Expression of nuclear factor-kappa B and target genes in gastric precancerous lesions and adenocarcinoma:Association with Helicobactor pylori cagA (+) infection

AIM:To examine the expression of nuclear factor kappaB (NF-κB) and its target genes in intestinal metaplasia (IM),dysplasia (DYS) and gastric carcinoma (GC) infected with Helicobacter pylori (H pylori) and to investigate the mechanism underlying Hpyloricytotoxin associated gene A(cag A) infection leading to gastric adenocarcinoma.METHODS: Expressions of NF-κB/p65 and its target genes:c-myc, cyclinD1 and bcl-xl were immunohistochemically examined in 289 cases of gastric biopsy and resection specimens from patients with IM, DYS and GC infected with H pylori. H pylori in the above mentioned tissues was detected by Warthin-Starry stain and rapid urease tests.IgG antibody to cagA in sera of the patients was measured by ELISA.RESULTS:The positive rates of NF-κB/p65 were significantly higher in groups with cagA of IMI-Ⅱ(28/33), IM III(48/52),DYSI(27/31), DY5 Ⅱ-Ⅲ(28/32), GC(35/40) than in groups without cagA of IMI-Ⅱ(4/17), IMⅢ(3/20), DYSI(3/20),DYSⅡ-Ⅲ(6/21), GC(10/23). The expressions of c-myc,cyclinD1, and bcl-xl were significantly higher in groups with cagA of IM Ⅲ(47/52, 49/52, 46/52), DYSⅡ-Ⅲ(29/32, 26/32,25/32) than in groups without cagA of IM Ⅲ(8/20, 7/20,5/20), DYSⅡ-Ⅲ(10/21, 8/21, 3/21), which were in conformity with the expression of NF-κB in IM Ⅲ, and DYSⅡ-Ⅲ. Asignificantly higher expression level of NF-κB/p65, c-myc,cyclinD1 and bcl-xl was detected in intestinal type GC(27/28,18/28, 22/28, 24/28) than in diffuse type GC(8/12, 3/12,3/12, 6/12), respectively.CONCLUSION: There may be two different molecular mechanisms in the occurrence of intestinal and diffuse type gastric carcinomas. Intestinal type gastric carcinoma is strongly associated with high expression of c-myc, cyclinD1 and bcl-xl through NF-κB/p65 activated by Hpylori cagA.Inhibiting the activity of NF-κB is an effective and promising way to prevent intestinal type gastric carcinoma.

Liquid structure of pure iron by X-ray diffraction

The liquid structure of pure iron at 1540, 1560 and 1580 deg C was studied byX-ray diffraction. The results show that near the melting point there is a medium-range orderstructure that fades away with the increasing temperature. The average nearest distance of atoms isalmost independent of the melts temperature, but the average coordination number, the atom clustersize and the atom number in an atom cluster all decrease with the increasing temperature of themelt. Near the melting point there are a lot of atom clusters in the pure iron melt. The atomcluster of pure iron has the body-centered cubic lattices, which are kept from the solid state. Andthe body-centered cubic lattices connect into network by occupying a same edge. The atoms in thesurrounding of the atom clusters are arranged disorderly.

Disk-like Tiles Derived from Complex Bases

For each positive integer k,the radix representation of the complex numbers in the base -k+i gives rise to a lattice self-affine tile T_k in the plane,which consists of all the complex numbers that can be expressed in the form∑_(j≥1)d_j(-k+i)^(-j),where d_j∈{0,1,2,...,k^2}.We prove that T_k is homeomorphic to the closed unit disk{z∈C:|z|≤1}if and only if k≠2.