4,156 research outputs found
Differences in clinicopathologic variables between Borrelia C6 antigen seroreactive and Borrelia C6 seronegative glomerulopathy in dogs.
BackgroundRapidly progressive glomerulonephritis has been described in dogs that seroreact to Borrelia burgdorferi, but no studies have compared clinicopathologic differences in Lyme-seroreactive dogs with protein-losing nephropathy (PLN) versus dogs with Borrelia-seronegative PLN.Hypothesis/objectivesDogs with Borrelia C6 antigen-seroreactive PLN have distinct clinicopathologic findings when compared to dogs with Borrelia seronegative PLN.AnimalsForty dogs with PLN and Borrelia C6 antigen seroreactivity and 78 C6-seronegative temporally matched dogs with PLN.MethodsRetrospective prevalence case-control study. Clinical information was retrieved from records of dogs examined at the University of California, Davis, Veterinary Medical Teaching Hospital. Histopathologic findings in renal tissue procured by biopsy or necropsy of dogs with PLN were reviewed.ResultsRetrievers and retriever mixes were overrepresented in seroreactive dogs (P < .001). Seroreactive dogs were more likely to have thrombocytopenia (P < .001), azotemia (P = .002), hyperphosphatemia (P < .001), anemia (P < .001), and neutrophilia (P = .003). Hematuria, glucosuria, and pyuria despite negative urine culture were more likely in seroreactive dogs (all P ≤ .002). Histopathologic findings were consistent with immune-complex glomerulonephritis in 16 of 16 case dogs and 7 of 23 control dogs (P = 006). Prevalence of polyarthritis was not different between groups (P = .17).Conclusions and clinical importanceC6 seroreactivity in dogs with PLN is associated with a clinicopathologically distinct syndrome when compared with other types of PLN. Early recognition of this syndrome has the potential to improve outcomes through specific aggressive and early treatment
ZOOM or Non-ZOOM? Assessing spinal cord diffusion tensor imaging protocols for multi-centre studies
The purpose of this study was to develop and evaluate two spinal cord (SC) diffusion tensor imaging (DTI) protocols, implemented at multiple sites (using scanners from two different manufacturers), one available on any clinical scanner, and one using more advanced options currently available in the research setting, and to use an automated processing method for unbiased quantification. DTI parameters are sensitive to changes in the diseased SC. However, imaging the cord can be technically challenging due to various factors including its small size, patient-related and physiological motion, and field inhomogeneities. Rapid acquisition sequences such as Echo Planar Imaging (EPI) are desirable but may suffer from image distortions. We present a multi-centre comparison of two acquisition protocols implemented on scanners from two different vendors (Siemens and Philips), one using a reduced field-of-view (rFOV) EPI sequence, and one only using options available on standard clinical scanners such as outer volume suppression (OVS). Automatic analysis was performed with the Spinal Cord Toolbox for unbiased and reproducible quantification of DTI metrics in the white matter. Images acquired using the rFOV sequence appear less distorted than those acquired using OVS alone. SC DTI parameter values obtained using both sequences at all sites were consistent with previous measurements made at 3T. For the same scanner manufacturer, DTI parameter inter-site SDs were smaller for the rFOV sequence compared to the OVS sequence. The higher inter-site reproducibility (for the same manufacturer and acquisition details, i.e. ZOOM data acquired at the two Philips sites) of rFOV compared to the OVS sequence supports the idea that making research options such as rFOV more widely available would improve accuracy of measurements obtained in multi-centre clinical trials. Future multi-centre studies should also aim to match the rFOV technique and signal-to-noise ratios in all sequences from different manufacturers/sites in order to avoid any bias in measured DTI parameters and ensure similar sensitivity to pathological changes
Trends in all-cause mortality during the scale-up of an antiretroviral therapy programme: a cross-sectional study in Lusaka, Zambia.
OBJECTIVE: To follow the trends in all-cause mortality in Lusaka, Zambia, during the scale-up of a national programme of antiretroviral therapy (ART). METHODS: Between November 2004 and September 2011, we conducted 12 survey rounds as part of a cross-sectional study in Lusaka, with independent sampling in each round. In each survey, we asked the heads of 3600 households to state the number of deaths in their households in the previous 12 months and the number of orphans aged less than 16 years in their households and investigated the heads' knowledge, attitudes and practices related to human immunodeficiency virus (HIV). FINDINGS: The number of deaths we recorded - per 100 person-years - in each survey ranged from 0.92 (95% confidence interval, CI: 0.78-1.09) in September 2011, to 1.94 (95% CI: 1.60-2.35) in March 2007. We found that mortality decreased only modestly each year (mortality rate ratio: 0.98; 95% CI: 0.95-1.00; P = 0.093). The proportion of households with orphans under the age of 16 years decreased from 17% in 2004 to 7% in 2011. The proportions of respondents who had ever been tested for HIV, had a comprehensive knowledge of HIV, knew where to obtain free ART and reported that a non-pregnant household member was receiving ART gradually increased. CONCLUSION: The expansion of ART services in Lusaka was not associated with a reduction in all-cause mortality. Coverage, patient adherence and retention may all have to be increased if ART is to have a robust and lasting impact at population level in Lusaka
Embracing additive manufacture: implications for foot and ankle orthosis design
<p>Abstract</p> <p>Background</p> <p>The design of foot and ankle orthoses is currently limited by the methods used to fabricate the devices, particularly in terms of geometric freedom and potential to include innovative new features. Additive manufacturing (AM) technologies, where objects are constructed via a series of sub-millimetre layers of a substrate material, may present the opportunity to overcome these limitations and allow novel devices to be produced that are highly personalised for the individual, both in terms of fit and functionality.</p> <p>Two novel devices, a foot orthosis (FO) designed to include adjustable elements to relieve pressure at the metatarsal heads, and an ankle foot orthosis (AFO) designed to have adjustable stiffness levels in the sagittal plane, were developed and fabricated using AM. The devices were then tested on a healthy participant to determine if the intended biomechanical modes of action were achieved.</p> <p>Results</p> <p>The adjustable, pressure relieving FO was found to be able to significantly reduce pressure under the targeted metatarsal heads. The AFO was shown to have distinct effects on ankle kinematics which could be varied by adjusting the stiffness level of the device.</p> <p>Conclusions</p> <p>The results presented here demonstrate the potential design freedom made available by AM, and suggest that it may allow novel personalised orthotic devices to be produced which are beyond the current state of the art.</p
Integrity of H1 helix in prion protein revealed by molecular dynamic simulations to be especially vulnerable to changes in the relative orientation of H1 and its S1 flank
In the template-assistance model, normal prion protein (PrPC), the pathogenic
cause of prion diseases such as Creutzfeldt-Jakob (CJD) in human, Bovine
Spongiform Encephalopathy (BSE) in cow, and scrapie in sheep, converts to
infectious prion (PrPSc) through an autocatalytic process triggered by a
transient interaction between PrPC and PrPSc. Conventional studies suggest the
S1-H1-S2 region in PrPC to be the template of S1-S2 -sheet in PrPSc, and
the conformational conversion of PrPC into PrPSc may involve an unfolding of H1
in PrPC and its refolding into the -sheet in PrPSc. Here we conduct a
series of simulation experiments to test the idea of transient interaction of
the template-assistance model. We find that the integrity of H1 in PrPC is
vulnerable to a transient interaction that alters the native dihedral angles at
residue Asn, which connects the S1 flank to H1, but not to interactions
that alter the internal structure of the S1 flank, nor to those that alter the
relative orientation between H1 and the S2 flank.Comment: A major revision on statistical analysis method has been made. The
paper now has 23 pages, 11 figures. This work was presented at 2006 APS March
meeting session K29.0004 at Baltimore, MD, USA 3/13-17, 2006. This paper has
been accepted for pubcliation in European Biophysical Journal on Feb 2, 200
Spectral Line-by-Line Pulse Shaping of an On-Chip Microresonator Frequency Comb
We report, for the first time to the best of our knowledge, spectral phase
characterization and line-by-line pulse shaping of an optical frequency comb
generated by nonlinear wave mixing in a microring resonator. Through
programmable pulse shaping the comb is compressed into a train of
near-transform-limited pulses of \approx 300 fs duration (intensity full width
half maximum) at 595 GHz repetition rate. An additional, simple example of
optical arbitrary waveform generation is presented. The ability to characterize
and then stably compress the frequency comb provides new data on the stability
of the spectral phase and suggests that random relative frequency shifts due to
uncorrelated variations of frequency dependent phase are at or below the 100
microHertz level.Comment: 18 pages, 4 figure
Impact of Scottish smoke-free legislation on smoking quit attempts and prevalence
<p><b>Objectives:</b> In Scotland, legislation was implemented in March 2006 prohibiting smoking in all wholly or partially enclosed public spaces. We investigated the impact on attempts to quit smoking and smoking prevalence.</p>
<p><b>Methods:</b> We performed time series models using Box-Jenkins autoregressive integrated moving averages (ARIMA) on monthly data on the gross ingredient cost of all nicotine replacement therapy (NRT) prescribed in Scotland in 2003–2009, and quarterly data on self-reported smoking prevalence between January 1999 and September 2010 from the Scottish Household Survey.</p>
<p><b>Results:</b> NRT prescription costs were significantly higher than expected over the three months prior to implementation of the legislation. Prescription costs peaked at £1.3 million in March 2006; £292,005.9 (95% CI £260,402.3, £323,609, p<0.001) higher than the monthly norm. Following implementation of the legislation, costs fell exponentially by around 26% per month (95% CI 17%, 35%, p<0.001). Twelve months following implementation, the costs were not significantly different to monthly norms. Smoking prevalence fell by 8.0% overall, from 31.3% in January 1999 to 23.7% in July–September 2010. In the quarter prior to implementation of the legislation, smoking prevalence fell by 1.7% (95% CI 2.4%, 1.0%, p<0.001) more than expected from the underlying trend.</p>
<p><b>Conclusions:</b> Quit attempts increased in the three months leading up to Scotland's smoke-free legislation, resulting in a fall in smoking prevalence. However, neither has been sustained suggesting the need for additional tobacco control measures and ongoing support.</p>
EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013 . Scientific opinion on Dietary Reference Values for fluoride
Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for fluoride, which are provided as Adequate Intake (AI) from all sources, including non-dietary sources. Fluoride is not an essential nutrient. Therefore, no Average Requirement for the performance of essential physiological functions can be defined. Nevertheless, the Panel considered that the setting of an AI is appropriate because of the beneficial effects of dietary fluoride on prevention of dental caries. The AI is based on epidemiological studies (performed before the 1970s) showing an inverse relationship between the fluoride concentration of water and caries prevalence. As the basis for defining the AI, estimates of mean fluoride intakes of children via diet and drinking water with fluoride concentrations at which the caries preventive effect approached its maximum whilst the risk of dental fluorosis approached its minimum were chosen. Except for one confirmatory longitudinal study in US children, more recent studies were not taken into account as they did not provide information on total dietary fluoride intake, were potentially confounded by the use of fluoride-containing dental hygiene products, and did not permit a conclusion to be drawn on a dose-response relationship between fluoride intake and caries risk. The AI of fluoride from all sources (including non-dietary sources) is 0.05 mg/kg body weight per day for both children and adults, including pregnant and lactating women. For pregnant and lactating women, the AI is based on the body weight before pregnancy and lactation. Reliable and representative data on the total fluoride intake of the European population are not available
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