An X-Ray Diffraction Study of Triglyceride Polymorphism

The polymorphism of an homologous series of highly purified mixed triglycerides has been studied using powder and single crystal X-ray diffraction techniques, in conjunction with thermal analysis and infrared spectroscopy. From thermal analysis, three polymorphs were identified. Single crystals of the most stable polymorph were obtained for two members of the series, 2-acetodimyristin (14-2-14) and 2-acetodipalmitin (16-2-16). Their unit-cell and sub-cell dimensions were used to interpret the powder data, and to provide preliminary general information about the crystal packing for this polymorph. Of the two other polymorphs identified, the first one (obtained by rapid cooling of the melt) is disordered, and transforms on standing, to a second, unstable intermediate polymorph. Infrared spectroscopy showed that for at least two of the three polymorphs, the long chain acyl groups of the triglycerides are in a parallel packing arrangement.

Abstract P3-12-24: Tumor-secreted predictive biomarkers of response to radiotherapy in breast cancer

Background:In breast cancer (BC), radiotherapy (RT) is used adjuvantly to prevent recurrence and also in the palliative setting. Clinical signs of RT response are often not apparent for several weeks post-treatment and we currently lack tools to predict or monitor tumor response to RT early during treatment. The aim was to identify tumor-secreted biomarkers whose release reflects response to RT, which could be monitored during treatment in the blood or intratumorally by an implantable biosensor, currently under development within the Implantable Microsystems for Personalised Anti-Cancer Therapy (IMPACT) program.

Methods: A series of experiments assessed the effect of different radiation doses (2-10Gy) on 3 human BC cell lines – MDA-MB-231 (ER-), MCF-7 (ER+) and HBL-100 (ER-) –, 1 canine breast cancer and 2 sheep lung cancer lines. Culture media was collected from each dose experiment at a range of post-radiation time-points (1-24 hours). Proteins were isolated from collected media for secretome mass spectrometry (MS) analysis. A subset of treatment/time conditions were repeated in the same BC cell lines and radioresistant (RR) derivatives from which RNA was extracted and analysed using Lexogen QuantSeq for whole-genome transcriptomics.In-lab candidate biomarker validation was carried out using immuhistochemistry (IHC), immunofluorescence (IF) and western blotting (WB) using validated antibodies. Levels of candidate biomarkers were also assessed in normal and untreated BC tissues using IHC. ELISA-based methods are currently under investigation for detection of the lead candidate biomarkers in the blood of large animal cancer models treated with RT.

Results: Biomarker discovery using the MS data revealed 4 promising candidates: EIF3G, SEC24C, YBX3 and TK1. These are released from BC and animal cancer cells sensitive to radiation in a dose-dependent manner 24 hours after treatment. Analysis of the transcriptomic data showed an 8-fold higher expression of the genes encoding the 4 candidates in the radio-sensitive parental cell lines compared to the RR cell lines. IF and WB confirmed lower intracellular expression of the 4 proteins in RR cells compared to the parental lines. WB of collected culture media confirmed release of each of the 4 candidates 24 hours after a 2Gy dose of radiation in only the parental lines. GAPDH was not found in these media samples, demonstrating that protein release was not due to cell lysis.

Conclusions:

· We have identified 4 promising biomarkers which are released from cancer cells sensitive to RT and not released from RR derivatives.

· All 4 candidates are released 24 hours after a 2Gy radiation dose, which fits with the current clinical dosing schedule where radiation is administered at 24 hour intervals. Ongoing work will elucidate if these biomarkers can be reliably detected in blood or intratumorally using implantable biosensors.

· There are currently no validated predictive tools to monitor RT response during treatment. If successfully validated, these biomarkers could have a clinical role in personalising RT dosing schedules and durations for solid tumors in the neoadjuvant and palliative setting, thus optimising treatment and preventing the administration of ineffective RT and its associated side effects.

Citation Format: Meehan J, Gray M, Turnbull AK, Martinez-Perez C, Bonello M, Ward C, Langdon SP, McLaughlin S, MacLennan M, Dixon JM, Wills J, Quinn N, Finich AJ, von Kriegsheim A, Cameron D, Kunkler IH, Murray A, Argyle D. Tumor-secreted predictive biomarkers of response to radiotherapy in breast cancer [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 P3-12-24.

Towards an international language for incontinence-associated dermatitis (IAD): design and evaluation of psychometric properties of the Ghent Global IAD Categorization Tool (GLOBIAD) in 30 countries

BACKGROUND

Incontinence-associated dermatitis (IAD) is a specific type of irritant contact dermatitis with different severity levels. An internationally accepted instrument to assess the severity of IAD in adults, with established diagnostic accuracy, agreement and reliability, is needed to support clinical practice and research.

OBJECTIVES

To design the Ghent Global IAD Categorization Tool (GLOBIAD) and evaluate its psychometric properties.

METHODS

The design was based on expert consultation using a three-round Delphi procedure with 34 experts from 13 countries. The instrument was tested using IAD photographs, which reflected different severity levels, in a sample of 823 healthcare professionals from 30 countries. Measures for diagnostic accuracy (sensitivity and specificity), agreement, interrater reliability (multirater Fleiss kappa) and intrarater reliability (Cohen's kappa) were assessed.

RESULTS

The GLOBIAD consists of two categories based on the presence of persistent redness (category 1) and skin loss (category 2), both of which are subdivided based on the presence of clinical signs of infection. The agreement for differentiating between category 1 and category 2 was 0·86 [95% confidence interval (CI) 0·86-0·87], with a sensitivity of 90% and a specificity of 84%. The overall agreement was 0·55 (95% CI 0·55-0·56). The Fleiss kappa for differentiating between category 1 and category 2 was 0·65 (95% CI 0·65-0·65). The overall Fleiss kappa was 0·41 (95% CI 0·41-0·41). The Cohen's kappa for differentiating between category 1 and category 2 was 0·76 (95% CI 0·75-0·77). The overall Cohen's kappa was 0·61 (95% CI 0·59-0·62).

CONCLUSIONS

The development of the GLOBIAD is a major step towards a better systematic assessment of IAD in clinical practice and research worldwide. However, further validation is needed.

Effect of portable non-invasive ventilation & environmental conditions on everyday activities

The current study examined the effect of non-invasive ventilation (NIV) within environments of differing temperature and humidity on several physiological and perceptual responses while performing six activities of daily living (i.e. putting on shirt/shoes/trousers, vacuuming, hanging towels, and walking on a treadmill). Sixteen healthy participants completed the activities of varying difficulty within four experimental conditions: with and without NIV; and in temperate (22°C, 40% relative humidity) and hot-humid environments (32°C, 70% relative humidity). Comparisons of physiological responses between conditions were examined via repeated measures ANOVAs. Overall, NIV resulted in similar physiological and perceptual responses within all environmental conditions for healthy participants. Further, NIV use increased heart rate during the most strenuous task (29.5±12.7 vs. 22.8±12.0bpm, p=0.008) indicating NIV use may stress cardiovascular functioning during moderate-high intensity activities. Tropical conditions did not alter physiological or perceptual responses during everyday tasks with NIV use by healthy adults. Future investigations examining the independent and combined impacts of task intensity, extreme environments and NIV use will clarify the benefits of NIV for healthy and clinical populations.

Benchmarking the research track record and level of appointment of Australian occupational therapy academics

BACKGROUND

Academic faculty are active contributors to the evidence base of the profession. Little is known about the research productivity of Australian occupational therapy academics.

METHODS

A bibliographic analysis of Australian occupational therapy faculty websites and corresponding Scopus citation database profiles was conducted. A description of current research productivity benchmarks and relationships with holding a doctorate, academic appointment level and institutional characteristics were explored.

RESULTS

The median H-index of Clinical and Associate Lecturers was 0, 1 for Lecturers, 4 for Senior Lecturers, 7.5 for Associate Professors and 13 for Professors. The number of publications and number of citing documents follows a Pareto tendency, where 20% of researchers are responsible for around 80% of the research track record of Australian occupational therapy academics.

CONCLUSION

The findings provide a benchmark for Australian occupational therapy faculty research track records and associations with appointment levels. This benchmark differs across countries and disciplines. The results raise considerations for enhancing the overall research track record of occupational therapy academics.

Commitment to physical activity and health: a case study of a Paralympic Gold medallist

BACKGROUND

Physical activity has been documented as both beneficial and detrimental for individuals with multiple sclerosis (MS). The varied experience highlights challenges associated with physical activity and MS, requiring a greater understanding of the experiences of exercise for individuals with MS.

OBJECTIVE

The purpose of this study was to explore how physical activity played a role in the life of a Paralympic Gold medallist. Carol was diagnosed with MS and went onto achieve the highest accolade in Paralympic sport.

METHODS

Narrative inquiry, within a single-case design, explored how physical activity played a role in Carol's life. The narrative was analysed through the lens of a salutogenic framework, which explores how individuals create health despite adverse circumstances.

FINDINGS

Carol's physical activity pathway explores life before and after her diagnosis, motivations to return to exercise and pathway to Paralympic Gold. Carol's experiences highlight how physical activity played a role during various stages of her life. Exercise had a significant role in Carol's life prior to diagnosis, it assisted in the management of MS and she cycled the elite level, winning a Paralympic Gold medal in para-cycling. Implications for Rehabilitation Physical activity has been reported as beneficial for multiple sclerosis management; however, there can be a fine line between the benefits and an overload that can harm. An elite athlete with multiple sclerosis maintained and sustained physical activity to the highest level in elite sport, incorporating a positive health outlook throughout different stages of her life. The case highlights how commitment and self-awareness of capabilities and limits may be useful self-management tools in increasing physical activity for individuals living with multiple sclerosis.

Changes in Lean Mass and Serum Myostatin with Habitual Protein Intake and High-Velocity Resistance Training

OBJECTIVES

Examine the associations between dietary protein intake, lean mass (LM), and serum myostatin (Mstn) levels among community-dwelling older adults participating in a 20-week high-velocity resistance training (HVRT) program.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal study consisted of 33 community-dwelling, older adults (mean age 77.0 years, SD = 6.4); all of which obtained physician clearance prior to study participation.

MEASUREMENTS

Twenty-five females and eight males were randomized to a control (CON) or HVRT group. Anthropometric measures were obtained via dual energy x-ray absorptiometry (DXA) and peripheral venous blood draw used for serum myostatin analysis. Exercise was performed twice per week for 20 consecutive weeks. Food intake estimation with a diet history questionnaire (DHQ) was used for protein intake comparison to the recommended dietary allowance (RDA). All measures were recorded both prior to and following study participation.

RESULTS

Altogether, protein was consumed in amounts more generous (1.01 ± 0.47 g·kg-1·d-1) than that of the RDA (0.8 g·kg-1·d-1). As a result of significant LM differences among men and women (p < 0.01), additional data were analyzed specific to sex. Serum myostatin was greater among females (6681.8 ± 3155.0 pg·mL-1) than males (5560.0 ± 2946.1 pg·mL-1); however, these values were not significantly different (p = 0.39). Combined, protein consumption and serum myostatin did not significantly influence LM among males (p = 0.09) or females (p = 0.71). Irrespective of training group, significant changes were not exhibited in dietary intake patterns, LM, or serum myostatin.

CONCLUSIONS

Contrary to the proposed hypothesis, results suggest protein consumption and circulating serum myostatin levels did not significantly influence LM among older adults. Although HVRT positively impacts LM, neither exercise group displayed significant changes in LM. Therefore, further research is needed examining dietary intake, exercise modality, and myostatin downregulation as non-pharmacological approaches to combating sarcopenia.