Hemostatic Testing in Companion Exotic Mammals

The mammalian hemostatic system is highly conserved, and companion exotic mammals are commonly used as biomedical models for normal and disordered hemostasis. Challenges associated with sample collection, test validation, and test interpretation have limited the use of these tests in clinical exotic animal practice. However, evaluation of platelet counts, coagulation screening times, and fibrin(ogen) degradation products can be valuable for monitoring exotic patients with a range of disease presentations including intoxications, anemia, systemic viral disease, hepatopathy, and endocrinopathy.

A UPLC-Q-TOF-MS-Based Metabolomics Approach to Screen out Active Components in Prepared Rhubarb for Its Activity on Noxious Heat Blood Stasis Syndrome

Background: Prepared rhubarb was obtained by steaming raw rhubarb with wine. Different from raw rhubarb with a purgative effect, prepared rhubarb shows effects of promoting blood circulation and removing blood stasis. However, the mechanisms of its action through regulating endogenous metabolites remain unclear.

Purpose: The purpose of this study was to explore active chemical components in prepared rhubarb for its activity on noxious heat blood stasis syndrome (NHBS) by comprehensive metabolomics profiling.

Study design: Plant extracts usually show their activities in a synergistic way; therefore, integrated omics was developed as a rational way for a better understanding of their biological effects and potential active compounds.

Methods: The activities of prepared rhubarb were evaluated by biochemical and metabolomic analysis; meanwhile, serum chemical profiles were sought using UHPLC-Q-TOF-MS. Gray correlation analysis (GCA) was used for calculating the underlying correlations between them.

Results: The metabolomics profiles of rat plasma from model and control groups were significantly different, with 31 endogenous metabolites changed by NHBS. Then, after the administration of prepared rhubarb, 18 of them were regulated. Multiple metabolic pathways were disturbed after NHBS modeling and restored by prepared rhubarb, among which had a greater impact on sphingolipid metabolism. A total of 28 compounds from prepared rhubarb absorbed into the plasma were identified, including nine prototypes and 19 metabolites. Statistical results suggested that rhein and its metabolites accounted for half of the top 10 active compounds in prepared rhubarb for its biomedical activities.

Conclusion: This study presented evidence for the therapeutic effects and active chemicals of prepared rhubarb on NHBS in the way of metabolomics.

Scientific and Regulatory Policy Committee Points to Consider: Biological Sample Retention From Nonclinical Toxicity Studies

Samples of biologic specimens and their derivatives (eg, wet tissues, paraffin-embedded tissue blocks, histology slides, frozen tissues, whole blood, serum/plasma, and urine) are routinely collected during the course of nonclinical toxicity studies. Good Laboratory Practice regulations and/or guidance specify minimum requirements for specimen retention duration, with the caveat that retention of biologic specimens need not extend beyond the duration of sample stability. However, limited availability of published data regarding stability for various purposes following storage of each specimen type has resulted in confusion, uncertainty, and inconsistency as to the appropriate duration for storage of these specimens. To address these issues, a working group of the Society of Toxicologic Pathology Scientific and Regulatory Policy Committee was formed to review published information, regulations, and guidance pertinent to this topic and to summarize the current practices and rationales for retention duration through a survey-based approach. Information regarding experiences reaccessing biologic specimens and performing sample stability investigations was also collected. Based on this combined information, the working group developed several points to consider that may be referenced when developing or revising sample retention practices. [Box: see text].

Enoxaparin prevents CXCL16/ADAM10-mediated cisplatin renal toxicity: Role of the coagulation system and the transcriptional factor NF-κB

BACKGROUND AND AIMS

C-X-C ligand 16 (CXCL16) is an exceptional chemokine that is expressed as transmembrane and soluble forms. Our aim is to shed lights on the role of CXCL16/ADAM10 (a disintegrin and metalloproteinase) in cisplatin (CP)-induced renal toxicity as well as possible protective effect of enoxaparin.

MAIN METHODS

Male albino mice were injected with CP (30 mg/kg, i.p.) in the presence or absence of enoxaparin (ENOX) (5 mg/kg, i.p.). Renal toxicity markers, serum level of cystatin-c, complete blood count (CBC), prothrombin time (Pt) and tissue expression of CXCL16, ADAM10, cluster of differentiation 3 (CD3), fibrinogen, tissue factor (TF), nuclear factor-κB (NF-κB) and tumour necrosis factor α (TNF-α) were measured. Besides, serum CXCL16 and histopathology were also analyzed.

KEY FINDINGS

CP increased renal toxicity markers, renal expression of CXCL16/ADAM10, fibrinogen, TF and CD3 tissue expression in a time-dependent manner, and elevated serum cystatin-c, CXCL16 and tissue TNF-α, NF-κB. Alternatively, ENOX restored the deteriorated parameters and reduced tissue level of NF-κB.

SIGNIFICANCE

This report, for the first time, showed that soluble CXCL16 resulting from ADAM10 cleavage may recruit T-cells to the renal glomeruli and tubules in CP toxicity. Furthermore, TF and fibrin, have similar expression and location pattern like CXCL16 and ADAM10 suggesting their possible interrelation. ENOX successfully restored the deteriorated parameters suggesting it may be an effective nephroprotective adjuvant therapy.

Dabigatran mitigates cisplatin-mediated nephrotoxicity through down regulation of thrombin pathway

Introduction

Cisplatin (CDDP) nephrotoxicity is one of the most significant complications limiting its use in cancer therapy.

Objectives

This study investigated the pivotal role played by thrombin in CDDP-mediated nephrotoxicity. This work also aimed to clarify the possible preventive effect of Dabigatran (Dab), a direct thrombin inhibitor, on CDDP nephrotoxicity.

Methods

Animals were grouped as follow; normal control group, CDDP nephrotoxicity group, CDDP + Dab 15, and CDDP + Dab 25 groups. Four days following CDDP administration, blood and urine samples were collected to evaluate renal function. Moreover, tissue samples were collected from the kidney to determine apoptosis markers, oxidative stress and histopathological evaluation. An immunofluorescence analysis of tissue factor (TF), thrombin, protease-activated receptor-2 (PAR2), fibrin, pERK1/2 and P53 proteins expression was also performed.

Results

Thrombin, pERK, cleaved caspase-3, and oxidative stress markers were significantly elevated in CDDP-treated group. However, pretreatment of animals with either low or high doses of Dab significantly improved kidney function and decreased oxidative stress and apoptotic markers.

Conclusion

We conclude that thrombin is an important factor in the pathogenesis of CDDP kidney toxicity via activation of ERK1/2, P53 and caspase-3 pathway, which can be effectively blocked by Dab.

Repeat-dose animal toxicity studies and genotoxicity study with deactivated alkaline serine protease (DASP), a protein low in phenylalanine (PHE)

Phenylketonuria (PKU) is an autosomal recessive inherited disorder affecting one in every 10,000 to 15,000 newborn children in the US each year. PKU patients' metabolism of an essential amino acid, phenylalanine (PHE), is impaired, resulting in concentrations of PHE in the circulating blood and brain that are potentially toxic. Individuals with PKU restrict dietary intakes of PHE by consuming medical foods formulated with low PHE concentrations. In this study, an alkaline serine protease (ASP) expressed in Bacillus licheniformis strain 2709, which is composed of >90% protein with a concentration of <0.25% PHE, was heat deactivated (becoming deactivated ASP (DASP)) and evaluated for safe use as an ingredient in foods, including medical foods. DASP was non-mutagenic with and without metabolic activation up to 5000 μg DASP/plate. 14-Day dietary studies supported a Maximum Tolerated Dose (MTD) of 115000 ppm DASP. In a 90-day dietary toxicity study, CRL SD CD® rats were administered 0, 28750, 57500, 115500 ppm DASP in the diet. No DASP-related adverse effects were observed at the high dose. As such, a No Observable Adverse Effect Level (NOAEL) of 115,500 ppm DASP or 6224.1 mg DASP/kg bw/day (males) and 7500.9 mg DASP/kg bw/day (females) was established.

Effects of storage over a 36-month period on coagulation factors in a canine plasma product obtained by use of plasmapheresis

OBJECTIVE

To evaluate stability of coagulation factors in canine plasma obtained by use of plasmapheresis and stored over a 36-month period.

SAMPLE

Canine plasma obtained by use of plasmapheresis acquired from a commercial blood bank.

PROCEDURES

Coagulation testing for fibrinogen concentration and activity of factors II, V, VII, VIII, and IX and von Willebrand factor was performed on canine plasma obtained by use of plasmapheresis. Samples were obtained for testing at 6-month intervals from plasma stored for up to 36 months.

RESULTS

A simple mixed linear regression model was created for each analysis. Median value for the fibrinogen concentration was > 150 mg/dL for all time points, except at 467, 650, and 1,015 days of storage. Median value for factor VIII was > 70% only at 650 days. Median value for factor V was > 50% through 650 days. Median value for factors VII and X was > 50% through 833 days, and median value for factors II and VII was > 50% through 1,015 days. Median value for von Willebrand factor was > 50% for the entire study (1,198 days). Median value for factor X was always < 50%.

CONCLUSIONS AND CLINICAL RELEVANCE

Coagulation factors degraded over time at variable rates, and all labile factors remained at > 50% activity for longer than 1 year. Plasma collected by plasmapheresis potentially offers prolonged life span of some clotting factors. Plasmapheresis is an acceptable form of canine plasma collection for transfusion purposes, and further studies should be performed to determine all of its benefits.

Interference With Coagulation Cascade as a Novel Approach to Counteract Cisplatin-Induced Acute Tubular Necrosis; an Experimental Study in Rats

Coagulation system activation plays an important role in the pathophysiology of different diseases. In spite of massive research regarding cisplatin-induced nephrotoxicity, the role of coagulation cascade in such toxicity is still questionable. Here, we aim to investigate the role of activation of coagulation system in the initiation of cisplatin-induced acute renal tubular necrosis. Moreover, the role of the anticoagulant rivaroxaban against such toxicity was investigated. Briefly, animals were classified into seven groups, eight rats each. Group 1 served as normal control group, groups (2–7) received i.p. single doses of cisplatin (6 mg/kg b.w), groups (6–7) were treated with rivaroxaban (5 and 7 mg/kg b.w, p.o., respectively) 7 days before cisplatin injection and completed for 4 days. Animals in groups (2, 3, and 4) were sacrificed after 1, 2 and 3 days of cisplatin injection, respectively, while groups (1, 5, 6, and 7) were sacrificed after 4 days of cisplatin injection. Serum cystatin-c, urea, creatinine and γ-glutamyl transferase, urinary Lipocaline-2, and KIM-1 protein densities, as well as glomerular filtration rate (GFR) were assessed. Immunofluorescence examination of glomeruli fibrin and tissue factor (TF) was also performed coupled with a histopathological study. Cisplatin administration increased expression of fibrin and TF starting 24 h of cisplatin injection even before renal failure markers elevated. Leukocytosis, thrombocytopenia, and increased prothrombin time were also observed. Cisplatin also induced tubular damage evidenced by increased serum cystatin-c, urea, and creatinine with significant decrease in GFR and Gamma glutamyl transferase (GGT) activity. Rivaroxaban significantly decreased elevation of fibrin and TF with significant reduction in serum creatinine, BUN and cystatin-c levels. Rivaroxaban also significantly improved hematological markers and histological features as well. This study showed that activation of coagulation system plays an important role in the pathophysiology of cisplatin-induced acute renal tubular damage. Interference with coagulation cascade may be a promising nephroprotective strategy against chemical nephrotoxicity.

Comparison of catheter thrombogenicity in a modified chandler loop model using goat blood

Thrombogenicity testing is a key component in the development of medical devices intended for contact with blood. The Chandler loop system has previously been used as an in vitro thrombogenicity testing method. In this study, we used a modified version of the Chandler loop model to evaluate its capacity to detect differential thrombogenic potential of different catheter materials using goat blood. We also sought to determine the optimal experimental conditions for detecting the thrombogenicity of catheter material. Using the Chandler loop system with goat blood we demonstrated that silicone catheters had a stronger thrombogenicity as compared to polyurethane catheters as evidenced by significantly larger thrombi (p < 0.001) and higher infusion pressures (p < 0.05). This is consistent with many, but not all, previous in vitro and in vivo studies comparing polyurethane to silicone catheters. The use of this modified Chandler loop system with goat blood may provide an additional in vitro testing platform for thrombogenicity testing of catheters. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3143-3151, 2018.

Changes of hematological references depends on storage period and temperature conditions in rats and dogs

Because changes in rat and dog hematological parameters according to storage conditions have been poorly documented, we sought to examine such changes. Blood analysis was performed using two hematology analyzers (ADVIA 2120i and Sysmex XN-V) after storage at room temperature and in cold storage for 5, 24, and 48 h, respectively. Interassay coefficients of variation for hematological parameters analyzed with the ADVIA 2120i and the XN-V showed similar. The levels of hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet (PLT) showed significant variations with time in blood samples of rats and dogs. The leukocyte subpopulation showed high variation with storage conditions. The data for leukocyte differential counts obtained using the ADVIA 2120i, XN-V, and a manual differential counting procedure showed good agreement for neutrophils and lymphocyte counts, but monocytes, eosinophils, and basophils showed differences between the procedures. In conclusions, most rat and dog hematological parameters showed minimal changes; however, some showed high variation with storage time and temperature, especially PLT and leukocyte subpopulations. In conclusion, when performing hematological analysis in dogs and rats, it will be exactitude to analyze blood samples in fresh condition and at least within 24 h in the cold storage.