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Honeybees (Apis mellifera) can be attacked by many eukaryotic parasites, and bacterial as well as viral pathogens. Especially in combination with the ectoparasitic mite Varroa destructor, viral honeybee diseases are becoming a major problem in apiculture, causing economic losses worldwide. Several horizontal transmission routes are described for some honeybee viruses. Here, we report for the first time the detection of viral sequences in semen of honeybee drones suggesting mating as another horizontal and/or vertical route of virus transmission. Since artificial insemination and controlled mating is widely used in honeybee breeding, the impact of our findings for disease transmission is discussed. 相似文献
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Mok SW Thelen KM Riemer C Bamme T Gültner S Lütjohann D Baier M 《Biochemical and biophysical research communications》2006,348(2):697-702
Prion diseases are fatal and at present there are neither cures nor palliative therapies known/available, which delay disease onset or progression. Cholesterol-lowering drugs have been reported to inhibit prion replication in infected cell cultures and to modulate inflammatory reactions. We aimed to determine whether simvastatin-treatment could delay disease onset in a murine prion model. Groups of mice were intracerebrally infected with two doses of scrapie strain 139A. Simvastatin-treatment commenced 100 days postinfection. The treatment did not affect deposition of misfolded prion protein PrP(res). However, expression of marker proteins for glia activation like major histocompatibility class II and galectin-3 was found to be affected. Analysis of brain cholesterol synthesis and metabolism revealed a mild reduction in cholesterol precursor levels, whereas levels of cholesterol and cholesterol metabolites were unchanged. Simvastatin-treatment significantly delayed disease progression and prolonged survival times in established prion infection of the CNS (p < or = 0.0003). The results suggest that modulation of glial responses and the therapeutic benefit observed in our murine prion model of simvastatin is not due to the cholesterol-lowering effect of this drug. 相似文献
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Dietary intake of plant sterols stably increases plant sterol levels in the murine brain 总被引:1,自引:0,他引:1
Vanmierlo T Weingärtner O van der Pol S Husche C Kerksiek A Friedrichs S Sijbrands E Steinbusch H Grimm M Hartmann T Laufs U Böhm M de Vries HE Mulder M Lütjohann D 《Journal of lipid research》2012,53(4):726-735
Plant sterols such as sitosterol and campesterol are frequently administered as cholesterol-lowering supplements in food. Recently, it has been shown in mice that, in contrast to the structurally related cholesterol, circulating plant sterols can enter the brain. We questioned whether the accumulation of plant sterols in murine brain is reversible. After being fed a plant sterol ester-enriched diet for 6 weeks, C57BL/6NCrl mice displayed significantly increased concentrations of plant sterols in serum, liver, and brain by 2- to 3-fold. Blocking intestinal sterol uptake for the next 6 months while feeding the mice with a plant stanol ester-enriched diet resulted in strongly decreased plant sterol levels in serum and liver, without affecting brain plant sterol levels. Relative to plasma concentrations, brain levels of campesterol were higher than sitosterol, suggesting that campesterol traverses the blood-brain barrier more efficiently. In vitro experiments with brain endothelial cell cultures showed that campesterol crossed the blood-brain barrier more efficiently than sitosterol. We conclude that, over a 6-month period, plant sterol accumulation in murine brain is virtually irreversible. 相似文献
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Gorny X Mikhaylova M Seeger C Reddy PP Reissner C Schott BH Helena Danielson U Kreutz MR Seidenbecher C 《Journal of neurochemistry》2012,122(4):714-726
The A kinase-anchoring protein AKAP79/150 is a postsynaptic scaffold molecule and a key regulator of signaling events. At the postsynapse it coordinates phosphorylation and dephosphorylation of receptors via anchoring kinases and phosphatases near their substrates. Interactions between AKAP79 and two Ca(2+) -binding proteins caldendrin and calmodulin have been investigated here. Calmodulin is a known interaction partner of AKAP79/150 that has been shown to regulate activity of the kinase PKC in a Ca(2+) -dependent manner. Pull-down experiments and surface plasmon resonance biosensor analyses have been used here to demonstrate that AKAP79 can also interact with caldendrin, a neuronal calcium-binding protein implicated in regulation of Ca(2+) -influx and release. We demonstrate that calmodulin and caldendrin compete for a partially overlapping binding site on AKAP79 and that their binding is differentially dependent on calcium. Therefore, this competition is regulated by calcium levels. Moreover, both proteins have different binding characteristics suggesting that the two proteins might play complementary roles. The postsynaptic enrichment, the complex binding mechanism, and the competition with calmodulin, makes caldendrin an interesting novel player in the signaling toolkit of the AKAP interactome. 相似文献
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Christian Seeger Xenia Gorny Pasham Parameshwar Reddy Constanze Seidenbecher U. Helena Danielson 《Journal of molecular recognition : JMR》2012,25(10):495-503
The kinetic and mechanistic details of the interaction between caldendrin, calmodulin and the B‐domain of AKAP79 were determined using a biosensor‐based approach. Caldendrin was found to compete with calmodulin for binding at AKAP79, indicating overlapping binding sites. Although the AKAP79 affinities were similar for caldendrin (KD = 20 n m ) and calmodulin (KD = 30 n m ), their interaction characteristics were different. The calmodulin interaction was well described by a reversible one‐step model, but was only detected in the presence of Ca2+. Caldendrin interacted with a higher level of complexity, deduced to be an induced fit mechanism with a slow relaxation back to the initial encounter complex. It interacted with AKAP79 also in the absence of Ca2+, but with different kinetic rate constants. The data are consistent with a similar initial Ca2+‐dependent binding step for the two proteins. For caldendrin, a second Ca2+‐independent rearrangement step follows, resulting in a stable complex. The study shows the importance of establishing the mechanism and kinetics of protein–protein interactions and that minor differences in the interaction of two homologous proteins can have major implications in their functional characteristics. These results are important for the further elucidation of the roles of caldendrin and calmodulin in synaptic function. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Background
The gold standard for the diagnosis of schistosomiasis is the detection of the parasite''s characteristic eggs in urine, stool, or rectal and bladder biopsy specimens. Direct detection of eggs is difficult and not always possible in patients with low egg-shedding rates. Confocal laser scanning microscopy (CLSM) permits non-invasive cell imaging in vivo and is an established way of obtaining high-resolution images and 3-dimensional reconstructions. Recently, CLSM was shown to be a suitable method to visualize Schistosoma mansoni eggs within the mucosa of dissected mouse gut. In this case, we evaluated the suitability of CLSM to detect eggs of Schistosoma haematobium in a patient with urinary schistosomiasis and low egg-shedding rates.Methodology/Principal Findings
The confocal laser scanning microscope used in this study was based on a scanning laser system for imaging the retina of a living eye, the Heidelberg Retina Tomograph II, in combination with a lens system (image modality). Standard light cystoscopy was performed using a rigid cystoscope under general anaesthesia. The CLSM endoscope was then passed through the working channel of the rigid cystoscope. The mucosal tissue of the bladder was scanned using CLSM. Schistoma haematobium eggs appeared as bright structures, with the characteristic egg shape and typical terminal spine.Conclusion/Significance
We were able to detect schistosomal eggs in the urothelium of a patient with urinary schistosomiasis. Thus, CLSM may be a suitable tool for the diagnosis of schistosomiasis in humans, especially in cases where standard diagnostic tools are not suitable. 相似文献40.
K Heikkilä ST Nyberg EI Fransson L Alfredsson D De Bacquer JB Bjorner S Bonenfant M Borritz H Burr E Clays A Casini N Dragano R Erbel GA Geuskens M Goldberg WE Hooftman IL Houtman M Joensuu KH Jöckel F Kittel A Knutsson M Koskenvuo A Koskinen A Kouvonen C Leineweber T Lunau IE Madsen LL Magnusson Hanson MG Marmot ML Nielsen M Nordin J Pentti P Salo R Rugulies A Steptoe J Siegrist S Suominen J Vahtera M Virtanen A Väänänen P Westerholm H Westerlund M Zins T Theorell M Hamer JE Ferrie 《PloS one》2012,7(7):e35463