The mRNA expression of ompF, invA and invE was associated with the ciprofloxacin-resistance in Salmonella.

Salmonella developed drug-resistance under durative antibiotic pressures pressure. The widespread prevalence of Salmonella has been associated with not only drug-resistance but also pathogenicity. Outer membrane porin proteins (OMPs) are critical for the drug resistance of bacteria. Virulence genes in Salmonella pathogenicity islands (SPIs) play key roles in the virulence of bacteria. In this study, we analyzed the expression levels of three critical genes in ciprofloxacin-resistant strains and ciprofloxacin-susceptible strains of Salmonella, including outer membrane porin protein F (ompF), virulence genes invA and invE. In the clinical ciprofloxacin-resistant strains of Salmonella, the expression level of ompF was decreased. Meanwhile, the expression levels of invA and invE were decreased except for only one strain, indicating generally decreased virulence. These results were also verified with ciprofloxacin-induced resistant strains. Thus, it was informative for understanding the drug-resistance in Salmonella. Monitoring drug-resistance and virulence relevant genes would be significant in the prevention and control of salmonellosis.

Carbon nanotubes altering specificity of repeated PCR and DNA integrity properties.

We have investigated the impact of aqueous suspension of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) on performance of repeated PCR, and discussed their thermal impact on DNA characteristics. Both SWCNTs and MWCNTs are found significantly enhancing the specificity of the repeated PCR and capable of inhibition of long DNA thermal degradation. SWCNTs performed a better specificity in repeated PCR than MWCNTs did. MWCNT-DNA binding was more favorable for protecting long DNA from thermal degradation than SWCNT-DNA binding. The results suggested that CNTs are very useful in repeated PCR working on limited amount of DNA resources.

Humoral immune responses in rabbits induced by an experimental inactivated severe acute respiratory syndrome coronavirus vaccine prepared from F69 strain.

BACKGROUND: The etiologic agent of severe acute respiratory syndrome (SARS) has been confirmed to be a novel coronavirus (CoV), namely SARS-CoV. Developing safe and effective SARS-CoV vaccines is essential for us to prevent the possible reemergence of its epidemic. Previous experiences indicate that inactivated vaccine is conventional and more hopeful to be successfully developed. Immunogenicity evaluation of an experimental inactivated SARS-CoV vaccine in rabbits was conducted and reported in this paper. METHODS: The large-scale cultured SARS-CoV F69 strain was inactivated with 0.4% formaldehyde and purified, then used as the immunogen combined with Freund's adjuvant. Eight adult New Zealand rabbits were immunized four times with this experimental inactivated vaccine. Twelve sets of rabbit serum were sampled from the third day to the seventy-fourth day after the first vaccination. The titers of specific anti-SARS-CoV IgG antibody were determined by indirect enzyme-linked immunosorbent assay, and the neutralizing antibody titers were detected with micro-cytopathic effect neutralization test. RESULTS: Rapid and potent humoral immune responses were induced by the inactivated SARS-CoV vaccine in all the eight test rabbits. Titers of both specific IgG antibody and neutralizing antibody peaked at about six weeks after first vaccination, with the maximum value of 1:81 920 and 1:20 480, respectively. After that, serum antibody levels remained at a plateau or had a slight decrease, though two boosters were given in the succedent 4 to 5 weeks. Cross neutralization response existed between SARS-CoV F69 strain and Z2-Y3 strain. CONCLUSIONS: The inactivated SARS-CoV vaccine made from F69 strain owns strong immunogenicity, and the cross neutralization response between the two different SARS-CoV strains gives a hint of the similar neutralizing epitopes, which provide stable bases for the development of inactivated SARS-CoV vaccines.

Probing starch-iodine interaction by atomic force microscopy.

We explored the interaction of iodine with three crystalline type starches, corn, potato, and sweet potato starches using atomic force microscopy. Results revealed that starch molecules aggregated through interaction with iodine solution as well as iodine vapor. Detailed fine structures such as networks, chains, and super-helical structures were found in iodide solution tests. The nanostructures formed due to iodine adsorption could help to understand the formation and properties of the starch-iodine complex.

Totally laparoscopic Billroth II gastrectomy with a novel, safe, simple, and time-saving anastomosis by only stapling devices.

BACKGROUND: Totally laparoscopic gastrectomy represents the evolution of laparoscopy-assisted gastrectomy. Most surgeons prefer laparoscopy-assisted gastrectomy rather than totally laparoscopic procedures because of technical difficulties of intracorporeal anastomosis. We created one novel stapling anastomosis without hand-sewn technique in totally laparoscopic Billroth II gastrectomy. The feasibility and early surgical outcomes of totally laparoscopic Billroth II gastrectomy with stapling anastomosis and with hand-sewn anastomosis were introduced in this study. METHODS: We retrospectively analyzed early surgical outcomes in 70 patients who underwent totally laparoscopic Billroth II distal gastrectomy for gastric cancer between January 2010 and July 2011. The patients were divided into hand-sewn and device groups according to whether intracorporeal anastomosis was performed by only hand-sewn technique (n = 36) or only stapling devices (n = 34). In the device group, the gastrojejunostomy was performed using a circular stapler, and an additional side-to-side jejunojejunostomy was made at the site of jejunal enterotomy. RESULTS: There was no difference in the mean number of lymph nodes retrieved in both groups. The blood loss (hand-sewn group 205.8 ± 37.4 vs. device group 201.2 ± 51.2 ml, p > 0.05) and hospital stay (hand-sewn group 6.5 ± 3.7 vs. device group 5.9 ± 4.1 days, p > 0.05) were similar in both groups. We found that intracorporeal anastomosis by totally stapling devices was associated with decreased operative time (hand-sewn group 239.0 ± 40.1 vs. device group 203.6 ± 27.9 min, p < 0.05). CONCLUSION: We suggest that intracorporeal anastomosis using only stapling devices in the described method was as safe and feasible as by hand-sewn technique. Moreover, it is a simple and time-saving method without any difficult hand-sewn procedures.