Acetylation and methylation of sperm histone 3 lysine 27 (H3K27ac and H3K27me3) are associated with bull fertility.

Epigenetic modifications in histones are crucial for proper sperm physiology, egg activation and reproductive development of males. The objectives of this study were to determine the conservation and interactomes of histone three (H3) and ascertain the expression dynamics of acetylated and methylated H3 lysine 27 (H3K27ac and H3K27me3) in spermatozoa from Holstein bulls with different fertility. Methods in immunocytochemistry and flow cytometry were used to evaluate the expression dynamics of H3K27ac and H3K27me3 in spermatozoa from 10 bulls with different in vivo fertility. Computational biology methods including Clustal Omega and Cytoscape were performed to determine the evolutionary conservation and interactome of H3. The post-translational modifications (PTM) of H3 (H3K27ac and H3K27me3) had different spatiotemporal dynamics in the sperm head. Intensities of methylation were higher than those of acetylation and inversely correlated between the two fertility groups (p = .0032). The interacting proteins of H3 are involved in critical subcellular processes such as regulation of methylation, nucleosome assembly, regulation of DNA replication and chromatin assembly. These results are significant because they help advance fundamental science and biotechnology of mammalian reproduction.

Effects of aspirin dose escalation on platelet function and urinary thromboxane and prostacyclin levels in normal dogs.

Established "low" aspirin dosages inconsistently inhibit platelet function in dogs. Higher aspirin dosages consistently inhibit platelet function, but are associated with adverse effects. The objectives of this study were to use an escalation in dosage to determine the lowest aspirin dosage that consistently inhibited platelet function without inhibiting prostacyclin synthesis. Eight dogs were treated with five aspirin dosages: 0.5 mg/kg q24h, 1 mg/kg q24h, 2 mg/kg q24h, 4 mg/kg q24h and 10 mg/kg q12h for 7 days. Utilizing aggregometry and a whole-blood platelet function analyzer (PFA-100), platelet function was evaluated before and after treatment. Urine 11-dehydro-thromboxane-B2 (11-dTXB2 ) and 6-keto-prostaglandin-F1α (6-keto-PGF1α ), were measured. Compared to pretreatment, there were significant post-treatment decreases in the maximum aggregometry amplitude and increases in the PFA-100 closure times for all dosages expect 0.5 mg/kg q24h. There was no difference in amplitude or closure time among the 2 mg/kg q24h, 4 mg/kg q24h, and 10 mg/kg q12h dosages. Compared to pretreatment values, there was a significant decrease in urinary 11-dTXB2 -to-creatinine and 6-keto-PGF1α -to-creatinine ratios, but there was no dose-dependent decrease for either metabolite. An aspirin dosage of 2 mg/kg q24h consistently inhibits platelet function without decreasing prostacyclin synthesis significantly more than lower aspirin dosages.

The effects of clopidogrel and omeprazole on platelet function in normal dogs.

Omeprazole is used concurrently with clopidogrel to reduce gastrointestinal adverse effects. In humans, the concurrent use of these two drugs can reduce the antiplatelet efficacy of clopidogrel. Our objective was to determine the effects of omeprazole and clopidogrel on platelet function in healthy dogs. A crossover study utilized turbidimetric aggregometry (ADP and collagen) and the PFA-100® with the collagen/ADP cartridge to evaluate platelet function in eight healthy dogs during the administration of clopidogrel (1 mg/kg/24 h p.o.), omeprazole (1 mg/kg/24 h p.o.), and a combination of clopidogrel and omeprazole. Drug metabolite concentrations were also measured. Compared to pretreatment, on Days 3 and 5, with ADP as the agonist, there was a significant decrease in maximum amplitude on aggregometry for both clopidogrel and clopidogrel/omeprazole groups. The following revealed no significant differences between clopidogrel and clopidogrel/omeprazole groups when compared on Days 3 and 5: maximum amplitude on aggregometry with ADP or collagen agonists, and PFA-100® closure times. When compared to the clopidogrel group, clopidogrel metabolite concentrations in the clopidogrel/omeprazole group were significantly higher on Days 3 and 5. The concurrent administration of omeprazole and clopidogrel in healthy dogs was associated with an increase in the plasma concentration of an inactive metabolite of clopidogrel, but does not significantly alter the antiplatelet effects of clopidogrel.

Effects of oral cyclosporine on canine T-cell expression of IL-2 and IFN-gamma across a 12-h dosing interval.

The duration of immunosuppressive effects following oral cyclosporine in dogs is unknown. This study used flow cytometry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to evaluate the effects of high-dose oral cyclosporine across a 12-h dosing interval. Expression of interleukin-2 (IL-2) and interferon-gamma (IFN-γ) was compared before and after 8 days of cyclosporine at 10 mg/kg every 12 h in six healthy dogs. Samples were collected at 0, 2, 4, and 8 h postdosing for analysis of unactivated and activated T-cell and whole blood cytokine expression using flow cytometry and qRT-PCR, respectively, and at 0, 2, 4, 6, 8, and 10 h postdosing for measurement of cyclosporine concentrations. Flow cytometry and qRT-PCR both demonstrated significant marked reductions in IL-2 and IFN-γ levels at 0, 2, 4, and 8 h after dosing compared to pretreatment levels (P < 0.05) for activated samples, with less consistent effects observed for unactivated samples. Both flow cytometry and qRT-PCR are viable techniques for measuring cyclosporine pharmacodynamics in dogs, yielding comparable results with activated samples. Two hours postdrug administration is the preferred time for concurrent assessment of peak drug concentration and cytokine expression, and T-cell activation is needed for optimal results.

Evaluating interventions against Salmonella in broiler chickens: applying synthesis research in support of quantitative exposure assessment.

A scoping study and systematic review-meta-analyses (SR-MAs) were conducted to evaluate the effectiveness of various interventions for Salmonella in broiler chicken, from grow-out farm to secondary processing. The resulting information was used to inform a quantitative exposure assessment (QEA) comparing various control options within the context of broiler chicken production in Ontario, Canada. Multiple scenarios, including use of two separate on-farm interventions (CF3 competitive exclusion culture and a 2% lactose water additive), a package of processing interventions (a sodium hydroxide scald water disinfectant, a chlorinated post-evisceration spray, a trisodium phosphate pre-chill spray and chlorinated immersion chilling) a package consisting of these farm and processing interventions and a hypothetical scenario (reductions in between-flock prevalence and post-transport concentration), were simulated and compared to a baseline scenario. The package of on-farm and processing interventions was the most effective in achieving relative reductions (compared to baseline with no interventions) in the concentration and prevalence of Salmonella by the end of chilling ranging from 89·94% to 99·87% and 43·88% to 87·78%, respectively. Contaminated carcasses entering defeathering, reductions in concentration due to scalding and post-evisceration washing, and the potential for cross-contamination during chilling had the largest influence on the model outcomes under the current assumptions. Scoping study provided a transparent process for mapping out and selecting promising interventions, while SR-MA was useful for generating more precise and robust intervention effect estimates for QEA. Realization of the full potential of these methods was hampered by low methodological soundness and reporting of primary research in this area.

Associations between vaccinations against protozoal and viral infections and Salmonella in broiler flocks.

Reducing the burden of Salmonella in broiler flocks presents a challenge for public health. Worldwide, grow-out broilers are routinely vaccinated to prevent or lessen clinical manifestation of other infections. In this exploratory analysis we tested if details of a routine vaccination programme delivered to conventional grow-out broilers were associated with the burden of Salmonella in the flock as it progressed through its production cycle. None of the flocks studied were vaccinated against Salmonella or received a competitive exclusion product. The flocks were reared on conventional grow-out farms in southeastern USA, and sampled in a prospective field observational study. We observed significant associations between the content and design of a grow-out vaccination programme targeting other infections and the probability of detecting Salmonella in the broiler flock at different time points throughout the production cycle. To the best of the authors' knowledge, this is the first field report of such associations.

Beneficial impact of exogenous arginine, cysteine and methionine on postharvest senescence of broccoli.

This study examined the ability of l-arginine, l-cysteine and l-methionine, to inhibit postharvest senescence of broccoli. Florets were dipped in aqueous solutions of the amino acids at concentrations from 1.0 to 100 mM and stored at 10 °C. A 5 mM dip was found to be optimal in delaying senescence as measured by retention of green colour, vitamin C and antioxidant activity, and a lower level of ethylene production, respiration, weight loss, phenylalanine ammonia lyase (PAL) activity and ion leakage with the benefits being similar for all three amino acids. Arginine, cysteine and methionine have Generally Recognised As Safe (GRAS) status and should have few impediments in obtaining regulatory approval for commercial use if similar effects were found for other leafy vegetables.

Intraoperative Ultrasound Applications in Intracranial Surgery.

The methods and use of intraoperative ultrasound in 33 canine and five feline patients and its ability to localize and identify anatomical structures and pathological lesions in canines and felines undergoing intracranial surgery are described from a case series. All were client-owned referral patients admitted for neurologic evaluation, with an advanced imaging diagnosis of an intracranial lesion, and underwent surgical biopsy or surgical removal of the lesion. Medical records, retrieval and review of imaging reports, and characterization of findings for all canine and feline patients show that intraoperative ultrasound guidance was used in intracranial procedures during the period of 2012 and 2019. Twenty-nine of the canine patients had intracranial tumors. The remainder had various other conditions requiring intracranial intervention. Three of the feline patients had meningiomas, one had a depressed skull fracture, and one had an epidural hematoma. The tumors appeared hyperechoic on intraoperative ultrasound with the exception of cystic portions of the masses and correlated with the size and location seen on advanced imaging. Statistical comparison of the size of images seen on ultrasound and on MRI for 20 of the canine tumors revealed no statistical differences. Neuroanatomical structures, including vascular components, were easily identified, and tumor images correlated well with preoperative advanced imaging. The authors conclude that intraoperative ultrasound is a valuable asset in intracranial mass removals and can augment surgical guidance in a variety of intracranial disorders that require surgery. This is the first known publication in veterinary surgery of using intraoperative ultrasound as a tool in the operating theater to identify, localize, and monitor the removal/biopsy of intracranial lesions in small animals undergoing craniotomy/craniectomy.

Kinetics of the homogeneous freezing of water.

Rates of homogeneous nucleation of ice in micrometre-sized water droplets are reported. Measurements were made using a new system in which droplets were supported on a hydrophobic substrate and their phase was monitored using optical microscopy as they were cooled at a controlled rate. Our nucleation rates are in agreement, given the quoted uncertainties, with the most recent literature data. However, the level of uncertainty in the rate of homogeneous freezing remains unacceptable given the importance of homogeneous nucleation to cloud formation in the Earth's atmosphere. We go on to use the most recent thermodynamic data for cubic ice (the metastable phase thought to nucleate from supercooled water) to estimate the interfacial energy of the cubic ice-supercooled water interface. We estimate a value of 20.8 +/- 1.2 mJ m(-2) in the temperature range 234.9-236.7 K.

Exploratory study of the 'weekend effect' for acute medical admissions to public hospitals in Queensland, Australia.

AIMS: To determine whether in-hospital deaths of patients admitted through emergency departments with acute exacerbations of chronic obstructive pulmonary disease (COPD), acute myocardial infarction, intracerebral haemorrhage and acute hip fracture are increased by weekend versus weekday admission (the 'weekend effect'). METHODS: We performed a retrospective analysis of statewide administrative data from public hospitals in Queensland, Australia, during the 2002/2003-2006/2007 financial years. The primary outcome was 30-day in-hospital mortality. The secondary outcome of 2-day in-hospital mortality helped determine whether increased mortality of weekend admissions was closely linked to weekend medical care. RESULTS: During the study period, there were 30 522 COPD, 17 910 acute myocardial infarction, 4183 acute hip fracture and 1781 intracerebral haemorrhage admissions. There was no significant weekend effect on 30-day in-hospital mortality for COPD (adjusted risk ratio = 0.92, 95% CI: 0.81-1.04, P= 0.222), intracerebral haemorrhage (adjusted risk ratio = 1.01, 95% CI: 0.86-1.16, P= 0.935) or acute hip fracture (adjusted risk ratio = 0.78, 95% CI: 0.54-1.03, P= 0.13). There was a significant weekend effect for acute myocardial infarction (adjusted risk ratio = 1.15, 95% CI: 1.03-1.26, P= 0.007). Two-day in-hospital mortality showed similar results. CONCLUSION: This is the first Australian study on the 'weekend effect' (in a cohort other than neonates), and the first study worldwide to assess specifically the weekend effect among COPD patients. Observed patterns were consistent with overseas research. There was a significant weekend effect for myocardial infarction. Further research is needed to determine whether location (e.g. rural), clinical (e.g. disease severity) and service provision factors (e.g. access to invasive procedures) influence the weekend effect for acute medical conditions in Australia.

The REFLECT statement: methods and processes of creating reporting guidelines for randomized controlled trials for livestock and food safety.

The conduct of randomized controlled trials in livestock with production, health, and food-safety outcomes presents unique challenges that may not be adequately reported in trial reports. The objective of this project was to modify the CONSORT (Consolidated Standards of Reporting Trials) statement to reflect the unique aspects of reporting these livestock trials. A two-day consensus meeting was held on November 18-19, 2008 in Chicago, Ill, United States of America, to achieve the objective. Prior to the meeting, a Web-based survey was conducted to identify issues for discussion. The 24 attendees were biostatisticians, epidemiologists, food-safety researchers, livestock production specialists, journal editors, assistant editors, and associate editors. Prior to the meeting, the attendees completed a Web-based survey indicating which CONSORT statement items may need to be modified to address unique issues for livestock trials. The consensus meeting resulted in the production of the REFLECT (Reporting Guidelines for Randomized Control Trials) statement for livestock and food safety (LFS) and 22-item checklist. Fourteen items were modified from the CONSORT checklist, and an additional sub-item was proposed to address challenge trials. The REFLECT statement proposes new terminology, more consistent with common usage in livestock production, to describe study subjects. Evidence was not always available to support modification to or inclusion of an item. The use of the REFLECT statement, which addresses issues unique to livestock trials, should improve the quality of reporting and design for trials reporting production, health, and food-safety outcomes.

The REFLECT statement: methods and processes of creating reporting guidelines for randomized controlled trials for livestock and food safety.

The conduct of randomized controlled trials in livestock with production, health, and food-safety outcomes presents unique challenges that might not be adequately reported in trial reports. The objective of this project was to modify the CONSORT (Consolidated Standards of Reporting Trials) statement to reflect the unique aspects of reporting these livestock trials. A 2-day consensus meeting was held on November 18-19, 2008 in Chicago, IL, to achieve the objective. Before the meeting, a Web-based survey was conducted to identify issues for discussion. The 24 attendees were biostatisticians, epidemiologists, food-safety researchers, livestock production specialists, journal editors, assistant editors, and associate editors. Before the meeting, the attendees completed a Web-based survey indicating which CONSORT statement items would need to be modified to address unique issues for livestock trials. The consensus meeting resulted in the production of the REFLECT (Reporting Guidelines for Randomized Control Trials) statement for livestock and food safety and 22-item checklist. Fourteen items were modified from the CONSORT checklist, and an additional subitem was proposed to address challenge trials. The REFLECT statement proposes new terminology, more consistent with common usage in livestock production, to describe study subjects. Evidence was not always available to support modification to or inclusion of an item. The use of the REFLECT statement, which addresses issues unique to livestock trials, should improve the quality of reporting and design for trials reporting production, health, and food-safety outcomes.

The change in prevalence of Campylobacter on chicken carcasses during processing: a systematic review.

A systematic review was conducted to evaluate the change in prevalence of Campylobacter on chicken carcasses during processing. A structured literature search of 8 electronic databases using the key words for "Campylobacter," "chicken," and "processing" identified 1,734 unique citations. Abstracts were screened for relevance by 2 independent reviewers. Thirty-two studies described prevalence at more than one stage during processing and were included in this review. Of the studies that described the prevalence of Campylobacter on carcasses before and after specific stages of processing, the chilling stage had the greatest number of studies (9), followed by washing (6), defeathering (4), scalding (2), and evisceration (1). Studies that sampled before and after scalding or chilling, or both, showed that the prevalence of Campylobacter generally decreased immediately after the stage (scalding: 20.0 to 40.0% decrease; chilling: 100.0% decrease to 26.6% increase). The prevalence of Campylobacter increased after defeathering (10.0 to 72.0%) and evisceration (15.0%). The prevalence after washing was inconsistent among studies (23.0% decrease to 13.3% increase). Eleven studies reported the concentration of Campylobacter, as well as, or instead of, the prevalence. Studies that sampled before and after specific stages of processing showed that the concentration of Campylobacter decreased after scalding (minimum decrease of 1.3 cfu/g, maximum decrease of 2.9 cfu/mL), evisceration (0.3 cfu/g), washing (minimum 0.3 cfu/mL, maximum 1.1 cfu/mL), and chilling (minimum 0.2 cfu/g, maximum 1.7 cfu/carcass) and increased after defeathering (minimum 0.4 cfu/g, maximum 2.9 cfu/mL). Available evidence is sparse and suggests more data are needed to understand the magnitude and mechanism by which the prevalence and concentration of Campylobacter changes during processing. This understanding should help researchers and program developers identify the most likely points in processing to implement effective control efforts. For example, if contamination will occur during defeathering and likely during evisceration, critical control points postevisceration are likely to have a greater effect on the end product going to the consumer.

Overturning circulation, nutrient limitation, and warming in the Glacial North Pacific.

Although the Pacific Ocean is a major reservoir of heat and CO2, and thus an important component of the global climate system, its circulation under different climatic conditions is poorly understood. Here, we present evidence that during the Last Glacial Maximum (LGM), the North Pacific was better ventilated at intermediate depths and had surface waters with lower nutrients, higher salinity, and warmer temperatures compared to today. Modeling shows that this pattern is well explained by enhanced Pacific meridional overturning circulation (PMOC), which brings warm, salty, and nutrient-poor subtropical waters to high latitudes. Enhanced PMOC at the LGM would have lowered atmospheric CO2-in part through synergy with the Southern Ocean-and supported an equable regional climate, which may have aided human habitability in Beringia, and migration from Asia to North America.

Antifungal effect of gaseous nitric oxide on mycelium growth, sporulation and spore germination of the postharvest horticulture pathogens, Aspergillus niger, Monilinia fructicola and Penicillium italicum.

AIM: To evaluate the antifungal activity of nitric oxide (NO) against the growth of the postharvest horticulture pathogens Aspergillus niger, Monilinia fructicola and Penicillium italicum under in vitro conditions. METHODS AND RESULTS: Different volumes of NO gas were injected into the Petri dish headspace to obtain the desired concentrations of 50-500 microl l(-1). The growth of the fungi was measured for 8 days of incubation in air at 25 degrees C. All concentrations of NO were found to produce an antifungal effect on spore germination, sporulation and mycelial growth of the three fungi, with the most effective concentration for A. niger and P. italicum being 100 and 500 microl l(-1) for M. fructicola. CONCLUSIONS: Short-term exposure to a low concentration of NO gas was able to inhibit the subsequent growth of A. niger, M. fructicola and P. italicum. SIGNIFICANCE AND IMPACT OF THE STUDY: NO gas has potential use as a natural fungicide to inhibit microbial growth on postharvest fruit and vegetables.

In vivo effects of aspirin and cyclosporine on regulatory T cells and T-cell cytokine production in healthy dogs.

Cyclosporine and aspirin are routinely used in combination to treat immune-mediated hemolytic anemia (IMHA) in dogs. Cyclosporine is a potent immunosuppressive agent that targets T cell production of the cytokines IL-2 and IFN-γ. Low-dose aspirin is often used to inhibit platelet function in dogs with IMHA, since these animals are prone to life-threatening thromboembolic disease. In rodents and humans, aspirin and cyclosporine have both been shown to variably affect T cell cytokine production, and also numbers of circulating regulatory T cells (Tregs). In dogs, it has not yet been determined if concurrent aspirin alters the effects of cyclosporine on T-cell cytokine expression, or if either drug influences Treg numbers. In a crossover study, seven healthy young adult dogs were given either oral high-dose cyclosporine (10 mg/kg Q12 h), oral low-dose aspirin (1 mg/kg Q24 h), oral high-dose aspirin (10 mg/kg Q12 h), or combined low-dose aspirin with cyclosporine, each for 8 days, with a washout of at least 2 weeks after each treatment. Activated T cell cytokine expression (IL-2 & IFN-γ) and percent CD4 + CD25 + FOXP3+ Tregs were evaluated using flow cytometry, both prior to and on the last day of treatment. The difference between pre- and post-treatment values for each group, as well as the difference between treatment groups, was evaluated. Cyclosporine significantly decreased IL-2 and IFN-γ expression when used alone or in combination with low-dose aspirin. High-dose aspirin, but not low-dose aspirin, also significantly decreased IL-2 expression, although the decrease was not as marked as that seen with cyclosporine alone or in combination with aspirin. Neither low-dose nor high-dose aspirin significantly affected IFN-γ expression. No drug or drug combination affected Treg numbers. Low-dose aspirin given with cyclosporine creates the same degree of T-cell cytokine suppression as does cyclosporine alone, suggesting that the two drugs can be used concurrently without significantly altering the immunosuppressive mechanism of action of cyclosporine.

Evaluation of SNAP cPL, Spec cPL, VetScan cPL Rapid Test, and Precision PSL Assays for the Diagnosis of Clinical Pancreatitis in Dogs.

BACKGROUND: The sensitivity, specificity, and agreement of 4 diagnostic assays (SNAP canine pancreatic lipase (cPL), specific cPL (Spec cPL), VetScan cPL Rapid Test, and Precision PSL) for pancreatitis in dogs have not been directly compared. HYPOTHESIS/OBJECTIVES: To determine the level of agreement among each of the 4 assays and a clinical suspicion score, level of agreement among the assays, and sensitivity and specificity of each assay in a clinically relevant patient group. ANIMALS: Fifty client-owned dogs with clinical signs of gastrointestinal disease. METHODS: Prospective study. History, physical examination, complete blood count, serum biochemistry, abdominal ultrasound examination, and the 4 diagnostic assays for pancreatitis were performed. Intraclass correlation coefficients (ICC) were used to determine the level of agreement between each assay and a clinical suspicion score determined by a panel of 5 board-certified veterinary internists. RESULTS: The ICC between the clinical suspicion score and the 4 assays were SNAP cPL, 0.61; Spec cPL, 0.68; VetScan cPL Rapid Test, 0.68; and Precision PSL, 0.60. The sensitivities of the assays ranged from 73.9 to 100.0%, whereas the specificities were SNAP cPL, 71.1-77.8%; Spec cPL, 74.1-81.1%; VetScan cPL Rapid Test, 76.9-83.8%; and Precision PSL, 64.0-74.3%. CONCLUSIONS AND CLINICAL IMPORTANCE: A good to excellent level of agreement was demonstrated among the 4 assays. The previously unreported sensitivity and specificity of the VetScan cPL Rapid Test were 73.9-83.3% and 76.9-83.8%, respectively. Results of any of the 4 diagnostic assays alone, in the absence of supporting clinical findings, are insufficient to establish a diagnosis of clinical pancreatitis in dogs.

Recovery of Campylobacter from commercial broiler hatchery trayliners.

Previous research has identified Campylobacter as one of the leading causes of foodborne illness. Poultry and poultry products have been identified as a major source of Campylobacter in human infections. Although many risk factors that contribute to Campylobacter levels have been identified, precise identification of the most effective sites for intervention has not been established. Epidemiological studies have identified that Campylobacter in the broiler breeder's reproductive tract, fertile eggs, and 2- to 3-wk-old broilers has the potential to contaminate day-of-hatch chicks. Numerous studies have shown that day-of-hatch broilers are Campylobacter-negative using conventional culture methods. The purpose of the present study was to demonstrate the prevalence of Campylobacter found in day-of-hatch broilers using a peptone water preenrichment followed by conventional Campylobacter culture methods. Using conventional tray liner (hatcheries) culture methods, the isolation distribution of Campylobacter from 8 commercial broiler hatcheries (n = 2,000) was evaluated. A total of 15 tray liners were positive from 3 different hatcheries. Of the 2,000 chick paper pad tray liners sampled, 0.75% were positive for Campylobacter. These data support previous findings indicating the potential for Campylobacter to be spread by vertical transmission. This is the first time that Campylobacter has been recovered from tray liners collected at commercial broiler hatcheries.

Effects of Leukoreduction and Storage on Erythrocyte Phosphatidylserine Expression and Eicosanoid Concentrations in Units of Canine Packed Red Blood Cells.

BACKGROUND: Storage of canine packed red blood cells (pRBCs) can increase erythrocyte phosphatidylserine (PS) expression and eicosanoid concentrations. HYPOTHESIS/OBJECTIVES: To determine the effects of leukoreduction on erythrocyte PS expression and eicosanoid concentrations in stored units of canine pRBCs. Our hypothesis was that leukoreduction would decrease PS expression and eicosanoid concentrations. ANIMALS: Eight healthy dogs. METHODS: In a cross-over study, units of whole blood were leukoreduced (LR) or non-LR and stored (10 and 21 days) as pRBCs. Samples were collected at donation, and before and after a simulated transfusion. PS expression was measured by flow cytometry, and concentrations of arachidonic acid (AA), prostaglandin F2α (PGF2α ), prostaglandin E2 (PGE2 ), prostaglandin D2 (PGD2 ), thromboxane B2 (TXB2 ), 6-keto-prostaglandin F1α (6-keto-PGF1α ), and leukotriene B4 (LTB4 ) were quantified by liquid chromatography-mass spectrometry. RESULTS: There was no change in PS expression during leukoreduction, storage, and simulated transfusion for non-LR and LR units. Immediately after leukoreduction, there was a significant increase in TXB2 and PGF2α concentrations, but during storage, these eicosanoids decreased to non-LR concentrations. In both LR and non-LR units, 6-keto-PGF1α concentrations increased during storage and simulated transfusion, but there was no difference between unit type. There was no difference in AA, LTB4 , PGE2 , and PGD2 concentrations between unit types. CONCLUSIONS AND CLINICAL IMPORTANCE: Leukoreduction, storage, and simulated transfusion do not alter erythrocyte PS expression. Leukoreduction causes an immediate increase in concentrations of TXB2 and PGF2α , but concentrations decrease to non-LR concentrations with storage. Leukoreduction does not decrease the accumulation of 6-keto-PGF1α during storage.

Rickettsia parkeri and "Candidatus Rickettsia andeanae" in Questing Amblyomma maculatum (Acari: Ixodidae) From Mississippi.

Amblyomma maculatum Koch (Acari: Ixodidae), the primary vector for Rickettsia parkeri, may also be infected with a rickettsia of unknown pathogenicity, "Candidatus Rickettsia andeanae." Infection rates with these rickettsiae vary geographically, and coinfected ticks have been reported. In this study, infection rates of R. parkeri and "Ca. R. andeanae" were evaluated, and rickettsial DNA levels quantified, in 335 questing adult A. maculatum collected in 2013 (n = 95), 2014 (n = 139), and 2015 (n = 101) from Oktibbeha County, MS. Overall infection rates of R. parkeri and "Ca. R. andeanae" were 28.7% and 9.3%, respectively, with three additional A. maculatum (0.9%) coinfected. While R. parkeri-infected ticks were detected all three years (34.7% in 2013; 13.7% in 2014; 43.6% in 2015), "Ca. R. andeanae" was not detected in 2013, and was detected at rates of 10.8% in 2014, and 15.8% in 2015. Interestingly, rickettsial DNA levels in singly-infected ticks were significantly lower in "Ca. R. andeanae"-infected ticks compared to R. parkeri-infected ticks (P < 0.0001). Thus, both infection rates and rickettsial DNA levels were higher for R. parkeri than "Ca. R. andeanae." Infection rates of R. parkeri were also higher, and "Ca. R. andeanae" lower, here compared to A. maculatum reported previously in Kansas and Oklahoma. As we continue to monitor infection rates and levels, we anticipate that understanding temporal changes will improve our awareness of human risk for spotted fever rickettsioses. Further, these data may lead to additional studies to evaluate potential interactions among sympatric Rickettsia species in A. maculatum at the population level.