305 research outputs found
Improved Wilson QCD simulations at light quark masses
We present preliminary results from UKQCD simulations at light quark masses
using two flavours of non-pertubatively improved Wilson fermions. We report on
the performance of the standard HMC algorithm at these quark masses where
m_pi/m_rho < 0.5 in comparison with simulations using improved staggered
quarks.Comment: Lattice 2002 (QCD spectrum and quark masses), 3 pages, 3 figure
International Lattice Data Grid
We propose the co-ordination of lattice QCD grid developments in different
countries to allow transparent exchange of gauge configurations in future,
should participants wish to do so. We describe briefly UKQCD's XML schema for
labelling and cataloguing the data. A meeting to further develop these ideas
will be held in Edinburgh on 19/20 December 2002, and will be available over
AccessGrid.Comment: Lattice2002(plenary
The nucleon mass in N_f=2 lattice QCD: finite size effects from chiral perturbation theory
In the framework of relativistic SU(2)_f baryon chiral perturbation theory we
calculate the volume dependence of the nucleon mass up to and including O(p^4).
Since the parameters in the resulting finite size formulae are fixed from the
pion mass dependence of the large volume nucleon masses and from phenomenology,
we obtain a parameter-free prediction of the finite size effects. We present
mass data from the recent N_f=2 simulations of the UKQCD and QCDSF
collaborations and compare these data as well as published mass values from the
dynamical simulations of the CP-PACS and JLQCD collaborations with the
theoretical expectations. Remarkable agreement between the lattice data and the
predictions of chiral perturbation theory in a finite volume is found.Comment: 23 pages, 5 figures; references added + minor corrections; one more
reference added, typo in eq.(25) corrected, additional clarifying remark
Axial and tensor charge of the nucleon with dynamical fermions
We present preliminary results for the axial and tensor charge of the nucleon
obtained from simulations with N_f=2 clover fermions. A comparison with chiral
perturbation theory is attempted.Comment: Talk presented at Lattice2004(weak), Fermilab, June 21-26, 2004, 3
pages, 3 figures, v2: one reference added, v3: acknowledgement extende
The axial charge of the nucleon on the lattice and in chiral perturbation theory
We present recent Monte Carlo data for the axial charge of the nucleon
obtained by the QCDSF-UKQCD collaboration for N_f=2 dynamical quarks. We
compare them with formulae from chiral perturbation theory in finite and
infinite volume and find a remarkably consistent picture.Comment: 6 pages, 3 figures, talk presented at Lattice2005 (weak matrix
elements), needs PoS.cl
The molecular species responsible for α₁‐antitrypsin deficiency are suppressed by a small molecule chaperone
The formation of ordered Z (Glu342Lys) α1‐antitrypsin polymers in hepatocytes is central to liver disease in α1‐antitrypsin deficiency. In vitro experiments have identified an intermediate conformational state (M*) that precedes polymer formation but this has yet to be identified in vivo. Moreover, the mechanism of polymer formation and their fate in cells have been incompletely characterised. We have used cell models of disease in conjunction with conformation‐selective monoclonal antibodies and a small molecule inhibitor of polymerization to define the dynamics of polymer formation, accumulation and secretion. Pulse‐chase experiments demonstrate that Z α1‐antitrypsin accumulates as short chain polymers that partition with soluble cellular components and are partially secreted by cells. These precede the formation of larger, insoluble polymers with a longer half‐life (10.9 +/‐ 1.7 h and 20.9 +/ 7.4 h for soluble and insoluble polymers respectively). The M* intermediate (or a byproduct thereof) was identified in the cells by a conformation‐specific monoclonal antibody. This was completely abrogated by treatment with the small molecule which also blocked the formation of intracellular polymers. These data allow us to conclude that: the M* conformation is central to polymerization of Z α1‐antitrypsin in vivo; preventing its accumulation represents a tractable approach for pharmacological treatment of this condition; polymers are partially secreted; and polymers exist as two distinct populations in cells whose different dynamics have likely consequences for the aetiology of the disease
Dynamics of extracellular matrix in ovarian follicles and corpora lutea of mice
Despite the mouse being an important laboratory species, little is known about changes in its extracellular matrix (ECM) during follicle and corpora lutea formation and regression. Follicle development was induced in mice (29 days of age/experimental day 0) by injections of pregnant mare’s serum gonadotrophin on days 0 and 1 and ovulation was induced by injection of human chorionic gonadotrophin on day 2. Ovaries were collected for immunohistochemistry (n=10 per group) on days 0, 2 and 5. Another group was mated and ovaries were examined on day 11 (n=7). Collagen type IV α1 and α2, laminin α1, β1 and γ1 chains, nidogens 1 and 2 and perlecan were present in the follicular basal lamina of all developmental stages. Collagen type XVIII was only found in basal lamina of primordial, primary and some preantral follicles, whereas laminin α2 was only detected in some preantral and antral follicles. The focimatrix, a specialised matrix of the membrana granulosa, contained collagen type IV α1 and α2, laminin α1, β1 and γ1 chains, nidogens 1 and 2, perlecan and collagen type XVIII. In the corpora lutea, staining was restricted to capillary sub-endothelial basal laminas containing collagen type IV α1 and α2, laminin α1, β1 and γ1 chains, nidogens 1 and 2, perlecan and collagen type XVIII. Laminins α4 and α5 were not immunolocalised to any structure in the mouse ovary. The ECM composition of the mouse ovary has similarities to, but also major differences from, other species with respect to nidogens 1 and 2 and perlecan
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Maintaining Clinical Freedom Whilst Achieving Value in Biologics Prescribing: An Integrated Cross-Specialty Consensus of UK Dermatologists, Rheumatologists and Gastroenterologists.
BACKGROUND: Biologics are now key drugs in the management of immune-mediated inflammatory diseases. However, the increasingly complex biologics environment and growing cost pressures in the UK have led to variability in drug commissioning and inequity of patient access across regions. OBJECTIVES: Our objectives were to provide consensus recommendations for enhancing the current situation in biologic prescribing in the UK by balancing clinical freedom with equitable distribution of biologics given the limited availability of resources. METHODS: A modified Delphi approach was used to reach integrated, cross-specialty consensus among dermatologists, rheumatologists and gastroenterologists practising within the English National Health Service (NHS). RESULTS: We describe the concepts of clinical freedom and clinical judgement and demonstrate how, together with patient choice, they can be exercised in the context of biologic prescribing in the NHS. We highlight that in England, local variations occur that are at odds with National Institute for Health and Care Excellence (NICE) guidance; these variably limit the degree to which clinicians can exercise clinical freedom and impact on equity of patient access to treatments. We define factors encompassing a drug's value and identify challenges to the measurement and interpretation of this concept, which can raise barriers to the freedom of clinical choice and appropriate prescribing decisions allowing practices of holistic and personalised medicine. Cross-specialty consensus recommendations on ensuring equitable access to biologics in the NHS while protecting appropriate and individualised drug selection for patients are provided. We have also provided strategies for improving physician-commissioner communication to harmonise equity of patient access to biologics across England and improve patient outcomes. Commentary from patient advisory groups indicates that they welcome our exploration that value does not equal cost and agree that there should be an emphasis on shared decision making, which requires the clinician to practice clinical freedom by aligning the patient's needs and preferences with available treatment choices. CONCLUSIONS: This consensus highlights the need to strike a balance between clinical freedom and short-term cost restrictions to support equitable resource distribution within the English NHS. Consideration of these recommendations may help to harmonise local, regional and national services and balance equity of patient access to biologic treatments with excellence in the NHS
The foot posture index, ankle lunge test, Beighton scale and the lower limb assessment score in healthy children: a reliability study
<p>Abstract</p> <p>Background</p> <p>Outcome measures are important when evaluating treatments and physiological progress in paediatric populations. Reliable, relevant measures of foot posture are important for such assessments to be accurate over time. The aim of the study was to assess the intra- and inter-rater reliability of common outcome measures for paediatric foot conditions.</p> <p>Methods</p> <p>A repeated measures, same-subject design assessed the intra- and inter-rater reliability of measures of foot posture, joint hypermobility and ankle range: the Foot Posture Index (FPI-6), the ankle lunge test, the Beighton scale and the lower limb assessment scale (LLAS), used by two examiners in 30 healthy children (aged 7 to 15 years). The Oxford Ankle Foot Questionnaire (OxAFQ-C) was completed by participants and a parent, to assess the extent of foot and ankle problems.</p> <p>Results</p> <p>The OxAFQ-C demonstrated a mean (SD) score of 6 (6) in adults and 7(5) for children, showing good agreement between parents and children, and which indicates mid-range (transient) disability. Intra-rater reliability was good for the FPI-6 (ICC = 0.93 - 0.94), ankle lunge test (ICC = 0.85-0.95), Beighton scale (ICC = 0.96-0.98) and LLAS (ICC = 0.90-0.98). Inter-rater reliability was largely good for each of the: FPI-6 (ICC = 0.79), ankle lunge test (ICC = 0.83), Beighton scale (ICC = 0.73) and LLAS (ICC = 0.78).</p> <p>Conclusion</p> <p>The four measures investigated demonstrated adequate intra-rater and inter-rater reliability in this paediatric sample, which further justifies their use in clinical practice.</p
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