Indolent feature of Helicobacter pylori-uninfected intramucosal signet ring cell carcinomas with CDH1 mutations.

BACKGROUND: In Helicobacter pylori (Hp)-uninfected individuals, diffuse-type gastric cancer (DGC) was reported as the most common type of cancer. However, the carcinogenic mechanism of Hp-uninfected sporadic DGC is largely unknown. METHODS: We performed whole-exome sequencing of Hp-uninfected DGCs and Hp-uninfected normal gastric mucosa. For advanced DGCs, external datasets were also analyzed. RESULTS: Eighteen patients (aged 29-78 years) with DGCs and nine normal subjects (28-77 years) were examined. The mutation burden in intramucosal DGCs (10-66 mutations per exome) from individuals aged 29-73 years was not very different from that in the normal gastric glands, which showed a constant mutation accumulation rate (0.33 mutations/exome/year). Unbiased dN/dS analysis showed that CDH1 somatic mutation was a driver mutation for intramucosal DGC. CDH1 mutation was more frequent in intramucosal DGCs (67%) than in advanced DGCs (27%). In contrast, TP53 mutation was more frequent in advanced DGCs (52%) than in intramucosal DGCs (0%). This discrepancy in mutations suggests that CDH1-mutated intramucosal DGCs make a relatively small contribution to advanced DGC formation. Among the 16 intramucosal DGCs (median size, 6.5 mm), 15 DGCs were pure signet ring cell carcinoma (SRCC) with reduced E-cadherin expression and a low proliferative capacity (median Ki-67 index, 2.4%). Five SRCCs reviewed endoscopically over 2-5 years showed no progression. CONCLUSIONS: Impaired E-cadherin function due to CDH1 mutation was considered as an early carcinogenic event of Hp-uninfected intramucosal SRCC. Genetic and clinical analyses suggest that Hp-uninfected intramucosal SRCCs may be less likely to develop into advanced DGCs.

[A Case Report of a Difficult to Diagnose, Extremely Well-Differentiated Stomach Adenocarcinoma Diagnosed by Biopsy].

A Japanese man in his 60s presented with complaints of epigastric pain and weight loss. A gastrointestinal endoscopy revealed multiple gastric ulcers and an irregular mound located on the wall of the lower gastric body along the greater curvature, which was suspected to be cancerous. A biopsy revealed that it was a Group 2 tumor even though the biopsy was repeated 4 times. He was referred to our hospital and 3 biopsies were performed. The final result classified the tumor as Group 4. The patient underwent surgery and the pathological examination revealed an extremely well-differentiated adenocarcinoma( EWDA). An EWDA is characterized by a well-formed mucinous gland with little or no nuclear atypia, which makes preoperative biopsy diagnosis difficult.

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.

Efficacy of probiotic treatment with Bifidobacterium longum 536 for induction of remission in active ulcerative colitis: A randomized, double-blinded, placebo-controlled multicenter trial.

BACKGROUND AND AIM: We conducted a randomized, double-blinded, placebo-controlled trial to investigate the efficacy of Bifidobacterium longum 536 (BB536) supplementation for induction of remission in Japanese patients with active ulcerative colitis (UC). METHODS: Fifty-six patients with mild to moderate UC were enrolled. Three patients had pancolitis, 36 had left-sided colitis, and 17 had proctitis. Patients were randomly treated with 2-3 × 10(11) freeze-dried viable BB536 (28 patients) or placebo (28 patients) for 8 weeks. RESULTS: In total, 63% of patients receiving BB536 showed clinical remission (UC disease activity index [UCDAI] ≤2) at week 8 compared to 52% of those receiving placebo (P = 0.395). We observed a significant decrease of UCDAI scores (3.8 ± 0.4 at baseline to 2.6 ± 0.4 at week 8) in the BB536 group (P < 0.01), whereas there was no significant decrease in the placebo group (P = 0.88). There was also a significant decrease in the Rachmilewitz endoscopic index (EI) and the Mayo subscore at week 8 in the BB536 group, whereas there was no significant decrease in the placebo group. A single patient in the BB536 group complained of a mild side-effect, but no other adverse effects were observed. CONCLUSION: Supplementation with BB536 was well tolerated and reduced UCDAI scores, EI and Mayo subscores after 8 weeks in Japanese patients with mild to moderately active UC.

Diagnosis of functioning pancreaticoduodenal neuroendocrine tumors.

Functioning pancreaticoduodenal neuroendocrine tumors (PD-NETs) are popular in a textbook, but they are still unfamiliar to a general clinician, and delay of diagnosis or misdiagnosis has been reported even today. It is a consensus that sporadic functioning PD-NET is cured only by surgical resection. So, early detection and early resection is the gold standard for the treatment of functioning PD-NET. Functioning PD-NETs in patients with multiple endocrine neoplasia type 1 (MEN 1) are often multiple. You should check about MEN 1 whenever you encountered multiple PD-NET. They are diagnosed in younger age than sporadic cases. In most cases they are accompanied with numerous microscopic or macroscopic nonfunctioning P-NETs, which are potentially metastatic and the most common cause of death in MEN 1 patients.

[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.

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.

Experimental immune-mediated pancreatitis in neonatally thymectomized mice immunized with carbonic anhydrase II and lactoferrin.

We previously reported that autoantibodies against carbonic anhydrase II and lactoferrin are frequently identified in patients with autoimmune-related pancreatitis. To clarify the role of carbonic anhydrase II and lactoferrin, we created animal models of autoimmune pancreatitis by immunizing neonatally thymectomized mice with carbonic anhydrase II and lactoferrin and also by transferring immunized spleen cells to nude mice. Neonatally thymectomized BALB/c mice were immunized with carbonic anhydrase II or lactoferrin followed by three booster injections (n = 10 in each group). We transferred whole, CD4+, or CD8+ spleen cells prepared from immunized neonatally thymectomized mice to nude mice (n = 5 in each group). Gene expression of IFN-gamma and IL-4 was investigated using semiquantitative reverse transcription-polymerase chain reaction. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling staining was used to examine apoptosis. In immunized neonatally thymectomized mice, the prevalence of inflammation was significantly higher in the pancreas. Inflammation was present in all mice receiving whole or CD4+ cells. There was no change in any of the mice receiving CD8+ cells or nonimmunized spleen cells. Carbonic anhydrase II or lactoferrin-immunized mice had apoptotic duct cells or acinar cells, respectively. Expression of the IFN-gamma gene was up-regulated in each group. Similar findings were observed in the salivary glands and liver. An immunologic mechanism against carbonic anhydrase II or lactoferrin is involved in the pathogenesis of these pancreatitis models, in which the effector cells are Th1-type CD4+ T cells.

New cytokine delivery system using gelatin microspheres containing interleukin-10 for experimental inflammatory bowel disease.

Interleukin (IL)-10 is an anti-inflammatory cytokine that suppresses the T helper 1 immune response and down-regulates macrophages and monocytes. The therapeutic effect of systemic administration of IL-10 for patients with inflammatory bowel disease, however, has not been satisfactory. We examined whether rectal administration of gelatin microspheres (GM) containing IL-10 (GM-IL-10) prevents colitis in IL-10-deficient (IL-10(-/-)) mice. GM-IL-10 and IL-10 alone were administered rectally. The colon was examined macroscopically and microscopically. IL-12 mRNA expression and CD40 expression in Mac-1-positive cells were also examined. Macroscopic and microscopic examination revealed marked improvement of colitis in IL-10(-/-) mice treated with GM-IL-10. mRNA expression of IL-12 in Mac-1-positive cells in GM-IL-10-treated mice was significantly decreased compared with that in the mice treated with IL-10 alone. Additionally, CD40 expression in Mac-1-positive cells in GM-IL-10-treated mice was decreased more prominently than in mice treated with IL-10 alone. The therapeutic effects of GM-IL-10 were associated with decreased expression of IL-12 mRNA and down-regulation of CD40 expression in Mac-1-positive cells. GM-IL-10 might be useful for treatment of patients with inflammatory bowel disease.