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71.
72.
Liene Dhooghe Sheila Maregesi Daneel Ferreira Filip Lemière Paul Cos Arnold Vlietinck Luc Pieters 《Phytochemistry》2010,71(7):785-791
Preliminary screening of a series of medicinal plants, traditionally used in Tanzania, showed an IC50 of 15.6-31.2 μg/ml for the crude extract of the root of Ormocarpum kirkii S. Moore (Papilionaceae) against Plasmodium falciparum. A bioguided isolation was performed in order to isolate the active constituents. Twelve constituents were obtained and identified using NMR and MS data, and optical rotation measurements. The compounds comprised seven (I-3,II-3)-biflavonoids, three (I-3,II-3)-bi-4-phenyldihydrocoumarins, an isoflavanone and a C-glucosylated flavone. Six compounds, liquiritigeninyl-(I-3,II-3)-naringenin, apigeninyl-(I-3,II-3)-naringenin, 7-O-β-D-glucopyranosylchamaejasmin, (3R,4S,3″R,4″S)-5,5″-di-O-methyldiphysin, 7-O-β-D-glucopyranosyldiphysin, and 4″-hydroxydiphysolone, were isolated in addition to six known components. The compounds were evaluated for antimicrobial activity in a broad screening panel, including P. falciparum. Seven of these showed antiplasmodial activity; isochamaejasmin being the most active with an IC50 of 7.3 ± 3.8 μM, but the selectivity was rather limited. Thus, these constituents may contribute, at least in part, to the antimalarial use of O. kirkii in traditional medicine. 相似文献
73.
Martin Rudwaleit Filip Van den Bosch Martina Kron Sonja Kary Hartmut Kupper 《Arthritis research & therapy》2010,12(3):R117
Introduction
Tumor necrosis factor (TNF) antagonists reduce the signs and symptoms of spondyloarthritides, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Our objective was to evaluate the effectiveness and safety of adalimumab, 40 mg every other week, for patients with AS or PsA and prior treatment with infliximab (IFX) and/or etanercept (ETN). 相似文献74.
Bert Vander Cruyssen Patrick Durez Rene Westhovens Filip De Keyser 《Arthritis research & therapy》2010,12(3):1-8
Introduction
This study is based on the results from a Belgian expanded access program in which patients with active refractory and erosive rheumatoid arthritis (RA) were treated with intravenous infusions of infliximab in combination with methotrexate. The objectives of this study were to evaluate the continuation rate of infliximab and its clinical effect over a 7-year period and to document the reasons for discontinuation.Methods
Between 2000 and 2001, 511 patients with severe and refractory RA were enrolled and treated with infliximab. After 7 years, apart from routine clinical follow-up, treating rheumatologists were asked to complete a questionnaire designed specifically for the present study to evaluate the current therapy with infliximab, the level of disease activity (Disease Activity Score in 28 joints [DAS28]) and the reasons for infliximab discontinuation.Results
After 7 years, 160 of 511 patients (31%) were still on infliximab treatment. The major reasons for infliximab discontinuation included lack of efficacy (104 patients), adverse events (107 patients) and elective change of therapy (70 patients). The majority of cases of treatment discontinuation for safety reasons occurred during the first 2 years. In contrast, discontinuation due to ineffectiveness showed a more constant rate over the 7-year period. Mean DAS for patients still on treatment with infliximab decreased from 5.7 (standard error [SE] 0.1) at baseline to 3.0 (SE 0.1) at year 4 and remained that low until year 7 (3.0 [SE 0.1]). Low disease activity (defined as DAS28 <3.2) was present in 60.9% of patients, and 45.5% achieved remission (DAS28 <2.6). DAS28 at the time of treatment discontinuation due to ineffectiveness decreased over the 7-year period from 5.6 (SE 0.3) in 2001 to 4.8 (SE 0.3) in 2008.Conclusions
This observational study revealed that patients who continue to receive infliximab experience sustained clinical benefit. The majority of safety issues occurred during the first 2 years of infliximab therapy. We observed that the DAS at the time of therapy discontinuation showed a trend to decrease over time. 相似文献75.
76.
Saito M Matsuura T Nagatsuma K Tanaka K Maehashi H Shimizu K Hataba Y Kato F Kashimori I Tajiri H Braet F 《The Journal of membrane biology》2007,217(1-3):115-121
Functional intact liver organoid can be reconstructed in a radial-flow bioreactor when human hepatocellular carcinoma (FLC-5),
mouse immortalized sinusoidal endothelial M1 (SEC) and A7 (HSC) hepatic stellate cell lines are cocultured. The structural
and functional characteristics of the reconstructed organoid closely resemble the in vivo liver situation. Previous liver organoid studies indicated that cell-to-cell communications might be an important factor
for the functional and structural integrity of the reconstructed organoid, including the expression of fenestrae. Therefore,
we examined the possible relationship between functional intact gap junctional intercellular communication (GJIC) and fenestrae
dynamics in M1-SEC cells. The fine morphology of liver organoid was studied in the presence of (1) irsogladine maleate (IM),
(2) oleamide and (3) oleamide followed by IM treatment. Fine ultrastructural changes were studied by transmission electron
microscopy (TEM) and scanning electron microscopy (SEM) and compared with control liver organoid data. TEM revealed that oleamide
affected the integrity of cell-to-cell contacts predominantly in FLC-5 hepatocytes. SEM observation showed the presence of
fenestrae on M1-SEC cells; however, oleamide inhibited fenestrae expression on the surface of endothelial cells. Interestingly,
fenestrae reappeared when IM was added after initial oleamide exposure. GJIC mediates the number of fenestrae in endothelial
cells of the liver organoid. 相似文献
77.
A thermodynamic perspective on food webs: quantifying entropy production within detrital-based ecosystems 总被引:1,自引:0,他引:1
Because ecosystems fit so nicely the framework of a "dissipative system", a better integration of thermodynamic and ecological perspectives could benefit the quantitative analysis of ecosystems. One obstacle is that traditional food web models are solely based upon the principles of mass and energy conservation, while the theory of non-equilibrium thermodynamics principally focuses on the concept of entropy. To properly cast classical food web models within a thermodynamic framework, one requires a proper quantification of the entropy production that accompanies resource processing of the food web. Here we present such a procedure, which emphasizes a rigorous definition of thermodynamic concepts (e.g. thermodynamic gradient, disequilibrium distance, entropy production, physical environment) and their correct translation into ecological terms. Our analysis provides a generic way to assess the thermodynamic operation of a food web: all information on resource processing is condensed into a single resource processing constant. By varying this constant, one can investigate the range of possible food web behavior within a given fixed physical environment. To illustrate the concepts and methods, we apply our analysis to a very simple example ecosystem: the detrital-based food web of marine sediments. We examine whether entropy production maximization has any ecological relevance in terms of food web functioning. 相似文献
78.
BACKGROUND AND AIMS: The European Chaerophyllum temulum and two North American Chaerophyllum species have a trans-Atlantic disjunct distribution. This work aimed to resolve requirements for dormancy break and germination of C. temulum seeds and to compare dormancy traits with those of the two North American congeners. METHODS: Phenology of germination and embryo growth was studied by regularly exhuming seeds sown in natural conditions. Temperature requirements for embryo growth, breaking of dormancy and germination were determined by incubating seeds under controlled laboratory conditions. Additionally the effect of GA(3) on germination was tested to determine the specific dormancy type. KEY RESULTS: In natural conditions, embryo growth starts in early winter. Seedlings emerge in late winter shortly after the embryos reached the critical ratio for embryo length to seed length (E : S) of approx. 0.95. Growth of the embryo only occurs during a prolonged incubation period at 5 degrees C. After stratification at 5 degrees C, which breaks physiological and morphological dormancy, seeds can germinate at a wide range of temperatures. GA(3) did not substitute for cold stratification in seeds placed at 23 degrees C. CONCLUSIONS: Chaerophyllum temulum has deep complex morphophysiological dormancy. This dormancy type differs considerably from that of the two North American congeners. 相似文献
79.
The aim of this article is to clarify the meaning of a naturalistic position within philosophy of biology, against the background of an alternative view, founded on the basic insights of transcendental philosophy. It is argued that the apparently minimal and neutral constraints naturalism imposes on philosophy of science turn out to involve a quite heavily constraining metaphysics, due to the naturalism's fundamental neglect of its own perspective. Because of its intrinsic sensitivity to perspectivity and historicity, transcendental philosophy can avoid this type of hidden metaphysics. 相似文献
80.
Filip Vandenbussche Dominique Van Der Straeten 《Journal of Plant Growth Regulation》2007,26(2):178-187
The plant hormone ethylene plays a pivotal role in steering various processes by regulating the biosynthesis, distribution,
or signal transduction of other hormones. Ethylene also mediates the effects of other hormones. Similarly, hormones control
the ethylene synthesis and signalling pathway. Eventually, integration of this network of signals leads to an appropriate
morphological or biochemical response. Consequently, this cross-talk results in the characteristic plasticity associated with
plant development. Here, the interplay of ethylene with other hormones is described for germination and seedling growth, stomatal
control, and tissue elongation. The mechanisms by which this occurs are discussed in more detail. 相似文献