Experimental test of the geometric model of image formation in bright-field microscopy

In the geometric optics approximation, an image formed by an objective lens replicates the distribution of intensity at the front focal plane of the objective. Although this fact represents a fundamental optical principle, its application to analysis of bright-field microscopic images was developed only recently and has not been tested experimentally. In this paper, we applied simple ray tracing to compute an image of a glass cylinder at various positions of the objective and to compare it to the experiment. We obtained a close match between theory and observation, except for a slight underestimation of the intensity in the middle part of the cylinder. The likely reason for this minor difference was constructive interference due to lens-like properties of a cylinder, which could not be accounted for by geometric approximation. We expect that such artefacts would be negligible in imaging of live cells, and the geometric approach would successfully complement the existing quantitative phase methods.

Respiratory surveillance for coal mine dust and artificial stone exposed workers in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand

Coal mine lung dust disease (CMDLD) and artificial stone (AS) silicosis are preventable diseases which have occurred in serious outbreaks in Australia recently. This has prompted a TSANZ review of Australia's approach to respiratory periodic health surveillance. While regulating respirable dust exposure remains the foundation of primary and secondary prevention, identification of workers with early disease assists with control of further exposure, and with the aims of preserving lung function and decreasing respiratory morbidity in those affected. Prompt detection of an abnormality also allows for ongoing respiratory specialist clinical management. This review outlines a medical framework for improvements in respiratory surveillance to detect CMDLD and AS silicosis in Australia. This includes appropriate referral, improved data collection and interpretation, enhanced surveillance, the establishment of a nationwide Occupational Lung Disease Registry and an independent advisory group. These measures are designed to improve health outcomes for workers in the coal mining, AS and other dust-exposed and mining industries.

Assessment of Worker Exposure to Occupational Organic Dust in a Hemp Processing Facility

The cultivation and processing of industrial hemp, Cannabis sativa L., is a developing industry in Australia. Exposure to hemp dust is demonstrated as producing reactive and respiratory health effects, potentially causing permanent lung disease or damage. The aim of this study was to assess the airborne organic dust concentrations generated in an Australian hemp processing facility. Personal sampling, in the breathing zone of exposed workers was undertaken for exposure to respirable dust, along with parallel static sampling for airborne concentrations of inhalable and respirable dust fractions. Both static and personal sampling showed that respirable dust concentrations (mg m-3) exceeded the Australian Institute of Occupational Hygienists (AIOH) recommended maximum exposure limit of 1 mg m-3 (respirable fraction) for dusts not otherwise specified, with mean exposures (mg m-3) of M = 1.33, standard deviation (SD) = 1.09 (range 0.07-3.67 mg m-3) and M = 4.49, SD = 4.49 (range 0.77-11.08 mg m-3). The results of the investigation indicate that workers in the hemp processing industry are at risk of developing permanent and disabling respiratory disease due to high dust exposure. There is no Australian occupational exposure limit specifically for hemp dust. It is recommended further research is needed and industry-specific guidance material or model code of practice developed to effectively control exposures.

Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review

BACKGROUND

Medicinal cannabis has received increased research attention over recent years due to loosening global regulatory changes. Medicinal cannabis has been reported to have potential efficacy in reducing pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and intractable childhood epilepsy. Yet its potential application in the field of psychiatry is lesser known.

METHODS

The first clinically-focused systematic review on the emerging medical application of cannabis across all major psychiatric disorders was conducted. Current evidence regarding whole plant formulations and plant-derived cannabinoid isolates in mood, anxiety, sleep, psychotic disorders and attention deficit/hyperactivity disorder (ADHD) is discussed; while also detailing clinical prescription considerations (including pharmacogenomics), occupational and public health elements, and future research recommendations. The systematic review of the literature was conducted during 2019, assessing the data from all case studies and clinical trials involving medicinal cannabis or plant-derived isolates for all major psychiatric disorders (neurological conditions and pain were omitted).

RESULTS

The present evidence in the emerging field of cannabinoid therapeutics in psychiatry is nascent, and thereby it is currently premature to recommend cannabinoid-based interventions. Isolated positive studies have, however, revealed tentative support for cannabinoids (namely cannabidiol; CBD) for reducing social anxiety; with mixed (mainly positive) evidence for adjunctive use in schizophrenia. Case studies suggest that medicinal cannabis may be beneficial for improving sleep and post-traumatic stress disorder, however evidence is currently weak. Preliminary research findings indicate no benefit for depression from high delta-9 tetrahydrocannabinol (THC) therapeutics, or for CBD in mania. One isolated study indicates some potential efficacy for an oral cannabinoid/terpene combination in ADHD. Clinical prescriptive consideration involves caution in the use of high-THC formulations (avoidance in youth, and in people with anxiety or psychotic disorders), gradual titration, regular assessment, and caution in cardiovascular and respiratory disorders, pregnancy and breast-feeding.

CONCLUSIONS

There is currently encouraging, albeit embryonic, evidence for medicinal cannabis in the treatment of a range of psychiatric disorders. Supportive findings are emerging for some key isolates, however, clinicians need to be mindful of a range of prescriptive and occupational safety considerations, especially if initiating higher dose THC formulas.

Prostate-specific Antigen Bounce After Stereotactic Body Radiotherapy for Prostate Cancer: A Pooled Analysis of Four Prospective Trials

AIMS

We conducted a pooled analysis of four prospective stereotactic body radiotherapy (SBRT) trials of low- and intermediate-risk prostate cancer to evaluate the incidence of prostate-specific antigen (PSA) bounce and its correlation with the time-dose-fraction schedule. The correlation between bounce with PSA response at 4 years (nadir PSA < 0.4 ng/ml) and biochemical failure-free survival (BFFS) was also explored.

MATERIALS AND METHODS

The study included four treatment groups: 35 Gy/five fractions once per week (QW) (TG-1; n = 84); 40 Gy/five fractions QW (TG-2; n = 100); 40 Gy/five fractions every other day (TG-3; n = 73); and 26 Gy/two fractions QW (TG-4; n = 30). PSA bounce was defined as a rise in PSA by 0.2 ng/ml (nadir + 0.2) or 2 ng/ml (nadir + 2.0) above nadir followed by a decrease back to nadir. Patients with fewer than three follow-up PSA tests were excluded from the pooled analysis.

RESULTS

In total, 287 patients were included, with a median follow-up of 5.0 years. The pooled 5-year cumulative incidence of bounce by nadir + 2.0 was 8%. The 2-year cumulative incidences of PSA bounce by nadir + 0.2 were 28.9, 21, 19.6 and 16.7% (P = 0.12) and by nadir + 2.0 were 7.2, 8, 2.7 and 6.7% (P = 0.32) for TG-1 to TG-4, respectively. Multivariable analysis revealed that for nadir + 2.0, pre-treatment PSA (odds ratio 0.49; 95% confidence interval 0.26-0.97) correlated with PSA bounce. Although PSA bounce by nadir + 0.2 (odds ratio 0.10; 95% confidence interval 0.04-0.24) and nadir + 2.0 (odds ratio 0.29; 95% confidence interval 0.09-0.93) was associated with a lower probability of PSA response at 4 years, there was no association between bounce by nadir + 0.2 (hazard ratio 0.36; 95% confidence interval 0.08-1.74) or nadir + 2 (hazard ratio 1.77; 95% confidence interval 0.28-11.07) with BFFS.

CONCLUSION

The incidence of PSA bounce was independent of time-dose-fraction schedule for prostate SBRT. One in 13 patients experienced a bounce high enough to be misinterpreted as biochemical failure, and clinicians should avoid early salvage interventions in these patients. There was no association between PSA bounce and BFFS.

Leading article: What has an Airbus A380 Captain got to do with OMFS? Lessons from aviation to improve patient safety

The understanding of why air accidents occur and all the factors involved with them has been a strong and constantly evolving driver for improving flight safety. While they are diverse professions, there are many similarities between flying commercial aircraft and surgery, particularly in relation to minimising risk and managing potentially fatal or catastrophic complications. Safety developments in the operating theatre seem to have lagged behind other High Risk Organisations (HROs). A 2018 Quality Care Commission report stated that never events are wholly preventable and expressed the need to learn from other industries. In this article we discuss various transferable lessons and procedures advocated from aviation that could be applied to OMFS in an attempt to improve team culture and safety for our patients.

Abstract P3-08-03: Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort

Although rare, Metaplastic Breast Carcinomas (MBC) account for significant global breast cancer mortality. This subgroup is extremely heterogeneous and by definition exhibits metaplastic change to squamous and/or mesenchymal elements, including but not limited to spindle, squamous, chondroid, osseous and rhabdomyoid elements. The WHO working group recognizes that the current classification is inadequate and in the interim, has suggested a purely descriptive classification. The mixed epithelial-mesenchymal morphology has led to speculation that MBC represent 'stem cell tumours'; in support of this, MBC have been shown to have a CD44+/CD24-/low phenotype. Clinically, patients present with tumours that are larger (higher stage), have increased likelihood of distant metastases at presentation and overall, have a reduced 5-year survival rate compared to Invasive Carcinoma-NST. Hence, this is a unique subtype with poor outcome but without a robust classification or understanding of the biology to aid clinical management. We present a detailed morphological, immunohistochemical and genomic analysis of a large series of MBC (n=347), as amassed through the Asia-Pacific MBC consortium. We consider our morphological dissection using the WHO subtyping guidelines and show that an increasing number of phenotypes in a mixed MBC (classified as WHO_1) significantly associates with a poor prognosis. Immunohistochemical analysis showed that a pure spindle (WHO_5) is significantly less likely to express vimentin, CK5/6, CK14, and CK19 than a mixed WHO_1 with spindle features. Similarly, a WHO_1 with chondroid features is less likely to express EGFR than WHO_1 with chondroid features and rhabdoid or osseous differentiation. Across the cohort, positivity for the AE1/3 antibody and a lack of EGFR expression both significantly associate with a better outcome. We report no significant association between patient age at diagnosis and breast cancer specific survival, nor between age and specific WHO MBC subtypes. We report a significant association between WHO_1 types and increasing tumour grade, and also between tumour size and grade, with tumour size being a highly significant prognostic indicator in this cohort. Our exome sequencing confirms a significant enrichment for TP53 and PTEN mutations in MBC, and intriguingly for concurrent mutations of TP53, PTEN and PIK3CA. A novel enrichment for NF1 mutations is also presented. In summary, we provide a thorough assessment of a large cohort of MBC, including morphology, survival, IHC and exome sequencing, and present our analysis contextualized by the WHO guidelines, extending the existing knowledge base of this rare tumour type.

Citation Format: McCart Reed AE, Kalaw E, Nones K, Bettington M, Lim M, Bennett J, Johnstone K, Kutasovic JR, Kazakoff S, Xu QC, Saunus JM, Reid LE, Black D, Niland C, Ferguson K, Gresshoff I, Raghavendra A, Liu JC, Kalinowski L, Reid AS, Davidson M, Pearson JV, Yamaguchi R, Harris G, Tse G, Papadimos D, Pathmanathan R, Pathmanathan N, Tan PH, Fox S, O'Toole S, Waddell N, Simpson PT, Lakhani SR. Dissecting the heterogeneity of metaplastic breast cancer: A morphological, immunohistochemical and genomic analysis of a large cohort [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 P3-08-03.

The potential distribution of the Russian wheat aphid (Diuraphis noxia): an updated distribution model including irrigation improves model fit for predicting potential spread

Diuraphis noxia (Kurdjumov), Russian wheat aphid, is one of the world's most invasive and economically important agricultural pests of wheat and barley. In May 2016, it was found for the first time in Australia, with further sampling confirming it was widespread throughout south-eastern regions. Russian wheat aphid is not yet present in New Zealand. The impacts of this pest if it establishes in New Zealand, could result in serious control problems in wheat- and barley-growing regions. To evaluate whether D. noxia could establish populations in New Zealand we used the climate modelling software CLIMEX to locate where potential viable populations might occur. We re-parameterised the existing CLIMEX model by Hughes and Maywald (1990) by improving the model fit using currently known distribution records of D. noxia, and we also considered the role of irrigation into the potential spread of this invasive insect. The updated model now fits the current known distribution better than the previous Hughes and Maywald CLIMEX model, particularly in temperate and Mediterranean areas in Australia and Europe; and in more semi-arid areas in north-western China and Middle Eastern countries. Our model also highlights new climatically suitable areas for the establishment of D. noxia, not previously reported, including parts of France, the UK and New Zealand. Our results suggest that, when suitable host plants are present, Russian wheat aphid could establish in these regions. The new CLIMEX projections in the present study are useful tools to inform risk assessments and target surveillance and monitoring efforts for identifying susceptible areas to invasion by Russian wheat aphid.

A Breast Screening Shawl to Help Aboriginal Women Feel More Comfortable and Culturally Safe

Background: It is recommended that Australian women aged 50-74 have a breast screen every two years. Aboriginal women have lower breast screening participation than the general population, and face barriers at a system, service and individual level including: • Cultural: lack of cultural awareness/safety at screening services • Fear: historical apprehension about health services due to the after effects of colonization and intergenerational trauma • Shame: feeling embarrassment/shame at being undressed in front of a stranger • Past experience: having a past unpleasant breast screen, or hearing about someone else' • Knowledge: lack of knowledge about screening • Logistics: not knowing service provider locations or limited access to transport During a 2016 project between BreastScreen Victoria (BSV) and Women's Health West, Aboriginal women discussed the need for a shawl to cover them during screening. This idea is based on a successful New Zealand model. Based on this, the Victorian Aboriginal Health Service (VAHS), Victorian Aboriginal Community Controlled Health Organization (VACCHO) and BSV formed a partnership to trial a breast screening shawl with Aboriginal women. A key principle underpinning the project is that success will reflect the degree to which this is an Aboriginal-led initiative, driven by the needs of Aboriginal women, and steered by community-based Aboriginal health organizations. Project aims: • Assess whether a cultural, strength based screening process increases engagement of Aboriginal women • Determine whether a screening shawl enhances comfort and culturally safety • Encourage breast screening services to develop culturally safe screening practices • Develop a flexible model that can be easily adapted by other Aboriginal health services to reproduce the shawl, in recognition of the diversity of Aboriginal communities Methods: This project adopted the following strategies: • A project steering group was established • The shawl will be trialled via a group booking at one BSV clinic • Before the group booking, BSV clinic staff will attend culturally safety training • On the trial day, women will attend an information session at VAHS about breast screening and receive their shawl, travel to the BSV clinic together for screening, and return to VAHS to discuss their experiences Results: The trial will be fully evaluated in 2018 to determine whether project aims were achieved. Conclusion: Key learnings to date are: • Breast screening interventions for Aboriginal women must be community-led to ensure they are culturally appropriate, safe and acceptable • Aboriginal women face a number of barriers to breast screening at a system, service and individual level • Health services play a critical role in adopting culturally safe screening practices • Developing a flexible model that can be easily adapted by other Aboriginal health services is critical in ensuring the sustainability and acceptability of the shawl.

Occupational health and safety in cannabis production: an Australian perspective

The legal Australian cannabis industry has been rapidly expanding due to increased awareness of the plant's therapeutic potential, as well its diverse range of applications including biofuel, textiles, building materials, food, nutritional supplement, and animal feed. The objective of this paper is to describe the current landscape of the commercial Australian cannabis industry, summarise occupational health and safety (OHS) hazards in cannabis-related working environments, and provide suggestions for safeguarding worker health and well-being in this emerging industry. A comprehensive search of peer-reviewed and grey literature published between 1900 and 2017 was undertaken to identify case studies and original epidemiological research on OHS hazards associated with the cannabis cultivation and the manufacture of cannabis-based products. The review found that the majority of OHS studies were undertaken in the hemp textile industry during the late twentieth century, with a small number of articles published from a variety of occupational environments including forensic laboratories and recreational marijuana farms. Cannabis harvesting and initial processing is labour intensive, and presents a physical hazard Depending on the operation, workers may also be exposed to a variety of biological, chemical, and physical hazards including: organic dusts, bioaerosols, pollen/allergens, volatile organic compounds, psychoactive substances (tetrahydrocannabinol [THC])), noise, and ultraviolet radiation. Little research has been undertaken on the exposure to inhalable organic dust and other bioaerosols during the commercial cultivation and manufacture of cannabis-based products. Furthermore, there is an absence of Australian-based research and OHS guidance materials to help professionals develop risk management strategies in this evolving industry. It is recommended that: Investigation into the toxicological properties of cannabis dusts, specifically in relation to potential occupational exposures during cultivation and manufacture, should be a priority. The interim adoption of the respirable cotton dust exposure standard of 0.2 mg/m3 for workplace exposure in hemp facilities until a cannabis workplace exposure standard is developed, and that exposure to medicinal cannabis containing THC are kept as low as reasonably practicable. An industry partnership be established for the development of an Australian health and safety guideline for the production of medicinal cannabis and hemp. A classification to meet the requirements of the Global Harmonization Scheme should be undertaken to ensure consistency in the use of safety and risk phrases in cannabis-related industries.

Suicide risk assessment among psychiatric inpatients: a systematic review and meta-analysis of high-risk categories

BACKGROUND

The clinical care of psychiatric patients is often guided by perceptions of suicide risk. The aim of this study was to examine the methods and results of studies reporting high-risk models for inpatient suicide.

METHODS

We conducted a registered meta-analysis according to PRISMA guidelines. We searched for relevant peer-reviewed cohort and controlled studies indexed in Medline, EMBASE and PsychINFO.

RESULTS

The pooled odds ratio (OR) among 18 studies reporting high-risk models for inpatient suicide was 7.1 [95% confidence interval (CI) 4.2-12.2]. Between-study heterogeneity in ORs was very high (range 0-94.8, first quartile 3.4, median 8.8, third quartile 26.1, prediction interval 0.80-63.1, I2 = 88.1%). The meta-analytically derived sensitivity was 53.1% (95% CI 38.2-67.5%, I2 = 95.9%) and specificity was 84.2% (95% CI 71.6-91.9%, I2 = 99.9%) with an associated meta-analytic area under the curve of 0.83. The positive predictive value of risk categorization among six cohort studies was 0.43% (95% CI 0.014-1.3%, I2 = 95.9%). A history of suicidal behavior and depressive symptoms or affective disorder was included in the majority of high-risk models.

CONCLUSIONS

Despite the strength of the pooled association between high-risk categorization and suicide, the very high degree of observed heterogeneity indicates uncertainty about our ability to meaningfully distinguish inpatients according to suicide risk. The limited sensitivity and low positive predictive value of risk categorization suggest that suicide risk models are not a suitable basis for clinical decisions in inpatient settings.