• Journal of Chest Surgery
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• v.21 no.6
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• pp.970-978
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• 1988

There is tendency of increasing number and decreasing age of patients who are indicated for Rastelli operation for their cyanotic congenital heart disease. So there is the need to find the criterion which saves the patients from early postoperative hemodynamic disturbances. We reviewed the 26 patients who had been performed Rastelli operation at Seoul national University Hospital from January 1981 to June 1988. mean age of the patients was 7.8*3.4 years[range 2.5-15years], mean body surface area[BSA] 0.79*0.25m2[range 0.49-1.51m2] and mean hematocrit 57.95*12%[range 48-80%]. We divided these patients into survived group and died group before postoperative 72 hours, and analyzed preoperative arterial oxygen saturation[SaO2], the ratio of diameter of right pulmonary artery to ascending aorta[RPA/AA], the ratio of both right and left pulmonary artery diameter to descending thoracic aorta[RPA+LPA/DTA], pulmonary artery index[PA index], cardiopulmonary bypass time, aorta cross-clamping time, postoperative perfusion state and total amount of dopamine infused postoperatively. The results showed that RPA+LPA/DTA and PA index were statistically significant factors to influence early postoperative cardiac death rate[P< 0.05]. Especially there were good linear correlations between PA index[X] and peripheral perfusion index[Y][Y= - 1.15+0.02 X, r=0.86, P<0.01]and between PA index[X] and total amount of dopamine infused before postoperative 72 hours[mg/kg, Y][Y=61.94 - 0.15 X, r=-0.80, P < 0.01]. Also there were tendencies that the higher RPA+LPA/DTA[Y], the better peripheral perfusion [X] and the lower need of dopamine[X], but no statistical significance.[Y=0.78+1.60 X, r =0. 49, P >0.05] And the discriminate analysis showed that patients with PA index over 221 mm2/BSA could undergo correction with 25 per cent of error rate. In conclusion, early postoperative hemodynamic states could be predicted by preoperatively measured PA index, and which can be used as a criterion for Rastelli operation performed on cyanotic congenital heart disease.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.243-246
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• 2001

A cavity delay filter module for IMT-2000 LPA has been developed with 0.9dB insertion loss, 0.1dB/0.6$^{\circ}$ gain/phase flatness. Broadband signal cancellation of the module has been simulated using the measured S parameter, and gain, phase and group delay have been matched to satisfy the signal cancellation of the module. In the experiment, the value of designed parameters are used and 40dB signal cancellation has been obtained over 100MHz bandwidth. Also the sampling cancellation has been shown to be the similar performance of the feedforward output cancellation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.959-966
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• 2006

This paper proposes a new concept about dual band predistortion linear power amplifier(PD LPA) using diplexer for digital cellular ($f_o$=880 MHz) and IMT-2000($f_o$=2,140 MHz) base stations. The diplexer is composed of low pass filter having defected ground structure(BGS) microstrip line and high pass filter having high-Q lumped capacitors and distributed elements. The proposed predistorter adopts a reflection type intermodulation signal generator with 3 dB hybrid coupler for good reflection characteristic. for a forward link one carrier CDMA IS-95A 1FA and WCDMA 1FA signal, the proposed dual band PD LPA shows the adjacent channel leakage ratio(ACLR) improvement about 10 dB and 9.36 dB for digital cellular and IMT-2000 band, respectively.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.439-452
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• 2018

This study aims to empirically structure the patterns of consumption and their effects on depression among the employed baby-boomers who were born in 1955 to in 1963. We used the 5th wave of Korea Retirement and Income Study(KReIS) in 2013 (n=2,585). The Latent Profile Analysis(LPA) estimated the empirical patterns of consumption and then a multiple regression analyzed the effect of consumption patterns on depression. The LPA results showed that the consumption patterns consist of four groups: Basic life-oriented class, Social life-oriented class, Home-based lifestyle class, and Advanced consumption-oriented class. The working baby boomers' depression was associated with their consumption patterns. Specifically, the social life-oriented class showed significantly lower depression than the basic life-oriented class and advanced consumption-oriented class. Other associates with higher levels of depression were found as lower education, having no spouse, lower self-rated health, higher levels of physical limitation, having a diagnosed disability, lower satisfaction with leisure activities, lower income, and lower subjective economic status in this study. Based on the results of this study, we propose the need for specialized financial intervention better for baby-boomers' retirement preparation in Korea.

• Journal of Ginseng Research
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• v.45 no.5
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• pp.575-582
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• 2021

Background: In ginseng, there exists a glycolipoprotein complex with a special form of lipid LPAs called Gintonin. The purpose of this study is to show that Gintonin has a therapeutic effect on rheumatoid arthritis through LPA2 receptors. Methods: Fibroblast-like synoviocytes (FLS) were treated with Gintonin and stimulated with interleukin (IL)-1β. The antioxidant effect of Gintonin was measured using MitoSOX and H₂DCFDA experiments. The anti-arthritic efficacy of Gintonin was examined by analyzing the expression levels of inflammatory mediators, phosphorylation of mitogen-activated protein kinase (MAPK) pathways, and translocation of nuclear factor kappa B (NF-κB)/p65 into the nucleus through western blot. Next, after treatment with LPAR2 antagonist, western blot analysis was performed to measure inflammatory mediator expression levels, and NF-κB signaling pathway. Carrageenan/kaolin-induced arthritis rat model was used. Rats were orally administered with Gintonin (25, 50, and 100 mg/kg) every day for 6 days. The knee joint thickness, squeaking score, and weight distribution ratio (WDR) were measured as the behavioral parameters. After sacrifice, H&E staining was performed for histological analysis. Results: Gintonin significantly inhibited the expression of iNOS, TNF-α, IL-6 and COX-2. Gintonin prevented NF-κB/p65 from moving into the nucleus through the JNK and ERK MAPK phosphorylation in FLS cells. However, pretreatment with an LPA2 antagonist significantly reversed these effects of Gintonin. In the arthritis rat model, Gintonin suppressed all parameters that were measured. Conclusion: This study suggests that LPA2 receptor plays a key role in mediating the anti-arthritic effects of Gintonin by modulating inflammatory mediators, the MAPK and NF-κB signaling pathways.

• Journal of Ginseng Research
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• v.47 no.3
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• pp.390-399
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• 2023

Background: Gintonin (GT), a Panax ginseng-derived lysophosphatidic acid receptor (LPAR) ligand, has positive effects in cultured or animal models for Parkinson's disease, Huntington's disease, and so on. However, the potential therapeutic value of GT in treating epilepsy has not yet been reported. Methods: Effects of GT on epileptic seizure (seizure) in kainic acid [KA, 55mg/kg, intraperitoneal (i.p.)]-induced model of mice, excitotoxic (hippocampal) cell death in KA [0.2 ㎍, intracerebroventricular (i.c.v.)]-induced model of mice, and levels of proinflammatory mediators in lipopolysaccharide (LPS)-induced BV2 cells were investigated. Results: An i.p. injection of KA into mice produced typical seizure. However, it was significantly alleviated by oral administration of GT in a dose-dependent manner. An i.c.v. injection of KA produced typical hippocampal cell death, whereas it was significantly ameliorated by administration of GT, which was related to reduced levels of neuroglial (microglia and astrocyte) activation and proinflammatory cytokines/enzymes expression as well as increased level of the Nrf2-antioxidant response via the upregulation of LPAR 1/3 in the hippocampus. However, these positive effects of GT were neutralized by an i.p. injection of Ki16425, an antagonist of LPA1-3. GT also reduced protein expression level of inducible nitric-oxide synthase, a representative proinflammatory enzyme, in LPS-induced BV2 cells. Treatment with conditioned medium clearly reduced cultured HT-22 cell death. Conclusion: Taken together, these results suggest that GT may suppress KA-induced seizures and excitotoxic events in the hippocampus through its anti-inflammatory and antioxidant activities by activating LPA signaling. Thus, GT has a therapeutic potential to treat epilepsy.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.1-11
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• 2024

Fresh ginseng is prone to spoilage due to its high moisture content. For long-term storage, most fresh ginsengs are dried to white ginseng (WG) or steamed for hours at high temperature/pressure and dried to form Korean Red ginseng (KRG). They are further processed for ginseng products when subjected to hot water extraction/concentration under pressure. These WG or KRG preparation processes affect ginsenoside compositions and also other ginseng components, probably during treatments like steaming and drying, to form diverse bioactive phospholipids. It is known that ginseng contains high amounts of gintonin lysophosphatidic acids (LPAs). LPAs are simple lipid-derived growth factors in animals and humans and act as exogenous ligands of six GTP-binding-protein coupled LPA receptor subtypes. LPAs play diverse roles ranging from brain development to hair growth in animals and humans. LPA-mediated signaling pathways involve various GTP-binding proteins to regulate downstream pathways like [Ca²⁺]_i transient induction. Recent studies have shown that gintonin exhibits anti-Alzheimer's disease and antiarthritis effects in vitro and in vivo mediated by gintonin LPAs, the active ingredients of gintonin, a ginseng-derived neurotrophin. However, little is known about how gintonin LPAs are formed in high amounts in ginseng compared to other herbs. This review introduces atypical or non-enzymatic pathways under the conversion of ginseng phospholipids into gintonin LPAs during steaming and extraction/concentration processes, which exert beneficial effects against degenerative diseases, including Alzheimer's disease and arthritis in animals and humans via LPA receptors.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.625-634
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• 2022

The objective of this study was to examine the relationship between physical activity (PA) level and functional fitness (FF) parameters in community-dwelling older adults aged 65 or above in Korea. Subjects' (M: 1,645; F: 2,394) PA level were assessed using a questionnaire. The subjects were divided into two groups: one below the recommended level of PA(LPA) and one above the recommended level (PA). PA was further classified by intensity level into medium- and high-intensity PA (MIPA and HIPA respectively) groups. FF was assessed based on six test items representing the following fitness areas: lower and upper body strength, agility and dynamic balance, flexibility, aerobic capacity, coordination, and body composition. Of the subjects, 36% met the recommended level of PA. Both MIPA and HIPA were superior to LPA in all FF items(p<.05). The HIPA group was significantly better in terms of agility and dynamic balance, coordination, and lower body strength (only in women) than was the MIPA group(p<.05). In conclusion, PA above the recommended level is needed to maintain functional fitness. In addition, HIPA seems to promote fall-related functional fitness and should be encouraged when safe and feasible.

• Biomolecules & Therapeutics
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• v.14 no.1
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• pp.25-29
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• 2006

We tested effects of bioactive lysophospholipids including lysophosphatidic acid (LPA), lysophosphatidylcholine (LPC), sphingosylphosphorylcholine (SPC), and sphingosine I-phosphate (S1P) on membrane potential in C6 glioma cells to understand action mechanism of the lysophospholipids. Membrane potential was estimated by measuring fluorescence change of DiBAC-loaded glioma cells. LPA largely increased membrane potential and the increase was gradually diminished. LPC also increased the membrane potential, however, the increase sustained. SPC induced smaller increase of membrane potential than LPC. SIP was not able to change the membrane potential. We tested effects of suramin and pertussis toxin on lysophospholipid-induced membrane potential increase. However, there wasn't any effect. The membrane potential increase was partially diminished in $Na^+$-free media, suggesting $Na^+$ influx as a component of membrane potential changes. Thus, involvement of $Na^+$ influx in the increase of membrane potential by lysophospholipids and independence of suramin-sensitive GPCRs and pertussis toxin-sensitive G proteins are found in this study.

• Molecules and Cells
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• v.37 no.9
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• pp.656-663
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• 2014

Gintonin, a novel, ginseng-derived G protein-coupled lysophosphatidic acid (LPA) receptor ligand, elicits $[Ca^{2+}]_i$ transients in neuronal and non-neuronal cells via pertussis toxin-sensitive and pertussis toxin-insensitive G proteins. The slowly activating delayed rectifier $K^+$ ($I_{Ks}$) channel is a cardiac $K^+$ channel composed of KCNQ1 and KCNE1 subunits. The C terminus of the KCNQ1 channel protein has two calmodulin-binding sites that are involved in regulating $I_{Ks}$ channels. In this study, we investigated the molecular mechanisms of gintonin-mediated activation of human $I_{Ks}$ channel activity by expressing human $I_{Ks}$ channels in Xenopus oocytes. We found that gintonin enhances $I_{Ks}$ channel currents in concentration- and voltage-dependent manners. The $EC_{50}$ for the $I_{Ks}$ channel was $0.05{\pm}0.01{\mu}g/ml$. Gintonin-mediated activation 1 of the $I_{Ks}$ channels was blocked by an LPA1/3 receptor antagonist, an active phospholipase C inhibitor, an $IP_3$ receptor antagonist, and the calcium chelator BAPTA. Gintonin-mediated activation of both the $I_{Ks}$ channel was also blocked by the calmodulin (CaM) blocker calmidazolium. Mutations in the KCNQ1 $[Ca^{2+}]_i$/CaM-binding IQ motif sites (S373P, W392R, or R539W)blocked the action of gintonin on $I_{Ks}$ channel. However, gintonin had no effect on hERG $K^+$ channel activity. These results show that gintonin-mediated enhancement of $I_{Ks}$ channel currents is achieved through binding of the $[Ca^{2+}]_i$/CaM complex to the C terminus of KCNQ1 subunit.