Acetylcholinesterase activity measurement and clinical features of delirium

Aims: Cholinergic deficiency is commonly implicated in the pathophysiology of delirium. We aimed to investigate the relationship between directly measured serum AChE activity and (1) clinical features of delirium and (2) outcomes, among older hospital patients with delirium. Methods: Hospitalized patients with delirium were recruited and delirium motor subtype, severity and duration of delirium were measured. Serum AChE activity was measured using a colorimetric assay. Results: The mean AChE activity for the whole sample was 2.46 μmol/μml/min (SD 1.75). Higher AChE activity was associated with increased likelihood of hypoactive delirium rather than the hyperactive or mixed subtype (OR 1.98, CI 1.10-3.59). Conclusion: Higher AChE activity was associated with hypoactive delirium, but did not predict outcomes. Simple enhancement of cholinergic neurotransmission may not be sufficient to treat deliriu

The role of corticosterone in human hypothalamic– pituitary–adrenal axis feedback

Objective  In humans, the glucocorticoid corticosterone circulates in blood at 10–20-fold lower levels than cortisol, but is found in higher relative amounts in postmortem brain samples. Access of cortisol and corticosterone to the central nervous system may not be equal. Additionally, the relative affinities for the glucocorticoid and mineralocorticoid receptors differ, such that corticosterone may play a significant role in human brain function. Design  We measured cortisol and corticosterone levels in paired plasma and cerebrospinal fluid (CSF) samples. To test the relative potency of cortisol vs. corticosterone on hypothalamic–pituitary–adrenal (HPA) feedback, subjects underwent a three-phase, single-blind, randomized study assessing the postmetyrapone ACTH response over 3 h to an intravenous bolus of vehicle, cortisol or corticosterone (0·15 mg/kg and 0·04 mg/kg). Participants  Outpatients undergoing diagnostic lumbar puncture who were subsequently deemed to be free of disease. Feedback was tested in healthy male volunteers. Measurements  Plasma and CSF corticosterone to cortisol ratio was calculated and the ACTH response over time after the bolus glucocorticoid measured. Results  Plasma corticosterone : cortisol was 0·069 ± 0·007; CSF corticosterone : cortisol was 0·387 ± 0·050 ( P <  0·001). Cortisol and corticosterone (0·15 mg/kg) suppressed ACTH vs. vehicle ( P =  0·002); there was no difference between corticosterone and cortisol. The 0·04 mg/kg dose had no effect on ACTH despite supraphysiological plasma corticosterone levels. Conclusions  Corticosterone contributes almost 40% of total active glucocorticoids (cortisol and corticosterone) in the CSF. Significant effects on HPA axis suppression were only seen with supraphysiological levels of corticosterone, suggesting that corticosterone is not important in this model of nonstress-induced ACTH hypersecretion, in which the effect of cortisol predominates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72329/1/j.1365-2265.2006.02540.x.pd

Experimental Determination of the Key Heat Transfer Mechanisms in Pharmaceutical Freeze Drying

Freeze-drying is often used in manufacture of pharmaceuticals to remove a solvent in such a way that the sensitive molecular structure of the active substance of a drug is least disturbed, and to provide a sterile powder that can be quickly and completely rehydrated. In this work heat transfer rates in a laboratory-scale freeze-dryer have been measured to investigate the contribution of different heat transfer modes. Pure water was partially dried under low-pressure conditions and sublimation rates were determined gravimetrically. The heat transfer rates were observed to be independent of the separation distance between a product vial and a dryer shelf and linearly dependent on the pressure in the free molecular limit. However, under higher pressures the heat transfer rates were independent of pressure and inversely proportional to the separation distance. Previous heat transfer studies in conventional freeze-drying cycles have attributed a dominant portion of the total heat transfer to radiation, the rest to conduction, whereas the convection has been found insignificant. While the measurements revealed the significance of the radiative and gas conduction components, the convective component was found to be comparable to the gas conduction contribution at pressures greater than 100mTorr. The current investigation suggests that the convective component of the heat transfer cannot be ignored at typical laboratory-scale freeze-drying conditions

Strandings of NE Atlantic gorgonians

Publisher policy: author can archive post-print on open access repository after an embargo period of 18 months. Publisher's version/PDF cannot be used. Must link to publisher version with DOI. Author's post-print must be released with a Creative Commons Attribution Non-Commercial No Derivatives License. publisher: Elsevier articletitle: Strandings of NE Atlantic gorgonians journaltitle: Biological Conservation articlelink: http://dx.doi.org/10.1016/j.biocon.2017.03.020 content_type: article copyright: © 2017 Elsevier Ltd. All rights reserved

2D characterization of near-surface V P/V S: surface-wave dispersion inversion versus refraction tomography

International audienceThe joint study of pressure (P-) and shear (S-) wave velocities (Vp and Vs ), as well as their ratio (Vp /Vs), has been used for many years at large scales but remains marginal in near-surface applications. For these applications, and are generally retrieved with seismic refraction tomography combining P and SH (shear-horizontal) waves, thus requiring two separate acquisitions. Surface-wave prospecting methods are proposed here as an alternative to SH-wave tomography in order to retrieve pseudo-2D Vs sections from typical P-wave shot gathers and assess the applicability of combined P-wave refraction tomography and surface-wave dispersion analysis to estimate Vp/Vs ratio. We carried out a simultaneous P- and surface-wave survey on a well-characterized granite-micaschists contact at Ploemeur hydrological observatory (France), supplemented with an SH-wave acquisition along the same line in order to compare Vs results obtained from SH-wave refraction tomography and surface-wave profiling. Travel-time tomography was performed with P- and SH- wave first arrivals observed along the line to retrieve Vtomo p and Vtomo s models. Windowing and stacking techniques were then used to extract evenly spaced dispersion data from P-wave shot gathers along the line. Successive 1D Monte Carlo inversions of these dispersion data were performed using fixed Vp values extracted from Vtomo p the model and no lateral constraints between two adjacent 1D inversions. The resulting 1D Vsw s models were then assembled to create a pseudo-2D Vsw s section, which appears to be correctly matching the general features observed on the section. If the pseudo-section is characterized by strong velocity incertainties in the deepest layers, it provides a more detailed description of the lateral variations in the shallow layers. Theoretical dispersion curves were also computed along the line with both and models. While the dispersion curves computed from models provide results consistent with the coherent maxima observed on dispersion images, dispersion curves computed from models are generally not fitting the observed propagation modes at low frequency. Surface-wave analysis could therefore improve models both in terms of reliability and ability to describe lateral variations. Finally, we were able to compute / sections from both and models. The two sections present similar features, but the section obtained from shows a higher lateral resolution and is consistent with the features observed on electrical resistivity tomography, thus validating our approach for retrieving Vp/Vs ratio from combined P-wave tomography and surface-wave profiling

A chromosome-level Amaranthus cruentus genome assembly highlights gene family evolution and biosynthetic gene clusters that may underpin the nutritional value of this traditional crop

Traditional crops historically provided accessible and affordable nutrition to millions of rural dwellers but have been neglected, with most modern agricultural systems over reliant on a small number of internationally-traded crops. Traditional crops are typically well-adapted to local agro-ecological conditions and many are nutrient-dense. They can play a vital role in local food systems through enhanced nutrition (especially where diets are dominated by starch crops), food security and livelihoods for smallholder farmers, and a climate-resilient and biodiverse agriculture. Using short-read, long-read and phased sequencing technologies we generated a high-quality chromosome-level genome assembly for Amaranthus cruentus, an under-researched crop with micronutrient- and protein-rich leaves and gluten-free seed, but lacking improved varieties, with respect to productivity and quality traits. The 370.9 MB genome demonstrates a shared whole genome duplication with a related species, Amaranthus hypochondriacus. Comparative genome analysis indicates chromosomal loss and fusion events following genome duplication that are common to both species, as well as fission of chromosome 2 in A. cruentus alone, giving rise to a haploid chromosome number of 17 (versus 16 in A. hypochondriacus). Genomic features potentially underlying the nutritional value of this crop include two A. cruentus-specific genes with a likely role in phytic acid synthesis (an anti-nutrient), expansion of ion transporter gene families, and identification of biosynthetic gene clusters conserved within the amaranth lineage. The A. cruentus genome assembly will underpin much-needed research and global breeding efforts to develop improved varieties for economically viable cultivation and realisation of the benefits to global nutrition security and agrobiodiversity