Geographic distribution of United States clinical trial sites utilized for guideline changing studies of cholesterol management

BACKGROUND

This study aimed to evaluate the geographic distribution of United States (US) clinical trial sites utilizedfor guideline changing studies of cholesterol management.

METHODS

Randomized trials evaluating pharmacologic interventions for cholesterol treatment and reporting location data (ie, zip code of trial sites) were identified. Location data was abstracted from ClinicalTrials.gov.

RESULTS

Half of US counties were over 30 miles from a study site and, social determinants of health were more favorable in counties with versus without clinical trial sites.

CONCLUSIONS

Stakeholders such as regulatory bodies andtrial sponsors should incentivize and support infrastructure that would enable a larger number of US counties to be utilized for clinical trial sites.

TRIAL REGISTRATION

Not applicable.

Comparison of Pyrrolobenzodiazepine Dimer Bis-imine versus Mono-imine: DNA Interstrand Cross-linking, Cytotoxicity, Antibody-Drug Conjugate Efficacy and Toxicity

Antibody-drug conjugates (ADC) delivering pyrrolobenzodiazepine (PBD) DNA cross-linkers are currently being evaluated in clinical trials, with encouraging results in Hodgkin and non-Hodgkin lymphomas. The first example of an ADC delivering a PBD DNA cross-linker (loncastuximab tesirine) has been recently approved by the FDA for the treatment of relapsed and refractory diffuse large B-cell lymphoma. There has also been considerable interest in mono-alkylating PBD analogs. We conducted a head-to-head comparison of a conventional PBD bis-imine and a novel PBD mono-imine. Key Mitsunobu chemistry allowed clean and convenient access to the mono-imine class. Extensive DNA-binding studies revealed that the mono-imine mediated a type of DNA interaction that is described as "pseudo cross-linking," as well as alkylation. The PBD mono-imine ADC demonstrated robust antitumor activity in mice bearing human tumor xenografts at doses 3-fold higher than those that were efficacious for the PBD bis-imine ADC. A single-dose toxicology study in rats demonstrated that the MTD of the PBD mono-alkylator ADC was approximately 3-fold higher than that of the ADC bearing a bis-imine payload, suggesting a comparable therapeutic index for this molecule. However, although both ADCs caused myelosuppression, renal toxicity was observed only for the bis-imine, indicating possible differences in toxicologic profiles that could influence tolerability and therapeutic index. These data show that mono-amine PBDs have physicochemical and pharmacotoxicologic properties distinct from their cross-linking analogs and support their potential utility as a novel class of ADC payload.

Lateral abdominal muscles of adults with hypermobility may be partially impaired during contraction

Background

Muscle function may be impaired in people with generalised hypermobility, yet prior studies have primarily focused on muscles within the extremities. We aimed to examine changes in lateral abdominal muscle (transversus abdominis (TrA) and the external (EO) and internal abdominal obliques (IO)) thickness and length during contraction between participants with and without hypermobility.

Methods

This cross-sectional study examined 12 participants with hypermobility and 12 age-matched, sex-matched, height-matched and weight-matched participants without hypermobility. The Beighton and Belavy-Owen-Mitchell score assessed systemic hypermobility. Muscle thickness and length were measured via panoramic ultrasound scans at rest and during contraction.

Results

When compared with rest across all lumbar levels (L1–L5), contraction produced a lesser increase in TrA thickness (β=0.03, p=0.034) for participants with hypermobility compared with control. No group-by-condition interaction was observed for TrA length across all lumbar levels (L1–L5; p=0.269). Contraction produced a greater decrease in EO thickness (β=0.08, p=0.002) at L3 only for participants with hypermobility compared with control. No group-by-condition interactions were observed for IO thickness.

Conclusion

Participants with hypermobility had partially impaired lateral abdominal muscle function given a lesser ability to increase TrA muscle thickness during contraction compared with controls.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Efficacy, Tolerability, and Pharmacokinetic Studies of Antibody-Drug Conjugates Containing a Low-Potency Pyrrolobenzodiazepine Dimer

Antibody-drug conjugate (ADC) research has typically focused on the release of highly potent cytotoxic agents to achieve antitumor efficacy. However, recently approved ADCs trastuzumab deruxtecan and sacituzumab govitecan release lower-potency topoisomerase inhibitors. This has prompted interest in ADCs that release lower-potency cytotoxic drugs to potentially enhance therapeutic index and reduce unwanted toxicity. Pyrrolobenzodiazepine (PBD) dimer ADCs have been widely investigated in human clinical trials, which have focused on high-potency PBDs. In this study, we evaluated five ADCs that release the low-potency PBD dimer SG3650. The relatively low cLogD for this agent facilitated higher drug-to-antibody ratio (DAR) conjugation without the need for antibody engineering or functionalization of the drug. The rank order of potency for DAR 2 site-specific ADCs (conjugated at the C239i position) matched the order for the corresponding free drugs in vitro. Despite free drug SG3650 being inactive in vivo, the DAR 2 ADCs derived from the corresponding drug-linker SG3584 showed antitumor efficacy in solid (anti-HER2) and hematological (anti-CD22) xenograft models. Antitumor activity could be enhanced by conjugating SG3584 to trastuzumab at higher DARs of 4 and 8 and by adjusting dosing and schedule. Higher-DAR conjugates were stable and displayed good rat pharmacokinetic profiles as measured by ELISA and LC-MS/MS. A single intravenous dose of isotype control SG3584 DAR 2 ADC resulted in no mortality in rats or monkeys at doses of up to 25 and 30 mg/kg, respectively. These findings suggest that further investigations of low-potency PBD dimers in ADCs that target hematological and solid tumors are warranted.

OP0152 A DEEP LEARNING FRAMEWORK FOR MRI DETECTION OF ACTIVE INFLAMMATORY AND STRUCTURAL CHANGES IN THE SACROILIAC JOINT CONSISTENT WITH AXIAL SPONDYLOARTHRITIS: AN INTERNATIONAL COLLABORATIVE STUDY

Background

Magnetic resonance tomography (MRI) plays a key role in the early diagnosis of axial spondyloarthritis (axSpA). However, the detection of changes indicative of axSpA requires specific expertise, which poses a challenge to non-specialized centers. Deep learning (an advanced machine learning method) based on training an artificial neural network may facilitate and support diagnostics in clinical practice.

Objectives

To create a reliable deep learning tool for the detection of active inflammatory and structural changes indicative of axSpA on MRI of sacroiliac joints.

Methods

In this study, MRIs of sacroiliac joints from 477 patients from four cohorts (GESPIC-AS, GESPIC-Crohn, GESPIC-Uveitis and OptiRef comprising 266 patients with and 211 without axSpA) were used to develop a deep learning framework (randomly divided into training, n=404, and validation, n=73, datasets). MRIs from the ASAS cohort (n=116) were used for independent testing (test dataset). Each examination in the training/validation dataset was evaluated for the presence of active inflammatory and structural changes indicative of SpA by six experienced, trained and calibrated readers and by seven expert readers in the test dataset. The presence of the changes was defined as the majority vote amongst readers. Discordant cases in the training/validation dataset underwent consensus reading. In addition, the test dataset was evaluated by three radiologists not specifically trained in SpA. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity and specificity.

Results

The prevalence of positive imaging findings for active inflammatory/structural changes indicative of axSpA was 41%/51% in the training/validation dataset and 22%/22% in the test dataset. The model for the detection of active inflammatory changes showed an AUC of 0.91 (0.83 – 0.97) – Figure 1 – and an accuracy of 84% on the validation dataset; the corresponding sensitivity and specificity were 96% and 76%, respectively. Despite a substantially lower prevalence of active inflammatory changes in the test dataset, the model showed good generalization with an AUC of 0.91 (0.84−0.97) and an accuracy of 75%; the sensitivity and specificity were 88% and 71%, respectively. The model demonstrated a similar performance on the validation and test datasets for the detection of active inflammatory changes fulfilling the ASAS definition. The model for the detection of structural changes indicative of axSpA showed good performance on the validation dataset with an AUC of 0.90 (0.82-0.96) for the detection of structural changes and an overall accuracy of 85%. The associated sensitivity and specificity were 95% and 75%, respectively. The model showed reasonable generalization to new data with an AUC of 0.89 (0.81−0.96) and an accuracy of 79%; the sensitivity and specificity were 85% and 78%, respectively. Overall, the model performed close to the individual human experts - Figure 1.

Conclusion

The developed framework allowed the detection of active inflammatory and structural changes indicative of axSpA on MRI. This approach may be used as an assistant tool in the diagnostic workflow.

Acknowledgements

GESPIC-AS has been financially supported by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung - BMBF). GESPIC-Crohn has been supported by the Clinical Research Unit grant from the Berlin Institute of Health (BIH). GESPIC-Uveitis has been supported by a research grant from AbbVie. OptiRef has been supported by a research grant from Novartis. The Assessment of Spondyloarthritis International Society (ASAS) has supported the project with a research grant and provided access to the MRI images of the ASAS calssifiaction cohort.

We want to thank colleagues who performed annotation of the images from the ASAS classification cohort: Pedro Machado, Mikkel Ostergaard, Suzanne Juhl Pedersen, Ulrich Weber. Further, we thank Torsten Karge for the development of the MRI reading interface for GESPIC and OptiRef images, Joel Paschke for development of the scoring interface for ASAS images.

LCA is grateful for her participation in the BIH Charité–Junior Clinician and Clinician Scientist Program and KKB is grateful for his participation in the BIH Charité Digital Clinician Scientist Program all funded by the Charité–Universitätsmedizin Berlin and the Berlin Institute of Health. JR is grateful for her participation in the BIH Charité–Junior Clinician and Clinician Scientist Program.

Disclosure of Interests

None declared

Ultrasound imaging measures of vertebral bony landmark distances are weakly to moderately correlated with intervertebral disc height as assessed by MRI

Objectives

To assess the validity and reliability of ultrasound-derived interbony landmark distances as a proxy for MRI-derived intervertebral disc (IVD) height.

Methods

This is a cross-sectional criterion validity study. Twelve college-aged participants without current low back pain completed both MRI and ultrasound imaging of the lumbar spine in a prone position. Single-segment and multisegment distances between the spinous and mammillary processes at the lumbar segments (L2/L3, L3/L4, L4/L5) were measured twice using ultrasound and analysed digitally. Sagittal slices of the lumbar spine were taken via T1-weighted MRI and IVD height, and the overall distance between IVDs L2/L3 and L4/L5 was imaged once and measured twice.

Results

There was moderate correlation between multilevel-based measurements (overall distance between L2 and L5, r=0.677, p=0.016) and the average across three levels (r=0.596, p=0.041) when using the spinous processes as bony landmarks. Single-segment measures were not significantly correlated (all: p>0.092). Accuracy and precision were better for the overall MRI-derived distance between the three IVDs from L2 and L5 MRI and the distance measured between the spinous processes L2–L5. There was excellent reliability within multiple measurements at each location, with intraclass correlation coefficient, ICC_(3,1), ranging from 0.93 to 0.99 (95% CI 0.82 to 0.99) for ultrasound and from 0.98 to 0.99 (95% CI 0.92 to 0.99) for MRI.

Conclusion

Findings do not support the use of ultrasound imaging for estimating single-segment IVD height, yet it may be used to measure the change in distance over time with a certain degree of precision based on its excellent reliability.

Internal and External Oblique Muscle Asymmetry in Sprint Hurdlers and Sprinters: A Cross-Sectional Study

The abdominal muscles are vital in providing core stability for functional movements during most activities. There is a correlation between side asymmetry of these muscles and dysfunction. Thus, the purpose of this study was to evaluate and compare trunk muscle morphology and trunk rotational strength between sprint hurdlers, an asymmetrical sport, and sprinters, a symmetrical sport. Twenty-one trained collegiate sprint hurdlers and sprinters were recruited for the study (Hurdlers: 4M, 7F; Sprinters: 8M, 2F), average age (years) hurdlers: 20 ± 1.2; sprinters: 20.4 ± 1.9, height (cm) hurdlers: 172.6 ± 10.2; sprinters: 181.7 ± 4.5, and weight (kg) hurdlers: 67.6 ± 12.0; sprinters: 73.9 ± 5.6. Using real-time ultrasound, panoramic images of the internal oblique (IO) and external oblique (EO) were obtained at rest and contracted (flexion and rotation) in a seated position for both right and left sides of the trunk. While wearing a specially crafted shoulder harness, participants performed three maximal voluntary trunk rotational contractions (MVC). The three attempts were then averaged to obtain an overall MVC score for trunk rotation strength. Average MVC trunk rotational strength to the right was greater among all participants, p < 0.001. The IO showed greater and significant thickness changes from resting to contracted state than the EO, this was observed in all participants. The IO side asymmetry was significantly different between groups p < 0.01. Hurdlers, involved in a unilaterally demanding sport, exhibited the expected asymmetry in muscle morphology and in trunk rotational strength. Interestingly, sprinters, although involved in a seemingly symmetrical sport, also exhibited asymmetrical trunk morphology and trunk rotational strength.

'They only smoke in the house when I'm not in': understanding the limited effectiveness of a smoke-free homes intervention

Background

Children’s second-hand smoke (SHS) exposure in the home is highest in socio-economically disadvantaged areas. Personalized household air-quality measurements can promote changes in smoking that reduce SHS exposure. The ‘First Steps 2 Smoke-free’ (FS2SF) intervention is the first to trial this approach delivered as part of health professionals’ routine work. This paper reports the findings of qualitative interviews with participants that explored their experiences of the intervention and why outcomes varied.

Methods

120 women were recruited from the NHS First Steps Programme, which supports disadvantaged mothers. They received either personalized feedback on their home air quality and advice on reducing SHS or standard SHS advice. Qualitative interviews with 15 mothers were analyzed thematically using the Capability, Opportunity, Motivation, Behaviour (COM-B) model.

Results

The intervention increased women’s capability to change home-smoking behaviour, through increasing awareness and salience of SHS risks to their children, and motivation to act. However, taking effective action was constrained by their limited social and environmental opportunities, including others’ smoking in the home.

Conclusions

The FS2SF intervention was ineffective as it was unable to fully address the precarious, complex life circumstances that make creating a smoke-free home particularly difficult for women experiencing intersecting dimensions of disadvantage.

Peripheral vascular access from the arms for invasive cardiac investigation using ultrasound guidance

Introduction

Vascular access for invasive cardiac investigations has traditionally been gained from the femoral vessels, however, a “radial-first” approach has become increasingly popular for coronary interventions [1]. Transradial access has shown lower complication rates, shorter admission times, and reduced healthcare costs for coronary interventions [4]. A “superior” approach via the jugular and subclavian veins have been reported for electrophysiology (EP) studies and radiofrequency catheter ablation (RFCA) but is associated with an increased risk of complications such as pneumo- and haemothorax [9].

Purpose

EP procedures often require the use of both venous and arterial catheters, and the potential advantage of non-femoral peripheral access is yet to be investigated. This study was performed to provide comprehensive anatomical evidence that the vessels of the arms are suitable for use during EP procedures, as assessed by vascular ultrasound.

Methods

A portable ultrasound device was used to measure the diameter of the brachial artery, brachial vein, basilic vein & cephalic vein on the left and right upper limbs of 63 healthy adult volunteers. Measurements were also taken of the circumference at the elbow and at the mid-bicep level on both arms. A subgroup of 15 volunteers had additional measurements taken of the same veins and artery on both arms with a tourniquet at the upper bicep level.

Results

The basilic vein was found to have the largest diameter with a median of 4.6 mm and 4.5 mm (right and left diameter, respectively), followed by the cephalic (median of 3.1 and 3.0 mm) and the brachial vein (median of 2.8 mm for both arms). 100% of volunteers had at least one vein that was equal to a 3 mm diameter (which would allow for a 8F sheath insertion), with 98% having 2 suitable veins and &gt;80% having 3 suitable venous vessels. More than 90% had a suitable diameter of more than 3 mm for both the right and left brachial artery. There was significant correlation between gender, and basilic vein and brachial artery diameters. There was no correlation between BMI, height, weight and elbow or bicep circumference.

Conclusion

To our knowledge, this is the first study to investigate the feasibility of adopting peripheral access in the electrophysiology lab. 100% of volunteers examined had one vein which was at least 3mm in size and would be suitable for 8F sheath insertion. We demonstrate the anatomic evidence that the vessels in the arm are capable of housing the size of sheath and catheters commonly used in the EP lab.

Funding Acknowledgement

Type of funding sources: None. Figure 2. measurementsFigure 3. Vessel diameters

1487 The Pied-Piper, How Gastroenteritis Led Us Astray. Fibromuscular Dysplasia: A Surgical Perspective of a Rare Vascular Disorder

Background

FMD is a rare idiopathic condition of abnormal cellular growth in medium/large arterial vessel walls. It has a frequency of approximately 0.02%, predominantly affecting middle-aged Caucasian women. It manifests mostly in renal and cerebrovascular arteries and can present as hypertension or stroke. Complications include aneurysms, stenosis and dissections. Characteristic angiographical finding is a “beads on a string” appearance. There is no current cure, but surgical or interventional involvement by angioplasty and stenting may play a role treatment.

Conclusions

This case elegantly highlights the ambiguity in diagnosis of abdominal pain in a general surgical setting; with a wide variety of differentials spanning multiple specialties, it emphasises the importance to consider rare presentations of equally rare pathologies. It is a celebration of the merits of a multi-disciplinary approach to solve complex clinical questions.

O-072 Markers of cardiometabolic health of adolescents conceived through assisted reproductive technologies (ART) appear reassuring

Study question

Is the cardiometabolic health of adolescents conceived through ART worse than that of their spontaneously-conceived counterparts?

Summary answer

The majority of cardiometabolic and vascular health parameters of ART-conceived adolescents are more favourable than those of their spontaneously-conceived counterparts of similar age.

What is known already

It has been proposed that ART induces epigenetic alterations during embryonic development which could lead to cardiometabolic disease later in life. However, individuals requiring ART may themselves be metabolically less healthy than the general population, which could lead to a genetically increased risk of cardiometabolic disorders in the offspring, rather than the ART procedure. The literature pertaining to cardiometabolic health of ART-conceived offspring is contradictory, but generally suggests unfavourable cardiometabolic health parameters. With over 8 million children and adults born through ART worldwide, it is imperative to investigate whether early signs of adverse cardiometabolic differences persist into adolescence and beyond.

Study design, size, duration

The Growing Up Healthy Study (GUHS) is a prospective study that recruited 303 ART-conceived adolescents, born 1991-2001 in Western Australia. Their health parameters, including cardiometabolic factors, were assessed and compared with spontaneously conceived counterparts of similar socioeconomic background and age from the Raine Study Generation 2 (Gen2). The 2868 Gen2 participants were born 1989-1992 and are representative of the Western Australian adolescent population. At age 16-17 (2013-2017), GUHS participants replicated assessments previously completed by Gen2.

Participants/materials, setting, methods

Cardiometabolic parameters were compared between 165 GUHS (male = 50.9%) and 1690 Gen2 (male = 49.8%) adolescents. Assessments consisted of a detailed questionnaire; health and demographic parameters, anthropometric assessments; height, weight, body-mass index (BMI), waist circumference and skinfold thickness, fasting serum biochemistry, arterial stiffness and blood pressure assessment using applanation tonometry, assessment of non-alcoholic fatty liver (NAFLD) and thickness of abdominal fat compartments using ultrasonography. Chi2, Fisher’s Exact and Mann-Whitney U tests, performed in SPSS V25, examined cohort differences.

Main results and the role of chance

GUHS adolescents appeared to be healthier from a cardiometabolic perspective than their Gen2 counterparts. They were leaner, with lower BMI (median: 21.23 vs. 22.06, P = 0.004), lower waist circumference (median: 74.10 vs. 76.75 cm, P = 0.031), and thinner skinfolds (triceps median: 12.1 vs. 14.0 mm, P = 0.019, subscapular median: 10.6 vs. 11.9 mm, P &lt; .001, mid-abdominal median: 16.0 vs. 19.9 mm, P &lt; 0.001, supraspinal median: 10.7 vs. 13.5 mm, P &lt; 0.001). No significant differences were detected in the following serum fasting parameters: glucose, insulin, HOMA-IR, LDL cholesterol, total cholesterol, cholesterol/HDL-ratio, triglycerides, CRP and ALT. HDL cholesterol levels were more favourable in GUHS (P &lt; 0.001). NAFLD was present in 10.9% of GUHS vs. 15.2% of Gen2 adolescents (P = 0.174), with no difference in steatosis severity score (P = 0.309). ART offspring had less subcutaneous adipose tissue (median: 8.0 vs. 14.0 mm, P &lt; .001), more visceral adipose tissue (median: 40.0 vs. 32.0 mm, P &lt; 0.001), with no difference in pre-peritoneal adipose tissue (P = 0.087). Measures of arterial stiffness were lower in GUHS. Pulse wave velocity: median 6.1 vs. 6.4 m/s, P &lt; 0.001 and heart rate corrected augmentation index: median -10.25 vs. -8.00, P = 0.006. No significant differences in blood pressure or heart rate were detected. Stratification by sex did not greatly alter the results.

Limitations, reasons for caution

Despite the substantial study size and the unique study design, we were unable to differentiate between different types of ART (e.g. IVF vs. ICSI), draw definite conclusions or relate outcomes to cause of infertility. Given the observational character of this study, causation cannot be proven.

Wider implications of the findings

In this study we did not detect any adverse effect of ART on cardiometabolic health at adolescence, in contrast to some studies. Given the lack of consensus, future well-designed and appropriately-powered studies are necessary to investigate cardiometabolic health in ART adults.

Trial registration number

not applicable

Reassembling protein complexes after controlled disassembly by top-down mass spectrometry in native mode

The combined use of electrospray ionization run in so-called "native mode" with top-down mass spectrometry (nTDMS) is enhancing both structural biology and discovery proteomics by providing three levels of information in a single experiment: the intact mass of a protein or complex, the masses of its subunits and non-covalent cofactors, and fragment ion masses from direct dissociation of subunits that capture the primary sequence and combinations of diverse post-translational modifications (PTMs). While intact mass data are readily deconvoluted using well-known software options, the analysis of fragmentation data that result from a tandem MS experiment - essential for proteoform characterization - is not yet standardized. In this tutorial, we offer a decision-tree for the analysis of nTDMS experiments on protein complexes and diverse bioassemblies. We include an overview of strategies to navigate this type of analysis, provide example data sets, and highlight software for the hypothesis-driven interrogation of fragment ions for localization of PTMs, metals, and cofactors on native proteoforms. Throughout we have emphasized the key features (deconvolution, search mode, validation, other) that the reader can consider when deciding upon their specific experimental and data processing design using both open-access and commercial software.

Extended field-of-view ultrasound imaging is reliable for measuring Transversus Abdominis muscle size at rest and during contraction

Background

The strength and size of core muscles, including the abdominal muscles, are crucial to proper function in most activities. Therefore, it is important to reliably assess these characteristics. Our primary objective was to determine if the length, thickness and cross-sectional area of the transversus abdominis (TrA) can be visualized independently from the internal and external abdominal oblique muscles using extended field of view ultrasound imaging at rest and with contraction and to establish its intra- and inter-tester reliability.

Methods

Twenty-six individuals were recruited to participate in the study (20 F, 6 M), average age 24.0 years (SD 9.4), height 170.7 cm (SD 8.6) and weight 63.9 kg (SD 9.0). From this total number of participants, two groups of 16 randomly selected participants were assessed to determine intra- and inter-tester reliability respectively. Extended field of view ultrasound images were obtained at three vertebral levels during rest and contraction in the side lying position for both the right and left sides of the trunk.

Results

Excellent intra-tester and inter-tester reliability was seen (ICC range of 0.972 to 0.984). The overall average percent standard error of the measurement for all measurements and locations was approximately 4%. The overall average minimal difference for the thickness measurement for the resting and contraction conditions combined were as follows: intratester 0.056 (0.014) cm and intertester 0.054 (0.017) cm, for area intratester 0.287 (0.086) cm² and intertester 0.289 (0.101) cm² and for length intratester 0.519 (0.097) cm and intertester 0.507 (0.085) cm.

Conclusions

Extended field of view ultrasound imaging is an effective method of reliably capturing clear images of the TrA during rest and contraction. It provides an efficient mechanism for the analysis of muscle morphology by being able to measure the cross-sectional area, thickness, and length on one image. This methodology is recommended for studies investigating TrA function and training.

Effects of Distal Mutations on Prolyl-Adenylate Formation of Escherichia coli Prolyl-tRNA Synthetase

Enzymes play important roles in many biological processes. Amino acid residues in the active site pocket of an enzyme, which are in direct contact with the substrate(s), are generally believed to be critical for substrate recognition and catalysis. Identifying and understanding how these "catalytic" residues help enzymes achieve enormous rate enhancement has been the focus of many structural and biochemical studies over the past several decades. Recent studies have shown that enzymes are intrinsically dynamic and dynamic coupling between distant structural elements is essential for effective catalysis in modular enzymes. Therefore, distal residues are expected to have impact on enzyme function. However, few studies have investigated the role of distal residues on enzymatic catalysis. In the present study, the effects of distal residue mutations on the catalytic function of an aminoacyl-tRNA synthetase, namely, prolyl-tRNA synthase, were investigated. The present study demonstrates that distal residues significantly contribute to catalysis of the modular Escherichia coli prolyl-tRNA synthetase by maintaining intrinsic protein flexibility.

Comparison of melphalan- And busulfan-based myeloablative conditioning in children undergoing allogeneic transplantation for acute myeloid leukemia or myelodysplasia

BACKGROUND

The optimal conditioning regimen for alloHCT in children with myeloid malignancies remains undefined.

PROCEDURE

We performed a retrospective review of children undergoing alloHCT for AML and MDS over a 10-year period (2008-2018) at our institution, comparing the outcomes of recipients of either a myeloablative busulfan- or reduced toxicity mel/thio-based conditioning regimen.

RESULTS

A total of 49 patients underwent alloHCT for AML/MDS (mel/thio, N = 21; busulfan, N = 28). Mel/thio recipients were selected due to pretransplant comorbidities. Recipients of mel/thio were more likely to have t-AML, and less likely to have MRD <0.1% at the time of alloHCT (57.1% vs 82.1%). Graft failure was more common in busulfan recipients; engraftment kinetics were similar between groups. Sinusoidal obstructive syndrome was diagnosed in 21% of busulfan and no mel/thio recipients (P = .03). One patient in each group died from TRM. Relapse incidence was comparable (mel/thio-29% vs busulfan-32%); however, relapse occurred significantly later in recipients of mel/thio conditioning (median d + 396 vs d + 137; P = .01). As a result, there was a trend toward improved OS at 1 and 3 years in mel/thio recipients (95% vs 74%, P = .06; and 75% vs 50%, P = .11; respectively).

CONCLUSION

In our single institution, when compared to myeloablative busulfan-based conditioning, use of a mel/thio-based reduced toxicity regimen resulted in comparable outcomes, despite higher risk patient and disease characteristics. Mel/thio recipients had both more comorbidities and higher risk disease profile, which did not translate into higher rates of either TRM or relapse.

Protocol for the development and validation procedure of the managing the link and strengthening transition from child to adult mental health care (MILESTONE) suite of measures

Background

Mental health disorders in the child and adolescent population are a pressing public health concern. Despite the high prevalence of psychopathology in this vulnerable population, the transition from Child and Adolescent Mental Health Services (CAMHS) to Adult Mental Health Services (AMHS) has many obstacles such as deficiencies in planning, organisational readiness and policy gaps. All these factors contribute to an inadequate and suboptimal transition process. A suite of measures is required that would allow young people to be assessed in a structured and standardised way to determine the on-going need for care and to improve communication across clinicians at CAMHS and AMHS. This will have the potential to reduce the overall health economic burden and could also improve the quality of life for patients travelling across the transition boundary. The MILESTONE (Managing the Link and Strengthening Transition from Child to Adult Mental Health Care) project aims to address the significant socioeconomic and societal challenge related to the transition process. This protocol paper describes the development of two MILESTONE transition-related measures: The Transition Readiness and Appropriateness Measure (TRAM), designed to be a decision-making aide for clinicians, and the Transition Related Outcome Measure (TROM), for examining the outcome of transition.

Methods

The TRAM and TROM have been developed and were validated following the US FDA Guidance for Patient-reported Outcome Measures which follows an incremental stepwise framework. The study gathers information from service users, parents, families and mental health care professionals who have experience working with young people undergoing the transition process from eight European countries.

Discussion

There is an urgent need for comprehensive measures that can assess transition across the CAMHS/AMHS boundary. This study protocol describes the process of development of two new transition measures: the TRAM and TROM. The TRAM has the potential to nurture better transitions as the findings can be summarised and provided to clinicians as a clinician-decision making support tool for identifying cases who need to transition and the TROM can be used to examine the outcomes of the transition process.

Trial registration

MILESTONE study registration: ISRCTN83240263 Registered 23-July-2015 - ClinicalTrials.gov NCT03013595 Registered 6 January 2017.

Improved Physical Stability of an Antibody-Drug Conjugate Using Host-Guest Chemistry

Antibody-drug conjugates (ADCs) are an emerging class of biopharmaceutical products for oncology, with the cytotoxic pyrrolobenzodiazepine (PBD) family of "warheads" well-established in the clinic. While PBDs offer high potency, they are also characterized by their hydrophobicity, which can make formulation of the ADC challenging. Several approaches have been investigated to improve the physicochemical properties of PBD-containing ADCs, and herein a supramolecular approach was explored using cucurbit[8]uril (CB[8]). The ability of CB[8] to simultaneously encapsulate two guests was exploited to incorporate a 12-mer polyethylene glycol harboring a methyl viologen moiety at one terminus (MV-PEG₁₂), together with a PBD harboring an indole moiety at the C2' position (SG3811). This formulation approach successfully introduced a hydrophilic PEG to mask the hydrophobicity of SG3811, improving the physical stability of the ADC while avoiding any loss of potency related to chemical modification.

Physical fitness and nutritional anthropometric status of children from disadvantaged communities in the Nelson Mandela Bay region

Background

Information about the relationships between physical fitness, body composition and nutrition has increased in recent years; however, little is known about physical fitness and the coexistence of under-/overnutrition among children living in disadvantaged areas.

Objectives

To determine the physical fitness status and its association with body composition, growth and selected socio-demographics in primary schoolchildren from disadvantaged communities in the Nelson Mandela Bay region.

Methods

Nine hundred and sixty-five children (49% girls, M=9.5 years) participated in this cross-sectional study. Height and weight were measured to establish body mass index, and height-for-age z-scores. Physical fitness was assessed using tests from the Eurofit Physical Fitness test battery (flexibility, upper/lower body muscular strength and cardiorespiratory fitness). Between-group differences and cross-sectional associations were examined with univariate (Chi²-tests, analyses of variance) and multivariate methods (mixed linear/logistic regression).

Results

Most children had normal weight (76.7%), while 4.5% were underweight and 18.7% were overweight/obese. Underweight children and children with stunted growth (11.5%) had lower average upper body strength (p<0.001). Overweight/obese children had lower scores in weight-bearing activities (p<0.001). Children with higher socio-economic status were more likely to be overweight and obese (p<0.001). In the multivariate analyses, sex, age, body mass index, and stunting were associated with children's physical fitness.

Conclusion

Fitness assessments seem to be a relevant measure of the current health status of children in disadvantaged settings. Compared to international norms, the children in this study had relatively low scores for both upper- and lower body muscular strength. Therefore, effective school-based intervention programmes should be developed to improve children's physical fitness in disadvantaged schools.

Pre-clinical pharmacology and mechanism of action of SG3199, the pyrrolobenzodiazepine (PBD) dimer warhead component of antibody-drug conjugate (ADC) payload tesirine

Synthetic pyrrolobenzodiazepine (PBD) dimers, where two PBD monomers are linked through their aromatic A-ring phenolic C8-positions via a flexible propyldioxy tether, are highly efficient DNA minor groove cross-linking agents with potent cytotoxicity. PBD dimer SG3199 is the released warhead component of the antibody-drug conjugate (ADC) payload tesirine (SG3249), currently being evaluated in several ADC clinical trials. SG3199 was potently cytotoxic against a panel of human solid tumour and haematological cancer cell lines with a mean GI₅₀ of 151.5 pM. Cells defective in DNA repair protein ERCC1 or homologous recombination repair showed increased sensitivity to SG3199 and the drug was only moderately susceptible to multidrug resistance mechanisms. SG3199 was highly efficient at producing DNA interstrand cross-links in naked linear plasmid DNA and dose-dependent cross-linking was observed in cells. Cross-links formed rapidly in cells and persisted over 36 hours. Following intravenous (iv) administration to rats SG3199 showed a very rapid clearance with a half life as short as 8 minutes. These combined properties of cytotoxic potency, rapid formation and persistence of DNA interstrand cross-links and very short half-life contribute to the emerging success of SG3199 as a warhead in clinical stage ADCs.

ADCT-402, a PBD dimer-containing antibody drug conjugate targeting CD19-expressing malignancies

Human CD19 antigen is a 95-kDa type I membrane glycoprotein in the immunoglobulin superfamily whose expression is limited to the various stages of B-cell development and differentiation and is maintained in the majority of B-cell malignancies, including leukemias and non-Hodgkin lymphomas of B-cell origin. Coupled with its differential and favorable expression profile, CD19 has rapid internalization kinetics and is not shed into the circulation, making it an ideal target for the development of antibody-drug conjugates (ADCs) to treat B-cell malignancies. ADCT-402 (loncastuximab tesirine) is a novel CD19-targeted ADC delivering SG3199, a highly cytotoxic DNA minor groove interstrand crosslinking pyrrolobenzodiazepine (PDB) dimer warhead. It showed potent and highly targeted in vitro cytotoxicity in CD19-expressing human cell lines. ADCT-402 was specifically bound, internalized, and trafficked to lysosomes in CD19-expressing cells and, following release of the PBD warhead, resulted in formation of DNA crosslinks that persisted for 36 hours. Bystander killing of CD19- cells by ADCT-402 was also observed. In vivo, single doses of ADCT-402 resulted in highly potent, dose-dependent antitumor activity in several subcutaneous and disseminated human tumor models with marked superiority to comparator ADCs delivering tubulin inhibitors. Dose-dependent DNA crosslinks and γ-H2AX DNA damage response were measured in tumors by 24 hours after single dose administration, whereas matched peripheral blood mononuclear cells showed no evidence of DNA damage. Pharmacokinetic analysis in rat and cynomolgus monkey showed excellent stability and tolerability of ADCT-402 in vivo. Together, these impressive data were used to support the clinical testing of this novel ADC in patients with CD19-expressing B-cell malignancies.

Abstract 3111A: ADCT-401/MEDI3726, a novel pyrrolobenzodiazepine (PBD)-based antibody-drug conjugate (ADC) targeting PSMA-expressing prostate cancers

Prostate-specific membrane antigen (PSMA) is an attractive target for an ADC approach as it is over-expressed by virtually all prostate cancers and its expression is highest in poorly-differentiated, metastatic and castration-resistant cases. PSMA has limited expression in non-prostatic tissues, it is not secreted or cleaved by PSMA-expressing cells, and it is constitutively internalized, a process that may be accelerated by specific antibody binding. ADCT-401/MEDI3726 is an ADC composed of a monoclonal antibody (J591), directed against human PSMA, site-specifically conjugated (drug-to-antibody ratio of 1.8) to a highly cytotoxic DNA cross-linking PBD dimer with a valine-alanine dipeptide linker. In vitro, ADCT-401/MEDI3726 demonstrated potent and specific cytotoxicity in a panel of PSMA-expressing prostate cancer cell lines, whereas its activity was greatly reduced in PSMA-negative cell lines. In vivo, ADCT-401/MEDI3726 showed strong antitumor activity against CWR22Rv1 and LNCaP human-derived prostate cancer xenograft models. In the CWR22Rv1 model, a tumor with low, heterogeneous PSMA expression, ADCT-401/MEDI3726 achieved dose-dependent antitumor activity when administered as single dose at either 0.33 or 1 mg/kg, which resulted in significant increase in survival compared to the vehicle-treated animals. Moreover, a single dose of ADCT-401/MEDI3726 showed remarkable superior antitumor activity compared to multiple doses of another PSMA-targeted ADC stochastically conjugated to the auristatin payload vcMMAE with a DAR of ~4. In the LNCaP model, ADCT-401/MEDI3726 resulted in dose-dependent antitumor activity when dosed once at 0.11, 0.33 or 1 mg/kg. In the PSMA-negative prostate cancer-derived PC3 xenograft model, ADCT-401/MEDI3726 and an isotope-control ADC showed limited tumor growth inhibition highlighting target-mediated antitumor activity. ADCT-401/MEDI3726 demonstrated potent and specific in vitro and in vivo antitumor activity in prostate cancer-derived models of differing levels of PSMA and this warrants further development of this ADC into the clinic.

Citation Format: Francesca Zammarchi, Simon Chivers, Karin Havenith, David G. Williams, Lauren Adams, Maria Mellinas-Gomez, Simon Corbett, Peter Tyrer, Francois D'Hooge, Song Cho, Nazzareno Dimasi, Mary Jane Hinrichs, Phil W. Howard, John A. Hartley, Patrick H. van Berkel. ADCT-401/MEDI3726, a novel pyrrolobenzodiazepine (PBD)-based antibody-drug conjugate (ADC) targeting PSMA-expressing prostate cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3111A. doi:10.1158/1538-7445.AM2017-3111A

The Impact of Dysphonic Voices on Healthy Listeners: Listener Reaction Times, Speech Intelligibility, and Listener Comprehension

PURPOSE

There is currently minimal information on the impact of dysphonia secondary to phonotrauma on listeners. Considering the high incidence of voice disorders with professional voice users, it is important to understand the impact of a dysphonic voice on their audiences.

METHODS

Ninety-one healthy listeners (39 men, 52 women; mean age = 23.62 years) were presented with speech stimuli from 5 healthy speakers and 5 speakers diagnosed with dysphonia secondary to phonotrauma. Dependent variables included processing speed (reaction time [RT] ratio), speech intelligibility, and listener comprehension. Voice quality ratings were also obtained for all speakers by 3 expert listeners.

RESULTS

Statistical results showed significant differences between RT ratio and number of speech intelligibility errors between healthy and dysphonic voices. There was not a significant difference in listener comprehension errors. Multiple regression analyses showed that voice quality ratings from the Consensus Assessment Perceptual Evaluation of Voice (Kempster, Gerratt, Verdolini Abbott, Barkmeier-Kraemer, & Hillman, 2009) were able to predict RT ratio and speech intelligibility but not listener comprehension.

CONCLUSIONS

Results of the study suggest that although listeners require more time to process and have more intelligibility errors when presented with speech stimuli from speakers with dysphonia secondary to phonotrauma, listener comprehension may not be affected.