Methotrexate-related lymphoproliferative disorder of the stomach in a patient with rheumatoid arthritis: a case of disease regression after methotrexate cessation.

We report the case of a 78-year-old woman with methotrexate-related gastric lymphoproliferative disorder (LPD). The patient had a history of rheumatoid arthritis (RA) and had been treated with methotrexate (MTX). Endoscopic examination revealed round elevated lesions in the stomach, and a biopsy specimen showed atypical lymphoid cell proliferation. Immunohistological study found these atypical cells to be positive for L-26 but not for CD3 or EBER. Therefore, we made a diagnosis of MTX-related LPD showing features of diffuse large B-cell lymphoma. Combined positron emission tomography-computed tomography (PET-CT) using 18F-fluorodeoxyglucose (FDG) showed increased avidity in the stomach in addition to slightly increased FDG-avidity in the mediastinum and left chest wall. We decided not to start chemotherapy but to discontinue administration of MTX, with follow-up using endoscopy and PET-CT. The endoscopic examinations after cessation of MTX demonstrated gradual regression of the elevated lesions. PET-CT 6 months after cessation showed no increased FDG avidity in the stomach. While disease regression was observed in the stomach, the other FDG-avid spots remained unchanged on PET-CT. Therefore, we performed chemotherapy as additional therapy. On PET-CT after chemotherapy, the FDG-avid spots remained unchanged for more than 1 year, and we eventually concluded that they were RA-related inflammatory lesions. In patients with MTX-related LPD, cessation of MTX may be a therapeutic option, but careful follow-up and chemotherapy in accordance with the clinical course are essential.

A case of insulinoma with non-alcoholic fatty liver disease: Roles of hyperphagia and hyperinsulinemia in pathogenesis of the disease.

Nonalcoholic fatty liver disease (NAFLD) is a serious health-related condition all over the world; the number of patients is increasing in Asian countries including Japan. Better understanding of its pathophysiology is required to develop effective therapeutics, as patients may go on to develop non-alcoholic steatohepatitis and hepatocellular carcinomas. While NAFLD is believed to be associated with metabolic risk factors such as obesity, diabetes, and dyslipidemia, its etiology remains largely unknown and the development or co-existence of NAFLD in patients with insulinoma has not been investigated. A 33-year-old male with an insulinoma, who had been hypoglycemic during the previous four years, developed abnormally elevated levels of liver enzymes and histological fatty liver characteristic of NAFLD by the time of admission to our hospital for resection of an insulinoma. His medical records for the previous eight years revealed that his bodyweight had increased gradually from 60 kg to 71 kg for seven years and then acutely increased to 79 kg in the latest one-year period. This sudden increase was thought to be due to the patient's self-described overeating of fruits to forestall hypoglycemia. Fresh fruits are rich in fructose, and the patient's triglycerides, alanine and aspartate transaminases showed an acute increase in the previous one-year period. After resection of the insulinoma, the levels of these parameters all were mostly restored, which suggests that hyperinsulinemia and subsequent hyperphagia played a role in the development of NAFLD in this case. This is the first report of patient with NAFLD and an insulinoma.

Sinusoidal obstructive syndrome with hypereosinophilia successfully treated with prednisolone.

A 60-year-old man was admitted to Tenri Hospital complaining of erythema and abdominal distention. There were marked liver damage and hypereosinophilia. The patient was suffering from portal hypertension and coagulation disorder. We diagnosed the patient clinically as suffering from veno-occlusive disease, or sinusoidal obstructive syndrome (SOS). The pathological finding of the liver biopsy specimen was compatible with SOS. All of the manifestations, liver function test, and hemodynamics subsided shortly after administration of steroid treatment and ursodeoxycholic acid. The pathogenesis was not identified but some allergic reaction was suspected.

[A case of AFP-producing gastric cancer resected after efficient S-1/CDDP combination chemotherapy].

A 62-year-old male was diagnosed as AFP-producing gastric cancer with lymph node metastases and multiple liver metastases. He was treated with S-1 and CDDP combination chemotherapy. At the end of the first course, both primary and metastatic lesions were remarkably decreased in size, and the serum AFP level was also decreased. The chemotherapy was effective against the cancer and led to a partial response (PR) according to the RECIST guideline. Following the nine months of PR, the primary lesion which had once nearly disappeared, emerged again. Because distant lymph node metastases and liver metastases were considered to have disappeared, distal gastrectomy with D2 lymphadenectomy was performed. The patient received S-1 monotherapy for 6 months after the operation. At present the patient has achieved progression-free survival for 1 year and 3 months after the operation. Though AFP-producing gastric cancer is known for its poor prognosis, combination treatment such as operation or hepatic arterial infusion chemotherapy may improve the prognosis in patients with advanced AFP-producing gastric cancer when systemic chemotherapy is effective.

Spontaneous regression of diffuse intrahepatic recurrence with portal vein tumor thrombus after resection of hepatocellular carcinoma.

We report a rare case of spontaneous regression of diffuse intrahepatic recurrence with portal vein tumor thrombus (PVTT) after resection of hepatocellular carcinoma (HCC). A 68-year-old man with hepatitis C virus-related liver cirrhosis presented with a 40 mm tumor in the right anterior segment of the liver. The tumor was diagnosed as HCC by typical imaging findings and elevated serum alpha-fetoprotein (AFP) (716 ng/ml) and protein induced by vitamin K absence II (PIVKA II) (8,100 ng/ml). A right anterior sectionectomy of the liver was performed. Microscopically, the tumor was moderately differentiated HCC. Four months after resection, a computed tomography (CT) scan showed diffuse intrahepatic recurrence with PVTT. Serum AFP was 12,319 ng/ml and PIVKA II was 168,000 ng/ml. The patient did not receive any further treatment for HCC including herbal medicine, and stopped smoking. Two years and 5 months later, no lesion was detected on a CT scan when serum AFP was 1.9 ng/ml. Ischemia due to main portal vein occlusion and rapid tumor growth might have induced tumor regression in the present case. Moreover, abstention from smoking might have improved his immunological function.

[A case of jejunal adenocarcinoma with serum DUPAN-2 elevation].

A 50-year-old woman was admitted to our hospital because of abdominal pain and vomiting. Ileus with ulcerated jejunal tumor was diagnosed and biopsy revealed adenocarcinoma. Because her serum level of DUPAN-2 was high, she was examined by PET scan, which revealed that she had a left ovarian mass in addition to the jejunal tumor. Surgical resection was performed: both tumors were adenocarcinoma, but the ovarian tumor was considered to be metastatic clinically and histologically. Immunostaining for DUPAN-2 was positive in the both tumors. The serum level of DUPAN-2 returned to normal after the surgery, and has been within normal limits for about 3 years without any additional therapy. This case shows a possible relation between small bowel adenocarcinoma and DUPAN-2.

Screening for improved activity of a transglutaminase from Streptomyces mobaraensis created by a novel rational mutagenesis and random mutagenesis.

Microbial transglutaminase (MTG) has been used extensively in academic research and the food industries through its cross-linking or posttranslational modification of proteins. Two enzyme engineering approaches were applied to improve MTG activity. One is a novel method of rational mutagenesis, called water-accessible surface hot-space region-oriented mutagenesis (WASH-ROM). One hundred and fifty-one point mutations were selected at 40 residues, bearing high solvent-accessibility surface area, within a 15 A space from the active site Cys64. Among them, 32 mutants showed higher specific activity than the wild type. The other is a random mutagenesis of the whole region of the MTG gene, coupled with a new plate assay screening system, using Corynebacterium Expression System CORYNEX. This in vivo system allowed us to readily distinguish the change in enzymatic activity by monitoring the intensity of enzymatic reaction-derived color zones surrounding recombinant cells. From the library of 24,000 mutants, ten were finally selected as beneficial mutants exhibiting higher specific activity than the wild type. Furthermore, we found that Ser199Ala mutant with additional N-terminal tetrapeptide showed the highest specific activity (1.7 times higher than the wild type). These various beneficial positions leading to increased specific activity of MTG were identified to achieve further enzyme improvements.

Direct determination of the insulin-insulin receptor interface using transferred cross-saturation experiments.

Insulin initiates metabolic control by binding to the insulin receptor (IR) on target cells. Kinetic and mutational analyses have revealed two binding sites on the insulin molecule and the residues that compose them. However, direct determination of the insulin-IR interface is required to distinguish those residues that contribute to receptor binding from those required for structural stability. Here, we successfully characterized one binding site using the nuclear magnetic resonance (NMR) transferred cross-saturation method, which can directly determine the binding interface of a large protein-protein complex. The results showed that this binding site contained three residues that have not been identified previously by mutational analyses. On the basis of the structure of the contact site, we also identified a molecule that can displace insulin from the IR. In addition, we discuss the mode of interaction between insulin and its receptor relative to the NMR analyses.

Esophageal involvement in microscopic polyangiitis: a case report and review of literature.

A 72-year-old man with cough and sputum showed esophageal wall thickening and pneumonia in chest computed tomography (CT) scan. Following endoscopy, we diagnosed reflux esophagitis and subscribed proton pump inhibitor. The esophageal lesion, however, was intractable. We diagnosed microscopic polyangiitis (MPA) because of vasculitis symptoms, cytoplasmic antineutrophil cytoplasmic antibodies (cANCA) in blood and no granulomatous change in the esophagus. We adopted pulse therapy of cyclophosphamide and oral prednisolone; the symptoms and esophageal lesion were markedly improved. We concluded that the esophageal lesion was an aspect of MPA. To our knowledge, this is the first report of esophageal involvement in MPA.

Antibody to hepatitis B core antigen and risk for hepatitis C-related hepatocellular carcinoma: a prospective study.

BACKGROUND: Previous exposure to hepatitis B virus (HBV) and occult HBV infection may have an important role in the development of hepatocellular carcinoma (HCC) in patients with chronic liver disease related to hepatitis C virus (HCV). OBJECTIVE: To prospectively study the association between antibody to hepatitis B core antigen (anti-HBc) and clinical outcomes in patients with HCV-related chronic liver disease. DESIGN: Prospective observational study. SETTING: Kyoto University Hospital and 14 regional core hospitals in Japan. PARTICIPANTS: 872 patients with chronic HCV infection (597 with chronic hepatitis and 275 with cirrhosis). MEASUREMENTS: Incidence of HCC on follow-up (from 1995 to 2005). RESULTS: Only 846 of the 872 enrolled patients were followed. Hepatocellular carcinoma occurred in 237 of 846 patients (28.0%) during follow-up. Among patients with cirrhosis, HCC was diagnosed in 85 of 141 patients (60.3%) with anti-HBc and 58 of 129 patients (45.0%) without HBV-related serologic markers. Of 224 patients with chronic hepatitis who had interferon monotherapy, 92 (41.1%) had sustained or transient disappearance of HCV RNA. None of the anti-HBc-negative patients who had a virologic response to interferon therapy developed HCC, whereas cancer was diagnosed in 4 of 37 anti-HBc-positive patients (10.8%) with a virologic response to interferon. On multivariate analysis using a Cox proportional hazards model, anti-HBc-positive results on serologic testing was an independent risk factor in patients with cirrhosis (incidence rate ratio, 1.58 [95% CI, 1.12 to 2.22]). LIMITATIONS: The study included only 1 assessment of smoking and alcohol consumption at study entry and did not precisely determine the duration of smoking or alcohol use. CONCLUSIONS: Anti-HBc-positive results on serologic testing are a marker of high risk for HCC among patients with HCV-related cirrhosis. Interferon therapy might be less effective in preventing HCC among patients with chronic hepatitis C who are anti-HBc-positive than in those with chronic hepatitis C who are anti-HBc-negative.

Direct determination of a membrane-peptide interface using the nuclear magnetic resonance cross-saturation method.

Membrane-peptide interactions are involved in many crucial biological and pharmacological activities. To clarify the interaction mode of membrane-peptide complexes, it is important to analyze both the dynamic properties and the contact residues of the membrane-bound peptide. In this study, we investigated the dynamic properties of a peptide bound to a lipid bilayer, using relaxation and amide-water exchange analyses, and directly determined the membrane-peptide interface, using the cross-saturation method. For the models of a lipid bilayer and a peptide, isotropic bicelles and mastoparan were used, respectively. The results indicate that mastoparan had a heterogeneous distribution of motion over various timescales and interacted with the lipid bilayer by using its hydrophobic side; the molecule was located within the lipid bilayer rather than on the surface, as thought previously. This study shows that the cross-saturation method is useful for determining the interface of not only protein-protein but also membrane-peptide complexes.

Efficacy of a Low-Dose Omeprazole-Based Triple-Therapy Regimen for Helicobacter pylori Eradication Independent of Cytochrome P450 Genotype : The Japanese MACH Study.

OBJECTIVES: To investigate the efficacies of two different triple-therapy regimens (standard versus low doses), and the influence of cytochrome P450 enzyme (CYP) genetic polymorphism on these efficacies, in Japanese patients undergoing Helicobacter pylori eradication treatment. METHODS: All patients received 1 week of triple therapy. Patients in group A (low-dose regimen) received omeprazole 40 mg/day + amoxicillin 1500 mg/day + clarithromycin 800 mg/day; patients in group B (standard-dose regimen) received omeprazole 40 mg/day + amoxicillin 2000 mg/day + clarithromycin 1000 mg/day. RESULTS: A total of 225 patients (113 in group A and 112 in group B) were randomised to one of the two triple-therapy regimens. The eradication rates were 78.8% (89/113 patients; 95% CI 70.1, 85.9) in group A and 83.0% (93/112 patients; 95% CI 74.8, 89.5) in group B. Genetic polymorphism of CYP2C19, a major metabolic enzyme of omeprazole, did not affect eradication rates, while susceptibility to clarithromycin greatly affected the success of eradication. The cumulative ulcer relapse rate at 24 weeks after endoscopically documented ulcer healing (30 weeks after completion of the drug regimen) was 8.3% for group A and 12.5% for group B (log rank test: p = 0.6248). However, comparison of the cumulative relapse rate of 6.7% in patients after successful H. pylori eradication with the relapse rate of 27.3% in those who failed H. pylori eradication revealed a significant difference in the remission-time curve (log rank test: p = 0.0047). This finding suggested the existence of a relationship between H. pylori eradication failure and ulcer relapse. Both drug regimens were well tolerated. Endoscopically proven reflux esophagitis developed in about 10% of patients after eradication, but was not clinically significant. CONCLUSIONS: One week of triple therapy with a low-dose regimen provides adequate H. pylori eradication in Japanese patients. CYP genetic polymorphism is of minimal clinical significance with both triple-therapy regimens.

Absolute configuration of a polyol fragment of blasticidin A, a specific inhibitor of aflatoxin production.

Blasticidin A (1) and aflastatin A (2), Streptomyces metabolites with similar structures, are specific inhibitors of aflatoxin production by Aspergillus parasiticus. The stereochemistry of the polyol fragment of 1 (3a) containing ten chiral centers was elucidated by applying acetonide and MTPA methods to a variety of acetonide derivatives of 3a, which determined the absolute configuration of 3a. By using the similar methods, the absolute configuration of the polyol fragment of 2 (4a) was determined, which was the same as that elucidated by J-based and other chemical methods previously.

Risk of HCV transmission after needlestick injury, and the efficacy of short-duration interferon administration to prevent HCV transmission to medical personnel.

BACKGROUND: We carried out this study to assess the risk of hepatitis C virus (HCV) transmission after needlestick injuries in medical personnel, and to evaluate the efficacy of short-duration interferon administration to prevent HCV transmission. METHODS: A total of 684 personnel who had been occupationally exposed to an anti-HCV-positive source and followed for more than 3 months were retrospectively examined. RESULTS: Of the 684 subjects, 279 (41%) were treated with 1 to 3 days of interferon either just after or 1 to 12 days after the injury. One case of HCV infection was found in each of the treated (1/279; 0.4%) and nontreated (1/405; 0.2%) groups. There was no significant difference in the transmission of HCV between the two groups. Both infected patients were treated with interferon after developing acute hepatitis, and HCV was subsequently cleared. CONCLUSIONS: There is a lower risk of HCV transmission after needlestick accident than previously reported, and short-duration interferon administration at an early stage after the needlestick injury, to prevent HCV transmission, is unnecessary.

Catheter US probe EUS evaluation of gastric cardia and perigastric vascular structures to predict esophageal variceal recurrence.

BACKGROUND: This study assessed the risk of recurrence of esophageal varices by evaluating the severity of cardia vascular structures in patients with portal hypertension by EUS with a catheter US probe before endoscopic variceal ligation. METHODS: Thirty consecutive patients with esophageal varices at high risk for bleeding were studied. Simultaneous conventional endoscopy and EUS with a 20 MHz catheter US probe were performed before endoscopic variceal ligation. By catheter US probe EUS findings, vascular structures in the gastric cardia were classified into 2 grades, mild and severe, and the relationship between the catheter US probe EUS findings and the recurrence rate of esophageal varices was analyzed. RESULTS: Catheter US probe EUS before endoscopic variceal ligation demonstrated cardial submucosal varices in all patients, whereas conventional endoscopy revealed cardial varices in only 21 patients (70.0%, NS). Patients with recurrent esophageal varices after endoscopic variceal ligation were more likely to have severe-grade perforating veins before treatment than those without recurrence (71.4% vs. 12.5%, p < 0.01). Patients with severe as opposed to mild-grade perforating veins before treatment had a significantly higher recurrence rate (90.9% vs. 21.0%, p < 0.01%). CONCLUSIONS: Catheter US probe EUS findings for cardial vascular structures before treatment are useful for predicting the likelihood of recurrence of esophageal varices.