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61.
TIR (Toll/IL-1 receptor) domains mediate interactions between TLR (Toll-like) or IL-1 family receptors and signaling adapters. While homotypic TIR domain interactions mediate receptor activation they are also usurped by microbial TIR domain containing proteins for immunosuppression. Here we show the role of a dimerized TIR domain platform for the suppression as well as for the activation of MyD88 signaling pathway. Coiled-coil dimerization domain, present in many bacterial TCPs, potently augments suppression of TLR/IL-1R signaling. The addition of a strong coiled-coil dimerization domain conferred the superior inhibition against the wide spectrum of TLRs and prevented the constitutive activation by a dimeric TIR platform. We propose a molecular model of MyD88-mediated signaling based on the dimerization of TIR domains as the limiting step. 相似文献
62.
Toivari M Nygård Y Kumpula EP Vehkomäki ML Benčina M Valkonen M Maaheimo H Andberg M Koivula A Ruohonen L Penttilä M Wiebe MG 《Metabolic engineering》2012,14(4):427-436
An NAD(+)-dependent D-xylose dehydrogenase, XylB, from Caulobacter crescentus was expressed in Saccharomyces cerevisiae, resulting in production of 17 ± 2 g D-xylonate l(-1) at 0.23 gl(-1)h(-1) from 23 g D-xylose l(-1) (with glucose and ethanol as co-substrates). D-Xylonate titre and production rate were increased and xylitol production decreased, compared to strains expressing genes encoding T. reesei or pig liver NADP(+)-dependent D-xylose dehydrogenases. D-Xylonate accumulated intracellularly to ~70 mgg(-1); xylitol to ~18 mgg(-1). The aldose reductase encoding gene GRE3 was deleted to reduce xylitol production. Cells expressing D-xylonolactone lactonase xylC from C. crescentus with xylB initially produced more extracellular D-xylonate than cells lacking xylC at both pH 5.5 and pH 3, and sustained higher production at pH 3. Cell vitality and viability decreased during D-xylonate production at pH 3.0. An industrial S. cerevisiae strain expressing xylB efficiently produced 43 g D-xylonate l(-1) from 49 g D-xylose l(-1). 相似文献
63.
BackgroundTraditional rehabilitation protocols for surgically treated metacarpal shaft fracture allow for return to play at 6-8 weeks post-operative. This may be devastating for the elite athlete. We outline a protocol that may allow for professional basketball players to successfully return to sport within four weeks following surgery.MethodsProfessional basketball players who sustained non-thumb metacarpal shaft fractures were included. All athletes underwent open reduction and internal fixation of the injured metacarpal. Patients were subsequently enrolled into an accelerated rehabilitation protocol.ResultsThe five athletes in our case series successfully passed return to sport testing within four weeks of surgery.ConclusionA plate and screw construct can potentially allow for professional basketball players to return to play in half the time. Future research studies should include a larger pool of athletes to further investigate accelerated rehabilitation following surgical fixation of metacarpal fractures. Level of Evidence: IV 相似文献
64.
Mari Valkonen Dominik Mojzita Merja Penttil? Mojca Ben?ina 《Applied and environmental microbiology》2013,79(23):7179-7187
The ability of cells to maintain pH homeostasis in response to environmental changes has elicited interest in basic and applied research and has prompted the development of methods for intracellular pH measurements. Many traditional methods provide information at population level and thus the average values of the studied cell physiological phenomena, excluding the fact that cell cultures are very heterogeneous. Single-cell analysis, on the other hand, offers more detailed insight into population variability, thereby facilitating a considerably deeper understanding of cell physiology. Although microscopy methods can address this issue, they suffer from limitations in terms of the small number of individual cells that can be studied and complicated image processing. We developed a noninvasive high-throughput method that employs flow cytometry to analyze large populations of cells that express pHluorin, a genetically encoded ratiometric fluorescent probe that is sensitive to pH. The method described here enables measurement of the intracellular pH of single cells with high sensitivity and speed, which is a clear improvement compared to previously published methods that either require pretreatment of the cells, measure cell populations, or require complex data analysis. The ratios of fluorescence intensities, which correlate to the intracellular pH, are independent of the expression levels of the pH probe, making the use of transiently or extrachromosomally expressed probes possible. We conducted an experiment on the kinetics of the pH homeostasis of Saccharomyces cerevisiae cultures grown to a stationary phase after ethanol or glucose addition and after exposure to weak acid stress and glucose pulse. Minor populations with pH homeostasis behaving differently upon treatments were identified. 相似文献
65.
66.
Astrocytes participate in the clearance of neurotransmitters by their uptake and subsequent enzymatic degradation. Histamine
as a polar and/or protonated molecule must use a carrier to be transported across the cell membrane, although a specific histamine
transporter has not been elucidated, yet. In this work we upgraded the kinetic studies of histamine uptake into neonatal rat
cultured type 1 astrocytes with quantum chemical calculations of histamine pKa values in conjunction with Langevin dipoles
solvation model as the first step toward microscopic simulation of transport. Our results indicate that astrocytes transport
histamine by at least two carrier mediated processes, a concentration gradient dependent passive and a sodium-dependent and
ATP-driven active transport. We also demonstrated that histamine protonation states depend on the polarity of the environment.
In conclusion we suggest that histamine, a polar molecule at physiological pH uses at least two different mechanisms for its
uptake into astrocytes –an electrodiffusion and Na+-dependent and ouabain sensitive active process. We emphasize relevance of knowledge of histamines protonation states at the
rate limiting step of its transport for microscopic simulation that will be possible when structure of histamine transporter
is known. 相似文献
67.
Katja Trobec Mojca Kerec Kos Stephan von Haehling Jochen Springer Stefan D. Anker Mitja Lainscak 《PloS one》2013,8(11)
Cachexia is a weight-loss process caused by an underlying chronic disease such as cancer, chronic heart failure, chronic obstructive pulmonary disease, or rheumatoid arthritis. It leads to changes in body structure and function that may influence the pharmacokinetics of drugs. Changes in gut function and decreased subcutaneous tissue may influence the absorption of orally and transdermally applied drugs. Altered body composition and plasma protein concentration may affect drug distribution. Changes in the expression and function of metabolic enzymes could influence the metabolism of drugs, and their renal excretion could be affected by possible reduction in kidney function. Because no general guidelines exist for drug dose adjustments in cachectic patients, we conducted a systematic search to identify articles that investigated the pharmacokinetics of drugs in cachectic patients. 相似文献
68.
Svegelj MB Stojan J Rižner TL 《The Journal of steroid biochemistry and molecular biology》2012,129(1-2):92-98
17β-Hydroxysteroid dehydrogenase and trihydroxynaphthalene reductase from the fungus Curvularia lunata (teleomorph: Cochliobolus lunatus; 17β-HSDcl and 3HNR, respectively) are two homologous short-chain dehydrogenase/reductase proteins that are 58% identical and have 86% similar amino acids. The minor differences in their substrate-binding regions are believed to be crucial for their substrate specificities. 3HNR shows high affinity for substrates with two rings, like trihydroxynaphthalene and 2,3-dihydro-2,5-dihydroxy-4H-benzopyran-4-one (DDBO), while 17β-HSDcl can accommodate ligands with four rings, like steroids. In the present study, we examined the role of Ala231 in 17β-HSDcl and Trp227 in 3HNR, as the potential key amino acids in the determination of substrate recognition based on size. We constructed Ala231Trp 17β-HSDcl and Trp227Ala 3HNR mutant proteins and used spectrophotometric analyses to compare their catalytic activities with those of the wild-type enzymes, for oxidation of 4-estrene-17β-ol-3-one and DDBO and for reduction of 4-estrene-3,17-dione and 9,10-phenanthrenequinone (PQ). The Ala231Trp side-chain substitution in 17β-HSDcl abolished and decreased (by 14.6-fold) the initial rates for steroid oxidation and reduction, respectively, while the initial rate for PQ reduction was increased 5.6-fold. The bulky Trp227Ala side-chain substitution in 3HNR enabled oxidation of 4-estrene-17β-ol-3-one, increased the initial rates for reduction of 4-estrene-3,17-dione and PQ by 4.5-fold and 1.5-fold, respectively, while the initial rate for DDBO oxidation was decreased 4.1-fold. Our TLC analysis and docking simulations also support these findings. Our study thus confirms the important roles of Ala231 in 17β-HSDcl and Trp227 in 3HNR, for the selection between larger and smaller substrates. Article from a special issue on steroids and microorganisms. 相似文献
69.
The leaf reflectance spectra (280–887 nm) of two heterophyllous aquatic plant species Polygonum amphibium (L.) and Nuphar luteum (L.) were compared and their relation to physical properties of the leaves examined. In P. amphibium contrasting environmental conditions along water–land gradient affected the majority of anatomical and morphological properties of leaves, but less differences were observed in photosynthetic pigment and total flavonoid contents. Leaf mass per area (LMA), palisade mesophyll, leaf thickness, trichome length and anthocyanin content per dry mass were correlated to the different parts of spectra. In N. luteum natant and submerged leaves differed significantly in all measured parameters. Chlorophyll a, anthocyanin and carotenoid contents per dry mass were related to reflectance in the red region, while leaf thickness, anthocyanin and total flavonoid contents per leaf area were related to reflectance in the near infrared region. Redundancy Analysis (RDA) indicated that in P. amphibium the average length of trichomes and LMA explained 72% and 6% variability of the spectra, whereas in N. luteum anthocyanin content per dry mass, explained 57% variability of the spectra. The comparison of natant leaves of both species showed that they were more similar than different leaf types within the single species. 相似文献
70.
CD8 T cell immunome analysis of Listeria monocytogenes 总被引:6,自引:0,他引:6
The identification of T cell epitopes is crucial for the understanding of the host response during infections with pathogenic microorganisms. Generally, the identification of relevant T cell responses is based on the analysis of T cell lines propagated in vitro. We used an ex vivo approach for the analysis of the CD8 T cell response against Listeria monocytogenes that is based upon the fractionation of naturally processed antigenic peptides and subsequent analysis with T cells in an enzyme-linked immunospot (ELISPOT) assay. Our data indicate that the direct ex vivo ELISPOT analysis of peptides extracted from infected tissues represents a versatile and potent test system for the analysis of the CD8 T cell immunome of microorganisms that furthermore requires neither the knowledge of the microbial genome nor of the specificity of responding T cells. 相似文献