• Clinical and Experimental Reproductive Medicine
• /
• 제31권1호
• /
• pp.67-74
• /
• 2004

Objective: This study was to examine in vitro neural cell differentiation pattern of the genetically modified human embryonic stem cells expressing tyrosine hydroxylase (TH). Materials and Methods: Human embryonic stem (hES, MB03) cell was transfected with cDNAs cording for TH. Successful transfection was confirmed by western immunoblotting. Newly transfected cell line (TH#2/MB03) was induced to differentiate by two neurogenic factors retinoic acid (RA) and b-FGF. Exp. I) Upon differentiation using RA, embryoid bodies (EB, for 4 days) derived from TH#2/MB03 cells were exposed to RA ($10^{-6}M$)/AA ($5{\times}10^{-2}mM$) for 4 days, and were allowed to differentiate in N2 medium for 7, 14 or 21 days. Exp. II) When b-FGF was used, neuronal precursor cells were expanded at the presence of b-FGF (10 ng/ml) for 6 days followed by a final differentiation in N2 medium for 7, 14 or 21 days. Neuron differentiation was examined by indirect immunocytochemistry using neuron markers (NF160 & NF200). Results: After 7 days in N2 medium, approximately 80% and 20% of the RA or b-FGF induced Th#2/MB03 cells were immunoreactive to anti-NF160 and anti-NF200 antibodies, respectively. As differentiation continued, NF200 in RA treated cells significantly increased to 73.0% on 14 days compared to that in b-FGF treated cells (53.0%, p<0.05), while the proportion of cells expressing NF160 was similarly decreased between two groups. However, throughout the differentiation, expression of TH was maintained ($\sim$90%). HPLC analyses indicated the increased levels of L-DOPA in RA treated genetically modified hES cells with longer differentiation time. Conclusion: These results suggested that a genetically modified hES cells (TH#2/MB03) could be efficiently differentiated in vitro into mature neurons by RA induction method.

• Biomolecules & Therapeutics
• /
• 제6권1호
• /
• pp.37-44
• /
• 1998

This study was performed to examine the effects of DA-9601, a novel antiulcer agent extracted from Artemisiae Herba, on radiation colitis in the rat. Female Wistar rats received a 30 Gy dose of irradiation to the 2 cm of distal colon in length using an intrarectal applicator system. 30 mg/tg or 100 mg/kg of DA- 9601 was administered orally 30 min before and 4 h after radiation on day 1. And the same dose of DA-9601 was given to the animals twice a day from day 2 to 14. As a reference control, sucralfate suspension (100 or 300 mg/head) was given as an enema based on the same treatment schedule of DA-9601. Body weight change and the frequency of diarrhea were recorded during the observation period as markers of radiationinduced injury, All animals were sacrificed on day 15 for evaluation of macro- and microscopic findings and mucosal myeloperoxidase (MPO) activity. Radiated animals showed diarrhea, mucosal redness and histologic changes characterized by edema and eosinophilic infiltration of the periglandular lamina propria with loss of colonic epithelium. Radiation also significantly increased mucosal MfO activity of affected colon f\\\\\\\\`<0.05). However, most of these changes were completely protected by oral administration with DA-9601. DA-9601 reduced radiation-induced histologic alteration significantly in a dose-related manner (P<0.05). In addition, mucosal MPO activity in rats receiving high dose of DA-9601 decreased significantly when compared with that in radiated control. High dose of sucralfate (300 mg/head) alleviated radiation-induced histologic lesion, but failed to reach statistical significance. The results of this study suggest that DA-9601 can be useful for the prevention of acute clinical symptoms of radiation proctocolitis and that decrease of mucosal MPO by DA-9601 plays a role in its protective mechanism(s), at least in part.

• Biomolecules & Therapeutics
• /
• 제23권2호
• /
• pp.189-194
• /
• 2015

P450 1A2 is responsible for the metabolism of clinically important drugs and the metabolic activation of environmental chemicals. Genetic variations of P450 1A2 can influence its ability to perform these functions, and thus, this study aimed to characterize the functional significance of three P450 1A2 allelic variants containing nonsynonymous single nucleotide polymorphisms (P450 $1A2^*8$, R456H; $^*15$, P42R; $^*16$, R377Q). Variants containing these SNPs were constructed and the recombinant enzymes were expressed and purified in Escherichia coli. Only the P42R variant displayed the typical CO-binding spectrum indicating a P450 holoenzyme with an expression level of ~ 170 nmol per liter culture, but no P450 spectra were observed for the two other variants. Western blot analysis revealed that the level of expression for the P42R variant was lower than that of the wild type, however the expression of variants R456H and R377Q was not detected. Enzyme kinetic analyses indicated that the P42R mutation in P450 1A2 resulted in significant changes in catalytic activities. The P42R variant displayed an increased catalytic turnover numbers ($k_{cat}$) in both of methoxyresorufin O-demethylation and phenacetin O-deethylation. In the case of phenacetin O-deethylation analysis, the overall catalytic efficiency ($k_{cat}/K_m$) increased up to 2.5 fold with a slight increase of its $K_m$ value. This study indicated that the substitution P42R in the N-terminal proline-rich region of P450 contributed to the improvement of catalytic activity albeit the reduction of P450 structural stability or the decrease of substrate affinity. Characterization of these polymorphisms should be carefully examined in terms of the metabolism of many clinical drugs and environmental chemicals.

• 한국약용작물학회지
• /
• 제19권6호
• /
• pp.456-463
• /
• 2011

The present study examined the effects of Korean white ginseng (WG, Panax ginseng C. A. Meyer) on the learning and memory function and the neural activity in rats with trimethyltin (TMT)-induced memory deficits. The rats were administered with saline or WG (WG 100 or 300 mg/kg, p.o.) daily for 21 days. The cognitive improving efficacy of WG on the amnesic rats, which was induced by TMT, was investigated by assessing the Morris water maze test and by performing immunohistochemistries on choline acetyltransferase (ChAT), acetylcholinesterase (AchE), cAMP responsive element binding protein (CREB) and brain derived neurotrophic factor (BDNF). The rats treated with TMT injection (control group) showed impaired learning and memory of the tasks, but the rats treated with TMT injection and WG administration produced significant improvement of the escape latency to find the platform in the Morris water maze at the 2nd and 4th days compared to that of the control group. In the retention test, the WG 100 and WG 300 groups showed significantly increased crossing number around the platform compared to that of the control group (p < 0.001). Consistently with the behavioral data, result of immunohistochemistry analysis showed that WG 100 mg/kg significantly alleviated the loss of BDNF-ir neurons in the hippocampus compared to that of the control group (p < 0.01). Also, treatment with WG has a trend to be increased the cholinergic neurons in the hippocampal CA1 and CA3 areas as compared to that of the control group. These results suggest that WG may be useful for improving the cognitive function via regulation of neurotrophic activity.

• The Korean Journal of Pain
• /
• 제12권2호
• /
• pp.177-182
• /
• 1999

Background: Clonidine, an ${\alpha}_2$ adrenergic agonist blocks nerve conduction. However, in our previous experiment we found that adrenaline neither blocks nerve conduction by itself nor augment nerve conduction blockade by lidocaine near clinical concentrations. Possible explanations are: 1) there may be antagonism between some of adrenergic receptors, 2) clonidine may block nerve conduction via non-adrenergic mechanism. The purpose of this study is to obtain dose-response curves of several different forms of adrenergic receptor agonist to see the relative potencies of each adrenergic receptors to block nerve conduction. Methods: Recordings of compound action potentials of A-fiber components (A-CAPs) were obtained from isolated sciatic nerves of adult male Sprague-Dawley rats. Nerve sheath of the sciatic nerve was removed and desheathed nerve bundle was mounted on a recording chamber. Single pulse stimuli (0.5 msec, supramaximal stimuli) were repeatedly applied (2Hz) to one end of the nerve and recordings of A-CAPs were made on the other end of the nerve. Dose-response curves of epinephrine, phenylephrine, isoproterenol, clonidine were obtained. Results: $ED_{50}$ of each adrenergic agonist was: $4.51\times10^{-2}$ M for epinephrine; phenylephrine, $7.74\times10^{-2}$ M; isoproterenol, $9.61\times10^{-2}$ M; clonidine, $1.57\times10^{-3}$ M. Conclusion: This study showed that only clonidine, ${\alpha}_2$ adrenergic agonist, showed some nerve blocking action while other adrenergic agonists showed similar poor degree of nerve blockade. This data suggest that non-effectiveness of epinephrine in blocking nerve conduction is not from the antagonism between adrenergic receptors.

• Biomolecules & Therapeutics
• /
• 제19권3호
• /
• pp.348-356
• /
• 2011

Liriope platyphylla is a medical herb that has long been used in Korea and China to treat cough, sputum, neurodigenerative disorders, obesity and diabetes. The aims of this study were to study the antidiabetic effects of the aqueous extract of L. platyphylla (AEtLP) through pancreatic and extrapancreatic actions. AEtLP were orally administrated to ICR mice once a day for 7 days. Of three different concentrations of AEtLP, only 10% AEtLP were low toxic to liver, based on body weight and serum biochemical analyses. However, 10% AEtLP-treated mice displayed signifi cant reduction of the glucose concentration and increased insulin concentration; no changes were noted using 5% and 15% AEtLP. Also, the increase of glucose transporter (Glut)-1 expression in liver was dependent on the concentration of AEtLP, and was regulated by the phosphorylation of Akt. The lowest expression of Glut-3 was observed in 15% AEtLP treated mice, followed by 10% AEtLP- and 5% AEtLP-treated mice. This pattern of Glut-3 expression was roughly in accord with the phosphorylation of c-Jun N-teminal kinase (JNK) in the mitogen-activated protein kinase (MAPK) pathway. Furthermore, a signifi cant rise of the superoxide dismutase activity (SOD) was detected in AEtLP-treated mice. The fi ndings suggest that AEtLP should be considered as a diabetes therapeutic candidate to induce insulin secretion from pancreatic ${\beta}$-cells and glucose uptake in liver cells.

• 대한화장품학회지
• /
• 제42권1호
• /
• pp.87-94
• /
• 2016

피부 손상은 주로 자외선, 열, 담배 등과 같은 환경적 요인으로부터 초래되는데, 이는 활성산소종의 과생성으로 인한 피부노화와 연관이 있는 것으로 알려져 있다. 돌배(Pyrus pyrifolia NAKAI)는 전 세계적으로 많이 소비되는 과일로써 항암, 항산화, 항염증효과가 알려져 있다. 본 연구에서는 돌배나무잎 추출물(Pyrus pyrifolia leaf extract, PPE)의 ultraviolet B (UVB)스트레스에 대한 피부 섬유아세포 보호효과를 검증하였다. Lactate dehydrogenase assay와 DCF-DA를 이용한 정성분석 실험은 PPE가 인간의 섬유아세포에서 UVB 스트레스에 의해 유발된 세포독성 및 과생성된 활성산소종을 농도 의존적으로 억제할 뿐만 아니라, 미토콘드리아 기능저하, 막전위 저하, 그리고 세포사멸과정의 핵심 인자인 caspase-3 활성도 유의하게 억제함을 보여주었다. 결론적으로, PPE는 UVB스트레스에 의해 과생성된 활성산소종을 억제시켰으며, 이로 인해 생기는 피부세포 사멸을 효과적으로 저해함을 확인하였다.

• 한국비블리아학회지
• /
• 제27권1호
• /
• pp.111-134
• /
• 2016

본 연구는 저자동시인용분석 기법을 이용하여 국내와 미국의 심장혈관학(Cardiovascular Research) 분야의 지적구조 규명을 목적으로 하였다. 이를 위해서 2008년부터 2014년까지 국내의 "대한심장학회지"와 미국의 Circulation, Circulation Research를 선정하여 인용빈도 기준으로 각각 45명과 53명의 저자를 추출하였다. 저자동시인용 행렬을 기반으로 다차원척도분석, 군집분석, 요인분석을 실시하였다. 분석결과는 심장혈관학 분야에서 국내와 미국 연구자들은 공통적으로 여러 분야에 걸쳐 다양한 세부 분야에서 연구 활동을 하는 경향을 보였다. 국내와 미국의 심장혈관학 분야는 핵심연구 영역으로 '심혈관질환 치료', '심혈관질환 진단', '심혈관질환 기초과학', '심혈관질환 예방'으로 나타났다. 국내와 미국의 가장 큰 차이로 볼 수 있는 것은 국내 연구는 임상 중심이며, 미국 연구는 기초 의학 중심인 것으로 나타났다. 국내의 경우는 '리듬장애' 분야가 나타났으며, 이에 반해 미국은 '심혈관계 작용약물' 분야를 찾아볼 수 있다. 또한 미국의 분석결과에서는 기초의학 분야의 세부분야인 '역학', '생물학', '생화학', '생리학' 분야가 뚜렷하게 구분되어 나타났다.

• Biomolecules & Therapeutics
• /
• 제19권2호
• /
• pp.187-194
• /
• 2011

Atherosclerosis and post-angiography restenosis are associated with intimal thickening and concomitant vascular smooth muscle cell (VSMC) proliferation. Obovatol, a major biphenolic component isolated from the Magnolia obovata leaf, is known to have anti-inflammatory and anti-tumor activities. The goal of the present study was to enhance the inhibitory effects of obovatol to improve its potential as a preventive or therapeutic agent in atherosclerosis and restenosis. Platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic smooth muscle cells (RASMCs) was examined in the presence or absence of a newly synthesized obovatol derivative, OD78. The observed anti-proliferative effect of OD78 was further investigated by cell counting and [$^3H$]-thymidine incorporation assays. Treatment with 1-4 ${\mu}M$ OD78 dose-dependently inhibited the proliferation and DNA synthesis of 25 ng/ml PDGF-BB-stimulated RASMCs. Accordingly, OD78 blocked PDGF-BB-induced progression from the $G_0/G_1$ to S phase of the cell cycle in synchronized cells. OD78 decreased the expression levels of CDK4, cyclin E, and cyclin D1 proteins, as well as the phosphorylation of retinoblastoma protein and proliferating cell nuclear antigen; however, it did not change the CDK2 expression level. In addition, OD78 inhibited downregulation of the cyclin-dependent kinase inhibitor (CKI) $p27^{kip1}$. However, OD78 did not affect the CKI $p21^{cip1}$ or phosphorylation of early PDGF signaling pathway. These results suggest that OD78 may inhibit PDGF-BB-induced RASMC proliferation by perturbing cell cycle progression, potentially through $p27^{kip1}$ pathway activation. Consequently, OD78 may be developed as a potential anti-proliferative agent for the treatment of atherosclerosis and angioplasty restenosis.

• Clinical and Experimental Pediatrics
• /
• 제52권5호
• /
• pp.567-575
• /
• 2009

목적 : 간질은 전세계인구의 0.5%에서 발병하며 유전적 성향이 많고, 이는 중추신경계의 과 흥분성에 기인한다고 알려져 있다. 최근 프로테오믹스기법의 발달로 질병관련 단백질 동정이 활발히 연구되어지고 있다. 더불어, 간질의 진단은 영상기법 및 뇌파 분석 등이 이용되고 있으나, 가장 손쉽고 경제적인 혈청단백질을 이용한 진단법은 확립되어 있지 못하다. 그러므로 본 연구에서는 측두엽 간질환자의 혈장 단백질을 분석하여 간질의 진단 표지단백질 및 질병관련단백질을 발굴하고자 하였다. 방 법 : 저자들은 8명의 측두엽 간질환자와 8명의 정상인 혈청을 비교하였다. 결 과 : 간질환자의 혈청에서 정상 혈청단백질과 유의하고 일관성 있는 차이를 보이는 12개의 단백질을 발견하였다. 그 중, 6개의 단백질을 동정하였고, 6개의 단백질은 동정하지 못하였다. 더불어, haptoglobin Hp2, PRO2675, immunoglobulin heavy chain constant region gamma 2와 1개의 명명되지 않은 단백질 및 3개의 미지의 단백질을 포함한 7개의 단백질은 간질환자의 혈액에서 증가하였다. 반면, MHC class I antigen, plasma retinol-binding protein precursor 및 3개의 미지의 단백질을 포함한 5개의 단백질은 감소하였다. 결 론 : MHC class I antigen, immunoglobulin heavy chain constant region gamma 2 및 수술 전에 증가하였던 3개의 미지의 단백질 중에서 1개, 감소하였던 3개의 미지의 단백질 중에서 2개를 포함한 모두 5개의 단백질은 간질을 일으키는 뇌 부위 절제 후 정상으로 회복되었다. 이는 이런 단백질들을 측두엽 간질의 진단 및 경과관찰인자로서, 활용할 수 있음을 시사한다. 나아가, 이러한 단백질들은 간질의 병태 생리 연구 및 새로운 치료약물개발의 표적 단백질로 활용될 수 있을 것이다.