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排序方式: 共有1122条查询结果,搜索用时 15 毫秒
81.
A new cytotoxic lobane diterpene, ineleganene (1), was isolated from the Formosan soft coral Sinularia inelegans. The structure of compound 1 was determined by 1D and 2D spectral analysis. 相似文献
82.
Investigation of a cytotoxic chloroform-soluble fraction of the stem of Casearia membranacea (Flacourtiaceae) led to the isolation of five new compounds, including one butenolide, casealactone (1), one chroman, caseamemin (2), two dolabellane diterpenoids, casearimene A (3) and casearimene B (4), one benzoquinol ether, casearinone (5), together with fifteen known compounds, including two amides, N- trans-feruloyltyramine (6) and N- cis-feruloyltyramine (7), six steroids, beta-sitosterol (8), stigmast-5-ene-3beta,7alpha-diol (9), stigmast-5-ene-3beta,7beta-diol (10), stigmastane-3beta,5alpha,6beta-triol (11), beta-sitostenone (12), beta-sitosterol 3- O-beta-glucoside (13), two triterpenoids, squalene (14) and friedelin (15), one lignan, (+/-)-syringaresinol (16), two benzenoids, syringaldehyde (17) and vanillic acid (18), one ester, methyl hexadecanoate (19), and anthraquinone (20), respectively. Among these isolates, 1 showed cytotoxicity against P-388 and HT-29 cancer cell lines in vitro, and 6 and 7 showed cytotoxicity against the P-388 cancer cell line. The structures of these compounds were determined by means of spectroscopic techniques, and the structure of 3 was confirmed by X-ray crystallographic analysis. 相似文献
83.
Aim of this study
Graptopetalum paraguayense E. Walther, a vegetable consumed in Taiwan, has been used in folk medicine for protection against liver injury, although its actual efficacy remains uncertain. Therefore, we investigated the protective effects of Graptopetalum paraguayense E. Walther against carbon tetrachloride (CCl4)-induced liver damage in rats.Materials and methods
Water extracts of Graptopetalum paraguayense E. Walther (WGP) were administered for 8 consecutive weeks to male Sprague-Dawley rats. And a dose-dependent manner in preventing liver damage was confirmed. Moreover, the major ingredient of WGP, gallic acid, was also orally administrated in the CCl4-induced rats. The hepatoprotective activity was assessed using various biochemical parameters such as antioxidant enzymes and histopathological studies.Results
WGP ranging from 50 to 300 mg/kg bw administrations significantly lowered serum aspartate transaminase (AST) and alanine transaminase (ALT) levels, and inhibited malondialdehyde (MDA) generation in CCl4-treated rats. WGP increased cellular GSH level and antioxidant enzymes, including superoxide dismutase, glutathione reductase, and catalase. Serum tumor necrosis factor-alpha (TNF-α) was decreased in the group treated with CCl4 plus WGP (150 and 300 mg/kg bw). Histopathological examination of livers showed that WGP reduced fatty degeneration, cytoplasmic vacuolization and necrosis in CCl4-treated rats. In contrary, 10 mg/kg bw of gallic acid was administrated, this dose was related with WGP (300 mg/kg bw), and had significantly decreased the AST and ALT compared to the CCl4-treated group. Aforesaid results suggested that gallic acid from WGP offered antioxidative activity against CCl4-induced oxidative liver damage.Conclusions
Taken together, this study is the first time to suggest that Graptopetalum paraguayense E. Walther exerts hepatoprotection via promoting antioxidative and anti-inflammatory properties against CCl4-induced oxidative liver damage. 相似文献84.
85.
Regional myocardial dysfunction: evaluation of patients with prior myocardial infarction with fast CT 总被引:1,自引:0,他引:1
Lipton MJ; Farmer DW; Killebrew EJ; Bouchard A; Dean PB; Ringertz HG; Higgins CB 《Radiology》1985,157(3):735-740
A prototype ultrafast cine computed tomographic (CT) scanner, designed specifically for cardiac imaging, was used to evaluate a preliminary series of patients with prior myocardial infarction (n = 21) and a control group without coronary artery disease (n = 5). Multilevel 50-msec CT scan exposures were obtained during peripheral intravenous bolus injections of contrast medium. A comparison was made between cine-CT scans and standard left ventriculographic images in assessing segmental left ventricular motion. Results indicate that cine CT, performed at sufficiently rapid speeds (20 scans per second) to allow useful analysis of regional ventricular wall motion, can provide adequate image quality. Analysis of 110 segments revealed a good correlation (90.9%) between the two techniques in characterizing normal from abnormal regional wall motion. Cine CT, based on this initial study, demonstrates considerable potential for evaluating not only cardiac chamber dimensions but also segmental wall dynamics. 相似文献
86.
Parathyroid localization. Clinical review 总被引:1,自引:0,他引:1
Recent advances in the techniques of preoperative parathyroid localization include ultrasonography, computed tomography, thallium-technetium subtraction scanning, magnetic resonance imaging, digital subtraction angiography with selective venous catheterization for PTH measurement, and ultrasound or CT-guided needle aspiration biopsy for cytological examination or PTH assay. These techniques are helpful for patients with hyperparathyroidism undergoing the initial operation, and essential for patients with persistent or recurrent hyperparathyroidism undergoing reoperation. Noninvasive procedures should be performed first, and the combination of any two positive studies localizes the tumor with near certainty. Invasive procedures have a higher risk of complications and are recommended only in selected patients before reoperation. 相似文献
87.
A Zielke S Hoffmann U Plaul Q Y Duh O H Clark M Rothmund 《Experimental and clinical endocrinology & diabetes》1999,107(6):361-369
Thyroid stimulating hormone (TSH) causes differentiation and epidermal growth factor (EGF) causes dedifferentiation of thyroid cells in vitro. In undifferentiated thyroid cancer cell lines, TSH stimulates tumor cell migration and invasion, a dedifferentiated function, presumably due to an escape of tumor cells from the control of differentiating growth factors. In a highly differentiated thyroid carcinoma cell line of Hürthle cell origin (XTC), we tested the hypothesis that TSH would stimulate thyroglobulin secretion (a differentiated function) more than EGF, and EGF would stimulate invasion (a de-differentiated function) more than TSH. Proliferation, adhesion, cell migration and invasion were measured by the MTT assay, human thyroglobulin by RIA and protease activity by substrate-gel zymography. TSH induced differentiated morphologic changes in XTC cells and stimulated secretion of human thyroglobulin in a dose dependent manner, whereas EGF did not. The effects of TSH on growth, adhesion, migration and invasion were dose dependent and biphasic, with an increase at low and a decrease at high concentrations of TSH. These effects were always more pronounced than those observed with EGE Gelatinolytic activity, consistent with metalloproteinase activity was revealed by zymography, but the pattern of secretion was not altered by neither TSH nor EGF. These results suggest, that TSH has pleiotropic effects on differentiated thyroid cancer cells in vitro that involve differentiated morphology and function but also affect features commonly associated with the malignant in vitro phenotype. 相似文献
88.
Data obtained on 426 consecutive patients referred to a breast center by 122 physicians, including family practitioners, general surgeons, and other specialists, showed that the obstetricians-gynecologists referred the greatest average number of patients per physician, with more than 50% of these referrals for screening mammography. Internists referred fewer patients by nearly a factor of ten, with only one-third of these patients referred for screening mammography. Internists may be the weakest link in the utilization of screening mammography. 相似文献
89.
Subsets of T- and B-lymphocytes were immunophenotyped in frozen thyroid tissues from 20 patients with Graves' disease by using the avidin-biotin-complex peroxidase method. A panel of B- and T-cell monoclonal antibodies were employed to detect the subsets of T cells, activated T cells, natural killer cells and B cells. Serum thyroglobulin and microsomal antibodies were also measured simultaneously from both the thyroid vein and the peripheral vein in 9 patients. The quantitative results found that an almost equal ratio of lymphocytes stained positively for Leu 3a (CD4) and T8 (CD8) in almost all specimens. Activated lymphocytes expressing T9, T10, and Tac (CD25) were sporadically noted in the interstitial areas. The lymphoid aggregates and follicles were B cell clusters. Natural killer cells appear to play an insignificant role in Graves' disease. The thyroid epithelial cells expressed HLA-DR (Ia+) and HLA-ABC, suggesting a possible localized immune reaction between antigen-presenting thyroid epithelial cells and lymphocytes. The titers of serum thyroglobulin and microsomal antibodies from either the thyroid vein or the peripheral vein showed no definite correlation with the lymphoid distribution of the thyroid tissues, implying that the in situ or local immunologic reaction may not reflect the status of systemic antibody production. The immunologic mechanism and pathogenesis of Graves' disease is reviewed and discussed. 相似文献
90.
The crystal structure and cytotoxicity of goniodiol-7-monoacetate from Goniothalamus amuyon. 总被引:1,自引:0,他引:1
Y C Wu C Y Duh F R Chang G Y Chang S K Wang J J Chang D R McPhail A T McPhail K H Lee 《Journal of natural products》1991,54(4):1077-1081
The styrylpyrone, goniodiol-7-monoacetate [1] [6R-(7R,8R-dihydro-7-acetoxy-8-hydroxystyryl)-5, 6-dihydro-2-pyrone], has been isolated from Goniothalamus amuyon, and its detailed molecular structure has been determined by X-ray crystallographic analysis. Goniodiol-7-monoacetate showed potent (ED50 values less than 0.1 microgram/ml) cytotoxicities against KB, P-388, RPMI, and TE671 tumor cells. 相似文献