• Proceedings of the Korean Biophysical Society Conference
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• 1999.06a
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• pp.20-20
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• 1999

Bacterial chemotaxis receptors are some of the simplest and most studied transmembrane receptors. Their simple signaling pathway has elements relevant for understanding the mechanisms for signal recognition, transduction through the membrane, relays among the molecules in the pathway, and adaptation to a persistent signal.(omitted)

• Biomedical Science Letters
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• v.20 no.3
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• pp.111-116
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• 2014

Human neutrophils play an essential role in the innate immune response and are involved in the pathogenesis of the severe and corticosteroid-resistant asthma. Asthma is characterized by an infiltration of inflammatory cells into the lung and by a cytokine release. The aim of this study is to investigate the effects of a bronchoalveolar lavage fluid (BALF) on the chemotaxis and apoptosis of neutrophils which were isolated from healthy subjects. The BALF of subjects with asthma induces the blood neutrophil chemotaxis in the opposite of that in normal subjects. The IL-8, IL-6, and monocyte chemoattractant protein-1 (MCP-1) levels in BALF were higher in subjects with asthma than in normal subjects. The BALF of normal and asthmatic subjects has no effect on neutrophil apoptosis of BALF. MCP-1 delays the constitutive apoptosis of normal blood neutrophils, but has no effect in normal BALF neutrophils. These results may indicate that inflammatory factors secreted by the lung tissue of patients with asthma trigger the neutrophil chemotaxis and also induce the neutrophil dysregulation.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.352-358
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• 2002

Blood monocytes are the precursors for the lipid-laden foam cells of early atherosclerotic lesions. Monocyte chemoattractant protein-1(MCP-1), a CC chemokine, and chemokine receptor 2 (CCR2) play a crucial role in the recruitment of monocytes to the vascular lesion. Using the human monocyte THP-1 cell line, we investigate the inhibitory effects of methanol extracts of 127 medicinal herbs on MCP-1 induced chemotaxis. Seven kinds of methanol extracts of medicinal herbs showed above 40% inhibitory effect with the concentration of $25{\mu}g/ml$. They were divide three fractions of $CHCI_3$, BuOH, $H_2O$ to use solvent partition. Among them, butanol extract of Junci Medulla and $CHCI_3$ extract of Clematidis Radix are showed significant inhibitory activities (above 50% inhibition) at the same concentration.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.129-142
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• 2005

Objective : Asthma is known as chronic airway inflammatory disease. This inflammation is conducted by various inflammatory cells including eosihophil. Chemotaxis is one way that circulating inflammatory cells invade a specific lesion. This study examines the degree to which Lonicerae Flos inhibits eosinophil chemotaxis at pulmonary epithelium after allergic stimulation. Material and Methods : Water extracts of Lonicerae Flos and pulmonary epithelial cell lines A549(human type II-like epithelial cells) and human eosinophils were used. Cytotoxic effects of Lonicerae Flos via MTS assay were estimated, as well as the effects of Lonicerae Flos on chemokines from prestimulated A549 cells by sandwich ELISA and RT-PCR. Chemotaxis assay was conducted on prestimulated eosinophils treated with Lonicerae Flos. Result : In this study $TNF-{\alpha}$ and IL-4, $IL-l{\beta}$ were seen to induced the accumulation of chemokines mRNA in the pulmonary epithelial cell lines A549 in a dose-dependent manner. Chemokines were inhibited by Liripois Tuber in a dose-dependent manner and especially, IL-8 and ICAM-l were inhibited considerably at $100\;{\mu}g/ml$ concentration of Lonicerae Flos. The eosinophil migration is inhibited in high concentration of Lonicerae Flos in a dose-dependent manner. Conclusion : These findings indicate that the supression of the expression of chemokines can be accomplished by Lonicerae Flos treatment, raising the possibility that Lonicerae Flos might be of therapeutic value in diseases such as asthma.

• Journal of Veterinary Clinics
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• v.22 no.2
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• pp.84-89
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• 2005

This study was undertaken to examine whether 1,2-benzopyrone affects on chemotactic activity of canine peripheral blood leukocytes. A modified Boyden chamber method was sed on chemotaxis evaluation. The direct treatments of 1,2-benzopyrone showed no ffects on the chemotaxis of peripheral blood mononuclear cells (PBMCs) and olymorphonuclear cells (PMNs). But chemotaxis of PMN was remarkably enhanced by ulture supernatant from PBMC but not PMN treated with 1,2-benzopyrone. Similarly, it as also increased by recombinant (r) interleukin (lL)­8. This chemotactic activity of MN was inhibited by addition of anti-rIL-8 polyclonal antibody. The chemotaxis of PBMC was not enhanced by culture supernatant from either PBMC or PMN treated with 1,2-benzopyrone. Therefore, these results suggested that the chemotactic activity of PMN ay be mainly mediated by IL-8-like factor(s) produced from PBMC treated with ,2-benzopyrone.

• Journal of Computing Science and Engineering
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• v.8 no.1
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• pp.1-10
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• 2014

The Bacterial Foraging Optimization Algorithm is a swarm intelligence optimization algorithm. This paper first analyzes the chemotaxis, as well as elimination and dispersal operation, based on the basic Bacterial Foraging Optimization Algorithm. The elimination and dispersal operation makes a bacterium which has found or nearly found an optimal position escape away from that position, which greatly affects the convergence speed of the algorithm. In order to avoid this escape, the sphere of action of the elimination and dispersal operation can be altered in accordance with the generations of evolution. Secondly, we put forward an algorithm of an adaptive adjustment of step length we called improved bacterial foraging optimization (IBFO) after making a detailed analysis of the impacts of the step length on the efficiency and accuracy of the algorithm, based on chemotaxis operation. The classic test functions show that the convergence speed and accuracy of the IBFO algorithm is much better than the original algorithm.

• KSBB Journal
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• v.24 no.1
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• pp.9-16
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• 2009

Chemotaxis is the movement of an organism toward chemical attractant and away from chemical repellents. Several bacteria are known to cometabolically degrade some pollutants and attracted to the pollutants. The chemotactic responses to these compounds influence the efficiency of bioremediation because the first precondition of pollutant degradation is definitely confrontation between microorganisms and pollutants. In this review, we summarize present knowledge of about the chemotactic mechanism to environmental pollutants of Pseudomonas species.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1355-1360
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• 2011

The interaction between the cell and the substrate is the most prominent feature affecting the migration of a crawling cell. This paper proposes a three-dimensional dynamic model using the diffuse interface description that reveals the effects of the interaction between a single crawling cell and the substrate during chemotactic migration. To illustrate the effects of interaction between the cell and the substrate, we consider the interfacial energy between the coexistent materials. Multiple mechanisms including the interface energy, chemotaxis effect, and diffusion, are addressed by employing a diffuse interface model.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.27-34
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• 1996

The phagocytosis and chemotaxis of murine macrophages after treated with saponin fractions are investigated. Phagocytic appearance against yeast was photographed by dying with Wright-Giemsa. Phagocytic activity of peritoneal macrophage was invreased in diol saponin treatment by 48% and was decreased in total saponin treatment by 35%. The ingestion of alveolar macrophage was increased by 50% maximally. Peritoneal chemotactic activity was shown in 17% increases and only diol saponin had effect in alveolar macrophage by 16%. According to SDS-PAGE method the contents of actin did not show any alterations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.2846-2866
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• 2022

Caenorhabditis elegans exhibits sophisticated chemotaxis behavior through two parallel strategies, klinokinesis and klinotaxis, executed entirely by a small nervous circuit. It is therefore suitable for inspiring fast and energy-efficient solutions for autonomous navigation. As a random search strategy, the Lévy walk is optimal for diverse animals when foraging without external chemical cues. In this study, by combining these biological strategies for the first time, we propose a spiking neural network model for search and contour tracking of specific concentrations of environmental variables. Specifically, we first design a klinotaxis module using spiking neurons. This module works in conjunction with a klinokinesis module, allowing rapid searches for the concentration setpoint and subsequent contour tracking with small deviations. Second, we build a random exploration module. It generates a Lévy walk in the absence of concentration gradients, increasing the chance of encountering gradients. Third, considering local extrema traps, we develop a termination module combined with an escape module to initiate or terminate the escape in a timely manner. Experimental results demonstrate that the proposed model integrating these modules can switch strategies autonomously according to the information from a single sensor and control steering through output spikes, enabling the model worm to efficiently navigate across various scenarios.