bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization rates, complications and costs of percutaneous liver biopsy: a population‐based study including 4275 biopsies
Authors: Myers Robert P. , Fong Andrew , Shaheen Abdel Aziz M.
Published: August 2010

Background: Liver biopsy is an important tool in the management of patients with liver disease. Because biopsy practices may be changing, we studied patterns of use in a large Canadian Health Region. We aimed to describe trends in biopsy utilization and the incidence and costs of complications from a population‐based perspective.

Methods: Administrative databases were used to identify percutaneous liver biopsies performed between 1994 and 2002. Significant complications were identified by reviewing medical records of patients hospitalized within 7 days of a biopsy and those with a diagnostic code indicative of a procedural complication. Analyses of biopsy rates employed Poisson regression.

Results: Between 1994 and 2002, 3627 patients had 4275 liver biopsies (median 1 per patient; range 1–12). Radiologists performed the majority (90%), particularly during the latter years (1994 vs. 2002: 73 vs. 98%; P<0.0001). The overall annual biopsy rate was 54.8 per 100 000 population with a 41% (95% CI 23–61%) increase between 1994 and 2002. Annual increases were greatest in males and patients 30–59 years. Thirty‐two patients (0.75%) had significant biopsy‐related complications (1994–1997 vs. 1998–2002: 1.28 vs. 0.44%; P=0.003). Pain requiring admission (0.51%) and bleeding (0.35%) were most common. Six patients (0.14%) died; all had malignancies. The median direct cost of a hospitalization for complications was $4579 (range $1164–29 641).

Conclusions: Liver biopsy rates are increasing likely owing to the changing epidemiology and management of common liver diseases. The similarity of the complication rate in our population‐based study with estimates from specialized centres supports the safety of this important procedure.
Intra‐operative application of real‐time tissue elastography for the diagnosis of liver tumours
Authors: Kato Koichi , Sugimoto Hiroyuki , Kanazumi Naohito , Nomoto Shuji , Takeda Shin , Nakao Akimasa
Published: August 2010

Objective: Real‐time tissue elastography (RTE) has made it possible to visualize tissue elasticity. The aim of this study was to evaluate the usefulness of RTE for the differential diagnosis of liver tumours during surgical exploration.

Methods: Fifty‐five liver tumours in 44 patients were examined with RTE, concomitant with routine intra‐operative ultrasonography. Elasticity images were classified into four types, from type A (even strain) to type D (no strain), according to the distribution and the degree of the strain contrasted with that of the surrounding liver [elasticity type of liver tumour (ETLT)]. We evaluated the consistency of the findings of RTE with the pathological diagnosis as a reference standard.

Results: All malignant lesions showed various degrees of strain reduction in the tumour tissue. Twenty‐one of 22 hepatocellular carcinomas (HCCs) were classified as type B with a sensitivity of 95.5%, a specificity of 90.9% and an accuracy of 92.7%, while all 24 metastatic adenocarcinomas were classified as either type C or type D with a sensitivity of 100%, a specificity of 80.6% and an accuracy of 89.1%.

Conclusion: Application of RTE in surgical exploration provided significant information about the elasticity of liver tumours. RTE, using a new criterion, ETLT, enabled us to distinguish rather accurately between two common malignancies: HCC and metastatic adenocarcinoma.
Hepatic fat and adenosine triphosphate measurement in overweight and obese adults using 1H and 31P magnetic resonance spectroscopy
Authors: Solga Steven F. , Horska Alena , Hemker Susanne , Crawford Stephen , Diggs Charalett , Diehl Anna Mae , Brancati Frederick L. , Clark Jeanne M.
Published: August 2010

Background/Aims: Magnetic resonance spectroscopy (MRS) measures hepatic fat and adenosine triphosphate (ATP), but magnetic resonance studies are challenging in obese subjects. We aimed to evaluate the inter‐ and intrarater reliability and stability of hepatic fat and ATP measurements in a cohort of overweight and obese adults.

Methods: We measured hepatic fat and ATP using proton MRS (1H MRS) and phosphorus MRS (31P MRS) at baseline in adults enrolled in the Action for Health in Diabetes (Look AHEAD) clinical trial at one site. Using logistic regression, we determined factors associated with successful MRS data acquisition. We calculated the intra‐ and inter‐rater reliability for hepatic fat and ATP based on 20 scans analysed twice by two readers. We also calculated the stability of these measures three times on five healthy volunteers.

Results: Of 244 participants recruited into our ancillary study, 185 agreed to MRS. We obtained usable hepatic fat data from 151 (82%) and ATP data from 105 (58%). Obesity was the strongest predictor of failed data acquisition; every unit increase in the body mass index reduced the likelihood of successful fat data by 11% and ATP data by 14%. The inter‐ and intrarater reliability were excellent for fat (intraclass correlation coefficient=0.99), but substantially more variable for ATP. Fat measures appeared relatively stable, but this was less true for ATP.

Conclusions: Obesity can hinder 1H and 31P MRS data acquisition and subsequent analysis. This impact was greater for hepatic ATP than hepatic fat.
Macaca radiata (bonnet monkey): a spontaneous model of nonalcoholic fatty liver disease
Authors: Nagarajan Perumal , Venkatesan Ramasamy , Kumar Mahesh , Usmani Abul , Majumdar Subeer S.
Published: August 2010

Background: Nonalcoholic fatty liver disease (NAFLD) is a well‐recognized condition that includes a spectrum of clinicopathology conditions ranging from steatotosis to cirrhosis and liver failure. Available animal models are not ideal as they show only a partial resemblance to characteristic human NAFLD.

Objective: This study was aimed at identifying a nonhuman primate model of NAFLD resembling features of human NAFLD, which will be useful in understanding the mechanism of the onset of this disease and for developing novel therapeutic modalities.

Methods: The histological status of the liver and serum levels of triglycerides (TG), cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) of aged bonnet monkeys were compared with that of the aged rhesus and adult bonnet monkeys. Histopathology and immunostaining of liver sections and oil red ‘O’ confirmed NAFLD in aged bonnet monkeys.

Results: Aged bonnet monkeys showed a significant (P<0.01) increase in serum TG, AST and ALT compared with aged rhesus and adult bonnet monkeys. Histopathology of the liver of aged bonnet macaques showed diffused microvesicular and macrovesicular fatty changes, perivenular and portal and perisinusoidal fibrosis with fatty degeneration of hepatocytes, and immunostaining of liver sections was suggestive of NAFLD.

Conclusion: The spontaneous occurrence of NAFLD in normal animals is rare, but aged bonnet monkeys may serve as a unique animal model for studies related to NAFLD because they mimic pathophysiological features of human NAFLD.
Inflammatory change of fatty liver induced by intraportal low‐dose lipopolysaccharide infusion deteriorates pancreatic insulin secretion in fructose‐induced insulin‐resistant rats
Authors: Hsieh Po‐Shiuan
Published: August 2010

Background: This study tested whether subacute inflammatory change of fatty liver induced by portal endotoxaemia is detrimental to pancreatic insulin secretion in fructose‐fed rats (FFRs) with fatty liver.

Methods: Rats were randomly assigned into two groups with a regular or fructose‐enriched diet for 8 weeks. Rats, after fructose feeding for 4 weeks, were further divided into three subgroups: on fructose diet alone, on fructose diet combined with intraportal saline or lipopolysaccharide (LPS) infusion (n=8 per group) for the next 4 weeks. In another set of experiments, the liver and pancreatic tissues were obtained for histological examination in these four groups. Pancreatic insulin secretion was evaluated by in vivo hyperglycaemic clamp study.

Results: Fasting plasma insulin concentrations and homoeostasis model assessment‐insulin resistance, an insulin resistance score, were significantly increased in FFRs but failed to change in rats with LPS treatment. The 4‐week intraportal LPS infusion significantly increased circulating aspartate transaminase, alanine transaminase and C‐reactive protein levels but did not alter endotoxin levels in FFRs. The increased white blood cell count was also noted in rats after intraportal LPS infusion for 2 and 4 weeks. The attenuated first‐phase and second‐phase insulin responses in FFRs shown in hyperglycaemic clamp were further deteriorated in those with intraportal LPS infusion. Increased histopathological scores of liver and pancreas shown in FFRs were further increased in those combined with portal endotoxaemia.

Conclusion: This study demonstrates that the chronic subacute inflammatory change of fatty liver induced by mild portal endotoxaemia could deteriorate insulin secretion in a rodent model of metabolic syndrome and fatty liver.
Prevention of paracentesis‐induced circulatory dysfunction: midodrine vs albumin. A randomized pilot study
Authors: Appenrodt Beate , Wolf Andrea , Grünhage Frank , Trebicka Jonel , Schepke Michael , Rabe Christian , Lammert Frank , Sauerbruch Tilman , Heller J.
Published: August 2010

Background/Aims: Large‐volume paracentesis in patients with cirrhosis and ascites induces arterial vasodilatation and decreases effective arterial blood volume, termed paracentesis‐induced circulatory dysfunction (PICD), which can be prevented by costly intravenous albumin. Vasoconstrictors, e.g. terlipressin, may also prevent PICD. The aim was to compare the less expensive vasoconstrictor midodrine, an α‐adrenoceptor agonist, with albumin in preventing PICD.

Methods: Twenty‐four patients with cirrhosis and ascites were randomly assigned to be treated with either midodrine (n=11) (12.5 mg three times per day; over 2 days) or albumin (n=13) (8 g/L of removed ascites) after large‐volume paracentesis. Effective arterial blood volume was assessed indirectly by measuring plasma renin and aldosterone concentration on days 0 and 6 after paracentesis; renal function and haemodynamic changes were also measured. PICD was defined as an increase in plasma renin concentration on day 6 by more than 50% of the baseline value.

Results: PICD developed in six patients of the midodrine group (60%) and in only four patients (31%) of the albumin group. Six days after paracentesis, the aldosterone concentration increased significantly in the midodrine group, but not in the albumin group.

Conclusions: This pilot study suggests that midodrine is not as effective as albumin in preventing circulatory dysfunction after large‐volume paracentesis in patients with cirrhosis and ascites.
Post‐transplant recurrent hepatitis C: immunohistochemical detection of hepatitis C virus core antigen and possible pathogenic implications
Authors: Pessôa Mário G. , Alves Venancio A.F. , Wakamatsu Alda , Gomes Joaquim G. , Maertens Geert , Van Der Borght Bart , Kim Michael , Ferrell Linda , Wright Teresa L.
Published: August 2010

Introduction: The mechanisms by which severe cholestatic hepatitis develops after liver transplantation are not fully understood. Reports on immunohistochemical distribution of hepatitis C virus (HCV) antigens are still scarce, but recently, HCV immunostaining was suggested for early diagnosis of cholestatic forms of recurrent hepatitis C in liver grafts. After purification, Rb246 pab anticore (aa1‐68) yielded specific, granular cytoplasmic staining in hepatocytes. Signal amplification through the Envision‐Alkaline Phosphatase System avoided endogenous biotin and peroxidase.

Aims/Methods: Rb246 was applied to liver samples of explants of 12 transplant recipients, six with the most severe form of post‐transplantation recurrence, severe cholestatic hepatitis (group 1) and six with mild recurrence (group 2). We also assessed immuno‐reactivity at two time‐points post‐transplantation (median 4 and 22 months) in both groups. HCV‐core Ag was semiquantified from 0 to 3+ in each time point. Serum HCV‐RNA was also measured on the different time points by branched DNA.

Results: In the early post‐transplant time point, one patient had a mild staining (1+), two patients had a moderate staining (2+) and the other three had no staining in group 1, compared with five patients with no staining (0) and one patient with mild staining (1+) in group 2. Late post‐transplant liver samples were available in nine patients, and two out of four samples in group 1 showed a mild staining, compared with no staining patients in five patients in group 2. Strikingly, on the explant samples, HCV immunostaining was strongly positive in group 1, and mildly positive in group 2. Two out of five samples showed 3+ staining, and three samples showed 2+ staining in group 1; two out of five samples showed no staining, two samples showed 1+ staining and one sample showed 2+ staining in group 2. Serum HCV‐RNA was significantly higher in group 1, on both time‐points post‐transplantation. HCV‐core Ag was not directly associated with serum HCV‐RNA on the different time points.

Conclusion: These preliminary results suggest that strong HCV immunostaining in the explant is predictive of more severe disease recurrence.
Living donor liver transplantation in hepatocellular carcinoma beyond the Milan criteria
Authors: Woo Hyun Young , Jang Jeong Won , Choi Jong Young , You Chan Ran , Jeong Soung Won , Bae Si Hyun , Yoon Seung Kew , Lee Young Sok , Kim Dong Goo
Published: August 2010

Background/Aims: In patients with hepatocellular carcinoma (HCC) exceeding the Milan criteria, the recurrence rate after liver transplantation is over 50%. We investigated pretransplant factor(s) that could predict recurrence after living donor liver transplantation (LDLT) in patients with HCC exceeding the Milan criteria.

Methods: Pre‐operative imaging showed that, of the 111 HCC patients who underwent LDLT between June 1995 and January 2006, 37 exceeded the Milan criteria. Clinical factors before LDLT were evaluated.

Results: The 1‐ and 3‐year cumulative recurrence rates were 35 and 55% respectively. Pretransplant risk factors for HCC recurrence were large tumour size (>6 cm, P=0.001), tumour exposed to the liver surface (P=0.014) and progressive disease after pretransplant treatment (P=0.038). The 2‐year HCC recurrence rates in patients with 0, 1, 2 and 3 factors were 0% (0/4), 9% (1/16), 80% (8/10) and 100% (7/7) respectively (P<0.001). The 2‐year survival rate was significantly higher in patients with 0 or 1 factor than in patients with two or more factors (P=0.022).

Conclusions: In patients with HCC exceeding the Milan criteria, the three pretransplant factors that may be useful for identifying those with high HCC recurrence potential after LDLT are tumour size >6 cm, progressive disease after pretransplant treatment and tumour exposed to the liver surface.
Origin of stellate cells from submesothelial cells in a developing human liver
Authors: Loo Christine K. C. , Wu Xiao‐Juan
Published: August 2010

Background: The embryonic origin of liver stellate cells is unknown.

Methods: We investigated the development of stellate cells in histological sections of human liver of 7–20 weeks gestation, using neural cell adhesion molecule (N‐CAM) to highlight stellate cells by the immunoperoxidase method.

Results: We observed a layer of submesothelial cells beneath the liver capsule in the first trimester of gestation, which express N‐CAM and desmin antigens by the immunoperoxidase method but not epithelial‐cadherin, smooth muscle actin or CD34 antigens, unlike hepatocytes and similar to septum transversum mesenchyme. In embryonic liver, stellate cells appeared to grow from pockets of submesothelial cells, with transitional forms observed between the cell types. The submesothelial cells morphologically resemble those described during the rapid growth phase in avian liver, which have been shown to be precursors of stellate cells. There is considerable evidence for epithelial–mesenchymal interactions during development, and we have also found that hepatocytes adjacent to the capsule and around the portal tracts show enhanced expression of β‐catenin in developing liver. These are sites in which stellate cells appeared to be concentrated.

Conclusion: We present evidence to suggest that stellate cells originate from submesothelial cells, which possibly derive from the septum transversum.
Median liver lobe of woodchuck as a model to study hepatic outflow obstruction: a pilot study
Authors: Dahmen Uta , Radtke A. , Schröder T. , Chi H. , Madrahimov N. , Lu M. , Schenk A. , Peitgen K. H. , Dirsch O.
Published: August 2010

Background: Hepatic vein outflow obstruction represents an important clinical problem in living‐liver transplantation. An animal model is required to study the influence of outflow obstruction on the intrahepatic regulation of liver perfusion and the subsequent effects on liver injury and recovery during liver regeneration. The size of woodchucks enables the use of standard clinical imaging procedures.

Aim: This study aims at describing hepatic vascular and territorial anatomy of the woodchuck liver based on a virtual three‐dimensional (3D) visualization of the hepatic vascular tree.

Methods: Woodchucks (n=6) were subjected to an all‐in‐one computed tomography (CT) after contrasting the vascular and the biliary tree. CT‐images were used for 3D‐reconstruction of hepatic and portal veins and calculation of the corresponding portal and hepatic vein territories and their respective volume using hepavision (MeVisLab). A virtual resection was performed following the Cantlie‐line and territories at risk were calculated.

Results: The median lobe of the woodchuck liver has a similar vascular supply and drainage as the human liver with two portal (right and left median portal vein) and three hepatic veins (left, middle and right median hepatic vein). The corresponding portal and hepatic vein subterritories are of a similar relative size compared with the human liver. Virtual splitting of the median lobe of the woodchuck liver revealed areas at risk of focal outflow obstruction, as observed clinically.

Conclusion: The median liver lobe of the woodchuck represents, to a small extent, the hepatic vascular anatomy of the human liver and is therefore a suitable potential model to correlate repeated imaging of impaired liver perfusion with histomorphological findings of liver damage and regeneration.
A 1H nuclear magnetic resonance‐based metabonomic approach for grading hepatic encephalopathy and monitoring the effects of therapeutic hypothermia in rats
Authors: Barba Ignasi , Chatauret Nicolas , García‐Dorado David , Córdoba Juan
Published: August 2010

Background:
There are no good biomarkers for grading hepatic encephalopathy (HE) and monitoring the effectiveness of therapeutic measures.

Methods:
We applied 1H nuclear magnetic resonance (NMR)‐based metabonomics of brain samples obtained from acute liver failure rats sacrificed after ligation of the hepatic artery (at 6 h, precoma and coma stages), sham‐operated controls and mild hypothermia (35 °C) for 6 or 15 h as a therapeutic measure.

Results:
Partial least square discriminant analysis established a classification model that scored the severity of encephalopathy. Animals treated with hypothermia did not develop manifestations of encephalopathy and were graded accordingly using the NMR‐based metabonomic approach. Hypothermic animals showed lower levels of alanine and lactate as well as higher levels of N‐acetylaspartate and myo‐inositol compared with normothermic animals. The course of metabolic deterioration was more rapid in the brainstem than in the cortex.

Conclusion:
Metabonomic analysis is capable of grading HE, detecting regional differences and monitoring the protective effects of hypothermia. This approach elucidates differences of brain energetic metabolism and compensatory osmotic response to explain the effects of hypothermia.
Hepatic fibrogenesis in response to chronic liver injury: novel insights on the role of cell‐to‐cell interaction and transition
Authors: Svegliati‐Baroni Gianluca , De Minicis Samuele , Marzioni Marco
Published: August 2010

Hepatic fibrosis represents the wound‐healing response process of the liver to chronic injury, independently from aetiology. Advanced liver fibrosis results in cirrhosis that can lead to liver failure, portal hypertension and hepatocellular carcinoma. Currently, no effective therapies are available for hepatic fibrosis. After the definition of hepatic stellate cells (HSCs) as the main liver extracellular matrix‐producing cells in the 1980s, the subsequent decade was dedicated to determine the role of specific cytokines and growth factors. Fibrotic progression of chronic liver diseases can be nowadays considered as a dynamic and highly integrated process of cellular response to chronic liver injury. The present review is dedicated to the novel mechanisms of cellular response to chronic liver injury leading to hepatic myofibroblasts' activation. The understanding of the cellular and molecular pathways regulating their function is crucial to counteract therapeutically the organ dysfunction caused by myofibroblasts' activation.
Pretransplant variables associated with quality of life in liver transplant recipients
Authors: Saab Sammy , Ibrahim Ayman B. , Surti Bijal , Durazo Francisco , Han Steven , Yersiz Hasan , Farmer Douglas G. , Ghobrial R. Mark , Goldstein Leonard I. , Tong Myron J. , Busuttil Ronald W.
Published: August 2010

Objective: With an increasing number of liver transplant recipients living, understanding quality‐of‐life issues is essential. Our goal is to identify pretransplant variables associated with post‐transplant quality of life in liver transplant recipients.

Methods: Three hundred and eight liver transplant recipients were administered the Short Form 36 and a basic demographical questionnaire. Variables associated with post‐transplant quality of life were studied in a multivariate regression analysis. Interaction terms were used to examine effect modification.

Results: Male gender, longer pretransplant work hours and interaction term between work hours and male gender were independently associated with Physical Functioning. Work hours positively correlated with Role‐Physical, while viral hepatitis and ascites were negatively associated with Role‐Physical. Ascites and viral hepatitis were independently negatively associated with Bodily Pain. Encephalopathy, hepatocellular carcinoma and viral hepatitis were independently associated with General Health. Ascites was also negatively associated with Social Functioning, Role‐Emotional, Bodily Pain, General Health and Vitality. Viral hepatitis was negatively correlated with Vitality and Mental Functioning.

Conclusions: Pretransplant variables such as ascites, encephalopathy, hepatocellular carcinoma, viral hepatitis, work hours, time unable to work and gender were significantly associated with post‐transplant quality of life in liver transplant recipients. Interventions addressing these issues may be initiated to improve the post‐transplant quality of life.
Hepatitis E and pregnancy: understanding the pathogenesis
Authors: Navaneethan Udayakumar , Al Mohajer Mayar , Shata Mohamed T.
Published: August 2010

Hepatitis E virus (HEV) is a single‐stranded RNA virus that causes large‐scale epidemics of acute viral hepatitis, particularly in developing countries. In men and non‐pregnant women, the disease is usually self‐limited and has a case‐fatality rate of less than <0.1%. However, in pregnant women, particularly from certain geographical areas in India, HEV infection is more severe, often leading to fulminant hepatic failure and death in a significant proportion of patients. In contrast, reports from Egypt, Europe and the USA have shown that the course and severity of viral hepatitis during pregnancy is not different from that in non‐pregnant women. The reasons for this geographical difference are not clear. The high mortality rate in pregnancy has been thought to be secondary to the associated hormonal (oestrogen and progesterone) changes during pregnancy and consequent immunological changes. These immunological changes include downregulation of the p65 component of nuclear factor (NF‐κB) with a predominant T‐helper type 2 (Th2) bias in the T‐cell response along with host susceptibility factors, mediated by human leucocyte antigen expression. Thus far, researchers were unable to explain the high HEV morbidity in pregnancy, why it is different from other hepatitis viruses such as hepatitis A with similar epidemiological features and the reason behind the difference in HEV morbidity in pregnant women in different geographical regions. The recent developments in understanding the immune response to HEV have encouraged us to review the possible mechanisms for these differences. Further research in the immunology of HEV and pregnancy is required to conquer this disease in the near future.
Increased flow‐mediated vasodilation in cirrhotic patients with ascites: relationship with renal resistive index
Authors: Cazzaniga Massimo , Salerno Francesco , Visentin Stefania , Cirello Ilaria , Donarini Cesare , Cugno Massimo
Published: August 2010

Background: Peripheral vasodilation is the key factor in the development of hyperdynamic circulation, sodium retention and functional renal failure in patients with cirrhosis. Brachial artery flow‐mediated dilation (FMD) after transient vascular occlusion is a non‐invasive method to assess the shear stress‐induced arterial vasodilation.

Aims: To evaluate FMD in cirrhotic patients with and without ascites and to assess the relationship between FMD and intrarenal resistances.

Methods: Flow‐mediated dilation was determined in 32 cirrhotic patients (22 with ascites) and 12 healthy controls and correlated with the intrarenal resistive index (RI) assessed by Doppler exploration.

Results: Basal diameter of the brachial artery was similar in healthy controls and in cirrhotic patients, whereas FMD was significantly higher in patients with cirrhosis and ascites [29.5% (range 10.3–50%)] than in pre‐ascitic patients [17.3% (range 2.4–48.5%)] and healthy control subjects [11.6% (range 5.1–17.8%)] (P<0.001). Intrarenal RI was significantly higher in patients with cirrhosis than in healthy subjects, and a direct relationship existed between FMD and intrarenal RI (r=0.66; P<0.00001).

Conclusions: These findings in vivo demonstrate that cirrhotic patients with ascites have an enhanced shear stress‐induced peripheral vasodilation, which is closely related to intrarenal vasoconstriction.
Extrahepatic metastasis of hepatocellular carcinoma: incidence and risk factors
Authors: Kanda Miho , Tateishi Ryosuke , Yoshida Haruhiko , Sato Takahisa , Masuzaki Ryota , Ohki Takamasa , Imamura Jun , Goto Tadashi , Yoshida Hideo , Hamamura Keisuke , Obi Shuntaro , Kanai Fumihiko , Shiina Shuichiro , Omata Masao
Published: August 2010

Background:Extrahepatic metastasis of hepatocellular carcinoma (HCC) is of growing importance as the survival of patients has been improved owing to advances in treatments to intrahepatic lesions.

Methods:To elucidate the incidence and risk factors of extrahepatic metastasis of HCC, we enrolled 1573 (1131 treatment‐naïve and 442 previously treated on referral) patients with HCC without extrahepatic tumour spread treated at the authors' department between 1990 and 2003. Patients received medical treatment including percutaneous ablation and transcatheter arterial chemoembolization, and followed by dynamic computed tomography (CT) or magnetic resonance imaging (MRI) and tumour markers every 3–4 months. Extrahepatic metastasis was diagnosed by plain X‐ray, CT, MRI and scintigraphy. Clinical parameters at the time of treatment to intrahepatic lesions were evaluated as a predictor of subsequent extrahepatic metastasis among the 1131 treatment‐naïve patients by Cox's proportional hazard model.

Results:During the average observation period of 3.9 years, extrahepatic metastasis was diagnosed in 123 in the treatment‐naïve and 53 in the patients treated previously. The incidence rate of extrahepatic metastasis, as detected during the lifetime after medical treatment of HCC, was approximately 13% at 5 years. Multivariate analysis with Cox proportional hazard model revealed that positivity for viral markers, lager tumour diameter, multiple tumour nodules, presence of vascular tumour invasion and elevated tumour markers were associated with the development of extrahepatic metastasis.

Conclusion:The incidence of extrahepatic metastasis of HCC diagnosed during clinical course was not frequent. Advanced intrahepatic lesions, presence of vascular tumour invasion, elevated tumour markers and presence of viral hepatitis were risk factors for extrahepatic metastasis.
Multinationals and the creation of Chinese trade linkages
Authors: Swenson Deborah L.
Published: August 2010

Abstract.  This paper studies the relationship between multinational firm proximity and the formation of new export connections by private Chinese exporters between 1997 and 2003. The results indicate that growth in the presence of multinational firms is positively associated with the formation of new trade by local Chinese firms. Further exploration suggests that information spillovers may drive this result, as the positive association due to own‐industry multinational presence is particularly strong in contexts where information improvements may be the most helpful. Thus, it appears that a growing presence of multinational firms may enhance the export capabilities of local domestic firms.
Free trade and the burden of domestic policy
Authors: Gulati Sumeet
Published: August 2010

Abstract.  Consider a small economy facing accession to a exogenously defined trade agreement. Before accession, the government controls trade and pollution policy. After accession, it retains control over pollution policy, but must allow free trade in all goods. This is a choice many governments face while joining trade agreements today. They decide whether greater market access to other members is more valuable than control over trade policy. I ask two questions. All else being equal what happens to environmental policy after accession? Second, what affects the choice of accession and how does this choice impact aggregate welfare? I show that a loss in control over trade policy alters the political incentives determining environmental policy. Before accession, producers can transfer a portion of their burden of environmental regulation to consumers through price increases. After accession the same regulation is borne entirely by producers. Owing to the change in burden, there exist plausible conditions under which the adoption of free trade can lead to more stringent environmental regulation, a reduction in the preferential treatment of special interest groups, and an increase in aggregate welfare.
Regionalism in standards: good or bad for trade?
Authors: Chen Maggie Xiaoyang , Mattoo Aaditya
Published: August 2010

Abstract.  Regional agreements on standards have been largely ignored by economists and blessed by multilateral trade rules. Using a constructed panel data that identifies the different types of agreements at the industry level, we find that such agreements increase the trade between participating countries but not necessarily with the rest of the world. Harmonization of standards may reduce the exports of excluded countries, especially in markets that have raised the stringency of standards. Mutual recognition agreements are more uniformly trade promoting unless they contain restrictive rules of origin, in which case intra‐regional trade increases at the expense of imports from other countries.
Strategic delay in market entry
Authors: Gunay Hikmet
Published: August 2010

Abstract.  Two firms are contemplating entry into a market that is viable for only one firm in a good state. We show that even if each firm receives a signal that perfectly reveals a good state, both might strategically delay entry, owing to the fear that the other firm might enter in the same period as well. We also find the conditions where the informed firm will let the rival firm know about the market's profitability and the two will merge to enter the market. We discuss the applications of this model to the oil industry and the generic drug industry.
Sexual orientation, work, and income in Canada
Authors: Carpenter Christopher S.
Published: August 2010

Abstract.  We provide the first evidence on sexual orientation and economic outcomes in Canada using confidential data that ask adults a direct question about their sexual orientation. Gay men have 12% lower personal incomes and lesbians have 15% higher personal incomes than otherwise similar heterosexual men and women, respectively. Different labour force patterns can account for some of the income differentials. We also document large differences in educational attainment, childrearing, and urbanicity that generally mirror patterns found in the US. Finally, we show that applying couples‐based approaches common in this literature greatly overstates the magnitudes of gay/straight income gaps.
Income effects and physician labour supply: evidence from the threshold system in Ontario
Authors: Kantarevic Jasmin , Kralj Boris , Weinkauf Darrel
Published: August 2010

Abstract.  We examine a reform to the physician threshold system in Ontario that provides a unique opportunity to assess the effect of fee changes on physician behaviour, free from the biases that potentially affect simple time‐series or cross‐section inference. We find that: (1) the income effects of fee changes are small, but significant; (2) the income effect dominates the substitution effect only for a minority of services with relatively low prices and high volumes; and (3) the cross effects of fee changes tend to be significant only for services with relatively high prices and low volumes.
Global labour markets, return, and onward migration
Authors: Aydemir Abdurrahman , Robinson Chris
Published: August 2010

Abstract.  There is increasing evidence that international migration is characterized by frequent return and onward migration. This has important consequences for the contribution of immigrants to the economy of the host country. Lack of longitudinal data has prevented much analysis of how frequently international migration involves a sequence of location decisions or how long the typical migrant stays in a host country. A newly available longitudinal data set covering all immigrants to Canada since 1980 provides the opportunity to address these issues. The results show that a large fraction of male immigrants who are of working age, especially among skilled workers and entrepreneurs, are highly internationally mobile.
Do economics journal archives promote replicable research?
Authors: McCullough B.D. , McGeary Kerry Anne , Harrison Teresa D.
Published: August 2010

Abstract.  All the long‐standing archives at economics journals do not facilitate the reproduction of published results. The data‐only archives at Journal of Business and Economic Statistics and Economic Journal fail in part because most authors do not contribute data. Results published in the FRB St. Louis Review can rarely be reproduced using the data+code in the journal archive. Recently created archives at top journals should avoid the mistakes of their predecessors. We categorize reasons for archives' failures and identify successful policies.
National Treatment and the optimal regulation of environmental externalities
Authors: Gulati Sumeet , Roy Devesh
Published: August 2010

Abstract.  We analyze the role of National Treatment in the regulation of environmental product standards for an open economy. A social planner uses product standards to control emissions from the consumption of a traded good. We show that whether National Treatment of standards interferes with welfare‐maximizing policy depends on the instruments available to the policy maker (consumption or emissions tax) and differences in the cost of complying with the standard. We also highlight the asymmetric incidence of the domestic and import product standard when taxes are suboptimal. This asymmetric incidence can also cause welfare‐maximizing policy to violate National Treatment.
Estimating labour supply elasticities under rationing: a structural model of time allocation behaviour
Authors: Prowse Victoria
Published: August 2010

Abstract This paper presents a structural model of the allocation of time to various non‐market activities and market work by couples and single men and women. Parameters are estimated using a sample taken from the UK 2000 Time Use Survey. Own‐wage effects are found to be positive for both men and women and are larger for cohabiting individuals than for singles. The presence of young children leads to a much larger increase in the time spent in home production by women than by men. However, the presence of young children causes men to increase their total time spent working by more than women.
Trade protection and bureaucratic corruption: an empirical investigation
Authors: Dutt Pushan
Published: August 2010

AbstractWe examine whether protectionist trade policies lead to increased bureaucratic corruption. Using multiple measures of corruption and trade policies, we find strong evidence that corruption is significantly higher in countries with protectionist trade policies. These results are robust to endogeneity concerns. Next, a panel‐data‐based GMM methodology is used to estimate a dynamic model of corruption. This estimator controls for country‐specific effects, potential endogeneity of trade policy, and existence of measurement errors afflicting the corruption data. The paper strengthens the case for trade liberalization and argues that trade reforms may lead to improvements in governance.
Wealth constraint and contractual arrangements
Authors: Dai Chifeng
Published: August 2010

Abstract We examine how a project owner optimally selects a project operator and motivates him to deliver an unobservable effort when potential operators are wealth constrained. We show that, when potential operators' abilities are common knowledge, an operator's share of realized profit can be increasing, invariant, or decreasing in his ability depending on the nature of production technology. However, when potential operators are privately informed about both their abilities and their effort supply, a bunching contract arises in equilibrium for a general class of production technology. In the case of bunching, all potential operators are selected equally often and awarded an equal share of realized profit. The finding provides an explanation for the relative uniformity of contract terms in many practical settings.
Viewpoint: Decision‐making in committees
Authors: Hao Li , Suen Wing
Published: August 2010

Abstract This article reviews recent developments in the theory of committee decision‐making. A committee consists of self‐interested members who make a public decision by aggregating imperfect information dispersed among them according to a pre‐specified decision rule. We focus on costly information acquisition, strategic information aggregation, and rules and processes that enhance the quality of the committee decision. Seeming inefficiencies of the committee decision‐making process such as over‐cautiousness, voting, and delay emerge as partial remedies to these incentive problems.
Firm survival, performance, and the exchange rate
Authors: Baggs Jen , Beaulieu Eugene , Fung Loretta
Published: August 2010

Abstract This paper examines the impact of exchange rate movements on firm survival and sales. We exploit detailed Canadian firm‐level data from 1986 to 1997, a period in which the Canadian dollar appreciated approximately 30% in the first six years and depreciated 30% in the later six years. We find that survival and sales are negatively associated with appreciations in the Canadian dollar. The impact on survival is less pronounced for more productive firms. The magnitude of the impact of exchange rate changes on firm survival and sales was comparable to the effect of CUSFTA‐mandated tariff changes.
Trade, technology, and unemployment: the role of endogenous skill formation
Authors: Kreickemeier Udo
Published: August 2010

Abstract This paper analyses trade in an asymmetric 2 × 2 × 2 world, where the two countries (‘Europe’ and ‘America’) differ in their preferences towards wage inequality. Fair wage considerations compress wage differentials in both countries. European workers are more averse to wage inequality, and Europe is characterized by lower wage differentials and higher unemployment. Allowing for endogenous skill formation, the effects of a globalization shock, global technological change, and a change in the educational capital stock on skill premia and employment levels are derived. In contrast to a model with exogenous factor supplies, international wage and unemployment differentials are affected by global shocks.
The effects of economic and political integration on fiscal decentralization: evidence from OECD countries
Authors: Stegarescu Dan
Published: August 2010

Abstract This paper examines the impact of economic and political integration on the vertical government structure. It argues that, by increasing the market size and the benefits of decentralized provision of public goods, integration triggered the recent process of decentralization in OECD countries. A panel analysis relates the degree of fiscal decentralization to economic and European integration, controlling for interregional heterogeneity, economies of scale, and institutions. The results mostly support a decentralizing effect of economic integration in general and of European integration in particular for heterogeneous EU countries, whereas participation of subnational governments in national decision‐making is associated with more centralization.
Effective global regularity and empirical modelling of direct, inverse, and mixed demand systems
Authors: McLaren Keith R. , Wong K.K. Gary
Published: August 2010

Abstract This paper utilizes the notion of ‘effective global regularity’ and the intuition stemming from Cooper and McLaren (1996)'s General Exponential Form to develop a family of ‘composite’ (product and ratio) direct, inverse and mixed demand systems. Apart from having larger regularity regions, the resulting specifications are also of potentially arbitrary rank, which can better approximate non‐linear Engel curves. We also make extensive use of duality theory and a numerical inversion estimation method to rectify the endogeneity problem encountered in the estimation of the mixed demand systems. We illustrate the techniques by estimating different types of demand systems for Japanese quarterly meat and fish consumption.
Heterogeneity, returns to scale, and collective action
Authors: Karaivanov Alexander
Published: August 2010

AbstractI analyze the effects of resource inequality and valuation heterogeneity on the provision of public goods with increasing or decreasing returns to scale in production. The existing literature typically takes the agents' characteristics as given and known to the researcher. In contrast, this paper compares collective action provision across groups of agents with resources and valuations for the public good drawn from different known joint distributions. Specifically, I characterize theexpectedequilibrium public good level as function of various distributional properties and moments. A resource‐valuation distribution that first‐order stochastically dominates another distribution always results in higher expected public good provision level, independent of the production technology. With decreasing returns to scale in the public good production, higher resource inequality results in higher expected provision. With increasing returns the same result holds when the mean resource level is relatively low, but expected provision decreases in inequality when the mean resource level is high. A parallel result holds for agents' valuations.
Information technology and economic performance in U.S industries
Authors: Ketteni Elena
Published: August 2010

Abstract We study the relationship between information technology (IT) and economic performance, to explore whether IT‐capital promotes productivity growth. We use a data set similar to that of previous researchers, but employ non‐parametric estimation techniques in order to directly estimate the output elasticities of IT for each industry and time period. We find that IT has a positive effect on productivity, which varies among industries and time. Moreover, adjustment costs are important when identifying this effect. Finally, IT‐capital growth appears to be raising income in all industries used in our sample, even those that experienced output reduction.
Economics of public good provision: auditing, outsourcing, and bribery
Authors: Fearon Gervan
Published: August 2010

Abstract This study investigates a government's contracting decision to audit or outsource the provision of a public good given a potential hidden bribe and information asymmetries. The key findings are the following. First, the bribe and price of the public good are increasing in the corruptibility of the department. Second, the bribe is decreasing in the firm's bargaining power. Third, a bribery equilibrium exists when the department's corruptibility is sufficiently high given the firm's bargaining power. A bribe involves extortion or a compensatory payment depending on the department's corruptibility. Only a compensatory bribe affects the department's contracting decision.
Do South‐South trade agreements increase trade? Commodity‐level evidence from COMESA
Authors: Mayda Anna Maria , Steinberg Chad
Published: August 2010

Abstract South‐South trade agreements are proliferating. Yet the impact of these agreements is largely unknown, as existing North‐North and North‐South micro‐level studies are likely to yield misleading predictions for South‐South trade agreements. This paper estimates the impact of COMESA on Uganda's imports between 1994 and 2003. Detailed import and tariff data at the 6‐digit Harmonized System level are used for more than 1,000 commodities. Based on a difference‐in‐difference estimation strategy, the paper finds that – in contrast to evidence from aggregate statistics – COMESA's preferential tariff liberalization has not considerably increased Uganda's trade with member countries, on average, across sectors. The effect, however, is heterogeneous across sectors. Finally, the paper finds no evidence of trade‐diversion effects.
Trade diversion under selective preferential market access
Authors: Borchert Ingo
Published: August 2010

Abstract The European Community (EC) operates a multi‐layered GSP scheme in which different groups of developing countries are granted varying degrees of market access. This paper analyzes the question of trade diversion among different categories of beneficiary countries ensuing from the selectivity of preferential market access. Evidence from a disaggregated panel data analysis reveals sizable intra‐developing country trade diversion. The losses for relatively disadvantaged countries in terms of forgone trade volume are estimated to range between about 2% to 20% of their total trade with the EC. The distortions are driven by highly substitutable, mostly labour‐intensive commodities.
Is job insecurity on the rise? Evidence from Canadian perception data
Authors: Brochu Pierre , Zhou Lu
Published: August 2010

Abstract This paper examines the unexplored issue of worker insecurity perception in Canada. Specifically, we explore for changes in worker perceptions of job security using Canadian Gallup data for the 1977–2006 period. We find that the high levels of perceived insecurity of the early to mid‐1990s were only cyclical in nature, not evidence of structural change. We also explore for differences across socio‐economic groups and find that university educated workers, full‐time workers, and white‐collar workers all felt relatively more secure about present and future job prospects. Interestingly, union members tend to be more concerned about job security (than non‐union).