Expression of E-cadherin in gastric carcinoma and its correlation with lymph node micrometastasis

AIM: To examine the expression of E-cadherin in the primary tumor and to evaluate its relationship with lymph node micrometastasis (LNM).METHODS: The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy using reverse transcription polymerase chain reaction (RT-PCR) assay in addition to H&E staining. Cytokeratin-20 (CK-20)gene marker was used in this assay. The level of E-cadherin expression in the primary tumor was examined by immunochemical technique (EliVisionTM plus).RESULTS: LNM was detected in 77 (12.5%) lymph nodes of 14 patients (46.7%) with gastric carcinoma. The incidence of LNM was significantly higher in the diffuse type (12 of 19 cases, 63.2%) than in the intestinal type of gastric carcinoma (2 of 11 cases, 18.2%, P = 0.026). The incidence of LNM also increased in accordance with the depth of tumor invasion. The loss of expression of E cadherin in primary tumors was found in 14 (46.7) of 30 tumors. The absence of E-cadherin expression was significantly associated with the Lauren classification (P = 0.026), lymph node metastasis (P = 0.011), the grade of differentiation (P = 0.004) and the lymphatic invasion (P = 0.001). Expression of E-cadherin was negative in 10 (71.4%) of the 14 patients with LNM, and in 4 (25%) of the 16 patients without LNM (P = 0.026). CONCLUSION: The current results indicate that the RT PCR assay is useful for the detection of LNM and can significantly increase the detection rate of lymph node metastasis in patients with gastric carcinoma. The Laurenclassification and depth of tumor invasion are significantlyassociated with lymph node micrometastases. Our findings also indicate that E-cadherin may play an important role in determining the growth type and differentiation of gastric carcinoma. The loss of E-cadherin expression may contribute to LNM.

Detection of anti-HAV antibody with dot immunogold filtration assay

AIM: To establish a rapid, sensitive and specific immunogold assay for detection of hepatitis A virus infection.METHODS: Rabbit monoclonal antibodies to anti-human IgM and IgG (Dako) were dotted on a nitrocellulose membrane (NCM) respectively to capture the human sera IgM and IgG. Then the captured antibodies would conjugate to HAV antigen, which was revealed by mouse anti-HAV IgG conjugated to gold particles. Final results were assessed by blind method.RESULTS: Sera from 96 patients with acute hepatitis were used for our study. Compared with well-recognized standard (Abbott Laboratory, USA), the sensitivity and specificity of IgM-DIGFA (self-made) were 91.3 % (42/46) and 96.0 %(48/50), and those of IgM-ELISA (Kehua, Shanghai) were 97.8 % (45/46) and 100.0 % (50/50). The identical results were produced from the study with reagents at different conditions, and the study was repeated in 15 negative sera and 10 positive sera. The serum anti-HAV IgG was tested with DIGFA at the same time. In comparison with ELISA,the sensitivity and specificity of DIGFA for IgG anti-HAV were 87.2 % (41/47) and 91.8 % (45/49), respectively.CONCLUSION: This assay can detect anti-HAV IgM and IgG simultaneously, and be done within 3 minutes. The simplicity, rapidity and specificity of the assay were useful for screening and epidemiological study.

Miniature ultrasonic probes for diagnosis and treatment of digestive tract diseases

AIM: To investigate the clinical value of miniature ultrasonic probes (MUPs) for the diagnosis and treatment of digestive tract diseases.METHODS: Endoscopic ultrasonography (EUS) was performed for patients with its indications with 7.5-20 MHz MUPs and double-cavity electronic endoscope. According to the diagnosis of MUPs, patients who had indications of treatment received endoscopic resection or surgical excision.Postoperative histological results were compared with the preoperative diagnosis of MUPs. A few patients without endoscopic resection or surgical excision were periodically followed up with MUPs.RESULTS: A total of 537 patients were examined by MUPs, of them, 256 were diagnosed with gastrointestinal submucosal lesions, 146 with pseudo-submucosal lesions,50 with digestive tract cancers, 17 with peptic ulcer, 11 with cholecystolithiasis, 8 with chronic pancreatitis, and 2 with achalasia and 47 were diagnosed as normal. After MUPs examinations, 220 patients received endoscopic resection or surgical excision, and the postoperative histological results of 211 patients were completely consistent with the preoperative diagnosis of MUPs. The diagnostic accuracy of MUPs was 95.9%. The result of follow-up with MUPs indicated that gastrointestinal leiomyoma, lipoma,phlebangioma and cyst were unchanged within 1-2 years.The patients who received endoscopic resection or centesis did not have any complications.CONCLUSION: MUPs are of value in diagnosing gastrointestinal submucosal lesions, staging of digestive tract cancers and biliary-pancreatic diseases. They play a very important role in making therapeutic plans.