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排序方式: 共有373条查询结果,搜索用时 15 毫秒
91.
Martin EA; Heydon RT; Brown K; Brown JE; Lim CK; White IN; Smith LL 《Carcinogenesis》1998,19(6):1061-1069
A novel HPLC system has been developed that has allowed the separation of
tamoxifen DNA adducts formed in the livers of rats and mice treated with
this drug. At least 13 different peaks have been separated from
32P-post-labelled DNA, with two major peaks jointly accounting for >60%
of the total adducts formed by tamoxifen in the livers of treated rats and
mice. This is a great improvement on the resolution obtained by thin layer
chromatography, which separates the adducts into one main product
consisting of a group of major adduct spots eluting together, plus several
other minor spots. Identification of the nature of some of the peaks has
been investigated. Comparisons of the products formed when
alpha-acetoxytamoxifen is reacted with DNA in vitro with 32P-post- labelled
liver DNA adducts from rats treated with tamoxifen or alpha-
hydroxytamoxifen in vivo, appear to confirm that a major route of
activation of tamoxifen in vivo is via alpha-hydroxylation. The resolving
power of this HPLC system has further extended this result to show that six
of the peaks, including the two major peaks, are formed by the reaction of
an activated alpha-hydroxytamoxifen with DNA. Activation of
4-hydroxytamoxifen by the peroxidase/H2O2 system in vitro gives a more
polar DNA adduct seen only at trace levels in liver DNA from
tamoxifen-treated rats and mice.
相似文献
92.
D.-A. HALLBCK M. JODAL M. MANNISCHEFF O. LUNDGREN 《Acta physiologica (Oxford, England)》1991,143(3):271-277
Using a freezing point depression method osmolality in the intestinal tissue of four mammals (gerbils, guinea-pigs, rabbits and rats) was estimated in vivo, during fluid transport from an isotonic electrolyte-glucose solution. Net fluid transport was also measured. In gerbils, guinea-pigs and rabbits tissue osmolality was also estimated during in vitro conditions. A marked hyperosmolality was observed in vivo in the upper parts of the villi of all four mammals studied. The tissue osmolality was significantly higher than that seen in the same species during in vitro conditions. A villus hyperosmolality was observed also in species which exhibited a net fluid secretion (guinea-pig, rabbit ileum), indicating that the fluid secretion emanated from the intestinal crypts. Based on the results of the present experiments and on observations made in earlier experiments performed on the cat, it is proposed that the villus hyperosmolality is created by a countercurrent multiplier present in the intestinal villus. The hyperosmolar compartment in the villus tissue creates the force that drives fluid from lumen to tissue. 相似文献
93.
George B Lenon Charlie CL Xue David F Story Frank CK Thien Sarah McPhee Chun G Li 《Chinese medicine》2007,2(1):2-8
Background
We demonstrated that a Chinese herbal formula, which we refer to as RCM-101, developed from a traditional Chinese medicine formula, reduced nasal and non-nasal symptoms of seasonal allergic rhinitis (SAR). The present study in primary and cultured cells was undertaken to investigate the effects of RCM-101 on the production/release of inflammatory mediators known to be involved in SAR. 相似文献94.
Prahalad Umachigi Sanjay G S Kumar KN Jayaveera Kumar DV Kishore Kumar CK Ashok R Dhanapal 《African journal of traditional, complementary, and alternative medicines》2007,4(4):481-487
Anthocephalus cadamba (Roxb.) Miq. Syn A. chinensis (Lamk) A. Rich (Rubiaceae) is ethnomedicinally widely used in the form of paste by tribe in western Ghats for treating skin diseases. In this context, antimicrobial potential of A. cadamba against a wide range of microorganisms was studied. To validate the ethnotherapeutic claims of the plant in skin diseases, wound healing activity was studied, besides antioxidant activity to understand the mechanism of wound healing. The alchoholic and aqueous extract of this plant showed significant antibacterial and antifungal activity against almost all the organisms: Micrococcus luteus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and four fungi Candida albicans, Trichophyton rubrum—dermatophyte fungi, Aspergillus niger, Aspergillus flavus and Aspergillus nidulans—systemic fungi, with especially good activity against the dermatophyte (Trichophyton rubrum) and some infectious bacteria (Escherichia coli, Proteus mirabilis and Staphylococcus aureus) with an MIC of 2.5 µg/disc. The results show that A. cadamba extract has potent wound healing capacity as shown from the wound contraction and increased tensile strength. The results also indicated that A. cadamba extract possesses potent antioxidant activity by inhibiting lipid peroxidation and increase in the superoxide dismutase (SOD) and catalase activity. 相似文献
95.
We report the case of an 8 week old infant with fulminant autoimmune haemolytic anaemia refractory to conventional immunomodulating treatment. Massive haemolysis resulted in cardiac decompensation and acute renal failure which necessitated mechanical ventilation and peritoneal dialysis. Rituximab, a chimeric anti-CD20 monoclonal antibody, halted progression of the haemolytic process, but the patient died of acute viral pneumonia and disseminated fungal infection. Earlier introduction of rituximab might have prevented the renal complications. Paediatricians should be aware of this useful therapeutic tool for treatment of refractory autoimmune haemolytic anaemia and balance its use against the risk of potential life threatening infection. 相似文献
96.
Background: Myelinatecl retinal nerve fibres around the optic nerve head can lead to an enlargement of blind spot with kinetic perimetry. Presumably extensive myelination will also decrease the visual sensitivity with static perimetry. This study reports the effect of myelination on static perimetry in several patients. Scanning laser polarimetry can measure the retinal nerve fibre layer thickness around the optic nerve head in vivo. This technique was applied at the myelination to investigate its effect on retinal nerve fibre layer thickness determination. Methods: Four eyes of three subjects with myelination around the optic nerve head were tested with Bjerrum screen at one metre to measure the blind spot size. They were followed by Humphrey Visual Field Analyser with a custom pattern to quantify the threshold level at the blind spot region. A GDx Nerve Fiber Analyser was used to measure the retinal nerve fibre layer thickness around the optic nerve head. Results: All the patients demonstrated an enlargement of the blind spot, with different extents, corresponding to the area of myelination. Threshold testing revealed a depression in the myelinated regions. The results for retinal nerve fibre layer were not conclusive with two eyes demonstrating thickening and two eyes showing no effect from myelination. Conclusions: A static field test with a modern visual field analyser may help to quantify the effect of myelination on visual sensitivity. More studies on the effect of myelination on retinal nerve fibre layer thickness measurement are suggested with more subjects involved. 相似文献
97.
Different measures of the proportion of variation in a dependent variable explained by covariates are reported by different standard programs for logistic regression. We review twelve measures that have been suggested or might be useful to measure explained variation in logistic regression models. The definitions and properties of these measures are discussed and their performance is compared in an empirical study. Two of the measures (squared Pearson correlation between the binary outcome and the predictor, and the proportional reduction of squared Pearson residuals by the use of covariates) give almost identical results, agree very well with the multiple R2 of the general linear model, have an intuitively clear interpretation and perform satisfactorily in our study. For all measures the explained variation for the given sample and also the one expected in future samples can be obtained easily. For small samples an adjustment analogous to R2adj in the general linear model is suggested. We discuss some aspects of application and recommend the routine use of a suitable measure of explained variation for logistic models. 相似文献
98.
99.
Topical glucocorticoids and suppression of contact sensitivity. A mouse bioassay of anti-inflammatory effects 总被引:1,自引:0,他引:1
A mouse model for assessment of the anti-inflammatory effect of topical glucocorticoids is described. Mice, sensitized to picryl chloride, had both ears painted with the sensitizer followed 2 hours later by the application of the topical steroid to one ear and the corresponding vehicle to the other. The contact sensitivity reaction, measured by swelling of the ear, was recorded 24 hours later. Dilutions of the steroid formulations inhibited the ear swelling in a manner related to dose-response. Suppression of the contact sensitivity reaction of the vehicle-treated ear as well was regarded as a systemic effect of the glucocorticoid. There seems to be a good correlation between the efficacy of the topical steroids assessed in this mouse model and the vasoconstrictor test on intact human skin. 相似文献
100.
Pronounced serum phosphate deficiency has been shown to be deleterious when starting parenteral nutrition in severely malnourished patients. The consequences of phosphate deficiency and the need for phosphate supplementation in critically ill patients are not well known. Thirty ICU patients randomized into two groups were studied. The patients received complete parenteral nutrition with and without addition of extra phosphate. The low phosphate group got 7.5 mmol phosphate (from the phospholipids in the fat emulsion) and the high phosphate group got 60-80 mmol phosphate/day. There were no significant differences in serum phosphate or calcium levels between the groups. In the high phosphate group the phosphate balance was positive and calcium balance zero while in the low phosphate group both phosphate and calcium balances were negative. The phosphate content in a standard nutrition programme is not sufficient to create a positive phosphate balance. With the addition of 80 mmol phosphate/day a positive balance was achieved. It is hard to establish guidelines for the administration of phosphate in ICU patients. 20-40 mmol may normally be satisfactory but we have shown that ICU patients may need and can tolerate up to 80 mmol/day. 相似文献