• Korean Journal of Environmental Biology
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• v.42 no.3
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• pp.332-344
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• 2024

Phosphine (PH₃) fumigation has been widely used for controlling storedgrain insect pests, causing the development of resistance of stored-grain insect pests to phosphine. PH₃ resistance in Sitophilus oryzae has been reported in Korea. However, PH₃ resistance in Tribolium castaneum has not been reported yet. This study was conducted to determine susceptibilities of T. castaneum collected from five different domestic locations to PH₃. The susceptibility to PH₃ was investigated using the FAO fumigation method. All domestic T. castaneum individuals were controlled by PH₃ at 0.04 g m^-3 . At 0.01 g m^-3, T. castaneum collected from two domestic locations did not exhibit 100% mortality. A P45S point mutation in dihydrolipoamide dehydrogenase (dld) gene was found in a PH₃-resistant strain of T. castaneum (Aus07), but not in five domestic stains or a PH₃-susceptible strain (Aus10). No significant difference was found in dld or cyt-b5-r gene expression across all tested strains. However, the Gyeongju-collected strain of T. castaneum showed more than a 1.7-fold increase in cyt-b5-r expression compared to the Aus07 strain. cDNA sequence analysis revealed that P45S (C133T) in the dld gene was only present in Aus07. A characteristic single nucleotide polymorphism in the cyt-b5-r gene sequence was identified in the five domestic strains. This study suggests that it is necessary to continuously monitor PH₃-susceptibility of T. castaneum in Korea to quickly identify resistant individuals and prevent the spread of PH₃ resistance through rapid control.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.385-392
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• 2006

Paclitaxel is an important chemotherapeutic agent for the treatment of human solid tumors. Multicellular resistance(MCR) is considered to be a major mechanism of resistance of human solid tumors to chemotherapeutic agent such as paclitaxel, which includes barriers to drug penetration through tumor tissues. Multicellular layers(MCL) cultures resemble in vivo tumor condition in terms of MCR and has been used successfully to produce clinically relevant data. In the present study, we evaluated the penetration characteristics and post-penetration anti-proliferative activity of paclitaxel using MCL of human colorectal cancer cells(DLD-1 and HT-29) grown in Transwell inserts. The penetration of $[^{14}C]-paclitaxel$ was slower than that of mannitol which penetrates via paracellular pathway in DLD-1 MCL. The penetration of $[^{14}C]-paclitaxel$ was faster in HT-29 MCL compared to DLD-1 MCL, i.e., at 10 ${\mu}M$ 100% and 40% penetration were observed after 48 hr incubation for HT-29 and DLD-1 cells, respectively. When calculated using anti-proliferative activity in the conditioned media of bottom chamber, the penetration after 24 hr was very limited(less than 50%) and concentration-dependent at the concentrations tested in both MCL's. These results suggest that limited and differential penetration of paclitaxel in tumor tissues may contribute to lower and differential efficacy against human solid tumors.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.889-895
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• 2006

Cytotoxic effects of extracts from Tremella fuciformis strain FB001 were evaluated on the DLD-1 human colon adenocarcinoma cell line and the content of polyphenolic compounds in the extracts were analyzed. Hexane, chloroform, and ethyl acetate subfractions (experimental setting I) exhibited cytotoxic effects on the human colon adenocarcinoma DLD-1 cell line with $IC_{50}$ values of 350, 400, and 450 ppm, respectively. When T. fuciformis was extracted sequentially with ether, ethyl acetate, chloroform, and ethanol (experimental setting II), the ether extract demonstrated potent cytotoxicity with an $IC_{50}$ value of 150 ppm, followed by ethyl acetate and chloroform fractions. If the first extraction solvent was chloroform instead of ether (experimental setting III), exposure of the cell line to chloroform, ethyl acetate, and ether extracts at 1,000 ppm led to cell death. High levels of phenolic compounds were estimated for all hydrophobic extracts, which exhibited cytotoxic effects. We propose that this useful information gives additional support to our understanding of the biology and utility of this particular mushroom.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.10 no.1
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• pp.64-75
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• 1999

Objective：The purpose of this study was to investigate the prevalence and characteristics of comorbid disorders and associated symptoms in pervasive developmental disorder(PDD) and to examine the correlation between associated symptoms and developmental characteristics in PDD children. Method：The sample consisted of 209 cases of PDD and 143 cases of developmental language disorder(DLD)(control group) who were treated at the Seoul National Mental Hospital from Jan. 1996 to Mar. 1999. The diagnostic work based on DSM-IV criteria was performed by one or two child psychiatrists, while the clinical feature was evaluated by doctors’s notes, occupational/speech therapy reports, and results of social maturity scale(SMS), childhood autism rating scale(CARS), and psycho-educational profile(PEP). Two groups were compared on a wide range of measures including comorbid disorders, associated symptoms, treatment drugs, and PEP. The relation between associated symptom & PEP was investigated in total(106 cases) and in each dignostic group. Sixty-four cases of PDD were divided into three groups by CARS and then compared on associated symptoms. Result：The prevalence of comorbid disorder was 19.6% in PDD, 41.2% in DLD. The rate of manifestation of 13 associated symptoms was 31.47% in PDD, 22.13% in DLD on the average. Associated symptoms significantly high in PDD were preoccupation, obsession, self-mutilation, stereotypy, sleep problems, and odd response. In total patient group, associated symptoms that significantly influenced PEP were preoccupation, self-stimulation, stereotypy, inappropriate affect, sleep problems, and odd response. But, in each diagnostic group, no associated symptom influenced PEP. Associated symptoms significantly different between the 3 groups of CARS were stereotypy, anxiety, and sleep problems. Conclusion：These preliminary results suggest that developmental characteristics may influence associated symptoms in PDD children and a realistic approach considering minute diagnosis by associated symptoms and comorbid disorders is required.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.857-862
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• 2005

This study investigated the proliferation and DNA synthesis inhibitory effect of concentrations ($0.01\%$, $0.1\%$, $0.25\%$, $0.5\%$) when added whole molecular-, 40 kDa-, or 10 kDa polymannuronate on human colon cancer cells, HT-29, DLD-1, and WiDr, in vitro. In order to determine the proliferation inhibitory effect of low-molecularized polymannuronate, the treatment of whole molecular-, 40 kDa-, 10 kDa-, polymannuronate ($0.25\%$) to the HT-29 cancer cells inhibited proliferation of cancer cells by $41\%$, $69.1\%$, and $75.6\%$, respectively. DLD-1 cancer cell was not relation of molecular weight and concentration. WiDr cancer cell depend on concentration without molecular weight. In addition, whole molecular-, 40 kDa-, 10 kDa poly mannuronate ($0.25\%$) significantly inhibited DNA synthesis of HT-29 cancer .cells by $78\%$, $58\%$, and $56\%$, respectively. And morphological changes not found under microscope by polymannuronate. Therefore polymannuronate would be helpful to colon cancer treatment as well as cancer prevention and this study would be the basic source for further research of polymannuronate.

• Journal of Pharmaceutical Investigation
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• v.36 no.5
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• pp.309-314
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• 2006

The multicellular layers(MCL) of human cancer cells is a three dimensional(3D) in vitro model for human solid tumors which has been used primarily for the assessment of avascular penetration of anti-cancer drugs. For anti-cancer drugs with penetration problem, MCL represents a good experimental model that can provide clinically relevant data. Calcein-AM is a fluorescent dye that demonstrates the cellular vitality in a graded manner in cancer cell culture system. In the present study, we evaluated the use of calcein-AM for determination of anti-proliferative activity of anti-cancer agents in MCL model of DLD-1 human colorectal cancer cells. Optical sectioning of confocal imaging was compromised with photonic attenuation and penetration barrier in the deep layers of MCL. By contrast, fluorescent measurement on the cryo-sections provided a feasible alternative. Cold pre-incubation did not enhance the calcein-AM distribution to a significant degree in MCL of DLD-1 cells. However, the simultaneous determination of drug penetration and cellular vitality appeared to be possible in drug treated MCL. In conclusion, these data suggest that calcein-AM can be used for the simultaneous determination of drug-induced anti-proliferative effect and drug penetration in MCL model.

• Journal of Pharmaceutical Investigation
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• v.36 no.1
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• pp.1-9
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• 2006

Human solid tumors exhibit a multicellular resistance (MCR) resulting from limited drug penetration and decreased sensitivity of tumor cells when interacting with their microenvironments. Multicellular cultures represent solid tumor condition in vivo and provide clinically relevant data. There is little data on antitumor effect of paclitaxel (PTX) in multicellular cultures although its MCR has been demonstrated. In the present study, we evaluated antiproliferative effects of PTX in multicellular layers (MCL) of DLD-1 human colorectal carcinoma cells. BrdU labeling index (LI), thickness of MCL, cell cycle distribution and cellular uptake of calcein were measured before and after exposure to PTX at 0.1 to 50 ${\mu}M$ for 24, 48 and 72 hrs. BrdU LI and thickness of MCL showed a concentration- and time-dependent decrease and the changes in both parameters were similar, i.e., 34.2% and 40.6% decrease in BrdU LI and thickness, respectively, when exposed to $50\;{\mu}M$ for 72 hr. The DLD-1 cells grown in MCL showed increase in $%G_{0}/G_{1}$ and resistance to cell cycle arrest and apoptosis compared to monolayers. Calcein uptake in MCL did not change upon PTX exposure, indicating technical problems in multicellular system. Overall, these data indicate that antitumor activity of PTX may be limited in human solid tumors (a multicellular system) and MCL may be an appropriate model to study further pharmacodynamics of PTX.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.105-115
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• 2012

In this paper, we propose a correction method using phoneme unit segmentation to solve misrecognition of Korean Texts in signboard images using weighted Disassemble Levenshtein Distance. The proposed method calculates distances of recognized texts which are segmented into phoneme units and detects the best matched texts from signboard text database. For verifying the efficiency of the proposed method, a database dictionary is built using 1.3 million words of nationwide signboard through removing duplicated words. We compared the proposed method to Levenshtein Distance and Disassemble Levenshtein Distance which are common representative text string comparison algorithms. As a result, the proposed method based on weighted Disassemble Levenshtein Distance represents an improvement in recognition rates 29.85% and 6% on average compared to that of conventional methods, respectively.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.691-696
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• 2002

Doxorubicin (DOX) is an active and broad spectrum chemotherapeutic agent. Increased inducible nitric oxide synthase (NOS) expression and/or activity have been reported in several human tumors. While the relationship between DOX treatment and the enzymatic activity of endothelial NOS has been well characterized, little is known about the effects of DOX on the expression of iNOS in human cancer cells. In the present study, we characterized the effects of DOX on the nitric oxide (NO) production by colorectal cancer cells, DLD-1. IFN-${\gamma}$/IL-1$\beta$ (CM) increased the production of NO, whereas pretreatment of DOX inhibited the production of NO in response to CM in a dose dependent manner. The increased expressions of iNOS mRNA and protein by CM were completely blocked by DOX without affecting the iNOS mRNA stability. However, DOX activated nuclear factor-kB (NF-kB) in response to CM. Furthermore, the expression of inhibitor kB$\alpha$ was reduced by DOX in a dose dependent manner. Collectively, DOX inhibited the production of NO by DLD-1 cells, which is not linked to well known transcription factor, NF-kB. Therefore, further studies on the possible mechanisms of inhibitory effects of NO production by DOX would be worth pursuing.

• YAKHAK HOEJI
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• v.49 no.6
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• pp.511-517
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• 2005

Low sensitivity to anticancer drugs such as 5-fluorouracil (5-FU) has been associated with decreased expression of genes involved in cell proliferation, apoptosis and metastasis. Recently, it has been shown that the expression levels of some of these genes are reduced by transcription inhibition due to epigenetic silencing on CpG islands. Therefore, epigenetic therapy has been proposed, where epigenetic silencing is repressed with DNA methyltransferase (DNMT) inhibitors and histone deacetylase (HDAC) inhibitors alone or in combination with other chemotherapeutic agents. The aim of our study was to evaluate the combination effect of 5-FU and its association with the status of epigenetic silencing using methylation-specific PCR of $p14^{ARF}$ when given with S-aza-2'-deoxycytidine (5-aza-dC), a DNMT inhibitor and depsipeptide, an HDAC inhibitor in DLD-1 human colorectal cancer cells. The combination of 5-aza-dC with depsipeptide showed a synergism and induced unmethylation of $p14^{ARF}$. However, triplet combination of 5-aza-dc/depsipeptide and 5-FU resulted in antagonistic effects and abrogated unmethylation of $p14^{ARF}$. These results suggest that unfavorable interaction of 5-aza-dC/depsipeptide with 5-FU in DLD-1 cells may be related with the failure in repression of epigenetic silencing, which warrants further investigation.