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961.
962.
Hyun Ah Kim Suyeon Lee Jeong-Hyun Park Sanghyun Lee Byung-Wan Lee Sung Hee Ihm 《Journal of drug targeting》2013,21(3):242-248
In this study, we developed an expression system of exendin-4, a glucagon-like peptide (GLP-1) analog, using a secretion signal peptide (SP) to facilitate exendin-4 secretion. For delivery of the exendin-4 expression system, high-molecular-weight polyethylenimine (25 kDa, PEI25k), low-molecular-weight polyethylenimine (2 kDa, PEI2k), and polyamidoamine (PAMAM) dendrimers were evaluated as gene carriers to Ins-1 β cells. As a result, PEI25k showed the highest transfection efficiency. For the construction of the exendin-4 expression vector, DNA coding the SP sequence was inserted upstream of the exendin-4 cDNA, resulting in the construction of pβ-SP-Ex-4. Transfection assay showed that the secretion level of exendin-4 increased in the pβ-SP-Ex-4 transfected cells, compared with the pβ-Ex-4 transfected cells. To identify the β-cell protection effect of pβ-SP-Ex-4 delivery, the Ins-1 β cells were transfected with pβ-SP-Ex-4 or pβ-Ex-4 and incubated under normoxia or hypoxia. An MTT assay showed that the pβ-SP-Ex-4 transfected cells had higher β-cell viability than the pβ-Ex-4 transfected cells under hypoxia. In addition, the pβ-SP-Ex-4 transfected cells exhibited lower caspase-3 activity than the pβ-Ex-4 transfected cells. Therefore, PEI25k/pβ-SP-Ex-4 complex may be useful to protect isolated β cells from apoptosis during transplantation. 相似文献
963.
Chang-Johng Kim Seung-Kil Cho Myung-Su Shin Hyun Cho Dong-Suk Ro Jong-Sei Park Chang-Soo Yook 《Archives of pharmacal research》1990,13(4):371-373
The hypoglycemic activity of water extracts of fifty six medicinal plants were evaluated in the streptozotocin-induced diabetic
mice. Twelve medicinal plants have significantly antidiabetic activity; Mori Radicis Cortex, Kwang Fang Chi Radix, Paeoniae
Radix, Eugeniae Flos, Atractylodis Rhizoma, Ophiopogonis Tuber, Rosae multiflorae Fructus, Glycyrrhizae Radix, Tetrapanacis
Medulla, Bigno, Forsythiae Fructus and Sophorae Radix. 相似文献
964.
Hye-Jung Park Hyeong-Geug Kim Jing-Hua Wang Min-Kyung Choi Jong-Min Han Jin-Seok Lee 《Drug and chemical toxicology》2016,39(1):111-118
Three chemotoxins including dimethylnitrosamine (DMN), carbon tetrachloride (CCl4), and thioacetamide (TAA) are commonly used in hepatofibrotic models. We aimed to draw characteristics of histopathology and pro-fibrogenic cytokines including TGF-β, PDGF and CTGF among three models. Rats were divided into six groups and intra-peritoneally injected with DMN (10?mg/kg, for three weeks, three consecutive days weekly), CCl4 (1.6?g/kg, for 10 weeks, twice weekly), TAA (200?mg/kg, for 12 weeks, twice weekly) or their corresponded treatment for each control group. The liver weights were decreased in DMN model, but not other models. Ascites were occurred as 3-, 2-, and 7-rats in DMN, CCl4, and TAA model, respectively. The lipid peroxidation was highest in CCl4 model, serum levels of liver enzymes were increased as similar severity. The hepatofibrotic alterations were remarkable in DMN and TAA model, but not CCl4 as evidenced by the Masson trichrome staining and hydroxyproline. The immunohistochemistry for α-SAM showed that the DMN model was most severely enhanced than other models. On the other hand, hepatic tissue levels of pro-fibrogenic cytokines including TGF-β, PDGF, and CTGF were generally increased in three models, but totally different among models or measurement resources. Especially, serum levels of three cytokines were remarkably increased by CCl4 injection and CTGF levels in both hepatic tissue and serum were highest in CCl4 group. Our results firstly demonstrated comparative study for features of morphological finding and pro-fibrogenic cytokines in serum and hepatic protein levels among three models. Above results would be a helpful reference for hepatofibrotic studies. 相似文献
965.
An allergic reaction ensues after antigen binds to mast cell or basophil high affinity IgE receptor, Fc epsilonRI, resulting in degranulation of various inflammatory mediators that produce various allergic symptoms. In this study, i) we isolated the active component for the inhibition of mast cell degranulation from the extract of leaves of Castanea crenata and identified it as quercetin; ii) we established the total synthesis procedure of quercetin; iii) using quercetin as positive control, we excavated some lead compounds that possess inhibitory activities for mast cell degranulation by screening the chemical libraries of 1,3-oxazolidine derivatives prepared by solid phase combinatorial chemistry. Some of 1,3-oxazolidine compounds possessing acetyl and 3',4'-dichlorophenyl group displayed strong inhibitory activities on Fc epsilonRI-mediated mast cell degranulation, suggesting that they can be used as lead compounds for the development of anti-allergic agents. 相似文献
966.
The hepatoprotective activity of lactic acid bacteria (Lactobacillus brevis HY7401, Lactobacillus acidophilus CSG and Bifidobacterium longum HY8001), which inhibited beta-glucuronidase productivity of intestinal microflora, on t-BHP- or CCl4-induced hepatotoxicity of mice were evaluated. These oral administration of lactic acid bacteria lowered beta-glucuronidase production of intestinal microflora as well as Escherichia coli HGU-3. When lactic acid bacteria at a dose of 0.5 or 2 g (wet weight)/kg was orally administered on CCl4-induced liver injury in mice, these bacteria significantly inhibited the increase of plasma alanine transferase and aspartate transferase activities by 17-57% and 57-66% of the CCl4 control group, respectively. These lactic acid bacteria also showed the potent hepatoprotective effect against t-BHP-induced liver injury in mice. The inhibitory effects of these lactic acid bacteria were more potent than that of dimethyl diphenyl bicarboxylate (DDB), which have been used as a commercial hepatoprotective agent. Among these lactic acid bacteria, L. acidophilus CSG exhibited the most potent hepatoprotective effect. Based on these findings, we insist that an inhibitor of beta-glucuronidase production in intestine, such as lactic acid bacteria, may be hepatoprotective. 相似文献
967.
Yusuf Osmanlolu Drew Parker Jacob A. Alappatt James J. Gugger Ramon R. DiazArrastia John Whyte Junghoon J. Kim Ragini Verma 《Human brain mapping》2022,43(13):3944
Traumatic brain injury (TBI) is a major public health problem. Caused by external mechanical forces, a major characteristic of TBI is the shearing of axons across the white matter, which causes structural connectivity disruptions between brain regions. This diffuse injury leads to cognitive deficits, frequently requiring rehabilitation. Heterogeneity is another characteristic of TBI as severity and cognitive sequelae of the disease have a wide variation across patients, posing a big challenge for treatment. Thus, measures assessing network‐wide structural connectivity disruptions in TBI are necessary to quantify injury burden of individuals, which would help in achieving personalized treatment, patient monitoring, and rehabilitation planning. Despite TBI being a disconnectivity syndrome, connectomic assessment of structural disconnectivity has been relatively limited. In this study, we propose a novel connectomic measure that we call network normality score (NNS) to capture the integrity of structural connectivity in TBI patients by leveraging two major characteristics of the disease: diffuseness of axonal injury and heterogeneity of the disease. Over a longitudinal cohort of moderate‐to‐severe TBI patients, we demonstrate that structural network topology of patients is more heterogeneous and significantly different than that of healthy controls at 3 months postinjury, where dissimilarity further increases up to 12 months. We also show that NNS captures injury burden as quantified by posttraumatic amnesia and that alterations in the structural brain network is not related to cognitive recovery. Finally, we compare NNS to major graph theory measures used in TBI literature and demonstrate the superiority of NNS in characterizing the disease. 相似文献
968.
C型钠尿肽抑制大鼠胃窦环行肌自发性收缩活动 总被引:3,自引:0,他引:3
Guo HS Cui X Cui YG Kim SZ Cho KW Li ZL Xu WX 《Acta pharmacologica Sinica》2003,24(10):1021-1026,1062
目的:研究钠尿肽对胃动力的作用及其可能的机制.方法:用四道记录仪记录胃窦环行肌条的自发性收缩活动;利用放射免疫技术测定cGMP的产生量;利用放射自显影技术分析钠尿肽受体在胃内的分布情况.结果:钠尿肽受体在大鼠胃的不同部位均有分布,但在胃窦部最多。ANP、BNP和CNP均能抑制胃窦环行肌条的自发性收缩,其中,CNP的作用尤为明显并呈剂量依赖关系.CNP的这种抑制性作用被鸟苷酸环化酶抑制剂LY83583所削弱,而用cGMF敏感的磷酸酯酶抑制剂zaparinist预处理时CNP的抑制作用明显增加.CNP明显提高胃窦环行肌cGMP的浓度.用非选择性钾通道阻断剂TEA预处理后发现CNP对胃窦环行肌自发性收缩活动的抑制作用明显减弱.结论:钠尿肽受体在大鼠的胃窦分布最多.CNP明显抑制大鼠胃窦环行肌的自发性收缩活动.CNP对大鼠胃窦环行肌自发性收缩活动的抑制效应是通过cGMP途径实现的.钾通道也参与CNP对大鼠胃窦平滑肌的舒张过程。 相似文献
969.
Meijie Tian Adam T. Cheuk Jun S. Wei Abdalla Abdelmaksoud Hsien-Chao Chou David Milewski Michael C. Kelly Young K. Song Christopher M. Dower Nan Li Haiying Qin Yong Yean Kim Jerry T. Wu Xinyu Wen Mehdi Benzaoui Katherine E. Masih Xiaolin Wu Zhongmei Zhang Sherif Badr Naomi Taylor Brad St. Croix Mitchell Ho Javed Khan 《The Journal of clinical investigation》2022,132(16)
970.
To enhance the formability of magnesium alloys, inhibition of basal texture development by the particle-stimulated nucleation (PSN) effect has attracted significant interest. However, its contribution to texture development is not easily observed due to the separation of texture from the conventional deformation behavior. This study aims to separate the Ca texture from the deformation behavior of AZX611 alloy and quantify it using scanning electron microscopy with electron backscatter diffraction (SEM-EBSD). Since Ca in the AZ61 magnesium alloy precipitated as Al2Ca, the hot-rolled magnesium alloys AZ31, AZ61, and AZX611 were used. High temperature compression was conducted at 723 K, the strain rate 0.05/s and 0.005/s and the true strain up to −1.0. Dynamic recrystallization was observed in each specimen and the Ca-free alloys showed dislocation glide at high strain rates and solute drag at low strain rates. When the dislocation glide dominated, basal texture was strengthened. In contrast, solute drag caused non-basal texture development. Precipitation hardening caused AZ61 to have higher flow stress than those of the Ca-free alloys by the PSN effect; its texture was observed separately because the PSN grain growth around the precipitation and orientation was specific, similar to the one developed at the solute atom drag. 相似文献