Sa1933 Reduced Expression of Nerve Growth Factor and Its Receptors in Scars of Healed Gastric Ulcers: A Major Mechanism Underlying Impaired Neural Plexus and Sensory Nerve Regeneration in Ulcer Scars and a Novel Causal Role in Abnormal Neovascularization?

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G A A b st ra ct s clarithromycin (1μg/ml). All these 7 clarithromycin-resistant strains had the BsaI site (Figure 1). We have found mutations site at A1825G, T1834C and A2147G mutation (Figure 2). None had the new BbsI cleavage site which is characteristic of the other relatively common mutation (A2143G). The sequence of the 23S rRNA gene of the ClaR strain no 34A has been submitted and the accession No is JX827460. We introduced the PCR fragments containing the relevant mutations amplified with primer pair as listed above from the chromosomal DNA of strain 3B (ClaS strain) into H. pylori 34 and 39 (ClaR strain). The relevant mutations in both transformants were confirmed by DNA sequencing to be the same as those in the donor strain. By examining their effects in an isogenic background, it was found that the MIC of clarithromycin was the same for both transformants (4 μg/ml). Conclusion: Our results show an increasing trend of h.pylori towards dual resistance with metronidazole and clarithromycin, but maintained sensitivity towards tetracycline and amoxicillin. Clarithromycin resistance was due to mutations at site A1825G, T1834C and A2147G of 23 S rRNA gene.