Highly saline fluids from a subducting slab as the source for fluid-rich diamonds.

The infiltration of fluids into continental lithospheric mantle is a key mechanism for controlling abrupt changes in the chemical and physical properties of the lithospheric root, as well as diamond formation, yet the origin and composition of the fluids involved are still poorly constrained. Such fluids are trapped within diamonds when they form and so diamonds provide a unique means of directly characterizing the fluids that percolate through the deep continental lithospheric mantle. Here we show a clear chemical evolutionary trend, identifying saline fluids as parental to silicic and carbonatitic deep mantle melts, in diamonds from the Northwest Territories, Canada. Fluid-rock interaction along with in situ melting cause compositional transitions, as the saline fluids traverse mixed peridotite-eclogite lithosphere. Moreover, the chemistry of the parental saline fluids--especially their strontium isotopic compositions--and the timing of host diamond formation suggest that a subducting Mesozoic plate under western North America is the source of the fluids. Our results imply a strong association between subduction, mantle metasomatism and fluid-rich diamond formation, emphasizing the importance of subduction-derived fluids in affecting the composition of the deep lithospheric mantle.

Wireless Pressure Ulcer Sensor: Validation in an Animal Model.

Pressure ulcers are increasingly prevalent in an aging population. The most commonly used method of pressure ulcer prevention is pressure off-loading achieved by physically turning bedbound patients or by using expensive, single application devices such as wheelchair cushions. Our aim is to approach the problem of pressure ulcer prevention in a new way: a wireless sensor worn by the patient at locations susceptible to pressure injury. The sensor will monitor local pressure over time and transmits the data wirelessly to a base station (in a hospital setting) or smartphone (for home care). When a condition that would be harmful to tissue is reached, an alert would enable immediate direct intervention to prevent development of a pressure ulcer. The goal of this study was to validate the sensor's use in a live animal model and to lay the foundation for building time-pressure curves to predict the probability of pressure injury. Sprague-Dawley rats underwent surgical implantation of bilateral steel discs deep to the latissimus dorsi muscles. After the animals recovered from the surgical procedure, pressure was applied to the overlying tissue using magnets of varying strengths (30-150 mm Hg) for between 1 and 8 hours. Our sensor was placed on the skin prior to magnet application to wirelessly collect data regarding pressure and time. Three days after pressure application, animals were killed, injuries were graded clinically, and biopsies were collected for histological analysis. Results reveal that all animals with magnet application for more than 2 hours had clinical evidence of ulceration. Similarly, histological findings of hemorrhage were associated with increased time of pressure application. However, at high pressures (120-150 mm Hg), there were ischemic changes within the muscular layer without corresponding skin ulceration. We have developed a wireless sensor that can be placed on any at-risk area of the body and has the potential to alert caregivers when patients are at risk of developing a pressure injury. Our sensor successfully transmitted pressure readings wirelessly in a live, mobile animal. Future studies will focus on safety and efficacy with human use and development of algorithms to predict the probability of pressure ulcer formation.

The dynamics of GABA signaling: Revelations from the circadian pacemaker in the suprachiasmatic nucleus.

Virtually every neuron within the suprachiasmatic nucleus (SCN) communicates via GABAergic signaling. The extracellular levels of GABA within the SCN are determined by a complex interaction of synthesis and transport, as well as synaptic and non-synaptic release. The response to GABA is mediated by GABAA receptors that respond to both phasic and tonic GABA release and that can produce excitatory as well as inhibitory cellular responses. GABA also influences circadian control through the exclusively inhibitory effects of GABAB receptors. Both GABA and neuropeptide signaling occur within the SCN, although the functional consequences of the interactions of these signals are not well understood. This review considers the role of GABA in the circadian pacemaker, in the mechanisms responsible for the generation of circadian rhythms, in the ability of non-photic stimuli to reset the phase of the pacemaker, and in the ability of the day-night cycle to entrain the pacemaker.

Overview of the SAMPL6 host-guest binding affinity prediction challenge.

Accurately predicting the binding affinities of small organic molecules to biological macromolecules can greatly accelerate drug discovery by reducing the number of compounds that must be synthesized to realize desired potency and selectivity goals. Unfortunately, the process of assessing the accuracy of current computational approaches to affinity prediction against binding data to biological macromolecules is frustrated by several challenges, such as slow conformational dynamics, multiple titratable groups, and the lack of high-quality blinded datasets. Over the last several SAMPL blind challenge exercises, host-guest systems have emerged as a practical and effective way to circumvent these challenges in assessing the predictive performance of current-generation quantitative modeling tools, while still providing systems capable of possessing tight binding affinities. Here, we present an overview of the SAMPL6 host-guest binding affinity prediction challenge, which featured three supramolecular hosts: octa-acid (OA), the closely related tetra-endo-methyl-octa-acid (TEMOA), and cucurbit[8]uril (CB8), along with 21 small organic guest molecules. A total of 119 entries were received from ten participating groups employing a variety of methods that spanned from electronic structure and movable type calculations in implicit solvent to alchemical and potential of mean force strategies using empirical force fields with explicit solvent models. While empirical models tended to obtain better performance than first-principle methods, it was not possible to identify a single approach that consistently provided superior results across all host-guest systems and statistical metrics. Moreover, the accuracy of the methodologies generally displayed a substantial dependence on the system considered, emphasizing the need for host diversity in blind evaluations. Several entries exploited previous experimental measurements of similar host-guest systems in an effort to improve their physical-based predictions via some manner of rudimentary machine learning; while this strategy succeeded in reducing systematic errors, it did not correspond to an improvement in statistical correlation. Comparison to previous rounds of the host-guest binding free energy challenge highlights an overall improvement in the correlation obtained by the affinity predictions for OA and TEMOA systems, but a surprising lack of improvement regarding root mean square error over the past several challenge rounds. The data suggests that further refinement of force field parameters, as well as improved treatment of chemical effects (e.g., buffer salt conditions, protonation states), may be required to further enhance predictive accuracy.

The amylase inhibitor montbretin A reveals a new glycosidase inhibition motif.

The complex plant flavonol glycoside montbretin A is a potent (Ki = 8 nM) and specific inhibitor of human pancreatic α-amylase with potential as a therapeutic for diabetes and obesity. Controlled degradation studies on montbretin A, coupled with inhibition analyses, identified an essential high-affinity core structure comprising the myricetin and caffeic acid moieties linked via a disaccharide. X-ray structural analyses of the montbretin A-human α-amylase complex confirmed the importance of this core structure and revealed a novel mode of glycosidase inhibition wherein internal π-stacking interactions between the myricetin and caffeic acid organize their ring hydroxyls for optimal hydrogen bonding to the α-amylase catalytic residues D197 and E233. This novel inhibitory motif can be reproduced in a greatly simplified analog, offering potential for new strategies for glycosidase inhibition and therapeutic development.

Glucose lowering effect of montbretin A in Zucker Diabetic Fatty rats.

Diabetes is an increasingly prevalent disease state with a global impact. It is important that effective and cost-efficient methods be developed to treat this disease state. Zucker diabetic fatty rats, an animal model of type 2 diabetes, were treated with montbretin A (MbA), a selective human pancreatic α-amylase inhibitor, isolated from the corms of the Crocosmia crocosmiiflora plant that may have potential as a glucose-lowering agent. The study purpose was to determine if MbA was an orally effective treatment for diabetes. The effect of MbA was compared to a current clinical treatment modality, acarbose that is associated with gastrointestinal side effects known to affect patient compliance. MbA and acarbose were administered daily in the drinking water. Body weight and fluid intake were measured daily to calculate dose consumption. Plasma glucose levels were determined twice weekly in both the fed and fasted state. At termination samples were collected to assess increased risk of secondary complications related to diabetes and oxidative stress. There was no effect of either MbA or acarbose treatment on insulin levels. Plasma glucose levels were significantly lower following MbA treatment in the ZT group which persisted throughout the study period (day 49: 12.1 ± 1.2 mM). However, while there was an initial decrease in plasma glucose levels in the acarbose-treated fatty group, this effect was not sustained (day 49: 20.6 ± 1.3 mM) through to termination. MbA improved the oxidative status of the fatty diabetic animals as well as attenuated markers for increased risk of cardiovascular complications associated with diabetes. This study demonstrated that, at a lower dose as compared to acarbose (10 mg/kg/day), chronic oral administration of MbA (7.5 mg/kg/day) was an effective glucose-lowering agent in the treatment of type 2 diabetes.

Sustained activation of GABAA receptors in the suprachiasmatic nucleus mediates light-induced phase delays of the circadian clock: a novel function of ionotropic receptors.

The suprachiasmatic nucleus (SCN) contains a circadian clock that generates endogenous rhythmicity and entrains that rhythmicity with the day-night cycle. The neurochemical events that transduce photic input within the SCN and mediate entrainment by resetting the molecular clock have yet to be defined. Because GABA is contained in nearly all SCN neurons we tested the hypothesis that GABA serves as this signal in studies employing Syrian hamsters (Mesocricetus auratus). Activation of GABAA receptors was found to be necessary and sufficient for light to induce phase delays of the clock. Remarkably, the sustained activation of GABAA receptors for more than three consecutive hours was necessary to phase-delay the clock. The duration of GABAA receptor activation required to induce phase delays would not have been predicted by either the prevalent theory of circadian entrainment or by expectations regarding the duration of ionotropic receptor activation necessary to produce functional responses. Taken together, these data identify a novel neurochemical mechanism essential for phase-delaying the 'master' circadian clock within the SCN as well as identifying an unprecedented action of an amino acid neurotransmitter involving the sustained activation of ionotropic receptors.

Prospective population-based cohort of inflammatory bowel disease in the biologics era: Disease course and predictors of severity.

BACKGROUND AND AIM: We have previously found high incidence of inflammatory bowel disease (IBD) in Australia. A population-based registry was established to assess disease severity, frequency of complications, and prognostic factors. METHODS: Incident cases were prospectively identified over 4 years. Early disease severity was assessed according to need for hospitalization and resective surgery and medication use. RESULTS: We report on the early outcomes (median 18 months, range 12-60 months) for 252 patients comprising 146 with Crohn's disease (CD), 96 with ulcerative colitis (UC), and 10 IBD undifferentiated. Eighty-seven percent of CD patients had inflammatory disease at diagnosis, and this reduced to 73% at 5 years (n = 38). Immunomodulators were prescribed in 57% of CD patients and 19% with UC. A third of all CD patients were hospitalized, the majority (77%) in the first 12 months. Risk factors for hospitalization included penetrating, perianal, and ileocolonic disease (P < 0.05). Twenty-four percent of UC patients were hospitalized, most within the first 12 months. Intestinal resection rates were 13% at 1 year in CD and 26% at 5 years. Risk factors include penetrating and stricturing disease (P < 0.001) and ileal involvement (P < 0.05). Colectomy rates in UC were 2% and 13% at 1 and 5 years. High C-reactive protein (CRP) at diagnosis was associated with colectomy. CONCLUSIONS: A high rate of inflammatory disease, frequent immunomodulator use in CD, and a low rate of surgery in both CD and UC were identified. In CD, ileal involvement and complex disease behavior are associated with a more severe disease course, while in UC a high CRP predicted this outcome.

Passive hind-limb cycling improves cardiac function and reduces cardiovascular disease risk in experimental spinal cord injury.

Spinal cord injury (SCI) causes altered autonomic control and severe physical deconditioning that converge to drive maladaptive cardiac remodelling. We used a clinically relevant experimental model to investigate the cardio-metabolic responses to SCI and to establish whether passive hind-limb cycling elicits a cardio-protective effect. Initially, 21 male Wistar rats were evenly assigned to three groups: uninjured control (CON), T3 complete SCI (SCI) or T3 complete SCI plus passive hind-limb cycling (SCI-EX; 2 × 30 min day(-1), 5 days week(-1) for 4 weeks beginning 6 days post-SCI). On day 32, cardio-metabolic function was assessed using in vivo echocardiography, ex vivo working heart assessments, cardiac histology/molecular biology and blood lipid profiles. Twelve additional rats (n = 6 SCI and n = 6 SCI-EX) underwent in vivo echocardiography and basal haemodynamic assessments pre-SCI and at days 7, 14 and 32 post-SCI to track temporal cardiovascular changes. Compared with CON, SCI exhibited a rapid and sustained reduction in left ventricular dimensions and function that ultimately manifested as reduced contractility, increased myocardial collagen deposition and an up-regulation of transforming growth factor beta-1 (TGFß1) and mothers against decapentaplegic homolog 3 (Smad3) mRNA. For SCI-EX, the initial reduction in left ventricular dimensions and function at day 7 post-SCI was completely reversed by day 32 post-SCI, and there were no differences in myocardial contractility between SCI-EX and CON. Collagen deposition was similar between SCI-EX and CON. TGFß1 and Smad3 were down-regulated in SCI-EX. Blood lipid profiles were improved in SCI-EX versus SCI. We provide compelling novel evidence that passive hind-limb cycling prevents cardiac dysfunction and reduces cardiovascular disease risk in experimental SCI.

Selective alpha(1)-adrenoceptor blockade prevents fructose-induced hypertension.

The purpose of this study was to investigate the effect of chronic treatment with prazosin, a selective α1-adrenoceptor antagonist, on the development of hypertension in fructose-fed rats (FFR). High-fructose feeding and treatment with prazosin (1 mg/kg/day via drinking water) were initiated simultaneously in male Wistar rats. Systolic blood pressure, fasted plasma parameters, insulin sensitivity, plasma norepinephrine (NE), uric acid, and angiotensin II (Ang II) were determined following 9 weeks of treatment. FFR exhibited insulin resistance, hyperinsulinemia, hypertriglyceridemia, and hypertension, as well as elevations in plasma NE and Ang II levels. Treatment with prazosin prevented the rise in blood pressure without affecting insulin levels, insulin sensitivity, uric acid, or Ang II levels, while normalizing plasma NE levels in FFR. These data suggest that over-activation of the sympathetic nervous system, specifically α1-adrenoceptors, contributes to the development of fructose-induced hypertension, however, this over-activation does not appear to an initial, precipitating event in FFR.

Positive surgical margins: rate, contributing factors and impact on further treatment: findings from the Prostate Cancer Registry.

OBJECTIVE: To describe the characteristics of patients with and without positive surgical margins (PSMs) and to analyse the impact of PSMs on secondary cancer treatment after radical prostatectomy (RP), with short-term follow-up. PATIENTS AND METHODS: We analysed data from 2385 consecutive patients treated using RP, who were notified to the Prostate Cancer Registry by 37 hospitals in Victoria, Australia between August 2008 and February 2012. Independent and multivariate models were constructed to predict the likelihood of PSMs. Independent and multivariate predictors of secondary treatment after RP in the initial 12 months after diagnosis were also assessed. RESULTS: Data on PSM status were collected for 2219/2385 (93%) patients. In total 592/2175 (27.2%) RPs resulted in PSMs; 102/534 (19.1%) in the low-risk group, 317/1218 (26.0%) in the intermediate-risk group, 153/387 (39.5%) in the high-risk group, and 9/11 (81.8%) in the very-high-risk disease group of patients. Patients having surgery in a hospital where <10 RPs occur each year were significantly more likely to have a PSM (incidence rate ratio [IRR] 1.44, 95% confidence interval [CI] 1.07-1.93) and those in the intermediate-, high- or very-high-risk groups (IRR 1.34, 95% CI 1.09-1.65, P = 0.007, IRR 1.96, 95% CI 1.57-2.45, P < 0.001 and IRR 3.81, 95% CI 2.60-5.60, P < 0.001, respectively) were significantly more likely to have a PSM than those in the low-risk group (IRR 2.50, 95% CI 1.23-5.11, P = 0.012). Patients with PSMs were significantly less likely to have been treated at a private hospital than a public hospital (IRR 0.76, 95% CI 0.63-0.93, P = 0.006) or to have undergone robot-assisted RP (IRR 0.69, 95% CI 0.55-0.87; P = 0.002) than open RP. Of the 2182 patients who underwent RP in the initial 12 months after diagnosis, 1987 (91.1%) received no subsequent treatment, 123 (5.6%) received radiotherapy, 47 (2.1%) received androgen deprivation therapy (ADT) and 23 (1.1%) received a combination of radiotherapy and ADT. Two patients (0.1%) received chemotherapy combined with another treatment. At a multivariate level, predictors of additional treatment after RP in the initial 12 months included having a PSM compared with a negative surgical margin (odds ratio [OR] 5.61, 95% CI 3.82-8.22, P < 0.001); pT3 compared with pT2 disease (OR 4.72, 95% CI 2.69-8.23, P < 0.001); and having high- or very-high-risk disease compared with low-risk disease (OR 4.36, 95% CI 2.24-8.50, P < 0.001 and OR 4.50, 95% CI 1.34-15.17, P = 0.015, respectively). Patient age, hospital location and hospital type were not associated with secondary treatment. Patients undergoing robot-assisted RP were significantly less likely to receive additional treatment than those receiving open RP (OR 0.59, 95% CI 0.39-0.88, P = 0.010). CONCLUSIONS: These data indicate an important association between hospital status and PSMs, with patients who underwent RP in private hospitals less likely than those in public hospitals to have a PSM. Patients treated in lower-volume hospitals were more likely to have a PSM and less likely to receive additional treatment after surgery in the initial 12 months, and robot-assisted RP was associated with fewer PSMs than was open RP in this non-randomized observational study. PSM status and pathological T3 disease are both important and independent predictors of secondary cancer treatment for patients undergoing RP. A robot-assisted RP approach appears to decrease the likelihood of subsequent treatment, when compared with the open approach.

Combined metoprolol and ascorbic acid treatment prevents intrinsic damage to the heart during diabetic cardiomyopathy.

Metabolic disturbances and oxidative stress have been highlighted as potential causative factors for the development of diabetic cardiomyopathy. The ß-blocker metoprolol is known to improve function in the diabetic rat heart and ameliorates the sequelae associated with oxidative stress, without lowering oxidative stress. The antioxidant ascorbic acid is known to improve function in the diabetic rat heart. We tested whether a combination of ascorbic acid and metoprolol treatment would improve function further than each drug individually. Control and streptozotocin-induced diabetic Wistar rats were treated with metoprolol (15 mg·(kg body mass)(-1)·day(-1), via an osmotic pump) and (or) ascorbic acid (1000 mg·(kg body mass)(-1)·day(-1), via their drinking water). To study the effect of treatment on the development of dysfunction, we examined time points before (5 weeks diabetic) and after (7 weeks diabetic) development of overt systolic dysfunction. Echocardiography and working-heart-perfusion were used to assess cardiac function. Blood and tissue samples were collected to assess the severity of disease and oxidative stress. While both drugs improved function, only ascorbic acid had effects on oxidative damage. Combination treatment had a more pronounced improvement in function. Our ß-blocker + antioxidant treatment strategy focused on oxidative stress, not diabetes specifically; therefore, it may prove useful in other diseases where oxidative stress contributes to the pathology.

Climate change: Comparing "green" and "polluting" nation-states.

Some nation-states, i.e., Norway, Sweden, and Denmark, repeatedly score the highest in environmental indicators such as the Environmental Performance Index (EPI) and the Climate Change Performance Index (CCPI). Their cities win environmental awards; they have well-developed recycling systems; they perform well with biodegradable waste; and their citizens show awareness of environmental problems, protesting publicly and even sueing their governing bodies if they don't do the same. For these and other reasons, recent scholarship defined these countries as "exemplary" green nation-states. The question is, which factors pushed them toward the green transition faster than others? And overall, what stops top polluting countries such as China, the United States and Russia from walking the same path? This article attempts to answer these questions by looking at climate change through a theoretical framework based on theories of nationalism and case studies of green nation-states. It compares three of said top polluting countries, China, the United States, and Russia, with "exemplary" green nation-states, and argues that the pace of greener nation-states rests on (1) a tradition of ecologism and environmentalism rooted in the long run, (2) the lock in of "green nationalism," a form of nationalism grounded on sustainability, (3) free and effective environmental movements, (4) inclusivity and welfare, and (5) a sense of national pride in environmental achievements. The available evidence seems to suggest that top polluting nation-states lack one or more of these factors.

Testosterone-dependent increase in blood pressure is mediated by elevated Cyp4A expression in fructose-fed rats.

Endothelial dysfunction and increased blood pressure following insulin resistance play an important role in the development of secondary cardiovascular complications. The presence of testosterone is essential for the development of endothelial dysfunction and increased blood pressure. Testosterone regulates the synthesis of vasoconstrictor eicosanoids such as 20-hydroxyeicosatetranoic acid (20-HETE). In a series of studies, we examined: (1) the role of the androgen receptor in elevating blood pressure and (2) the effects of Cyp4A-catalyzed 20-HETE synthesis on vascular reactivity and blood pressure in fructose-fed rats. In the first study, intact and castrated male rats were made insulin resistant by feeding fructose for 9 weeks following which their superior mesenteric arteries (SMA) were isolated and examined for changes in endothelium-dependent relaxation in the presence and absence of 1-aminobenzotriazole (ABT) and N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS), which are inhibitors of 20-HETE synthesis. In another study, male rats were treated with either ABT or the androgen receptor blocker, flutamide, following which changes in insulin sensitivity, blood pressure, and vascular Cyp4A expression were measured. In the final study, HET0016, which is a more selective inhibitor of 20-HETE synthesis, was used to confirm our earlier findings. Treatment with HET0016 or ABT prevented or ameliorated the increase in blood pressure. Gonadectomy or flutamide prevented the increase in both the Cyp4A and blood pressure. Furthermore, both ABT and DDMS improved relaxation only in the intact fructose-fed rats. Taken together our results suggest that in the presence of testosterone, the Cyp4A/20-HETE system plays a key role in elevating the blood pressure secondary to insulin resistance.

The effects of phentolamine on fructose-fed rats.

Metabolic syndrome (MS) is a combination of medical disorders that increase the risk of developing cardiovascular disease and diabetes. MS is associated with obesity, increased blood pressure, hyperlipidemia, and hyperglycemia. This study was designed to investigate the pharmacological profile of phentolamine, a nonselective α adrenergic receptor antagonist, in the prevention of increased blood pressure in fructose-fed rats. Phentolamine prevented the fructose-induced increase in systolic blood pressure without affecting insulin sensitivity and major metabolic parameters. The levels of plasma noradrenaline and angiotensin II, 2 proposed contributors to the development of fructose-induced elevated blood pressure, were examined. Neither noradrenaline nor angiotensin II levels were affected by phentolamine treatment. Since overproduction of nitric oxide has been shown to lead to an elevation in peroxynitrite, the role of oxidative stress, a proposed mechanism of fructose-induced elevated blood pressure and insulin resistance, was examined by measuring plasma levels of total nitrate/nitrite. Plasma nitrate/nitrite was significantly elevated in all fructose-fed animals, regardless of treatment with phentolamine. Another proposed contributor toward fructose-induced MS is an elevation in uric acid levels. In this experiment, plasma levels of uric acid were found to be increased by dietary fructose and were unaffected by phentolamine treatment.

Changes to publication requirements made at the XVIII International Botanical Congress in Melbourne - what does e-publication mean for you?

Changes to the International Code of Botanical Nomenclature are decided on every 6 years at Nomenclature Sections associated with International Botanical Congresses (IBC). The XVIII IBC was held in Melbourne, Australia; the Nomenclature Section met on 18-22 July 2011 and its decisions were accepted by the Congress at its plenary session on 30 July. Several important changes were made to the Code as a result of this meeting that will affect publication of new names. Two of these changes will come into effect on 1 January 2012, some months before the Melbourne Code is published. Electronic material published online in Portable Document Format (PDF) with an International Standard Serial Number (ISSN) or an International Standard Book Number (ISBN) will constitute effective publication, and the requirement for a Latin description or diagnosis for names of new taxa will be changed to a requirement for a description or diagnosis in either Latin or English. In addition, effective from 1 January 2013, new names of organisms treated as fungi must, in order to be validly published, include in the protologue (everything associated with a name at its valid publication) the citation of an identifier issued by a recognized repository (such as MycoBank). Draft text of the new articles dealing with electronic publication is provided and best practice is outlined. To encourage dissemination of the changes made to the International Code of Nomenclature for algae, fungi, and plants, this article will be published in BMC Evolutionary Biology, Botanical Journal of the Linnean Society, Brittonia, Cladistics, MycoKeys, Mycotaxon, New Phytologist, North American Fungi, Novon, Opuscula Philolichenum, PhytoKeys, Phytoneuron, Phytotaxa, Plant Diversity and Resources, Systematic Botany and Taxon.