Involvement of Nox2 NADPH oxidase in adverse cardiac remodeling after myocardial infarction.

Oxidative stress plays an important role in the development of cardiac remodeling after myocardial infarction (MI), but the sources of oxidative stress remain unclear. We investigated the role of Nox2-containing reduced nicotinamide-adenine dinucleotide phosphate oxidase in the development of cardiac remodeling after MI. Adult Nox2(-/-) and matched wild-type (WT) mice were subjected to coronary artery ligation and studied 4 weeks later. Infarct size after MI was similar in Nox2(-/-) and WT mice. Nox2(-/-) mice exhibited significantly less left ventricular (LV) cavity dilatation and dysfunction after MI than WT mice (eg, echocardiographic LV end-diastolic volume: 75.7+/-5.8 versus 112.4+/-12.3 microL; ejection fraction: 41.6+/-3.7 versus 32.9+/-3.2%; both P

High-dose adenosine overcomes the attenuation of myocardial perfusion reserve caused by caffeine.

Objectives:
We studied whether an increase in adenosine dose overcomes caffeine antagonism on adenosine-mediated coronary vasodilation.

Background:
Caffeine is a competitive antagonist at the adenosine receptors, but it is unclear whether caffeine in coffee alters the actions of exogenous adenosine, and whether the antagonism can be surmounted by increasing the adenosine dose.

Methods:
Myocardial perfusion scintigraphy (MPS) was used to assess adenosine-induced hyperemia in 30 patients before (baseline) and after coffee ingestion (caffeine). At baseline, patients received 140 µg/kg/min of adenosine combined with low-level exercise. For the caffeine study, 12 patients received 140 µg/kg/min of adenosine (standard) and 18 patients received 210 µg/kg/min (high dose) after caffeine intake (200 mg). Myocardial perfusion was assessed semiquantitatively and quantitatively, and perfusion defect was characterized according to the presence of reversibility.

Results:
Caffeine reduced the magnitude of perfusion abnormality induced by standard adenosine as measured by the summed difference score (SDS) (12.0 ± 4.4 at baseline vs. 4.1 ± 2.1 after caffeine, p < 0.001) as well as defect size (18% [3% to 38%] vs. 8% [0% to 22%], p < 0.01), whereas it had no effect on the abnormalities caused by high-dose adenosine (SDS, 7.7 ± 4.0 at baseline vs. 7.8 ± 4.2 after caffeine, p = 0.7). There was good agreement between baseline and caffeine studies for segmental defect category (kappa = 0.72, 95% confidence interval: 0.65 to 0.79) in the high-dose group. An increase in adenosine after caffeine intake was well tolerated.

Conclusions:
Caffeine in coffee attenuates adenosine-induced coronary hyperemia and, consequently, the detection of perfusion abnormality by adenosine MPS. This can be overcome by increasing the adenosine dose without compromising test tolerability.

Personal Injury Liability in Sport: Emerging Trends

Violent play during the course of a game or sport is not a new phenomenon; accompanying legal proceedings are. This article considers personal injury liability for injuries inflicted by a participant upon an opponent during a sporting pursuit. The jurisdictional focus is on England and Wales. The sporting emphasis of the article is on competitive, body contact games. The legal emphasis is on the tort of negligence. Analogous to the law of criminal assault, breach of "implied sporting consent" or the volenti of the claimant will be seen as central in application, as assessed through a number of objective criteria, including the skill level of the injuring party and whether that defendant was acting in "reckless disregard" of the claimant's safety. These criteria or evidential guidelines, which emerge from a careful doctrinal analysis of the relevant case law, are seen as crucial to the examination of the appropriate degree of care in negligence within the prevailing circumstances of sport. The article also searches for some theoretical coherency within the case law, premising it on Fletcher's idea of reciprocal risk-taking. In addition, the underlying policy-related issue of sport's social utility is discussed, as are practical matters relating to vicarious liability, insurance and the measure of damages for "lost sporting opportunity". Moreover, it will be shown that personal injury claims relating to sports participant liability now extend to a consideration of the duties of coaches, referees, sports governing bodies and schools. Finally, this article is set against the backdrop of an apparently spiralling "compensation culture" and the concomitant threat that that "blame culture" poses for the future promotion, operation and administration of sport.

Probabilistic classification of acute myocardial infarction from multiple cardiac markers

Logistic regression and Gaussian mixture model (GMM) classifiers have been trained to estimate the probability of acute myocardial infarction (AMI) in patients based upon the concentrations of a panel of cardiac markers. The panel consists of two new markers, fatty acid binding protein (FABP) and glycogen phosphorylase BB (GPBB), in addition to the traditional cardiac troponin I (cTnI), creatine kinase MB (CKMB) and myoglobin. The effect of using principal component analysis (PCA) and Fisher discriminant analysis (FDA) to preprocess the marker concentrations was also investigated. The need for classifiers to give an accurate estimate of the probability of AMI is argued and three categories of performance measure are described, namely discriminatory ability, sharpness, and reliability. Numerical performance measures for each category are given and applied. The optimum classifier, based solely upon the samples take on admission, was the logistic regression classifier using FDA preprocessing. This gave an accuracy of 0.85 (95% confidence interval: 0.78-0.91) and a normalised Brier score of 0.89. When samples at both admission and a further time, 1-6 h later, were included, the performance increased significantly, showing that logistic regression classifiers can indeed use the information from the five cardiac markers to accurately and reliably estimate the probability AMI. © Springer-Verlag London Limited 2008.

Interviewing children with acquired brain injury (ABI).

Research into the lives of children with acquired brain injury (ABI) often neglects to incorporate children as participants, preferring to obtain the opinions of the adult carer (e.g. McKinlay et al., 2002). There has been a concerted attempt to move away from this position by those working in children’s research with current etiquette highlighting the inclusion of children and the use of a child-friendly methodology (Chappell, 2000). Children with disabilities can represent a challenge to the qualitative researcher due to the combination of maintaining the child’s attention and the demands placed on them by their disability. The focus of this article is to discuss possible impediments to interviewing children with acquired brain injury (ABI) and provide an insight into how the qualitative researcher may address these.

Extravascular lung water indexed to predicted body weight is a novel predictor of intensive care unit mortality in patients with acute lung injury

Objectives: Acute lung injury and the acute respiratory distress syndrome are characterized by noncardiogenic pulmonary edema, which can be assessed by measurement of extravascular lung water. Traditionally, extravascular lung water has been indexed to actual body weight (mL/kg). Because lung size is dependent on height rather than weight, we hypothesized indexing to predicted body weight may be a better predictor of mortality in acute lung injury/acute respiratory distress syndrome.

Type XVIII collagen degradation products in acute lung injury

Introduction In acute lung injury, repair of the damaged alveolar-capillary barrier is an essential part of recovery. Endostatin is a 20 to 28 kDa proteolytic fragment of the basement membrane collagen XVIII, which has been shown to inhibit angiogenesis via action on endothelial cells. We hypothesised that endostatin may have a role in inhibiting lung repair in patients with lung injury. The aims of the study were to determine if endostatin is elevated in the plasma/bronchoalveolar lavage fluid of patients with acute lung injury and ascertain whether the levels reflect the severity of injury and alveolar inflammation, and to assess if endostatin changes occur early after the injurious lung stimuli of one lung ventilation and lipopolysaccharide (LPS) challenge.

Predictors of mortality in acute lung injury during the era of lung protective ventilation

Background: Lung protective ventilation has been widely adopted for the management of acute lung injury (ALI) and acute respiratory distress syndrome ( ARDS). Consequently, ventilator associated lung injury and mortality have decreased. It is not known if this ventilation strategy changes the prognostic value of previously identified demographic and pulmonary predictors of mortality, such as respiratory compliance and the arterial oxygen tension to inspired oxygen fraction ratio (Pao(2)/Fio(2)).

Perceptions of exercise among people who have not attended cardiac rehabilitation following myocardial infarction.

Perceptions of exercise among nonattenders of cardiac rehabilitation (CR) were explored using semistructured interviews. Analysis indicated that participants did not recognize the cardiovascular benefits of exercise, and perceived keeping
active through daily activities as sufficient for health. Health professionals were perceived to downplay the importance of exercise and CR, and medication was viewed as being more important than exercise for promoting health. The content of CR programmes and the benefits of exercise need to be further explained to patients post-MI, and in a manner that communicates to patients that these programmes are valued by significant others, particularly health professionals.

Cardiac rehabilitation uptake following myocardial infarction: cross-sectional study in primary care

Background Policies suggest that primary care should be more involved in delivering cardiac rehabilitation. However, there is a lack of information about what is known in primary care regarding patients' invitation or attendance. Aim To determine, within primary care, how many patients are invited to and attend rehabilitation after myocardial infarction (MI), examine sociodemographic factors related to invitation, and compare quality of life between those who do and do not attend. Design of study Review of primary care paper and computer records; cross-sectional questionnaire. Setting Northern Ireland general practices (38); stratified sample, based on practice size and health board area. Method Patients, identified from primary care records, 12-16?weeks after a confirmed diagnosis of MI, were posted questionnaires, including a validated MacNew post-MI quality-of-life questionnaire. Practices returned anonymised data for non-responders. Results Information about rehabilitation was available for 332 of the 432 patients identified (76.9%): 162 (37.5%) returned questionnaires. Of the total sample, 54.4% (235/432) were invited and 37.0% (160/432) attended; of those invited, 68.1% (160/235) attended. Invited patients were younger than those not invited (mean age 63?years [standard deviation SD 16] versus 68.5?years [SD 16]); mean difference 5.5?years (95% confidence interval [CI] = 1.7 to 9.3). Among questionnaire responders, those who attended were younger and reported better emotional, physical, and social functioning than non-attenders (P = 0.01; mean differences 0.44 (95% CI = 0.11 to 0.77), 0.48 (95% CI = 0.10 to 0.85) and 0.54 (95% CI = 0.15 to 0.94) respectively). Conclusion Innovative strategies are needed to improve cardiac rehabilitation uptake, integration of hospital and primary care services, and healthcare professionals' awareness of patients' potential for health gain after MI.