Helicobacter pylori (Hp) is a unipolar, microaerobic, multiflagellar, spiral-shaped Gram-negative bacterium that survives and colonizes human gastric mucosa. As a classⅠcarcinogen associated with gastric cancer, long-term stimulation of gastric mucosa by Hp can cause atrophic gastritis, peptic ulcer, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. It has been reported that Hp can cause epithelial-mesenchymal transition (EMT) in gastric epithelial cells, thereby inducing gastric cancer. We review the mechanism of Hp-induced EMT in gastric epithelial cells, in order to provide new insights for early diagnosis and targeted therapy of gastric cancer.

The main mineral component of natural tooth was determined as calcium apatite many years ago; most of them exist in the form of hydroxyapatite with different crystallites. If a tooth decayed, the crystalline of hydroxyapatite would be changed and decomposed. In our experiment, a natural tooth with caries was measured by high resolution XRD equipment: X'pert Pro. Three spots which included normal enamel, normal dentin and caries tissue were analyzed. The results showed that tooth was a kind of biological mixed crystal composed of many crystal phases, the main crystal phase was hydroxyapatite. From normal enamel to normal dentin and to caries tissue, the length of the a-axis of hydroxyapatite crystallite increased, the length of the c-axis of hydroxyapatite crystallite remained unchanged. The crystal sizes were: normal enamel D002 = 27.600 nm; normal dentin D002 = 16.561 nm; caries tissue D002 = 13.163 nm. Crystallinity: normal enamel>normal dentin>caries tissue. According to our experiment, tooth could be conveniently studied by high resolution microdiffracion XRD equipment.
Dental Caries ; metabolism ; Dental Enamel ; chemistry ; Dentin ; chemistry ; Humans ; Tooth ; chemistry ; X-Ray Diffraction ; methods