Massively parallel reporter assays and mouse transgenic assays provide complementary information about neuronal enhancer activity

Genetic studies find hundreds of thousands of noncoding variants associated with psychiatric disorders. Massively parallel reporter assays (MPRAs) and in vivo transgenic mouse assays can be used to assay the impact of these variants. However, the relevance of MPRAs to in vivo function is unknown and transgenic assays suffer from low throughput. Here, we studied the utility of combining the two assays to study the impact of non-coding variants. We carried out an MPRA on over 50,000 sequences derived from enhancers validated in transgenic mouse assays and from multiple fetal neuronal ATAC-seq datasets. We also tested over 20,000 variants, including synthetic mutations in highly active neuronal enhancers and 177 common variants associated with psychiatric disorders. Variants with a high impact on MPRA activity were further tested in mice. We found a strong and specific correlation between MPRA and mouse neuronal enhancer activity including changes in neuronal enhancer activity in mouse embryos for variants with strong MPRA effects. Mouse assays also revealed pleiotropic variant effects that could not be observed in MPRA. Our work provides a large catalog of functional neuronal enhancers and variant effects and highlights the effectiveness of combining MPRAs and mouse transgenic assays.

The clinical, imaging, pathological and genetic landscape of bottom-of-sulcus dysplasia

Bottom-of-sulcus dysplasia (BOSD) is increasingly recognized as a cause of drug-resistant, surgically-remediable, focal epilepsy, often in seemingly MRI-negative patients. We describe the clinical manifestations, morphological features, localization patterns and genetics of BOSD, with the aims of improving management and understanding pathogenesis. We studied 85 patients with BOSD diagnosed between 2005-2022. Presenting seizure and EEG characteristics, clinical course, genetic findings and treatment response were obtained from medical records. MRI (3 T) and 18F-FDG-PET scans were reviewed systematically for BOSD morphology and metabolism. Histopathological analysis and tissue genetic testing were performed in 64 operated patients. BOSD locations were transposed to common imaging space to study anatomical location, functional network localization and relationship to normal MTOR gene expression. All patients presented with stereotyped focal seizures with rapidly escalating frequency, prompting hospitalization in 48%. Despite 42% patients having seizure remissions, usually with sodium channel blocking medications, most eventually became drug-resistant and underwent surgery (86% seizure-free). Prior developmental delay was uncommon but intellectual, language and executive dysfunction were present in 24%, 48% and 29% when assessed preoperatively, low intellect being associated with greater epilepsy duration. BOSDs were missed on initial MRI in 68%, being ultimately recognized following repeat MRI, 18F-FDG-PET or image postprocessing. MRI features were grey-white junction blurring (100%), cortical thickening (91%), transmantle band (62%), increased cortical T1 signal (46%) and increased subcortical FLAIR signal (26%). BOSD hypometabolism was present on 18F-FDG-PET in 99%. Additional areas of cortical malformation or grey matter heterotopia were present in eight patients. BOSDs predominated in frontal and pericentral cortex and related functional networks, mostly sparing temporal and occipital cortex, and limbic and visual networks. Genetic testing yielded pathogenic mTOR pathway variants in 63% patients, including somatic MTOR variants in 47% operated patients and germline DEPDC5 or NPRL3 variants in 73% patients with familial focal epilepsy. BOSDs tended to occur in regions where the healthy brain normally shows lower MTOR expression, suggesting these regions may be more vulnerable to upregulation of MTOR activity. Consistent with the existing literature, these results highlight (i) clinical features raising suspicion of BOSD; (ii) the role of somatic and germline mTOR pathway variants in patients with sporadic and familial focal epilepsy associated with BOSD; and (iii) the role of 18F-FDG-PET alongside high-field MRI in detecting subtle BOSD. The anatomical and functional distribution of BOSDs likely explain their seizure, EEG and cognitive manifestations and may relate to relative MTOR expression.

1295 Virtual Fracture Clinic: An Audit of Referral Quality and Service Effectiveness

Aim

Assessment of referral quality to the virtual fracture clinic (VFC) at the Liverpool University Hospital foundation trust compared to the standards set out by the Glasgow virtual fracture clinic pathway. As a secondary aim the effectiveness of the VFC in diverting patients not requiring further clinical management away from face-to-face specialist physical fracture clinics (PFC) was assessed.

Method

Outcomes of 1st attendances were collected for standard PFC's before the implementation of the VFC at our centre. This data was comparatively analysed to the outcomes of 1st ‘attendances' of VFCs post-service implementation. To assess VFC referral quality fracture type was recorded and compared to the standard set out by the Glasgow virtual fracture pathway which states that a selection of simple stable fractures should be discharged from ED directly with patient advice and telephone support.

Results

We analysed 529 PFC first attendances and 402 VFC first attendances. We saw a variety of simples stable fractures (21%) in the VCF including: Distal radial, Fifth metatarsal, Minor radial head, Fifth metacarpal, Mallet finger, which could have been managed with direct ED discharge and telephone support. 19.4% of PFC attendance resulted in discharge without a change in management as compared to 22.1% of 1st attendances for the VFC.

Conclusions

The VFC clinic has shown itself as an effective service in re-directing patients from face-to-face appointments, evidenced by the comparative rates of patient discharge on first attendance. This study has laid the foundation for improving referral quality to the VFC. Collaborative efforts between Orthopaedics and ED could improve VFC clinic efficiency further.

Severe childhood speech disorder: Gene discovery highlights transcriptional dysregulation

OBJECTIVE

Determining the genetic basis of speech disorders provides insight into the neurobiology of human communication. Despite intensive investigation over the past 2 decades, the etiology of most speech disorders in children remains unexplained. To test the hypothesis that speech disorders have a genetic etiology, we performed genetic analysis of children with severe speech disorder, specifically childhood apraxia of speech (CAS).

METHODS

Precise phenotyping together with research genome or exome analysis were performed on children referred with a primary diagnosis of CAS. Gene coexpression and gene set enrichment analyses were conducted on high-confidence gene candidates.

RESULTS

Thirty-four probands ascertained for CAS were studied. In 11/34 (32%) probands, we identified highly plausible pathogenic single nucleotide (n = 10; CDK13, EBF3, GNAO1, GNB1, DDX3X, MEIS2, POGZ, SETBP1, UPF2, ZNF142) or copy number (n = 1; 5q14.3q21.1 locus) variants in novel genes or loci for CAS. Testing of parental DNA was available for 9 probands and confirmed that the variants had arisen de novo. Eight genes encode proteins critical for regulation of gene transcription, and analyses of transcriptomic data found CAS-implicated genes were highly coexpressed in the developing human brain.

CONCLUSION

We identify the likely genetic etiology in 11 patients with CAS and implicate 9 genes for the first time. We find that CAS is often a sporadic monogenic disorder, and highly genetically heterogeneous. Highly penetrant variants implicate shared pathways in broad transcriptional regulation, highlighting the key role of transcriptional regulation in normal speech development. CAS is a distinctive, socially debilitating clinical disorder, and understanding its molecular basis is the first step towards identifying precision medicine approaches.

Focal cortical hypermetabolism in atypical benign rolandic epilepsy

OBJECTIVE

Atypical benign rolandic epilepsy (BRE) is an underrecognized and poorly understood manifestation of a common epileptic syndrome. Most consider it a focal epileptic encephalopathy in which frequent, interictal, centrotemporal spikes lead to negative motor seizures and interfere with motor and sometimes speech and cognitive abilities. We observed focal cortical hypermetabolism on PET in three children with atypical BRE and investigated the spatial and temporal relationship with their centrotemporal spikes.

METHODS

EEG, MRI and PET were performed clinically in three children with atypical BRE. The frequency and source localization of centrotemporal spikes was determined and compared with the location of maximal metabolic activity on PET.

RESULTS

Cortical hypermetabolism on thresholded PET t-maps and current density reconstructions of centrotemporal spikes overlapped in each child, in the central sulcus region, the distances between the "centers of maxima" being 2 cm or less. Hypermetabolism was not due to recent seizures or frequent centrotemporal spikes at the time of FDG uptake.

SIGNIFICANCE

The findings suggest that localized, increased cortical activity, in the region of the EEG focus, underlies the negative clinical manifestations of atypical BRE. Similar findings are reported in the broader group of epileptic encephalopathies associated with electrical status epilepticus in sleep.

R-GEM-Lenalidomide versus R-GEM-P as second-line treatment of diffuse large B-cell lymphoma: results of the UK NRCI phase II randomised LEGEND trial

Outcome of patients with relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL) remains poor, highlighting the need for novel treatment approaches. The multicentre randomised phase II LEGEND trial evaluated lenalidomide in combination with rituximab, methylprednisolone and gemcitabine (R-GEM-L) vs. standard R-GEM-P as second-line treatment of DLBCL. The study closed early to recruitment after the planned interim analysis failed to demonstrate a complete response (CR) rate of ≥ 40% in either arm. Among 34 evaluable patients, 7/18 (38.9%) achieved CR with R-GEM-L and 3/16 (18.8%) with R-GEM-P. Median event-free and overall survival was 3.5/3.8 months and 10.8/8.3 months for R-GEM-L and R-GEM-P, respectively. The incidence of grade ≥ 3 toxicities was 52% in R-GEM-L and 83% in R-GEM-P. Efficacy and tolerability of R-GEM-L seem comparable with R-GEM-P and other standard salvage therapies, but a stringent design led to early trial closure. Combination of lenalidomide with gemcitabine-based regimens should be further evaluated in r/r DLBCL.

Individualised MRI training for paediatric neuroimaging: A child-focused approach

Magnetic Resonance Imaging (MRI) in paediatric cohorts is often complicated by reluctance to enter the scanner and head motion-related imaging artefacts. The process is particularly challenging for children with neurodevelopmental disorders where coping with novel task demands in an unfamiliar setting may be more difficult due to symptom-related deficits or distress. These issues often give rise to excessive head motion that can significantly reduce the quality of images acquired, or render data unusable. Here we report an individualised MRI training procedure that enables children with Autism Spectrum Disorders (ASD) to better tolerate the MRI scanner environment based on a child-focused approach and individualised familiarisation strategies, including a pre-visit interview, familiarisation package, and personalised rewards. A medical imaging mobile application was utilised to familiarise participants to multi-sensory aspects of the neuroimaging experience through a variety of themed mini-games and activities. The MRI training procedure was implemented for monozygotic twins (n = 12; 6 twin pairs; age range 7.1–12.9 years) concordant or discordant for ASD. MRI image quality indices were better or comparable to images acquired from a large independent multi-centre ASD cohort. Present findings are promising and suggest that child-focused strategies could improve the quality of paediatric neuroimaging in clinical populations.

Positive Development and Changes in Self-Rated Health Among Young Sexual Minority Males: The P18 Cohort Study

We seek to move beyond a deficits-based approach, which has dominated our understanding of health and wellbeing in in young sexual minority males (YSMM), by examining how indicators of positive development are associated with development of positive self-rated health in YSMM. Using data from a prospective cohort study of YSMM (n = 514; 18-22 years old; 36.9% Hispanic/Latino, 15.6% non-Hispanic Black, 30.2% White, 16.9% other/multi-racial), we examined how three measures of positive development-the Life Orientation Test, the Satisfaction with Life Scale (SWLS) and the Social Responsibility Scale (SRS) were associated with self-rated health (SRH), a valid and reliable measure of self-assessed general health status. Findings suggest that YSMM who self-identified as homosexual reported higher SRH while those who reported higher levels of substance use and mental health burdens reported lower SRH. Second, in linear growth models controlling for mental health burdens and substance use, higher scores on all measures of positive development were associated with higher ratings of SRH over time. In conclusion, the presence of positive development characteristics, specifically generalized optimism, life satisfaction and social responsibility, may buffer against negative SRH assessments. Health promotion programs focusing on positive development may more effectively promote health and well-being among YSMM.

Potential delays in referral and assessment for epilepsy surgery in children with drug-resistant, early-onset epilepsy

OBJECTIVE

To study potential delays in epilepsy surgery in children with drug-resistant epilepsy (DRE) of early-onset.

METHODS

Medical records were reviewed from 87 children with DRE and seizure onset before age 3 years who underwent epilepsy surgery between 2006 and 2015. Information was obtained about each child's epilepsy, treatment and specific time points in management. Time intervals along diagnostic, investigative, treatment and referral pathways were calculated.

RESULTS

Median ages at seizure onset, when seen in the epilepsy surgery program and surgery were 5.9 (IQR 10), 19 (IQR 29) and 36 (IQR 67) months; the median delay from seizure onset to surgery was 30 (IQR 67) months. Most children were promptly diagnosed, treated, investigated and seen by a pediatric neurologist. Focal abnormalities were reported on initial EEGs and MRIs in most children, and DRE developed within a median of 6.3 months from commencement of medication. There were median durations of 6.2 months between seeing a neurologist and being seen in the epilepsy surgery program, and then 6.1 months in determining surgical candidacy. Median durations from potential indications for a surgical evaluation to agreed surgical candidacy were 10 (DRE), 12 (focal MRI) and 17 (focal EEG) months. Children received a median of six antiepileptic drugs prior to surgery. Median interval from agreed surgical candidacy to surgery was only 3 months. There were longer durations from seizure onset to surgery in children needing PET (p = 0.001) and in children with seizure-free periods (p < 0.001), and shorter durations in children with a history of infantile spasms (p = 0.01).

SIGNIFICANCE

Delays in referral of children for epilepsy surgery are reported. Delays in assessment may be specific to centralized children's hospitals in public health systems.

miR-21 expression and clinical outcome in locally advanced pancreatic cancer: exploratory analysis of the pancreatic cancer Erbitux, radiotherapy and UFT (PERU) trial

Background

Locally advanced pancreatic cancer (LAPC) is associated with high mortality, and biomarker-driven treatment approach is currently lacking. This study evaluated safety and efficacy of a combination approach of chemotherapy followed by chemo-radiotherapy (CRT) +/− cetuximab, and the prognostic role of miR-21 in patients with LAPC treated with a multimodality approach.

Patients and Methods

This was a randomised phase II trial in which patients with inoperable LAPC were offered gemcitabine and capecitabine (GEM-CAP) for 16 weeks. Patients with stable disease or response after GEM-CAP were randomised to capecitabine or UFT plus radiotherapy (RT) (A), or capecitabine or UFT plus cetuximab plus RT (B). The primary outcome of the study was overall survival (OS). Clinical outcome was compared according to baseline circulating miR-21 levels.

Results

17 patients were enrolled and treated with GEM-CAP, with 13 patients achieving disease control and being randomised to arms A (n:7) and B (n:6). After a median follow-up of 61.2 months, median progression free survival (PFS) was 10.4 months and 12.7 months, median OS was 15.8 months and 22.0 months in arms A and B respectively (p > 0.05). Patients with high baseline plasma miR-21 had worse PFS (3.5 vs. 12.7 months; p:0.032) and OS (5.1 vs 15.3 months; p:0.5) compared to patients with low miR-21. Circulating miR-21 levels reflected miR-21 expression within the tissues.

Conclusions

Addition of Cetuximab to CRT following induction chemotherapy did not improve survival. High miR-21 baseline plasma expression was associated with poor clinical outcome in LAPC patients treated with induction chemotherapy followed by chemo-radiotherapy.

Risk factors for the development of autism spectrum disorder in children with tuberous sclerosis complex: protocol for a systematic review

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant condition, caused by mutations in either the TSC1 or TSC2 gene. It has widespread systemic manifestations and is associated with significant neurological morbidity. In addition to seizures and cerebral pathology including cortical tubers, subependymal nodules, subependymal giant cell astrocytoma and abnormal white matter, there are recognised neuropsychiatric difficulties including intellectual disability, autism spectrum disorder (ASD) and a range of learning and behaviour problems, recently conceptualised as "tuberous sclerosis-associated neuropsychiatric disorders", or "TAND". ASD in TSC is of particular importance because (1) it affects up to 50% of people with TSC and is a source of considerable difficulty for them and their families and (2) it provides a model for considering neurobiological pathways involved in ASD. Multiple factors are implicated in the development of ASD in TSC, including (1) seizures and related electrophysiological factors, (2) cerebral pathology, (3) genotype and (4) child characteristics. However, the neurobiological pathway remains unclear. We will conduct a systematic review to investigate and synthesise existing evidence about the role of these risk factors, individually and in combination, in leading to the development of ASD.

METHODS

Our review will report on all studies that include one or more of four predefined risk factors in the development of ASD in children with TSC. We will search five databases: MEDLINE, EMBASE, PubMed, The Cochrane Library and Web of Science (Conference Proceedings Citation Index). Studies will be selected for reporting after two authors independently (1) review all titles and abstracts, (2) read full text of all appropriate papers and (3) assess for bias using the Newcastle-Ottawa Scale recommended by the Guidelines for Meta-Analysis and Systematic Reviews of Observational Studies (MOOSE guidelines) and the ROBINS-I.

DISCUSSION

To our knowledge, this is the first systematic review investigating multiple risk factors in the development of ASD in children with TSC. Clarifying the evidence in this area will be important to researchers in the field and to clinicians providing prognostic information to families.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016042841.

School-Age Outcomes of Early Intervention for Preterm Infants and Their Parents: A Randomized Trial

OBJECTIVE

To examine the child and parental outcomes at school age of a randomized controlled trial of a home-based early preventative care program for infants born very preterm and their caregivers.

METHODS

At term-equivalent age, 120 infants born at a gestational age of <30 weeks were randomly allocated to intervention (n = 61) or standard care (n = 59) groups. The intervention included 9 home visits over the first year of life focusing on infant development, parental mental health, and the parent-infant relationship. At 8 years' corrected age, children's cognitive, behavioral, and motor functioning and parental mental health were assessed. Analysis was by intention to treat.

RESULTS

One hundred children, including 13 sets of twins, attended follow-up (85% follow-up of survivors). Children in the intervention group were less likely to have mathematics difficulties (odds ratio, 0.42; 95% confidence interval [CI], 0.18 to 0.98; P = .045) than children in the standard care group, but there was no evidence of an effect on other developmental outcomes. Parents in the intervention group reported fewer symptoms of depression (mean difference, -2.7; 95% CI, -4.0 to -1.4; P < .001) and had reduced odds for mild to severe depression (odds ratio, 0.14; 95% CI, 0.03 to 0.68; P = .0152) than parents in the standard care group.

CONCLUSIONS

An early preventive care program for very preterm infants and their parents had minimal long-term effects on child neurodevelopmental outcomes at the 8-year follow-up, whereas primary caregivers in the intervention group reported less depression.

Patient-delivered partner medication in the UK: an unlawful but popular choice

Current methods of contact tracing are only partially effective. Patient-delivered partner medication (PDPM), in which patients are dispensed antibiotics for their sexual partner(s), has been shown to reduce persistent and recurrent infections. We performed a questionnaire to canvass opinions of UK staff and patients about PDPM. The response rate was 72% (88/122) for staff and 90% (473/525) for patients. The majority of staff (81%) thought that PDPM would be acceptable to patients, and should be combined with written information and a recommendation to attend a clinic. Patients were mostly (59%) in favour of PDPM, 87% thought it would make it easier to abstain from sex during treatment, and 94% indicated that after being given antibiotics by a partner, they would attend a clinic for tests. Concerns expressed by staff and patients included drug allergies, potential lack of information provided to partners, management of complicated infection, pregnancy and medicolegal implications.

The influence of industry sponsorship on the reporting of subgroup analyses within phase III randomised controlled trials in gastrointestinal oncology

PURPOSE

Correct interpretation of subgroup analyses (SGA) is important as it influences selection of therapeutic interventions for patient subsets. The primary aim of our study was to compare reporting of SGA between industry and non-industry sponsored trials.

METHODS

We performed a systematic literature review and extracted data from journal articles (JA) and conference abstracts (CA) published over a decade reporting SGA results of phase III randomised controlled gastrointestinal (GI) oncology trials with patient participants of ≥150.

RESULTS

In JA, SGA was reported in 100/145 (69%) trials: 41/54 industry sponsored (76%; 95% confidence interval [CI]: 63-86%) and 59/91 non-industry sponsored (65%; 95% CI: 55-74%) trials (p = 0.16). In CA, SGA was reported in 86/204 (42%) trials: 43/83 industry sponsored (52%; 95% CI: 41-62%) and 43/121 non-industry sponsored (36%; 95% CI: 28-44%) trials (p = 0.02). Number of SGA performed per trial was significantly larger for industry compared to non-industry sponsored trials in both JA (median 6 versus 2, p = 0.003) and CA (median 1 versus 0, p = 0.023). Claims of subgroup effect were made in 52% of trials in JA and 50% in CA, with significant test of interaction evident in only 25% of JA and 16% of CA, with no difference between industry and non-industry trials. Industry sponsored trials with a significant primary end-point reported more SGA (p < 0.001 JA; p = 0.046 CA).

CONCLUSIONS

Industry sponsored trials reported more SGA. Claimed subgroup effects were often not accompanied by significant interaction test; thus circumspection should be adopted when using SGA to deviate from standard therapeutic decision-making in GI oncology.

HPLC & NMR-based forced degradation studies of ifosfamide: The potential of NMR in stability studies

PURPOSE

The aim of this study is to conduct a forced degradation study on ifosfamide under several stress conditions to investigate the robustness of the developed HPLC method. It also aims to provide further insight into the stability of ifosfamide and its degradation profile using both HPLC and NMR.

METHODS

Ifosfamide solutions (20mg/mL; n=15, 20mL) were stressed in triplicate by heating (70°C), under acidic (pH 1 & 4) and alkaline (pH 10 & 12) conditions. Samples were analysed periodically using HPLC and FT-NMR.

RESULTS AND DISCUSSION

Ifosfamide was most stable under weakly acidic conditions (pH 4). NMR results suggested that the mechanism of ifosfamide degradation involves the cleavage of the PN bond. For all stress conditions, HPLC was not able to detect ifosfamide degradation products that were detected by NMR.

CONCLUSION

These results suggest that the developed HPLC method for ifosfamide did not detect the degradation products shown by NMR. It is possible that degradation products co-elute with ifosfamide, do not elute altogether or are not amenable to the detection method employed. Therefore, investigation of ifosfamide stability requires additional techniques that do not suffer from the aforementioned shortcomings.

Abstract 3589: Validation of the role of circulating tumor DNA (ctDNA) in tracking mechanisms of resistance to anti-EGFR monoclonal antibodies (AE-mABs): preliminary results of the PROSPECT-C prospective trial

Background: AE-mABs (cetuximab and/or panitumumab) have been approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC) patients (pts). Indeed, previous studies have identified mutations (MTs)/amplifications in RAS/RAF/MEK kinase pathway as the main genetic events promoting primary and acquired resistance to these mABs. RAS status is frequently established on archival material, as tumour re-biopsy may not be always feasible. PROSPECT-C is a prospective trial aiming to define novel and known mechanisms of resistance to AE-mABs by obtaining repeated biopsies and sequential bloods from pts receiving AE-mABs for chemo-refractory mCRC.

Here we present the preliminary results of the PROSPECT-C liquid biopsy study where the goals were to: 1) confirm the ability of ctDNA to determine RAS status prior to treatment; 2) determine any discordance of RAS status between archival material and ctDNA; 3) confirm the ability of ctDNA to track emerging MTs in the RAS pathway.

Materials and Methods: Plasma was collected at baseline (BL), every 4 weeks and at progression (PD). ctDNA was isolated using the QIAamp Circulating Nucleic Acid Kit (Qiagen) and analyzed by digital droplet PCR (QX200 Bio-Rad) for MTs in KRAS-G12D, KRAS-G13D, KRAS-G12V, KRAS-Q61HA&gt;T, KRAS-Q61HA&gt;C, and BRAF-V600E. In the next steps, plasma samples with no MTs in the first series of hotspots will be tested for the remaining KRAS hotspots, NRAS, EGFR, PIK3CA MTs and KRAS, c-MET and HER-2 amplifications (Data to be presented).

Results: Twenty-four pts (all treated with AE-mAB monotherapy) with KRAS WT tumors (from archival tissue) have been treated on this ongoing study; 16/24 had ctDNA analysis (mean age 62 years, 62.5% males) so far. All pts were heavily pre-treated; 58.3%, 31.3% and 12.5% received 2, 3 and 4 lines of prior therapies respectively. Of 15 pts with BL samples, 5 had MTs at BL; 2 with KRAS-G12D, 1 with KRAS Q61HA&gt;T and 2 pts with BRAF-V600E (in the latter case concordance was found with the archival material). Best response was found to be PD in 4/5 pts and stable disease in 1/5pt with BL MTs; 2 with BRAF MTs progressed in &lt;2 months (mo). The median progression free survival (PFS) for pts with BL MTs was 1.8 mo. Five pts with no MT at BL developed one or more MTs later; those included 4 with KRAS-G12D, 3 with KRAS-G13D and 2 with KRASQ61HA&gt;T (median PFS = 4.8 mo). 3/15 (20%) pts showed discordance in RAS MTs between archival material (WT) and baseline bloods (MT); all of them progressed within 3 mo.

Conclusions: Liquid biopsies can be a useful tool in determining and tracking RAS MTs in pts undergoing anti-EGFR therapy for mCRC. ctDNA analysis to assess RAS mutational status prior to receiving AE-mABs in our series showed 20% discordance between the archival solid and BL liquid biopsies, which may account for resistance to these therapies.

Citation Format: Khurum Khan, George Vlachogianis, David Cunningham, Jens Hahne, Mahnaz Darvish-Damavandi, Sarah Barton, Francesco Trevisani, Giulia Mentrast, Clare Peckitt, Andrea Lampis, Chiara Braconi, Nasir Khan, Ruwaida Begum, Naureen Starling, Sheela Rao, David Watkins, Annette Bryant, Ian Chau, Nicola Valeri. Validation of the role of circulating tumor DNA (ctDNA) in tracking mechanisms of resistance to anti-EGFR monoclonal antibodies (AE-mABs): preliminary results of the PROSPECT-C prospective trial. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3589. doi:10.1158/1538-7445.AM2015-3589

The surgically remediable syndrome of epilepsy associated with bottom-of-sulcus dysplasia

OBJECTIVE

To determine clinical and EEG features that might help identify patients with epilepsy harboring small, intrinsically epileptogenic, surgically treatable, bottom-of-sulcus dysplasias (BOSDs).

METHODS

Retrospective review of clinical records, EEG, MRI, and histopathology in 32 patients with drug-resistant epilepsy and MRI-positive (72% 3.0 tesla), pathologically proven (type 2B cortical dysplasia) BOSDs operated at our centers during 2005-2013.

RESULTS

Localization of BOSDs was frontal in 19, insula in 5, parietal in 5, and temporal in 3, on the convexity or interhemispheric surfaces. BOSDs were missed on initial MRI at our centers in 22% of patients. Patients presented with focal seizures during infancy in 9, preschool years in 15, and school years in 8 (median age 5 years). Seizures were stereotyped, predominantly nocturnal, and typically nonconvulsive, with semiology referable to the fronto-central or perisylvian regions. Seizures occurred at high frequency during active periods, but often went into prolonged remission with carbamazepine or phenytoin. Intellect was normal or borderline, except in patients with seizure onset during infancy. Scalp EEG frequently revealed localized interictal epileptiform discharges and ictal rhythms. Patients underwent lesionectomy (median age 14 years) guided by electrocorticography and MRI, with prior intracranial EEG monitoring in only one patient. Twenty-eight patients (88%) became seizure-free, and 20 discontinued antiepileptic medication (median follow-up 4.1 years).

CONCLUSIONS

In patients with cryptogenic focal epilepsy, this clinical presentation and course should prompt review of or repeat MRI, looking for a BOSD in the frontal, parietal, or insula cortex. If a BOSD is identified, the patient might be considered for single-stage lesionectomy.

Rituximab, Gemcitabine, Cisplatin and Methylprednisolone (R-GEM-P) is an effective regimen in relapsed diffuse large B-cell lymphoma

BACKGROUND

Patients with relapsed diffuse large B-cell lymphoma (DLBCL) have a poor prognosis. Gemcitabine, methylprednisolone, cisplatin +/- rituximab (GEM-P+/-R) is a salvage regimen with limited overlap in toxicity with first-line therapy and short duration of inpatient delivery.

METHODS

We assessed the efficacy and safety of GEM-P+/-R in a retrospective single-centre analysis including patients meeting criteria of ≥ 18 yr of age, histologically proven DLBCL, treated between 2001 and 2011 in second-line with gemcitabine 1000 mg/m(2) day 1, 8 and 15, methylprednisolone 1000 mg day 1-5, cisplatin 100 mg/m(2) day 15 (replaced with carboplatin AUC5 if contraindication/toxicity) +/- rituximab 375 mg/m(2) day 1 and 15, every 28 d.

RESULTS

Forty-five patients aged 25-74 received a median of three cycles of GEM-P+/-R; 64% received rituximab. In 44 evaluable patients receiving GEM-P+/-R, overall response rate (ORR) was 48%; in 28 evaluable patients treated with rituximab + GEM-P (R-GEM-P), ORR was 61%. With median follow-up of 50.5 months (95% CI: 28.3-72.7), 3-yr overall survival (OS) from start of GEM-P+/-R was 31.4% (95% CI: 16.5-46.3); in patients treated with R-GEM-P, 3-yr OS was 49.1% (95% CI: 28.7-69.5). Predominant grade ≥ 3 toxicities were haematological; thrombocytopenia 69%, neutropenia 60% and febrile neutropenia 7%.

CONCLUSION

R-GEM-P is a deliverable regimen with useful activity in second-line treatment of DLBCL. Our data suggest that rituximab should be given concurrently.

Target Mediated Drug Disposition Model of CPHPC in Patients with Systemic Amyloidosis

The amyloid deposits that cause disease in systemic amyloidosis always contain the normal plasma protein, serum amyloid P (SAP) component. SAP is the target of a novel immunotherapy approach now being developed to eliminate amyloid deposits. The treatment is enabled by, and critically depends on, the use of the drug (R)-1-[6-[(R)-2-carboxy-pyrrolidin-1-yl]-6-oxo-hexanoyl]pyrrolidine-2-carboxylic acid (CPHPC, GSK2315698, Ro 63-8695), which depletes circulating SAP almost completely but leaves some SAP in amyloid deposits for specific recognition by subsequently administered therapeutic anti-SAP antibodies. Herein, we report a mechanistic model that predicts, with clinically acceptable precision, the exposure-response relationship for CPHPC, both in healthy individuals and in patients with systemic amyloidosis. The model covariates are gender, renal function, total amyloid load, and presence of hepatic amyloid, all of which are known at baseline. The model is being used to predict individualized dosing regimens in an ongoing, first-in-human study with anti-SAP antibodies.

Altered cortical thickness following prenatal sodium valproate exposure

Prenatal exposure to sodium valproate (VPA) is associated with neurodevelopmental impairments. Cortical thickness was measured in 16 children exposed prenatally to VPA and 16 controls. We found increased left inferior frontal gyrus (IFG; BA45) and left pericalcarine sulcus (BA18) thickness, an association between VPA dose and right IFG thickness, and a close relationship between verbal skills and left IFG thickness. A significant interaction between group and hemispheric IFG thickness showed absence of the normal asymmetry in the IFG region of VPA-exposed children. These data provide preliminary insights into the putative neural basis of difficulties experienced by some VPA-exposed children.

GEM-P chemotherapy is active in the treatment of relapsed Hodgkin lymphoma

Hodgkin lymphoma (HL) is a relatively chemosensitive malignancy. However, for those who relapse, high-dose chemotherapy with autologous stem cell transplant is the treatment of choice which relies on adequate disease control with salvage chemotherapy. Regimens commonly used often require inpatient administration and can be difficult to deliver due to toxicity. Gemcitabine and cisplatin have activity in HL, non-overlapping toxicity with first-line chemotherapeutics, and may be delivered in an outpatient setting. In this retrospective single-centre analysis, patients with relapsed or refractory HL treated with gemcitabine 1,000 mg/m(2) day (D)1, D8 and D15; methylprednisolone 1,000 mg D1-5; and cisplatin 100 mg/m(2) D15, every 28 days (GEM-P) were included. Demographic, survival, response and toxicity data were recorded. Forty-one eligible patients were identified: median age 27. One hundred and twenty-two cycles of GEM-P were administered in total (median 3 cycles; range 1-6). Twenty of 41 (48 %) patients received GEM-P as second-line treatment and 11/41 (27 %) as third-line therapy. Overall response rate (ORR) to GEM-P in the entire cohort was 80 % (complete response (CR) 37 %, partial response 44 %) with 14/15 CR confirmed as a metabolic CR on PET and ORR of 85 % in the 20 second-line patients. The most common grade 3/4 toxicities were haematological: neutropenia 54 % and thrombocytopenia 51 %. Median follow-up from the start of GEM-P was 4.5 years. Following GEM-P, 5-year progression-free survival was 46 % (95 % confidence interval (CI), 30-62 %) and 5-year overall survival was 59 % (95 % CI, 43-74 %). Fourteen of 41 patients proceeded directly to autologous transplant. GEM-P is a salvage chemotherapy with relatively high response rates, leading to successful transplantation in appropriate patients, in the treatment of relapsed or refractory HL.

Thinking about trauma: the unique contributions of event centrality and posttraumatic cognitions in predicting PTSD and posttraumatic growth

Researchers have been investigating possible pathways to negative (posttraumatic stress disorder [PTSD]) and positive (posttraumatic growth [PTG]) reactions to trauma in recent decades. Two cognitive constructs, event centrality and posttraumatic cognitions, have been implicated to uniquely predict PTSD symptoms in an undergraduate sample. The current pair of studies attempted to (a) replicate this finding in an undergraduate sample, (b) replicate this finding in a treatment-seeking sample, and (c) explore whether these 2 cognitive constructs uniquely predict PTG. The first study consisted of 500 undergraduate students, whereas the second study consisted of 53 treatment-seeking clients. Results indicated both posttraumatic cognitions and event centrality uniquely predicted PTSD in the undergraduate (R(2) = .46) and treatment-seeking samples (R(2) = .46). These 2 cognitive constructs also predicted PTG in the undergraduate sample (R(2) = .37), but only posttraumatic cognitions predicted PTG in the treatment-seeking sample (R(2) = .17). The relationships between PTG varied, depending on whether PTG for high or low event-centrality events were assessed. The original model was supported within both populations for PTSD symptoms, and its extension to PTG was supported within the treatment-seeking sample. These results underscore cognitive and narrative factors in the progression of trauma.

Corpus callosum size and shape alterations in adolescent inhalant users

Inhalants, frequently abused during adolescence, are neurotoxic to white matter. We investigated the impact of inhalant misuse on the morphology of the corpus callosum (CC), the largest white matter bundle in the brain, in an adolescent sample of inhalant users [n = 14; mean age = 17.3; standard deviation (SD) = 1.7], cannabis users (n = 11; mean age = 19.7; SD = 1.7) and community controls (n = 9; mean age = 19.5; SD = 2.6). We identified significant morphological differences in the CC among inhalant users compared with community controls. There were no morphological differences between inhalant and cannabis users. Our findings may represent the early stages of neurobiological damage associated with chronic inhalant misuse.

Social support network characteristics and sexual risk taking among a racially/ethnically diverse sample of young, urban men who have sex with men

Associations between social support network characteristics and sexual risk among racially/ethnically diverse young men who have sex with men (YMSM) were examined using egocentric network data from a prospective cohort study of YMSM (n = 501) recruited in New York City. Bivariate and multivariable logistic regression analyses examined associations between social support network characteristics and sexual risk taking behaviors in Black, Hispanic/Latino, and White YMSM. Bivariate analyses indicated key differences in network size, composition, communication frequency and average relationship duration by race/ethnicity. In multivariable analyses, controlling for individual level sociodemographic, psychosocial and relationship factors, having a sexual partner in one's social support network was associated with unprotected sexual behavior for both Hispanic/Latino (AOR = 3.90) and White YMSM (AOR = 4.93). Further examination of key network characteristics across racial/ethnic groups are warranted in order to better understand the extant mechanisms for provision of HIV prevention programming to racially/ethnically diverse YMSM at risk for HIV.

A dedicated clinic for HIV-positive individuals over 50 years of age: a multidisciplinary experience

The HIV-infected population is ageing. Issues including polypharmacy and co-morbidities led us to develop a dedicated clinic for HIV-infected individuals over 50. We describe our service evaluation after two years. The over 50 clinic commenced in January 2009. The team comprises a registrar, consultant, nurse practitioner and is supported by a pharmacist and mental health services. Patients undergo a full medication and drug interactions review, neurocognitive assessment, adherence self-assessment and investigations including therapeutic drug monitoring (TDM), coronary artery calcium scores (CACS) and bone mineral density. Over two years of activity, 150 patients attended the service. Median (range) age was 58 (50-88), all were on combined antiretroviral therapy and 38% (57/150) were on ≥3 non-HIV drugs. CACS was high (>90th centile) in 14%. Thirty-eight percent had osteopaenia and 18% had osteoporosis requiring treatment. Thirteen out of 125 men had an increased prostate specific antigen, four were diagnosed with prostate cancer. Drug interaction, TDM and neurocognitive assessments were useful for several patients. Asymptomatic patients over 50 in long-term follow-up had new pathologies detected through targeted screening. The clinic has improved general practitioner (GP) liaison and facilitated closer working relationships with other specialties. Patients have reacted positively to the clinic, particularly as many do not routinely access their GP.

Environmental lithium exposure in the North of Chile--I. Natural water sources

Lithium as an essential element for human life is still a subject of controversy. However, it is accepted that it does have profound neurological effects and is a valuable treatment for bipolar disease. Generally, it occurs in barely trace amounts in groundwater with few major exceptions. One of these is the Northern area of Chile where all potable water and many of the food stuffs contain high levels of lithium; between 100 and 10,000 times higher than most rivers in North America. Inevitably, the local population has been exposed to these levels in their drinking water for as long as the region has been populated. The present report details lithium levels in all the surface water sources of Northern Chile with comparison to that elsewhere. The implications for the local population are discussed and their situation compared to those exposed to other sources of lithium pollution.

Are we ready to stratify treatment for diffuse large B-cell lymphoma using molecular hallmarks?

The division of the heterogeneous entity of diffuse large B-cell lymphoma (DLBCL) into the ontogenic phenotypes of germinal center B-cell-like (GCB) and activated B-cell-like (ABC) is optimally determined by gene expression profiling (GEP), although simpler immunohistochemistry (IHC) algorithms are alternatively being used. The cell-of-origin (COO) classification assists in prognostication and may be predictive of response to therapy. Mounting data suggests that IHC methods of classifying COO may be inaccurate. GEP categorization of COO is superior in defining prognostically and biologically distinct DLBCL subtypes, but current barriers to its widescale use include inaccessibility, cost, and lack of methodological standardization and prospective validation. The poorer prognosis of ABC-DLBCL is frequently associated with constitutive activity in the NF-κB pathway and aberrations in upstream or downstream regulators of this pathway. The molecular mechanisms underlying lymphomagenesis in GCB-DLBCL are arguably less well defined, but C-REL amplification and mutations in BCL-2 and EZH2 are common. New technologies, such as next-generation sequencing, are rapidly revealing novel pathogenic genetic aberrations, and DLBCL treatment strategies are increasingly being designed focusing on distinctive pathogenic drivers within ontogenic phenotypes. This review examines emerging molecular targets and novel therapeutic agents in DLBCL, and discusses whether stratifying therapy for DLBCL using molecular features is merited by current preclinical and clinical evidence.

Three different approaches to Transversus abdominis planeblock: a cadaveric study

AIM

The transversus abdominis plane (TAP) block is a new technique for providing analgesia to the anterior abdominal wall. There is ongoing debate regarding access point for TAP block. The aim of this cadaveric study was to compare the spread of 40 mL of dye using three different approaches to TAP: subcostal , via the mid-axillary and via the lumbar triangle of Petit (LTOP).

METHODS

Injection of black dye into the TAP was performed for each hemi-abdominal wall of 13 embalmed human cadavers by using 3 different access points: subcostal (9 hemi-abdomens), mid-axillary (9) and LTOP (8). This was followed by dissection to determine the extent of dye spread and nerve involvement in the dye injection. The shapes of the dye were traced onto clear plastic, which was then photographed. These digital photographs were loaded into the mathematical software programme Matlab, and the outline of the dye spread was digitised using a piecewise cubic spline, enabling the shapes to be plotted on a graph and the areas to be calculated.

RESULTS

The area of the dye spread for subcostal, mid-axillary and LTOP was 85.1 (T7-L1), 58.9 (T10-L1) and 77.9 cm² (T10-L1), respectively. There was statistically significant difference between area of dye spread between subcostal and mid-axillary approach (p<0.01).

CONCLUSIONS

This dye injection study in a cadaver model indicates that subcostal approach is associated with a larger area of spread of dye than the mid-axillary approach. Dye injected through subcostal, mid-axillary and LTOP approaches demonstrated different nerve involvement.

Thickness profile generation for the corpus callosum using Laplace's equation

The corpus callosum facilitates communication between the cerebral hemispheres. Morphological abnormalities of the corpus callosum have been identified in numerous psychiatric and neurological disorders. To quantitatively analyze the thickness profile of the corpus callosum, we adapted an automatic thickness measurement method, which was originally used on magnetic resonance (MR) images of the cerebral cortex (Hutton et al. [2008]: NeuroImage 40:1701-10; Jones et al. [2002]: Hum Brain Mapp 11:12-32; Schmitt and Böhme [2002]: NeuroImage 16:1103-9; Yezzi and Prince [2003]: IEEE Trans Med Imaging 22:1332-9), to MR images of the corpus callosum. The thickness model was derived by computing a solution to Laplace's equation evaluated on callosal voxels. The streamlines from this solution form non-overlapping, cross-sectional contours the lengths of which are modeled as the callosal thickness. Apart from the semi-automated segmentation and endpoint selection procedures, the method is fully automated, robust, and reproducible. We compared the Laplace method with the orthogonal projection technique previously published (Walterfang et al. [2009a]: Psych Res Neuroimaging 173:77-82; Walterfang et al. [2008a]: Br J Psychiatry 192:429-34; Walterfang et al. [2008b]: Schizophr Res 103:1-10) on a cohort of 296 subjects, composed of 86 patients with chronic schizophrenia (CSZ), 110 individuals with first-episode psychosis, 100 individuals at ultra-high risk for psychosis (UHR; 27 of whom later developed psychosis, UHR-P, and 73 who did not, UHR-NP), and 55 control subjects (CTL). We report similar patterns of statistically significant differences in regional callosal thickness with respect to the comparisons CSZ vs. CTL, UHR vs. CTL, UHR-P vs. UHR-NP, and UHR vs. CTL.

Corpus callosum morphology and relationship to orbitofrontal and lateral ventricular volume in teenagers with first-presentation borderline personality disorder

Previous studies have demonstrated alterations to fronto-limbic circuitry and callosal structure in borderline personality disorder (BPD). We predicted that a first-presentation BPD cohort who demonstrated orbitofrontal cortex (OFC) reductions would show regional reductions in the anterior corpus callosum.

METHOD

Twenty teenage first-presentation BPD patients and twenty matched healthy controls underwent Magnetic resonance imaging (MRI) was performed in 20 teenaged first-presentation BPD patients and 20 matched healthy controls. Corpus callosum size and shape and ventricular volume were estimated using established methods and compared between the two groups. The relationship between illness variables and callosal morphology was also examined. OFC volume was correlated with callosal and ventricular variables.

RESULTS

BPD participants and controls did not differ on measures of callosal size or shape, or ventricular size. BPD participants showed an alteration to the pattern of age-related expansions seen in the callosum. BPD participants with a history of trauma did not demonstrate significant neuroanatomical differences from those without. OFC volumes did not correlate with the thickness of the anterior corpus callosum.

CONCLUSION

Gross neuroanatomical changes are not present at the level of the callosum in teenagers with first-presentation BPD. Changes seen in other studies might reflect factors associated with the duration of BPD, such as recurrent comorbidity with axis I disorders, or treatment.