636 research outputs found
Abundant Trimethylornithine Lipids and Specific Gene Sequences Are Indicative of Planctomycete Importance at the Oxic/Anoxic Interface in <i>Sphagnum</i>-Dominated Northern Wetlands
Northern wetlands make up a substantial terrestrial carbon sink and are often dominated by decay-resistant Sphagnum mosses.Recent studies have shown that planctomycetes appear to be involved in degradation of Sphagnum-derived debris. Novel trimethylornithine(TMO) lipids have recently been characterized as abundant lipids in various Sphagnum wetland planctomyceteisolates, but their occurrence in the environment has not yet been confirmed. We applied a combined intact polar lipid (IPL) andmolecular analysis of peat cores collected from two northern wetlands (Saxnäs Mosse [Sweden] and Obukhovskoye [Russia]) inorder to investigate the preferred niche and abundance of TMO-producing planctomycetes. TMOs were present throughout theprofiles of Sphagnum bogs, but their concentration peaked at the oxic/anoxic interface, which coincided with a maximum abundanceof planctomycete-specific 16S rRNA gene sequences. The sequences detected at the oxic/anoxic interface were affiliatedwith the Isosphaera group, while sequences present in the anoxic peat layers were related to an uncultured planctomycete group.Pyrosequencing-based analysis identified Planctomycetes as the major bacterial group at the oxic/anoxic interface at the Obukhovskoyepeat (54% of total 16S rRNA gene sequence reads), followed by Acidobacteria (19% reads), while in the Saxnäs Mossepeat, Acidobacteria were dominant (46%), and Planctomycetes contributed to 6% of the total reads. The detection of abundantTMO lipids in planctomycetes isolated from peat bogs and the lack of TMO production by cultures of acidobacteria suggest thatplanctomycetes are the producers of TMOs in peat bogs. The higher accumulation of TMOs at the oxic/anoxic interface and thechange in the planctomycete community with depth suggest that these IPLs could be synthesized as a response to changing redoxconditions at the oxic/anoxic interface
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The effect of amblyopia treatment on stereoacuity
Purpose: To explore how stereoacuity changes in patients while they are being treated for amblyopia.
Methods: The Monitored Occlusion Treatment for Amblyopia Study (MOTAS) comprised 3 distinct phases. In the first phase, baseline, assessments of visual function were made to confirm the initial visual and binocular visual deficit. The second phase, refractive adaptation, now commonly termed “optical treatment,” was an 18-week period of spectacle wear with measurements of logMAR visual acuity and stereoacuity with the Frisby test at weeks 0, 6, 12, and 18. In the third phase, occlusion, participants were prescribed 6 hours of patching per day.
Results: A total of 85 children were enrolled (mean age, 5.1 ± 1.5 years). In 21 children amblyopia was associated with anisometropia; in 29, with strabismus; and in 35, with both. At study entry, poor stereoacuity was associated with poor visual acuity (P < 0.001) in the amblyopic eye and greater angle of strabismus (P < 0.001). Of 66 participants, 25 (38%) who received refractive adaptation and 19 (29%) who received occlusion improved by at least one octave in stereoacuity, exceeding test–retest variability. Overall, 38 (45%) improved one or more octaves across both treatment phases. Unmeasureable stereoacuity was observed in 56 participants (66%) at study entry and in 37 (43%) at study exit.
Conclusions: Stereoacuity improved for almost one half of the study participants. Improvement was observed in both treatment phases. Factors associated with poor or nil stereoacuity at study entry and exit were poor visual acuity of the amblyopic eye and large-angle strabismus
Imaging the pulmonary extracellular matrix
The pulmonary extracellular matrix (ECM) plays an important role in the structure and function of the lung. In many respiratory diseases the profile of the ECM reflects pathological changes. The capacity to visualize the ECM and its alterations is of considerable importance to facilitate a better understanding of pulmonary diseases and eventually augment therapeutic solutions. This short review summarizes the current and novel possibilities for imaging the pulmonary ECM by the use of computed tomography (CT), optical coherence tomography (OCT), confocal laser endomicroscopy (CLE) and molecular imaging. While not all these techniques are as yet implemented in standard clinical practice, we address their main features along with the key possibilities for the future
Effects on muscle performance of NSAID treatment with Piroxicam versus placebo in geriatric patients with acute infection-induced inflammation. a double blind randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Inflammation is the main cause of disease-associated muscle wasting. In a previous single blind study we have demonstrated improved recovery of muscle endurance following celecoxib treatment in hospitalized geriatric patients with acute infection. Here we further evaluate NSAID treatment with piroxicam in a double blind RCT and investigate the role of cytokines and heat shock proteins (Hsp) with respect to muscle performance. We hypothesized that NSAID treatment would preserve muscle performance better than antibiotic treatment alone, by reducing infection-associated inflammation and by increasing expression of cytoprotective Hsp.</p> <p>Methods</p> <p>Consecutive admissions to the geriatric ward were screened. 30 Caucasian patients, median age 84.5 years, with acute infection-induced inflammation and serum levels of CRP > 10 mg/L were included and randomized to active treatment with 10 mg piroxicam daily or placebo. Assessment comprised general clinical and biochemical parameters, 25 cytokines in serum, intra-and extracellular Hsp27 and Hsp70, Elderly Mobility Scale (EMS) scores, grip strength (GS), fatigue resistance (FR) and lean body mass (LBM). Patients were evaluated until discharge with a maximum of 3 weeks after treatment allocation.</p> <p>Results</p> <p>EMS scores, FR and grip work (GW), a measure taking into account GS and FR, significantly improved with piroxicam, but not with placebo. Early decreases in IL-6 serum levels with piroxicam correlated with better muscle performance at week 2. Basal expression of Hsp27 in monocytes without heat challenge (WHC) was positively correlated with FR at baseline and significantly increased by treatment with piroxicam compared to placebo. Profound modifications in the relationships between cytokines or Hsp and changes in muscle parameters were observed in the piroxicam group.</p> <p>Conclusions</p> <p>Piroxicam improves clinically relevant measures of muscle performance and mobility in geriatric patients hospitalized with acute infection-induced inflammation. Underlying mechanisms may include modifications in the cytokine network and increases in monocytic expression of cytoprotective Hsp27.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN96340690">ISRCTN96340690</a></p
Carbon-isotope discrimination by leaves of Flaveria species exhibiting different amounts of C 3 -and C 4 -cycle co-function
Carbon-isotope ratios were examined as δ 13 C values in several C 3 , C 4 , and C 3 −C 4 Flaveria species, and compared to predicted δ 13 C, values generated from theoretical models. The measured δ 13 C values were within 4‰ of those predicted from the models. The models were used to identify factors that contribute to C 3 -like δ 13 C values in C 3 −C 4 species that exhibit considerable C 4 -cycle activity. Two of the factors contributing to C 3 -like δ 13 C values are high CO 2 leakiness from the C 4 pathway and pi/pa values that were higher than C 4 congeners. A marked break occurred in the relationship between the percentage of atmospheric CO 2 assimilated through the C 4 cycle and the δ 13 C value. Below 50% C 4 -cycle assimialtion there was no significant relationship between the variables, but above 50% the δ 13 C values became less negative. These results demonstrate that the level of C 4 -cycle expression can increase from, 0 to 50% with little integration of carbon transfer from the C 4 to the C 3 cycle. As expression increaces above 50%, however, increased integration of C 3 - and C 4 -cycle co-function occurs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47473/1/425_2004_Article_BF00394765.pd
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