The Catholic University of Daegu is the largest Catholic-affiliated university in South Korea. The main campus is located some distance outside Daegu in neighboring Hayang Town, with two smaller campuses within Daegu. The university enrolls about 17,000 students. Wikipedia.
News Article | May 25, 2017
Antibiotic combinations prove effective against two ESKAPE pathogens, a sextet of superbugs that cause the majority of US hospital infections BUFFALO, N.Y. - In the fight against super bacteria, University at Buffalo scientists are relying on strength in numbers to win the battle against drug resistance. A team of researchers found that combinations of three antibiotics - that are each ineffective against superbugs when used alone - are capable of eradicating two of the six ESKAPE pathogens when delivered together. ESKAPE pathogens are a group of antimicrobial-resistant bacteria that pose a grave threat, causing more than 2 million infections and nearly 23,000 deaths a year, according to the Centers for Disease Control and Prevention. The six super bacteria are also responsible for a substantial number of infections in hospitals. The new, triple combination treatments provide a new weapon in the evolutionary arms race between modern medicine and harmful bacteria. "These bacteria are extremely problematic and have become resistant to nearly all available antibiotics. We needed to think differently to attack this problem," says Brian Tsuji, PharmD, an author on two recent studies and associate professor in the Department of Pharmacy Practice in the UB School of Pharmacy and Pharmaceutical Sciences. One study, "Polymyxin-resistant, carbapenem-resistant Acinetobacter baumannii is eradicated by a triple combination of agents that lack individual activity," was published in the May issue of the Journal of Antimicrobial Chemotherapy, while another study, "Polymyxin B-Based Triple Combinations Wage War Against KPC-2-producing Klebsiella pneumoniae: New Dosing Strategies for Old Allies," was published in the April issue of Antimicrobial Agents and Chemotherapy. Non-traditional combinations of medication are frequently used to fight against superbug infections, however, questions remain over proper dosage and which combinations are most effective. The UB researchers tested combinations of the antibiotics polymyxin B, meropenem and ampicillin-sulbactam against the pathogen Acinetobacter baumannii. The bacterium Klebsiella pneumoniae was treated with polymyxin B, meropenem, and rifampin. "Each antibiotic was chosen to complement the other drugs' mechanisms of bacterial killing," says Justin Lenhard, PharmD, first author on the investigation of Acinetobacter baumannii and former postdoctoral researcher in Tsuji's lab. Lenhard is now an assistant professor at California Northstate University College of Pharmacy. "By combining antimicrobials that exert their bacterial killing in different ways, it is possible to outmaneuver the ESKAPE pathogens and completely overwhelm the bacteria's defensive countermeasures," he said. The medications were applied to the bacterial samples individually, in pairs and in triple combinations. Both the time needed for the antibiotics to kill the bacteria and the time it took for the pathogens to repopulate were measured. For the tests on Acinetobacter baumannii, none of the antibiotics were able to kill the bacteria when used alone. Of the pairs of antibiotics, only the grouping of polymyxin B and meropenem was able to effectively kill the pathogen, but the bacteria gradually regrew over three days. The triple combination achieved a similar kill rate to the pair of polymyxin B and meropenem, but the addition of ampicillin-sulbactam prevented regrowth of the pathogen. Within 96 hours, no viable bacteria cells were detected after exposure to all three antibiotics. The tests against Klebsiella pneumoniae were led by Zackery Bulman, PharmD, a postdoctoral researcher in Tsuji's lab. Individual antibiotics were unable to sustain the killing of bacteria over a 24-hour period. The most effective double combination was polymyxin B and rifampin, which killed bacteria for up to 30 hours before the population regrew to initial levels. The triple combination of polymyxin B, meropenem, and rifampin produced the highest kill rates and tripled the time it took for bacteria to regrow to 72 hours. Rifampin, the researchers suspect, temporarily suppresses the antibiotic resistance of Klebsiella pneumoniae, allowing the trio to destroy the bacteria. Additional research is required to validate the treatments against other clinically relevant strains of bacteria, but the results of both studies are promising. "These new antibiotic combinations may help to guide therapy in infections where no treatments appear to exist," says Tsuji. The research was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health. Investigators on the study, "Polymyxin B-Based Triple Combinations Wage War Against KPC-2-producing Klebsiella pneumoniae: New Dosing Strategies for Old Allies," include Bulman and Patricia N. Holden, UB School of Pharmacy and Pharmaceutical Sciences; Michael J. Satlin and Thomas J. Walsh, Weill Cornell Medical College in Cornell University; Liang Chen and Barry N. Kreiswirth, New Jersey Medical School in Rutgers University; Beom Soo Shin, Catholic University of Daegu; Alan Forrest, Eshelman School of Pharmacy in the University of North Carolina; and Roger L. Nation and Jian Li, Monash Institute of Pharmaceutical Sciences in Monash University. Additional researchers on the study, "Polymyxin-resistant, carbapenem-resistant Acinetobacter baumannii is eradicated by a triple combination of agents that lack individual activity," include Forrest; Shin; Nation; Li; Visanu Thamlikitkul, Department of Medicine in Mahidol University; Fernanda P. Silveira, University of Pittsburgh Medical Center; Samira M. Garonzik, UB School of Pharmacy and Pharmaceutical Sciences; Xun Tao and Jürgen B. Bulitta, College of Pharmacy in the University of Florida; and Keith S. Kaye, University of Michigan Medical School.
Yang J.-H.,Catholic University of Daegu
Phytotherapy Research | Year: 2012
Fucoidan is a sulphated polysaccharide extracted from brown seaweed and possesses a wide range of pharmacological properties including antiallergic and immunologic activities. The present study attempted to examine the effectiveness of fucoidan from Undaria pinnatifida in the treatment of atopic dermatitis (AD) in the NC/Nga mice model. Three per cent fucoidan or 0.1% dexamethasone was topically applied to the dorsal skin of AD-induced mice for 4 weeks. The dermatitis severity scores and scratch counts of fucoidan or dexamethasone-treated animals were significantly lower than the control group. Histological analysis showed that the number of mast cells infiltrating into skin lesions and the epidermis thickness were significantly decreased after the treatments. Levels of serum histamine and IgE were also decreased. There was no significant difference on improvement of AD-like symptoms between fucoidan and dexamethasone. To elucidate possible mechanism of action, effects of fucoidan on regulation of AD-associated chemokines, such as thymus- and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) and regulated upon activation, normal T-cell expressed and secreted (RANTES) chemokine, were investigated in human epidermal keratinocytes. Fucoidan significantly inhibited mRNA expression of these chemokines in a dose-dependent manner. This is the first animal study to demonstrate that fucoidan has significant effects on improving AD-like conditions as effective as dexamethasone, a well-recognized corticosteroid remedy for the disease. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.
Loladze I.,Catholic University of Daegu
eLife | Year: 2014
Mineral malnutrition stemming from undiversified plant-based diets is a top global challenge. In C3 plants (e.g. rice, wheat), elevated concentrations of atmospheric carbon dioxide (eCO2) reduce protein and nitrogen concentrations, and can increase the total nonstructural carbohydrates (TNC; mainly starch, sugars). However, contradictory findings have obscured the effect of eCO2 on the ionome - the mineral and trace-element composition - of plants. Consequently, CO2-induced shifts in plant quality have been ignored in the estimation of the impact of global change on humans. This study shows that eCO2 reduces the overall mineral concentrations (-8%, 95% confidence interval: -9.1 to -6.9, p<0.00001) and increases TNC:minerals > carbon:minerals in C3 plants. The meta-analysis of 7,761 observations, including 2,264 observations at state of the art FACE centers, covers 130 species/cultivars. The attained statistical power reveals that the shift is systemic and global. Its potential to exacerbate the prevalence of 'hidden hunger' and obesity is discussed.
Yang J.-H.,Catholic University of Daegu
Chemosphere | Year: 2010
Widespread contamination of perfluorooctanoic acid (PFOA) in the marine environment draws a great concern over its ecotoxicological impact on marine mammals and wildlife. In the present study, male Japanese medaka (Oryzias latipes) was adapted to seawater to mimic the marine environment and was then exposed to the nominal concentrations of 10, 50, 100mgL-1 PFOA for 7d. There were no impact on survival, relative liver and gonad size, and condition factor (measure of growth) at any concentration tested. Peroxisomal acyl-CoA oxidase (ACO) activity was elevated at the highest dose with a marginal significance (P=0.06). The increase of ACO activity was paralleled by the significant upregulation of PPAR-α expression at the same dose. PFOA induced a significant inhibition of catalase (CAT) activity at high doses with no changes of superoxide dismutase (SOD) or glutathione peroxidase (GPx) activities in the liver. These results strongly suggest that PFOA may induce peroxisomal fatty acid oxidation and impose the oxidative stress through the alteration of cellular oxidative homeostasis in the liver. PFOA increased the mRNA levels of proinflammatory cytokines such as IL-6, TNF-α and IL-1β, suggesting that it may be involved in inflammation and tissue injury. This study may contribute to understanding the mechanism of PFOA-induced hepatic toxicity in Japanese medaka and assessing the potential risk of PFOA in marine fish and wildlife. In addition, the present results obtained at the high concentrations may provide important biological endpoints relevant to situations such as environmental spills. © 2010 Elsevier Ltd.
Yang J.-M.,Catholic University of Daegu
IEEE Transactions on Automatic Control | Year: 2010
In this note, we examine the control of asynchronous sequential machines with adversarial inputs. The considered asynchronous machine is of input/output type, where access to the state of the machine is not available. The adversarial input represents an unknown disturbance that can provoke unauthorized state transitions. The problem is to develop output feedback controllers that counteract the effects of the adversarial input, while controlling the machine so that the closed-loop system can match a prescribed model. The existence of appropriate corrective controllers depends on certain reachability and detectability properties of the machine and the model. © 2010 IEEE.
Min B.,Catholic University of Daegu
Korean Journal of Physiology and Pharmacology | Year: 2013
Vitamin D deficiency is prevalent, primarily due to limited sun exposure, which may be observed in urban areas, or as a result of modern lifestyles. Common myths about vitamin D persist, including that it is mostly obtained from the diet and is only essential for bone and mineral homeostasis. Nonetheless, advances in biomedical science suggest that vitamin D is a hormone that is integral to numerous physiologic functions in most cells and tissues. Therefore, abnormal vitamin D levels may contribute to health disturbances. A number of recent reports on potential associations between vitamin D deficiency and cardiovascular disease have highlighted its role in this system. A focus over the previous decade has been to better understand the mechanisms behind vitamin D regulation and the pathophysiology associated with suboptimal vitamin D levels. Vitamin D deficiency is highly associated with the incidence of cardiovascular diseases, even when considering other well-known risk factors. In this process, the renin-angiotensin system is disrupted, and hypertension and endothelial dysfunction contribute to the risk of cardiovascular disease. Likewise, clinical outcomes upon the normalization of vitamin D levels have been investigated in different patient populations. It makes sense that vitamin D supplementation to improve vitamin D status among vitamin D-deficient individuals could be useful without requiring a sudden lifestyle change. This manuscript provides a brief overview of vitamin D metabolism and the vitamin D receptor. It also summarizes the current clinical research relating to vitamin D supplementation and its effects on hypertension and endothelial dysfunction in cardiovascular medicine.
Yang J.-M.,Catholic University of Daegu
Automatica | Year: 2011
The problem of model matching for asynchronous sequential machines consists of finding a feedback controller for a given open-loop machine so that the resulting closed-loop machine matches a desired model. In this paper, the control objective is extended to model matching inclusion in which the behavior of the closed-loop system should be contained in that of the model. The supremal controllable sub-model is characterized as an asynchronous machine with the largest behavior set contained in a given model that can be matched by the closed-loop machine via state feedback control. An effective computational algorithm is developed and an example is provided for illustration. © 2011 Elsevier Ltd. All rights reserved.
Bae I.-H.,Catholic University of Daegu
Future Generation Computer Systems | Year: 2014
This paper presents a method for recognition of Activities of Daily Living (ADL) in smart homes. Recognition of activities of daily living and tracking them can provide unprecedented opportunities for health monitoring and assisted living applications, especially for elderly people and people with memory deficits. This paper presents Recognizing Activities of Daily Living (RADL) by discovering and monitoring patterns of ADLs in sensor equipped smart homes. The RADL is composed of two components: smart home management monitoring and ADL pattern monitoring. This paper studies the ontology base and the reasoning that are the main parts of ADL pattern monitoring. The ontology for RADL is designed and the prototype system of RADL is implemented using Protégé and Jess tools. Also, the ontology for RADL is verified by OntoCheck in automatic mode and evaluated by a metric-based approach in manual mode. © 2013 Elsevier B.V. All rights reserved.
Park. S.-H.,Catholic University of Daegu
Optics Express | Year: 2015
Light emission characteristics of ultraviolet (UV) BxAlyGa1-x-yN/AlN quantum well (QW) structures were using the multiband effective-mass theory. The TE-polarized spontaneous emission is found to be significantly improved owing to the decrease in the latticemismatch between the well and the substrate with the inclusion of boron. However, the spontaneous emission peak begins to decrease when the boron composition exceeds a critical value (x = 0.08 for y = 0.2), which is mainly due to an increase in the heavy-hole effective mass. In addition, in the case of QW structures with higher Al composition (y > 0.5), the light emission is shown to decrease with increasing the boron composition because the characteristic of the topmost valence subband is changed to the crystal-field splitoff hole band. Hence, we expect that BxAlyGa1-x-yN/AlN QW structures with y < 0.5 can be used as a TE-polarized light source with a high efficiency. © 2015 Optical Society of America.
Yang J.-M.,Catholic University of Daegu
IEEE Transactions on Automatic Control | Year: 2012
This note presents a control scheme for fault diagnosis and tolerance in asynchronous sequential machines. The considered asynchronous machine is subject to permanent faults, so the system remains in the faulty condition indefinitely after the occurrence of fault inputs. When the machine has a certain structural redundancy, we can design a corrective controller and observer that diagnose faults and compensate the closed-loop system so that it can maintain the normal input/output behavior. The proposed framework is based on the output feedback control scheme and asynchronous techniques. © 2012 IEEE.