Manabu Sawaya

Improved visibility of colorectal flat tumors using image-enhanced endoscopy.

Colonoscopy is considered the gold standard for detecting colorectal tumors; however, conventional colonoscopy can miss flat tumors. We aimed to determine whether visualization of colorectal flat lesions was improved by autofluorescence imaging and narrow‐band imaging image analysis in conjunction with a new endoscopy system. Eight physicians compared autofluorescent, narrow‐band, and chromoendoscopy images to 30 corresponding white‐light images of flat tumors. Physicians rated tumor visibility from each image set as follows: +2 (improved), +1 (somewhat improved), 0 (equivalent to white light), −1 (somewhat decreased), and −2 (decreased). The eight scores for each image were totalled and evaluated. Interobserver agreement was also examined. Autofluorescent, narrow‐band, and chromoendoscopy images showed improvements of 63.3% (19/30), 6.7% (2/30), and 73.3% (22/30), respectively, with no instances of decreased visibility. Autofluorescence scores were generally greater than narrow‐band scores. Interobserver agreement was 0.65 for autofluorescence, 0.80 for narrow‐band imaging, and 0.70 for chromoendoscopy. In conclusion, using a new endoscopy system in conjunction with autofluorescent imaging improved visibility of colorectal flat tumors, equivalent to the visibility achieved using chromoendoscopy.

Expression of melanoma differentiation associated gene 5 is increased in human gastric mucosa infected with Helicobacter pylori

Helicobacter pylori infection is associated with gastroduodenal diseases. Melanoma differentiation associated gene 5 (MDA5) plays a role in antiviral host defense. We investigated the effect of H pylori infection on MDA5 expression in human gastric mucosa. Biopsy samples from the antrum and corpus were obtained from 33 patients. MDA5 mRNA and protein were examined by real-time PCR and immunohistochemical staining. Histological gastritis was graded according to updated Sydney System. MDA5 mRNA was significantly increased in the antrum infected with H pylori. MDA5 protein positively stained in infiltrating mononuclear cells. MDA5 mRNA expression was significantly correlated with the grade of glandular atrophy (rs = 0.767) and intestinal metaplasia (rs = 0.748) in the corpus with H pylori infection. These results indicate that MDA5 may be involved in innate immune reactions against H pylori and associate with glandular atrophy and intestinal metaplasia in patients with H pylori infection.

MORPHOMETRY FOR MICROVESSELS IN EARLY GASTRIC CANCER BY NARROW BAND IMAGING-EQUIPPED MAGNIFYING ENDOSCOPY

Background and Aim:  Microvascular architecture is a variable characterizing early gastric cancer (EGC) against the background. The aims of the present study were to measure morphological variables of the microvessels and to compare the variables between EGC and the background.

Gastric lipoma successfully treated by endoscopic unroofing

A 64‐year‐old Japanese man was diagnosed with a tumor of the stomach. From the findings of an upper gastrointestinal endoscopy, computed tomography scan and endoscopic ultrasonography, the tumor was suggestive of a gastric lipoma. He was successfully treated by an endoscopic unroofing technique. There remained residual tumor just after unroofing, but it disappeared a month later. There remained only a scar and there has been no recurrence.

Difference of p53AIP1 mRNA Expression in Gastric Mucosa Between Patients With Gastric Cancer and Chronic Gastritis Infected With Helicobacter pylori

Goals To examine the significance of alteration of p53-regulated apoptosis-induced protein 1 (p53AIP1) expression in gastric carcinogenesis in patients with Helicobacter pylori infection. Background H. pylori infection induces gastric mucosal inflammation and DNA damage of epithelial cells, which associate with gastric carcinogenesis. p53AIP1 is expressed after DNA damage and induces apoptosis in human cell lines. Study Endoscopic antral and corpus biopsies were obtained from 13 patients with chronic gastritis and 17 with gastric cancer. Expression of p53AIP1 and p53DINP1 mRNA was examined by semiquantitative reverse transcription polymerase chain reaction and mutation of p53 codon-46 was studied by direct sequence analysis. The grade of gastritis was assessed according to the updated Sydney System. Results were compared between patients with gastric cancer and chronic gastritis. Results In the antrum, p53AIP1 mRNA expression was significantly lower in patients with gastric cancer than in those with chronic gastritis (P<0.05). In patients with chronic gastritis, expression of p53AIP1 mRNA was significantly higher in the antrum than in the corpus (P<0.05). In patients with chronic gastritis, antral mucosa with high p53AIP1 expression tended to have severe intestinal metaplasia. No mutation was found at p53 codon-46. Conclusions In H. pylori-infected gastric mucosa expression of p53AIP1 would be higher when the inflammation is severe or intestinal metaplasia is present. Insufficient expression of p53AIP1 may play a role in gastric carcinogenesis in patients infected with H. pylori infection.

Influence of endoscopic submucosal dissection on serum levels of pepsinogens in patients with early gastric cancer

Background:  The serum levels of pepsinogens (PG) have been considered to be a useful marker for assessing the risk of metachronous gastric cancer in patients who undergo endoscopic submucosal dissection. However, the influence of endoscopic submucosal dissection (ESD) on serum levels of PG has not yet been examined. The aim of this study was to examine whether the level of PG after ESD can be used to predict the risk of metachronous cancer.

Evaluation of the clinical relevance of hrgA gene in patients with Helicobacter pylori infection.

BACKGROUND/AIMS Patients with gastric cancer in some Asian populations were infected more frequently with hrgA-positive H. pylori. The aim of this study was to examine the usefulness of hrgA to predict the clinical outcome of H. pylori infection. METHODOLOGY Forty four patients with gastric cancer (35 intestinal and 9 diffuse type cancer) and 51 control subjects were studied. Presence of hrgA gene in H. pylori strains isolated from biopsy specimens was examined by PCR. Biopsy specimens were also obtained for histological assessment of gastritis. RESULTS Nine of 44 patients with gastric cancer (20.4%) and 11 of 51 control subjects (21.6%) were infected with hrgA-positive strain (NS). In patients with gastric cancer, prevalence of hrgA-positive strain was 20.0% in patients with intestinal type cancer (7/35) and 22.2% with diffuse type cancer (2/9) (NS). In control subjects, the prevalence of hrgA-positive infection was not associated with gastric mucosal inflammatory infiltration and glandular atrophy. CONCLUSIONS Infection with hrgA-positive strain was not frequent among patients with gastric cancer. Presence of hrgA gene would not be a useful marker to predict clinical outcome of patients infected with H. pylori in this series of Japanese patients.

Bleeding Meckel Diverticulum Associated with a Vitellointestinal Artery Aneurysm Found on Preoperative Angiography: Report of a Case

An 18-year-old man was admitted to a local hospital with abdominal pain and bloody stool. Upper and lower gastrointestinal endoscopy failed to show any bleeding sites; however, an angiography of the superior mesenteric artery done on hospital day 4 showed an abnormal artery with an aneurysm, branching from the ileal artery. This artery was thought to be the vitellointestinal artery, a feeding artery of Meckel diverticulum. After embolization, he was transferred to our hospital, where we performed emergency laparotomy with partial resection of the ileum, including a bleeding Meckel diverticulum. Pathological examination revealed ectopic gastric mucosa and peptic ulceration, which we assumed was the origin of the bleeding. The patient had an uneventful postoperative course. Visceral artery aneurysms are rare but important vascular lesions because of their potential for fatal rupture. Although a minimally invasive procedure can be performed for a vitellointestinal artery aneurysm in patients with asymptomatic Meckel diverticulum, we treated our patient surgically because he presented with hemorrhagic shock and had been unresponsive to an H2-receptor antagonist.

Estimation of perioperative invasiveness of colorectal endoscopic submucosal dissection evaluated by energy metabolism

The aim of this study was to assess the perioperative invasiveness of endoscopic submucosal dissection for colorectal cancer quantitatively by using energy metabolism. In fifty-three patients who underwent endoscopic submucosal dissection for colorectal cancer, resting energy expenditure using an indirect calorimeter, body weight and basal energy expenditure using the Harris–Benedict equation before and after endoscopic submucosal dissection. Resting energy expenditure/body weight and resting energy expenditure/basal energy expenditure were 19.7 ± 2.5 kcal/kg/day and 0.96 ± 0.12 on the day of endoscopic submucosal dissection, whereas one day after the endoscopic submucosal dissection they increased to 21.0 ± 2.9 kcal/kg/day and 1.00 ± 0.13 (p<0.001 and p<0.05, respectively). The stress factor on the postoperative day 1 was computed as 1.06. The increase was lower comparing with that experienced for surgery, suggesting that the perioperative invasiveness of colorectal endoscopic submucosal dissection is lower in comparison to that during surgery. Furthermore, in spite of technical difficulty, stress factor of colorectal endoscopic submucosal dissection was approximately equal to that of gastric endoscopic submucosal dissection. (The study of the resting energy metabolism and stress factor using an indirect calorimeter in the perioperative period of endoscopic operation: UMIN000027135)

The Resolution of Helicobacter suis-associated Gastric Lesions after Eradication Therapy

A reddish depressed lesion was found in the corpus of the stomach of a 56-year-old man. Gastric biopsy showed no findings of mucosa-associated lymphoid tissue lymphoma, including lympho-epithelial lesions. A urea breath test, stool antigen test and serum IgG antibody to Helicobacter pylori test were negative. Magnifying endoscopy using narrow-band-imaging showed no malignant structures. Gastric biopsy specimens were subjected to immunohistochemistry and a polymerase chain reaction, which identified Helicobacter suis infection. Triple therapy with esomeprazole, metronidazole, and amoxicillin was administered for 10 days. Three months later, endoscopy showed the significant improvement of the lesion. H. suis infection should be considered in chronic gastritis patients without H. pylori infection.