Sung-Moo Park

Lactobacillus acidophilus Expressing Recombinant K99 Adhesive Fimbriae Has an Inhibitory Effect on Adhesion of Enterotoxigenic Escherichia coli

The most common enteric colibacillosis in neonatal and newborns is caused by enterotoxigenic Escherichia coli (ETEC). Colonization of ETEC in the small intestine is associated with adhesions using fimbriae, which is known as a specific adhesion factor and provides highly specific means for anchoring and prerequisite for an infectious agent. In the present study we have engineered Lactobacillus acidophilus to produce recombinant K99 fimbriae, which is used for the colonization to the intestine of pigs. The expression of K99 fimbrial protein was confirmed using SDS‐PAGE, immunoblot and agglutination analyses. To evaluate a function of the K99 fimbrial protein, inhibition and competition tests were performed on pre‐screened intestinal brush border from pigs. The tests showed that recombinant L. acidophilus, not control L. acidophilus, had a significant inhibitory effect to and competition against K99+ E. coli in a dose dependent manner. In conclusion, we demonstrated that recombinant K99 fimbriae producing L. acidophilus was able to prevent E. coli binding to intestinal brush border.

Age-associated changes in nicotine dependence

OBJECTIVES Nicotine is the primary factor responsible for tobacco dependence among individuals who smoke. Nicotinic receptors and nicotine-associated metabolism, two significant aspects of nicotine dependence, are influenced by age. To date, however, the relationship between age and nicotine dependence has not been investigated. STUDY DESIGN Cross-sectional. METHODS Data were obtained from the national smoking cessation programme for South Korea. Data obtained from current smokers in 2008 (n = 338,566) were used as baseline measures. Nicotine dependence was determined by the Fagerström Test for Nicotine Dependence (FTND). Cigarettes per day (CPD) and FTND were the dependent variables. As CPD is a major component of FTND, scores on the FTND minus scores related to CPD were also used as a dependent variable. The relationships between age and the dependent variables (FTND, CPD, partial FTND) were investigated. Quadratic regression models were used to test the non-linear relationship between age and nicotine dependence after adjusting for other covariates. RESULTS Analyses relying on nicotine dependence (FTND and partial FTND scores) and CPD produced similar results in relation to age. Specifically, the values of all three dependent variables increased with age until approximately 50 years of age, at which point they decreased. Additionally, nicotine dependence and CPD were associated with age of smoking initiation, smoking duration, alcohol-related problems, body mass index and residential area. After adjusting for other nicotine-dependence-related factors, the linear and quadratic terms of age were statistically significant in the multiple regression models. CONCLUSIONS In the present study, both nicotine dependence and CPD displayed an inverse U-shaped relationship with age, with a significant peak at 50 years of age. The results suggest that tobacco control policies should target issues related to nicotine dependence according to age group.

Randomized multicentre trial comparing external and internal pancreatic stenting during pancreaticoduodenectomy.

There is no consensus on the best method of preventing postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD). This multicentre, parallel group, randomized equivalence trial investigated the effect of two ways of pancreatic stenting after PD on the rate of POPF.

Exploring the Genetic Signature of Body Size in Yucatan Miniature Pig

Since being domesticated about 10,000–12,000 years ago, domestic pigs (Sus scrofa domesticus) have been selected for traits of economic importance, in particular large body size. However, Yucatan miniature pigs have been selected for small body size to withstand high temperature environment and for laboratory use. This renders the Yucatan miniature pig a valuable model for understanding the evolution of body size. We investigate the genetic signature for selection of body size in the Yucatan miniature pig. Phylogenetic distance of Yucatan miniature pig was compared to other large swine breeds (Yorkshire, Landrace, Duroc and wild boar). By estimating the XP-EHH statistic using re-sequencing data derived from 70 pigs, we were able to unravel the signatures of selection of body size. We found that both selections at the level of organism, and at the cellular level have occurred. Selection at the higher levels include feed intake, regulation of body weight and increase in mass while selection at the molecular level includes cell cycle and cell proliferation. Positively selected genes probed by XP-EHH may provide insight into the docile character and innate immunity as well as body size of Yucatan miniature pig.

Sublingual administration of bacteria-expressed influenza virus hemagglutinin 1 (HA1) induces protection against infection with 2009 pandemic H1N1 influenza virus.

Influenza viruses are respiratory pathogens that continue to pose a significantly high risk of morbidity and mortality of humans worldwide. Vaccination is one of the most effective strategies for minimizing damages by influenza outbreaks. In addition, rapid development and production of efficient vaccine with convenient administration is required in case of influenza pandemic. In this study, we generated recombinant influenza virus hemagglutinin protein 1 (sHA1) of 2009 pandemic influenza virus as a vaccine candidate using a well-established bacterial expression system and administered it into mice via sublingual (s.l.) route. We found that s.l. immunization with the recombinant sHA1 plus cholera toxin (CT) induced mucosal antibodies as well as systemic antibodies including neutralizing Abs and provided complete protection against infection with pandemic influenza virus A/CA/04/09 (H1N1) in mice. Indeed, the protection efficacy was comparable with that induced by intramuscular (i.m.) immunization route utilized as general administration route of influenza vaccine. These results suggest that s.l. vaccination with the recombinant non-glycosylated HA1 protein offers an alternative strategy to control influenza outbreaks including pandemics.

Ginsenoside fractions regulate the action of monocytes and their differentiation into dendritic cells

Background Panax ginseng (i.e., ginseng) root is extensively used in traditional oriental medicine. It is a modern pharmaceutical reagent for preventing various human diseases such as cancer. Ginsenosides—the major active components of ginseng—exhibit immunomodulatory effects. However, the mechanism and function underlying such effects are not fully elucidated, especially in human monocytes and dendritic cells (DCs). Methods We investigated the immunomodulatory effect of ginsenosides from Panax ginseng root on CD14+ monocytes purified from human adult peripheral blood mononuclear cells (PBMCs) and on their differentiation into DCs that affect CD4+ T cell activity. Results After treatment with ginsenoside fractions, monocyte levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 increased through phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK), but not p38 mitogen-activated protein kinase (MAPK). After treatment with ginsenoside fractions, TNF-α production and phosphorylation of ERK1/2 and JNK decreased in lipopolysaccharide (LPS)-sensitized monocytes. We confirmed that DCs derived from CD14+ monocytes in the presence of ginsenoside fractions (Gin-DCs) contained decreased levels of the costimulatory molecules CD80 and CD86. The expression of these costimulatory molecules decreased in LPS-treated DCs exposed to ginsenoside fractions, compared to their expression in LPS-treated DCs in the absence of ginsenoside fractions. Furthermore, LPS-treated Gin-DCs could not induce proliferation and interferon gamma (IFN-γ) production by CD4+ T cells with the coculture of Gin-DCs with CD4+ T cells. Conclusion These results suggest that ginsenoside fractions from the ginseng root suppress cytokine production and maturation of LPS-treated DCs and downregulate CD4+ T cells.

Randomized clinical trial of preoperative skin antisepsis with chlorhexidine gluconate or povidone–iodine

Skin antiseptic agents are used to prevent surgical‐site infection (SSI); few trials have reported the superiority of any specific agent in clean‐contaminated abdominal surgery. This RCT was designed to compare the effectiveness of chlorhexidine gluconate and povidone–iodine.

Apoptotic Effects of Cordycepin Through the Extrinsic Pathway and p38 MAPK Activation in Human Glioblastoma U87MG Cells.

We first demonstrated that cordycepin inhibited cell growth and triggered apoptosis in U87MG cells with wild-type p53, but not in T98G cells with mutant-type p53. Western blot data revealed that the levels of procaspase-8, -3, and Bcl-2 were downregulated in cordycepintreated U87MG cells, whereas the levels of Fas, FasL, Bak, cleaved caspase-3, -8, and cleaved PARP were upregulated, indicating that cordycepin induces apoptosis by activating the death receptor-mediated pathway in U87MG cells. Cordycepin-induced apoptosis could be suppressed by only SB203580, a p38 MAPK-specific inhibitor. These results suggest that cordycepin triggered apoptosis in U87MG cells through p38 MAPK activation and inhibition of the Akt survival pathway.

Development of Safe and Effective RSV Vaccine by Modified CD4 Epitope in G Protein Core Fragment (Gcf)

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in infants and young children worldwide, but currently no safe and effective vaccine is available. The RSV G glycoprotein (RSVG), a major attachment protein, is an important target for the induction of protective immune responses during RSV infection. However, it has been thought that a CD4+ T cell epitope (a.a. 183–195) within RSVG is associated with pathogenic pulmonary eosinophilia. To develop safe and effective RSV vaccine using RSV G protein core fragment (Gcf), several Gcf variants resulting from modification to CD4+ T cell epitope were constructed. Mice were immunized with each variant Gcf, and the levels of RSV-specific serum IgG were measured. At day 4 post-challenge with RSV subtype A or B, lung viral titers and pulmonary eosinophilia were determined and changes in body weight were monitored. With wild type Gcf derived from RSV A2 (wtAGcf), although RSV A subtype-specific immune responses were induced, vaccine-enhanced disease characterized by excessive pulmonary eosinophil recruitment and body weight loss were evident, whereas wtGcf from RSV B1 (wtBGcf) induced RSV B subtype-specific immune responses without the signs of vaccine-enhanced disease. Mice immunized with Th-mGcf, a fusion protein consisting CD4+ T cell epitope from RSV F (F51–66) conjugated to mGcf that contains alanine substitutions at a.a. position 185 and 188, showed higher levels of RSV-specific IgG response than mice immunized with mGcf. Both wtAGcf and Th-mGcf provided complete protection against RSV A2 and partial protection against RSV B. Importantly, mice immunized with Th-mGcf did not develop vaccine-enhanced disease following RSV challenge. Immunization of Th-mGcf provided protection against RSV infection without the symptom of vaccine-enhanced disease. Our study provides a novel strategy to develop a safe and effective mucosal RSV vaccine by manipulating the CD4+ T cell epitope within RSV G protein.

Intranasal immunization with plasmid DNA encoding spike protein of SARS-coronavirus/polyethylenimine nanoparticles elicits antigen-specific humoral and cellular immune responses

BackgroundImmunization with the spike protein (S) of severe acute respiratory syndrome (SARS)-coronavirus (CoV) in mice is known to produce neutralizing antibodies and to prevent the infection caused by SARS-CoV. Polyethylenimine 25K (PEI) is a cationic polymer which effectively delivers the plasmid DNA.ResultsIn the present study, the immune responses of BALB/c mice immunized via intranasal (i.n.) route with SARS DNA vaccine (pci-S) in a PEI/pci-S complex form have been examined. The size of the PEI/pci-S nanoparticles appeared to be around 194.7 ± 99.3 nm, and the expression of the S mRNA and protein was confirmed in vitro. The mice immunized with i.n. PEI/pci-S nanoparticles produced significantly (P < 0.05) higher S-specific IgG1 in the sera and mucosal secretory IgA in the lung wash than those in mice treated with pci-S alone. Compared to those in mice challenged with pci-S alone, the number of B220+ cells found in PEI/pci-S vaccinated mice was elevated. Co-stimulatory molecules (CD80 and CD86) and class II major histocompatibility complex molecules (I-Ad) were increased on CD11c+ dendritic cells in cervical lymph node from the mice after PEI/pci-S vaccination. The percentage of IFN-γ-, TNF-α- and IL-2-producing cells were higher in PEI/pci-S vaccinated mice than in control mice.ConclusionThese results showed that intranasal immunization with PEI/pci-S nanoparticles induce antigen specific humoral and cellular immune responses.