Automated particle recognition for engine soot nanoparticles

A pre-trained convolution neural network based on residual error functions (ResNet) was applied to the classification of soot and non-soot carbon nanoparticles in TEM images. Two depths of ResNet, one 18 layers deep and the other 50 layers deep, were trained using training-validation sets of increasing size (containing 100, 400 and 1400 images) and were assessed using an independent test set of 200 images. Network training was optimised in terms of mini-batch size, learning rate and training length. In all tests, ResNet18 and ResNet50 had statistically similar performances, though ResNet18 required only 25-35% of the training time of ResNet50. Training using the 100-, 400- and 1400-image training-validation sets led to classification accuracies of 84%, 88% and 95%, respectively. ResNet18 and ResNet50 were also compared for their ability to categorise soot and non-soot nanoparticles via a fivefold cross-validation experiment using the entire set of 800 images of soot and 800 images of non-soot. Cross-validation was repeated 3 times with different training durations. For all cross-validation experiments, classification accuracy exceeded 91%, with no statistical differences between any of the network trainings. The most efficient network was ResNet18 trained for 5 epochs, which reached 91.2% classification after only 84 s of training on 1600 images. Use of ResNet for classification of 1000 images, the amount suggested for reliable characterisation of soot sample, requires <4 s, compared with >30 min for a skilled operator classifying images manually. Use of convolution neural networks for classification of soot and non-soot nanoparticles in TEM images is highly promising, particularly when manually classified data sets have already been established.

Application of the PRECEDE-PROCEED model for the development of a community pharmacy ear health intervention for rural populations

Introduction

The World Health Organisation has identified ear disease to be a major public health problem in rural and remote communities, with access to services an identified barrier. (1) Rural community pharmacists are recognised as highly skilled, accessible and trusted health professionals. An innovative service “LISTEN UP” (Locally Integrated Screening and Testing Ear aNd aUral Program) has been implemented in two remote community pharmacies in Australia. The service involves patients with an ear complaint self-presenting to a participating pharmacy and receiving a clinical examination by a pharmacist, who has completed accredited training in ear health, otoscopy and tympanometry. “LISTEN UP” has been developed using the PRECEDE-PROCEED planning model.(2) The PRECEDE component of the model assesses social, epidemiological, behavioural, environmental, educational and ecological factors to inform the development of an intervention.(2) The PROCEED-component consists of pilot testing and evaluation.

Aim

To describe an ecological approach to health promotion via the application of the PRECEDE-PROCEED planning model to develop a rural community pharmacy-based ear health intervention.

Methods

PRECEDE (Predisposing, Reinforcing, and Enabling Constructs in Educational Diagnosis) provided a framework to plan and develop a locally relevant and community focused program. This included research and engagement via meetings, surveys and interviews of consumers, pharmacists, health professionals and stakeholders. PROCEED (Policy, Regulatory, and Organisational Constructs in Educational and Environmental Development) outlined the structure for implementing and evaluating the intervention that was developed in the PRECEDE process. A pilot study has been included in PROCEED segment to allow improvement before implementing and evaluating the final model. Data will be collected in the pilot study via semi-structured interviews and surveys. This will be analysed using descriptive statistics and thematic analysis of qualitative data.

Results

As part of the PRECEDE segment a social assessment was undertaken via mixed method studies of rural consumers, pharmacists and health professionals. Hearing testing was ranked as the seventh (from twenty-six) most important expanded pharmacy service by both consumer and health professional groups. An epidemiological assessment found extensive ear disease in rural and remote locations resulting in complications and hearing loss. Behavioural and environment assessments identified eleven ear health interventions which include hearing screening [3], otoscopy pilot studies [2], audiometry services [1], specific education for undergraduate pharmacy students [2] and a pharmacy-based clinic [3]. However none of the interventions described a framework for continued service provision. Policy and regulation assessment was undertaken to align the intervention within the regulatory framework. The application of this model is partially complete with the study protocol for the intervention developed and the initial pilot study in progress. This study’s strengths include its applicability to rural populations and the limited evidence base that currently exists. It is however limited by the small size of the pilot study and application of this model to a national intervention would be useful for future.

Conclusions

The application of the PRECEDE-PROCEED model demonstrates the applicability of this planning model for developing and evaluating an ear health intervention with a particular focus on community pharmacies in rural and remote locations.

References

1. World Health Organisation. Deafness and hearing loss; 2020. Available from: https://www.who.int/health-topics/hearing-loss#tab=tab_1 [Accessed: 15/9/2020]

2. Binkley CJ, Johnson KW. Application of the PRECEDE-PROCEED Planning Model in Designing an Oral Health Strategy. J Theory Pract Dent Public Health. 2013;1(3):http://www.sharmilachatterjee.com/ojs-2.3.8/index.php/JTPDPH/article/view/89

The effect of a digital training tool to aid chest image interpretation: Hybridising eye tracking technology and a decision support tool

INTRODUCTION

Eye tracking technology, checklists and search strategies have been demonstrated as useful aids in image interpretation. A training tool was developed, by the research team, which included these features. This study aimed to evaluate the effect of the training tool on participant image interpretation performance.

METHODS

The study was carried out with reporting radiographers who had either commenced training in chest image interpretation (n = 12) or were trained in musculoskeletal image interpretation (n = 23) (total n = 35). Participants were allocated to a control or intervention group. Participants completed an initial assessment at recruitment and re-attended nine months later for a follow-up assessment. The intervention group were given unlimited access to a digital training tool. During assessments participants interpreted 20 chest images whilst using eye tracking technology (total of 1400 images were interpreted). A confidence level was obtained from participants on their diagnosis and a questionnaire, to obtain demographic data, was completed following the assessment.

RESULTS

Improvements were seen in the confidence of intervention group participants (p < 0.05). False Positive (FP) scores decreased for both the control and intervention group (p < 0.05), this decrease was from 4.20 to 3.20 for the control group and from 5.87 to 3.27 for the intervention group. True Negative (TN) scores increased, from 5.13 to 6.73 for the intervention group (p < 0.05). Mean decision time decreased for both the control and intervention group.

CONCLUSION

The tool led to positive effects on participant performance and could be a useful aid in chest image interpretation learning.

IMPLICATIONS FOR PRACTICE

Improvements in performance were observed with a digital tool. The tool could improve image interpretation methods and training.

Chromosomal radiosensitivity of triple negative breast cancer patients

Purpose: Based on clinical and molecular data, breast cancer is a heterogeneous disease. Breast cancers that have no expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are defined as triple negative breast cancers (TNBCs); luminal cancers have different expressions of ER, PR and/or HER2. TNBCs are frequently linked with advanced disease, poor prognosis and occurrence in young African women, and about 15% of the cases are associated with germline BRCA1/2 mutations. Since radiotherapy is utilized as a principle treatment in the management of TNBC, we aimed to investigate the chromosomal instability and radiosensitivity of lymphocytes in TNBC patients compared to luminal breast cancer patients and healthy controls using the micronucleus (MN) assay. The effect of mutations in breast cancer susceptibility genes on chromosomal radiosensitivity was also evaluated.Methods: Chromosomal radiosensitivity was evaluated in the G0 (83 patients and 90 controls) and S/G2 (34 patients and 17 controls) phase of the cell cycle by exposing blood samples from all patients and controls to 2 and 4 Gy ionizing radiation (IR).Results: In the G0 MN assay, the combined cohort of all breast cancer, TNBC and luminal patients' exhibit significantly elevated spontaneous MN values compared to controls indicating chromosomal instability. Chromosomal radiosensitivity is also significantly elevated in the combined cohort of all breast cancer patients compared to controls. The TNBC patients, however, do not exhibit enhanced chromosomal radiosensitivity. Similarly, in the S/G2 phase, 76% of TNBC patients do not show enhanced chromosomal radiosensitivity compared to the controls. In both the G0 and S/G2 phase, luminal breast cancer patients demonstrate a shift toward chromosomal radiosensitivity compared to TNBC patients and controls.Conclusions: The observations of the MN assay suggest increased chromosomal instability and chromosomal radiosensitivity in South African breast cancer patients. However, in TNBC patients, the irradiated MN values are not elevated. Our results suggest that the healthy lymphocytes in TNBC patients could handle higher doses of IR.

A matched comparison study of hepatitis C treatment outcomes in the prison and community setting, and an analysis of the impact of prison release or transfer during therapy

Prisoners are a priority group for hepatitis C (HCV) treatment. Although treatment durations will become shorter using directly acting antivirals (DAAs), nearly half of prison sentences in Scotland are too short to allow completion of DAA therapy prior to release. The purpose of this study was to compare treatment outcomes between prison- and community-based patients and to examine the impact of prison release or transfer during therapy. A national database was used to compare treatment outcomes between prison treatment initiates and a matched community sample. Additional data were collected to investigate the impact of release or transfer on treatment outcomes. Treatment-naïve patients infected with genotype 1/2/3/4 and treated between 2009 and 2012 were eligible for inclusion. 291 prison initiates were matched with 1137 community initiates: SVRs were 61% (95% CI 55%-66%) and 63% (95% CI 60%-66%), respectively. Odds of achieving a SVR were not significantly associated with prisoner status (P=.33). SVRs were 74% (95% CI 65%-81%), 59% (95% CI 42%-75%) and 45% (95% CI 29%-62%) among those not released or transferred, transferred during treatment, or released during treatment, respectively. Odds of achieving a SVR were significantly associated with release (P<.01), but not transfer (P=.18). Prison-based HCV treatment achieves similar outcomes to community-based treatment, with those not released or transferred during treatment doing particularly well. Transfer or release during therapy should be avoided whenever possible, using anticipatory planning and medical holds where appropriate.

BRCA1, BRCA2 and PALB2 mutations and CHEK2 c.1100delC in different South African ethnic groups diagnosed with premenopausal and/or triple negative breast cancer

Background

Current knowledge of the aetiology of hereditary breast cancer in the four main South African population groups (black, coloured, Indian and white) is limited. Risk assessments in the black, coloured and Indian population groups are challenging because of restricted information regarding the underlying genetic contributions to inherited breast cancer in these populations. We focused this study on premenopausal patients (diagnosed with breast cancer before the age of 50; n = 78) and triple negative breast cancer (TNBC) patients (n = 30) from the four South African ethnic groups. The aim of this study was to determine the frequency and spectrum of germline mutations in BRCA1, BRCA2 and PALB2 and to evaluate the presence of the CHEK2 c.1100delC allele in these patients.

Methods

In total, 108 South African breast cancer patients underwent mutation screening using a Next-Generation Sequencing (NGS) approach in combination with Multiplex Ligation-dependent Probe Amplification (MLPA) to detect large rearrangements in BRCA1 and BRCA2.

Results

In 13 (12 %) patients a deleterious mutation in BRCA1/2 was detected, three of which were novel mutations in black patients. None of the study participants was found to have an unequivocal pathogenic mutation in PALB2. Two (white) patients tested positive for the CHEK2 c.1100delC mutation, however, one of these also carried a deleterious BRCA2 mutation. Additionally, six variants of unknown clinical significance were identified (4 in BRCA2, 2 in PALB2), all in black patients. Within the group of TNBC patients, a higher mutation frequency was obtained (23.3 %; 7/30) than in the group of patients diagnosed before the age of 50 (7.7 %; 6/78).

Conclusion

This study highlights the importance of evaluating germline mutations in major breast cancer genes in all of the South African population groups. This NGS study shows that mutation analysis is warranted in South African patients with triple negative and/or in premenopausal breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1913-6) contains supplementary material, which is available to authorized users.

Observations of body mass index in Duchenne muscular dystrophy: a longitudinal study

BACKGROUND/OBJECTIVES

Nutritional issues that are associated with Duchenne muscular dystrophy (DMD) remain poorly understood. The aim of this analysis was to describe and explore longitudinal observations of body mass index (BMI) in a cohort of children with DMD.

SUBJECTS/METHODS

Anthropometric and clinical characteristics were collected retrospectively and longitudinally for boys with DMD seen in two large neuromuscular clinics. BMI Z-scores were determined using the Centers for Disease Control and Prevention reference values for children (2000).

RESULTS

Medical records (n=193) were examined from which 75% were included for analysis. The mean age of the cohort at the time of data collection was 11.9 years, with 72% of patients currently or previously using steroids. The highest prevalence of obesity based on the BMI Z-score was 50% at the age of 10 years. Longitudinally, BMI Z-scores from the age of 2 to 12 years plot approximately one s.d. above the mean, after which there is a marked and progressive decline. BMI gainers were identified for whom BMI Z-score increased by 1.65 units compared with the 0.09 units in non-gainers. BMI gainers were younger when they had their first BMI measurement (5.9 vs 7.2 years), and this measure was significantly lower compared with the non-gainers (BMI Z-score: 0.04 vs 1.17). In this cohort, BMI was associated with age, ambulatory status and lung function.

CONCLUSIONS

This study demonstrates that boys with DMD using steroid therapy experience shifts in BMI. A declining BMI appears to be associated with increasing age. Interpretation of growth patterns is limited here by a lack of normative growth references in DMD.

Impact of intrapancreatic or extrapancreatic bile duct involvement on survival following pancreatoduodenectomy for common bile duct cancer

BACKGROUND

The clinicopathological factors that influence survival following pancreatoduodenectomy (PD) for common bile duct (CBD) cancer are not well known. This study aimed to investigate the effect of tumour involvement of the intrapancreatic versus extrapancreatic CBD on margin status, overall (OS) and disease-free (DFS) survival.

METHODS

This was a retrospective study of patients who underwent PD for CBD cancer between 2001 and 2009. Pathological examination was performed according to a previously described standardized protocol based on axial slicing. Clinicopathological data and outcome in terms of margin status, DFS and OS were compared between cancers involving exclusively the intrapancreatic CBD (CBDin) and those involving the extrapancreatic CBD, in isolation or combined with invasion of the intrapancreatic part of the duct (CBDex).

RESULTS

A total of 66 patients were enrolled. Most CBD cancers were locally advanced (97 per cent pathological (p) T3, 76 per cent pN1). Microscopic margin involvement (R1) was more frequent in CBDex than in CBDin cancers (34 of 39 versus 13 of 27; P = 0.001), more often multifocal (P < 0.001) and more frequently affected the periductal margin (P = 0.005). Venous resection was more often required for CBDex cancers (P = 0.009). CBDex cancers were associated with worse OS (median 21 versus 28 months; P = 0.020) and DFS (14 versus 31 months; P = 0.015), but the rate and site of recurrence did not differ. Metastasis to more than two lymph nodes was an independent predictor of OS and DFS.

CONCLUSION

CBDex cancer is associated with a higher rate of R1 resection and venous resection after PD, and has a worse outcome than CBDin cancer.

Probiotic VSL#3 prevents antibiotic-associated diarrhoea in a double-blind, randomized, placebo-controlled clinical trial

BACKGROUND

Antibiotic-associated diarrhoea (AAD) is a frequent complication of systemic antibiotic therapy and Clostridium difficile-associated diarrhoea (CDAD) is its most serious form due to associated morbidity and mortality.

AIM

This trial aimed to investigate whether the probiotic VSL#3 prevents AAD and CDAD in average-risk hospital patients.

METHODS

Adult hospital inpatients exposed to systemic antibiotics were recruited to this multicentre, randomized, double-blind, placebo-controlled trial. One sachet of VSL#3 or placebo was given twice daily for the length of the antibiotics course and for seven days thereafter. Primary outcomes were AAD and CDAD.

FINDINGS

Patients randomized to active (N = 117) and placebo (N = 112) groups were well-matched for baseline demographic patient data. No cases of CDAD were detected. The rate of AAD was significantly lower in the active group on per protocol analysis (0% active vs 11.4% placebo; P = 0.006). On intention-to-treat analysis the difference in AAD incidence (4.3% active vs 8.9% placebo; P = 0.19) was not significant.

CONCLUSIONS

VSL#3 is associated with a significant reduction in the incidence of AAD in average-risk hospital inpatients exposed to systemic antibiotics. As the incidence of CDAD has fallen sharply, no cases of CDAD were found. Probiotic administration as prophylaxis for CDAD may not be indicated in average-risk hospital patients.