• Environmental Mutagens and Carcinogens
• /
• v.22 no.2
• /
• pp.112-124
• /
• 2002

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to exert detrimental toxicities on various organ systems including reproductive, cardiovascular, nervous, or dermal system. Immunomodulatory effects of TCDD is thymic atrophy, downregulation of cytotoxic T or B lymphocyte differentiation and activation, which were demonstrated using experimental animals, whereas immunotoxicity in human has not been investigated well. This study was proceeded to evaluate general immunologic spectrum of the Korean Vietnam War veterans exposed to TCDD during their operation, and compare with that of the non-exposed control subjects with similar age. Regarding composition and quantity, immune cells in peripheral blood collected from the TCDD-exposed was not much different from those of the control except decreased red blood cell, hemoglobin and hematocrit level. Furthermore, plasma IgG2, G3, and G4 isotype distribution was similar between two groups, but IgG1 level was significantly lowered in the TCDD-exposed, indicating a TCDD-mediated functional alteration of B cells. Significantly enhanced level of IgE in plasma, a hallmark of dermal or respiratory allergic response, was also observed in the TCDD-exposed compared with that of the control. Elevated generation of IL-4 and IL-10 was resulted from in vitro stimulation of T cells with PMA plus ionomycin or PHA, respectively, from the TCDD-exposed in comparison to those of the control, suggesting a skewed type-2 response. In addition, the level of IFN${\gamma}$, a multifunctional cytokine for T cell-mediated immunity, was lowered in the TCDD-exposed with upregulation of tumor necrosis factor $\alpha$. The present study suggests that TCDD exposure disturbs immunohomeostasis in humans observed as an aberrant plasma IgE and IgG1 levels and dysregulation of T cell activities.

• The Korean Journal of Mycology
• /
• v.41 no.2
• /
• pp.112-117
• /
• 2013

Phytophthora capsici is one of major limiting factors in production of pepper and other important crops worldwide by causing foliage blight and rot on fruit and root. Increased demand for the replacement of fungicides has led to searching a promising strategy to control the fungal diseases. To meet eco-friendly agriculture practice, we isolated microorganisms and assessed their beneficial effects on plant health and disease control efficacy. A total of 360 bacterial strains were isolated from rhizosphere soil of healthy pepper plants, and categorized to 5 representative isolates based on colony morphology. Among the 5 bacterial strains (GJ-1, GJ-4, GJ-5, GJ-11, GJ-12), three bacterial strains (GJ-1, GJ-11, GJ-12) presented antifungal activity against P. capsici in an fungal inhibition assay. In phosphate solubilization and siderophore production, the strain GJ-1 was more effective than others. The strain GJ-1 was identified as Bacillus sp. using 16S rDNA analysis. Bacillus sp. GJ-1 was also found to be effective in inhibiting other plant pathogenic fungi, including Rhizoctonia solani, Pythium ultimum and Fusarium solani. Therefore, the Bacillus sp. GJ-1 can serve as a biological control agent against fungal plant pathogens.

• Analytical Science and Technology
• /
• v.23 no.3
• /
• pp.240-246
• /
• 2010

A technique for the determination of trace Cu(II) in various real samples by FAAS after the column preconcentration onto p-dichlorobenzene-SA adsorbent, which is microcrystalline p-dichlorobenzene loaded with salicylaldoxime (SA) has been developed. Several experimental conditions such as pH of the sample solution, the amount of chelating agent salicylaldoxime, the amount of adsorbent p-dichlorobenzene-SA, and flow rate of sample solution were optimized. The interfering effects of various concomitant ions were investigated. $CN^-$ interfered more seriously than any other ions. However, the interference by $1\;{\mu}g\;mL^{-1}\;CN^-$ could be overcome completely by controlling the concentration of Ni(II) to $20\;{\mu}g\;mL^{-1}$. The linear range, correlation coefficient ($R^2$) and detection limit obtained by this technique were $3.0\sim100\;ng\;mL^{-1}$, 0.9901, and $3.1\;ng\;mL^{-1}$, respectively. For validating this technique, the aqueous samples (wastewater, reservoir water and stream water) and the food samples (orange juice, fresh egg and skim milk) were used. Recovery yields of 93~104% were obtained. These measured mean values were not differents from ICP-MS data at 95% confidence level. The good results were obtained from the experiments using the rice flour certified reference material (CRM) sample. Based on the experimental results, it was found that this technique could be applied to the preconcentration and determination of Cu(II) for various real samples.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.1
• /
• pp.11-19
• /
• 2016

Objectives: Exposure to volatile organic compounds such as trichloroethylene(TCE) and perchloroethylene(PCE), along with Agent Orange, that were issued around Camp Carroll US Army Base situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do Province, Korea. The main objective of this study was to assess the exposure to TCE and PCE of residents of the area surrounding Camp Carroll. Methods: The TCE, PCE and trichloroethanol(TCEOH) concentrations in blood and trichlroroacetic acid(TCA) and TCEOH concentrations in urine were measured and analyzed in a total of 1,033 residents around Camp Carroll. TCA and TCEOH are metabolites of TCE and PCE, respectively. The information on demographic characteristics and exposure variables in relation to underground water were obtained through a questionnaire completed by the subjects. Results: TCE, PCE and TCEOH concentrations were not detected in blood. Detection rates of TCA and TECOH concentrations in urine were 98.5% and 36.6%, respectively. Creatinine-corrected average TCA and TCEOH concentrations were $12.23{\pm}23.81{\mu}g/g$ and $0.66{\pm}4.31{\mu}g/g$, respectively. A significant difference was not shown between the drinking group and no drinking group for underground water, which was assumed as a potential route of exposure to TCE and PCE through the consumption of ground water. However, females drinking ground water showed a significantly higher mean level of TCA in urine than did males. There was no significant difference according to drinking ground water as a potential source of exposure to TCE and PCE in residents around Camp Carroll. Conclusions: Considering the statistical analysis of factors affecting exposure to TCE and PCE in ground water along with previous reports, TCA in urine as exposure to TCE and PCE might not be appropriate because it is found in chlorinated drinking water. Therefore, TCA concentration in urine may be the result of drinking of chlorinated water.

• Proceedings of the KACD Conference
• /
• 2008.05a
• /
• pp.213-223
• /
• 2008

The objective of this study was to compare dentin shear bond strength (DSBS) of dentin bonding agents (DBAs) cured with a plasma arc (PAC) light curing unit (LCU) and those cured with a light emitting diode (LED) LCU. Optical properties were also analyzed for Elipar freelight 2 (3M ESPE); LED LCU, Apollo 95E (DMT Systems); PAC LCU and VIP Junior (Bisco); Halogen LCU. The DBAs used for DSBS test were Scotchbond Multipurpose (3M ESPE), Singlebond 2 (3M ESPE) and Clearfil SE Bond (Kuraray). After DSBS testing, fractured specimens were analyzed for failure modes with SEM. The total irradiance and irradiance between 450 nm and 490 nm of the LCUs were different. LED LCU showed narrow spectral distribution around its peak at 462 nm whereas PAC and Halogen LCU showed a broad spectrum. There were no significant differences in mean shear bond strength among different LCUs (P > 0.05) but were significant differences among different DBAs (P < 0.001).

• The Korean Journal of Mycology
• /
• v.44 no.4
• /
• pp.377-381
• /
• 2016

Abnormal chloranthy was observed on Prunus mume trees grown in an orchard in Uiseong, Gyeongbuk province, Korea in 2015. Flower buds showing chloranthy were covered with numerous orange-colored sori, which were confirmed to contain spermogonia and aeciospores by stereo microscopy and light microscopy. When observed using scanning electron microscope, the aeciospores were globose, ellipsoid, or ovoid, and measured $22.8{\sim}35.6{\times}19.8{\sim}36.8{\mu}m$, with a verrucae wall ornamentation. To construct a phylogeny, the large and small subunit regions of rDNA were sequenced and compared with those of allied species by the maximum likelihood method. The isolated fungus species showed high similarities with Caeoma makinoi (Teleomorph: Blastospora smilacis), which was previously isolated from P. mume in Japan. Therefore, we initially report this fungal agent parasitic on P. mume as C. makinoi in Korea and name the disease it causes as "flower bud chloranthy disease".

• Restorative Dentistry and Endodontics
• /
• v.33 no.3
• /
• pp.213-223
• /
• 2008

The objective of this study was to compare dentin shear bond strength (DSBS) of dentin bonding agents (DBAs) cured with a plasma arc (PAC) light curing unit (LCU) and those cured with a light emitting diode (LED) LCU. Optical properties were also analyzed for Elipar freelight 2 (3M ESPE); LED LCU, Apollo 95E (DMT Systems); PAC LCU and VIP Junior (Bisco); Halogen LCU. The DBAs used for DSBS test were Scotchbond Multipurpose (3M ESPE), Singlebond 2 (3M ESPE) and Clearfil SE Bond (Kuraray). After DSBS testing, fractured specimens were analyzed for failure modes with SEM. The total irradiance and irradiance between 450 nm and 490 nm of the LCUs were different. LED LCU showed narrow spectral distribution around its peak at 462 nm whereas PAC and Halogen LCU showed a broad spectrum. There were no significant differences in mean shear bond strength among different LCUs (P > 0.05) but were significant differences among different DBAs (P < 0.001)