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51.
Influenza epidemics arise through the accumulation of viral genetic changes. The emergence of new virus strains coincides with a higher level of influenza-like illness (ILI), which is seen as a peak of a normal season. Monitoring the spread of an epidemic influenza in populations is a difficult and important task. Twitter is a free social networking service whose messages can improve the accuracy of forecasting models by providing early warnings of influenza outbreaks. In this study, we have examined the use of information embedded in the Hangeul Twitter stream to detect rapidly evolving public awareness or concern with respect to influenza transmission and developed regression models that can track levels of actual disease activity and predict influenza epidemics in the real world. Our prediction model using a delay mode provides not only a real-time assessment of the current influenza epidemic activity but also a significant improvement in prediction performance at the initial phase of ILI peak when prediction is of most importance. 相似文献
52.
Migyeong Jo Sanghwan Ko Bora Hwang Sung-Won Min Ji Yeon Ha Ji Chul Lee Se-Eun Jang Sang Taek Jung 《Biotechnology and bioengineering》2020,117(8):i-i
The immunoglobulin G (IgG) molecule has a long circulating serum half-life (~3 weeks) through pH- dependent FcRn binding-mediated recycling. To hijack the intracellular trafficking and recycling mechanism of IgG as a way to extend serum persistence of non-antibody therapeutic proteins, we have evolved the ectodomain of a low-affinity human FcγRIIa for enhanced binding to the lower hinge and upper CH2 region of IgG, which is very far from the FcRn binding site (CH2–CH3 interface). High-throughput library screening enabled isolation of an FcγRIIa variant (2A45.1) with 32-fold increased binding affinity to human IgG1 Fc (equilibrium dissociation constant: 9.04 × 10−7 M for wild type FcγRIIa and 2.82 × 10−8 M for 2A45.1) and significantly improved affinity to mouse serum IgG compared to wild type human FcγRIIa. The in vivo pharmacokinetic profile of PD-L1 fused with engineered FcγRIIa (PD-L1–2A45.1) was compared with that of PD-L1 fused with wild type FcγRIIa (PD-L1–wild type FcγRIIa) and human PD-L1 in mice. PD-L1–2A45.1 showed 11.7- and 9.7-fold prolonged circulating half-life (t1/2) compared to PD-L1 when administered intravenously and intraperitoneally, respectively. In addition, the AUCinf of PD-L1–2A45.1 was two-fold higher compared to that of PD-L1–wild type FcγRIIa. These results demonstrate that engineered FcγRIIa fusion offers a novel and successful strategy for prolonging serum half-life of therapeutic proteins. 相似文献
53.
Jeyoun Jang Minhui Cho Hae-Ri Lee Kiweon Cha Jeong-Hoon Chun Kee-Jong Hong Jungchan Park Gi-eun Rhie 《Biochimica et Biophysica Acta (BBA)/General Subjects》2013
Background
The poly-γ-d-glutamic acid (PGA) capsule, a major virulence factor of Bacillus anthracis, protects bacilli from immune surveillance and allows its unimpeded growth in the host. Recently, the importance of the PGA in the pathogenesis of anthrax infection has been reported. The PGA capsule is associated with lethal toxin (LT) in the blood of experimentally infected animals and enhances the cytotoxicity of LT.Methods
To investigate the role of anti-PGA Abs on progression of anthrax infection, two mouse anti-PGA mAbs with Kd values of 0.8 μM and 2.6 μM respectively were produced and in silico three dimensional (3D) models of mAbs with their cognitive PGA antigen complex were analyzed.Results
Anti-PGA mAbs specifically bound encapsulated B. anthracis H9401 and showed opsonophagocytosis activity against the bacteria with complement. The enhancement effect of PGA on LT-mediated cytotoxicity was confirmed ex vivo using mouse bone marrow-derived macrophages and was effectively inhibited by anti-PGA mAb. Passive immunization of mAb completely protected mice from PGA-enhanced LT toxicity and partially rescued mice from anthrax spore challenges. 3D structure models of these mAbs and PGA complex support specific interactions between CDR and cognitive PGA. These results indicate that mouse mAb against PGA capsule prevents the progress of anthrax disease not only by eliminating the vegetative form of encapsulated B. anthracis but also by inhibiting the enhanced cytotoxic activity of LT by PGA through specific binding with PGA capsule antigen.General significance
Our results suggest a potential role for PGA antibodies in preventing and treating anthrax infection. 相似文献54.
Jennifer Jooyoun Kim Ji Hyung Kim Young-Kyung Kwon Kae Kyoung Kwon Sung-Hyun Yang Jiyi Jang Soo-Jin Heo Heung-Sik Park Won-Kyo Jung Youngdeuk Lee Do-Hyung Kang Chulhong Oh 《Current microbiology》2013,67(6):742-747
An aerobic, Gram-negative, coccoid to short rod-shaped and non-flagellated marine bacterial strain S354T was isolated from seawater of Micronesia. The strain was capable to degrade agar-forming slight depression into agar plate. Growth occurred at a temperature range of 12–44 °C, a pH range of 5–9, and a salinity range of 1–7 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences suggested that S354T belongs to the family Flammeovirgaceae. The novel strain was most closely related to Limibacter armeniacum YM 11-185T with similarity of 92.5 %. The DNA G+C content was 43.8 mol%. The major fatty acids (>10 %) were iso-C15:0 and C16:1 ω5c. The predominant isoprenoid quinone was determined to be MK-7. Polar lipid profile of S354T consisted of phosphatidylethanolamine, unknown polar lipid, and unknown glycolipids. Based on the phenotypic, phylogenetic, biochemical, and physiological tests conducted in this study, S354T is proposed to represent a type strain of a novel genus and species. The 16S rRNA gene sequence of S354T is registered in GenBank under the accession number JQ639084. The type of strain Algivirga pacifica gen. nov., sp. nov. is S354T (=KCCM 90107T=JCM 18326T). 相似文献
55.
Dae Hwan Lee Ji Hyeon Ahn Joon Ha Park Bing Chun Yan Jeong-Hwi Cho In Hye Kim Jae-Chul Lee Sang-Hun Jang Myoung Hyo Lee In Koo Hwang Seung Myung Moon Bonghee Lee Jun Hwi Cho Hyung-Cheul Shin Jin Sang Kim Moo-Ho Won 《Cellular and molecular neurobiology》2013,33(5):615-624
Aging is an inevitable process that occurs in the whole body system accompanying with many functional and morphological changes. Inflammation is known as one of age-related factors, and inflammatory changes could enhance mortality risk. In this study, we compared immunoreactivities of inflammatory cytokines, such as interleukin (IL)-2 (a pro-inflammatory cytokine), its receptor (IL-2R), IL-4 (an anti-inflammatory cytokine), and its receptor (IL-4R) in the cervical and lumbar spinal cord of young adult (2–3 years old) and aged (10–12 years old) beagle dogs using immunohistochemistry and western blotting. IL-2 and IL-2R-immunoreactive nerve cells were found throughout the gray matter of the cervical and lumbar spinal cord of young adult and aged dogs. In the spinal cord neurons of the aged dog, immunoreactivity and protein levels were apparently increased compared with those in the young adult dog. Change patterns of IL-4- and IL-4R-immunoreactive cells and their protein levels were also similar to those in IL-2 and IL-2R; however, IL-4 and IL-4R immunoreactivity in the periphery of the neuronal cytoplasm in the aged dog was much stronger than that in the young adult dog. These results indicate that the increase of inflammatory cytokines and their receptors in the aged spinal cord might be related to maintaining a balance of inflammatory reaction in the spinal cord during normal aging. 相似文献
56.
Song Ah Choi Jong Won Yun Hee Sung Park Jang Won Choi 《Molecular biology reports》2013,40(2):1753-1765
The proteins in plasma perform many important functions in the body, and the protein profiles of the plasma vary under different physiological and pathological conditions. In an attempt to identify novel marker proteins for diabetes prognosis, we examined the effect of hypoglycemic dipeptide cyclo (His-Pro) (CHP) on the differential regulation of plasma proteins in streptozocin-induced diabetic rats and genetically-diabetic (ob/ob) mice. The orally-administrated CHP produced an excellent hypoglycemic effect in both animal models, lowering the average plasma glucose level by over 50 %. In the 2-DE analysis of the plasma, a total of 23 spots among 500 visualized spots were found to be differentially regulated, and they were identified by MALDI/TOF mass spectrometry. These proteins include the down-regulation of Apo E and the up-regulation of FGA, Apo A-I, Apo A-IV, and A1M in STZ-induced diabetic rats. Moreover, CHP significantly reduced the plasma protein levels of FGB, FGC, F12, C1QTNF5, and SPA3K, as well as increased the abundance of A1M, A2M, Apo E, and TTR in genetically-diabetic mice. In conclusion, alteration in the regulation of these proteins indicates that this treatment may be successful in overcoming the diabetic state. The present proteomic data can serve as the basis for the development of specific evidence-based interventions allowing for the prevention and treatment of diabetes. 相似文献
57.
Kyung‐Min Lee Yeon‐Joo Choi Sun‐Hye Shin Min‐Kyung Choi Hyeon‐Je Song Heung‐Chul Kim Terry A. Klein Allen L. Richards Kyung‐Hee Park Won‐Jong Jang 《Microbiology and immunology》2013,57(7):487-495
Rickettsia monacensis, a spotted fever group rickettsia, was isolated from Ixodes nipponensis ticks collected from live‐captured small mammals in South Jeolla province, Korea in 2006. Homogenates of tick tissues were inoculated into L929 and Vero cell monolayers using shell vial assays. After several passages, Giemsa staining revealed rickettsia‐like organisms in the inoculated Vero cells, but not the L929 cells. Sequencing analysis revealed that the ompA‐small part (25–614 bp region), ompA‐large part (2849–4455 bp region), nearly full‐length ompB (58–4889 bp region) and gltA (196–1236 bp region) of the isolates had similarities of 100%, 99.8%, 99.3% and 99.5%, respectively, to those of R. monacensis. Furthermore, phylogenetic analysis showed that the isolate was grouped into the cluster in the same way as R. monacensis in the trees of all genes examined. These results strongly suggest that the isolate is closely related to R. monacensis. As far as is known, this is the first report of isolation of R. monacensis from ticks in Korea. 相似文献
58.
Ae Kyung Park Jin Ho Moon Eun Hyuk Jang Hyun Park In Young Ahn Ki Seog Lee Young Min Chi 《Proteins》2013,81(3):531-537
Glutathione‐S‐transferases have been identified in all the living species examined so far, yet little is known about their function in marine organisms. In a previous report, the recently identified GST from Antarctic bivalve Laternula elliptica (LeGST) was classified into the rho class GST, but there are several unique features of LeGST that may justify reclassification, which could represent specific shellfish GSTs. Here, we determined the crystal structure of LeGST, which is a shellfish specific class of GST. The structural analysis showed that the relatively open and wide hydrophobic H‐site of the LeGST allows this GST to accommodate various substrates. These results suggest that the H‐site of LeGST may be the result of adaptation to their environments as sedentary organisms. Proteins 2013. © 2012 Wiley Periodicals, Inc. 相似文献
59.
Hye Jung Lee Sailila E. Abdula Dae Won Jang Sung-Han Park Ung-Han Yoon Yu Jin Jung Kwon Kyoo Kang Ill Sup Nou Yong-Gu Cho 《Plant cell reports》2013,32(10):1521-1529
Key message
Overexpression of OsGS gene modulates oxidative stress response in rice after exposure to cadmium stress. Our results describe the features of transformants with enhanced tolerance to Cd and abiotic stresses.Abstract
Glutamine synthetase (GS) (EC 6.3.1.2) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine. Exposure of plants to cadmium (Cd) has been reported to decrease GS activity in maize, pea, bean, and rice. To better understand the function of the GS gene under Cd stress in rice, we constructed a recombinant pART vector carrying the GS gene under the control of the CaMV 35S promoter and OCS terminator and transformed using Agrobacterium tumefaciens. We then investigated GS overexpressing rice lines at the physiological and molecular levels under Cd toxicity and abiotic stress conditions. We observed a decrease in GS enzyme activity and mRNA expression among transgenic and wild-type plants subjected to Cd stress. The decrease, however, was significantly lower in the wild type than in the transgenic plants. This was further validated by the high GS mRNA expression and enzyme activity in most of the transgenic lines. Moreover, after 10 days of exposure to Cd stress, increase in the glutamine reductase activity and low or no malondialdehyde contents were observed. These results showed that overexpression of the GS gene in rice modulated the expression of enzymes responsible for membrane peroxidation that may result in plant death. 相似文献60.