machine learning.

Radiation-induced lung injury (RILI) is a dose-limiting toxicity for cancer patients receiving thoracic radiotherapy. As such, it is important to characterize metabolic associations with the early and late stages of RILI, namely pneumonitis and pulmonary fibrosis. Recently, Raman spectroscopy has shown utility for the differentiation of pneumonitic and fibrotic tissue states in a mouse model; however, the specific metabolite-disease associations remain relatively unexplored from a Raman perspective. This work harnesses Raman spectroscopy and supervised machine learning to investigate metabolic associations with radiation pneumonitis and pulmonary fibrosis in a mouse model. To this end, Raman spectra were collected from lung tissues of irradiated/non-irradiated C3H/HeJ and C57BL/6J mice and labelled as normal, pneumonitis, or fibrosis, based on histological assessment. Spectra were decomposed into metabolic scores via group and basis restricted non-negative matrix factorization, classified with random forest (GBR-NMF-RF), and metabolites predictive of RILI were identified. To provide comparative context, spectra were decomposed and classified via principal component analysis with random forest (PCA-RF), and full spectra were classified with a convolutional neural network (CNN), as well as logistic regression (LR). Through leave-one-mouse-out cross-validation, we observed that GBR-NMF-RF was comparable to other methods by measure of accuracy and log-loss (p > 0.10 by Mann-Whitney U test), and no methodology was dominant across all classification tasks by measure of area under the receiver operating characteristic curve. Moreover, GBR-NMF-RF results were directly interpretable and identified collagen and specific collagen precursors as top fibrosis predictors, while metabolites with immune and inflammatory functions, such as serine and histidine, were top pneumonitis predictors. Further support for GBR-NMF-RF and the identified metabolite associations with RILI was found as CNN interpretation heatmaps revealed spectral regions consistent with these metabolites.

Reassessing lead protective garment assessment using ICRP 103 tissue weighting factors.

Lead protective garments worn by medical staff in the presence of x-rays develop defects over time. This work proposes a novel method of assessing the protective efficacy of the garments as defects develop. The proposed method applies updated radiobiology data from ICRP 103. This work applied the as low as reasonably achievable principle to devise a formula through which a maximum allowed defect area in lead protective garments can be calculated. This formula depends on the cross-sectional areas (A) and ICRP 103 tissue weighting factors (wt) of the most radiosensitive and overlapping organs protected by the garment, the maximum allowed additional effective dose to the garment wearer due to the defects (d), and the unattenuated absorbed dose at the surface of the garment (D). The maximum allowed defect areas are separated into three regions:above the waist, below the waist, andthyroid. To be conservative, it was assumed thatD= 50 mGy yr-1, andd= 0.3 mSv yr-1. Also conservatively, transmission was assumed to be 0%, as employing a non-zero transmission factor would increase the maximum allowed defect area. Maximum allowed defect areas were as follows: 370 mm2for above the waist, 37 mm2for below the waist, and 279 mm2for the thyroid. These values can be compared to commonly published values which are 670 mm2for an apron, 15 mm2over the gonads, and 11-20 mm2for the thyroid. The proposed method for lead protective garment assessment is highly adaptable as values can be adjusted as radiobiology data are updated, and as values such as radiation dose limits vary across jurisdictions. Future works will include collection of data for unattenuated dose to apron (D) as it varies across professions, so that garments may be allowed different defect areas if relegated to individuals of specific professions.

Engagement of parents in on-line social support interventions.

The purpose of this scoping review was to determine what the relevant research informs us about which parents of children with chronic disease and/or disability are likely to engage in an on-line social support program and why they choose to be engaged. The review included 16 peer-reviewed research reports about on-line social support offered to parents of children with chronic disease and/or disability. It was conducted using scoping review approaches recommended by H. Arskey and L. O'Malley (2005). A key finding of this review is that it appears that the development of on-line social support interventions for parents may not have integrated what is known in the field of Internet technology as necessary to engage users. This has implications for nurses wishing to provide on-line social support for parents. As well, it highlights future directions for research, including investigations of which parents are likely to engage in on-line social support interventions and the features of the intevention that will attract and sustain them as participants.

Ripples in the water: a toolkit for Aboriginal people on hemodialysis.

In 2004-2005, the authors were engaged in a community-based research study with people of Elsipogtog First Nation to determine the causes of and solutions to non-adherence among community members with chronic kidney disease. This study highlighted the need for a toolkit intended for Aboriginal people who are required to undergo hemodialysis at a dialysis unit in a city away from their rural community, so that they are sufficiently educated, supported and resourced to access and experience culturally relevant health care. This paper presents the findings of a two-year community-based research study to develop the prototype or model for such a toolkit. The research involved meeting with nine community members in group meetings at least monthly over the two years to determine what such a toolkit should include and how it should best be presented. It also entailed an extensive review of relevant literature and relevant educational materials, as well as individual interviews with key stakeholders. The project resulted in a culturally relevant toolkit that can be staged according to people's readiness for the information and that fosters collaborative discussions between patients, family members and health care practitioners.