• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.7
• /
• pp.3219-3226
• /
• 2014

Chemotherapy continues to be a mainstay of cancer treatment, although drug resistance is a major obstacle. Lipid metabolism plays a critical role in cancer pathology, with elevated ether lipid levels. Recently, alkylglyceronephosphate synthase (AGPS), an enzyme that catalyzes the critical step in ether lipid synthesis, was shown to be up-regulated in multiple types of cancer cells and primary tumors. Here, we demonstrated that silencing of AGPS in chemotherapy resistance glioma U87MG/DDP and hepatic carcinoma HepG2/ADM cell lines resulted in reduced cell proliferation, increased drug sensitivity, cell cycle arrest and cell apoptosis through reducing the intracellular concentration of lysophosphatidic acid (LPA), lysophosphatidic acid-ether (LPAe) and prostaglandin E2 (PGE2), resulting in reduction of LPA receptor and EP receptors mediated PI3K/AKT signaling pathways and the expression of several multi-drug resistance genes, like MDR1, MRP1 and ABCG2. ${\beta}$-catenin, caspase-3/8, Bcl-2 and survivin were also found to be involved. In summary, our studies indicate that AGPS plays a role in cancer chemotherapy resistance by mediating signaling lipid metabolism in cancer cells.

• Journal of fish pathology
• /
• v.7 no.1
• /
• pp.37-46
• /
• 1994

A total 103 strains of Edwardsiella tarda was isolated from eel culture-ponds and examined for drug resistance, distribution and transferabilities of R plasmids. The drugs used were lincomycin(LM), penicillin(PM), sulfamethazine(SF), sulfadimethoxine(SD), cephalosprin(CP), chloramphenicol(CH), streptomycin(SM), oxytetracycline(OT), ampicillin(AP), oxolinic acid(OA), kanamycin(KM), amikacin(AK), gentamicin(GM) and enrofloxacin(EF). Two strains were resistant to the all drugs used, and all isolates were multiply resistant to drugs(at least 8 among 14 drugs), mostly restricted to LM(103 strains), PM(103 strains), SD(103 strains), SF(103 strains), CP(102 strains), CM(101 strains), SM(100 strains), OT(94 strains), AM(92 strains), OA(80 strains), KM(60 strains), AK(30 strains), GM(19 strains) and EF(14 strains), in combination at high degree showing 34 different drug resistant patterns. The most frequently encountered patterns were LM PM SD SF CP CH SM OT AP OA KM(22 strains, 22.4%) followed by LM PM SD SF CP CH SM OT AP OT(12 strains, 11.7%). LM PM SD SF CP CH SM OT AP(7 strains, 6.8%), LM PM SD SF CP CH SM OT AP OA KM AK GM(6 strains, 5.8%) and LM PM SD SF CP CH SM OT AM OX KM AK GM(6 strains, 5.8%). Transfer experiment of drug resistance showed that of 103 resistant strains, 100 strains(97%) transferred part or all resistance to all drugs, indicating that most isolates carried conjugally transferrable R plasmids determining multiple drugs. The most frequently observed transferarble R plasmids were LM PM SD SF CP CH SM OT AP OA(10 strains), LM PM SD SF CP CH SM OT AP OX KM(7 strains) and LM PM SD SF CP CH AP OA(7 strains). These results sugested that eel culture-ponds were highly contaminated with different strains of Edwardsiella tarda, and that contaminated bacteria might be highly multiple resistant strains to drugs, carring transferable R plasmids.

• Pediatric Infection and Vaccine
• /
• v.16 no.1
• /
• pp.6-12
• /
• 2009

There are relatively few novel antimicrobial agents despite the dramatic increase in antimicrobial resistance and multiple drug resistance of clinical isolates worldwide. Vancomycin is still the most widely used antibiotic for treating resistant Gram-positive coccal infections in children, especially for methicillin-resistant Staphylococcus aureus. For children with Gram-positive coccal infections where vancomycin is not effective or older therapeutic agents cannot be tolerated, linezolid, quinupristin-dalfopristin or daptomycin may be useful in the appropriate clinical setting. For Gram-negative bacterial infections, new carbapenems await clinical application. Tebipenem pivoxil is a novel oral carbapenem undergoing clinical trials for acute otitis media in pediatric patients. Antiviral drug development is now progressing at the pace of antibiotic development 30 years ago. Newer antiviral agents used for the treatment of herpes viruses and hepatitis C virus infections in children are included in this review.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.3
• /
• pp.1105-1109
• /
• 2015

Chemoresistance is the most common cause of chemotherapy failure during breast cancer (BCA) treatment. It is generally known that the mechanisms of chemoresistance in tumors involve multiple genes and multiple signaling pathways,; if appropriate drugs are used to regulate the mechanisms at the gene level, it should be possible to effectively reverse chemoresistance in BCA cells. It has been confirmed that chemoresistance in BCA cells could be reversed by ginsenoside Rh2 (G-Rh2). Preliminary studies of our group identified some drugresistance specific miRNA. Accordingly, we proposed that G-Rh2 could mediate drug-resistance specific miRNA and corresponding target genes through the gene regulatory network; this could cut off the drug-resistance process in tumors and enhance treatment effects. G-Rh2 and breast cancer cells were used in our study. Through pharmaceutical interventions, we could explore how G-Rh2 could inhibit chemotherapy resistance in BCA, and analyze its impact on related miRNA and target genes. Finally, we will reveal the anti-resistance molecular mechanisms of G-Rh2 from a different angle in miRNA-mediated chemoresistance signals among cells.

• Tuberculosis and Respiratory Diseases
• /
• v.81 no.3
• /
• pp.222-227
• /
• 2018

Background: Rifampicin (RFP) is one of the principal first-line drugs used in combination chemotherapies against Mycobacterium tuberculosis, and its use has greatly shortened the duration of chemotherapy for the successful treatment of drug-susceptible tuberculosis. Compensatory mutations have been identified in rpoC that restore the fitness of RFP-resistant M. tuberculosis strains with mutations in rpoB. To investigate rpoC mutation patterns, we analyzed 93 clinical M. tuberculosis isolates from patients in South Korea. Methods: Drug-resistant mycobacterial isolates were cultured to determine their susceptibility to anti-tubercular agents. Mutations in rpoC were identified by sequencing and compared with the relevant wild-type DNA sequence. Results: In total, 93 M. tuberculosis clinical isolates were successfully cultured and tested for drug susceptibilities. They included 75 drug-resistant tuberculosis species, of which 66 were RFP-resistant strains. rpoC mutations were found in 24 of the 66 RFP-resistant isolates (36.4%). Fifteen different types of mutations, including single mutations (22/24, 91.7%) and multiple mutations (2/24, 8.3%), were identified, and 12 of these mutations are reported for the first time in this study. The most frequent mutation involved a substitution at codon 452 (nt 1356) resulting in amino acid change F452L. Conclusion: Fifteen different types of mutations were identified and were predominantly single-nucleotide substitutions (91.7%). Mutations were found only in dual isoniazid- and RFP-resistant isolates of M. tuberculosis. No mutations were identified in any of the drug-susceptible strains.

• Microbiology and Biotechnology Letters
• /
• v.31 no.3
• /
• pp.230-234
• /
• 2003

The Bacillus subtilis YvaE protein, the small multidrug resistance (SMR) family (TC #2.A. 7.1), is shown to catalyze efflux of multiple cationic drugs including many disinfectants, when it was cloned and expressed in Escherichia coli. When the yvaD gene was coexpressed with yvaE gene, the yvaD protein, encoded within a single operon with the yvaE gene, is shown to counteract the action ofYvaE. By ethidium efflux analysis, the cells harvoring a vector with yvaE gene showed a rapid ethidium efflux, compared with the control cells. These results clearly suggest that YvaE mediates drug export from the cell cytoplasm.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.9
• /
• pp.1460-1466
• /
• 2015

In this study, the prevalence of Shiga toxin-producing Escherichia coli (STEC) was investigated among raw meat or meat products from slaughterhouses and retail markets in South Korea, and their potential for antibiotic resistance and virulence was further analyzed. A total of 912 raw meats, including beef, pork, and chicken, were collected from 2008 to 2009. E. coli strains were frequently isolated in chicken meats (176/233, 75.9%), beef (102/217, 42.3%), and pork (109/235, 39.2%). Putative STEC isolates were further categorized, based on the presence or absence of the Shiga toxin (stx) genes, followed by standard O-serotyping. Polymerase chain reaction assays were used to detect the previously defined virulence genes in STEC, including Shiga toxins 1 and Shiga toxin 2 (stx1 and 2), enterohemolysin (ehxA), intimin (eaeA), STEC autoagglutination adhesion (saa), and subtilase cytotoxin (subAB). All carried both stx1 and eae genes, but none of them had the stx2, saa, or subAB genes. Six (50.0%) STEC isolates possessed the ehxA gene, which is known to be encoded by the 60-megadalton virulence plasmid. Our antibiogram profiling demonstrated that some STEC strains, particularly pork and chicken isolates, displayed a multiple drug-resistance phenotype. RPLA analysis revealed that all the stx1-positive STEC isolates produced Stx1 only at the undetectable level. Altogether, these results imply that the locus of enterocyte and effacement (LEE)-positive strains STEC are predominant among raw meats or meat products from slaughterhouses or retail markets in Korea.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.22 no.3
• /
• pp.268-276
• /
• 2015

Purpose: The purpose of this study was to identify factors which influence the management of MultiDrug -Resistant Organisms (MDROs) by nurses in Intensive Care Units (ICUs). Methods: Data were collected from December 8 to 20, 2013 and participants were 163 ICU nurses working in one general hospital. The Health Belief Model tool and knowledge and management of MDROs infection tools were used in the study. Descriptive statistics, t-test, analysis of variances, Pearson correlation coefficients and multiple regression were used to analyze the data. Results: Knowledge, perceived susceptibility, and perceived benefits had a significant influence on MRSA (Methicillin Resistant Staphylococcus Aureus,) and MDRAB (Multidrug Resistant Acinetobacter Baumannii) infection management when all the other variables were considered. Significant variable which had influence on VRE (Vancomycin Resistant Eenterococci) infection management were perceived susceptibility and perceived benefits. Conclusion: Perceived susceptibility and perceived benefits had significant influence on MDROs infection management. Emphasis needs to be on the perceived susceptibility and perceived benefits of MDROs infection management when providing an educational program for ICU nurses.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.5
• /
• pp.508-515
• /
• 2014

The contamination status of Vibrio parahaemolyticus in commercially valuable shellfish from the south and west coasts of Korea and the antimicrobial resistance patterns of isolated V. parahaemolyticus were investigated from July through October, 2011. The range of V. parahaemolyticus concentrations in oysters Crassostrea gigas and short neck clams Venerupis philippinarum was <30~290 MPN/100 g and <30~46,000 MPN/100 g, respectively, and greater than 10,000 MPN/100 g of V. parahaemolyticus was detected from 7 of 40 short neck clams. During the survey period, 436 strains of V. parahaemolyticus were isolated (129 from oysters and 307 from short-neck clams) and the antimicrobial resistance patterns of all of the isolates were examined. Antimicrobial resistance against at least one antibiotic was seen in 79.8% of the oyster isolates (103 strains) and 63.8% of the short neck clam isolates (196 strains). The antimicrobial resistance patterns were relatively simple because the antimicrobial resistance of the isolates was simply due to resistance to ampicillin. Only one oyster isolate and three short neck clam isolates showed multiple antibiotic resistance, i.e., resistance against more than four antibiotics.

• Journal of Ginseng Research
• /
• v.48 no.3
• /
• pp.276-285
• /
• 2024

Diabetes mellitus (DM) is a systemic disorder of energy metabolism characterized by a sustained elevation of blood glucose in conjunction with impaired insulin action in multiple peripheral tissues (i.e., insulin resistance). Although extensive research has been conducted to identify therapeutic targets for the treatment of DM, its global prevalence and associated mortailty rates are still increasing, possibly because of challenges related to long-term adherence, limited efficacy, and undesirable side effects of currently available medications, implying an urgent need to develop effective and safe pharmacotherapies for DM. Phytochemicals have recently drawn attention as novel pharmacotherapies for DM based on their clinical relevance, therapeutic efficacy, and safety. Ginsenosides, pharmacologically active ingredients primarily found in ginseng, have long been used as adjuvants to traditional medications in Asian countries and have been reported to exert promising therapeutic efficacy in various metabolic diseases, including hyperglycemia and diabetes. This review summarizes the current pharmacological effects of ginsenosides and their mechanistic insights for the treatment of insulin resistance and DM, providing comprehensive perspectives for the development of novel strategies to treat DM and related metabolic complications.