The effect of flavor content in e-liquids on e-cigarette emissions of carbonyl compounds

Qu, Yao,Kim, Ki-Hyun,Szulejko, Jan E. Elsevier 2018 Environmental research Vol.166 No.-

<P><B>Abstract</B></P> <P> <B>T</B>he effect of flavors on carbonyl compound (CC) emission factors (EF) from electronic cigarettes (ECs) vaping was investigated at the default vaping (voltage) setting in all experiments using a total of 21 lab-made e-liquid samples (five different types of retail flavorant bases: beverage/dessert/fruit/mint/tobacco). Each flavorant base was added to a separate unflavored base composed of a 1:1 mixture of propylene glycol/vegetable glycerol (PG/VG) at four levels (5/10/30/50% (v/v)). The e-liquid CC levels increased linearly with flavorant base content, 1.3–10.5 times (R<SUP>2</SUP>: 0.762–0.999). The vaping CC EFs increased linearly with flavorant base content (if ≥ 10%) from 1.0 to 92 times (R<SUP>2</SUP>: 0.431–0.998). For flavorant base content of 0%, 5%, and 10%, the EFs ranged from undetected to 0.11 μg puff<SUP>−1</SUP> (acetone). The 40-year cancer risk due to formaldehyde (70 kg EC user inhaling 5% flavorant base content e-liquid: 120 puffs day<SUP>−1</SUP>) is estimated to be 2.0E-06 (highest) compared to 1.0E-06 for the 1:1 PG:VG base. Most formaldehyde vaped from the fruit flavored e-liquid was the flavorant base. The CC concentrations in EC liquids (before vaping) were approximately linear with e-liquid flavorant base content. Retail e-liquid product information labels should be guided to provide a complete list of all ingredients, their concentrations, and carbonyl compound EFs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electronic cigarettes (e-cigarettes or ECs) are designed to deliver nicotine to a smoker. </LI> <LI> The flavorings in e-liquids were considered safe but raised concerns due to potential toxicity. </LI> <LI> In this study, we investigated the effects of flavor content on CC emissions from EC vaping. </LI> <LI> The CC amounts (before/during vaping) was estimated from the flavor content in the e-liquid. </LI> <LI> The effects of flavor content in e-liquids on vaping CC emissions warrant attention. </LI> </UL> </P>

The effect of varying battery voltage output on the emission rate of carbonyls released from e-cigarette smoke

Qu, Yao,Szulejko, Jan E.,Kim, Ki-Hyun,Jo, Sang-Hee Elsevier 2019 Microchemical journal Vol.145 No.-

<P><B>Abstract</B></P> <P>The effect of vaping voltage (range: 3.6 to 7.0 V) on the emission of carbonyl compounds (CC) from electronic cigarettes (ECs) was investigated in this study. Changes in the CC levels were compared between prior to (e–liquid samples) and after vaping (EC-aerosol samples) using a total of six different e-liquid samples. Three of them were lab-made binary e-liquid solutions (composed only of propylene glycol (PG) and vegetable glycerin (VG) at the following 3 mixing ratios: 7:3, 5:5, and 10:0), while the remaining three were retail e-liquid products. The CCs in aerosol samples were captured from 10 EC puffs on 2,4-dinitrophenylhydrazine (DNPH) cartridges (2 s puff duration with a 10 s interpuff interval). All six e-liquids analyzed prior to EC use contained formaldehyde (FA) and acetaldehyde (AA) in the range of 0.12–50.0 and 0.53–14.9 μg mL<SUP>−1</SUP>, respectively. As the vaping voltage increased from 3.6 to 7.0 V, their emission factors increased from 1.12 to 1.64 and from 1.30 to 2.02 (μg puff<SUP>−1</SUP>), respectively. Such patterns were also observed for other CCs. The 40-year cancer risk (CR) of FA and CA for a typical user (120 puffs day<SUP>−1</SUP>) was estimated to be 7.0 × 10<SUP>−4</SUP>–1.1 × 10<SUP>−3</SUP> and 3.2 × 10<SUP>−5</SUP>–1.4 × 10<SUP>−4</SUP>, respectively; these CR values increased by 1.2 and 1.7–2.0 times, respectively with an increase in vaping voltage (3.6–7.0 V). The CR due to FA exposure from the three tested retail e-liquids was estimated to be 2.6–56 times higher than that of traditional tobacco cigarettes. Therefore, the use of ECs may expose users to high levels of certain CCs (like FA and AA), which may increase the risk for cancer in humans.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electronic cigarettes (e-cigarettes or ECs) are widely used around the world. </LI> <LI> Use of EC releases infamous pollutants (e.g., carbonyl compounds (CCs) - formaldehyde (FA)). </LI> <LI> A heating element is activated to vaporize the e-liquid to release various CCs like FA. </LI> <LI> Here, the effect of EC vaping voltage was investigated with regard to CC emission factors. </LI> <LI> Accordingly, we quantified CCs in two different phases (EC liquid vs. aerosolized samples). </LI> </UL> </P>

Insecticide susceptibility of Ephemera orientalis (Ephemeroptera: Ephemeridae) and two mosquito species, Anopheles sinensis and Culex pipiens in the Republic of Korea

E-Hyun Shin,Chan PARK,김현경,이동규,Soon-Il Kim,Hyesook KANG,Kyu-Sik Chang 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.3

Field-collected populations of mayflies, Ephemera orientalis were tested for susceptibility to 10 different insecticides using a direct-contact mortality bioassay. Ephemera orientalis subimagoes were susceptible to the insecticides chlorpyrifos, fenitrothion and chlorfenapyr with LD_50 values of 69.7, 78.8 and 81.9 μg/♀, and adults had LD_50 values of 71.9, 78.8 and 85.4 μg/♀, respectively. Susceptibility ratios (SRs) of subimagoes and adults of E. orientalis to the 10 insecticides were 1.0 to1.2 folds. The mayflies showed higher susceptibility to organophosphates than to pyrethroids. The SRs of Anopheles sinensis to E. orientalis were 514 to 1438 folds higher for organophosphates (LD_50 values of 0.05 to 0.23 μg/♀) and 62 to 1155 folds higher for pyrethroids (LD_50 values of 0.13 to 2.41 μg/♀). The SRs of Culex pipiens to E. orientalis were 606 to 3595 folds higher for organophosphates with LD_50 values of 0.02–0.17 μg/♀ and 81 to 1365 folds higher for pyrethroids with LD_50values of 0.11–1.83 μg/♀. These results indicate that the use of ineffective insecticides will result in unsatisfactory control against field populations of the subimagoes and adults of E. orientalis.

Association of Extracellular Cleavage of E-Cadherin Mediated by MMP-7 with HGF-Induced in vitro Invasion in Human Stomach Cancer Cells

Lee, K.H.,Choi, E.Y.,Hyun, M.S.,Jang, B.I.,Kim, T.N.,Kim, S.W.,Song, S.K.,Kim, J.H.,Kim, J.-R. S. Karger AG 2007 European surgical research Vol.39 No.4

<P><I>Background:</I> Proteolytic shedding of the ectodomain of a variety of transmembrane proteins, including cell-to-cell adhesion molecules, has been observed in solid cancers. We have investigated whether extracellular cleavage of E-cadherin mediated by matrix metalloproteinase-7 (MMP-7) is involved in hepatocyte growth factor (HGF) induced in vitro invasion in stomach cancer cells. <I>Methods:</I> The effects of HGF on the expression of E-cadherin/β-catenin and MMP-7 at both the protein and mRNA levels were assessed in stomach cancer cells, NUGC-3 and MKN-28, and in cells in which the expression of MMP-7 was downregulated by transfection with a MMP-7 short hairpin RNA plasmid. <I>Results:</I> Treatment with HGF increased the extracellular cleavage of E-cadherin and the release of MMP-7 and reduced the level of E-cadherin in a dose- and time-dependent manner. HGF treatment repressed the phosphorylation of β-catenin in a Triton-soluble fraction, but enhanced this phosphorylation in a Triton-insoluble fraction. The association of E-cadherin with β-catenin was decreased by HGF treatment in the Triton-soluble fraction. In addition, treatment of MMP-7 short hairpin RNA transfected NUGC-3 cells with HGF resulted in no extracellular cleavage of E-cadherin and also decreased the in vitro cell invasion. <I>Conclusions:</I> These results suggest that incubation with HGF mediated the release of MMP-7, resulting in extracellular cleavage of E-cadherin from stomach cancer cells. This might be a key mechanism in HGF-induced in vitro invasion and metastasis.</P><P>Copyright © 2007 S. Karger AG, Basel</P>

韓國産 槍線蟲 上科의 分類學的 硏究

Young Eoun CHOI,E. GERAERT,Hyun Sil BAEK 한국응용곤충학회 1997 한국응용곤충학회지 Vol.36 No.1

한국산 창선충상과 연구 결과로, Dorylaimidae, Aporcelaimidae, Qudsianematidae, Nordiidae등 4과에서 Dorylaimus, Laimydorus, Mesodorylaimus, Sectollema, Labrollema, Eudorylaimus, Ecumellicus, Discolaimus, Ellchodelus, Oriverutus의 10속에 속하는 Dorylaimus stagllalis, Laimydorus siddiqi, Mesodorylaimus IIsitatlls, Sectollema basilgoodeyi, Labrollema hyalillum, L. lIepalellse, L. vulvapapillatum, Elidorylaimlis carteri, E. pseudocarteri, Ecumenicus monhystera, Discolaimus major, Enchodelus Longidens, E. Itopedorlls, E. macrodorlls, Oriverutlls pagarus등 15종의 한국 미기록종을 발표한다. A study on the Dorylaimoidea from Korea yielded the following fifteen species belonging to 10 different genera, Dorylaimus stagnalis, Laimydorus siddiqi, Mesodorylaimus usitatus, Sectonema basilgoodeyi, Labronema hyalinum, L. nepalense, L. vulvapapillatum, Eudorylaimus carteri, E. pseudocarteri, Ecumenicus monhystera, Discolaimus major, Enchodelus longidens, E. hopedorus, E. macrodorus, Oriverutus pagarus. They represent four families: Dorylaimidae, Aporcelaimidae, Qudsianematidae, Nordiidae.

Insecticide susceptibility of Ephemera orientalis (Ephemeroptera: Ephemeridae) and two mosquito species, Anopheles sinensis and Culex pipiens in the Republic of Korea

Kyu-sik Chang,Chan Park,Hyun kyung Kim,E-Hyun Shin 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

Field-collected populations of mayflies, Ephemera orientalis were tested for susceptibility to 10 different insecticides using a direct-contact mortality bioassay. Ephemera orientalis subimagoes were susceptible to the insecticides chlorpyrifos, fenitrothion and chlorfenapyr with LD50 values of 69.7, 78.8 and 81.9μg/♀, and adults had LD50 values of 71.9, 78.8 and 85.4μg/♀, respectively. Susceptibility ratios(SRs) of subimagoes and adults of E. orientalis to the 10 insecticides were 1.0 to1.2 folds. The mayflies showed higher susceptibility to organophosphates than to pyrethroids. The SRs of Anopheles sinensis to E. orientalis were 514 to 1,438 fold higher for organophosphates (LD50 values of 0.05 to 0.23μg/♀) and 62 to 1,155 fold higher forpyrethroids (LD50 values of 0.13 to 2.41μg/♀). The SRs of Culex pipiens to E. orientalis were 606 to 3,595 fold higher for organophosphates with LD50 values of 0.02-0.17μg/♀ and 81 to 1,365 fold higher for pyrethroids with LD50 values of 0.11- 1.83μg/♀. These results indicate that the use of ineffective insecticides will result in unsatisfactory control against field populations of the subimagoes and adults of E. orientalis. This work was supported by a research grant from the National Vector Control and Surveillance work performed by the Korean National Institute of Health.

Prediction of Growth of Escherichia coli O157 : H7 in Lettuce Treated with Alkaline Electrolyzed Water at Different Temperatures

Tian Ding,Yong-Guo Jin,S. M. E. Rahman,Jai-Moung Kim,Kang-Hyun Choi,Gye-Sun Choi,오덕환 한국식품위생안전성학회 2009 한국식품위생안전성학회지 Vol.24 No.3

This study was conducted to develop a model for describing the effect of storage temperature (4, 10, 15, 20, 25, 30 and 35oC) on the growth of Escherichia coli O157 : H7 in ready-to-eat (RTE) lettuce treated with or without (control) alkaline electrolyzed water (AIEW). The growth curves were well fitted with the Gompertz equation, which was used to determine the specific growth rate (SGR) and lag time (LT) of E. coli O157 : H7 (R2 = 0.994). Results showed that the obtained SGR and LT were dependent on the storage temperature. The growth rate increased with increasing temperature from 4 to 35oC. The square root models were used to evaluate the effect of storage temperature on the growth of E. coli O157 : H7 in lettuce samples treated without or with AIEW. The coefficient of determination (R2), adjusted determination coefficient (R2 Adj), and mean square error (MSE) were employed to validate the established models. It showed that R2 and R2 Adj were close to 1 (> 0.93), and MSE calculated from models of untreated and treated lettuce were 0.031 and 0.025, respectively. The results demonstrated that the overall predictions of the growth of E. coli O157 : H7 agreed with the observed data. This study was conducted to develop a model for describing the effect of storage temperature (4, 10, 15, 20, 25, 30 and 35oC) on the growth of Escherichia coli O157 : H7 in ready-to-eat (RTE) lettuce treated with or without (control) alkaline electrolyzed water (AIEW). The growth curves were well fitted with the Gompertz equation, which was used to determine the specific growth rate (SGR) and lag time (LT) of E. coli O157 : H7 (R2 = 0.994). Results showed that the obtained SGR and LT were dependent on the storage temperature. The growth rate increased with increasing temperature from 4 to 35oC. The square root models were used to evaluate the effect of storage temperature on the growth of E. coli O157 : H7 in lettuce samples treated without or with AIEW. The coefficient of determination (R2), adjusted determination coefficient (R2 Adj), and mean square error (MSE) were employed to validate the established models. It showed that R2 and R2 Adj were close to 1 (> 0.93), and MSE calculated from models of untreated and treated lettuce were 0.031 and 0.025, respectively. The results demonstrated that the overall predictions of the growth of E. coli O157 : H7 agreed with the observed data.

Screening of Lactobacilli Derived from Fermented Foods and Partial Characterization of Lactobacillus casei OSY-LB6A for Its Antibacterial Activity against Foodborne Pathogens

Hyun-Jung Chung,Ahmed E. Yousef 한국식품영양과학회 2009 Preventive Nutrition and Food Science Vol.14 No.2

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at 60~100℃ for 10~20 min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

Screening of Lactobacilli Derived from Fermented Foods and Partial Characterization of Lactobacillus casei OSY-LB6A for Its Antibacterial Activity against Foodborne Pathogens

Chung, Hyun-Jung,Yousef, Ahmed E. The Korean Society of Food Science and Nutrition 2009 Preventive Nutrition and Food Science Vol.14 No.2

Various fermented foods were screened in search of food-grade bacteria that produce bacteriocins active against Gram-negative pathogens. An isolate from a mold-ripened cheese presented antibacterial activity against Gram-positive and Gram-negative bacteria. The most active isolate was identified as Lactobacillus casei by a biochemical method, ribotyping, and membrane lipid analysis, and was designated as OSY-LB6A. The cell extracts of the isolate showed inhibition against Escherichia coli p220, E. coli O157, Salmonella enerica serovar Enteritidis, Salmonella Typhimurium, and Listeria monocytogenes. The antibacterial nature of the cell extract from the isolate was confirmed by eliminating the inhibitory effects of acid, hydrogen peroxide, and lytic bacteriophages. The culture supernatant and cell extract retained antibacterial activity after heating at $60{\sim}100^{\circ}C$ for $10{\sim}20$ min. The activity of the cell extract from Lb. casei was eliminated by pronase and lipase. Finally, the cell extract showed a bactericidal mode of action against E. coli in phosphate buffer solution, but it was bacteriostatic in broth medium and food extracts.

Conjugated Linoleic Acid Reduction of Vascular Endothelial Growth Factor Expression in Murine Mammary Tumor Cells through Alteration of Prostaglandin E₂

Jung-Hyun Kim,Neil E. Hubbard,Debora Lim,Kent L. Erickson 한국식품영양과학회 2006 Preventive Nutrition and Food Science Vol.11 No.1

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid that have been used to reduce the incidence, growth and metastasis of breast, colon, prostate and gastric cancer in animals. CLA could reduce tumor growth by altering angiogenesis; a process requiring associated angiogenic factors such as vascular endothelial growth factor (VEGF). In this study, we determined whether CLA could modulate the expression of VEGF in murine mammary tumor cells and adipocytes. The c9, t11-CLA isomer reduced VEGF transcripts and protein when mammary tumor cells were stimulated with PMA. That isomer also reduced VEGF expression in unstimulated mouse 3T3-L1 adipocytes. Since VEGF can be regulated by cyclooxygenase-2 (COX-2), we determined whether CLA could alter COX-2 enzyme expression and PGE₂ production. The c9, t11-CLA isomer reduced not only COX-2 enzyme expression but also PGE₂ production. Thus, c9, t11-CLA could modulate neovascularization by alteration of VEGF expression from mammary tumor cells and adipocytes by reducing COX-2 metabolites.