Comparison of nonparametric and parametric methods for time-frequency heart rate variability analysis in a rodent model of cardiovascular disease.

The aim of time-varying heart rate variability spectral analysis is to detect and quantify changes in the heart rate variability spectrum components during nonstationary events. Of the methods available, the nonparametric short-time Fourier Transform and parametric time-varying autoregressive modeling are the most commonly employed. The current study (1) compares short-time Fourier Transform and autoregressive modeling methods influence on heart rate variability spectral characteristics over time and during an experimental ozone exposure in mature adult spontaneously hypertensive rats, (2) evaluates the agreement between short-time Fourier Transform and autoregressive modeling method results, and (3) describes the advantages and disadvantages of each method.

Genetics of equine bleeding disorders.

Genetic bleeding disorders can have a profound impact on a horse's health and athletic career. As such, it is important to understand the mechanisms of these diseases and how they are diagnosed. These diseases include haemophilia A, von Willebrand disease, prekallikrein deficiency, Glanzmann's Thrombasthenia and Atypical Equine Thrombasthenia.

Canine platelets express functional Toll-like receptor-4: lipopolysaccharide-triggered platelet activation is dependent on adenosine diphosphate and thromboxane A2 in dogs.

Background: Functional Toll-like receptor 4 (TLR4) has been characterized in human and murine platelets indicating that platelets play a role in inflammation and hemostasis during sepsis. It is unclear whether canine platelets could express functional TLR4 by responding to its ligand, lipopolysaccharide (LPS). We sought to determine if dogs express functional TLR4 and if LPS-induced platelet activation requires co-stimulation with ADP or thromboxane A (TxA).

Pharmacokinetics and competitive pharmacodynamics of ADP-induced platelet activation after oral administration of clopidogrel to horses.

Objective: To determine pharmacokinetics and pharmacodynamics after oral administration of a single dose of clopidogrel to horses.

Animals: 6 healthy adult horses.

Procedures: Blood samples were collected before and at various times up to 24 hours after oral administration of clopidogrel (2 mg/kg).

Equine platelet concentrate preparation and validation.

Background: Development of equine platelet concentrate (PC) would aid management of cases requiring transfused platelets (PLTs), where adminstration of whole-blood or platelet-rich plasma (PRP) might be contraindicated.

Objectives: To test and validate a method for production of an equine PRP-PC product.

Animals: Six healthy Thoroughbred geldings from a research herd.

A Comparative Review of Neutrophil Extracellular Traps in Sepsis.

Sepsis is the leading cause of critical illness and mortality in human beings and animals. Neutrophils are the primary effector cells of innate immunity during sepsis. Besides degranulation and phagocytosis, neutrophils also release neutrophil extracellular traps (NETs), composed of cell-free DNA, histones, and antimicrobial proteins.

In Vitro Canine Neutrophil Extracellular Trap Formation: Dynamic and Quantitative Analysis by Fluorescence Microscopy.

In response to invading pathogens, neutrophils release neutrophil extracellular traps (NETs), which are extracellular networks of DNA decorated with histones and antimicrobial proteins. Excessive NET formation (NETosis) and citH3 release during sepsis is associated with multiple organ dysfunction and mortality in mice and humans but its implications in dogs are unknown. Herein, we describe a technique to isolate canine neutrophils from whole blood for observation and quantification of NETosis.

A novel approach to identifying and quantifying neutrophil extracellular trap formation in septic dogs using immunofluorescence microscopy.

Background: Canine neutrophils release neutrophil extracellular traps (NETs) in response to lipopolysaccharide but NETs from clinical septic dogs had not been identified. The primary aim is to describe the methodology of identifying and quantifying neutrophil extracellular traps (NETs) in cytology samples of septic foci in dogs with sepsis using immunofluorescence microscopy. Cytology samples including endotracheal tracheal wash (ETW), bronchoalveolar lavage (BAL), abdominal and pleural effusion collected from 5 dogs (3 septic, 2 non-septic) were fixed, permeabilized and stained for myeloperoxidase (MPO), citrullinated histone H3 (citH3) and cell-free DNA (cfDNA).

Ultrafine Particulate Matter Combined With Ozone Exacerbates Lung Injury in Mature Adult Rats With Cardiovascular Disease.

Particulate matter (PM) and ozone (O3) are dominant air pollutants that contribute to development and exacerbation of multiple cardiopulmonary diseases. Mature adults with cardiovascular disease (CVD) are particularly susceptible to air pollution-related cardiopulmonary morbidities and mortalities. The aim was to investigate the biologic potency of ultrafine particulate matter (UFPM) combined with O3 in the lungs of mature adult normotensive and spontaneously hypertensive (SH) Wistar-Kyoto rats.

Lipopolysaccharide-induced neutrophil extracellular trap formation in canine neutrophils is dependent on histone H3 citrullination by peptidylarginine deiminase.

Neutrophils release neutrophil extracellular traps (NETs), which are extracellular chromatin decorated with histones and antimicrobial proteins. Although known for antimicrobial properties, overzealous production of NETs (NETosis) may lead to cytotoxicity and multiple organ failure in sepsis. Pathogen-induced NETosis has been extensively studied in mice but its importance in dogs remains largely unknown.

Comparison of equine platelet function and survival in whole blood collected in acid-citrate-dextrose solution or citrate-phosphate-dextrose-adenine solution.

Background: Equine whole blood collection and storage methods have been evaluated to assess red blood cell viability; however, platelet (PLT) viability has not been comprehensively assessed.

Objectives: The purpose of the study was to compare viability of PLTs collected in whole blood into 2 different anticoagulants.

Methods: Whole blood from 6 healthy adult Thoroughbred horses was collected into citrate-phosphate-dextrose-adenine (CPDA) or acid-citrate-dextrose (ACD).

Early Life Wildfire Smoke Exposure Is Associated with Immune Dysregulation and Lung Function Decrements in Adolescence.

The long-term health effects of wildfire smoke exposure in pediatric populations are not known. The objectives of this study were to determine if early life exposure to wildfire smoke can affect parameters of immunity and airway physiology that are detectable with maturity. We studied a mixed-sex cohort of rhesus macaque monkeys that were exposed as infants to ambient wood smoke from a series of Northern California wildfires in the summer of 2008.

Platelet Activation and Clopidogrel Effects on ADP-Induced Platelet Activation in Cats with or without the A31P Mutation in MYBPC3.

Background: Clopidogrel is commonly prescribed to cats with perceived increased risk of thromboembolic events, but little information exists regarding its antiplatelet effects.

Objective: To determine effects of clopidogrel on platelet responsiveness in cats with or without the A31P mutation in the MYBPC3 gene. A secondary aim was to characterize variability in feline platelet responses to clopidogrel.

Association of Factor V Secretion with Protein Kinase B Signaling in Platelets from Horses with Atypical Equine Thrombasthenia.

Background: Two congenital bleeding diatheses have been identified in Thoroughbred horses: Glanzmann thrombasthenia (GT) and a second, novel diathesis associated with abnormal platelet function in response to collagen and thrombin stimulation.

Hypothesis/objectives: Platelet dysfunction in horses with this second thrombasthenia results from a secretory defect.

Animals: Two affected and 6 clinically normal horses.

TCDD and omeprazole prime platelets through the aryl hydrocarbon receptor (AhR) non-genomic pathway.

The role of the aryl hydrocarbon receptor (AhR) in hemostasis has recently gained increased attention. Here, we demonstrate, by qRT-PCR and western blot, that human platelets express both AhR mRNA and AhR protein. AhR protein levels increase in a dose dependent manner when incubated with either 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or omeprazole.

Biological dose response to PM2.5: effect of particle extraction method on platelet and lung responses.

Particulate matter (PM) exposure contributes to respiratory diseases and cardiopulmonary mortality. PM toxicity is related to sources and composition, such as abundance of polycyclic aromatic hydrocarbons (PAHs). We exposed adult male BALB/c mice, via oropharyngeal aspiration, to a range of doses of PM2.

Comparison of the platelet-rich plasma and buffy coat protocols for preparation of canine platelet concentrates.

Background: Platelet (PLT) concentrates (PC) can be produced via the buffy coat (BC) or platelet-rich plasma (PRP) protocols. The 2 methods have not been compared with canine blood.

Objectives: The aims of the study were to compare the PLT, WBC, and RBC concentrations, in vitro PLT function, and markers of platelet storage lesion (PSL) in canine PC generated by 2 different protocols, and determine microbial growth throughout storage.

Ultrastructure and growth factor content of equine platelet-rich fibrin gels.

Objective: To compare fiber diameter, pore area, compressive stiffness, gelation properties, and selected growth factor content of platelet-rich fibrin gels (PRFGs) and conventional fibrin gels (FGs).

Sample: PRFGs and conventional FGs prepared from the blood of 10 healthy horses.

Procedures: Autologous fibrinogen was used to form conventional FGs.

Platelet activation in cats with hypertrophic cardiomyopathy.

Background: Cats with hypertrophic cardiomyopathy (HCM) are at risk for development of systemic thromboembolic disease. However, the relationship between platelet activation state and cardiovascular parameters associated with HCM is not well described.

Objectives: To characterize platelet activation by flow cytometric evaluation of platelet P-selectin and semiquantitative Western blot analysis of soluble platelet-endothelial cell adhesion molecule-1 (sPECAM-1).

Synovial fluid growth factor and cytokine concentrations after intra-articular injection of a platelet-rich product in horses.

Platelet-rich plasma (PRP) products may be useful for treatment of joint disease in horses, but may contain undesirable pro-inflammatory cytokines in addition to growth factors. This study investigated whether autologous PRP increases synovial fluid growth factor and cytokine concentrations when injected into normal equine metacarpophalangeal and metatarsophalangeal (fetlock) joints. Fetlock joints of seven healthy horses received one of four treatments: saline, resting PRP, CaCl2-activated PRP or thrombin-activated PRP.

Intra-articular use of a platelet-rich product in normal horses: clinical signs and cytologic responses.

Objectives: (1) To report the clinical and synovial effects of a platelet-rich product (PRPr) in normal equine joints, (2) to assess the persistence of platelets within synovial fluid after intra-articular injection, (3) to compare responses to different preparations of that product, and (4) to evaluate a gravity filtration system for PRPr preparation in horses.

Study Design: Experimental.

Methods: A platelet-rich saline product (PRPr) was prepared from 7 normal horses using a proprietary preparation device and was divided into 3 treatments: resting, CaCl2 -activated (23 mM, final), and bovine thrombin-activated (10 U/mL, final).

Seasonal influences on CAPs exposures: differential responses in platelet activation, serum cytokines and xenobiotic gene expression.

Increasing evidence suggests a role for a systemic pro-coagulant state in the pathogenesis of cardiac dysfunction subsequent to inhalation of airborne particulate matter (PM). We evaluated platelet activation, systemic cytokines and pulmonary gene expression in mice exposed to concentrated ambient particulate matter (CAPs) in the summer of 2008 (S08) and winter of 2009 (W09) from the San Joaquin Valley of California, a region with severe PM pollution episodes. Additionally, we characterized the PM from both exposures including organic compounds, metals, and polycyclic aromatic hydrocarbons.

Response of Northern Elephant Seal platelets to pressure and temperature changes: a comparison with human platelets.

Mammalian blood platelets are activated by physiological agonists such as collagen or thrombin, or by physical stimuli such as cold temperatures and rapid decompression. Marine mammals regularly experience cold temperatures, high pressures and rapid decompression while diving, yet do not appear to suffer from thrombotic events during routine dive activity. We evaluated the effects of cold temperature and high pressure excursions on Northern Elephant Seal (NES) platelets and compared NES platelet response to that of human platelets subjected to identical stimuli.