Yasunori Kaneko

USEFULNESS OF DOUBLE BALLOON ENTEROSCOPY AND VIDEO CAPSULE ENDOSCOPY FOR THE DIAGNOSIS AND MANAGEMENT OF PRIMARY FOLLICULAR LYMPHOMA OF THE GASTROINTESTINAL TRACT IN ITS EARLY STAGES

Aim:  The aim of this study is to evaluate the usefulness of double balloon enteroscopy (DBE) and video capsule endoscopy (VCE) in patients with primary follicular lymphoma (FL) of the gastrointestinal (GI) tract. Furthermore, we estimate the effectiveness of chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone) including rituximab for them.

Altered expression of CDX-2, PDX-1 and mucin core proteins in ''Ulcer-associated cell lineage (UACL)'' in Crohn's disease

The ulcer-associated cell lineage (UACL) induced at the site of ileac chronic ulceration in Crohn’s disease has been reported to show histological differentiation resembling gastric pyloric mucosa. To clarify the significance of homeobox gene-encoded transcription factors in the formation of the UACL in Crohn’s disease, we investigated the immunohistochemical expression of gastrointestinal mucins (MUC5AC for gastric surface mucous cells; MUC6 for gastric gland mucous cells, and MUC2 for intestinal goblet cells) and homeobox gene-encoded transcription factors (CDX-2 for intestinal mucosa and PDX-1 for pyloric mucosa) in the UACL. The analysis was undertaken on ileal mucosa obtained from ileal resections performed in 19 patients with active Crohn’s disease of the small bowel. The UACL was observed in nine patients. In the UACL, expression of mucous cells with a foveolar-structure showed immunoreactivity to MUC5AC, and the mucous cells with a glandular structure showed immunoreactivity to MUC6, and the expression of MUC2 was decreased. In addition, we detected the decreased expression of CDX-2 along with the increased expression of PDX-1 in the UACL. The UACL showed histological differentiation simulating gastric pylori mucosa. The down-regulation of CDX-2 and the up-regulation of PDX-1 could be an important mechanism in the induction of the UACL.

Gastric inflammatory fibroid polyp manifesting massive bleeding and marked morphological changes for a short period.

was difficult to restore the tumor into the stomach by snare wire, requiring several tries. EUS showed a homogeneous hypoechoic tumor with a distinct border in the third sonographic gastric layer. Endoscopic snare polypectomy was performed 5 days after EUS. At this time, the shape of the tumor was markedly changed compared with findings of the prior endoscopy; most of the mucosa covering the tumor had peeled off, its oval shape had become distorted, and it had reduced in size (Fig. 1d). Moreover, fresh blood was oozing from the tumor, and coffee grounds-like material adhered to its surface (Fig. 1d). The resected specimen was 4.5 2.5 cm in size. This tumor was diagnosed as an IFP according to the microscopic findings, which revealed proliferation of fibroblasts and collagen fibers with infiltration of mononuclear cells and eosinophils (Fig. 2). Since endoscopic polypectomy, no further symptoms of anemia or tarry stools have occurred in this patient. In this case, the tumor was observed prolapsing to the duodenal bulb. This tumor was quite large; possibly, the tumor was incarcerated in the duodenal bulb in association with strangulation by the pyloric ring at the time of prolapse. This process could cause necrosis and depletion of the tumor surface mucosa, which resulted in the marked morphological changes observed in our case. Although prolapse to the duodenal bulb has sometimes been reported in gastric IFP,1 prolapse was reversible in all previous cases, and no previous report has described morphological changes resembling those seen in our case.

Helicobacter pylori infection increases cell kinetics in human gastric epithelial cells without adhering to proliferating cells

We investigated the effect of H. pylori infection on cell proliferation of gastric mucosa using immunostaining for H. pylori or Ki67. H. pylori cells attached to surface mucous cells covering luminal surface and the upper part of gastric foveolae, and up‐regulated the proliferative activity of gastric epithelial cells without adhering to the proliferating epithelial cells.

Ultrastructure of Helicobacter pylori in human gastric mucosa and H. pylori-infected human gastric mucosa using transmission electron microscopy and the high-pressure freezing-freeze substitution technique

BackgroundConventional ultrastructural analyses of Helicobacter pylori and H. pylori-infected gastric mucosa by transmission electron microscopy (TEM) have limitations because of structural artifacts introduced during fixation.MethodsWe used high-pressure freezing (HPF) followed by freeze substitution for TEM to investigate the ultrastructure of H. pylori and H. pylori-infected gastric mucosa. For HPF–freeze substitution, human gastric biopsy specimens were placed in the HPF instrument at a pressure of approximately 2000 atm at the temperature of liquid nitrogen. Specimens were then transferred to an instrument for freeze substitution. Specimens were first placed in acetone containing 2% OsO4 at −85°C. The temperature was increased to −3°C, followed by embedding in Quetol 812. Ultrathin sections were double-stained by uranium acetate/lead nitrate. HPF and conventionally prepared samples were examined by TEM.ResultsThe H. pylori envelope was clearly seen to consist of an outer membrane, periplasmic space, and plasma membrane. The periplasmic space was filled with electron-dense materials. A peptidoglycan layer was only occasionally visible. A thick, very fine filamentous or reticular fringe corresponding to the bacterial glycocalyx was seen surrounding the H. pylori cells. At the adhesion loci of H. pylori to gastric epithelial cells, H. pylori was connected to the epithelial cells by very fine, thickly arranged filaments or more closely, with a contact zone. The epithelial cells showed indentations or pedestals.ConclusionsThe well-developed, thick bacterial glycocalyx of H. pylori appears to strongly interact with external cellular components and may play an important role in the adhesion of H. pylori to epithelial cells.