Yun Jeung Kim

Inhibitory effects of rapamycin on the different stages of hepatic fibrosis.

AIM To investigate and compare the inhibitory effects of rapamycin in the different stages of liver fibrosis. METHODS We performed bile duct ligation (BDL) in male Wistar rats (n = 24). The experimental rats were classified into four groups: the BDL(+)/Rapa(-) group (un-treated control, n = 4), the BDL(+)/Rapa(+) group (treated 14 d after BDL, n = 8), the BDL(+)/Rapa(++) group (treated on the day after BDL, n = 8), and the BDL(-)/Rapa(-) group (un-treated, sham -operated control, n = 4). The BDL(+)/Rapa(+) and BDL(+)/Rapa(++) groups were administered rapamycin (2 mg/kg) for 28 d. The liver tissues were tested by immunohistochemical staining for α-smooth muscle actin (α-SMA) and cytokeratin. RESULTS The liver mRNA levels of transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF) were measured using the polymerase chain reaction. The protein levels of liver p70s6K and p-p70s6k were determined using Western blotting. α-SMA expression was lowest in the BDL(+)/Rapa(++)group. TGF-β1 and PDGF expression levels in the rapamycin-treated group were lower than those in the un-treated group and higher than those in the control groups (TGF-β1: 0.23 ± 0.00 vs 0.34 ± 0.01, 0.23 ± 0.0 vs 0.09 ± 0.00, P < 0.0001; PDGF: 0.21 ± 0.00 vs 0.34 ± 0.01, 0.21 ± 0.0 vs 0.09 ± 0.00, P < 0.0001). The p70s6k and p-p70s6k levels decreased in the treated groups and were lowest in the BDL(+)/Rapa(++)group (p70s6k: 1.05 ± 0.17 vs 1.30 ± 0.56, 0.40 ± 0.01 vs 1.30 ± 0.56, P < 0.0001; p-p70s6k: 1.40 ± 0.5 vs 1.67 ± 0.12, 0.70 ± 0.01 vs 1.67 ± 0.12, P < 0.0001). CONCLUSION The results of our study indicate that rapamycin has inhibitory effects on liver fibrosis, and the treatment is most effective in the early stages of fibrosis.

Clinical Outcomes of Endoscopic Submucosal Dissection for Undifferentiated or Submucosal Invasive Early Gastric Cancer

Background/Aims Early gastric cancer (EGC) that is undifferentiated or shows submucosal invasion has not been generally accepted as an indication for endoscopic treatment. But recently, experiences with endoscopic submucosal dissection (ESD) for undifferentiated EGC or submucosal invasive (SM) EGC have increased. The aim of this study was to evaluate clinical outcomes of ESD for EGC with undifferentiation or submucosal invasion. Methods Between August 2005 and August 2009, among 210 EGCs treated using ESD at our hospital, 18 lesions were diagnosed as undifferentiated gastric cancer and 41 as SM gastric cancer. A retrospective analysis was done on the medical records of these patients. Results Mean follow-up periods were 19.39±11.2 months. During the follow-up period, local recurrence was noted in 4 lesions. Local recurrence rates of the EGC groups (group 1, mucosal cancer with undifferentiation; group 2, SM cancer with differentiation; group 3, SM cancer with undifferentiation) were 10%, 4.5%, and 50%, respectively. Groups 1 and 2 were not significantly different in local recurrence rates compared to the mucosal cancer with differentiation group (p=0.061, p=0.125, respectively). The undifferentiated EGC group was significantly lower in curability using ESD than the differentiated EGC group (55.6% vs. 89.6%, p=0.000). The curability of the SM EGC group was lower than the mucosal EGC group (36.6% vs. 98.9%). Conclusions Complete resection using ESD is difficult in undifferentiated and SM gastric cancers. SM cancer with undifferentiation should be treated immediately by salvage operation. For mucosal cancer with undifferentiation or SM cancer with differentiation, one should consider careful short-term follow-up.

Reactivation of tuberculosis in hepatocellular carcinoma treated with transcatheter arterial chemoembolization: A report of 3 cases.

Pulmonary tuberculosis is an opportunistic infection that can be reactivated in immunocompromised conditions, for example, in malignancy or after liver transplantation. Hepatocellular carcinoma (HCC) has a high mortality rate because it is frequently diagnosed at an advanced stage. Although surgical resection is the established curative measure for HCC, it is only feasible for early-stage HCC. Transcatheter arterial chemoembolization (TACE) is the most common treatment modality for patients with unresectable HCC. However, repeated TACE sessions and, occasionally, the tumor itself can further impair the reserve hepatic function and immunity. We report 3 recent cases of HCC with reactivation of pulmonary tuberculosis after TACE.

Recurrent Renal Leiomyosarcoma Mimicking a Colonic Submucosal Tumor: A Case Report

A primary leiomyosarcoma of the kidney is a rare, but highly aggressive, neoplasm, accounting for only 0.1% of all invasive renal tumors. Local or systemic recurrence is common, but a leiomyosarcoma is difficult to diagnose preoperatively. We recently encountered an interesting case of an unusual recurrence of a renal leiomyosarcoma. A 57-year-old woman visited our hospital complaining of lower abdominal pain. Four years previously, she had undergone a left nephrectomy. She had a primary leiomyosarcoma of the kidney that had been misdiagnosed as a renal cell carcinoma. Colonoscopy revealed the presence of a lesion similar to a submucosal tumor in the descending colon. Postoperative pathologic examination confirmed that the mass was a recurrent leiomyosarcoma. We report this unusual case and present a review of the literature.