Kyu-Wan Lee

Adenovirus-mediated Suicide Gene Therapy Using the Human Telomerase Catalytic Subunit (hTERT) Gene Promoter Induced Apoptosis of Ovarian Cancer Cell Line

Telomerase is a ribonucleoprotein complex the function of which is to add telomeric repeats (TTAGGG)n to chromosomal ends, and it is known to play an important role in cellular immortalization. Telomerase is highly active in most tumor cells, yet not in normal cells. As such, it may have possible applications in cancer gene therapy. Telomerase consists of two essential components, telomerase RNA template (hTR) and catalytic subunit (hTERT). hTERT is expressed only in cells and tissues positive for telomerase activity, i.e., tumor and fetal cells. We here tested the possibility of the utilization of the hTERT promoter in targeted cancer gene therapy. We cloned the hTERT promoter in the replace of the CMV promoter and sub-cloned HSV-TK gene to be controlled by hTERT gene promoter in adenovirus shuttle plasmid. Then we constructed recombinant adenovirus Ad-hT-TK, and infected them into normal and human gynecological cancer cell lines. Through these experiments, we identified the selective tumor specific cell death by Ad-hT-TK. Furthermore, FACS analysis and TUNEL assay suggests that the reduced viability is mediated through the induction of apoptosis, indicating that this approach may be a useful method for suppressing cancer growth in targeted cancer gene therapy. These results show that Ad-hT-TK could be used for gynecological cancer gene therapy.

Effect of TCDD on corpus cavernosum histology and smooth muscle physiology.

A polyhalogenated aromatic hydrocarbon, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is one of the most potent toxic environmental pollutants. Decreases in spermatogenesis and the ability to conceive and carry a pregnancy to term are the most sensitive signs of reproductive toxicity by TCDD in the mammal, but no report of its effect on the erectile function exists. We performed this study to investigate the effect of TCDD on the erectile function. New Zealand white rabbits were treated intraperitoneally with 1 μg/kg of TCDD. At 4 (Gr I) and 8 (Gr II) weeks after the administration of TCDD, cavernosal tissues were harvested for strip study in the organ bath and testes were prepared for histologic examination. Compared to the maximal amplitude of 17.1±4.12 mN in normal control (Gr III), the contractions to cumulative concentrations of NE (10−8–10−4 M) were significantly decreased to 6.57±1.34 and 5.45±1.01 mN in Groups I and II, respectively. Compared to 51.12±7.38% in Gr III, relaxation to cumulative concentration (10−8–10−4 M) of acetylcholine was significantly decreased to 17.25±2.17% (Gr I) and 9.73±2.17% (Gr II) at a concentration of 10−4 M, respectively. Compared to 75.12±13.18% in Gr III, relaxation to cumulative concentration (10−8–10−4 M) of SNP was significantly decreased to 31.49±7.89% (Gr I) and 18.54±6.12% (Gr II) at a concentration of 10−4 M, respectively. Histologically, intracavernosal fibrosis, abnormal subtunical deposition of fat and decreased sinusoidal space with consequent increase of trabecular smooth muscle contents were identified in TCDD-treated groups. In TCDD-treated animals, seminiferous tubules showed a decrease of germ cells with vacuolar degeneration and apoptotic cells. Spermatids were hardly seen. These results suggest that TCDD inhibits spermatogenesis and has a potential harmful effect on erectile function via changes of corpus cavernosum histology and smooth muscle physiology.

Prototype tactile feedback system for examination by skin touch

Diagnosis of conditions such as psoriasis and atopic dermatitis, in the case of induration, involves palpating the infected area via hands and then selecting a ratings score. However, the score is determined based on the testers experience and standards, making it subjective. To provide tactile feedback on the skin, we developed a prototype tactile feedback system to simulate skin wrinkles with PHANToM OMNI.

3D skin surface reconstruction from a single image by merging global curvature and local texture using the guided filtering for 3D haptic palpation

Skin surface evaluation has been studied using various imaging techniques. However, all these studies had limited impact because they were performed using visual exam only. To improve on this scenario with haptic feedback, we propose 3D reconstruction of the skin surface using a single image. Unlike extant 3D skin surface reconstruction algorithms, we utilize the local texture and global curvature regions, combining the results for reconstruction.