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91.
Xiaofeng Bao ?sa Gylfe Gail L. Sturdevant Zheng Gong Shuang Xu Harlan D. Caldwell Mikael Elofsson Huizhou Fan 《Journal of bacteriology》2014,196(16):2989-3001
Chlamydiae are widespread Gram-negative pathogens of humans and animals. Salicylidene acylhydrazides, developed as inhibitors of type III secretion system (T3SS) in Yersinia spp., have an inhibitory effect on chlamydial infection. However, these inhibitors also have the capacity to chelate iron, and it is possible that their antichlamydial effects are caused by iron starvation. Therefore, we have explored the modification of salicylidene acylhydrazides with the goal to uncouple the antichlamydial effect from iron starvation. We discovered that benzylidene acylhydrazides, which cannot chelate iron, inhibit chlamydial growth. Biochemical and genetic analyses suggest that the derivative compounds inhibit chlamydiae through a T3SS-independent mechanism. Four single nucleotide polymorphisms were identified in a Chlamydia muridarum variant resistant to benzylidene acylhydrazides, but it may be necessary to segregate the mutations to differentiate their roles in the resistance phenotype. Benzylidene acylhydrazides are well tolerated by host cells and probiotic vaginal Lactobacillus species and are therefore of potential therapeutic value. 相似文献
92.
Raymond H. G. Klaassen Roine Strandberg Mikael Hake Patrik Olofsson Anders P. Tøttrup Thomas Alerstam 《Journal of avian biology》2010,41(2):200-207
Loop migration among birds is characterized by the spring route lying consistently west or east of the autumn route. The existence of loops has been explained by general wind conditions or seasonal differences in habitat distribution. Loop migration has predominantly been studied at the population level, for example by analysing ring recoveries. Here we study loop migration of individual marsh harriers Circus aeruginosus tracked by satellite telemetry. We show that despite a generally narrow migration corridor the harriers travelled in a distinct clockwise loop through Africa and southern Europe, following more westerly routes in spring than in autumn. We used the Normalized Difference Vegetation Index (NDVI) to identify potential feeding habitat in Africa. Suitable habitat seemed always more abundant along the western route, both in spring and autumn, and no important stopover site was found along the eastern route. Observed routes did thus not coincide with seasonal variation in habitat availability. However, favourable habitat might be more important during spring migration, when the crossing of the Sahara seems more challenging, and thus habitat availability might play an indirect role in the harriers’ route choice. Grid‐based wind data were used to reconstruct general wind patterns, and in qualitative agreement with the observed loop marsh harriers predominantly encountered westerly winds in Europe and easterly winds in Africa, both in autumn and in spring. By correlating tail‐ and crosswinds with forward and perpendicular movement rates, respectively, we show that marsh harriers are partially drifted by wind. Thus, we tentatively conclude that wind rather than habitat seems to have an overriding effect on the shape of the migration routes of marsh harriers. General wind conditions seem to play an important role also in the evolution of narrow migratory loops as demonstrated for individual marsh harriers. 相似文献
93.
Yan-Ru Lou Ferdinand Molnár Mikael Peräkylä Shengjun Qiao Allan V. Kalueff René St-Arnaud Carsten Carlberg Pentti Tuohimaa 《The Journal of steroid biochemistry and molecular biology》2010,118(3):162-170
25-Hydroxyvitamin D3 1α-hydroxylase encoded by CYP27B1 converts 25-hydroxyvitamin D3 into 1α,25-dihydroxyvitamin D3, a vitamin D receptor ligand. 25-Hydroxyvitamin D3 has been regarded as a prohormone. Using Cyp27b1 knockout cells and a 1α-hydroxylase-specific inhibitor we provide in four cellular systems, primary mouse kidney, skin, prostate cells and human MCF-7 breast cancer cells, evidence that 25-hydroxyvitamin D3 has direct gene regulatory properties. The high expression of megalin, involved in 25-hydroxyvitamin D3 internalisation, in Cyp27b1?/? cells explains their higher sensitivity to 25-hydroxyvitamin D3. 25-Hydroxyvitamin D3 action depends on the vitamin D receptor signalling supported by the unresponsiveness of the vitamin D receptor knockout cells. Molecular dynamics simulations show the identical binding mode for both 25-hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3 with the larger volume of the ligand-binding pocket for 25-hydroxyvitamin D3. Furthermore, we demonstrate direct anti-proliferative effects of 25-hydroxyvitamin D3 in human LNCaP prostate cancer cells. The synergistic effect of 25-hydroxyvitamin D3 with 1α,25-dihydroxyvitamin D3 in Cyp27b1?/? cells further demonstrates the agonistic action of 25-hydroxyvitamin D3 and suggests that a synergism between 25-hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3 might be physiologically important. In conclusion, 25-hydroxyvitamin D3 is an agonistic vitamin D receptor ligand with gene regulatory and anti-proliferative properties. 相似文献
94.
Background
The ability of a gene to cause a disease is known to be associated with the topological position of its protein product in the molecular interaction network. Pleiotropy, in human genetic diseases, refers to the ability of different mutations within the same gene to cause different pathological effects. Here, we hypothesized that the ability of human disease genes to cause pleiotropic effects would be associated with their network properties. 相似文献95.
96.
Development and characterization of an oat TILLING-population and identification of mutations in lignin and β-glucan biosynthesis genes 总被引:1,自引:0,他引:1
Aakash Chawade Per Sikora Marcus Bräutigam Mikael Larsson Vivekanand Vivekanand Montedar All Nakash Tingsu Chen Olof Olsson 《BMC plant biology》2010,10(1):86
Background
Oat, Avena sativa is the sixth most important cereal in the world. Presently oat is mostly used as feed for animals. However, oat also has special properties that make it beneficial for human consumption and has seen a growing importance as a food crop in recent decades. Increased demand for novel oat products has also put pressure on oat breeders to produce new oat varieties with specific properties such as increased or improved β-glucan-, antioxidant- and omega-3 fatty acid levels, as well as modified starch and protein content. To facilitate this development we have produced a TILLING (Targeting Induced Local Lesions IN Genomes) population of the spring oat cultivar SW Belinda. 相似文献97.
Markus Klint Mikael Thollesson Erik Bongcam-Rudloff Svend Birkelund Anders Nilsson Björn Herrmann 《BMC microbiology》2010,10(1):81
Background
The histone-like protein Hc2 binds DNA in Chlamydia trachomatis and is known to vary in size between 165 and 237 amino acids, which is caused by different numbers of lysine-rich pentamers. A more complex structure was seen in this study when sequences from 378 specimens covering the hctB gene, which encodes Hc2, were compared. 相似文献98.
Anania C Gustafsson T Hua X Su J Vikström M de Faire U Heimbürger M Jogestrand T Frostegård J 《Arthritis research & therapy》2010,12(6):R214
Introduction
The risk of cardiovascular disease (CVD) and atherosclerosis is reported to be increased in systemic lupus erythematosus (SLE). We recently reported a negative association between natural IgM-antibodies against phosphorylcholine (anti-PC) in the general population, high anti-PC levels leading to decreased atherosclerosis development and low levels to increased risk of CVD. Potential mechanisms include anti-inflammatory properties and inhibition of uptake of oxidized low density lipoprotein (LDL) in macrophages. The objective herein was to study atherosclerosis in SLE in detail and in relation to traditional and non-traditional risk factors. 相似文献99.
Maria Rehnberg Mikael Brisslert Sylvie Amu Kiandoht Zendjanchi Gunilla Håwi Maria I Bokarewa 《Arthritis research & therapy》2010,12(3):R111
Introduction
Rheumatoid arthritis (RA) is frequently complicated with infections. The aim of our study was to evaluate vaccination response in patients with RA after B-cell depletion by using rituximab. 相似文献100.