164 research outputs found
Free serum haemoglobin is associated with brain atrophy in secondary progressive multiple sclerosis.
Background A major cause of disability in secondary progressive multiple sclerosis (SPMS) is progressive brain atrophy, whose pathogenesis is not fully understood. The objective of this study was to identify protein biomarkers of brain atrophy in SPMS. Methods We used surface-enhanced laser desorption-ionization time-of-flight mass spectrometry to carry out an unbiased search for serum proteins whose concentration correlated with the rate of brain atrophy, measured by serial MRI scans over a 2-year period in a well-characterized cohort of 140 patients with SPMS. Protein species were identified by liquid chromatography-electrospray ionization tandem mass spectrometry. Results There was a significant (p<0.004) correlation between the rate of brain atrophy and a rise in the concentration of proteins at 15.1 kDa and 15.9 kDa in the serum. Tandem mass spectrometry identified these proteins as alpha-haemoglobin and beta-haemoglobin, respectively. The abnormal concentration of free serum haemoglobin was confirmed by ELISA (p<0.001). The serum lactate dehydrogenase activity was also highly significantly raised (p<10-12) in patients with secondary progressive multiple sclerosis. Conclusions An underlying low-grade chronic intravascular haemolysis is a potential source of the iron whose deposition along blood vessels in multiple sclerosis plaques contributes to the neurodegeneration and consequent brain atrophy seen in progressive disease. Chelators of free serum iron will be ineffective in preventing this neurodegeneration, because the iron (Fe2+) is chelated by haemoglobin
The significance and expectations of HIV cure research among people living with HIV in Australia.
Most people living with HIV (PLHIV) with reliable access to antiretroviral treatment (ART) have a life expectancy similar to uninfected populations. Despite this, HIV can negatively affect their social and psychological wellbeing. This study aimed to enhance understanding of the expectations PLHIV hold for HIV cure research and the implications this has for HIV cure research trials. We interviewed 20 Australian PLHIV about their expectations for HIV cure research outcomes and the impact a potential cure for HIV may have on their everyday lives. Data were analysed thematically, using both inductive and deductive approaches. The significance of a cure for HIV was expressed by participants as something that would offer relief from their sense of vigilance or uncertainty about their health into the future. A cure was also defined in social terms, as alleviation from worry about potential for onward HIV transmission, concerns for friends and family, and the negative impact of HIV-related stigma. Participants did not consider sustained medication-free viral suppression (or remission) as a cure for HIV because this did not offer certainty in remaining virus free in a way that would alleviate these fears and concerns. A cure was seen as complete elimination of HIV from the body. There is an ethical need to consider the expectations of PLHIV in design of, and recruitment for, HIV cure-related research. The language used to describe HIV cure research should differentiate the long-term aspiration of achieving complete elimination of HIV from the body and possible shorter-term therapeutic advances, such as achieving medication free viral suppression
SUPPORT Tools for evidence-informed health Policymaking (STP) 5: Using research evidence to frame options to address a problem
This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers
SUPPORT Tools for evidence-informed health Policymaking (STP) 7: Finding systematic reviews
This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers
Thermonuclear Stability of Material Accreting onto a Neutron Star
We present a global linear stability analysis of nuclear fuel accumulating on
the surface of an accreting neutron star and we identify the conditions under
which thermonuclear bursts are triggered. The analysis reproduces all the
recognized regimes of hydrogen and helium bursts, and in addition shows that at
high accretion rates, near the limit of stable burning, there is a regime of
``delayed mixed bursts'' which is distinct from the more usual ``prompt mixed
bursts.'' In delayed mixed bursts, a large fraction of the fuel is burned
stably before the burst is triggered. Bursts thus have longer recurrence times,
but at the same time have somewhat smaller fluences. Therefore, the parameter
alpha, which measures the ratio of the energy released via accretion to that
generated through nuclear reactions in the burst, is up to an order of
magnitude larger than for prompt bursts. This increase in alpha near the
threshold of stable burning has been seen in observations. We explore a wide
range of mass accretion rates, neutron star radii and core temperatures, and
calculate a variety of burst properties. From a preliminary comparison with
data, we suggest that bursting neutron stars may have hot cores, with T_{core}
>~ 10^{7.5} K, consistent with interior cooling via the modified URCA or
similar low-efficiency process, rather than T_{core} ~ 10^7 K, as expected for
the direct URCA process. There is also an indication that neutron star radii
are somewhat small <~ 10 km. Both of these conclusions need to be confirmed by
comparing more careful calculations with better data.Comment: 67 pages, 19 figures, final version to appear in The Astrophysical
Journal, vol. 599, no. 1, Dec. 10, 200
The Diabetes Manual trial protocol – a cluster randomized controlled trial of a self-management intervention for type 2 diabetes [ISRCTN06315411]
Background
The Diabetes Manual is a type 2 diabetes self-management programme based upon the clinically effective 'Heart Manual'. The 12 week programme is a complex intervention theoretically underpinned by self-efficacy theory. It is a one to one intervention meeting United Kingdom requirements for structured diabetes-education and is delivered within routine primary care.
Methods/design
In a two-group cluster randomized controlled trial, GP practices are allocated by computer minimisation to an intervention group or a six-month deferred intervention group. We aim to recruit 250 participants from 50 practices across central England. Eligibility criteria are adults able to undertake the programme with type 2 diabetes, not taking insulin, with HbA1c over 8% (first 12 months) and following an agreed protocol change over 7% (months 13 to 18). Following randomisation, intervention nurses receive two-day training and delivered the Diabetes Manual programme to participants. Deferred intervention nurses receive the training following six-month follow-up. Primary outcome is HbA1c with total and HDL cholesterol; blood pressure, body mass index; self-efficacy and quality of life as additional outcomes. Primary analysis is between-group HbA1c differences at 6 months powered to give 80% power to detect a difference in HbA1c of 0.6%. A 12 month cohort analysis will assess maintenance of effect and assess relationship between self-efficacy and outcomes, and a qualitative study is running alongside.
Discussion
This trial incorporates educational and psychological diabetes interventions into a single programme and assesses both clinical and psychosocial outcomes. The trial will increase our understanding of intervention transferability between conditions, those diabetes related health behaviours that are more or less susceptible to change through efficacy enhancing mechanisms and how this impacts on clinical outcomes
Variations of Surveillance Practice for Patients with Bone Sarcoma: A Survey of Australian Sarcoma Clinicians
Advancing the field of health systems research synthesis.
Those planning, managing and working in health systems worldwide routinely need to make decisions regarding strategies to improve health care and promote equity. Systematic reviews of different kinds can be of great help to these decision-makers, providing actionable evidence at every step in the decision-making process. Although there is growing recognition of the importance of systematic reviews to inform both policy decisions and produce guidance for health systems, a number of important methodological and evidence uptake challenges remain and better coordination of existing initiatives is needed. The Alliance for Health Policy and Systems Research, housed within the World Health Organization, convened an Advisory Group on Health Systems Research (HSR) Synthesis to bring together different stakeholders interested in HSR synthesis and its use in decision-making processes. We describe the rationale of the Advisory Group and the six areas of its work and reflects on its role in advancing the field of HSR synthesis. We argue in favour of greater cross-institutional collaborations, as well as capacity strengthening in low- and middle-income countries, to advance the science and practice of health systems research synthesis. We advocate for the integration of quasi-experimental study designs in reviews of effectiveness of health systems intervention and reforms. The Advisory Group also recommends adopting priority-setting approaches for HSR synthesis and increasing the use of findings from systematic reviews in health policy and decision-making
The Significance of Hair for Face Recognition
Hair is a feature of the head that frequently changes in different situations. For this reason much research in the area of face perception has employed stimuli without hair. To investigate the effect of the presence of hair we used faces with and without hair in a recognition task. Participants took part in trials in which the state of the hair either remained consistent (Same) or switched between learning and test (Switch). It was found that in the Same trials performance did not differ for stimuli presented with and without hair. This implies that there is sufficient information in the internal features of the face for optimal performance in this task. It was also found that performance in the Switch trials was substantially lower than in the Same trials. This drop in accuracy when the stimuli were switched suggests that faces are represented in a holistic manner and that manipulation of the hair causes disruption to this, with implications for the interpretation of some previous studies
Phylogeography of Recently Emerged DENV-2 in Southern Viet Nam
Revealing the dispersal of dengue viruses (DENV) in time and space is central to understanding their epidemiology. However, the processes that shape DENV transmission patterns at the scale of local populations are not well understood, particularly the impact of such factors as human population movement and urbanization. Herein, we investigated trends in the spatial dynamics of DENV-2 transmission in the highly endemic setting of southern Viet Nam. Through a phylogeographic analysis of 168 full-length DENV-2 genome sequences obtained from hospitalized dengue cases from 10 provinces in southern Viet Nam, we reveal substantial genetic diversity in both urban and rural areas, with multiple lineages identified in individual provinces within a single season, and indicative of frequent viral migration among communities. Focusing on the recently introduced Asian I genotype, we observed particularly high rates of viral exchange between adjacent geographic areas, and between Ho Chi Minh City, the primary urban center of this region, and populations across southern Viet Nam. Within Ho Chi Minh City, patterns of DENV movement appear consistent with a gravity model of virus dispersal, with viruses traveling across a gradient of population density. Overall, our analysis suggests that Ho Chi Minh City may act as a source population for the dispersal of DENV across southern Viet Nam, and provides further evidence that urban areas of Southeast Asia play a primary role in DENV transmission. However, these data also indicate that more rural areas are also capable of maintaining virus populations and hence fueling DENV evolution over multiple seasons
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