Insulin-like growth factor binding protein-5 as a biomarker for detection of early liver disease

Study identifying an Insulin-like growth factor binding protein-5 as a biomarker for detection of early liver disease presented at the annual congress of the british toxicology societ

Development of an invasively monitored porcine model of acetaminophen-induced acute liver failure

Background: The development of effective therapies for acute liver failure (ALF) is limited by our knowledge of the pathophysiology of this condition, and the lack of suitable large animal models of acetaminophen toxicity. Our aim was to develop a reproducible invasively-monitored porcine model of acetaminophen-induced ALF. Method: 35kg pigs were maintained under general anaesthesia and invasively monitored. Control pigs received a saline infusion, whereas ALF pigs received acetaminophen intravenously for 12 hours to maintain blood concentrations between 200-300 mg/l. Animals surviving 28 hours were euthanased. Results: Cytochrome p450 levels in phenobarbital pre-treated animals were significantly higher than non pre-treated animals (300 vs 100 pmol/mg protein). Control pigs (n=4) survived 28-hour anaesthesia without incident. Of nine pigs that received acetaminophen, four survived 20 hours and two survived 28 hours. Injured animals developed hypotension (mean arterial pressure; 40.8+/-5.9 vs 59+/-2.0 mmHg), increased cardiac output (7.26+/-1.86 vs 3.30+/-0.40 l/min) and decreased systemic vascular resistance (8.48+/-2.75 vs 16.2+/-1.76 mPa/s/m3). Dyspnoea developed as liver injury progressed and the increased pulmonary vascular resistance (636+/-95 vs 301+/-26.9 mPa/s/m3) observed may reflect the development of respiratory distress syndrome. Liver damage was confirmed by deterioration in pH (7.23+/-0.05 vs 7.45+/-0.02) and prothrombin time (36+/-2 vs 8.9+/-0.3 seconds) compared with controls. Factor V and VII levels were reduced to 9.3 and 15.5% of starting values in injured animals. A marked increase in serum AST (471.5+/-210 vs 42+/-8.14) coincided with a marked reduction in serum albumin (11.5+/-1.71 vs 25+/-1 g/dL) in injured animals. Animals displayed evidence of renal impairment; mean creatinine levels 280.2+/-36.5 vs 131.6+/-9.33 mumol/l. Liver histology revealed evidence of severe centrilobular necrosis with coagulative necrosis. Marked renal tubular necrosis was also seen. Methaemoglobin levels did not rise >5%. Intracranial hypertension was not seen (ICP monitoring), but there was biochemical evidence of encephalopathy by the reduction of Fischer's ratio from 5.6 +/- 1.1 to 0.45 +/- 0.06. Conclusion: We have developed a reproducible large animal model of acetaminophen-induced liver failure, which allows in-depth investigation of the pathophysiological basis of this condition. Furthermore, this represents an important large animal model for testing artificial liver support systems

Human hepatic HepaRG cells maintain high intrinsic CYP450 activity/metabolism and significantly outperform standard HepG2/C3A cells used in drug pharmacology applications

Introduction: Conventional in vitro human hepatic models for drug testing are based on the use of cell lines or primary human hepatocytes (PHHs). However, limited availability, inter-donor functional variability and early phenotypic alterations of PHHs in vitro restrict their use; whilst cell lines such as HepG2/C3As lack a substantial and variable set of liver-specific functions, specifically, CYP450 activity. In this study we compared CYP450 activity/ metabolism between HepG2/C3A and human HepaRG cells as hepatic models for pre-clinical drug testing. Methods: Human hepatic cell lines [HepG2/C3A or HepaRG] were grown to >80% confluence on collagen-I-coated plates and treated (in triplicates) 24 h with prototypical inducers rifampicin (CYP3A4) and omeprazole (CYP1A2), [n=3]. 50μM testosterone or phenacetin were added and supernatant and cell samples taken after 2 hours of incubation at 37°C. CYP1A2/3A4 activity [P450-Glo™-Luminometry; Promega] was determined (Figure 1). Relative turnover of testosterone [HPLC] and phenacetin [LC-MS/MS] metabolites was also measured. Cell phenotype was assessed by light-microscopy, histology (PAS-Glycogen), CYP3A4, F-actin/phalloidin, and JC-1 fluorescent-staining. Results: Figure 1 shows HepaRG CYP1A2/3A4 activity was 40-80x fold >> HepG2/C3A cells [P<0.001]; Drug profiling revealed HepaRGs had both enhanced production of major metabolites of phenacetin and testosterone and more intact drug metabolism compared with HepG2/C3A. In contrast with HepG2/C3A, HepaRGs displayed a more intact hepatic phenotype, including: Strong positive glycogen, CYP3A4 staining, high JC-1-positive intrinsic metabolic activity (ΔΨm) and organotypic gross morphology. Discussion / Conclusion: HepaRG cells may represent a more physiologically-relevant pre-clinical platform for CYP450 activation/ inhibition, safety pharmacology, as well as drug-drug interaction studies

Nomenclature and semantic description of vascular lesions in small bowel capsule endoscopy: an international Delphi consensus statement

Background and study aims \u2002Nomenclature and descriptions of small bowel (SB) vascular lesions in capsule endoscopy (CE) are scarce in the medical literature. They are mostly based on the reader's opinion and thus differ between experts, with a potential negative impact on clinical care, teaching and research regarding SBCE. Our aim was to better define a nomenclature and to give a description of the most frequent vascular lesions in SBCE. Methods \u2002A panel of 18 European expert SBCE readers was formed during the UEGW 2016 meeting. Three experts constructed an Internet-based four-round Delphi consensus, but did not participate in the voting process. They built questionnaires that included various still frames of vascular lesions obtained with a third-generation SBCE system. The 15 remaining participants were asked to rate different proposals and description of the most common SB vascular lesions. A 6-point rating scale (varying from 'strongly disagree' to 'strongly agree') was used successive rounds. The consensus was reached when at least 80\u200a% voting members scored the statement within the 'agree' or 'strongly agree'. Results \u2002Consensual terms and descriptions were reached for angiectasia/angiodysplasia, erythematous patch, red spot/dot, and phlebectasia. A consensual description was reached for more subtle vascular lesions tentatively named "diminutive angiectasia" but no consensus was reached for this term. Conclusion \u2002An international group has reached a consensus on the nomenclature and descriptions of the most frequent and relevant SB vascular lesions in CE. These terms and descriptions are useful in daily practice, for teaching and for medical research purposes