OBJECTIVES: Cigarette smoking is associated with carcinogenesis owing to the mutagenic and genotoxic effects of cigarette smoke. The aim of this study was to evaluate the mutagenic and genotoxic effects of Korean cigarettes using in vitro assays. METHODS: We selected 2 types of cigarettes (TL and TW) as benchmark Korean cigarettes for this study, because they represent the greatest level of nicotine and tar contents among Korean cigarettes. Mutagenic potency was expressed as the number of revertants per μg of cigarette smoke condensate (CSC) total particulate matter whereas genotoxic potency was expressed as a concentration-dependent induction factor. The CSC was prepared by the International Organization for Standardization 3308 smoking method. CHO-K1 cells were used in vitro micronucleus (MNvit) and comet assays. Two strains of Salmonella typhimurium (Salmonella enterica subsp.enterica; TA98 and TA1537) were employed in Ames tests. RESULTS: All CSCs showed mutagenicity in the TA98 and TA1537 strains. In addition, DNA damage and micronuclei formation were observed in the comet and MNvit assays owing to CSC exposure. The CSC from the 3R4F Kentucky reference (3R4F) cigarette produced the most severe mutagenic and genotoxic potencies, followed by the CSC from the TL cigarette, whereas the CSC from the TW cigarette produced the least severe mutagenic and genotoxic potencies. CONCLUSIONS: The results of this study suggest that the mutagenic and genotoxic potencies of the TL and TW cigarettes were weaker than those of the 3R4F cigarette. Further study on standardized concepts of toxic equivalents for cigarettes needs to be conducted for more extensive use of in vitro tests.
Benchmarking ; Carcinogenesis ; Comet Assay ; DNA Damage ; In Vitro Techniques ; Kentucky ; Methods ; Micronucleus Tests ; Nicotine ; Particulate Matter ; Salmonella typhimurium ; Smoke* ; Smoking ; Tobacco Products*

OBJECTIVES: Cigarette smoking is associated with carcinogenesis owing to the mutagenic and genotoxic effects of cigarette smoke. The aim of this study was to evaluate the mutagenic and genotoxic effects of Korean cigarettes using in vitro assays. METHODS: We selected 2 types of cigarettes (TL and TW) as benchmark Korean cigarettes for this study, because they represent the greatest level of nicotine and tar contents among Korean cigarettes. Mutagenic potency was expressed as the number of revertants per μg of cigarette smoke condensate (CSC) total particulate matter whereas genotoxic potency was expressed as a concentration-dependent induction factor. The CSC was prepared by the International Organization for Standardization 3308 smoking method. CHO-K1 cells were used in vitro micronucleus (MNvit) and comet assays. Two strains of Salmonella typhimurium (Salmonella enterica subsp.enterica; TA98 and TA1537) were employed in Ames tests. RESULTS: All CSCs showed mutagenicity in the TA98 and TA1537 strains. In addition, DNA damage and micronuclei formation were observed in the comet and MNvit assays owing to CSC exposure. The CSC from the 3R4F Kentucky reference (3R4F) cigarette produced the most severe mutagenic and genotoxic potencies, followed by the CSC from the TL cigarette, whereas the CSC from the TW cigarette produced the least severe mutagenic and genotoxic potencies. CONCLUSIONS: The results of this study suggest that the mutagenic and genotoxic potencies of the TL and TW cigarettes were weaker than those of the 3R4F cigarette. Further study on standardized concepts of toxic equivalents for cigarettes needs to be conducted for more extensive use of in vitro tests.
Benchmarking ; Carcinogenesis ; Comet Assay ; DNA Damage ; In Vitro Techniques ; Kentucky ; Methods ; Micronucleus Tests ; Nicotine ; Particulate Matter ; Salmonella typhimurium ; Smoke* ; Smoking ; Tobacco Products*

In recent decades, titanium dioxide (TiO2) nanoparticles have been used in various applications, including paints, coatings, and food. However, data are lacking on the toxicological aspects associated with their use. The aim of this study was to assess the inhalation toxicity of TiO2 nanoparticles in rats by using inhalation exposure. Male Wistar rats were exposed to TiO2 nanoparticles for 2 weeks (6 hr/day, 5 days/week) at a mean mass concentration of 11.39 +/- 0.31 mg/m3. We performed time-course necropsies at 1, 7, and 15 days after exposure. Lung inflammation and injury were assessed on the basis of the total and individual cell counts in bronchoalveolar lavage fluid (BALF), and by biochemical assays, including an assay for lactate dehydrogenase (LDH). Furthermore, histopathological examination was performed to investigate the lungs and nasal cavity of rats. There were no statistically significant changes in the number of BALF cells, results of biochemical assays of BALF and serum, and results of cytokine analysis. However, we did observe histopathological changes in the nasal cavity tissue. Lesions were observed at post-exposure days 1 and 7, which resolved at post-exposure day 15. We also calculated the actual amounts of TiO2 nanoparticles inhaled by the rats. The results showed that the degree of toxicity induced by TiO2 nanoparticles correlated with the delivered quantities. In particular, exposure to small particles with a size of approximately 20 nm resulted in toxicity, even if the total particle number was relatively low.
Animals ; Bronchoalveolar Lavage Fluid ; Cell Count ; Humans ; Inhalation ; Inhalation Exposure ; L-Lactate Dehydrogenase ; Lung ; Male ; Nanoparticles ; Nasal Cavity ; Paint ; Pneumonia ; Rats ; Rats, Wistar ; Titanium

Cigarette smoke is a major risk factor for several diseases, including chronic obstructive pulmonary and cardiovascular diseases. The toxicity of the cigarette smoke can be determined in vitro. The cytotoxicity test of the cigarette smoke is commonly conducted using the cigarette smoke condensate (CSC) and cigarette smoke extract (CSE). The CSC and CSE methods are well known for sampling of the particles and water-soluble compounds in the cigarette smoke, respectively. In this study, the CSC and CSE were analyzed by using a gas chromatography-mass spectrometry (GC-MS) system equipped with a wax column for separation of the volatile organic compounds. The cytotoxic effect of the CSC and CSE were evaluated thoroughly by comparing the analytical results of the CSC and CSE samples. The total concentration of the volatile organic compounds detected in the CSC sample was similar to that in the CSE sample based on the peak area. Except for the dimethyl sulfoxide solvent, nicotine had the highest concentration in the CSC sample, while acetonitrile had the highest concentration in the CSE sample. The compositions were as follows: (1) CSC sample: 55.8% nicotine, 18.0% nicotyrine, 3.20% 1,2,3-propanetriol, triacetate, 1.28% ethyl chloride, 1.22% phenol, etc. and (2) CSE sample: 18.7% acetonitrile, 18.0% acetone, 12.5% 2-hydroxy-2-methyl-propanenitrile, 8.98% nicotine, 5.86% nicotyrine, etc. In this manner, to accurately examine the cytotoxicity of the cigarette smoke using CSC or CSE, the components and their concentrations in the CSC and CSE samples should be considered.
Acetone ; Cardiovascular Diseases ; Dimethyl Sulfoxide ; Ethyl Chloride ; Gas Chromatography-Mass Spectrometry ; In Vitro Techniques ; Nicotine ; Phenol ; Risk Factors ; Smoke ; Tobacco Products ; Volatile Organic Compounds

Cigarette smoke is a major risk factor for several diseases, including chronic obstructive pulmonary and cardiovascular diseases. The toxicity of the cigarette smoke can be determined in vitro. The cytotoxicity test of the cigarette smoke is commonly conducted using the cigarette smoke condensate (CSC) and cigarette smoke extract (CSE). The CSC and CSE methods are well known for sampling of the particles and water-soluble compounds in the cigarette smoke, respectively. In this study, the CSC and CSE were analyzed by using a gas chromatography-mass spectrometry (GC-MS) system equipped with a wax column for separation of the volatile organic compounds. The cytotoxic effect of the CSC and CSE were evaluated thoroughly by comparing the analytical results of the CSC and CSE samples. The total concentration of the volatile organic compounds detected in the CSC sample was similar to that in the CSE sample based on the peak area. Except for the dimethyl sulfoxide solvent, nicotine had the highest concentration in the CSC sample, while acetonitrile had the highest concentration in the CSE sample. The compositions were as follows: (1) CSC sample: 55.8% nicotine, 18.0% nicotyrine, 3.20% 1,2,3-propanetriol, triacetate, 1.28% ethyl chloride, 1.22% phenol, etc. and (2) CSE sample: 18.7% acetonitrile, 18.0% acetone, 12.5% 2-hydroxy-2-methyl-propanenitrile, 8.98% nicotine, 5.86% nicotyrine, etc. In this manner, to accurately examine the cytotoxicity of the cigarette smoke using CSC or CSE, the components and their concentrations in the CSC and CSE samples should be considered.
Acetone ; Cardiovascular Diseases ; Dimethyl Sulfoxide ; Ethyl Chloride ; Gas Chromatography-Mass Spectrometry ; In Vitro Techniques ; Nicotine ; Phenol ; Risk Factors ; Smoke* ; Tobacco Products* ; Volatile Organic Compounds*

Background: The study examined the prevalence of suicidal ideation and suicide attempts among registrants of public community healthcare centers and compared between the characteristics of mental and general healthcare center (GHC) registrants. Methods: The study measured lifetime suicidal behaviors, psychosocial variables, psychiatric comorbidities, and suicide related factors. Results: A total of 132 (73.7%) and 126 (42.3%) mental and GHC registrants, respectively, reported a history of suicidal ideation; whereas 64 (35.8%) and 29 (9.7%) of mental and GHC registrants, respectively, reported a history of suicidal attempts. Scores of the Beck Depression Inventory (BDI) for both suicidal ideation groups were above the severe level, although only 2% of GHC group recognized their diagnoses of depressive disorders. Conclusion The study observed high suicidal risk among the mental and GHC registrants. High BDI scores and unevaluated depression under score the need for screening and provision of appropriate early interventions in public community healthcare centers.

The incidence rate of lung cancer is continually increasing, and lung cancer is the leading cause of cancer-related death worldwide. Nevertheless, few therapeutic methods are available for lung cancer. Therefore, establishing appropriate lung cancer animal models is important to investigate mechanisms and to evaluate new drugs for lung cancer. In the present study, we transplanted non-small cell lung cancer A549 human adenocarcinoma cells (2x10(4), 2.0x10(5), and 2.0x10(6) cells) into the right lobe of BALB/c nude mice via the intercostal space to develop an orthotopic lung cancer animal model that is minimally invasive and similar to human lung cancer. We then investigated the incidence rate and severity of lung cancer according to the A549 cell number (2x10(4), 2.0x10(5), and 2.0x10(6) cells) and transplantation periods (4~23 days). Lung cancer development was confirmed with gross examination, which was supported by histopathological examination. These results indicate that the incidence rate and severity of lung cancer was increased depending on the number of transplanted cells and transplantation period which the cell number and duration are increasing risk of lung cancer. Thus, this study can provide appropriate reference data to develop an orthotopic lung cancer animal model using the non-small cell lung cancer A549 cell line for researching mechanisms and evaluating candidate drugs, including various approaches for treating lung cancer.
Adenocarcinoma ; Animals ; Carcinoma, Non-Small-Cell Lung ; Cell Count ; Cell Line ; Humans ; Incidence ; Lung ; Lung Neoplasms ; Mice ; Mice, Nude ; Models, Animal ; Transplants