Size-Based Method for Enrichment of Circulating Tumor Cells from Blood of Colorectal Cancer Patients

Circulating tumor cells (CTCs) are precursors of the metastatic cascade, which is responsible for 90% of all cancer-related deaths. CTCs arise from solid tumors and travel through the bloodstream and lymphatic system. Developments in the isolation and analysis of CTCs promise potential biomarker assays for detection and monitoring of cancer through a minimally invasive procedure. Despite this, the precise role of CTCs in metastasis remains poorly characterized, mainly due to the low density of CTCs (1-10 CTCs per 10 mL of blood) present in patient blood and the lack of robust methods for their isolation in a standard laboratory setting. CellSearch is currently the only FDA-approved CTC enrichment protocol, but limitations of this EpCAM-based method include cost, availability, and the use of a single surface marker for capture. To address these limitations, we have optimized an existing method, MetaCell, which exploits the differences in size of CTCs compared to other blood cells for CTC enrichment from blood. MetaCell contains a membrane with 8 μm pores, and blood is filtered through this kit by capillary action and CTCs, which are typically larger than the pores and remain on top of the membrane, while most leukocytes pass through the pores. The membrane along with these CTCs can be detached and transferred to 6-well plates for culturing or directly used for characterization. Here, we provide a detailed protocol for enrichment of CTCs using the filtration device MetaCell and a procedure for characterization of CTCs by immunohistochemical staining.

283 AN EXPLORATION OF THE IRISH NATIONAL FRAILTY EDUCATION PROGRAMME ON PRACTICE: A FRAILTY FACILITATOR'S PERSPECTIVE

Background

Frailty is associated with a range of adverse outcomes in older adults requiring prevention, early detection and management. Interprofessional collaboration in education and practice can facilitate integrated care for older people in the management of frailty. In Ireland, an interprofessional National Frailty Education Programme (NFEP) is delivered in partnership between the National Clinical Programme for Older People (NCPOP) and The Irish Longitudinal Study on Ageing (TILDA). On completion of the NFEP, Frailty Facilitators return to their regional/local frailty networks to deliver the programme to healthcare professionals across disciplines and settings. The aim of this study is to explore the impact of the National Frailty Education Programme on practice.

Methods

A qualitative exploratory approach was adopted to elicit the perspectives of Frailty Facilitators on the impact of the NFEP on practice. Purposive sampling was employed across frailty networks nationwide. Focus groups were conducted, and data were analysed using thematic analysis.

Results

Twenty-four participants from five frailty networks took part in five focus groups across Ulster, Leinster and Connaught. Frailty Facilitators collaborated to deliver education on frailty in their local networks following the NFEP. Management support particularly that provided by the Centres for Midwifery and Nurse Education was deemed a significant enabler of frailty education. Strong interprofessional alliances were developed that enhanced communication between primary and secondary care settings in the care of older people. The medical profession were noted to have low participation in the frailty networks. The results revealed widespread use of frailty instruments for assessment and a shared understanding and language on frailty.

Conclusion

The NFEP had a clear impact on Frailty Facilitator’s practice. Conceptualisation and reflection on frailty related practice was in evidence across the frailty networks thus enabling multidisciplinary teams to manage the care of an older person with frailty in an integrated way.

Impact of clinical data veracity on cancer genomic research

Genomic analysis of tumours is transforming our understanding of cancer. However, while a great deal of attention is paid to the accuracy of the cancer genomic data itself, less attention has been paid to the accuracy of the associated clinical information that renders the genomic data useful for research. In this Brief Communication, we suggest that omissions and errors in clinical annotations have a major impact on the interpretation of cancer genomic data. We describe our discovery of annotation omissions and errors when reviewing an already carefully annotated colorectal cancer gene expression dataset from our laboratory. The potential significance of clinical annotation omissions and errors was then explored using simulation analyses with an independent genomic dataset. We suggest that the completeness and veracity of clinical annotations accompanying cancer genomic data requires renewed focus by the oncology research community, both when planning new collections and when interpreting existing cancer genomic data.

Short-term High-Intensity Interval Training Improves Fitness Before Surgery: A Randomised Clinical Trial

PURPOSE

Improving cardiopulmonary reserve, or peak oxygen consumption( V ˙ O_2peak ), may reduce postoperative complications, however this may be difficult to achieve between diagnosis and surgery. Our primary aim was to assess the efficacy of an approximate 14-session, preoperative High Intensity Interval Training(HIIT) program to increase V ˙ O_2peak by a clinically-relevant 2 mL·kg^-1 ·min^-1 . Our secondary aim was to document clinical outcomes.

METHODOLOGY

In this prospective study, participants aged 45-85 undergoing major abdominal surgery were randomised to standard care or 14 sessions of HIIT over 4 weeks. HIIT sessions involved approximately thirty minutes of stationary cycling. Interval training alternated one minute of high (with the goal of reaching 90% max heart rate at least once during the session) and low/moderate intensity cycling. Cardiopulmonary exercise testing(CPET) measured the change in V ˙ O_2peak from baseline to surgery. Clinical outcomes included postoperative complications, length of stay(LOS) and Short Form-36 quality of life questionnaire(SF-36).

RESULTS

Of 63 participants, 46 completed both CPETs and 50 completed clinical follow-up. There was a significant improvement in the HIIT group's mean ± SD V ˙ O_2peak (HIIT 2.87 ± 1.94 mL·kg¹ ·min^-1 vs standard care 0.15 ± 1.93, with an overall difference of 2.73 mL·kg¹ ·min^-1 95%CI [1.53, 3.93] p<0.001). There were no statistically significant differences between groups for clinical outcomes, although the observed differences consistently favoured the exercise group. This was most notable for total number of complications (0.64 v 1.16 per patient, p=0.07), SF-36 physical component score (p=0.06), and LOS (mean 5.5 v 7.4 days, p=0.07).

CONCLUSIONS

There was a significant improvement in V ˙ O_2peak with a four-week preoperative HIIT program. Further appropriately-powered work is required to explore the impact of preoperative HIIT on postoperative clinical outcomes.

Human liver-derived MAIT cells differ from blood MAIT cells in their metabolism and response to TCR-independent activation

Mucosal associated invariant T (MAIT) cells are anti-microbial innate-like T cells that are abundant in blood and liver. MAIT cells express a semi-invariant T-cell receptor (TCR) that recognizes a pyrimidine ligand, derived from microbial riboflavin synthesis, bound to MR1. Both blood and liver derived (ld)-MAIT cells can be robustly stimulated via TCR or by cytokines produced during bacterial or viral infection. In this study, we compared the functional and transcriptomic response of human blood and ld-MAIT cells to TCR signals (Escherichia coli or the pyrimidine ligand) and cytokines (IL-12 + IL-18). While the response of blood and ld-MAIT cells to TCR signals were comparable, following cytokine stimulation ld-MAIT cells were more polyfunctional than blood MAIT cells. Transcriptomic analysis demonstrated different effector programmes of ld-MAIT cells with the two modes of activation, including the enrichment of a tissue repair signature in TCR-stimulated MAIT cells. Interestingly, we observed enhancement of IL-12 signaling and fatty acid metabolism in untreated ld-MAIT cells compared with blood MAIT cells. Additionally, MAIT cells from blood and liver were modulated similarly by TCR and cytokine signals. Therefore, we report that blood and ld-MAIT cells are fundamentally different but undergo conserved changes following activation via TCR or by cytokines.

Type I interferons are important co-stimulatory signals during T cell receptor mediated human MAIT cell activation

Mucosal associated invariant T (MAIT) cells are abundant unconventional T cells that can be stimulated either via their TCR or by innate cytokines. The MAIT cell TCR recognises a pyrimidine ligand, derived from riboflavin synthesising bacteria, bound to MR1. In infection, bacteria not only provide the pyrimidine ligand but also co-stimulatory signals, such as TLR agonists, that can modulate TCR-mediated activation. Recently, type I interferons (T1-IFNs) have been identified as contributing to cytokine-mediated MAIT cell activation. However, it is unknown whether T1-IFNs also have a role during TCR-mediated MAIT cell activation. In this study, we investigated the co-stimulatory role of T1-IFNs during TCR-mediated activation of MAIT cells by the MR1 ligand 5-amino-6-d-ribitylaminouracil/methylglyoxal. We found that T1-IFNs were able to boost interferon-γ and granzyme B production in 5-amino-6-d-ribitylaminouracil/methylglyoxal-stimulated MAIT cells. Similarly, influenza virus-induced T1-IFNs enhanced TCR-mediated MAIT cell activation. An essential role of T1-IFNs in regulating MAIT cell activation by riboflavin synthesising bacteria was also demonstrated. The co-stimulatory role of T1-IFNs was also evident in liver-derived MAIT cells. T1-IFNs acted directly on MAIT cells to enhance their response to TCR stimulation. Overall, our findings establish an important immunomodulatory role of T1-IFNs during TCR-mediated MAIT cell activation.

Protocol, and practical challenges, for a randomised controlled trial comparing the impact of high intensity interval training against standard care before major abdominal surgery: study protocol for a randomised controlled trial

BACKGROUND

Risk factors, such as the number of pre-existing co-morbidities, the extent of the underlying pathology and the magnitude of the required operation, cannot be changed before surgery. It may, however, be possible to improve the cardiopulmonary fitness of the patient with an individualised exercise program. We are performing a randomised controlled trial (RCT) assessing the impact of High Intensity Interval Training (HIIT) on preoperative cardiopulmonary fitness and postoperative outcomes in patients undergoing major abdominal surgery.

METHODS

Consecutive eligible patients undergoing elective abdominal surgery are being randomised to HIIT or standard care in a 1:1 ratio. Participants allocated to HIIT will perform 14 exercise sessions on a stationary cycle ergometer, over a period of 4-6 weeks before surgery. The sessions, which are individualised, aim to start with ten repeated 1-min blocks of intense exercise with a target of reaching a heart rate exceeding 90% of the age predicted maximum, followed by 1 min of lower intensity cycling. As endurance improves, the duration of exercise is increased to achieve five 2-min intervals of high intensity exercise followed by 2 min of lower intensity cycling. Each training session lasts approximately 30 min. The primary endpoint, change in peak oxygen consumption (Peak VO2) measured during cardiopulmonary exercise testing, is assessed at baseline and before surgery. Secondary endpoints include postoperative complications, length of hospital stay and three clinically validated scores: the surgical recovery scale; the postoperative morbidity survey; and the SF-36 quality of life score. The standard deviation for changes in Peak VO2 will be assessed after the first 30 patients and will be used to calculate the required sample size.

DISCUSSION

We want to assess if 14 sessions of HIIT is sufficient to improve Peak VO2 by 2 mL/kg/min in patients undergoing major abdominal surgery and to explore the best clinical endpoint for a subsequent RCT designed to assess if improving Peak VO2 will translate into improving clinical outcomes after surgery.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12617000587303 . Registered on 26 April 2017.

Limits to sustained energy intake XXIV: impact of suckling behaviour on the body temperatures of lactating female mice

The objective of this study was to investigate the potential causes of high body temperature (Tb) during lactation in mice as a putative limit on energy intake. In particular we explored whether or not offspring contributed to heat retention in mothers while suckling. Tb and physical activity were monitored in 26 female MF1 mice using intraperitoneally implanted transmitters. In addition, maternal behaviour was scored each minute for 8 h d(-1) throughout lactation. Mothers that raised larger litters tended to have higher Tb while nursing inside nests (P < 0.05), suggesting that nursing offspring may have influenced heat retention. However, Tb during nursing was not higher than that recorded during other behaviours. In addition, the highest Tb during the observation period was not measured during nursing behaviour. Finally, there was no indication that mothers discontinued suckling because of a progressive rise in their Tb while suckling. Tb throughout lactation was correlated with daily increases in energy intake. Chronic hyperthermia during lactation was not caused by increased heat retention due to surrounding offspring. Other factors, like metabolic heat produced as a by-product of milk production or energy intake may be more important factors. Heat dissipation limits are probably not a phenomenon restricted to lactation.

Colorectal tumour associated macrophages are more pro-inflammatory than adjacent control bowel tissue macrophage populations (TUM6P.1003)

Infiltration of macrophages in colorectal cancer is associated with patient prognosis. Using multiparameter flow cytometry, multiple distinct macrophage populations were detected in tumour tissue recovered from colorectal cancer patients, highlighting the heterogeneity of myeloid populations within complex tissues. Population frequencies of five key macrophage populations were assessed in tumour and matched non-transformed bowel tissue to reveal specific changes caused by the direct presence of the tumour. The frequency of conventional (pro-inflammatory) macrophages (CD45+CD11b+CD33-CD64+CD14-CD206+CD163-) was significantly increased in tumour tissue compared to healthy bowel tissue. This population was analogous to pro-inflammatory IL-12-producing macrophages derived in vitro from blood. A large population of gut resident macrophages was also observed in both tumour and control bowel tissue. “Homeostatic” gut resident macrophages (CD45+CD33+CD14-CD11b-CD64-) and “inflammatory” gut resident macrophages (CD45+CD33+CD14+CD11b+CD64+) were decreased and increased, respectively, in tumour tissue compared with healthy bowel tissue of the same patients. This suggests that macrophages provide a pro-inflammatory environment within the tumour tissue and may explain why these cells are often associated with improved patient outcome in colorectal cancer. Data gained from this study could be used for future investigation of macrophages as both prognostic and therapeutic targets.

Inflammatory and regulatory T cells contribute to a unique immune microenvironment in tumor tissue of colorectal cancer patients (P2145)

Colorectal cancer (CRC) is a leading causes of cancer mortality. T cells play a crucial role in the elimination of cancer. Despite their importance little in known about the composition of the T cell subsets in CRC and how the cancer cells can affect these subsets. Using a novel analytical flow cytometric approach, we have analysed T cell subsets in CRC tumor tissue and matched non-transformed bowel tissue. We discovered that the tumor has a lower frequency of effector T cells, but a higher frequency of both regulatory and inflammatory T cells, compared with associated non-transformed bowel tissue. To study the functional interactions of these cell subsets, methods have been established to isolate live, unmanipulated T cell subsets from tumor tissue and non-transformed bowel tissue. Effector T cells (IFNγ +), regulatory T cells (CD25hi, FoxP3+) and inflammatory T cells (IL-17+) have been isolated from CRC tumor tissue or non-transformed bowel tissue. Ex vivo studies have shown that effector T cells from the tumor tissue proliferate less, and are unable to produce IL-2 upon stimulation, than effector T cells from non-transformed bowel tissue. In addition, regulatory T cells isolated from non-transformed bowel tissue actively inhibit proliferation of T cells from the same tissue. These data describe an immune microenvironment in colorectal cancer unique, in both phenotype and function, to the tumor tissue and distinct from the surrounding non-transformed bowel tissue.

Regionally acquired intestinal failure data suggest an underestimate in national service requirements

OBJECTIVES, SETTING AND PATIENTS: With complete case referral for prolonged parenteral nutrition (PN) beyond term equivalent, serving a stable population of 1.25 million people, we describe the long-term outcome and survival of patients referred to an intestinal failure (IF) nutrition support team over the first 8 years of existence at a regional paediatric centre, and extrapolate to potential numbers of national home parenteral nutrition (HPN) cases and intestinal transplantation data.

DESIGN AND OUTCOME MEASURES

Retrospective analysis detailing patient demographics, interventions, use of HPN, occurrence of intestinal failure-associated liver disease (IFALD), and outcomes of enteral adaptation, survival, and referral for and receipt of organ transplantation.

RESULTS

23 patients were referred over 8 years, 20 being PN dependent within the neonatal period. Diagnoses included short bowel syndrome (SBS) (18), neuromuscular abnormalities (4) and congenital enterocyte disorder (1). 12 696 days of PN were delivered with 314 confirmed episodes of sepsis at a median of 12 episodes per patient. 144 central venous catheters (CVCs) were required at a median of four per patient. IFALD occurred in 17 (73%) patients, with 10 (44%) referred for transplant assessment. Thirteen (56%) children received HPN. Overall mortality was 44%. A significant predictor for survival in the SBS group was residual bowel >40 cm (82% vs 28%, p = 0.049).

CONCLUSIONS

Survival for IF at 56% was lower than reported from non-UK supra-regional centres, and nationally collected data, possibly reflecting pre-selected referral populations. Data from regional centres with complete ascertainment may be important both when counselling parents and when planning regional and national HPN and IF specialist services.

Analyses of livestock production, waste storage, and pathogen levels and prevalences in farm manures

Survey results describing the levels and prevalences of zoonotic agents in 1,549 livestock waste samples were analyzed for significance with livestock husbandry and farm waste management practices. Statistical analyses of survey data showed that livestock groups containing calves of <3 months of age, piglets, or lambs had higher prevalences and levels of Campylobacter spp. and Escherichia coli O157 in their wastes. Younger calves that were still receiving milk, however, had significantly lower levels and prevalence of E. coli O157. Furthermore, when wastes contained any form of bedding, they had lowered prevalences and levels of both pathogenic Listeria spp. and Campylobacter spp. Livestock wastes generated by stock consuming a diet composed principally of grass were less likely to harbor E. coli O157 or Salmonella spp. Stocking density did not appear to influence either the levels or prevalences of bacterial pathogens. Significant seasonal differences in prevalences were detected in cattle wastes; Listeria spp. were more likely to be isolated in March to June, and E. coli O157 was more likely to be found in May and June. Factors such as livestock diet and age also had significant influence on the levels and prevalences of some zoonotic agents in livestock wastes. A number of the correlations identified could be used as the basis of a best-practice disposal document for farmers, thereby lowering the microbiological risks associated with applying manures of contaminated livestock to land.

A critical role for the parabrachial nucleus in generating central nervous system responses elicited by a systemic immune challenge

Using Fos immunolabelling as a marker of neuronal activation, we investigated the role of the parabrachial nucleus in generating central neuronal responses to the systemic administration of the proinflammatory cytokine interleukin-1beta (1 microg/kg, i.a.). Relative to intact animals, parabrachial nucleus lesions significantly reduced the number of Fos-positive cells observed in the central amygdala (CeA), the bed nucleus of the stria terminalis (BNST), and the ventrolateral medulla (VLM) after systemic interleukin-1beta. In a subsequent experiment in which animals received parabrachial-directed deposits of a retrograde tracer, it was found that many neurons located in the nucleus tractus solitarius (NTS) and the VLM neurons were both retrogradely labelled and Fos-positive after interleukin-1beta administration. These results suggest that the parabrachial nucleus plays a critical role in interleukin-1beta-induced Fos expression in CeA, BNST and VLM neurons and that neurons of the NTS and VLM may serve to trigger or at least influence changes in parabrachial nucleus activity that follows systemic interleukin-1beta administration.

Treatment of perianal abscess and fistula-in-ano in children

Drain, don't probe

Prenatal diagnosis and management of urethral obstruction

Eighteen cases of bladder outlet obstruction were diagnosed at Queen Mother's Hospital, Glasgow, over a period of 6 years. Commonest cause was posterior urethral valve in 11 cases (61%). Oligohydramnios was present in 78% of cases with a mortality of 67% mainly due to pulmonary hypoplasia. The 6 surviving infants (33%) underwent early postnatal surgery. Two of these have chronic renal failure on follow-up.

Thrombolysis with low dose tissue plasminogen activator

Two cases of vena caval thrombosis in infants were successfully treated with low dose (0.01-0.05 mg/kg/hour) local infusions of tissue plasminogen activator after conventional anticoagulant treatment had been unsuccessful. This approach is useful for clots associated with indwelling intravascular catheters, and a low dose infusion of tissue plasminogen activator as a regional application is recommended to achieve clot lysis with minimal systemic effects.

Acute pancreatitis: a fatal complication of treatment of bullous pemphigoid with systemic corticosteroids

Acute pancreatitis may be a rare complication of systemic corticosteroids, although this is disputed. We describe a patient with bullous pemphigoid whose treatment was complicated by fatal acute pancreatitis. The question of a cause and effect relationship is discussed with reference to the literature. We emphasise the way that corticosteroids modified the presentation of acute pancreatitis in this case.