Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite

The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.

Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite

The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.

1199Reduction in blood pressure following renal denervation for patients with differing baseline cardiovascular risk

Background

Lowering blood pressure (BP) reduces clinical events. Renal denervation (RDN) is under investigation for treatment of uncontrolled hypertension and might represent a particularly attractive option for patients with high cardiovascular (CV) risk. To evaluate this proposal, it is important to determine whether baseline CV risk impacts the efficacy of RDN in lowering BP.

Purpose

We evaluated whether BP changes after RDN were dependent on baseline CV risk.

Methods

AHA/ACC Atherosclerosis CV Disease (ASCVD) risk score was calculated for patients in the Global Symplicity Registry (GSR; NCT01534299), a global registry of RDN in patients with uncontrolled hypertension, using baseline office systolic BP, total/HDL cholesterol measurements, diabetic and smoking status, gender, age, and number of baseline anti-hypertensive medications. Patients were separated into 3 groups based on ASCVD risk scores: <10%, ≥10% and <20% and ≥20%. Baseline demographics and 24-hour systolic BP changes at 6 months and 1, 2 and 3 years were compared between groups, as well as rates of adverse events at 3 years.

Results

Individual ASCVD risk scores were calculated for 1,434 patients in GSR. The median ASCVD risk score was 19.4% and 403 patients had a risk score of <10%, 326 a risk score of ≥10 and <20%, and 705 a risk score ≥20%. Patients with ASCVD risk score ≥20% had a higher baseline office systolic BP, were significantly older, and had higher rates of prior myocardial infarction and/or diabetes (all p<0.0001 compared to patients with lower risk scores). RDN reduced BP similarly across all groups of patients. Changes in 24-hour systolic BP at 6 months and 1, 2 and 3 years are shown in Figure 1. Adverse events at 3 years are shown in Table 1.

Adverse events at 3 years ASCVD risk score <10% ASCVD risk score ≥10% & <20% ASCVD risk score ≥20% p-value (N=265) (N=224) (N=468) Death 3 (1.1) 5 (2.2) 41 (8.8) <0.0001 Cardiovascular death 3 (1.1) 2 (0.9) 23 (4.9) 0.0017 Myocardial infarction 6 (2.3) 6 (2.7) 11 (2.4) 0.9513 Stroke 8 (3.0) 9 (4.0) 24 (5.1) 0.3894 Hospitalization for new onset heart failure 4 (1.5) 7 (3.1) 26 (5.6) 0.0194 Values are proportions reported as n (%).

Conclusions

BP changes after RDN were similar for patients with varying baseline ASCVD risk scores, suggesting uniform BP-lowering efficacy of RDN regardless of patients' baseline CV risk. The impact of baseline risk on clinical event reduction by RDN-induced BP reduction will need to be evaluated in further studies.

Acknowledgement/Funding

The Global SYMPLICITY Registry is funded by Medtronic.

Point-of-care Hepatitis C virus testing and linkage to treatment in an Australian inner-city emergency department

BACKGROUND

In Australia, Hepatitis C Virus (HCV) treatment is declining, despite broad access to direct-acting antiviral medication. People who inject drugs are proportionally over-represented in emergency department presentations. Emergency department assessment of people who have injected drugs for HCV presents an opportunity to engage this marginalised population with treatment. We describe the outcomes of risk-based screening and point-of-care anti-HCV testing for emergency department patients, and linkage to outpatient antiviral treatment.

METHODS

During the three-month study period, consecutive adult patients who presented to the emergency department during the study times were screened for risk factors and offered the OraQuick oral HCV antibody test. Those with reactive results were offered venepuncture in the emergency department for confirmatory testing and direct-acting antiviral treatment in clinic. The main outcome measures were the number and proportion of viremic participants that were linked to the hepatitis clinic, commenced treatment and achieved a sustained viral response. Secondary outcome measures were the proportion (%) of presentations screened that were oral antibody reactive, and the prevalence and type of HCV risk factors.

RESULTS

During the study period, 2408 of the 3931 (61%) presentations to the emergency department were eligible for screening. Of these 2408 patients, 1122 (47%) participated, 307 (13%) declined participation and 977 (41%) could not be approached during their time in the emergency department. Among the 1122 participants, 378 (34%) reported at least one risk factor. Subsequently, 368 (97%) of the 378 participants underwent OraQuick anti-HCV test, and 50 (14%) had a reactive result. A risk factor of ever having injected drugs was present in 44 (88%) of participants who were sero-positive. Of the 45 that had blood tested, 30 (67%) were HCV ribonucleic acid (RNA) positive. Three participants died. Of the 27 remaining participants, 10 (37%) commenced treatment and 7 of these 10 (70%) obtained a cure. There was a high rate of homelessness (24%) among anti-HCV positive participants.

CONCLUSION

Among emergency department participants with a risk factor for HCV, positive serology was common using a rapid point-of-care test. A history of injecting drug use was identified as the risk factor with highest yield for positive HCV serology, and is suitable as a single screening question. However, linkage to care post ED presentation was low in this marginalised population. There is a need for new pathways to improve the care cascade for marginalised individuals living with HCV infection.

Childhood adversity, mental health and suicide (CHASE): a methods protocol for a longitudinal case-control linked data study

Introduction

Suicide is a tragic outcome with devastating consequences. In 2018, Scotland experienced a 15% increase in suicide from 680 to 784 deaths. This was marked among young people, with an increase of 53% in those aged 15-24, the highest since 2007. Early intervention in those most at risk is key, but identification of individuals at risk is complex, and efforts remain largely targeted towards universal suicide prevention strategies with little evidence of effectiveness.

Recent evidence suggests childhood adversity is a predictor of subsequent poor social and health outcomes, including suicide. This protocol reports on methodology for harmonising lifespan hospital contacts for childhood adversity, mental health, and suicidal behaviour. This will inform where to 1) focus interventions, 2) prioritise trauma-informed approaches, and 3) adapt support avenues earlier in life for those most at risk.

Methods

This study will follow a case-control design. Scottish hospital data (physical health SMR01; mental health SMR04; maternity/birth record SMR02; mother’s linked data SMR01, SMR04, death records) from 1981 to as recent as available will be extracted for people who died by suicide aged 10-34, and linked on Community Health Index unique identifier. A randomly selected control population matched on age and geography at death will be extracted in a 1:10 ratio. International Classification of Disease (ICD) codes will be harmonised between ICD9-CM, ICD9, ICD10-CM and ICD10 for childhood adversity, mental health, and suicidal behaviour.

Results

ICD codes for childhood adversity from four key studies are reported in two categories, 1) Maltreatment or violence-related codes, and 2) Codes suggestive of maltreatment. ‘Clinical Classifications Software’ ICD codes to operationalise mental health codes are also reported. Harmonised lifespan ICD categories were achieved semi-automatically, but required labour-intensive supplementary manual coding. Cross-mapped codes are reported.

Conclusion

There is a dearth of evidence about touchpoints prior to suicide. This study reports methods and harmonised ICD codes along the lifespan to understand hospital contact patterns for childhood adversity, which come to the attention of hospital practitioners.

Key words

Childhood Adversity, Adverse Childhood Experiences, Mental Health, Self-harm, Suicide, Suicidality, Violence, Hospital episodes, Routine Data, Data Linkage, Study Protocol

Elevated fibrinogen, von Willebrand factor, and Factor VIII confer resistance to dilutional coagulopathy and activated protein C in normal pregnant women

BACKGROUND

Gestational changes in coagulation factor concentrations include elevations in fibrinogen, Factor VIII, and von Willebrand factor (vWF). We hypothesised that blood samples from term pregnant (TP) subjects are less prone to coagulation disturbances from haemodilution compared with those from non-pregnant (NP) females.

METHODS

Blood samples were collected from 15 NP and 15 TP subjects. In vitro haemodilution with normal saline was assessed by modified Clauss fibrinogen assay, factor activity, flow-chamber assay, and thromboelastometry. The impact of human fibrinogen concentrate (hFC), cryoprecipitate, and vWF/Factor VIII (FVIII) concentrate replacement in diluted TP and NP blood was compared. Thrombin generation and activated protein C sensitivity were assessed.

RESULTS

TP blood contained twice the concentrations of fibrinogen, FVIII, and vWF relative to NP blood (P<0.0001). Platelet thrombus formation (PTF) under flow was reduced by 99.2% and 69.2% in diluted NP and TP blood, respectively. Platelet thrombus formation was partially restored by adding vWF/FVIII, but not hFC or cryoprecipitate. Fibrin clot firmness approached the threshold of 10 mm in diluted NP blood, and clot firmness was effectively restored by hFC, but not by vWF/FVIII. In the presence of thrombomodulin, peak thrombin generation was decreased by 86.7% in NP plasma, but by 31.8% in TP plasma (P<0.0001 vs NP plasma), indicating reduced activated protein C sensitivity in TP plasma. Both elevated FVIII and haemodilution contributed to activated protein C insensitivity.

CONCLUSIONS

Our in vitro model showed relative resistance of TP blood to dilutional coagulation changes with respect to platelet adhesion, fibrin polymerisation, and thrombin generation. Careful therapeutic monitoring for different pro-haemostatic agents in pregnant women is warranted.

Cord injury after spinal anaesthesia in a patient with previously undiagnosed Klippel-Feil syndrome

This report presents an obstetric patient with no significant past medical history who underwent spinal anaesthesia for a category-three caesarean section. On examination, she had asymmetrical scapular alignment and a mild scoliosis of the lumbar spine with no functional limitation. Postoperatively the patient developed neuropathic pain symptoms in the right leg which failed to resolve with conventional analgesia. Cervical and lumbar spine magnetic resonance imaging was performed resulting in a diagnosis of a low-lying tethered spinal cord terminating at the level of L5 and congenital fusion of the C7/T1 vertebrae. A tethered spinal cord is a rare condition, which in this case had been completely asymptomatic. However, we suggest that the patient displayed musculoskeletal signs not previously widely reported, which could have indicated the presence of a potential underlying neural tube defect. Based on the imaging findings and the presence of Sprengel's deformity, the patient was diagnosed with Klippel-Feil syndrome.

Estimating Aspergillus fumigatus exposure from outdoor composting activities in England between 2005 and 14

Bioaerosols, ubiquitous in ambient air, are released in elevated concentrations from composting facilities with open-air processing areas. However, spatial and temporal variability of bioaerosols, particularly in relation to meteorology, is not well understood. Here we model relative concentrations of Aspergillus fumigatus at each postcode-weighted centroid within 4 km of 217 composting facilities in England between 2005 and 2014. Facilities were geocoded with the aid of satellite imagery. Data from existing bioaerosol modelling literature were used to build emission profiles in ADMS. Variation in input parameters between each modelled facility was reduced to a minimum. Meteorological data for each composting facility was derived from the nearest SCAIL-Agriculture validated meteorological station. According to our results, modelled exposure risk was driven primarily by wind speed, direction and time-varying emissions factors incorporating seasonal fluctuations in compostable waste. Modelled A.fumigatus concentrations decreased rapidly from the facility boundary and plateaued beyond 1.5-2.0 km. Where multiple composting facilities were within 4 km of each other, complex exposure risk patterns were evident. More long-term bioaerosol monitoring near facilities is needed to help improve exposure estimation and therefore assessment of any health risks to local populations.

Hepatic steatosis is highly prevalent across the paediatric age spectrum, including in pre-school age children

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children is 8% in the general population, and 34% in the context of obesity. There is a paucity of data on the prevalence of hepatic steatosis in healthy children in Ontario.

AIMS

To determine the prevalence of hepatic steatosis using abdominal computed tomography (CT) scans in a cohort of previously healthy children across the paediatric age spectrum in Ontario, Canada, and to determine any association between measures of abdominal adiposity and hepatic steatosis.

METHODS

Retrospective review of the SickKids Trauma Database from 2004-2015. Previously healthy children ages 1-17 years having undergone an abdominal CT scan as a part of routine trauma assessment were included, and those with an intra-abdominal injury excluded. Steatosis was defined as a difference between liver and spleen attenuation ≤-25HU. The percentage of the total area occupied by abdominal subcutaneous adipose and visceral adipose tissue was measured. Anthropometrics and baseline demographics were collected.

RESULTS

A total of 503 (51% male) children with mean (±SD) age 9.5 ± 4.5 years and weight z-score of 0.37 ± 1.05 were studied. Seventy-seven (15%, 95% CI [12%-18%]) had hepatic steatosis; no differences found between sexes or across age quartiles. The abdominal subcutaneous adipose tissue area was greater in those with hepatic steatosis compared to those without (32% [22-42] vs 24% [17-36], P = 0.003). The visceral adipose tissue area was significantly greater in older children ≥9.8 years with hepatic steatosis (7.7% [5.1-10] vs 6.6% (4.9-8.5), P = 0.04).

CONCLUSION

Hepatic steatosis was highly prevalent in previously healthy children in Ontario, including children of pre-school age. We found an association between hepatic steatosis and abdominal subcutaneous adipose tissue, and in older children with visceral adipose tissue.

Who's challenging who training for staff empathy towards adults with challenging behaviour: cluster randomised controlled trial

BACKGROUND

One in five adults with intellectual disabilities (ID) known to services display challenging behaviours (CBs), and these individuals are at risk for restrictive practices and poor care. Staff attitudes may contribute to the development and/or maintenance of CBs. We investigated the effectiveness of co-produced Who's Challenging Who? training delivered by people with ID to staff.

METHOD

This study involved a cluster randomised controlled trial (RCT) of Who's Challenging Who? training with follow-up at six and 20 weeks post-randomisation.

PARTICIPANTS

two staff from each of 118 residential care settings for adults with ID at least one of whom displayed aggressive CB.

PRIMARY OUTCOME

Self-reported Staff Empathy for people with Challenging Behaviour Questionnaire.

ANALYSIS

intention to treat of all randomised settings. ISCRTN registration: ISRCTN53763600.

RESULTS

118 residential settings (including 236 staff) were randomised to either receive training (59 settings) or to receive training after a delay (59 settings). The primary analysis included data from 121 staff in 76 settings (51% of staff, 64% of settings). The adjusted mean difference on the transformed (cubed) Staff Empathy for people with Challenging Behaviour Questionnaire score at the primary end point was 1073.2 (95% CI: -938.1 to 3084.5, P = 0.296) in favour of the intervention group (effect size Cohen's d = .19).

CONCLUSIONS

This is the first large-scale RCT of a co-produced training course delivered by people with ID. Findings indicated a small positive (but statistically non-significant) effect on increased staff empathy at 20 weeks, and small to moderate effects for staff reported secondary outcomes in favour of the intervention group.

On the Pathogenesis of Syringomyelia: A Review

Discussion of the pathogenesis of syringomyelia involves considering the origin of the fluid and also the forces which cause that fluid to break down the structure of the cord. When cerebrospinal fluid (CSF) appears to be the destructive element, it commonly enters through a patent central canal running from the fourth ventricle to the inside of the syrinx. In both clinical and experimental situations pressure differences may be measured which suck on the hindbrain, particularly the cerebellar tonsils, producing deformities. These pressure differences may also suck fluid into the syrinx. In other cases, even when a communication does not appear to be patent, the hindbrain abnormalities are usually present and suck effect may usually be demonstrated and its correction be accompanied by clinical improvement. Other sources of fluid within a syrinx include liquefaction of haematomata after traumatic paraplegia and transudation of fluid from intrinsic spinal tumours. Once fluid is present within a cord cavity it may pulsate upwards and downwards in response to fluid movements in the subarachnoid space, the most energetic of which result from venous influences. Such movement, ‘slosh’, may cause the cavities to extend at either end giving rise to upward and downward extension from a post-traumatic cord cyst and sometimes to syringobulbia. Cord ischaemia, venous congestion and transport of fluid along perivascular spaces may all play a part in the maintainance of cord cavities or the progression of the clinical disabilities.

Laryngeal recurrence sites in patients previously treated with transoral laser microsurgery for squamous cell carcinoma

BACKGROUND

The laryngeal framework provides a natural barrier preventing tumour spread to extralaryngeal structures. Transoral laser microsurgery (TLM) for laryngeal squamous cell carcinoma (SCC) may violate these boundaries, altering the pathways of tumor spread for potential recurrences. Our project objective is to describe laryngeal SCC recurrence patterns and overall survival in patients requiring total laryngectomy (TL) after TLM.

METHODS

Patients undergoing TLM for laryngeal SCC requiring salvage TL were identified from a prospective CO2 laser database containing all patients undergoing TLM for head and neck malignancies at the QEII Health Sciences Center in Halifax, Nova Scotia between March 2002 - May 2014. Surgical pathology reports were analyzed for tumor characteristics, extent of recurrence and invasion of local structures. Kaplan-Meier analyses were performed to evaluate overall survival, disease specific survival (DSS) and locoregional control.

RESULTS

Fifteen patients were identified from the database as receiving salvage TL for recurrent disease after initial TLM resection for laryngeal SCC. Final pathology reports demonstrated that 67% (10/15) of patients had thyroid cartilage involvement while 53% (9/15) of patients had cricoid cartilage involvement on salvage TL pathology. 33% (5/15) of patients had perineural invasion and 27% (4/15) had lymphovascular invasion. Mean and median follow-up times were 36.7 months and 26.8 months respectively (range 3.9-112.6). The Kaplan-Meier estimate for overall survival at 36 months was 40% post TL with a standard error (SE) of 13.6%. DSS was 47% (SE 14.2%), and locoregional control was 55% (SE 14.5%) post TL.

CONCLUSIONS

Laryngeal recurrence sites following TLM seem to be consistent with historical data at known laryngeal sites of vulnerability. Treatment with TLM does not predispose patients to a lower rate of locoregional control and overall survival after total laryngectomy and salvage outcomes are consistent with literature values.

Effective macrophage delivery using RAFT copolymer derived nanoparticles

We use reversible addition fragmentation chain transfer (RAFT) polymerisation to prepare block copolymers that are subsequently assembled into nanoparticles. The prepared nanoparticles were extensively taken up by primary murine macrophages and are effective in the delivery of a cell impenetrable cargo.

Evaluation of genes associated with human myxomatous mitral valve disease in dogs with familial myxomatous mitral valve degeneration

Myxomatous mitral valve disease (MMVD) is the most common heart disease in the dog. It is believed to be heritable in Cavalier King Charles spaniels (CKCS) and Dachshunds. Myxomatous mitral valve disease is a familial disease in human beings as well and genetic mutations have been associated with its development. We hypothesized that a genetic mutation associated with the development of the human form of MMVD was associated with the development of canine MMVD. DNA was isolated from blood samples from 10 CKCS and 10 Dachshunds diagnosed with MMVD, and whole genome sequences from each animal were obtained. Variant calling from whole genome sequencing data was performed using a standardized bioinformatics pipeline for all samples. After filtering, the canine genes orthologous to the human genes known to be associated with MMVD were identified and variants were assessed for likely pathogenic implications. No variant was found in any of the genes evaluated that was present in least eight of 10 affected CKCS or Dachshunds. Although mitral valve disease in the CKCS and Dachshund is a familial disease, we did not identify genetic cause in the genes responsible for the human disease in the dogs studied here.