The Mitochondrial Permeability Transition (MPT) pore is a voltage-sensitive unselective channel known to instigate necrotic cell death during cardiac disease. Recent models suggest that the isomerase cyclophilin D (CypD) regulates the MPT pore by binding to either the F0F1-ATP synthase lateral stalk or the mitochondrial phosphate carrier (PiC). Here we confirm that CypD, through its N-terminus, can directly bind PiC. We then generated cardiac-specific mouse strains overexpressing or with decreased levels of mitochondrial PiC to assess the functionality of such interaction. While PiC overexpression had no observable pathologic phenotype, PiC knockdown resulted in cardiac hypertrophy along with decreased ATP levels. Mitochondria isolated from hearts of these mouse lines and their respective non-transgenic controls had no divergent phenotype in terms of oxygen consumption and Ca2+-induced MPT, as assessed by swelling and Ca2+-retention measurements. These results provide genetic evidence indicating that the mitochondrial PiC is not a critical component of the MPT pore.

Cardiac dysfunction in the aged heart reflects abnormalities in cardiomyocyte Ca(2+) homeostasis including altered Ca(2+) cycling through the sarcoplasmic reticulum (SR). The ryanodine receptor antagonist dantrolene exerts antiarrhythmic effects by preventing spontaneous diastolic Ca(2+) release from the SR. We tested the hypothesis that dantrolene prevents spontaneous Ca(2+) release without altering excitation-contraction coupling in aged myocardium. Left ventricular cardiomyocytes isolated from young (3 to 4 mo) and aged (24-26 mo) C57BL/6 mice were loaded with the Ca(2+) indicator fluo-4. Amplitudes of action potential-induced Ca(2+) transients at 1-Hz pacing were similar between young and aged mice, yet cell shortening was impaired in aged mice. Isoproterenol (1 μM) increased Ca(2+) transient amplitude and cell shortening to identical levels in young and aged; dantrolene (1 μM) had no effect on Ca(2+) transients or cell shortening during pacing. Under Ca(2+) overload conditions induced with 10 mM extracellular Ca(2+) concentration, spontaneous Ca(2+) waves were of diminished amplitude and associated with lower SR Ca(2+) content in aged versus young mice. Despite no effect in young mice, dantrolene increased SR Ca(2+) content and Ca(2+) wave amplitude in aged mice. In the presence of isoproterenol following rest from 1-Hz pacing, Ca(2+) spark frequency was elevated in aged mice, yet the time to spontaneous Ca(2+) wave was similar between young and aged mice; dantrolene decreased Ca(2+) spark frequency and prolonged the time to Ca(2+) wave onset in aged mice with no effect in young mice. Thus dantrolene attenuates diastolic Ca(2+) release in the aged murine heart that may prove useful in preventing cardiac dysfunction.

The Frank-Starling mechanism, whereby increased diastolic filling leads to increased cardiac output, depends on increasing the sarcomere length (Ls) of cardiomyocytes. Ventricular stiffness increases with advancing age, yet it remains unclear how such changes in compliance impact sarcomere dynamics in the intact heart. We developed an isolated murine heart preparation to monitor Ls as a function of left ventricular pressure and tested the hypothesis that sarcomere lengthening in response to ventricular filling is impaired with advanced age. Mouse hearts isolated from young (3-6 mo) and aged (24-28 mo) C57BL/6 mice were perfused via the aorta under Ca(2+)-free conditions with the left ventricle cannulated to control filling pressure. Two-photon imaging of 4-{2-[6-(dioctylamino)-2-naphthalenyl]ethenyl}1-(3-sulfopropyl)-pyridinium fluorescence was used to monitor t-tubule striations and obtain passive Ls between pressures of 0 and 40 mmHg. Ls values (in μm, aged vs. young, respectively) were 2.02 ± 0.04 versus 2.01 ± 0.02 at 0 mmHg, 2.13 ± 0.04 versus 2.23 ± 0.02 at 5 mmHg, 2.21 ± 0.03 versus 2.27 ± 0.03 at 10 mmHg, and 2.28 ± 0.02 versus 2.36 ± 0.01 at 40 mmHg, indicative of impaired sarcomere lengthening in aged hearts. Atomic force microscopy nanoindentation revealed that intact cardiomyocytes enzymatically isolated from aged hearts had increased stiffness compared with those of young hearts (elastic modulus: aged, 41.9 ± 5.8 kPa vs. young, 18.6 ± 3.3 kPa; P = 0.006). Impaired sarcomere lengthening during left ventricular filling may contribute to cardiac dysfunction with advancing age by attenuating the Frank-Starling mechanism and reducing stroke volume.

Goal and target setting is a basic precondition to effective management and the basis for accountability for both the use of health services and for achieving health care outcomes 1 Target setting has long been seen within business as an essential part of formulating any strategy. Targets should be related to actions known to be effective, be achievable but challenging, and be able to be monitored through indicators (see box).2 Targets can highlight key aspects of policy and act as a stimulus to increase commitment to policy implementation. Careless target setting, however, based on inadequate data or unrealistic short term objectives, can be counterproductive in that the resulting targets may discourage action and place unnecessary stress on those expected to achieve them. [3][4][5] The publication of the consultative documents The Health of the Nation in 1991 and Scotland's Health: A Challenge To Us All in 1992 heralded a new government approach to health planning, central to which was a need to identify clear objectives and specific targets for improving health.6 7 These targets were to be identified in each of the key areas of greatest health concern and where the greatest opportunity for real improvements in health could be realised. Their main aim is to stimulate and direct coordinated action. 6 Although it was envisaged that the results of target setting would be assessed, no published reports have looked at the results of target setting for health in the UK. A number of key questions posed in the BMJ five years ago are still unanswered: Do targets inspire, motivate and encourage coordination and common purpose among health workers and organisations?Can they engage other sectors at local and national level?Will they mobilise support from ordinary people and communities? 8 In this article we take the opportunity provided by the recent adoption of breast feeding targets by all Scottish health boards to look at one example of target setting in the NHS in Scotland. Breast feeding targetsIn 1993 the national review of food and nutrition in Scotland recommended the adoption of targets for breast feeding, 9 and in November 1994 the Secretary of State for Scotland announced a national target: more than 50% of women to be still breast feeding their babies at six weeks of life by the year 2005 (an annual increase of 1.3% in the percentage of mothers breast feeding every year from 1990). The Management Executive of the NHS in Scotland reinforced this by asking all health board general managers to advise them of proposals for local breast feeding targets and milestones in line with local circumstances by January 1995. 10The case for setting breast feeding targets in Scotland is well founded: breast feeding rates are the second lowest in Europe and among the lowest in the world.11 There is good evidence that raising these rates would improve health in children by preventing diarrhoeal episodes [12][13][14] and reducing the numbers of cases of lower respiratory infection, 14 15 necrotising Health targets: desira...

development with an ethyl-acetate, pyridine, water solvent system, the galactose is detected by means of a sensitive location reagent for reducing sugars. The reagent described by Flynn et al. (1953) has been found especially well suited to this purpose. 6