Hui-Young Lee

In Vivo Alternative Testing with Zebrafish in Ecotoxicology

Although rodents have previously been used in ecotoxicological studies, they are expensive, time-consuming, and are limited by strict legal restrictions. The present study used a zebrafish (Danio rerio) model and generated data that was useful for extrapolating toxicant effects in this system to that of humans. Here we treated embryos of the naive-type as well as a transiently transfected zebrafish liver cell line carrying a plasmid (phAhRE-EGFP), for comparing toxicity levels with the well-known aryl hydrocarbon receptor (AhR)-binding toxicants: 3,3,4,4,5-pentachlorobiphenyl (PCB126), 2,3,7,8-tetrachlorodibenzo-p-dioxin, and 3-methylcholanthrene. These toxicants induced a concentration-dependent increase in morphological disruption, indicating toxicity at early life-stages. The transient transgenic zebrafish liver cell line was sensitive enough to these toxicants to express the CYP1A1 regulated enhanced green fluorescent protein. The findings of this study demonstrated that the zebrafish in vivo model might allow for extremely rapid and reproducible toxicological profiling of early life-stage embryo development. We have also shown that the transient transgenic zebrafish liver cell line can be used for research on AhR mechanism studies.

Cutaneous metastasis to the scalp from squamous cell carcinoma of the cervix

Carcinoma of the cervix is a common neoplasm. Early detection and improved treatment techniques have resulted in better control of cancer and longer survival, however, invasive and metastatic disease still occur. Cervical cancer usually spreads through direct local extension and via the lymphatics, haematogenous metastasis is relatively infrequent and cutaneous metastases are very rare. Metastasis to the scalp is extremely rare and only three cases of scalp metastasis from cervical cancer have been reported in the literature. We now report a patient with cervical cancer who presented with metastasis to this very unusual site.

Protective effects of vitamin E against 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) induced toxicity in zebrafish embryos

3,3,4,4,5-Pentachlorinated biphenyls 126 (PCB126) is a global environmental contaminant that can induce cellular oxidative stress. We investigated whether vitamin E can protect against toxicity from PCB126 during zebrafish (Danio rerio) development. Zebrafish embryos were exposed to 100nM PCB126 and compared with a second group that was co-exposed with 100muM vitamin E until 5 days post fertilization. PCB126 induced pericardial sac edema, yolk sac edema, and growth retardation in zebrafish embyos. In contrast, vitamin E co-exposure group did not show any gross changes. Real-time PCR results showed that vitamin E co-exposure group were restored to control group for the expression levels of heat shock protein 70 Cognate, aryl hydrocarbon receptor type-2, cytochrome P450 1A, and superoxide dismutase-1. These data give insights into the use of vitamin E to reduce PCB126-mediated toxicity and into the use of zebrafish embryos for exploring mechanisms underlying the oxidative potential of AHR agonists.

Immunoenhancing effects of a new probiotic strain, Lactobacillus fermentum PL9005

The immunoenhancing effects of Lactobacillus fermentum PL9005 were assessed via mouse intragastric inoculation. The number of immunoglobulin A-positive cells in the small intestine, CD4+ T lymphocytes in the peripheral blood, and the lymphocyte proliferation response to mitogen stimulation (lipopolysaccharide) increased in mice fed L. fermentum PL9005. The lactic acid concentration also increased dose dependently in the small intestine of mice fed L. fermentum PL9005. No differences were found in body weight, food intake, and clinical signs between mice fed L. fermentum PL9005 and the control group. Results indicated that L. fermentum PL9005 is a probiotic with immunoenhancing properties.

Highly expressed recombinant human follicle- stimulating hormone from Chinese hamster ovary cells grown in serum-free medium and its effect on induction of folliculogenesis and ovulation

OBJECTIVEnTo develop efficient Chinese hamster ovary (CHO) cells that express recombinant human FSH (rhFSH) in serum-free conditions and to investigate the effect of this newly synthesized rhFSH on folliculogenesis and ovulation.nnnDESIGNnExperimental study.nnnSETTINGnSeoul National University, South Korea.nnnANIMALSnForty immature hypophysectomized rats and 40 androgen-sterilized mice.nnnINTERVENTION(S)nA stable single CHO cell that expresses rhFSH at a high level was obtained by introducing the human chorionic gonadotropin (hCG) alpha-subunit and FSH beta-subunit genes. After purification processing, we investigated the effect of this newly synthesized rhFSH on folliculogenesis in hypophysectomized rats and ovulation in androgen-sterilized mice.nnnMAIN OUTCOME MEASURE(S)nThe ovary weight, uterine weight, number of follicles, and ovarian morphology were evaluated in immature hypophysectomized rats. The number of ovulated oocytes and ovarian morphology were examined in androgen-sterilized mice.nnnRESULT(S)nAfter purification processing, we analyzed the new rhFSH using matrix-associated laser desorption ionization-time of flight and found that this new rhFSH increased both ovarian weight and uterine weight in hypophysectomized rats and induced ovulation in androgen-sterilized mice.nnnCONCLUSION(S)nThis newly synthesized rhFSH might be safely used in anovulatory infertile woman as well as in ovulation induction protocols for subfertile women.

Protective and therapeutic effects of an extract mixture of alder tree, labiate herb, milk thistle green bean-rice bran fermentation, and turnip against ethanol-induced toxicity in the rat.

An herbal extract mixture and yogurt added to the herbal extract mixture were tested for their protective and therapeutic effects on ethanol-induced liver injury. The herbal extract mixture, yogurt and commercial drugs were used for treatment for two weeks prior to administering a single oral dose of ethanol (3 g/kg body weight). The herbal extract mixture and yogurt added to the herbal extract mixture were found to provide protection against ethanol-induced toxicity comparable to the commercial drug treatment, according to the serum and histopathological analysis. It was also shown that co-treatment with herbal extract mixture and yogurt against a triple oral dose of ethanol (2 g/kg body weight, over one week) provided protection against ethanol toxicity. After the initial set of experiments, the herbal extract mixture and yogurt treatments were extended for three more weeks. When compared to the positive control, further treatment with both the herbal extract and yogurt significantly reduced liver injury and resulted in a lower grade of lipid deposition.