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101.
Erpenbeck VJ Malherbe DC Sommer S Schmiedl A Steinhilber W Ghio AJ Krug N Wright JR Hohlfeld JM 《American journal of physiology. Lung cellular and molecular physiology》2005,288(4):L692-L698
Recent studies have shown that surfactant components, in particular the collectins surfactant protein (SP)-A and -D, modulate the phagocytosis of various pathogens by alveolar macrophages. This interaction might be important not only for the elimination of pathogens but also for the elimination of inhaled allergens and might explain anti-inflammatory effects of SP-A and SP-D in allergic airway inflammation. We investigated the effect of surfactant components on the phagocytosis of allergen-containing pollen starch granules (PSG) by alveolar macrophages. PSG were isolated from Dactylis glomerata or Phleum pratense, two common grass pollen allergens, and incubated with either rat or human alveolar macrophages in the presence of recombinant human SP-A, SP-A purified from patients suffering from alveolar proteinosis, a recombinant fragment of human SP-D, dodecameric recombinant rat SP-D, or the commercially available surfactant preparations Curosurf and Alveofact. Dodecameric rat recombinant SP-D enhanced binding and phagocytosis of the PSG by alveolar macrophages, whereas the recombinant fragment of human SP-D, SP-A, or the surfactant lipid preparations had no effect. In addition, recombinant rat SP-D bound to the surface of the PSG and induced aggregation. Binding, aggregation, and enhancement of phagocytosis by recombinant rat SP-D was completely blocked by EDTA and inhibited by d-maltose and to a lesser extent by d-galactose, indicating the involvement of the carbohydrate recognition domain of SP-D in these functions. The modulation of allergen phagocytosis by SP-D might play an important role in allergen clearance from the lung and thereby modulate the allergic inflammation of asthma. 相似文献
102.
The bat fauna of 35 islands in a large lake in central Sweden were examined using ultrasound detectors. We tested the hypothesis that there is no difference in species number between the mainland and the island fauna. Eight species were found. Species numbers were analysed against island area, area of some habitats (coniferous forest, deciduous forest, semi-open habitats and open habitats), degree of isolation (distance from mainland and from stepping stones) and time spent searching for bats. Species number increased with area of deciduous forest. Presence of houses tended to increase species number. There seems to be a negative relationship between species number and degree of isolation (nearly significant). The results suggest that at least three species, Myotis brandti (Eversmann, 1845), M. mystacinus (Kuhl, 1819) and Plecotus auritus (Linnaeus, 1758), are negatively affected by forest patchiness. These species occurred mainly on large islands. Thus, the results do not support the hypothesis. The reasons why some species avoid open habitats are discussed. 相似文献
103.
Gene expression of myogenic factors and phenotype-specific markers in electrically stimulated muscle of paraplegics. 总被引:2,自引:0,他引:2
104.
Loy A Schulz C Lücker S Schöpfer-Wendels A Stoecker K Baranyi C Lehner A Wagner M 《Applied and environmental microbiology》2005,71(3):1373-1386
For simultaneous identification of members of the betaproteobacterial order "Rhodocyclales" in environmental samples, a 16S rRNA gene-targeted oligonucleotide microarray (RHC-PhyloChip) consisting of 79 probes was developed. Probe design was based on phylogenetic analysis of available 16S rRNA sequences from all cultured and as yet uncultured members of the "Rhodocyclales." The multiple nested probe set was evaluated for microarray hybridization with 16S rRNA gene PCR amplicons from 29 reference organisms. Subsequently, the RHC-PhyloChip was successfully used for cultivation-independent "Rhodocyclales" diversity analysis in activated sludge from an industrial wastewater treatment plant. The implementation of a newly designed "Rhodocyclales"-selective PCR amplification system prior to microarray hybridization greatly enhanced the sensitivity of the RHC-PhyloChip and thus enabled the detection of "Rhodocyclales" populations with relative abundances of less than 1% of all bacteria (as determined by fluorescence in situ hybridization) in the activated sludge. The presence of as yet uncultured Zoogloea-, Ferribacterium/Dechloromonas-, and Sterolibacterium-related bacteria in the industrial activated sludge, as indicated by the RHC-PhyloChip analysis, was confirmed by retrieval of their 16S rRNA gene sequences and subsequent phylogenetic analysis, demonstrating the suitability of the RHC-PhyloChip as a novel monitoring tool for environmental microbiology. 相似文献
105.
Asmita Banerjee Sylvia Nürnberger Simone Hennerbichler Sabrina Riedl Christina M. A. P. Schuh Ara Hacobian Andreas Teuschl Johann Eibl Heinz Redl Susanne Wolbank 《Cell and tissue banking》2014,15(2):227-239
Human amniotic membrane (hAM) is a tissue containing cells with proven stem cell properties. In its decellularized form it has been successfully applied as nerve conduit biomaterial to improve peripheral nerve regeneration in injury models. We hypothesize that viable hAM without prior cell isolation can be differentiated towards the Schwann cell lineage to generate a possible alternative to commonly applied tissue engineering materials for nerve regeneration. For in vitro Schwann cell differentiation, biopsies of hAM of 8 mm diameter were incubated with a sequential order of neuronal induction and growth factors for 21 days and characterized for cellular viability and the typical glial markers glial fibrillary acidic protein (GFAP), S100β, p75 and neurotrophic tyrosine kinase receptor (NTRK) using immunohistology. The secretion of the neurotrophic factors brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) was quantified by ELISA. The hAM maintained high viability, especially under differentiation conditions (90.2 % ± 41.6 day 14; 80.0 % ± 44.5 day 21 compared to day 0). Both, BDNF and GDNF secretion was up-regulated upon differentiation. The fresh membrane stained positive for GFAP and p75 and NTRK, which was strongly increased after culture in differentiation conditions. Especially the epithelial layer within the membrane exhibited a change in morphology upon differentiation forming a multi-layered epithelium with intense accumulations of the marker proteins. However, S100β was expressed at equal levels and equal distribution in fresh and cultured hAM conditions. Viable hAM may be a promising alternative to present formulations used for peripheral nerve regeneration. 相似文献
106.
Lucía Carrasco Andreas Gattinger Andreas Fließbach Antonio Roldán Michael Schloter Fuensanta Caravaca 《Microbial ecology》2010,60(2):265-271
The objective of this study was to compare the microbial community composition and biomass associated with the rhizosphere
of a perennial gramineous species (Lygeum spartum L.) with that of an annual (Piptatherum miliaceum L.), both growing in semiarid mine tailings. We also established their relationship with the contents of potentially toxic
metals as well as with indicators of soil quality. The total phospholipid fatty acid (PLFA) amount was significantly higher
in the rhizosphere soil of the annual species than in the rhizosphere soil of the perennial species. The fungal/bacterial
PLFA ratio was significantly greater in the perennial species compared to the annual species. The fatty acid 16:1ω5c, the
fungal/bacterial PLFA ratio and monounsaturated/saturated PLFA ratio were correlated negatively with the soluble contents
of toxic metals. The cyc/prec (cy17:0 + cy19:0/16:1ω7 + 18:1ω7) ratio was correlated positively with the soluble contents
of Pb, Zn, Al, Ni, Cd, and Cu. The results of the PLFA analysis for profiling microbial communities and their stress status
of both the plant species indicate that perennial and annual gramineous species appear equally suitable for use in programmes
of revegetation of semiarid mine tailings. 相似文献
107.
Factors influencing limit values for pine needle litter decomposition: a synthesis for boreal and temperate pine forest systems 总被引:1,自引:0,他引:1
B. Berg M. P. Davey A. De Marco B. Emmett M. Faituri S. E. Hobbie M.-B. Johansson C. Liu C. McClaugherty L. Norell F. A. Rutigliano L. Vesterdal A. Virzo De Santo 《Biogeochemistry》2010,100(1-3):57-73
We synthesized available data for decomposition of pine (Pinus) needle litter in pine forests to determine the litter chemical characteristics and climate factors that explained variation in the limit value, i.e. the level of accumulated mass loss at which the decomposition process either continues at a very low rate or possibly stops. Our data base included 56 separate studies on decomposition of pine needle litter, spanning Scots pine, lodgepole pine, Aleppo pine, stone pine and white pine, mainly incubated at the site of collection. Studies had 5 to 19 samplings, on average 10, and the decomposition was followed to a mass loss ranging from 47 to 83%, on average 67%. The periods from 3.0 to 5.4 years, on average 3.9 years, were of sufficient duration to allow estimates of limit values of decomposition. We used a linear mixed model with regression effects to relate limit values to potential explanatory variables, namely the sites’ long-term mean annual temperature (MAT) and mean annual precipitation (MAP) and to substrate-chemistry factors. Regarding the latter, we explored two models; one that included initial concentrations of water solubles, lignin, N, P, K, Ca, Mg, and Mn and one that included only lignin, N, Ca, and Mn to focus on those nutrients known to influence lignin degradation. Using backward elimination significant explanatory variables were determined. For litter decomposed in its site of origin we found the limit value to depend mainly on the initial concentration of Mn, with higher Mn concentrations resulting in higher accumulated mass loss. Thus, litter with higher Mn reached a higher limit value and left a smaller stable fraction. This is likely due to the fact that Mn is an essential component of ligninolytic enzymes important for degrading litter in the later stages of decomposition. Manganese has received little attention in decomposition studies to date. Given its significance in this synthesis, the role of Mn in influencing variation in the late stages of decomposition among ecosystems and among litters of other genera besides Pinus deserves further attention. 相似文献
108.
The yeast glucose transporters Hxt1, Hxt2, Hxt3, Hxt4, Hxt6, Hxt7 and Gal2, individually expressed in an hxt1-7 null mutant strain, demonstrate the phenomenon of countertransport. Thus, these transporters, which are the most important glucose transporters in Saccharomyces cerevisiae, are facilitated diffusion transporters. Apparent K(m)-values from high to low affinity, determined from countertransport and initial-uptake experiments, respectively, are: Hxt6 0.9+/-0.2 and 1.4+/-0.1 mM, Hxt7 1.3+/-0.3 and 1.9+/-0.1 mM, Gal2 1.5 and 1.6+/-0.1 mM, Hxt2 2.9+/-0.3 and 4.6+/-0.3 mM, Hxt4 6.2+/-0.5 and 6.2+/-0.3 mM, Hxt3 28.6+/-6.8 and 34.2+/-3.2 mM, and Hxt1 107+/-49 and 129+/-9 mM. From both independent methods, countertransport and initial uptake, the same range of apparent K(m)-values was obtained for each transporter. In contrast to that in human erythrocytes, the facilitated diffusion transport mechanism of glucose in yeast was symmetric. Besides facilitated diffusion there existed in all single glucose transport mutants, except for the HXT1 strain, significant first-order behaviour. 相似文献
109.
Marco Dollinger René Müller-Wille Florian Zeman Michael Haimerl Christoph Niessen Lukas P. Beyer Sven A. Lang Andreas Teufel Christian Stroszczynski Philipp Wiggermann 《PloS one》2015,10(8)