• Title/Summary/Keyword: NAC-type

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Characterization of the high mannose asparagine-linked oligosaccharides synthesized by microfilariae of Dirofilaria immitis (심장사상충 자충이 합성한 high mannose asparagine-linked oligosaccharides의 분자화학적 분석)

  • 강승원
    • Parasites, Hosts and Diseases
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    • v.32 no.2
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    • pp.101-110
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    • 1994
  • This report describes the structures of high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by the microfilariae of Diroflcrio immitis. Microfilariae of D. immitis were incubated in vitro in media containing 2-(3H) mannose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with pronase and fractionation by chromatography on concanavalin A Sepharose. Thirty eight percent of 2- (3H) mannose incorporated into the microalariae of D. immitis glycopeptides was recovered in high mannose-type asparagine-linked oligosaccharides which were bound to the immobilized lectin. Upon treatment of 2-(3H) mannose labeled glycopeptides with endo - β- N- acetylglu co saminidase H , the high mannose type chains were released and their structures were determined by high performance liquid chromatography and exoglycosidase digestion. The major species of high mannose-type chains synthesized by microfilariae of D. immitis have the composition Man5GlcNAc2, Man6ClcNAc2, Man7GlcNAc2, and Man8GlcNAc2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by vertebrates.

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Diagnostic Accuracy of Magnetic Resonance Imaging Features and Tumor-to-Nipple Distance for the Nipple-Areolar Complex Involvement of Breast Cancer: A Systematic Review and Meta-Analysis

  • Jung Hee Byon;Seungyong Hwang;Hyemi Choi;Eun Jung Choi
    • Korean Journal of Radiology
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    • v.24 no.8
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    • pp.739-751
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    • 2023
  • Objective: This systematic review and meta-analysis evaluated the accuracy of preoperative breast magnetic resonance imaging (MRI) features and tumor-to-nipple distance (TND) for diagnosing occult nipple-areolar complex (NAC) involvement in breast cancer. Materials and Methods: The MEDLINE, Embase, and Cochrane databases were searched for articles published until March 20, 2022, excluding studies of patients with clinically evident NAC involvement or those treated with neoadjuvant chemotherapy. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Two reviewers independently evaluated studies that reported the diagnostic performance of MRI imaging features such as continuity to the NAC, unilateral NAC enhancement, non-mass enhancement (NME) type, mass size (> 20 mm), and TND. Summary estimates of the sensitivity and specificity curves and the summary receiver operating characteristic (SROC) curve of the MRI features for NAC involvement were calculated using random-effects models. We also calculated the TND cutoffs required to achieve predetermined specificity values. Results: Fifteen studies (n = 4002 breast lesions) were analyzed. The pooled sensitivity and specificity (with 95% confidence intervals) for NAC involvement diagnosis were 71% (58-81) and 94% (91-96), respectively, for continuity to the NAC; 58% (45-70) and 97% (95-99), respectively, for unilateral NAC enhancement; 55% (46-64) and 83% (75-88), respectively, for NME type; and 88% (68-96) and 58% (40-75), respectively, for mass size (> 20 mm). TND had an area under the SROC curve of 0.799 for NAC involvement. A TND of 11.5 mm achieved a predetermined specificity of 85% with a sensitivity of 64%, and a TND of 12.3 mm yielded a predetermined specificity of 83% with a sensitivity of 65%. Conclusion: Continuity to the NAC and unilateral NAC enhancement may help predict occult NAC involvement in breast cancer. To achieve the desired diagnostic performance with TND, a suitable cutoff value should be considered.

Mixture Study for Early-age Strength Improvement of NAC-typed High-strength Concrete Piles (NAC 방식 고강도 콘크리트 파일의 초기강도증진을 위한 배합에 대한 연구)

  • Yi, Seong Tae;Noh, Jae Ho;Heo, Hyung Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.2
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    • pp.58-64
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    • 2012
  • Due to the influence of global oil prices, industrial productivity, which oil consumption is high, was significantly reduced. AC type of high-strength PHC piles is being manufactured through twice the steam curing process and this have resulted in a significant rise for product's manufacturing costs. NAC way other types of file manufacturing process has the advantage of reducing manufacturing costs by a turn of the steam curing. Nevertheless, because the initial strength be poor than that of AC method, shipment is being after the curing period of approximately three days. In addition, the growth of the product enhance with curing period can not be avoided, as a result, cost of inventory is acting as the rise. Piles by the AC method is immediately shipped after curing, damaging problems does not occur when they are introduced to the field site (for example, pile on-site). In the case of NAC, however, at least after the curing period of three days and after expressing the strength of 80 MPa or more, they are shipped on the scene. Therefore, NAC type has problems as follows: (1) increase in moderate inventory holding costs with type and (2) breakage in the field due to lack of strength. In this study, for NAC-typed PHC files, mixing characteristics research for the strength development at 1 day equivalent to AC method were conducted and strength characteristics with changes of original materials were evaluated were also identified.

Overexpression of OsNAC17 enhances drought tolerance in rice

  • Kim, Tae Hwan;Kim, Ju-Kon
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.168-168
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    • 2017
  • Drought conditions during cultivation reduce agricultural production yield less than a theoretical maximum yield under normal condition. Plant specific NAC transcription factors in rice are known to play an essential roles in stress resistance transcriptional regulation. In this study, we report the rice (Oryza sativa L japonica) NAM, AFTF and CUC transcription factor OsNAC17, which is predominantly induced by abiotic stress in leaf, was contribute to the drought tolerance mediated reactive oxygen species (ROS) in transgenic rice plants. Constitutive (PGD1) promoter was introduced to overexpress OsNAC17 and produced the transgenic PDG1:OsNAC17. Overexpression of OsNAC17 throughout the whole plant improved drought resistance phenotype at the vegetative stage. Morphological characteristics such as grain yield, grain filling rate, and total grain weight improved by 22~64% over wild type plants under drought conditions during the reproductive stage. The improved drought tolerance in transgenic rice was involved in reducing stomatal density up to 15% than in wild type plants and in increasing reactive oxygen species-scavenging enzyme. DEG profiling experiment identified 119 up-regulated genes by more than twofold (P<0.01). These genes included UDP-glycosyltransferase family protein, similar to 2-alkenal reductase (NADPH-dependent oxireductase), similar to retinol dehydrogenase 12, Lipoxygenase, and NB-ARC domain containing protein related in cell death. Furthermore, OsNAC17 was act as a transcriptional activator, which has an activation domain in C-terminal region. These result demonstrate that the overexpression of OsNAC17 improve drought tolerance by regulating ROS scavenging enzymes and by reducing stomatal density

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Overview of Mucolipidosis Type II and Mucolipidosis Type III α/β

  • Kim, Su Jin
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.2 no.1
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    • pp.1-4
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    • 2016
  • Mucolipidosis type II (MLII; MIM#252500) and type III alpha/beta (MLIIIA; MIM#252600) very rare lysosomal storage disease cause by reduced enzyme activity of GlcNAc-1-phosphotransferase. ML II is caused by a total or near total loss of GlcNAc-1-phosphotransferase activity whether enzymatic activity in patient with ML IIIA is reduced. While ML II and ML III share similar clinical features, including skeletal abnormalities, ML II is the more severe in terms of phenotype. ML III is a much milder disorder, being characterized by latter onset of clinical symptoms and slower progressive course. GlcNAc-1-phosphotransferase is encoded by two genes, GNPTAB and GNPTG, mutations in GNPTAB give rise to ML II or ML IIIA. To date, more than 100 different GNPTAB mutations have been reported, causing either ML II or ML IIIA. Despite development of new diagnostic approach and understanding of disease mechanism, there is no specific treatment available for patients with ML II and ML IIIA yet, only supportive and symptomatic treatment is indicated.

Generation of Bacterial Blight Resistance Rice with Transcription Factor OsNAC69-overexpressing (전사인자 OsNAC69-과발현을 통한 흰잎마름병 저항성 벼 제작)

  • Park, Sang Ryeol;Cha, Eun-Mi;Moon, Seok Jun;Shin, Dongjin;Hwang, Duk-Ju;Ahn, Il-Pyung;Bae, Shin-Chul
    • Korean Journal of Breeding Science
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    • v.43 no.5
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    • pp.457-463
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    • 2011
  • Plant specific gene family, NAC (NAM, ATAF, and CUC) transcription factors have been characterized for their roles in plant growth, development, and stress tolerance. In this study, we isolated OsNAC69 gene and analyzed expression level by inoculation of bacterial leaf blight pathogen, Xanthomonas oryzae pv. oryzae (Xoo). NAC transcription factor family can be divided into five groups (I-V). On the basis of phylogenetic analysis, OsNAC69 was fall into group II. OsNAC69 was strongly induced 1 hr after infected with Xoo. To investigate its biological function in the rice, we constructed vector for overexpression in rice, and then generated transgenic rice lines. Gene expression of OsNAC69-overexpressed transgenic rice lines were analyzed by northern blot. Analysis of disease resistance to pathogen Xoo, nine OsNAC69-overexpressed transgenic rice lines showing high expression level of OsNAC69 were shown more resistant than wild type. These results suggest that OsNAC69 gene may play regulatory role during pathogen infection.

2-Nonadecanone Alleviates Depression through Inflammation Relief in SD Rat

  • Lee, Gil-Hyun;Hyun, Kyung-Yae
    • Biomedical Science Letters
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    • v.24 no.3
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    • pp.206-212
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    • 2018
  • Depression is a type of mood disorder characterized by hypochondriasis, decreased appetite, and insomnia. Depression is a disease that affects more than 100 million people worldwide. 2-Nonadecanone (NAC) is a bioactive substance that constitutes Fomes fomentarius, and NAC is expected to have an antidepressant effect. By using the forced swimming test (FST), we investigated the effects of treatment with NAC on immobility subacutely in rats after oral dosing once a day for 2 days. Serum levels of cytokine interleukin-1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were determined by enzyme-linked immunosorbent assay (ELISA). Nuclear factor-2 (Nrf-2) and inducible nitric oxide synthases (iNOS) were analyzed by western blot method. NAC dose-dependently decreased immobility in the FST. NAC dosedependently decreased FST-induced increase of cytokine levels, as manifested by significantly stronger effects on $IL-1{\beta}$ and $TNF-{\alpha}$ levels at higher doses than the lowest dose of NAC. Western blot analysis showed that Nrf-2 was significantly lower in the NAC-treated group than in the disease-induced group. The iNOS results were also significantly lower in the NAC-treated group than in the other groups. Considering FST results, the antidepressant effect of NAC is effective. Considering the results of cytokine and protein expression, this anti-depressant effect may be related to the anti-inflammatory effect. Therefore, it can be said that the anti-inflammatory effect of NAC increases the antidepressant effect in the FST experiment.

Molecular Cloning and Substrate Specificity of Human NeuAc ${\alpha}$2,3Gal${\beta}$ 1,3GalNAc GalNac ${\alpha}$2,6-Sialyltransferase (hST6GalNac IV)

  • Lee, Young-Choon;Kim, Kyoung-Sook;Kim, Sang-Wan;Min, Kwan-Sik;Kim, Cheorl-Ho;Choo, Young-Kug
    • Journal of Life Science
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    • v.11 no.1
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    • pp.57-64
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    • 2001
  • The cDNA encoding human NeuAc ${\alpha}$2,3Gal$\beta$ 1,3GalNAc GalNac ${\alpha}$2,6-Sialyltransferase (hST6GalNac IV) was isolated by screening of human fetal liver cDNA library with a DNA probe generated from the cDNA sequence of mouse ST6Gal NAc IV (mkST6GalNAc IV). The cDNA sequence included an open reading frame coding for 302 amino acids, and comparative analysis of this cDNA with mST6GalNAc IV showed that each sequence of the predicted coding region contains 88% and 85% identifies in nucleotide and amino acid levels, respecively. The primary structure of this enzyme suggested a putative domain structure, like that in other glycosyltransferases, consisting of a short N-terminal cytoplamic domain, a transmembrane domain and a large C-terminal active domain. This enzyme expressed in COS-7 cells echibited transferase activity toward NeuAc ${\alpha}$2,3Gal$\beta$ 1,3GalNAc, fetuin and GM1b, although the activity toward the later is very low, no significant activity being detected toward Gal${\beta}$ 1,3Gal NAc or asialofetuin, the other glycoprotein substrates tested. The $^{14}$ C-sialylated residue of fetuin sialylated by this enzyem with CMP-[$^{14}$C]NeuAc was sensitive to treatment with ${\alpha}$2,8-specific sialidase of Vibrio cholerae but resistant to treatment with ${\alpha}$2,3-specific sialidase (NaNase I), and ${\alpha}$2,3- and ${\alpha}$2,8-specific sialidase of Newcastle disease virus. These results clearly indicated that the expressed enzyme is a type of GalNAc ${\alpha}$2,6-sialyltransferase like mST6GalNAc IV, which requires sialic acid residues linked to Gal${\beta}$1,3GalNAc-residues for its activity.

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PIK3CA Mutations and Neoadjuvant Therapy Outcome in Patients with Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: A Sequential Analysis

  • Seo, Youjeong;Park, Yeon Hee;Ahn, Jin Seok;Im, Young-Hyuck;Nam, Seok Jin;Cho, Soo Youn;Cho, Eun Yoon
    • Journal of Breast Cancer
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    • v.21 no.4
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    • pp.382-390
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    • 2018
  • Purpose: PIK3CA mutation is considered to be a possible cause for resistance to neoadjuvant chemotherapy (NAC) in human epidermal growth factor receptor 2 (HER2)-positive breast cancer. We investigated the association between PIK3CA mutations and the outcome of NAC in HER2-positive breast cancers. Methods: A total of 100 HER2-positive breast cancer patients who had undergone NAC and surgery between 2004 and 2016 were examined. Mutation status was sequentially assessed in pre-NAC, post-NAC, and recurrent specimens taken from these patients. Results: PIK3CA mutations were identified in the sequential specimens of 17 patients (17.0%). These 17 patients experienced shorter disease-free survival (DFS) than the rest of the patients (58.3 months vs. 119.3 months, p=0.020); however, there was no significant difference in pathologic complete response (pCR) and overall survival (OS) (pCR, 17.6% vs. 33.7%, p=0.191; OS, 84.5 months vs. 118.0 months, p=0.984). While there was no difference in pCR between the wild-type and mutant PIK3CA groups in pre-NAC specimens (25.0% vs. 31.8%, p=0.199), PIK3CA mutations correlated with lower pCR in postNAC specimens (0.0% vs. 24.3%, p<0.001). Multivariate analysis revealed significantly worse DFS in the mutant PIK3CA group than in the wild-type group (hazard ratio, 3.540; 95% confidence interval, 1.001-12.589; p=0.050). Moreover, the DFS curves of the change of PIK3CA mutation status in sequential specimens were significantly different (p=0.016). Conclusion: PIK3CA mutation in HER2-positive breast cancer was correlated with a lower pCR rate and shorter DFS. These results suggest that PIK3CA mutation is a prognostic marker for NAC in HER2-positive breast cancer, especially in post-NAC specimens.

Upregulation of Dendritic Arborization by N-acetyl-D-Glucosamine Kinase Is Not Dependent on Its Kinase Activity

  • Lee, HyunSook;Dutta, Samikshan;Moon, Il Soo
    • Molecules and Cells
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    • v.37 no.4
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    • pp.322-329
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    • 2014
  • N-acetylglucosamine kinase (GlcNAc kinase or NAGK; EC 2.7.1.59) is highly expressed and plays a critical role in the development of dendrites in brain neurons. In this study, the authors conducted structure-function analysis to verify the previously proposed 3D model structure of GlcNAc/ATP-bound NAGK. Three point NAGK mutants with different substrate binding capacities and reaction velocities were produced. Wild-type (WT) NAGK showed strong substrate preference for GlcNAc. Conversion of Cys143, which does not make direct hydrogen bonds with GlcNAc, to Ser (i.e., C143S) had the least affect on the enzymatic activity of NAGK. Conversion of Asn36, which plays a role in domain closure by making a hydrogen bond with GlcNAc, to Ala (i.e., N36A) mildly reduced NAGK enzyme activity. Conversion of Asp107, which makes hydrogen bonds with GlcNAc and would act as a proton acceptor during nucleophilic attack on the ${\gamma}$-phosphate of ATP, to Ala (i.e., D107A), caused a total loss in enzyme activity. The overexpression of EGFP-tagged WT or any of the mutant NAGKs in rat hippocampal neurons (DIV 5-9) increased dendritic architectural complexity. Finally, the overexpression of the small, but not of the large, domain of NAGK resulted in dendrite degeneration. Our data show the effect of structure on the functional aspects of NAGK, and in particular, that the small domain of NAGK, and not its NAGK kinase activity, plays a critical role in the upregulation of dendritogenesis.