Lack of association between the 807 C/T polymorphism of glycoprotein Ia gene and post-treatment platelet reactivity after aspirin and clopidogrel in patients with acute coronary syndrome

Variability in platelet response to antiplatelet therapy and its clinical relevance have been well described. However, the underlying mechanisms remain unclear. It was the aim of the present study to assess whether the response to aspirin and clopidogrel may be influenced by the 807 C/T polymorphism of the glycoprotein Ia (GpIa) gene in patients with non-ST elevation acute coronary syndrome (NSTE ACS). Six hundred one NSTE ACS patients were included in our study and were divided into three groups: CC homozygotes, CT heterozygotes ad TT homozygotes. All patients received loading doses of 600 mg clopidogrel and 250 mg aspirin at least 12 hours before blood samples were drawn. Post-treatment platelet reactivity was assessed by post treatment ADP 10 microM-induced platelet aggregation (ADP-Ag), VASP phosphorylation (PRI VASP) and P-selectin expression. Non-response to dual antiplatelet therapy was defined by high post-treatment platelet reactivity (HPPR=ADP-Ag > 70%). Significant variability in the distribution of platelet parameters was observed in the overall study population. No significant difference in platelet parameters profiles was observed within patients having the same genotype, for ADP-Ag (p=0.33), PRIVASP (p=0.72) and P-selectin expression (p=0.37). The genotype frequencies of the 807 C/T polymorphism of the GpIa gene were similar in responders and non-responders defined by persistent HPPR (p=0.104). In conclusion, our study did not show any influence of 807 C/T polymorphism of GpIa gene on post-treatment platelet reactivity assessed by ADP-Ag, PRI VASP or P-selectin expression in 601 NSTE ACS patients.     

Spectrin-based skeleton in red blood cells and malaria

PURPOSE OF REVIEW: Malaria represents one of the most important selective factors affecting human populations. Several inherited diseases of red blood cells lead to resistance at the erythrocytic stage. Among patients who experience hereditary elliptocytosis related to mutations of erythrocyte membrane proteins, molecular studies have shown the prevalence of particular spectrin mutations in patients from black ethnic extraction, leading one to question the selection of new malaria-resistant genes. RECENT FINDINGS: Prospective epidemiological and molecular studies in West Africa have confirmed the prevalence (between 0.6 and 1.6%) of particular spectrin mutations related to hereditary elliptocytosis. These studies have also revealed the frequency of alpha-spectrin chain polymorphisms, associated in cis with elliptocytogenic spectrin mutations and defining particular spectrin allele haplotypes. Culture studies of Plasmodium falciparum in elliptocytes bearing such elliptocytogenic alleles of spectrin showed that these alleles are supplementary genetic factors of malaria resistance in vitro. SUMMARY: Certain instances of spectrin mutations or polymorphisms have not yet been shown to constitute new factors of innate resistance to malaria in vivo. Epidemiological surveys of hereditary elliptocytosis and parasite culture studies, however, have argued that the relationships between parasite and spectrin-based skeleton should be examined more closely and the molecular interactions between parasite ligands and particular spectrin chain domains should be characterized.     

Metabolic syndrome, plasma lipid, lipoprotein and glucose levels, and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)

To clarify the role of metabolic factors in endometrial carcinogenesis, we conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC), and examined the relation between prediagnostic plasma lipids, lipoproteins, and glucose, the metabolic syndrome (MetS; a cluster of metabolic factors) and endometrial cancer risk. Among pre- and postmenopausal women, 284 women developed endometrial cancer during follow-up. Using risk set sampling, 546 matched control subjects were selected. From conditional logistic regression models, high-density lipoprotein cholesterol (HDL-C) levels were inversely associated with risk body mass index (BMI)-adjusted relative risk (RR) for top versus bottom quartile 0.61 (95% confidence intervals (CI) 0.38-0.97), P(trend) = 0.02). Glucose levels were positively associated with risk (BMI-adjusted RR top versus bottom quartile 1.69 (95% CI 0.99-2.90), P(trend) = 0.03), which appeared stronger among postmenopausal women (BMI-adjusted RR top versus bottom tertile 2.61 (95% CI 1.46-4.66), P(trend) = 0.0006, P(heterogeneity) = 0.13) and never-users of exogenous hormones (P(heterogeneity) = 0.005 for oral contraceptive (OC) use and 0.05 for hormone replacement therapy-use). The associations of HDL-C and glucose with risk were no longer statistically significant after further adjustment for obesity-related hormones. Plasma total cholesterol, Low-density lipoprotein cholesterol (LDL-C), and triglycerides were not significantly related to overall risk. The presence of MetS was associated with risk (RR 2.12 (95% CI 1.51-2.97)), which increased with the number of MetS factors (P(trend) = 0.02). An increasing number of MetS factors other than waist circumference, however, was marginally significantly associated with risk only in women with waist circumference above the median (P(interaction) = 0.01). None of the associations differed significantly by fasting status. These findings suggest that metabolic abnormalities and obesity may act synergistically to increase endometrial cancer risk.     

Proteomic profiling of cold thyroid nodules

Cold thyroid nodules (CTNs) represent a frequent endocrine disorder accounting for up to 85% of thyroid nodules in a population living in an iodine-deficient area. Benign CTNs need to be distinguished from thyroid cancer, which is relatively rare. The molecular etiology of benign CTNs is unresolved. To obtain novel insights into their pathogenesis, protein expression profiling was performed in a series of 27 solitary CTNs (10 follicular adenoma and 20 adenomatous nodules) and surrounding normal thyroid tissues using two-dimensional gel electrophoresis combined with mass spectrometry analysis, Western blotting, and immunohistochemistry. The proteome analysis revealed a specific fingerprint of CTNs with up-regulation of three functional systems: 1) thyroid cell proliferation, 2) turnover of thyroglobulin, and 3) H2O2 detoxification. Western blot analysis and immunohistochemistry confirmed the proteome data and showed that CTNs exhibit significant up-regulation of proteins involved in thyroid hormone synthesis yet are deficient in T4-containing thyroglobulin. This is consequential to intranodular iodide deficiency, mainly due to cytoplasmic sodium iodide symporter localization, and portrays the CTN as an activated proliferating lesion with an intranodular hypothyroid milieu. Furthermore, we provide preliminary evidence that up-regulation of H2O2 generation in CTNs could override the antioxidative system resulting in oxidative stress, which is suggested by the finding of raised 8-oxo-guanidine DNA adduct formation in CTNs.     

Core-controlled polymorphism in virus-like particles

This study concerns the self-assembly of virus-like particles (VLPs) composed of an icosahedral virus protein coat encapsulating a functionalized spherical nanoparticle core. The recent development of efficient methods for VLP self-assembly has opened the way to structural studies. Using electron microscopy with image reconstruction, the structures of several VLPs obtained from brome mosaic virus capsid proteins and gold nanoparticles were elucidated. Varying the gold core diameter provides control over the capsid structure. The number of subunits required for a complete capsid increases with the core diameter. The packaging efficiency is a function of the number of capsid protein subunits per gold nanoparticle. VLPs of varying diameters were found to resemble to three classes of viral particles found in cells (T=1, 2, and 3). As a consequence of their regularity, VLPs form three-dimensional crystals under the same conditions as the wild-type virus. The crystals represent a form of metallodielectric material that exhibits optical properties influenced by multipolar plasmonic coupling.     

Induction of antigen-specific regulatory T lymphocytes by human dendritic cells expressing the glucocorticoid-induced leucine zipper

Dendritic cells (DCs) determine whether antigen presentation leads to immune activation or to tolerance. Tolerance-inducing DCs (also called regulatory DCs) act partly by generating regulatory T lymphocytes (Tregs). The mechanism used by DCs to switch toward regulatory DCs during their differentiation is unclear. We show here that human DCs treated in vitro with glucocorticoids produce the glucocorticoid-induced leucine zipper (GILZ). Antigen presentation by GILZ-expressing DCs generates CD25(high)FOXP3(+)CTLA-4/CD152(+) and interleukin-10-producing Tregs inhibiting the response of CD4(+) and CD8(+) T lymphocytes. This inhibition is specific to the antigen presented, and only proliferating CD4(+) T lymphocytes express the Treg markers. Interleukin-10 is required for Treg induction by GILZ-expressing DCs. It is also needed for the suppressive function of Tregs. Antigen-presenting cells from patients treated with glucocorticoids generate interleukin-10-secreting Tregs ex vivo. These antigen-presenting cells produce GILZ, which is needed for Treg induction. Therefore, GILZ is critical for commitment of DCs to differentiate into regulatory DCs and to the generation of antigen-specific Tregs. This mechanism may contribute to the therapeutic effects of glucocorticoids.     

Radiofrequency Thermal Ablation of Breast Cancer Local Recurrence: A Phase II Clinical Trial

Background  The role of radiofrequency (RF) ablation to treat local recurrence of breast cancer is unknown. Methods  We conducted a two-stage phase II clinical trial. Eligible patients had a histologically confirmed noninflammatory and ≤3 cm ipsilateral breast tumor recurrence. The tumor site was identified by intraoperative sonography. A LeVeen needle electrode (RadioTherapeutics Corp, Mountain View, Calif) was inserted into a single site within the tumor and radiofrequency ablation was performed using a RF-2000 generator (RadioTherapeutics Corp). After completion of radiofrequency, a mastectomy was performed. Conventional staining and nicotinamide adenine dinucleotide-diaphorase (NADH-diaphorase) cell viability staining were performed. Results  During the first stage, procedures were uneventful. Conventional, cytokeratin, and NADH-diaphorase staining identified persistent viable tumor cells in the RF-ablated region in three patients. This phase II trial was stopped after completion of the first stage because of insufficient efficacy. Conclusion  We demonstrate in this study that RF ablation is a potential technique to destroy local recurrence of breast tumors but the technique we tested in this phase II clinical trial had insufficient efficacy to recommend its use in routine.     

Metabolic syndrome, haemostasis and thrombosis

The metabolic syndrome (metS), a concurrence of abdominal fat, disturbed glucose and insulin metabolism, dyslipidemia, and hypertension has been strongly associated not only with subsequent development of type 2 diabetes but also with atherothrombosis. The physiopathology of this association is complex. The metS affects the thrombogenicity of circulating blood. Apart from its effect on platelets, a procoagulant and hypofibrinolytic state has been identified; mainly the result of the inflammatory state, dyslipidemia, and liver fat accumulation that accompany the MetS. Among haemostasis disturbances, the strong rise in the inhibitor of plasminogen activator type 1 plasma level is the most documented abnormality implicating the participation of the oxidative stress and inflammatory state developed during the metS. Endothelial dysfunction is also a central feature. Moreover, secretion products of fat tissues (adipokines) are now thought to have direct modulating effects on the vascular and the circulating cells. In support of these data, the metS, may predispose not only to atherosclerosis but also to venous thrombosis.