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排序方式: 共有628条查询结果,搜索用时 31 毫秒
591.
In seeds of SOLANUM DULCAMARA L. the 4,4-dimethylsterols cycloartenol, lanosterol, cycloartanol, 24-dihydrolanosterol, 24-methylenecycloartanol, and 24-methylenelanost-8-en-3beta-ol, the 4alpha-methylsterols 31-norcycloartenol, 31-norlanosterol, 31-norlanost-8-en-3beta-ol, lophenol, cycloeucalenol, obtusifoliol, gramisterol, and citrostadienol and the sterols cholesterol, 24-methylenecholesterol, campesterol, isofucosterol, sitosterol, and stigmasterol were identified by GC and GC/MS. The biosynthesis of these compounds is discussed. Additionally the spirostanoles tigogenin and diosgenin were isolated. The N-analoges spirosolanoles soladulcidine and solasodine were identified by TLC. The seeds contain 28% oil, of which the fatty acid composition has been examined. The predominant fatty acids are linolic acid (18:2) and oleic acid (18:1). 相似文献
592.
Eduard Escrich Montserrat Solanas Raquel Moral Irmgard Costa Laura Grau 《Clinical & translational oncology》2006,8(12):868-883
There is a wealth of evidence supporting the relationship between dietary lipids and cancer, particularly those of the breast,
colon and rectum and prostate. The main support comes from the international correlational studies and, especially, from experimental
ones. The evidence from human analytical studies is less consistent because of several conflicting findings, probably due
to methodological issues. Experiemntally, it has been clearly demonstrated that quantity and type of dietary lipids as well
as the particular critical phases of the carcinogenesis in which they act, are the essential factors in this relationship.
Thus, whereas high dietary intake of n-6 polyunsaturated fatty acids (PUFA), primarily LA, and saturated fat has tumor-enhancing
effects, long chain n-3 PUFA, CLA and GLA have inhibitory effects. Monounsaturated fatty acids (MUFA), mainly OA, present
in high quantities in olive oil, seem to be protective although some inconsistent results have been reported. Bioactive compounds
of virgin olive oil may also account for the protective effect of this oil, which is the main source of fat in the Mediterranean
diet. Experimental studies have also provided evidence of several putative mechanisms of action of dietary lipids on cancer.
Lipids can influence the hormonal status, modify cell membranes structure and function, cell signalling transduction pathways
and gene expression, and modulate the function of the immune system. Although further studies are needed to evaluate and verify
these mechanisms in humans, based on the multiple ways dietary lipids can act, they may have an important influence on tumorigenesis. 相似文献
593.
Drug interactions with patient-controlled analgesia 总被引:2,自引:0,他引:2
Patient-controlled analgesia (PCA) has become standard procedure in the clinical treatment of pain. Its widespread use in patients with all kinds of diseases opens a variety of possible interactions between analgesics used for PCA and other drugs that might be administered concomitantly to the patient. Many of these drug interactions are of little clinical importance. However, some drug interactions have been reported to result in serious clinical problems. Drug interactions can either predominantly affect the pharmacokinetics or pharmacodynamics of the drug. Most important pharmacokinetic drug interactions occur at the level of drug metabolism or protein binding. Acceleration of methadone metabolism caused by cytochrome P450 (CYP) 3A4 induction by antiretroviral drugs or rifampicin (rifampin) has caused methadone withdrawal symptoms. Lack of morphine formation from codeine as a result of CYP2D6 inhibition by quinidine results in an almost complete loss of the analgesic effects of codeine. Alterations of methadone protein binding caused by an inhibition of alpha1-acid glycoprotein synthesis by alkylating substances are another possibility for predominantly pharmacokinetically based drug interactions during PCA. Furthermore, inhibition of P-glycoprotein by anticancer drugs could result in altered transmembrane transport of morphine, methadone or fentanyl, although this has not been shown to be of clinical relevance. Synergistic effects of systemically administered opioids with spinally or topically delivered opioids or anaesthetics have been reported frequently. The same is true for the opioid-sparing effects of coadministered non-opioid analgesics. Antidepressants, anticonvulsants or alpha2-adrenoreceptor agonists have also been shown to exert additive analgesic effects when administered together with an opioid. Inconsistent findings, however, are reported regarding the treatment of patients with opioid-induced nausea and sedation, since coadministration of antiemetics either increased or decreased the respective adverse effects or revealed additional unwanted drug effects. 相似文献
594.
595.
Geographic Information Systems and travel health 总被引:1,自引:0,他引:1
Questions dealing with space and/or location have always been integral to understanding and addressing health issues, such as charting the spread of a disease. Health researchers have traditionally used paper maps to explore the spatial dimensions of health. However, due to advances in technology, it is now possible to ask such questions using a suite of computer-based methods and tools that are collectively known as a Geographic Information System (GIS). 相似文献
596.
Graumann R Paris I Martinez-Alvarado P Rumanque P Perez-Pastene C Cardenas SP Marin P Diaz-Grez F Caviedes R Caviedes P Segura-Aguilar J 《Polish journal of pharmacology》2002,54(6):573-579
Although it is generally accepted that free radicals are involved in the neurodegenerative process occurring in the dopaminergic neurons of the nigro-striatal system in Parkinson's disease, the exact mechanism of neurodegeneration in vivo is still unknown. We propose that the degeneration of dopaminergic nigrostriatal system in this condition may depend on: (a) existence of free dopamine which oxidizes to aminochrome as a consequence of: (i) overproduction of dopamine; (ii) inhibition and/or low expression of synaptic vesicle catecholamine transporter; (iii) inhibition or low expression of monoamine oxidases; (b) one-electron reduction of aminochrome to leukoaminochrome o-semiquinone radical, which induces neurotoxicity, due to inhibition of DT-diaphorase or the existence of a polymorphism with a point mutation (C --> T) in the cDNA 609 expressing an inactive DT-diaphorase. We suggest that DT-diaphorase plays a neuroprotective role in dopaminergic neurons, which is supported by the following observations: (i) Cu-toxicity is dependent on DT-diaphorase inhibition with dicoumarol in RCSN-3 cells derived from the rat substantia nigra; (ii) the cytotoxic effect of monoamine oxidase-A inhibitor amiflamine in RCSN-3 cells is increased by 2.4-fold (p < 0.001) in the presence of the inhibitor of DT-diaphorase, dicoumarol; (iii) concomitant intracerebral administration of manganese (Mn3+) together with the DT-diaphorase inhibitor dicoumarol into the left medial forebrain bundle produced a behavioral pattern characterized by contralateral rotational behavior when the rats were stimulated with apomorphine, in a manner similar to that observed in animals injected unilaterally with 6-hydroxydopamine; (iv) incubation of RCSN-3 cells with salsolinol in the presence of DT-diaphorase inhibitor significantly decreased cell survival by 2.5-fold (p < 0.001). 相似文献
597.
Raquel Moral Raquel Escrich Montserrat Solanas Elena Vela Irmgard Costa M. Carme Ruíz de Villa 《Nutrition and cancer》2013,65(3):410-420
Based on the importance of early-life events in breast cancer risk, we have investigated the effects of high-fat diets on maturation, mammary gland development, and its susceptibility to transformation. Female Sprague-Dawley rats were fed a lowfat (LF), high corn oil (HCO), or high extra-virgin olive oil (HOO) diet from weaning and gavaged with 7,12-dimethylbenz[a]anthracene. Body weight and mass increased in the HCO group compared to the LF group. The vaginal opening was advanced in both high-fat groups, especially in the HCO group. This HCO group also had increased body weight around puberty, more corpora lutea at post-puberty, and tended to have higher kisspeptin levels in the hypothalamus. Both high-fat diets induced subtle modifications in the morphology of the mammary gland, with no changes on β-casein or hormone receptors expression in the gland. The HCO diet had a clearly stimulating effect of carcinogenesis, inducing the earliest appearance of tumors and the highest tumor incidence and yield, whereas the HOO diet seemed to have a weak enhancing effect, increasing tumor yield. Our data suggest a strong influence of the HCO diet in sexual maturation and mammary cancer risk, while rats fed the HOO diet were more similar to the controls. 相似文献
598.
Shin EM Zhou HY Guo LY Kim JA Lee SH Merfort I Kang SS Kim HS Kim S Kim YS 《International immunopharmacology》2008,8(11):1524-1532
The anti-inflammatory effects of glycyrol, a benzofuran coumarin isolated from Glycyrrhizae Radix, were studied. Glycyrol of 5, 25 and 50 microM dose-dependently inhibited nitric oxide (NO) production by down-regulating inducible nitric oxide synthase (iNOS), and alleviated cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW264.7 macrophages, in both the mRNA and the protein. Furthermore, glycyrol dose-dependently decreased the mRNA of the pro-inflammatory cytokines IL-1beta and IL-6. LPS-induced NF-kappaB activation was prevented in RAW264.7 macrophages by inhibition of I-kappaBalpha phosphorylation. In addition, administration of glycyrol (30 and 100 mg/kg, i.p) reduced the thickness of carrageenan-induced mouse-paw edema swelling. Taken together, our results indicate that glycyrol is an important anti-inflammatory constituent of Glycyrrhizae Radix, and that its anti-inflammatory effect is attributed to the inhibition I-kappaBalpha phosphorylation. 相似文献
599.
Bourquin C van der Haar ME Anz D Sandholzer N Neumaier I Endres S Skerra A Schwab ME Linington C 《European journal of pharmacology》2008,588(1):99-105
Antibodies against the neurite outgrowth inhibitor Nogo-A enhance axonal regeneration following spinal cord injury. However, antibodies directed against myelin components can also enhance CNS inflammation. The present study was designed to assess the efficacy of DNA vaccination for generating antibodies against Nogo-A and to study their pathogenic potential in a mouse model for multiple sclerosis. Mice were immunized by a single i.m. injection of a plasmid expression vector encoding either full length membrane-integral Nogo-A equipped with a signal peptide or two versions of its large N-terminal extramembrane region. The presence of serum antibodies to Nogo-A was measured 4 weeks after injection by ELISA, Western blotting and immunohistochemistry. DNA vaccination efficiently induced production of Nogo-A-specific antibodies that recognized recombinant, intracellular Nogo-A in cell culture but also stained native Nogo-A on the oligodendrocyte surface. Experimental autoimmune encephalomyelitis was induced in DNA-vaccinated mice by immunization with proteolipid peptide (a.a. 139-154). In contrast to vaccination with DNA encoding myelin oligodendrocyte glycoprotein that exacerbates this disease, Nogo-A DNA vaccination did not enhance clinical severity of disease. In summary, DNA vaccination is a simple and efficient method for generating an antibody response to Nogo-A. No pathogenicity was observed even during a full-blown inflammatory response of the central nervous system. 相似文献
600.
Lötsch J Belfer I Kirchhof A Mishra BK Max MB Doehring A Costigan M Woolf CJ Geisslinger G Tegeder I 《Clinical chemistry》2007,53(6):1010-1015
BACKGROUND: A haplotype in the GTP cyclohydrolase 1 (dopa-responsive dystonia) gene (GCH1) is associated with decreased persistent pain. The aim of the present study was to develop a screening method for the pain-protective haplotype. METHODS: Complete genetic information for all 15 GCH1 DNA positions constituting the pain-protective GCH1 haplotype was available from 278 patients. In silico analyses, including discriminant analysis of the most frequent haplotypes, identified distinctive DNA positions that allow detection of the pain-protective haplotype at high sensitivity and specificity with the smallest possible number of DNA positions. Pyrosequencing(trade mark) assays were subsequently developed for these DNA positions, established with 662 DNA samples from healthy volunteers, and prospectively validated with a random selection of DNA samples genotyped for all 15 DNA positions. RESULTS: Diagnosis of the pain-protective GCH1 haplotype was possible with 100% sensitivity and specificity by screening for just 3 GCH1 genetic variants that span the entire DNA range of the haplotype: c.-9610G>A (dbSNP rs8007267G>A) in the 5' untranslated region, c.343 + 8900A>T (dbSNP rs3783641A>T) in intron 1, and c.*4279 (dbSNP rs10483639C>G) in the 3' untranslated region. Test sensitivity and specificity were still >95% with 2 or even just 1 of these GCH1 DNA positions. CONCLUSIONS: In silico analysis of complex GCH1 gene haplotypes reduced the requisite number of tested DNA positions from 15 to 3 while maintaining the reliability, specificity, and sensitivity of the genetic diagnosis. This screening method could reduce laboratory diagnostic efforts and facilitate investigations of the pain-protective GCH1 haplotype. 相似文献