Pharmacological EZH2 inhibition combined with retinoic acid treatment promotes differentiation and apoptosis in rhabdomyosarcoma cells.

BACKGROUND: Rhabdomyosarcomas (RMS) are predominantly paediatric sarcomas thought to originate from muscle precursor cells due to impaired myogenic differentiation. Despite intensive treatment, 5-year survival for patients with advanced disease remains low (< 30%), highlighting a need for novel therapies to improve outcomes. Differentiation therapeutics are agents that induce differentiation of cancer cells from malignant to benign. The histone methyltransferase, Enhancer of Zeste Homolog 2 (EZH2) suppresses normal skeletal muscle differentiation and is highly expressed in RMS tumours. RESULTS: We demonstrate combining inhibition of the epigenetic modulator EZH2 with the differentiating agent retinoic acid (RA) is more effective at reducing cell proliferation in RMS cell lines than single agents alone. In PAX3-FOXO1 positive RMS cells this is due to an RA-driven induction of the interferon pathway resulting in apoptosis. In fusion negative RMS, combination therapy led to an EZH2i-driven upregulation of myogenic signalling resulting in differentiation. In both subtypes, EZH2 is significantly associated with enrichment of trimethylated lysine 27 on histone 3 (H3K27me3) in genes that are downregulated in untreated RMS cells and upregulated with EZH2 inhibitor treatment. These results provide insight into the mechanism that drives the anti-cancer effect of the EZH2/RA single agent and combination treatment and indicate that the reduction of EZH2 activity combined with the induction of RA signalling represents a potential novel therapeutic strategy to treat both subtypes of RMS. CONCLUSIONS: The results of this study demonstrate the potential utility of combining EZH2 inhibitors with differentiation agents for the treatment of paediatric rhabdomyosarcomas. As EZH2 inhibitors are currently undergoing clinical trials for adult and paediatric solid tumours and retinoic acid differentiation agents are already in clinical use this presents a readily translatable potential therapeutic strategy. Moreover, as inhibition of EZH2 in the poor prognosis FPRMS subtype results in an inflammatory response, it is conceivable that this strategy may also synergise with immunotherapies for a more effective treatment in these patients.

Cardiac ion channels associated with unexplained stillbirth - an immunohistochemical study.

OBJECTIVES: Despite the use of post-mortem investigations, approximately 20% of stillbirths remain unexplained. Cardiac ion channelopathies have been identified as a cause of death in Sudden Infant Death Syndrome (SIDS) and could be associated with unexplained stillbirths. This study aimed to understand if the expression or localisation of cardiac ion channels associated with channelopathies were altered in cases of unexplained stillbirths. METHODS: A case control study was conducted using formalin-fixed cardiac tissue from 20 cases of unexplained stillbirth and a control group of 20 cases of stillbirths from intrapartum hypoxia. 4 µm tissue sections were stained using haematoxylin and eosin, Masson's trichrome (MT) and Elastic van Gieson (EVG). Immunohistochemistry (IHC) was performed using antibodies against CACNA1G, KCNJ2, KCNQ1, KCNH2 and KCNE1. The cardiac conduction system in samples stained with MT and EVG could not be identified. Therefore, the levels of immunoperoxidase staining were quantified using QuPath software. RESULTS: The nuclear-cytoplasmic ratio of sections stained with haematoxylin and eosin was higher for the hypoxia group (hypoxia median 0.13 vs. 0.04 unexplained, p < 0.001). CACNA1G (unexplained median 0.26 vs. hypoxia 0.30, p=0.009) and KCNJ2 (unexplained median 0.35 vs. hypoxia 0.41, p=0.001) had lower staining intensity in the unexplained stillbirth group. There were no statistically significant differences in the staining intensity of KCNQ1, KCNH2 and KCNE1. CONCLUSIONS: Two ion channels associated with channelopathies demonstrated lower levels of expression in cases of unexplained stillbirth. Further genetic studies using human tissue should be performed to understand the association between channelopathies and otherwise unexplained stillbirths.

Biallelic TMEM260 variants cause truncus arteriosus, with or without renal defects.

Only two families have been reported with biallelic TMEM260 variants segregating with structural heart defects and renal anomalies syndrome (SHDRA). With a combination of genome, exome sequencing and RNA studies, we identified eight individuals from five families with biallelic TMEM260 variants. Variants included one multi-exon deletion, four nonsense/frameshifts, two splicing changes and one missense change. Together with the published cases, analysis of clinical data revealed ventricular septal defects (12/12), mostly secondary to truncus arteriosus (10/12), elevated creatinine levels (6/12), horse-shoe kidneys (1/12) and renal cysts (1/12) in patients. Three pregnancies were terminated on detection of severe congenital anomalies. Six patients died between the ages of 6 weeks and 5 years. Using a range of stringencies, carrier frequency for SHDRA was estimated at 0.0007-0.007 across ancestries. In conclusion, this study confirms the genetic basis of SHDRA, expands its known mutational spectrum and clarifies its clinical features. We demonstrate that SHDRA is a severe condition associated with substantial mortality in early childhood and characterised by congenital cardiac malformations with a variable renal phenotype.

Enzyme replacement therapy and hematopoietic stem cell transplant: a new paradigm of treatment in Wolman disease.

BACKGROUND: Wolman disease is a rare, lysosomal storage disorder in which biallelic variants in the LIPA gene result in reduced or complete lack of lysosomal acid lipase. The accumulation of the substrates; cholesterol esters and triglycerides, significantly impacts cellular function. Untreated patients die within the first 12 months of life. Clinically, patients present severely malnourished, with diarrhoea and hepatosplenomegaly, many have an inflammatory phenotype, including with hemophagocytic lymphohistiocytosis (HLH). Hematopoietic stem cell transplant (HCT) had been historically the only treatment available but has a high procedure-related mortality because of disease progression and disease-associated morbidities. More recently, enzyme replacement therapy (ERT) with dietary substrate reduction (DSR) has significantly improved patient survival. However, ERT is life long, expensive and its utility is limited by anti-drug antibodies (ADA) and the need for central venous access. RESULTS: We describe five Wolman disease patients diagnosed in infancy that were treated at Royal Manchester Children's Hospital receiving ERT with DSR then HCT-multimodal therapy. In 3/5 an initial response to ERT was attenuated by ADA with associated clinical and laboratory features of deterioration. 1/5 developed anaphylaxis to ERT and the other patient died post HCT with ongoing HLH. All patients received allogeneic HCT. 4/5 patients are alive, and both disease phenotype and laboratory parameters are improved compared to when they were on ERT alone. The gastrointestinal symptoms are particularly improved after HCT, with reduced diarrhoea and vomiting. This allows gradual structured normalisation of diet with improved tolerance of dietary fat. Histologically there are reduced cholesterol clefts, fewer foamy macrophages and an improved villous structure. Disease biomarkers also show improvement with ERT, immunotherapy and HCT. Three patients have mixed chimerism after HCT, indicating a likely engraftment-defect in this condition. CONCLUSION: We describe combined ERT, DSR and HCT, multimodal treatment for Wolman disease. ERT and DSR stabilises the sick infant and reduces the formerly described prohibitively high, transplant-associated mortality in this condition. HCT abrogates the problems of ERT, namely attenuating ADA, the need for continuing venous access, and continuing high cost drug treatment. HCT also brings improved efficacy, particularly evident in improved gastrointestinal function and histology. Multimodal therapy should be considered a new paradigm of treatment for Wolman disease patients where there is an attenuated response to ERT, and for all patients where there is a well-matched transplant donor, in order to improve long term gut function, tolerance of a normal diet and quality of life.

The diagnostic and prognostic significance of liver histology in alcoholic hepatitis.

BACKGROUND: Liver biopsy may be of diagnostic and prognostic value but its role in alcoholic hepatitis (AH) has been controversial. AIM: To assess the utility of liver biopsy in the assessment of clinically severe AH METHODS: The histological features of alcoholic steatohepatitis (ASH) were recorded and scored in patients enrolled in the Steroids or Pentoxifylline for Alcoholic Hepatitis (STOPAH) trial who underwent liver biopsy. These features were then assessed relative to outcome and established clinical prognostic scores. RESULTS: The STOPAH trial recruited 1068 patients; biopsies were obtained in 182 (17%). One hundred and sixty-one biopsies were adequate for histological assessment and 140 (87%) were diagnostic for ASH. Only three biopsies (2%) did not have histological features of alcohol-related liver injury. In biopsies performed prior to randomisation, ASH was identified in 92.5% of patients meeting clinical trial definitions of severe AH. In biopsies with ASH, taken before or within 48 hours of randomisation, survival differences between Alcoholic Hepatitis Histological Score (AHHS) groups were not significant: comparison of mild / moderate (91%: 21 of 23 patients) with severe (78%: 29 of 37 patients) groups: P = 0.18. The AHHS was not superior to clinical scores of prognosis: area under the curve for 28-day mortality was 0.728, compared with 0.799 for the Glasgow alcoholic hepatitis score and 0.728 for the MELD score. CONCLUSION: Liver histology taken before treatment rarely changes the diagnosis in patients meeting strict criteria for a clinical diagnosis of AH. The AHHS is similar to clinical scores in determining prognosis. Clinical trial registration EudraCT reference number: 2009-013897-42. ISRCTN reference number: 88782125. MREC number: 09/MRE09/59. UKCRIN ID: 9143.

De Novo Lipogenesis Alters the Phospholipidome of Esophageal Adenocarcinoma.

The incidence of esophageal adenocarcinoma is rising, survival remains poor, and new tools to improve early diagnosis and precise treatment are needed. Cancer phospholipidomes quantified with mass spectrometry imaging (MSI) can support objective diagnosis in minutes using a routine frozen tissue section. However, whether MSI can objectively identify primary esophageal adenocarcinoma is currently unknown and represents a significant challenge, as this microenvironment is complex with phenotypically similar tissue-types. Here, we used desorption electrospray ionization-MSI (DESI-MSI) and bespoke chemometrics to assess the phospholipidomes of esophageal adenocarcinoma and relevant control tissues. Multivariate models derived from phospholipid profiles of 117 patients were highly discriminant for esophageal adenocarcinoma both in discovery (AUC = 0.97) and validation cohorts (AUC = 1). Among many other changes, esophageal adenocarcinoma samples were markedly enriched for polyunsaturated phosphatidylglycerols with longer acyl chains, with stepwise enrichment in premalignant tissues. Expression of fatty acid and glycerophospholipid synthesis genes was significantly upregulated, and characteristics of fatty acid acyls matched glycerophospholipid acyls. Mechanistically, silencing the carbon switch ACLY in esophageal adenocarcinoma cells shortened glycerophospholipid chains, linking de novo lipogenesis to the phospholipidome. Thus, DESI-MSI can objectively identify invasive esophageal adenocarcinoma from a number of premalignant tissues and unveils mechanisms of phospholipidomic reprogramming. SIGNIFICANCE: These results call for accelerated diagnosis studies using DESI-MSI in the upper gastrointestinal endoscopy suite, as well as functional studies to determine how polyunsaturated phosphatidylglycerols contribute to esophageal carcinogenesis.

Aurora A Kinase Inhibition Destabilizes PAX3-FOXO1 and MYCN and Synergizes with Navitoclax to Induce Rhabdomyosarcoma Cell Death.

The clinically aggressive alveolar rhabdomyosarcoma (RMS) subtype is characterized by expression of the oncogenic fusion protein PAX3-FOXO1, which is critical for tumorigenesis and cell survival. Here, we studied the mechanism of cell death induced by loss of PAX3-FOXO1 expression and identified a novel pharmacologic combination therapy that interferes with PAX3-FOXO1 biology at different levels. Depletion of PAX3-FOXO1 in fusion-positive (FP)-RMS cells induced intrinsic apoptosis in a NOXA-dependent manner. This was pharmacologically mimicked by the BH3 mimetic navitoclax, identified as top compound in a screen from 208 targeted compounds. In a parallel approach, and to identify drugs that alter the stability of PAX3-FOXO1 protein, the same drug library was screened and fusion protein levels were directly measured as a read-out. This revealed that inhibition of Aurora kinase A most efficiently negatively affected PAX3-FOXO1 protein levels. Interestingly, this occurred through a novel specific phosphorylation event in and binding to the fusion protein. Aurora kinase A inhibition also destabilized MYCN, which is both a functionally important oncogene and transcriptional target of PAX3-FOXO1. Combined treatment with an Aurora kinase A inhibitor and navitoclax in FP-RMS cell lines and patient-derived xenografts synergistically induced cell death and significantly slowed tumor growth. These studies identify a novel functional interaction of Aurora kinase A with both PAX3-FOXO1 and its effector MYCN, and reveal new opportunities for targeted combination treatment of FP-RMS. SIGNIFICANCE: These findings show that Aurora kinase A and Bcl-2 family proteins are potential targets for FP-RMS.

MerTK expressing hepatic macrophages promote the resolution of inflammation in acute liver failure.

OBJECTIVE: Acute liver failure (ALF) is characterised by overwhelming hepatocyte death and liver inflammation with massive infiltration of myeloid cells in necrotic areas. The mechanisms underlying resolution of acute hepatic inflammation are largely unknown. Here, we aimed to investigate the impact of Mer tyrosine kinase (MerTK) during ALF and also examine how the microenvironmental mediator, secretory leucocyte protease inhibitor (SLPI), governs this response. DESIGN: Flow cytometry, immunohistochemistry, confocal imaging and gene expression analyses determined the phenotype, functional/transcriptomic profile and tissue topography of MerTK+ monocytes/macrophages in ALF, healthy and disease controls. The temporal evolution of macrophage MerTK expression and its impact on resolution was examined in APAP-induced acute liver injury using wild-type (WT) and Mer-deficient (Mer-/-) mice. SLPI effects on hepatic myeloid cells were determined in vitro and in vivo using APAP-treated WT mice. RESULTS: We demonstrate a significant expansion of resolution-like MerTK+HLA-DRhigh cells in circulatory and tissue compartments of patients with ALF. Compared with WT mice which show an increase of MerTK+MHCIIhigh macrophages during the resolution phase in ALF, APAP-treated Mer-/- mice exhibit persistent liver injury and inflammation, characterised by a decreased proportion of resident Kupffer cells and increased number of neutrophils. Both in vitro and in APAP-treated mice, SLPI reprogrammes myeloid cells towards resolution responses through induction of a MerTK+HLA-DRhigh phenotype which promotes neutrophil apoptosis and their subsequent clearance. CONCLUSIONS: We identify a hepatoprotective, MerTK+, macrophage phenotype that evolves during the resolution phase following ALF and represents a novel immunotherapeutic target to promote resolution responses following acute liver injury.

Defective monocyte oxidative burst predicts infection in alcoholic hepatitis and is associated with reduced expression of NADPH oxidase.

OBJECTIVE: In order to explain the increased susceptibility to serious infection in alcoholic hepatitis, we evaluated monocyte phagocytosis, aberrations of associated signalling pathways and their reversibility, and whether phagocytic defects could predict subsequent infection. DESIGN: Monocytes were identified from blood samples of 42 patients with severe alcoholic hepatitis using monoclonal antibody to CD14. Phagocytosis and monocyte oxidative burst (MOB) were measured ex vivo using flow cytometry, luminometry and bacterial killing assays. Defects were related to the subsequent development of infection. Intracellular signalling pathways were investigated using western blotting and PCR. Interferon-γ (IFN-γ) was evaluated for its therapeutic potential in reversing phagocytic defects. Paired longitudinal samples were used to evaluate the effect of in vivo prednisolone therapy. RESULTS: MOB, production of superoxide and bacterial killing in response to Escherichia coli were markedly impaired in patients with alcoholic hepatitis. Pretreatment MOB predicted development of infection within two weeks with sensitivity and specificity that were superior to available clinical markers. Accordingly, defective MOB was associated with death at 28 and 90 days. Expression of the gp91 phox subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was reduced in patients with alcoholic hepatitis demonstrating defective MOB. Monocytes were refractory to IFN-γ stimulation and showed high levels of a negative regulator of cytokine signalling, suppressor of cytokine signalling-1. MOB was unaffected by 7 days in vivo prednisolone therapy. CONCLUSIONS: Monocyte oxidative burst and bacterial killing is impaired in alcoholic hepatitis while bacterial uptake by phagocytosis is preserved. Defective MOB is associated with reduced expression of NADPH oxidase in these patients and predicts the development of infection and death.

Achieving an early pregnancy following allogeneic uterine transplantation in a rabbit model.

OBJECTIVE: Uterine transplantation (UTx) has been proposed as a treatment option for women diagnosed with absolute uterine factor infertility (AUFI). The goal of UTx remains achieving pregnancy and live birth of a healthy neonate following allogeneic UTx. Our aim was to assess whether fertility was possible following allogeneic uterine transplantation (UTx), when the recipient had demonstrated long-term survival and had been administered immunosuppression. STUDY DESIGN: Nine allogeneic UTx in New Zealand White rabbits were performed using a pre-determined protocol. Tacrolimus was the immunosuppressant selected. Embryos were transferred into both cornua of the sole living recipient via a mini-midline laparotomy. The pregnancy was monitored with regular reproductive profiles and serial trans-abdominal ultrasound to measure conceptus growth (gestation sac and crown rump length (CRL)). RESULTS: In the sole surviving doe a gestation sac was visualised on ultrasound from Day 9 (D9) after embryo transfer. Gestation sac diameter and CRL increased from D9 to D16 but by D18 the gestation sac had reduced in size. The fetus was no longer visible, suggesting fetal resorption had occurred. Subsequent scans on D22 and D25 did not demonstrate a gestation sac. Scheduled necropsy on D27 and histopathology confirmed evidence of a gravid uterus and presence of a gestational sac. A single episode of acute rejection occurred on D13. CONCLUSION: Pregnancy was achieved after rabbit allogeneic UTx but serial ultrasound suggested that fetal demise occurred prior to scheduled necropsy. The study represents only the third example of conception and pregnancy following an animal allogeneic UTx.

Achieving uterine auto-transplantation in a sheep model using iliac vessel anastomosis: a short-term viability study.

OBJECTIVE: To investigate, develop and evaluate anatomical, surgical and anastomotic aspects necessary for a successful uterine transplant in a large-animal model. DESIGN: Sheep model; longitudinal study involving five ewes. SETTING: Royal Veterinary College, London, UK. POPULATION: Five ewes of proven fertility. METHODS: The uterine allograft along with the internal iliacs, and uterine arterial and venous tree all intact were harvested en bloc. An end-to-side anastomosis was performed between the external iliac vessels and the internal iliac vessels of the graft using 6-0 polypropylene. Successful reperfusion of the graft was initially judged by the color shift of the uterus during reperfusion. Blood flow past the venous and arterial anastomotic sites was also ensured by visual inspection, together with pulse oximetry and multispectral imaging. MAIN OUTCOME MEASURES: Operative details (retrieval, ischemic, clamping, reperfusion and recipient hysterectomy duration); physiological profiles; gross morphology and histopathology. RESULTS: Five autotransplants were performed. One procedure was abandoned because of the inappropriate size of sheep model. Another procedure was halted because the animal suffered from respiratory failure in the immediate intra-operative period. Three transplants were completed. In those, at least two of four possible anastomoses were finished and the grafted uteri demonstrated immediate perfusion and appropriate viability 45 min post-operatively. CONCLUSIONS: Internal to external iliac vessel anastomoses are an acceptable surgical technique that should be applied in a human model to ensure adequate subsequent uterine perfusion.

Uterine allotransplantation in a rabbit model using aorto-caval anastomosis: a long-term viability study.

OBJECTIVE: Uterine transplantation (UTx) has been proposed as a treatment option for women diagnosed with absolute uterine factor infertility. Allogeneic UTx has been attempted in a number of animal models, but achieving an adequate blood supply for the transplanted uterus still presents the biggest challenge. Microvascular re-anastomosis was unsuccessful in a number of animal models. The aim was to assess whether a large vessel aortic-caval vascular patch technique can bring about long-term graft survival after allogeneic UTx in a rabbit model. STUDY DESIGN: A longitudinal study involving uterine cross transplantations (n=9 donors, n=9 recipients) was performed in New Zealand white rabbits using an aortic-caval macrovascular patch harvested as part of the uterine allograft. All rabbits were allogeneic and of proven fertility, with at least one previous litter each. The end result of the donor graft harvest was a total hysterectomy transecting across the vagina and the most lateral aspects of the uterine horns together with an aortic-caval macrovascular patch (aorta, inferior vena cava, common and internal iliacs, and uterine arterial and venous tree). Tacrolimus (500 µg twice daily) was administered for immunosuppression post-transplant. The recipients were closely monitored until death or euthanasia. RESULTS: In this case series, long-term rabbit survival was 11% (n=1). Surgical survival was 56% (n=5). Three rabbits (UTx #3, #4 and #8) died intra-operatively as a result of blood aspiration, ventricular hematoma, and massive hemorrhage. Three does (#1, #2, #7 and #9) died within the first 24 h as a result of the veno-vena and anastomosis breakdown. Does #6 and #9 died secondary to pre-operative pneumonia and a pulmonary embolus, respectively. Only one rabbit survived longer than a month. CONCLUSION: Our method used a macrovascular patch technique to ensure adequate blood supply to the donor uterine graft. We have demonstrated the feasibility of uterine allotransplantation using this technique in the rabbit, but were unable to demonstrate a higher long-term survival percentage because of issues related to using a rabbit model.

Histopathological and immunohistochemical features of early hydatidiform mole in relation to subsequent development of persistent gestational trophoblastic disease.

OBJECTIVE: To examine histomorphological and immunohistochemical findings in hydatidiform moles to determine whether any features can reliably predict clinical behavior. STUDY DESIGN: Blinded semiquantitative review of histological and immunohistochemical findings in cases of partial hydatidiform mole (PHM) (N = 50) and complete hydatidiform mole (CHM) which either spontaneously resolved (N = 50) or required chemotherapy (N = 50). Immunostains assessed included MLH1, MSH2, nm23, TERT, p53, EGFR, and CerbB2 based on previous data. RESULTS: There were marked morphological differences in various criteria between CHMs and PHMs, including the proportion of villi with abnormal trophoblast hyperplasia (29% vs. 6%, respectively). However, there were no significant differences in any morphological parameters between CHMs that spontaneously resolved and those that subsequently required chemotherapy. Similarly, there were no clinically useful differences regarding any immunostaining scores between CHM groups. CONCLUSION: Neither morphological nor immunohistochemical features can reliably predict subsequent requirement of chemotherapy in CHMs.

Stat2 loss leads to cytokine-independent, cell-mediated lethality in LPS-induced sepsis.

Deregulated Toll-like receptor (TLR)-triggered inflammatory responses that depend on NF-κB are detrimental to the host via excessive production of proinflammatory cytokines, including TNF-α. Stat2 is a critical component of type I IFN signaling, but it is not thought to participate in TLR signaling. Our study shows that LPS-induced lethality in Stat2(-/-) mice is accelerated as a result of increased cellular transmigration. Blocking intercellular adhesion molecule-1 prevents cellular egress and confers survival of Stat2(-/-) mice. The main determinant of cellular egress in Stat2(-/-) mice is the genotype of the host and not the circulating leukocyte. Surprisingly, lethality and cellular egress observed on Stat2(-/-) mice are not associated with excessive increases in classical sepsis cytokines or chemokines. Indeed, in the absence of Stat2, cytokine production in response to multiple TLR agonists is reduced. We find that Stat2 loss leads to reduced expression of NF-κB target genes by affecting nuclear translocation of NF-κB. Thus, our data reveal the existence of a different mechanism of LPS-induced lethality that is independent of NF-κB triggered cytokine storm but dependent on cellular egress.

Tumour-to-tumour metastases: prostate carcinoma metastasising to a renal oncocytoma.

This is a case report of prostate carcinoma metastasising to a renal oncocytoma. The report demonstrates the unusual presentation of metastases from a common cancer to a common benign tumour, and reviews the rare phenomenon of tumour-to-tumour metastases.

Pancreatic adenocarcinoma presenting with sudden onset bilateral deafness secondary to metastatic leptomeningeal infiltration.

Deafness is a very common problem in older persons. We present a case of metastatic adenocarcinoma of the pancreas with deafness being the patient's only reason for seeking medical attention. The patient had bilateral vestibulocochlear nerve palsies with associated lower motor neurone facial nerve palsies and a bulbar palsy. Magnetic resonance imaging of his brain was unremarkable. It was only on post-mortem histology that tumour infiltrating the leptomeninges was demonstrated. Leptomeningeal metastases are rarely associated with adenocarcinoma of the pancreas. A review of the literature reveals only two other case reports of mestatic pancreatic carcinoma presenting with deafness but both had demonstrable temporal bone lesions on MRI as opposed to the meninges.

Emergency department management of undifferentiated abdominal pain with hyoscine butylbromide and paracetamol: a randomised control trial.

OBJECTIVE: To compare the effectiveness of paracetamol, hyoscine butylbromide and the combination of paracetamol plus hyoscine butylbromide (paracetamol + hyoscine butylbromide) in the management of patients with acute undifferentiated abdominal pain attending the emergency department (ED). SETTING: A large teaching hospital with an annual ED census of 120,000 adult patients. METHODS: A prospective, randomised placebo controlled trial of a convenience sample of patients attending the ED. The trial compared the analgesic effect of intravenous hyoscine butylbromide, oral paracetamol and the combination of both drugs using a Visual Analogue Scale pain scoring tool. Rescue analgesia was administered when pain was inadequately controlled by trial medication. RESULTS: 132 patients were recruited to the trial. At 30 min, all analgesic combinations produced significant similar levels of pain relief. At 60 min after administration of the trial medication, mean reductions in pain scores for patients receiving paracetamol only were significantly greater than those receiving paracetamol + hyoscine butylbromide (ANCOVA model, p=0.0180). No relationship was seen between treatment arm and the need for rescue analgesia (χ(2), p value=0.846). CONCLUSION: The trial data suggest that oral paracetamol is at least as effective as intravenous hyoscine butylbromide and a combination of both drugs in the management of acute undifferentiated abdominal pain presenting to the ED. Based on these results and factors such as cost and tolerability, we recommend single agent paracetamol as the agent of choice for the management of acute mild to moderate undifferentiated abdominal pain. TRIAL REGISTRATION NUMBER: MHRA Ref: 19717/0226/001-0001; European Clinical Trials Database. EUDRAct No: 2006-005395-40.