Multi-night measurement for diagnosis and simplified monitoring of obstructive sleep apnoea

Substantial night-to-night variability in obstructive sleep apnoea (OSA) severity has raised misdiagnosis and misdirected treatment concerns with the current prevailing single-night diagnostic approach. In-home, multinight sleep monitoring technology may provide a feasible complimentary diagnostic pathway to improve both the speed and accuracy of OSA diagnosis and monitor treatment efficacy. This review describes the latest evidence on night-to-night variability in OSA severity, and its impact on OSA diagnostic misclassification. Emerging evidence for the potential impact of night-to-night variability in OSA severity to influence important health risk outcomes associated with OSA is considered. This review also characterises emerging diagnostic applications of wearable and non-wearable technologies that may provide an alternative, or complimentary, approach to traditional OSA diagnostic pathways. The required evidence to translate these devices into clinical care is also discussed. Appropriately sized randomised controlled trials are needed to determine the most appropriate and effective technologies for OSA diagnosis, as well as the optimal number of nights needed for accurate diagnosis and management. Potential risks versus benefits, patient perspectives, and cost-effectiveness of these novel approaches should be carefully considered in future trials.Bastien Lechat, Hannah Scott, Jack Manners, Robert Adams, Simon Proctor, Sutapa Mukherjee, Peter Catcheside, Danny J. Eckert, Andrew Vakulin, Amy C. Reynold

1D Self-Assembly and Ice Recrystallization Inhibition Activity of Antifreeze Glycopeptide-Functionalized Perylene Bisimides

Antifreeze glycoproteins (AFGPs) are polymeric natural products that have drawn considerable interest in diverse research fields owing to their potent ice recrystallization inhibition (IRI) activity. Self-assembled materials have emerged as a promising class of biomimetic ice growth inhibitor, yet the development of AFGP-based supramolecular materials that emulate the aggregative behavior of AFGPs have not yet been reported. Here, we demonstrate the first example of the 1D self-assembly and IRI activity of AFGP-functionalized perylene bisimides (AFGP-PBIs). Glycopeptide-functionalized PBIs underwent 1D self-assembly in water and showed modest IRI activity, which could be tuned through substitution of the PBI core. This work presents essential proof-of-principle for the development of novel IRIs as potential supramolecular cryoprotectans and glycoprotein mimics

Hexitols as major intermediates of glucose assimilation by mycelium of Puccinia graminis

Mycelium of Puccinia graminis was grown for 4 d on 200 mM D-[U-14C]glucose followed by a cold chase for 30 h. Analysis of cellular metabolites during the chase indicated significant turnover only in carbohydrates soluble in 80% (w/v) ethanol. A kinetic analysis of the depletion of [14C] in pools of free sugars and sugar alcohols indicated that the trehalose pools and a small proportion (12-16%) of the mannitol and glucitol pools did not turn over, whilst pools of glucose, fructose, and the remainder of the hexitols became totally,depleted of label during the chase. Because the [14C] was totally lost from the pools of glucose and fructose prior to the hexitols, it was deduced that both of these hexoses were precursors of the hexitols. Estimation of the carbon fluxes through pools indicated that 52, 36 and 16% of the carbon from glucose was assimilated via glucitol, fructose and mannitol respectively, demonstrating that glucitol could not have originated from fructose as sole precursor. After offering D-[U-14C]glucitol, [14C] was assimilated into trehalose phosphate, glucans and amino acids, but not into free glucose or fructose. These data indicate that hexitols are quantitatively important intermediates during the assimilation of glucose by Puccinia graminis

Metabolism of 2-deoxy-d-glucose by axenically grown mycelia of Puccinia graminis

To obtain information on the pathway(s) of assimilation of glucose by the wheat stem rust fungus (Puccinia graminis f. sp. tritici), axenically grown mycelia were incubated with the glucose analog 2-deoxy-d-[U-14C]glucose (2dG), and the kinetics of movement of label into intracellular metabolites was determined. During the first 5 minutes after adding substrate, free 2dG was transported into the cell, followed by phosphorylation. Further incubation over 5 h resulted in the accumulation of large pools of phosphorylated derivatives of 2dG and 2-deoxygluconate, and the accumulation of free dideoxytrehalose, 2-deoxyglucitol, 2-deoxygluconate, and traces of 2-deoxygalactose. A lag in the accumulation of 2-deoxyglucitol, without the prior accumulation of 2-deoxyglucitol phosphates, supports the view that glucitol is synthesized by direct reduction of free hexoses(s). The kinetics of labeling indicates that the major route of metabolism was oxidation of 2dG phosphate(s) to 2-deoxygluconate phosphate(s), from which free 2-deoxygluconate was released as a major end product; this is the first demonstration of this pathway of metabolism of 2dG in a fungus

Differential expression of peroxidase isogenes during the early stages of infection of the tropical forage legume Stylosanthes humilis by Colletotrichum gloeosporioides

Infection of Stylosanthes humilis by the fungal phytopathogen Colletotrichum gloeosporioides is associated with an increase in peroxidase enzyme activity within 24 h postinoculation. Peroxidase gene expression was investigated as a first step towards understanding the regulation and functional importance of this host response to fungal attack. Four distinct cDNAs Shpx 2, 5, 6, and 12, isolated from a cDNA library of S. humilis contained deduced amino acid (aa) sequence motifs characteristic of peroxidases. Three of these (Shpx 2, 5, and 6) were full-length and their deduced proteins each fell into a different homology group based on comparisons with other plant peroxidases. Each cDNA appeared to hybridize to only one or two genes in S. humilis. mRNAs corresponding to Shpx2, Shpx6, and Shpx12 were expressed relatively abundantly in young leaves, with lesser expression of Shpx2 and Shpx6 and no expression of Shpx12 detected in roots. No expression of these genes was detected in stems or old leaves. The mRNA of Shpx5 was relatively abundant in stems and to a lesser extent in young leaves. However, infection of young leaves with C. gloeosporioides greatly increased expression of the mRNAs of Shpx2 and Shpx6 but not Shpx5 nor Shpx12 compared to mock-inoculated controls. The mRNA of Shpx6 was strongly induced by the pathogen 4 h postinoculation, a time which precedes fungal penetration, while Shpx2 was induced to higher levels than controls at 24 h after inoculation. The mRNAs of both Shpx2 and Shpx6 but not Shpx5 and Shpx12 were also induced by wounding.(ABSTRACT TRUNCATED AT 250 WORDS

An antimicrobial peptide from the Australian native Hardenbergia violacea provides the first functionally characterised member of a subfamily of plant defensins

An antimicrobial peptide (HvAMP1) was isolated from seeds of the Australian native legume Hardenbergia violacea (Schneev.) Stearn. The peptide is 47 amino acid residues in length, contains 8 cysteines, and has a molecular weight of 5392 and a predicted pI of 10.41. HvAMP1 inhibited the growth of several plant pathogenic fungi at concentrations as low as 1 μM in vitro and produced distinct hyphal distortion and increased branching. This antimicrobial activity was greatly diminished in the presence of 1 mM CaCl and 50 mM KCl. The purified peptide at 40 μM did not inhibit three different α-amylase enzymes. A eukaryotic cell-free translation system showed inhibition approaching 50% in the presence of ~100 μM of HvAMP1. The viability of plant and mammalian cells cultured in vitro was not adversely affected by concentrations of HvAMP1 as high as 40 mM. The amino acid sequence of HvAMP1 contained the consensus amino acids that define the plant defensin family of peptides. The HvAMP1 amino acid sequence showed 87% and 57% identity with the amino acid sequences deduced from cDNA sequences from defensins of Vigna unguiculata and Pisum sativum, respectively. Other plant defensin sequences showed less than 33% amino acid identity to the peptide. Therefore, HvAMP1 and the putative plant defensins of cowpea and pea define a distinct sequence subfamily of plant defensins which is at present limited to members of the Fabaceae. HvAMP1 is the first member of this subfamily to be purified and functionally characterised. The antimicrobial activity of HvAMP1 suggests a defensive role for this subfamily of peptides