10,953 research outputs found

    The Plant-Derived Chalcone 2,2',5'-Trihydroxychalcone Provides Neuroprotection against Toll-Like Receptor 4 Triggered Inflammation in Microglia

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    Chalcones are plant metabolites with potential for therapeutic exploitation as antioxidant, anti-inflammatory, and antiproliferative agents. Here we explored the neuroprotective effects of 2,2',5'-trihydroxychalcone (225THC), a potent antioxidant with radical-scavenging properties. 225THC was found to be a potent inhibitor of apoptosis in stimulated primary rat neuronal cultures. This was likely mediated by an anti-inflammatory effect on microglial cells since 225THC inhibited LPS-stimulated TNF-Ī± and IL-6 secretion from primary rat microglia and modulated the cytokine/chemokine profile of BV2 microglial cells. Additionally, 225THC inhibited LPS-evoked inducible nitric oxide synthase expression but did not influence endogenous superoxide generation. Microglial flow cytometric analyses indicated the 225THC treatment induced a shift from an M1-like phenotype to a more downregulated microglial profile. Taken together these data suggest that the chalcone 2,2',5'-trihydroxychalcone can modulate neuroinflammatory activation in brain-derived microglia and holds promise as a therapeutic in neuroinflammatory conditions

    The Underestimation Of Egocentric Distance: Evidence From Frontal Matching Tasks

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    There is controversy over the existence, nature, and cause of error in egocentric distance judgments. One proposal is that the systematic biases often found in explicit judgments of egocentric distance along the ground may be related to recently observed biases in the perceived declination of gaze (Durgin & Li, Attention, Perception, & Psychophysics, in press), To measure perceived egocentric distance nonverbally, observers in a field were asked to position themselves so that their distance from one of two experimenters was equal to the frontal distance between the experimenters. Observers placed themselves too far away, consistent with egocentric distance underestimation. A similar experiment was conducted with vertical frontal extents. Both experiments were replicated in panoramic virtual reality. Perceived egocentric distance was quantitatively consistent with angular bias in perceived gaze declination (1.5 gain). Finally, an exocentric distance-matching task was contrasted with a variant of the egocentric matching task. The egocentric matching data approximate a constant compression of perceived egocentric distance with a power function exponent of nearly 1; exocentric matches had an exponent of about 0.67. The divergent pattern between egocentric and exocentric matches suggests that they depend on different visual cues

    Regional and temporal changes in AIDS in Europe before HAART

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    In a prospective observational study 4485 patients from 46 clinical centres in 17 European countries were followed between April 1994 and November 1996. Information on AIDS-defining events (ADEs) were collected together with basic demographic data, treatment history and laboratory results. The centres were divided into four geographical regions (north, central, south-west and south-east) so that it was possible to identify any existing regional differences in ADEs. The regional differences that we observed included a higher risk of all forms of Mycobacterium tuberculosis infections (Tb) and wasting disease in the south-west and an increased risk of infections with the Mycobacterium avium complex (MAC) in the north. In Cox multivariable analyses, where north was used as the reference group, we observed hazard ratios of 6.87, 7.77, 2.29 and 0.16 (P < 0.05 in all cases) for pulmonary Tb, extrapulmonary Tb, wasting disease and MAC respectively in the south-west. Pneumocystis carinii pneumonia (PCP) was less commonly diagnosed in the central region (RH = 0.51, 95% CI 0.32-0.79, P = 0.003) and most common in the south-east (RH = 1.04, 95% CI 0.71-1.51, P = 0.85). Comparisons with a similar 'AIDS in Europe' study that concentrated on the early phase of the epidemic reveal that most of the regional differences that were observed in the 1980s still persist in the mid-1990s

    Evaluating the impact of trigeminal neuralgia

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    Patients with idiopathic trigeminal neuralgia (TN) were categorised into 3 subtypes (n 5 225). Group 1 (n 5 155, 68.9%) had TN without concomitant pain, group 2 (n532, 14.2%) had TN with intermittent concomitant pain, and group 3 (n539, 16.9%) had TN with autonomic symptoms. We tested 2 hypotheses: (1) that different pain profiles would be associated with the different groups; (2) that the severe pain associated with TN would impact negatively on activities of daily living and thereby result in disability as defined by the World Health Organisation. A different pain profile was found across the groups. We obtained unequivocal evidence that TN causes disability with up to 45% of patients being absent from usual daily activities 15 days or more in the past 6 months. On the Hospital Anxiety and Depression Scale, 35.7% patients had mild-to-severe depression and over 50% were anxious. The Pain Catastrophizing Scale showed that 78% of patients had considerable negative thoughts with scores.20 and a mean score of 36.4. Prior to referral, only 54% had been prescribed carbamazepine while opioids had been prescribed in 14.6% of the patients. Prior to referral, over 80% had already been to 1 specialist centre which had not provided appropriate management. Patients with TN report varied characteristics but all result in some degree of psychosocial disability especially before adequate therapy is attained

    A degradatory fate for CCR4 suggests a primary role in Th2 inflammation.

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    CCR4 is the sole receptor for the chemokines CCL22 and CCL17. Clinical studies of asthmatic airways have shown levels of both ligands and CCR4+ Th2 cells to be elevated, suggestive of a role in disease. Consequently, CCR4 has aroused much interest as a potential therapeutic target and an understanding of how its cell surface expression is regulated is highly desirable. To this end, receptor expression, receptor endocytosis, and chemotaxis were assessed using transfectants expressing CCR4, CCR4+ human T cell lines, and human Th2 cells polarized in vitro. CCL17 and CCL22 drove rapid endocytosis of CCR4 in a dose-dependent manner. Replenishment at the cell surface was slow and sensitive to cycloheximide, suggestive of de novo synthesis of CCR4. Constitutive CCR4 endocytosis was also observed, with the internalized CCR4 found to be significantly degraded over a 6-h incubation. Truncation of the CCR4 C-terminus by 40 amino acids had no effect on cell surface expression, but resulted in significant impairment of ligand-induced endocytosis. Consequently, migration to both CCL17 and CCL22 was significantly enhanced. In contrast, truncation of CCR4 did not impair constitutive endocytosis or degradation, suggesting the use of alternative receptor motifs in these processes. We conclude that CCR4 cell surface levels are tightly regulated, with a degradative fate for endocytosed receptor. We postulate that this strict control is desirable, given that Th2 cells recruited by CCR4 can induce the further expression of CCR4 ligands in a positive feedback loop, thereby enhancing allergic inflammation

    The use of conservation biomass feedstocks as potential bioenergy resources in the United Kingdom

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    A number of countries have introduced energy policies to reduce the emission of carbon dioxide which, in the case of bio-heat, has resulted in increased use of small wood burning stoves and boilers, particularly in Europe. There are issues surrounding the supply of sustainable wood feedstock, prompting a desire to utilise local biomass resources. This includes biomass generated through the management of natural woodlands in nature reserves and conservation areas. These management practices can also extend to other areas, such as raised bog wildernesses and estuary Reed beds. We term the biomass from this resource as conservation biomass. This study is concerned with the viability of this resource as a fuel within the United Kingdom, and combustion tests were carried out using a small domestic stove. It was concluded that there is as much as 500 kt yāˆ’1 that could be used in this way

    Acute hospital-based services used by adults during the last year of life in New South Wales, Australia: A population-based retrospective cohort study

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    Ā© 2015 Goldsbury et al. Background: There is limited information about health care utilisation at the end of life for people in Australia. We describe acute hospital-based services utilisation during the last year of life for all adults (aged 18+ years) who died in a 12-month period in Australia's most populous state, New South Wales (NSW). Methods: Linked administrative health data were analysed for all adults who died in NSW in 2007 (the most recent year for which cause of death information was available for linkage for this study). The data comprised linked death records (2007), hospital admissions and emergency department (ED) presentations (2006-2007) and cancer registrations (1994-2007). Measures of hospital-based service utilisation during the last year of life included: number and length of hospital episodes, ED presentations, admission to an intensive care unit (ICU), palliative-related admissions and place of death. Factors associated with these measures were examined using multivariable logistic regression. Results: Of the 45,749 adult decedents, 82 % were admitted to hospital during their last year of life: 24 % had >3 care episodes (median 2); 35 % stayed a total of >30 days in hospital (median 17); 42 % were admitted to 2 or more different hospitals. Twelve percent of decedents spent time in an ICU with median 3 days. In the metropolitan area, 80 % of decedents presented to an ED and 18 % had >3 presentations. Overall 55 % died in a hospital or inpatient hospice. Although we could not quantify the extent and type of palliative care, 24 % had mention of "palliative care" in their records. The very elderly and those dying from diseases of the circulatory system or living in the least disadvantaged areas generally had lower hospital service use. Conclusions: These population-wide health data collections give a highly informative description of NSWhospital-based end-of-life service utilisation. Use of hospital-based services during the last year of life was common, with substantial variation across sociodemographic groups, especially defined by age, cause of death and socioeconomic classification of the decedents' place of residence. Further research is now needed to identify the contributors to these findings. Gaps in data collection were identified - particularly for palliative care and patient-reported outcomes. Addressing these gaps should facilitate improved monitoring and assessment of service use and care

    Photoluminescence and cathodoluminescence studies of diatoms - natureā€™s own nano-porous silica structures.

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    Photoluminescence (PL) and cathodoluminescence (CL) data are presented for the silica frustules of some fresh water diatoms. The diatom frustules consist of a nano-porous silica structure that may possibly be exploited for optoelectronic or photonic applications. This work represents what we believe to be the first report of the CL and PL properties of this naturally occurring source of nano-porous silica.Australian and New Zealand Institutes of Physic
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