EP-368 Intraoperative identification of colorectal cancer lesions using indocyanine green labelled antibodies in preclinical murine models

Aims

The ability to identify cancerous tissue intraoperatively has the potential to allow for real time identification of involved margins, lymph node involvement and extra-colonic deposits. Here we investigate whether antibodies targeting a novel receptor, anonymously referred to as LN1, a frequently over expressed protein in colorectal cancer (CRC), labelled with indocyanine green (ICG) can be used for the intraoperative detection of malignant tissue in preclinical models.

Methods

Representative metastatic CRC models were generated in 20 NSG mice using HCT116 human CRC cells. Mice were treated with either intravenous ICG labelled LN1 antibodies (LN1-ICG) or control treatments (untreated, free ICG or cotreatment unlabelled LN1 blocking antibody + LN1-ICG). Signal intensity of normal and malignant tissue was quantified from near infrared (NIR) endoscopy and IVIS® in-vivo imaging system.

Results

LN1-ICG labelled antibodies was highly effective in identifying cancerous lesions down to 500nm diameter. Quantification of NIR and IVIS images demonstrate significantly greater tumour signal in the LN1-ICG group versus controls (p=0.004 and p=0.001 respectively). Examination of normal organ tissues demonstrated signal in the liver and digestive tract in keeping with hepatobiliary clearance of ICG but nil further off-site accumulation of LN1-ICG. No difference in signal from the liver, small bowel or colon was noted between groups (p>0.05).

Conclusion

LN1-ICG labelled antibodies were highly effective at identifying even small cancerous deposits in murine models. It is highly likely that these effects could be replicated in human procedures which may allow for perioperative identification of extra-colonic deposits, involved tumour margins or lymph node involvement.

Foreign body reaction to spilled gastric contents mimicking peritoneal metastasis of colorectal cancer

Colorectal cancer represents the third most common cancer worldwide. The presence of peritoneal metastasis of colorectal cancer indicates Stage 4 disease with poor prognosis. We report a case of a foreign body reaction to plant material spilled during previous surgery, which mimicked peritoneal metastases. A 62-year-old male was found to have recto-sigmoid adenocarcinoma on colonoscopy. At the time of resection, peritoneal nodules were identified throughout the peritoneal cavity with the appearance of metastases. The resection was aborted, a diverting colostomy was fashioned and biopsies of the nodules were taken. The histology showed a foreign body reaction to plant material that was spilled during a sleeve gastrectomy that was performed 4 years prior. The patient subsequently underwent anterior resection with anastomosis and has recovered from surgery.

Acute presentation of multi-cystic peritoneal mesothelioma

Multi-cystic peritoneal mesothelioma (MCPM) is a rare intra-abdominal neoplasm that occurs most commonly in young females. The disease usually presents as an incidental finding or with sub-acute abdominal pain. The mainstay of treatment is complete excision; however, local recurrence frequently occurs and malignant transformation has been reported. We describe a unique case of MCPM that presented with acute abdominal pain.

A 32-year-old female presented with a 24-hour history of abdominal pain. Computed tomography abdomen demonstrated a low-density mass with surrounding inflammatory changes anterior to the ascending colon, which was initially thought to represent an abscess. A percutaneous drain was inserted; however, only clear fluid was aspirated and the lesion did not resolve. The patient subsequently underwent laparoscopy which identified a cystic structure overlying the ascending colon. The structure was excised whole with histology demonstrating MCPM. The patient recovered from surgery and will undergo a period of surveillance.

A case report of ductal carcinoma of the breast metastasizing to the bowel

Breast cancer is one of the most common cancers affecting women. Frequent metastatic sites include liver, lungs and bone. Gastrointestinal metastases are a rare entity. We report a case of ductal carcinoma metastasizing to the sigmoid colon.

A 74-year female was found to have a mass at her sigmoid colon on surveillance colonoscopy. The initial histology showed poorly differentiated carcinoma. Further immunohistochemical staining revealed poorly differentiated metastatic ductal breast carcinoma 27 years after her primary breast cancer. She proceeded to resection and had an uneventful recovery. She remains alive with stable retroperitoneal lymph node and tail of pancreas metastatic disease.

Perforated Meckel's diverticulitis secondary to a corn kernel obstruction of lumen in an elderly patient

Meckel’s diverticulum (MD) is the most common congenital malformation of the gastrointestinal tract. The most frequent complications are bleeding, intestinal obstruction, intussusception and neoplasm. Perforation because of diverticulitis is very rare and usually associated to foreign bodies. We report a case of an elderly man who presented with right iliac fossa pain, raised inflammatory markers and a computer tomography (CT) scan suggestive of Meckel’s diverticulitis. He underwent a laparoscopic converted to open small bowel resection and primary anastomosis for perforated MD, which revealed a corn kernel at its base in the absence of ectopic gastric or pancreatic tissue. Symptomatic and perforated MD secondary to a phytobezoar is extremely rare in elderly patients, hence the importance of clinical suspicion in patients with abdominal pain, independent from their age, to avoid delay in diagnosis, which can lead to increased morbidity and mortality in this demographic.

CT diagnosis of ilioinguinal lymph node metastases in melanoma using radiological characteristics beyond size and asymmetry

Background

Diagnosis of lymph node (LN) metastasis in melanoma with non-invasive methods is challenging. The aim of this study was to evaluate the diagnostic accuracy of six LN characteristics on CT in detecting melanoma-positive ilioinguinal LN metastases, and to determine whether inguinal LN characteristics can predict pelvic LN involvement.

Methods

This was a single-centre retrospective study of patients with melanoma LN metastases at a tertiary cancer centre between 2008 and 2016. Patients who had preoperative contrast-enhanced CT assessment and ilioinguinal LN dissection were included. CT scans containing significant artefacts obscuring the pelvis were excluded. CT scans were reanalysed for six LN characteristics (extracapsular spread (ECS), minimum axis (MA), absence of fatty hilum (FH), asymmetrical cortical nodule (CAN), abnormal contrast enhancement (ACE) and rounded morphology (RM)) and compared with postoperative histopathological findings.

Results

A total of 90 patients were included. Median age was 58 (range 23–85) years. Eighty-eight patients (98 per cent) had pathology-positive inguinal disease and, of these, 45 (51 per cent) had concurrent pelvic disease. The most common CT characteristics found in pathology-positive inguinal LNs were MA greater than 10 mm (97 per cent), ACE (80 per cent), ECS (38 per cent) and absence of RM (38 per cent). In multivariable analysis, inguinal LN characteristics on CT indicative of pelvic disease were RM (odds ratio (OR) 3.3, 95 per cent c.i. 1.2 to 8.7) and ECS (OR 4.2, 1.6 to 11.3). Cloquet’s node is known to be a poor predictor of pelvic spread. Pelvic LN disease was present in 50 per cent patients, but only 7 per cent had a pathology-positive Cloquet’s node.

Conclusion

Additional CT radiological characteristics, especially ECS and RM, may improve diagnostic accuracy and aid clinical decisions regarding the need for inguinal or ilioinguinal dissection.

Preexisting and de novo humoral immunity to SARS-CoV-2 in humans

Zoonotic introduction of novel coronaviruses may encounter preexisting immunity in humans. Using diverse assays for antibodies recognizing SARS-CoV-2 proteins, we detected preexisting humoral immunity. SARS-CoV-2 spike glycoprotein (S)-reactive antibodies were detectable using a flow cytometry-based method in SARS-CoV-2-uninfected individuals and were particularly prevalent in children and adolescents. They were predominantly of the immunoglobulin G (IgG) class and targeted the S2 subunit. By contrast, SARS-CoV-2 infection induced higher titers of SARS-CoV-2 S-reactive IgG antibodies targeting both the S1 and S2 subunits, and concomitant IgM and IgA antibodies, lasting throughout the observation period. SARS-CoV-2-uninfected donor sera exhibited specific neutralizing activity against SARS-CoV-2 and SARS-CoV-2 S pseudotypes. Distinguishing preexisting and de novo immunity will be critical for our understanding of susceptibility to and the natural course of SARS-CoV-2 infection.

Preexisting and de novo humoral immunity to SARS-CoV-2 in humans

Zoonotic introduction of novel coronaviruses may encounter preexisting immunity in humans. Using diverse assays for antibodies recognizing SARS-CoV-2 proteins, we detected preexisting humoral immunity. SARS-CoV-2 spike glycoprotein (S)-reactive antibodies were detectable using a flow cytometry-based method in SARS-CoV-2-uninfected individuals and were particularly prevalent in children and adolescents. They were predominantly of the immunoglobulin G (IgG) class and targeted the S2 subunit. By contrast, SARS-CoV-2 infection induced higher titers of SARS-CoV-2 S-reactive IgG antibodies targeting both the S1 and S2 subunits, and concomitant IgM and IgA antibodies, lasting throughout the observation period. SARS-CoV-2-uninfected donor sera exhibited specific neutralizing activity against SARS-CoV-2 and SARS-CoV-2 S pseudotypes. Distinguishing preexisting and de novo immunity will be critical for our understanding of susceptibility to and the natural course of SARS-CoV-2 infection.

Adapting to the Coronavirus Pandemic: Building and Incorporating a Diagnostic Pipeline in a Shared Resource Laboratory

In March 2020, with lockdown due to the coronavirus pandemic underway, the Francis Crick Institute (the Crick) regeared its research laboratories into clinical testing facilities. Two pipelines were established, one for polymerase chain reaction and the other for Serology. This article discusses the Cricks Flow Cytometry Science Technology Platform (Flow STP) role in setting up the Serology pipeline. Pipeline here referring to the overarching processes in place to facilitate the receipt of human sera through to a SARs‐CoV‐2 enzyme‐linked immunosorbent assay result. We examine the challenges that had to be overcome by a research laboratory to incorporate clinical diagnostics and the processes by which this was achieved. It describes the governance required to run the service, the design of the standard operating procedures (SOPs) and pipeline, the setting up of the assay, the validation required to show the robustness of the pipeline and reporting the results of the assay. Finally, as the lockdown started to ease in June 2020, it examines how this new service affects the daily running of the Flow STP. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals LLC on behalf of International Society for Advancement of Cytometry.

Drain fluid amylase as a sensitive biomarker for the early detection of anastomotic leakage in ileal pouch surgery

AIM

We studied the levels of amylase in drain fluid to investigate its utility as a biomarker of anastomotic leak in ileal pouch patients who did not have a covering loop ileostomy. The luminal contents of the small intestine are high in amylase. Ileal J pouches are formed for restoration of continuity in patients with ulcerative colitis after removal of the colon and rectum. A drain is placed alongside the ileal pouch in the pelvis.

METHOD

This study is a retrospective analysis of prospectively collected daily drain fluid amylase levels in consecutive patients undergoing restorative proctectomy and ileal J pouch anal anastomosis, without a covering loop ileostomy, between November 2016 and April 2018.

RESULTS

Thirteen patients underwent surgery without a covering loop ileostomy. Two patients suffered an anastomotic leak and were returned to theatre, one on day 5 and the other on day 6 postoperatively. The mean daily drain fluid amylase level in those who did not leak was between 25 and 46 U/l with a range of 22-139 U/l for all samples collected. In the two patients who suffered a clinical leak the drain fluid amylase level rose to 22 432 and 10 212 U/l on the day of clinical leak diagnosis. The mean rectal tube (intraluminal) amylase level was 63 097 U/l as measured on day 1 postoperatively.

CONCLUSION

In this small cohort of patients, the measurement of drain fluid amylase is a highly sensitive biomarker of clinical anastomotic leak.

Treatment of bleeding episodes in haemophilia A complicated by a factor VIII inhibitor in patients receiving Emicizumab. Interim guidance from UKHCDO Inhibitor Working Party and Executive Committee

Emicizumab is a bispecific antibody that activates FX to FXa in the absence of FVIII. It has been shown to reduce bleeding episodes in people with haemophilia A complicated by a FVIII inhibitor. Despite the protection against bleeds, some breakthrough bleeds are inevitable and these may require additional haemostatic treatment. Emicizumab has been associated with severe adverse events when co-administered with activated prothrombin complex concentrate. To minimize the risk of adverse events, the UK Haemophilia Centre Doctors' Organisation issues the following updated interim guidance to its Inhibitor Guidelines for managing patients receiving Emicizumab based on the limit published information available in February 2018.

Urinary incontinence in male dogs under primary veterinary care in England: prevalence and risk factors

OBJECTIVE

To estimate prevalence and identify demographic risk factors for urinary incontinence in male dogs.

METHODS AND METHODS

The study population included all dogs within the VetCompass database from September 1, 2009 to July 7, 2013. Electronic patient records were searched for urinary incontinence cases; demographic and clinical information were extracted and analysed.

RESULTS

Of 109,428 male dogs attending 119 clinics in England, there were an estimated 1027 dogs diagnosed with urinary incontinence, giving a prevalence of 0.94% (95% confidence interval: 0.88 to 1.00). Breeds with highest odds of incontinence in male dogs (compared with mixed breed dogs) included the bull mastiff (odds ratio: 17.21, 95% confidence interval: 6.65 to 44.56, case=5, non-case=314, P<0.001), Irish red setter (odds ratio: 12.79, 95% confidence interval: 4.83 to 33.84, case=5, non-case=142, P<0.001), fox terrier (odds ratio: 9.60, 95% confidence interval: 3.68 to 25.05, case=5, non-case=176, P < 0.001), bulldog (odds ratio: 5.72, 95% confidence interval: 2.24 to 14.59, case=5, non-case=929, P<0.001) and boxer (odds ratio: 3.65, 95% confidence interval: 1.84 to 7.25, case=10, non-case=1470, P<0.001). Increased odds of urinary incontinence were associated with greater age (age 9 to 12 years, odds ratio: 10.46, 95% confidence interval: 6.59 to 16.62, n=12,348, P<0.001) and being insured (odds ratio: 1.96, 95% confidence interval: 1.53 to 2.51, n=26,202, P<0.001). There was no association with castration or bodyweight using multi-variable analysis.

CLINICAL SIGNIFICANCE

The overall prevalence of urinary incontinence in male dogs is approximately 1%, which may be higher than expected given the sparsity of reports describing this problem. In contrast to bitches, neutering and bodyweight were not associated with greater odds of urinary incontinence, which is important when giving neutering advice.

International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain, and for thromboplastin, recombinant, human, plain

Essentials Two candidate International Standards for thromboplastin (coded RBT/16 and rTF/16) are proposed. International Sensitivity Index (ISI) of proposed standards was assessed in a 20-centre study. The mean ISI for RBT/16 was 1.21 with a between-centre coefficient of variation of 4.6%. The mean ISI for rTF/16 was 1.11 with a between-centre coefficient of variation of 5.7%.

SUMMARY

Background The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current Fourth International Standards are running low. Candidate replacement materials have been prepared. This article describes the calibration of the proposed Fifth International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). Methods An international collaborative study was carried out for the assignment of International Sensitivity Indexes (ISIs) to the candidate materials, according to the World Health Organization (WHO) guidelines for thromboplastins and plasma used to control oral anticoagulant therapy with vitamin K antagonists. Results Results were obtained from 20 laboratories. In several cases, deviations from the ISI calibration model were observed, but the average INR deviation attributabled to the model was not greater than 10%. Only valid ISI assessments were used to calculate the mean ISI for each candidate. The mean ISI for RBT/16 was 1.21 (between-laboratory coefficient of variation [CV]: 4.6%), and the mean ISI for rTF/16 was 1.11 (between-laboratory CV: 5.7%). Conclusions The between-laboratory variation of the ISI for candidate material RBT/16 was similar to that of the Fourth International Standard (RBT/05), and the between-laboratory variation of the ISI for candidate material rTF/16 was slightly higher than that of the Fourth International Standard (rTF/09). The candidate materials have been accepted by WHO as the Fifth International Standards for thromboplastin, rabbit plain, and thromboplastin, recombinant, human, plain.

Diagnostic laboratory for bleeding disorders ensures efficient management of haemorrhagic disorders

Haemorrhagic disorders like Postpartum haemorrhage and Dengue haemorrhagic fever are life threatening and requires an active and efficient transfusion service that could provide the most appropriate blood product which could be effective in managing them. This would essentially require prompt identification of the coagulopathy so that the best available product can be given to the bleeding patient to correct the identified haemostatic defect which will help control the bleeding. This would only be possible if the transfusion service has a laboratory to correctly detect the haemostatic defect and that too with an accuracy and precision which is ensured by a good laboratory quality assurance practices. These same processes are necessary for the transfusion services to ensure the quality of the blood products manufactured by them and that it contains adequate amounts of haemostasis factors which will be good to be effective in the management of haemorrhagic disorders. These issues are discussed in detail individually in the management of postpartum haemorrhage and Dengue haemorrhagic fever including when these can help in the use of rFVIIa in Dengue haemorrhagic fever. The requirements to ensure good-quality blood products are made available for the management of these disorders and the same have also been described.

Management of paediatric tuberculosis in leading UK centres: unveiling consensus and discrepancies

SETTING

Large specialist paediatric TB clinics in the UK.

OBJECTIVE

To evaluate clinical practice and compare with national and international guidelines.

DESIGN

A survey based on an electronic questionnaire on the management of latent tuberculous infection (LTBI) and tuberculosis (TB) disease was conducted in 13 specialist paediatric TB clinics. The consensus and discrepancies were evaluated by descriptive analysis.

RESULTS

Practice was reportedly different when choosing age limits for preventive treatment for TB contacts with initially negative tuberculin skin tests (TSTs), interpretation of TST results and use of interferon-gamma release assays (IGRAs) in the context of LTBI. In relation to management of children with TB disease, practices varied for duration of treatment of osteoarticular TB, monitoring for ethambutol ocular toxicity and use of pyridoxine. There was limited experience with multidrug-resistant TB (MDR-TB), and over half of the clinics monitored MDR-TB contacts without giving preventive treatment.

CONCLUSIONS

The survey showed heterogeneity in several aspects of clinical care for children with TB. Available paediatric TB guidelines differ substantially, explaining the wide variations in management of childhood TB. Prospective paediatric studies are urgently required to inform and standardise clinical practice, especially in the context of evolving drug resistance.

Alterations in coagulation following major liver resection

The international normalised ratio is frequently raised in patients who have undergone major liver resection, and is assumed to represent a potential bleeding risk. However, these patients have an increased risk of venous thromboembolic events, despite conventional coagulation tests indicating hypocoagulability. This prospective, observational study of patients undergoing major hepatic resection analysed the serial changes in coagulation in the early postoperative period. Thrombin generation parameters and viscoelastic tests of coagulation (thromboelastometry) remained within normal ranges throughout the study period. Levels of the procoagulant factors II, V, VII and X initially fell, but V and X returned to or exceeded normal range by postoperative day five. Levels of factor VIII and Von Willebrand factor were significantly elevated from postoperative day one (p < 0.01). Levels of the anticoagulants, protein C and antithrombin remained significantly depressed on postoperative day five (p = 0.01). Overall, the imbalance between pro- and anticoagulant factors suggested a prothrombotic environment in the early postoperative period.

Selection and dynamics of embryonic stem cell integration into early mouse embryos

The process by which pluripotent cells incorporate into host embryos is of interest to investigate cell potency and cell fate decisions. Previous studies suggest that only a minority of the embryonic stem cell (ESC) inoculum contributes to the adult chimaera. How incoming cells are chosen for integration or elimination remains unclear. By comparing a heterogeneous mix of undifferentiated and differentiating ESCs (serum/LIF) with more homogeneous undifferentiated culture (2i/LIF), we examine the role of cellular heterogeneity in this process. Time-lapse ex vivo imaging revealed a drastic elimination of serum/LIF ESCs during early development in comparison with 2i/LIF ESCs. Using a fluorescent reporter for naive pluripotency (Rex1-GFP), we established that the acutely eliminated serum/LIF ESCs had started to differentiate. The rejected cells were apparently killed by apoptosis. We conclude that a selection process exists by which unwanted differentiating cells are eliminated from the embryo. However, occasional Rex1(-) cells were able to integrate. Upregulation of Rex1 occurred in a proportion of these cells, reflecting the potential of the embryonic environment to expedite diversion from differentiation priming to enhance the developing embryonic epiblast.

Rmax: A systematic approach to evaluate instrument sort performance using center stream catch

Sorting performance can be evaluated with regard to Purity, Yield and/or Recovery of the sorted fraction. Purity is a check on the quality of the sample and the sort decisions made by the instrument. Recovery and Yield definitions vary with some authors regarding both as how efficient the instrument is at sorting the target particles from the original sample, others distinguishing Recovery from Yield, where the former is used to describe the accuracy of the instrument's sort count. Yield and Recovery are often neglected, mostly due to difficulties in their measurement. Purity of the sort product is often cited alone but is not sufficient to evaluate sorting performance. All of these three performance metrics require re-sampling of the sorted fraction. But, unlike Purity, calculating Yield and/or Recovery calls for the absolute counting of particles in the sorted fraction, which may not be feasible, particularly when dealing with rare populations and precious samples. In addition, the counting process itself involves large errors. Here we describe a new metric for evaluating instrument sort Recovery, defined as the number of particles sorted relative to the number of original particles to be sorted. This calculation requires only measuring the ratios of target and non-target populations in the original pre-sort sample and in the waste stream or center stream catch (CSC), avoiding re-sampling the sorted fraction and absolute counting. We called this new metric Rmax, since it corresponds to the maximum expected Recovery for a particular set of instrument parameters. Rmax is ideal to evaluate and troubleshoot the optimum drop-charge delay of the sorter, or any instrument related failures that will affect sort performance. It can be used as a daily quality control check but can be particularly useful to assess instrument performance before single-cell sorting experiments. Because we do not perturb the sort fraction we can calculate Rmax during the sort process, being especially valuable to check instrument performance during rare population sorts.

Proposed genitalia contouring guidelines in anal cancer intensity-modulated radiotherapy

OBJECTIVE

Intensity-modulated radiotherapy (IMRT) for anal canal carcinoma (ACC) is associated with favourable toxicity outcomes. Side effects include sexual dysfunction, skin desquamation, pain and fibrosis to perineum and genitalia region. The genitalia are situated anterior to the primary ACC between two inguinal regions providing a challenging structure to avoid. Techniques improving outcomes require robust, consistent genitalia contouring to ensure standardization and production of fully optimized IMRT plans. Official recommendations for genitalia contouring are lacking. We describe a potential genitalia contouring atlas for ACC radiotherapy.

METHODS

Following a review of genitalia CT anatomy, a contouring atlas was generated for male and female patients positioned prone and supine. Particular attention was paid to the reproducibility of the genitalia contour in all planes.

RESULTS

Male and female genitalia positioned prone and supine are described and represented visually through a contouring atlas. Contoured areas in males include penis and scrotum, and in females include clitoris, labia majora and minora. The muscles, bone, prostate, vagina, cervix and uterus should be excluded. The genitalia contour extends laterally to inguinal creases and includes areas of fat and skin anterior to the symphysis pubis for both genders.

CONCLUSION

This atlas provides descriptive and visual guidance enabling more consistent genitalia delineation for both genders when prone and supine. The atlas can be used for other sites requiring radiotherapy planning.

ADVANCES IN KNOWLEDGE

This atlas presents visual contouring guidance for genitalia in ACC radiotherapy for the first time. Contouring methods provide reproducible genitalia contours that allow the provision of accurate dose toxicity data in future studies.

Sequencing of a patient with balanced chromosome abnormalities and neurodevelopmental disease identifies disruption of multiple high risk loci by structural variation

Balanced chromosome abnormalities (BCAs) occur at a high frequency in healthy and diseased individuals, but cost-efficient strategies to identify BCAs and evaluate whether they contribute to a phenotype have not yet become widespread. Here we apply genome-wide mate-pair library sequencing to characterize structural variation in a patient with unclear neurodevelopmental disease (NDD) and complex de novo BCAs at the karyotype level. Nucleotide-level characterization of the clinically described BCA breakpoints revealed disruption of at least three NDD candidate genes (LINC00299, NUP205, PSMD14) that gave rise to abnormal mRNAs and could be assumed as disease-causing. However, unbiased genome-wide analysis of the sequencing data for cryptic structural variation was key to reveal an additional submicroscopic inversion that truncates the schizophrenia- and bipolar disorder-associated brain transcription factor ZNF804A as an equally likely NDD-driving gene. Deep sequencing of fluorescent-sorted wild-type and derivative chromosomes confirmed the clinically undetected BCA. Moreover, deep sequencing further validated a high accuracy of mate-pair library sequencing to detect structural variants larger than 10 kB, proposing that this approach is powerful for clinical-grade genome-wide structural variant detection. Our study supports previous evidence for a role of ZNF804A in NDD and highlights the need for a more comprehensive assessment of structural variation in karyotypically abnormal individuals and patients with neurocognitive disease to avoid diagnostic deception.

Topical steroids for chronic wounds displaying abnormal inflammation

INTRODUCTION

Chronic, non-healing wounds are often characterised by an excessive, and detrimental, inflammatory response. We review our experience of using a combined topical steroid, antibiotic and antifungal preparation in the treatment of chronic wounds displaying abnormal and excessive inflammation.

METHODS

A retrospective review was undertaken of all patients being treated with a topical preparation containing a steroid (clobetasone butyrate 0.05%), antibiotic and antifungal at a tertiary wound healing centre over a ten-year period. Patients were selected as the primary treating physician felt the wounds were displaying excessive inflammation. Healing rates were calculated for before and during this treatment period for each patient. Changes in symptom burden (pain, odour and exudate levels) following topical application were also calculated.

RESULTS

Overall, 34 ulcers were identified from 25 individual patients (mean age: 65 years, range: 37-97 years) and 331 clinic visits were analysed, spanning a total time of 14,670 days (7,721 days 'before treatment' time, 6,949 days 'during treatment' time). Following treatment, 24 ulcers demonstrated faster rates of healing, 3 ulcers showed no significant change in healing rates and 7 were healing more slowly (p=0.0006). Treatment generally reduced the burden of pain and exudate, without affecting odour.

CONCLUSIONS

In normal wound healing, inflammation represents a transient but essential phase of tissue repair. In selected cases, direct application of a steroid containing agent has been shown to improve healing rates, presumably by curtailing this phase. Further evaluation is required to establish the role of preparations containing topical steroids without antimicrobials in the management of chronic wounds.

Tissue-specific analysis of chromatin state identifies temporal signatures of enhancer activity during embryonic development

Chromatin modifications are associated with many aspects of gene expression, yet their role in cellular transitions during development remains elusive. Here, we use a new approach to obtain cell type-specific information on chromatin state and RNA polymerase II (Pol II) occupancy within the multicellular Drosophila melanogaster embryo. We directly assessed the relationship between chromatin modifications and the spatio-temporal activity of enhancers. Rather than having a unique chromatin state, active developmental enhancers show heterogeneous histone modifications and Pol II occupancy. Despite this complexity, combined chromatin signatures and Pol II presence are sufficient to predict enhancer activity de novo. Pol II recruitment is highly predictive of the timing of enhancer activity and seems dependent on the timing and location of transcription factor binding. Chromatin modifications typically demarcate large regulatory regions encompassing multiple enhancers, whereas local changes in nucleosome positioning and Pol II occupancy delineate single active enhancers. This cell type-specific view identifies dynamic enhancer usage, an essential step in deciphering developmental networks.

Changes in the levels of factor VIII and von Willebrand factor in the puerperium

To determine changes in Factor VIII (FVIII) and von Willebrand Factor (VWF) in the first 3 days of the puerperium. A prospective study assessing FVIII clotting activity, VWF activity and antigen levels in 95 women (with singleton uncomplicated pregnancies) during labour and on days 1, 2 and 3 of the puerperium. There were no significant differences in FVIII, VWF:Ag and VWF:CB on days 1 and 2 of the puerperium compared with levels during labour. There was a significant decrease in VWF:Ag (P = 0.009) and VWF:CB (P = 0.04) on day 3. Age, ethnicity, duration of labour and mode of delivery did not have any significant effect on the changes in FVIII and VWF levels. The pregnancy induced increase in FVIII and VWF is maintained in the first 48 h after delivery. VWF levels start to decline on day 3 postdelivery.

Segmental liver hyperintensity in malignant biliary obstruction on diffusion weighted MRI: associated MRI findings and relationship with serum alanine aminotransferase levels

OBJECTIVES

Segmental liver hyperintensity can be observed in malignant biliary obstruction on diffusion weighted MRI (DW-MRI). We describe MRI findings associated with this sign and evaluate whether DW-MRI segmental hyperintensity has any relationship with serum alanine aminotransferase (ALT) levels.

METHODS

The DW-MRI T(1) weighted, T(2) weighted and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced T(1) weighted images obtained in 21 patients with hepatic malignancy, who demonstrated biliary obstruction and segmental hyperintensity on DW-MRI (b=0-750 s mm(-2)), were retrospectively reviewed by 2 readers blinded to clinical results. DW-MRI hyperintense liver segments were recorded as hypointense, isointense or hyperintense relative to normal liver on T(1)/T(2) weighted imaging. It was also noted whether contrast enhancement was similar to that observed in normal liver or diminished in the hepatocellular phase. The mean apparent diffusion coefficient (ADC) value (×10(-3) s mm(-2)) of DW-MRI hyperintense segments, normal liver and tumour were compared using Student's t-test. The frequency of MRI findings was corroborated with serum ALT levels, which reflect hepatocyte injury.

RESULTS

DW-MRI hyperintense segments frequently showed T(1) hyperintensity (10/21), T(2) hyperintensity (19/21) and/or diminished contrast enhancement (15/21). Tumours showed significantly lower mean ADC values than liver (1.23 ± 0.08 vs 1.43 ± 0.05; p=0.013). Segments showing concomitant T(1) hyperintensity had lower mean ADC values than liver (1.30 ± 0.05 vs 1.43 ± 0.05; p=0.023). The patients (8/10) with concomitant T(1) and DW-MRI segmental hyperintensity showed elevated ALT levels (p=0.030, Fisher's exact test).

CONCLUSION

Concomitantly high T(1) weighted and DW-MRI signal in liver segments was associated with lower ADC values and abnormal liver function tests, which could reflect underlying cellular swelling and damage.

Enhanced thrombin generation in patients with cirrhosis-induced coagulopathy

BACKGROUND

Prothrombin time (PT) and the international normalized ratio (INR) are still routinely measured in patients with liver cirrhosis to 'assess' their bleeding risk despite the lack of correlation with the two. Thrombin generation (TG) assays are global assays of coagulation that are showing promise in assessing bleeding and thrombosis risks.

AIM

To study the relationship between the INR and TG profiles in cirrhosis-induced coagulopathy.

METHODS

Seventy-three patients with cirrhosis were studied. All TG parameters were compared with those from a normal control group. Contact activation was prevented using corn trypsin inhibitor. TG was also assayed in the presence of Protac(®). The endogenous thrombin potential (ETP) ratio was derived by dividing the ETP with Protac® by the ETP without Protac®.

RESULTS

The INR (mean 1.7) did not correlate with the ETP and the velocity of TG (P > 0.05). There was no difference between the lag time and ETP of the two groups (P > 0.05). The velocity of TG was increased in cirrhosis (67.95 ± 34.8 vs. 45.05 ± 25.9 nM min⁻¹ ; P = 0.016) especially in patients with INRs between 1.21 and 2.0. Both the ETP with Protac(®) and the ETP ratio were increased in cirrhosis (mean 1074 ± 461.4 vs. 818 ± 357.9 nM min, P = 0.004 and 0.80 ± 0.21 vs. 0.44 ± 0.15, P ≤ 0.0001, respectively).

CONCLUSION

Despite a raised INR, TG parameters are consistent with a hypercoagulable profile in cirrhosis-related coagulopathy. This confirms that the PT or INR should not be used to assess bleeding risk in these patients, and other parameters, such as TG, need to be explored as clinical markers of coagulopathy.

Plutonium worker dosimetry

Epidemiological studies of the relationship between risk and internal exposure to plutonium are clearly reliant on the dose estimates used. The International Commission on Radiological Protection (ICRP) is currently reviewing the latest scientific information available on biokinetic models and dosimetry, and it is likely that a number of changes to the existing models will be recommended. The effect of certain changes, particularly to the ICRP model of the respiratory tract, has been investigated for inhaled forms of (239)Pu and uncertainties have also been assessed. Notable effects of possible changes to respiratory tract model assumptions are (1) a reduction in the absorbed dose to target cells in the airways, if changes under consideration are made to the slow clearing fraction and (2) a doubling of absorbed dose to the alveolar region for insoluble forms, if evidence of longer retention times is taken into account. An important factor influencing doses for moderately soluble forms of (239)Pu is the extent of binding of dissolved plutonium to lung tissues and assumptions regarding the extent of binding in the airways. Uncertainty analyses have been performed with prior distributions chosen for application in epidemiological studies. The resulting distributions for dose per unit intake were lognormal with geometric standard deviations of 2.3 and 2.6 for nitrates and oxides, respectively. The wide ranges were due largely to consideration of results for a range of experimental data for the solubility of different forms of nitrate and oxides. The medians of these distributions were a factor of three times higher than calculated using current default ICRP parameter values. For nitrates, this was due to the assumption of a bound fraction, and for oxides due mainly to the assumption of slower alveolar clearance. This study highlights areas where more research is needed to reduce biokinetic uncertainties, including more accurate determination of particle transport rates and long-term dissolution for plutonium compounds, a re-evaluation of long-term binding of dissolved plutonium, and further consideration of modeling for plutonium absorbed to blood from the lungs.

Optimizing warfarin reversal--an ex vivo study

BACKGROUND

Warfarin reversal is a common clinical situation. This is commonly performed using vitamin K and, depending on the urgency, fresh frozen plasma (FFP), prothrombin complex concentrates (PCCs), or activated factor VII. Even though PCCs are widely used, the ideal dosing regimen is far from established.

OBJECTIVES

To verify differences in warfarin reversal patterns using FFP, recombinant FVIIa (rFVIIa), and PCC; and to test the hypothesis that supratherapeutic International Normalized Ratios (INRs) might not correlate with thrombin generation (TG) and identify the ideal concentrations of PCC required to reverse various INR thresholds.

METHODS

We studied the effects of FFP, rFVIIa and Beriplex P/N on the INR and TG, using the calibrated automated thrombography assay in ex vivo warfarinized plasma. Plasmas with different INRs were spiked with different concentrations of Beriplex P/N.

RESULTS

Beriplex P/N was the only agent that completely normalized TG and the INR. The endogenous thrombin potential (ETP) and the peak thrombin showed a significant negative correlation with all INRs. The ETP and velocity of TG reached a plateau at an INR of approximately 4.0. A concentration equivalent to a dose of 30 IU kg(-1) Beriplex P/N normalized the ETP, the INR, FII, FVII, FIX and FX of samples with INRs > or = 4.0. Higher doses resulted in hypercoagulable TG patterns. A concentration equivalent to a dose of 20 IU kg(-1) was sufficient to reverse warfarin at an INR range of 2.0-3.9, as judged by the same tests.

CONCLUSIONS

Warfarin reversal algorithms could be simplified with the adoption of this strategy utilizing two doses of PCC, depending on the INR of the patient. This would also lead to cost reductions and, possibly, a reduction in thrombotic risk.

Comparison of dose estimation from occupational exposure to 239Pu using different modelling approaches

Several approaches are available for bioassay interpretation when assigning Pu doses to Mayak workers. First, a conventional approach is to apply ICRP models per se. An alternative method involves individualised fitting of bioassay data using Bayesian statistical methods. A third approach is to develop an independent dosimetry system for Mayak workers by adapting ICRP models using a dataset of available bioassay measurements for this population. Thus, a dataset of 42 former Mayak workers, who died of non-radiation effects, with both urine bioassay and post-mortem tissue data was used to test these three approaches. All three approaches proved to be adequate for bioassay and tissue interpretation, and thus for Pu dose reconstruction purposes. However, large discrepancies are observed in the resulting quantitative dose estimates. These discrepancies can, in large part, be explained by differences in the interpretation of Pu behaviour in the lungs in the context of ICRP lung model. Thus, a careful validation of Pu lung dosimetry model is needed in Mayak worker dosimetry systems.