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排序方式: 共有367条查询结果,搜索用时 31 毫秒
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Adnan Ayhanci Sibel Günes Varol Sahinturk Sila Appak Ruhi Uyar Mustafa Cengiz Yilmaz Altuner Suzan Yaman 《Biological trace element research》2010,136(2):171-179
The anticancer drug cyclophosphamide (CP) has nephrotoxic effects besides its urotoxicity, which both in turn limit its clinical
utility. The nephrotoxicity of CP is less common compared to its urotoxicity, and not much importance has been given for the
study of mechanism of CP-induced nephrotoxicity so far. Overproduction of reactive oxygen species (ROS) during inflammation
is one of the reasons of the kidney injury. Selenoproteins play crucial roles in regulating ROS and redox status in nearly
all tissues; therefore, in this study, the nephrotoxicity of CP and the possible protective effects of seleno l-methionine (SLM) on rat kidneys were investigated. Forty-two Sprague–Dawley rats were equally divided into six groups of seven
rats each. The control group received saline, and other rats were injected with CP (100 mg/kg), SLM (0.5 or 1 mg/kg), or CP + SLM
intraperitoneally. Malondialdehyde (MDA) and glutathione (GSH) levels in kidney homogenates of rats were measured, and kidney
tissues were examined under the microscope. CP-treated rats showed a depletion of renal GSH levels (28% of control), while
CP + SLM-injected rats had GSH values close to the control group. MDA levels increased 36% of control following CP administration,
which were significantly decreased after SLM treatment. Furthermore, these biochemical results were supported by microscopical
observations. In conclusion, the present study not only points to the therapeutic potential of SLM in CP-induced kidney toxicity
but also indicates a significant role for ROS and their relation to kidney dysfunction. 相似文献
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Sugarcane plants were developed that produce the sucrose isomers trehalulose and isomaltulose through expression of a vacuole‐targeted trehalulose synthase modified from the gene in ‘Pseudomonas mesoacidophila MX‐45’ and controlled by the maize ubiquitin (Ubi‐1) promoter. Trehalulose concentration in juice increased with internode maturity, reaching about 600 mm , with near‐complete conversion of sucrose in the most mature internodes. Plants remained vigorous, and trehalulose production in selected lines was retained over multiple vegetative generations under glasshouse and field conditions. 相似文献
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The temporal variability of the viral impact on bacterioplankton during the summer-winter transition in the North Sea was determined and artificial neural networks (ANNs) were developed to predict viral production and the frequency of infected bacterial cells (FIC). Viral production and FIC were estimated using a virus-dilution approach during four cruises in the southern North Sea between July and December 2000 and an additional cruise in June 2001. Supplementary data such as bacterial production, and bacterial and viral abundance were collected to relate changes in FIC and viral production to the dynamics of other biotic parameters. Average viral abundance varied between 4.4 x 10(6) ml(-1) in December and 29.8 x 10(6) ml(-1) in July. Over the seasonal cycle, viral abundance correlated best with bacterial production. Average bacterial abundance varied between 0.5 x 10(6) ml(-1) in December and 1.3 x 10(6) ml(-1) in July. Monthly average values of FIC ranged from 9% in September to 39% in June and the average viral production from 11 x 10(4) ml(-1) h(-1) in December to 35 x 10(4) ml(-1) h(-1) in July. The data set was used to develop ANN-based models of viral production and FIC. Viral production was modelled best using sampling time, and bacterial and viral abundance as input parameters to an ANN with two hidden neurons. Modelling of FIC was performed using bacterial production as an additional input parameter for an ANN with three hidden neurons. The models can be used to simulate viral production and FIC based on regularly recorded and easily obtainable parameters such as bacterial production, bacterial and viral abundance. 相似文献
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BACKGROUND: A circadian rhythm of symptoms has been reported in allergic rhinitis and some studies have shown the dosing time of antihistamines to be of importance for optimizing symptom relief in this disease. The objective of this study was to examine the efficacy of morning vs. evening dosing of the antihistamine desloratadine at different time points during the day. METHODS: Patients >/= 18 years, with seasonal allergic rhinitis received desloratadine 5 mg orally once daily in the morning (AM-group) or evening (PM-group) for two weeks. Rhinorrhea, nasal congestion, sneezing and eye symptoms were scored morning and evening. Wilcoxon rank sum and 2-way ANOVA test were used. RESULTS: Six-hundred and sixty-three patients were randomized; 336 in the AM-group; 327 in the PM-group. No statistically significant differences were seen between the AM and PM group at any time points. In the sub-groups with higher morning or evening total symptom score no difference in treatment efficacy was seen whether the dose was taken 12 or 24 hours before the higher score time. There was a circadian variation in baseline total symptom score; highest during daytime and lowest at night. The circadian variation in symptoms was reduced during treatment. This reduction was highest for daytime symptoms. CONCLUSIONS: A circadian rhythm was seen for most symptoms being more pronounced during daytime. This was less apparent after treatment with desloratadine. No statistically significant difference in efficacy was seen whether desloratadine was given in the morning or in the evening. This gives the patients more flexibility in choosing dosing time. 相似文献
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A simple model for the cooperative stabilisation of actin filaments by phalloidin and jasplakinolide
The stabilisation of magnesium actin filaments by phalloidin and jasplakinolide was studied using the method of differential scanning calorimetry. The results showed that actin could adapt three conformations in the presence of drugs. One conformation was adapted in direct interaction with the drug, while another conformation was identical to that observed in the absence of drugs. A third conformation was induced through allosteric inter-protomer interactions. The effect of both drugs propagated cooperatively along the actin filaments. The number of the cooperative units determined by using a quantitative model was larger for jasplakinolide (15 actin protomers) than for phalloidin (7 protomers). 相似文献
40.
3D reconstruction of the pelvis from bi-planar radiography 总被引:1,自引:0,他引:1
Mitton D Deschênes S Laporte S Godbout B Bertrand S de Guise JA Skalli W 《Computer methods in biomechanics and biomedical engineering》2006,9(1):1-5
3D personalized models are more and more requested for clinical and biomechanical studies. Techniques based on bi-planar X-rays present the advantage of a low radiation dose for the patient. However, up to now, such techniques have shown limited accuracy in the case of pelvis reconstruction. This study proposes and validates a method providing accurate 3D personalized model of the pelvis from bi-planar X-rays. The algorithm is based on the fast computation of an initial solution followed by local deformations based on 2D anatomical points and contours that are digitized in both radiographs. Results were close to CT-scan reconstructions (mean difference 1.6 mm and differences under 4.3 mm for 95% of the points). Moreover, 3D morphometry of the pelvis could be obtained with an accuracy of 5%. This technique provides 3D patient specific model with a low radiation dose. 相似文献