No abstract

No abstract

Background/Aims-Endoscopic ultrasonography is expected to be useful for invasion depth staging of early gastric cancer. A prospective blind study of the staging characteristics of endoscopy and endoscopic ultrasonography for early gastric cancer was performed. Methods-Findings of endoscopy and endoscopic ultrasonography using a 20 MHz thin ultrasound probe were independently reviewed and the results of 52 early gastric cancer lesions analysed. Results-The overall accuracy rates in invasion depth staging of early gastric cancer were 63% for endoscopy and 71% for endoscopic ultrasonography. No statistically significant diVerences were observed in overall accuracy. Endoscopic ultrasonography tended to overstage, and lesions that were classified as mucosal cancer by endoscopic ultrasonography were very likely (95%) to be limited to the mucosa on histological examination. All 16 lesions staged as mucosal cancer independently but coincidentally by both methods were histologically limited to the mucosa. Conclusions-Endoscopic ultrasonography is expected to compensate for the understaging of lesions with submucosal invasion that are endoscopically staged as mucosal cancer. (Gut 1999;44:361-365) Keywords: early gastric cancer; endoscopic ultrasonography; endoscopyThe first use of the ultrasonic endoscope was reported in 1980, and the use of endoscopic ultrasonography (EUS) has become widespread for examination of the biliary tract, gall bladder, pancreas, and gastrointestinal tract. [1][2][3][4][5] In the field of stomach diseases, the importance of tumour staging of gastric cancer has been increasing with the development of the endoscopic resection technique.6-8 EUS has been expected to be useful for invasion depth staging of early gastric cancer.9-13 Although EUS using the appropriate instrument (7.5-12.5 MHz) is useful for advanced gastric cancer, optical control of such a large instrument for small lesions is not easy and the resolution is insuYcient for the precise observation of superficial lesions. The recent introduction of high frequency thin endoscopic ultrasound probes has enabled us to perform target scanning with high resolution of even very small gastric cancer lesions under endoscopic control. [14][15][16] Conventional endoscopy has been the most useful diagnostic modality for early gastric cancer.17 18 Unfortunately, there are only a few reports on the relation between the tumour invasion depth staging characteristics of endoscopy and EUS. Therefore the true role of EUS in early gastric cancer depth staging is still unclear. To obtain fundamental data to answer such questions, we previously performed a retrospective non-blinded pilot study of the staging characteristics of endoscopy and EUS in 108 early gastric cancer lesions. 19 The overall accuracy rates for staging depth of invasion for endoscopy and EUS were 72.2 and 64.8% respectively. Staging characteristics with regard to understaging and overstaging of the two methods were significantly diVerent. EUS showed a higher overstaging rate. Le...

Reports on the isolation of amoxicillin-resistant Helicobacter pylori are increasing worldwide, which may cause serious problems in eradication therapy. To elucidate the mechanism of amoxicillin resistance of H. pylori, penicillin-binding proteins (PBPs) of amoxicillin-resistant strains isolated in Korea were analysed. Three PBPs (66, 63 and 60 kDa) were identified in both amoxicillin-resistant and -susceptible strains using biotinylated ampicillin, and the PBP profiles were very similar irrespective of the difference in amoxicillin susceptibility. We obtained clones with moderate resistance from an amoxicillin-susceptible strain, HPK5, by transformation with genomic DNA from an amoxicillin-resistant strain, HPA116. In a resistance-induced clone, HPO1, the affinity of PBP1 for amoxicillin was reduced. The pbp1 genes from HPA116, HPO1 and HPK5 were cloned and sequenced. The nucleotide sequences of pbp1 from HPA116 and HPO1 were almost identical, whereas that of HPK5 was quite different. Both the ORFs of HPA116 and HPO1 pbp1 have four substitutions and one insertion of amino acid residues compared with those of HPK5 and other sensitive strains. All the mutations, except one, are in the C-terminal half of the 659-amino-acid sequence containing the penicillin-binding modules. DNA fragments containing either full-length or a C-terminal half of pbp1 could transform HPK5 to have resistance, indicating that changes in the penicillin-binding core of PBP1 are involved in the amoxicillin resistance of H. pylori isolated in Korea.

If oesophageal carcinoma is detected in the superficial stage, the prognosis is better than for advanced oesophageal carcinoma. But the factors which predict the prognosis and treatment policy remain unclear. Matrix metalloproteinase-7 (MMP-7) and matrix metalloproteinase-9 (MMP-9) have been reported to have close associations with tumour invasion and metastasis. In this study, we retrospectively studied the relations between MMP-7 and MMP-9 expression in immunohistochemistry, clinicopathologic factors, and prognosis in 55 superficial oesophageal carcinomas. MMP-7 and MMP-9 expression occurred in 23.6% and 47.3% of the patients, respectively. MMP-7 expression was significantly correlated with the presence of nodal metastasis (P ¼ 0.004). MMP-9 expression was significantly correlated with the depth of tumour invasion (P ¼ 0.004), lymphatic permeation (P ¼ 0.001), nodal metastasis (P ¼ 0.049), and pathologic differentiation grade (P ¼ 0.003). By the log-rank test, MMP-7 expression and MMP-9 expression on the invasive front were related to the prognosis. In multivariate analysis, MMP-9 expression on the invasive front was an independent prognostic indicator. The combined expression of MMP-7 and MMP-9 may be a good marker for the degree of malignancy of oesophageal cancer and for the presence of lymphatic metastasis.