784 research outputs found
Archaeological Excavation and Earthwork Survey in the Butterfly Garden, Castle Moat and Water Meadow, Berkeley Castle, Gloucestershire, 2005
No full textReport on Archaeological Excavations and Earthwork Survey in the Butterfly Garden, Castle Moat and Water Meadow, Berkeley Castle, Gloucestershire, 200
Renal function, plasma homocysteine and carotid atherosclerosis in elderly people
No full textAlthough epidemiological studies suggest that people with minor impairment of renal function are at higher risk of stroke and coronary heart disease, the mechanisms underlying this relation are unclear. One explanation may lie with observations that deterioration in renal function is accompanied by elevations in plasma homocysteine concentrations. There is evidence that moderate hyperhomocysteinemia may play a causal role in atherosclerotic disease. We investigated the relations between renal function, plasma homocysteine and atherosclerosis of the carotid arteries in 128 men and women aged 69–74 years. Renal function was assessed by creatinine clearance and serum creatinine. Duplex ultrasonography was used to quantify the degree of stenosis in the extracranial carotid arteries. Severity of carotid atherosclerosis was greatest in men and women with the poorest renal function, whether measured by creatinine clearance or serum creatinine. After adjustment for plasma homocysteine, pulse pressure and other cardiovascular risk factors, the odds ratio for having carotid stenosis >30% was 4.3 (95% CI 1.4–12.9) in those whose creatinine clearance rate was 55 ml/min or less compared with those whose creatinine clearance rate was >73 ml/min. Even small decrements in renal function were associated with increased risk; people whose creatinine clearance rate was between 56 and 73 ml/min had an odds ratio of 3.8 (95% CI 1.2–11.9). Plasma homocysteine concentrations were significantly higher in people with poorer renal function, but they did not explain the associations we found between carotid atherosclerosis and creatinine clearance or serum creatinine
Malawi: History, culture, and geography of music
No full textThe contribution presents a survey of the music traditions documented in Malawi since the second half of the last Century. It is based both on updated international bibliography and the moat recent fieldwork by the author
Cost-utility of transcatheter aortic valve implantation for inoperable patients with severe aortic stenosis treated by medical management: a UK cost-utility analysis based on patient-level data from the ADVANCE study.
No full textOBJECTIVE: To use patient-level data from the ADVANCE study to evaluate the cost-effectiveness of transcatheter aortic valve implantation (TAVI) compared to medical management (MM) in patients with severe aortic stenosis from the perspective of the UK NHS.
METHODS: A published decision-analytic model was adapted to include information on TAVI from the ADVANCE study. Patient-level data informed the choice as well as the form of mathematical functions that were used to model all-cause mortality, health-related quality of life and hospitalisations. TAVI-related resource use protocols were based on the ADVANCE study. MM was modelled on publicly available information from the PARTNER-B study. The outcome measures were incremental cost-effectiveness ratios (ICERs) estimated at a range of time horizons with benefits expressed as quality-adjusted life-years (QALY). Extensive sensitivity/subgroup analyses were undertaken to explore the impact of uncertainty in key clinical areas.
RESULTS: Using a 5-year time horizon, the ICER for the comparison of all ADVANCE to all PARTNER-B patients was £13 943 per QALY gained. For the subset of ADVANCE patients classified as high risk (Logistic EuroSCORE >20%) the ICER was £17 718 per QALY gained). The ICER was below £30 000 per QALY gained in all sensitivity analyses relating to choice of MM data source and alternative modelling approaches for key parameters. When the time horizon was extended to 10 years, all ICERs generated in all analyses were below £20 000 per QALY gained.
CONCLUSION: TAVI is highly likely to be a cost-effective treatment for patients with severe aortic stenosis
J Inherit Metab Dis
No full textAnalysis of blood phenylalanine is central to the monitoring of patients with phenylketonuria (PKU) and age-related phenylalanine target treatment-ranges (0-12\u2009years; 120-360\u2009\u3bcmol/L, and\u2009>12\u2009years; 120-600\u2009\u3bcmol/L) are recommended in order to prevent adverse neurological outcomes. These target treatment-ranges are based upon plasma phenylalanine concentrations. However, patients are routinely monitored using dried bloodspot (DBS) specimens due to the convenience of collection. Significant differences exist between phenylalanine concentrations in plasma and DBS, with phenylalanine concentrations in DBS specimens analyzed by flow-injection analysis tandem mass spectrometry reported to be 18% to 28% lower than paired plasma concentrations analyzed using ion-exchange chromatography. DBS specimens with phenylalanine concentrations of 360 and 600\u2009\u3bcmol/L, at the critical upper-target treatment-range thresholds would be plasma equivalents of 461 and 768\u2009\u3bcmol/L, respectively, when a reported difference of 28% is taken into account. Furthermore, analytical test imprecision and bias in conjunction with pre-analytical factors such as volume and quality of blood applied to filter paper collection devices to produce DBS specimens affect the final test results. Reporting of inaccurate patient results when comparing DBS results to target treatment-ranges based on plasma concentrations, together with inter-laboratory imprecision could have a significant impact on patient management resulting in inappropriate dietary change and potentially adverse patient outcomes. This review is intended to provide perspective on the issues related to the measurement of phenylalanine in blood specimens and to provide direction for the future needs of PKU patients to ensure reliable monitoring of metabolic control using the target treatment-ranges.CC999999/ImCDC/Intramural CDC HHSUnited States
Impact of alternative metrics on estimates of extent of occurrence for extinction risk assessment
No full textIn International Union for Conservation of Nature (IUCN) Red List assessments, extent of occurrence (EOO) is a key measure of extinction risk. However, the way assessors estimate EOO from maps of species’ distributions is inconsistent among assessments of different species and among major taxonomic groups. Assessors often estimate EOO from the area of mapped distribution, but these maps often exclude areas that are not habitat in idiosyncratic ways and are not created at the same spatial resolutions. We assessed the impact on extinction risk categories of applying different methods (minimum convex polygon, alpha hull) for estimating EOO for 21,763 species of mammals, birds, and amphibians. Overall, the percentage of threatened species requiring down listing to a lower category of threat (taking into account other Red List criteria under which they qualified) spanned 11–13% for all species combined (14–15% for mammals, 7–8% for birds, and 12–15% for amphibians). These down listings resulted from larger estimates of EOO and depended on the EOO calculation method. Using birds as an example, we found that 14% of threatened and near threatened species could require down listing based on the minimum convex polygon (MCP) approach, an approach that is now recommended by IUCN. Other metrics (such as alpha hull) had marginally smaller impacts. Our results suggest that uniformly applying the MCP approach may lead to a one-time down listing of hundreds of species but ultimately ensure consistency across assessments and realign the calculation of EOO with the theoretical basis on which the metric was founded
Defining dried blood spot diameter: implications for measurement and specimen rejection rates
No full textObjectives: Dried blood spot (DBS) specimen acceptance guidelines recommend rejecting specimens based on DBS size, often expressed as a diameter. Computer vision methods can estimate DBS size from images obtained from standalone equipment, smartphone cameras or existing laboratory instrumentation. However, no consensus definition of DBS diameter exists. We assessed how different DBS diameter definitions affect measurement and specimen rejection rates. Methods: We compared computer vision estimates of DBS diameter on 1,991 DBS using two different calculation methods and on 22 DBS where paired images were taken from either side of the filter paper. We modelled the impact on specimen rejection rate in >163,000 DBS specimens. Results: Two different calculation methods for DBS diameter showed a mean difference <0.1 mm for circular DBS. Greater variability was observed for incorrectly applied DBS with a mean (standard deviation) difference of 0.29 (0.41) mm. DBS diameter measured from the front of the filter paper was approximately 0.41 (0.25) mm larger than from the back of the filter paper. Changing the DBS diameter definition could more than double the number of insufficient DBS (<8 mm), potentially leading to 4,000 additional repeat collections annually in the UK newborn screening programme. Conclusions: DBS diameter definition can have a small but important and easily avoidable impact on measurement, impacting specimen rejection rates. We recommend that DBS diameter is defined as the diameter of a circle with equal area to the DBS, when measured from the opposite side of the filter paper to blood application
A computer vision approach to the assessment of dried blood spot size and quality in newborn screening
No full textBackground
Dried blood spot (DBS) size and quality affect newborn screening (NBS) test results. Visual assessment of DBS quality is subjective.
Methods
We developed and validated a computer vision (CV) algorithm to measure DBS diameter and identify incorrectly applied blood in images from the Panthera DBS puncher. We used CV to assess historical trends in DBS quality and correlate DBS diameter to NBS analyte concentrations in 130,620 specimens.
Results
CV estimates of DBS diameter were precise (percentage coefficient of variation 14 mm. CV identified a reduction in unsuitable NBS specimens from 25.5% in 2015 to 2% in 2021. Each mm decrease in DBS diameter decreased analyte concentrations by up to 4.3%.
Conclusions
CV can aid assessment of DBS size and quality to harmonize specimen rejection both within and between laboratories
Effect of dried blood spot quality on newborn screening analyte concentrations and recommendations for minimum acceptance criteria for sample analysis
No full textBACKGROUND: The analysis of dried blood spots has been used routinely for newborn screening since the early 1970s, and the number of disorders screened has expanded substantially in recent years. However, there is a lack of evidence regarding minimum blood spot quality acceptance criteria for sample analysis.
METHODS: Blood pools were spiked with phenylalanine, tyrosine, leucine, methionine, octanoylcarnitine, decanoylcarnitine, isovalerylcarnitine, glutarylcarnitine, thyroid-stimulating hormone, and immunoreactive trypsinogen to concentrations at the analytical cutoffs used in UK screening protocols. We evaluated the effect of sample volume applied to the card (10, 20, 50, 75, and 100 μL), punch location (central vs peripheral), and sample quality (double layering, applying blood to both sides of the filter paper, multispotting, applying insufficient sample, and compressing the sample after application).
RESULTS: Compression of blood spots produced significantly lower results (14%–44%) for all analytes measured (P < 0.001). Smaller blood spots produced significantly lower results (15%–24% for 10-μL vs 50-μL sample size) for all analytes at all concentrations measured (P < 0.001). Results obtained from peripheral punches were higher than those from a central punch, although this did not reach statistical significance for all analytes. Insufficient and multispotted samples demonstrated heterogeneous results.
CONCLUSIONS: All blood spots containing ≤20 μL (blood spot diameter <8 mm), those in which blood has not fully penetrated the filter paper, and all samples with evidence of compression should be rejected, since there is a risk of producing false-negative results
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