Repair of damaged intestinal mucosa in a mouse model of sepsis.

BACKGROUND: The intestine is not only the main target attacked by sepsis but also the vital organ which mediated sepsis. The recovery of the damaged intestinal barrier structure and function is related to the occurrence and outcome of multiple organ dysfunction syndrome (MODS). How to protect and reduce the damage of the intestinal mucosa and how to promote the reconstruction of the intestinal mucosa have been the important topics in sepsis for many years. This study aimed to investigate the influential factors of intestinal mucosal reconstruction after intestinal epithelial injury in vivo in a mouse model of sepsis. METHODS: Mice were subjected to cecal ligation and puncture (CLP) for induction of sepsis to assess intestinal mucosal damage, epithelial cell apoptosis, and transformed number of goblet cells, and to detect the concentration of TNF-α, IL-1 and TGF-ß1 and TFF3 (trefoil factor 3) expression in the small intestinal mucosa. All above were performed by HE staining, western blot, ELISA and immunohistochemistry respectively. The experimental animals were divided into a sepsis group and a sham-operation group. The animals with sepsis were separately killed at 6 (7 animals), 24 (7 animals) and 48 hours (7 animals) after CLP. RESULTS: Injured intestinal mucosa was observed in the 3 groups under a light microscope, in which damage scores in the 24-hour and 48-hour groups were higher than in the 6-hour group and no difference was found between the two groups. Moreover, less of goblet cells or other epithelial cells adjacent to the injured surface migrated into the wound to cover the denuded area. The number of goblet cells was substantially decreased in the three CLP groups compared with the sham-operation group. Protein levels of IL-1 and TNF-α were significantly increased by 3-4 fold at all time points when compared with the sham-operation group, and cleaved caspase-3 by 4 fold. Although TFF3 expression was modestly increased for 6 hours after the onset of CLP, it appeared to decline at 24 hours and 48 hours as shown by Western blot. A similar tendency was observed upon TGF-ß1, i.e. the protein level was not elevated at 24 hours and 48 hours, but increased modestly at 6 hours. CONCLUSIONS: Sepsis from CLP shows less restitution on the surface of injured intestinal mucosa. There is evidence that both constant inflammatory reaction and epithelial cell apoptosis may affect mucosal reestablishment of the intestine at the onset of sepsis. Mucosa after severe sepsis showed the state of high inflammation, and declined goblet cell function and mucosal reconstruction, which affected the repair of damaged intestinal barrier. Constant inflammatory reaction, and declined goblet cell function and mucosal reconstruction ability may affect the reestablishment of intestinal mucosa at the onset of sepsis.

In vitro comparison of the biological activity of alumina ceramic and titanium particles associated with aseptic loosening.

Prosthetic wear particles are thought to play a central role in the initiation and development of periprosthetic osteolysis, leading to aseptic loosening of prostheses. This study aimed to compare the biological activity of ceramic and titanium particles that are associated with particle-induced, aseptic joint loosening. Different sizes of alumina-ceramic particles and titanium particles were prepared to stimulate murine macrophage cells RAW 264.7, of which the expressions of tumor necrosis factor alpha (TNF-alpha) and receptor activator of nuclear factor-κB ligand (RANKL) were measured by qPCR and ELISA at various time points. In the presence of all particles, the expression of TNF-alpha increased in a time-dependent manner, whereas the expression of RANKL showed no regular expression patterns. Notably, particles of smaller sizes provoked significantly higher levels of TNF-alpha and RANKL than those of larger sizes. Compared to the titanium particles, the ceramic particles provoked a significantly lower production of TNF-alpha. Thus, the bioactivities of titanium and alumina ceramic particles were inversely proportional to the sizes of the particles, and the expression of RANKL was not parallel to that of TNF-alpha. The successful outcome of ceramic-on-ceramic artificial joint prostheses may be attributed to the low biological activity of ceramic particles, as evidenced here.

Knockdown of hTERT by SiRNA suppresses growth of Capan-2 human pancreatic cancer cell via the inhibition of expressions of Bcl-2 and COX-2.

OBJECTIVE: To investigate the effects of human telomerase reverse transcriptase (hTERT) on the growth of Capan-2 human pancreatic cancer cell and apoptosis. METHODS: Cell proliferation, apoptosis and cell cycle were analyzed by cell counting and flow cytometry. mRNA and protein expressions of hTERT, Bcl-2 and cyclooxygenase (COX)-2 were assessed by real time PCR and Western blot. RESULTS: Cell growth was significantly inhibited by 26.39 percent 24 h after hTERT-small interference RNA (siRNA) transfection (50 nmol/L) with a 100 percent silencing efficiency (P < 0.05). The inhibition rates of cell proliferation were 46.77 percent, 70.61 percent, 84.71 percent and 85.99 percent at 2, 3, 5 and 7 days after transfection, respectively (P < 0.001). Early and late apoptotic cells increased significantly (especially 24 h after transfection) (P < 0.001). The cell cycle was suppressed significantly as manifested by the increase of cells in the G0/G1 phase and the decrease of cells in the S phase and G2/M phase (P < 0.01). The expressions of Bcl-2 mRNA and COX-2 mRNA were inhibited significantly 48 h after transfection: the inhibition rates were 86.86 percent and 100 percent, respectively (P < 0.001). Levels of Bcl-2 protein were downregulated by 58.54 percent and 63.44 percent and the levels of COX-2 protein were downregulated by 50.06 percent and 82.77 percent at 48 h and 72 h after transfection, respectively. CONCLUSION: Knockdown of hTERT by siRNA can inhibit the growth of Capan-2 cell. The inhibitory effect is associated with the downregulation of Bcl-2 and COX-2.

[Study on the tectology change of rectum wall above the hemorrhoids].

OBJECTIVE: To investigate the histomorphological characteristics and its significance of rectum wall above hemorrhoids. METHODS: Tissues of rectum wall above hemorrhoids were obtained after stapled hemorrhoidopexy from 21 patients with grade III-IV internal hemorrhoids. Seven macroscopically normal rectal tissues collected from upper rectal cancer patients without a history of hemorrhoids served as control. Masson trichrome staining was performed for detecting smooth muscles and collagen in the tissues. The expression of type III collagen was detected by using immunohistochemical staining in the two groups. RESULTS: Morphological abnormalities, such as fragment, rupture, disorganization were found in smooth muscle of proximal rectal tissues above the piles, and it was statistically different from the distal rectal tissues above the piles and control tissues (all P < 0.05). Moreover, hyperplasia of type III collagen in both muscularis mucosa and rectum wall in tissues above hemorrhoids were observed, no such changes was found in the control tissues. CONCLUSIONS: The range of pathological changes in hemorrhoids is beyond the anal cushions. The pathological changes of the smooth muscle and the type III collagen in the tissues above the piles are the pathological basis of hemorrhoids.

[Toxicity of cationic liposome Lipofectamine 2000 in human pancreatic cancer Capan-2 cells].

OBJECTIVE: To investigate the toxicity of cationic liposome Lipofectamine 2000 (Lipo) in human pancreatic cancer Capan-2 cells. METHODS: Capan-2 cells were cultured in the presence of Lipo at toxic concentrations, and the cell growth, apoptosis and cell cycle changes were evaluated by cell counting and flow cytometry. RESULTS: The concentrations of both Lipo and siRNA affected the transfection efficiency. In a transfection volume of 2 ml, the presence of 5 microl Lipo resulted in slowed growth of Capan-2 cells, which was especially obvious after 3 days (P<0.001). Prolonged culture of the transfected cells caused significant increases in early apoptotic cells (P<0.05) and in the damaged or necrotic cells (P<0.001), and resulted in reduced viable cells (P<0.01); these changes became obvious after a 48-hour culture, which also increased the ratio of G(0)/G(1) phase cells (P<0.05) and decreased those of G(2)/M phase cells (P<0.01), S phase cells (P<0.01), and the late apoptotic cells (P<0.05). CONCLUSION: Toxic concentrations of Lipo can affect the growth, apoptosis and cell cycles of Capan-2 cells in vitro, and this urges careful concentration selection when using Lipo for gene transfer into different cells.