Expression of Tie-2 and angiopoietin-1 and -2 in early phase of ulcer healing.

BACKGROUND: Angiogenesis is an important process in tissue development and wound healing. The Tie-2 receptor tyrosine kinases and ligands, angiopoietin (Ang)-1 and -2 have been postulated to play key roles in vascular development. The purpose of this study was to evaluate the expression of Tie-2 and Ang-1 and -2 in an acetic acid-induced gastric ulcer healing process in rats. METHODS: Gastric specimens were obtained at 0 (control), 1, 3, 5, 7, and 14 days after ulcer induction for reverse transcription polymerase chain reaction (RT-PCR), Western blot analysis, and immunohistochemical analysis. RESULTS: Expression of Tie-2 and Ang-1 and -2 mRNAs was detected in normal gastric tissue and ulcerative tissues by RT-PCR. Western blot analysis revealed that Tie-2 expression reached a maximum on the third to fifth days. Expression of Ang-1 and -2 peaked on the first day. Ang-1 expression gradually became weaker in 2 weeks, whereas Ang-2 expression returned to normal in a few days. Immunohistochemically, Tie-2 was expressed constitutively in the endothelial cells of pre-existing vessels of the gastric wall, and Tie-2 expression was increased in the new capillaries of the ulcer base. CONCLUSIONS: These findings suggest that Tie-2 and Ang-1 and -2 play an important role in angiogenesis in the early phase of ulcer healing.

IL-11 up-regulates Tie-2 expression during the healing of gastric ulcers in rats.

AIM: To investigate Tie-2 expression during the repair of acetic acid-induced gastric ulcers in rats treated with recombinant human IL-11 (rhIL-11) and in untreated control animals. METHODS: Gastric ulcers were induced in male Wistar rats by applying acetic acid to the fundus of the stomach. RhIL-11 (100 microg/kg twice daily, subcutaneously) was administered from two days before ulcer induction and continued for five days after the induction. Control rats received bovine serum albumin. Gastric specimens were collected at 3 and 5 days after the induction of ulcer for immunohistochemical observation, Western blotting, and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Immunohistochemical and Western blot analysis demonstrated that Tie-2 expression was enhanced in the rhIL-11-treated rats compared with the control animals at both intervals. CONCLUSION: These findings suggested that IL-11 could accelerate ulcer healing, in part, by up-regulating Tie-2 expression and promoting angiogenesis.

Differences in endoscopic classification of early colorectal carcinoma between China and Japan: a comparative study.

AIM: To compare the differences in the endoscopic classification of early colorectal carcinoma (CRC) between Japan and China. METHODS: Ten cases of early CRC were included in the study. After reviewing the color pictures of these cases, 5 Japanese endoscopists and 5 Chinese endoscopists made their classificatory diagnosis individually using the current Japanese classification, and indicated their findings on which the diagnosis was based. RESULTS: Some lesions diagnosed by the Japanese endoscopists as IIa or IIa plus IIc, were classified as Is or Isp by the Chinese endoscopists. For superficial lesions consisting of elevation plus central depression, IIa plus depression, IIa plus IIc or IIc plus IIa were classified according to the ratio of elevated area/depressed area. However, international as well as interobserver difference still existed in the classification of such lesions. In addition, most Chinese endoscopists overlooked slightly depressed part on the top of a protruded lesion. Laterally spreading tumor, a special type of IIa, was identified as LST by some Japanese endoscopists. CONCLUSION: Discrepancies on macroscopic classification for early CRC do exist between Japanese and Chinese endoscopists, which are found not only in terminology but also in recognition of some lesions. In order to develop a universal classification, it needs for international communication and cooperation.

Pedunculated rectal carcinoid removed by endoscopic mucosal resection: a case report.

Carcinoid tumors generally appear as yellow/gray or tan submucosal nodules. We experienced a case of pedunculated rectal carcinoid showing a mushroom-like appearance. The case was a forty years old woman who was admitted to our hospital due to rectal bleeding. Colonoscopy revealed a pedunculated polyp presenting a mushroom-shaped appearance measuring 13 mm in diameter in the rectum. The histological diagnosis of specimens obtained by biopsy was adenocarcinoma and transanal ultrasonography revealed the tumor localization within the submucosal layer in the rectum. Endoscopic mucosal resection (EMR) was performed. Histopathological examination established the diagnosis of carcinoid tumor in the rectum. Frequencies of the pedunculated type in rectal carcinoids were reported to be 2.4% to 7.1% in the literature. Because of its rarity, pedunculated configuration may confuse the endoscopic diagnosis of carcinoids. Treatment for carcinoids of 1 to 1.5 cm in size remains controversial. Although such tumors are technically respectable by EMR, careful attention must be paid in dealing with these tumors because there may be unexpected behaviors of the tumors.