Functional analysis of the glycero-manno-heptose 7-phosphate kinase domain from the bifunctional HldE protein, which is involved in ADP-L-glycero-D-manno-heptose biosynthesis

The core oligosaccharide component of the lipopolysaccharide can be subdivided into inner and outer core regions. In Escherichia coli, the inner core consists of two 3-deoxy-d-manno-octulosonic acid and three glycero-manno-heptose residues. The HldE protein participates in the biosynthesis of ADP-glycero-manno-heptose precursors used in the assembly of the inner core. HldE comprises two functional domains: an N-terminal region with homology to the ribokinase superfamily (HldE1 domain) and a C-terminal region with homology to the cytidylyltransferase superfamily (HldE2 domain). We have employed the structure of the E. coli ribokinase as a template to model the HldE1 domain and predict critical amino acids required for enzyme activity. Mutation of these residues renders the protein inactive as determined in vivo by functional complementation analysis. However, these mutations did not affect the secondary or tertiary structure of purified HldE1, as judged by fluorescence spectroscopy and circular dichroism. Furthermore, in vivo coexpression of wild-type, chromosomally encoded HldE and mutant HldE1 proteins with amino acid substitutions in the predicted ATP binding site caused a dominant negative phenotype as revealed by increased bacterial sensitivity to novobiocin. Copurification experiments demonstrated that HldE and HldE1 form a complex in vivo. Gel filtration chromatography resulted in the detection of a dimer as the predominant form of the native HldE1 protein. Altogether, our data support the notions that the HldE functional unit is a dimer and that structural components present in each HldE1 monomer are required for enzymatic activity.

Identification of lesion components that influence visual function in age related macular degeneration

To explore the relation between lesion composition as assessed by fundus photography and fluorescein angiography with clinical measures of vision in eyes of patients with age related macular degeneration (AMD).

z'-band Ground-based Detection of the Secondary Eclipse of WASP-19b

We present the ground-based detection of the secondary eclipse of the transiting exoplanet WASP-19b. The observations were made in the Sloan z' band using the ULTRACAM triple-beam CCD camera mounted on the New Technology Telescope. The measurement shows a 0.088% ± 0.019% eclipse depth, matching previous predictions based on H- and K-band measurements. We discuss in detail our approach to the removal of errors arising due to systematics in the data set, in addition to fitting a model transit to our data. This fit returns an eclipse center, T 0, of 2455578.7676 HJD, consistent with a circular orbit. Our measurement of the secondary eclipse depth is also compared to model atmospheres of WASP-19b and is found to be consistent with previous measurements at longer wavelengths for the model atmospheres we investigated.

Components of Shame and Eating Disturbance among Clinical and Non-Clinical Populations

OBJECTIVE: To examine the association between components of shame (characterological, behavioural and bodily) and eating disturbance.

METHOD: This was a cross sectional study of 859 female and 256 male participants from the general population [non-clinical (NCP)] and 167 female participants from an eating disordered population [clinical (CP)] completing the Experience of Shame Scale. The NCP samples also completed the Eating Attitudes Test-26, and the CP samples completed the Eating Disorder Risk Composite of the Eating Disorder Inventory-3. Participants were recruited via schools/colleges, eating disorder charities and the Internet.

RESULTS: Bodily and characterological shame were independently predictive of eating disturbance in female NCP samples (both, p?<?.001); bodily shame was uniquely predictive of eating disturbance for the male NCP (p?<?.05) and female CP samples (p?<?.001).

CONCLUSION: The aetiology of eating disturbance may be different for male and female NCP samples. The male NCP and the female CP samples displayed a similar pathway to eating disturbance. It is important to acknowledge the different components of shame associated with eating disturbance in different populations.

The importance of validating the diagnosis of coronary heart disease when measuring secondary prevention:a cross-sectional study in general practice

To compare levels of recorded risk factors and drug treatment between patients with validated and non-validated diagnoses of coronary heart disease (CHD) in Northern Ireland.

The impact of antibiotic use on the incidence and resistance pattern of extended-spectrum beta-lactamase-producing bacteria in primary and secondary healthcare settings

Aims: The objective of the present study was to study the relationship between hospital antibiotic use, community antibiotic use and the incidence of extended-spectrum beta-lactamase (ESBL)-producing bacteria in hospitals, while assessing the impact of a fluoroquinolone restriction policy on ESBL-producing bacteria incidence rates. METHODS: The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (ARIMA) model was built to relate antibiotic use to ESB-producing bacteria incidence rates and resistance patterns over a 5 year period (January 2005-December 2009). Results: Analysis showed that the hospital incidence of ESBLs had a positive relationship with the use of fluoroquinolones in the hospital (coefficient = 0.174, P= 0.02), amoxicillin-clavulanic acid in the community (coefficient = 1.03, P= 0.03) and mean co-morbidity scores for hospitalized patients (coefficient = 2.15, P= 0.03) with various time lags. The fluoroquinolone restriction policy was implemented successfully with the mean use of fluoroquinolones (mainly ciprofloxacin) being reduced from 133 to 17 defined daily doses (DDDs)/1000 bed days (P <0.001) and from 0.65 to 0.54 DDDs/1000 inhabitants/day (P= 0.0007), in both the hospital and its surrounding community, respectively. This was associated with an improved ciprofloxacin susceptibility in both settings [ciprofloxacin susceptibility being improved from 16% to 28% in the community (P <0.001)] and with a statistically significant reduction in ESBL-producing bacteria incidence rates. Discussion: This study supports the value of restricting the use of certain antimicrobial classes to control ESBL, and demonstrates the feasibility of reversing resistance patterns post successful antibiotic restriction. The study also highlights the potential value of the time-series analysis in designing efficient antibiotic stewardship. © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

Secondary Outcomes in a Clinical Trial of Carotenoids with Coantioxidants versus Placebo in Early Age-Related Macular Degeneration

Purpose: To report the secondary outcomes in the Carotenoids with Coantioxidants in Age-Related Maculopathy trial.

Design: Randomized double-masked placebo-controlled clinical trial (registered as ISRCTN 94557601).

Participants: Participants included 433 adults 55 years of age or older with early age-related macular degeneration (AMD) in 1 eye and late-stage disease in the fellow eye (group 1) or early AMD in both eyes (group 2).

Intervention: An oral preparation containing lutein (L), zeaxanthin (Z), vitamin C, vitamin E, copper, and zinc or placebo. Best-corrected visual acuity (BCVA), contrast sensitivity (CS), Raman spectroscopy, stereoscopic colour fundus photography, and serum sampling were performed every 6 months with a minimum follow-up time of 12 months.

Main Outcome Measures: Secondary outcomes included differences in BCVA (at 24 and 36 months), CS, Raman counts, serum antioxidant levels, and progression along the AMD severity scale (at 12, 24, and 36 months).

Results: The differential between active and placebo groups increased steadily, with average BCVA in the former being approximately 4.8 letters better than the latter for those who had 36 months of follow-up, and this difference was statistically significant (P = 0.04). In the longitudinal analysis, for a 1-log-unit increase in serum L, visual acuity was better by 1.4 letters (95% confidence interval, 0.3-2.5; P = 0.01), and a slower progression along a morphologic severity scale (P = 0.014) was observed.

Conclusions: Functional and morphologic benefits were observed in key secondary outcomes after supplementation with L, Z, and coantioxidants in persons with early AMD.

Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2012 American Academy of Ophthalmology.

The use of a GA to improve the postbuckling strength of stiffened composite panels susceptible to secondary instabilities

The use of genetic algorithms (GAs) for structural optimisation is well established but little work has been reported on the inclusion of damage variables within an optimisation framework. This approach is particularly useful in the optimisation of composite structures which are prone to delamination damage. In this paper a challenging design problem is presented where the objective was to delay the catastrophic failure of a postbuckling secondary-bonded stiffened composite panel susceptible to secondary instabilities. It has been conjectured for some time that the sudden energy release associated with secondary instabilities may initiate structural failure, but this has proved difficult to observe experimentally. The optimisation methodology confirmed this indirectly by evolving a panel displaying a delayed secondary instability whilst meeting all other design requirements. This has important implication in the design of thin-skinned lightweight aerostructures which may exhibit this phenomenon.

A study of secondary instabilities in postbuckling composite aerostructures

A number of experimental studies have shown that postbuckling stiffened composite panels, loaded in uniaxial compression, may undergo secondary instabilities, characterised by an abrupt change in the buckled mode-shape of the skin between the supporting stiffeners. In this study high-speed digital speckle photogrammetry is used to gain further insight into an I-stiffened panel's response during this transient phase. This energy-dissipating phenomenon will be shown to be able to cause catastrophic structural failure in vulnerable structures. It is therefore imperative that an accurate and reliable methodology is available to predict this phenomenon. The shortcomings of current non-linear implicit solution schemes, found in most commercially-available finite element codes, are discussed. A robust and efficient strategy, which utilises an automated quasi-, static/pseudo-transient hybrid scheme, is presented in this paper and validated using a number of experimental tests. This approach is shown to be able to predict mode-jumping with good accuracy.