Effects of Blood Flow Restriction Resistance Training on Autonomic and Endothelial Function in Persons with Parkinson's Disease

Background

Autonomic dysfunction precedes endothelial dysfunction in Parkinson's disease (PD) and causes blood pressure and circulation abnormalities that are highly disruptive to one's quality of life. While exercise interventions have proven helpful for motor symptoms of PD, improving associated non-motor symptoms is limited. Low-intensity resistance training with blood flow restriction (LIRT-BFR) improves autonomic dysfunction in non-PD patients and high-intensity resistance training (HIRT) is recommended for motor symptom improvements for people with PD (PwPD).

Objective

To determine the effects of LIRT-BFR and HIRT on homocysteine and autonomic and endothelial function in PwPD and to determine the hemodynamic loads during LIRT-BFR and HIRT in PwPD using a novel exercise protocol.

Methods

Thirty-eight PwPD were assigned LIRT-BFR, HIRT or to a control (CNTRL) group. The LIRT-BFR and HIRT groups exercised three days per week for four weeks. The LIRT-BFR protocol used 60% limb occlusion pressure (LOP) and performed three sets of 20 repetitions at 20% of the one-repetition maximum (1RM). The HIRT group performed three sets of eight repetitions at 80% 1RM. The CNTRL group was asked to continue their normal daily routines.

Results

LIRT-BFR significantly improved orthostatic hypotension (p = 0.026), homocysteine levels (p < 0.001), peripheral circulation (p = 0.003), supine blood pressure (p = 0.028) and heart rate variability (p = 0.041); LIRT-BFR improved homocysteine levels (p < 0.018), peripheral circulation (p = 0.005), supine blood pressure (p = 0.007) and heart rate variability (p = 0.047) more than HIRT; and hemodynamic loads for LIRT-BFR and HIRT were similar.

Conclusions

LIRT-BFR may be more effective than HIRT for autonomic and endothelial function improvements in PwPD and hemodynamic loads may be lessened in LIRT-BFR protocols using single-joint exercises with intermittent blood flow restriction. Further research is needed to determine if non-motor symptoms improve over time and if results are sustainable.

Sacral fracture stabilisation using dorsal transiliac locking plates: 12 cases (2017-2023)

OBJECTIVES

To describe the clinical presentations, outcomes and complications associated with the use of dorsal transiliac locking plates to stabilise sacral fractures in dogs and cats.

MATERIALS AND METHODS

A single-centre retrospective analysis of all patients that presented with sacral fractures between February 2017 and February 2023 that were managed surgically using paired dorsal transiliac locking plates. Twelve animals met the criteria for inclusion in a retrospective clinical case series. An owner questionnaire was employed to assess long-term outcomes.

RESULTS

Eleven dogs and one cat with a mean age of 3.1 years (range 0.6 to 8.8) were included. Eleven patients presented following a motor vehicle accident and most were either non-ambulatory (n=8) or displayed severe unilateral hindlimb lameness (n=4). Nine sacral fractures were considered Anderson type II and three Anderson type V. The plate fixation was augmented with additional surgical stabilisation in 11 cases. Eleven patients were ambulatory at discharge and all cases healed uneventfully without major surgical or postoperative complications. Long-term follow-up (>60 days) was available in 10 animals at a mean of 694 days (range 65 to 1805) and owner-assessed outcomes via questionnaire were reported as good to excellent in all cases.

CLINICAL SIGNIFICANCE

The application of transiliac locking plates provided sufficient stability to facilitate sacral fracture healing with minimal clinical complications. This method represents a robust and safe option to stabilise sacral fractures in dogs and cats, offering an alternative to iliosacral lag screw fixation.

Frequency, kinetics and determinants of viable SARS-CoV-2 in bioaerosols from ambulatory COVID-19 patients infected with the Beta, Delta or Omicron variants

Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10μm and <5μm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV > 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5μm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.

A modified triple tibial osteotomy for management of canine cranial cruciate ligament disease: retrospective assessment of 309 procedures (2017-2020)

CASE HISTORY

Medical records from a single referral hospital (Animal Referral Hospital, Sinnamon Park, Australia) of dogs treated with modified triple tibial osteotomy (TTO) for management of cranial cruciate ligament (CrCL) disease from June 2017 to June 2020 were reviewed. Modifications to the originally described TTO procedure included a modified wedge angle calculation and performing the tibial osteotomies without the use of pre-drilled guide holes.

CLINICAL FINDINGS

A total of 253 dogs met the inclusion criteria. Two dogs were excluded, leaving 251 dogs that had undergone 309 procedures for assessment, and data from these, including complications, were reviewed. Complete, partial competent, and partial incompetent rupture of the cranial cruciate ligament was identified in 202/309 (65.4%), 79/309 (25.6%), and 28/309 (9.1%) stifles, respectively. Medial meniscal injury was identified in 207/309 (67.0%) stifles at the time of initial surgery.

TREATMENT AND OUTCOME

Fifty-eight dogs had bilateral procedures, including both single-session and staged surgeries, and 48 of these were available for analyses. The modifications to the TTO procedure described herein resulted in a median wedge angle of 21° and a median post-operative tibial plateau angle of 5.8°. Tibial compression testing following surgery indicated elimination of cranial tibial thrust in all stifles in this series. The most common intra-operative complication was tibial tuberosity fracture (15/309; 4.9%). Minor post-operative complications occurred in 37/309 (12.0%) procedures, with infection being the most common (27/309; 8.7%). Major post-operative complications occurred in 9/309 (2.9%) procedures. The intra- and post-operative complication rates for dogs undergoing bilateral single-session TTO were both 8.3% (2/24). The intra- and post-operative complication rates for dogs undergoing bilateral staged TTO were both 4.2% (1/24). The low number of complications for both the bilateral single-session and bilateral staged TTO groups precluded statistical analysis. All complications resolved uneventfully as determined by the attending surgeon.

CLINICAL RELEVANCE

The modified TTO technique described here was safe and effective for the management of canine CrCL disease in the dogs included in the case series. Findings of this study suggest that, with careful case selection, the modified TTO may be performed as a bilateral single-session procedure in dogs with concurrent bilateral cranial cruciate ligament disease. Future studies analysing the effects of these modifications on stifle biomechanics would be beneficial.

ABBREVIATIONS

CrCL: Cranial cruciate ligament; SSI: Surgical site infection; TPA: Tibial plateau angle; TPLO: Tibial plateau levelling osteotomy; TTA: Tibial tuberosity advancement; TTO: Triple tibial osteotomy.

MRI prediction of fetal lung volumes and the impact on counselling

AIM

To assess whether lung volume percentages in congenital diaphragmatic hernia (CDH) differ depending on which formula is used to calculate the expected volume for gestation and any potential impact this may have on perinatal counselling.

MATERIALS AND METHODS

Forty-seven patients with left-sided CDH who had undergone fetal magnetic resonance imaging (MRI) at Sheffield Teaching Hospitals were reviewed. The lung volumes were measured on MRI and compared with the volumes that would be expected at the given gestation for each patient. Expected values were calculated using four formulae from the literature and the authors' in-house method. These measurements were used to calculate the percentage total lung volume observed compared with the expected lung volume in a healthy fetus of the same gestation. The differences in percentage lung volumes using these five methods were then compared with how they relate to predicted rates of survival. How predicted survival would change depending on which formula was used to calculate the percentage lung volume was investigated with a view to how this may change the counselling given to a family.

RESULTS

In 10/47 (21%) patients, there was no change in the predicted percentage chance of survival depending on which formula was used to calculate the predicted lung volume. In 37/47 (79%), the predicted chance of survival changed depending on which formula was used to calculate the expected lung volume at the given gestation. In 20 (47%) of these cases, the change in predicted survival depending on which formula used was 45% (i.e., from 25% to 70% survival in four and from 50% to 95% survival in 16) and in two cases (4%) this difference was 70% (i.e., from 25% predicted survival to 95% predicted survival).

CONCLUSION

There are several different methods for calculating expected lung volumes for any given gestation. When used to estimate the percentage lung volume in patients with CDH, there is a large difference in values depending on which method is used. This in turn leads to a large variation in predicted survival with some patients in this study having either a 25% or 95% chance of survival depending on which method is used. This has a huge impact on perinatal counselling and the difficult decisions made by families.

Acceptability and use of waist-worn physical activity monitors in Jamaican adolescents: lessons from the field

OBJECTIVE

We report our experience with a validated waist-worn activity monitor in Jamaican adolescents attending urban high schools. Seventy-nine adolescents from the Global Diet and Activity Research (GDAR) study, recruited from 5 urban Jamaican high schools (two coeducational (n = 37), two all-female schools (n = 32) and one all-boys school (n = 10)) were asked to wear Actigraph wGT3X-BT accelerometers for 7 days (24-h), removing the device only when bathing or swimming. They also logged wake up and bed times in an activity diary. Accelerometry was considered valid if at least 4 days with ≥ 10-h monitor wear were recorded. Validity was compared by adolescent demographic and school characteristics. We also reviewed the students' written feedback on objective physical activity measurement.

RESULTS

Participants, 80.5% female, had a mean age of 15.5 ± 0.8 years with 60% attending schools in low-income communities. Accelerometer return rates were > 98% with 84% providing valid data. Validity did not vary by age group, sex and school setting. While participants were excited about participating in the accelerometer sub-study, commonly reported challenges included monitor discomfort during sleep and maintaining the study diary. Objective measurement of physical activity using 24-h waist-worn accelerometers is feasible and acceptable in Jamaican adolescents.

Randomised controlled trial of the short-term effects of osmotic-release oral system methylphenidate on symptoms and behavioural outcomes in young male prisoners with attention deficit hyperactivity disorder: CIAO-II study

BACKGROUND

Research has shown that 20-30% of prisoners meet the diagnostic criteria for attention-deficit hyperactivity disorder (ADHD). Methylphenidate reduces ADHD symptoms, but effects in prisoners are uncertain because of comorbid mental health and substance use disorders.

AIMS

To estimate the efficacy of an osmotic-release oral system methylphenidate (OROS-methylphenidate) in reducing ADHD symptoms in young adult prisoners with ADHD.

METHOD

We conducted an 8-week parallel-arm, double-blind, randomised placebo-controlled trial of OROS-methylphenidate versus placebo in male prisoners (aged 16-25 years) meeting the DSM-5 criteria for ADHD. Primary outcome was ADHD symptoms at 8 weeks, using the investigator-rated Connors Adult ADHD Rating Scale (CAARS-O). Thirteen secondary outcomes were measured, including emotional dysregulation, mind wandering, violent attitudes, mental health symptoms, and prison officer and educational staff ratings of behaviour and aggression.

RESULTS

In the OROS-methylphenidate arm, mean CAARS-O score at 8 weeks was estimated to be reduced by 0.57 points relative to the placebo arm (95% CI -2.41 to 3.56), and non-significant. The responder rate, defined as a 20% reduction in CAARS-O score, was 48.3% for the OROS-methylphenidate arm and 47.9% for the placebo arm. No statistically significant trial arm differences were detected for any of the secondary outcomes. Mean final titrated dose was 53.8 mg in the OROS-methylphenidate arm.

CONCLUSIONS

ADHD symptoms did not respond to OROS-methylphenidate in young adult prisoners. The findings do not support routine treatment with OROS-methylphenidate in this population. Further research is needed to evaluate effects of higher average dosing and adherence to treatment, multi-modal treatments and preventative interventions in the community.

Understanding the Role of Support in Digital Mental Health Programs With Older Adults: Users' Perspective and Mixed Methods Study

BACKGROUND

Digital mental health interventions have the potential to increase mental health support among isolated older adults. However, the older adult population can experience several barriers to accessing and using digital health resources and may need extra support to experience its benefits.

OBJECTIVE

This paper aimed to understand what older adults experience as an important aspect of support during engagement in a digital mental health program. The program entailed 3 months of staff support to participate in digital literacy training and engage with the digital mental health platform myStrength, which offers support for a range of mental health challenges, including depression and anxiety.

METHODS

A total of 30 older adults participated in surveys and interviews to assess their experience of participating in a digital mental health program provided by county mental health services. As part of the program, participants attended 4 classes of digital literacy training, had access to the digital mental health platform myStrength for 2 months with staff support (and 10 months after the program without support), and received support from program staff during the entire 3-month program. Survey data were analyzed using descriptive statistics, and interview data were analyzed using thematic analysis.

RESULTS

A thematic analysis of the interview data revealed that participants valued ongoing support in 3 main areas: technical support to assist them in using technology, guided support to remind them to use myStrength and practice skills they had learned, and social support to enable them to connect with others through the program. Furthermore, participants reported that social connections was the most important aspect of the program and that they were mainly motivated to participate in the program because it was recommended to them by trusted others such as a community partner or because they believed it could potentially help others.

CONCLUSIONS

Our findings can be used to inform the design of future digital mental health programs for older adults who may have unique support needs in terms of dedicated technical support and ongoing guided support to use technology and social support to increase social connectedness.

Cereal grain mineral micronutrient and soil chemistry data from GeoNutrition surveys in Ethiopia and Malawi

The dataset comprises primary data for the concentration of 29 mineral micronutrients in cereal grains and up to 84 soil chemistry properties from GeoNutrition project surveys in Ethiopia and Malawi. The work provided insights on geospatial variation in the micronutrient concentration in staple crops, and the potential influencing soil factors. In Ethiopia, sampling was conducted in Amhara, Oromia, and Tigray regions, during the late-2017 and late-2018 harvest seasons. In Malawi, national-scale sampling was conducted during the April–June 2018 harvest season. The concentrations of micronutrients in grain were measured using inductively coupled plasma mass spectrometry (ICP-MS). Soil chemistry properties reported include soil pH; total soil nitrogen; total soil carbon (C); soil organic C; effective cation exchange capacity and exchangeable cations; a three-step sequential extraction scheme for the fractionation of sulfur and selenium; available phosphate; diethylenetriaminepentaacetic acid (DTPA)-extractable trace elements; extractable trace elements using 0.01 M Ca(NO₃)₂ and 0.01 M CaCl₂; and isotopically exchangeable Zn. These data are reported here according to FAIR data principles to enable users to further explore agriculture-nutrition linkages.

Measurement(s)	Trace Element • soil chemical properties
Technology Type(s)	Inductively-Coupled Plasma Mass Spectrometry
Factor Type(s)	Geography • Staple cereal crop
Sample Characteristic - Organism	Staple cereal food crops
Sample Characteristic - Environment	Smallholder farming
Sample Characteristic - Location	Ethiopia • Malawi

A multimodality intervention to improve musculoskeletal health, function, metabolism, and well-being in spinal cord injury: study protocol for the FIT-SCI randomized controlled trial

BACKGROUND

A spinal cord injury (SCI) is a devastating, life-changing event that has profoundly deleterious effects on an individual's health and well-being. Dysregulation of neuromuscular, cardiometabolic, and endocrine organ systems following an SCI contribute to excess morbidity, mortality and a poor quality of life. As no effective treatments currently exist for SCI, the development of novel strategies to improve the functional and health status of individuals living with SCI are much needed. To address this knowledge gap, the current study will determine whether a Home-Based Multimodality Functional Recovery and Metabolic Health Enhancement Program that consists of functional electrical stimulation of the lower extremity during leg cycling (FES-LC) plus arm ergometry (AE) administered using behavioral motivational strategies, and testosterone therapy, is more efficacious than FES-LC plus AE and placebo in improving aerobic capacity, musculoskeletal health, function, metabolism, and wellbeing in SCI.

METHODS

This single-site, randomized, placebo-controlled, parallel group trial will enroll 88 community-dwelling men and women, 19 to 70 years of age, with cervical and thoracic level of SCI, ASIA Impairment Scale grade: A, B, C, or D, 6 months or later after an SCI. Participants randomized to the multimodality intervention will undergo 16 weeks of home-based FES-LC and AE training plus testosterone undecanoate. Testosterone undecanoate injections will be administered by study staff in clinic or by a visiting nurse in the participant's home. The control group will receive 16 weeks of home-based FES-LC and AE exercise plus placebo injections. The primary outcome of this trial is peak aerobic capacity, measured during an incremental exercise testing protocol. Secondary outcomes include whole body and regional lean and adipose tissue mass; muscle strength and power; insulin sensitivity, lipids, and inflammatory markers; SCI functional index and wellbeing (mood, anxiety, pain, life satisfaction and depressive symptoms); and safety.

DISCUSSION

We anticipate that a multimodality intervention that simultaneously addresses multiple physiological impairments in SCI will result in increased aerobic capacity and greater improvements in other musculoskeletal, metabolic, functional and patient-reported outcomes compared to the control intervention. The findings of this study will have important implications for improving the care of people living with an SCI.

TRIAL REGISTRATION

ClinicalTrials.gov :  ( NCT03576001 ). Prospectively registered: July 3, 2018.

Soil and landscape factors influence geospatial variation in maize grain zinc concentration in Malawi

Dietary zinc (Zn) deficiency is widespread globally, and in particular among people in sub-Saharan Africa (SSA). In Malawi, dietary sources of Zn are dominated by maize and spatially dependent variation in grain Zn concentration, which will affect dietary Zn intake, has been reported at distances of up to ~ 100 km. The aim of this study was to identify potential soil properties and environmental covariates which might explain this longer-range spatial variation in maize grain Zn concentration. Data for maize grain Zn concentrations, soil properties, and environmental covariates were obtained from a spatially representative survey in Malawi (n = 1600 locations). Labile and non-labile soil Zn forms were determined using isotopic dilution methods, alongside conventional agronomic soil analyses. Soil properties and environmental covariates as potential predictors of the concentration of Zn in maize grain were tested using a priori expert rankings and false discovery rate (FDR) controls within the linear mixed model (LMM) framework that informed the original survey design. Mean and median grain Zn concentrations were 21.8 and 21.5 mg kg⁻¹, respectively (standard deviation 4.5; range 10.0–48.1). A LMM for grain Zn concentration was constructed for which the independent variables: soil pH_(water), isotopically exchangeable Zn (Zn_E), and diethylenetriaminepentaacetic acid (DTPA) extractable Zn (Zn_DTPA) had predictive value (p < 0.01 in all cases, with FDR controlled at < 0.05). Downscaled mean annual temperature also explained a proportion of the spatial variation in grain Zn concentration. Evidence for spatially dependent variation in maize grain Zn concentrations in Malawi is robust within the LMM framework used in this study, at distances of up to ~ 100 km. Spatial predictions from this LMM provide a basis for further investigation of variations in the contribution of staple foods to Zn nutrition, and where interventions to increase dietary Zn intake (e.g. biofortification) might be most effective. Other soil and landscape factors influencing spatially dependent variation in maize grain Zn concentration, along with factors operating over shorter distances such as choice of crop variety and agronomic practices, require further exploration beyond the scope of the design of this survey.

Pes varus correction in dachshunds with mini hybrid external skeletal fixators

AIM

To evaluate the clinical and radiographic outcome of pes varus deformity correction in dachshunds managed with acute medial opening wedge osteotomy of the distal tibia and stabilised with a mini hybrid external skeletal fixator (HESF).

METHODS

Surgical correction involved a transverse osteotomy over the premeasured location at the distal tibia and application of a IMEX mini HESF. All corrections were evaluated using centre of rotation and angulation methodology.

RESULTS

Medical records and radiographies of 20 dachshunds (28 pes varus corrections) were reviewed. All osteotomies healed and fixators were removed between 6 and 12 weeks. Lameness resolved in 18 dachshunds (90%) and significantly improved in two dachshunds (10%). Lateral patella luxation (LPL) was detected in 11/28 (39.2%) of the involved pelvic limbs, all of which resolved following pes varus correction. Mean frontal plane alignment (FPA) of the normal and abnormal tibiae were 12.3° valgus (range: 4°-18°) and 25° Varus (range: 16°-41°) respectively. Angular correction ranged between 30° and 50° (Mean: 39°) and the mean post-operative FPA was 13° valgus (range: 5°-21°).

CLINICAL SIGNIFICANCE

Pes varus deformity in dachshunds can be corrected by medial opening wedge osteotomy of the distal tibia stabilised by HESF. Single-session bilateral pes varus corrections can also be performed with minimal morbidity. LPL was commonly detected in dogs with pes varus deformity and all resolved spontaneously following pes varus correction alone.

147 ‘CHAMPIONING CONTINENCE’—ESTABLISHMENT OF A MULTIDISCIPLINARY CONTINENCE PROMOTION WORKING GROUP IN AN ACUTE TEACHING HOSPITAL

Background

In line with the National Frailty Programme1, patients over the age of 75 admitted to hospital should have a comprehensive geriatric assessment including the assessment of current continence status and any history of incontinence. Up to 39% of adults are reported to develop new onset urinary incontinence during admission to hospital2,3, however studies show that is it a problem not always identified by staff members,4. In response to these observations within an acute teaching hospital, a continence working party was formed involving members of nursing, physiotherapy and occupational therapy colleagues to explore the current practice and culture relating to continence management.

Methods

The group established key objectives which were broken into four strands;

1. Audit of documentation of baseline continence on admission (therapy and nursing).

2. Obtaining access to additional types of continence wear.

3. Staff education.

4. Pre and post education survey.

Results

1. Audit of documentation demonstrated poor standards of documentation of baseline continence. This led to an amendment to questioning prompts on therapy initial assessment forms and a plan to further evaluate the nursing documentation.

2. A wider array of continence wear has been made available on the wards providing greater options for patients.

3. Staff education session was compiled by a specialist physiotherapist and is widely available for staff to access on the hospitals online training portal.

4. Pre-education surveys have been completed with a view to re-administering following education roll-out.

Conclusion

The aim of this multidisciplinary working group is to equip staff with the correct resources, knowledge, and confidence to ensure best practice promotion of continence on the targeted wards. This project is the first strand of a wider culture changed that is needed around continence promotion for older adults in the acute setting.

Rapid rollout of a pacemaker home monitoring service during the 2020 COVID-19 pandemic

Introduction

In an effort to reduce non-essential face to face contact during the COVD pandemic our pacemaker service was restructured in March 2020 to home monitoring only. Home monitors were issued at implant and wound reviews were done remotely via photo messages at one month or if prompted by the patient. Existing patients were given monitors on an ad hoc basis. A dedicated physiologist worked off site on home monitoring clinics. We assessed the impact on our service and on patient experience of these changes one year after implementation.

Methods

Baseline characteristics of age at implant and distance of home address from hospital were collected from all patients undergoing pacemaker home monitoring. Patients were surveyed using an adapted version of the Generic Short Patient Experiences Questionnaire (GS-PEQ). Comparison was made with our standard face-to-face follow-up model (1, 3, and 12 months).

Results

Data was collected for 326 patients. 233 received a new permanent pacemaker from March 2020 onwards and 93 existing patients were issued with a home monitor. Average age at pacemaker implant was 80.6 years (±9.9 years). The average one-way distance from home to outpatient clinic saved was 15.1 miles (±10.4 miles). 567 face-to-face appointments were saved. On an average day the off-site physiologist reviewed over 100 patient records a day, contacted 10 patients by phone and dictated reports on 20 patients (14 clinic patients and 6 alerts).

Of patients surveyed 88% agreed with the statement “I feel safe being cared for solely with a remote monitoring service” and 84% agreed with the statement “I receive the same standard of care via remote monitoring and face-to-face appointments”. Time saved by avoiding a face to face appointment was more than 1 hour for 90% of respondents. Respondents requested communication of reassuring monitoring, the ability to contact the pacing team in the event of concerns and clearer instructions for the home monitoring device.

Only 34% of newly implanted patients were able to send a photo message of their wound without prompting. We did not get a post procedure photo in 38% and the rest either spoke to us about the wound or had a face-to face visit. There was a significant difference in mean age between those who sent a photo (73.7 years) and those who didn't (81.4 years) (P=0.0006).

Conclusion

Rapid role out of a remote monitoring service for permanent pacemakers across a large county was feasible, produced significant savings in clinic time and was well received by patients. There were significant time savings for physiologists and patients. However remote wound monitoring in elderly patients was problematic due to the difficulty of sending photo messages.

Funding Acknowledgement

Type of funding sources: None.

The nutritional quality of cereals varies geospatially in Ethiopia and Malawi

Micronutrient deficiencies (MNDs) remain widespread among people in sub-Saharan Africa1-5, where access to sufficient food from plant and animal sources that is rich in micronutrients (vitamins and minerals) is limited due to socioeconomic and geographical reasons4-6. Here we report the micronutrient composition (calcium, iron, selenium and zinc) of staple cereal grains for most of the cereal production areas in Ethiopia and Malawi. We show that there is geospatial variation in the composition of micronutrients that is nutritionally important at subnational scales. Soil and environmental covariates of grain micronutrient concentrations included soil pH, soil organic matter, temperature, rainfall and topography, which were specific to micronutrient and crop type. For rural households consuming locally sourced food-including many smallholder farming communities-the location of residence can be the largest influencing factor in determining the dietary intake of micronutrients from cereals. Positive relationships between the concentration of selenium in grain and biomarkers of selenium dietary status occur in both countries. Surveillance of MNDs on the basis of biomarkers of status and dietary intakes from national- and regional-scale food-composition data1-7 could be improved using subnational data on the composition of grain micronutrients. Beyond dietary diversification, interventions to alleviate MNDs, such as food fortification8,9 and biofortification to increase the micronutrient concentrations in crops10,11, should account for geographical effects that can be larger in magnitude than intervention outcomes.

OP0090 CLASSIFICATION OF PATIENTS WITH RELAPSING POLYCHONDRITIS BASED ON SOMATIC MUTATIONS IN UBA1

Background:

Somatic mutations in ubiquitin activating enzyme 1 (UBA1) cause a newly defined syndrome known as VEXAS. [1] More than fifty percent of patients currently identified with VEXAS meet diagnostic criteria for relapsing polychondritis (RP).

Objectives:

To determine the prevalence VEXAS within a cohort of patients with RP, to compare their clinical, laboratory, and immunologic features and to develop a clinical algorithm to inform genetic screening for VEXAS among patients with RP.

Methods:

Exome and targeted sequencing of the UBA1 gene was performed in a prospective observational cohort of patients with RP. Clinical and immunological characteristics of patients with RP were compared based on presence or absence of UBA1 mutations. Random forest was used to derive a clinical algorithm to identify patients with UBA1 mutations. Immune populations were quantified by multipanel flow cytometry. Categorical and continuous variables were compared using the chi square or Kruskal-Wallis test. P<0.05 defined statistical significance.

Results:

Seven of 92 patients with RP (7.6%) were confirmed to have UBA1 mutations (VEXAS-RP). Six additional patients with VEXAS-RP from other cohorts were included for subsequent analyses. Patients with VEXAS-RP were all male, older at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. Patients with RP as compared with VEXAS-RP had a significantly higher prevalence of airway chondritis, costochondritis and tenosynovitis/arthralgias. (Table). Mortality was significantly greater in VEXAS-RP than RP (27% vs 2% p=0.01). Maximum ESR, CRP, and mean corpuscular volume (MCV) values were significantly greater in VEXAS-RP. Absolute monocyte, lymphocyte, and platelet counts were significantly lower in VEXAS-RP. A decision tree based on male sex, MCV>100 fl and Platelet count<200 K/ul classified between VEXAS-RP and RP with 100% sensitivity and 96% specificity.

Table 1.

Clinical Characteristics of patients with RP vs VEXAS-RP

All Patientsn=98RPn=85VEXAS-RPn=13p valueDemographic CharacteristicsRace, White n (%)90 (92)77 (91)13 (100)0.59Sex, Male n (%)26 (27)13 (15)13 (100)<0.0001Age, Symptom onset, years, Median (IQR)38 (30-47)37 (28-43)56 (54-64)<0.0001Clinical SymptomsFever n (%)33 (34)20 (24)13 (100)<0.0001Ear chondritis n (%)61 (62)48 (56)13 (100)0.0015Nose chondritis n (%)83 (85)71 (84)12 (92)0.68Airway chondritis n (%)37 (38)37 (44)0 (0)0.0015Tenosynovitis/arthalgias n (%)83 (85)77 (91)6 (46)0.0005Skin involvement n (%)33 (34)22 (2611 (85)<0.0001Laboratory ValuesESR, mm/hr, median (IQR)12 (6-22)11 (5-19)66.5 (42-110)<0.0001CRP, mg/L, median (IQR)2.9 (0.8-9.6)1.9 (0.6-6.3)17.7 (9.6-99.5)<0.0001Platelet count (k/uL)246(201-299)258 (227-312)145 (100-169)<0.0001MCV fL93.05 (90-98)92.2 (89-95)105 (102-115)<0.0001Absolute lymphocyte count1.6 (1.1-2.3)1.78(1.4-2.4)0.92 (0.5-1.2)<0.0001CT scan abnormalitiesPulmonary infiltrates n (%)16 (16.33)6 (7.06)10 (77)<0.0001ComplicationsDeath n (%)6 (6)3 (4)3 (23)0.029Unprovoked DVT12 (12)4 (5)8 (62)<0.0001

N number; IQR = interquartile range

Conclusion:

Mutations in UBA1 are causal for disease in a subset of patients with RP. These patients are defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.

References:

[1]Beck DB, Ferrada MA, Sikora KA, Ombrello AK, Collins JC, Pei W, Balanda N, Ross DL, Ospina Cardona D, Wu Z et al: Somatic Mutations in UBA1 and Severe Adult-Onset Autoinflammatory Disease. N Engl J Med 2020, 383(27):2628-2638.

Disclosure of Interests:

None declared

Cervical dilatation and preparation prior to outpatient hysteroscopy: a systematic review and meta-analysis

BACKGROUND

There are uncertainties about the benefit of routine cervical preparation and/or cervical dilatation before outpatient hysteroscopy.

OBJECTIVE

To determine if cervical preparation and/or routine mechanical dilatation reduces pain during outpatient hysteroscopy.

SEARCH STRATEGY

MEDLINE, EMBASE, CINAHL and CENTRAL were searched on 19 October 2020, using keywords 'hysteroscopy', 'cervical preparation', 'cervical ripening', 'cervical dilatation', 'outpatient', 'office' and/or 'ambulatory' and associated medical subject headings.

SELECTION CRITERIA

Randomised controlled trials investigating the benefit of cervical preparation and/or cervical dilatation on pain in women undergoing outpatient hysteroscopy were included.

DATA COLLECTION AND ANALYSIS

Two independent reviewers selected eligible trials and extracted data on pain, feasibility, adverse events and satisfaction/acceptability for meta-analysis.

MAIN RESULTS

The literature search yielded 807 records, of which 24 were included for review and 19 provided data for meta-analysis. No trials investigated the role of routine mechanical cervical dilatation. Cervical preparation significantly reduced pain during outpatient hysteroscopy; standard mean difference (SMD) -0.67, 95% confidence interval (CI) -1.05 to -0.29. Feasibility also improved as priming provided significantly easier hysteroscopic entry (SMD 0.89, 95% CI 0.32-1.46), greater cervical dilatation (SMD 0.81, 95% CI 0.08-1.53) and shorter procedural times (SMD -0.51, 95% CI -0.88 to -0.13). Cervical preparation, however, incurred significantly more adverse effects, mainly comprising genital tract bleeding, abdominal pain and gastrointestinal symptoms (odds ratio 2.94, 95% CI 1.58-5.47). There were limited data regarding satisfaction, acceptability and complications.

CONCLUSIONS

Cervical preparation reduces pain and improves feasibility associated with outpatient hysteroscopy but increases the risk of adverse effects.

TWEETABLE ABSTRACT

Cervical preparation before outpatient hysteroscopy reduces pain, enhances feasibility but increases adverse effects.

Spatial prediction of the concentration of selenium (Se) in grain across part of Amhara Region, Ethiopia

Grain and soil were sampled across a large part of Amhara, Ethiopia in a study motivated by prior evidence of selenium (Se) deficiency in the Region's population. The grain samples (teff, Eragrostis tef, and wheat, Triticum aestivum) were analysed for concentration of Se and the soils were analysed for various properties, including Se concentration measured in different extractants. Predictive models for concentration of Se in the respective grains were developed, and the predicted values, along with observed concentrations in the two grains were represented by a multivariate linear mixed model in which selected covariates, derived from remote sensor observations and a digital elevation model, were included as fixed effects. In all modelling steps the selection of predictors was done using false discovery rate control, to avoid over-fitting, and using an α-investment procedure to maximize the statistical power to detect significant relationships by ordering the tests in a sequence based on scientific understanding of the underlying processes likely to control Se concentration in grain. Cross-validation indicated that uncertainties in the empirical best linear unbiased predictions of the Se concentration in both grains were well-characterized by the prediction error variances obtained from the model. The predictions were displayed as maps, and their uncertainty was characterized by computing the probability that the true concentration of Se in grain would be such that a standard serving would not provide the recommended daily allowance of Se. The spatial variation of grain Se was substantial, concentrations in wheat and teff differed but showed the same broad spatial pattern. Such information could be used to target effective interventions to address Se deficiency, and the general procedure used for mapping could be applied to other micronutrients and crops in similar settings.

Solid Cherenkov detector for studying nucleosynthesis in inertial confinement fusion

Measuring gamma rays emitted from nuclear reactions gives insight into their nuclear structure. Notably, there are several nuclear reactions that produce gamma rays at ∼1 MeV-3 MeV energies such as T(⁴He, γ)⁷Li, ⁴He(³He, γ)⁷Be, and ¹²C(p, γ)¹³N, which may solve questions lingering about big-bang nucleosynthesis and stellar nucleosynthesis. To observe 1 MeV-3 MeV gamma rays in an inertial confinement fusion system, a new style of the Cherenkov detector was developed using aerogel and fused silica as a Cherenkov medium. Utilizing the OMEGA laser facility, both aerogel and fused silica media were compared with the existing gas-medium Cherenkov detector to validate the concept. Gamma ray measurements from high yield inertial confinement fusion implosions (deuterium-tritium and deuterium-³He) demonstrated that aerogel and fused silica were viable Cherenkov media, paving the way for a potential optimized detector to make these cross section measurements on OMEGA or the National Ignition Facility.

P731 When cardiac imaging saves the day - a rare cause of embolic stroke

INTRODUCTION

Hypereosinophilic syndrome (HES) is a rare disorder characterised by infiltration of tissues by eosinophils. Myocardial infiltration occurs in 50-60% of HES and leads to a condition called Loeffler’s endocarditis. Eosinophilic protein toxicity initiates endomyocardial necrosis. This is followed by a thrombotic stage and finally by endomyocardial fibrosis leading to a form of restrictive cardiomyopathy. Thrombosis is often located in the apical region of the ventricles and can result in stroke, which is the most devastating neurological consequence of hyperoesinophilia. We describe a case of a patient that presented with neurological symptoms and was found to have multiple embolic strokes secondary to Loeffler’s endocarditis.

CASE

A 57-year-old female presented to our institution with new onset confusion and reduced level of consciousness. Initial neurological assessment was consistent with encephalopathy. She had a 2-year history of eosinophilia that had been investigated by the haematology and rheumatology teams with no obvious aetiology identified.

Initial haematological investigations showed a raised eosinophil count at 13mmol/L. Her cerebral MRI scan showed multiple embolic infarcts and therefore a transthoracic echo (TTE) was booked. This did not show any obvious intracardiac cause of emboli although the appearances of the LV apex were suspicious of thrombus. This was confirmed later, on contrast imaging (Fig 1). Staphylococcus aureus was grown in a single blood culture specimen raising the suspicion of infective endocarditis and a transoeosophageal echocardiogram (TOE) ruled out vegetations but again illustrated the apical filling defect despite absence of wall motion abnormalities (Fig 2). Finally, a cardiac MRI was arranged and this confirmed the diagnosis of Loeffler’s endocarditis with endomyocardial fibrosis and superimposed LV thrombus (Fig 3). She was treated with anticoagulation and steroids and her eosinophil count normalised before discharge. She remains well with no recurrence at two months post-event.

DISCUSSION

The diagnosis of Loeffler’s endocarditis depends on the presence high eosinophil count in combination with cardiac involvement on imaging. Transthoracic echocardiography can provide useful information such as apical thickening and thrombus in the left ventricle. As in our case, contrast TTE often provides further detail however contrast-enhanced cardiac MRI remains a key tool in the diagnosis and monitoring of this condition. It provides an assessment of systolic and diastolic function, tissue characterisation and typical features notably endomyocardial fibrosis and thrombosis on late enhancement imaging.

CONCLUSIONS

We presented a case where cardiac imaging has revealed the diagnosis in a patient presenting with systemic symptoms. We encourage clinicians to use multi-modality cardiac imaging as this has an invaluable role in the diagnostic process of complex patients.

Abstract P731 Figure.

Abstract P4-09-08: Shared-patient physician networks and their impact on the uptake of genomic testing in early-stage breast cancer

Background: Oncotype DX (ODX) or 21-gene recurrence score genomic testing is used to stratify risk and determine appropriate treatment in women with early-stage breast cancer (BC). Diffusion of ODX by way of physician networks has not been studied.

Objective: To determine the association between physician network connections, defined by shared patients, and the use of ODX testing.

Methods: SEER-Medicare claims from 2008-2012 were used to identify a cohort of woman with a diagnosis of BC from registry/ICD codes, continuously enrolled in Medicare fee-for-service Part A and B one year prior to and one year following diagnosis. We identify receipt of ODX from the associated CPT code, claim reimbursement, and performing NPI. To look at the influence of network connections on ODX use, we split the study into two time periods: early adoption from 2008-2009, and late from 2010-2012. Medical oncologists with a BC-related claim in the cohort above, and any rendered BC-related service are considered 'connected' if they shared two or more BC patients. Analyses describe these connections and explore the association between connectedness to an early adopting medical oncologist and ODX use in parallel physician and patient-level analyses using generalized linear mixed models with a hospital referral region-specific random effect. Models control for physician and patient-level characteristics where applicable.

Results:24,463 women met study criteria; 12,874 were diagnosed with BC in the early adoption time period (1,790 received ODX) and 11,589 were diagnosed in the late period (2,334 received ODX). 2,073 medical oncologists treated these patients from 2008-2009. The mean number of BC patients treated per medical oncologist was 86.8 during the early adoption period, and medical oncologists had a median number of peer connections of 11 (IQR: 7-18). Early adopting medical oncologists had higher numbers of peer connections and higher average patient counts than non-early adopters. A higher percentage of female medical oncologists were early adopters (39%) then male medical oncologists (33%) (p&lt;0.02). Among non-early adopting oncologists, peer connection to at least two early adopting providers in 2008-2009 is associated with a 3.2 (95% CI: 2.0-4.9) times increase in the odds of ordering ODX in 2010-2012 after adjustment for physician gender and time in practice. In patient-level models with controls for physician and patient characteristics, seeing a medical oncologist with connections to at least two early adopting physicians is associated with a 1.6 times (95% CI: 1.1-2.2) increase in the odds of receiving ODX testing in 2010-2012.

Conclusions: We observe a positive adjusted association between connectedness to an early-adopting physician and ODX prescribing/use in both physician-level and patient-level analyses. These results suggest that provider networks may help diffuse new technologies, and that BC genomic testing is likely to be an area of shared practices between providers. Efforts to increase testing, where appropriate, may benefit from a range of peer-to-peer connection strategies.

Citation Format: Rotter J, Wilson L, Greiner M, Pollack C, Dinan M. Shared-patient physician networks and their impact on the uptake of genomic testing in early-stage breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-09-08.

The induction of core pluripotency master regulators in cancers defines poor clinical outcomes and treatment resistance

Stem cell characteristics have been associated with treatment resistance and poor prognosis across many cancer types. The ability to induce and regulate the pathways that sustain these characteristic hallmarks of lethal cancers in a novel in vitro model would greatly enhance our understanding of cancer progression and treatment resistance. In this work, we present such a model, based simply on applying standard pluripotency/embryonic stem cell media alone. Core pluripotency stem cell master regulators (OCT4, SOX2 and NANOG) along with epithelial–mesenchymal transition (EMT) markers (Snail, Slug, vimentin and N-cadherin) were induced in human prostate, breast, lung, bladder, colorectal, and renal cancer cells. RNA sequencing revealed pathways activated by pluripotency inducing culture that were shared across all cancers examined. These pathways highlight a potential core mechanism of treatment resistance. With a focus on prostate cancer, the culture-based induction of core pluripotent stem cell regulators was shown to promote survival in castrate conditions—mimicking first line treatment resistance with hormonal therapies. This acquired phenotype was shown to be mediated through the upregulation of iodothyronine deiodinase DIO2, a critical modulator of the thyroid hormone signalling pathway. Subsequent inhibition of DIO2 was shown to supress expression of prostate specific antigen, the cardinal clinical biomarker of prostate cancer progression and highlighted a novel target for clinical translation in this otherwise fatal disease. This study identifies a new and widely accessible simple preclinical model to recreate and explore underpinning pathways of lethal disease and treatment resistance.

History of military psychology

Military psychology is a specialist discipline within applied psychology. It entails the application of psychological science to military operations, systems and personnel. The specialty was formally founded during World War I in the UK and the USA, and it was integral to many early concepts and interventions for psychological and neuropsychological trauma. It also established a fundamental basis for the psychological assessment and selection of military personnel. During and after World War II, military psychology continued to make significant contributions to aviation psychology, cognitive testing, rehabilitation psychology and many models of psychotherapy. Military psychology now consists of several subspecialties, including clinical, research and occupational psychology, with the latter often referred to in the USA as industrial/organisational psychology. This article will provide an overview of the origins, history and current composition of military psychology in the UK, with select international illustrations also being offered.

High resolution, high signal-to-noise crystal spectrometer for measurements of line shifts in high-density plasmas

The Orion high-resolution x-ray (OHREX) spectrometer has been a successful tool for measuring the shapes of density-broadened spectral lines produced in short-pulse heated plasmas at the Orion laser facility. We have recently outfitted the instrument with a charge-couple device (CCD) camera, which greatly increased the accuracy with which we can perform line-shift measurements. Because OHREX is located on the outside of the Orion target chamber, no provisions for the shielding of electromagnetic pulses are required. With the CCD, we obtained a higher signal-to-noise ratio than we previously obtained with an image-plate detector. This allowed us to observe structure in the image produced by the diffraction from the two OHREX crystals, which was highly reproducible from shot to shot. This structure will ultimately limit the accuracy of our spectroscopic measurements.

Las Competencias de Salud Global para Estudiantes de Enfermería: Percepciones de Docentes en América Latina

Objetivo: El propósito de este estudio fue describir las percepciones de docentes de enfermería de habla hispana en América Latina, sobre las competencias relacionadas a la salud global que deben mostrar los estudiantes de enfermería del pregrado. Métodos: Este estudio descriptivo fue basado en una muestra de  docentes de escuelas de enfermería miembros de la Asociación Latinoamericana de Escuelas y Facultades de Enfermería (ALADEFE) y de la Asociación de Escuelas de la Zona Centro Sur de México,  las cuales recibieron un correo electrónico con una liga para responder una encuesta electrónica por Survey Monkey©. La encuesta incluyó una lista de 30 competencias en salud global dividida en seis dimensiones. Los docentes indicaron en una escala Likert de 4 puntos la relevancia de cada competencia para la educación de enfermería en el nivel de pregrado (1 = Completamente en desacuerdo; 2 = En desacuerdo; 3 = De acuerdo; 4 = Completamente de acuerdo). Resultados: En total, 110 profesores de nueve países respondieron a la encuesta.  El promedio de cada ítem fue entre 3.0 - 4.0, esto indica que los profesores estuvieron de acuerdo en que todas las competencias son relevantes para la formación de estudiantes de enfermería a nivel de pregrado. Conclusiones: Los resultados de este estudio sugirieron que estas competencias deben ser incluidas en los currículos de enfermería a nivel de pregrado, para formar a los estudiantes en su labor como enfermeras y enfermeros en un mundo globalizado y  prepararlos para contribuir a la Cobertura y el Acceso Universal a la Salud (Salud Universal).

Hysterectomy and incidence of depressive symptoms in midlife women: the Australian Longitudinal Study on Women's Health

AIMS

There is limited longitudinal research that has looked at the longer term incidence of depressive symptoms, comparing women with a hysterectomy to women without a hysterectomy. We aimed to investigate the association between hysterectomy status and the 12-year incidence of depressive symptoms in a mid-aged cohort of Australian women, and whether these relationships were modified by use of exogenous hormones.

METHODS

We used generalised estimating equation models for binary outcome data to assess the associations of the incidence of depressive symptoms (measured by the 10-item Centre for Epidemiologic Studies Depression Scale) across five surveys over a 12-year period, in women with a hysterectomy with ovarian conservation, or a hysterectomy with bilateral oophorectomy compared with women without a hysterectomy. We further stratified women with hysterectomy by their current use of menopausal hormone therapy (MHT). Women who reported prior treatment for depression were excluded from the analysis.

RESULTS

Compared with women without a hysterectomy (n = 4002), both women with a hysterectomy with ovarian conservation (n = 884) and women with a hysterectomy and bilateral oophorectomy (n = 450) had a higher risk of depressive symptoms (relative risk (RR) 1.20; 95% confidence interval (CI) 1.06-1.36 and RR 1.44; 95% CI 1.22-1.68, respectively). There were differences in the strength of the risk for women with a hysterectomy with ovarian conservation, compared with those without, when we stratified by current MHT use. Compared with women without a hysterectomy who did not use MHT, women with a hysterectomy with ovarian conservation who were also MHT users had a higher risk of depressive symptoms (RR 1.57; 95% CI 1.31-1.88) than women with a hysterectomy with ovarian conservation but did not use MHT (RR 1.17; 95% CI 1.02-1.35). For women with a hysterectomy and bilateral oophorectomy, MHT use did not attenuate the risk. We could not rule out, however, that the higher risk seen among MHT users may be due to confounding by indication, i.e. MHT was prescribed to treat depressive symptoms, but their depressive symptoms persisted.

CONCLUSIONS

Women with a hysterectomy (with and without bilateral oophorectomy) have a higher risk of new incidence of depressive symptoms in the longer term that was not explained by lifestyle or socio-economic factors.

A REVIEW OF ANALYTICAL MODELS OF STRAY RADIATION EXPOSURES FROM PHOTON- AND PROTON-BEAM RADIOTHERAPIES

External-beam radiation therapy is safe, effective and widely used to treat cancer. With 5-year cancer survival for adults above 70%, increasingly research is focusing on quantifying and reducing treatment-related morbidity. Reducing exposures to healthy tissues is one strategy, which can be accomplished with advanced-technology radiotherapies, such as intensity-modulated photon therapy and proton therapy. Both of these modalities provide good conformation of the therapeutic dose to the tumor volume, but they also deliver stray radiation to the whole body that increases the risk of radiogenic second cancers. To minimize these risks, one needs to create and compare candidate treatment plans that explicitly take into account these risks. Currently, clinical practice does not include routine calculation of stray radiation exposure and, consequently, the assessment of corresponding risks is difficult. In this article, we review recent progress toward stray dose algorithms that are suitable for large-scale clinical use. In particular, we emphasize the current state of physics-based dose algorithms for intensity-modulated photon radiotherapy and proton therapy.

Differential Morphological and Biochemical Recovery from Chemotherapy-Induced Peripheral Neuropathy Following Paclitaxel, Ixabepilone, or Eribulin Treatment in Mouse Sciatic Nerves

The reversibility of chemotherapy-induced peripheral neuropathy (CIPN), a disabling and potentially permanent side effect of microtubule-targeting agents (MTAs), is becoming an increasingly important issue as treatment outcomes improve. The molecular mechanisms regulating the variability in time to onset, severity, and time to recovery from CIPN between the common MTAs paclitaxel and eribulin are unknown. Previously (Benbow et al. in Neurotox Res 29:299-313, 2016), we found that after 2 weeks of a maximum tolerated dose (MTD) in mice, paclitaxel treatment resulted in severe reductions in axon area density, higher frequency of myelin abnormalities, and increased numbers of Schwann cell nuclei in sciatic nerves. Biochemically, eribulin induced greater microtubule-stabilizing effects than paclitaxel. Here, we extended these comparative MTD studies to assess the recovery from these short-term effects of paclitaxel, eribulin, and a third MTA, ixabepilone, over the course of 6 months. Paclitaxel induced a persistent reduction in axon area density over the entire 6-month recovery period, unlike ixabepilone- or eribulin-treated animals. The abundance of myelin abnormalities rapidly declined after cessation of all drugs but recovered most slowly after paclitaxel treatment. Paclitaxel- and ixabepilone- but not eribulin-treated animals exhibited increased Schwann cell numbers during the recovery period. Tubulin composition and biochemistry rapidly returned from MTD-induced levels of α-tubulin, acetylated α-tubulin, and end-binding protein 1 to control levels following cessation of drug treatment. Taken together, sciatic nerve axons recovered more rapidly from morphological effects in eribulin- and ixabepilone-treated animals than in paclitaxel-treated animals and drug-induced increases in protein expression levels following paclitaxel and eribulin treatment were relatively transient.

Characterisation of a sub-20 ps temporal resolution pulse dilation photomultiplier tube

A pulse-dilation photomultiplier tube (PD-PMT) with sub-20 ps temporal resolution has been developed for use with γ-ray-sensitive gas Cherenkov detectors at the National Ignition Facility to improve the diagnosis of nuclear fusion burn history and the areal density of the remaining capsule ablator. The pulse-dilation mechanism entails the application of a time-dependent, ramp waveform to a photocathode-mesh structure, introducing a time-dependent photoelectron accelerating potential. The electric field imparts axial velocity dispersion to outgoing photoelectrons. The photoelectron pulse is dilated as it transits a drift region prior to amplification in a microchannel plate and read out with a digital oscilloscope. We report the first measurements with the prototype PD-PMT demonstrating nominal <20 ps FWHM across a 400 ps measurement window and <30 ps FWHM for an extracted charge up to 300 pC. The output peak areas are linear to within 20% over 3 orders of magnitude of input intensity. 3D particle in cell simulations, which included space charge effects, have been carried out to investigate the device temporal magnification, resolution, and linearity.

FBXW7 regulates DISC1 stability via the ubiquitin-proteosome system

Disrupted in schizophrenia 1 (DISC1) is a multi-functional scaffolding protein that has been associated with neuropsychiatric disease. The role of DISC1 is to assemble protein complexes that promote neural development and signaling, hence tight control of the concentration of cellular DISC1 in neurons is vital to brain function. Using structural and biochemical techniques, we show for we believe the first time that not only is DISC1 turnover elicited by the ubiquitin proteasome system (UPS) but that it is orchestrated by the F-Box protein, FBXW7. We present the structure of FBXW7 bound to the DISC1 phosphodegron motif and exploit this information to prove that disruption of the FBXW7-DISC1 complex results in a stabilization of DISC1. This action can counteract DISC1 deficiencies observed in neural progenitor cells derived from induced pluripotent stem cells from schizophrenia patients with a DISC1 frameshift mutation. Thus manipulation of DISC1 levels via the UPS may provide a novel method to explore DISC1 function.

Time-resolved measurements of fast electron recirculation for relativistically intense femtosecond scale laser-plasma interactions

A key issue in realising the development of a number of applications of high-intensity lasers is the dynamics of the fast electrons produced and how to diagnose them. We report on measurements of fast electron transport in aluminium targets in the ultra-intense, short-pulse (<50 fs) regime using a high resolution temporally and spatially resolved optical probe. The measurements show a rapidly (≈0.5c) expanding region of Ohmic heating at the rear of the target, driven by lateral transport of the fast electron population inside the target. Simulations demonstrate that a broad angular distribution of fast electrons on the order of 60° is required, in conjunction with extensive recirculation of the electron population, in order to drive such lateral transport. These results provide fundamental new insight into fast electron dynamics driven by ultra-short laser pulses, which is an important regime for the development of laser-based radiation and particle sources.