Understanding the core principles of a 'modified ketogenic diet': a UK and Ireland perspective

BACKGROUND

Many centres across the UK and Ireland anecdotally report using a 'modified ketogenic diet' (MKD) as a treatment for refractory epilepsy. Although a MKD is within the spectrum of ketogenic diets (KDs), there is little literature reporting upon its definition, use or clinical effectiveness. We aimed to understand the core principles of MKD practice and to assess whether and how the MKD differs from other KD protocols.

METHODS

An online survey, designed by a consensus group of ketogenic dietitians, was circulated to 39 KD centres across the UK and Ireland. It consisted of 35 questions regarding dietetic practice when providing MKD.

RESULTS

Eighteen centres completed the questionnaire: 13 paediatric, three adult and two combined centres. All dietitians based MKD 'prescriptions' on estimated total energy requirements. The average macronutrient profile was 75% fat and 5% carbohydrate, with protein ad libitum. Carbohydrate and fat targets were implemented via weighed portions (carbohydrate lists n = 18; fat lists n = 13) and 'household measures' (carbohydrate lists n = 2; fat lists n = 3). Of the centres, 94% (n = 17) adjusted macronutrients over time; these decisions were based on ketone levels and seizures in most cases (83%; n = 14). Ketogenic nutritional products available on prescription were used by 10 centres (56%) when initiating and by all centres when 'fine-tuning' the MKD.

CONCLUSIONS

A modified ketogenic diet in the UK and Ireland is a hybrid KD, adopting principles from other established KD protocols and defining new elements unique to the MKD. Further research into the clinical and cost-effectiveness of MKD would be of benefit.

Abstract P5-10-01: Using whole genome sequencing and somatic mutation signatures to unravel insight into familial breast cancer aetiology

Approximately 10-15% of breast cancers are associated with a strong family history of disease. Pathogenic variants in BRCA1, BRCA2 or other moderate to highly penetrant susceptibility genes (e.g. TP53, ATM, CHEK2, PALB2 and PTEN) account for a number of breast cancer families. However, for over 50% of families the underlying genetic contribution to their risk remains unknown (termed here as non-BRCA1/2). This has a profound impact for how individuals and their families are managed in the clinic. We applied whole genome sequencing (WGS) to determine whether somatic mutation analysis can reveal insight into the aetiology of familial breast cancer. The full repertoire of somatic mutations was evaluated in 26 BRCA1, 22 BRCA2 and 32 non-BRCA1/2 tumours; including SNPs, indels, copy number changes and structural rearrangements, and mutational signatures. Genomes were also analysed using the HRD Index and HRDetect, as predictors of homologous recombination deficiency. BRCA1, BRCA2 and non-BRCA1/2 tumours exhibited a different burden of mutations, a different spectrum of mutational signatures and different telomere length. Based on collective patterns of mutation signatures, tumours were classified as 'BRCA1-like', 'BRCA2-like' or 'non-BRCA1/2-like' with a 15% rate of tumour re-classification from their original clinical BRCA status. The results demonstrate the power of WGS to differentiate between BRCA1 and BRCA2 driven tumours; in the identification of double-pathogenic germline mutation carriers based on the resulting somatic mutation signature; and in the interpretation of BRCA unclassified variants. WGS of tumour genomes reveals fascinating insights into tumour aetiology and could compliment current genetic testing of breast cancer families.

Citation Format: Simpson P, Nones K, Johnson J, Newell F, Patch A-M, Thorne H, Kazakoff S, De Luca X, Parsons M, Ferguson K, Reid L, McCart Reed A, Srihari S, Lakis V, Davidson A, Mukhopadhyay P, Holmes O, Xu Q, Wood S, Leonard C, Beasley J, Degasperi A, Nik-Zainal S, Ragan M, Spurdle A, Khanna KK, Lakhani S, Pearson J, Chenevix-Trench G, Waddell N. Using whole genome sequencing and somatic mutation signatures to unravel insight into familial breast cancer aetiology [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-10-01.

Revealing Color Forces with Transverse Polarized Electron Scattering

The Spin Asymmetries of the Nucleon Experiment measured two double spin asymmetries using a polarized proton target and polarized electron beam at two beam energies, 4.7 and 5.9 GeV. A large-acceptance open-configuration detector package identified scattered electrons at 40° and covered a wide range in Bjorken x (0.3<x<0.8). Proportional to an average color Lorentz force, the twist-3 matrix element, d[over ˜]_{2}^{p}, was extracted from the measured asymmetries at Q^{2} values ranging from 2.0 to 6.0  GeV^{2}. The data display the opposite sign compared to most quark models, including the lattice QCD result, and an unexpected scale dependence. Furthermore, when combined with the neutron data in the same Q^{2} range the results suggest a flavor independent average color Lorentz force.

Building Conceptions of Cognitive Enhancement: University Students' Views on the Effects of Pharmacological Cognitive Enhancers

BACKGROUND

Use of prescription stimulants for cognitive enhancement in healthy individuals has been of growing interest to the academic community. University students can be prone to use these pharmacological cognitive enhancers (PCEs) for their perceived academic benefits.

OBJECTIVES

We aimed to understand university students' beliefs about the factors influencing PCE use, the cognitive and health effects of the drugs, and how these conceptions are interrelated.

METHODS

Data were collected through focus groups with 45 students at the University of Toronto in 2015/2016. We used thematic analysis to extract key themes and cooccurrence coefficients to evaluate the overlap between these themes.

RESULTS

We found that participants perceived users as either struggling students or high-achieving ones. Alleged benefits of PCEs included enhanced focus, attention, memorization, and grades, but did not include increased intelligence or long-term cognitive enhancement. Participants disagreed on whether ADHD diagnosis would affect how PCEs worked and how "needing the drug" was determined. Mentions of nonspecific side effects were common, as was the possibility of misuse (e.g., addiction, abuse). Though not an initial aim of the study, we uncovered patterns pertaining to whom participants used as sources of information about different themes. We propose that social learning theory provides a useful framework to explain how the experiences of peers may shape the conceptions of our participants. Conclusions/Importance: Our findings highlight that conceptions surrounding PCEs are multileveled, and informed by a variety of sources, including peers. This should be considered in the development of interventions geared toward university students.

Case Report: Spontaneous Hemorrhage of a Rare Renal Tumor in the Native Kidney of a Renal Transplant Recipient

Renal cancers are some of the most common solid organ malignancies found during follow-up of patients who have undergone renal transplantation (RT). In this case report, we describe a life-threatening spontaneous hemorrhage of a rare subtype of renal cell carcinoma in the native kidney of a 27-year-old man, 4 years after RT. After fluid resuscitation and stabilization, the patient underwent emergent open radical nephrectomy with the final histopathology reporting T1bN0Mx mucinous tubular and spindle cell (MTSC) carcinoma. This case report highlights the need to consider an underlying malignancy in patients who presents with spontaneous hemorrhage of native kidneys after RT.

Long-Term Parenteral Nutrition: Problems with Venous Access

Long-term parenteral nutrition requires central venous access, often difficult in patients who have had several central venous catheterizations. Therapy may be complicated by thrombosis and sepsis which may further compromise central access. We report five cases illustrating such difficulties and suggest that these patients be referred early to specialist centres where experienced catheter insertion and management results in a greatly reduced incidence of complications.

Intrapartum glycaemic control and neonatal hypoglycaemia in pregnancies complicated by diabetes: a systematic review

AIMS

To examine whether, in neonates of mothers with Type 1, Type 2 and gestational diabetes, in-target intrapartum glycaemic control was associated with a lower risk of neonatal hypoglycaemia compared with out-of-target glycaemic control.

METHODS

We searched PubMed and EMBASE for all available publications, regardless of year, based on a published protocol (PROSPERO CRD42016052439). Studies were excluded if they did not report original data or were animal studies. Data were extracted from published reports in duplicate using a prespecified data extraction form. The main outcome of interest was the association between in-target intrapartum glycaemic control and neonatal hypoglycaemia.

RESULTS

We screened 2846 records for potential study inclusion; 23 studies, including approximately 2835 women with diabetes, were included in the systematic review. Only two of those studies specifically examined in-target vs out-of-target intrapartum glycaemic control. Of the studies included, six showed a relationship between intrapartum glucose and neonatal hypoglycaemia, five others showed a relationship in at least one of the analyses performed and 12 did not find a significant relationship. Only one study was identified as having a low risk of bias.

CONCLUSIONS

There is a paucity of high-quality data supporting the association of glucose during labour and delivery with neonatal hypoglycaemia in pregnancies complicated by diabetes. Further studies are required to examine the impact of tight glycaemic targets in labour.

Auditory verbal hallucinations in first episode psychosis – an fMRI symptom capture study

Introduction

Neurobiological models of auditory verbal hallucination (AVH) have been advanced by symptom capture functional magnetic resonance imaging (fMRI), where participants self-report hallucinations during scanning. To date, regions implicated are those involved with language, memory and emotion. However, previous studies focus on chronic schizophrenia, thus are limited by factors, such as medication use and illness duration. Studies also lack detailed phenomenological descriptions of AVHs. This study investigated the neural correlates of AVHs in patients with first episode psychosis (FEP) using symptom capture fMRI with a rich description of AVHs. We hypothesised that intrusive AVHs would be associated with dysfunctional salience network activity.

Methods

Sixteen FEP patients with frequent AVH completed four psychometrically validated tools to provide an objective measure of the nature of their AVHs. They then underwent fMRI symptom capture, utilising general linear models analysis to compare activity during AVH to the resting brain.

Results

Symptom capture of AVH was achieved in nine patients who reported intrusive, malevolent and uncontrollable AVHs. Significant activity in the right insula and superior temporal gyrus (cluster size 141 mm3), and the left parahippocampal and lingual gyri (cluster size 121 mm3), P < 0.05 FDR corrected, were recorded during the experience of AVHs.

Conclusions

These results suggest salience network dysfunction (in the right insula) together with memory and language processing area activation in intrusive, malevolent AVHs in FEP. This finding concurs with others from chronic schizophrenia, suggesting these processes are intrinsic to psychosis itself and not related to length of illness or prolonged exposure to antipsychotic medication.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Sex steroid hormones in relation to Barrett's esophagus: an analysis of the FINBAR Study

Previously, we observed strong positive associations between circulating concentrations of free testosterone and free dihydrotestosterone (DHT) in relation to Barrett's esophagus in a US male military population. To replicate these findings, we conducted a second study of sex steroid hormones and Barrett's esophagus in the Factors Influencing the Barrett/Adenocarcinoma Relationship (FINBAR) Study based in Northern Ireland and Ireland. We used mass spectrometry to quantitate EDTA plasma concentrations of nine sex steroid hormones and ELISA to quantitate sex hormone-binding globulin in 177 male Barrett's esophagus cases and 185 male general population controls within the FINBAR Study. Free testosterone, free DHT, and free estradiol were estimated using standard formulas. Multivariable logistic regression estimated odds ratios (OR) and 95% confidence intervals (95%CI) of associations between exposures and Barrett's esophagus. While plasma hormone and sex hormone-binding globulin concentrations were not associated with all cases of Barrett's esophagus, we did observe positive associations with estrogens in younger men (e.g. estrone + estradiol OR_{continuous per ½IQR}  = 2.92, 95%CI:1.08, 7.89), and free androgens in men with higher waist-to-hip ratios (e.g. free testosterone OR_{continuous per ½IQR}  = 2.71, 95%CI:1.06, 6.92). Stratification by body mass index, antireflux medications, and geographic location did not materially affect the results. This study found evidence for associations between circulating sex steroid hormones and Barrett's esophagus in younger men and men with higher waist-to-hip ratios. Further studies are necessary to elucidate whether sex steroid hormones are consistently associated with esophageal adenocarcinogenesis.

Abstract P3-14-07: Neoadjuvant radiotherapy in mastectomy and immediate autologous free flap reconstruction. Findings from the primary radiotherapy and DIEP flap (PRADA) pilot study

Background:

The need for post mastectomy radiotherapy (PMRT), may preclude reconstructive surgeons from offering patients immediate, autologous reconstruction. This is due to historical evidence suggesting high rates of short- and long-term complications as well as poorer aesthetic outcomes. As the indications for PMRT broaden this practice denies an ever-increasing number of women the benefit of an immediate reconstruction.

Aim:

This pilot study evaluates the safety of offering radiotherapy prior to mastectomy and immediate DIEP flap reconstruction.

Methods:

Women planned for neoadjuvant chemotherapy (NAcT), mastectomy (following unsuccessful breast conservation surgery (BCS) or upfront selection) and PMRT were offered a change in sequencing of RT at two academic breast surgery units in London, UK. Data was prospectively captured on 19 women, including: patient demographics, treatment details, tumour characteristics, oncological and post-operative outcomes. Operative parameters included unplanned return to theatre [RTT] &lt;30 days, mastectomy skin flap necrosis, and evidence of wound infection at 5 days, 4 and 12 weeks post-operatively. All mastectomies, were performed by one of 3 breast surgeons (DH, FAM, DRL) using a circumareolar incisions with one patient undergoing a vertical pattern incision for skin reduction.

Results:

The cohort demonstrated a broad range of age, body mass index (BMI) and mastectomy weight [mean (range): age=46 years (28-72); BMI = 28.4 kg/m2 (23-37.6) and specimen weight=678gm (257-1040)]. The mean time from completion of NAcT to neoadjuvant radiotherapy (NART) was 31.1 days (9-49 days), and time from completion of NART to mastectomy and DIEP was 17.8 days (13-24 days). There was one unplanned RTT at 72 hours for an evacuation of haematoma, 1 revision of micro-vascular anastomosis, 1 clinical fat necrosis requiring formal excision and 1 wound debridement and primary closure for poor wound healing (vertical pattern skin reduction). There were no flap failures and no mastectomy envelope necrosis. With a mean follow-up of 16.2 months, there were no loco-regional recurrences, 5 distant relapses with mean presentation at 13.7 months and 2 breast-cancer related deaths at 13.9 and 22.2months respectively.

Conclusion:

This pilot study suggests that mastectomy and DIEP reconstruction is surgically feasible within 4 weeks of completing NART. In this small cohort of oncologically high-risk women with altered sequencing of RT we did not observe flap failure or post-mastectomy skin flap necrosis. A larger multicentre study with aesthetic assessment, PROMS and translational aspects is planned.

Citation Format: Thiruchelvam P, Hadjiminas D, Cleator S, Wood S, Leff D, Jallali N, James S, MacNeill F. Neoadjuvant radiotherapy in mastectomy and immediate autologous free flap reconstruction. Findings from the primary radiotherapy and DIEP flap (PRADA) pilot study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-14-07.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Distinct subclonal tumour responses to therapy revealed by circulating cell-free DNA

BACKGROUND

The application of precision medicine in oncology requires in-depth characterisation of a patient's tumours and the dynamics of their responses to treatment.

PATIENTS AND METHODS

We used next-generation sequencing of circulating cell-free DNA (cfDNA) to monitor the response of a KIT p.L576P-mutant metastatic vaginal mucosal melanoma to sequential targeted, immuno- and chemotherapy.

RESULTS

Despite a KIT mutation, the response to imatinib was mixed. Unfortunately, tumours were not accessible for molecular analysis. To study the mechanism underlying the mixed clinical response, we carried out whole-exome sequencing and targeted longitudinal analysis of cfDNA. This revealed two tumour subclones; one with a KIT mutation that responded to imatinib and a second KIT-wild-type subclone that did not respond to imatinib. Notably, the subclones also responded differently to immunotherapy. However, both subclones responded to carboplatin/paclitaxel, and although the KIT-wild-type subclone progressed after chemotherapy, it responded to subsequent re-administration of paclitaxel.

CONCLUSION

We show that cfDNA can reveal tumour evolution and subclonal responses to therapy even when biopsies are not available.

El Niño and coral larval dispersal across the eastern Pacific marine barrier

More than 5,000 km separates the frequently disturbed coral reefs of the Eastern Tropical Pacific (ETP) from western sources of population replenishment. It has been hypothesized that El Niño events facilitate eastward dispersal across this East Pacific Barrier (EPB). Here we present a biophysical coral larval dispersal model driven by 14.5 years of high-resolution surface ocean current data including the extreme 1997–1998 El Niño. We find no eastward cross-EPB connections over this period, which implies that ETP coral populations decimated by the 1998 bleaching event can only have recovered from eastern Pacific sources, in congruence with genetic data. Instead, rare connections between eastern and central Pacific reefs are simulated in a westward direction. Significant complexity and variability in the surface flows transporting larvae mean that generalized upper-ocean circulation patterns are poor descriptors of inter-regional connectivity, complicating the assessment of how climate change will impact coral gene flow Pacific wide.

Over 5,000 km of open ocean separate central and eastern Pacific coral reefs. Here, the authors combine a biophysical dispersal model with genetic data to show that eastern Pacific coral populations have been isolated from western sources of larval recruitment since the 1997-98 El Niño-induced bleaching event.

Caustic ingestion injury of the upper aerodigestive tract in adults

Adult ingestion of caustic substances is an unusual but serious surgical problem, with injuries likely to be more extensive than those in the corresponding paediatric population. After initial stabilisation and airway management, clinicians are presented with a complex multisystemic problem, frequently requiring a multidisciplinary approach involving several surgical disciplines and associated therapies. A new multidisciplinary team was convened to discuss complex ingestion injury in adults and established techniques were used to bring forward a proposed treatment algorithm. An algorithm may potentially improve clinical efficacy and risk in the management of these complex patients.