Normohomocysteinaemia and vitamin-treated hyperhomocysteinaemia are associated with similiar risks of cardiovascular events in patients with premature peripheral arterial occlusive disease. A prospective cohort study

Objectives. Mild hyperhomocysteinaemia (HHC), fasting or after methionine loading, is associated with an increased risk and severity of atherosclerotic vascular disease. Post-methionine and fasting HHC are responsive to treatment with vitamin

A more active lifestyle in persons with a recent spinal cord injury benefits physical fitness and health

Study design:A prospective cohort study. Objectives:To study the longitudinal relationship between objectively measured everyday physical activity level, and physical fitness and lipid profile in persons with a recent spinal cord injury (SCI).Setting:A rehabilitation centre in the Netherlands and the participant's home environment. Methods:Data of 30 persons with a recent SCI were collected at the start of active rehabilitation, 3 months later, at discharge from inpatient rehabilitation, and 1 year after discharge. Physical activity level (duration of dynamic activities as % of 24 h) was measured with an accelerometry-based activity monitor. Regarding physical fitness, peak oxygen uptake (VO2peak) and peak power output (POpeak) were determined with a maximal wheelchair exercise test, and upper extremity muscle strength was measured with a handheld dynamometer. Fasting blood samples were taken to determine the lipid profile. Results:An increase in physical activity level was significantly related to an increase in VO2peak and POpeak, and an increase in physical activity level favourably affected the lipid profile. A nonsignificant relation was found with muscle strength. Conclusion:Everyday physical activity seems to have an important role in the fitness and health of persons with a recent SCI. An increase in physical activity level was associated with an increase in physical fitness and with a lower risk of cardiovascular disease.Spinal Cord advance online publication, 6 December 2011; doi:10.1038/sc.2011.152

Comparison of spontaneous with controlled mode of ventilation in tonsillectomy

Methods: This randomized study compares spontaneous versus controlled ventilation in 60 ASA I and II patients undergoing tonsillectomy as regards haemodynamic stability, recovery characteristics, intra- and immediate postoperative complications and surgical impressions.Results: The patients in the balanced anaesthesia (B) group showed less haemodynamic variability compared to baseline after tracheal intubation, mouth gag application and removal and incision. Two patients had dysrhythmias in the B group compared to six in the spontaneous breathing (S) group. Six patients in the S group had a rise in endtidal carbon dioxide concentration above 7.8 kPa (60 mmHg). Recovery scores were higher in the B group at 10 and 20 min into recovery. The surgical impression of bleeding and jaw relaxation was similar with both groups. The incidence of postoperative nausea and vomiting and agitation was higher in the S group but did not achieve statistical significance.CONCLUSION: Use of balanced anaesthesia offered more haemodynamic stability and a rapid recovery

Processing methods for photoacoustic Doppler flowmetry with a clinical ultrasound scanner

Photoacoustic flowmetry (PAF) based on time-domain cross correlation of photoacoustic signals is a promising technique for deep tissue measurement of blood flow velocity. Signal processing has previously been developed for single element transducers. Here, the processing methods for acoustic resolution PAF using a clinical ultrasound transducer array are developed and validated using a 64-element transducer array with a -6 dB detection band of 11 to 17 MHz. Measurements were performed on a flow phantom consisting of a tube (580  μm inner diameter) perfused with human blood flowing at physiological speeds ranging from 3 to 25  mm  /  s. The processing pipeline comprised: image reconstruction, filtering, displacement detection, and masking. High-pass filtering and background subtraction were found to be key preprocessing steps to enable accurate flow velocity estimates, which were calculated using a cross-correlation based method. In addition, the regions of interest in the calculated velocity maps were defined using a masking approach based on the amplitude of the cross-correlation functions. These developments enabled blood flow measurements using a transducer array, bringing PAF one step closer to clinical applicability

Acoustic resolution photoacoustic Doppler flowmetry using a transducer array: optimising processing for velocity contrast

This work demonstrates the first measurements of blood flow velocity using photoacoustic flowmetry (PAF) employing a transducer array. The measurements were made in a flow phantom consisting of a tube (580 μm inner diameter) containing blood flowing steadily at physiological speeds ranging from 3 mm/s to 25 mm/s. Velocity measurements were based on the generation of two successive photoacoustic (PA) signals using two laser pulses with a wavelength of 1064 nm; the PA signals were detected using a 64-element transducer array with a -6 dB detection bandwidth of 11-17 MHz. We developed a processing pipeline to optimise a cross-correlation based velocity measurement method comprising the following processing steps: image reconstruction, filtering, displacement detection, and masking. We found no difference in flow detection accuracy when choosing different image reconstruction algorithms (time reversal, Fourier transformation, and delay-and-sum). High-pass filtering and wallfiltering were however found to be essential pre-processing steps in order to recover the correct displacement information. We masked the calculated velocity map based on the amplitude of the cross-correlation function in order to define the region of interest corresponding to highest signal amplitude. These developments enabled blood flow measurements using a transducer array, bringing PAF one step closer to clinical applicability

The cost-effectiveness of increasing alcohol taxes: a modelling study

<p>Abstract</p> <p>Background</p> <p>Excessive alcohol use increases risks of chronic diseases such as coronary heart disease and several types of cancer, with associated losses of quality of life and life-years. Alcohol taxes can be considered as a public health instrument as they are known to be able to decrease alcohol consumption. In this paper, we estimate the cost-effectiveness of an alcohol tax increase for the entire Dutch population from a health-care perspective focusing on health benefits and health-care costs in alcohol users.</p> <p>Methods</p> <p>The chronic disease model of the National Institute for Public Health and the Environment was used to extrapolate from decreased alcohol consumption due to tax increases to effects on health-care costs, life-years gained and quality-adjusted life-years gained, A Dutch scenario in which tax increases for beer are planned, and a Swedish scenario representing one of the highest alcohol taxes in Europe, were compared with current practice in the Netherlands. To estimate cost-effectiveness ratios, yearly differences in model outcomes between intervention and current practice scenarios were discounted and added over the time horizon of 100 years to find net present values for incremental life-years gained, quality-adjusted life-years gained, and health-care costs.</p> <p>Results</p> <p>In the Swedish scenario, many more quality-adjusted life-years were gained than in the Dutch scenario, but both scenarios had almost equal incremental cost-effectiveness ratios: €5100 per quality-adjusted life-year and €5300 per quality-adjusted life-year, respectively.</p> <p>Conclusion</p> <p>Focusing on health-care costs and health consequences for drinkers, an alcohol tax increase is a cost-effective policy instrument.</p

Multi-Timescale Perceptual History Resolves Visual Ambiguity

When visual input is inconclusive, does previous experience aid the visual system in attaining an accurate perceptual interpretation? Prolonged viewing of a visually ambiguous stimulus causes perception to alternate between conflicting interpretations. When viewed intermittently, however, ambiguous stimuli tend to evoke the same percept on many consecutive presentations. This perceptual stabilization has been suggested to reflect persistence of the most recent percept throughout the blank that separates two presentations. Here we show that the memory trace that causes stabilization reflects not just the latest percept, but perception during a much longer period. That is, the choice between competing percepts at stimulus reappearance is determined by an elaborate history of prior perception. Specifically, we demonstrate a seconds-long influence of the latest percept, as well as a more persistent influence based on the relative proportion of dominance during a preceding period of at least one minute. In case short-term perceptual history and long-term perceptual history are opposed (because perception has recently switched after prolonged stabilization), the long-term influence recovers after the effect of the latest percept has worn off, indicating independence between time scales. We accommodate these results by adding two positive adaptation terms, one with a short time constant and one with a long time constant, to a standard model of perceptual switching

Models for Prediction of Factor VIII Half-Life in Severe Haemophiliacs: Distinct Approaches for Blood Group O and Non-O Patients

BACKGROUND: Von Willebrand factor (VWF) is critical for the in vivo survival of factor VIII (FVIII). Since FVIII half-life correlates with VWF-antigen pre-infusion levels, we hypothesized that VWF levels are useful to predict FVIII half-life. METHODOLOGY: Standardized half-life studies and analysis of pre-infusion VWF and VWF-propeptide levels were performed in a cohort of 38 patients with severe haemophilia A (FVIII <1 IU/ml), aged 15-44 years. Nineteen patients had blood-group O. Using multivariate linear regression-analysis (MVLR-analysis), the association of VWF-antigen, VWF-propeptide, age and body-weight with FVIII half-life was evaluated. PRINCIPAL FINDINGS: FVIII half-life was shorter in blood-group O-patients compared to non-O-patients (11.5+/-2.6 h versus 14.3+/-3.0 h; p = 0.004). VWF-antigen levels correlated with FVIII half-life considerably better in patients with blood-group non-O than O (Pearson-rank = 0.70 and 0.47, respectively). Separate prediction models evolved from MVLR-analysis for blood-group O and non-O patients, based on VWF-antigen and VWF/propeptide ratio. Predicted half-lives deviated less than 3 h of observed half-life in 34/38 patients (89%) or less than 20% in 31/38 patients (82%). CONCLUSION: Our approach may identify patients with shorter FVIII half-lives, and adapt treatment protocols when half-life studies are unavailable. In addition, our data indicate that survival of FVIII is determined by survival of endogenous VWF rather than VWF levels per se