• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.273-273
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• 2013

Recently, Point-of-care (POC) testing microdevices enable to do the patient monitoring, drug screening, pathogen detection in the outside of hospital. Immunochromatographic strip (ICS) is one of the diagnostic technologies which are widely applied to POC detection. Relatively low cost, simplicity to use, easy interpretations of the diagnostic results and high stability under any circumstances are representative advantages of POC diagnosis. It would provide colorimetric results more conveniently, if the genetic analysis microsystem incorporates the ICS as a detector part. In this work, we develop a reverse transcriptase-polymerase chain reaction (RT-PCR) microfluidic device integrated with a ROSGENE strip for colorimetric influenza H1N1 virus detection. The integrated RT-PCR- ROSGENE device is consist of four functional units which are a pneumatic micropump for sample loading, 2 ${\mu}L$ volume RT-PCR chamber for target gene amplification, a resistance temperature detector (RTD) electrode for temperature control, and a ROSGENE strip for target gene detection. The device was fabricated by combining four layers: First wafer is for RTD microfabrication, the second wafer is for PCR chamber at the bottom and micropump channel on the top, the third is the monolithic PDMS, and the fourth is the manifold for micropump operation. The RT-PCR was performed with subtype specific forward and reverse primers which were labeled with Texas-red, serving as a fluorescent hapten. A biotin-dUTP was used to insert biotin moieties in the PCR amplicons, during the RT-PCR. The RT-PCR amplicons were loaded in the sample application area, and they were conjugated with Au NP-labeled hapten-antibody. The test band embedded with streptavidins captures the biotin labeled amplicons and we can see violet colorimetric signals if the target gene was amplified with the control line. The off-chip RT-PCR amplicons of the influenza H1N1 virus were analyzed with a ROSGENE strip in comparison with an agarose gel electrophoresis. The intensities of test line was proportional to the template quantity and the detection sensitivity of the strip was better than that of the agarose gel. The test band of the ROSGENE strip could be observed with only 10 copies of a RNA template by the naked eyes. For the on-chip RT-PCR-ROSGENE experiments, a RT-PCR cocktail was injected into the chamber from the inlet reservoir to the waste outlet by the micro-pump actuation. After filling without bubbles inside the chamber, a RT-PCR thermal cycling was executed for 2 hours with all the microvalves closed to isolate the PCR chamber. After thermal cycling, the RT-PCR product was delivered to the attached ROSGENE strip through the outlet reservoir. After dropping 40 ${\mu}L$ of an eluant buffer at the end of the strip, the violet test line was detected as a H1N1 virus indicator, while the negative experiment only revealed a control line and while the positive experiment a control and a test line was appeared.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.211-226
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• 2019

Pig CD45, the leukocyte common antigen, is encoded by the PTPRC gene and CD45 is a T cell-type specific tyrosine phosphatase with alternative splicing of its exons. The CD45 is a coordinated regulator of T cell antigen receptor (TCR) signal transduction achieved by dephosphorylating the phosphotyrosine of its substances, including $CD3{\zeta}$ chain of TCR, Lck, Fyn, and Zap-70 kinase. A dysregulation of CD45 is associated with a multitude of immune disease and has been a target for immuno-drug discovery. To characterize its key structural features with the effects of regulating TCR signaling, this study predicted the unknown structure of pig CD45RO (the smallest isoform) and the complex structure bound to the ITAM (REEpYDV) of $CD3{\zeta}$ chain via homology modeling and docking the peptide, based on the known human CD45 structures. These features were integrated into the structural plasticity of extracellular domains and functional KNRY and PTP signature motifs (the role of a narrow entrance into ITAM binding site) of the tyrosine phosphatase domains in a cytoplasmic region from pig CD45RO. This contributes to the selective recognition of phosphotyrosine from its substrates by adjusting the structural stability and binding affinity of the complex. The characterized features of pigCD45RO can be applied in virtual screening of the T-cell specific immunomodulator.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.474-483
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• 2019

Vascular endothelial growth factor (VEGF) plays a pivotal role in pathologic ocular neovascularization and vascular leakage via activation of VEGF receptor 2 (VEGFR2). This study was undertaken to evaluate the therapeutic mechanisms and effects of the tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a VEGFR2 inhibitor, in the development of vascular permeability and choroidal neovascularization (CNV). In cultured human retinal microvascular endothelial cells (HRMECs), treatment with RLYE blocked VEGF-A-induced phosphorylation of VEGFR2, Akt, ERK, and endothelial nitric oxide synthase (eNOS), leading to suppression of VEGF-A-mediated hyper-production of NO. Treatment with RLYE also inhibited VEGF-A-stimulated angiogenic processes (migration, proliferation, and tube formation) and the hyperpermeability of HRMECs, in addition to attenuating VEGF-A-induced angiogenesis and vascular permeability in mice. The anti-vascular permeability activity of RLYE was correlated with enhanced stability and positioning of the junction proteins VE-cadherin, ${\beta}$-catenin, claudin-5, and ZO-1, critical components of the cortical actin ring structure and retinal endothelial barrier, at the boundary between HRMECs stimulated with VEGF-A. Furthermore, intravitreally injected RLYE bound to retinal microvascular endothelium and inhibited laser-induced CNV in mice. These findings suggest that RLYE has potential as a therapeutic drug for the treatment of CNV by preventing VEGFR2-mediated vascular leakage and angiogenesis.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.801-812
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• 2021

In order to delivery biotin to skin, ethosomes containing both biotin and ceramide were researched by using high pressure homogenizer. Biotin was utilized as a drug and ceramide NP was utilized as a supporter of bilayer. The biotin was entrapped in aqueous core, while ceramide NP was packed in the bilayer of the ethosomes. Looking at the physical properties of vesicles containing ceramide NP, the sized was 80~130 nm, the polydispersity index was 0.09~0.16, and the zeta potential was -40~-49 mV. In vesicles without ceramide NP, the size was 124.80±1.46 nm, and the zeta potential and polydispersity index were -45.48±1.27 mV and 0.088±0.018, respectively. Therefore, the ethosome with ceramide NP has improved physical properties of vesicles compared to the ethosome without ceramide NP. Skin absorption rates of ethosomes with ceramide NP were 6.13~14.98%, while skin absorption rate of ethosome without ceramide NP was 7.08% at 12 h. In conclusion, ethosomes containing ceramide NP not only improved the skin absorption efficiency, but had also a positive effect on the stability of vesicles.

• Journal of Ginseng Research
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• v.45 no.2
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• pp.228-235
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• 2021

Backgroud: Ginsenoside compound K (GK) is a major metabolite of protopanaxadiol-type ginsenosides and has remarkable anticancer activities in vitro and in vivo. This work used an ionic cross-linking method to entrap GK within O-carboxymethyl chitosan (OCMC) nanoparticles (Nps) to form GK-loaded OCMC Nps (GK-OCMC Nps), which enhance the aqueous solubility and stability of GK. Methods: The GK-OCMC Nps were characterized using several physicochemical techniques, including x-ray diffraction, transmission electron microscopy, zeta potential analysis, and particle size analysis via dynamic light scattering. GK was released from GK-OCMC Nps and was conducted using the dialysis bag diffusion method. The effects of GK and GK-OCMC Nps on PC3 cell viability were measured by using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Fluorescent technology based on Cy5.5-labeled probes was used to explore the cellular uptake of GK-OCMC Nps. Results: The GK-OCMC NPs had a suitable particle size and zeta potential; they were spherical with good dispersion. In vitro drug release from GK-OCMC NPs was pH dependent. Moreover, the in vitro cytotoxicity study and cellular uptake assays indicated that the GK-OCMC Nps significantly enhanced the cytotoxicity and cellular uptake of GK toward the PC3 cells. GK-OCMC Nps also significantly promoted the activities of both caspase-3 and caspase-9. Conclusion: GK-OCMC Nps are potential nanocarriers for delivering hydrophobic drugs, thereby enhancing water solubility and permeability and improving the antiproliferative effects of GK.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.179-184
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• 2021

Stratum corneum known as a skin barrier, which maintains water in skin, is the outer layer of the skin. Natural moisturizing factors (NMF) are one of the constituents in stratum corneum and amino acids are the highest components among NMF. In this study, we designed stearic acid-based solid lipid nanoparticles (SLNs) for improved skin penetration of serine (Ser). Ser-capsulated SLN was manufactured by double-melting emulsification method. The mean particle size and zeta potential of SLNs were 256.30 ~ 416.93 nm and -17.60 ~ -35.27 mV, respectively. The higher the degree of hydrophobicity or hydrophilicity of emulsifiers, the smaller the particle size and the higher the stability and capsulation rate. In addition, skin penetration was conducted using SkinEthic^TM RHE which is one of the reconstructed human epidermis models. The results of Ser penetration demonstrated that all SLNs enhanced than serine solution. The amount of enhanced Ser penetration from SLNs were approximately 4.1 ~ 6.2 times higher than that from Ser solution. Therefore, Ser-loaded SLN might be a promising drug delivery system for moisturizing formulation in cosmeceutical.

• Analytical Science and Technology
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• v.31 no.4
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• pp.161-170
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• 2018

The epidemic of disorders associated with synthetic stimulants, such as methamphetamine (MA) and amphetamine (AP), is a health, social, legal, and financial problem. Owing to the high potential of their abuse and addiction, reliable analytical methods are required to detect and identify MA, AP, and their metabolites in biological samples. Thus, a dilute-and-shoot liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) was developed for simultaneous determination of MA, 4-hydroxymethamphetamine (4HMA), AP, and 4-hydroxyamphetamine (4HA) in urine. Urine sample ($100{\mu}L$) was mixed with $50{\mu}L$ of mobile phase consisting of 0.4 % formic acid and methanol and $50{\mu}L$ of working internal-standard solution. Aliquots of $8{\mu}L$ diluted urine was injected into the LC-MS/MS system. For all analytes, chromatographic separation was performed using a C18 reversed-phase column with gradient elution and a total run time of 5 min. The identification and quantification were performed by multiple reaction monitoring (MRM). Linear least-squares regression was conducted to generate a calibration curve, with $1/x^2$ as the weighting factor. The linear ranges were 2.0-200, 1.0-800, and 10-2500 ng/mL for 4HA and 4HMA, AP, and MA, respectively. The inter- and intraday precisions were within 6.6 %, whereas the inter- and intraday accuracies ranged from -14.9 to 11.3 %. The low limits of quantification were 2.0 ng/mL (4HA and 4HMA), 1.0 ng/mL (AP), and 10 ng/mL (MA). The proposed method exhibited satisfactory selectivity, dilution integrity, matrix effect, and stability, which are required for validation. Moreover, the purification efficiency of high-speed centrifugation was clearly higher than 6-15 % for QC samples (n=5), which was higher than that of the membrane-filtration method. The applicability of the proposed method was tested by forensic analysis of urine samples from drug abusers.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.1-25
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• 1996

The pathogenesis of atherosclerosis can not be summarized as a single process. Lipid infiltration hypothesis and endothelial injury hypothesis have been proposed and investigated. Recent developments show that there are many points of potential interactions between them and that they can actually be regarded as two phases of a single, unifying hypothesis. Among the many risk factors of atherosclerosis, plasma homocysteine and lipoprotein(a) draw a considerable interest because they are independent indicators of atherogenicity. Triglyceride (TG)-rich lipoproteins (chylomicron and VLDL) are not considered to be atherogenic but they are related to the metabolism of HDL cholesterol and indirectly related to coronary heart disease (CHD). LDL can of itself be atherogenic but the oxidative products of this lipoprotein are more detrimental. HDL cholesterol has been considered to be a favorable cholesterol. The so-called 'causalist view' claims that HDL traps excess cholesterol from cellular membranes and transfers it to TG-rich lipoproteins that are subsequently removed by hepatic receptors. In the so-called 'noncausalist view', HDL does not interfere directly with cholesterol deposition in the arterial wall but instead reflects he metabolism of TG-rich lipoproteins and their conversion to atherogenic remnants. Approximately 70-80% of the human population shows an effective feedback control mechanism in cholesterol homeostasis. Type of dietary fat has a significant effect on the lipoprotein cholesterol metabolism and atherosclerosis. Generally, saturated fatty acids elevate and PUFA lower serum cholesterol, whereas MUFA have no specific effect. EPA and DHA inhibit the synthesis of TG, VLDL and LDL, and may have favourable effects on some of the risk factors. Phospholipids, particularly lecithin, have an antiatherosclerotic effect. Essential phospholipids (EPL) may enhance the formation of polyunsaturated cholesteryl ester (CE) which is less sclerotic and more easily dispersed via enhanced hydrolysis of CE in the arterial wall. Also, neutral fecal steroid elimination may be enhanced and cholesterol absorption reduced following EPL treatment. Antioxidants protect lipoproteins from oxidation, and cells from the injury of toxic, oxidized LDL. The rationale for lowering of serum cholesterol is the strong association between elevation of plasma or serum cholesterol and CHD. Cholesterol-lowing, especially LDL cholesterol, to the target level could be achieved using diet and combination of drug therapy. Information on the link between cholesterol and CHD has decreased egg consumption by 16-25%. Some clinical studies have indicated that dietary cholesterol and egg have a significant hypercholesterolemic effect, while others have indicated no effect. These studies differed in the use of purified cholesterol or cholesterol in eggs, in the range of baseline and challenge cholesterol levels, in the quality and quantity of concomitant dietary fat, in the study population demographics and initial serum cholesterol levels, and clinical settings. Cholesterol content of eggs varies to a certain extent depending on the age, breed and diet of hens. However, egg yolk cholesterol level is very resistant to change because of the particular mechanism involved in yolk formation. Egg yolk contains a factor of factors responsible for accelerated cholesterol metabolism and excretion compared with crystalline cholesterol. One of these factors could be egg lecithin. Egg lecithin may not be as effective as soybean lecithin in lowering serum cholesterol level due probably to the differences of fatty acid composition. However, egg lecithin may have positive effects in hypercholesterolemia by increasing serum HDL level and excretion of fecal cholesterol. The association of serum cholesterol with egg consumption has been widely studied. When the basal or control diet contained little or no cholesterol, consumption of 1 or 2 eggs daily increased the concentration of plasma cholesterol, whereas that of the normolipemic persons on a normal diet was not significantly influenced by consuming 2 to 3 eggs daily. At higher levels of egg consumption, the concentration of HDL tends to increase as well as LDL. There exist hyper-and hypo-responders to dietary (egg) cholesterol. Identifying individuals in both categories would be useful from the point of view of nutrition guidelines. Dietary modification of fatty acid composition has been pursued as a viable method of modifying fat composition of eggs and adding value to eggs. In many cases beneficial effects of PUFA enriched eggs have been demonstrated. Generally, consumption of n-3 fatty acids enriched eggs lowered the concentration of plasma TG and total cholesterol compared to the consumption of regular eggs. Due to the highly oxidative nature of PUFA, stability of this fat is essential. The implication of hepatic lipid accumulation which was observed in hens fed on fish oils should be explored. Nutritional manipulations, such as supplementation with iodine, inhibitors of cholesterol biosynthesis, garlic products, amino acids and high fibre ingredients, have met a limited success in lowering egg cholesterol.

• Korean Journal of Hospice Care
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• v.2 no.1
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• pp.58-74
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• 2002

This paper constitutes a descriptive investigation and used a structured questionnaire to investigate nurses' and doctors' recognition of cancer patients. The subjects were extracted from the medical personnel working at the internal medicine, the surgery ward, the obstetrics and gynecology department, the pediatrics department, the cancer ward, and the emergency room of five general hospitals located in Seoul and Gyeonggi Province. The research lasted from August, 2001 to September 2001. Total 137 nurses and 65 doctors were included and made out the questionnaires directly distributed by the investigator. The study tool was also developed by the investigator and consisted of such items as the demographic and social characteristics, the medical personnel's recognition degree of cancer and cancer patients, their recognition of the management of cancer patients, and their participation in a hospice. The results were analyzed using the SPSS Window program in terms of technological statistics, ranks, t-test, and ANOVA. The reliability was represented in Cronbach' α=.75. The nurses' and doctors' recognition degree of cancer and cancer patients had an overall average of 3.86 at the 5 point-scale. The items that received an average of 4.0 or more included 'Medical personnel should explain about the cancer cure plans to the cancer patient and his or her family', 'A patient whose case has been diagnosed as a terminal cancer should be notified of it, 'If I were a cancer patient, I would want to get informed of it,' and 'Cancer shall be conquered whenever it is'. In the meantime, the items that received an average of 3.0 or less was 'My relationship with the cancer patient's family has gotten worse since I announced his or her impending death.' And according to the general characteristics and the difference test, the recognition degree of cancer and cancer patient was high among the subgroups of nurses, females, married persons, who were in their 30s, who had a family member that was a cancer patient, and who received a hospice education. The biggest number of the nurses and doctors saw 'a gradual approach over several days'(68.8%) as a method to tell a cancer patient about his or her cancer diagnosis or impending death. Those who usually tell tragic news were the physician in charge(62.8%), the family members or relatives(32.1%) and the clergymen(3.8%) in the order. The greatest number of them recommended a cancer patient's home as the place where he or she should face death because they thought 'it would stabilize his or her mentality'(91.9%) while a number of them recommended the hospital because they 'should give the psychological satisfaction to the patient'(40%) or 'should try their best until the last moment of the patient's death'(30%). A majority of the medical personnel regarded 'smoking or drinking' and 'diet' as the causes of cancer. The biggest symptom of a cancer patient was 'pain' and the pain management of a cancer patient was mostly impeded by the 'excessive fear of drug addiction, tolerance to drugs and side effects of drugs' by medical personnel, the patient, and his or her family. The most frequently adopted treatment plan of a terminal cancer patient was 'to do whatever the patient or his or her family wants' to resort to a hospice' and 'to continue active treatment efforts' in the order. The biggest reasons why a terminal cancer patient went to see a doctor were 'pain alleviation' 'control of symptoms other than pain(intravenous supply)' and 'incapability of the patient's family' in the order. Terminal cancer patients placed their major concern in 'spiritual(religious) matter' 'emotional matters' their family' 'existence' and 'physical matters' in the order. 113(58.5%) of the whole medical personnel answered they 'would recommend' an alternative treatment to a terminal cancer patient mostly because they assumed it would 'stabilize the patient's mentality.' Meanwhile, 80(41.5%) of them chose 'not to recommend it mostly due to the unverified effects and high cost of it(78.7%). A majority of them, I. e. 190(94.1%) subjects said they 'would recommend' a hospice to a terminal cancer patient mostly because they thought it would help the patient to 'mentally prepare'(66.6%) Only 17.3% of them, however, had received a hospice education, most of which was done through the hospital duty education(41.4%) and volunteer training(34.5%). The follows are results of this study: 1. The nurses and the doctors turned out to be still passive and experience confusion in dealing with a cancer patient despite their great sense of responsibility for him or her. 2.Nurses and Doctors realize the need of a hospice, but an extremely small number of them participate in a hospice education or performance. Thus, a whole recognition of a hospice should be changed, for which purpose a hospice education for nurses and doctors should be provided. 3.Terminal cancer patients preferred their home to a hospital as the place to face their impending death because they felt it would bring 'mental stability.' And most of nurses and doctors think it would be unnecessary for them to be hospitalized just for control of their symptoms. Accordingly a terminal cancer patient can be cared at home, and a home hospice care needs to be activated.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.17-26
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• 2012

Purpose: This study mainly focuses on the patients treated with chemically stable radiopharmaceutical product $^{99m}Tc$-HMPAO (d,l-hexamethylpropylene amine oxime) which yielded reduced image quality due to a decreased brain extraction rate. $^{99m}Tc$-HMPAO will be examined further to determine whether this product may be accounted as a factor for this cause. Material and Methods: From January 2010 until December 2010, out of 272 patients who were all subjected to $^{99m}Tc$-HMPAO brain blood flow SPECT scans resulting from Cerebral Infarction; 23 patients(ages $55.3{\pm}9$, 21 males, 3 females) with decreased tissue extraction rate were examined in detail. The radiopharmaceutical product $^{99m}Tc$-HMPAO was used on patients with normal brain tissue exchange rate as well as those with reduced rate in order to prove its' chemical stability. The patients' age, sex, blood pressure, existence of diabetes, drug use, current health status, known side effects from CT/MRI, examination of the patients' past SPECT before/after images were accounted to determine the factors and correlations affecting the rate of blood tissue extractions. Result: After multiple linear regression analysis, there were no unusual correlations between the 6 factors excluding sex, and before/after examination images. Male subjects showed reduced brain tissue extraction rate than the females ($p$ > 0.05) 91.3% male, 8.7% female. Wilcoxon Matched-Pairs Signed-Ranks Test was used on the before/after images which yielded a value of 0.06, which did not indicate a significant amount of difference on the 2 tests ($p$ > 0.05). As a result, the before/after images indicated similar brain tissue extraction rates, and there were variations depending on the individual patient. Conclusion: The effects of the chemically stable radiopharmaceutical product $^{99m}Tc$-HMPAO depended on the patient's personal characteristics and status, therefore was considered to be a factor in reducing brain tissue extraction rate. The related articles of $^{99m}Tc$-HMPAO cerebral blood flow SPECT speculates a cerebrovascular disease and factors resulting from portal veins, and it was not possible to pin point the exact cause of decreasing brain tissue extraction rate. However, the $^{99m}Tc$-HMPAO cerebral blood flow SPECT scan proved to be extremely useful in tracking and inspecting brain diseases, as well as offering accurate results from patients suffering from reduced brain tissue extraction rates.