Immune Activation Reduces Sperm Quality in the Great Tit

Mounting an immune response against pathogens incurs costs to organisms by its effects on important life-history traits, such as reproductive investment and survival. As shown recently, immune activation produces large amounts of reactive species and is suggested to induce oxidative stress. Sperm are highly susceptible to oxidative stress, which can negatively impact sperm function and ultimately male fertilizing efficiency. Here we address the question as to whether mounting an immune response affects sperm quality through the damaging effects of oxidative stress. It has been demonstrated recently in birds that carotenoid-based ornaments can be reliable signals of a male's ability to protect sperm from oxidative damage. In a full-factorial design, we immune-challenged great tit males while simultaneously increasing their vitamin E availability, and assessed the effect on sperm quality and oxidative damage. We conducted this experiment in a natural population and tested the males' response to the experimental treatment in relation to their carotenoid-based breast coloration, a condition-dependent trait. Immune activation induced a steeper decline in sperm swimming velocity, thus highlighting the potential costs of an induced immune response on sperm competitive ability and fertilizing efficiency. We found sperm oxidative damage to be negatively correlated with sperm swimming velocity. However, blood resistance to a free-radical attack (a measure of somatic antioxidant capacity) as well as plasma and sperm levels of oxidative damage (lipid peroxidation) remained unaffected, thus suggesting that the observed effect did not arise through oxidative stress. Towards the end of their breeding cycle, swimming velocity of sperm of more intensely colored males was higher, which has important implications for the evolution of mate choice and multiple mating in females because females may accrue both direct and indirect benefits by mating with males having better quality sperm.

Outcome in adult patients after arterial switch operation for transposition of the great arteries

BACKGROUND: The arterial switch operation (ASO) is currently the treatment of choice in neonates with transposition of the great arteries (TGA). The outcome in childhood is encouraging but only limited data for long-term outcome into adulthood exist. METHODS AND RESULTS: We studied 145 adult patients (age>16, median 25years) with ASO followed at our institution. Three patients died in adulthood (mortality 2.4/1000-patient-years). Most patients were asymptomatic and had normal left ventricular function. Coronary lesions requiring interventions were rare (3 patients) and in most patients related to previous surgery. There were no acute coronary syndromes. Aortic root dilatation was frequent (56% patients) but rarely significant (>45mm in 3 patients, maximal-diameter 49mm) and appeared not to be progressive. There were no acute aortic events and no patient required elective aortic root surgery. Progressive neo-aortic-valve dysfunction was not observed in our cohort and only 1 patient required neo-aortic-valve replacement. Many patients (42.1%), however, had significant residual lesions or required reintervention in adulthood. Right ventricular outflow tract lesions or dysfunction of the neo-pulmonary-valve were frequent and 8 patients (6%) required neo-pulmonary-valve replacement. Cardiac interventions during childhood (OR 3.0, 95% CI 1.7-5.4, P<0.0001) were strong predictors of outcome (cardiac intervention/significant residual lesion/death) in adulthood. CONCLUSIONS: Adult patients with previous ASO remain free of acute coronary or aortic complications and have low mortality. However, a large proportion of patients require re-interventions or present with significant right sided lesions. Life-long cardiac follow-up is, therefore, warranted. Periodic noninvasive surveillance for coronary complications appears to be safe in adult ASO patients.

The arterial switch operation in Europe for transposition of the great arteries: a multi-institutional study from the European Congenital Heart Surgeons Association

OBJECTIVES: This study analyzes the results of the arterial switch operation for transposition of the great arteries in member institutions of the European Congenital Heart Surgeons Association. METHODS: The records of 613 patients who underwent primary arterial switch operations in each of 19 participating institutions in the period from January 1998 through December 2000 were reviewed retrospectively. RESULTS: A ventricular septal defect was present in 186 (30%) patients. Coronary anatomy was type A in 69% of the patients, and aortic arch pathology was present in 20% of patients with ventricular septal defect. Rashkind septostomy was performed in 75% of the patients, and 69% received prostaglandin. There were 37 hospital deaths (operative mortality, 6%), 13 (3%) for patients with an intact ventricular septum and 24 (13%) for those with a ventricular septal defect (P < .001). In 36% delayed sternal closure was performed, 8% required peritoneal dialysis, and 2% required mechanical circulatory support. Median ventilation time was 58 hours, and intensive care and hospital stay were 6 and 14 days, respectively. Although of various preoperative risk factors the presence of a ventricular septal defect, arch pathology, and coronary anomalies were univariate predictors of operative mortality, only the presence of a ventricular septal defect approached statistical significance (P = .06) on multivariable analysis. Of various operative parameters, aortic crossclamp time and delayed sternal closure were also univariate predictors; however, only the latter was an independent statistically significant predictor of death. CONCLUSIONS: Results of the procedure in European centers are compatible with those in the literature. The presence of a ventricular septal defect is the clinically most important preoperative risk factor for operative death, approaching statistical significance on multivariable analysis.

Ventricular arrhythmias and sudden death in adults after a Mustard operation for transposition of the great arteries

AIMS: To examine the prevalence of sustained ventricular tachycardia (VT) and sudden death (SD) in adults with atrial repair of transposition of the great arteries (TGA) and to determine associated risk factors. METHODS AND RESULTS: In a single-centre review, we studied the outcome of 149 adults (mean age 28 +/- 7 years) who had undergone a Mustard operation for TGA. During a mean follow-up of 9 +/- 6 years, sustained VT and/or SD occurred in 9% (13/149) of the cohort. Sustained VT/SD was more likely to occur in patients with associated anatomic lesions [hazard ratio (HR) 4.9, 95% CI 1.5-16.0], with NYHA class >or=III (HR 9.8, 95% CI 3.0-31.6) and with an impaired subaortic right ventricular (RV) ejection fraction (EF) (HR 2.2, 95% CI 1.2-4.0 per 10% decrease in EF). There was an inverse correlation between the RV-EF and both age and QRS duration. Patients with a QRS duration >or=140 ms were at highest risk of sustained VT/SD (HR 13.6, 95% CI 2.9-63.4). Atrial tachyarrhythmia was detected in 66 (44%) patients, but was not a statistically significant predictor of sustained VT/SD in our adult population (HR 2.7, 95% CI 0.6-13.0). CONCLUSION: Sustained VT/SD in adults after a Mustard operation for TGA are more common than previously described. Age, systemic ventricular function, and QRS duration are interrelated and are associated with VT/SD. A QRS duration >or=140 ms helps to identify the high risk patient.

Congenitally corrected transposition of the great arteries in an 80 year old woman

Congenitally corrected transposition of the great arteries (CCTGA) is a rare form of congenital heart disease characterised by atrioventricular as well as ventriculoarterial discordance. It is usually associated with a variety of severe intracardiac defects. Few patients with this abnormality survive past 50 years. An 80 year old woman was admitted to the hospital because of mild congestive heart failure. Cardiac examination revealed a 4/6 holosystolic and a 2/6 decrescendo diastolic murmur at the left sternal border. Radiography, echocardiography, and computed tomography confirmed newly diagnosed CCTGA without associated intracardiac defects.

Unconventional Monetary Policy and the Great Recession: Estimating the Macroeconomic Effects of a Spread Compression at the Zero Lower Bound

We explore the macroeconomic effects of a compression in the long-term bond yield spread within the context of the Great Recession of 2007–09 via a time-varying parameter structural VAR model. We identify a “pure” spread shock defined as a shock that leaves the policy rate unchanged, which allows us to characterize the macroeconomic consequences of a decline in the yield spread induced by central banks’ asset purchases within an environment in which the policy rate is constrained by the effective zero lower bound. Two key findings stand out. First, compressions in the long-term yield spread exert a powerful effect on both output growth and inflation. Second, conditional on available estimates of the impact of the Federal Reserve’s and the Bank of England’s asset purchase programs on long-term yield spreads, our counterfactual simulations suggest that U.S. and U.K. unconventional monetary policy actions have averted significant risks both of deflation and of output collapses comparable to those that took place during the Great Depression.