J.-M. Dogné

More on: Calibration for the measurement of microparticles: Needs, interests, and limitations of calibrated polystyrene beads for flow cytometry-based quantification of biological microparticles

See also Chandler WL, Yeung W, Tait JF. A new microparticle size calibration standard for use in measuring smaller microparticles using a new flow cytometer. J Thromb Haemost 2011; 9: 1216–24; Robert S, Poncelet P, Lacroix R, Raoult D, Dignat‐George F. More on: calibration for the measurement of microparticles: value of calibrated polystyrene beads for flow cytometry‐based sizing of biological microparticles. This issue, pp 1676–8; Chandler WL, Yeung W, Tait JF. More on: calibration for the measurement of microparticles: the authors respond. This issue, pp 1681–2.

Assessment of the performances of AcuStar HIT and the combination with heparin-induced multiple electrode aggregometry: A retrospective study

BACKGROUND Early diagnosis of immune heparin-induced thrombocytopenia (HIT) is challenging. HemosIL® AcuStar HIT and heparin-induced multiple electrode aggregometry (HIMEA) were recently proposed as rapid diagnostic methods. OBJECTIVES We conducted a study to assess performances of AcuStar HIT-IgG (PF4-H) and AcuStar HIT-Ab (PF4-H). The secondary objective was to compare the performances of the combination of Acustar HIT and HIMEA with standardised clinical diagnosis. METHODS Sera of 104 suspected HIT patients were retrospectively tested with AcuStar HIT. HIMEA was performed on available sera (n=81). The clinical diagnosis was established by analysing in a standardized manner the patients medical records. These tests were also compared with PF4-Enhanced®, LTA, and SRA in subsets of patients. Thresholds were determined using ROC curve analysis with clinical outcome as reference. RESULTS Using the recommended thresholds (1.00AU), the negative predictive value (NPV) of HIT-IgG and HIT-Ab were 100.0% (95% CI: 95.9%-100.0% and 95.7%-100.0%). The positive predictive value (PPV) were 64.3% (95% CI: 35.1%-87.2.2%) and 45.0% (95% CI: 23.2%-68.6%), respectively. Using our thresholds (HIT-IgG: 2.89AU, HIT-Ab: 9.41AU), NPV of HIT-IgG and HIT-Ab were 100.0% (95% CI: 96.0%-100.0% and 96.1%-100.0%). PPV were 75.0% (95% CI: 42.7%-94.5%) and 81.8% (95% CI: 48.3%-97.7%), respectively. Of the 79 patients with a medium-high pretest probability score, 67 were negative using HIT-IgG (PF4-H) test at our thresholds. HIMEA was performed on HIT-IgG positive patients. Using this combination, only one patient on 79 was incorrectly diagnosed. CONCLUSION Acustar HIT showed good performances to exclude the diagnosis of HIT. Combination with HIMEA improves PPV.

Bioactivity and hemocompatibility study of amorphous hydrogenated carbon coatings produced by pulsed magnetron discharge.

Literature contains very few data about the potential biomedical application of amorphous hydrogenated carbon (a-C:H) thin films deposited by reactive pulsed magnetron discharge even so it is one of the most scalable plasma deposition technique. In this article, we show that such a C2H2 pulsed magnetron plasma produces high quality coating with good hemocompatibility and bioactive response: no effect on hemolysis and hemostasis were observed, and proliferation of various cell types such as endothelial, fibroblast, and osteoblast-like cells was not affected when the deposition conditions were varied. Cell growth on a-C:H coatings is proposed to take place by a two-step process: the initial cell contact is affected by the smooth topography of the a-C:H coatings, whereas the polymeric-like structure, together with a moderate hydrophilicity and a high hydrogen content, directs the posterior cell spreading while preserving the hemocompatible behavior.

The use of PIXE for engineered nanomaterials quantification in complex matrices

Engineered nanomaterials (ENMs) quantification in complex media is an area under development, much demanded by stakeholders due to the introduction of a myriad of consumer products containing ENMs. In this work, Particle-Induced X-ray Emission (PIXE) will be shown as capable of quantifying ENMs in complex media for both in vivo and in vitro assessments using minimal conditioning. ENM quantifications (SiC, TiC, SiO2) were performed on complex media (rat feces, rat lungs and cell culture), with applied ENM concentrations corresponding to ranges of interest for in vivo or in vitro assessments. The case studies presented in this work show the capability and versatility of PIXE measurements for biopersistence, biodistribution and dose assessment studies.

Inactivation of human coagulation factor X by a protease of the pathogen Capnocytophaga canimorsus

Essentials Capnocytophaga canimorsus causes severe dog bite related blood stream infections. We investigated if C. canimorsus contributes to bleeding abnormalities during infection. The C. canimorsus protease CcDPP7 causes factor X dysfunction by N‐terminal cleavage. CcDPP7 inhibits coagulation in vivo, which could promote immune evasion and trigger hemorrhage.

What is the impact of Silicon Carbide nanoparticles to the mineral composition of rat lungs? A PIXE-μPIXE comparative study

The exposure to nanomaterials can yield changes in the mineral composition of tissues which may have long term health repercussions. In this study, the changes in mineral composition of rat lungs, exposed to a nanoaerosol of silicon carbide (SiC), has been studied by means of global and local ion beam probes with the Particle-Induced X-ray Emission (PIXE) technique, measuring the whole lung contents and selected areas where SiC was found, respectively. It was found that from a global perspective there is a small decrease in the mineral contents (phosphorous, sulphur, chlorine and potassium) of the lung except for Ca, while locally these mineral contents tend fluctuate.

The impact of instilled carbide nanoparticles on rat lungs: an in vivo perspective on acute intratracheal instillation

In order to study a scenario of acute high concentration exposure via the pulmonary pathway of silicon carbide and titanium carbide nanoparticles, female Wistar rats were administered by intratracheal instillation doses of 0.5 and 5 mg/rat of each nanomaterial. Inflammatory parameters were studied: protein concentration, lactate dehydrogenase activity, total cell count and differentiated cell count (macrophages, neutrophils, oesonophils, lymphocytes). The genotoxicity potential was assessed by the formation of micronuclei from pneumocytes type II. It was found that silicon carbide nanoparticles induce an inflammatory response and a dose dependent genotoxicity, although the genotoxicity levels are comparably lower to the inflammatory response.