Exploring the Role of Rehabilitation Medicine within an Inclusion Health Context: Examining a Population at Risk from Homelessness and Brain Injury in Edinburgh.

People experiencing homelessness are at risk from a number of comorbidities, including traumatic brain injury, mental health disorders, and various infections. Little is known about the rehabilitation needs of this population. This study took advantage of unique access to a specialist access GP practice for people experiencing homelessness and a local inclusion health initiative to explore the five-year period prevalence of these conditions in a population of people experiencing homelessness through electronic case record searches and to identify barriers and facilitators to healthcare provision for this population in the context of an interdisciplinary and multispecialist inclusion health team through semi-structured interviews with staff working in primary and secondary care who interact with this population. The five-year period prevalence of TBI, infections, and mental health disorders was 9.5%, 4%, and 22.8%, respectively. Of those who had suffered a brain injury, only three had accessed rehabilitation services. Themes from thematic analysis of interviews included the impact of psychological trauma, under-recognition of the needs of people experiencing homelessness, resource scarcity, and the need for collaborative and adaptive approaches. The combination of quantitative and qualitative data suggests a potential role for rehabilitation medicine in inclusion health initiatives.

A Simple Elimination of the Thermal Convection Effect in NMR Diffusiometry Experiments.

Thermal convection is always present when the temperature of an NMR experiment is different from the ambient one. Most often, it falsifies the value of the diffusion coefficient determined by NMR diffusiometry using a PGSE NMR experiment. In spite of common belief, it acts not only at higher temperatures but also at temperatures lower than in the laboratory. Sodium alkyl-sulfate monomers and micelles in D2O solvent were used as model molecules measured at T = 319 K in order to show that thermal convection sometimes remains hidden in experiments. In this paper, we demonstrate that the increase in apparent diffusion coefficient with increasing diffusion time is a definite indicator of thermal convection. Extrapolation to zero diffusion time can also be used to obtain the real diffusion coefficient, likewise applying the less sensitive pulse sequences designed for flow compensation or the expensive hardware, e.g., sapphire or Shigemi NMR tubes, to decrease the temperature gradient. Further, we show experiments illustrating the effect of a long diffusion time in which the periodic changes of the echo intensity with gradient strength appear as predicted by theories.

Beware of phosphate: evidence of specific dendrimer-phosphate interactions.

Dendrimers are extensively studied for drug delivery and catalysis, most of which are pH dependent. Phosphate buffer solutions (PBSs) are often used to adjust the pH. We have found that phosphate ions become incorporated into poly(amidoamine) (PAMAM) dendrimer molecules by forming H-bonds with tertiary nitrogens. We show that this specific interaction between H2PO4- and HPO42- ions and generation five PAMAM dendrimers causes a decrease in hydrodynamic size, disturbing the outcome of the size exclusion chromatography analysis. We monitored this interaction by 1H and 31P high resolution NMR, NMR-diffusiometry, pH-potentiometry and infrared spectroscopy. Failing to take into account this effect may lead to incorrect conclusions and misinterpreting interactions of PAMAM dendrimers with drug molecules and subsequently incorrect dosing. The phosphate salts of amino terminated generation five PAMAM dendrimers are stable for years when stored in the dark, even in dilute aqueous solutions, which has important implications for the shelf-life of dendrimer-based drug delivery systems.

Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans.

Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST) produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L-1 ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.

Activation energy associated with the electromigration of oligosaccharides through viscosity modifier and polymeric additive containing background electrolytes.

The activation energy related to the electromigration of oligosaccharides can be determined from their measured electrophoretic mobilities at different temperatures. The effects of a viscosity modifier (ethylene glycol) and a polymeric additive (linear polyacrylamide) on the electrophoretic mobility of linear sugar oligomers with α1-4 linked glucose units (maltooligosaccharides) were studied in CE using the activation energy concept. The electrophoretic separations of 8-aminopyrene-1,3,6-trisulfonate-labeled maltooligosaccharides were monitored by LIF detection in the temperature range of 20-50°C, using either 0-60% ethylene glycol (viscosity modifier) or 0-3% linear polyacrylamide (polymeric additive) containing BGEs. Activation energy curves were constructed based on the slopes of the Arrhenius plots. With the use of linear polyacrylamide additive, solute size-dependent activation energy variations were found for the maltooligosaccharides with polymerization degrees below and above maltoheptaose (DP 7), probably due to molecular conformation changes and possible matrix interaction effects.

The intracellular galactoglycome in Trichoderma reesei during growth on lactose.

Lactose (1,4-0-ß-D-galactopyranosyl-D-glucose) is used as a soluble carbon source for the production of cellulases and hemicellulases for-among other purposes-use in biofuel and biorefinery industries. The mechanism how lactose induces cellulase formation in T. reesei is enigmatic, however. Previous results from our laboratory raised the hypothesis that intermediates from the two galactose catabolic pathway may give rise to the accumulation of intracellular oligogalactosides that could act as inducer. Here we have therefore used high-performance anion-exchange chromatography-mass spectrometry to study the intracellular galactoglycome of T. reesei during growth on lactose, in T. reesei mutants impaired in galactose catabolism, and in strains with different cellulase productivities. Lactose, allo-lactose, and lactulose were detected in the highest amounts in all strains, and two trisaccharides (Gal-ß-1,6-Gal-ß-1,4-Glc/Fru and Gal-ß-1,4-Gal-ß-1,4-Glc/Fru) also accumulated to significant levels. Glucose and galactose, as well as four further oligosaccharides (Gal-ß-1,3/1,4/1,6-Gal; Gal-ß-1,2-Glc) were only detected in minor amounts. In addition, one unknown disaccharide (Hex-ß-1,1-Hex) and four trisaccharides were also detected. The accumulation of the unknown hexose disaccharide was shown to correlate with cellulase formation in the improved mutant strains as well as the galactose pathway mutants, and Gal-ß-1,4-Gal-ß-1,4-Glc/Fru and two other unknown hexose trisaccharides correlated with cellulase production only in the pathway mutants, suggesting that these compounds could be involved in cellulase induction by lactose. The nature of these oligosaccharides, however, suggests their formation by transglycosylation rather than by glycosyltransferases. Based on our results, the obligate nature of both galactose catabolic pathways for this induction must have another biochemical basis than providing substrates for inducer formation.

Direct amidation of poly(gamma-glutamic acid) with benzylamine in dimethyl sulfoxide.

Partially benzylamidated, amphipathic poly(gamma-glutamic acid) (BzPGA) was synthesized from poly(gamma-glutamic acid) (PGA) and benzylamine by direct amidation in dimethyl sulfoxide (DMSO). Benzylamine and PGA were heated in DMSO for 1 to 26 h at temperatures between 110 and 130 degrees C, producing derivatives of various degrees of benzylamidation as a function of the reaction time and temperature. Neither any carboxyl-activating agent nor catalyst is needed for the reaction to proceed. After purification by dialysis, the product was identified by 1H and 13C 1D and 2D NMR in DMSO-d(6). BzPGA prepared by the new direct amidation method was identical to that obtained with a conventional carbodiimide-mediated reaction in water. The one-pot amidation procedure described in the present article can probably be applied to the synthesis of amides from other amines and carboxylic acids.

Shear-dependent morphology of von Willebrand factor bound to immobilized collagen.

We have developed an immunogold von Willebrand factor (VWF) detection method that permits almost complete coverage of individual VWF molecules, and by this unequivocal localization and morphologic analysis of collagen-bound VWF by atomic force microscopy (AFM). Perfusion of gel filtration-purified VWF in parallel plate perfusion chambers over glass coverslips coated with calf skin collagen, followed by AFM imaging in air, enabled us to assess possible morphologic differences between VWF bound at low (0.07 N/m(2) = 0.7 dynes/cm(2)) and high (4.55 N/m(2) = 45.5 dynes/cm(2)) shear stresses. No significant differences in VWF morphology were found, the molecules were oriented almost randomly, and there were no clear signs of VWF "uncoiling" either at a high or at a low shear regime. After perfusing 1 microg/mL VWF for 5 minutes, surface coverage at high shear was almost twice the one seen at low shear, and some larger and more irregularly shaped VWF molecules could be seen at high shear. This difference disappeared, however, at 15 minutes of perfusion and was probably caused by diffusion kinetics. Moreover, the presence of 68 x 10(9)/L washed fixed platelets in the perfusate did not have any visible effect on VWF morphology at high versus low shear stress. These findings suggest that shear stress does not influence significantly the overall molecular morphology of VWF during its binding to collagen-coated surface and are consistent with a constitutively expressed affinity of collagen-bound VWF for glycoprotein Ib.