Anti-angiogenic drugs: direct anti-cancer agents with mitochondrial mechanisms of action

Components of the mitochondrial electron transport chain have recently gained much interest as potential therapeutic targets. Since mitochondria are essential for the supply of energy that is required for both angiogenic and tumourigenic activity, targeting the mitochondria represents a promising potential therapeutic approach for treating cancer. Here we investigate the established anti-angiogenesis drugs combretastatin A4, thalidomide, OGT 2115 and tranilast that we hypothesise are able to exert a direct anti-cancer effect in the absence of vasculature by targeting the mitochondria. Drug cytotoxicity was measured using the MTT assay. Mitochondrial function was measured in intact isolated mitochondria using polarography, fluorimetry and enzymatic assays to measure mitochondrial oxygen consumption, membrane potential and complex I–IV activities respectively. Combretastatin A4, OGT 2115 and tranilast were both shown to decrease mitochondrial oxygen consumption. OGT 2115 and tranilast decreased mitochondrial membrane potential and reduced complex I activity while combretastatin A4 and thalidomide did not. OGT 2115 inhibited mitochondrial complex II–III activity while combretastatin A4, thalidomide and tranilast did not. Combretastatin A4, thalidomide and OGT 2115 induced bi-phasic concentration-dependent increases and decreases in mitochondrial complex IV activity while tranilast had no evident effect. These data demonstrate that combretastatin A4, thalidomide, OGT 2115 and tranilast are all mitochondrial modulators. OGT 2115 and tranilast are both mitochondrial inhibitors capable of eliciting concentration-dependent reductions in cell viability by decreasing mitochondrial membrane potential and oxygen consumption

Ab initio calculation of the neutron-proton mass difference

The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14\% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We performed lattice quantum-chromodynamics and quantum-electrodynamics computations with four nondegenerate Wilson fermion flavors and computed the neutron-proton mass-splitting with an accuracy of $300$ kilo-electron volts, which is greater than $0$ by $5$ standard deviations. We also determine the splittings in the $\Sigma$, $\Xi$, $D$ and $\Xi_{cc}$ isospin multiplets, exceeding in some cases the precision of experimental measurements.Comment: 57 pages, 15 figures, 6 tables, revised versio

Multimodality imaging in congenital heart disease-related pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) in adult patients with congenital heart disease (CHD) is associated with increased morbidity and mortality. The present review aims to discuss the clinical applications of invasive and non-invasive diagnostic modalities and to describe the strengths and weaknesses of each technique. Chest radiograph is an inexpensive investigation providing information on pulmonary arterial and hilar dilatation, pruning of peripheral pulmonary arteries and cardiomegaly. Transthoracic two-dimensional and Doppler echocardiography is the most widely used imaging tool. It provides information on cardiac anatomy and an estimate of haemodynamics and biventricular remodelling and function. In addition, echocardiography is valuable in assessing prognosis and monitoring the efficacy of therapy. Structural and functional changes associated with CHD-PAH, mainly affecting the right ventricle and pulmonary circulation, may represent an ideal target for evaluation with cardiac magnetic resonance. This non-invasive imaging modality has a low biological impact. CT plays an important role for patients with limited echocardiographic windows and those who are unable to undergo MRI (claustrophobia, poor compliance, presence of a pacemaker/implantable cardioverter defibrillator). It is the modality of choice for detailed assessment of pulmonary vessel obstruction or thrombosis. Finally, heart catheterisation remains the gold standard for diagnosing and confirming PAH in patients with CHD and for shunt evaluation. The diagnostic assessment of CHD-PAH requires great expertise and a deep knowledge of both CHD and PAH pathophysiology and should take place in a tertiary centre, where multiple data can be appropriately integrated and applied clinically.Pulmonary arterial hypertension (PAH) in adult patients with congenital heart disease (CHD) is associated with increased morbidity and mortality. The present review aims to discuss the clinical applications of invasive and non-invasive diagnostic modalities and to describe the strengths and weaknesses of each technique. Chest radiograph is an inexpensive investigation providing information on pulmonary arterial and hilar dilatation, pruning of peripheral pulmonary arteries and cardiomegaly. Transthoracic two-dimensional and Doppler echocardiography is the most widely used imaging tool. It provides information on cardiac anatomy and an estimate of haemodynamics and biventricular remodelling and function. In addition, echocardiography is valuable in assessing prognosis and monitoring the efficacy of therapy. Structural and functional changes associated with CHD-PAH, mainly affecting the right ventricle and pulmonary circulation, may represent an ideal target for evaluation with cardiac magnetic resonance. This non-invasive imaging modality has a low biological impact. CT plays an important role for patients with limited echocardiographic windows and those who are unable to undergo MRI (claustrophobia, poor compliance, presence of a pacemaker/implantable cardioverter defibrillator). It is the modality of choice for detailed assessment of pulmonary vessel obstruction or thrombosis. Finally, heart catheterisation remains the gold standard for diagnosing and confirming PAH in patients with CHD and for shunt evaluation. The diagnostic assessment of CHD-PAH requires great expertise and a deep knowledge of both CHD and PAH pathophysiology and should take place in a tertiary centre, where multiple data can be appropriately integrated and applied clinically