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Objectives: To determine etravirine concentrations in CSF in HIV-infected patients., Methods: Twelve HIV-1 adult antiretroviral-experienced patients receiving an etravirine-containing regimen for at least 1 month were enrolled. Both CSF and blood samples were taken around 12 h after the last etravirine dose. Liquid chromatography-tandem mass spectrometry was used to determine etravirine concentrations, and HIV-1 viral load was determined by real-time PCR (limit of detection 40 copies/mL)., Results: Twelve blood and 12 CSF samples were collected. The median CD4 count was 333 (84-765) cells/mm(3) and the median plasma HIV-1 viral load was <40 (range <40-1777) copies/mL. The median time on etravirine was 34 (range 4-140) weeks. The median etravirine concentration in plasma was 611.5 (range 148-991) ng/mL. The median CSF etravirine concentration was 7.24 (range 3.59-17.9) ng/mL; in all cases, values were above the IC(50) range (0.39-2.4 ng/mL). The median etravirine CSF:plasma ratio was 0.01 (range 0.005-0.03). The CSF viral load was >40 copies/mL in one patient and plasma viral load was still detectable after 4 weeks of therapy., Conclusions: Etravirine achieves concentrations several times greater than the IC(50) range in CSF. All patients with undetectable plasma viral load were virologically suppressed in CSF while receiving an etravirine-containing regimen. Etravirine may help in controlling HIV-1 in CNS.

Factor V Leiden, is a variant of human factor V (FV), also known as proaccelerin, which leads to a hypercoagulable state. Along these years, factor V Leiden (FVL) has been studied from the pathophysiologic point of view, and research has been focused on finding clinical approaches for the management of the FVL associated to a trombophilic state. Less attention has been paid about the possible role of FVL in inflammatory conditions known to be present in different disorders such as uremia, cirrhosis, liver transplantation, depression as well as sepsis, infection or, inflammatory bowel disease (IBD). Whether platelet FVL will increase the activation of coagulation and/or in which proportion is able to determine the final outcome in the previously mentioned inflammatory conditions is a subject that remains uncertain. This paper will review the association of FVL with inflammation. Specifically, it will analyze the important role of the endothelium and the contribution of other inflammatory components involved at both the immune and vascular levels. This paper will also try to emphasize the importance of being a FVL carrier in associations to diseases where a chronic inflammation occurs, and how this condition may be determinant in the progression and outcome of a specific clinic situation.

Introduction: Platelet activation leads to signal transduction mechanisms, in which phosphotyrosine proteins play a relevant role., Material and Methods: Platelet suspensions were independently activated by collagen and thrombin in the absence and in the presence of two tyrosine kinase inhibitors, tyrphostin 47 and genistein. Samples were processed to visualize morphological changes by electron microscopy, to evaluate changes in cytoskeletal assembly, to analyze modifications in the expression of activation dependent antigens, and the procoagulant activity at the surface level by flow cytometry. Additional experiments applying flow conditions were performed to assess the effect of inhibiting tyrosine phosphorylation on primary platelet adhesion and fibrin formation., Results: Inhibition of tyrosine phosphorylation blocked shape change and cytoskeletal assembly induced by collagen, and inhibited, though partially, those effects due to thrombin. Both activating agents induced the expression of the intraplatelet antigens CD62P and CD63 at the surface, although only collagen promoted expression of anionic phospholipids. Both tyrphostin 47 and genistein prevented those effects. The extent of platelet adhesion on both collagen-coated and subendothelial surfaces was significantly diminished by the presence of the tyrosine kinase inhibitors assayed. Fibrin formation was also significantly reduced., Conclusions: Platelet shape change and secretion during platelet activation depends on tyrosine phosphorylation. In addition, primary adhesion of platelets induces signaling through tyrosine kinases to achieve full spreading, and results in the exposure of a procoagulant surface on platelets.

Background: Platelet-derived microparticles (MPs) are believed to play an important role in coagulation and inflammatory disorders. Unfortunately, MP size renders them difficult to study and analyze by conventional flow cytometry., Methods: We analyzed and characterized platelet-derived MPs, using antibodies against the major surface glycoproteins (GP), the platelet activation antigen P-selectin (CD62P), and a marker of procoagulant activity (phosphatidylserine exposure). MPs were generated by exposure of platelets to thrombin receptor activating peptide (TRAP) or ionophore. Both agonists induced significant microvesiculation of platelets, and the resulting MPs were analyzed by a new digital flow cytometer: Becton-Dickinson FACSAria., Results: Membrane GPs were equally well represented in MPs generated by either reagent. In contrast, P-selectin was more intensely expressed in TRAP-MPs, while phosphatidylserine (PS) expression was markedly increased in ionophore-MPs. Two distinct populations of TRAP-MPs (one PS-positive and another PS-negative) were apparent. The latter characteristic facilitated sorting of MPs according to their PS exposure., Conclusions: The data presented herein show a significant improvement in the methodology applied until now to the characterization of MPs. The ability to characterize and sort MP subpopulations may help to resolve their contributions to normal and pathological functions.

Background: Several strategies are being developed to reduce the risk of pathogen transmission associated with platelet (PLT) transfusion., Study Design and Methods: The impact of a new technology for pathogen reduction based on riboflavin plus illumination (Mirasol PRT, Navigant Biotechnologies, Inc.) at 6.2 and 12.3 J per mL on functional and biochemical characteristics of PLTs was evaluated. PLT concentrates (PCs) obtained by apheresis were treated with Mirasol PRT and stored at 22 degrees C. Modifications in major PLT glycoproteins (GPIbalpha, GPIV, and GPIIb-IIIa), adhesive ligands (von Willebrand factor [VWF], fibrinogen [Fg], and fibronectin), activation antigens (P-selectin and LIMP), and apoptotic markers (annexin V binding and factor [F]Va) were analyzed by flow cytometry. Adhesive and cohesive PLT functions were evaluated with well-established perfusion models. Studies were performed on the preparation day (Day 0) and during PCs storage (Days 3 and 5)., Results: Levels of glycoproteins remained stable during storage in PCs treated with 6.2 J per mL pathogen reduction technology (PRT) and similar to those observed in nontreated PCs. When 12.3 J per mL PRT was applied, however, levels of GPIbalpha moderately decreased on Days 3 and 5. VWF, Fg, and FVa were not modified in their expression levels, either by treatment or by storage period. Fibronectin appeared more elevated in all PRT samples. A progressive increase in P-selectin and LIMP expression and in annexin V binding was observed during storage of PRT-treated PCs. Functional studies indicated that 6.2 J per mL Mirasol PRT-treated PLTs preserved adhesive and cohesive functions to levels compatible with those observed in the respective control PCs., Conclusion: PLT function was well preserved in PCs treated with 6.2 J per mL Mirasol PRT and stored for 5 days.