A randomized, non-inferiority trial comparing two bivalent killed, whole cell, oral cholera vaccines (Euvichol vs Shanchol) in the Philippines.

Background: Currently, there are two oral cholera vaccines (OCV) that are prequalified by the World Health Organization. Both (Dukoral and Shanchol) have been proven to be safe, immunogenic, and effective. As the global supply of OCV remains limited, we assessed the safety and immunogenicity of a new low cost, killed, bivalent OCV (Euvichol) in the Philippines.

Distinguishing between genotoxic and non-genotoxic hepatocarcinogens by gene expression profiling and bioinformatic pathway analysis.

A rapid and sensitive method to determine the characteristics of carcinogens is needed. In this study, we used a microarray-based genomics approach, with a short-term in vivo model, in combination with insights from statistical and mechanistic analyses to determine the characteristics of carcinogens. Carcinogens were evaluated based on the different mechanisms involved in the responses to genotoxic carcinogens and non-genotoxic carcinogens.

Identification of EBP50 as a specific biomarker for carcinogens via the analysis of mouse lymphoma cellular proteome.

To identify specific biomarkers generated upon exposure of L5178Y mouse lymphoma cells to carcinogens, 2-DE and MALDI-TOF MS analysis were conducted using the cellular proteome of L5178Y cells that had been treated with the known carcinogens, 1,2-dibromoethane and O-nitrotoluene and the noncarcinogens, emodin and D-mannitol. Eight protein spots that showed a greater than 1.5-fold increase or decrease in intensity following carcinogen treatment compared with treatment with noncarcinogens were selected.

Moesin is a biomarker for the assessment of genotoxic carcinogens in mouse lymphoma.

1,2-Dibromoethane and glycidol are well known genotoxic carcinogens, which have been widely used in industry. To identify a specific biomarker for these carcinogens in cells, the cellular proteome of L5178Y mouse lymphoma cells treated with these compounds was analyzed by 2-dimensional gel electrophoresis (2-DE) and MALDI-TOF mass spectrometry (MS). Of 50 protein spots showing a greater than 1.

Identification of biomarkers of chemically induced hepatocarcinogenesis in rasH2 mice by toxicogenomic analysis.

Toxicogenomic approaches have been applied to chemical-induced heptocarcinogenesis rodent models for the identification of biomarkers of early-stage hepatocarcinogenesis and to help clarify the underlying carcinogenic mechanisms in the liver. In this study, we used toxiciogenomic methods to identify candidate biomarker genes associated with hepatocarcinogenesis in rasH2 mice. Blood chemical, histopathologic, and gene expression analyses of the livers of rasH2 mice were performed 7 and 91 days after the administration of the genotoxic hepatocarcinogens 2-acetylaminofluorene (AAF) and diethylnitrosoamine (DEN), the genotoxic carcinogen melphalan (Mel), and the nongenotoxic noncarcinogen 1-naphthylisothiocynate (ANIT).

Melphalan modulates the expression of E7-specific biomarkers in E7-Tg mice.

HPV oncoproteins are selectively retained and expressed in HPV infected carcinoma cells. The E7 oncoprotein interacts with the tumour suppressor Rb, and leads to the progression of oncogenesis. In a previous study, E7 biomarkers were identified in E7 Tg mice.

Melphalan inhibits adenoma development through modulating the expression of K-ras-specific markers in K-ras Tg mice.

In previous research, we focused on the discovery of K-ras biomarkers, and effects of genotoxic carcinogens on their expression were investigated in this study. It is well-known that mutated K-ras gene is involved in approximately 30% of human cancers such as lung cancer. To search for K-ras oncogene-induced modulators in lung tissues of K-ras transgenic mice, we analyzed K-ras-specific genes and proteins related to cancer development, signal transduction, inflammation as well as tumor suppression in a previous study.

Telomerase reverse transcriptase related with telomerase activity regulates tumorigenic potential of mouse embryonic stem cells.

Embryonic stem cell (ESC) research gave rise to the possibility that stem cell therapy could be used in the treatment of incurable diseases such as neurodegenerative disorders. However, problems related to the tumorigenicity of undifferentiated ESCs must be resolved before such cells can be used in the application of cell replacement therapies. In the present study, we attempted to determine biomarkers that predicted tumor formation of undifferentiated ESCs in vivo.

26-Week carcinogenicity study of di-isodecyl phthalate by dietary administration to CB6F1-rasH2 transgenic mice.

This study examined the carcinogenic potential of di-isodecyl phthalate (DIDP) in rasH2 mice. DIDP was administered to 15 rasH2 mice/gender/group at dietary levels of 0, 0.1, 0.

Improving gene expression similarity measurement using pathway-based analytic dimension.

Background: Gene expression similarity measuring methods were developed and applied to search rapidly growing public microarray databases. However, current expression similarity measuring methods need to be improved to accurately measure similarity between gene expression profiles from different platforms or different experiments.

Results: We devised new gene expression similarity measuring method based on pathway information.

Pulmonary toxicity and kinetic study of Cy5.5-conjugated superparamagnetic iron oxide nanoparticles by optical imaging.

Recent advances in the development of nanotechnology and devices now make it possible to accurately deliver drugs or genes to the lung. Magnetic nanoparticles can be used as contrast agents, thermal therapy for cancer, and be made to concentrate to target sites through an external magnetic field. However, these advantages may also become problematic when taking into account safety and toxicological factors.

Genotoxicity Studies on Carrageenan: Short-term Assays.

Carrageenan is a naturally-occurring sulfated polygalactan which has been widely used in the dairy industry and a gelling agent in non-dairy products. In this study, four short-term genotoxicity assays were investigated to evaluate the potential genotoxic effects of carrageenan. The mutagenic-ity of carrageenan was evaluated up to a maximum dose of 5 mg/plate in Ames test.

Profiling of transcripts and proteins modulated by the E7 oncogene in the lung tissue of E7-Tg mice by the omics approach.

The E6 and E7 oncoproteins of human papilloma virus (HPV) type 16 have been known to cooperatively induce the immortalization and transformation of primary keratinocytes. We established an E7 transgenic mouse model to screen HPV-related biomakers using the omics approach. The methods used to identify HPV-modulated factors were genomics analysis by microarray using the Affymetrix 430 2.

Profiling of transcripts and proteins modulated by K-ras oncogene in the lung tissues of K-ras transgenic mice by omics approaches.

The mutated K-ras gene is involved in approximately 30% of human cancers. In order to search for K-ras oncogene-induced modulators in lung tissues of K-ras transgenic mice, we performed microarray and proteomics (LC/ESI-MS/MS) analysis. Genes (RAB27b RAS family, IL-1RA, IL-33, chemokine ligand 6, epiregulin, EGF-like domain and cathepsin) related to cancer development (Wnt signaling pathway) and inflammation (chemokine/cytokine signaling pathway, Toll receptor signaling) were up-regulated while genes (troponin, tropomodulin 2, endothelial lipase, FGFR4, integrin alpha8 and adenylate cyclase 8) related to the tumor suppression such as p53 pathway, TGF-beta signaling pathway and cadherin signaling pathway were down-regulated by K-ras oncogene.

Studies on the Genotoxic Effects of Wood Smoke Flavors.

Smoke flavors based on the thermal decomposition of wood have been applied to a variety of food products as an alternative for traditional smoking. Despite its increasing use, the available genotoxicity data on wood smoke flavors (WSF) are still controversial. Thus, potential genotoxic effects of WSF in four short-term genotoxicity assays were investigated, which included the Ames assay, chromosomal aberration assay, micronucleus test and the alkaline comet assay.

Spread of nontuberculous mycobacteria from 1993 to 2006 in Koreans.

In Korea, the prevalence of nontuberculous mycobacterial (NTM) pulmonary disease has risen, observed primarily in immunocompetent patients with or without preexisting lung disease. The purpose of this study was to determine the frequency of various species of NTM isolates from respiratory specimens in a single institution over a 14-year period in Korea. All samples referred to our reference laboratory over a 14-year period in Korea were analyzed.

Epiregulin expression by Ets-1 and ERK signaling pathway in Ki-ras-transformed cells.

Epiregulin belongs to the epidermal growth factor family, binds to the epidermal growth factor receptor, and its expression is upregulated in various cancer cells, but the regulatory mechanism is unclear. We investigated the regulatory mechanism of epiregulin expression in Ki-ras-transformed cancer cells. In 267B1/Ki-ras cells, the RAF/MEK/ERK pathway was constitutively activated, epiregulin was up-regulated, and the expression and phosphorylation of Ets-1 were augmented.

Sensitization of the apoptotic effect of gamma-irradiation in genistein-pretreated CaSki cervical cancer cells.

Radiotherapy is currently applied in the treatment of human cancers. We studied whether genistein would enhance the radiosensitivity and explored its precise molecular mechanism in cervical cancer cells. After co-treatment with genistein and irradiation, the viability, cell cycle analysis, and apoptosis signaling cascades were elucidated in CaSki cells.

Expression and purification of human papillomavirus 18 L1 virus-like particle from saccharomyces cerevisiae.

Cervical cancer caused by human papillomavirus (HPV) might be successfully prevented by HPV vaccination and screening. HPV vaccination and HPV serology assays have been investigated using HPV virus-like particles (VLPs). In this study we produced HPV18 L1 VLPs in Saccharomyces cerevisiae and purified them.

Comparison of Cell Transformation Assay Using Murine Fibroblasts and Human Keratinocytes.

The cell transformation assays (CTA) were performed using BALB/3T3 murine fibroblasts and HaCaT human keratinocytes in order to evaluate concordance between both CTAs and carcinogenicity with compounds differing in their genotoxic and carcinogenic potential. Six test articles were evaluated, two each from three classes of compounds: genotoxic carcinogens (2-amino-5-nitrophenol and 4-nitroquinoline-N-oxide), genotoxic noncarcinogens (8-hydroxyquinoline and benzyl alcohol), and nongenotoxic carcinogens (methyl carbamate and N-nitrosodiphenylamine). Any foci of size ≥ 2 mm regardless of invasiveness and piling was scored as positive in CTA with BALB/3T3.

Comparative proteomic analysis of virulent Korean Mycobacterium tuberculosis K-strain with other mycobacteria strain following infection of U-937 macrophage.

In Korea, the Mycobacterium tuberculosis K-strain is the most prevalent clinical isolates and belongs to the Beijing family. In this study, we conducted comparative porteomics of expressed proteins of clinical isolates of the K-strain with H37Rv, H37Ra as well as the vaccine strain of Mycobacterium bovis BCG following phagocytosis by the human monocytic cell line U-937. Proteins were analyzed by 2-D PAGE and MALDITOF-MS.

Generation of monoclonal antibody recognized by the GXXXG motif (glycine zipper) of prion protein.

To develop monoclonal antibodies (MAbs) to react with normal prion protein (PrPC) and abnormal isoform of prion protein (PrPSc), PrPSc was isolated from brains of 263 K scrapie-infected hamsters and immunized to PrP knockout mice. We developed two hybridomas, 3F10 and 1C5 (IgG1), of which epitope mappings were screened by using glutathione S-transferase (GST) fusion proteins of recombinant hamster prion protein and suitable peptides. 3F10 showed a high affinity for hamster and mouse PrP and was demonstrated to recognize the residues 137-151.

Purification and immunogenicity study of human papillomavirus type 16 L1 protein in Saccharomyces cerevisiae.

Human papillomavirus 16 virus-like particle (HPV16 VLP) vaccines expressed in Saccharomyces cerevisiae are under Phase III trial and are expected to be on the market in the near future. We have established a convenient and economical system for the prophylactic study of vaccines derived from HPV16 VLPs, and neutralization tests to standardize HPV serological methodology as a measure of validation. To purify HPV16 VLPs, yeast cells expressing HPV16 L1 protein were cultured and purified on a small scale by ultracentrifugation and size-exclusion and cation-exchange chromatography using open columns.

The apoptotic effect of intercalating agents on HPV-negative cervical cancer C-33A cells.

Cervical cancer is one of the leading causes of female cancer death worldwide with about 500,000 deaths per year. Both mitomycin C and cisplatin are alkylating agents, which bind and intercalate DNA, and thus used as anti-cancer drugs. In these studies, we focused on investigating the apoptotic effects of intercalating agents on HPV-negative cervical cancer C-33A cells.

Diffusion of bioactive molecules through the walls of the medial tissue-engineered hybrid ePTFE grafts for applications in designs of vascular tissue regeneration.

Strategies of better vascular tissue engineering may require delivery of soluble bioactive signals in cell culture medium to the cells in tissue-regenerating constructs. We measured the diffusivity and permeability of model tissue-engineering bioactive molecules such as water and heparin through the walls of both a hybrid ePTFE graft and a porcine carotid artery, a model vascular tissue. While diffusivities of H(3)-water and H(3)-heparin were measured as 3.