Development of a bivalent conjugate vaccine candidate against malaria transmission and typhoid fever.

Immune responses to poorly immunogenic antigens, such as polysaccharides, can be enhanced by conjugation to carriers. Our previous studies indicate that conjugation to Vi polysaccharide of Salmonella Typhi may also enhance immunogenicity of some protein carriers. We therefore explored the possibility of generating a bivalent vaccine against Plasmodium falciparum malaria and typhoid fever, which are co-endemic in many parts of the world, by conjugating Vi polysaccharide, an approved antigen in typhoid vaccine, to Pfs25, a malaria transmission blocking vaccine antigen in clinical trials.

Macrolide resistance mechanisms and virulence factors in erythromycin-resistant Campylobacter species isolated from chicken and swine feces and carcasses.

Resistance to antimicrobials was measured in 73 isolates of Campylobacter jejuni (C. jejuni) and 121 isolates of Campylobacter coli (C. coli) from chicken and swine feces and carcasses in Korea.

Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg.

Prevalence and molecular characterization of CTX-M β-lactamase-producing Escherichia coli isolated from healthy swine and cattle.

The purpose of this study was to determine the prevalence and characteristics of CTX-M β-lactamases in Escherichia coli among healthy swine and cattle in Korea. A total of 1212 fecal samples obtained from healthy pigs (n=558) and cattle (n=654) were screened for CTX-M-type extended spectrum β-lactamase (ESBL)-producing E. coli isolates.

Prevalence of plasmid-mediated quinolone resistance determinants among Escherichia coli isolated from food animals in Korea.

The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants in Escherichia coli isolated from food-producing animals and to characterize the PMQR-positive isolates. A total of 365 E. coli isolates which were either nalidixic acid resistant and ciprofloxacin susceptible (NAL(R)-CIP(S); n=185), or nalidixic acid and ciprofloxacin resistant (NAL(R)-CIP(R); n=180) were assessed for the presence of PMQR determinants by polymerase chain reaction.

Molecular characterization of extended-spectrum-β-lactamase-producing and plasmid-mediated AmpC β-lactamase-producing Escherichia coli isolated from stray dogs in South Korea.

A total of 47 extended-spectrum-cephalosporin-resistant Escherichia coli strains isolated from stray dogs in 2006 and 2007 in the Republic of Korea were investigated using molecular methods. Extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase phenotypes were identified in 12 and 23 E. coli isolates, respectively.

Aberrant methylation of ADAMTS1 in non-small cell lung cancer.

ADAMTS1 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs) is an extracellular matrix metalloproteinase with protease activity and antiangiogenic activity. It has been suggested that ADAMTS1 plays an important role in tumor growth and metastasis. In this study, we examined ADAMTS1 expression in non-small cell lung cancer (NSCLC), and we also evaluated whether the loss of ADAMTS1 expression is due to aberrant methylation of the gene.

Identification of polymorphisms in the XIAP gene and analysis of association with lung cancer risk in a Korean population.

The X-linked inhibitor of apoptosis protein (XIAP) is a potent mammalian IAP, and has been shown to play an important role in development and progression of cancer. Polymorphisms in the XIAP gene may influence XIAP production or activity, thereby modulating susceptibility to lung cancer. To test this hypothesis, we first screened for polymorphisms in the XIAP gene by direct sequencing of genomic DNA samples from 27 healthy Korean women and then performed a case-control study to evaluate the association between the polymorphisms and the risk of lung cancer.

EGFR, ERBB2, and KRAS mutations in Korean non-small cell lung cancer patients.

The epidermal growth factor receptor (EGFR), and its family members play an important role in the development and progression of lung cancers. It has been reported that somatic mutations in the tyrosine kinase domain of the EGFR or ERBB2 genes occur in a subset of patients with lung cancer. We searched for mutations of the EGFR, ERBB2, and KRAS genes in surgically resected non-small cell lung cancers (NSCLCs) to determine the prevalence of these mutations in Korean lung cancer patients.

No association between dinucleotide repeat polymorphism in intron 1 of the epidermal growth factor receptor gene EGFR and risk of lung cancer.

The tyrosine kinase receptor EGFR pathway is one of the oncogenic signaling cascades involved in lung cancer, mediating the epidermal growth factor receptor gene EGFR. First-intron polymorphisms with greater numbers of CA dinucleotide repeats tend to downregulate EGFR expression, which suggests that this polymorphism may modulate susceptibility to lung cancer. The present hospital-based case-control study evaluated the possible association of CA repeat polymorphism in the EGFR gene with risk of lung cancer in a Korean population.

No association between p73 G4C14-to-A4T14 polymorphism and the risk of lung cancer in a Korean population.

A member of the p53 family, p73 may play an important role in the development of lung cancer. Variations in the DNA sequence in the p73 gene can lead to alterations in the production of p73 and/or activity, which can affect an individual's susceptibility to lung cancer. To test this hypothesis, this study examined the association between the G4C14-to-A4T14 polymorphism in the p73 gene and the risk of lung cancer in a Korean population.

Polymorphisms in the caspase-8 gene and the risk of lung cancer.

Caspase-8 (CASP-8) is an initiator CASP in the cell death receptor-mediated apoptotic pathway, and plays an important role in the development of cancer. Polymorphisms and their haplotypes in the CASP-8 gene can result in alterations in CASP-8 expression and/or activity, thereby modulating the susceptibility to lung cancer. To test this hypothesis, we examined the association of -678_-673delAGTAAG (-678del) and IVS12-19G-->A polymorphisms and their haplotypes with the risk of lung cancer in a Korean population.

Polymorphisms in the hMSH2 gene and the risk of primary lung cancer.

Polymorphisms in the DNA repair genes may be associated with differences in the capacity to repair DNA damage, and so this can influence an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of hMSH2 -118T>C, IVS1+9G>C, IVS10+12A>G, and IVS12-6T>C genotypes and their haplotypes with the risk of lung cancer in a Korean population. The hMSH2 genotypes were determined in 432 lung cancer patients and in 432 healthy controls who were frequency matched for age and gender.

Relationship between cyclooxygenase 8473T>C polymorphism and the risk of lung cancer: a case-control study.

Background: Cyclooxygenase-2 (COX-2) plays an important role in the development of lung cancer. DNA sequence variations in the COX-2 gene may lead to altered COX-2 production and/or activity, and so they cause inter-individual differences in the susceptibility to lung cancer. To test this hypothesis, we investigated the association between the 8473T>C polymorphism in the 3'-untranslated region of the COX-2 gene and the risk of lung cancer in a Korean population.

Polymorphisms in TGF-beta1 gene and the risk of lung cancer.

Background: Transforming growth factor-beta1 (TGF-beta1) functions as a suppressor of tumor initiation by inhibiting cellular proliferation or by promoting cellular differentiation or apoptosis in the early phase of cancer development. Variations in the DNA sequence in the TGF-beta1 gene may lead to altered TGF-beta1 production and/or activity, and so this can modulate an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of the TGF-beta1 -509C > T and 869T > C (L10P) polymorphisms and their haplotypes with the risk of lung cancer in a Korean population.

O6-alkylguanine-DNA alkyltransferase gene polymorphisms and the risk of primary lung cancer.

O6-alkylguanine-DNA alkyltransferase (AGT) plays an important role in the repair of O6-alkylguanine adducts, which are major mutagenic lesions produced by environmental carcinogens. Polymorphisms in the AGT gene may affect the capacity to repair DNA damage and thereby have influence on individual's susceptibility to smoking-related cancer. To test this hypothesis, we investigated the potential association of AGT polymorphisms (485C > A, Leu53Leu (C > T) and Leu84Phe] with the risk of lung cancer in a Korean population.

XPC polymorphisms and lung cancer risk.

Polymorphisms in DNA repair genes may be associated with differences in the capacity to repair DNA damage and thereby influence an individual's susceptibility to smoking-related cancer. To test this hypothesis, we investigated the potential association of 7 XPC polymorphisms (-449G-->C, -371G-->A, -27G-->C, Val499Arg, PAT-/+, IVS11-5C-->A and Lys939Gln) and their haplotypes with lung cancer risk in a Korean population. XPC genotypes were determined in 432 lung cancer patients and 432 healthy controls frequency-matched for age and sex.