Clinical utility of purgative bowel preparation before capsule endoscopy: a multicenter, blinded, randomized controlled trial.

BACKGROUND AND AIMS: Optimal bowel preparation before capsule endoscopy (CE) is currently unknown. In this multicenter, blinded, randomized controlled trial, we assessed clinical effectiveness of 2 types of purgative regimen and a control arm of clear fluid only. METHODS: Patients with suspected small intestinal bleeding were randomized into 3 arms: arm A, clear fluids only for 18 hours before CE and simethicone 200 mg in 150 mL water immediately before CE; arm B, same as A + 2 L of polyethylene glycol (PEG) 12 hours before CE; and arm C, same as A + 1 L PEG + sodium ascorbate 3 hours before CE. To assess diagnostic yield, lesions were classified either as highly relevant (P2) or less relevant (P0 or P1) lesions. Small-bowel visualization quality (SBVQ) was assessed using the Brotz score. Patient tolerability was assessed using the visual analog scale (0-10, with lower scores indicating better tolerability). RESULTS: Two hundred twenty-nine patients completed the study. The mean age was 58.7 years (95% confidence interval, 29.3-87.9), and 47.2% were men. There was no significant difference in diagnosis of P2 lesions in arms A, B, and C (48.7%, 48.0%, and 45.9%, respectively; P = .94). Overall SBVQ and distal SBVQ were similar across the 3 arms (P = .94 and P = .68, respectively). Patients reported better tolerability in arm A (mean score, 1.5) compared with arms B and C (mean score, 3.5 and 2.6, respectively; P < .001). CONCLUSIONS: The use of a purgative bowel preparation before CE does not improve diagnostic yield or small-bowel visualization and is associated with lower patient tolerance. (Clinical trial registration number: ACTRN 12614000883617.).

Hepatitis C virus-induced hepatocyte cell death and protection by inhibition of apoptosis.

Chronic hepatitis C virus (HCV) infection results in progressive liver fibrosis leading to cirrhosis and liver cancer. The mechanism for this remains unclear but hepatocyte apoptosis is thought to play a major role. Hepatocyte apoptosis in human liver tissue was determined by immunohistochemistry for cytokeratin 18 (M30 CytoDEATH) and cleaved poly(ADP-ribose) polymerase (PARP). In vitro studies were performed with replication-defective recombinant adenoviruses expressing HCV proteins (rAdHCV) to study the effects of HCV on cell death in Huh7 cells, primary mouse hepatocytes (PMoHs) and primary human hepatocytes (PHHs). Cell viability and apoptosis were studied using crystal violet assays and Western blots probed for cleaved caspase-3 and cleaved PARP, with and without treatment with the pan-caspase inhibitor Q-VD-OPh and necrostatin-1. Liver tissue of HCV-infected patients expressed elevated levels of apoptotic markers compared with HCV-negative patients. rAdHCV infection reduced cell viability compared with uninfected controls and cells infected with control virus (rAdGFP). Huh7, PMoHs and PHHs infected with rAdHCV showed significantly increased levels of apoptotic markers compared with uninfected controls and rAdGFP-infected cells. In rAdHCV-infected Huh7, treatment with Q-VD-OPh and necrostatin-1 both improved cell viability. Q-VD-Oph also reduced cleaved PARP in rAdHCV-infected Huh7 and PMoHs. Hepatocyte apoptosis is known to be increased in the livers of HCV-infected patients. HCV promoted cell death in primary and immortalized hepatocytes, and this was inhibited by Q-VD-OPh and necrostatin-1. These findings indicate that HCV-induced cell death occurs by both apoptosis and necroptosis, and provide new insights into the mechanisms of HCV-induced liver injury.

AB038. Establishing a reliable semi-automated segmentation method for assessing chemoradiotherapy effects on the non-tumoral brain.

BACKGROUND: Current voxel-based morphometry (VBM) studies of chemoradiotherapy effects on healthy tissues of the glioblastoma multiforme (GBM) brain face a challenge with neuroanatomical distortions (tumor, tumor edema, and resection cavities) and limited comparisons can be drawn across studies due to lack of a universally accepted software package. Our aim is to compare current semi-automated segmentation methods and optimize them for reliability in investigating the effects of chemoradiotherapy on GBM patients. METHODS: A publicly available dataset was used based on predefined inclusion and exclusion criteria. VBM pipelines CAT12 and FSL were tested and optimized to reduce the impact of neuroanatomical distortions. T1-weighted images were screened, and post-processed with FSL and CAT12. Gray matter (GM) and white matter (WM), and cerebrospinal fluid (CSF) volumes of whole brain, tumour-containing and non-tumor containing hemispheres, pre- and post-chemoradiotherapy were calculated and analyzed with Wilcoxon signed-rank tests. Agreement and consistency between FSL and CAT12 were assessed using Bland-Altman plots and intraclass correlation coefficients (ICCs). RESULTS: Post-chemoradiotherapy GM volumes were significantly reduced in whole brain with a compensatory significant increase in CSF volumes, while WM volumes had no significant changes. Similar trends were noted in tumor-containing and non-tumor-containing hemispheres. Bland-Altman plots showed good agreement between FSL and CAT12 processed GM and WM volumes of whole brain, tumor-containing, and non-tumor-containing hemispheres. ICC ≥0.70 was observed in GM [0.70 (0.53-0.82)] and WM [0.75 (0.60-0.85)] volumes of non-tumor-containing hemisphere, and WM [0.71 (0.55-0.83)] volumes of whole brain. GM volumes of tumor-containing hemisphere had good agreement but surprisingly, poor consistency [0.50 (0.25-0.68)]. CSF volumes in non-tumor-containing hemisphere had better agreement and consistency [0.55 (0.32-0.71)] than whole brain [0.49 (0.25-0.67)] and tumor-containing hemisphere CSF [0.36 (0.10-0.58)] volumes. Visual inspection revealed both CAT12 and FSL mis-segmented in the presence of neuroanatomical distortion although CAT12 was more susceptible in the presence of a hematoma. CONCLUSIONS: VBM studies of chemoradiotherapy effects on the brain post-tumor resection remain challenging due to neuroanatomical distortions. A reliable alternative is to use non-tumor-containing hemispheres with no anatomical distortion. Should tumor-containing brains be used, FSL is a more suitable choice, especially in the presence of hematoma distortion.

Endoscopic variceal ligation for primary prophylaxis of esophageal variceal hemorrhage in pre-liver transplant patients.

Endoscopic variceal ligation (EVL) is widely used to prevent esophageal variceal bleeding in patients with advanced cirrhosis. However, the safety and efficacy of EVL in this setting have not been clearly established. This study included 300 adult patients with cirrhosis on our liver transplant waitlist who underwent upper gastrointestinal endoscopy. Esophageal varices deemed to be at high risk of bleeding were banded until eradication or transplantation. A retrospective review of patient notes and endoscopy databases was undertaken, and the number of banding episodes, complications, and patient outcomes were recorded. Forty-two of 300 patients presented with or had previous variceal bleeding prior to referral and were excluded from the analysis. Of the remaining 258 patients, 101 underwent a total of 259 banding episodes (2.6 per patient) with a median follow-up post-banding of 18.4 months per patient (a total of 150 patient years). Failed prophylaxis occurred in 2 patients (2%), and there were 3 episodes (1.2%) of acute hematemesis from band-induced ulceration. One patient (1%) had mild esophageal stricturing post-banding without dysphagia. Four of 36 patients (11%) previously found to have moderately sized or larger varices that were not banded presented with hematemesis due to variceal bleeding and were subsequently banded. None of the patients that received banding died because of bleeding or failed to receive a transplant as a result of banding complications. This study shows that in liver transplant candidates, EVL is highly effective in preventing first variceal bleed. Although banding carries a small risk of band-induced bleeding, this rate is low in comparison with the predicted rate of variceal bleeding in this population.

Effect of Immunosuppressive Agents on Hepatocyte Apoptosis Post-Liver Transplantation.

INTRODUCTION: Immunosuppressants are used ubiquitously post-liver transplantation to prevent allograft rejection. However their effects on hepatocytes are unknown. Experimental data from non-liver cells indicate that immunosuppressants may promote cell death thereby driving an inflammatory response that promotes fibrosis and raises concerns that a similar effect may occur within the liver. We evaluated apoptosis within the liver tissue of post-liver transplant patients and correlated these findings with in vitro experiments investigating the effects of immunosuppressants on apoptosis in primary hepatocytes. METHODS: Hepatocyte apoptosis was assessed using immunohistochemistry for M30 CytoDEATH and cleaved PARP in human liver tissue. Primary mouse hepatocytes were treated with various combinations of cyclosporine, tacrolimus, sirolimus, or MMF. Cell viability and apoptosis were evaluated using crystal violet assays and Western immunoblots probed for cleaved PARP and cleaved caspase 3. RESULTS: Post-liver transplant patients had a 4.9-fold and 1.7-fold increase in M30 CytoDEATH and cleaved PARP compared to normal subjects. Cyclosporine and tacrolimus at therapeutic concentrations did not affect hepatocyte apoptosis, however when they were combined with MMF, cell death was significantly enhanced. Cell viability was reduced by 46% and 41%, cleaved PARP was increased 2.6-fold and 2.2-fold, and cleaved caspase 3 increased 2.2-fold and 1.8-fold following treatment with Cyclosporine/MMF and Tacrolimus/MMF respectively. By contrast, the sirolimus/MMF combination did not significantly reduce hepatocyte viability or promote apoptosis. CONCLUSION: Commonly used immunosuppressive drug regimens employed after liver transplantation enhance hepatocyte cell death and may thus contribute to the increased liver fibrosis that occurs in a proportion of liver transplant recipients.

Gallbladder perforation following transarterial chemoembolisation; a rare but serious complication.

Transarterial chemoembolisation (TACE) is the mainstay of treatment for large or multifocal hepatocellular carcinoma (HCC). However, this procedure is not without potential complications. We report the case of a 72-year-old man with cirrhosis with HCC treated by TACE using drug-eluting beads. He developed persistent fever and severe right upper quadrant pain post-procedure. CT abdomen revealed a large fluid collection closely abutting the gallbladder and tracking inferiorly along the right flank. This fluid collection originated from the gallbladder and contained locules of gas with a contrast-enhancing wall, consistent with an infected biloma. These imaging findings confirmed gallbladder perforation complicating TACE. The development of gallbladder perforation post-TACE from acute ischaemic cholecystitis producing gallbladder wall necrosis is exceedingly rare. The presence of gallbladder perforation must be recognised in patients with persisting symptoms and imaging evidence of a perihepatic fluid collection because specific treatment with intravenous antibiotics and percutaneous drainage of the biloma is necessary.

Enhanced apoptosis in post-liver transplant hepatitis C: effects of virus and immunosuppressants.

Hepatitis C (HCV)-infected patients have a poorer survival post-liver transplantation compared to patients transplanted for other indications, since HCV recurrence post-transplant is universal and commonly follows an aggressive course. There is increasing evidence that in the non-transplant setting, induction of hepatocyte apoptosis is one of the main mechanisms by which HCV drives liver inflammation and fibrosis, and that HCV proteins directly promote apoptosis. Recent studies have shown that post-liver transplant, there is a link between high levels of HCV replication, enhanced hepatocyte apoptosis and the subsequent development of rapidly progressive liver fibrosis. Although the responsible mechanisms remain unclear, it is likely that immunosuppressive drugs play an important role. It is well known that immunosuppressants impair immune control of HCV, thereby allowing increased viral replication. However there is also evidence that immunosuppressants may directly induce apoptosis and this may be facilitated by the presence of high levels of HCV replication. Thus HCV and immunosuppressants may synergistically interact to further enhance apoptosis and drive more rapid fibrosis. These findings suggest that modulation of apoptosis within the liver either by changing immunosuppressive therapy or the use of apoptosis inhibitors may help prevent fibrosis progression in patients with post-transplant HCV disease.

Torrential upper gastrointestinal bleeding from 'downhill' oesophageal varices complicating long term central venous access for total parenteral nutrition.

Oesophageal varices usually develop in the setting of portal hypertension secondary to chronic liver disease. However, superior vena cava (SVC) obstruction can result in 'downhill' varices forming in the upper oesophagus. A case of torrential upper gastrointestinal bleeding from SVC obstruction due to chronic central venous access for home total parenteral nutrition is described. It is suggested that in patients presenting with gastrointestinal bleeding in the setting of SVC obstruction, 'downhill' varices should be suspected. The current literature is discussed regarding management of such varices. It is recommended that endoscopic variceal surveillance be carried out in patients with known SVC obstruction.

Catching a chameleon: IgG4-related systemic disease.

IgG4-related systemic disease (IRSD) is a recently described entity with protean manifestations. We describe a patient who developed inflammation and fibrosis in multiple organs over 20 years, sequentially involving his pancreas, bile ducts, gallbladder, submandibular and lacrimal glands, and kidneys. He had an elevated serum IgG4 level. Retrospective analysis of biopsies showed strongly positive tissue immunostaining for IgG4, confirming the diagnosis of IRSD. This case illustrates the natural history of partially treated IRSD and its varied clinical presentations. Early diagnosis and treatment is important, as the condition is highly steroid-responsive.

Magnetic resonance colonography for colorectal cancer screening in patients with Lynch syndrome gene mutation.

Lynch syndrome gene carriers have a 50-80% risk of colorectal cancer (CRC). Current guidelines recommend yearly colonoscopy, with associated procedure-related risks. Magnetic resonance colonography (MRC) was evaluated as a non-invasive alternative for CRC screening in this high-risk population. Adult Lynch syndrome gene carriers underwent both screening procedures on the same day. MRI radiologists read the scans and rated image quality. Endoscopists performed colonoscopy unaware of MRC findings until after procedure completion. If lesions were detected, their number, size and location were noted. Post-procedure, patients compared discomfort and inconvenience of MRC and colonoscopy on a visual analogue scale. Thirty patients were recruited. 83% of the MRC scans were of adequate to good quality. MRC detected three lesions in three patients (70, 36, 17 mm). All 3 were independently detected on colonoscopy, excised and found to be CRC. MRC failed to detect a 3 mm CRC found on colonoscopy. CRC prevalence was 13%. Colonoscopy detected a further 30 polyps, all <10 mm. Of these, 17 were hyperplastic polyps and 10 normal mucosa. Colonoscopy had a false positive rate of 32% as defined by histology. MRC failed to detect any polyp <10 mm. Mean patient discomfort scores were 20% for MRC and 68% for colonoscopy, P = 0.003. Mean patient inconvenience scores were 54% for MRC and 52% for colonoscopy, P = 0.931. MRC was reliable in detecting large polyps, potentially CRC. However MRC currently has poor sensitivity in detecting small polyps, limiting its utility in adenoma screening at this time. MRC was associated with less discomfort than CC.

Morpholino-functionalized silicon nanowire biosensor for sequence-specific label-free detection of DNA.

We investigated Morpholino-functionalized silicon nanowires (SiNWs) as a novel gene chip platform for the sequence-specific label-free detection of DNA. Morpholino attachment and subsequent Morpholino-DNA hybridization on silicon surface was characterized by X-ray photoelectron spectroscopy and fluorescence microscopy. The resultant Morpholino-modified surfaces showed high specificity of recognition for DNA. Subsequently, by using the same protocol, the surface of the SiNW biosensor was functionalized with Morpholino, and this was used for label-free Morpholino-DNA hybridization detection. Real-time measurements of the Morpholino-functionalized SiNW biosensor exhibited a decrease in a time-dependent conductance when complementary and mutant DNA samples were added. Furthermore, identification of fully complementary versus mismatched DNA samples was carried out by the Morpholino-functionalized SiNW biosensor. We demonstrated that DNA detection using the Morpholino-functionalized SiNW biosensor could be carried out to the hundreds of femtomolar range. The Morpholino-functionalized SiNWs show a novel biosensor for label-free and direct detection of DNA with good selectivity, and a promising application in gene expression.

Highly sensitive and reversible silicon nanowire biosensor to study nuclear hormone receptor protein and response element DNA interactions.

To thoroughly understand the role that estrogen receptors partake in regulation of gene expression, characterization of estrogen receptors (ERs) and estrogen-response elements (EREs) interactions is essential. In the work, we present a highly sensitive and reusable silicon nanowire (SiNW) biosensor to study the interactions between human ER proteins (ER, α and ß subtypes) and EREs (dsDNA). The proteins were covalently immobilized on the SiNW surface. Various EREs including wild-type, mutant and scrambled DNA sequences were then applied to the protein-functionalized SiNW surface. Due to negatively charged dsDNA, binding of the EREs to the ERs on the n-type SiNW biosensor leads to the accumulation of negative charges on the surface, thereby inducing increase in resistance. The results show that the specificity of the ERE-ERα binding is higher than that of the ERE-ERß binding, what is more, the mutant ERE reduces the binding affinity for both ERα and ERß. By applying various concentrations of wild-type ERE to the bound ERα, a very low concentration of 10 fM wild-type ERE was found to be able to bind to the ERα. The reversible association and dissociation between ERα and wt-ERE was achieved, pointing to a reusable biosensor for protein-DNA binding. Through the study, we have established the SiNW biosensor as a promising method in providing comprehensive study for hormone receptor-response element interactions.

Giant cardiac myxoma.

Although cardiac myxomas remain an uncommon group of malignancies, they are the most common form of primary cardiac tumour. Clinical presentations can be varied with local cardiac haemodynamic consequences, valvular insufficiency or even embolic phenomena. We present a case of a 46-year-old man with chronic abdominal pain and discuss a number of diagnostic challenges that were confronted up until a definitive diagnosis of cardiac myxoma was made. The resultant outcome was excellent with the patient achieving complete recovery from long term disabling symptoms.