Inhibition of pulmonary cancer progression by epidermal growth factor receptor-targeted transfection with Bcl-2 and survivin siRNAs.

Clinical application of small interfering RNA (siRNA) in cancer therapy has been limited by the lack of an efficient systemic siRNA delivery system. In this report we describe an efficient siRNA delivery system directed to metastasized tumors, especially in the lungs. Anticancer siRNA was condensed in the presence of 9-arginine peptides (9Arg) and then complexed with cationic O,O'-dimyristyl-N-lysyl glutamate liposomes conjugated to antibodies against the epidermal growth factor receptor (EGFR). The ternary complex of optimized anti-EGFR-9Arg-lipoplexes exhibited efficient siRNA transfection of LS174T-Luc cancer cells grown in culture or orthotopically in mouse lungs. Anti-tumor Bcl-2/survivin siRNAs loaded in the anti-EGFR-9Arg-lipoplexes effectively suppressed transcription of their target genes, resulting in an efficient cancer cell death. Repeated intravenous administrations of the anti-EGFR-9Arg-lipoplexes effectively inhibited tumor growth in the mouse lungs and prolonged survival of the mice compared with nontargeted lipoplexes. These results suggest that the ternary complexes of anti-EGFR-9Arg-lipoplexes might have clinical applications in RNA interference cancer therapy.

Hepatic resection for hepatocellular carcinoma meeting Milan criteria in Child-Turcotte-Pugh class a patients with cirrhosis.

This study evaluated whether hepatic resection is a reasonable strategy as an initial treatment for hepatocellular carcinoma (HCC) meeting Milan criteria in patients with compensated cirrhosis. From the database of 435 consecutive patients with resection of HCC between July 1994 and May 2007, 213 patients were found to have Child-Turcotte-Pugh class A cirrhosis and HCC meeting Milan criteria, as shown by preoperative image studies. We examined long-term survivals and patterns of recurrence after hepatic resection among those patients. Overall survival rates at 1, 3, 5, and 10 years were 92%, 78%, 69%, and 52%, respectively, and 1-, 3-, 5-, and 10-year disease-free survival rates were 79%, 57%, 44%, and 19%, respectively. Pathological review indicated that 36/213 patients (16.9%) had another nodule and/or gross vascular invasion. Microvascular invasion, tumor size, and histological grade of cirrhosis were independent risk factors for recurrence. Sixty percent of recurrent cases met the Milan criteria. The six patients who underwent living donor salvage liver transplantation (OLT) for intrahepatic recurrence were alive without recurrence at a median of 24 (range = 8-31) months. These favorable data suggest that hepatic resection is a good option for small HCCs in patients with compensated cirrhosis; and salvage OLT may be reserved for patients with recurrences.

Duct-to-duct biliary reconstructions and complications in 100 living donor liver transplantations.

OBJECTIVE: We evaluated the risk factors for biliary complications and surgical procedures for duct-to-duct reconstructions in adult living donor liver transplantation (LDLT). PATIENTS AND METHODS: From February 2005 to March 2008, we performed 100 cases of adult LDLT with duct-to-duct biliary reconstruction, using 64 right lobe grafts, 33 left lobe grafts, and 3 right lateral grafts. We employed 4 types of duct-to-duct procedures: all interrupted 6-0 Prolene suture (group 1, n = 9); continuous posterior and interrupted anterior wall 6-0 Prolene suture (group 2, n = 49); all continuous 7-0 Prolene suture (group 3, n = 26); and all continuous 7-0 Prolene suture with external stent (group 4, n = 16). Biliary complications were defined as an anastomosis stricture or a leakage. RESULTS: Thirty-four patients experienced biliary complications during the follow-up period (median, 27 months). The incidence of stricture was 27% and that of leakage, 8%. There were no perioperative, intraoperative, or anatomic risk factors for biliary complications, except the type of duct-to-duct procedure. Group 1 and 2 patients showed higher incidences of biliary strictures than groups 3 and 4 (43.1% vs 4.7%; P = .00). Group 3 patients experienced a higher incidence of bile leakage than the other groups (23.1% vs 2.7%; P = .004). CONCLUSIONS: The type of biliary reconstruction is a factor affecting biliary complications following duct-to-duct anastomosis in LDLT. Duct-to-duct biliary anastomosis with 7-0 monofilament suture and a small external stent is a feasible procedure in LDLT that significantly reduces the incidence of biliary complications.

Salvage liver transplantation for recurrent hepatocellular carcinoma after liver resection: feasibility of the Milan criteria and operative risk.

INTRODUCTION: Although the Milan criteria are widely accepted for liver transplantation (OLT) for hepatocellular carcinoma (HCC), they have not been fully evaluated as feasible for salvage liver transplantation (SLT) of recurrent HCC after hepatic resection. The operative difficulties of SLT increase the operative risk. The aim of this study was to evaluate the feasibility of the Milan criteria for SLT and its operative complications. PATIENTS AND METHODS: From March 2005 to November 2007, 46 HCC patients received OLT including 15 SLTs after prior partial hepatectomy (SLT group) and 31 primary OLTs (PLT group). RESULTS: There was no postsurgical hospital mortality among the SLT group but one case in the PLT group due to pneumonia followed by sepsis. There was no difference in the incidence of surgical complications between the two groups. Overall survival rates of SLT group patients were similar to those of the PLT group (P = .14), especially comparing both groups of patients within the Milan criteria (P = .89). There was no recurrence of HCC among the patients within the Milan criteria. CONCLUSIONS: SLT is a feasible procedure for recurrent HCC meeting the Milan criteria; the operative risk of the SLT is also acceptable.

Effective anatomic reconstruction of the middle hepatic vein in modified right lobe graft living donor liver transplantation.

INTRODUCTION: Adult liver transplantation using the right lobe graft without a middle hepatic vein (MHV; modified right lobe graft) has widely been used to compensate for the cadaveric organ shortage. To provide appropriate functional graft volume in the right lobe graft used for living donor liver transplantation (LDLT), successful reconstruction of the MHV is required. We have described herein the effectiveness of an anatomic MHV reconstruction technique with tailoring donor hepatectomy and uniformed MHV reconstruction for modified right lobe grafts. MATERIALS AND METHODS: From December 2005 to August 2006, 15 adult patients received modified right lobe graft LDLT using a donor hepatectomy technique that exposed the right side of the MHV combined with a bench procedure that reconstructed the modified right lobe graft into the shape of extended right lobe graft, and a modified piggyback anastomosis. RESULTS: A total of 42 V5/V8s were reconstructed with 15 newly formed MHVs. The mean estimated congestion area was 4.2+/-2.7% of the total graft volume on computed tomography. The mean pressure gradient between the reconstructed MHV and the recipient inferior vena cava was 2.1+/-1.6 mmHg on postoperative day (POD) 7. None of the patients required any procedure for an outflow problem. The patency rates of the reconstructed MHV and its tributaries were 100% (15/15) and 95.2% (40/42), respectively, at POD 30; 100% (15/15) and 73.8% (31/42) at POD 60; and 86.7% (13/15) and 54.8% (23/42) at POD 90. All recipients are currently alive with good liver function. CONCLUSION: Our procedure seems to be effective for the reconstruction of MHV and its tributaries, and could make modified right lobe graft into the anatomic figure of extended right lobe graft as well as achieve the physiologic advantages of an extended right lobe graft.

ESHAP plus G-CSF as an effective peripheral blood progenitor cell mobilization regimen in pretreated non-Hodgkin's lymphoma: comparison with high-dose cyclophosphamide plus G-CSF.

The ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin) regimen has been shown to be effective as an active salvage therapy for lymphoma. Mobilizing stem cells following ESHAP should decrease time to transplantation by making separate mobilizing chemotherapy (MC) unnecessary, while controlling a patient's lymphoma. We therefore assessed the mobilization potential of ESHAP plus G-CSF in 26 patients (ESHAP group) with non-Hodgkin's lymphoma (NHL) and compared these results with those of 24 patients with NHL who received high-dose (4 g/m2l) cyclophosphamide (HDCY) as MC (HDCY group). The age, sex, and radiotherapy to the axial skeleton were well matched between groups, but the number of patients with poor mobilization predictors was higher in the ESHAP group. Significantly higher numbers of CD34+ cells (x 10(6)/kg) (17.1+/-18.8 vs 5.8+/-5.0, P=0.03) and apheresis day 1 CD34+ cells (x 10(6)/kg) (5.5+/-6.6 vs 1.7+/-2.0, P=0.014) were collected from the ESHAP group than from the HDCY group, and the number of patients who achieved an optimal CD34+ cell target of 5 x 10(6)/kg was higher in the ESHAP group (81 vs 50%, P=0.022). Log-rank test revealed that time to target peripheral blood progenitor cell collection (> or =5 x 10(6)/kg) was shorter in the ESHAP group (P=0.007). These results indicate that ESHAP plus G-CSF is an excellent mobilization regimen in patients with relapsed and poor-risk aggressive NHL.

Long-term evaluation of mice model infected with Helicobacter pylori: focus on gastric pathology including gastric cancer.

BACKGROUND: Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models. AIM: Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model. METHODS: Four-week-old specific pathogen free C57BL/6 mice (n = 115) were infected with SS1, the mouse-adapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed. RESULTS: After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis, but did not show any evidence of gastric adenoma, dysplasia or carcinoma. PCNA positive cells were most abundant after 50 weeks and tended to decrease thereafter up to 80 weeks, whereas apoptosis began to be noted 8 weeks after H. pylori infection, showing 7-8 apoptotic cells/high power field, and tending to increase as time passed. Normally observed neutral mucin decreased during the experiment, showing the most marked decrease 50 weeks after H. pylori infection. In contrast, acidic mucin was noted from 50 weeks after infection. CONCLUSION: The SS1-infected mouse seems to be a suitable animal model for H. pylori-related research, and H. pylori itself does not induce gastric cancer in normal wild-type mouse model following long-term exposure, which could be explained by the balance that exists between cell proliferation and apoptosis.

Expression of multidrug resistance-associated protein1,P-glycoprotein, and thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection.

Both 5-fluorouracil and doxorubicin are commonly used agents in chemotherapy of gastric cancer in adjuvant setting as well as metastatic disease. In a variety of malignancies, high expression of multidrug resistance-associated protein1 and P-glycoprotein has been associated with resistance to doxorubicin, whereas 5-fluorouracil resistance has correlated with the level of thymidylate synthase expression. We evaluated the expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase using immunohistochemistry in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection and investigated the association between their expression and clinicopathologic characteristics including prognosis of the patients. While high expression (> or =5% of tumour cells positive) of multidrug resistance-associated protein1 and P-glycoprotein was observed in 70 patients (68%) and 42 patients (41%), respectively, 65 patients (63%) had primary tumours with high expression (> or =25% of tumour cells positive) of thymidylate synthase. There was a significant association between multidrug resistance-associated protein1 and P-glycoprotein expression (P<0.0001) as well as P-glycoprotein and thymidylate synthase expression (P<0.0001). High multidrug resistance-associated protein1 and P-glycoprotein expressions were associated with well and moderately differentiated histology (P<0.0001 and P=0.03, respectively) and intestinal type (P<0.0001 and P=0.009, respectively). High multidrug resistance-associated protein1 expression correlated with lymph node metastasis (P=0.037), advanced stage (P=0.015), and older age (P=0.021). Five-year disease-free survival and overall survival of total patients were 55.2% and 56.2%, respectively, with a median follow-up of 68 months. There were no significant differences in disease-free survival and overall survival according to the expression of multidrug resistance-associated protein1 (P=0.902 and P=0.975, respectively), P-glycoprotein (P=0.987 and P=0.955, respectively), and thymidylate synthase (P=0.604 and P=0.802, respectively). Concurrent high expression of these proteins (high multidrug resistance-associated protein1/P-glycoprotein, high multidrug resistance-associated protein1/thymidylate synthase, high P-glycoprotein/thymidylate synthase) did not correlate with disease-free survival or overall survival. Even high expression of all three proteins was not associated with poor disease-free survival (P=0.919) and overall survival (P=0.852). In conclusion, high expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase did not predict poor prognosis of gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy. A larger study including patients treated with surgical resection alone would be necessary.

Conditional loss of TGF-beta signalling leads to increased susceptibility to gastrointestinal carcinogenesis in mice.

BACKGROUND: Downregulation of TGF-beta receptors is implicated in colon cancer development. Inactivation of either of the two transmembrane serine/threonine kinases, TGF-beta1 types I/II receptors, is now implicated in carcinogenesis, especially gastrointestinal carcinogenesis. METHODS: We generated transgenic mice, called pS2-dnRII or ITF-dnRII, of which the dominant negative mutant of the TGF-beta type II receptor was expressed under the control of tissue-specific promoters, the pS2 promoter for stomach and ITF for intestine. They were either infected with H.pylori (ATCC 43504 strain, CagA+ and VacA+) or administered with azoxymethane to determine the significance of loss of TGF-beta signalling in gastrointestinal carcinogenesis. RESULTS: Gastric adenocarcinoma developed in pS2-dnRII mice, whereas only chronic active gastritis was noted in wild-type littermates after 36 weeks of H.pylori infection. Mice lacking in TGF-beta signalling specifically in the stomach showed a significantly higher proliferation cell nuclear antigen-labelling index when infected with H.pylori than wild-type littermates (P < 0.01). Development of colonic aberrant crypt foci was provoked in mice by intraperitoneal injections of azoxymethane, and ITF-dnRII mice showed significantly higher incidences of ACF and colon cancers than wild-type littermates. CONCLUSIONS: Maintaining normal TGF-beta signalling in the gastrointestinal tract seems to be important either for preventing abnormal mucosal proliferation, or for suppressing or retarding carcinogenesis.

The experiences of hilar skeletonization for the treatment of locally advanced proximal bile duct cancer.

BACKGROUND/AIMS: Because proximal bile duct cancer easily involves the surrounding tissue, tumor cells often remain after apparent macroscopically complete radical resection. We evaluated the effect of resective modality of these tumors on prognosis and the effect of postoperative radiotherapy on survival of patients with microscopic residual tumor following local resection in locally advanced proximal bile duct cancer. METHODOLOGY: From November, 1990 to October, 1993, 45 proximal bile duct cancer patients who received local excision were entered onto this prospective, nonrandomized study. The patients were divided into three groups after operation, 16 patients with curative resection; 15 noncurative resection; and 14 nonresection. Patients who had positive lymph nodes or microscopic cancer cells in resection margin or adjacent major vessels, were treated with postoperative external radiotherapy, 5040 cGy for 40 days. RESULTS: The overall 1-, 2-, and 5-year survival of the patients was 62.2%, 24.4%, and 15.6%, respectively. The overall mean and median survival of patients was 24.1 +/- 3.98 (mean +/- SE) months and 13 +/- 0.74 months, respectively. Survival rates between resection and nonresection showed a statistically significant difference (P < 0.05). However, survival rates between curative resection and noncurative resection with postoperative radiotherapy were not statistically significant (P > 0.05). CONCLUSIONS: The resection is the treatment of choice for locally advanced proximal bile duct cancer, if resectable and the noncurative resection followed by postoperative external radiotherapy may be beneficial to the patients with locally advanced proximal bile duct cancer.

Glomus tumor of the stomach: CT findings.

We present the radiologic findings of gastric glomus tumors in two patients, in whom upper gastrointestinal series and computed tomography (CT) were primarily used for diagnosis. The diagnosis was surgically confirmed. Contrast-enhanced CT showed peripheral nodular or homogeneous strong enhancement in the arterial phase and prolonged enhancement in the delayed phase.

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection.

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.

Perigastric lymph node status can be a simple prognostic parameter in patients with gastric cancer.

BACKGROUND/AIMS: The number of metastatic lymph nodes has been a significant prognostic factor after curative resection of gastric cancer and adopted as a new UICC classification of nodal stages in gastric cancer. The extent of lymphadenectomy is another significant factor but has been fiercely debated. Regardless of the type of lymphadenectomy, perigastric lymph node dissection is always carried out. In this study, we examined whether the number of metastatic perigastric nodes can be a prognostic indicator of gastric cancer. METHODOLOGY: For the purpose of evaluating perigastric lymph node status, a retrospective study was carried out with 760 patients who underwent curative gastric resection from June 1994 to November 1998. RESULTS: The 4-year cumulative survival rate was 64% and the survival rate decreased significantly when the number of positive perigastric nodes exceeded 3. Comparing with the patients having 0-2 positive perigastric nodes, patients whose metastatic perigastric lymph nodes exceeded 3 or more exhibited deeper tumor invasion, larger tumor size and older age. Multivariate analysis identified the number of positive perigastric nodes, together with depth of tumor invasion, as the strongest independent prognostic factors for survival. CONCLUSIONS: We suggest that the number of metastatic perigastric nodes can be used as a simple prognostic parameter in patients with gastric cancer and that intensive follow-up and adjuvant chemotherapy should be recommended for the patients with more than 3 metastatic perigastric nodes.

Relation between the risk of gallstone pancreatitis and characteristics of gallstone in Korea.

BACKGROUND/AIMS: Pancreatitis is a serious complication of patients with gallstones. However, risk factors of gallstone pancreatitis were unpredictable until recently. In Korea, characteristics of gallstones are different from Western countries. The present study was designed to determine differences in the risk of gallstone pancreatitis and characteristics of gallstones in Korean patients. METHODOLOGY: Clinical data were collected on patients undergoing laparoscopic cholecystectomy. The physical characteristics of gallstones recovered at surgery were also recorded. Patients with gallstone pancreatitis were compared with patients who had uncomplicated biliary pain. RESULTS: In a logistic regression model, acute gallstone pancreatitis was associated with a stone diameter of less than 5 mm (odds ratio: 3.3695; P = 0.0352) and with stone number of more than 20 (odds ratio: 3.8686; P = 0.0361). No other variable, including pigment stone, age, and sex, remained statistically significant in the adjusted analysis (P > 0.05). CONCLUSIONS: Patients with at least 1 gallstone smaller than 5 mm in diameter and stone number more than 20 each have a more than 3-fold increased risk of presenting with acute gallstone pancreatitis. The composition of gallstones, especially pigment stones, was not an important risk factor in gallstone pancreatitis in Korean patients with stones having a different composition than those from Western countries.

Intraportal insulin therapy after partial hepatectomy for hepatoma patients with insulinopenia.

BACKGROUND/AIMS: This prospective study was carried out in order to assess the role of intraportal insulin infusion after partial hepatectomy in hepatoma patients with insulinopenia. METHODOLOGY: Of the 38 patients who underwent hepatic resection for hepatocellular carcinoma from August 1994 to August 1995, 21 patients took an oral glucose tolerance test with insulin measurement preoperatively. Five patients were treated postoperatively with intraportal insulin infusion, as follows: A 16-gauge catheter was inserted into a reopened umbilical vein and fixed in place by a few absorbable stitches. Regular insulin was administered just after the operation at the rate of 2 units/hour for 2-3 weeks. Blood glucose levels were maintained between 150 and 200 mg/dL. Arterial ketone body ratio was used in monitoring the function of the liver during the perioperative periods. RESULTS: Ten patients (47.6%) were found to be insulinopenic. In the insulin therapy group (n = 5), the arterial ketone body ratio of 3 patients recovered within a few hours after the operation, and that of the remaining 2 patients recovered on the 1st postoperative day. But in the control group (n = 5), none of the 5 cases had an arterial ketone body ratio of more than 0.7 on the day of operation. The arterial ketone body ratio returned to normal on the 1st postoperative day in 2 cases, on the 2nd postoperative day in 1 case, and on the 5th day in 1 case. The arterial ketone body ratio recovery time was shorter in the intraportal insulin therapy group than in the control group (P = 0.042). CONCLUSIONS: Intraportal insulin infusion after hepatectomy via the reopened umbilical vein may be a very simple and safe means of promoting recovery of remnant liver function after hepatectomy in hepatoma patients with insulinopenia.

Hepatocellular carcinoma with tumor thrombi in the bile duct.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC), presenting as obstructive jaundice caused by tumor thrombi in the bile duct, is rare. The authors report on clinical experiences and evaluate the results of different treatment modalities for this disease. METHODOLOGY: We experienced 549 cases of HCC at Ajou University Hospital from June 1994 through January 1998. Among them, 10 cases with gross evidence of tumor thrombi in the bile duct were treated with different resection methods and interventions, and then compared with those receiving short-term results. RESULTS: Eight out of 10 patients underwent exploratory laparotomy: right lobectomy with extrahepatic bile duct resection in 2 cases; right lobectomy with tumor thrombectomy in 2 cases; left lobectomy and caudate lobectomy with extra-hepatic bile duct resection in 2 cases: T-tube drainage in 1 case and biopsy only with post-operative internal biliary stent, in 1 case. Survival times of these patients were 39 months (still alive); 38 months (still alive); 8 months (died); 8 months (died); 8 months (still alive); 1 month (still alive); 14 months (died); 8 months (died), respectively. Of the 2 non-surgical cases, 1 underwent PTBD only and the other had endoscopic removal of the thrombi. Their survival times were 18 days (died) and 24 months (still alive with recurrence), respectively. The 4 cases, with right lobectomy or left lobectomy including extrahepatic bile duct resection, had relatively long-term disease-free survival (39 months, 38 months, 8 months and 1 month after operation, respectively). However, there were no differences in survival between the partial hepatectomy procedure with removal of tumor thrombi and the simple drainage procedure without tumor resection. CONCLUSIONS: Although the number of patients in this study is small, our results suggest that: 1) For the improvement of survival, it seems necessary to perform major hepatic resection with removal of the extrahepatic bile duct. 2) If hepatic resection cannot be accomplished with bile duct resection due to limited liver function, non-surgical modalities should be considered instead of surgery because no differences in prognosis between the 2 groups exist.

Significant correlation between serum level of hepatocyte growth factor and progression of gastric carcinoma.

Hepatocyte growth factor (HGF) can promote proliferation of many types of tumor cells including gastric cancer cells. To study the role of HGF in the progression of gastric carcinoma, HGF levels were measured by an enzyme immunoassay (EIA) system in sera of gastric cancer patients and followed up the levels after the operation. The mean serum HGF level in 212 healthy control subjects, 140 patients with primary gastric cancer, and 13 patients with recurrent gastric cancer were 0.199 +/- 0.073, 0.325 +/- 0.209, and 0.578 +/- 0.258 ng/ml, respectively. The increase of the levels was significantly correlated with the progression of tumor stage. The levels decreased to normal levels 1 month after curative resection of the tumors. However, the levels did not decrease significantly in nonresected cases. During the follow-up of the patients for several months, the level was significantly increased in recurrent gastric cancer patients, whereas there was no increase in nonrecurrent patients. In conclusion, the serum HGF levels significantly correlated with the aggressiveness of the tumors, suggesting an important role of HGF in the progression of gastric carcinoma.

Expression of vascular endothelial growth factor in otitis media.

Increased vascular permeability and endothelial cell growth are important in the pathogenesis of otitis media with effusion (OME) and the vascular endothelial growth factor (VEGF) is known to play an important role in the increased vascular permeability and angiogenesis. To date, at least five isoforms of the VEGF family have been identified as VEGF transcripts, encoding polypeptides of 206, 189, 165, 145 and 121, but their physiological roles are unclear. The purpose of this study was to investigate the expression of VEGF, in both endotoxin-induced OME of the rat and human otitis media. We instilled endotoxin and saline as a control into the middle ear cavity of the rat. Middle ear mucosa were taken at 0 h, 1 h, 3 h, 6 h, 12 h, 1 day, 3 days, 7 days and 14 days and the expression of VEGF mRNA and VEGF protein was evaluated using semi-quantitative RT-PCR and immunohistochemistry. Expression of VEGF164 mRNA and VEGF120 mRNA was first identified 1 h after endotoxin instillation and was dramatically increased over the period 6 h-1 day and then progressively decreased by day 7. The level of expression of VEGF120 mRNA was slightly higher than that of VEGF164 mRNA and that of VEGF164 mRNA was much higher than that of VEGF188 mRNA. Immunostaining revealed expression of VEGF during 6 h to day 3 and its expression was localized to ciliated cells and some inflammatory cells. We also performed RT-PCRs of cDNA from middle ear fluids of 8 human OME patients and middle ear mucosa of 4 chronic otitis media patients for the identification of VEGF mRNA expression. VEGF121 mRNA was highly expressed in all samples compared with VEGF165 mRNA. These results suggest that VEGF may be primarily responsible for increased vascular permeability and endothelial cell growth in OME and that VEGF seems to play a significant role in the pathogenesis of OME.