• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.1
• /
• pp.94-99
• /
• 2007

Many cases of acute cardiac shock and cardiac arrest in emergency room and ICU have been increasing. In this case, ECMO with centrifugal pump has been used generally. However, due to the heavy weight and big size, the system is not adequate for emergency cases. And other defects of this system are that membrane oxygenator's pressure is high and blood are exposed to the air. There was some tries of ECMO using pulsatile pump, but it was found that the weak point of these system is high peak pressure and hemolysis. The mechanism of twin pulsatile pump is that Membrane oxygenator Outlet Pump(MOP) make negative pressure when Membrane oxygenator Inlet Pump(MIP) provides high positive pressure, and the negative pressure will decrease positive pressure of Membrane Oxygenator. Our group analyzed this advantage through In-Vitro and 12 Cases In-Vivo test.

• Journal of Biomedical Engineering Research
• /
• v.18 no.4
• /
• pp.429-438
• /
• 1997

Mechanical valve is one of the most widely used implantable artificial organs of which the reliability is so important that its failure means the death of patient. Therefore early noninvasive detection is essentially required, though mechanical valve failure with thrombosis is the most common. The objective of this paper is to detect the thrombosis formation by spectral analysis and neural network. Using microphone and amplifier, we measured the sound from the mechanical valve which is attached to the pneumatic ventricular assist device. The sound was sampled by A/D converter(DaqBook 100) and the periodogram is the main algorithm for obtaining spectrum. We made the thrombosis models using pellethane and silicon and they are thrombosis model on the valvular disk, around the sewing ring and fibrous tissue growth across the orifice of valve. The performance of the measurment system was tested firstly using 1 KHz sinusoidal wave. The measurement system detected well 1KHz spectrum as expected. The spectrum of normal and 5 kinds of thrombotic valve were obtained and primary and secondary peak appeared in each spectrum waveform. We find that the secondary peak changes according to the thrombosis model. So to distinguish the secondary peak of normal and thrombotic valve quantatively, 3 layer back propagation neural network, which contains 7, 000 input node, 20 hidden layer and 1 output was employed The trained neural network can distinguish normal and valve with more than 90% probability. As a conclusion, the noninvasive monitoring of implanted mechanical valve is possible by analysing the acoustical spectrum using neural network algorithm and this method will be applied to the performance evaluation of other implantable artificial organs.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.3
• /
• pp.470-486
• /
• 1995

Mammary epithelial cells contain a subpopulation of cells with a large proliferativ potential which are responsible for the maintenance of glandular cellularity and are the progenitor cells of mammary cancer. These clonogens give rise to multicellular clonal alveolar or ductal units(AU or DU) on transplantation and hormonal stimulation. To isolate putative mammary clonogens, enzymatically monodispersed rat mammary epithelial cells from organoid cultures and from intact glands are sorted by flow cytometry according to their affinity for FITC labeled peanut lectin(PNA) and PE labeled anti-Thy-1.1 antibody(Thy-1.1) into four subpopulations : cells negative to both PNA and Thy-1.1(B-), PNA+cells, Thy-1.1+cells, and cells positive to both reagents(B+). The in vivo transplantation assays indicate that the clonogenic fractions of PNA+cells from out-growths of organoids in primary cultures for three days in complete hormone medium(CHM) are significantly higher than those of cells from other subpopulations derived from cultrues or from intact glands. Extracellular matrix(ECM) is a complex of several proteins that regulated cell function ; its role in cell growth and differentiation and tissue-specific gene expression. It can act as a positive as well as a negative regulator of cellular differentiation depending on the cell type and the genes studied. Regulation by ECM is closely interrelated with the action of other regulators of cellular function, such as growth factors and hormones. Matrigel supports the growth and development of several different multicellular colonies from mammary organoids and from monodispersed epithelial cells in culture. Several types of colonies are observed including stellate colonies, duct-like structures, two- and three-dimensional web structures, squamous organoids, and lobulo-duct colonies. Organoids have the greatest proliferative potential and formation of multi-cellular structures. Phase contrast micrographs demonstrate extensive intracellular lipid accumulation within the web structures and some of duct-like colonies. At the immunocytochemical and electron micrograph level, casein proteins are predominantly localized near the apical surface of the cells or in the lumen of duct-like or lobulo-duct colonies. Squamous colonies are comprised of several layers of squamous epithelium surrounding keratin pearls as is typical fo squamous metaplasia(SM). All-trans retinoic acid(RA) inhibits the growth of SM. The frequency of lobulo-ductal colony formation increased with the augmentation of RA concentration in these culture conditions. The current study models could provide powerful tools not only for understanding cell growth and differentiation of epithelial cells, but also for the isolation and characterization of mammary clonogenic stem cells.

• Polymer(Korea)
• /
• v.34 no.3
• /
• pp.274-281
• /
• 2010

In this study, PEG-PLA(or PLGA) amphiphilic di-block copolymers were synthesized by ring opening polymerization of D,L-lactide(or glycolide) and applied to polymeric micelle system for solubilization of a rosiglitazone as diabetes drug. The drug could be efficiently loaded into the polymer micelle by solid dispersion technique, and the drug-loaded micelles were characterized and evaluated as a drug delivery carrier by fluorescence spectrometer, DSC, and DLS measurements. The colloidal stability of drug loaded micelles in aqueous media could be enhanced by addition of 2-hydroxy-N-picolylnitinamide as a hydrotropic agent. The polymer micelles also showed biocompatible and nontoxic properties in vitro cell viability using MTT assay, and the drug loaded micelles were observed to be more effective than free drug for decreasing glucose in blood of rats.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.64-72
• /
• 2023

Despite several advances in identification of cardiac transcription factors, there are still needs to find new bioactive molecules that promote cardiomyogenesis from stem cells to highly efficient myocardial differentiation. We analyzed Illumina expression microarray data of mouse embryonic stem cells (mESCs)-derived cardiomyocytes. 276 genes were upregulated (≥ 4fold) in mESCs-derived cardiomyocytes compared undifferentiated ESCs. Secreted phosphoprotein 2 (Spp2) is one of candidates and is known to inhibit bone morphogenetic protein 2 (BMP2) signal transduction as a pseudoreceptor for BMP2. However, its function in cardiomyogenesis is unknown. We confirmed that Spp2 expression increased during the differentiation into functional cardiomyocytes using mESCs, TC-1/Kh2 and E14. Interestingly, Spp2 secretion transiently increased 3 days after formation of embryoid bodies (EBs), indicating that the extracellular secretion of Spp2 is involved in the differentiation of ESCs into cardiomyocytes. To characterize Spp2, we performed experiments using the C2C12 mouse myoblast cell line, which has the property of shifting the differentiation pathway from myoblastic to osteoblastic by treatment with BMP2. Similar to the differentiation of ESCs, transcription of Spp2 increased as C2C12 myoblasts differentiated into myotubes. In particular, Spp2 secretion increased dramatically in the early stage of differentiation. Furthermore, treatment with Spp2-Flag recombinant protein promoted the differentiation of C2C12 myoblasts into myotubes. Taken together, we suggest a novel bioactive protein Spp2 that differentiates ESCs into cardiomyocytes. This may be useful for understanding the molecular pathways of cardiomyogenesis and for experimental or clinical promotion of stem cell therapy for ischemic heart diseases.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.41 no.3
• /
• pp.233-240
• /
• 2014

An in vitro study on cariogenic potential of four over-the-counter nutritional supplements for children was performed. The experimental groups were four over-the-counter nutritional supplements. The positive control group was 10% sucrose solution (S), and the negative control group was artificial saliva (T). The pH of each group, the buffering capacities, acid production, the microhardness changes of the bovine teeth specimens were measured. The pH of all experimental groups were lower than critical pH 5.5 where enamel demineralization starts. The buffering capacity of the Hama Vitamin Pharm (Hamsoa Pharm Co., Korea) was highest, and the Smart Chewable Vitamin A (JW Pharm Co., Korea) had the lowest buffering capacity. The reduction rates of the pH of the experimental groups were significantly higher than that of the negative control group (p < 0.05). The microhardness of enamel of all experimental groups and the positive control group significantly decreased. In contrast, the microhardness of enamel of the negative control group significantly increased after experiment (p < 0.05). The reduction rate of the microhardness of enamel of the Hama Vitamin Pharm (Hamsoa Pharm Co., Korea) was significantly higher and Hikid Plus (Sanga Pharm Co., Korea) was significantly lower than the other experimental groups.

• Childhood Kidney Diseases
• /
• v.15 no.2
• /
• pp.138-145
• /
• 2011

Purpose : To test whether the expression of ${\beta}$-catenin, a component of podocyte as a filtration molecule, would be altered by puromycin aminonucleoside (PAN) in the cultured podocyte in vitro. Methods : We cultured rat glomerular epithelial cells (GEpC) with various concentrations of PAN and examined the distribution of ${\beta}$-catenin by confocal microscope and measured the change of ${\beta}$-catenin expression by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Results :We found that ${\beta}$-catenin relocalized from peripheral cytoplasm to inner cytoplasm, therefore, intercellular separations were seen in confluently cultured cells by high concentrations of PAN in immunofluorescence views. In Western blotting of GEpC, PAN ($50{\mu}g/mL$) decreased ${\beta}$-catenin expression by 34.9% at 24 hrs and 34.3% at 48 hrs, compared to those in without PAN condition (P<0.05). In RT-PCR, high concentrations ($50{\mu}g/mL$) of PAN also decreased ${\beta}$-catenin mRNA expression similar to protein suppression by 25.4% at 24 hrs and 51.8% at 48 hrs (P<0.05). Conclusion : Exposure of podocytes to PAN in vitro relocates ${\beta}$-catenin internally and reduces ${\beta}$-catenin mRNA and protein expression, which could explain the development of proteinuria in experimental PAN-induced nephropathy.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.3
• /
• pp.547-558
• /
• 1997

Background : Tumor necrosis factor(TNF) has been considered as an important candidate for cancer gene therapy based on its potent anti-tumor activity. However, since the efficiency of current techniques of gene transfer is not satisfactory, the majorities of current protocols is aiming the in vitro gene transfer to cancer cells and re-introducing genetically modified cancer cells to hoot. In previous study, it was shown that TNF-sensitive cancer cells transfected with TNF-$\alpha$ cDNA would become highly resistant to TNF. Understanding the mechanisms of TNF-resistance in TNF-$\alpha$ gene transfected cancer cells would be an important step for improving the efficacy of cancer gene therapy as well as for better understandings of tumor biology. This study was designed to evaluate the role of new protective protein synthesis in the acquired resistance to TNF of TNF-$\alpha$ gene transfected cancer cells. Method : We transfected TNF-$\alpha$ c-DNA to WEHI164, a murine fibrosarcoma cell line, using retroviral vector(pLT12SN(TNF)) and confirm the expression of TNF with PCR, ELISA, MIT assay. Then we determined the TNF resistance of TNF gene transfected cells(WEHI164-TNF) and the changes of TNF sensitivities after treatments with actinomycin D(transcription inhibitor) and cycloheximide ( translation inhibitor). Results : WEHI164 which was sensitive to TNF became resistant to TNF after being transfected with TNF-$\alpha$ gene and the resistance to TNF was partially reversed after treatment with actinomycin D, but not with cycloheximide. Conclusion : The acquired resistance to TNF after TNF-$\alpha$ gene transfection may be associated with synthesis of some protective proteins.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.41-41
• /
• 2018

차꼬리고사리(Asplenium trichomanes L.)는 남방계식물로 제주도에 자생하는 것으로 알려져 있으며, 잎에 광택이 있고 총생하는 식물이다. 주로 실내 외 조경 및 분화소재로 이용되며, 한방에서는 철각봉미초라하여 뿌리를 포함한 전초를 이질, 임병, 만성질염, 월경불순 및 요통의 약재로 사용한다. 또한 식물구계학적 특정식물종 IV급, 적색자료목록 준위협 (NT)에 분류된 식물로 보호가 필요하다. 본 연구는 차꼬리고사리의 대량생산을 위한 기내전엽체 증식 및 기외포자체 형성조건을 구명하고자 수행되었다. 실험재료는 포자를 기내 발아시켜 전엽체를 획득한 다음 8주 간격으로 계대하면서 확보하였다. 전엽체의 증식과 생육에 적합한 배지를 비교하고자, 1/4, 1/2, 1, 2MS와 Knop배지를 조성하여 배양하였다. 배양은 전엽체 300mg을 메스로 균일하게 다지는 방법을 이용하였으며, 배양환경은 온도 $25{\pm}1.0^{\circ}C$, 광도 $30{\pm}1.0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 광주기 16/8h(light/dark)로 조절되었다. 실험결과, 1MS배지에 배양된 전엽체의 생체중이 4.3g으로 가장 많이 증가하였다. 형태형성발달도 하트형의 전엽체로 정상적으로 유도되었으며, 생식기관도 관찰되었다. 전엽체로부터 포자체의 형성을 유도하고자, 원예상토, 피트모스, 펄라이트 및 마사토의 비율을 5종류로 달리하여 혼합된 토양을 사각분($7.5{\times}7.5{\times}7.5cm$)에 충진하였다. 전엽체 1g과 증류수 25mL를 핸드블랜더로 10초간 분쇄하여 토양표면에 분주하는 실험방법을 사용하였다. 재배환경은 온도 $25{\pm}1.0^{\circ}C$, 광도 $43{\pm}2.0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 광주기 16/8h(light/dark)로 유지하면서 12주간 재배되었다. 실험결과, 원예상토 단용, 원예상토와 펄라이트가 2:1(v:v)로 혼합된 토양, 원예상토와 마사토가 2:1(v:v)로 혼합된 토양에서 각 31.7, 24.3, 19.3개의 포자체가 생산되었다. 한편 포자체의 생육은 원예상토 단용 토양에서 엽수, 엽장, 엽폭 등의 수치가 비교적 우수하였다. 따라서 차꼬리고사리의 전엽체는 MS배지에 배양하고 증식된 전엽체를 원예상토에 분주하여 포자체의 형성을 유도하는 것이 가장 효과적이었다.

• Journal of Life Science
• /
• v.23 no.12
• /
• pp.1557-1561
• /
• 2013

Carbonic anhydrase isozymes are a widespread, zinc-containing metalloenzyme family. The enzyme catalyzes the reversible inter-conversion of $CO_2$ and $HCO_3$. This reaction is the main role played by CA enzymes in physiological conditions. This enzyme has been found in virtually all organisms, and at least 16 isozymes have been isolated in mammals. Unlike mammals, there is little information available regarding CA isozymes in the tissues of non-mammalian groups, such as fish. Carbonic anhydrase is very important in the osmotic and acid-base regulation in fish. It is well-known that the gills of fish play the most important role in acid-base relevant ion transfer, the transfer of $H^+$ and/or $HCO_3^-$, for the maintenance of systemic pH. Rainbow trout, Oncorhynchus mykiss, is the most important freshwater fish species in the aquaculture industry of Korea, with annual production increasing each year. In addition, environmental toxicology research has shown that rainbow trout is known to be the species that is most susceptible to environmental toxins. Consequently, carbonic anhydrase was detected in rainbow trout, Oncorhynchus mykiss. The isolated protein showed the specific band with a molecular weight of 30 kDa and pI of 7.0, and it was identified as being carbonic anhydrase. The immunohistochemical result demonstrated that the carbonic anhydrase was located in the epithelial cells of the gills.