Endogenous serum erythropoietin and no-reflow in patients with ST-elevation myocardial infarction.

BACKGROUND: In models of acute ischaemia, erythropoietin (EPO) administration has been found to attenuate vascular injury largely through reduced apoptosis, suppressed inflammation and increased nitric oxide availability. We studied the association between circulating endogenous EPO and no-reflow in patients with first ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). METHODS: Blood sampling was performed before PPCI. Consecutive patients with (n = 24) or without (n = 24) evidence of angiographic no-reflow after PPCI were enrolled. Angiographic no-reflow was defined as Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 2 or as TIMI flow = 3 but with myocardial blush grade < 2. We also assessed electrocardiographic (ECG) no-reflow as ≤ 50% resolution of maximal ST elevation 60 min after PPCI. RESULTS: Baseline characteristics did not correlate significantly with EPO concentrations. In contrast, both angiographic and ECG no-reflow correlated with lower EPO levels at univariate analysis [median (interquartile): 4·2 (0·6-9·5) vs. 12·2 (5·2-20·3) mIU mL(-1), P = 0·001, and 4·0 (0·6-7·1) vs. 9·3 (1·0-12·6) mIU mL(-1), P = 0·01, respectively]. At multivariable analysis, decreasing EPO tertiles and left anterior descending as the infarct-related artery were the only factors that predicted both angiographic and ECG no-reflow (P = 0·017 and P = 0·02 for EPO; P < 0·005 and P > 0·05 for left anterior descending artery, respectively). CONCLUSIONS: We found an independent, graded, inverse relation between endogenous EPO levels and angiographic and ECG no-reflow following PPCI. In animal models of ischaemia, EPO has been found to be protective. In humans, endogenous EPO may contribute to offset the mechanisms responsible for no-reflow.

Birth of a hotspot of intraspecific genetic diversity: notes from the underground.

Hotspots of intraspecific diversity have been observed in most species, often within areas of putative Pleistocene refugia. They have thus mostly been viewed as the outcome of prolonged stability of large populations within the refugia. However, recent evidence has suggested that several other microevolutionary processes could also be involved in their formation. Here, we investigate the contribution of these processes to current range-wide patterns of genetic diversity in the Italian endemic mole Talpa romana, using both nuclear (30 allozyme loci) and mitochondrial markers (cytochrome b sequences). Southern populations of this species showed an allozyme variation that is amongst the highest observed in small mammals (most populations had an expected heterozygosity of 0.10 or above), which was particularly unexpected for a subterranean species. Population genetic, phylogeographic and historical demographic analyses indicated that T. romana populations repeatedly underwent allopatric differentiations followed by secondary admixture within the refugial range in southern Italy. A prolonged demographic stability was reliably inferred from the mitochondrial DNA data only for a population group located north and east of the Calabrian peninsula, showing comparatively lower levels of allozyme variability, and lacking evidence of secondary admixture with other groups. Thus, our results point to the admixture between differentiated lineages as the main cause of the higher levels of diversity of refugial populations. When compared with the Pleistocene evolutionary history recently inferred for species from both the same and other geographic regions, these results suggest the need for a reappraisal of the role of gene exchange in the formation of intraspecific hotspots of genetic diversity.

Contribution of the supraspinatus to the external rotator lag sign: kinematic and electromyographic pattern in an in vivo model.

HYPOTHESIS: The external rotation lag sign (ERLS) is a test designed to assess the integrity of the supraspinatus (SSP) and infraspinatus tendons. This study intends to determine the electromyographic pattern of shoulder girdle muscles during a series of ERLS tasks conducted at full adduction and 20 degrees of elevation to figure out the better way to perform the test. The second aim is to assess the final contribution of the SSP to the ERLS by measuring the amount of lag after an SSP block induced by botulinum toxin. MATERIALS AND METHODS: Ten subjects with healthy shoulders were examined by a series of five ERLS trials at full adduction and 20 degrees of elevation in the scapular plane. Surface and intramuscular electromyographic activity of the shoulder girdle muscles was recorded and normalized against either the mean activity of all the muscles or the peak activity. The lag was simultaneously measured by an infrared optoelectronic system before and after the selective block of the SSP muscle. RESULTS: The SSP contributed 20% of the electrical activities during the ERLS, which was found to be significantly greater than the contributions of the other shoulder girdle muscles, except for the infraspinatus. The selective block of the SSP caused a lag of 4 degrees in all 10 shoulders at 20 degrees but no increase in lag at 0 degrees of elevation. CONCLUSIONS: The ERLS is potentially able to detect an isolated SSP tear if the test is performed correctly (20 degrees of abduction). The deltoid and biceps muscles are almost silent during the test, limiting confounding factors.

[Body mass index and cardiovascular events: the "obesity paradox"]. / Recenti acquisizioni sui rapporti tra indice di massa corporea e danno cardiovascolare: il "paradosso dell'obesità".

Excessive body mass among healthy subjects carries an increased risk of subsequent cardiovascular events. Excess weight implies the presence of white, viscero-abdominal fat, that promotes insulin-resistance, is infiltrated by macrophages, and is less differentiated compared to subcutaneous or brown fat. Conversely, among patients with cardiovascular disease, slim patients have a greater risk of recurrent atherothrombotic events than fatter patients ("obesity paradox"). Lean patients with cardiovascular disease, on average, have more comorbidities and haemorrhagic complications than their heavier counteparts, and probably they conceal predisposing factors that are still unknown and therefore difficult to treat.

[Recent advances in atherothrombotic diseases]. / Recenti progressi in tema di aterotrombosi.

New concepts in the field of atherothrombosis include the human potential to repair and regenerate areas of vascular damage through endogenous growth factors, and the identification of uncommon arterial thrombophilias that promote atherothrombosis. The endogenous factors erythropoietin and insulin-like growth factor-1 are emerging as robust opponents of the vascular and hemostatic alterations that occur in atherothrombosis. Both factors activate the intracellular Akt pathway and the biosynthesis of constitutive nitric oxide, with anti-apoptotic, insulin-sensitizing, vasodilator, anti-inflammatory, antioxidant and antiplatelet effects, all of which oppose arterial degeneration and occlusion. Additionally, erythropoietin and insulin-like growth factor-1 induce the mobilization of stem cells that can differentiate and repair areas of vascular damage thereby halting the progression towards established disease. In selected patients with an arterial thrombotic event, we believe it is justified to search for an uncommon acquired or inherited thrombophilic condition in the presence of at least one of the following: young age, recurrent events, lack of traditional metabolic or acquired vascular risk factors, and no significant artery stenoses at angiography. In these groups of patients, and in those with a marked family history of thrombosis, the prevalence of several functional polymorphisms of genes involved in the hemostatic system is significantly higher compared with controls. Acquired thrombophilias that should be searched for include the antiphospholipid syndrome, systemic lupus erythematosus, and myeloproliferative disorders.