• Bulletin of the Korean Chemical Society
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• 제12권2호
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• pp.178-181
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• 1991

The crystal structure of dehydrated fully $Cd^{2+}$-exchanged zeolite A evacuated at $2{\times}10^{-6}$ Torr and $450^{\circ}C (a = 12.225(2){\AA})$ and of its ethylene sorption complex (a = 12.219(2) ${\AA}$) have been determined by single crystal X-ray diffraction techniques in the cubic space group Pm3m at $21(1)^{\circ}$. The structures were refined to final error indices, $R_1$ = 0.063 and $R_2$ = 0.065 with 266 reflections and $R_1$ = 0.055 and $R_2$ = 0.062 with 260 reflections, respectively, for which $I{\gg}3{\sigma}(I)$. In both structures, six $Cd^{2+}$ ions lie at two distinguished three-fold axes of unit cell. Dehydrated $Cd_6$-A sorbs 4 ethylene molecules per unit cell at $25^{\circ}C$ (vapor pressure of ethylene is ca. 100 Torr). Each $Cd^{2+}$ ion forms a lateral ${pi}$ complex with an ethylene molecule. Four $Cd^{2+}$ ions exist in a nearly tetrahedral environment, 2.210(7)${\AA}$ apart from three framework oxygen ions (considering ethylene molecule as a monodentate ligand) and $2.67(6){\AA}$ from each carbon atom of ethylene molecule.

• 한국수산과학회지
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• 제34권5호
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• pp.521-525
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• 2001

국내에서 다량 생산되는 갈조류인 미역포자엽, 다시마, 톳, 모자반으로부터 fucoidan을 추출, 분획하여 Pb와 Cd의 흡착 특성을 조사하였다. 4종의 갈조류에서 추출한 fucoidan의 분획물 모두 Pb의 흡착량이 Cd보다 높았으며, 시료간에는 미역포자엽 분획물 (Fr-3.0)이 Pb와 Cd 모두 흡착력이 상대적으로 우수하였다. pH와 농도 변화에 따른 홉착력의 변화는 $C_f$ (잔류농도)가 50mg/L까지는 pH 간 차이가 없었으나, 농로가 증가함에 따라 pH 5.5 처리구가 다른 처리구에 비하여 흡착량이 증가하였다. 실험을 통하여 얻은 Pb 와 Cd의 최대 흡착량은 pH 5.5에서 각각 94mg/g ($C_f$164mg/L), 64mg/g ($C_f$197mg/L)였으며 Langmuir sorption model을 통해 구한 최대 흡착량은 pH 5.5에서 각각 178mg/g, 122mg/g이었다. Cd 공존시 Pb 흘착량은 $C_f$가 낮을 범위에서는 변화가 없었으나 $C_f$가 증가함에 따라 공존 이온의 흡착 방해로 인하여 감소하였다.

• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.56-64
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• 2005

Two distinct CD3 homologue genes, $CD3\gamma/\delta\;and\;CD\varepsilon$, were isolated from a olive flounder leukocyte cDNA library and a BAC library. $CD3\gamma/\delta$ consisted of 961 bp encoding 178 amino acid residues, and $CD3\varepsilon$ consisted of 1006 bp encoding 164 amino acid residues. When compared with other known CD3 peptide sequences, the most conserved region of the two olive flounder CD3 chain peptides are the cytoplasmic domain and the least conserved are the extracellular domain. A phylogenetic analysis based on the deduced amino acid sequence grouped the two olive flounder CD3 sequences with $CD3\varepsilon$ and $CD3\gamma/\delta$, respectively. The olive flounder CD3 cluster (consisting of $CD3\varepsilon\;and\;CD3\gamma/\delta$) spans only 10.4 kb. The $CD3\varepsilon\;and\;CD3\gamma/\delta$ genes are oppositely transcribed only 3.8 kb apart. Both olive flounder CD3 genes have five exons. The two olive flounder CD3 genes were predominantly expressed in PBLs, kidney, spleen, and gills.

• IMMUNE NETWORK
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• 제7권4호
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• pp.173-178
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• 2007

Background: We studied the role for expression of CD40 and CD40L by CD4 and CD8 T cells in the generation of CD8 T cell response to minor histocompatibility antigen, H60. H60 is a cellular antigen to which CD8 responses require CD4 T cell help. Methods: CD40- or CD40L-deficient mice were adoptively transferred with normal CD4 or CD8 T cells or with memory CD4 or CD8 T cells, and were immunized with male H60 congenic splenocytes to induce CD8 T cell response to H60. Peripheral blood CD8 T cell from the immunized mice were stained with the H60 tetramer. Results: CD8 T cell response to H60 was not induced in both CD40- and CD40L-deficient mice. Adoptive transfer of $CD40^{+/+}$ CD8 T cells into CD40-deficient mice did not compensate the defect in inducing CD8 T cell response to H60, while the H60-specific CD8 T cells were activated in the CD40-deficient mice that were adoptively transferred with $CD40^{+/+}$ CD4 T cells. Adoptive transfer of $CD40L^{+/+}$ CD4 T cells into CD40L-deficient mice induced primary CD8 T cell response for H60 and the presence of $CD40L^{+/+}$ CD4 T cells was required even for memory CD8 T cells response to H60. Conclusion: Our results suggest that the CD40-CD40L interaction mediates the delivery of CD4 T cell help to naive and memory H60-specific CD8 T cells. While the expression of CD40L by CD4 T cells is essential, signaling through CD40 on CD8 T cells is not required for the induction of CD8 T cell response to H60.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1996년도 제48차 추계 학술대회 연제집
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• pp.177-178
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• 1996

• Clinical and Experimental Pediatrics
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• 제58권5호
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• pp.178-182
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• 2015

Purpose: The purpose of this study was to determine the frequency of $CD4^+CD25^+FoxP3^+$ regulatory T cells (Treg) in the peripheral blood of patients with childhood chronic immune thrombocytopenic purpura (ITP) exhibiting thrombocytopenia and spontaneous remission. The findings of this study indicate the possibility of predicting spontaneous recovery and pathogenesis of childhood chronic ITP. Methods: Eleven children with chronic ITP (seven thrombocytopenic and four spontaneous remission cases; mean age, 8.8 years; range, 1.7-14.9 years) were enrolled in this study. Five healthy children and eight healthy adults were included as controls. The frequency of Treg was evaluated by flow cytometry in the peripheral blood. Results: In this study, four patients (36%) achieved spontaneous remission within 2.8 years (mean year; range, 1.0-4.4 years). The frequency of Treg was significantly lower in patients with persisting thrombocytopenia ($0.13%{\pm}0.09%$, P<0.05), than that in the patients with spontaneous remission ($0.30%{\pm}0.02%$), healthy adults controls ($0.55%{\pm}0.44%$), and healthy children controls ($0.46%{\pm}0.26%$). A significantly positive correlation was found between the frequency of Treg and the platelet count in children. Conclusion: These data suggest that a lower frequency of Treg contributes to the breakdown of self-tolerance, and may form the basis for future development of specific immunomodulatory therapies. Furthermore, Treg frequency has prognostic implication toward the natural course and long-term outcomes of childhood chronic ITP.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제16권3호
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• pp.178-184
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• 2013

Purpose: The clinical presentations of inflammatory bowel disease (IBD) prior to diagnosis are so diverse or vague that many of them waste time before final diagnosis. This study was undertaken to know the medical history of the pediatric patients until the final diagnosis could be reached. Methods: The medical records of all pediatric patients who were diagnosed with IBD (Crohn's disease [CD] in 14 children, ulcerative colitis [UC] in 17) during the last 13 years were reviewed. We investigated the length of the diagnostic time lag, chief clinical presentation, and any useful laboratory predictor among the routinely performed examinations. Indeterminate colitis was not included. Results: The mean ages of children at the final diagnosis was similar in both diseases. As for the pre-clinical past history of bowel symptoms in CD patients, 5 were previously healthy, 9 had had 1-3 gastrointestinal (GI) symptoms, weight loss, bloody stool, anemia and rectal prolapse. With UC, 9 were previously healthy, 8 had had 1-3 GI symptoms, bloody stool, anorexia. The average diagnostic time lag with CD was 3.36 months, and with UC 2.2 months. Body mass index (BMI) and the initial basic laboratory data (white blood cell, hemoglobin, mean corpuscular volume, serum albumin, and serum total protein) were lower in CD, statistically significant only in BMI. Conclusion: IBD shows diverse clinical symptoms before its classical features, making the patients waste time until diagnosis. It is important to concern possibility of IBD even in the mildly sick children who do not show the characteristic symptoms of IBD.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.171-178
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• 1991

The two-stage enzyme reactor, packed with cyclodextrin glucanotransferase (CGTase) immobilized on Amberite IRA 900, coupled with ultrafiltration membrane was investigated for continuous production of cyclodextrin (CD). 5% (w/v) of soluble starch was partially cyclized, in the 0.1 l first-stage immobilized enzyme reactor, up to CD conversion yield of 10% (w/w) at retention time of 0.56hr and 1.5 units of immobilized CGTase/1g of carrier. In the second stage main immobilized enzyme reactor capacity of 1.5 l, the maximum CD conversion yield of 39% (w/v) was achieved at retention time of 2.8hr and 0.47 unit of CGTase/1 g of carrier. Unreacted residual dextrin was fractionated with ultrafiltration membrane, and then, recycled into the second-stage main bioreactor to increase the CD conversion yield. The most suitable membrane size and the volume concentration ratio (concentrate: filterate) for recycling of unreacted residual dextrin were found to be 5K dalton and 4:6, respectively. CD conversion yield was increased about 3~4% upon co-immobilization of pulluanase along with CGTase. Spent Amberite IRA 900 can be reutilized consecutively more than 3 times for immobilization of CGTase after regeneration.

• Journal of Microbiology and Biotechnology
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• 제32권4호
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• pp.397-404
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• 2022

Natural killer (NK) cell activity is more attenuated in hepatocellular carcinoma (HCC) patients than normal. Hypoxic-inducible factor (HIF)-1α is highly expressed in tumors to maintain their metabolism in a hypoxic environment. The expression of HIF-1α in cancers can lead to cell growth, proliferation, invasion/metastasis and immune escape. Although apigenin, a flavonoid, is known to have various biological activities, it has not been demonstrated in NK cell immune activity in HCC cells. In this study, NK-92 cells were directly cocultured with HCC SK-Hep1 cells for 24 h to evaluate NK cell activity in HCC cells or HCC cells expressing HIF-1α by apigenin. NK cell cytotoxicity to HCC cells expressing HIF-1α was significantly increased, and NK cell-activating receptors, NKG2D, NKp30 and NKp44 were highly expressed. The activating effect of apigenin on NK cells substantially induced apoptosis in HCC cells expressing HIF-1α through high expression of CD95L on the surface of NK-92 cells. Moreover, apigenin excellently inhibited the level of TGF-β1 in a coculture of NK cells and HCC cells. In conclusion, apigenin seems to be a good compound that increases NK cell cytotoxicity to HCC cells by controlling HIF-1α expression.

• 한국미생물·생명공학회지
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• 제30권4호
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• pp.293-297
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• 2002

효모 S. cerevisiae에서 B. stearothermophilus 유래의 CGTase를 발현 생산하였으며, 분비, 생산된 단백질을 정제하여 그 특성을 조사하였다. 재조합 효모 S. cerevisiae 2805/pVT- CGTS가 생산하는 CGTase의 분자량은 효모에서 발현될 때 고당쇄가 부가되어 야생형의 68kDa에 비해 15-160% 증가된 약 78-178 kDa으로 나타났다. 효모 S. cerevisiae에서 발현된 CGTase의 효소반응 최적활성조건은 pH7.0, $65^{\circ}C$였고, 열안정성에 있어서 $75^{\circ}C$에서 약 90%의 잔존활성을 가질 정도로 내열성이 개선되었다. 효모 S. cerevisiae에서 발현된 CGTase는 5% soluble starch를 기질로 약 40.2%의 CD 전환율 및 3 : 6 : 1의 $\alpha$-, $\beta$-, ${\gamma}$-CD의 생산 비율을 나타내어 야생형과 별다른 변화가 없었다.