The long-term conditioning effects of physical training on cardiorespiratory interaction in 11 young healthy males were studied. Significant increases in maximum oxygen uptake (VO2max) (P < 0.05) and decreases in heart rate (P < 0.05) were achieved in all subjects following a 6-week training programme consisting of cycling for 25 min each day at a work level that increased heart rate to 85% of maximum. Heart rate variability, measured as the differences between the maximum and minimum R-R interval in a respiratory cycle, increased in nine of the subjects and decreased in two. The respiratory-cycle-related high-frequency peak in the power spectral plot of R-R variability also showed significant increases in the same nine subjects and decreases in two. The latter result was similar after normalisation of the data for changes in heart rate by calculating the common coefficient of variance [symbol: see text], where HF is the high-frequency component of the power spectral plots, using a further measure of vagal tone it was shown that, for all subjects, the R-R interval change in response to isometric contractions of the arm flexors in one respiratory cycle were significantly greater after training. These data suggest that cardiac vagal tone is increased by aerobic training for all subjects and that this is accompanied by a respiratory sinus arrhythmia (RSA) in most, but may be associated with a decrease in RSA in subjects with a very low (< 50 beats.min-1 heart rate.
Background: Given current evidence, the use of allopurinol for the prevention of major cardiovascular events (acute cardiovascular syndrome (ACS) or cardiovascular mortality) in patients undergoing coronary artery bypass graft (CABG), after index ACS or heart failure remains unknown. Methods: Multiple databases were queried to identify studies comparing the efficacy of allopurinol in patients undergoing CABG, after ACS or heart failure. The unadjusted odds ratio (OR) was calculated using a random effect model. Results: A total of nine studies comprising 850 patients (allopurinol 480, control 370) were identified. The pooled OR of periprocedural ACS (OR: 0.25, 95% confidence interval (CI): 0.06-0.96, P = 0.05) and cardiovascular mortality (OR: 0.22, 95% CI: 0.07-0.71, P = 0.01) was significantly lower in patients receiving allopurinol during CABG compared to patients in the control group. The overall number needed to treat (NNT) to prevent one ACS event was 11 (95% CI: 7-28), while the NNT to prevent one death was 24 (95% CI: 13-247). By contrast, the odds of cardiovascular mortality in the allopurinol group were not significantly different from the control group in patients on long-term allopurinol after ACS or heart failure (OR: 0.33, 95% CI: 0.01-8.21, P = 0.50) and (OR: 1.12, 95% CI: 0.39-3.20, P = 0.83), respectively. Similarly, the use of allopurinol did not reduce the odds of recurrent ACS events at 2 years (OR: 0.32, 95% CI: 0.03-3.18, P = 0.33). Conclusions: Periprocedural use of allopurinol might be associated with a significant reduction in the odds of ACS and cardiovascular mortality in patients undergoing CABG. Allopurinol, however, offers no long-term benefits in terms of secondary prevention of ACS or mortality. Larger scale studies are needed to validate our findings.
Humoral hypercalcemia of malignancy (HHM) can be caused by ectopic paraneoplastic production of 1, 25 dihydroxy vitamin D due to the hyperactivity of the 1 alpha-hydroxylase enzyme. We present a case of a 19-year-old female who was admitted with bilateral dysgerminomas and significant hypercalcemia. Hypercalcemia was initially managed medically and then resolved with the surgical resection of the tumors. Although most cases are attributed to a high parathyroid hormone-related peptide (PTHrP) and bone metastases, <1% of cases can result from paraneoplastic production of 1,25 dihydroxyvitamin D due to increased activity of 1 alpha-hydroxylase.This is one of the rare cases of hypercalcemia, which not only adds to the limited number of cases of hypercalcemia associated with dysgerminoma but also is the first case report showing that vitamin D can be a paraneoplastic factor itself.
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