Evaluation of the LaserCyte: an in-house hematology analyzer for dogs and cats

In the present study, the LaserCyte instrument, a fully automated flow cytometer for use in veterinary practice, was evaluated for dogs and cats. Precision (coefficient of variation, CV) for red blood cell (RBC) parameters was ≤3.9%, for reticulocytes between 14.9 and 102%, for white blood cells (WBC) between 3 and 9.5%, for neutrophils between 3.9 and 6.5%, for lymphocytes between 7 and 17.9%, for monocytes between 4.9 and 13.1%, for eosinophils between 10.4 and 32.1%, for basophils between 7.8 and 32%, for platelets between 3.1 and 13.2%, and for platelet indices between 0 and 28.2%. The range of linearity extended the reference ranges. The agreement with reference methods (coefficient of correlation, r) were ≥0.96 (RBC), ≥0.94 (hematocrit), ≥0.96 (hemoglobin), ≥0.95 (mean corpuscular volume), ≥0.94 (WBC), ≥0.93 (neutrophils), ≥0.77 (lymphocytes), ≥0.77 (monocytes), ≥0.29 (eosinophils), ≥0.03 (basophils), ≥0.13 (reticulocytes), and ≥0.86 (platelets). The LaserCyte allowed the correct assessment of RBC and WBC parameters with respect to clinical relevance in the majority of samples. Lymphocytopenia was detected in only 51 out of 89 cases and monocytopenia in one out of 11 cases. The reticulocyte counts were correctly estimated in 85 out of 149 cases. It was concluded that the LaserCyte allowed reliable determination of the RBC parameters, WBCs, neutrophils in both species and platelets in dogs. Based on its capability to reliably determine feline platelets and of the parameters mentioned above, this instrument is considered a useful in-house analyzer for the veterinary practice. Qualitative microscopic assessment of blood smears is still necessary for detecting abnormal cell morphologies, certain cell precursors and blood parasite

Effect of dog breed and body conformation on vertical ground reaction forces, impulses, and stance times

OBJECTIVES: To assess whether fully normalised vertical ground reaction forces and stance times obtained at a trot depend on dog breed or body conformations. METHODS: Peak vertical forces (PVF), vertical impulses (VI), stance times (ST), and ratio of forelimb impulse to total impulse (RVI) of 54 dogs of seven different breeds were normalised to body weight and body size according to the theory of dynamic similarity, and were tested for differences between breeds. Breeds were Borzoi, Bernese Mountain dog, Great Dane, Labrador Retriever, Landseer, Rhodesian Ridgeback, and Rottweiler. Body length ratio (BLR) and body mass index (BMI) were also compared between breeds. RESULTS: Significant differences between breeds were found for the normalised forelimb PVF, VI and ST, and hindlimb PVF. Looking at individual breeds, it was most evident that Borzois had a lower forelimb VI, and a higher hindlimb PVF than the other breeds. This resulted in Borzois having a lower RVI compared to other dogs, indicating a more caudally located centre of gravity. Only a few differences in gait parameters were found between other dog breeds. The BMI was significantly lower in Borzois than in other breeds, but was otherwise not associated with gait parameters. CLINICAL SIGNIFICANCE: Force plate data of dogs of different breeds are not necessarily comparable, even after full normalisation to body weight and body size. Group comparisons should only be made when the groups consist of breeds with similar body conformation

New P-T-t data on the metamorphic sole of the Amasia ophiolites and implications for the geodynamical process, NW of the Sevan-Akera suture zone, Lesser Caucasus (Armenia)

International audienceThe ophiolites of the Lesser Caucasus belong to the Tethyan Ophiolitic Belt. In the northwestern part of the Sevan Akera suture zone (Lesser Caucasus, Armenia) ophiolites correspond to a major obduction of oceanic crust over the South Armenian continental block. Near the locality of Amasia (NW Armenia), our mapping evidenced a series of (1) unmetamorphosed gabbroic oceanic crust, resting on (2) serpentinites and a greenschist grade tectonic mélange composed of deformed pillow-basalts, radiolarites and cherts, and (3) a basal slice of garnet amphibolites bearing similar compositional features as the ophiolite. They are sliced by post Eocene thrusts related to the shortening of the suture after the collision of the South Armenian Block (Sosson et al., 2010). Structural observations allow us to consider these metamorphic rocks (garnet amphibolites and quartz-garnet-oligoclase-amphibole-chlorite schistes) to be the sole of the obducted ophiolite. The metamorphic rocks allow the evaluation of pressure-temperature-time conditions endured by the base of the oceanic crust during the obduction of the Armenian ophiolite series. Pressure and temperature estimations were obtained by calculating equilibrium conditions between different mineral phases which coexist in the sample coupled with whole rock geochemistry using the software PERPLEX. The P-T data show a counterclockwise path with (1) a HT-LP peak of P = 6-7 kbar and T > 630_C, followed by MP-MT peak at P = 8-10 kbar and T = 600_C. In order to further constrain the evolution of the amphibolites and build a P-T-t path using 40Ar/39Ar dating on amphiboles and white micas (phengite). The ages obtained on both HT and MT peaks are similar within error (90.8 Ma ± 3.0 (2σ), and 90.8 Ma ± 1.2 (2 σ), respectively), which suggests a very rapid cooling of the metamorphic sole during its stacking in the subduction zone. The counterclockwise path determined confirms the observations made below the Oman ophiolite by Goffé et al. (1988). This path is also in agreement with a scaling process of oceanic crust during the obduction. In this scenario slices of oceanic crust would have been dragged under the obduction front below a relatively hot oceanic crust. Afterwards, these slices would then have been amphibolitized along a HT-MP geothermal gradient. Rapidly, a thickening of the system at c. 91-90 Ma, and underthrusting of amphibolites would have caused the conditions to change to MP-MT. This infers that the South Armenian Block enters the subduction zone at this date. A recent study has shown metamorphic rocks in the same structural setting were affected by a HP metamorphism in the Blue Schist facies (Rolland et al., 2009). The age of this blue schist of Stepanavan, Armenia is slightly older (95-91 Ma) (Galoyan et al., 2009) than the amphibolites of Amasia (91-90 Ma). This assumes the occurrence of an active subduction just before the development of the HT-MP metamorphism of Amasia. References: Galoyan, G., Rolland, Y., Sosson, M., Corsini, M., Billo, S., Verati, C., Melkonyan, R., 2009. Geology, geochemistry and 40Ar/39Ar dating of the Sevan ophiolites (Lesser Caucasus, Armenia): Evidence for Jurassic Back-arc opening and hot spot event between the South Armenian Block and Eurasia. Journal of Asian Earth Science, 34, 135-153. Goffé, B., Michard, A., Kienast, J.R., Le Mer, O., 1988. A case of obduction-related high-pressure, lowtemperature metamorphism in upper crustal nappes, Arabian continental margin, Oman: P-T paths and kinematic interpretation. Tectonophysics, 151, 363-386. Rolland, Y., Billo, S., Corsini, M., Sosson, M., Galoyan, G., 2009. Blueschists of the Amassia-Stepanavan Suture Zone (Armenia): linking Tethys subduction history from E-Turkey toW-Iran. International Journal of Earth Science, 98, 533-550. Sosson, M., Rolland, Y., Müller, C., Danelian, T., Melkonyan, R., Kekelia, S., Adamia, S., Badazadeh, V., Kangarli, T., Avagyan, A., Galoyan, G., Mosar, J., 2010. Subduction, obduction and collision in the Lesser Caucasus (Armenia, Azernaijan, Georgia), new insights. Geological Society, London, Special Publications, 340, 329-352

A protosolar nebula origin for the ices agglomerated by Comet 67P/Churyumov-Gerasimenko

The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the protosolar nebula. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the protosolar nebula. On the basis of existing laboratory and modeling data, we find that the N$_2$/CO and Ar/CO ratios measured in the coma of the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA instrument aboard the European Space Agency's Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N$_2$/CO and Ar/CO ratios in 67P/Churyumov-Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov-Gerasimenko is impoverished in Ar and N$_2$, the volatile enrichments observed in Jupiter's atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.Comment: The Astrophysical Journal Letters, in pres

Evaluation of an Electrolyte Analyser for Measurement of Concentrations of Ionized Calcium and Magnesium in Cats

The goal of this study was to evaluate the Nova CRT 8 electrolyte analyser for determination of concentrations of ionized calcium (Cai) and magnesium (Mgi) in cats, todetermine the effects of sample handling and storage and to establish reference ranges. The precision and analytical accuracy of the Nova CRT 8 analyser were good. The concentrations of Cai and Mgi were significantly lower in aerobically handled serum samples than in those handled anaerobically. The concentrations of Cai and Mgi differed significantly among whole blood, plasma and serum. In anaerobically handled serum, the concentration of Cai was stable for 8 h at 22°C, for 5 days at 4°C and for 1 week at −20°C. The concentration of Mgi was stable for 4 h at 22°C but for less than 24 h at 4°C and for less than 1 week at −20°C. In serum from 36 cats, the reference ranges were 1.20-1.35 mmol/L for Cai and 0.47-0.59 mmol/L for Mgi. The Nova CRT 8 electrolyte analyser is suitable for determination of Cai and Mgi concentrations in cats. Anaerobically handled serum samples are recommended and, stored at room temperature, they yield accurate results when analysed within 4

Immunodiagnosis of primary Toxoplasma gondii infection in sheep by the use of a P30 IgG avidity ELISA

Abstract.: Toxoplasma gondii is a protozoan parasite with a worldwide distribution. In both sheep and humans, if the parasite is encountered during pregnancy, fetal infection and abortion can occur. Therefore, Toxoplasma infection in sheep has a major economic impact upon sheep farming. Clinically, there is a need to distinguish recent (acute) infections from longstanding (chronic) infections. However, current serological techniques, such as detection of anti-T. gondii IgG, cannot discriminate between acute and chronic infections. Increasing immunoglobulin avidity is a good determining factor of how recent an infection is. In this study, we describe the application and validation of a T. gondii IgG avidity ELISA, based on the use of an affinity-purified, native T. gondii P30 antigen. The assay was used to examine sera from eight sheep experimentally infected with T. gondii and found that all seroconverted within 21days post-infection (p.i.), beginning with avidities that were initially low but that increased over time, with all sheep reaching high IgG avidity within 10weeks p.i. In addition, sera from clinically healthy but T. gondii-seropositive lambs and ewes and seropositive ewes with a history of abortion were also subjected to a preliminary serological investigation. High IgG avidities were found in 80% of the seropositive lambs, in 90% of the clinically healthy ewes and in 97% of the ewes with abortion problems. These findings indicate that the animals had most likely contacted the parasite a longer time ag

Correlation of radiographic changes after tibial tuberosity advancement in dogs with cranial cruciate-deficient stifles with functional outcome

OBJECTIVE: To (1) evaluate radiographic changes associated with osteoarthrosis (OA) before and after tibial tuberosity advancement (TTA) and (2) determine if these changes are indicative of limb function as determined by kinetic gait analysis. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n=35) with cranial cruciate ligament (CCL) deficient stifles (38). METHODS: Variables recorded were: complete or partial CCL rupture, meniscal lesions, arthroscopically graded cartilage lesions, complications, and revision surgeries. Radiographic evaluation and kinetic gait analysis (vertical ground reaction forces [GRFs]) were conducted pre- and 4-16 months postoperatively (mean, 5.9 months). Radiographs were evaluated without knowledge of operative findings and functional outcome. A score (0-3) based on new bone production at 11 specific sites was used to grade OA. Soft tissue changes were classified separately as normal or excessive. Preoperative scores were correlated with clinical variables. Postoperative scores and progression of OA scores were correlated with clinical variables and GRFs. RESULTS: OA remained unchanged in 17 joints and progressed in 21 (55%). Dogs with meniscal lesions had higher OA scores preoperatively, but not at follow-up. Dogs with severe cartilage lesions at surgery had more progression of OA. GRFs improved after surgery and were not correlated with any of the radiographic OA scores. CONCLUSION: Progression of OA was greater in the presence of severe cartilage lesions at surgery. OA scores were not correlated with GRFs. CLINICAL RELEVANCE: Progression of OA is generally expected to occur after TTA despite improvement of limb function

The Armenian and NW Anatolian ophiolites: new insights for the closure of the Tethys domain and obduction onto the South Armenian Block and Anatolian-Tauride Platform before collision through dynamic modeling

International audienceIn the Lesser Caucasus three main domains are distinguished from SW to NE: (1) the South Armenian Block (SAB), a Gondwanian-derived continental terrane; (2) scattered outcrops of ophiolites coming up against the Sevan-Akera suture zone; and (3) the Eurasian plate. The Armenian ophiolites represent remnants of an oceanic domain which disappeared during Eurasia-Arabia convergence. Previous works using geochemical whole-rock analyses, 40Ar/39Ar and paleontological dating have shown that the ophiolite outcrops throughout this area were emplaced during the Late Cretaceous as one non-metamorphic preserved ophiolitic nappe of back-arc origin that formed during Middle to Late Jurassic. From these works, tectonic reconstructions include two clearly identified subductions, one related to the Neotethys subduction beneath the Eurasian margin and another to intra-oceanic subduction responsible for the opening of the back-arc basin corresponding to the ophiolites of the Lesser Caucasus. The analysis of the two stages of metamorphism of the garnet amphibolites of the ophiolite obduction sole at Amasia (M1: HT-LP peak of P = 6-7 kbar and T > 630°C; M2; MP-MT peak at P = 8-10 kbar and T = 600°C) has allowed us to deduce the onset of subduction of the SAB at 90 Ma for this locality, whichage coincides with other paleontological ages at the obduction front. A preliminary paleomagnetic survey has also brought quantification to the amount of oceanic domain which disappeared by subduction between the SAB and Eurasia before collision. We propose a dynamic finite element model using ADELI to test the incidence of parameters such as the density of the different domains (or the interval between the densities), closing speed (or speeds if sporadic), the importance and interactions of mantle discontinuities with the subducting lithosphere and set a lithospheric model. Our field observations and analyses are used to validate combinations of factors. The aim is to better qualify the predominant factors and quantify the conditions leading to the onset of obduction, the paradox of dense oceanic lithosphere emplaced on top of a continental domain, after subduction and prior to collision. The results of this modeling are also compared to new observations of the assumed eastward extension of this ophiolitic nappe in NW Anatolia. Analyses of the Refahiye ophiolites show similar geochemical signatures as the Armenian ophiolites, due to a similar setting of formation (back-arc). The impact of the obduction of such a vast oceanic domain is not to be taken for granted when considering the following collision stage

Organics in comet 67P – a first comparative analysis of mass spectra from ROSINA–DFMS, COSAC and Ptolemy

The ESA Rosetta spacecraft followed comet 67P at a close distance for more than 2 yr. In addition, it deployed the lander Philae on to the surface of the comet. The (surface) composition of the comet is of great interest to understand the origin and evolution of comets. By combining measurements made on the comet itself and in the coma, we probe the nature of this surface material and compare it to remote sensing observations. We compare data from the double focusing mass spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission and previously published data from the two mass spectrometers COSAC (COmetary Sampling And Composition) and Ptolemy on the lander. The mass spectra of all three instruments show very similar patterns of mainly CHO-bearing molecules that sublimate at temperatures of 275 K. The DFMS data also show a great variety of CH-, CHN-, CHS-, CHO2- and CHNO-bearing saturated and unsaturated species. Methyl isocyanate, propanal and glycol aldehyde suggested by the earlier analysis of the measured COSAC spectrum could not be confirmed. The presence of polyoxymethylene in the Ptolemy spectrum was found to be unlikely. However, the signature of the aromatic compound toluene was identified in DFMS and Ptolemy data. Comparison with remote sensing instruments confirms the complex nature of the organics on the surface of 67P, which is much more diverse than anticipated