Association of uric acid with mortality in patients with stable coronary artery disease

ObjectiveThe association between uric acid and cardiovascular disease is poorly studied. We undertook this study to assess whether uric acid level predicts clinical outcome in patients with stable coronary artery disease (CAD) treated with percutaneous coronary intervention (PCI).Materials/MethodsThis study included 8149 patients with stable CAD who underwent PCI. Uric acid was measured before angiography. The primary end point was 1-year mortality. Quartiles of quartiles of uric acid were: 1.49 to < 5.49 mg/dl (1st quartile; n=2032 patients), 5.49 to < 6.40 mg/dl (2nd quartile; n=1981 patients), 6.40 to < 7.50 mg/dl (3rd quartile; n=2093 patients) and 7.50 to 21.90 mg/dl (4th quartile; n=2043 patients).ResultsThere were 196 deaths during the 1-year follow-up. The numbers of deaths (Kaplan-Meier estimates) according to uric acid quartiles were: 35 deaths (1.8%) in the 1st quartile, 30 deaths (1.6%) in the 2nd quartile, 45 deaths (2.2%) in the 3rd quartile and 86 deaths (4.3%) in the 4th quartile (unadjusted hazard ratio [HR]=1.60, 95% confidence interval [CI] 1.38-1.86, P < 0.001 for each standard deviation [SD] increase in the logarithmic scale). After adjustment for traditional cardiovascular risk factors, renal function and inflammatory status, the association between uric acid and 1-year mortality remained significant (adjusted HR=1.26, 95% CI 1.07-1.48; P=0.005 for each standard deviation increase in the logarithmic scale). Uric acid improved predictivity of the multivariable model regarding mortality (P=0.040).ConclusionsElevated level of uric acid is an independent predictor of 1-year mortality in patients with stable CAD treated with PCI.     

Prognostic value of uric acid in patients with acute coronary syndromes

The association between uric acid and cardiovascular disease is incompletely understood. In particular, the prognostic value of uric acid in patients with acute coronary syndromes who undergo percutaneous coronary intervention has not been studied. This study included 5,124 patients with acute coronary syndromes who underwent percutaneous coronary intervention: 1,629 with acute ST-segment elevation myocardial infarction, 1,332 with acute non-ST-segment elevation myocardial infarction, and 2,163 with unstable angina. The primary end point was 1-year mortality. Patients were divided into quartiles according to uric acid level as follows: quartile 1, 1.3 to <5.3 mg/dl; quartile 2, 5.3 to <6.3 mg/dl; quartile 3, 6.3 to <7.5 mg/dl; and quartile 4, 7.5 to 18.4 mg/dl. There were 450 deaths during follow-up: 80 deaths in quartile 1, 77deaths in quartile 2, 72 deaths in quartile 3, and 221 deaths in quartile 4 of uric acid (Kaplan-Meier estimates of 1-year mortality 6.4%, 6.2%, 5.6%, and 17.4%, respectively; unadjusted hazard ratio 3.05, 95% confidence interval 2.54 to 3.67, p <0.001 for fourth vs first quartile of uric acid). After adjustment for traditional cardiovascular risk factors, renal function, and inflammatory status, the association between uric acid and mortality remained significant, with a 12% increase in the adjusted risk for 1-year mortality for every 1 mg/dl increase in the uric acid level. Uric acid improved the discriminatory power of the predictive model regarding 1-year mortality (absolute integrated discrimination improvement 0.008, p = 0.005). In conclusion, elevated levels of uric acid are an independent predictor of 1-year mortality across the whole spectrum of patients with acute coronary syndromes treated with percutaneous coronary intervention.     

Evidence that membrane-bound G protein-coupled melatonin receptors MT1 and MT2 are not involved in the neuroprotective effects of melatonin in focal cerebral ischemia

Melatonin is synthesized and released by the pineal gland in a circadian rhythm, and many of its peripheral actions are mediated via membrane MT1 and MT2 receptors. Apart from its metabolic functions, melatonin is a potent neuroprotective molecule owing to its antioxidative actions. The roles of MT1 and MT2 in the neuroprotective effects of melatonin and cell signaling after cerebral ischemia remain unknown. With the use of MT1 and MT2 knockout (mt1/2(-/-) ) mice treated with melatonin, we evaluated brain injury, edema formation, inducible nitric oxide synthase (iNOS) activity, and signaling pathways, including CREB, ATF-1, p21, Jun kinase (JNK)1/2, p38 phosphorylation, resulting from ischemia/reperfusion injury. We show that the infarct volume and brain edema do not differ between mt1/2(-/-) and wild-type (WT) animals, but melatonin treatment decreases infarct volume in both groups and brain edema in WT animals after middle cerebral artery occlusion. Notably, melatonin's neuroprotective effect was even more pronounced in mt1/2(-/-) animals compared to that in WT animals. We also demonstrate that melatonin treatment decreased CREB, ATF-1, and p38 phosphorylation in both mt1/2(-/-) and WT mice, while p21 and JNK1/2 were reduced only in melatonin-treated WT animals in the ischemic hemisphere. Furthermore, melatonin treatment lowered iNOS activity only in WT animals. We provide evidence that the absence of MT1 and MT2 has no unfavorable effect on ischemic brain injury. In addition, the neuroprotective effects of melatonin appear to be mediated through a mechanism independent of its membrane receptors. The underlying mechanism(s) should be further studied using selective melatonin receptor agonists and antagonists.     

Histopathological and functional effects of antimony on the renal cortex of growing albino rat

Contamination of the environment with antimony compounds may affect human health through the persistent exposure to small doses over a long period. Sixty growing male albino rats, weighing 43-57 grams, utilized in this study. The animals were divided into 3 groups; each of 20 rats: animals of group I served as control, animals of group II received 6 mg/kg body weight antimony trisulfide daily for 8 weeks with drinking water, and those of group III received the same dose by the same route for 12 weeks. The Malpighian renal corpuscles showed distortion, destruction and congestion of glomerular tuft, vacuoles in the glomeruli, peritubular haemorrhage, obliteration of Bowman’s space, and thickening with irregularity of Bowman’s membrane. The proximal convoluted tubules demonstrated patchy loss of their brush border, thickening of the basement membrane with loss of its basal infoldings, disarrangement of the mitochondria, pleomorphic vacuoles in the cytoplasm, apical destruction of the cells, apical migration of the nuclei, and absence of microvilli. On the other hand, peri-tubular hemorrhage, apical vacuolation, small atrophic nuclei, swelling of mitochondria, obliteration of the lumina, destruction of cells, and presence of tissue debris in the lumina, were observed in the distal convoluted tubules. The present work demonstrated the hazardous effect of antimony on the renal function as evidenced by the significant increase of the level of blood urea, serum creatinine, and serum sodium and potassium. In conclusion, this study proposed that continuous oral administration of antimony for 8 and 12 weeks has hazardous toxic effect on the structure and function of the kidney in growing albino rat. Based on the results of the present study, it is recommended to avoid the use of any drinking water contaminated with antimony compounds and forbidden its use in infants and children foods.     

Results of endovascular treatment of middle cerebral artery aneurysms after first giving consideration to clipping

Background

Middle cerebral artery (MCA) aneurysms are among the more challenging aneurysms for endovascular treatment. We report a contemporary 5-year experience with endovascular therapy for MCA aneurysms at a high-volume neurovascular center.

Methods

Review of prospectively maintained intracranial aneurysm database.

Results

Between 2005 and 2009, 148 patients underwent treatment of 149 MCA aneurysms at our hospital, of which 33 patients with 34 aneurysms underwent endovascular therapy. Among these 33 patients, 14 presented with subarachnoid hemorrhage. Eleven patients were treated with stent-assisted coiling, 1 with balloon-assisted coiling, and the remainder with coiling alone. Three patients required repeat endovascular treatment. There were 7 periprocedural complications, including intraprocedural aneurysm rupture resulting in death in 2 patients. Two patients died at later dates from remote aneurysm rehemorrhage. Average follow-up of remaining patients was 17.1 months radiographically, and 20.3 months clinically. Average modified Rankin scale (mRS) score at last follow up was 2.09, with 17 patients with mRS 0/1 and 5 patients with mRS 2. Fifteen patients showed evidence of radiographic residual at last follow up: 13 were simple neck residuals. Unruptured status and saccular aneurysms were associated with mRS 0/1 outcome (each p?<?0.05).

Conclusions

At our hospital, MCA aneurysms are being treated with endovascular techniques, but in a minority of patients. Despite the rate of residual neck remnants, few retreatments were necessary and few rehemorrhages occurred. The periprocedural complication rate was not insignificant; therefore, in more recent years and at present, most MCA aneurysms are considered for clipping first at our center.