2,166 research outputs found

    Plasminogen Activator Inhibitor-1 Regulates Myoendothelial Junction Formation

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    Rationale: Plasminogen activator inhibitor-1 (PAI-1) is a biomarker for several vascular disease states; however, its target of action within the vessel wall is undefined. Objective: Determine the ability of PAI-1 to regulate myoendothelial junction (MEJ) formation. Methods and Results: MEJs are found throughout the vasculature linking endothelial cells (ECs) and vascular smooth muscle cells. Using a vascular cell coculture we isolated MEJ fractions and performed two-dimensional differential gel electrophoresis. Mass spectrometry identified PAI-1 as being enriched within MEJ fractions, which we confirmed in vivo. In the vascular cell coculture, recombinant PAI-1 added to the EC monolayer significantly increased MEJs. Conversely, addition of a PAI-1 monoclonal antibody to the EC monolayer reduced the number of MEJs. This was also observed in vivo where mice fed a high fat diet had increased PAI-1 and MEJs and the number of MEJs in coronary arterioles of PAI-1(-/-) mice was significantly reduced when compared to C57Bl/6 mice. The presence of MEJs in PAI-1(-/-) coronary arterioles was restored when their hearts were transplanted into and exposed to the circulation of C57Bl/6 mice. Application of biotin-conjugated PAI-1 to the EC monolayer in vitro confirmed the ability of luminal PAI-1 to translocate to the MEJ. Functionally, phenylephrine-induced heterocellular calcium communication in the vascular cell coculture was temporally enhanced when recombinant PAI-1 was present, and prolonged when PAI-1 was absent. Conclusion: Our data implicate circulating PAI-1 as a key regulator of MEJ formation and a potential target for pharmacological intervention in diseases with vascular abnormalities (eg, diabetes mellitus). (Circ Res. 2010; 106: 1092-1102.

    The effects of licence disqualification on drink-drivers: Is it the same for everyone?

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    © 2017 Elsevier Ltd Drink-driving remains a major road safety concern that creates a significant social burden. Licence disqualification continues to play a key role in drink driving deterrence and sanctions together with police enforcement to address the problem in most motorised countries. However, on-going questions remain regarding the differing effect of licence disqualification periods between first time and repeat offenders, and between other sub-groups of offenders. As a result, this study aimed to determine whether: (a) differences exist in re-offence rates of convicted drink-drivers between: the period between committing the drink-driving offence and licence disqualification (pre-licence disqualification), during the period of licence disqualification, and after being re-licensed (post-licence restoration); and (b) differential effects of offence rates are evident based on Blood Alcohol Content (BAC), gender, age, repeat offender status and crash involvement at the time of offence. The sample consisted of 29,204 drink-driving offenders detected in Victoria, Australia between 1 January 1996 and 30 September 2002. The analysis indicated that licence disqualifications were effective as drink-driving offenders had a significantly lower rate of offending (both drink-driving and other traffic offences) during licence disqualifications compared to pre-licence disqualification and post-licence restoration periods. The influence of licence disqualification appeared to extend beyond the disqualification period, as offence rates were lower during post-licence restoration than during pre-licence disqualification. Interestingly, the highest rate of offending (both for drink-driving and other traffic offences) was during the pre-licence disqualification period, which suggests offenders are particularly vulnerable to drink and drive while waiting to be sanctioned. A consistent pattern of results was evident across genders and age groups. Additionally, those who were involved in a crash at the same time as their index offence had lower offence rates (compared to those who were not involved in a crash) for all periods, although for general traffic offences, the offence rate was highest in the post-licence restoration period for those who had a crash at index offence. This indicates that being involved in a crash may deter these offenders, at least in the short-term. The implications of the results for managing both first time and repeat offenders are discussed

    Run-to-tumble variability controls the surface residence times of E. coli bacteria

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    Motile bacteria are known to accumulate at surfaces, eventually leading to changes in bacterial motility and bio-film formation. We use a novel two-colour, three-dimensional Lagrangian tracking technique, to follow simultaneously the body and the flagella of a wild-type Escherichia coli{\it Escherichia~coli}. We observe long surface residence times and surface escape corresponding mostly to immediately antecedent tumbling. A motility model accounting for a large behavioural variability in run-time duration, reproduces all experimental findings and gives new insights into surface trapping efficiency

    Population analysis and the effects of Gaussian basis set quality and quantum mechanical approach: main group through heavy element species

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    Atomic charge and its distribution across molecules provide important insight into chemical behavior. Though there are many studies on various routes for the determination of atomic charge, there are few studies that examine the broader impact of basis set and quantum method used over many types of population analysis methods across the periodic table. Largely, such a study of population analysis has focused on main-group species. In this work, atomic charges were calculated using several population analysis methods including orbital-based methods (Mulliken, Löwdin, and Natural Population Analysis), volume-based methods (Atoms-in-Molecules (AIM) and Hirshfeld), and potential derived charges (CHELP, CHELPG, and Merz-Kollman). The impact of basis set and quantum mechanical method choices upon population analysis has been considered. The basis sets utilized include Pople (6-21G**, 6-31G**, 6-311G**) and Dunning (cc-pVnZ, aug-cc-pVnZ; n = D, T, Q, 5) basis sets for main group molecules. For the transition metal and heavy element species examined, relativistic forms of the correlation consistent basis sets were used. This is the first time the cc-pVnZ-DK3 and cc-pwCVnZ-DK3 basis sets have been examined with respect to their behavior across all levels of basis sets for atomic charges for an actinide. The quantum methods chosen include two density functional (PBE0 and B3LYP), Hartree-Fock, and second-order Møller-Plesset perturbation theory (MP2) approaches

    Accurate Enthalpies of Formation of Alkali and Alkaline Earth Metal Oxides and Hydroxides:  Assessment of the Correlation Consistent Composite Approach (ccCA)

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    Computing the enthalpies of formation for alkali metal and alkaline earth metal oxides (MxO) and hydroxides [M(OH)n] using the Gaussian-n (Gn) and Weismann-n (Wn) ab initio model chemistries is difficult due to an improper treatment of core-valence electron correlation effects. Using a new model chemistry called the correlation consistent Composite Approach (ccCA), enthalpies of formation were determined for eight different alkali/alkaline earth metal oxides and hydroxides. Unlike the Gn and Wn model chemistries, which must be modified to properly account for core-valence electron correlation, the standard implementations of the ccCA provide acceptable results, and all enthalpies of formation obtained with the ccCA are within the accepted range of recommended values

    A prospective study to assess the value of MMP-9 in improving the appropriateness of urgent referrals for colorectal cancer

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    Background Bowel cancer is common and is a major cause of death. Most people with bowel symptoms who meet the criteria for urgent referral to secondary care will not be found to have bowel cancer, and some people who are found to have cancer will have been referred routinely rather than urgently. If general practitioners could better identify people who were likely to have bowel cancer or conditions that may lead to bowel cancer, the pressure on hospital clinics may be reduced, enabling these patients to be seen more quickly. Increased levels of an enzyme called matrix metalloproteinase 9 (MMP-9) have been found to be associated with such conditions, and this can be measured from a blood sample. This study aims to find out whether measuring MMP-9 levels could improve the appropriateness of urgent referrals for patients with bowel symptoms. Methods People aged 18 years or older referred to a colorectal clinic will be asked to complete a questionnaire about symptoms, recent injuries or chronic illnesses (these can increase the level of matrix metalloproteinases) and family history of bowel cancer. A blood sample will be taken from people who consent to take part to assess MMP-9 levels, and the results of examination at the clinic and/or investigations arising from the clinic visit will be collected from hospital records. The accuracy of MMP-9 will be assessed by comparing the MMP-9 level with the resulting diagnosis. The combination of factors (e.g. symptoms and MMP-9 level) that best predict a diagnosis of malignancy (invasive disease or polyps) will be determined. Discussion Although guidelines are in place to facilitate referrals to colorectal clinics, symptoms alone do not adequately distinguish people with malignancy from people with benign conditions. This study will establish whether MMP-9 could assist this process. If this were the case, measurement of MMP-9 levels could be used by general practitioners to assist in the identification of people who were most likely to have bowel cancer or conditions that may lead to bowel cancer, and who should, therefore, be referred most urgently to secondary car
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