The burden of skin and soft tissue, bone and joint infections in an Australian cohort of people who inject drugs

INTRODUCTION

There are currently limited data regarding the clinical and economic significance of skin and soft tissue infections (SSTI) and bone and joint infections in Australian people who inject drugs (PWID).

METHODS

Retrospective cohort study in adult PWID admitted to Monash Health, a large heath care network with six hospitals in Victoria, Australia. Inpatients were identified using administrative datasets and International Classification of Disease (ICD-10) coding for specific infection-related conditions. Cost analysis was based on mean ward, intensive care and hospital-in-the-home (HITH) lengths of stay. Spinal infections and endocarditis were excluded as part of previous studies.

RESULTS

A total of 185 PWID (61 female, 124 male, median age 37) meeting the study criteria were admitted to Monash Health between January 2010 and January 2021. Admitting diagnoses included 78 skin abscesses, 80 cellulitis, 17 septic arthritis, 4 osteomyelitis, 3 thrombophlebitis and 1 each of necrotising fasciitis, vasculitis and myositis. Pain (87.5%) and swelling (75.1%) were the most common presenting complaints. Opioids (67.4%) and methamphetamine (37.5%) were the most common primary drugs injected. Almost half (46.5%) of patients had concurrent active hepatitis C (HCV) infection on admission. Hepatitis B (HBV) and Human Immunodeficiency Virus (HIV) were uncommon. The most significant causative organism was methicillin-susceptible Staphylococcus aureus (24.9%). In 40.0% (74/185) no organism was identified. Patients required a median acute hospital stay of 5 days (2-51 days). There were 15 patients admitted to the intensive care unit (ICU) with median duration 2 days. PICC line insertion for antibiotics was required in 16.8% of patients, while 51.4% required surgical intervention. Median duration of both oral and IV antibiotic therapy was 11 days. Almost half (48.6%) of patients were enrolled in an opioid maintenance program on discharge. Average estimated expenditure was AUD $16, 528 per admission.

CONCLUSION

Skin and soft tissue and joint infections are a major cause of morbidity for PWID. Admission to hospital provides opportunistic involvement of addiction specialty services.

Impact of changing from autopsy to post-mortem CT in an entire HM Coroner region due to a shortage of available pathologists

A significant problem facing routine medicolegal coroner-referred autopsies is a shortfall of pathologists prepared to perform them. This was particularly acute in Lancashire, where the coroner decided to initiate a service that relied on post-mortem computed tomography (PMCT). This involved training anatomical pathology technologists (APTs) to perform external examinations, radiographers to perform scans, and radiologists to interpret them. The service started in 2018 and now examines over 1,500 cases per year. This study outlines the PMCT process using NHS staff, with CT equipment and logistics managed by the commercial sector. It compares the demographics and outcomes of PM investigations for two 6-month periods: the autopsy service prior to 2018, and then the PMCT service. These data were then compared with previous UK PMCT data. Referrals for adult non-suspicious deaths were made in 913 cases of which 793 (87%) had PMCT between 01/10/2018 and 31/03/2019. Fifty-six cases had autopsy after PMCT, so 81% of cases potentially avoided autopsy. The PMCT service did not delay release of bodies to the next-of-kin. Comparing the cause of death given shows no difference in the proportions of natural and unnatural deaths. There was an increase in diagnosis of coronary artery disease for PMCT, with less respiratory diagnoses, a feature not previously demonstrated. These data suggest PMCT is a practical solution for potentially failing autopsy services. By necessity, this involves changes in diagnoses, as PMCT and autopsy have different strengths and weakness, but the ability to pick up unnatural death appears unaffected.

Impact of the COVID-19 pandemic on a post-mortem CT service for adult non-suspicious death

Due to the COVID-19 pandemic, the post-mortem computed tomography (PMCT) service was expanded from three to seven cases per day to help mortuary services and avoid invasive autopsy. Additional targeted angiography and pulmonary ventilation procedures were stopped and triage rules relaxed to allow more indications to be scanned, including those requiring toxicology. A service evaluation was performed for the first 3-months of the COVID-19 pandemic compared to the equivalent period the previous year to study the impact of these changes. It was found that, despite the increase in deaths regionally, coronial referrals remained about 100 per month, a reduction in referral rate. The number undergoing PMCT rose from 28% to 74% of cases. Turnaround time remained the same. For cases triaged to PMCT, the need for subsequent autopsy increased from 7.9% to 15.8%. No significant changes were seen in diagnosis rates, including cardiac or respiratory. There was an increase in patients with coronary death without severe coronary calcification who underwent autopsy after PMCT. These may have been diagnosed by targeted coronary angiography. Fifty-three cases requiring toxicology/biochemistry had PMCT, with 38 having PMCT only. In 8/11 (72.7%) cases with normal PMCT and toxicology as the key diagnostic test, autopsy was performed prior to results. This suggests the pathology team were reluctant to risk an "unascertained" outcome. This study shows that it is possible to increase PMCT services by widening referral criteria and by limiting the use of enhanced imaging techniques, without significantly changing diagnosis rates of key diseases; however, selectively restarting targeted angiography may help avoid autopsy in some cases.

Experimental Observations of Laser-Driven Tin Ejecta Microjet Interactions

The study of high-velocity particle-laden flow interactions is of importance for the understanding of a wide range of natural phenomena, ranging from planetary formation to cloud interactions. Experimental observations of particle dynamics are sparse given the difficulty of generating high-velocity flows of many particles. Ejecta microjets are micron-scale jets formed by strong shocks interacting with imprinted surfaces to generate particle plumes traveling at several kilometers per second. As such, the interaction of two ejecta microjets provides a novel experimental methodology to study interacting particle streams. In this Letter, we report the first time sequences of x-ray radiography images of two interacting tin ejecta microjets taken on a platform designed for the OMEGA Extended Performance (OMEGA EP) laser. We observe that the microjets pass through each other unattenuated for the case of 11.7±3.2  GPa shock pressures and jet velocities of 2.2±0.5  km/s but show strong interaction dynamics for 116.0±6.1  GPa shock pressures and jet velocities of 6.5±0.5  km/s. We find that radiation-hydrodynamic simulations of the experiments are able to capture many aspects of the collisional behavior, such as the attenuation of jet velocity in the direction of propagation, but are unable to match the full spread of the strongly interacting cloud.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

LDI-MS scanner: Laser desorption ionization mass spectrometry-based biosensor standardization

Amperometric biosensors have been widely utilized for the cost-effective and rapid analysis of various bioanalytes, for example glucose. However, a lack of standardization and validation procedures remains a major limitation in biosensor development. Therefore, despite rapid advances in material science driving the development of amperometric biosensors, to date only a few biosensors, detecting a limited range of analytes, are available on the market. It is believed, once this issue is addressed, it can significantly facilitate the next step in the overall concept "go to the market" production and implementation of amprerometric biosensors for a large industrial scale. Herein, we report on the use of laser desorption ionization mass spectrometry (LDI-MS) for the standardization of amperometric biosensors, based upon a complete and non-destructive characterization and validation of layer-by-layer (LbL) biosensors at each fabrication step. We reveal that specific ionization pathways of mediators, polymers and enzymes from the biosensor surface allows for robust quality control during LbL biosensor manufacture. Furthermore, this LDI-MS approach can also be used to monitor, and therefore ensure, the encapsulation of enzymes in one-step nanobiosensors. Specifically, we show that LDI-MS can be used for the rapid chemical profiling of LbL biosensors and one-step synthesized nanobiosensors, as well as to assess their synthesis quality and to monitor for batch-to-batch and intra- and inter-day changes in their function and behavior. Our novel approach will thus contribute to the future development, improved design and fine tuning of both conventional LbL-fabricated amperometric biosensors and one-step designed nanobiosensors.

Early Life Parechovirus Infection Neurodevelopmental Outcomes at 3 Years: A Cohort Study

OBJECTIVE

To investigate the long-term developmental and behavioral outcomes in an established cohort of children hospitalized as infants with human parechovirus (HPeV) infection and sepsis-like illness.

STUDY DESIGN

The HPeV cohort was composed of children 3 years of age after HPeV infection and hospitalization in early infancy that occurred during a well-documented HPeV genotype 3 outbreak in Australia. We assessed neurodevelopmental and behavioral outcomes using the Bayley Scales of Infant and Toddler Development-III and the Child Behavior Checklist. We compared their outcomes with a subsample of healthy control infants drawn from the independently sampled Triple B Pregnancy Cohort Study.

RESULTS

Fifty children, with a mean age of 41 months, were followed for 3 years after hospital admission with HPeV infection. There were 47 children whose original illness was fever without source or sepsis-like illness and 3 who had encephalitis. All children in the HPeV cohort showed age-specific development within the population normal range on the Bayley Scales of Infant and Toddler Development-III. There was no difference in developmental attainment compared with 107 healthy control infants after adjusting for measured confounders. The HPeV cohort showed higher average scores on the Child Behavior Checklist and a higher frequency of clinical range scores compared with healthy controls.

CONCLUSIONS

Although HPeV sepsis-like illness did not result in neurodevelopmental delay at 3 years of age, it was associated with increased behavioral problems compared with healthy controls. The behavioral problems reached a clinical threshold in a minority of children. Results inform clinical management and planning for children after severe HPeV infection in infancy.

Predictors for 30-day mortality and complications following radiologically inserted gastrostomies: a single centre, large cohort review

AIM

To measure the 30-day mortality and delayed complication rates following radiologically inserted gastrostomy (RIG) placement and determine the predictive risk factors for 30-day mortality and delayed complications to aide pre-procedure informed consent.

MATERIALS AND METHODS

Retrospective analysis was undertaken of RIG insertions between July 2012 and August 2017 at a single tertiary centre, which included 373 patients (56% male; median age: 65 years, range: 19-92 years). Data were collected from electronic databases on patient demographics, RIG indication, all-cause mortality, complication rates, patient co-morbidities, and biochemical/haematological parameters. Multivariate analysis was performed to identify predictive risk factors for complications and mortality.

RESULTS

The RIG procedural success rate was 97.9%. The overall 30-day mortality rate was 7.8%; associated with pre-procedural haemoglobin <130 g/l in men (p=0.030, odds ratio [OR] 23.38), white cell count >11×10⁹/l (p=0.001, OR 4.18), C-reactive protein >10 mg/l (p=0.003, OR 10.10) and international normalised ratio (INR) >1.2 (p=0.03, OR 4.63). Inpatient RIG referrals were associated with 10% 30-day mortality; compared to 1.1% for outpatients (p=0.028, OR 9.51). The incidence of immediate and delayed complications was 2.4% and 42.1%, respectively. Neuromuscular disease was associated with gastrostomy dislodgement (p=0.0001, OR 4.99) and fracture (p=0.0009, OR 13.45), cerebrovascular disease with gastrostomy dislodgement (p=0.009, OR 2.51), cardiovascular disease with sepsis 30-days post-RIG (p=0.02, OR 2.94), and diabetes mellitus with gastrostomy dislodgement (p=0.0001, OR 29.45), fracture (p=0.027, OR 5.63) and stoma site infections (p=0.0003, OR 7.16).

CONCLUSION

RIG 30-day mortality was significantly associated with inpatient procedures compared to outpatient, and a range of biochemical/haematological parameters that suggest infection pre-intervention. It is advised that the markers of infection and catabolism are investigated pre-intervention, which may reduce mortality and complication rates.

Towards one-step design of tailored enzymatic nanobiosensors

NP-based enzymatic biosensors were prepared by the simultaneous encapsulation of glucose and alcohol oxidases, Nafion and noble metal NPs via co-deposition from a phosphate multiple electrolyte on top of the sensor surface.

Post-mortem CT: is coronary angiography required in the presence of a high coronary artery calcium score?

AIM

To test whether a high coronary artery score predicts that the subsequent post-mortem computed tomography (PMCT) with angiography (PMCTA) will diagnose significant coronary artery disease (CAD); to test the diagnostic impact of assuming there is significant CAD based on a high coronary artery calcium (CAC) score alone; and (3) to test whether the clinical CAC score threshold (400) is the most accurate to make this prediction.

MATERIALS AND METHODS

CAC scoring and PMCTA were performed in cases of adult sudden natural death. Angiography was reviewed to determine if there was sufficient CAD to give as the cause of death. Data were analysed to test whether high calcium score predicts significant CAD.

RESULTS

PMCTA with CAC score was successful in 100/104 PMCT examinations and in 87/100 angiography examinations (87%). Forty-six cases (46%) had a CAC score of >400, the clinical level of severe disease. CAD was given as the cause of death in 31 (67%) of these cases. Angiography was successful in 39 of these cases (84.7%) and showed severe CAD in all but one (97%). Twenty-five (25%) cases were diagnosed with a CAD death without a high CAC score.

CONCLUSION

Although CAC score can neither diagnose nor exclude death due to CAD, the addition of angiography adds little diagnostic information to a high CAC score. If PMCT investigation is to exclude trauma and provide a medical cause of death on the "balance of probabilities", angiography is not required when the calcium score >400. This could reduce the number of patients requiring angiography by almost 50%.

Development of methods for the preparation of radiopure 82Se sources for the SuperNEMO neutrinoless double-beta decay experiment

A radiochemical method for producing 82Se sources with an ultra-low level of contamination of natural radionuclides (40K, decay products of 232Th and 238U) has been developed based on cation-exchange chromatographic purification with reverse removal of impurities. It includes chromatographic separation (purification), reduction, conditioning (which includes decantation, centrifugation, washing, grinding, and drying), and 82Se foil production. The conditioning stage, during which highly dispersed elemental selenium is obtained by the reduction of purified selenious acid (H2SeO3) with sulfur dioxide (SO2) represents the crucial step in the preparation of radiopure 82Se samples. The natural selenium (600 g) was first produced in this procedure in order to refine the method. The technique developed was then used to produce 2.5 kg of radiopure enriched selenium (82Se). The produced 82Se samples were wrapped in polyethylene (12 μm thick) and radionuclides present in the sample were analyzed with the BiPo-3 detector. The radiopurity of the plastic materials (chromatographic column material and polypropylene chemical vessels), which were used at all stages, was determined by instrumental neutron activation analysis. The radiopurity of the 82Se foils was checked by measurements with the BiPo-3 spectrometer, which confirmed the high purity of the final product. The measured contamination level for 208Tl was 8–54 μBq/kg, and for 214Bi the detection limit of 600 μBq/kg has been reached.

Search for Neutrinoless Quadruple-β Decay of ^{150}Nd with the NEMO-3 Detector

We report the results of a first experimental search for lepton number violation by four units in the neutrinoless quadruple-β decay of ^{150}Nd using a total exposure of 0.19 kg yr recorded with the NEMO-3 detector at the Modane Underground Laboratory. We find no evidence of this decay and set lower limits on the half-life in the range T_{1/2}>(1.1-3.2)×10^{21}  yr at the 90% C.L., depending on the model used for the kinematic distributions of the emitted electrons.

The BiPo-3 detector

The BiPo-3 detector is a low radioactive detector dedicated to measuring ultra-low natural contaminations of ²⁰⁸Tl and ²¹⁴Bi in thin materials, initially developed to measure the radiopurity of the double β decay source foils of the SuperNEMO experiment at the μBq/kg level. The BiPo-3 technique consists in installing the foil of interest between two thin ultra-radiopure scintillators coupled to low radioactive photomultipliers. The design and performances of the detector are presented. In this paper, the final results of the ²⁰⁸Tl and ²¹⁴Bi activity measurements of the first enriched ⁸²Se foils are reported for the first time, showing the capability of the detector to reach sensitivities in the range of some μBq/kg.

Minimising the impact of errors in the interpretation of CT images for surveillance and evaluation of therapy in cancer

Radiological error is inevitable and usually multifactorial. Error can be secondary to radiologist-specific causes, including cognitive and perceptive errors or ambiguity of report, or system-related causes, including inadequate, misleading, or incorrect clinical information, poor imaging technique, excessive workload, and poor working conditions. In this paper, we discuss a systematic approach to reduce errors in oncological radiology reporting, thus reducing risk to the patient. Rather than attempt to discuss all types of error, we concentrate on the most important and commonly occurring errors that we have encountered over 20 years of practice, based on weekly discrepancy reviews of our practice and independent reviews of clinical and research imaging from other institutions. This review focuses on computed tomography (CT) reporting for staging, surveillance, and response assessment of cancer patients, but the messages apply to all imaging methods.

Reproductive performance in ewes fed varying levels of cut lucerne pasture around conception

Elevated intakes of protein and energy may increase embryo mortality, but it is not clear whether fresh lucerne (Medicago sativa) pasture poses a risk. A two-year pen study using oestrous synchronised and artificially inseminated Merino ewes (n=175 in 2013 and 215 in 2014) evaluated whether feeding freshly cut lucerne pasture (mean crude protein 19.7%, metabolisable energy 9.4MJ/kg DM) at maintenance or ad libitum during different periods around insemination altered reproductive performance in comparison with ewes fed a Control diet (mean crude protein 7.8%, metabolisable energy 9.0MJ/kg DM) of pelleted faba bean hulls and oat grain hulls at maintenance. The proportion of pregnant ewes carrying multiple fetuses was reduced (P=0.026) when ewes were fed lucerne ad libitum between days 0 and 17 after insemination compared with the Control diet (0.18 and 0.34, respectively), but not when ewes were fed lucerne ad libitum between days 0 and 7 after insemination (0.22). Reproductive performance, including the proportion of ewes pregnant and the proportion with multiple fetuses, was not different (P>0.05) when ewes were fed lucerne at maintenance between days 0 and 7 compared with the Control diet. While reproductive performance was similar when ewes were fed lucerne at maintenance between 0 and 17 days after artificial insemination compared with pellets at maintenance, fetal numbers per pregnant ewe were reduced by feeding lucerne ad libitum after insemination.

Adult post-mortem imaging in traumatic and cardiorespiratory death and its relation to clinical radiological imaging

The use of post-mortem imaging is expanding throughout the world with increasing use of advanced imaging techniques, such as contrast-enhanced CT and MRI. The questions asked of post-mortem imaging are complex and can be very different, for example for natural sudden death investigation will focus on the cause, whereas for trauma the cause of death is often clear, but injury patterns may be very revealing in investigating the background to the incident. Post-mortem imaging is different to clinical imaging regarding both the appearance of pathology and the information required, but there is much to learn from many years of clinical research in the use of these techniques. Furthermore, it is possible that post-mortem imaging research could be used not only for investigating the cause of death but also as a model to conduct clinically relevant research. This article reviews challenges to the development of post-mortem imaging for trauma, identification and cardiorespiratory death, and how they may be influenced by current clinical thinking and practice.

A new variable for SRS plan quality evaluation based on normal tissue sparing: the effect of prescription isodose levels

OBJECTIVE

A new dosimetric variable, dose-dropping speed (DDS), was proposed and used to evaluate normal tissue sparing among stereotactic radiosurgery (SRS) plans with different prescription isodose lines.

METHODS

40 plans were generated for 8 intracranial SRS cases, prescribing to isodose levels (IDLs) ranging from 50% to 90% in 10% increments. Whilst maintaining similar coverage and conformity, plans at different IDLs were evaluated in terms of normal tissue sparing using the proposed DDS. The DDS was defined as the greater decay coefficient in a double exponential decay fit of the dose drop-off outside the planning target volume (PTV), which models the steep portion of the drop-off. Provided that the prescription dose covers the whole PTV, a greater DDS indicates better normal tissue sparing.

RESULTS

Among all plans, the DDS was found to be the lowest for the prescription at 90% IDL and the highest for the prescription at 60% or 70%. The beam profile slope change in the penumbra and its field size dependence were explored and given as the physical basis of the findings.

CONCLUSION

A variable was proposed for SRS plan quality evaluation. Using this measure, prescriptions at 60% and 70% IDLs were found to provide best normal tissue sparing.

ADVANCES IN KNOWLEDGE

A new variable was proposed based on which normal tissue sparing was quantitatively evaluated, comparing different prescription IDLs in SRS.

Post-mortem computed tomography ventilation; simulating breath holding

Whilst the literature continues to report on advances in the use of post-mortem computed tomography (PMCT), particularly in relation to post-mortem angiography, there are few papers published that address the diagnostic problems related to post-mortem changes in the lungs and ventilation. We present a development of previous methods to achieve ventilated PMCT (VPMCT). We successfully introduced a supraglottic airway in 17/18 cases without causing overt damage, despite rigor mortis. Using a clinical portable ventilator, we delivered continuous positive airway pressure to mimic clinical breath-hold inspiratory scans. This caused significant lung expansion and a reduction in lung density and visible normal post-mortem changes. All thoracic pathology identified at autopsy, including pneumonia, was diagnosed on VPMCT in this small series. This technique provides a rapid form of VPMCT, which can be used in both permanent and temporary mortuaries, allowing for the post-mortem radiological comparison of pre-ventilation and post-ventilation images mimicking expiratory and inspiratory phases. We believe that it will enhance the diagnostic ability of PMCT in relation to lung pathology.

The multifaceted effects of omega-3 polyunsaturated Fatty acids on the hallmarks of cancer

Omega-3 polyunsaturated fatty acids, in particular eicosapentaenoic acid, and docosahexaenoic acid have been shown to have multiple beneficial antitumour actions that affect the essential alterations that dictate malignant growth. In this review we explore the putative mechanisms of action of omega-3 polyunsaturated fatty acid in cancer protection in relation to self-sufficiency in growth signals, insensitivity to growth-inhibitory signals, apoptosis, limitless replicative potential, sustained angiogenesis, and tissue invasion, and how these will hopefully translate from bench to bedside.

The effect on toxicology, biochemistry and immunology investigations by the use of targeted post-mortem computed tomography angiography

It is recognised in autopsy practice that investigations such as toxicology can be affected by post-mortem change. Post-mortem computed tomography angiography (PMCT-A) involves the injection of contrast agents. This could cause dilution of a biological fluid sample or cause the circulation of blood after death by mechanical pumping, and thus has the potential to affect laboratory investigations. We undertook a small sample study to consider whether targeted PMCT-A had any significant effect on subsequent samples taken for biochemical, toxicological or immunological investigations. Although the results of our study do illustrate differences between the pre and post PMCT-A results, these differences are considered not to be of diagnostic significance and not due to the direct effect of targeted PMCT-A.

Imaging vascular function for early stage clinical trials using dynamic contrast-enhanced magnetic resonance imaging

Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. Key Points • Tumour vascular function is key to tumour development and treatment • Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess tumour vascular function • Thus DCE-MRI with pharmacokinetic models can assess novel treatments • Many recent developments are advancing the accuracy of and information from DCE-MRI • Establishing common methodology across multiple centres is challenging and requires accepted guidelines.