A clinical and optical evaluation of a modified lens for irregular corneae

BACKGROUND

Correction of high regular and irregular astigmatism with rigid gas-permeable contact lenses can result in discomfort, compromised corneal physiology and fluctuations in visual acuity due to excessive lens movement. Using a non-probability sample, this study explored the optical, clinical and subjective performance of a modified countersunk piggyback lens (MCL) for the management of high regular and irregular corneal astigmatic refractive conditions, as the first phase for a larger randomised control study of the efficacy of the custom piggyback MCL system.

METHOD

The sample was a single group of 10 patients (n = 17 eyes) selected primarily on the basis of a history of failure with conventional management regimes. The objective clinical and optical performance of the MCL used in the management of high degrees of regular and irregular corneal astigmatic conditions was assessed, including measures of visual performance and ocular health. Subjective performance of the MCL was evaluated by patient feedback.

RESULTS

Objective and subjective measures were analysed using appropriate statistical analyses. There was a significant improvement in the uncorrected vision and visual acuity (VA) with the MCL, as well as a significant improvement in refractive status. There was no statistically significant increase in adverse ocular responses with the MCL. Statistical analysis of the subjective responses indicated a strong acceptance of the MCL by all subjects, thus supporting the objective analysis indicating the superior performance of the MCL over prior conventional treatment regimens.

DISCUSSION

The custom piggyback MCL performed successfully in the management of a range of high regular and irregular astigmatic conditions, which have been unsuccessfully managed with a range of conventional optical corrections. Despite the additional cost and handling implications of the two-lens system, the MCL was well accepted by all subjects due to its superior optical and clinical performance.

Safety and effectiveness of the TREO stent graft for the endovascular treatment of abdominal aortic aneurysms

OBJECTIVE

The short- and mid-term outcomes of endovascular aortic aneurysm repair have made it a standard treatment of abdominal aortic aneurysms. However, newer generation devices have yet to demonstrate improved long-term rates for complications, reinterventions, and survival. The TREO stent graft is a latest generation device and was evaluated for approval in the United States.

METHODS

In a multicenter, nonrandomized, investigational device exemption clinical trial, we assessed the safety and effectiveness of the TREO device, with core laboratory assessment of the imaging studies and an independent adjudication of safety. The primary effectiveness endpoint was successful aneurysm treatment at 1 year. The primary safety endpoint was the incidence of major adverse events (MAE) at 30 days.

RESULTS

A total of 150 patients (132 men; 88.0%) with infrarenal abdominal aortic (87.3%) or aortoiliac (12.7%) aneurysms were enrolled. The data were normally distributed. The mean age was 71.7 ± 7.4 years. The MAE incidence at 30 days was 0.7%. One subject experienced two MAE: myocardial infarction and procedural blood loss of 1000 mL. The proportion of successful aneurysm treatment at 1 year was 93.1%. Longer term follow-up continues, with no aneurysm-related mortality at the latest follow-up. At 3 years, the cumulative all-cause mortality and incidence of type I and type III endoleaks was 10.7% (n = 16), 2.7% (n = 4), and 0% (n = 0), respectively. In addition, aneurysm sac shrinkage >5 mm at 3 years had occurred in 54.3% of patients, and 9.3% had required a secondary intervention (n = 14).

CONCLUSIONS

The safety and effectiveness of endovascular repair of abdominal aneurysms with TREO were demonstrated, with 93.1% successful aneurysm treatment at 1 year and aneurysm sac shrinkage >5 mm at 3 years in 54.3% of patients. Long-term follow-up continues to determine whether these favorable outcomes will be sustained.

Effects of route of administration on oxytocin-induced changes in regional cerebral blood flow in humans

Could nose-to-brain pathways mediate the effects of peptides such as oxytocin (OT) on brain physiology when delivered intranasally? We address this question by contrasting two methods of intranasal administration (a standard nasal spray, and a nebulizer expected to improve OT deposition in nasal areas putatively involved in direct nose-to-brain transport) to intravenous administration in terms of effects on regional cerebral blood flow during two hours post-dosing. We demonstrate that OT-induced decreases in amygdala perfusion, a key hub of the OT central circuitry, are explained entirely by OT increases in systemic circulation following both intranasal and intravenous OT administration. Yet we also provide robust evidence confirming the validity of the intranasal route to target specific brain regions. Our work has important translational implications and demonstrates the need to carefully consider the method of administration in our efforts to engage specific central oxytocinergic targets for the treatment of neuropsychiatric disorders.

A39 NOVEL GAIN OF FUNCTION NON-RECEPTOR TYROSINE KINASE MUTATIONS ARE LINKED TO THE PATHOGENESIS OF VEOIBD

Background

Very early-onset inflammatory bowel disease (VEOIBD) is an emerging global disease, that results in inflammation of the digestive tract. Severe forms of VEOIBD can be caused by mutations in a single gene (monogenic variants) and, can result in death. A candidate gene which codes for a non-receptor tyrosine kinase (nRTK) has recently been implicated as a monogenic cause of IBD (unpublished). Whole exome sequencing was performed in two unrelated children who presented with symptoms of IBD identifying two distinct de novo gain of function mutations (S550Y and P342T). Both mutations are located in the highly conserved region of the nRTK, and were predicted to have similar downstream effects. Furthermore, four other patients with a variety of adult-onset immune disorders have recently been identified with rare variants in the same gene (M450I, R42P, A353T, V433M, S550F) but, their potential gain of function status remains to be determined. Studies show that this nRTK is an essential mediator in inflammation. It is expressed in both intestinal epithelial and immune cells however, its role in infantile IBD is unclear. This protein is first activated by phosphorylation and is linked to activating downstream transcription factors such as ERK and JNK. All these target proteins play a meaningful role in intestinal inflammation in patients with IBD.

Aims

Since we identified P342T and S550Y to be gain of function, we wanted to determine if the new variants exhibit a similar downstream impact on target protein expression levels when compared with S550Y and P342T. We also wanted to identify if all variants can be rescued with a known nRTK inhibitor. It is hypothesized that the new variants are gain of function and that all variants can be rescued with the inhibitor.

Methods

Using western blot analysis, the activation of ERK, JNK and nRTK was compared between wildtype (WT) and mutants. This in vitro method helped identify the degree of activation. For the second part of the study, HEK293T cells were treated with inhibitor to test for a rescue of phenotypes via western blot analysis.

Results

Results show an increased activation of nRTK, ERK and JNK in all variants with S550Y and S550F having the highest activation. Furthermore, pharmacological inhibition using small molecular kinase inhibitors resulted in decreased activation of nRTK, ERK and JNK suggesting a rescue of phenotypes.

Conclusions

Characterizing the downstream functional impact of these nRTK variants is an important first step to determine if gain of function nRTK mutations drive IBD. With a rising prevalence of IBD worldwide, these findings may lead to the development of pharmacological nRTK inhibitors as a novel personalized therapeutic approach for these patients and possibly for the broader IBD population.

Funding Agencies

CIHR

Short-term safety and effectiveness of sugammadex for surgical patients with end-stage renal disease: a two-centre retrospective study

Sugammadex is a novel reversal agent for aminosteroid neuromuscular blocking drugs, especially rocuronium. Given its renal excretion, sugammadex is not recommended for patients with end-stage renal disease; however, reports exist of its use in this group of patients. This two-institutional retrospective observational study aimed to review the safety profile and effectiveness of sugammadex in surgical patients with end-stage renal disease who required pre-operative renal replacement therapy. Adult surgical patients with end-stage renal disease requiring pre-operative renal replacement therapy, who received sugammadex between April 2016 and January 2019, were studied. The primary outcome was the incidence of postoperative tracheal re-intubation within 48 h. The secondary outcome was the incidence of deferred tracheal extubation in the operating theatre. One hundred and fifty-eight patients were identified from 125,653 surgical patients: 48 patients (30%) underwent renal transplantation and 110 (70%) underwent non-renal transplantation procedures. There were 22 instances (14%) of deferred tracheal extubation due to surgical and/or pre-existing medical conditions. Out of the 136 patients who had the tracheal tube removed at the end of the procedure, three patients had their trachea re-intubated within 48 h: two patients developed pulmonary oedema resulting from volume overload; and one patient had worsening sepsis. No incidence of recurrence of neuromuscular blockade was observed. Of note, 24 (18%) patients were found to have incomplete neuromuscular blockade reversal with neostigmine but administration of sugammadex led to successful tracheal extubation. In conclusion, sugammadex appears to be safe and effective in adult patients with end-stage renal disease receiving pre-operative renal replacement therapy.

Comparison of Epidemiology and Outcomes in Neuro-Oncology Between the East and the West: Challenges and Opportunities

Although neoplasms of the brain and central nervous system (CNS) are relatively uncommon, comprising only 1-2% of the overall cancer burden, they represent a substantial source of morbidity and mortality worldwide. The age-adjusted annual incidence of CNS tumours is reportedly low; however, there is substantial global variability in its incidence, with nearly a five-fold difference between regions with the highest rates in developed countries in the West and those with the lowest rates in developing countries in South-East Asia, including India, possibly attributable to key differences in environmental factors, genetic susceptibilities and cultural practices, as well as resource constraints in low-middle income countries precluding precise ascertainment and accurate diagnosis. The burden of CNS tumours is further compounded by the fact that they require highly specialised and skilled multidisciplinary care, including access to modern neuroimaging, neurosurgery, neuropathology and molecular biology, radiotherapy, chemotherapy and rehabilitation services, which may not be widely available in an integrated manner in large parts of the world with a large variation in clinical pathways, non-uniformity of care and resultant heterogeneity in clinical outcomes. CNS tumours encompass a heterogeneous spectrum of histopathological entities with differences in presentation, distinct molecular/genetic alterations, diverse biological behaviour and varying clinical outcomes. Survival is highly dependent on histology, grade and molecular biology, but varies widely across continents, even for the same tumour type and grade. In general, survival is higher in children with primary brain tumours than in adults, largely due to the differences in histological distribution across age groups. However, there is widespread variability, with 5-year survival for paediatric brain tumours being <40% in some low-middle income countries compared with 70-80% in the developed world. This review compares the descriptive epidemiology and clinical outcomes of primary brain tumours between the East and the West that pose unique challenges but also provide new opportunities in contemporary neuro-oncological practice.

POPPIE: protocol for a randomised controlled pilot trial of continuity of midwifery care for women at increased risk of preterm birth

Background

High rates of preterm births remain a UK public health concern. Preterm birth is a major determinant of adverse infant and longer-term outcomes, including survival, quality of life, psychosocial effects on the family and health care costs. We aim to test whether a model of care combining continuity of midwife care with rapid referral to a specialist obstetric clinic throughout pregnancy, intrapartum and the postpartum period is feasible and improves experience and outcomes for women at increased risk of preterm birth.

Methods

This pilot, hybrid, type 2 randomised controlled implementation trial will recruit 350 pregnant women at increased risk of preterm birth to a midwifery continuity of care intervention or standard care. The intervention will be provided from recruitment (antenatal), labour, birth and the postnatal period, in hospital and community settings and in collaboration with specialist obstetric clinic care, when required. Standard care will be the current maternity care provision by NHS midwives and obstetricians at the study site. Participants will be followed up until 6–8 weeks postpartum. The composite primary outcome is the appropriate initiation of any specified interventions related to the prevention and/or management of preterm labour and birth. Secondary outcomes are related to: recruitment and attrition rates; implementation; acceptability to women, health care professionals and stakeholders; health in pregnancy and other complications; intrapartum outcomes; maternal and neonatal postnatal outcomes; psycho-social health; quality of care; women’s experiences and health economic analysis. The trial has 80% power to detect a 15% increase in the rate of appropriate interventions (40 to 55%). The analysis will be by ‘intention to treat’ analysis.

Discussion

Little is known about the underlying reasons why and how models of midwifery continuity of care are associated with fewer preterm births, better maternal and infant outcomes and more positive experiences; nor how these models of care can be implemented successfully in the health services. This will be the first study to provide direct evidence regarding the effectiveness, implementation and evaluation of a midwifery continuity of care model and rapid access to specialist obstetric services for women at increased risk of preterm birth.

Trial registration

ISRCTN37733900. Retrospectively registered on 21 August 2017.

Analysis of the ROADSTER pivotal and extended-access cohorts shows excellent 1-year durability of transcarotid stenting with dynamic flow reversal

OBJECTIVE

We report the 1-year outcomes of the Safety and Efficacy Study for Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial. This trial introduced a novel transcarotid neuroprotection system (NPS), the ENROUTE transcarotid NPS (Silk Road Medical Inc, Sunnyvale, Calif). Postoperative results demonstrated that the use of the ENROUTE transcarotid NPS is safe and effective. The aim of this study was to evaluate the safety of transcarotid artery revascularization (TCAR) and to present the 1-year outcomes.

METHODS

This study is a prospective, single-arm clinical trial. Current enrollment occurs in 14 centers. Primary end points were incidence rates of ipsilateral stroke at 1 year after TCAR. Occurrence of stroke was ascertained by an independent Clinical Events Committee. Patients with anatomic or medical high-risk factors for carotid endarterectomy (CEA) were eligible to be enrolled in the ROADSTER trial.

RESULTS

Overall, 165 patients were included in the long-term follow-up (112 of 141 patients from the pivotal phase and 53 of 78 patients from the extended access). Mean age was 73.9 years (range, 42.1-91.3 years). Patients aged 75 years and older were 43.3% of the cohort. The majority of patients were white (92.7%) and male (75.2%). Most patients were asymptomatic (79.9%). Anatomic risk factors were distributed as follows: contralateral carotid artery occlusion (11.0%), tandem stenosis of >70% (1.8%), high cervical carotid artery stenosis (25.0%), restenosis after CEA (25.6%), bilateral stenosis requiring treatment (4.3%), and hostile neck (14.6%). Medical high-risk criteria included two-vessel coronary artery disease (14.0%) and severe left ventricular dysfunction with ejection fraction <30% (1.8%). In general, 43.3% of patients had at least one anatomic high-risk factor, whereas 29.9% of patients had medical high-risk factors. Both subsets of factors were present simultaneously in 26.8% of the cohort. At 1-year follow-up, ipsilateral stroke incidence rate was 0.6%, and seven patients (4.2%) died. None of the deaths were neurologic in origin.

CONCLUSIONS

TCAR with dynamic flow reversal had previously shown favorable 30-day perioperative outcomes. This excellent performance seems to extend to 1 year after TCAR as illustrated in this analysis. The promising results from the ROADSTER trial likely stem from the novel cerebral protection provided through the ENROUTE transcarotid NPS in comparison to distal embolic protection devices as well as the transcarotid approach's circumventing diseased aortic arch manipulation and minimizing embolization. TCAR offers a safe and durable revascularization option for patients who are deemed to be at high risk for CEA.

Feasibility of measuring memory response to increasing dexmedetomidine sedation in children

BACKGROUND

The memory effect of dexmedetomidine has not been prospectively evaluated in children. We evaluated the feasibility of measuring memory and sedation responses in children during dexmedetomidine sedation for non-painful radiological imaging studies. Secondarily, we quantified changes in memory in relation to the onset of sedation.

METHODS

A 10 min bolus of dexmedetomidine (2 mcg kg^-1) was given to children as they named simple line drawings every five s. The absence of sedation was identified as any verbal response, regardless of correctness. After recovery, recognition memory was tested with correct Yes/No recognitions (50% novel pictures) and was matched to sedation responses during the bolus period (subsequent memory paradigm).

RESULTS

Of 64 accruals, 30 children (mean [SD]6.1 (1.2) yr, eight male) received dexmedetomidine and completed all study tasks. Individual responses were able to be modelled successfully in the 30 children completing all the study tasks, demonstrating feasibility of this approach. Children had 50% probability of verbal response at five min 40 s after infusion start, whereas 50% probability of subsequent recognition memory occurred sooner at four min five s.

CONCLUSIONS

Quantifying memory and sedation effects during dexmedetomidine infusion in verbal children was possible and demonstrated that memory function was present until shortly before verbal unresponsiveness occurred. This is the first study to investigate the effect of dexmedetomidine on memory in children.

CLINICAL TRIAL REGISTRATION

NCT 02354378.

Neutron capture cross-sections for 159Tb isotope in the energy range of 5 to 17 MeV

The neutron capture cross-sections have been measured for the ¹⁵⁹Tb(n, γ)¹⁶⁰Tb reaction at the spectrum average peak neutron energies of 5.08 ± 0.165, 12.47 ± 0.825, and 16.63 ± 0.95 MeV respectively. The experiment has been carried out using the standard neutron activation technique and off-line γ-ray spectrometry. The present measurement has been done for the energies where very few measured results are available in the data library. The results have been compared with ENDF/B-VII.1 and JENDL-4.0 data libraries. The present results have also been supported by theoretical predictions of nuclear model code TALYS 1.9. Detailed covariance analysis was carried out to find the uncertainty and the correlations among the measured cross-sections.

Grey matter volume and thickness abnormalities in young people with a history of childhood abuse

BACKGROUND

Childhood abuse is associated with abnormalities in brain structure and function. Few studies have investigated abuse-related brain abnormalities in medication-naïve, drug-free youth that also controlled for psychiatric comorbidities by inclusion of a psychiatric control group, which is crucial to disentangle the effects of abuse from those associated with the psychiatric conditions.

METHODS

Cortical volume (CV), cortical thickness (CT) and surface area (SA) were measured in 22 age- and gender-matched medication-naïve youth (aged 13-20) exposed to childhood abuse, 19 psychiatric controls matched for psychiatric diagnoses and 27 healthy controls. Both region-of-interest (ROI) and whole-brain analyses were conducted.

RESULTS

For the ROI analysis, the childhood abuse group compared with healthy controls only, had significantly reduced CV in bilateral cerebellum and reduced CT in left insula and right lateral orbitofrontal cortex (OFC). At the whole-brain level, relative to healthy controls, the childhood abuse group showed significantly reduced CV in left lingual, pericalcarine, precuneus and superior parietal gyri, and reduced CT in left pre-/postcentral and paracentral regions, which furthermore correlated with greater abuse severity. They also had increased CV in left inferior and middle temporal gyri relative to healthy controls. Abnormalities in the precuneus, temporal and precentral regions were abuse-specific relative to psychiatric controls, albeit at a more lenient level. Groups did not differ in SA.

CONCLUSIONS

Childhood abuse is associated with widespread structural abnormalities in OFC-insular, cerebellar, occipital, parietal and temporal regions, which likely underlie the abnormal affective, motivational and cognitive functions typically observed in this population.