• Development and Reproduction
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• v.19 no.1
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• pp.43-51
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• 2015

Connexin (Cx) is a complex which allows direct communication between neighboring cells via exchange of signaling molecules and eventually leads to functional harmony of cells in a tissue. The initial segment (IS) is an excurrent duct of male reproductive tract and expression of numerous genes in the IS are controlled by androgens and estrogens. The effects of these steroid hormones on gene expression in the IS during postnatal development have not extensively examined. The present research investigated expressional modulation of Cx isoforms in the IS by exogenous exposure to estrogen agonist, estradiol benzoate (EB), or androgen antagonist, flutamide (Flu), at weaning age. Two different doses of EB or Flu were subcutaneously administrated in 21-day old of male rats, and expressional changes of Cx isoforms in the adult IS were analyzed by quantitative real-time PCR. Treatment of a low-dose EB ($0.015{\mu}g/kg$ body weight) resulted in an increased expression of Cx31 gene and a decreased expression of Cx37 gene. A high-dose EB ($1.5{\mu}g/kg$ body weight) treatment caused an increase of Cx31 gene expression. Increased levels of Cx30.3 and Cx40 transcripts were observed with a low-dose Flu ($500{\mu}g/kg$ body weight) treatment. Treatment of high-dose Flu (50 mg/kg body weight) led to expressional increases of Cx30.3, 40, and 43 genes. Our previous and present findings suggest differential responsiveness on gene expression of Cx isoforms in the IS by androgens and estrogens at different postnatal ages.

• BMB Reports
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• v.28 no.3
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• pp.221-226
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• 1995

Dopamine mediates inhibitory responses in Helix aspersa neurons from the right parietal lobe ("F-lobe") of the circumoesophageal ganglia. The effects appeared as a dose-dependent hyperpolarization of the plasma membrane and a decrease in the occurrence of spontaneous action potentials. The average hyperpolarization with 5 ${\mu}m$ dopamine was -12 mV (${\pm}1.5$mV, S.D., n=12). Dopamine also modulated the currents 'responsible for shaping the action potentials in these neurons. When dopamine was added and action potentials were triggered by an injection of current, the initial depolarization was slowed, the amplitude and the duration of action potentials were decreased, and the after-hyperpolarization was more pronounced. The amplitude and the duration of action potential were reduced about 15 mV and about 13% by 5 ${\mu}m$ dopamine, respectively. The effects of dopamine on the resting membrane potentials and the action potentials of Helix neurons were dose-dependent in the concentration range 0.1 ${\mu}m$ to 50 ${\mu}m$. In order to show 1) that the effects of dopamine were mediated by dopamine receptors rather than by direct action on ionic channels and 2) which type of dopamine receptor might be responsible for the various effects, we assayed the ability of mammalian dopamine receptor antagonists, SCH-23390 (antagonist of D1 receptor) and spiperone (antagonist of D2 receptor), to block the dopamine-dependent changes. The D1 and D2 antagonists partially inhibited the dopamine-dependent hyperpolarization and the decrease in action potential amplitude. They both completely blocked the decrease in action potential duration and the increase in action potential after-hyperpolarization. The dopamine-induced slowdown of the depolarization in the initial phase of the action potentials was less effected by SCH-23390 and spiperone. From the results we suggest 1) that Helix F-lobe neurons may have a single type of dopamine receptor that binds both SCH-23390 and spiperone and 2) that the dopamine receptor of Helix F-lobe neurons may be homologous with and primitive to the family of mammalian dopamine receptors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.517-526
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• 2000

In this paper, we propose the trellis coded spread spectrum communication system with one channel signal selection of the subset by the PN code. This paper proposes the Viterbi decoder that have the squared Euclidean distance of the order phase difference as well as 1st order phase difference as the branch metrics by using the multiple symbol detection method. TCM method was developed to overcome limited power and bandwidth efficiently in digital communication. we multiply one of convolution code's output data to PN code for applying TCM to the spread spectrum. We investigated the performance of the direct sequence/spread spectrum communication system with trellis coded modulation. In this system, we could improved the coding gain in the spread spectrum.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.95-99
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• 2008

Eosinophil degranulation plays a crucial role in tissue inflammatory reactions associated with helminth parasitic infections and allergic diseases. Paragonimus westermani, a lung fluke causing human paragonimiasis, secretes a large amount of cysteine proteases, which are involved in nutrient uptake, tissue invasion, and modulation of hos's immune responses. There is, however, limited information about the response of eosinophils to direct stimulation by cysteine proteases (CP) secreted by P. westermani. In the present study, we tested whether degranulation and superoxide production from human eosinophils can be induced by stimulation of the 2 CP (27 kDa and 28 kDa) purified from excretory-secretory products (ESP) of P. westermani newly excysted metacercariae (PwNEM). A large quantity of eosinophil-derived neurotoxin (EDN) was detected in the culture supernatant when human eosinophils isolated from the peripheral blood were incubated with the purified 27 kDa CP. Furthermore, the 27 kDa CP induced superoxide anion production by eosinophils in time- and dose-dependent manners. In contrast, the purified 28 kDa CP did not induce superoxide production and degranulation. These findings suggest that the 27 kDa CP secreted by PwNEM induces superoxide production and degranulation of human eosinophils, which may be involved in eosinophil-mediated tissue inflammatory responses during the larval migration in human paragonimiasis.

• Toxicological Research
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• v.26 no.3
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• pp.223-232
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• 2010

Artesunate, a semi-synthetic derivative of artemisinin, is used primarily as a treatment for malaria. Its effects on the central nervous system, general behavior, and cardiovascular, respiratory, and other organ systems were studied using mice, rats, guinea pigs, and dogs. Artesunate was administered orally to mice at doses of 125, 250, and 500 mg/kg and to rats and guinea pigs at 100, 200, and 400 mg/kg. In dogs, test drugs were administered orally in gelatin capsules at doses of 50, 100, and 150 mg/kg. Artesunate induced insignificant changes in general pharmacological studies, including general behavior, motor coordination, body temperature, analgesia, convulsion modulation, blood pressure, heart rate (HR), and electrocardiogram (ECG) in dogs in vivo; respiration in guinea pigs; and gut motility or direct effects on isolated guinea pig ileum, contractile responses, and renal function. On the other hand, artesunate decreased the HR and coronary flow rate (CFR) in the rat in vitro; however, the extent of the changes was small and they were not confirmed in in vivo studies in the dog. Artesunate increased hexobarbital-induced sleeping time in a dose-related manner. Artesunate induced dose-related decreases in the volume of gastric secretions and the total acidity of gastric contents, and induced increases in pH at a dose of 400 mg/kg. However, all of these changes were observed at doses much greater than clinical therapeutic doses (2.4 mg/kg in humans, when used as an anti-malarial). Thus, it can be concluded that artesunate is safe at clinical therapeutic doses.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.153-164
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• 1988

The potential role of endogenous opioid peptides (EOPS) in cardiovascular regulation has only recently been entertained. EOPS have been localized in brain, spinal cord, autonomic ganglia, particularly the adrenal gland, and many other peripheral tissues. There are at least five major types of opioid receptors; namely ${\mu},\;{\delta},\;k,\;{\sigma},\;and\;{\varepsilon}$ and Experimental evidence indicates that cardiovascular actions of the peptide are mediated primarily by ${\mu},\;{\delta}$ and k receptors, and that these receptor types may be allosterically coupled. In anesthetized rabbits met-enkephalin decreased blood pressure and heart rate, which closely paralleled a reduction in sympathetic discharge. Naloxone, but not naloxone methobromide, antagonized these effects, which suggests a central site of action of met-enkephalin. A number of autonomic agents, particularly adrenergic ${\alpha}$-and, ${\beta}-agonists$ and antagonists modify the cardiovascular actions of met-enkephalin. Experiments in reserpine-treated and adrenalectomized rats provide no evidence of sympathetic nervous system involvement in the pressor responses to intravenous injection of opioid peptides, but rather suggest a direct peripheral action. Finally, activation of a beta-endorphinergic pathway projecting from the arcuate nucleus to the nucleus tractos solitarii in rats can cause naloxone reversible hypotension and bradycardia. There is evidence to implicate this pathway in antihypertensive drug action and in the modulation of baroreflex activity.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3010-3022
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• 1997

Expert system is one of AI area which was came out at the end of 19705s. It simulates the human's way of thinking to give solutions of Problem in many applications. Most expert system consists of many components such as inference engine, knowledge base, and so on. Especially the performance of expert system depends on the control of enfficiency of inference engine. Inference engine has to get features; tirst, if possible to minimize restrictions when the knowledge base is constructed second, it has to serve various kinds of inferencing methods. In this paper, we design and implement the inference engine which is able to support the general functions to knowledge domain and inferencing method. For the purpose, forward chaining, backward chaining, and direct chaining was employed as an inferencing method in order to be able to be used by user request selectively. Also we not on1y selected production system which makes one ease staradization and modulation to obtain knowledges in target domain, but also constructed knowledge base by means of Extended Clause Bit Metrics (ECBM). Finally, the performance evaluation of inference engine between Rete pattern matching and ECBM has been done.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3711-3719
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• 2016

Drawbacks of conventional cancer treatments, with lack of specificity and cytotoxicity using current approaches, underlies the necessity for development of a novel approach, gene-directed cancer therapy. This has provided novel technological opportunities in vitro and in vivo. This review focuses on a member of an apoptosis inhibitor family, survivin, as a valuable target. Not only the gene but also its promoter are applicable in this context. This article is based on a literature survey, with especial attention to RNA interference as well as tumor-specific promoter action. The search engine and databases utilized were Science direct, PubMed, MEDLINE and Google. In addition to cell-cycle modulation, apoptosis inhibition, interaction in cell-signaling pathways, cancer-selective expression, survivin also may be considered as specific target through its promoter as a novel treatment for cancer. Our purpose in writing this article was to create awareness in researchers, emphasizing relation of survivin gene expression to potential cancer treatment. The principal result and major conclusion of this manuscript are that survivin structure, biological functions and applications of RNA interference systems as well as tumor-specific promoter activity are of major interest for cancer gene therapy.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.6
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• pp.18-26
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• 1999

This paper presents the architecture and design of a DSSS MODEM ASIC chip for wireless local area networks (WLAN). The implemented MODEM chip supports the DSSS physical layer specifications of the IEEE 802.11. The chip consits of a transmitter and a receiver which contain a CRC encoder/decoder, a differential encoder/decoder, a frequency offset compensator and a timing recovery circuit. The chip supports various data rates, i.e., 4,2 and 1Mbps and provides both DBPSK and DQPSK for data modulation. We have performed logic synthesis using the $SAMSUNG^{TM}$ $0.6{\mu}m$ gate array library and the implemented chip consists of 53,355 gates. The MODEM chip operates at 44MHz, the package type is 100-pin QFP and the power consumption is 1.2watt at 44MHz. The implemented MODEM architecture shows lower BER compared with the Harris HSP3824.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.9-17
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• 2015

The development of wireless communication technology and change in the ICT market has led to the development of the M2M service and technology. Under these circumstances, the M2M environment has been the focus of communication environment construction between machines without control or direct intervention of human being. With characteristics of wireless communication environment, the possibility of being exposed to numerous security threats and safe communication security technology have becoming an issue an important requirements for problems such as data exposure, forgery, modulation, deletion, and privacy. This research analyzes requirements of trapdoor collision hash, generates keys between groups under the M2M environment by using the specificity of trapdoor, and suggests technology to exchange keys with session keys. Further, it also suggests techniques to confirm authentication of device and gateway in accordance with group key generation. The techniques herein suggested are confirmed as safe methods in that they have attack resistance such as Masquerade Attack, Man-in-the-Middle Attack, and Replay Attack in the group communication block by using the speciality of collision message and collision hash.