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81.
Michiel Etienne Janssens Dirk Geysen Katleen Broos Ine De Goeyse Johan Robbens Filip Van Petegem Jean-Pierre Timmermans Yves Guisez 《Amino acids》2010,38(5):1617-1626
The hepatitis B core (HBc) protein has been used successfully in numerous experiments as a carrier for heterologous peptides.
Folding and capsid formation of the chimeric proteins is not always achieved easily. In silico analyses were performed to
provide further comprehension of the feasibility for predicting successful capsid formation. In contrast to previous work,
we show that common in silico predictions do not ensure assembly into particles. We included new considerations regarding
capsid formation of HBc fusion proteins. Not only the primary sequence and the length of the inserts seem important, also
the rigidity, the distance between the N and the C-terminus and the presence of cysteines, which could form disulphide bonds,
could influence proper capsid formation. Furthermore, new conformational insights were formulated when linkers were added
to create extra flexibility of the chimeric particles. Different hypotheses were suggested to clarify the obtained results.
To this extent, the addition of glycine-rich linkers could lower high rigidity of the insert, removal of the strain of the
core protein or ease interaction between the HBc and the insert. Finally, we observed specific changes in capsid formation
properties when longer linkers were used. These findings have not been reported before in this and other virus-like particle
carriers. In this study, we also propose a new high-yield purification protocol for fusion proteins to be used in vaccination
experiments with the carrier protein or in comparative studies of particulate or non-particulate HBc fusion proteins. 相似文献
82.
Mireia Martín-Satué Elise G. Lavoie Michel Fausther Joanna Lecka Elisabet Aliagas Filip Kukulski Jean Sévigny 《Histochemistry and cell biology》2010,133(6):659-668
Extracellular ATP and its hydrolysis product adenosine modulate various reproductive functions such as those requiring contraction,
steroidogenesis, and maintenance of fluid composition. Interestingly, adenosine might act as a key capacitative effector for
mammalian spermatozoa to acquire the capacity for fertilisation. Extracellular nucleotide levels are affected by cell surface
ectonucleotidases, amongst which the ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) family regroups the most abundant
and effective enzymes to hydrolyse ATP and ADP to AMP in physiological conditions. In the male reproductive tract three members
of this family have been indentified: NTPDase1, NTPDase2 and NTPDase3 (Martín-Satué et al. in Histochem Cell Biol 131:615–628,
2009). The purpose of the present study was to characterize in the male reproductive tract the expression profile of the main
enzyme responsible for the generation of adenosine from AMP, namely the ecto-5′-nucleotidase (CD73). The enzyme was identified
by immunological techniques and by in situ enzymatic assays, including inhibition experiments with α,β-methylene-ADP, a specific
CD73 inhibitor. High levels of ecto-5′-nucleotidase were detected in testes in association with both germinal and somatic
cells, in smooth muscle cells throughout the tract, in secretory epithelia from exocrine glands, and remarkably, in principal
cells of epididymis, where co-localization with NTPDase3 was found. The relevance of this co-expression on nucleotide hydrolysis
in these cells directly involved in the control of sperm fluid composition was addressed biochemically. This study suggests
close regulation of extracellular nucleoside and nucleotide levels in the genital tract by ecto-5′-nucleotidase that, in concurrence
with NTPDases, may impact male fertility. 相似文献
83.
Zbigniew Szybiński Stanisław Walas Paweł Zagrodzki Grzegorz Sokołowski Filip Gołkowski Halina Mrowiec 《Biological trace element research》2010,138(1-3):28-41
The purpose of this work was to determine trace element levels in urine and evaluate possible associations between urinary iodine concentration (UIC), other trace elements (Cr, Cu, Fe, Mn, Na, Se, Zn), toxic elements (Cd, Pb), anthropometrical measures (body weight and height), glycemic indices (serum insulin and glucose), and several parameters related to thyroid function (thyroid stimulating hormone, free thyroxine, antithyroid peroxidase antibodies, thyroid volume, and thyroid echogenicity) in pregnant women. One hundred sixty-nine participants were recruited. The whole study group, originating from Krakow region, comprised three subgroups belonging to three trimesters: I trimester (n?=?28), II trimester (n?=?83), and III trimester (n?=?58). Trace elements were determined using inductively coupled plasma mass/(atomic emission) spectrometry. Partial least square model was used to reveal correlation structure between parameters investigated, as well as a possible causal relationship between dependent parameters and potentially explanatory parameters. Results obtained for trace and toxic elements in urine were comparable with results of other authors, although the study group was not homogenous. We confirmed (1) low iodine excretion in pregnant women, (2) the existence of statistically significant correlation between UIC and urinary selenium, and (3) lack of correlation between latter parameter and typical indices of thyroid function. Urinary selenium correlated with other urinary trace elements, but physiological significance of this finding remains uncertain. The fact that a large number of pregnant women fail to meet dietary recommendations for iodine is the major reason for concern. 相似文献
84.
Kroata Hazler Pilepić Miranda Morović Filip Orač Marija Šantor Vanja Vejnović 《Biologia》2010,65(5):805-812
The chloroplast DNA of 43 species including 16 sections from the genus Hypericum was studied by PCR-RFLP analysis. The PCR-amplified products of four cpDNA regions, trnC-trnD, psbC-trnS, trnL-trnF and rbcL were digested with four restriction endonucleases. A high level of interspecific variation was detected while intraspecific
diversity was not observed. The resulting parsimony analysis indicated the monophyletic assemblage of the sections Androsaemum, Olympia, Drosocarpium and Trigynobrathys. Monophyly of Hypericum is weakly supported, but close relationships of H. perforatum and H. maculatum are indicated. The members of Ascyreia are weakly resolved, but clustering of H. kouytchense and H. oblongifolium is well supported, however, H. reptans is nested with Olympia. CpDNA profiles and the positions on the parsimony tree indicate that the chloroplast donor among the putative parents of
the hybrid species H. ×inodorum is H. androsaemum. 相似文献
85.
86.
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
87.
Katleen Van Steendam Kelly Tilleman Marlies De Ceuleneer Filip De Keyser Dirk Elewaut Dieter Deforce 《Arthritis research & therapy》2010,12(4):R132
Introduction
Rheumatoid arthritis (RA) is an inflammatory disease, which results in destruction of the joint. The presence of immune complexes (IC) in serum and synovial fluid of RA patients might contribute to this articular damage through different mechanisms, such as complement activation. Therefore, identification of the antigens from these IC is important to gain more insight into the pathogenesis of RA. Since RA patients have antibodies against citrullinated proteins (ACPA) in their serum and synovial fluid (SF) and since elevated levels of citrullinated proteins are detected in the joints of RA patients, citrullinated antigens are possibly present in IC from RA patients. 相似文献88.
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89.
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90.
Aim To investigate the distribution of local flowering plant species richness in areas surrounding American universities.
Methods Species richness in university counties was compared with neighbouring counties. Data were derived from Synthesis of the North American Flora ( http://www.phylosystems.com/prepublication ). Probabilities of the resultant distribution were calculated, and the results were also simulated.
Results In almost every case there were more species reported in the university county than in its neighbours. Several possible explanations were considered. We conclude that the key element is the presence of botanists in these counties who have, apparently, paid more attention to plants near at hand, and found more species of them there.
Main conclusions Ecologists must be aware that numerical data that appear very solid, collected over many decades, may represent not only the qualities of 'nature' but also something of the collectors of the data. 相似文献
Methods Species richness in university counties was compared with neighbouring counties. Data were derived from Synthesis of the North American Flora ( http://www.phylosystems.com/prepublication ). Probabilities of the resultant distribution were calculated, and the results were also simulated.
Results In almost every case there were more species reported in the university county than in its neighbours. Several possible explanations were considered. We conclude that the key element is the presence of botanists in these counties who have, apparently, paid more attention to plants near at hand, and found more species of them there.
Main conclusions Ecologists must be aware that numerical data that appear very solid, collected over many decades, may represent not only the qualities of 'nature' but also something of the collectors of the data. 相似文献