Détermination d'intervalles de référence des bilans d'hémostase de routine chez le chien sain déterminés avec un analyseur STA-Satellite (Diagnostica Stago) : étude expérimentale

Dans cette étude, les intervalles de référence du temps de Quick (TQ), du temps de céphaline plus activateur (TCA), du fibrinogène (FIB) et de l’antithrombine (AT) ont été déterminés conformément aux recommandations internationales. Les coefficients de variation de l’imprécision de l’analyseur STA Satellite® étaient respectivement de 3,9%, 1,3%, 6,9% et 5,1% pour le TQ, le TCA, le FIB et l’AT. A 4°C, les spécimens citratés étaient stables jusqu’à 8 heures pour le sang total et pendant 36heures pour le plasma, excepté pour la mesure du TCA, qui était légèrement augmentée (< 1 seconde). Les intervalles de référence nonparamétriques, déterminés grâce au plasma citraté de 139 chiens de pure race, en bonne santé et à jeun, étaient de 6,9-8,8 secondes, 13,1-17,2 secondes, 1,24-4,30 g/L et 104-188% respectivement

Canine reference intervals for coagulation markers using the STA Satellite and the STA-R Evolution analyzers

The aim of the current study was to determine canine reference intervals for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, and antithrombin (AT) according to international recommendations. The STA Satellite coefficients of variation of within-laboratory imprecision were 3.9%, 1.3%, 6.9%, and 5.1% for PT, APTT, fibrinogen, and AT, respectively. At 4uC, citrated specimens were stable up to 8 hr for whole blood and 36 hr for plasma, except for APTT, which increased slightly (<1 sec). Nonparametric reference intervals determined in citrated plasma from 139 healthy fasting purebred dogs were 6.9–8.8 sec, 13.1–17.2 sec, 1.24–4.30 g/l, and 104–188% for PT, APTT, fibrinogen, and AT, respectively. Based on Passing–Bablok comparison between STA Satellite and STA-R Evolution using 60 frozen specimens from a canine plasma bank, the corresponding reference intervals were transferred to the STA-R Evolution: 7.1–9.2 sec, 12.9–17.3 sec, 1.20–4.43 g/l, and 94–159% for PT, APTT, fibrinogen, and AT, respectively

Prednisone-induced resistance in canine multicentric lymphoma A clinical and molecular approach to understanding the role of NR3C1, ABCB1 (MDR1), 11B-HSD1, and 11B-HSD2

Resistance to prednisone develops rapidly and essentially universally when dogs with lymphoma are treated with corticosteroids such as prednisone. We studied naturally occurring mechanisms of prednisone resistance by assessing the level of expression of the following genes in dogs with clinical evidence of prednisone resistance: the glucocorticoid receptor NR3C1, ABCB1 (formerly MDR1), 11B-HSD1, and 11B-HSD2. We hypothesized that, when compared to pre-treatment samples, prednisone-resistant lymphoma samples, would have (1) decreased NR3C1 and 11B-HSD1 expression; (2) increased 11B-HSD2 expression and (3) unchanged ABCB1 expression. To test this hypothesis, seven dogs with naïve multicentric lymphoma were enrolled prospectively and treated with daily oral prednisone. Gene expression of NR3C1, ABCB1, 11B-HSD1, and 11B-HSD2 in lymph nodes was evaluated by real time RT-PCR. Expression levels at diagnosis and at time of clinical resistance to prednisone were compared longitudinally using a Wilcoxon signed-rank test. Dogs were treated with prednisone for a median of 68 days (range, 7 to 201 days). Relative to pretreatment samples, prednisone treatment was associated with decreased expression of the NR3C1 gene in lymph node biopsies of all dogs with high-grade lymphoma when clinical resistance to prednisone was observed (6 dogs, p=0.031). Interestingly, one dog with indolent T-zone lymphoma had increased expression of NR3C1. Resistance could not be consistently attributed to variations in ABCB1, 11B-HSD1 or 11B-HSD2 expression. Marked increase of the expression of 11B-HSD1 or 11B-HSD2 was exhibited in 2 dogs. In conclusion, decreased expression of the glucocorticoid receptor (NR3C1 gene) may play a role in conferring resistance to prednisone in dogs with lymphoma. Results do not indicate a broad role for ABCB1, 11B-HSD1 and 11B-HSD2 in the emergence of prednisone resistance in dogs with lymphoma

Détermination d'intervalles de référence des bilans d'hémostase de routine chez le chien sain déterminés avec un analyseur STA-Satellite (Diagnostica Stago) (étude expérimentale)

Dans cette étude, les intervalles de référence du temps de Quick (TQ), du temps de céphaline plus activateur (TCA), du fibrinogène (FIB) et de l antithrombine (AT) ont été déterminés conformément aux recommandations internationales. Les coefficients de variation de l imprécision de l analyseur STA Satellite® étaient respectivement de 3,9%, 1,3%, 6,9% et 5,1% pour le TQ, le TCA, le FIB et l AT. A 4C, les spécimens citratés étaient stables jusqu à 8 heures pour le sang total et pendant 36heures pour le plasma, excepté pour la mesure du TCA, qui était légèrement augmentée (< 1 seconde). Les intervalles de référence nonparamétriques, déterminés grâce au plasma citraté de 139 chiens de pure race, en bonne santé et à jeun, étaient de 6,9-8,8 secondes, 13,1-17,2 secondes, 1,24-4,30 g/L et 104-188% respectivement.TOULOUSE-EN Vétérinaire (315552301) / SudocSudocFranceF

Effects of Iron-Oxide Nanoparticle Surface Chemistry on Uptake Kinetics and Cytotoxicity in CHO-K1 Cells

Superparamagnetic iron-oxide nanoparticles (SPIONs) show great promise for multiple applications in biomedicine. While a number of studies have examined their safety profile, the toxicity of these particles on reproductive organs remains uncertain. The goal of this study was to evaluate the cytotoxicity of starch-coated, aminated, and PEGylated SPIONs on a cell line derived from Chinese Hamster ovaries (CHO-K1 cells). We evaluated the effect of particle diameter (50 and 100 nm) and polyethylene glycol (PEG) chain length (2k, 5k and 20k Da) on the cytotoxicity of SPIONs by investigating cell viability using the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine B (SRB) assays. The kinetics and extent of SPION uptake by CHO-K1 cells was also studied, as well as the resulting generation of intracellular reactive oxygen species (ROS). Cell toxicity profiles of SPIONs correlated strongly with their cellular uptake kinetics, which was strongly dependent on surface properties of the particles. PEGylation caused a decrease in both uptake and cytotoxicity compared to aminated SPIONs. Interestingly, 2k Da PEG-modifed SPIONs displayed the lowest cellular uptake and cytotoxicity among all studied particles. These results emphasize the importance of surface coatings when engineering nanoparticles for biomedical applications