1,796 research outputs found
Introducing new joint replacements to clinical practice.
Requires collaboration between clinicians and regulators, together with comprehensive surveillance dat
ISOTOPIC ANALYSIS OF JURASSIC (CALLOVIAN) MOLLUSKS FROM THE CHRISTIAN MALFORD LAGERSTATTE (UK): IMPLICATIONS FOR OCEAN WATER TEMPERATURE ESTIMATES BASED ON BELEMNOIDS
Isotopic data (C and O) derived from Callovian (Middle Jurassic) mollusks (bivalves, ammonites and belemnoids, including true belemnites and Belemnotheutis) are presented from a narrow stratigraphic interval in the Christian Malford LagerstĂ€tte, UK. The exceptionally well-preserved mollusks include aragonite-calcite pairs precipitated by individual belemnite animals that enable an assessment of possible âvitalâ effects and the reliability of using belemnite calcite to determine ocean water compositions. The oxygen isotope data derived from the calcitic rostra of the belemnites (Cylindroteuthis) show modest variability, ranging from â1.2 to 0.9â° (V-PDB), while their accompanying aragonitic phragmocones range from â1.4 to 0.0â°. Data derived from the ammonite Kosmoceras show some scatter, with oxygen isotope values varying from â3.6 to â0.2â°. The aragonite data from Cylindroteuthis, Kosmoceras and Belemnotheutis all overlap, suggesting they inhabited similar (surface) water depths. However, the corresponding data from the calcitic rostra of the Cylindroteuthis specimens suggest temperatures ⌠5°C cooler. As we have analyzed aragonite-calcite pairs, the discrepancy cannot be explained by environmental effects. Though clearly a vital effect, it is difficult to resolve whether the temperatures derived from the aragonite (phragmocone) are too warm or from the calcite (rostrum) are too cool. Consequently, the applicability of standard paleotemperature equations to Cylindroteuthid belemnite rostra remains unproven. Sequentially sampled ontogenetic isotope data derived from Belemnotheutis phragmocones reveal only modest ÎŽ18O variation, consistent with limited movement between warmer (shallower) and cooler (deeper) waters. A coincidental systematic pattern of ÎŽ13C enrichment may signal changes in metabolic activity associated with a shift in ecology or feeding with age
A Randomized Controlled Trial of Angiotensin-Converting Enzyme Inhibition for Skeletal Muscle Dysfunction in COPD
BACKGROUND: Skeletal muscle impairment is a recognized complication of COPD, predicting mortality in severe disease. Increasing evidence implicates the renin-angiotensin system in control of muscle phenotype. We hypothesized that angiotensin-converting enzyme (ACE) inhibition would improve quadriceps function and exercise performance in COPD.
METHODS: This double-blind, randomized placebo-controlled trial investigated the effect of the ACE inhibitor, fosinopril, on quadriceps function in patients with COPD with quadriceps weakness. Primary outcomes were change in quadriceps endurance and atrophy signaling at 3 months. Quadriceps maximum voluntary contraction (QMVC), mid-thigh CT scan of the cross-sectional area (MTCSA), and incremental shuttle walk distance (ISWD) were secondary outcomes.
RESULTS: Eighty patients were enrolled (mean [SD], 65 [8] years, FEV1 43% [21%] predicted, 53% men). Sixty-seven patients (31 fosinopril, 36 placebo) completed the trial. The treatment group demonstrated a significant reduction in systolic BP (Îâ10.5 mm Hg; 95% CI, â19.9 to â1.1; P = .03) and serum ACE activity (Îâ20.4 IU/L; 95% CI, â31.0 to â9.8; P < .001) compared with placebo. No significant between-group differences were observed in the primary end points of quadriceps endurance half-time (Î0.5 s; 95% CI, â13.3-14.3; P = .94) or atrogin-1 messenger RNA expression (Îâ0.03 arbitrary units; 95% CI, â0.32-0.26; P = .84). QMVC improved in both groups (fosinopril: Î1.1 kg; 95% CI, 0.03-2.2; P = .045 vs placebo: Î3.6 kg; 95% CI, 2.1-5.0; P < .0001) with a greater increase in the placebo arm (between-group, P = .009). No change was shown in the MTCSA (P = .09) or ISWD (P = .51).
CONCLUSIONS: This randomized controlled trial found that ACE inhibition, using fosinopril for 3 months, did not improve quadriceps function or exercise performance in patients with COPD with quadriceps weakness
Genetics of CM-proteins (A-hordeins) in barley
The CM-proteins, which are the main components of the A-hordeins, include four previously described proteins (CMa-1, CMb-1, CMc-1, CMd-1), plus a new one, CMe-1, which has been tentatively included in this group on the basis of its solubility properties and electrophoretic mobility. The variability of the five proteins has been investigated among 38 Hordeum vulgare cultivars and 17 H. spontaneum accessions. Proteins CMa-1, CMc-1 and CMd-1 were invariant within the cultivated species; CMd was also invariant in the wild one. The inheritance of variants CMb-1/CMb-2 and CMe-1/CMe-2,2 was studied in a cross H. spontaneum x H. vulgare. The first two proteins were inherited as codominantly expressed allelic variations of a single mendelian gene. Components CMe-2,2 were jointly inherited and codominantly expressed with respect to CMe-1. Gene CMb and gene(s) CMe were found to be unlinked. The chromosomal locations of genes encoding CM-proteins were investigated using wheat-barley addition lines. Genes CMa and CMc were associated with chromosome 1, and genes CMb and CMd with chromosome 4. These gene locations further support the proposed homoeology of chromosomes 1 and 4 of barley with chromosomes groups 7 and 4 of wheat, respectively. Gene(s) CMe has been assigned to chromosome 3 of barley. The accumulation of protein CMe-1 is totally blocked in the high lysine mutant Riso 1508 and partially so in the high lysine barley Hiproly
Assessment of material loss of retrieved magnetically controlled implants for limb lengthening
PURPOSE: We aimed to understand wear from the telescopic component of PRECICE nails, which are used for distraction osteogenesis of the femur or tibia. We also aimed to identify any correlation between implant performance and patient factors. METHODS: This retrieval study involved 11 magnetically controlled intramedullary nails from nine patients who had achieved the targeted leg length. All the nails were assessed macroscopically and microscopically for wear. All implants were radiographed to assess the internal mechanism. A Talyrond 365 (Taylor Hobson, Leicester, UK) roundness measuring machine was used to generate three-dimensional surface maps of the telescopic components to allow for measurement of wear. RESULTS: Visual assessment of all the nails showed evidence of wear from the telescopic component. The radiographs revealed that all the nails had intact internal mechanism and no evidence of fractured pins. The roundness measuring machine showed that the quantity of wear was lowest in the latest design of the PRECICE nail. There was no significant correlation between wear and the two patient factors (duration of the lengthening phase, the time of implantation) included in this study. CONCLUSION: This study is the first to investigate the performance of the three different designs of the PRECICE system with a focus on wear. We found that the latest design had the best implant performance. We are confident of the continued success of the PRECICE system and reassure surgeons and patients that they are unlikely to encounter problems with the implant related to wear
Lipids and nutrition of the southern rock lobster, Jasus edwardsii, from hatch to puerulus
We examined the lipid class and fatty-acid composition of the southern rock lobster, Jasus edwardsii, phyllosomas larvae and puerulus stage to improve understanding of their nutrition in relation to aquaculture. Lipid is critical in the nutrition of larval crustaceans, including lobsters. Specimens were from Tasmanian waters, Australia, and North Island, New Zealand, waters. Analyses were by TLC-FID and capillary GC and GC-MS. Phyllosomas larvae and nektonic pueruli were low in storage lipid (triacylglycerol), and phospholipid was the major lipid class. Sterol, mainly cholesterol, was the next most abundant class. The ratio of the essential omega-3 fatty acid eicosapentaenoic acid (EPA) to the omega-6 fatty acid arachidonic acid (AA) was lower in newly hatched phyllosomas (1.2-1.3) than in other phyllosomas (stages III-XI; 2.8-6.7) and pueruli (3.8). Ratios of the omega-3 fatty acid DHA (docosahexaenoic acid) to EPA were also lower in newly hatched phyllosomas (0.5) than in later-stage phyllosomas (1.5-2.1) and pueruli (1.2). We have followed up these compositional data by successfully enriching the live diet (Artemia) of early phyllosomas with AA, EPA and DHA. This dietary manipulation has achieved ratios of these key polyunsaturated fatty acids similar to those of wild phyllosomas. These findings will be of significance to the future of rock-lobster aquaculture
Exploring the equity of GP practice prescribing rates for selected coronary heart disease drugs: a multiple regression analysis with proxies of healthcare need
Background
There is a small, but growing body of literature highlighting inequities in GP practice prescribing rates for many drug therapies. The aim of this paper is to further explore the equity of prescribing for five major CHD drug groups and to explain the amount of variation in GP practice prescribing rates that can be explained by a range of healthcare needs indicators (HCNIs).
Methods
The study involved a cross-sectional secondary analysis in four primary care trusts (PCTs 1â4) in the North West of England, including 132 GP practices. Prescribing rates (average daily quantities per registered patient aged over 35 years) and HCNIs were developed for all GP practices. Analysis was undertaken using multiple linear regression.
Results
Between 22â25% of the variation in prescribing rates for statins, beta-blockers and bendrofluazide was explained in the multiple regression models. Slightly more variation was explained for ACE inhibitors (31.6%) and considerably more for aspirin (51.2%). Prescribing rates were positively associated with CHD hospital diagnoses and procedures for all drug groups other than ACE inhibitors. The proportion of patients aged 55â74 years was positively related to all prescribing rates other than aspirin, where they were positively related to the proportion of patients aged >75 years. However, prescribing rates for statins and ACE inhibitors were negatively associated with the proportion of patients aged >75 years in addition to the proportion of patients from minority ethnic groups. Prescribing rates for aspirin, bendrofluazide and all CHD drugs combined were negatively associated with deprivation.
Conclusion
Although around 25â50% of the variation in prescribing rates was explained by HCNIs, this varied markedly between PCTs and drug groups. Prescribing rates were generally characterised by both positive and negative associations with HCNIs, suggesting possible inequities in prescribing rates on the basis of ethnicity, deprivation and the proportion of patients aged over 75 years (for statins and ACE inhibitors, but not for aspirin)
A retrieval analysis of the Precice intramedullary limb lengthening system
OBJECTIVES:
The Precice nail is the latest intramedullary lengthening nail with excellent early outcomes. Implant complications have led to modification of the nail design. The aim of this study was to perform a retrieval study of Precice nails following lower-limb lengthening and to assess macroscopical and microscopical changes to the implants and evaluate differences following design modification, with the aim of identifying potential surgical, implant, and patient risk factors.
METHODS:
A total of 15 nails were retrieved from 13 patients following lower-limb lengthening. Macroscopical and microscopical surface damage to the nails were identified. Further analysis included radiology and micro-CT prior to sectioning. The internal mechanism was then analyzed with scanning electron microscopy and energy dispersive x-ray spectroscopy to identify corrosion.
RESULTS:
Seven male and three female patients underwent 12 femoral lengthenings. Three female patients underwent tibial lengthening. All patients obtained the desired length with no implant failure. Surface degradation was noted on the telescopic part of every nail design, less on the latest implants. Microscopical analysis confirmed fretting and pitting corrosion. Following sectioning, black debris was noted in all implants. The early designs were found to have fractured actuator pins and the pin and bearings showed evidence of corrosive debris. The latest designs showed evidence of biological deposits suggestive of fluid ingress within the nail but no corrosion.
CONCLUSION:
This study confirms less internal corrosion following modification, but evidence of titanium debris remains. We recommend no change to current clinical practice. However, potential reuse of the Precice nail, for secondary limb lengthening in the same patient, should be undertaken with caution
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