Leptonic-decay-constant ratio f(K+)/f(π+) from lattice QCD with physical light quarks

A calculation of the ratio of leptonic decay constants f(K+)/f(π+) makes possible a precise determination of the ratio of Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |V(us)|/|V(ud)| in the standard model, and places a stringent constraint on the scale of new physics that would lead to deviations from unitarity in the first row of the CKM matrix. We compute f(K+)/f(π+) numerically in unquenched lattice QCD using gauge-field ensembles recently generated that include four flavors of dynamical quarks: up, down, strange, and charm. We analyze data at four lattice spacings a ≈ 0.06, 0.09, 0.12, and 0.15 fm with simulated pion masses down to the physical value 135 MeV. We obtain f(K+)/f(π+) = 1.1947(26)(37), where the errors are statistical and total systematic, respectively. This is our first physics result from our N(f) = 2+1+1 ensembles, and the first calculation of f(K+)/f(π+) from lattice-QCD simulations at the physical point. Our result is the most precise lattice-QCD determination of f(K+)/f(π+), with an error comparable to the current world average. When combined with experimental measurements of the leptonic branching fractions, it leads to a precise determination of |V(us)|/|V(ud)| = 0.2309(9)(4) where the errors are theoretical and experimental, respectively.

Alternative treatment strategies for carious primary teeth: An overview of the evidence

BACKGROUND

Dental decay in children's primary teeth is a major health problem in the Great Britain with, in some areas, nearly 60% of five-year-olds having some experience of caries and 16% already having had at least one tooth extracted. Whilst currently accepted best practice for the management of carious primary teeth involves complete caries removal and placement of a plastic restoration, such conventional treatment is unpopular with general dental practitioners. Indeed, less than 15% of carious cavities in five-year-olds are currently restored and as such, there has been recent interest in alternative 'minimal intervention' treatment techniques for managing dental caries.

REVIEW

This review summarises the literature and also recent research efforts directed towards understanding the role of alternative treatment regimens including: (1) alternative techniques for cavity preparation and excavation and (2) the isolation of the carious process (in some cases, using cariostatic materials) from the oral environment or sealing in dental caries.

Improved glycaemic control with vildagliptin added to insulin, with or without metformin, in patients with type 2 diabetes mellitus

AIM

The aim of this study is to assess the efficacy and safety of vildagliptin 50 mg bid as add-on therapy to insulin in type 2 diabetes mellitus (T2DM).

METHODS

This is a multicentre, double-blind, placebo-controlled, parallel group, clinical trial in T2DM patients inadequately controlled by stable insulin therapy, with or without metformin. Patients received treatment with vildagliptin 50 mg bid or placebo for 24 weeks.

RESULTS

In all, 449 patients were randomized to vildagliptin (n = 228) or placebo (n = 221). After 24 weeks, the difference in adjusted mean change in haemoglobin A1c (HbA1c) between vildagliptin and placebo was -0.7 ± 0.1% (p < 0.001) in the overall study population, -0.6 ± 0.1% (p < 0.001) in the subgroup also receiving metformin and -0.8 ± 0.2% (p < 0.001) in the subgroup without metformin. Vildagliptin therapy was well tolerated and had a similarly low incidence of hypoglycaemia compared with placebo (8.4 vs. 7.2%, p = 0.66) in spite of improved glycaemic control, and was not associated with weight gain. (+0.1 vs. -0.4 kg).

CONCLUSIONS

Vildagliptin 50 mg bid added to insulin significantly reduced HbA1c in patients with T2DM inadequately controlled by insulin, with or without metformin. Vildagliptin was well tolerated, with a safety profile similar to placebo. These results were achieved without weight gain or an increase in hypoglycaemia incidence or severity in spite of improved glycaemic control.

Refining new-physics searches in B→Dτν with lattice QCD

The semileptonic decay channel B→Dτν is sensitive to the presence of a scalar current, such as that mediated by a charged-Higgs boson. Recently, the BABAR experiment reported the first observation of the exclusive semileptonic decay B→Dτ(-)ν, finding an approximately 2σ disagreement with the standard-model prediction for the ratio R(D)=BR(B→Dτν)/BR(B→Dℓν), where ℓ = e,μ. We compute this ratio of branching fractions using hadronic form factors computed in unquenched lattice QCD and obtain R(D)=0.316(12)(7), where the errors are statistical and total systematic, respectively. This result is the first standard-model calculation of R(D) from ab initio full QCD. Its error is smaller than that of previous estimates, primarily due to the reduced uncertainty in the scalar form factor f(0)(q(2)). Our determination of R(D) is approximately 1σ higher than previous estimates and, thus, reduces the tension with experiment. We also compute R(D) in models with electrically charged scalar exchange, such as the type-II two-Higgs-doublet model. Once again, our result is consistent with, but approximately 1σ higher than, previous estimates for phenomenologically relevant values of the scalar coupling in the type-II model. As a by-product of our calculation, we also present the standard-model prediction for the longitudinal-polarization ratio P(L)(D)=0.325(4)(3).

Potassium accumulation as dynamic modulator of neurohypophysial excitability

Activity-dependent modulation of excitable responses from neurohypophysial axons and their secretory swellings has long been recognized as an important regulator of arginine vasopressin and oxytocin release during patterned stimulation. Various activity-dependent mechanisms, including action potential broadening, potassium accumulation, and autocrine or paracrine feedback, have been proposed as underlying mechanisms. However, the relevance of any specific mechanism on net excitability in the intact preparation, during different levels of overall activation, and during realistic stimulation with trains of action potentials has remained largely undetermined. Using high-speed optical recordings and potentiometric dyes, we have quantified the dynamics of global excitability under physiologically more realistic conditions, that is in the intact neurohypophysis during trains of stimuli at varying frequencies and levels of overall activity. Net excitability facilitated during stimulation at low frequencies or at low activity. During persistent high-intensity or high-frequency stimulation, net excitability became severely depressed. Depression of excitable responses was strongly affected by manipulations of extracellular potassium levels, including changes to resting [K(+)](out), increases of interstitial spaces with hypertonic solutions and inhibition of Na(+)/K(+) ATPase activity. Application of the GABA(A) receptor blocker bicuculline or manipulations of Ca(2+) influx showed little effect. Numerical simulation of K(+) accumulation on action potentials of individual axons reproduced optically recorded population responses, including the overall depression of action potential (AP) amplitudes, modest AP broadening and the prominent loss of hyperpolarizing undershoots. Hence, extracellular potassium accumulation dominates activity-dependent depression of neurohypophysial excitability under elevated stimulation conditions. The intricate dependence on the short-term stimulation history and its resulting feedback on neurohypophysial excitability renders [K(+)](out) accumulation a surprisingly complex mechanism for regulating axonal excitability and subsequent neuroendocrine release.

Use of mobile telephone short message service (SMS) as a reminder: the effect on patient attendance

AIM

To evaluate the operational and financial efficacy of sending short message service (SMS) mobile telephone text message to patients with outpatient clinic appointments.

STUDY DESIGN

Patients scheduled to attend an outpatient appointment at the Dept. Paediatric Dentistry, Edinburgh Dental Institute, Scotland, during October 2007 and who had mobile telephone contact details were sent a reminder SMS text 24hr prior to their appointment. An historical control group were selected from October 2006.

RESULTS

Data were available for 276 (F: 146; M: 130) and 433 (F: 228; M: 205) patient attendances during 2006 and 2007 respectively. Overall, 10.4% and 23.9% of the SMS and historical group failed to attend (FTA) respectively and the difference was statistically significant (Chi Square = 6.95, p = 0.008, 1 d.f). There was a reduction in the FTA rate for the specialist paediatric staff dentists from 29.2% to 24.4% for 2006 and 2007 respectively. The cost of sending text messages was 28.15 pound (approx. 30 euro) for October 2007.

CONCLUSIONS

The use of SMS text messages as a reminder may reduce the failure to attend rate for outpatient paediatric dental appointments.

Efficacy and safety of vildagliptin monotherapy during 2-year treatment of drug-naïve patients with type 2 diabetes: comparison with metformin

The present study was a 52-week extension of a previously published, multi-center, randomized, parallel-group study. The aim of this extension study was to compare the efficacy and tolerability of vildagliptin and metformin in drug-naïve patients with type 2 diabetes over 104 weeks. The extension population comprised 305 patients randomized to vildagliptin (100 mg daily) and 158 patients randomized to metformin (2 000 mg daily). Pioglitazone was added as rescue medication if fasting glucose was >10 mmol/l; data from patients receiving rescue medication were excluded from the primary analysis. Baseline HbA (1c) averaged 8.4+/-0.1% in patients randomized to vildagliptin and 8.8+/-0.1% in those randomized to metformin. The adjusted mean change from baseline to study endpoint was -1.0+/-0.1% in vildagliptin-treated patients and -1.5+/-0.1% in those receiving metformin (p<0.001 vs. vildagliptin). These results were similar to those reported after the 1-year core phase of the study. The adjusted mean changes in body weight from baseline to endpoint were 0.5+/-0.4 kg and -2.5+/-0.5 kg in the vildagliptin and metformin groups, respectively. One or more adverse event (AE) was reported by 82.2% of patients receiving vildagliptin and by 87.3% of those receiving metformin (p<0.001). Gastrointestinal AEs were more common in patients receiving metformin (45.6%) than in those receiving vildagliptin (25.0%, p<0.001 vs. metformin). One hypoglycemic event occurred after strenuous exercise in a single patient receiving vildagliptin (0.3%). In conclusion, both vildagliptin and metformin monotherapy provided clinically meaningful decreases in HbA (1c) over 2 years in drug-naïve patients with type 2 diabetes. Vildagliptin was weight neutral, while weight loss was observed with metformin; however, metformin was associated with significantly worse gastrointestinal tolerability.

Paediatric minor oral surgical procedures under inhalation sedation and general anaesthetic: a comparison of variety and duration of treatment

AIM

To develop baseline data in relation to paediatric minor oral surgical procedures undertaken with both general anaesthesia and nitrous oxide inhalation sedation within a Hospital Dental Service.

STUDY DESIGN

Data were collected prospectively over a three-year period from May 2003 to June 2006 for patients attending the Departments of Paediatric Dentistry, Dundee Dental Hospital and Ninewells Hospital, NHS Tayside, Great Britain, for all surgical procedures undertaken with either inhalation sedation or general anaesthetic. Both operator status and the procedure being undertaken were noted. In addition, the operating time was recorded.

RESULTS

Data for 166 patients (F: 102; M: 64) with a median age of 12.50 (inter-quartile range 10.00, 14.20) years showed that 195 surgical procedures were undertaken. Of these 160 and 35 were with general anaesthetic and sedation respectively. The surgical removal of impacted, carious and supernumerary unit(s) accounted for 53.8% of all procedures, whilst the exposure of impacted teeth and soft tissue surgery represented 34.9% and 11.3% of procedures respectively. The median surgical time for techniques undertaken with sedation was 30.00 (inter-quartile range 25.00, 43.50) minutes whilst that for general anaesthetic was similar at 30.00 (inter-quartile range 15.25, 40.00) minutes (not statistically significant, (Mann Whitney U, W = 3081.5, P = 0.331).

CONCLUSIONS

The majority of paediatric minor oral surgical procedures entail surgical exposure or removal of impacted teeth. The median treatment time for most procedures undertaken with either general anaesthetic or nitrous oxide sedation was 30 minutes.

Knowledge of paediatric dentistry by recently-qualified general dentists: a pilot study

AIM

To determine an overview of opinions and knowledge of paediatric dentistry amongst a group of recently-qualified dentists working within the Scottish Hospital Dental Service.

STUDY DESIGN

A prospective questionnaire-based survey undertaken at Dundee Dental Hospital and School, NHS Tayside, Scotland. The survey evaluated dentists' opinion of managing the child patient and the location of dental treatment as well as knowledge of trauma, minor oral surgery, developmental disorders, mixed dentition problems and joint paediatric/orthodontic scenarios.

RESULTS

Data were available for 15 dentists (M: 7; F: 8), median age 25.00 (inter-quartile range 25.40, 27.20) years. Of the respondents, 73.3% enjoyed treating children, although concerns regarding the management of both dental trauma and paediatric minor oral surgery cases were noted by 93.3% and 100% of dentists respectively. Concerning the location of treatment for the child patient, 66.7% believed that this should be 'shared-care' between the general dental practitioners (GDP) and Community Dental Service (CDS), whilst 20.0% and 13.3% observed that this should be undertaken within the CDS and GDP respectively. None of the dentists felt that treatment should be undertaken either privately or within the hospital services. Overall, dentists were best able to answer questions relating to mixed dentition and paediatric/orthodontic problems and least able to do so for minor oral surgical conditions.

CONCLUSION

This pilot study offers baseline data regarding both opinions and also knowledge of paediatric dentistry amongst a group of recently-qualified dentists. Further educational opportunities in this discipline at the postgraduate level may be beneficial.

A comparison of knowledge of local analgesia, pulp therapy and restoration of primary molar teeth amongst dental students, dentists and dental therapists within a dental hospital setting

AIM

To gain an overview of knowledge of local analgesia, pulpal therapy and restorative procedures in the primary dentition amongst dental undergraduate students (DS), dental therapy students (DTS), recently-qualified dentists (QD) and dental therapists (DT), working within a Dental Hospital setting.

STUDY DESIGN

A survey undertaken at Dundee Dental Hospital and School, NHS Tayside, United Kingdom to determine current knowledge regarding the use of local analgesia, pulp anatomy and pulp therapy techniques in addition to restoration of primary teeth.

RESULTS

Data were available for 24 individuals (DS: 5; QD: 6; DTS: 8; DT: 5). Deficiencies in knowledge regarding the maximum safe dose for local analgesia, pulp canal anatomy, pulp therapy medicaments and the preparation required prior to placement of a pre-formed metal crown were noted in both student and staff groups.

CONCLUSIONS

The knowledge of basic dental procedures for children amongst a group of dental students, student dental therapists and recently qualified dentists and dental therapists, was found to be imperfect. These findings indicate that more research is needed on the educational procedures used in the transfer of such knowledge and skills. Deficiencies in knowledge were identified in all areas assessed. Courses should be designed at both the pre- and postgraduate level to address and avoid such gaps in knowledge.

Inhibition of epidermal growth factor receptor signalling reduces hypercalcaemia induced by human lung squamous-cell carcinoma in athymic mice

The purpose of this study was to evaluate the role of the epidermal growth factor receptor (EGFR) in parathyroid hormone-related protein (PTHrP) expression and humoral hypercalcaemia of malignancy (HHM), using two different human squamous-cell carcinoma (SCC) xenograft models. A randomised controlled study in which nude mice with RWGT2 and HARA xenografts received either placebo or gefitinib 200 mg kg⁻¹ for 3 days after developing HHM. Effectiveness of therapy was evaluated by measuring plasma calcium and PTHrP, urine cyclic AMP/creatinine ratios, and tumour volumes. The study end point was at 78 h. The lung SCC lines, RWGT2 and HARA, expressed high levels of PTHrP mRNA as well as abundant EGFR protein, but very little erbB2 or erbB3. Both lines expressed high transcript levels for the EGFR ligand, amphiregulin (AREG), as well as, substantially lower levels of transforming growth factor-α (TGF-α), and heparin binding-epidermal growth factor (HB-EGF) mRNA. Parathyroid hormone-related protein gene expression in both lines was reduced 40–80% after treatment with 1 μM of EGFR tyrosine kinase inhibitor PD153035 and precipitating antibodies to AREG. Gefitinib treatment of hypercalcaemic mice with RWGT2 and HARA xenografts resulted in a significant reduction of plasma total calcium concentrations by 78 h. Autocrine AREG stimulated the EGFR and increased PTHrP gene expression in the RWGT2 and HARA lung SCC lines. Inhibition of the EGFR pathway in two human SCC models of HHM by an anilinoquinazoline demonstrated that the EGFR tyrosine kinase is a potential target for antihypercalcaemic therapy.

Development of a measure to assess the impact of epilepsy on people with an intellectual disability: the Glasgow Epilepsy Outcome Scale - Client version (GEOS-C)

BACKGROUND

Epilepsy is common in people with intellectual disability, yet clinicians and researchers seldom obtain information directly from the client. The development and preliminary validation of a novel measure for use with people with mild to moderate intellectual disabilities is described.

METHODS

Focus group methods (6 groups; 24 participants) identified issues of concern, and qualitative analysis (NUD*IST) was applied to derive items and themes for a draft scale. Psychometric scale development techniques were then used in a pilot study and subsequent field-testing to investigate validity and reliability (n = 46).

RESULTS

A total of 148 issues of concern was reduced initially to 52 and then to 42 items using these methods. The derived scale comprised sub-scales reflecting (1) concerns about having seizures; (2) about injury; (3) about issues during; and (4) after seizures; (5) about medication; (6) about what people think; and (7) about daily life. Cronbach alpha for the Glasgow Epilepsy Outcome Scale - Client version (GEOS-C) was 0.92, and ranged from 0.64-0.81 for the sub-scales. Relatively weak associations (r <or= 0.40), between client and family carer, staff carer or clinician views, suggests that proxy reports are not good predictors of how people with epilepsy themselves are feeling. Preliminary validation suggests that the GEOS-C can discriminate on variables of clinical importance.

CONCLUSIONS

The GEOS-C complements existing GEOS measures, can be completed in 5-15 min depending upon the level of support required, and may provide a valuable clinical and research tool. Further validational work and appraisal of sensitivity are required.