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Evolution of In Silico Strategies for Protein-Protein Interaction Drug Discovery
No full textThe advent of advanced molecular modeling software, big data analytics, and high-speed processing units has led to the exponential evolution of modern drug discovery and better insights into complex biological processes and disease networks. This has progressively steered current research interests to understanding protein-protein interaction (PPI) systems that are related to a number of relevant diseases, such as cancer, neurological illnesses, metabolic disorders, etc. However, targeting PPIs are challenging due to their "undruggable" binding interfaces. In this review, we focus on the current obstacles that impede PPI drug discovery, and how recent discoveries and advances in in silico approaches can alleviate these barriers to expedite the search for potential leads, as shown in several exemplary studies. We will also discuss about currently available information on PPI compounds and systems, along with their usefulness in molecular modeling. Finally, we conclude by presenting the limits of in silico application in drug discovery and offer a perspective in the field of computer-aided PPI drug discovery
Analysis of Polycyclic Aromatic Hydrocarbons in Ambient Aerosols by Using One-Dimensional and Comprehensive Two-Dimensional Gas Chromatography Combined with Mass Spectrometric Method: A Comparative Study
No full textAdvanced separation technology paired with mass spectrometry is an ideal method for the analysis of atmospheric samples having complex chemical compositions. Due to the huge variety of both natural and anthropogenic sources of organic compounds, simultaneous quantification and identification of organic compounds in aerosol samples represents a demanding analytical challenge. In this regard, comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS) has become an effective analytical method. However, verification and validation approaches to quantify these analytes have not been critically evaluated. We compared the performance of gas chromatography with quadrupole mass spectrometry (GC-qMS) and GCxGC-TOFMS for quantitative analysis of eighteen target polycyclic aromatic hydrocarbons (PAHs). The quantitative obtained results such as limits of detection (LODs), limits of quantification (LOQs), and recoveries of target PAHs were approximately equivalent based on both analytical methods. Furthermore, a larger number of analytes were consistently identified from the aerosol samples by GCxGC-TOFMS compared to GC-qMS. Our findings suggest that GCxGC-TOFMS would be widely applicable to the atmospheric and related sciences with simultaneous target and nontarget analysis in a single run
Testing an explanatory model for preventing college students' problem gambling
No full textPurpose: A mediated model of Korean college students' problem gambling based on Blaszczynski and Nower's pathway model is developed and tested to explore mediating roles of self-control and irrational gambling beliefs in the association between emotionally vulnerable variables and problem gambling. Methods: 273 student participants recruited from 4 universities in Seoul and Gyeonggi, Korea responded. Data were collected with a structured self-report questionnaire comprising measures of problem gambling, depression, anxiety, coping styles, irrational gambling belief, and self-control. Results: The modified research model provides a reasonable fit to the data. Depression, anxiety, reflective coping, irrational beliefs, and self-control turned out to have direct effects on problem gambling, while indirect effects were reported in some suppressive and reactive styles. These predictors account for 38% of the college students' problem gambling. Conclusion: The findings suggest that developing intervention programs for reducing depression, anxiety, irrational gambling beliefs, and increasing reflective coping and self-control are needed to prevent Korean college students'problem gambling. © 2018 Korean Academy of Community Health Nursing.Ministry of Science, ICT and Future Plannin
Multimorbidity and health-related quality of life in Koreans aged 50 or older using KNHANES 2013-2014
No full textBackground: Multimorbidity negatively affects health outcomes and impairs health-related quality of life (HRQoL). We assessed the prevalence of multimorbidity in Koreans aged 50 and older, taking into consideration their socioeconomic status, and estimated the loss in HRQoL due to multimorbidity. Methods: This study is based on an analysis of data for adults aged 50 and older derived from the cross-sectional nationally representative Korean National Health and Nutrition Examination Survey conducted in 2013-14. The five most prevalent chronic diseases and disease dyads were identified. The impact of the degree of multimorbidity, sex, and socioeconomic status on the European Quality of Life 5 Dimension (EQ-5D) index score were analyzed. Marital status, educational attainment, household income, basic livelihood security benefit, and occupation were considered as socioeconomic factors. Results: The analysis included 5996 adults aged 50 years and older with males comprising 46.6%. Two or more chronic diseases were present in 26.8% of the participants aged 50 and older and 37.9% of the participants aged 65 and older. The most prevalent dyadic combination was hypertension and dyslipidemia in the 50 and older group, and hypertension and osteoarthritis in the 65 and older age group. Hypertension dominated the multimorbidity combinations (four of the five most prevalent multimorbidity dyads), while a few conditions such as osteoarthritis had a relatively large influence on quality of life. In addition to the degree of multimorbidity, female and lower socioeconomic status were associated with significantly lower EQ-5D index scores. Conclusions: Integrated, holistic healthcare based on a patient-oriented perspective for earlier, more effective intervention, targeting multimorbidity is warranted. Special consideration should be given to patients with low socioeconomic status
Comparison of ramosetron and ondansetron for the treatment of established postoperative nausea and vomiting after laparoscopic surgery: A prospective, randomized, double-blinded multicenter trial
No full textBackground: Postoperative nausea and vomiting (PONV) is a common complication after surgery, which increases physical and psychological discomfort and delays recovery. The aim of this study was to test the hypothesis that ramosetron is comparable to ondansetron for the treatment of established PONV after laparoscopic surgery using a prospective, randomized, double-blinded, noninferiority study. Methods: Patients who had at least two risk factors of PONV and underwent laparoscopic surgery under general anesthesia were assessed for eligibility. Patients who developed PONV within the first 2 h after anesthesia received ondansetron (4 mg) or ramosetron (0.3 mg) intravenously in a randomized double-blind manner. Patients were then observed for 24 h after drug administration. The incidence of nausea and vomiting, severity of nausea, rescue antiemetic necessity, and adverse effects at 0-2 or 2-24 h after drug administration was evaluated. The primary endpoint was the rate of patients exhibiting a complete response, defined as no emesis and no further rescue antiemetic medication for 24 h after drug administration. Results: Among the 583 patients, 210 (36.0%) developed PONV and were randomized to either the ondansetron (n=105) or ramosetron (n=105) group. Patient’s characteristics were similar between the groups. The complete response rate was 44.1% in the ondansetron group and 52.9% in the ramosetron group after 24 h of initial antiemetic administration. The incidence of adverse events was not different between the groups. Conclusion: We found evidence to support the noninferiority of ramosetron (0.3 mg) compared to ondansetron (4 mg) for the treatment of established PONV in moderate to high-risk patients undergoing laparoscopic surgery. © 2018 Choi et al
Out of Asia: Mitochondrial evolutionary history of the globally introduced supralittoral isopod Ligia exotica
No full textThe native ranges and invasion histories of many marine species remain elusive due to a dynamic dispersal process via marine vessels. Molecular markers can aid in identification of native ranges and elucidation of the introduction and establishment process. The supralittoral isopod Ligia exotica has a wide tropical and subtropical distribution, frequently found in harbors and ports around the globe. This isopod is hypothesized to have an Old World origin, from where it was unintentionally introduced to other regions via wooden ships and solid ballast. Its native range, however, remains uncertain. Recent molecular studies uncovered the presence of two highly divergent lineages of L. exotica in East Asia, and suggest this region is a source of nonindigenous populations. In this study, we conducted phylogenetic analyses (Maximum Likelihood and Bayesian) of a fragment of the mitochondrial 16S ribosomal (r)DNA gene using a dataset of this isopod that greatly expanded previous representation from Asia and putative nonindigenous populations around the world. For a subset of samples, sequences of 12S rDNA and NaK were also obtained and analyzed together with 16S rDNA. Our results show that L. exotica is comprised of several highly divergent genetic lineages, which probably represent different species. Most of the 16S rDNA genetic diversity (48 haplotypes) was detected in East and Southeast Asia. Only seven haplotypes were observed outside this region (in the Americas, Hawai'i, Africa and India), which were identical or closely related to haplotypes found in East and Southeast Asia. Phylogenetic patterns indicate the L. exotica clade originated and diversified in East and Southeast Asia, and only members of one of the divergent lineages have spread out of this region, recently, suggesting the potential to become invasive is phylogenetically constrained. © 2018 Hurtado et al.National Science Foundatio
Achieving 14.4% Alcohol-Based Solution-Processed Cu(In,Ga)(S,Se)2 Thin Film Solar Cell through Interface Engineering
No full textAn optimization of band alignment at the p-n junction interface is realized on alcohol-based solution-processed Cu(In,Ga)(S,Se)2 (CIGS) thin film solar cells, achieving a power-conversion-efficiency (PCE) of 14.4%. To obtain a CIGS thin film suitable for interface engineering, we designed a novel "3-step chalcogenization process" for Cu2-xSe-derived grain growth and a double band gap grading structure. Considering S-rich surface of the CIGS thin film, an alternative ternary (Cd,Zn)S buffer layer is adopted to build favorable "spike" type conduction band alignment instead of "cliff" type. Suppression of interface recombination is elucidated by comparing recombination activation energies using a dark J-V-T analysis. © 2018 American Chemical Society.Korea Institute of Energy Technology Evaluation and Plannin
Paralog Specificity Determines Subcellular Distribution, Action Mechanism, and Anticancer Activity of TRAP1 Inhibitors
No full textAlthough Hsp90 inhibitors can inhibit multiple tumorigenic pathways in cancer cells, their anticancer activity has been disappointingly modest. However, by forcing Hsp90 inhibitors into the mitochondria with mitochondrial delivery vehicles, they were converted into potent drugs targeting the mitochondrial Hsp90 paralog TRAP1. Here, to improve mitochondrial drug accumulation without using the mitochondrial delivery vehicle, we increased freely available drug concentrations in the cytoplasm by reducing the binding of the drugs to the abundant cytoplasmic Hsp90. After analyzing X-ray cocrystal structures, the purine ring of the Hsp90 inhibitor 2 (BIIB021) was modified to pyrazolopyrimidine scaffolds. One pyrazolopyrimidine, 12b (DN401), bound better to TRAP1 than to Hsp90, inactivated the mitochondrial TRAP1 in vivo, and it exhibited potent anticancer activity. Therefore, the rationale and feasible guidelines for developing 12b can potentially be exploited to design a potent TRAP1 inhibitor. © 2017 American Chemical Society.Ulsan National Institute of Science and Technolog
Gut microbiota and physiologic bowel 18F-FDG uptake
No full textBackground: We investigated the association between physiologic bowel FDG uptake and gut microbiota. FDG uptake in the normal large and small intestine is widely variable both in distribution and intensity. The etiology of physiologic bowel 18F-FDG activity remains unknown. Results: We included 63 healthy male subjects. After overnight fasting, blood samples and 18F-FDG PET/CT scans were taken. Fecal samples were collected, and gut microbiota were analyzed by 16S rRNA gene-pyrosequencing. The physiologic bowel FDG uptake was classified into three groups by visual assessment and measured using the maximum and mean standardized uptake value. We used the total bowel to liver uptake ratio (TBRmax and TBRmean). There was no significant difference in age, BMI, or lipid profiles between groups. To identify specific microbial taxa associated with the bowel FDG uptake while accounting for age and BMI, we performed a generalized linear model. At the genus level, the group with focal or intense FDG uptake in the intestine was associated with low abundance of unclassified Clostridiales. The group with intestinal FDG uptake lower than the liver was associated with high abundance of Klebsiella. TBRmax and TBRmean were negatively associated with abundance of unclassified Enterobacteriaceae. Conclusion: We cautiously speculate that physiologic bowel FDG activity might be caused by an increase in intestinal permeability and may reflect an impaired barrier function in the intestine. © 2017, The Author(s).Korea Institute of Science and Technology Informatio
A metagenomic analysis provides a culture-independent pathogen detection for atopic dermatitis
No full textPurpose: Atopic dermatitis (AD) is an inflammatory skin disease, significantly affecting the quality of life. Using AD as a model system, we tested a successive identification of AD-associated microbes, followed by a culture-independent serum detection of the identified microbe. Methods: A total of 43 genomic DNA preparations from washing fluid of the cubital fossa of 6 healthy controls, skin lesions of 27 AD patients, 10 of which later received treatment (post-treatment), were subjected to high-throughput pyrosequencing on a Roche 454 GS-FLX platform. Results: Microbial diversity was decreased in AD, and was restored following treatment. AD was characterized by the domination of Staphylococcus, Pseudomonas, and Streptococcus, whereas Alcaligenaceae (f), Sediminibacterium, and Lactococcus were characteristic of healthy skin. An enzyme-linked immunosorbent assay (ELISA) showed that serum could be used as a source for the detection of Staphylococcus aureus extracellular vesicles (EVs). S. aureus EV-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) were quantified in the serum. Conclusions: A metagenomic analysis together with a serum detection of pathogen-specific EVs provides a model for successive identification and diagnosis of pathogens of AD. © The Korean Academy of Asthma, Allergy and Clinical Immunology