CDK activity at the centrosome regulates the cell cycle

In human cells and yeast, an intact "hydrophobic patch" substrate docking site is needed for mitotic cyclin centrosomal localization. A hydrophobic patch mutant (HPM) of the fission yeast mitotic cyclin Cdc13 cannot enter mitosis, but whether this is due to defective centrosomal localization or defective cyclin-substrate docking more widely is unknown. Here, we show that artificially restoring Cdc13-HPM centrosomal localization promotes mitotic entry and increases CDK (cyclin-dependent kinase) substrate phosphorylation at the centrosome and in the cytoplasm. We also show that the S-phase B-cyclin hydrophobic patch is required for centrosomal localization but not for S phase. We propose that the hydrophobic patch is essential for mitosis due to its requirement for the local concentration of cyclin-CDK with CDK substrates and regulators at the centrosome. Our findings emphasize the central importance of the centrosome as a hub coordinating cell-cycle control and explain why the cyclin hydrophobic patch is essential for mitosis.

RNA polymerase II dynamics and mRNA stability feedback scale mRNA amounts with cell size

A fundamental feature of cellular growth is that total protein and RNA amounts increase with cell size to keep concentrations approximately constant. A key component of this is that global transcription rates increase in larger cells. Here, we identify RNA polymerase II (RNAPII) as the limiting factor scaling mRNA transcription with cell size in budding yeast, as transcription is highly sensitive to the dosage of RNAPII but not to other components of the transcriptional machinery. Our experiments support a dynamic equilibrium model where global RNAPII transcription at a given size is set by the mass action recruitment kinetics of unengaged nucleoplasmic RNAPII to the genome. However, this only drives a sub-linear increase in transcription with size, which is then partially compensated for by a decrease in mRNA decay rates as cells enlarge. Thus, limiting RNAPII and feedback on mRNA stability work in concert to scale mRNA amounts with cell size.

A survey in the West Midlands of the United Kingdom of current practice in managing hypotension in lower segment caesarean section under spinal anaesthesia

BACKGROUND

Spinal anaesthesia, the most common form of anaesthesia for caesarean section, leads to sympathetic blockade and profound maternal hypotension resulting in adverse maternal and neonatal outcomes. Hypotension, nausea and vomiting remain common but until the publication of the National Institute of Health and Care Excellence (NICE) 2021 guidance, no national guideline existed on how best to manage maternal hypotension following spinal anaesthesia for caesarean section. A 2017 international consensus statement recommended prophylactic vasopressor administration to maintain a systolic blood pressure of >90% of an accurate pre-spinal value, and to avoid a drop to <80% of this value. This survey aimed to assess regional adherence to these recommendations, the presence of local guidelines for management of hypotension during caesarean section under spinal anaesthesia, and the individual clinician's treatment thresholds for maternal hypotension and tachycardia.

METHODS

The West Midlands Trainee-led Research in Anaesthesia and Intensive Care Network co-ordinated surveys of obstetric anaesthetic departments and consultant obstetric anaesthetists across 11 National Health Service Trusts in the Midlands, England.

RESULTS

One-hundred-and-two consultant obstetric anaesthetists returned the survey and 73% of sites had a policy for vasopressor use; 91% used phenylephrine as the first-line drug but a wide range of recommended delivery methods was noted and target blood pressure was only listed in 50% of policies. Significant variation existed in both vasopressor delivery methods and target blood pressures.

CONCLUSIONS

Although NICE has since recommended prophylactic phenylephrine infusion and a target blood pressure, the previous international consensus statement was not adhered to routinely.

Body mass index associated differences in cardiac stress energetics in type 2 diabetes

Background

Patients with T2D and heart disease have normal body mass index (BMI), suggesting that diabetes and obesity mediate cardiovascular change by different mechanisms. Changes in cardiac energy metabolism in lean diabetic patients during exercise stress have not been previously reported.

Objectives

We aimed to assess if there are BMI-associated differences in cardiac stress metabolism in patients with T2D.

Methods

Twenty-five overweight T2D patients (O-T2D) and eleven lean T2D patients (LnT2D), age- and ethnicity-matched and with no other comorbidities were studied. Patients were on oral hypoglycaemics only and were free of diabetes complications. Participants underwent rest and dobutamine stress phosphorus magnetic resonance spectroscopy (31P-MRS) and cardiovascular magnetic resonance (CMR) at 3T for the assessment of myocardial phosphocreatine to ATP ratio (PCr/ATP) as a measure of myocardial energetics, biventricular volumes, rest and stress left ventricular (LV) ejection fraction, global longitudinal shortening, and mitral in-flow E/A ratio for assessment of diastolic function and perfusion.

Intravenous Dobutamine was administered at a dose of 10μg/kg/min, increasing at 90 second intervals up to a maximum of 40 μg/kg/min to achieve a target heart rate of 65% of the age-predicted maximal heart rate. Mean rate pressure product (RPP) was recorded at rest and stress. Heart rate was maintained at target for the duration of the 31P-MRS and stress CMR cine, mitral in-flow and perfusion acquisitions.

Results

The cardiac volumes, systolic or diastolic function and LV mass were similar between LnT2D and O-T2D. Although the O-T2D patients had a numerically lower rest and stress PCr/ATP ratio, this did not reach statistical significance. Resting PCr/ATP was reduced in LnT2D and O-T2D patients similarly. However, LnT2D showed a greater reduction in PCr/ATP (stress PCr/ATP LnT2D 1.51±0.2 vs O-T2D 1.41±0.25, p=0.02) despite similar increases in RPP. Stress myocardial blood flow (MBF) was also significantly lower in the O-T2D patients. There were significant correlations of BMI with LV mass (r=0.35, p=0.03); stress LVEF (r=−0.34, p=0.04); stress MBF stress (r=−0.53, p=0.001) and stress E/A (r=0.46, p=0.01) (figure 1).

Conclusions

Despite their better stress perfusion and similar glycaemic control, LnT2D show worse metabolic reserve characterised by more significant decrements in energetics in response to hemodynamic stress compared to overweight patients with T2D. Higher BMI correlates inversely with stress myocardial blood flow and with stress left ventricular ejection fraction. The presence of these subtle alterations in measures of stress metabolism and perfusion might signify a distinct metabolic phenotype of “lean diabetic cardiomyopathy”. Future studies are needed to further delineate alterations in cardiac energy metabolism in lean and overweight/obese type 2 diabetes patients, and their role in the development of cardiac dysfunction.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Wellcome TrustBHF

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

First Leptophobic Dark Matter Search from the Coherent-CAPTAIN-Mills Liquid Argon Detector

We report the first results of a search for leptophobic dark matter (DM) from the Coherent-CAPTAIN-Mills (CCM) liquid argon (LAr) detector. An engineering run with 120 photomultiplier tubes (PMTs) and 17.9×10^{20} protons on target (POT) was performed in fall 2019 to study the characteristics of the CCM detector. The operation of this 10-ton detector was strictly light based with a threshold of 50 keV and used coherent elastic scattering off argon nuclei to detect DM. Despite only 1.5 months of accumulated luminosity, contaminated LAr, and nonoptimized shielding, CCM's first engineering run has already achieved sensitivity to previously unexplored parameter space of light dark matter models with a baryonic vector portal. With an expected background of 115 005 events, we observe 115 005+16.5 events which is compatible with background expectations. For a benchmark mediator-to-DM mass ratio of m_{V_{B}}/m_{χ}=2.1, DM masses within the range 9  MeV≲m_{χ}≲50  MeV are excluded at 90% C. L. in the leptophobic model after applying the Feldman-Cousins test statistic. CCM's upgraded run with 200 PMTs, filtered LAr, improved shielding, and 10 times more POT will be able to exclude the remaining thermal relic density parameter space of this model, as well as probe new parameter space of other leptophobic DM models.

Core control principles of the eukaryotic cell cycle

Cyclin-dependent kinases (CDKs) lie at the heart of eukaryotic cell cycle control, with different cyclin-CDK complexes initiating DNA replication (S-CDKs) and mitosis (M-CDKs)^1,2. However, the principles on which cyclin-CDK complexes organize the temporal order of cell cycle events are contentious³. One model proposes that S-CDKs and M-CDKs are functionally specialized, with substantially different substrate specificities to execute different cell cycle events^4-6. A second model proposes that S-CDKs and M-CDKs are redundant with each other, with both acting as sources of overall CDK activity^7,8. In this model, increasing CDK activity, rather than CDK substrate specificity, orders cell cycle events^9,10. Here we reconcile these two views of core cell cycle control. Using phosphoproteomic assays of in vivo CDK activity in fission yeast, we find that S-CDK and M-CDK substrate specificities are remarkably similar, showing that S-CDKs and M-CDKs are not completely specialized for S phase and mitosis alone. Normally, S-CDK cannot drive mitosis but can do so when protein phosphatase 1 is removed from the centrosome. Thus, increasing S-CDK activity in vivo is sufficient to overcome substrate specificity differences between S-CDK and M-CDK, and allows S-CDK to carry out M-CDK function. Therefore, we unite the two opposing views of cell cycle control, showing that the core cell cycle engine is largely based on a quantitative increase in CDK activity through the cell cycle, combined with minor and surmountable qualitative differences in catalytic specialization of S-CDKs and M-CDKs.

Analytical Validation of a Deep Neural Network Algorithm for the Detection of Ovarian Cancer

Early detection of ovarian cancer, the deadliest gynecologic cancer, is crucial for reducing mortality. Current noninvasive risk assessment measures include protein biomarkers in combination with other clinical factors, which vary in their accuracy. Machine learning can be applied to optimizing the combination of these features, leading to more accurate assessment of malignancy. However, the low prevalence of the disease can make rigorous validation of these tests challenging and can result in unbalanced performance.

The value of a negative genetic result when triaging an adnexal mass

e17553

Background: The baseline risk for ovarian cancer in the general population is 1.2%1. However, women with germline variants in ovarian cancer-associated genes can have a much higher baseline risk for ovarian cancer, up to 54%2. Such a difference in baseline risk presents a triaging challenging for physicians when evaluating adnexal masses. It is well known that identifying pathogenic variants in hereditary cancer syndrome genes often leads to changes in care. Less is known about the utility of negative genetic testing results, specifically in the context of adnexal mass assessment. Methods: An observational, prospective study was designed to examine the clinical impact of multivariate index assay (MIA) and germline genetic testing in patients with a known adnexal mass planned for surgery. Inclusion criteria were: female subjects aged 18-65, presence of an adnexal mass, receiving MIA, and consideration of germline genetic testing. Enrolled physicians selected patients under their care that met inclusion criteria and filled out a short survey describing how the results of each test impacted clinical management. This study was considered IRB-exempt as all information was de-identified. Results: 23 patients were enrolled that received both MIA and germline genetic testing. 21 cases had negative genetic testing and two had positive genetic testing. Both patients with positive genetic testing had low-risk MIA results. Both had risk-reduction surgery with benign findings. Three patients had high-risk MIA results with negative genetic results. All patients had a serial monitoring plan of care. Nine patients with low-risk MIA results and negative genetic results proceeded to surgery. No malignancies were reported. Of the 21 patients with negative genetic results, 17 were not immediately planned for surgery. Conclusions: While not reaching statistical significance, there is a strong association between a negative genetic result and non-immediate surgical intervention. While positive genetic testing results may lead to more aggressive, prophylactic surgical management, negative genetic results may support an expectant management approach. Effectively ruling out the most common hereditary cancer predisposition syndromes may provide physicians with useful insight into a patient's baseline risk. [Table: see text]

A de novo paradigm for male infertility

De novo mutations are known to play a prominent role in sporadic disorders with reduced fitness. We hypothesize that de novo mutations play an important role in severe male infertility and explain a portion of the genetic causes of this understudied disorder. To test this hypothesis, we utilize trio-based exome sequencing in a cohort of 185 infertile males and their unaffected parents. Following a systematic analysis, 29 of 145 rare (MAF < 0.1%) protein-altering de novo mutations are classified as possibly causative of the male infertility phenotype. We observed a significant enrichment of loss-of-function de novo mutations in loss-of-function-intolerant genes (p-value = 1.00 × 10^-5) in infertile men compared to controls. Additionally, we detected a significant increase in predicted pathogenic de novo missense mutations affecting missense-intolerant genes (p-value = 5.01 × 10^-4) in contrast to predicted benign de novo mutations. One gene we identify, RBM5, is an essential regulator of male germ cell pre-mRNA splicing and has been previously implicated in male infertility in mice. In a follow-up study, 6 rare pathogenic missense mutations affecting this gene are observed in a cohort of 2,506 infertile patients, whilst we find no such mutations in a cohort of 5,784 fertile men (p-value = 0.03). Our results provide evidence for the role of de novo mutations in severe male infertility and point to new candidate genes affecting fertility.

Risk of contracting SARS-CoV-2 (COVID-19) from hospital admission and the impact of protection efforts on acute stroke treatment

Background

It is unclear how interventions designed to restrict community and in-hospital exposure to the SARS-CoV-2 (COVID-19) virus influenced stroke care for patients seeking acute treatment. Therefore, we aimed to determine how these COVID-19 interventions impacted acute stroke treatment times and to assess the risk of contracting COVID-19 due to their stay in our medical center.

Methods

Retrospective, single center, two-phase study evaluating hospital and community trends from 12/2019 – 04/2020 compared to the previous year and pre/post (n = 156/93) intervention implementation. Phase I assessed stroke treatment times, delay to hospital arrival, and witnessed stroke volume. Phase II, a post-implementation telephone survey, assessed risk of developing symptoms or testing positive for COVID-19.

Results

Stroke volume declined by 29% (p < .05) from April to March compared to the previous year. However, no significant delays in seeking medical care (pre Mdn=112, post Mdn=95, p = .34) was observed. Witnessed stroke volume decreased 11% (p < .001) compared to the pre-implementation group, but no significant delay in IV alteplase (pre Mdn=22 mins; post Mdn=26 mins, p = .08) nor endovascular treatment (pre Mdn=60 mins; post Mdn=80 mins, p = .45) was observed. In Phase II, 63 patients participated, two tested (3%) COVID-19 positive during admission and four (6%) within two weeks of discharge. COVID-19 contraction risk during and after hospitalization remained similar to the general population (RR=1.75, 95%CI: 0.79–3.63). Overall results indicated a marked decrease in stroke volume, no significant delays to either seek or provide acute stroke care were evident, and COVID-19 contraction risk was low.

Conclusions

Seeking acute stroke medical care outweighs the risk of COVID-19 exposure.

Abstract P153: SARS-CoV-2 (COVID-19) Protection Efforts on Acute Stroke Treatment

Introduction: It is unclear how the interventions designed to restrict community and in-hospital exposure to the SARS-CoV-2 virus affected the care for stroke patients seeking acute treatment. The objective of the following study was to determine the impact COVID-19 has had on the treatment times for patients evaluated as acute stroke alerts at Baptist Hospital of Miami (BHM). A co-primary objective of the study was to assess the risk of contracting SARS-CoV-2 within 2 weeks from hospital discharge.

Methods: This retrospective, two phase study was conducted between December 2019 and April 2020. In phase one, we assessed time from symptom onset to hospital arrival, number of strokes with witnessed onset, and in-hospital treatment times pre & post implementation of Covid-19 preventive exposure measures. In phase two of the study, a telephone survey was conducted on the post implementation group to assess the risk of patients developing symptoms or testing positive for SARS-CoV-2 from hospital admission up to two weeks post discharge.

Results: Phase I demonstrated there was a 40% decline in stroke volume, but no significant delay to seek medical attention post implementation of the SARS prevention strategies. On average individuals in the pre-group (n=155) waited approximately 260 minutes (SE=24) to seek medical attention vs. 203 minutes (SE=27) minutes for the post-group (n=87). However, there was nearly a six-fold increase in the percentage of cases with unknown symptom onset post implementation of COVID-19 safety precautions. There was significant delay in administering IV alteplase, increasing from 24 mins (n=16) to 33 mins (n=21) post implementation; delays observed for endovascular treatment were not significant (pre, n=13 mean= 73 mins, post n=12 mean= 82 mins). The volume of patients treated with either IV alteplase and/or endovascular treatment remained similar. Phase II of the study is on-going, results will be available for the ISC.

Discussion: The COVID-19 crisis in our community was associated with a six-fold increase in the percentage of cases with unknown stroke onset time. Besides a marked decrease in stroke volume, we did not evidence significant delays to either seek or provide acute stroke care outside a modest increase in door to needle time.

Opicapone: A third generation COMT inhibitor

•

Opicapone is a 3rd generation catechol-O-methyl transferase (COMT) inhibitor approved in April 2020 by the FDA.

•

Opicapone is used once daily as adjunctive to levodopa/carbidopa to reduce “off” periods in patients with Parkinson’s disease.

•

In clinical trials BIPARK I and II, 50 mg of opicapone once daily was shown to be noninferior to entacapone and reduced the mean off time by about 50 min when compared to placebo.

•

Most common treatment-emergent adverse events for opicapone were dyskinesia, falls, insomnia, and elevated blood creatine phosphokinase levels; it has not been associated with severe hepatic impairment.

Objective: To provide a drug review of the newly FDA approved catechol-O-methyl transferase (COMT) inhibitor, opicapone, for the use of end-of-motor motor fluctuation in adults with Parkinson’s disease. Data sources: A literature search of Pubmed was performed till May 2020 using the following key terms: opicapone, Ongentys, and BIA 9-1067. Review articles, clinical trials, and drug monographs were reviewed. Study selection and data extraction: Relevant English-language monographs and studies conducted in humans were considered. Data synthesis: Opicapone was FDA approved for the treatment of end-of-motor motor fluctuation in adults with Parkinson’s disease in April 2020 based on two published randomized clinical trials that were 14 to 15 weeks in duration called BIPARK I and BIPARK II. Based on the clinical trials, 50 mg of opicapone once daily was shown to be noninferior to entacapone and reduced the mean off time by about 50 min when compared to placebo. Most common treatment-emergent adverse events were dyskinesia, falls, insomnia, and elevated blood creatine phosphokinase levels. Relevance to patient care and clinical practice: Opicapone overcomes the limitations associated with other COMT inhibitors since it is dosed once daily, well tolerated, and has not been associated with the risk of hepatic failure. When switching from entacapone to opicapone a reduction in “off” time of −39.3 min was also seen. Conclusions: Opicapone is a once daily 3rd generation COMT inhibitor that has the potential to benefit patients with Parkinson’s disease who are experiencing end-of-motor fluctuations.

UK national and regional trends in cardiovascular magnetic resonance usage – the British Society of CMR survey results

Background

CMR is an imaging modality recommended for multiple indications. Access to CMR is a key issue for its clinical use. We surveyed all CMR units in the UK.

Methods

An online survey of CMR units in the UK, with responses analysed by region and compared with population data.

Results

Response rate was 100% (Table). The UK performed a total of 102,886 scans in 2017, and 117,967 in 2018 representing a 1-year 14.7% increase and a 10-year increase of 573% compared to 2008 data (20,597).By head of population in 2018 there were 1,776 CMR scans per million people, with significant variation nationally and regionally, e.g. 4,256 per million in London vs. 396 per million in Wales (Figure). Mean number of scans per unit was 1,404, (range 98–10,000) with wide variation in referral to diagnostic times (mean 45.7 days, range 5–180) (Figure).

Clinical indications for CMR were: heart failure 21%, cardiomyopathy 27%, function and viability 22%, stress 24%, vascular disease 5%, valvular 5%, myocarditis/pericardial 10%, paediatric /congenital 10%, others e.g. transplant/masses 4%, with overlap. There were 358 consultants reporting CMR in 2018 (234 (65%) cardiologists and 124 (35%) radiologists). 81% of units had a CMR service for patients with pacemakers and defibrillators.

Conclusion

The survey shows the state of CMR in the UK. The 10-year growth has been remarkable, but there are wide disparities in terms of use, access and wait times with potential implications for clinical care. Action is needed to make access equitable across the UK.

Figure 1

Funding Acknowledgement

Type of funding source: None

Stratifying the prognostic capability of cardiovascular magnetic resonance in severe aortic stenosis: a machine learning approach

Background

Cardiovascular magnetic resonance (CMR) demonstrates promise in improving patient risk stratification in aortic stenosis (AS). We explored whether machine learning might provide further insights into the prognostic capability of CMR parameters.

Methods

Severe AS patients (n=440) undergoing AVR were prospectively enrolled across 10 international sites, and CMR performed prior to AVR. A machine learning prediction model using a random survival forest (RSF) was trained with 29 variables, including 13 CMR, 4 echocardiography, and 12 clinical parameters, using post-AVR mortality as an outcome. The impact of the important variables on the outcome (partial dependency) was examined.

Results

The most predictive CMR parameters in the RSF model were the extracellular volume fraction (ECV%), followed by right ventricular ejection fraction (RVEF), late gadolinium enhancement (LGE%), and indexed left ventricular end-diastolic volume (LVEDVi). Regarding the partial effects, the predicted mortality increased strongly once the ECV% exceeded 26.5% (Figure 1A). The LGE% was associated with an increased risk of mortality, which reached a plateau beyond the level of 2% (Figure 1C). There were U-shaped relationships between mortality and both RVEF and LVEDVi, with the lowest mortality seen at RVEF 70% and LVEDVi 68ml/m2 (Figure 1B, D). These trends of predicted outcomes by each variable were verified in the Kaplan-Meier curves and Cox analyses (Table). In both Cox and RSF models, the predictability was substantially increased when these four CMR parameters were added to conventional clinical risk factors. An AS-CMR risk score comprised of these four parameters presented a stepwise increase in mortality with increasing adverse CMR features (p&lt;0.001).

Conclusions

Our machine learning analysis using RSF has identified ECV%, RVEF, LGE%, and LVEDVi as key prognostic markers in severe AS with a nonlinear influence of each parameter on mortality post-AVR.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was supported by grants from the Korean Health Technology R & D Project, Ministry of Health, Welfare & Family Affairs, Republic of Korea (HI16C0225 and HI15C0399) and the National Institute for Health Research (NIHR) infrastructure at Leeds.

Lumateperone: A Novel Antipsychotic for Schizophrenia

OBJECTIVE

To provide a concise review of the new Food and Drug Administration (FDA)-approved antipsychotic, lumateperone, for use in schizophrenia.

DATA SOURCES

A literature search of PubMed was performed (January 2000 to May 2020) using the following key terms: lumateperone, Caplyta, and ITI-007. Abstracts from conferences, review articles, clinical trials, and drug monographs were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language monographs and studies conducted in humans were considered.

DATA SYNTHESIS

Lumateperone was FDA approved for the treatment of schizophrenia in December 2019 based on 2 published randomized, double-blind, placebo-controlled trials. Lumateperone's pharmacology is consistent with that of other second-generation antipsychotics in that it has a higher affinity for the serotonin (5-HT_2A) receptors compared with dopamine (D₂) receptors but with lower affinities for α-1 and histaminergic receptors. In addition, it serves as a presynaptic dopamine partial agonist, serotonin reuptake inhibitor, and an indirect modulator of glutamatergic systems. Based on the 4-week clinical trials, lumateperone was well tolerated. Most common treatment-emergent adverse events were headache, somnolence, and dizziness.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

At this time, lumateperone had a statistically significant reduction in Positive and Negative Syndrome Scale when compared with placebo and was not significantly associated with the extrapyramidal symptoms (EPS) and metabolic adverse effects commonly seen with other antipsychotics.

CONCLUSIONS

Lumateperone has the potential to benefit individuals with schizophrenia who are intolerant to the EPSs or metabolic adverse effects of other antipsychotics. However, further head-to-head trials with commercially available antipsychotics are still required to assist in establishing its role in treatment.

THU0342 DECLINE IN SUBCLINICAL SYSTEMIC SCLEROSIS PRIMARY HEART INVOLVEMENT ASSOCIATES WITH POOR PROGNOSTIC FACTORS AND ACTIVE INTERSTITIAL LUNG DISEASE

Background:

Primary systemic sclerosis heart involvement (pSSc-HI) is described in the majority of SSc patients when sensitive methods such as cardiovascular magnetic resonance (CMR) are used1. The natural history of these subclinical findings are unknown.

Objectives:

To evaluate for interval change in subclinical pSSc-HI, the association between change in CMR abnormalities and disease phenotype and whether disease modifying antirheumatic (DMARD) and/or vasodilator treatment influence the CMR course.

Methods:

SSc patients, fulfilling the 2013 ACR/EULAR criteria, with no cardiovascular (CV) disease, diabetes and no more than 2 CV risk factors had two CMRs performed (V1 & V2; minimum 1 year apart). A 3T CMR with late gadolinium enhancement (LGE), T1 mapping for extracellular volume (ECV of diffuse fibrosis) quantification and stress perfusion was undertaken.

Results:

31 SSc patients were evaluated, with median (IQR) follow up (between the 2 CMR scans) of 33 (17, 37) months. Median (IQR) age was 52 (47,60), 32% had diffuse cutaneous SSc, 52% interstitial lung disease (ILD), 29% Scl70+.

4/31 patients had a non-ischaemic LGE pattern suggesting focal fibrosis at V1, with no change in the pattern, distribution, or median (IQR) LGE scar mass between V1 and V2 [1.88 (1.01, 6.34) vs 1.70 (1.21, 4.18)]. At V2, 2 additional patients showed focal fibrosis, of which one had an episode of clinically diagnosed myocarditis. No significant change in ECV, T1 native, myocardial perfusion reserve (MPR) or left ventricle (LV) volumes and function were noted at V2 compared with V1 (p>0.01).

SSc patients with either increase in pre-existing LGE scar mass (n=1) or new fibrosis were all dcSSc, with ILD, 2 Scl70+. A reduction in forced vital capacity and total lung capacity associated with a reduction in LV ejection fraction (LVEF) (rho=0.413, p=0.021; rho-0.335, p=0.07) and MPR (rho=0.543, p=0.007; rho=0.627, p=0.002).

Patients receiving DMARD treatment had higher baseline LV end-diastolic volume compared to those with no DMARD treatment [mean (SD) 78 (19) vs 69 (10), p=0.167]. A decrease in LV stroke volume and an increase in T1 native at V1 vs V2 was noted for those on DMARD [mean (SD) 49 (8) vs 46 (8), p =0.023; 1208 (65) vs 1265 (56), p=0.008 respectively] (Figure 1). No significant change in CMR measures in those receiving vasodilator or angiotensin-converting-enzyme inhibitor treatment was noted (p>0.01).

Figure 1.

Mean (SD) of T1 native, LVSV/BSA, LVEF, and LVEDV/BSA at V1 compared to V2 in those with and without DMARD treatment. BSA, body surface area; DMARD, disease modifying antirheumatic drugs; EDV, end-diastolic volume; SV, stroke volume; LV left ventricular; EF, ejection fraction.

Conclusion:

This first, pilot longitudinal study of CMR-defined subclinical pSSc-HI suggests largely stable appearances with follow-up. Progression of new focal fibrosis and decline in LV function and MPR, where observed, associated with poor prognostic factors of SSc and ILD progression. Consistent with this, individuals on DMARD appeared to show interval decline. Larger longitudinal studies are warranted to confirm these findings and inform on utility of CMR monitoring of subclinical pSSc-HI in poor prognosis SSc.

References:

[1]Ntusi NA et al, J Cardiovasc Magn Reson. 2014

Disclosure of Interests:

Raluca-Bianca Dumitru: None declared, Lesley Anne Bissell: None declared, Bara Erhayiem: None declared, Graham Fent: None declared, Ananth Kidambi: None declared, Giuseppina Abignano: None declared, John Greenwood: None declared, John Biglands: None declared, Francesco Del Galdo: None declared, Sven Plein: None declared, Maya H Buch Grant/research support from: Pfizer, Roche, and UCB, Consultant of: Pfizer; AbbVie; Eli Lilly; Gilead Sciences, Inc.; Merck-Serono; Sandoz; and Sanofi

The ORNATE India Project: United Kingdom-India Research Collaboration to tackle visual impairment due to diabetic retinopathy

INTRODUCTION

The ORNATE India project is funded by the UK Research and Innovation (UKRI) through the Global Challenges Research Fund. The aim is to build research capacity and capability in India and the UK to tackle global burden of diabetes-related visual impairment. As there are over 77 million people with diabetes in India, it is challenging to screen every person with diabetes annually for sight-threatening diabetic retinopathy (DR). Therefore, alternate safe approaches need to be developed so that those at-risk of visual impairment due to DR is identified promptly and treated.

METHODS

The project team utilised diverse global health strategies and research methods to co-design work packages to build research capacity and capability to ensure effective, affordable and efficient DR services are made available for the population. The strategies and methods employed included health system strengthening; implementation science; establishing care pathways; co-designing collaborative studies on affordable technologies, developing quality standards and guidelines to decrease variations in care; economic analysis; risk modelling and stratification. Five integrated work packages have been developed to deal with all aspects of DR care. These included implementation of a DR screening programme in the public health system in a district in Kerala, evaluating regional prevalence of diabetes and DR and assessing ideal tests for holistic screening for diabetes and its complications in 20 areas in India, utilising artificial intelligence on retinal images to facilitate DR screening, exploring biomarker and biosensor research to detect people at risk of diabetes complications, estimating cost of blindness in India and risk modelling to develop risk-based screening models for diabetes and its complications. A large collaborative network will be formed to propagate research, promote shared learning and bilateral exchanges between high- and middle-income countries to tackle diabetes-related blindness.

P2707Invasive coronary physiology during primary percutaneous coronary intervention in patients treated with intracoronary alteplase or placebo: the double-blind T-TIME physiology substudy

Background

Impaired microcirculatory reperfusion worsens prognosis post-primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). Intracoronary (IC) alteplase targets persisting thrombus post-reperfusion & distal embolisation. In the T-TIME trial microvascular obstruction on cardiac magnetic resonance (CMR) did not differ with IC alteplase vs placebo.

Purpose

To prospectively determine if index of microcirculatory resistance (IMR) is lower & coronary flow reserve (CFR) or resistive reserve ratio (RRR) are higher (improved) with IC alteplase, & to provide mechanistic insights.

Methods

A pre-planned substudy of the main protocol. From 2016–2017, STEMI patients from 3 UK hospitals ≤6 hrs ischaemic time were randomised in a 1:1:1 dose-ranging, double-blind design. Following standard care reperfusion, alteplase (10 or 20mg) or placebo was infused over 5–10 mins proximal to the culprit lesion pre-stenting. IMR (primary outcome), CFR & RRR (secondary outcomes) were measured in the culprit artery post-PCI. Physiology results were obscured from clinicians acquiring the data, to maintain blinding. CMR was performed 2 days & 3 months post-STEMI. Subgroup analyses were prespecified including by ischaemic time (<2 hours, 2–4 hrs, >4 hrs) & IMR threshold >32.

Results

In 144 patients (mean age 59 yrs, 80% male), IMR, CFR or RRR post-PCI did not differ with alteplase vs placebo (Table). Patients with ischaemic time <2 hrs had a dose related increase in CFR (placebo 1.2 [IQR 1.1–1.7], alteplase 10mg 1.4 [IQR 1.0–1.8], alteplase 20mg 2.0 [IQR 1.8–2.3] p=0.01 for interaction) & RRR (placebo 1.5 [IQR 1.3–1.9], alteplase 10mg 1.6 [1.1–2.2], alteplase 20mg 2.2 [2.0–2.6], p=0.03 for interaction). In subjects with post-PCI IMR>32, % ST-resolution at 60 mins was worse with alteplase 10mg vs placebo (23.1±53.9 vs 50.9±31.5) & in those with IMR≤32% ST-resolution at 60 mins was better with alteplase 20mg vs placebo (68.0±30.7 vs 39.1±43.2), p=0.002 for interaction. The CMR findings in the substudy & overall trial populations were consistent.

Main results Placebo Alteplase 10mg Alteplase 20mg (n=53) (n=41) (n=50) IMR, median (IQR) 33.0 (17.0–57.0) 22.0 (17.0–42.0) 37.0 (20.0–57.8) p=0.15 p=0.78 CFR, median (IQR) 1.3 (1.1–1.8) 1.4 (1.1–1.9) 1.5 (1.1–2.0) p=0.92 p=0.74 RRR, median (IQR) 1.6 (1.3–2.2) 1.6 (1.4–2.6) 1.8 (1.3–2.4) p=0.69 p=0.81 P-values for comparison of alteplase with placebo.

Conclusions

In acute STEMI with ischaemic time ≤6 hrs, IMR, CFR or RRR post-PCI did not differ with alteplase vs placebo. In those with shorter ischaemic times (<2 hrs) CFR & RRR, but not IMR, were improved with alteplase. We observed interactions between alteplase dose, ischaemic time & mechanisms of effect.

Acknowledgement/Funding

Dr Maznyczka is funded by a fellowship from the British Heart Foundation (FS/16/74/32573). T-TIME was funded by grant 12/170/4 from NIHR-EME

Charge migration in photo-ionized aromatic amino acids

Attosecond pump-probe spectroscopy is a unique tool for the direct observation of the light-activated electronic motion in molecules and it offers the possibility to capture the first instants of a chemical reaction. Recently, advances in attosecond technology allowed the charge migration processes to be revealed in biochemically relevant molecules. Although this purely electronic process might be key for a future chemistry at the electron time scale, the influence of this ultrafast charge flow on the reactivity of a molecule is still debated. In this work, we exploit extreme ultraviolet attosecond pulses to activate charge migration in two aromatic amino acids, namely phenylalanine and tryptophan. Advanced numerical calculations are performed to interpret the experimental data and to discuss the effects of the nuclear dynamics on the activated quantum coherences. By comparing the experimental results obtained in the two molecules, we show that the presence of different functional groups strongly affects the fragmentation pathways, as well as the charge rearrangement. The observed charge dynamics indeed present peculiar aspects, including characteristic periodicities and decoherence times. Numerical results indicate that, even for a very large molecule such as tryptophan, the quantum coherences can survive the nuclear dynamics for several femtoseconds. These results open new and important perspectives for a deeper understanding of the photo-induced charge dynamics, as a promising tool to control the reactivity of bio-relevant molecules via photo-excitation. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.

TP1-11 MS-STAT2: a phase 3 trial of high dose simvastatin in secondary progressive multiple sclerosis

Objectives

Disease modifying treatment for secondary progressive multiple sclerosis (SPMS) represents a major unmet need. We outline here the rationale for the MS-STAT2 trial – a phase 3 study of simvastatin in decreasing clinical progression in SPMS. MS-STAT2 will be a landmark study not only for patients with SPMS, but also for the area of drug repurposing and academically led clinical trials as a whole.

Design

Multicentre, double blind, parallel group randomised placebo-controlled trial. It follows the positive outcome from the phase 2 MS-STAT1 trial, which demonstrated a 43% reduction in the annualised rate of brain atrophy compared to placebo.1

Subjects

1180 patients with SPMS with an expanded disability status scale (EDSS) score of 4.0–6.5. Patients need to show evidence of disease progression over the preceding 2 years.

Methods

Subject will be recruited at 28 sites across the UK, and randomised to simvastatin 80 mg or matched placebo and assessed every 6 months over the 3 year trial.

Results

The primary outcome measure is time to 6 month confirmed disability progression, based on change in Expanded Disability Status Scale (EDSS) scores compared to baseline. Secondary outcomes include assessments of cognition, walking, upper limb function and vision. Sub-studies will include advanced imaging outcomes, ocular coherence tomography and fluid biomarkers.

Conclusions

MS-STAT2 is set to be a pivotal trial for SPMS. Recruitment has now commenced and further sites are welcome.

Reference

Chataway J, et al. MS-STAT. Lancet2014;383:2213–21.

Protein Contamination of the Laryngeal Mask Airway and its Relationship to Re-use

The Laryngeal Mask Airway is a reusable device for maintaining the patency of a patient's airway during general anaesthesia. The device can be reused after it has been cleaned and sterilized. Protein contamination of medical instruments is a concern and has been found to occur despite standard sterilization techniques. The reason for the concern relates to the possibility of the transmission of prions and the risk of developing a neurodegenerative disorder such as Creutzveldt-Jacob disease. The purpose of this study was to quantify the amount of protein contamination that occurs, and to relate this to the number of times the Laryngeal Mask Airway has been used. Fifty previously used Classic Laryngeal Masks were collected after routine sterilization and packaging. The devices were immersed in protein detecting stain and then visual inspection performed to assess the degree and distribution of the staining. The researcher was blinded to the number of times the Laryngeal Mask Airway had been used. Linear regression analysis of the degrees of staining of the airway revealed that protein contamination occurs after the first use of the device and this increases with each subsequent use. This finding highlights the concern that the currently used cleaning and sterilization methods do not prevent the accumulation of proteinaceous material on Laryngeal Mask Airways. Consideration should be given to the search for more efficient cleaning and sterilization techniques or the use of disposable devices.

Fission yeast telosomes: non-canonical histone-containing chromatin structures dependent on shelterin and RNA

Despite the prime importance of telomeres in chromosome stability, significant mysteries surround the architecture of telomeric chromatin. Through micrococcal nuclease mapping, we show that fission yeast chromosome ends are assembled into distinct protected structures ('telosomes') encompassing the telomeric DNA repeats and over half a kilobase of subtelomeric DNA. Telosome formation depends on the conserved telomeric proteins Taz1 and Rap1, and surprisingly, RNA. Although yeast telomeres have long been thought to be free of histones, we show that this is not the case; telomere repeats contain histones. While telomeric histone H3 bears the heterochromatic lys9-methyl mark, we show that this mark is dispensable for telosome formation. Therefore, telomeric chromatin is organized at an architectural level, in which telomere-binding proteins and RNAs impose a unique nucleosome arrangement, and a second level, in which histone modifications are superimposed upon the higher order architecture.

Abstract P3-06-04: Bcl-2 functional converters inhibit tumor growth and metastatic potential in zebrafish xenografts

While potential therapies might have pronounced success in the simplified settings in cell culture medium, many drugs fail or underperform when cancer cells are encased in a complex 3D microenvironment. Although, rat and mouse models will continue to be the gold standard for in vivo data in drug discovery, zebrafish xenograft models have emerged as a powerful model that can quickly and efficiently deliver in vivo drug efficacy data before commitment to expensive and time consuming rodent models. We have discovered several compounds that work as B-cell lymphoma 2 (Bcl-2) functional converters and activate Bcl-2 into a killer instead of its native anti-apoptotic role. In this study, we use a zebrafish xenograft model to evaluate the ability of these compounds to inhibit xenograft tumor growth of Bcl-2 expressing cancer cells, including triple negative breast cancers. Live fluorescent imaging of cancer cells within zebrafish embryos revealed a decrease in cancer cell growth while under treatment of compounds. Furthermore, the agents that converted Bcl-2 into pro-apoptotic protein also inhibited the metastatic potential of the cancer cells. Therefore, this study demonstrates zebrafish xenograft techniques that can be used to quickly and efficiently obtain in vivo drug discovery data. Moreover, we report novel Bcl-2 functional converter compounds that can effectively reduce xenograft tumor growth and its ability to invade tissue in a living 3D environment and establish the role of Bcl-2 in cancer progression.

Citation Format: Gamble J, Pearce M, Kopparapu P, Jang HS, Tanguay R, Greenwood J, Kolluri S. Bcl-2 functional converters inhibit tumor growth and metastatic potential in zebrafish xenografts [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-06-04.

Genome-wide screen for cell growth regulators in fission yeast

Cellular growth control is important for all living organisms, but experimental investigation into this problem is difficult because of the complex range of growth regulatory mechanisms. Here, we have used the fission yeast Schizosaccharomyces pombe to identify potential master regulators of growth. At the restrictive temperature, the S. pombe pat1^ts mei4Δ strain enters the meiotic developmental program, but arrests in meiotic G2 phase as mei4⁺ is essential for meiotic progression. These cells do not grow, even in an abundance of nutrients. To identify regulators of growth that can reverse this growth arrest, we introduced an ORFeome plasmid library into the pat1^tsmei4Δ strain. Overexpression of eight genes promoted cell growth; two of these were core RNA polymerase subunits, and one was sck2⁺ , an S6 kinase thought to contribute to TORC1 signalling. Sck2 had the greatest effect on cell growth, and we also show that it significantly increases the cellular transcription rate. These findings indicate, for the first time, that global transcriptional control mediated through S6 kinase signalling is central to cellular growth control.

Perampanel (Fycompa): A Review of Clinical Efficacy and Safety in Epilepsy

Perampanel (Fycompa): a review of clinical efficacy and safety in epilepsy.

Development of a Low Toxicity PMR-type Polyimide for Advanced Composite Applications

The thermosetting polyimide, PMR-15, is the leading contender for use in polymer matrix composites intended for high temperature applications. Although the properties of PMR-15 are generally good, its widespread use in aircraft and aeroengines has been hampered by a number of drawbacks. Among these are microcracking due to thermal cycling, irreproducibility of processing and the toxicity of the methylene diamine comonomer. The aim of the work reported here was to develop a PMR-type polyimide with properties equivalent to conventional PMR-15 but with none of the drawbacks. A key target of the work was to reduce the hazards associated with the use of methylene dianiline (MDA). Consequently, much of the work involved screening formulations in which MDA was replaced by a diamine of reduced toxicity. One formulation, coded B1, has been identified of which initial results look extremely promising. This formulation uses a partially fluorinated, four-ring diamine of low toxicity. This material was synthesized in-house and subsequently scaled-up in a semi-commercial process. Prepreg was manufactured on commercial equipment. Cure cycles were developed using mechanical spectrometry (RDS). Laminates were made by autoclave molding, and mechanical properties before and after high temperature ageing were determined. Preliminary results show that the B1 formulation compares favorably with conventional PMR-15.

Factors related to HPV vaccine uptake and 3-dose completion among women in a low vaccination region of the USA: an observational study

BACKGROUND

To assess the demographic and attitudinal factors associated with HPV vaccine initiation and completion among 18-26 year old women in Utah.

METHOD

Between January 2013 and December 2013, we surveyed 325 women from the University of Utah Community Clinics about their HPV vaccine related beliefs and behaviors. Odds ratios (ORs) were estimated from logistic regression models to identify variables related to HPV vaccine initiation and series completion.

RESULTS

Of the 325 participants, 204 (62.8 %) had initiated the vaccine and 159 (48.9 %) had completed the 3-dose series. The variables associated with HPV vaccine initiation were lower age (OR = 1.18 per year); being unmarried (OR = 3.62); not practicing organized religion (OR = 2.40); knowing how HPV spreads (OR = 6.29); knowing the connection between HPV and cervical cancer (OR = 3.90); a belief in the importance of preventive vaccination (OR = 2.45 per scale unit); strength of doctor recommendation (OR = 1.86 per scale unit); and whether a doctor's recommendation was influential (OR = 1.70 per scale unit). These variables were also significantly associated with HPV vaccine completion.

CONCLUSION

The implications of these findings may help inform policies and interventions focused on increasing HPV vaccination rates among young women. For example, without this information, programs might focus on HPV awareness; however, the results of this study illustrate that awareness is already high (near saturation) in target populations and other factors, such as strong and consistent physician recommendations, are more pivotal in increasing likelihood of vaccination. Additionally, our findings indicate the need for discussions of risk assessment be tailored to the young adult population.