Safety and efficacy of long-term tolvaptan therapy for decompensated liver cirrhosis.

AIM: Recently, the short-term efficacy of the vasopressin V2 receptor antagonist tolvaptan for the treatment of ascites in cirrhosis was reported. However, the long-term effects remain unknown. Here, we report the clinical features of decompensated cirrhosis treated using long-term tolvaptan therapy, and evaluate its safety and efficacy. METHODS: Fifty-five cirrhotic patients hospitalized due to ascites, despite receiving appropriate diuretic treatment, were treated with tolvaptan. We excluded 35 patients due to liver transplant (20.0%), death (28.6%), poor general status (14.3%), improved ascites (5.7%) or other reasons (31.4%). In 20 cases treated with tolvaptan for 6 months, total body water (TBW) and extracellular fluids (ECW) were measured using bioelectric impedance analysis (BIA) with an InBody720. RESULTS: The median age of the 20 patients was 64 years (range, 48-90), and 60% were male. The etiology of cirrhosis included hepatitis C (45%), alcohol-induced (20%) and other (35%). The percentage of patients with Child-Pugh class A, B and C was 0%, 40% and 60%, respectively. Biochemical findings revealed that serum creatinine levels and estimated glomerular filtration rate were not affected during 6 months of treatment with tolvaptan, and there was no renal disturbance. The median serum sodium levels were increased from 138 to 139 mEq/L, but serious adverse events related to renal and liver function were not observed. Data also revealed that long-term treatment reduced the BIA-estimated ECW/TBW ratio. CONCLUSION: Long-term tolvaptan treatment was a safe and effective treatment for decompensated cirrhosis.

Clinicopathological significance of somatic RNF43 mutation and aberrant expression of ring finger protein 43 in intraductal papillary mucinous neoplasms of the pancreas.

Mutations in RNF43, which encodes the ubiquitin E3 ligase ring finger protein 43, were recently found in intraductal papillary mucinous neoplasms of the pancreas. We evaluated somatic mutations of RNF43 and the expression of ring finger protein 43 as well as their associations with the molecular and clinicopathological features in 176 surgically resected intraductal papillary mucinous neoplasms. Frozen tissues were available for 57 cases and were used for next-generation sequencing analysis of the entire coding exons of RNF43. Formalin-fixed and paraffin-embedded tissues from all 176 cases were used for the immunohistochemical analysis of the expression of ring finger protein 43. Mutations detected with the next-generation sequencing analysis were validated by using Sanger sequencing. Statistical analysis was used to evaluate the associations between RNF43 aberrations and molecular and clinicopathological features including GNAS mutations, KRAS mutations, loss of SMA and MAD4 homologue expression, tumor protein 53 overexpression, tumor grade, histological type, mural nodule detection, macroscopic type, stage, recurrence, and survival. Somatic RNF43 mutations were found in 8 (14%) of the 57 examined cases, and included 5 frameshift mutations (p.F69fs, p.S264fs, p.L311fs, p.R363fs, and p.V490fs), 1 non-sense mutation (p.Q153X), and 2 missense mutations (p.I164N and p.P310A). The expression of ring finger protein 43 was downregulated in 52 (29.5%) of the 176 examined cases. RNF43 mutations were significantly associated with the downregulated expression of ring finger protein 43 (P=0.011), GNAS mutation (P=0.020), and mural nodule detection (P=0.038). The expression of ring finger protein 43 was not associated with any clinicopathological features except RNF43 mutation. These results indicate that RNF43 mutation might cause downregulation of the expression of ring finger protein 43 and play a crucial role and associate synergistically with GNAS mutation during development of intraductal papillary mucinous neoplasm of the pancreas.

Primary hyperoxaluria complicated with liver cirrhosis: A case report.

Primary hyperoxaluria (PH) is a rare, autosomal recessive disorder characterized by overproduction of oxalate caused by a deficiency in a hepatic enzyme. The excess oxalate combines with calcium in the kidneys to form deposits of calcium oxalate, which can lead to nephrocalcinosis and renal failure. PH type 1 (PH1), the most common form of this disease, is caused by a deficiency of the liver-specific enzyme alanine/glyoxylate aminotransferase (AGT). Liver transplantation is performed as a definitive therapy for PH to correct the enzyme defect. Usually, liver depositions are limited and liver function is normal without fibrosis. Here, we report an adult case of liver cirrhosis caused by PH1. A 28-year-old woman was admitted to our hospital under suspicion of PH1 and the presence of nephrocalcinosis. The patient had suffered from kidney stone recurrences from 17 years of age, and was initiated on hemodialysis due to renal failure at the age of 27 years. The serum level of oxalic acid was high, whereas the AGT level in the liver tissue was decreased. Thus, the patient was definitively diagnosed with PH1. Although she had normal liver function, surface nodularity and splenomegaly were detected by computed tomography, suggesting liver cirrhosis. The native liver showed micronodular cirrhosis and portal fibrosis. Several arterioles were filled with rhomboid and polyhedral refractile oxalate crystals and various portal tracts showed these crystals. Our case suggests that long-term oxalosis can lead to liver cirrhosis; thus, PH should be considered one of the causes of liver cirrhosis.

Localization of the Patency Capsule by Abdominal Tomosynthesis.

BACKGROUND/AIMS: A patency capsule (PC) is used to assess intestinal patency in patients with known or suspected stricture, but PC localization by plain abdominal X-ray (AXR) is difficult in those patients in whom the PC is not detected in the feces. Tomosynthesis is a promising, cost-effective, and low-radiation digital tomographic technique. This prospective study evaluated its use for PC localization in the intestinal tract. METHODS: The study subjects were 49 patients in whom the PC was not detected in the feces and was identified intra-abdominally on AXR films. PC localization in the small or large intestines by AXR alone or by tomosynthesis with AXR was compared with abdominal computed tomography (CT), which is the gold standard. RESULTS: The PC was judged in the large and small intestines in 22 and 27 patients by AXR alone versus 34 and 15 patients, respectively, by tomosynthesis combined with AXR. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for PC detection by AXR alone were 52.9, 53.3, 56.2, 50.0, and 53.1%, respectively. The same parameters were 100, 100, 100, 100, and 100%, respectively, for tomosynthesis with AXR, which were identical to those of CT. CONCLUSIONS: Tomosynthesis with AXR is superior to AXR alone, though similar to CT, with respect to localization of the PC.

Identification of commensal flora-associated antigen as a pathogenetic factor of autoimmune pancreatitis.

OBJECTIVES: Autoimmune pancreatitis (AIP) is a chronic fibro-inflammatory disease of the pancreas constituting, in part, a recently defined nosological entity of IgG4-related systemic sclerosing diseases. The pathogenetic factors of AIP have not been fully elucidated. We previously established a mouse model of AIP using chronic exposure to a commensal bacteria, Escherichia coli. METHODS: To determine the pathogenetically relevant antigen of E. coli, the outer membrane fractions of E. coli were subjected to two-dimensional gel electrophoresis followed by immunoblotting against sera from the AIP model. Immunoreactive spots were determined using MALDI TOF/MS and Mascot search. The recombinant protein of the identified antigen was examined for their ability to induce AIP-like disorder in C57BL/6 mice. Furthermore, the antibody titer against that antigen was determined in AIP patients. RESULTS: One representative spot reacting with sera from E. coli-inoculated mice was identified as FliC from E. coli, based on the results of TOF/MS. The repeated inoculation of recombinant FliC in C57BL/6 mice induced AIP-like pancreatitis and higher titers of anti-lactoferrin and anti-carbonic anhydrase II. Sera from patients with AIP had the highest antibody titer, while those from patients with pancreatic diseases other than AIP had a higher antibody titer against E. coli and FliC, compared with pancreatic disease-free controls. CONCLUSIONS: FliC from E. coli may pathogenetically generate an AIP-like inflammation status. A reconsideration of the importance of commensal bacteria as an environmental factor(s) capable of inducing autoimmunity could provide insight to overcoming AIP.

The discrete nature and distinguishing molecular features of pancreatic intraductal tubulopapillary neoplasms and intraductal papillary mucinous neoplasms of the gastric type, pyloric gland variant.

Intraductal tubulopapillary neoplasms (ITPNs) are composed of tubulopapillary glands with high-grade dysplasia in the pancreatic duct. Intraductal papillary mucinous neoplasms of the gastric type, pyloric gland variant (IPMN-PGs) are composed of tubular glands mimicking pyloric glands with low-grade dysplasia and were formerly called intraductal tubular adenomas. Because of their apparent common tubular morphology, IPMN-PGs and ITPNs could be associated. While the former might progress to the latter, this has not been fully assessed. In this study, we compared the molecular features of ITPNs and IPMN-PGs to determine their association using formalin-fixed, paraffin-embedded tissues of 14 ITPNs and 15 IPMN-PGs. Somatic mutations in PIK3CA, GNAS, KRAS, and BRAF were determined by Sanger sequencing. Expression of phosphorylated AKT was examined by immunohistochemistry. Somatic PIK3CA mutations were found in 3 of 14 ITPNs (21.4%) but in none of the IPMN-PGs (p = 0.0996). In contrast, GNAS mutations were found in none of the ITPNs but in 9 of 15 IPMN-PGs (60.0%; p < 0.001). KRAS mutations were detected in 1 of 14 ITPNs (7.1%) and 12 of 15 IPMN-PGs (80.0%; p < 0.001). BRAF mutation was found in one ITPN but in none of the IPMN-PGs. Phosphorylated AKT expression in ITPNs was significantly more evident than that in IPMN-PGs (p = 0.0401). These results indicate that ITPNs and IPMN-PGs are molecularly distinct, suggesting that IPMN-PG does not progress to ITPN. Furthermore, the molecular features of IPMN-PGs are confirmed to be identical to those of IPMNs reported elsewhere. These results validate the current World Health Organization system that classifies pancreatic intraductal neoplasms into IPMN and ITPN and confirm that IPMN-PG is not a benign counterpart of ITPN. The term 'intraductal tubular adenoma' should be eliminated and replaced with IPMN-PG.

Clinical profile of primary biliary cirrhosis with features of autoimmune hepatitis: Importance of corticosteroid therapy.

AIM: The aim of this study was to elucidate the clinical and histological features, response to corticosteroid therapy and long-term outcome of primary biliary cirrhosis (PBC) with features of autoimmune hepatitis (AIH). METHODS: Among 280 PBC patients under ursodeoxycholic acid administration, we identified 28 patients with AIH features fulfilling the following criteria: sustained high levels of serum aminotransferases and high immunoglobulin G levels with positivity for antinuclear antibodies or anti-smooth muscle antibodies (ASMA) and/or histological features of moderate to severe interface hepatitis or moderate to severe lobular hepatitis. We analyzed PBC patients with AIH features, focusing mainly on therapeutic responses to corticosteroids. RESULTS: Patients with PBC with AIH features included 26 women (93%). Their median age was 55 years, and the median follow-up period was 7.5 years. Eight of these 28 patients were not actually treated with corticosteroids due to medical conditions. Among the 20 patients receiving corticosteroid therapy, 15 were responders and five were non-responders. A high alkaline phosphatase (ALP) level, negativity for ASMA and positivity for gp210 were identified as risk factors for lack of a response to corticosteroid therapy. Among 28 PBC patients with AIH features, the responders to corticosteroids had an excellent prognosis, while those who could not be treated with corticosteroids and non-responders to corticosteroids had a poor outcome. CONCLUSION: Patients with PBC with AIH features benefit from corticosteroid therapy. Features of PBC such as high ALP level, negativity for ASMA and positivity for gp210 appear to predict a poor response to corticosteroids.

Clinical and pathological features of solid pseudopapillary neoplasms of the pancreas at a single institution.

AIMS: The aim of this study was to determine the clinicopathological features and surgical management of solid pseudopapillary neoplasms (SPNs) of the pancreas at a single institution. METHODS: We investigated 34 patients (5 males and 29 females) who underwent surgery for pathologically confirmed SPNs between 1994 and 2012. RESULTS: Clinical symptoms were absent in 58.8% of the patients. The median tumor diameter was 42.7 mm. All tumors were successfully removed by R0 resection. Pathologically, 5.9% had duodenum invasion and 2.9% had pancreatic serosal invasion, but there was no lymph node metastasis. Radiological findings showed calcification in 39.4% of the patients, capsule formation in 51.5%, cystic components in 69.7%, solid components in 93.9% and internal bleeding in 36.4%. Immunohistochemically, neuron-specific enolase was positive in 100% of the patients, nuclear accumulation of ß-catenin in 100% and CD10 in 78.8%. There were no recurrences reported at the median follow-up (67 months). Regarding gender differences, the cystic component in radiological imaging was the only significant finding among the features studied (p = 0.01). CONCLUSIONS: R0 resection with appropriate procedures appears to be sufficient for patients with SPNs, even for locally invasive tumors. There were no significant differences between genders except for the cystic component on radiological imaging.

Questionnaire survey on lifestyle of patients with nonalcoholic steatohepatitis.

Lack of exercise and excessive food intake are known to be the important causes of nonalcoholic steatohepatitis (NASH). To elucidate the relationship between lifestyle and NASH, we surveyed exercise and dietary habits, comparing them among 171 biopsy-proven NASH patients, 29 nonalcoholic fatty liver (NAFL) patients and 49 normal subjects. Dietary habits including the duration of dinner time, amount of rice at dinner, and weekly frequencies of meat, fries, Chinese noodles, sweets, and instant food consumption were significantly different in male NASH patients compared to normal male subjects. In women, differences were seen in the amount of rice at dinner, frequency of eating out, and proclivity for sweets. In male NASH patients, the frequency of physical exercise was significantly lower. The lifestyle tendencies of NASH were almost similar to those of NAFL. In the comparison between obese NASH and non-obese NASH, no clear lifestyle differences were found. In conclusion, the most striking result of this survey was that the lifestyle of males contributed significantly to the development of NASH. These results point to treatment of NASH in males. In female NASH patients, lifestyle differences were minimal, and the effects of other factors such as genetic background will need to be investigated.

Hepatic and extrahepatic malignancies in cirrhosis caused by nonalcoholic steatohepatitis and alcoholic liver disease.

BACKGROUND: To clarify the carcinogenic factors associated with steatohepatitis, we investigated the characteristic features of hepatic and extrahepatic malignancies in patients with cirrhotic nonalcoholic steatohepatitis (NASH-LC) and cirrhotic alcoholic liver disease (ALD-LC). METHODS: A total of 72 patients with NASH-LC and 85 with ALD-LC (both biopsy-proven steatohepatitis without hepatocellular carcinoma [HCC]) were assessed with regard to the development of hepatic and extrahepatic malignancies. Risk factors for HCC were analyzed. RESULTS: During follow-up, 10 NASH-LC patients and 6 ALD-LC patients developed HCC. The 5-year HCC development rate was similar for these 2 groups, being 10.5% in the NASH-LC group and 12.3% in the ALD-LC group. After adjusting for age and gender, the HCC development rates were also similar. Risk factors for HCC in the NASH-LC group were older age, higher γ-GTP level, and higher Child-Pugh score as determined by Cox hazards analysis. Regarding risk factors in the ALD-LC group, no risk factor was found by Cox hazards analysis, although diabetes mellitus led to a significantly higher HCC rate by log-rank test (p = 0.013). Regarding extrahepatic cancer, only 1 NASH-LC patient (1.4%) developed endometrial cancer. In contrast, 7 ALD-LC patients (8.2%) had other cancers (p = 0.052). CONCLUSIONS: Comparison between NASH-LC and ALD-LC revealed similar HCC development curves. However, the risk factors for HCC and extrahepatic malignancies differed between the 2 diseases. In ALD-LC, the incidences of HCC and extrahepatic cancer are similar. When treating LC patients with NASH or ALD, the risk factors and extrahepatic malignancies associated with ALD-LC should be assessed.

Targeting of MAPK-associated molecules identifies SON as a prime target to attenuate the proliferation and tumorigenicity of pancreatic cancer cells.

BACKGROUND: Pancreatic cancer is characterized by constitutive activation of mitogen-activated protein kinase (MAPK). Activation of MAPK is associated with the upregulation of genes implicated in the proliferation and survival of pancreatic cancer cells. We hypothesized that knockdown of these MAPK-associated molecules could produce notable anticancer phenotypes. METHODS: A RNA interference-mediated knockdown screening of 78 MAPK-associated molecules previously identified was performed to find molecules specifically associated with proliferation of pancreatic cancer cells in vitro. Expression of an identified molecule in pancreatic cancer tissues was examined by immunohistochemistry. In vivo tumorigenicity of cancer cells with stable knockdown of the molecule was assayed by using xenograft models. Flow cytometry and live cell imaging were employed to assess an association of the molecule with cell cycle. RESULTS: The knockdown screening revealed that knockdown of SON, the gene encoding SON, which is a large serine/arginine-rich protein involved in RNA processing, substantially suppressed pancreatic cancer cell proliferation and survival in vitro and tumorigenicity in vivo. SON expression was higher in ductal adenocarcinomas than in cells of normal ducts and precursor lesions in pancreatic cancer tissues. Knockdown of SON induced G2/M arrest and apoptosis in cultured cancer cells. The suppressive effect of SON knockdown on proliferation was less pronounced in cultured normal duct epithelial cells. SON formed nuclear speckles in the interphase of the cell cycle and dispersed in the cytoplasm during mitosis. Live cell imaging showed that SON diffusely dispersed in the early mitotic phase, accumulated in some foci in the cytoplasm in the late mitotic phase, and gradually reassembled into speckles after mitosis. CONCLUSION: These results indicate that SON plays a critical role in the proliferation, survival, and tumorigenicity of pancreatic cancer cells, suggesting that SON is a novel therapeutic molecular target for pancreatic cancer.

Involvement of commensal bacteria may lead to dysregulated inflammatory and autoimmune responses in a mouse model for chronic nonsuppurative destructive cholangitis.

BACKGROUND: We previously reported a mouse model of primary biliary cirrhosis (PBC)-like chronic nonsuppurative destructive cholangitis (CNSDC), in which frequent injections of Streptococcus intermedius induced CNSDC and autoantibody production. The present study was performed to verify the model by examining 1) the reappearance of the PBC-like CNSDC after lymphocyte transfer from model to naïve mice, 2) the involvement of autophagy, and 3) the influence of the strain difference. METHODS: Mice were inoculated with S. intermedius weekly for 8 weeks, then sacrificed to obtain samples. Spleen cells obtained from S. intermedius-inoculated mice were transferred to RAG2(-/-) mice. RESULTS: CNSDC and elevated serum level of anti-gp210 titers were observed in S. intermedius-inoculated C57BL/6 mice, similar to the results of our previous report using BALB/c mice. Portal inflammation was induced in the livers of RAG2(-/-) mice by the transfer of spleen cells from S. intermedius-inoculated C57BL/6 mice. Among the inflammatory cells in the RAG2(-/-) mice, CD3-positive cells were predominant. Autophagosome-like structures were detected histologically, in the cytoplasm of infiltrated cells around the bile ducts in the livers of S. intermedius-inoculated both C57BL/6 and BALB/c mice. In S. intermedius-inoculated C3H/HeJ mice, inflammation in the portal area was less extensive than that in the hepatic parenchyma. CONCLUSION: Bacterial component(s) and sequentially upregulated innate and acquired immune responses, accompanied by autophagy, might trigger CNSDC, via autoimmune mechanisms. Throughout the generation of bacteria-triggered PBC-like CNSDC, strain difference may influence the response to S. intermedius-inoculation in the liver.

A randomized phase II trial of intra-arterial chemotherapy using SM-11355 (Miriplatin) for hepatocellular carcinoma.

BACKGROUND: SM-11355 is a platinum complex developed to treat hepatocellular carcinoma (HCC) via administration into the hepatic artery as a sustained-release suspension in iodized oil. We conducted a multicenter phase II trial in patients with HCC to evaluate the efficacy and safety of SM-11355, using a Zinostatin stimalamer suspension in iodized oil as a reference. METHODS: Patients with unresectable HCC were randomized 2:1 to receive administration of the SM-11355 or Zinostatin stimalamer suspension into the hepatic artery. A second injection was given 4-12 weeks later. Efficacy was evaluated by CT 3 months after treatment and categorized as therapeutic effect (TE) V to I, where TE V was defined as disappearance or 100% necrosis of all treated tumors. RESULTS: A total of 122 patients were evaluated for efficacy and toxicity (SM-11355, n = 83; Zinostatin stimalamer, n = 39). Baseline characteristics were similar in the two groups. The TE V rates were 26.5% (22/83) and 17.9% (7/39) in the SM-11355 and Zinostatin stimalamer groups, respectively. In the SM-11355 group,the most frequent drug-related adverse events (AEs) of ≥ grade 3 were elevated AST, elevated ALT, thrombocytopenia, and hyperbilirubinemia. The AEs with the largest difference between the two groups (SM-11355 vs. Zinostatin stimalamer) were hepatic vascular injury (0 vs. 48.4%) and eosinophilia (84.3 vs. 41.0%). The 2-year and 3-year survival rates were 75.9% vs. 70.3% and 58.4% vs. 48.7%, respectively. CONCLUSIONS: The results suggest that SM-11355 in iodized oil has similar efficacy to Zinostatin stimalamer and that repeated dosing of SM-11355 is possible without hepatic vascular injury in cases of relapse.

Molecular characteristics and biological behaviours of the oncocytic and pancreatobiliary subtypes of intraductal papillary mucinous neoplasms.

Intraductal papillary mucinous neoplasm (IPMN) consists of four epithelial subtypes. Of those, pancreatobiliary and oncocytic types are recently recognized and relatively uncommon, and usually exhibit high-grade dysplasia. The biological properties and molecular characteristics of these two types have not been well documented. The few molecular studies of the oncocytic type showed absence of KRAS mutations commonly seen in the other subtypes, raising the possibility that the oncocytic type is distinct from the other subtypes. Thus, we examined clinicopathological features and molecular alterations of the two subtypes. The study cohort consisted of 12 pancreatobiliary and 18 oncocytic IPMN cases. KRAS, BRAF, and PIK3CA mutations and TP53, SMAD4, and ß-catenin expression were analysed, and the results of molecular and clinicopathological profiles were compared between the two subtypes. KRAS mutations were identified in the oncocytic type, but less frequently than the pancreatobiliary type (17% versus 58%, p = 0.048). BRAF mutation was found in a single oncocytic tumour, and no PIK3CA mutations were seen in any of the study cohort. TP53 overexpression was less frequent in the oncocytic type than in the pancreatobiliary type (11% versus 58%, p = 0.013). Invasive components were present in 50% of the oncocytic and 92% of the pancreatobiliary types, with lymph node metastasis more frequently seen in the latter, corresponding to better outcomes in the former (5-year survival rates: 93% versus 32%, p = 0.014). Our demonstration of KRAS and BRAF mutations in the oncocytic-type IPMN supports a role for the activation of the RAS-MAPK pathway in this tumour type. However, the less frequent TP53 overexpression associated with the significantly lower rates of invasion and nodal disease in the oncocytic type correlates with better outcomes compared to the pancreatobiliary type.

Amendment of the Japanese consensus guidelines for autoimmune pancreatitis, 2020.

In response to the latest knowledge and the amendment of the Japanese diagnostic criteria for autoimmune pancreatitis (AIP) in 2018, the Japanese consensus guidelines for managing AIP in 2013 were required to be revised. Three committees [the professional committee for developing clinical questions (CQs) and statements by Japanese specialists; the expert panelist committee for rating statements by the modified Delphi method; and the evaluating committee of moderators] were organized. Twenty specialists in AIP extracted the specific clinical statements from a total of 5218 articles (1963-2019) from a search in PubMed and the Cochrane Library. The professional committee made 14, 9, 5, and 11 CQs and statements for the current concept and diagnosis, extra-pancreatic lesions, differential diagnosis, and treatment, respectively. The expert panelists regarded the statements as valid after a two-round modified Delphi approach with individually rating these clinical statements, in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid. After evaluation by the moderators, the amendment of the Japanese consensus guidelines for AIP has been proposed in 2020.

A mouse model of autoimmune pancreatitis with salivary gland involvement triggered by innate immunity via persistent exposure to avirulent bacteria.

The pathogenesis of autoimmune pancreatitis (AIP) remains unknown. Here, we investigated the possible involvement of chronic, persistent exposure to avirulent bacteria in the pathogenesis of AIP. C57BL/6 mice were inoculated with heat-killed Escherichia coli weekly for 8 weeks. At 1 week and up to 12 months after the final inoculation, the mice were killed to obtain samples. At 1 week after the final E. coli inoculation, marked cellular infiltration with fibrosis was observed in the exocrine pancreas. Cellular infiltration in the exocrine pancreas was still observed up to 12 months after the completion of E. coli inoculation. At 10 months after the final inoculation, duct-centric fibrosis became obvious. Inflammation around the ducts in the salivary glands was also observed. Furthermore, sera from heat-killed E. coli-inoculated mice possessed anti-carbonic anhydrase, anti-lactoferrin, and antinuclear antibodies. Exposure to E. coli-triggered AIP-like pancreatitis in C57BL/6 mice. We propose a hypothetical mechanism for AIP pathogenesis. During the initiation phase, silently infiltrating pathogen-associated molecular patterns (PAMP) and/or antigen(s) such as avirulent bacteria might trigger and upregulate the innate immune system. Subsequently, the persistence of such PAMP attacks or stimulation by molecular mimicry upregulates the host immune response to the target antigen. These slowly progressive steps may lead to the establishment of AIP and associated extrapancreatic lesions. Our model might be useful for clarifying the pathogenesis of AIP.

Long-term bacterial exposure can trigger nonsuppurative destructive cholangitis associated with multifocal epithelial inflammation.

Bacterial infection has become a focus of attention in the pathogenesis of primary biliary cirrhosis (PBC). We earlier reported that the bacterial lipoteichoic acid was detected at the sites of inflammation around damaged bile ducts in the livers of PBC, and PBC patients' sera showed high titers against streptococcal histone-like protein. Here, we investigated whether chronic bacterial exposure could trigger PBC-like epithelial cell damage in normal mouse. BALB/c mice were repeatedly inoculated with various bacteria for 8 weeks. At 1 week (Group 1) and 3, 4, or 20 months (long term; Group 2) after the final inoculation, mice were killed to obtain samples. In the livers of the Streptococcus intermedius (S.i.)-inoculated mice in Group 1, cellular infiltration was predominantly observed around the bile ducts over the hepatic parenchyma. In the S.i.-inoculated mice in Group 2, portal but not parenchymal inflammation was observed in the livers, and periductal cellular infiltrates were detected in the salivary glands. Both S.i.-inoculated Groups 1 and 2 BALB/c mice sera had antibodies against HuCCT1 biliary epithelial cells, anti-nuclear antibodies, and anti-gp210 antibodies, but not anti-mitochondrial antibodies. Immunoreactivity to histone-like DNA-binding protein of S.i. (S.i.-HLP) was detectable around the sites of chronic nonsuppurative destructive cholangitis in the portal area in the livers of both S.i.-inoculated Groups 1 and 2 BALB/c mice. Furthermore, anti-S.i.-HLP antibody bound to synthetic gp210 peptide, as well. Bacteria triggered PBC-like cholangitis, multifocal epithelial inflammation, and autoantibody production. Bacteria are likely involved in the pathogenesis of PBC and of associated multifocal epithelial inflammation.

Involvement of the IL-22/REG Ialpha axis in ulcerative colitis.

The Regenerating gene (REG) Ialpha protein, a trophic and/or anti-apoptotic factor, is important in the pathophysiology of gastrointestinal inflammation. Interleukin (IL)-22 is a recently identified cytokine that is suggested to have pivotal roles in inflammatory bowel diseases. We therefore investigated the involvement of the IL-22/REG Ialpha axis and examined the mechanism of regulation of REG Ialpha expression by IL-22 stimulation in ulcerative colitis (UC) mucosa. Expression of IL-22, IL-22 receptor 1 (IL-22R1), and REG Ialpha in UC mucosa was analyzed by real-time RT-PCR and immunohistochemistry. The effects of IL-22 on REG Ialpha protein expression were examined using a small-interfering RNA for STAT3, an MAPK inhibitor or a PI3K inhibitor. The element responsible for IL-22-induced REG Ialpha promoter activation was determined by a promoter deletion and electrophoretic mobility shift assay. The expression of IL-22 was enhanced in infiltrating inflammatory cells, and that of IL-22R1 and REG Ialpha was concurrently enhanced in the inflamed epithelium in UC mucosa. The levels of REG Ialpha and IL-22 mRNA expression were strongly correlated, and the distributions of REG Ialpha- and IL-22R1-positive epithelial cells were very similar. IL-22 simulation enhanced the expression of REG Ialpha protein through STAT3 tyrosine phosphorylation in colon cancer cells. The IL-22-responsive element was located between -142 and -134 in the REG Ialpha promoter region. REG Ialpha protein may have a pathophysiological role as a biological mediator for immune cell-derived IL-22 in the UC mucosa.

Association of epidermal growth factor receptor and mitogen-activated protein kinase with cystic neoplasms of the pancreas.

The molecular pathobiology of pancreatic cystic neoplasms is poorly understood. The aim of this study was to know the involvement of epidermal growth factor receptor (EGFR) and its downstream targets in the serous cystic neoplasms and the mucinous cystic neoplasms of the pancreas. In a total of 72 pancreatic cystic neoplasms, including 39 serous cystic neoplasms and 33 mucinous cystic neoplasms, we examined the expression of native and phosphorylated EGFR, mitogen-activated protein kinase (MAPK), and AKT by immunohistochemistry and somatic mutations in EGFR, KRAS, BRAF, and PIK3CA, by direct sequencing. We also assessed the copy numbers of EGFR transcripts and the amplification of the EGFR gene in some of the samples. We found that EGFR, phosphorylated EGFR, MAPK, and phosphorylated MAPK were evidently expressed in 100, 54, 100, and 69% of the serous cystic neoplasms, and in 12%, none, 33, and 27% of the mucinous cystic neoplasms, respectively; the expression was significantly higher and more prevalent in the serous cystic neoplasms than in the mucinous cystic neoplasms. The expression of AKT and phosphorylated AKT was low in both the types of neoplasms. On average, EGFR transcripts in the serous cystic neoplasms and the mucinous cystic neoplasms increased 53.5- and 2.5-fold, respectively, as compared with that in normal tissues, with the increase in the former being significantly greater than that in the latter. Amplification of the EGFR gene was not detected in any of the examined serous cystic neoplasms. None of the tumors had mutations in any of the examined portions of the genes, except two mucinous cystic neoplasms with mutations in codon-12 of KRAS. These results indicate that EGFR and MAPK are actively involved in the pathobiology of serous cystic neoplasms and may therefore be potential diagnostic markers and therapeutic targets in patients with the above mentioned types of neoplasms.

Epidermoid cyst in intrapancreatic accessory spleen: radiological findings including superparamagnetic iron oxide-enhanced magnetic resonance imaging.

It is crucial to differentiate between nonneoplastic and neoplastic cysts of the pancreas by images. An epidermoid cyst in intrapancreatic accessory spleen (IPAS) is a rare pancreatic cyst that should be managed nonsurgically as well as other nonneoplastic cyst. However, the imaging features of an epidermoid cyst in IPAS have not been organized. We therefore reviewed articles describing cases of epidermoid cyst in IPAS, with 6 additional cases to explore the imaging findings.