• Journal of Microbiology and Biotechnology
• /
• 제11권5호
• /
• pp.749-755
• /
• 2001

High Electromagnetic Field (EMF) with an intensity of 1 mT (Tesla) inhibited the growth of both human normal lung and immune T cell down to $20-30\%$, compared to that of an unexposed case. The human T-cells, Jurkat, were more severely affected by EMF than the human lung cells, which showed a relatively slow cell growth and substantial releas of $Ca^+2$ (3.5 times higher than the human T-cells). However, the growth of hepatoma carcinoma, Hep3B, was enhanced by twice that of an unexposed case. The EMF intensity and exposure time did not affect the growth of the cancer cells very much, while it significantly affected the growth of normal cells. Accordingly, it is possible that EMFs may play a role in the initiation of cancer. The EMFs disturbed the signal transduction and membrane systems, such that a five times higher amount of PKC-${\alpha}$ was released from the cell membrane than in the control. Extended exposure to EMFs, for more than 48 hours, also led to 1 $90\%$ necrotic death pattern from apoptotic cell death. Finally, EMF at an intensity of 1mT with a 24-T exposure promoted the differentiation of HL-60 cells to monocytes/macrophages, possibly causing potential acute leukemia.

• KSBB Journal
• /
• 제11권3호
• /
• pp.288-294
• /
• 1996

CHO 세포를 0.5%, 1 %. 2%, 3%, 4% 및 5% 놓도의 FBSd를 함유한 MEMa 배지에 $1{\times}10^4cells/\textrm{cm}^2 와 2{\times}10^4cells/\textrm{cm}^2$의 초기 농도로 정치배양하여 세포 성장과 EPO 생산 특성을 조사하였다. 혈청 농도와 접종 농도를 증가시킴에 따라 세포 증식 속도와 최대 세포 농도가 증가하는 경향을 보였으며, 적절한 혈청 농도의 선택이 세포 성장의 최적화에 필 요하다고 할 수 있다. 세포 성장 도중에 무혈청배지로 교환한 결과 세포 성장과 EPO 생산이 증가되었다. 배지를 교환하지 않았을 경우 세포 성장이 최대 ($2.1{\times}10^5cells/\textrm{cm}^2$)에 도달된 후 급격히 세포농도가 감소하는 높은 사멸율을 보이고, EPO의 최대 농도 도 2,380units/mL에 불과하였으나, 무혈청배지로 교환한 배양에서는 세포 성장이 크게 증가하여 $6.2{\times}105cells/$\textrm{cm}^2$의 최대 세포농도와 7,470units/mL 의 EPO 농도를 얻었다. 따라서 CHO 세포 성장과 E EPO 생산과는 상호 연관이 있으며, 세포배양으로 EPO 생산을 극대화하기 위해서는 CHO 세포의 고 농도 배양이 필요하다고 할 수 있다.

• Food Science and Biotechnology
• /
• 제18권4호
• /
• pp.971-977
• /
• 2009

The most abundant tea catechin, epigallocatechin-3-gallate (EGCG), has been reported to inhibit cell proliferation and induce apoptosis in many types of cancer cells. In the present study, effects of EGCG on the growth of oral epithelial cells including CAL-27 oral squamous carcinoma cells and dysplastic oral keratinocytes (DOK) were investigated. EGCG inhibited growth of CAL-27 cells and DOK with $IC_{50}$ of 14.4-21.0 and 5.8-14.2 ${\mu}M$ after 24 and 48 hr incubation, respectively. EGCG was significantly less effective in inhibiting DOK growth. The effects of EGCG, however, were dramatically less pronounced in the presence of superoxide dismutase (SOD) and catalase. Inhibitory effects of EGCG on CAL-27 cell growth were also much less pronounced in the presence of fetal bovine serum (FBS). EGCG induced caspase-3 activation in both CAL-27 and DOK cells in a serum free condition without SOD/catalase; in the presence of 10% FBS and SOD/catalase, EGCG, even at 100 ${\mu}M$, did not affect cell growth. The present results indicate that EGCG inhibited oral cell growth with higher potency to more malignant CAL-27 cells than DOK, and the effects were markedly altered by SOD/catalase and serum content in media.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제31권1호
• /
• pp.27-34
• /
• 2009

Angiogenesis is essential for solid tumor growth and progression. Among the pro-angiogenetic factors, vascular endothelial growth factor(VEGF), also known as vascular permeability factor, is the most important as a mitogen for vascular endothelium. The VEGF family of molecules currently consists of six growth factors, VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-E, and placenta growth factor(PlGF). Over-expression of PlGF is associated with angiogenesis under pathological conditions such as ischemia, inflammation, and cancer. Hence, the goal of this study is to identify the correlation of clinicopathlogical factors and the up-regulation of PlGF expression in oral squamous cell carcinoma. We studied the immunohistochemical staining of PlGF, PlGF gene expression and a real time quantitative RT-PCR in 20 specimens of 20 patients with oral squamous cell carcinoma. The results were as follows. 1. In the immunohistochemical study of poorly differentiated and invasive oral squamous cell carcinoma, the high level staining of PlGF was observed. And the correlation between immunohistopathological PlGF expression and histological differentiation of specimens was significant (Pearson correlation analysis, significance [r] >0.6, P < .05). 2. In the PlGF gene RT-PCR analysis, PlGF expression was more in tumor tissue than in adjacent normal tissue. Paired-samples analysis determined the difference of PlGF mRNA expression level between the cancer tissue and the normal tissue (Student's t - test, P < .05) These findings suggest that up-regulation of the PlGF gene may play a role in progression and local metastasis in invasive oral squamous cell carcinoma.

• 한국미생물·생명공학회지
• /
• 제26권5호
• /
• pp.435-441
• /
• 1998

Red beet(Beta vulagris L.) 모상근의 회분배양을 이용한 천연색소인 betacyanin 생산 최적화를 위해 광도, C/N ratio, 인산의 농도를 각각 변화시켜 세포생육과 색소 생산성에 관한 동력학적 분석을 실시했다. 광도변화에 따른 배양 결과 3 klux의 경우 0.3(1/day)의 최대 비 생육속도와 0.11(mg/g-dry cell/day)의 최대 비 생산속도 그리고 14 k1ux에서 0.242(1/day)의 최대 비 생육속도와 0.125(mg/g-dry cell/day)의 최대 비 생산속도를 나타냈다. 광도와 균체의 생육관계를 검토한 결과 광도에 따른 세포 생육은 photoinhibition model이 적용됨이 확인되었다. Red beet 모상근으로부터 betacyanin의 생산은 partially growth related process임이 입증됐다. 이에 따른 세포당 최대 betacyanin 생산을 나타내는 $\alpha$는 0.3756 (mg/cell)이며, 최대 생산속도를 나타내는 $\beta$는 0.001 (mg/g-cel1/day)로 측정됐다. C/N ratio에 따른 실험결과 42.1(w/w)에서 0.26(1/day)의 최대 비생육 속도를 나타내었으나 최대 비 생산속도는 31.6(w/w)에서 0.075(mg/g-cell/day)를 나타냈다. 인 농도에 대한 균체의 생육 및 물질 생산성의 관계를 검토한 결과 1.25mM에서 0.31(1/day)의 비생육 속도와 0.134(mg/g-dry cell/day) 비생산 속도를 나타내었다. 최적 조건을 결정하기 위한 response surface methodology(RSM)결과 세포 생육과 betacyanin의 최대 생산을 위한 최적 광도는 5.5 (klux),최적 C/N ratio와 인의 농도는 27(w/w), 1.25 (mM)로 결정됐다. 그리고 0.1 $\mu$M kinetin 첨가시 대조구에 비해 비생산성이 0.085(mg/g-dry cell/day)로 증가함이 입증됐다. Normal조건과 optimum조건의 비교결과 세포의 농도인 X(g-dry wt./L)가 8와 16, betacyanin의 생산량인 P(mg/L)가 4.48과 12.5, 그리고 optimum 조건에서 최대비 생육속도인 $\mu$$_{max}$ 가 0.375와 그리고 최대비 생산속도인 q$^{max}$ $_{p}$ 는 0.134로 약 2배로서 최적화가 되었다.

• Biomaterials and Biomechanics in Bioengineering
• /
• 제1권1호
• /
• pp.1-12
• /
• 2014

Polymer multilayered hydrogels were prepared on a titanium alloy (Ti) substrate using a layer-by-layer (LBL) process to load a cell growth factor. Two water-soluble polymers were used to fabricate the multilayered hydrogels, a phospholipid polymer with both N, N-dimethylaminoethyl methacrylate (DMAEMA) units and 4-vinylphenylboronic acid (VPBA) units [poly(MPC-co-DMAEMA-co-VPBA) (PMDV)], and the polysaccharide alginate (ALG). PMDV interacted with ALG through a selective reaction between the VPBA units in PMDV and the hydroxyl groups in ALG and through electrostatic interactions between the DMAEMA units in PMDA and the anionic carboxyl groups in ALG. First, the Ti substrate was covered with photoreactive poly vinyl alcohol, and then the Ti alloy was alternately immersed in the respective polymer solutions to form the PMDV/ALG multilayered hydrogels. In this multilayered hydrogel, vascular endothelial growth factor (VEGF) was introduced in different layers during the LbL process under mild conditions. Release of VEGF from the multilayered hydrogels was dependent on the location; however, release continued for 2 weeks. Endothelial cells adhered to the hydrogel and proliferated, and these corresponded to the VEGF release profile from the hydrogel. We concluded that multilayered hydrogels composed of PMDV and ALG could be loaded with cell growth factors that have high activity and can control cell functions. Therefore, this system provides a cell function controllable substrate based on the controlled release of biologically active proteins.

• Journal of Microbiology and Biotechnology
• /
• 제9권4호
• /
• pp.414-421
• /
• 1999

Helicobacter pylori were found to be resistant to azide but sensitive to vanadate, suggesting that defect in the P-type ATPase activity rather than F-type ATPase would be lethal to cell survival or growth. To elucidate the relationship between this enzyme inhibition and H. pylori death, we determined the effect of omeprazole (OMP) plus vanadate on enzyme activity and cell growth. The minimum inhibitory concentration (MIC; ca. 0.8$\mu$mol/disk) of vanadate for H. pylori growth was lowered over l0-fold with the aid of OMP, whereby its inhibitory potential toward the P-type ATPase activity was diametrically increased. Alternatively, we found that this enzyme activity was essential for active transport in H. pylori. From these observations, we strongly suggest that the immediate cause of the growth inhibition of H. pylori cells with OMP and/or vanadate might be defective in the cell's active transport due to the lack of P-type ATPase activity. From the spectral data with circular dichroism (CD) spectroscopy, we found that activated OMP (OAS) at concentration below MIC did not disrupt helical structures of membrane proteins. Separately, we determined the cytopathic effect of OAS by SDS-PAGE, indicating the change in the production of cytoplasmic protein but not cell membrane.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
• /
• pp.159-162
• /
• 2000

유가식배양을 통한 고농도배양에서 계면활성제와 산소전달물질의 첨가는 세포의 고밀도와 배지의 고점도로 인해 발생하는 nutrient의 물질전달제한과 산소부족현상을 효과적으로 해결하였다. Pluronic 10R-5는 Pluronic F-68과 같은 triblock copolymer 구조이며 세포생장의 저해를 나타내지 않았다. 그러나 diblock copolymer구조이며 소수성 부분이 hydrocarbon block인 Plurafac A-38은 세포의 생장을 저해함을 관찰할 수 있었다. 따라서 장기간의 유가식배양이나 perfusion 배양을 수행할 경우 세포의 생존도를 증대시켜 유용물질의 생산성을 높일 수 있으며 여러 형태의 bioreactor에서 고농도 배양을 가능케 하여 유용물질 생산성을 높일수 있을 것이라고 기대된다.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제17권3호
• /
• pp.191-198
• /
• 2017

Background: For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. Method: In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. Results: The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). Conclusion: Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits.

• 한국미생물·생명공학회지
• /
• 제19권5호
• /
• pp.521-535
• /
• 1991

Cephalosporium 배양시 균체의 형태학적 측면을 고려한 cephalosporin C 생합성에 대한 모델식을 제안하였다. 제한기질로 glucose와 methionine을 고려한 double-substrate 모델을 설정하였는데 여기서 glucose는 균체의 증식 정도를, methionine은 균체의 증식속도를 제어하게 된다. Cephalosporin C의 생산은 균체의 형태학적 분화와 밀접한 관계가 있다. 한편 cephalosporin C의 생산성을 증대시키기 위해 모델식을 유가식 배양에 응용하였다.