PURPOSE: To investigate whether Imatinib mesylate (IM) could inhibit the transdifferentiation of the lens epithelial cells (LECs) into fibroblasts using the capsular bag model. METHODS: In the capsular bag model, LECs were cultured by exposure to IM at various concentrations for 3 min. The effect of IM was analysed by observing the covering area, numbers of alpha-SMA positive cell, and BrdU incorporated proliferating cells. The same analysis was performed in the culture of LECs with TGF-beta. RESULTS: The covering area was significantly decreased by the treatment of 30 micro M IM, and the positive cells for alpha-SMA and BrdU were also decreased by IM treatment in a dose dependent manner. In addition, increasing TGF-beta concentration accelerated transdifferentiation, but suppressed the acceleration of the transdifferentiation induced by TGF-beta. CONCLUSIONS: In the capsular bag model, IM effectively inhibited not only the transdifferentiation of LECs into fibroblasts but also the TGF-beta induced acceleration of the transdifferentiation.
Acceleration ; Bromodeoxyuridine ; Epithelial Cells* ; Fibroblasts* ; Mesylates* ; Transforming Growth Factor beta ; Imatinib Mesylate

BACKGROUND: Endoscopic mucosal resection (EMR) is now in clinical use for the management of mucosal and submucosal tumors of the stomach (including early gastric cancer), but its use is limited by the size, depth, and the location of the tumor. METHODS: After the introduction of a new concept of laparoscopic intra-gastric surgery (L.I.G.S.) in which all trocars and surgical instruments are inserted directly into the gastric cavity to perform the resection of mucosal or submucosal lesions of the stomach by Dr. Ohashi, sixteen patients with a mucosal or a submucosal tumor in the posterior wall of the stomach have been successfully treated by L.I.G.S. in our hospital since 1995. RESULTS: 2 patients with early gastric cancer, 9 with a leiomyoma, and 5 with polyps. Twelve (87.5%) of the tumors were located in the antrum and 4 (12.5%) in the body. L.I.G.S. was successfully done on 14 patients (93%) with conversion to a minilaparotomy in 1 patient. The leiomyoma located in the lesser curvature was treated by L.I.G.S. through an anterior gastrotomy using hand suturing. The operationg time was about 100-160 minutes for the L.I.G.S., 120 minutes in the conversion case, and 180 minutes in the L.I.G.S. through an anterior gastrotomy. Postoperative pain was negligible in all cases, and the patients were discharged uneventfully six to seven days after surgery. The follow-up period was 1 to 37 months, and there were no recurrences. The important points of this approach are confirmation of the location of the tumor by both gastrofiberscopy and laparoscopy, excluding the determination of regional lymph node metastasis by endoscopic ultrasonography, and proper selection of the trocar sites. CONCLUSION: We conclude that L.I.G.S. is technically feasible, safe, and useful for a mucosal or a submucosal tumor in the posterior wall of the stomach and that it should be considered as a viable alternative to endoscopic mucosal resection and conventional gastric resection.
Endosonography ; Follow-Up Studies ; Hand ; Humans ; Laparoscopy ; Laparotomy ; Leiomyoma ; Lymph Nodes ; Neoplasm Metastasis ; Pain, Postoperative ; Polyps ; Recurrence ; Stomach ; Stomach Neoplasms ; Surgical Instruments