• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.815-821
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• 2005

Among the various artificial neural networks the backpropagation network (BPN) has become a standard one. One of the components in a neural network is an activating function or a transfer function of which a representative function is a sigmoid. We have discovered that by updating the slope parameter of a sigmoid function simultaneous with the weights could improve performance of a BPN.

• 대한약리학회:학술대회논문집
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• 2006.11a
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• pp.62-62
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• 2006

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.169-174
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• 2021

Mutations in the luteinizing hormone/chorionic gonadotropin receptors (LH/CGRs), representatives of the G protein-coupled receptor family, have been rapidly identified over the last 20 years. This review aims to compare and analyze the data reported the activating and inactivating mutations of the LH/CGRs between human, rat, equine and fish, specifically (Japanese eel Anguilla japonica). Insights obtained through detailed study of these naturally-occurring mutations provide a further update of structure-function relationship of these receptors. Specifically, we present a variety of data on eel LH/CGR. These results provide important information about LH/CGR function in fish and the regulation of mutations of the highly conserved amino acids in glycoprotein hormone receptors.

• The Journal of the Korea Contents Association
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• v.16 no.5
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• pp.58-67
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• 2016

Pragmatic language impairment is closely related to the executive function difficulties in patients with acquired brain injury(ABI). This study was designed to explore the correlation between two domains following ABI. Thirty-five participants with ABI were grouped into 21 aphasics due to stroke and 14 TBIs. All subjects were over 55 years old. Measures of two domains were administered to all participants. As a result, figurative language comprehension and functional/symbolic language were significantly correlated with the activating task in aphasic group. All tasks were significantly correlated in TBI group. Aphasic patients' figurative language comprehension significantly predicted the activating task. In TBI group, figurative language expression and functional/symbolic language were the predictable tasks of planning and activating, respectively. Current study demonstrates the evidence of a significant association between pragmatic language and executive function, and provides appropriate tasks used for cognitive-linguistic intervention of individuals with ABI.

• Development and Reproduction
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• v.25 no.3
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• pp.133-143
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• 2021

In contrast to the human lutropin receptor (hLHR) and rat LHR (rLHR), very few naturally occurring mutants in other mammalian species have been identified. The present study aimed to delineate the mechanism of signal transduction by three constitutively activating mutants (designated M410T, L469R, and D590Y) and two inactivating mutants (D383N and Y546F) of the eel LHR, known to be naturally occurring in human LHR transmembrane domains. The mutants were constructed and measured cyclic adenosine monophosphate (cAMP) accumulation via homogeneous time-resolved fluorescence assays in Chinese hamster ovary (CHO)-K1 cells. The activating mutant cells expressing eel LHR-M410T, L469R, and D590Y exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response without agonist treatment, respectively. However, inactivating mutant cells expressing D417N and Y558F did not completely impaired signal transduction. Specifically, signal transduction in the cells expressing activating mutant L469R was not occurred with a further ligand stimulation, showing that the maximal response exhibited approximately 53% of those of wild type receptor. Our results suggested that the constitutively activating mutants of the eel LHR consistently occurred without agonist treatment. These results provide important information of LHR function in fish and regulation with regard to mutations of highly conserved amino acids in glycoprotein hormone receptors.

• BMB Reports
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• v.28 no.4
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• pp.316-322
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• 1995

The GTPase activating protein (GAP) can function both as a negative regulator and an effector of $p21^{ras}$. Overexpression of GAP in NIH-3T3 cells has been shown to inhibit transformation by ms or src. To investigate the function of GAP in a differentiative system, we overexpressed this protein in the nerve growth factor (NGF)-responsive PC12 cell line. Two-fold overexpression of GAP caused a delay of several days in the onset of NGF- but not FGF-induced neuronal differentiation of PC12 cells. However, the NGF-induced activation or tyrosine phosphorylation of upstream (Trk, PLC-${\gamma}1$, SHC) and downstream (B-Raf and $p44^{mapk/erk1}$) components of $p21^{ras}$, signalling cascade was not altered by GAP overexpression. Therefore, the change of phenotype induced by GAP was probably not due to GAP functioning as a negative regulator of $p21^{ras}$. Rather, we found that NGF-induced tyrosine phosphorylation of SNT, a specific target of neurotrophin-induced tyrosine kinase activity, was inhibited by GAP overexpression. SNT is thought to function upstream or independent of $p21^{ras}$. Thus in PC12 cells, overexpressed GAP may control the rate of neuronal differentiation through a pathway involving SNT rather than the $p21^{ras}$ signalling pathway.

• Development and Reproduction
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• v.25 no.4
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• pp.225-234
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• 2021

The present study aimed to investigate the mechanism of cell surface receptor loss by two constitutively activating mutants (designated L469R, and D590Y) and two inactivating mutants (D417N and Y558F) of the luteinizing hormone receptor (LHR) in the Japanese eel Anguilla japonica, known to naturally occur in human LHR transmembrane domains. We investigated cell surface receptor loss using an enzyme-linked immunosorbent assay in HEK 293 cells. The expression level of wild-type eel LHR was considered to be 100%, and the expression levels of L469R and D417N were 97% and 101%, respectively, whereas the expression levels of D590Y and Y558F slightly increased to approximately 110% and 106%, respectively. The constitutively activating mutants L469R and D590Y exhibited a decrease in cell surface loss in a manner similar to that of wild-type eel LHR. The rates of loss of cell surface agonist-receptor complexes were observed to be very rapid (2.6-6.2 min) in both the wild-type eel LHR and activating mutants. However, cell surface receptor loss in the cells expressing inactivating mutants D417N and Y558F was slightly observed in the cells expressing inactivating mutants D417N and Y558F, despite treatment with a high concentration of agonist. These results provide important information on LHR function in fish and the regulation of mutations of highly conserved amino acids in glycoprotein hormone receptors.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.41-47
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• 2000

Gonadotropin receptors are members of the seven-transmembrane (TM) receptor family, Point mutations in the lutropin/choriogonadotropin receptor (LH/CGR) have been shown to cause constitutive activation which results in precocious puberty in affected males, We introduced one of the mutation, D556Y, into the LH/CG receptor and the same high affinity binding mutant (D556Y) receptor clone cell for wild type LH/CGR (LH/CGR-wt) was chosen for further analysis, In contrast to cells expressing LH/CGR-wt, it was demonstrated that the mutant receptor exhibited markedly increased basal cAMP production in the absence of agonist, suggesting that autonomous Leydig cell activity in familial male-precocious puberty (FMPP) is caused by a constitutively activating LH/CGR.

• Hanyang Medical Reviews
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• v.33 no.1
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• pp.59-64
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• 2013

Cancer remains the leading cause of death worldwide despite intense efforts in developing innovative treatments. Current approaches in cancer therapy are mainly directed to a selective targeting of cancer cells to avoid potential side effects associated with conventional therapy. In this respect, Natural killer (NK) cells have gained growing attention and are now being considered as promising therapeutic tools for cancer therapy owing to their intrinsic ability to rapidly recognize and kill cancer cells, while sparing normal healthy cells. NK cells play a key role in the first line of defense against transformed and virus-infected cells. NK cells sense their target through a whole array of receptors, both activating and inhibitory. Functional outcome of NK cell against target cells is determined by the balance of signals transmitted from diverse activating and inhibiting receptors. Despite significant progress made in the role of NK cells attack as a pivotal sentinel in tumor surveillance, the molecular has been that regulate NK cell responses remain unclear, which restricts the use of NK cells as a therapeutic measure. Accordingly, current efforts for NK cell-based cancer therapy have largely relied on the strategies that are based on the manipulation of inhibitory receptor function. However, if we better understand the mechanisms governing NK cell activation, including those mediated by diverse activating receptors, this knowledge can be applied to the development of optimal design for cancer immunotherapy by targeting NK cells.

• Clinical and Experimental Pediatrics
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• v.53 no.8
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• pp.795-800
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• 2010

Purpose: B cell-activating factor (BAFF) is a tumor-necrosis factor (TNF) superfamily member best known for its role in the survival and maturation of B cells. BAFF activity is observed in naive cells as well as in effector/memory T cells. We aimed to explore whether BAFF in sputum is expressed at elevated levels in asthmatic airways and associated with eosinophilic inflammation, pulmonary function, and bronchial hyperresponsiveness in children. Methods: One hundred and fifty-four asthmatic children and 98 healthy children were enrolled in the study. Sputum supernatants were collected and sputum BAFF and eosinophil cationic protein (ECP) levels were measured. We performed pulmonary function tests and methacholine challenge tests, while measuring total eosinophil count, total serum IgE, and serum ECP in all subjects. Results: Asthmatic children had significantly higher levels of BAFF in induced sputum [26.50 (10.50-100.27) pg/mL] compared to healthy children [18.32 (7.68-44.63) pg/mL; $P$=0.011]. Sputum BAFF positively correlated with sputum eosinophils (${\gamma}$=0.406, $P$<0.001) and sputum ECP (${\gamma}$=0.789, $P$<0.001). Significant negative correlations were found between sputum BAFF and FEV1 (${\gamma}$=-0.291, $P$<0.001) or post-bronchodilator FEV1 (${\gamma}$=-0.334, $P$<0.001), whereas nonsignificant correlations were found between sputum BAFF and bronchial hyperresponsiveness, serum eosinophil count, and serum ECP. Conclusion: These findings suggest that BAFF may play a role in childhood asthma, and BAFF levels in sputum could be a supportive marker that represents airway inflammation, especially eosinophilic inflammation.