T2-weighted cardiovascular magnetic resonance in acute cardiac disease

Cardiovascular magnetic resonance (CMR) using T2-weighted sequences can visualize myocardial edema. When compared to previous protocols, newer pulse sequences with substantially improved image quality have increased its clinical utility. The assessment of myocardial edema provides useful incremental diagnostic and prognostic information in a variety of clinical settings associated with acute myocardial injury. In patients with acute chest pain, T2-weighted CMR is able to identify acute or recent myocardial ischemic injury and has been employed to distinguish acute coronary syndrome (ACS) from non-ACS as well as acute from chronic myocardial infarction

Beyond equilibrium climate sensitivity

ISSN:1752-0908ISSN:1752-089

Caspase Regulation of Genotoxin-Induced Neural Precursor Cell Death

Neural precursor cells (NPCs) critically regulate brain morphogenesis and recent studies have revealed an unexpectedly high frequency of NPC chromosomal abnormalities and apoptosis in the developing brain. We have shown previously that the apoptotic response of NPCs to genotoxic agents is dependent on p53 and caspase-9, but not Bax or caspase-3 expression. In this study, we found that NPCs deficient in Apaf-1, or both the pro-apoptotic multidomain Bcl-2 family members Bax and Bak, were resistant to cytosine arabinoside and γ-irradiation-induced apoptosis. Inhibitors of gene transcription, protein translation, and caspase activity also blocked genotoxin-induced NPC apoptosis. Although caspase-3 and caspase-6 were both cleaved in response to DNA damage, neither of these effector caspases was critical for apoptosis. Genotoxin-induced NPC death was accompanied by the generation of reactive oxygen species and could be inhibited by several known antioxidants. Conversely, DNA damage-induced reactive oxygen species generation was inhibited significantly by gene disruption of p53, Apaf-1, or caspase-9, and combined deficiency of Bax and Bak, but not by caspase-3 or caspase-6 deficiency. These studies suggest that caspase-9 activation is both necessary and sufficient for genotoxin-induced neural precursor cell reactive oxygen species generation and death. © 2003 Wiley-Liss, Inc

Relationship between ventilatory function and age in master athletes and a sedentary reference population

Abstract Ageing is accompanied with a decline in respiratory function. It is hypothesised that this may be attenuated by high physical activity levels. We performed spirometry in master athletes (71 women; 84 men; 35–86 years) and sedentary people (39 women; 45 men; 24–82 years), and calculated the predicted lung age (PLA). The negative associations of age with forced expiratory volume in 1 s (FEV1; 34 mL·year−1) and other ventilatory parameters were similar in controls and master athletes. FEV1pred was 9 % higher (P<0.005) and PLA 15 % lower (P00.013) in athletes than controls. There were no significant differences between endurance and power athletes and sedentary people in maximal inspiratory and expiratory pressure. Neither age-graded performance nor weekly training hours were significantly related to lung age. Life-long exercise does not appear to attenuate the age-related decrease in ventilatory function. The better respiratory function in master athletes than age-matched sedentary people might be due to self-selection and attrition bias