Proposal of Evaluation Method for Leukoreduction Blood Filter and Evaluation of Domestic Filter / 대한수혈학회지

BACKGROUND: A leukoreduction filter was recently developed in Korea to reduce various kinds of adverse transfusion reactions. The objective of this study was to propose a domestic evaluation system for leukoreduction filters and to apply this evaluation system to assess the newly developed leukoreduction filter. METHODS: We prepared packed red blood cells from 60 units of whole blood (400 mL) collected from 60 normal individuals and evaluated the efficacy of the newly developed filter (FINECELL, KOLON INDUSTRIES, Gumi, Korea) and a control filter (RCM1, Haemonetics, MA, USA). To verify the evaluation system, we assessed the filtration time, residual leukocyte count, RBC recovery, RBC hemolysis, hemoglobin concentration, and hematocrit using a control filter RCM1 and compared the results with those of an evaluation performed by the American Red Cross (ARC) in 2013. We then evaluated the efficacy of the test filter FINECELL using the methods established in this study and compared the results with those of the control filter RCM1. RESULTS: The results of the current study were similar to those of the ARC with the control filters. The test filters developed in Korea were not inferior to commonly used control filters regarding residual leukocyte count, RBC recovery, and RBC hemolysis at 35 days after filtration. All of the results in the evaluation satisfied the international standards. CONCLUSION: These results of this study showed that the efficacy of the newly developed domestic leukoreduction filter were satisfactory and will contribute to improvement of quality of blood components in Korea.

Establishment of hydrochloric acid/lipopolysaccharide-induced pelvic inflammatory disease model

Pelvic inflammatory disease (PID), which is one of the most problematic complications experienced by women with sexually transmitted diseases, frequently causes secondary infections after reproductive abnormalities in veterinary animals. Although the uterus is self-protective, it becomes fragile during periods or pregnancy. To investigate PID, bacteria or lipopolysaccharide (LPS) extracted from gram negative bacteria has been used to induce the disease in several animal models. However, when LPS is applied to the peritoneum, it often causes systemic sepsis leading to death and the PID was not consistently demonstrated. Hydrochloric acid (HCl) has been used to induce inflammation in the lungs and stomach but not tested for reproductive organs. In this study, we developed a PID model in mice by HCl and LPS sequential intracervical (i.c.) administration. The proinflammatory cytokines, interleukin (IL)-1β, IL-6 and tumor necrosis factor-α, were detected in the mouse uterus by western blot analysis and cytokine enzyme-linked immunosorbent assay after HCl (25 mg/kg) administration i.c. followed by four LPS (50 mg/kg) treatments. Moreover, mice exhibited increased infiltration of neutrophils in the endometrium and epithelial layer. These results suggest that ic co-administration of HCl and LPS induces PID in mice. This new model may provide a consistent and reproducible PID model for future research.

Bacteroides fragilis Toxin Induces IL-8 Secretion in HT29/C1 Cells through Disruption of E-cadherin Junctions

Enterotoxigenic Bacteroides fragilis (ETBF) is a human gut commensal bacteria that causes inflammatory diarrhea and colitis. ETBF also promotes colorectal tumorigenesis in the Min mouse model. The key virulence factor is a secreted metalloprotease called B. fragilis toxin (BFT). BFT induces E-cadherin cleavage, cell rounding, activation of the beta-catenin pathway and secretion of IL-8 in colonic epithelial cells. However, the precise mechanism by which these processes occur and how these processes are interrelated is still unclear. E-cadherin form homophilic interactions which tethers adjacent cells. Loss of E-cadherin results in detachment of adjacent cells. Prior studies have suggested that BFT induces IL-8 expression by inducing E-cadherin cleavage; cells that do not express E-cadherin do not secrete IL-8 in response to BFT. In the current study, we found that HT29/C1cells treated with dilute trypsin solution induced E-cadherin degradation and IL-8 secretion, consistent with the hypothesis that E-cadherin cleavage causes IL-8 secretion. However, physical damage to the cell monolayer did not induce IL-8 secretion. We also show that EDTA-mediated disruption of E-cadherin interactions without E-cadherin degradation was sufficient to induce IL-8 secretion. Finally, we determined that HT29/C1 cells treated with LiCl (beta-catenin activator) induced IL-8 secretion in a dose-dependent and time-dependent manner. Taken together, our results suggest that BFT induced IL-8 secretion may occur by the following process: E-cadherin cleavage, disruption of cellular interactions, activation of the beta-catenin pathway and IL-8 expression. However, we further propose that E-cadherin cleavage per se may not be required for BFT induced IL-8 secretion.

Iron-fortified recombinant Saccharomyces cerevisiae producing Sus scrofa ferritin heavy-chain recovers iron deficiency in mice / 대한수의학회지

In this study, we produced iron-fortified yeast (Saccharomyces cerevisiae) producing Sus scrofa ferritin heavy-chain to provide iron supplementation in anemic piglets. We determined whether iron-ferritin accumulated in recombinant yeasts could improve iron deficiency in mice. C57BL/6 male mice exposed to Fe-deficient diet for 2 weeks were given a single dose of ferrous ammonium sulfate (FAS), ferritin-producing recombinant yeast (APO), or APO reacted with iron (Fe2+) (FER). The bioavailability of recombinant yeasts was examined by measuring body weight gain, hemoglobin concentration and hematocrit value 1 week later. In addition, ferritin protein levels were evaluated by western blot analysis and iron stores in tissues were measured by inductively coupled plasma spectrometer. We found that anemic mice treated with FER exhibited increased levels of ferritin heavy-chain in spleen and liver. Consistently, this treatment restored the iron concentration in these tissues. In addition, this treatment significantly increased hemoglobin value and the hematocrit ratio. Furthermore, FER treatment significantly enhanced body weight gain. These results suggest that the iron-fortified recombinant yeast strain is bioavailable.

Th17 Responses Are Not Induced in Dextran Sodium Sulfate Model of Acute Colitis

Dextran sodium sulfate (DSS) is a widely used chemical model for inflammatory bowel disease (IBD). It is thought that imbalances in the T helper (Th) cell subsets contribute to IBD. Recent studies suggest that the acute DSS-colitis model is polarized toward a Th1/Th17 profile based on RT-PCR analysis of colonic tissues. In the current study we determined whether colonic Th cells from DSS-colitis mice were skewed toward the Th17 profile. Mice were treated with 5% DSS for 7 days and colonic T cells isolated and examined for production of IFN-gamma (Th1 cell), IL-4 (Th2 cell) and IL-17 (Th17 cell) by intracellular flow cytometry. We found that the percentage of colonic Th17 cells were similar to non-treated controls but the percentage of Th1 cells were elevated in DSS-colitis mice. These results suggest that in the acute DSS-colitis model the colonic Th cells exhibit a Th1 profile and not a Th17 profile.

Psychometric Analysis of Comprehensive Basic Medical Sciences Examination / 한국의학교육

PURPOSE: Since 2000, the Korea University Medical College has conducted Comprehensive Basic Medical Sciences Examination as a summative test. Summative assessment must be dependable in that it meets the highest standards of reliability and validity. The purpose of this study were to examine the validity and reliability of Comprehensive Basic Medical Sciences Examination and to improve the quality of the examination. METHODS: The subject of this study was the examination materials and scores of the test. We conducted exploratory factor analysis to testify validity. Cronbach alpha coefficient was used to examine the reliability. RESULTS: Only one factor was extracted from exploratory factor analysis. Its eigen value was 4.61 and it explained 65.93% of total variance. We could infer the extracted factor as an ability of basic medical sciences knowledge. The reliability coefficient of the test was ranged from 0.45 to 0.74. Of the total 335 item, overall acceptable items were 206(58.0%); the range of difficulty was 0.21~1.00 and discriminative indices were higher than 0.20. CONCLUSION: We confirmed the Comprehensive Basic Medical Sciences Examination in 2000 met the relative highest standards of reliability and validity. Item analysis could be of help to improve the quality of examination

In vitro and In vivo Characterization of EL4 Cell Transfected with TGF-B1 cDNA / 대한면역학회지

Transforming growth factor-B1 (TGF-B1) is well known to be one of the most potent Immunosuppressive cytokines. To determine whether TGF-B1 secreted in the latent form can be immunoregulatory, TGF-B1 cDNA driven by the human -actin promotor was transfected into a murine thymoma cell line, EL4 cells. The transfectants (ELJ4) secreted a latent torm of TGF-B1 at a concentration of 5 ng/ml under the influence of TPA. Transfected TGF-b1 transcripts was readily detected by RT-PCR in ELJ4 cells regardless of the presence of TPA, but not in EL4 cells. In addition, we found the degree of Thy-B1 expression, IL-2 secretion and the proliferation rate are not altered by the transfection. Finally, EL4 and ELJ4 cells were injected into C57BU6 mice (syngenic strain), subcutaneously. Tumor cell masses derived from both cell populations survived longer than 1 wk, and the size of tumor derived from ELJ4 was three times larger (2.5 cm of diameter) than that from EL4. Virtually, there was no histopathological difference between two tumors. Taken together, the results from the present study indicates that EL4 thymomas transfected with TGF-1 secretes a latent form of TGF-B1 which may suppress host immune defence system.