• Biomedical Science Letters
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• v.16 no.4
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• pp.377-380
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• 2010

In this study, we investigated the effect of egg yolk lipids (EYL) on collagen ($10\;{\mu}g/ml$)-stimulated platelet aggregation in vivo. Dietary EYL significantly inhibited collagen-induced platelet aggregation, in addition, increased the formation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), intracellular $Ca^{2+}$-antagonist as aggregation-inhibiting molecules, in collagen-stimulated platelets. These results suggest that EYL inhibits the collagen-induced platelet aggregation by up-regulating the cAMP and cGMP production. On the other hands, prothrombin time (PT) on extrinsic pathway of blood coagulation was potently prolonged by dietary EYL in vivo. These findings suggest that EYL prolongs the internal time between the conversion of fibrinogen to fibrin. Accordingly, our data demonstrate that EYL may be a crucial tool for a negative regulator during platelet activation and blood coagulation on thrombotic diseases.

• Biomedical Science Letters
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• v.24 no.1
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• pp.15-22
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• 2018

Pristimerin is a triterpene compound isolated from plant extracts that reportedly possesses antitumor, antioxidant, and anti-inflammatory activities. The current study was designed to evaluate the antitumor effects of pristimerin on human colon cancer cells. Treatment of the human colon cancer cells, HCT116 and SW480, with pristimerin led to a dose-dependent decrease in cell proliferation. Flow cytometry experiments showed that pristimerin increased cell apoptotic rate and decreased the mitochondrial membrane potential in HCT116 and SW480 cells. Western blot assay showed that pristimerin induced increased cleavage of caspase-3, -7, -8, and poly ADP ribose polymerase. Treatment with pristimerin also caused a marked decrease in the expression of Bcl-2 and Bcl-xL. Additionally, the levels of phosphorylated AKT and forkhead box O3a (FOXO3a) were decreased in pristimerin-treated colon cancer cells. Taken together, our study illustrated that pristimerin promoted apoptosis via the AKT/FOXO3a signaling pathway in colon cancer cells, elucidating that it might be considered as a potential agent for colon cancer therapy.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.393-395
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• 2002

We propose a method which can replace the DR when measuring performance evaluation parameters of antiscatter grids for DR. We used conventional x-ray films to produce grid images, which were scanned by a film digitizer. The digitizer could provide sampling interval of 87 micrometers and pixel depth of 12 bits. Grid line frequencies were measured using aliasing effect and non-uniformities of grids were measured by transforming scanned pixel values of film images into optical densities.

• Biomedical Science Letters
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• v.20 no.2
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• pp.70-76
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• 2014

In this study, we investigated the effect of DMSO, a highly dipolar organic liquid, in collagen ($5{\mu}g/ml$)-stimulated platelet aggregation. DMSO inhibited platelet aggregation at 0.5% by inhibiting production of thromboxane $A_2$ ($TXA_2$) which was associated with blocking cyclooxygenase (COX)-1 activity and $TXA_2$ synthase. In addition, DMSO significantly increased the formation of cyclic adenosine monophosphate (cAMP) from adenosine triphosphate (ATP) and cyclic guanosine monophosphate (cGMP) from guanosine triphosphate (GTP). On the other hand, DMSO (0.1~0.5% concentration) did not affect the LDH release which indicates the cytotoxicity. Based on these results, DMSO has anti-platelet effect by regulation of several platelet signaling pathways, therefore we suggest that DMSO could be a novel strategy on many thrombotic disorders.

• BMB Reports
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• v.53 no.7
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• pp.357-366
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• 2020

Currently, most biological research relies on conventional experimental techniques that allow only static analyses at certain time points in vitro or ex vivo. However, if one could visualize cellular dynamics in living organisms, that would provide a unique opportunity to study key biological phenomena in vivo. Intravital microscopy (IVM) encompasses diverse optical systems for direct viewing of objects, including biological structures and individual cells in live animals. With the current development of devices and techniques, IVM addresses important questions in various fields of biological and biomedical sciences. In this mini-review, we provide a general introduction to IVM and examples of recent applications in the field of immunology, oncology, and vascular biology. We also introduce an advanced type of IVM, dubbed real-time IVM, equipped with video-rate resonant scanning. Since the realt-ime IVM can render cellular dynamics with high temporal resolution in vivo, it allows visualization and analysis of rapid biological processes.

• Biomedical Science Letters
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• v.13 no.4
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• pp.319-324
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• 2007

One-tube nested polymerase chain reaction (PCR) was evaluated for its efficacy in detecting Mycobacterium leprae in biopsy samples from leprosy patients. Primers were derived from the M leprae-specific element (RLEP) sequences which yield a 230 bp fragment. The specificity and the sensitivity of the one-tube nested PCR were compared with those of single PCR for detecting M leprae. The results showed that the one-tube nested PCR was about 100 times more sensitive than that of the single indicating the one-tube nested primer sets developed in this study can be an effective screening tool for the detection of M leprae in clinical diagnostic laboratories.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.121-122
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• 1998

To induce perturbed magnetic field variations in the range of auto prescans permitted, we chose artificially shim values and applied manualy as DC offsets to X, Y, Z gradient amplifiers. The STEAM spectra were obtained from a localized region (8ml) of phantom's center and a Marquart Algorithm is employed to quantify MRS spectra. Results indicated that Creatine (Cr) which had a good correlation between a signal intensity and an area, changed little bit and showed extremly a stabilized state in perturbed magnetic field variations. Therefore, during the MRS experiments, to minimize the SNR reduction by means of unavoidable inhomogeneous magnetic fields, the present study suggested that the quantification method of relative ratios produced by replacing Cr concentration with standard quantify was most desirable.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.146-151
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• 1993

A new hydrodynamic mock circulation system was developed, which can test prosthetic heart valves of various sizes in order to obtain valve parameters, such as pressure drop, regurgitation and valve performance index with a high reproducibility. High reproducibility can be obtained only under equal testing conditions, i.e., the compliance, resistance and inertance of the mock circulation system must be constant parameter estimation using actual pressure and flow data was applied to calculate these systemic variables in order to adjust them to create the necessary equal testing conditions.

• The Journal of Korean Academic Society of Nursing Education
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• v.23 no.4
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• pp.389-397
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• 2017

Purpose: This study was conducted to examine awareness of biomedical ethics, and to identify affecting factors of the awareness of biomedical ethics in nursing students. Methods: The subjects consisted of 266 nursing students their third and fourth years of study. The data were collected from October to December, 2015 by self-report using questionnaires. Data analysis was performed using SPSS/WIN 18.0, descriptive statistics, t-test, ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficient, and multiple regression analysis. Results: The mean score of the awareness of biomedical ethics was $2.81{\pm}0.22$, perception of death was $3.15{\pm}0.36$, and knowledge of brain death, organ donation, and organ transplant was $12.12{\pm}3.02$. The prediction factors of awareness of biomedical ethics were gender (${\beta}=.29$, p<.001), participation in religious activity (${\beta}=.23$, p=.015), and perception of death (${\beta}=.20$, p=.016). The explanation power was 17.1%. Conclusion: These results showed that education about biomedical ethics is necessary for nursing students, and the development of biomedical ethics educational programs should reflect affecting factors.

• Biomedical Science Letters
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• v.24 no.3
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• pp.275-279
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• 2018

Inflammatory bowel disease (IBD) is increasing in prevalence in developed countries but the cause of this increase is unclear. In animal models of IBD and in human IBD patients, alterations in the tight junctional proteins have been observed, suggesting that the intestinal microflora may penetrate the underlying colonic tissue and promote inflammation. Enterotoxigenic Bacteroides fragilis (ETBF) causes inflammatory diarrhea in human and is implicated in inflammatory bowel diseases. However, it is unclear whether alterations in tight junctional proteins occur during ETBF infection in mice. In this brief communication, we report that ETBF infection induces up-regulation of claudin-2 and down-regulation of claudin-5 through B. fragilis toxin (BFT) activity in the large intestine of C57BL/6 mice. In contrast, BFT did not induce changes in tight junctional proteins in the HT29/C1 cell line, suggesting that analysis of biological activity of BFT in vivo is important for evaluating ETBF effects.