Fulminant ectopic Cushing's syndrome caused by metastatic small intestine neuroendocrine tumour - a case report and review of the literature.

Cushing's syndrome (CS) secondary to adrenocorticotropic hormone (ACTH) producing tumours is a severe condition with a challenging diagnosis. Ectopic ACTH-secretion often involves neuroendocrine tumours (NET) in the respiratory tract. ACTH-secreting small intestine neuro-endocrine tumours (siNET) are extremely rare entities barely reported in literature. This review is illustrated by the case of a 75-year old woman with fulminant ectopic CS caused by a ACTH-secreting metastatic siNET. Severe hypokalemia, fluid retention and refractory hypertension were the presenting symptoms. Basal and dynamic laboratory studies were diagnostic for ACTH-dependent CS. Extensive imaging studies of the pituitary and thorax-abdomen areas were normal, while [68Ga]Ga-DOTATATE PET-CT revealed increased small intestine uptake in the left iliac fossa. The hypercortisolism was well controlled with somatostatin analogues, after which a debulking resection of the tumour was performed. Pathological investigation confirmed a well-differentiated NET with sporadic ACTH immunostaining and post-operative treatment with somatostatin analogues was continued with favourable disease control.

Evaluating the accuracy of three international guidelines in identifying the risk of malignancy in pancreatic cysts: a retrospective analysis of a surgical treated population.

BACKGROUND AND STUDY AIMS: The international consensus Fukuoka guideline (Fukuoka ICG), The European evidence-based guideline on pancreatic cystic neoplasms (European EBG) and the American Gastroenterological Association institute guideline on the diagnosis and management of asymptomatic neoplastic pancreatic cysts (AGA IG) are 3 frequently cited guidelines for the risk stratification of neoplastic pancreatic cysts. The aim of this study was to assess the accuracy of detecting malignant cysts by strictly applying these guidelines retrospectively to a cohort of surgically resected pancreatic cysts. PATIENTS AND METHODS: 72 resected cysts were included in the analysis. Invasive carcinoma, high grade dysplasia and neuro-endocrine tumour were considered as "malignant cysts" for the purpose of the study. RESULTS: 32% of the resected cysts were malignant. The analysis showed that the Fukuoka ICG, European EBG and AGA IG had a sensitivity of 66,8%, 95,5%, 80%; a specificity of 26,8%, 11,3%, 43,8%; a positive predictive value of 31,8%, 35%, 47,1% and a negative predicted value of 61,1%, 83,3%, 77,8% respectively. The missed malignancy rate was respectively 11,3%, 1,5%, 7,7% and surgical overtreatment was respectively 48,4%, 59,1%, 34,6%. CONCLUSION: In this retrospective analysis, the European EBG had the lowest rate of missed malignancy at the expense of a high number of "unnecessary" resections. The Fukuoka ICG had the highest number of missed malignancy. The AGA IG showed the lowest rate of unnecessary surgery at the cost of a high number of missed malignancy. There is need to develop better biomarkers to predict the risk of malignancy.

Regression of multiple hepatocellular adenomas after cessation of oral contraceptive pills: a case report and review of the current literature.

Hepatocellular adenoma (HCA) is an uncommon benign liver neoplasm usually solitary and identified incidentally on imaging. We report a case of a 50-year old female who was diagnosed with multiple hepatic adenomas of the inflammatory subtype. After discontinuation of oral contraception a decrease of both the number and size of the liver lesions was seen on magnetic resonance imaging (MRI) without the need of further intervention. The major challenge in the clinical management of patients with multiple HCAs resides in the risk assessment for future complications. In the case of multiple HCAs subtype seemed to be more relevant than the actual number of lesions. Because little is known about the natural evolution in patients with multiple HCAs, we performed a review of the current literature with focus on the different subtypes and their clinical relevance.

The PDGFRα-laminin B1-keratin 19 cascade drives tumor progression at the invasive front of human hepatocellular carcinoma.

Human hepatocellular carcinomas (HCCs) expressing the biliary/hepatic progenitor cell marker keratin 19 (K19) have been linked with a poor prognosis and exhibit an increase in platelet-derived growth factor receptor α (PDGFRα) and laminin beta 1 (LAMB1) expression. PDGFRα has been reported to induce de novo synthesis of LAMB1 protein in a Sjogren syndrome antigen B (La/SSB)-dependent manner in a murine metastasis model. However, the role of this cascade in human HCC remains unclear. This study focused on the functional role of the PDGFRα-La/SSB-LAMB1 pathway and its molecular link to K19 expression in human HCC. In surgical HCC specimens from a cohort of 136 patients, PDGFRα expression correlated with K19 expression, microvascular invasion and metastatic spread. In addition, PDGFRα expression in pre-operative needle biopsy specimens predicted poor overall survival during a 5-year follow-up period. Consecutive histological staining demonstrated that the signaling components of the PDGFRα-La/SSB-LAMB1 pathway were strongly expressed at the invasive front. K19-positive HCC cells displayed high levels of α2ß1 integrin (ITG) receptor, both in vitro and in vivo. In vitro activation of PDGFRα signaling triggered the translocation of nuclear La/SSB into the cytoplasm, enhanced the protein synthesis of LAMB1 by activating its internal ribosome entry site, which in turn led to increased secretion of laminin-111. This effect was abrogated by the PDGFRα-specific inhibitor crenolanib. Importantly LAMB1 stimulated ITG-dependent focal adhesion kinase/Src proto-oncogene non-receptor tyrosine kinase signaling. It also promoted the ITG-specific downstream target Rho-associated coiled-coil containing protein kinase 2, induced K19 expression in an autocrine manner, invadopodia formation and cell invasion. Finally, we showed that the knockdown of LAMB1 or K19 in subcutaneous xenograft mouse models resulted in significant loss of cells invading the surrounding stromal tissue and reduced HepG2 colonization into lung and liver after tail vein injection. The PDGFRα-LAMB1 pathway supports tumor progression at the invasive front of human HCC through K19 expression.

Combined or Serial Liver and Lung Transplantation for Epithelioid Hemangioendothelioma: A Case Series.

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor with variable biological and clinical behavior. There is increasing experience with liver transplantation (LiTx) for hepatic EHE, even in cases of extrahepatic disease localization. Until now, no cases of lung transplantation (LuTx) had been reported for pulmonary EHE. This report describes three cases of EHE with multifocal disease in patients who underwent either serial or combined LiTx and LuTx.

Potentiation of adverse effects of cold by warm ischemia in circulatory death donors for porcine liver transplantation.

BACKGROUND: Wider use of donors after circulatory death (DCD) could reduce mortality on the liver transplantation waiting list. We previously reported that pig livers exposed to ≥ 30 minutes of warm ischemia followed by 4 hours of cold ischemia are at high risk of primary graft nonfunction. We sought to determine how prolonged cold ischemia, after a short, normally well-tolerated period of warm ischemia affects graft function and recipient survival using a porcine model of liver transplantation. MATERIALS AND METHODS: Livers were transplanted after exposure to no warm plus 4 hours cold ischemia (group 1); 15 minutes of warm and 4 hours of cold ischemia (group 2); no warm and 8 hours of cold ischemia (group 3); or 15 minutes of warm and 8 hours of cold ischemia (group 4). Recipient survival, graft dysfunction incidence, liver function (prothrombin time), hepatocellular damage (aspartate aminotransferase), sinusoidal cell function (hyaluronic acid), and inflammation (tumor necrosis factor-α) were recorded after transplantation. Biopsies were scored for ischemia-reperfusion injury. RESULTS: Day 4 survival in group 4 was 0% versus 100%, 83%, and 100% in groups 1, 2, and 3, respectively. Recipients in group 4 exposed to short warm but prolonged cold ischemia displayed severe graft dysfunction, the highest peak transaminase, the greatest inflammatory response, more sinusoidal endothelial cell dysfunction and, the worst histologic score for ischemia-reperfusion injury. CONCLUSIONS: Liver grafts from DCD donors, even when exposed to short periods of warm ischemia, did not tolerate prolonged cold ischemia well and should be transplanted without delay.

Idiopathic noncirrhotic portal hypertension is associated with poor survival: results of a long-term cohort study.

BACKGROUND: Idiopathic noncirrhotic portal hypertension (INCPH) is a rare disease in the Western world. As a result, little is known about the clinical characteristics and outcome of these patients. Survival in these patients is considered to be similar to that of the general population. AIM: To investigate the clinical manifestations, pathophysiology, outcome and determinants of survival in Western INCPH patients. METHODS: Multicentre cohort study of INCPH patients. RESULTS: A total of 62 patients were followed for a median time of 90 months (range 24-310). Initial manifestations leading to the diagnosis of INCPH were related to portal hypertension in 82% of the patients. Histological signs of portal blood supply disturbances were present in nearly all patients. During follow-up, 12 of 62 patients developed liver decompensation, of which four were considered for liver transplantation. One patient died in the context of variceal bleeding. Hepatocellular carcinoma was not observed during follow-up. A total of 23 patients died during follow-up, only four of them due to liver related mortality. The Kaplan-Meier estimates for overall survival were 100% (95% CI 95-100%), 78% (95% CI 67-89%) and 56% (95% CI 40-72%) at 1, 5 and 10 years respectively. Survival for INCPH was significantly decreased (P < 0.001) compared to survival of the general population. Ascites was an independent predictor of poor outcome. CONCLUSIONS: In comparison to the general population, survival in INCPH patients is poor. Mortality is related to associated disorders and medical conditions occurring at older age. Patients rarely die due to liver related complications. Patients with ascites have a poor prognosis.

Characterisation of the hepatic progenitor cell compartment in normal liver and in hepatitis: an immunohistochemical comparison between dog and man.

The liver progenitor cell compartment in the normal canine liver and in spontaneous canine acute (AH) and chronic hepatitis (CH) was morphologically characterised and compared to its human equivalents. Immunohistochemistry was performed for cytokeratin-7 (CK7), human hepatocyte marker (Hep Par 1), multidrug resistance-associated protein-2 (MRP2), and breast cancer resistance protein (BCRP) on paraffin and frozen sections from canine and human tissues. Normal liver showed similar morphology and immunohistochemical reaction of the progenitor cell compartment/canal of Hering in man and dog. In addition, a ductular reaction, comparable in terms of severity, location and immunohistochemical characteristics, was observed in canine and human AH and CH. CK7 was a good marker for canine progenitor cells, including intermediate cells, which were positively identified in cases of AH and CH. In both species, BCRP was expressed in both hepatocytes and bile ducts of the normal liver, and in ductular reaction in AH and CH. MRP2 detected bile canalicular membranes in man and dog. These findings underline the similarities between canine and human liver reaction patterns and may offer mutual advantage for comparative research in human and canine spontaneous liver diseases.

Stem and progenitor cells for liver repopulation: can we standardise the process from bench to bedside?

There has been recent progress in the isolation and characterisation of stem/progenitor cells that may differentiate towards the hepatic lineage. This has raised expectations that therapy of genetic or acquired liver disease might be possible by transplanting stem/progenitor cells or their liver-committed progeny. However, it is currently impossible to determine from the many documented studies which of the stem/progenitor cell populations are the best for therapy of a given disease. This is largely because of the great variability in methods used to characterise cells and their differentiation ability, variability in transplantation models and inconsistent methods to determine the effect of cell grafting in vivo. This manuscript represents a first proposal, created by a group of investigators ranging from basic biologists to clinical hepatologists. It aims to define standardised methods to assess stem/progenitor cells or their hepatic lineage-committed progeny that could be used for cell therapy in liver disease. Furthermore standardisation is suggested both for preclinical animal models to evaluate the ability of such cells to repopulate the liver functionally, and for the ongoing clinical trials using mature hepatocytes. Only when these measures have been put in place will the promise of stem/progenitor-derived hepatocyte-based therapies become reality.

Pharmacological IKK2 inhibition blocks liver steatosis and initiation of non-alcoholic steatohepatitis.

BACKGROUND: Non-alcoholic-steatohepatitis (NASH) leading to fibrosis, end-stage cirrhosis and hepatocellular carcinoma is an increasing health problem in the Western world. Thus, the need for new therapeutic approaches is increasing. IKK2 plays a key role in the development of NASH by mediating inflammation and insulin resistance. AIM: Here the beneficial effects of a pharmacological IKK2 inhibitor (AS602868) on initial stages of NASH progression were tested. METHODS: Mice were fed with a high sucrose diet (HSD) and daily-administered AS602868 and vehicle. The impact of AS602868 on NASH progression was studied using biochemical, histological and molecular markers. RESULTS: AS602868 treatment prevented HSD-induced weight gain and visceral fat accumulation. In adipose tissue, AS602868-treated mice exhibited a lower degree of infiltrated macrophages along with reduced proinflammatory cytokine production. Further analysis demonstrated that AS602868 treatment efficiently inhibited nuclear factor (NF)-kappaB activation in liver non-parenchymal cells and as a consequence attenuated the inflammatory response in the liver. Accordingly, in HSD/AS602868 mice, liver and adipose tissue adiponectin levels remained at levels comparable with those of control chow-fed mice, while they were decreased in HSD/vehicle animals. Additionally, AS602868 improved lipid beta-oxidation mediated by peroxisome proliferator-activated receptor (PPAR) alpha and PPARgamma. Systemic pharmacological IKK2 inhibition by AS602868 treatment efficiently prevented liver steatosis and inflammation, and improved antioxidant response. All this contributed to attenuation of NASH progression as evidenced by lower hepatocyte apoptosis and early stages of liver fibrosis. CONCLUSION: The data demonstrate that AS602868-mediated IKK2 inhibition represents a new therapeutic approach to prevent dietary-induced NASH progression.

Squamous cell carcinoma antigen in human liver carcinogenesis.

BACKGROUND: Squamous cell carcinoma antigen (SCCA) is a serine protease inhibitor that can be overexpressed in hepatocellular carcinoma (HCC) at both molecular and protein level, but no data are available on its expression in pre-malignant stages. AIM: To assess SCCA expression by immunohistochemistry in HCC and its nodular precursors in cirrhotic livers. METHODS: 55 nodules from 42 explanted livers were evaluated: 7 large regenerative nodules (LRNs), 7 low-grade dysplastic nodules (LG-DNs), 10 high-grade DNs (HG-DNs), and 31 HCC. SCCA expression was semiquantitatively scored on a four-tiered scale. RESULTS: SCCA hepatocyte immunostaining was always restricted to the cytoplasm, mainly exhibiting a granular pattern. Stain intensity varied, ranging from weak to very strong. Within the nodules, positive cells were unevenly distributed, either scattered or in irregular clusters. The prevalence of SCCA expression was 29% in LRNs, 100% in DNs and 93% in HCC. A significant difference emerged in both prevalence and score for LRNs versus LG-DNs (p<0.039), HG-DNs (p = 0.001), and HCC (p = 0.000). A barely significant difference (p = 0.49) was observed between LG-DNs and HG-DNs, while no difference in SCCA expression was detected between HG-DNs and HCC. Cirrhotic tissue adjacent to the nodules was positive in 96% of cases, with a significant difference in the score (p = 0.000) between hepatocytes adjacent to HCC and those surrounding LRNs. DISCUSSION: This study provides the first evidence that aberrant SCCA expression is an early event in liver cell carcinomatous transformation.

Effect of nutritional supplement challenge in patients with isolated high-grade prostatic intraepithelial neoplasia.

OBJECTIVES: To investigate, through a prospective follow-up study, the effects of a dietary supplementation challenge in men with isolated high-grade prostatic intraepithelial neoplasia (HGPIN). METHODS: The effects of a 6-month supplementation challenge with selenium, vitamin E, and soy isoflavonoids in men diagnosed with isolated HGPIN on biopsy were evaluated. A total of 100 patients entered the study. Of the 100 men, 29 were excluded because they refused additional biopsies or were noncompliant with the protocol, 71 underwent repeat biopsies at 3 months, and 58 underwent a third set at 6 months. The prostate-specific antigen (PSA) level was recorded at inclusion and before each set of biopsies. The study endpoint was defined as the diagnosis of PCa at 3 months or the histopathologic status at 6 months. RESULTS: At the study endpoint, PCa had been found in 24 men (33.8%), HGPIN in 34 (47.9%), and no HGPIN or carcinoma in 13 (18.3%). The PCa risk throughout the study period was 25.0% in the group with a stable or decreasing PSA level (n = 48, 67.6%) and 52.2% in the group with an increasing PSA level (n = 23, 32.4%). This difference was statistically significant (P = 0.0458). Isolated HGPIN remaining at the first repeat biopsy and the percentage of initial cores with HGPIN were significant predictors of PCa at additional biopsies. CONCLUSIONS: The results of our study have shown that a decrease in the PSA level while taking a selenium, vitamin E, and soy isoflavonoids supplement predicts for a significantly lower risk of PCa in future biopsies. The percentage of initial biopsy cores with HGPIN and isolated HGPIN remaining at the first repeat biopsy are significant predictors of PCa in future biopsies.

High-grade clear cell renal cell carcinoma has a higher angiogenic activity than low-grade renal cell carcinoma based on histomorphological quantification and qRT-PCR mRNA expression profile.

Clear cell renal cell carcinoma (CC-RCC) is a highly vascularised tumour and is therefore an attractive disease to study angiogenesis and to test novel angiogenesis inhibitors in early clinical development. Endothelial cell proliferation plays a pivotal role in the process of angiogenesis. The aim of this study was to compare angiogenesis parameters in low nuclear grade (n=87) vs high nuclear grade CC-RCC (n=63). A panel of antibodies was used for immunohistochemistry: CD34/Ki-67, carbonic anhydrase IX, hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF). Vessel density (MVD - microvessel density), endothelial cell proliferation fraction (ECP%) and tumour cell proliferation fraction (TCP%) were assessed. mRNA expression levels of angiogenesis stimulators and inhibitors were determined by quantitative RT-PCR. High-grade CC-RCC showed a higher ECP% (P=0.049), a higher TCP% (P=0.009), a higher VEGF protein expression (P<0.001), a lower MVD (P< 0.001) and a lower HIF-1alpha protein expression (P=0.002) than low-grade CC-RCC. Growth factor mRNA expression analyses revealed a higher expression of angiopoietin 2 in low-grade CC-RCC. Microvessel density and ECP% were inversely correlated (Rho=-0.26, P=0.001). Because of the imperfect association of nuclear grade and ECP% or MVD, CC-RCC was also grouped based on low/high MVD and ECP%. This analysis revealed a higher expression of vessel maturation and stabilisation factors (placental growth factor, PDGFB1, angiopoietin 1) in CC-RCC with high MVD, a group of CC-RCC highly enriched in low nuclear grade CC-RCC, with low ECP%. Our results suggest heterogeneity in angiogenic activity and vessel maturation of CC-RCC, to a large extent linked to nuclear grade, and, with probable therapeutic implications.

Transrectal ultrasound in the staging of clinical T3a prostate cancer.

INTRODUCTION: The clinical staging of T3a prostate cancer is usually based on digital rectal examination (DRE). Overstaging of clinical T3a prostate cancer is present in 13-27% of the cases presented and understaging is in the range of 30%. The value of transrectal ultrasound (TRUS) as a staging tool is not generally accepted. The purpose of this study is to determine whether TRUS can refine the local staging in unilateral clinical T3a (cT3a) prostate cancer. PATIENTS AND METHODS: Between 1987 and 2004, 200 patients were staged as unilateral cT3a prostate cancer by DRE. All patients underwent radical prostatectomy and bilateral pelvic lymphadenectomy. Preoperative TRUS staging was performed for all patients. Final histopathological staging was compared with DRE and TRUS staging. The operable group (OG) was defined as T2 to unilateral T3a, and the advanced group (AG) was defined as bilateral T3a to T4. RESULTS: All DRE patients were assumed operable. However, in this group histopathology showed 27.0% of the patients had advanced disease. TRUS confirmed 184 patients to be operable (140 having unilateral cT3a, 44 patients having cT1c to cT2). Sixteen patients were considered to have advanced disease by TRUS. Importantly, in this group, 68.7% of the cases were indeed confirmed to have advanced disease by histopathology. CONCLUSION: TRUS can be used to refine clinical staging in unilateral cT3a prostate cancer. In cases where TRUS indicates advanced disease, it might be wise to trust the TRUS staging, rather than the DRE.

The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin.

AIMS: Cytokeratin (CK) 7 and CK19 expression, present in hepatic progenitor cells (HPCs) and in cholangiocytes but not in normal hepatocytes, has been reported in some hepatocellular carcinomas (HCCs); however, the incidence and relevance of this expression in HCC in Caucasians is not known. Therefore, our aim was to study the occurrence and clinicopathological characteristics of HCC expressing CK7 and/or CK19 in 109 Caucasian patients. METHODS AND RESULTS: The expression of hepatocellular differentiation markers (Hepar, canalicular polyclonal carcinoembryonic antigen), biliary/progenitor cell markers (CK7, CK19), alpha-fetoprotein (AFP), p53 and beta-catenin in HCC was semiquantitatively assessed by immunohistochemistry. Of 109 HCCs, 78 were CK7-/CK19- (72%), 13 CK7+/CK19- (12%), seven CK7-/CK19+ (6%), 11 CK7+/CK19+ (10%). CK19 expression was significantly associated with elevated serum AFP (400 ng/ml) (P = 0.023), tumour AFP expression (P < 0.0001), presence in serum of anti-hepatitis B core (P = 0.016), less fibrosis in non-neoplastic parenchyma (P = 0.009) and less nuclear beta-catenin expression (P = 0.021). CK7 expression was significantly associated with elevated serum bilirubin (> 2 mg/dl) (P = 0.0005) and less nuclear beta-catenin expression (P = 0.003). HCC expressing CK19 had a higher rate of recurrence (P = 0.009, hazard ratio 12.5, n = 31) after liver transplantation compared with CK19- tumours. CONCLUSIONS: In our series, 28% of HCCs contained cells expressing CK7 and/or CK19. They potentially derive from HPCs. The higher recurrence rate of CK19+ HCC after transplantation suggests a worse prognosis for these HCCs compared with CK19- HCC.

Liver stem cells and their implication in hepatocellular and cholangiocarcinoma.

In the liver, several cell types have the longevity that is needed to be the cell of origin of a cancer: hepatocytes, cholangiocytes and progenitor cells. The latter are located in the most peripheral branches of the biliary tree, the ductules and canals of Hering. The most important risk factors for liver cancer are chronic viral hepatitis B and C and alcoholic and non-alcoholic steatohepatitis. In these and other chronic liver diseases, progenitor cell activation is seen, rendering them a target cell population for carcinogenesis. The degree of activation is positively correlated with the inflammatory activity and the stage of the disease. Recently, it has been shown that in the cirrhotic stage of most chronic liver diseases, the hepatocytes become senescent owing to telomere shortening. This makes it even more plausible that at least part of the hepatocellular carcinomas originate from a progenitor cell. Hepatocellular carcinomas expressing progenitor cell/ductular markers like cytokeratin 19 have a more aggressive clinical course. It is therefore important to recognize this entity.

The effect of imatinib mesylate on the contractility of isolated rabbit myometrial strips.

BACKGROUND: C-kit receptor expressing interstitial cells generate and coordinate the electrical signals that control peristalsis in the gut. However, the function of interstitial cells in the myometrium is not known. METHODS: (1) Sections of rabbit myometrium were subjected to immunohistochemical staining for the c-kit receptor. (2) Spontaneously contracting myometrial strips from New Zealand White rabbits near term were mounted in an organ bath and attached to a tension-recording device. The effect of increased concentrations of the c-kit receptor antagonist imatinib mesylate on these contractions was observed. The main outcome measures were the change in frequency, amplitude and duration of contraction. RESULTS: (1) Multipolar cells expressing c-kit were identified in the fibromuscular septum confirming the presence of interstitial cells in rabbit myometrium. (2) Imatinib decreased the amplitude of contractions by approximately 20% at 100 microM. No effect was seen at lower concentrations. No effect of imatinib on frequency or duration of contractions was observed at any of the concentrations studied. CONCLUSIONS: In isolated rabbit myometrium, acute inhibition of the c-kit receptor by imatinib mesylate affects only the amplitude of spontaneous contractions at concentrations, the equivalent of x10-100 the normal therapeutic concentration.

A stable model of cirrhotic portal hypertension in the rat: thioacetamide revisited.

BACKGROUND: Cirrhotic animal models are vital to investigate complications of chronic liver disease. We chronologically characterized the effect of thioacetamide, administrated orally and adapted weekly to weight changes, focusing on the optimal moment to obtain all typical features of portal hypertension and cirrhosis. MATERIALS AND METHODS: Male Wistar rats, 200-250 g, were intoxicated for 6, 12 or 18 weeks (n = 8 per group), respectively, and compared with age-matched controls (n = 4 per group). An in-situ perfusion model was used to evaluate intrahepatic resistance and endothelial function. Splanchnic blood flow and portosystemic shunting were assessed by a perivascular flow probe. RESULTS: Rats intoxicated for 6 or 12 weeks had no mortality and histologically showed hepatitis and advanced fibrosis, respectively. At 18 weeks, mortality was 16% (on a total of 56 animals) and only at that moment all animals showed homogenous macronodular cirrhosis with signs of high-grade hepatocellular dysplasia. Portal hypertension was present at 12 weeks (11 +/- 0.4 vs. 5.9 +/- 0.4 mmHg, P < 0.001), but was not associated with the hyperdynamic state until 18 weeks (12.1 +/- 0.8 vs. 5.6 +/- 0.5 mmHg, P < 0.001). At this latter time-point, we also observed increased intrahepatic resistance associated with endothelial dysfunction, hyperresponsiveness to vasoconstrictors, splanchnic hyperaemia and portosystemic shunting. These alterations were associated with increased systemic levels of nitrate/nitrite and thromboxane A(2). CONCLUSION: Thioacetamide, adapted to weekly weight changes, leads to a homogenous, reproducible model of cirrhosis in the rat in 18 weeks, which is associated with all the typical characteristics of portal hypertension, including endothelial dysfunction.