Antiplatelet treatment of cardiovascular disease: a translational research perspective

Platelet mediated thrombosis is the primary cause of ischemic event occurrence in patients with cardiovascular disease. The P2Y12 receptor plays a central role in thrombus generation and is therefore a major target for pharmacologic therapy. Although various clinical trials have demonstrated the efficacy of dual antiplatelet therapy with aspirin and clopidogrel, recurrent ischemic events occur in approximately 10% of patients with acute coronary artery syndromes. Recent translational research studies have explored the various limitations of dual antiplatelet therapy including wide response variability and resistance. The association of ischemic event occurrence with high on-treatment platelet reactivity to adenosine diphosphate has been reported in recent small studies suggesting that the latter may be a quantifiable and modifiable risk factor. Recent studies have identified a potential therapeutic target for P2Y12 inhibitors that may influence the future development of personalized antiplatelet treatment strategies aimed at the reduction of ischemic event occurrence in high risk patients. Finally, based on the current evidence platelet reactivity may become a standard of care risk factor measured in all patients with cardiovascular disease.     

Patterns of cytokine expression in AIDS-related non-Hodgkin's lymphoma

The pathogenesis of AIDS-related non-Hodgkin's lymphomas (AIDS-NHL) involves accumulation of genetic lesions, stimulation and selection by antigen, as well as infection by viruses. Deregulation of cytokine loops has also been proposed to contribute to AIDS-NHL development, although data are available only for a limited number of cytokines. In this study we have utilized a panel of AIDS-NHL cell lines to investigate in detail the pattern of tumour expression and production of a wide spectrum of cytokines. The cytokines investigated included interleukin (IL)-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-13, TNFα, TNFβ, IFNγ, TGFβ₂, G-CSF, GM-CSF and SCF. The AIDS-NHL cell lines utilized were representative of both AIDS-related Burkitt lymphoma (AIDS-BL) and AIDS-related body cavity-based lymphoma (AIDS-BCBL). Overall, AIDS-NHL were found to produce IL-6, IL-10 and TNFβ, although with different patterns depending upon the biological features of the tumour. Production of high levels of IL10 preferentially associated with Epstein-Barr virus (EBV) positive AIDS-BL and AIDS-BCBL, although lower levels of the cytokine were also detectable among EBV-negative AIDS-BL. Production of IL-6 was restricted to EBV-positive AIDS-BL and AIDS-BCBL, whereas it was absent among EBV-negative AIDS-BL. Production of TNFβ clustered with AIDS-BL, whereas this was absent among AIDS-BCBL. These results define that the pattern of cytokine expression of AIDS-NHL depends upon the biological features of the tumour and may have implications for the pathogenesis of these disorders.     

Platelet activating factor-acetylhydrolase (PAF-AH) activity and HDL levels, but not PAF-AH gene polymorphisms, are associated with successful aging in Sicilian octogenarians

BACKGROUND AND AIMS: Aging is associated with an increased risk of developing atherosclerosis. Subjects over 80 years of age without cardiovascular disease provide a model to investigate the protective factors increasing their resistance to atherosclerotic disease. Platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme associated with low density lipoprotein (LDL) and high density lipoprotein (HDL) inactivating platelet-activating factor (PAF) and preventing LDL oxidation by hydrolysis of oxidized phospholipids. The aim of the present study was to evaluate the contribution of the PAFAH gene Arg92His, Ile198Thr and Ala379Val polymorphisms to resistance toward developing cardiovascular events in healthy Sicilian octogenarians. METHODS: Distribution of PAF-AH genotypes and activity, and biochemical parameters, were compared between 100 octogenarians and 200 healthy adults. RESULTS: The individuals in the elderly group displayed significantly higher levels of HDL-C (p<0.001) and plasma (p<0.001) and HDL (p<0.001) PAF-AH activity. Analysis of PAFAH genotype distributions showed no significant differences between octogenarians and controls. No differences among PAF-AH genotypes with respect to plasma and HDL PAF-AH activity were found in either group. CONCLUSIONS: Our results provide no evidence of a significant association between the PAF-AH gene Arg92His, Ile198Thr and Ala379Val polymorphisms and successful aging in Sicilians. They also emphasize that, in these subjects, aging is characterized by increased levels of PAF-AH activity and HDL-C.     

Cardiovascular risk profile and morbidity in subjects affected by type 2 diabetes mellitus with and without diabetic foot

Diabetic foot syndrome (DFS) is the most frequent cause of hospitalization of diabetic patients and one of the most economically demanding complications of diabetes. People with diabetes have been shown to have higher mortality than people without diabetes. On this basis, the aim of our study was to evaluate the possible role of diabetic foot as a cardiovascular risk marker in patients with type 2 diabetes mellitus. We enrolled 102 consecutive patients with type 2 diabetes mellitus with diabetic foot and 123 patients with type 2 diabetes mellitus without limb lesions to compare the prevalence of main cardiovascular risk factors, subclinical cardiovascular disease, previous cardiovascular morbidity, and incidence of new vascular events on a 5-year follow-up. Diabetic patients with diabetic foot were more likely to have a higher prevalence of cardiovascular risk factors such as hypercholesterolemia, hypertriglyceridemia, hyperuricemia, and microalbuminuria or proteinuria, a higher prevalence of a previous cardiovascular morbidity (coronary artery disease, transient ischemic attack/ischemic stroke, diabetic retinopathy), and a higher prevalence of subclinical cardiovascular disease. Furthermore, diabetic patients with foot ulceration showed, on a 5-year follow-up, a higher incidence of new-onset vascular events (coronary artery disease, transient ischemic attack/ischemic stroke, diabetic retinopathy). At multivariate analysis, duration of diabetes, age, hemoglobin A1c, and DFS maintained a significant association with cardiovascular morbidity; but DFS presence showed the highest hazard ratio.     

Immunoglobulin and T cell receptor gene rearrangements and in situ immunophenotyping in lymphoproliferative disorders

Summary We investigated for rearrangements of the immunoglobulin (Ig) heavy and light chain genes and of the T cell receptor (TCRT) and (TCr) genes 45 biopsy samples from a variety of lymphoproliferative disorders. They were diagnosed histopathologically and immunophenotypically as non-Hodgkin's lymphomas (NHLs) of the B cell type (19 cases), NHLs of the T cell type (3 cases), NHLs of undetermined cell type (3 cases), atypical lymphoid proliferation (1 case) and AIDS-related lymphadenopathies with florid polyclonal follicular hyperplasia (19 cases). A monoclonal proliferation of B cells was shown by DNA analysis in all 19 B cell NHLs. In two immunohistologically determined T cell NHLs (both diagnosed as mycosis fungoides) the cells had rearrangements of TCr gene, whereas in the third case (lymphoblastic NHL) the cells had rearrangements of Ig heavy chain and TCr and TCr genes. None of the B cell NHLs exhibited TCrand TCr gene rearrangement bands. All the undetermined cell NHLs demonstrated rearrangements of Ig heavy chain gene associated with the germ line TCrand TCr genes; in two cases light chain gene rearrangements were also found. The atypical lymphoid proliferation, in which the differential diagnosis was between a reactive or malignant process, and two out of 19 cases of florid polyclonal follicular hyperplasia showed a clonal B cell population by DNA analysis. This study indicates that there was a strong correlation between the rearrangements of specific genes and the immunophenotype of the NHL; moreover, DNA analysis of tissue biopsy specimens from phenotypically undetermined cell NHLs and from equivocal lymphoid proliferation using Ig and TCR gene probes yelded an answer in the cases analyzed. The significance of clonal B cell expansions found in two AIDS-related lymphadenopathies should be interpreted with caution.This work was supported in part by a Grant No 86.00644.44 from the Consiglio Nazionale delle Ricerche, Progetto Finalizzato Oncologia, Rome, and by the Associazione Italiana per la Ricerca sul Cancro, Milan, Italy     

Expression of functional interleukin-3 receptors on Hodgkin and Reed-Sternberg cells

The human interleukin-3 receptor (IL-3R) is a heterodimeric complex consisting of an IL-3-specific alpha chain (IL-3Ralpha) and a common beta chain (beta(c)), this latter shared with the receptors for granulocyte-macrophage colony-stimulating factor and IL-5. Despite extensive research on cytokine circuitries regulating proliferation and survival of tumor cells in Hodgkin's disease (HD) the functional expression of IL-3Rs in this pathobiological entity has not yet been investigated. In the present study, we demonstrate that the great majority (>90%) of malignant Hodgkin and Reed-Sternberg cells of classic HD (19 of 19 analyzed cases) express IL-3Ralpha by immunostaining of frozen sections and cell suspensions from involved lymph nodes. Accordingly, HD cell lines (L428, KMH2, HDLM2, L1236) expressed the alpha and beta chains of IL-3R both at the mRNA and protein level, with a molecular size of IL-3Ralpha identical (70 kd) to that expressed by human myeloid cells. Exogenous IL-3 promoted the growth of cultured Hodgkin and Reed-Sternberg cells, such effect being potentiated by IL-9 co-stimulation, and was able to partially rescue tumor cells from apoptosis induced by serum deprivation. This data suggests an involvement of IL-3/IL-3R interactions in the cellular growth of HD through paracrine mechanisms.     

Sulfur radical species form gold deposits on Earth

Current models of the formation and distribution of gold deposits on Earth are based on the long-standing paradigm that hydrogen sulfide and chloride are the ligands responsible for gold mobilization and precipitation by fluids across the lithosphere. Here we challenge this view by demonstrating, using in situ X-ray absorption spectroscopy and solubility measurements, coupled with molecular dynamics and thermodynamic simulations, that sulfur radical species, such as the trisulfur ion S3−, form very stable and soluble complexes with Au⁺ in aqueous solution at elevated temperatures (>250 °C) and pressures (>100 bar). These species enable extraction, transport, and focused precipitation of gold by sulfur-rich fluids 10–100 times more efficiently than sulfide and chloride only. As a result, S3− exerts an important control on the source, concentration, and distribution of gold in its major economic deposits from magmatic, hydrothermal, and metamorphic settings. The growth and decay of S3− during the fluid generation and evolution is one of the key factors that determine the fate of gold in the lithosphere.The formation of gold deposits on Earth requires aqueous fluids that extract gold from minerals and magmas and transport and precipitate the metal as economic concentrations in ores that are three to six orders of magnitude larger than the Au mean content (∼0.001 ppm) of common crustal and mantle rocks (1–9). However, natural data on gold contents in fluids are very scarce due to difficulties of direct access to deep geothermal fluid samples, rarity of representative fluid inclusions trapped in minerals, and analytical limitations for this chemically most inert metal (1, 4, 9, 10). The paucity of direct data makes it difficult to quantify the capacity of the fluids to transport gold and the factors controlling the sources, formation, and distribution of the economic resources of gold and associated metals across the lithosphere. Thus, knowledge of gold speciation and solubility in the fluid phase is required.Terrestrial hydrothermal fluids systematically contain sulfur and chloride—compounds that have long been known to favor gold dissolution in aqueous solution (e.g., refs. 11 and 12). Following this common knowledge, the interpretation of gold transfers across the lithosphere has been based on the fundamental assumption that only hydrogen sulfide (HS⁻) and chloride (Cl⁻) can form stable complexes with aurous gold, Au⁺, which is the main gold oxidation state in hydrothermal fluids (1–6, 11–15). Among these species, aurous bis(hydrogen sulfide), Au(HS)2−, and dichloride, AuCl2−, have long been regarded as the major carriers of gold in hydrothermal fluids, depending on temperature (T), pressure (P), acidity (pH), redox potential (f_O2), and salt and sulfur concentrations (1, 5, 6, 13, 15). In addition, other minor hydroxide, chloride, and sulfide species (AuOH, AuCl, AuHS) have also been tentatively suggested in some studies to account for the low Au solubility (typically part-per-billion level, ppb) measured in dilute S- and Cl-poor experimental solutions (e.g., refs. 6 and 15). Most available data suggest that the sulfide complexes attain significant concentrations (>1 ppm Au) only in H₂S-rich neutral-to-alkaline (pH > 6–7) solutions at low-to-moderate temperatures (<250–300 °C), whereas the chloride complexes contribute to Au solubility only in highly acidic (pH < 3) chloride-rich (typically >10 wt% NaCl equivalent) and strongly oxidizing [above the oxygen fugacity of the hematite–magnetite (HM) buffer] solutions above 300 °C.In between these two contrasting hydrothermal solution compositions lies a vast domain of geological fluids, which are commonly generated by magma degassing at depth (2, 3, 9) or prograde metamorphism of sedimentary rocks at high temperatures (7, 8, 10). These fluids are characterized by variable salt content, slightly acidic to neutral pH, and the presence of both oxidized (sulfate and sulfur dioxide) and reduced (H₂S) sulfur forms in a wide temperature range (∼300–700 °C). Predicted concentrations of the gold sulfide and chloride species in such fluids are generally rather low (<0.1–1.0 ppm) to account for a number of enigmatic features of gold geochemistry such as the existence of large deposits without relation to magmatic plutons in metamorphic and sedimentary rocks (e.g., Carlin-type and orogenic) implying deep, likely mantle-derived, Au-rich sources, the observation of highly anomalous Au grades (up to thousands of parts per million) in hydrothermal veins, and huge variations (more than three orders of magnitude) of the ratio of Au to other metals (e.g., Cu, Ag, Mo) in ores (1–4, 6–10, 16). These fluids, which have created the major part of economic gold resources on Earth (1–4), may carry much higher Au concentrations, of tens to hundreds of parts per million, as reported from rare fluid inclusion analyses (4, 6, 9, 10) and a few laboratory experiments of Au solubility (17–20). How gold is transported by such fluids remains, however, controversial, and a variety of other species with H₂S, Cl, As, and alkali metal ligands (3, 14, 17–20) or Au nanoparticles (4, 6, 12) were suggested. Thus, a consistent picture of Au speciation and transport in deep and hot crustal fluids is lacking, hampering our understanding of geochemical fluxes of gold across the lithosphere and the formation of gold economic resources.In particular, all existing Au speciation models ignore sulfur radical species such as the trisulfur ion S3−, which is ubiquitous in chemical and engineering products (21) and was recently shown to be stable in the aqueous fluid phase over a wide temperature (T from 200 °C to ∼700 °C) and pressure (P from saturated vapor pressure to ∼30 kbar) range (22–24). The omission of S3− in current models of hydrothermal fluids is due to its very rapid breakdown to sulfate and sulfide in aqueous solution upon cooling, which prohibits the detection of S3− in experimental and natural fluid (and melt) samples brought to ambient conditions. It is thus only recently that the abundance and thermodynamic stability of this important sulfur species could be systematically characterized at high T−P using in situ Raman spectroscopy (22–24). These studies showed that significant amounts of trisulfur ion (>10–100 ppm) may be reached in fluids typical of magmatic and metamorphic environments, which are characterized by elevated dissolved S concentrations (>1,000 ppm), slightly acidic to neutral pH (between ∼3 and 7), and redox conditions enabling coexistence of sulfate (or sulfur dioxide) and hydrogen sulfide.To quantify the effect of S3− on Au behavior in hydrothermal fluids, here we combined in situ X-ray absorption spectroscopy (XAS) and hydrothermal reactor measurements with first-principles molecular dynamics (FPMD) and thermodynamic modeling of Au local atomic structure and solubility in aqueous solutions saturated with gold metal and containing hydrogen sulfide, sulfate and S3− (SI Appendix). These solutions are representative of fluids that formed major types of gold deposits in the crust: 200–500 °C, 300–1,000 bar, 0.1–3.0 wt% S, 3 < pH < 8, and oxygen fugacity f_O2 between the nickel−nickel oxide (NNO) and HM buffer (1–4).     

Clinical impact of simultaneous complete revascularization vs. culprit only primary angioplasty in patients with st-elevation myocardial infarction and multivessel disease: a meta-analysis

Primary Percutaneous Intervention (PCI) is the treatment of choice for acute ST-elevation myocardial infarction (STEMI). Nearly half of STEMI patients have multivessel (MV) disease that has been associated with worse survival. However, current guidelines recommend to treat only the culprit artery (COR) during the acute procedure. Thus, the aim of the current study was to perform a meta-analysis of trials comparing MV PCI vs. COR for STEMI patients with MV disease. Medline/CENTRAL and Web were searched for comparative studies (both randomized and non randomized trials) about MV PCI vs. COR for STEMI patients reporting mortality, re-PCI and re-MI data. Primary endpoint was 30-day mortality. The meta-analysis included 10 studies (2 randomized and 8 registries; N = 31224). As compared with COR, MV PCI significantly reduced long term rate of re-PCI (OR [95% CI] = 0.47 [0.28–0.78], P = 0.003) without increasing 30-day mortality (OR [95% CI] = 1.30 [0.79–2.12], P = 0.31) and long term re-MI (OR [95% CI] = 0.94 [0.43–2.06], P = 0.88). This meta-analysis showed safety and efficacy of MV PCI approach as compared with COR, with a significant reduction in rate of revascularizations, but no advantages in death and re-MI.     

Spatial Competences in Prader–Willi Syndrome: A Radial Arm Maze Study

The present study was aimed at investigating the spatial abilities in Prader–Willi syndrome (PWS) by using the Radial Arm Maze (RAM) task. We trained PWS individuals with the deletion subtype in two different RAM paradigms that tapped different aspects of spatial memory. To evaluate the extent of spatial deficit in PWS individuals, it seemed interesting to compare their performances with those of individuals with Williams syndrome (WS) in which deficits in spatial abilities have been well described. The two syndromic groups were compared to typically developing (TD) individuals mental-age and gender matched. The findings evidenced the impairment of PWS individuals in solving the RAM task with variable severity depending on the paradigm requests. Since the RAM is a task that allows the acquisition of spatial competences through the movement, we advance that the spatial deficits observed in PWS individuals may be related to the malfunctioning of spatial and motor integrative processing.