Publications

There is an increase in reactive oxygen and nitrogen species in cardiomyocytes during myocardial ischemia/reperfusion injury. This leads to oxidative DNA damage and activation of nuclear repair enzymes such as poly(ADP-ribose) polymerase-1 (PARP-1). PARP-1 activation promotes DNA repair under normal conditions. However, excessive activation of PARP-1 leads to cell death. We report that PARP-1 enzymatic activity is directly inhibited by minocycline, and we propose that one mechanism of minocycline cardioprotection is the result of PARP-1 inhibition. Using cultured adult rat cardiac myocytes, we evaluated the mechanism of minocycline protection in which PARP-1 activation was induced by simulated ischemia/reperfusion injury using oxygen–glucose deprivation.We found an increase in reactive oxygen species production, PARP-1 activation, and PARP-1-mediated cell death after simulated ischemia/reperfusion. Cell death was significantly reduced by the PARP inhibitors 3, 4-dihydro-5-[4-(1-piperidinyl)butoxy]-1(2H)-isoquinolinone (10 μM) and PJ-34 (500 nM) or by minocycline (500 nM). Cellular NAD(+) depletion and poly(ADP-ribose) formation, which are biochemical markers of PARP-1 activation, were also blocked by minocycline. Finally, simulated ischemia/reperfusion led to induction of the mitochondrial permeability transition, which was prevented by minocycline. Therefore, we propose that the protective effect of minocycline on cardiac myocyte survival is the result of inhibition of PARP-1 activity.

OBJECTIVE

To identify predictors of bone remodelling in children and young adults with SLE.

METHODS

Ninety subjects with SLE aged 8-22 years underwent yearly measurements of height, bone age, bone turnover markers, serum Type I IFNs, SLEDAI and BMD. Predictors of bone turnover were examined using serum osteocalcin as a marker of bone formation and both serum tartrate-resistant acid phosphatase (TRAP) and urine N-telopeptide (NTx) as markers of bone resorption.

RESULTS

Subjects demonstrated short stature, high BMI and bone age delay. A spine BMD Z-score of less than -2.0 was seen in 16.1% of subject visits. Serum osteocalcin was negatively correlated with glucocorticoid dose (Spearman rank correlation coefficient R = -0.34, P < 0.0001) but was not associated with SLEDAI after adjustment for confounders. Serum TRAP was negatively associated with SLEDAI, even after controlling for confounders (P = 0.04). Similar results were obtained for urine NTx. There was a negative association between TRAP and serum IFN-β (P = 0.03).

CONCLUSIONS

In this population of children and young adults with moderate lupus disease activity, glucocorticoid dose was a negative predictor of bone formation, whereas lupus disease activity was not. Interestingly, lupus disease activity was a negative predictor of bone resorption, suggesting that lupus disease activity is not the primary factor contributing to the bone deficits of childhood-onset SLE. The potential protective role of IFN-β and the effects of SLE treatment on bone loss require further study.

BACKGROUND

Training patients are the first individuals in whom a physician uses an investigational device. There is great variability in the use of data from training patients in the absence of guidelines. The prevalence and extent of data reporting from training patients in cardiovascular device studies submitted for US Food and Drug Administration (FDA) approval has not been characterized.

METHODS

Information on training patients was abstracted from the Summary of Safety and Effectiveness Data summarizing cardiovascular device premarket applications approved by the FDA from 2000 through 2007. We examined the numbers and characteristics of training patients and the inclusion of their results in end-point analyses.

RESULTS

There were 78 cardiovascular device summaries in this 8-year period, of which 17 (22%) involved training patients. Of the 123 studies in the summaries, 20 (16%) used training patients. All studies excluded training patients from efficacy analyses and 19 of 20 (95%) excluded them from safety analyses. Sixteen of 20 (80%) did not provide any outcome data, and 15 of 20 (75%) did not check for outcome differences between training and nontraining treatment patients. Eighteen of 20 (90%) did not provide demographic information on training patients, and 14 of 20 (70%) did not prespecify guidelines for their enrollment.

CONCLUSIONS

Training patients comprise a considerable proportion of patients receiving investigational cardiovascular devices, but their results are excluded from FDA submissions. Their exclusion from analyses means that safety and efficacy outcomes may look better than actual results. Guidelines on the use and inclusion of results for training patients would improve accuracy on results reporting.