[A case report of pancreatic serous cystadenoma coexistent with adenosquamous carcinoma].

A 70-year-old man was admitted to our hospital because a mass was incidentally found in the body of the pancreas. The mass was suspected to be serous cystadenoma from the findings of abdominal enhanced computed tomography, magnetic resonance imaging and endoscopic ultrasonography. In addition, another solid mass was detected in the pancreatic head on imaging tests. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed stenosis both of the main pancreatic duct at the head and bile duct, but the brushing cytology of the bile duct at ERCP showed no malignant cells. However, the findings of several examinations strongly suggested the coexistence of a serous cystadenoma and a pancreatic cancer, therefore we conducted spleen-preserving total pancreatectomy, and the pathological findings of the resected specimen showed serous cystadenoma coexistence with pancreatic adenosquamous carcinoma.

Improvement of scotopic electroretinograms and night blindness with recovery of serum zinc levels.

BACKGROUND: We sought to determine the cause of reduced scotopic and photopic electroretinograms (ERGs) and night blindness in a 46-year-old man with liver dysfunction but no history of alcoholism. CASE: A 46-year-old Japanese man with a complaint of visual difficulties in dim light for 1 month. OBSERVATIONS: By electrophysiological investigation, the patient was found to have low levels of serum zinc and vitamin A on admission. The rod b wave was unrecordable, and the bright-flash ERGs were reduced, with the a wave > b wave. The amplitudes of the cone and 30-Hz flicker responses were also reduced, and their implicit times were prolonged. Three weeks after admission, the patient's serum zinc level recovered to normal levels, but his serum vitamin A level was still low. The symptoms of night blindness were gone, and the rod ERGs and single bright-flash responses were within normal limits. However, the cone ERGs and 30-Hz flicker responses were still depressed. CONCLUSIONS: The recovery of scotopic function together with the recovery of zinc but not vitamin A levels suggests that the ERG changes were most likely related to low zinc levels.

Prospective study on early virologic response to treatment with interferon alpha-2b plus ribavirin in patients with chronic hepatitis C genotype 1b.

To evaluate the predictive value of early virologic response (EVR) of achieving a sustained virologic response (SVR), an open, prospective trial including 42 patients with chronic hepatitis C genotype 1b was performed with directly observed 24-week treatment with interferon alpha-2b plus ribavirin. We assessed the predictive values of EVR at days 3, 7, 14, and weeks 4, 8, and 12 of the SVR. The SVR in an intention-to-treat analysis was 19.0%. Patients who reached SVR presented a significantly faster reduction in plasma viral load. Stepwise multiple logistic regression analysis of the factors (gender, age, IFN dosage, ribavirin dosage, HCV RNA, ISDR, and loss of HCV RNA at week 4) revealed that loss of HCV RNA at week 4 was the only independent variable of treatment outcome (P=0.0039). A viral load at treatment day 3 above 100kIU/ml, at day 7 above 50kIU/ml, and at day 14 above 10kIU/ml was 100% predictive for virologic non-response in all except 1 patient. The cutoff levels for HCV RNA at days 3 and 14 of treatment were associated with an algorithm of the failure to detect HCV RNA after 12 weeks of treatment. In conclusions, a very early virologic response assessment could be useful for prediction of later outcome of combination therapy in chronic hepatitis C genotype 1b.

A case of a teenage boy with eosinophilic gastroenteritis with esophageal involvement developing a hemorrhagic duodenal ulcer.

A boy in his early teens visited our hospital with chief complaints of hematemesis and tarry stools. Upper gastrointestinal endoscopy identified a hemorrhagic duodenal ulcer, for which hemostasis was performed using a clip. Proton pump inhibitor (PPI) administration diminished the ulcer but relapse occurred after PPI discontinuation. The esophagus showed concentric rings and longitudinal linear furrows considered to be characteristic of eosinophilic esophagitis. Biopsies of the duodenal ulcer and the esophagus revealed marked infiltration of eosinophils, leading to a diagnosis of eosinophilic gastroenteritis with esophageal involvement. Steroid treatment was initiated, and the duodenal ulcer and esophagitis resolved. Endoscopic findings characteristic of eosinophilic esophagitis were key to the diagnosis of eosinophilic gastroenteritis.

Differential caspase-9-dependent signaling pathway between tumor necrosis factor receptor- and Fas-mediated hepatocyte apoptosis in mice.

BACKGROUND/AIMS: Two apoptosis signaling pathways, which are used by different cell types, are identified. The activation of caspases is critical for the apoptosis process. The aim of this study was to investigate the effects of the caspase-9 inhibitor Ac-LEHD-CHO on tumor necrosis factor receptor (TNFR)- and Fas-mediated hepatocyte apoptosis in vivo, in order to evaluate the similarities and distinctions between TNFR- and Fas-mediated signaling pathways. METHODS: BALB/c mice were intravenously injected with d-galactosamine (GalN, 20 mg/mouse)/tumor necrosis factor-alpha (TNF-alpha, 0.5 microg/mouse), or alphaFas (10 microg/mouse) 30 min after treatment with the caspase-9 inhibitor Ac-LEHD-CHO or pan-caspase inhibitor Z-VAD-fmk. Liver injury was assessed biochemically and histologically. Cytochrome c release and processing of procaspases in the liver were analyzed by Western blotting. Activities of caspases were measured using a fluorogenic peptide substrate. RESULTS: Pretreatment with Z-VAD-fmk prevented liver injury and hepatocyte apoptosis induced by either GalN/TNF-alpha or alphaFas. On the other hand, pretreatment with Ac-LEHD-CHO prevented GalN/TNF-alpha-induced hepatotoxicity and hepatocyte apoptosis but not alphaFas-induced liver injury and apoptosis. Both inhibitors reduced the activities of caspase-9 and -3 in the livers of mice administered by GalN/TNF-alpha. However, unlike Z-VAD-fmk, Ac-LEHD-CHO did not inhibit caspase-3 activation in alphaFas-treated mice, although this inhibitor attenuated caspase-9. CONCLUSION: Fas may rely on both caspase-8 activation (extrinsic pathway) and mitochondria (intrinsic pathway) to activate caspase-3. If the mitochondria-dependent pathway is blocked, the other pathway can compensate. In contrast, TNFR may mediate hepatocellular apoptosis mainly through the mitochondria-mediated caspase-9 activation pathway alone.

Prevention of hepatic fibrosis in nonobese diabetic mice: a critical role for interferon-gamma.

BACKGROUND/AIMS: Nonobese diabetic (NOD) mice, a model of type I diabetes mellitus, harbor certain unique defects in their immune system. The aim of this study was to investigate how NOD mice show hepatic injury and subsequent fibrogenic responses. METHODS: Hepatic fibrosis was induced by intraperitoneal injections of dimethylnitrosamine (DMN), and assessed biochemically and histologically. Expressions of cytokine messenger RNA (mRNA) in the liver were determined. RESULTS: In a model of liver cirrhosis induced by dimethylnitrosamine (DMN), we found that NOD mice had lower levels of hepatic fibrosis and better survival than control ICR mice. The resistance to DMN-induced lethality in NOD mice was independent of apoptosis and necrosis of hepatocytes, but apparently due to the prevention of hepatic fibrosis. We also found increased inductions of interferon-gamma (IFN-gamma) mRNA in the liver of NOD mice and of intracellular IFN-gamma from intrahepatic T cells following DMN administration. Treatment with neutralizing anti-IFN-gamma-antibody cancelled the inhibition of hepatic fibrosis in NOD mice. CONCLUSIONS: These results suggest that IFN-gamma is effective for inhibiting hepatic fibrosis and that genetic host factors may be important in determining differential responses to injury.

Normal liver regeneration and liver cell apoptosis after partial hepatectomy in tumor necrosis factor-alpha-deficient mice.

AIMS/BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is known as a proinflammatory cytokine that has been implicated as a contributing factor in a number of disease processes. TNF-alpha also influences liver repair following hepatotoxic damage, and regeneration following partial hepatectomy (PH). The aim of this study was to assess the mechanism by which TNF-alpha influences liver cell apoptosis and regeneration following PH in TNF-alpha-deficient (TNF-alpha(-/-)) mice. METHODS: PH was performed in wild mice and TNF-alpha(-/-) mice. RESULTS: In both groups, serum alanine aminotransferase and serum total bilirubin levels comparably peaked at 6 and 48 h after PH, respectively. No differences were observed in hepatocyte proliferation, as determined by mitotic and the proliferating cell nuclear antigen labeling indices, between TNF-alpha(+/+) and TNF-alpha(-/-) mice. Few terminal deoxynucleotidyl transferase nick end-labeling-positive hepatocytes were seen in either type of mice. Nuclear factor-kappa B DNA binding activity in the remaining liver of TNF-alpha(-/-) mice after PH was similar to that of control mice. Ribonuclease protection assay showed that transforming growth factor beta1 mRNA was up-regulated comparably in the livers of the two groups, and that other cytokines were hardly seen in either. Interleukin-6/ signal transducer and activator of transcription-3-dependent pathway was not affected in TNF-alpha(-/-) mice. CONCLUSIONS: These findings suggest that TNF-alpha has little influence on liver regeneration and liver cell apoptosis after PH in mice.

Analysis of gene expression profile induced by hepatocyte nuclear factor 4alpha in hepatoma cells using an oligonucleotide microarray.

Hepatocyte nuclear factor 4alpha (HNF-4alpha), a liver-specific transcription factor, plays a significant role in many liver-specific functions, including lipid, glucose, drug, and ammonia metabolism, and also in embryonal liver development. However, its functions and regulation are not yet clearly understood. In this study, we constructed an adenovirus vector carrying rat HNF-4alpha cDNA and transfected the adenovirus to human hepatoma cells, HuH-7, to enforce expression of the exogenous HNF-4alpha gene. We analyzed HNF-4alpha-induced genes using cDNA microarray technology, which included over 9000 genes. As a result, 62 genes showed a greater than 2.0-fold change in expression level after the viral transfection. Fifty-six genes were consistently induced by HNF-4alpha overexpression, and six genes were repressed. To assess HNF-4alpha function, we attempted to classify the genes, which had been classified by their encoding protein functions in a previous report. We could classify 45 genes. The rest of the HNF-4alpha-sensitive genes were unclassified (4 genes) or not identified (13 genes). Among the classified genes, almost half of the induced genes (26 of 40) were related to metabolism genes and particularly to lipid metabolism-related genes. This cDNA microarray analysis showed that HNF-4alpha is one of the central liver metabolism regulators.

Leflunomide protects from T-cell-mediated liver injury in mice through inhibition of nuclear factor kappaB.

Leflunomide is a novel immunosuppressive and anti-inflammatory agent for the treatment of autoimmune disease. The aim of this study was to investigate whether leflunomide protects from liver injury induced by concanavalin A (Con A), a T-cell-dependent model of liver damage. BALB/c mice were injected with 25 mg/kg Con A in the presence or absence of 30 mg/kg leflunomide. Liver injury was assessed biochemically and histologically. Levels of circulating cytokines and expressions of cytokine messenger RNA (mRNA) in the liver and the spleen were determined. Treatment with leflunomide markedly reduced serum transaminase activities and the numbers of dead liver cells. Leflunomide significantly inhibited increases in plasma tumor necrosis factor alpha (TNF-alpha) and interleukin 2 concentrations, and also reduced TNF-alpha mRNA expression in the liver after administration of Con A. These findings were supported by the results in which leflunomide administration decreased the number of T lymphocytes infiltrating the liver as well as inhibiting their production of TNF-alpha. Activation of nuclear factor kappaB (NF-kappaB), which regulates TNF-alpha production, was inhibited in the liver of mice treated with leflunomide, resulting in a reduction of TNF-alpha production from lymphocytes infiltrating the liver. In conclusion, leflunomide is capable of regulating T-cell-mediated liver injury in vivo and that this event may depend on the decrease of TNF-alpha production in the liver through inhibition of NF-kappaB activation caused by leflunomide.

Inhibition of nuclear factor kappaB and phosphatidylinositol 3-kinase/Akt is essential for massive hepatocyte apoptosis induced by tumor necrosis factor alpha in mice.

BACKGROUND/AIMS: Tumor necrosis factor (TNF)-alpha itself does not induce liver injury in normal mice or hepatocytes. Rather, this event, especially in vitro, is explained by the fact that the TNF-alpha/TNF receptor system not only triggers downstream signals leading to apoptosis but also induces an antiapoptotic pathway through the activation of nuclear factor (NF)-kappaB. The aim of this study was to determine whether inhibition of antiapoptotic pathways influences the susceptibility of mice to TNF-alpha. Here, we focused on the roles of NF-kappaB and phosphatidylinositol 3-kinase (PI3K)-regulated serine/threonine kinase Akt. METHODS: TNF-alpha was administered to BALB/c mice after treatment with an adenovirus expressing a mutant form IkappaBalpha (Ad5IkappaB), the PI3K inhibitor wortmannin, or both. Liver injury was assessed biochemically and histologically. The expression of Bcl-2 family members and caspase activity were examined. RESULTS: In the mice livers, treatment with Ad5IkappaB or the wortmannin suppressed the activation of NF-kappaB or Akt, respectively. Suppression of either NF-kappaB or Akt showed a slight increase in transaminase levels and focal liver cell death after TNF-alpha administration. However, in mice treated with both Ad5IkappaB and wortmannin, TNF-alpha administration resulted in massive hepatocyte apoptosis and hemorrhagic liver destruction in mice. The combination of Ad5IkappaB, wortmannin, and TNF-alpha markedly increased the activation of caspase-3 and -9, and activated caspase-8 to a lesser degree, suggesting that TNF-alpha-induced hepatocyte apoptosis is dependent on type II cell death signaling pathway, probably through the mitochondria. Inhibition of the NF-kappaB and PI3K/Akt pathways had no effect on expression of Bcl-2 families. CONCLUSION: The inducible activation of NF-kappaB and constitutive activation of Akt regulate hepatocyte survival against TNF-alpha, which occurs independent of Bcl-2 families.