Osteoprotegerin and Myocardial Fibrosis in Patients with Aortic Stenosis

Left ventricular myocardial fibrosis in patients with aortic stenosis (AS) confers worse prognosis. Plasma osteoprotegerin (OPG), a cytokine from the TNF receptor family, correlates with the degree of valve calcification in AS, reflecting the activity of the tissue RANKL/RANK/OPG (receptor activator of nuclear factor κΒ ligand/RANK/osteoprotegerin) axis, and is associated with poorer outcomes in AS. Its association with myocardial fibrosis is unknown. We hypothesised that OPG levels would reflect the extent of myocardial fibrosis in AS. We included 110 consecutive patients with AS who had undergone late-gadolinium contrast enhanced cardiovascular magnetic resonance (LGE-CMR). Patients were characterised according to pattern of fibrosis (no fibrosis, midwall fibrosis, or chronic myocardial infarction fibrosis). Serum OPG was measured with ELISA and compared between groups defined by valve stenosis severity. Some 36 patients had no fibrosis, 38 had midwall fibrosis, and 36 had chronic infarction. Patients with midwall fibrosis did not have higher levels of OPG compared to those without fibrosis (6.78 vs. 5.25 pmol/L, p = 0.12). There was no difference between those with midwall or chronic myocardial infarction fibrosis (6.78 vs. 6.97 pmol/L, p = 0.27). However, OPG levels in patients with chronic myocardial infarction fibrosis were significantly higher than those without fibrosis (p = 0.005)

Characterisation of chilean hazelnut (gevuina avellana) tissues : light microscopy and cell wall polysaccharides

By applying several differential staining techniques and light microscopy, the structure and composition of Chilean hazelnut (Gevuina avellana) seeds were analysed. The structure of the G avellana seed is very simple, with a thin, heavily lignified seed coat and two voluminous cotyledons. The embryo food reserves are uniformly distributed over the cotyledon cells. The cell wall polysaccharides were recovered from the alcohol-insoluble residue by mild treatment with warm chlorite solution and sequential extraction with alkali solutions of increasing concentration. FT-IR spectra in the 1200–850 cm-1 region were used together with chemometric techniques to distinguish the hemicellulosic and pectic polysaccharides in the extracts. The most abundant extracts were fractionated by graded precipitation in ethanol. A xyloglucan was identified by 1H and 13C NMR as the major hemicellulosic polysaccharide, with a sugar composition of 4Glc:3.5Xyl:1Gal:0.5Fuc. The hazelnut cell walls are composed of equivalent amounts of pectic polysaccharides, xyloglucans and cellulose.Fundação para a Ciência e Tecnologia (FCT) - PRAXIS XXI/BPD/18824/99. Research Unit 62/94, QOPNA (Aveiro, Portugal). INCO-DC 96-2205 (OLNOCO)

AXY3 encodes a α-xylosidase that impacts the structure and accessibility of the hemicellulose xyloglucan in Arabidopsis plant cell walls

Xyloglucan is the most abundant hemicellulose in the walls of dicots such as Arabidopsis. It is part of the load-bearing structure of a plant cell and its metabolism is thought to play a major role in cell elongation. However, the molecular mechanism by which xyloglucan carries out this and other functions in planta is not well understood. We performed a forward genetic screen utilizing xyloglucan oligosaccharide mass profiling on chemically mutagenized Arabidopsis seedlings to identify mutants with altered xyloglucan structures termed axy-mutants. One of the identified mutants, axy3.1, contains xyloglucan with a higher proportion of non-fucosylated xyloglucan subunits. Mapping revealed that axy3.1 contains a point mutation in XYLOSIDASE1 (XYL1) known to encode for an apoplastic glycoside hydrolase releasing xylosyl residues from xyloglucan oligosaccharides at the non-reducing end. The data support the hypothesis that AXY3/XYL1 is an essential component of the apoplastic xyloglucan degradation machinery and as a result of the lack of function in the various axy3-alleles leads not only to an altered xyloglucan structure but also a xyloglucan that is less tightly associated with other wall components. However, the plant can cope with the excess xyloglucan relatively well as the mutant does not display any visible growth or morphological phenotypes with the notable exception of shorter siliques and reduced fitness. Taken together, these results demonstrate that plant apoplastic hydrolases have a larger impact on wall polymer structure and function than previously thought

Inducible expression of Pisum sativum xyloglucan fucosyltransferase in the pea root cap meristem, and effects of antisense mRNA expression on root cap cell wall structural integrity

Mitosis and cell wall synthesis in the legume root cap meristem can be induced and synchronized by the nondestructive removal of border cells from the cap periphery. Newly synthesized cells can be examined microscopically as they differentiate progressively during cap development, and ultimately detach as a new population of border cells. This system was used to demonstrate that Pisum sativum L. fucosyl transferase (PsFut1) mRNA expression is strongly expressed in root meristematic tissues, and is induced >2-fold during a 5-h period when mitosis in the root cap meristem is increased. Expression of PsFut1 antisense mRNA in pea hairy roots under the control of the CaMV35S promoter, which exhibits meristem localized expression in pea root caps, resulted in a 50–60% reduction in meristem localized endogenous PsFut1 mRNA expression measured using whole mount in situ hybridization. Changes in gross levels of cell wall fucosylated xyloglucan were not detected, but altered surface localization patterns were detected using whole mount immunolocalization with CCRC-M1, an antibody that recognizes fucosylated xyloglucan. Emerging hairy roots expressing antisense PsFut1 mRNA appeared normal macroscopically but scanning electron microscopy of tissues with altered CCRC-M1 localization patterns revealed wrinkled, collapsed cell surfaces. As individual border cells separated from the cap periphery, cell death occurred in correlation with extrusion of cellular contents through breaks in the wall

Studies on radio frequency propagation characteristics for underground coalmine communications

418-422A basic understanding of the behaviour of electromagnetic wave propagation through strata is the fundamental requirement to design a suitable wireless communication system for underground mines. Background information on radio propagation and its limitations, in a particular confined space can be known only after the measurement. Both electromagnetic propagation studies and modelling of propagation coverage, ultimately help in selecting the best suitable frequency and designing appropriate wireless communication system for underground mine. The paper discusses different aspects for propagation modelling and the experiment conducted in the laboratory to understand the propagation characteristics through coal. It is found that 6 MHz frequency is the best suitable frequency for propagation of electromagnetic wave through coal

Euroscore II and STS Risk Model Scores in Aortic Stenosis: Can We Rely on Them?

Introduction The European System for Cardiac Operative Risk Evaluation II (EuroSCORE) and Society of Thoracic Surgeons (STS) risk models provide a method of predicating mortality of patients undergoing cardiac surgery. However, their validity in transcatheter aortic valve implantation (TAVI) remains controversial with some studies supporting its use as a good predictor of mortality whilst others find no association. We sought to investigate the validity of both EuroSCORE II and STS score as predictors of mortality in a real-life cohort of patients undergoing a TAVI.Methods Between 2010–2014, 115 (79 ± 8 years old; 56 male) consecutive patients with severe AS scheduled for TAVI had EuroSCORE and STS score calculated prior to intervention. The patients were followed up for a median 187 days (IQR 93,1520).Results During follow up, 27 patients died. Neither EuroSCORE nor STS were associated with prognosis in this cohort. EuroSCORE was not significantly associated with mortality, hazard ratio 1.33 per log unit (p = 0.28, 95% CI 0.90–2.20). This was similar to STS score, hazard ratio 1.08 per log unit (p = 0.78 95% CI 0.63 – 1.87). However, both confidence intervals are relatively wide indicating that more patients are required to substantiate this finding.Conclusions In this small cohort of patients, it would appear that neither EuroSCORE II nor STS are associated with overall survival. This cohort included many patients with poor mobility, previous CABG with LIMA graft and significant comorbidities not included in EuroSCORE/STS calculation. The scores might therefore have underestimated the true risk. More studies and more patients are required to further assess their validity. Although such scores have been accurately validated for open-heart surgery, we recommend that they should be interpreted with caution when attempting to predict risk in patients undergoing a TAVI.Abstract 43 Figure 1 Area under the curves (AUC) for both STS and Euroscore II. Both follow the diagonal line suggesting that they are not good predictors of outcome%U http://heart.bmj.com/content/heartjnl/102/Suppl_6/A31.full.pd