Comparison of Multiplate, Platelet Function Analyzer-200, and Plateletworks in Healthy Dogs Treated with Aspirin and Clopidogrel.

BACKGROUND: Platelet function testing may be warranted to assess response to aspirin and clopidogrel. HYPOTHESIS/OBJECTIVES: To evaluate the effects of aspirin, clopidogrel, or combination therapy using 3 platelet function tests: Multiplate Analyzer (MP), Platelet Function Analyzer-200 (PFA), and Plateletworks (PW). ANIMALS: Six healthy laboratory Beagles. METHODS: Randomized double-blind placebo-controlled study (crossover design). Dogs were given aspirin 1 mg/kg, clopidogrel 2 mg/kg, or combination therapy for 1 week each, with a washout period of 2 weeks. Platelet function was assessed on days 0 and 7 of each phase using MP (adenosine diphosphate [ADP], arachidonic acid [AA], collagen [COL] agonists), PFA (P2Y, COL-ADP [CADP], COL-Epinephrine [CEPI] cartridges), and PW (ADP, AA, COL agonists). Platelet counts were obtained with impedance and optical counters. RESULTS: For MP, mean aggregation was decreased for COL and AA with combination therapy and for ADP with all treatments. For PFA, mean CT was increased for the CEPI cartridge with aspirin; and for the P2Y and CADP cartridges with clopidogrel or combination therapy. More dogs receiving clopidogrel showed an increase in PFA CT using the P2Y than the CADP cartridge. For PW, mean aggregation was decreased for AA with all treatments; for ADP with clopidogrel or combination therapy; and for COL with clopidogrel. The PW results with the 2 hematology counters showed almost perfect agreement. CONCLUSION AND CLINICAL IMPORTANCE: All platelet function tests detected treatment effects in some dogs and may have utility for monitoring therapy.

Improving a high-efficiency, gated spectrometer for x-ray Thomson scattering experiments at the National Ignition Facility.

We are developing x-ray Thomson scattering for applications in implosion experiments at the National Ignition Facility. In particular we have designed and fielded MACS, a high-efficiency, gated x-ray spectrometer at 7.5-10 keV [T. Döppner et al., Rev. Sci. Instrum. 85, 11D617 (2014)]. Here we report on two new Bragg crystals based on Highly Oriented Pyrolytic Graphite (HOPG), a flat crystal and a dual-section cylindrically curved crystal. We have performed in situ calibration measurements using a brass foil target, and we used the flat HOPG crystal to measure Mo K-shell emission at 18 keV in 2nd order diffraction. Such high photon energy line emission will be required to penetrate and probe ultra-high-density plasmas or plasmas of mid-Z elements.

Thrombomodulin Expression in Tissues From Dogs With Systemic Inflammatory Disease.

Thrombomodulin (TM) is a membrane glycoprotein expressed on endothelial cells, which plays a major role in the protein C anticoagulation pathway. In people with inflammation, TM expression can be down-regulated on endothelial cells and a soluble form released into circulation, resulting in increased risk of thrombosis and disseminated intravascular coagulation. TM is present in dogs; however, there has been minimal investigation of its expression in canine tissues, and the effects of inflammation on TM expression in canine tissues have not been investigated. The objective of this study was to evaluate endothelial TM expression in tissues from dogs with systemic inflammatory diseases. A retrospective evaluation of tissue samples of lung, spleen, and liver from dogs with and without systemic inflammatory diseases was performed using immunohistochemistry (IHC) and a modified manual IHC scoring system. TM expression was significantly reduced in all examined tissues in dogs diagnosed with septic peritonitis or acute pancreatitis.

Hypercoagulability and ACTH-dependent hyperadrenocorticism in dogs.

BACKGROUND: Dogs with hyperadrenocorticism are at risk of thromboembolic disease, which might be caused by an underlying hypercoagulable state. HYPOTHESIS/OBJECTIVES: To assess hemostatic function in dogs with ACTH-dependent hyperadrenocorticism (ADHAC) before and after treatment. ANIMALS: Nineteen dogs with ADHAC and 40 normal dogs. METHODS: Prospective, observational study. Dogs with ADHAC were recruited from the referral hospital patient population; normal dogs were recruited from staff and students at the study's institution. Hemostasis was assessed before and at 3 and 6 months after treatment with trilostane (T0, T3, T6) by kaolin-activated thrombelastography with platelet mapping (TEG-PM), prothrombin time, activated partial thromboplastin time, fibrinogen concentration, and antithrombin activity (AT). RESULTS: Dogs with ADHAC had statistically significantly increased α-angle (P < .01) and maximum amplitude (MA)(thrombin) (P < .01) on TEG-PM, and significantly decreased κ (P < .005) at T0, T3, and T6. Platelet count (P < .001) and fibrinogen concentration (P < .001), but not AT activity, were increased in dogs with ADHAC at T0, T3, and T6. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with ADHAC have thrombelastographic evidence of hypercoagulability and remained hypercoagulable during treatment. AT deficiency does not appear to be involved in the pathogenesis of hypercoagulability in this population.

Angiofibroma of the nasal cavity in 13 dogs.

This case series describes a rare entity, nasal angiofibroma, in 13 dogs that were presented to the University of Wisconsin, School of Veterinary Medicine from 1988 to 2000. All dogs in this case series presented with clinical signs and radiographic changes that were strongly suggestive of a locally invasive neoplasm. However, histopathology completed on transnostral core biopsy samples revealed benign appearing vascular proliferation with secondary lymphosuppurative inflammation was established despite cytologic criteria of malignancy present in five dogs. On the basis of the outcomes in this case series, nasal angiofibroma should be considered a differential for dogs presenting with clinical signs consistent with a malignant nasal tumour.

Images of the laser entrance hole from the static x-ray imager at NIF.

The static x-ray imager at the National Ignition Facility is a pinhole camera using a CCD detector to obtain images of Hohlraum wall x-ray drive illumination patterns seen through the laser entrance hole (LEH). Carefully chosen filters, combined with the CCD response, allow recording images in the x-ray range of 3-5 keV with 60 µm spatial resolution. The routines used to obtain the apparent size of the backlit LEH and the location and intensity of beam spots are discussed and compared to predictions. A new soft x-ray channel centered at 870 eV (near the x-ray peak of a 300 eV temperature ignition Hohlraum) is discussed.

Effect of dietary omega-3 and omega-6 fatty acids on clotting activities of Factor V, VII and X in fatty liver haemorrhagic syndrome-susceptible laying hens.

1. The relationship between concentrations of omega-3 and omega-6 fatty acids in plasma and Factor V, VII and X clotting activities was determined using a crossover feeding trial with diets supplemented with either soy oil or flax oil. 2. Laying hens on the soy diet, which is high in omega-6 fatty acids, had substantially higher clotting activity for all three factors compared to laying hens on the flax diet that was high in omega-3 fatty acids. 3. Positive associations were seen between liver haemorrhage score and the percentage of liver weight and between the percentage of liver weight and the severity of haemorrhagic and fatty changes seen on histology. 4. These results support the hypothesis that concentrations of omega-6 and omega-3 fatty acids in plasma affect clotting activity; however, there was no relationship between the extent of liver haemorrhages and the composition of plasma fatty acids.

Serum acute phase protein concentrations in dogs with autoimmune hemolytic anemia.

BACKGROUND: Serial monitoring of acute phase protein (APP) concentrations in canine autoimmune hemolytic anemia (AIHA) has not been reported. HYPOTHESES: Acute canine AIHA is accompanied by an acute phase response (APR) characterized by increased C-reactive protein (CRP) and alpha1-acid glycoprotein (AAG) concentrations and decreased albumin concentrations. ANIMALS: Twenty-seven dogs with AIHA and 11 control dogs. METHODS: Prospective, cohort study. CRP, AAG, and albumin concentrations, white blood cell (WBC) count, and packed cell volume (PCV) were determined at admission (day 1), every 48 hours until death or discharge, and on days 30, 90, 180, and 365. RESULTS: Compared with controls, CRP and AAG concentrations were increased and albumin concentration was decreased in dogs with AIHA (days 1-7; P < .002) and normalized with disease stabilization (days 9-365; P > .05). APP concentrations on day 1 were not predictive of survival, duration of hospitalization, or number of blood transfusions (P= .153-.940). PCV correlated with APP concentrations over time (CRP r=-.600, AAG r=-.665, albumin r= .533; P < .0001) as did WBC count (CRP r= .253, AAG r= .486, albumin r=-.246; P < .006). Day 1 CRP concentration was lower for dogs that received corticosteroids before referral (115.3 microg/mL) compared with dogs that did not (191.2 microg/mL; P= .02). CONCLUSIONS: An APR occurs in canine AIHA. Initial APP concentrations are not predictive of acute survival, correlate with hematologic markers of remission, and normalize rapidly with disease stabilization.

An ion Doppler spectrometer instrument for ion temperature and flow measurements on SSPX.

A high-resolution ion Doppler spectrometer (IDS) has been installed on the sustained spheromak plasma experiment to measure ion temperatures and plasma flow. The system is composed of a 1 m focal length Czerny-Turner spectrometer with a diffraction grating line density of 2400 lines/mm, which allows for first order spectra between 300 and 600 nm. A 16-channel photomultiplier tube detection assembly combined with output coupling optics provides a spectral resolution of 0.0126 nm/channel. We calculate in some detail the mapping of curved slit images onto the linear detector array elements. This is important in determining the wavelength resolution and setting the optimum vertical extent of the slit. Also, because of the small wavelength window of the IDS, a miniature fiber-optic survey spectrometer sensitive to a wavelength range 200-1100 nm and having a resolution of 0.2 nm is used to obtain a time-integrated spectrum for each shot to verify specific impurity line radiation. Several measurements validate the systems operation. Doppler broadening of C III 464.72 nm line in the plasma shows time-resolved ion temperatures up to 250 eV for hydrogen discharges, which is consistent with neutral particle energy analyzer measurements. Flow measurements show a sub-Alfvenic plasma flow ranging from 5 to 45 kms for helium discharges.

Influence of plasma lipid composition on activity of Factors V, VII and X in Single Comb White Leghorn and Fatty Liver Haemorrhagic Syndrome-susceptible laying hens.

1. Plasma lipids were investigated to determine whether they influence the biological activities of specific coagulation proteins Factors V, VII and X. 2. Factor activities decreased when lipids were depleted from the plasma of Single Comb White Leghorn (SCWL) and Fatty Liver Haemorrhagic Syndrome-susceptible (FLHS) laying hens. 3. Addition of lipids removed from SCWL laying hens and FLHS-susceptible laying hens into lipid-depleted plasma of both bird strains caused an increase and decrease, respectively, in Factors V and X activities. 4. Omega-3 fatty acids were negatively correlated to Factors V, VII and X activities. When bird strain was considered, it was significant for Factor X in SCWL laying hens. Omega-6 fatty acids were positively correlated with Factors VII and X for FLHS-susceptible laying hens. 5. The results suggest that the type of fatty acid in plasma phospholipids influences the activities of Factors V, VII and X and by altering lipid composition in the plasma, activities of coagulation factors may be affected.

Neutral particle analyzer measurements on the SSPX spheromak.

A neutral particle analyzer is used to measure the time-resolved energy spectrum of neutral hydrogen leaving a spheromak plasma. A gas cell filled with 10-50 mTorr of helium is used to strip electrons from incoming neutral hydrogen, lowering the minimum detectable energy well below that obtained with thin foils. Effective neutral particle temperature is calculated by fitting a Maxwellian energy distribution to the measured energy spectrum above and below approximately 300 eV. A computational model with approximated profiles of plasma density and neutral density is used with the measured neutral hydrogen flux to estimate the ion temperature. Measurement of the power flux due to neutral hydrogen emitted at the measurement location is extended to the whole plasma surface to estimate the total charge exchange power loss from the plasma. The initial results indicate that the charge exchange power loss represents only 2% of the total input gun power during the sustainment phase of the discharge.

Impairment of innate immune responses of airway epithelium by infection with bovine viral diarrhea virus.

Bovine viral diarrhea virus (BVDV) infection is an important risk factor for development of shipping fever pneumonia in feedlot cattle, and infects but does not cause morphologic evidence of damage to airway epithelial cells. We hypothesized that BVDV predisposes to bacterial pneumonia by impairing innate immune responses in airway epithelial cells. Primary cultures of bovine tracheal epithelial cells were infected with BVDV for 48 h, then stimulated with LPS for 16 h. Expression of tracheal antimicrobial peptide (TAP) and lingual antimicrobial peptide (LAP) mRNA was measured by quantitative RT-PCR, and lactoferrin concentrations were measured in culture supernatant by ELISA. BVDV infection had no detectable effect on the constitutive expression of TAP and LAP mRNA or lactoferrin concentration in culture supernatant. LPS treatment provoked a significant increase in TAP mRNA expression and lactoferrin concentration in the culture supernatant (p<0.01), and these effects were significantly (p<0.02, p<0.01) abrogated by prior infection of the tracheal epithelial cells with the type 2 ncp-BVDV isolate. In contrast, infection with the type 1 ncp-BVDV isolate had no effect on TAP mRNA expression or lactoferrin secretion. LPS treatment induced a significant (p<0.001) upregulation of LAP mRNA expression, which was not significantly affected by prior infection with BVDV. These data indicate that infection with a type 2 BVDV isolate inhibits the LPS-induced upregulation of TAP mRNA expression and lactoferrin secretion by tracheal epithelial cells, suggesting a novel mechanism by which this virus abrogates respiratory innate immune responses and predisposes to bacterial pneumonia in cattle.

Increasing the magnetic helicity content of a plasma by pulsing a magnetized source.

By operating a magnetized coaxial gun in a pulsed mode it is possible to produce large voltage pulses of duration approximately 500 mus while reaching a few kV, giving a discrete input of helicity into a spheromak. In the sustained spheromak physics experiment (SSPX), it is observed that pulsing serves to nearly double the stored magnetic energy and double the temperature. We discuss these results by comparison with 3D MHD simulations of the same phenomenon.

Flow cytometric immunophenotype of canine lymph node aspirates.

Increasing availability of reagents able to distinguish subtypes of lymphocytes and other leukocytes has enabled greater understanding of lymphocyte biology and pathology in the dog. Lymphocytes in circulation most commonly are subjected to immunophenotypic assessment by flow cytometry, but needle aspirates of lymph nodes can be similarly suitable for immunophenotypic examination. In this investigation, the feasibility of immunophenotyping samples obtained by needle aspiration of lymph nodes from 32 dogs with no physical abnormalities and 6 dogs with lymphoma was determined. In addition, samples from 6 dogs were stored overnight at 4 degrees C and reanalyzed 24 hours later. For each sample, stained smear preparations were examined microscopically for lymphocyte morphology, neoplasia, and the presence of inflammatory cells. Expression of antigens on a corresponding sample of aspirated cells was determined by flow cytometric detection of antibody binding on a minimum of 10,000 events. The distribution of data was determined with Anderson-Darling tests, and reference intervals incorporating the central 95% of values were established. Adequate samples were obtained from 30 of 32 clinically normal dogs. Immunophenotypic results after 24 hours of storage were consistent with those obtained immediately after sampling. Reference intervals for lymphocyte subsets from normal dog lymph nodes were similar to the proportions of CD3+, CD4+, CD8+, and CD21+ lymphocytes found in blood. Aspirates of enlarged lymph nodes from dogs with lymphoma were readily classified by this technique. Aspiration of lymph nodes from dogs for comprehensive analysis by flow cytometry is feasible and applicable to immunophenotyping of lymphoma.

New mode of operating a magnetized coaxial plasma gun for injecting magnetic helicity into a spheromak.

By operating a magnetized coaxial plasma gun continuously with just sufficient current to enable plasma ejection, large gun-voltage spikes (approximately 1 kV) are produced, giving the highest sustained voltage approximately 500 V and highest sustained helicity injection rate observed in the Sustained Spheromak Physics Experiment. The spheromak magnetic field increases monotonically with time, exhibiting the lowest fluctuation levels observed during formation of any spheromak (B/B>/=2%). The results suggest an important mechanism for field generation by helicity injection, namely, the merging of helicity-carrying filaments.

Suppression of MHD fluctuations leading to improved confinement in a gun-driven spheromak.

Magnetic fluctuations have been reduced to approximately 1% during discharges on the Sustained Spheromak Physics Experiment by shaping the spatial distribution of the bias magnetic flux in the device. In the resulting quiescent regime, the safety factor profile is nearly flat in the plasma and the dominant ideal and resistive MHD modes are greatly reduced. During this period, the temperature profile is peaked at the magnetic axis and maps onto magnetic flux contours. Energy confinement time is improved over previous reports in a driven spheromak.

Numerical simulation of the superplastic forming of dental and medical prostheses.

A relatively recent development in prostheses manufacture is the use of superplastic forming technology formerly associated with industrial applications such as aerospace components. This paper considers the finite element incremental flow formulation for the simulation of the forming of thin and moderately thick titanium alloy sheet dental and medical prostheses and, in particular, the determination of the pressure-time cycle. Issues concerning material characteristics are discussed, and the process is illustrated by a number of examples. The application of finite element simulation in this context is ongoing, nevertheless interim conclusions are drawn and future directions for research are identified.

Oxygen free radical damage to DNA. Translesion synthesis by human DNA polymerase eta and resistance to exonuclease action at cyclopurine deoxynucleoside residues.

Cyclopurine deoxynucleosides are common DNA lesions generated by exposure to reactive oxygen species under hypoxic conditions. The S and R diastereoisomers of cyclodeoxyadenosine on DNA were investigated separately for their ability to block 3' to 5' exonucleases. The mammalian DNA-editing enzyme DNase III (TREX1) was blocked by both diastereoisomers, whereas only the S diastereoisomer was highly efficient in preventing digestion by the exonuclease function of T4 DNA polymerase. Digestion in both cases was frequently blocked one residue before the modified base. Oligodeoxyribonucleotides containing a cyclodeoxyadenosine residue were further employed as templates for synthesis by human DNA polymerase eta (pol eta). pol eta could catalyze translesion synthesis on the R diastereoisomer of cyclodeoxyadenosine. On the S diastereoisomer, pol eta could catalyze the incorporation of one nucleotide opposite the lesion but could not continue elongation. Although pol eta preferentially incorporated dAMP opposite the R diastereoisomer, elongation continued only when dTMP was incorporated, suggesting bypass of this lesion by pol eta with reasonable fidelity. With the S diastereoisomer, pol eta mainly incorporated dAMP or dTMP opposite the lesion but could not elongate even after incorporating a correct nucleotide. These data suggest that the S diastereoisomer may be a more cytotoxic DNA lesion than the R diastereoisomer.

Strong functional interactions of TFIIH with XPC and XPG in human DNA nucleotide excision repair, without a preassembled repairosome.

In mammalian cells, the core factors involved in the damage recognition and incision steps of DNA nucleotide excision repair are XPA, TFIIH complex, XPC-HR23B, replication protein A (RPA), XPG, and ERCC1-XPF. Many interactions between these components have been detected, using different physical methods, in human cells and for the homologous factors in Saccharomyces cerevisiae. Several human nucleotide excision repair (NER) complexes, including a high-molecular-mass repairosome complex, have been proposed. However, there have been no measurements of activity of any mammalian NER protein complex isolated under native conditions. In order to assess relative strengths of interactions between NER factors, we captured TFIIH from cell extracts with an anti-cdk7 antibody, retaining TFIIH in active form attached to magnetic beads. Coimmunoprecipitation of other NER proteins was then monitored functionally in a reconstituted repair system with purified proteins. We found that all detectable TFIIH in gently prepared human cell extracts was present in the intact nine-subunit form. There was no evidence for a repair complex that contained all of the NER components. At low ionic strength TFIIH could associate with functional amounts of each NER factor except RPA. At physiological ionic strength, TFIIH associated with significant amounts of XPC-HR23B and XPG but not other repair factors. The strongest interaction was between TFIIH and XPC-HR23B, indicating a coupled role of these proteins in early steps of repair. A panel of antibodies was used to estimate that there are on the order of 10(5) molecules of each core NER factor per HeLa cell.