Biogenic methane contributes to the food web of a large,shallow lake

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Serum lipidomics meets cardiac magnetic resonance imaging: profiling of subjects at risk of dilated cardiomyopathy

Dilated cardiomyopathy (DCM), characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA) on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7-9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI) to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance.     

Myelomeningocele: need for long-time complex follow-up—an observational study

The purpose of this study was to describe the relationship between pelvic inclination (PI) and lumbar lordosis (LL). Pelvic inclination and pelvic tilt are two different names for the same metric. The geometrical parameters of the spine and pelvis were measured using surface topography scanning, and the data was explored for any physical relationships using principal component analysis. Once widely assumed to be a direct correlation, research in the 1980s first cast doubt upon the PI to LL relationship. And yet, other studies have suggested a relationship does exist. Decades later, the rehabilitation professionals often still rely on this supposed correlation when making decisions about rehabilitation treatment interventions. This theoretical relationship requires further clarification, which is explored herein. Surface topography imaging is a technology that has proven to be a radiation-free way to produce accurate, reliable skeletal alignment measures. Patient data from one physical rehabilitation clinic was collected at the time of initial assessment. Patients presented with a wide range of musculoskeletal complaints. Surface topography scans were performed on 107 patients at the commencement and completion of their therapy. Principal component analysis was performed on the collected data to determine how these spine and pelvic alignment parameters changed between the two points in time and what trends and/or relationships exist between the parameters. Our analysis evaluated eight spinal and pelvic measurements as input and focused on LL and PI as the two principal components at time points of beginning and completion of treatment. Pelvic inclination and lumbar lordosis changed during treatment but were not correlated. Our data demonstrates that pelvic inclination and lumbar lordosis do not have a predictable relationship as previously assumed.     

Recent oceanic long-distance dispersal and divergence in the amphi-Atlantic rain forest genus Renealmia L.f. (Zingiberaceae)

Renealmia L.f. (Zingiberaceae) is one of the few tropical plant genera with numerous species in both Africa and South America but not in Asia. Based on phylogenetic analysis of nuclear ribosomal internal transcribed spacer (ITS) and chloroplast trnL-F DNA, Renealmia is shown to be monophyletic with high branch support. Low sequence divergence found in the two genome regions (ITS: 0-2.4%; trnL-F: 0-1.9%) suggests recent diversification within the genus. Molecular divergence age estimates give further support to the recent origin of the genus and show that Renealmia has attained its amphi-Atlantic distribution by an oceanic long-distance dispersal event from Africa to South America during the Miocene or Pliocene (15.8-2.7 My ago). Some support is found for the hypothesis that speciation in neotropical Renealmia was influenced by the Andean orogeny. Speciation has been approximately simultaneous on both sides of the Atlantic, but increased taxon sampling is required to compare the speciation rates between the New World and Old World tropics.     

Growth Inhibition of <Emphasis Type="Italic">Streptococcus mutans</Emphasis> with Low Xylitol Concentrations

No studies on the concentration dependency of the inhibition of Streptococcus mutans with xylitol are available. We studied xylitol-induced growth inhibition of two type strains, S. mutans NCTC 10449 and Ingbritt, and three clinical isolates of S. mutans. The strains were grown in Brain Hearth Infusion Medium in the presence of 0.001% (0.066 mM), 0.005% (0.33 mM), 0.01% (0.66 mM), 0.1% (6.6 mM), and 1% (66 mM) xylitol. Growth was followed by measuring the absorbance at a wavelength of 660 nm. The highest xylitol concentration tested in this study, 1%, showed mean inhibition percentages ranging from 61% to 76% when the growth inhibition of the five strains was compared to the control without xylitol at log-phase. For 0.1% xylitol, the inhibition percentages ranged from 22% to 59%. A concentration dependency was seen in the growth inhibition, with 0.01% xylitol being the lowest xylitol concentration inhibiting all five strains significantly (p < 0.001). The growth inhibition percentages determined for 0.01% xylitol, however, were low, and the inhibition was significantly weaker as compared to 0.1% and 1% xylitol. Our results suggest that low xylitol concentrations of 0.1% (6.6 mM) could inhibit mutans streptococci in vivo but even lower xylitol concentrations may be inhibitory.     

Green fluorescent protein (GFP) fusion constructs in gene therapy research

The history of green fluorescent protein (GFP) as a marker is less than 10 years old, but it has already made a major impact on many areas of natural sciences, especially on cell biology and histochemistry. GFP can be detected in living cells without selection or staining and it can be fused to other proteins to yield fluorescent chimeras. The potential of GFP has also been recognised by gene therapy researchers and various GFP-tagged therapeutic proteins have been constructed. These chimeric proteins have been used to determine the expression level, site and time course of the therapeutic gene, or the correlation between gene transfer rate and therapeutic outcome. This review summarises the status of the applications of GFP fusions in gene therapy research.     

Removal of cell surface heparan sulfate increases TACE activity and cleavage of ErbB4 receptor

Background  

Nuclear localization of proteolytically formed intracellular fragment of ErbB4 receptor tyrosine kinase has been shown to promote cell survival, and nuclear localization of ErbB4 receptor has been described in human breast cancer. Tumor necrosis factor alpha converting enzyme (TACE) initiates the proteolytic cascade leading to ErbB4 intracellular domain formation. Interactions between matrix metalloproteases and heparan sulfate have been described, but the effect of cell surface heparan sulfate on TACE activity has not been previously described.     

Molecular characterization and homology modeling of spermidine synthase from <Emphasis Type="Italic">Synechococcus</Emphasis> sp. PCC 7942

Spermidine synthase (Spds) catalyzes the formation of spermidine by transferring the aminopropyl group from decarboxylated S-adenosylmethionine (dcSAM) to putrescine. The Synechococcus spds gene encoding Spds was expressed in Escherichia coli. The purified recombinant enzyme had a molecular mass of 33 kDa and showed optimal activity at pH 7.5, 37?°C. The enzyme had higher affinity for dcSAM (K _m, 20 µM) than for putrescine (K _m, 111 µM) and was highly specific towards the diamine putrescine with no activity observed towards longer chain diamines. The three-dimensional structural model for Synechococcus Spds revealed that most of the ligand binding residues in Spds from Synechococcus sp. PCC 7942 are identical to those of human and parasite Spds. Based on the model, the highly conserved acidic residues, Asp89, Asp159 and Asp162, are involved in the binding of substrates putrescine and dcSAM and Pro166 seems to confer substrate specificity towards putrescine.