Bunzo Matsuura

Biochemical response to ursodeoxycholic acid predicts long-term outcome in Japanese patients with primary biliary cirrhosis.

Aim:u2002 There is an ongoing need for predictors of long‐term outcomes for patients with primary biliary cirrhosis (PBC). Biochemical response to ursodeoxycholic acid (UDCA) has been introduced to predict development of symptoms by our group (Ehime criteria) and to predict long‐term outcomes in Western countries (Paris, Barcelona and Rotterdam criteria). The aim of this study was to evaluate whether these criteria are also useful to predict long‐term outcomes in Japanese patients with PBC.

Clinical significance of B cell-activating factor in autoimmune pancreatitis.

Objectives: Overexpression of B Cell-activating factor (BAFF) is involved in autoimmunity, but little is known about its role in autoimmune pancreatitis (AIP). The aim of this study was to investigate the role of BAFF in the diagnosis and pathogenesis of AIP. Methods: Patients with AIP (n = 19) were compared with 2 disease control groups (chronic pancreatitis [n = 17] and pancreatic cancer [n = 15]) and a healthy subject group (n = 19). Serum BAFF levels were assessed using an enzyme-linked immunosorbent assay. The expressions of BAFF and BAFF receptor in the pancreatic tissue of patients with AIP were estimated using immunohistochemistry. Results: Mean serum BAFF levels were higher in the patients with AIP than in the patients with chronic pancreatitis, the patients with pancreatic cancer, and the healthy subjects (P < 0.0001 for all groups). Using the cutoff value of 1389 pg/mL, the sensitivity and specificity to differentiate AIP from disease and healthy controls were 89.5% and 92.2%, respectively. Glucocorticoid therapy decreased serum BAFF levels below 1389 pg/mL in all patients with AIP (P < 0.0001). B Cell-activating factor and BAFF receptor were expressed on cells infiltrating the pancreas of patients with AIP. Conclusions: B Cell-activating factor could be a novel marker for diagnosis and treatment response in AIP and may contribute to its pathogenesis.

Impaired dendritic cell functions disrupt antigen-specific adaptive immune responses in mice with nonalcoholic fatty liver disease

Background/aimsThe magnitude of antigen-specific immunity was assessed in a murine model of nonalcoholic fatty liver diseases (NAFLD). Because antigen-specific immunity was diminished in NAFLD mice, the underlying mechanisms were evaluated through analysis of the functions of antigen-presenting dendritic cells (DC) and other immunocytes.MethodsFor 12xa0weeks, NAFLD mice received a high-fat (60%) and high-calorie (520xa0kcal/100xa0g) diet. C57BL/6 mice (controls) received a standard diet. NAFLD mice and control mice were immunized with hepatitis B vaccine containing hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg). Antibody to HBsAg (anti-HBs), HBsAg and HBcAg-specific cellular immune response and functions of whole spleen cells, T lymphocytes, B lymphocytes and spleen DCs of NAFLD and control mice were assessed in vitro.ResultsLevels of anti-HBs and the magnitude of proliferation of HBsAg and HBcAg-specific lymphocytes were significantly lower in NAFLD mice than control mice (Pxa0<xa00.05). The spleen cells of NAFLD mice produced significantly higher levels of inflammatory cytokines (Pxa0<xa00.05) and exhibited significantly increased T cell proliferation compared with control mice (Pxa0<xa00.05). However, the antigen processing and presenting capacities of spleen DCs were significantly decreased in NAFLD mice compared with control mice (Pxa0<xa00.05). Palmitic acid, a saturated fatty acid, caused diminished antigen processing and presenting capacity of both murine and human DCs.ConclusionsNonalcoholic fatty liver disease mice exhibit decreased magnitudes of antigen-specific humoral and cellular immune responses. This effect is mainly, if not solely, due to impaired antigen processing and presentation capacities of DC.

Amino acid imbalance in patients with chronic liver diseases.

Aim:u2002 The aim of this study is to clarify the amino acid imbalance in patients with chronic hepatitis (CH) as well as those with liver cirrhosis (LC).

Regulatory Dendritic Cells Pulsed with Carbonic Anhydrase I Protect Mice from Colitis Induced by CD4+CD25− T Cells

Inflammatory bowel disease (IBD), which is characterized by a dysregulated intestinal immune response, is postulated to be controlled by intestinal self-antigens and bacterial Ags. Fecal extracts called cecal bacterial Ag (CBA) have been implicated in the pathogenesis of IBD. In this study, we identified a major protein of CBA related to the pathogenesis of IBD and established a therapeutic approach using Ag-pulsed regulatory dendritic cells (Reg-DCs). Using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry, carbonic anhydrase I (CA I) was identified as a major protein of CBA. Next, we induced colitis by transfer of CD4+CD25− T cells obtained from BALB/c mice into SCID mice. Mice were treated with CBA- or CA I-pulsed Reg-DCs (Reg-DCsCBA or Reg-DCsCA1), which expressed CD200 receptor 3 and produced high levels of IL-10. Treatment with Reg-DCsCBA and Reg-DCsCA1 ameliorated colitis. This effect was shown to be Ag-specific based on no clinical response of irrelevant Ag (keyhole limpet hemocyanin)-pulsed Reg-DCs. Foxp3 mRNA expression was higher but RORγt mRNA expression was lower in the mesenteric lymph nodes (MLNs) of the Reg-DCsCA1–treated mice compared with those in the MLNs of control mice. In the MLNs, Reg-DCsCA1–treated mice had higher mRNA expression of IL-10 and TGF-β1 and lower IL-17 mRNA expression and protein production compared with those of control mice. In addition, Reg-DCsCBA–treated mice had higher Foxp3+CD4+CD25+ and IL-10–producing regulatory T cell frequencies in MLNs. In conclusion, Reg-DCsCA1 protected progression of colitis induced by CD4+CD25− T cell transfer in an Ag-specific manner by inducing the differentiation of regulatory T cells.

Characteristics of Small Bowel Tumors Detected by Double Balloon Endoscopy

BackgroundA few reports suggest that the emergence of double balloon endoscopy (DBE) has likely changed the clinical picture of small bowel tumors (SBTs).AimTo further clarify the characteristics of SBTs detected by DBE.MethodsA retrospective chart review was conducted in 227 patients who had undergone DBE.ResultsThe SBT group contained more symptomatic patients than the non-SBT group (90% vs. 49%, Pxa0<xa00.0005) with a significantly higher rate of gastrointestinal symptoms at presentation (72% vs. 33%, Pxa0<xa00.005). Twenty patients (8.8%) were eventually diagnosed with SBT, and their indications for DBE were obscure gastrointestinal bleeding (nxa0=xa05), abdominal pain (nxa0=xa05), abdominal fullness (nxa0=xa05), vomiting (nxa0=xa02), and diarrhea (nxa0=xa01). Tumors were located in the jejunum in 14 patients (70%) and in the ileum in 6 (30%). A final histological diagnosis was assigned to all 20 patients: primary adenocarcinoma (nxa0=xa08, 40%), malignant lymphoma (nxa0=xa05, 25%), metastatic cancer (nxa0=xa04, 20%), gastrointestinal stromal tumor (nxa0=xa01, 5%), carcinoid tumor (nxa0=xa01, 5%) and inflammatory fibroid polyp (nxa0=xa01, 5%). Stenosis or ulceration were the most frequently observed endoscopic findings (nxa0=xa013, 65%). All primary adenocarcinomas and three of four (75%) metastatic cancers showed stenosis or ulceration. Three of five (60%) malignant lymphomas showed multiple lymphomatous polyps. All patients but one underwent surgical resection or chemotherapy or both.ConclusionDBE is a safe and useful procedure that enables a precise diagnosis of SBTs.

Mutational analysis of predicted extracellular domains of human growth hormone secretagogue receptor 1a

The Class A family of guanine nucleotide-binding protein (G protein)-coupled receptors that includes receptors for motilin, ghrelin, and growth hormone secretagogue (GHS) has substantial potential importance as drug targets. Understanding of the molecular basis of hormone binding and receptor activation should provide insights helpful in the development of such drugs. We previously reported that Cys residues and the perimembranous residues in the extracellular loops and amino-terminal tail of the motilin receptor are critical for peptide ligand, motilin, binding and biological activity. In the current work, we focused on the predicted extracellular domains of the human GHS receptor 1a, and identified functionally important residues by using sequential deletions ranging from one to twelve amino acid residues and site-directed replacement mutagenesis approach. Each construct was transiently expressed in COS cells, and characterized for ghrelin- and growth hormone releasing peptide (GHRP)-6-stimulated intracellular calcium responses and ghrelin radioligand binding. Cys residues in positions 116 and 198 in the first and second extracellular loops and the perimembranous Glu¹⁸⁷ residue in the second extracellular loop were critical for ghrelin and GHRP-6 biological activity. These results suggest that Cys residues in the extracellular domains in this family of Class A G protein-coupled receptor is likely involved in the highly conserved and functionally important disulfide bond, and that the perimembranous residues contribute peptide ligand binding and signaling.

Critical residues in the transmembrane helical bundle domains of the human motilin receptor for erythromycin binding and activity.

The motilin receptor belongs to a family of Class I G protein-coupled receptors, and is an important endogenous regulator of gastrointestinal motor function. Motilin and erythromycin, two chemically distinct full agonists of the motilin receptor, are known to bind to distinct regions of this receptor, based on previous systematic mutagenesis of extracellular regions that dissociated the effects on these two agents. The action of these different chemical classes of agonists likely yields a common activation state of the cytosolic face of this receptor that is responsible for interaction with its G protein. In the current work, we studied the predicted transmembrane (TM) domains of this receptor for functional responses to motilin and erythromycin. Motilin receptor constructs were prepared in which each residue in the TM domains was mutated to alanine or valine. Each construct was expressed in COS cells and characterized for motilin and erythromycin binding and intracellular calcium responses stimulated by both agonists. Constructs with mutations of residues, Asp94, Leu95, Arg97 and Trp99 in TM2, Ser169 in TM4, and Tyr321 and Glu325 in TM6, were responsible for the negative impact on biological activity stimulated by erythromycin, but had no effect on motilin responses. On the other hand, constructs with mutations of residues, Leu113 in TM3, Pro172 in TM4, Trp250 and Tyr255 in TM5, and Gln334 in TM7, were negatively responsive to both erythromycin and motilin. These data support important roles of new regions in the TM domains of the motilin receptor for erythromycin action, suggesting differential mechanisms of actions by peptidyl and non-peptidyl ligands.

Severe hypoglycemia associated with insulin-like growth factor II-producing liver metastasis from gastric carcinoma treated with overnight total parenteral nutrition via a central vein catheter reserve port

Hypoglycemia caused by insulin-like growth factor II is difficult to control. A 77-year-old woman was diagnosed with gastric cancer and multiple liver metastases in September 2006 and underwent chemotherapy; however, at that time there were no symptoms of hypoglycemia. From January 2007 onwards, hypoglycemic comas and symptoms of hypoglycemia began to appear frequently. Her serum level of insulin was normal; thus, we suspected the presence of big insulin-like growth factor II was causing the hypoglycemia. This was proven by Western immunoblotting and we diagnosed non-islet cell tumor hypoglycemia associated with gastric cancer. Overnight nutrition provided via a central venous catheter port to prevent hypoglycemia allowed the patient to become ambulant and to remain free of hypoglycemic coma at follow-up until her death 7xa0months later.

High Orotate Phosphoribosyltransferase Gene Expression Predicts Complete Response to Chemoradiotherapy in Patients with Squamous Cell Carcinoma of the Esophagus

Objective: Chemoradiotherapy (CRT) is a possible alternative to surgery for esophageal cancer. As complete response (CR) to CRT is essential for a good prognosis, potential biomarkers predictive of CR were explored. Methods: Endoscopic tumor biopsies were obtained from 41 patients with stage II–III esophageal squamous cell carcinoma before 5-fluorouracil/cisplatin-based definitive CRT. cDNA was derived from RNA isolated from microdissected tumor cells. mRNA expression levels of 10 genes involved in CRT or tumor biology were measured using quantitative real-time RT-PCR. Results: Expression levels of orotate phosphoribosyltransferase (OPRT) and dihydrofolate reductase mRNA were significantly higher in the CR group compared with the non-CR group (p = 0.0206 and 0.0191, respectively). Matrix metalloproteinase 9 mRNA expression was significantly lower in the CR group (p = 0.0436). CR rates were significantly higher in patients with node-negative disease and high expression levels of OPRT and dihydrofolate reductase genes (p = 0.0448, 0.0104 and 0.0104, respectively). No significant difference in CR rates was observed for other variables. Multivariate analysis revealed that high OPRT gene expression was an independent predictive factor of CR (p = 0.0192). It was also significantly associated with good prognosis (p = 0.0450). Conclusion: High OPRT gene expression may be a predictive factor of CR to 5-fluorouracil/cisplatin-based CRT in esophageal cancer.