Clinical bleeding diathesis, laboratory haemostatic aberrations and survival in dogs infected with Angiostrongylus vasorum: 180 cases (2005-2019)

OBJECTIVES

Bleeding diathesis is a complication in dogs infected with Angiostrongylus vasorum. This retrospective study investigated clinical and laboratory haemostatic differences in A. vasorum-positive dogs with and without signs of bleeding and impact of bleeding on survival.

MATERIALS AND METHODS

Demographics, type of clinical bleeding, haematocrit and a range of haemostatic tests, including thromboelastography and derived velocity curves were retrospectively registered from A. vasorum-positive dogs. All parameters were compared between dogs with and without signs of bleeding using univariable analyses. Binomial and multinomial regression models were applied to examine specific indicators in the bleeding dogs. P-values were false discovery rate adjusted, and adjusted P<0.05 was considered significant.

RESULTS

One hundred and eighty dogs entered the study, including 65 dogs (36.1%) presenting with bleeding diathesis. Different types of cutaneous and mucosal bleeding were the most common clinical findings. Twenty dogs presented with neurological signs associated with intracranial and intra-spinal bleeding. One hundred and thirty-seven dogs had haematological and/or haemostatic laboratory analyses performed. Haematocrit, platelet count, thromboelastographic angle, maximum amplitude, global clot strength, maximum rate of thrombin generation and total thrombin generation were decreased, while prothrombin time was prolonged in bleeding dogs. Survival rate of bleeding dogs was lower at hospital discharge (76.9%) and 1 month after diagnosis (66.0%) than in dogs without signs of bleeding (94.8% and 90.1% at discharge and at 1 month, respectively).

CLINICAL SIGNIFICANCE

Several haemostatic aberrations were detected in A. vasorum-positive dogs with bleeding diathesis. Bleeding was identified as an important negative prognostic indicator in A. vasorum-positive dogs.

Comparison of visual assessments of anisocytosis in canine blood smears and analyzer-calculated red blood cell distribution width

Red blood cell distribution width (RDW) and visual assessments of anisocytosis assess variability in erythrocyte size. Veterinary studies on the correlation between the two methods and on observer agreement are scarce. The objectives were to assess the correlation of the grading of anisocytosis by means of conventional microscopy of canine blood smears to RDW, and to assess intra- and inter-observer variation in assessing the degree of anisocytosis. The study included 100 canine blood samples on which blood smear examination and RDW measurement were performed. RDW was measured on the Advia 2120i analyzer. The degree of anisocytosis was based on a human grading scheme assessing the ratio between the size of the representative largest red blood cell and that of the representative smallest red blood cell (1+ if <2x, 2+ if 2-3x, 3+ if 3-4x, and 4+ if >4x). Three observers participated and assessed the blood smears by conventional microscopy twice, 3 weeks apart by each observer. The correlation was assessed for each observer on each occasion using Kendahl-tau-b analysis. Intra-observer agreement was assessed using quadratically weighted kappa. Inter-observer agreement was assessed using free-marginal multi-rater kappa. Anisocytosis graded on blood smears correlated significantly with RDW values as assessed by Kendahl-tau-b ranging between 0.37 and 0.51 (p < 0.0001). Intra-observer agreement ranged from weak to moderate with resulting kappa-coefficients being 0.58, 0.68, and 0.75, respectively. Inter-observer agreement was weak (Kappa-values 0.44). The weak to moderate observer agreement in the visual assessment of anisocytosis indicates that the more precise and more repeatable RDW measurement should be used for clinical decision-making.

Association of serum and fecal microRNA profiles in cats with gastrointestinal cancer and chronic inflammatory enteropathy

BACKGROUND

Differentiation of gastrointestinal cancer (GIC) from chronic inflammatory enteropathies (CIE) in cats can be challenging and often requires extensive diagnostic testing. MicroRNAs (miRNAs) have promise as non-invasive biomarkers in serum and feces for diagnosis of GIC.

HYPOTHESIS/OBJECTIVES

Cats with GIC will have serum and fecal miRNA profiles that differ significantly from healthy cats and cats with CIE. Identify serum and fecal miRNAs with diagnostic potential for differentiation between cats with GIC and CIE as compared to healthy cats.

ANIMALS

Ten healthy cats, 9 cats with CIE, and 10 cats with GIC; all client-owned.

METHODS

Cats were recruited for an international multicenter observational prospective case-control study. Serum and feces were screened using small RNA sequencing for miRNAs that differed in abundance between cats with GIC and CIE, and healthy cats. Diagnostic biomarker potential of relevant miRNAs from small RNA sequencing and the literature was confirmed using reverse transcription quantitative real-time PCR (RT-qPCR).

RESULTS

Serum miR-223-3p was found to distinguish between cats with GIC and CIE with an area under the curve (AUC) of 0.9 (95% confidence interval [CI], 0.760-1.0), sensitivity of 90% (95% CI, 59.6-99.5%), and specificity of 77.8% (95% CI, 45.3-96.1%). Serum miR-223-3p likewise showed promise in differentiating a subgroup of cats with small cell lymphoma (SCL) from those with CIE. No fecal miRNAs could distinguish between cats with GIC and CIE.

CONCLUSION AND CLINICAL IMPORTANCE

Serum miR-223-3p potentially may serve as a noninvasive diagnostic biomarker of GIC in cats, in addition to providing a much needed tool for the differentiation of CIE and SCL.

Association of fecal and serum microRNA profiles with gastrointestinal cancer and chronic inflammatory enteropathy in dogs

BACKGROUND

Reliable biomarkers to differentiate gastrointestinal cancer (GIC) from chronic inflammatory enteropathy (CIE) in dogs are needed. Fecal and serum microRNAs (miRNAs) have been proposed as diagnostic and prognostic markers of GI disease in humans and dogs.

HYPOTHESIS/OBJECTIVES

Dogs with GIC have fecal and serum miRNA profiles that differ from those of dogs with CIE.

AIMS

(a) identify miRNAs that differentiate GIC from CIE, (b) use high-throughput reverse transcription quantitative real-time PCR (RT-qPCR) to establish fecal and serum miRNA panels to distinguish GIC from CIE in dogs.

ANIMALS

Twenty-four dogs with GIC, 10 dogs with CIE, and 10 healthy dogs, all client-owned.

METHODS

An international multicenter observational prospective case-control study. Small RNA sequencing was used to identify fecal and serum miRNAs, and RT-qPCR was used to establish fecal and serum miRNA panels with the potential to distinguish GIC from CIE.

RESULTS

The best diagnostic performance for distinguishing GIC from CIE was fecal miR-451 (AUC: 0.955, sensitivity: 86.4%, specificity: 100%), miR-223 (AUC: 0.918, sensitivity: 90.9%, specificity: 80%), and miR-27a (AUC: 0.868, sensitivity: 81.8%, specificity: 90%) and serum miR-20b (AUC: 0.905, sensitivity: 90.5%, specificity: 90%), miR-148a-3p (AUC: 0.924, sensitivity: 85.7%, specificity: 90%), and miR-652 (AUC: 0.943, sensitivity: 90.5%, specificity: 90%). Slightly improved diagnostic performance was achieved when combining fecal miR-451 and miR-223 (AUC: 0.973, sensitivity: 95.5%, specificity: 90%).

CONCLUSIONS AND CLINICAL IMPORTANCE

When used as part of a diagnostic RT-qPCR panel, the abovementioned miRNAs have the potential to function as noninvasive biomarkers for the differentiation of GIC and CIE in dogs.

Investigation of two different human d-dimer assays in the horse

Background

D-dimer has value as a marker of thrombosis in critically ill horses and can provide additional information about prognosis. However, there are currently no equine species-specific d-dimer assays available, nor has there been any formal investigation of the applicability of human d-dimer assays in horses, so it is unknown, which assay performs best in this species. The aim of this study was therefore to evaluate and compare two human d-dimer assays for their applicability in horses.

The study included four groups of horses: clinically healthy horses, horses with gastrointestinal (GI) disease and mild systemic inflammation based on low serum amyloid A (SAA) (low SAA group), horses with GI disease and strong systemic inflammation based on high SAA (high SAA group) and, horses with thrombotic GI disease caused by Strongylus vulgaris (also called non-strangulating intestinal infarction (NSII)) (NSII group). The assays evaluated were the STAGO STA-Liatest D-di + (Stago) and NycoCard™ D-dimer (NycoCard). Intra- and inter-coefficients of variation (CV) were assessed on two d-dimer concentrations, and linearity under dilution was evaluated. A group comparison was performed for both assays across the four groups of horses. A Spaghetti plot, Spearman Correlation, Passing Bablok regression and Bland–Altman plot were used to compare methods in terms of agreement.

Results

Ten horses were included in the clinically healthy group, eight in the low SAA group, eight in the high SAA group, and seven in the NSII group. For the Stago assay, intra- and inter-CVs were below the accepted level except for one inter-CV. The NycoCard assay did not meet the accepted level for any of the CVs. The linearity under dilution was acceptable for both the Stago and NycoCard. In the group comparison, both methods detected a significantly higher d-dimer concentration in the high SAA and NSII groups compared to the clinically healthy group. Method agreement showed slightly higher d-dimer concentrations with NycoCard compared to Stago. The overall agreement was stronger for the lower d-dimer concentrations.

Conclusion

Both the Stago and the NycoCard were found to be applicable for use in horses but were not directly comparable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03313-5.

Comparison of automated total nucleated cell counts vs manual cell counts in the amniotic fluid for the classification of disease status in healthy and diseased pigs

BACKGROUND

An increase in the total nucleated cell count (TNCC) of amniotic fluid can detect inflammation in the amniotic cavity. Traditionally, a manual count is employed, but the technique suffers from inaccuracy and is labor intensive. Automated cell counting could enhance precision and timeliness.

OBJECTIVES

We aimed to analyze the cell counts in the amniotic fluid of preterm pigs using an automated method and compared the results with manual cell counts. We also tested if increased TNCC is associated with an inflammatory group in a porcine model of chorioamnionitis.

METHODS

Amniotic fluids from 34 preterm pigs were analyzed blindly using two automatic settings of the ADVIA 2120i hematology analyzer (whole blood [WB] and cell poor [CP] settings) and manually by two observers using Neubauer chambers. Inter- and intra-variability were calculated. The correlation analysis of TNCC/μL in amniotic fluid was determined between the methods, including Deming and Bland-Altman analyses. Fischer's exact tests compared the known health status of the pigs to the outcomes of the automatic and manual TNCC.

RESULTS

Inter- and intra-observer variability of the manual TNCC were high, although the correlation of TNCC between (r = .95, P < .0001) and within observers (r = .98, P < .0001; r = .89, P < .0001) was good. Correlation between the manual and CP TNCC was moderate and significant (r = .50, P = .014). Manual and WB TNCC were not correlated. The CP (P = .003) and manual (P = .0001) analyses accurately classified the disease state of the pigs.

CONCLUSIONS

An acceptable correlation between automatic CP TNCC and manual counting was demonstrated. Both methods could accurately classify the disease state of the pigs.

Diagnosis of primary hyperfibrinolysis and in vitro investigation of the inhibitory effects of tranexamic acid in a group of dogs with sarcomas - A pilot study

Primary hyperfibrinolysis is not well characterised in canine cancer. This prospective case-control pilot study aimed to evaluate tissue plasminogen activator-modified thromboelastography (tPA-TEG) for diagnosis of primary hyperfibrinolysis in dogs with cancer and establish the in vitro therapeutic concentration of tranexamic acid (TXA). Nine dogs with sarcomas and normocoagulable thromboelastograms and 11 healthy dogs were included. For each a whole blood tPA-TEG, and four tPA-TEGs with added TXA in different concentrations were analysed. Lysis percentage at 30/60 min following maximal amplitude (LY30/60), clot lysis index (CL30/60), maximum rate of lysis (MRL), and total lysis (L) were investigated as diagnostic parameters of primary hyperfibrinolysis. In vitro TXA concentrations needed to inhibit 50% (IC50) and 90% (IC90) of the fibrinolytic potential were compared between groups. Significant primary hyperfibrinolysis (LY30 (P = 0.0001), LY60 (P = 0.003), CL30 (P = 0.01), and L (P = 0.02)) was observed in dogs with sarcomas. IC50 and IC90 of in vitro TXA for normalizing LY30 were 13.34 (SE 1.52) and 31.10 (SE 3.01) mg/L for dogs with sarcomas and 4.41 (SE 5.84) and 20.00 (SE 6.18) mg/L for healthy dogs. IC50 and IC90 for normalizing LY60 were 22.18 (SE 1.27) and 58.94 (SE 5.47) mg/L for dogs with sarcomas and 11.25 (SE 2.82) and 56.20 (SE 11.61) mg/L for healthy dogs. The IC50 for LY60 was significantly increased for dogs with sarcomas (P = 0.0003). Primary hyperfibrinolysis was documented by tPA-TEG in dogs with sarcomas. In vitro IC50 and IC90 for TXA were established. Clinical studies are required to establish therapeutic dosages in vivo.

Presence of nucleosomes in plasma and increased thrombin generation in dogs with acute and chronic gastroenteropathies

Neutrophil extracellular traps (NETs) which contain nucleosomes protect the host by eliminating extracellular pathogens. However, any inflammatory stimuli can activate NETs and eventually lead to an immune overreaction leading to autoimmune diseases and thrombosis. Acute/chronic gastroenteropathies(aGE/cGE) are prevalent in dogs, and are associated with a strong inflammatory component. The aim of this study was to investigate if dogs with aGE and cGE have increased concentrations of nucleosomes indicative of NETs formation, and whether increased concentrations of nucleosomes are associated with hypercoagulability determined by increased thrombin generation. Twenty-six dogs were enrolled. The dogs were healthy (n = 11), or presented with aGE(n = 7) or cGE(n = 8). Minimum database including CRP, APTT, PT and fibrinogen, was obtained from all dogs. Citrated plasma was batched and used for subsequent analyses. Nucleosome concentration was analysed using a Cell-Death Detection ELISA-kit and thrombin generation by a calibrated automated thrombogram assay. No statistical differences in nucleosome concentrations were present between the groups. Although a numerically increased concentration of nucleosomes where seen in dogs with aGE(median;range) (0.019 AU;0.003-0.088) and cGE(0.023 AU;0.011-0.256) compared to controls(0.007 AU;0.003-0.042). One dog with GI-lymphoma demonstrated a markedly increased concentration of nucleosomes (0.256 AU). Dogs with aGE showed increased thrombin generation by increased peak (p = 0.03) and endogenous thrombin potential (p = 0.03); and increased CRP (p = 0.001), fibrinogen (p = 0.0002) and prolonged APTT (p = 0.03) compared to controls. This proof of concept study demonstrates that dogs with aGE and cGE have presence of nucleosomes with marked increase in one dog with GI-lymphoma. Nucleosomes might be linked to haemostatic alterations in dogs with inflammatory and neoplastic diseases.

Stability and profiling of urinary microRNAs in healthy cats and cats with pyelonephritis or other urological conditions

Background

Specific biomarkers of pyelonephritis (PN) in cats are lacking. MicroRNAs (miRNAs) have diagnostic potential in human nephropathies.

Objectives

To investigate the presence/stability of miRNAs in whole urine of cats and the discriminatory potential of selected urinary miRNAs for PN in cats.

Animals

Twelve healthy cats, 5 cats with PN, and 13 cats with chronic kidney disease (n = 5), subclinical bacteriuria (n = 3), and ureteral obstructions (n = 5) recruited from 2 companion animal hospitals.

Methods

Prospective case‐control study. Expression profiles of 24 miRNAs were performed by quantitative PCR (qPCR). Effect of storage temperature (4°C [24 hours], −20°C, and −80°C) was determined for a subset of miRNAs in healthy cats.

Results

Urinary miR‐4286, miR‐30c, miR‐204, miR4454, miR‐21, miR‐16, miR‐191, and miR‐30a were detected. For the majority of miRNAs tested, storage at 4°C and −20°C resulted in significantly lower miRNA yield compared to storage at −80°C (mean log2fold changes across miRNAs from −0.5  ± 0.4 SD to −1.20 ± 0.4 SD (4°C versus −80°C) and from −0.7 ± 0.2 SD to −1.20 ± 0.3 SD (−20°C versus −80°C)). Cats with PN had significantly upregulated miR‐16 with a mean log2fold change of 1.0 ± 0.4 SD, compared with controls (−0.1 ± 0.2, P = .01) and other urological conditions (0.6 ± 0.3, P = .04).

Conclusions

Upregulation of miR16 might be PN‐specific, pathogen‐specific (Escherichia coli), or both.

Evaluation of fecal microRNA stability in healthy cats

Background

Gastrointestinal (GI) cancer accounts for 14% of feline malignancies. There is a great need for reliable noninvasive diagnostic biomarkers to reach a timely diagnosis and initiate treatment. Fecal microRNAs (miRNAs) could be such a biomarker and have shown great potential in colorectal screening in people but have yet to be investigated in cats.

Objectives

We aimed to evaluate the presence and stability of feline fecal miRNA under different storage conditions (room temperature [RT], 4, and −20°C) and to evaluate the expression levels of specific fecal miRNAs collected on three separate days (days 1, 4, and 7) in healthy cats.

Methods

Healthy cats were prospectively recruited. Fecal samples were collected, aliquoted, and stored for 24 hours at RT and then transferred to −20°C, stored for 24 hours at 4°C and then transferred to −20°C, or were immediately placed at −20°C on day 1 or at −20°C on days 4 and 7 postcollection. Expression of 22 miRNAs was investigated using quantitative real‐time PCR.

Results

Ten miRNA assays worked well, and one, let‐7b, was used for normalization. No differences in miRNA expression were seen between the three storage temperatures for the nine miRNAs investigated. Only miR‐26a showed a significant increase in expression between samples of days 1 and 7. The rest of the miRNAs levels were stable over time.

Conclusions

Fecal miRNA can be isolated from healthy cats. The expression was stable at different temperatures and for most of the miRNAs over time. Prospective studies evaluating fecal miRNA as biomarkers in cats with GI neoplasia are warranted.

Analytical validation of platelet microparticle quantification in cats

BACKGROUND

Cardiogenic embolism (CE) in cats is a devastating condition primarily associated with hypertrophic cardiomyopathy (HCM). Hypercoagulability may pose a risk for thrombus formation; however, no single test can predict CE development. Platelet microparticles (PMPs) released from platelet membranes are associated with thrombosis in humans.

OBJECTIVES

The aims were to validate flow cytometric PMP quantification in cats analytically and, in a pilot study, evaluate the procoagulant annexin V (AnV) positive PMP concentration in healthy cats and cats with asymptomatic HCM.

METHODS

With CD61 as a platelet marker, CD61⁺ AnV⁺ PMPs (0.3-1.0 μm) were quantified in citrated whole blood (WB) and platelet-poor plasma (PPP) using flow cytometry. Analyses were performed in 6 healthy cats and 5 cats with asymptomatic HCM. The coefficient of variation (CV) for duplicate (intra-assay) and parallel (inter-assay) analyses were calculated.

RESULTS

PMP concentrations were quantified with acceptable intra-assay CV for WB (CD61⁺ /AnV^- ; 2.4%, 0.2%-8.4% (median, range), CD61⁺ /AnV⁺ ; 3.8%, 0.1%-12.5%) and PPP (CD61⁺ /AnV^- ; 5.0%, 0.7%-12.8%, CD61⁺ /AnV⁺ ; 7.4%, 0.5%-15.3%), and acceptable inter-assay CV for WB in 10/11 cats (CD61⁺ /AnV^- ; 6.2%, 1.4%-13.3%, CD61⁺ /AnV⁺ ; 6.4%, 0.7%-17.2%), but unacceptable for PPP (CD61⁺ /AnV^- ; 15.6%, 5.8%-42.7%, CD61⁺ /AnV⁺ ; 27.8%, 8.4%-77.1%). For WB PMP concentrations, the pilot data demonstrated no differences between healthy cats and cats with asymptomatic HCM (4/5 with left ventricular outflow obstruction) for either the CD61⁺ /AnV^- or the CD61⁺ /AnV⁺ PMPs.

CONCLUSIONS

Only WB PMP concentrations could be quantified reliably in cats in a clinical setting. PMP concentrations did not differ between healthy and asymptomatic HCM cats in this pilot study.

Evaluation of microRNA Stability in Plasma and Serum from Healthy Dogs

BACKGROUND

Early and specific detection of cancer is of great importance for successful treatment of the disease. New biomarkers, such as microRNAs, could improve treatment efficiency and survival ratio. In human medicine, deregulation of microRNA profiles in circulation has shown great potential as a new type of biomarker for cancer diagnostics. There are, however, few studies of circulating microRNAs in dogs. Extracellular circulating microRNAs have shown a high level of stability in human blood and other body fluids. Nevertheless, there are still important issues to be solved before microRNAs can be applied routinely as a clinical tool, one of them being their stability over time in media commonly used for blood sampling.

OBJECTIVE

Evaluation of the stability of microRNA levels in plasma and serum from healthy dogs after storage at room temperature for different time points before being processed.

METHODS

The levels of four microRNAs (cfa-let-7a, cfa-miR-16, cfa-miR-23a and cfa-miR-26a) known to be stably expressed from other canine studies, have been measured by quantitative real-time PCR (qPCR).

RESULTS

MicroRNA levels were found sufficiently stable for gene profiling in serum- and plasma stored at room temperature for 1 hour but not for samples stored at room temperature for 24 hours.

CONCLUSION

Storage at room temperature of serum and plasma samples intended for microRNA profiling should be kept for a minimum period of time before proceeding with RNA isolation. For the four microRNAs investigated in the present study, we did not find significant differences in microRNA levels between serum and plasma samples from the same time point.

Evaluation of microRNA stability in feces from healthy dogs

BACKGROUND

Gastrointestinal cancer accounts for approximately 8% of all canine malignancies. Early detection of cancer may have a tremendous impact on both treatment options and prognosis. MicroRNAs (miRNAs), a class of noncoding RNAs that can be found stably expressed in body fluids and feces, have been suggested as valuable human cancer biomarkers.

OBJECTIVES

The purpose of the study was to investigate the feasibility of detecting miRNAs in canine feces and to determine the miRNA stability in fecal samples stored at different temperatures for different duration.

METHODS

The levels of 4 Canine familiaris (cfa) miRNAs (cfa-miR-16, cfa-miR-20a, cfa-miR-21, and cfa-miR-92a) were investigated by quantitative real-time PCR(qPCR) in fecal samples from 10 healthy dogs. Fecal samples were collected at 3 different time points and samples from the first time point were stored at different temperatures and for a different duration.

RESULTS

A statistically significant difference was found in miRNA levels from samples stored at room temperature compared with samples stored at -20°C for cfa-miR-16 and cfa-miR-21. No significant difference was found in the level of the investigated miRNAs over time.

CONCLUSIONS

Overall, miRNAs are present in dog feces at measurable levels. Some miRNAs seem to be subject to a higher degree of degradation in samples stored at room temperature for 24 hours compared with samples frozen after collection at -20°C. The investigated miRNAs were stably expressed over time. This study provides the basis for further research on miRNA expression profiles as biomarkers for gastrointestinal cancer in dogs.

Altered collagen turnover in factor VIII-deficient rats with hemophilic arthropathy identifies potential novel serological biomarkers in hemophilia

Essentials Joint bleeding in hemophilia may induce significant remodeling of the extracellular matrix. Biomarkers of collagen turnover were investigated in a F8-/- rat model of hemophilic arthropathy. Biomarkers of cartilage degradation increased significantly during development of arthropathy. Basement membrane and interstitial matrix turnover changed significantly following hemarthrosis.

SUMMARY

Background Hemophilic arthropathy is a severe complication of hemophilia. It is caused by recurrent bleeding into joint cavities, which leads to synovial inflammation, fibrosis, cartilage degradation and bone remodeling. Extracellular matrix remodeling of affected tissues is a hallmark of these pathological processes. Objectives The aim of this study was to use serological biomarkers of collagen turnover to evaluate extracellular matrix remodeling in a factor VIII-deficient rat model of hemophilic arthropathy. Methods F8-/- rats and wild-type littermate controls were subjected to repeated knee bleeds induced by needle puncture on days 0 and 14. Development of arthropathy was confirmed by histology after termination on day 28. Serum samples were collected at baseline and throughout the study and analyzed for biomarkers of collagen turnover, including collagens of the basement membrane (type IV collagen), the interstitial matrix (collagen types III, V and VI) and cartilage (type II collagen). Results In F8-/- rats, induced knee bleeding and subsequent development of arthropathy caused significant alterations in collagen turnover, measured as changes in serological biomarkers of basement membrane turnover, interstitial matrix turnover and cartilage degradation. Biomarkers of type II collagen degradation correlated significantly with cartilage degradation and degree of arthropathy. Hemophilic rats had a 50% higher turnover of the basement membrane than wild-type littermates at baseline. Conclusions Joint bleeding and hemophilic arthropathy cause changes in turnover of extracellular matrix collagens in hemophilic rats. Biomarkers of collagen turnover may be used to monitor joint bleeding and development of blood-induced joint disease in hemophilia.

The F8(-/-) rat as a model of hemophilic arthropathy

Essentials Validating the F8 rat as a new intermediate-size animal model of hemophilic arthropathy. Factor VIII (FVIII) treated F8(-/-) rats suffered induced hemarthrosis analyzed by histopathology. F8 (-/-) animals develop hemophilic arthropathy upon hemarthrosis, preventable by FVIII treatment. The F8 (-/-) rat presents as a new pharmacologic model of hemophilic arthropathy.

SUMMARY

Background Translational animal models of hemophilia are valuable for determining the pathobiology of the disease and its co-morbidities (e.g. hemophilic arthropathy, HA). The biologic mechanisms behind the development of HA, a painful and debilitating condition, are not completely understood. We recently characterized a F8(-/-) rat, which could be a new preclinical model of HA. Objectives To establish the F8(-/-) rat as a model of HA by determining if the F8(-/-) rat develops HA resembling human HA after an induced joint bleed and whether a second joint bleed causes further disease progression. Methods Wild-type and F8(-/-) rats were treated with vehicle or recombinant human factor VIII (rhFVIII) prior to a needle-induced joint bleed. Joint swelling was measured prior to injury, the following 7 days and upon euthanasia. Histologic sections of the joint were stained, and athropathic changes identified and scored with regard to synovitis, bone remodelling, cartilage degradation and hemosiderin deposition. Results Vehicle-treated F8(-/-) rats experienced marked joint swelling and developed chronic degenerative joint changes (i.e. fibrosis of the subsynovial membrane, chondrocyte loss and excessive bone remodeling). Treatment with rhFVIII reduced or prevented swelling and degenerative joint changes, returning the F8(-/-) animals to a wild-type phenotype. Conclusion The hemophilic phenotype of the F8(-/-) rat resulted in a persistent hemarthrosis following an induced joint bleed. This caused development of HA resembling human HA, which was prevented by rhFVIII treatment, confirming the potential of the F8(-/-) rat as a model of HA.

Prevalence, Antimicrobial Resistance and Risk Factors for Thermophilic Campylobacter Infections in Symptomatic and Asymptomatic Humans in Tanzania

The genus Campylobacter comprises members known to be a leading cause of foodborne gastrointestinal illness worldwide. A study was conducted to determine the epidemiology and antimicrobial resistance of Campylobacter in humans in Morogoro, Eastern Tanzania. Isolation of Campylobacter from stool specimens adopted the Cape Town protocol. Campylobacter isolates were preliminarily identified by conventional phenotypic tests and subsequently confirmed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and polymerase chain reaction. Antimicrobial resistance testing employed the disc diffusion method. A small proportion of the test isolates was also subjected to agar dilution method. Risk factors for human illness were determined in an unmatched case-control study. Thermophilic Campylobacter were isolated from 11.4% of the screened individuals (n = 1195). The agreement between PCR and MALDI-TOF was perfect (κ = 1.0). Symptomatics and young individuals were infected with higher numbers than asymptomatic and adults, respectively. The majority (84.6%) of the isolates were C. jejuni and the remaining were C. coli. Isolates had highest resistance (95.6%) for colistin sulphate and lowest for ciprofloxacin (22.1%). The rates of resistance for other antibiotics (azithromycin, erythromycin, tetracycline, cephalothin, gentamycin, nalidixic acid, ampicillin, amoxycillin, norfloxacin, chloramphenicol) ranged from 44.1% to 89%. Comparison between disc diffusion and agar dilution methods indicated a good correlation, and the tests were in agreement to each other (κ ≥ 0.75). Human illness was found to be associated with young age and consumption of chicken meat and pre-prepared salad. Our data indicate the presence of antibiotic-resistant thermophilic Campylobacter in humans in the study area. There is a need for routine investigation of the presence of the organisms in gastroenteritis aetiology, including determination of their antibiotic susceptibilities.

A novel F8 -/- rat as a translational model of human hemophilia A

BACKGROUND

In preclinical hemophilia research, an animal model that reflects both the phenotype and the pathology of the disease is needed.

OBJECTIVES

Here, we describe the generation and characterization of a novel genetically engineered F8(-/-) rat model.

METHODS

The rats were produced on a Sprague Dawley background with the zinc finger nuclease technique. A founder with a 13-bp deletion in exon 16 causing a premature translational stop in the C-terminal part of the A3 domain of factor VIII was selected, and a breeding colony was established.

RESULTS

Seventy per cent of the homozygous rats had clinically manifest spontaneous hemorrhagic episodes that needed treatment. The F8(-/-) rats had no detectable FVIII activity, and had a significantly prolonged activated partial thromboplastin time (APTT) and clot formation time as compared with wild-type (WT)/WT rats. In vitro spiking of rat plasma with human recombinant FVIII resulted in dose-dependent normalization of the APTT.

CONCLUSION

On the basis of the targeted deletion in F8, and the distinct physical and analytic characteristics of the rat, we conclude that an FVIII-deficient rat strain has been generated that has the potential to contribute greatly to translational research.

The presence of antiphospholipid antibodies in healthy Bernese Mountain Dogs

BACKGROUND

The role of antiphospholipid antibodies in the prolonged activated partial thromboplastin time (aPTT) previously identified in healthy Bernese Mountain Dogs remains unknown. In people, an isolated prolonged aPTT without evidence of bleeding might be because of a thrombophilic condition caused by antiphospholipid antibodies.

OBJECTIVE

To examine if prolonged aPTT in healthy Bernese Mountain Dogs is because of antiphospholipid antibodies.

ANIMALS

Twenty-two healthy Bernese Mountain Dogs and 10 healthy adult dogs of various breeds.

METHODS

Prospective case control study. Healthy Bernese Moutain Dogs were examined twice over 6 months. Dogs were investigated for the presence of lupus anticoagulants and anticardiolipin (aCL) antibodies by the use of multiple aPTT tests with low and high lupus anticoagulant sensitivities, a mixing study, and an ELISA test for aCL antibody optical density to detect solid phase antiphospholipid antibodies.

RESULTS

In all, 15 of 22 healthy Bernese Mountain Dogs were positive for lupus anticoagulants. The Bernese Mountain Dogs had markedly higher levels of aCL antibodies compared with the control dogs (P = .006). In all, 7 of 21 of the Bernese Mountain Dogs were positive for both lupus anticoagulants and aCL antibodies, whereas 4 of 21 Bernese Mountain Dogs were negative for both.

CONCLUSIONS AND CLINICAL IMPORTANCE

Lupus anticoagulants and aCL antibodies could be the cause of prolonged aPTT in healthy Bernese Mountain Dogs. The importance of the antiphospholipid antibodies in the dogs remains unknown.

MLST clustering of Campylobacter jejuni isolates from patients with gastroenteritis, reactive arthritis and Guillain-Barré syndrome

AIMS

To determine the diversity and population structure of Campylobacter jejuni (C. jejuni) isolates from Danish patients and to examine the association between multilocus sequence typing types and different clinical symptoms including gastroenteritis (GI), Guillain-Barré syndrome (GBS) and reactive arthritis (RA).

METHODS AND RESULTS

Multilocus sequence typing (MLST) was used to characterize 122 isolates, including 18 from patients with RA and 8 from patients with GBS. The GI and RA isolates were collected in Denmark during 2002-2003 and the GBS isolates were obtained from other countries. In overall, 51 sequence types (STs) were identified within 18 clonal complexes (CCs). Of these three CCs, ST-21, ST-45 and ST-22 clonal complexes accounted for 64 percent of all isolates. The GBS isolates in this study significantly grouped into the ST-22 clonal complex, consistent with the PubMLST database isolates. There was no significant clustering of the RA isolates.

CONCLUSIONS

Isolates from Denmark were found to be highly genetically diverse. GBS isolates grouped significantly with clonal complex ST-22, but the absence of clustering of RA isolates indicated that the phylogenetic background for this sequela could not be reconstructed using variation in MLST loci. Possibly, putative RA-associated genes may vary, by recombination or expression differences, independent of MLST loci.

SIGNIFICANCE AND IMPACT OF THE STUDY

MLST typing of C. jejuni isolates from Danish patients with gastroenteritis confirmed that the diversity of clones in Denmark is comparable to that in other European countries. Furthermore, a verification of the grouping of GBS isolates compared to RA isolates provides information about evolution of the bacterial population resulting in this important sequela.

Imported schistosomiasis in Europe: sentinel surveillance data from TropNetEurop

BACKGROUND

Schistosomiasis is a major parasitic disease, increasingly imported into temperate climates by immigrants from and travelers to endemic areas.

METHOD

To generate valid data on imported infectious diseases to Europe and to recognize trends over time, the European Network on Imported Infectious Diseases Surveillance (TropNetEurop) was founded in 1999. Three hundred and thirty-three reports of schistosomiasis were analyzed for epidemiologic and clinical features.

RESULTS

Male patients accounted for 64% of all cases. The average age of all patients was 29.5 years. The majority of patients were of European origin (53%). Europeans traveled predominantly for tourism (52%). Main reasons for travel for people from endemic areas were immigration and refuge (51%) and visits to relatives and friends (28%). The majority of infections were acquired in Africa; 92 infections were clearly attributable to Schistosoma haematobium, 130 to Schistosoma mansoni, and 4 to Schistosoma intercalatum. Praziquantel was the only treatment used. No deaths were recorded.

CONCLUSION

TropNetEurop sentinel provides valuable epidemiologic and clinical data on imported schistosomiasis to Europe.

Epidemiology and clinical features of imported dengue fever in Europe: sentinel surveillance data from TropNetEurop

Travelers have the potential both to acquire and to spread dengue virus infection. The incidence of dengue fever (DF) among European travelers certainly is underestimated, because few centers use standardized diagnostic procedures for febrile patients. In addition, DF is currently not reported in most European public health systems. Surveillance has commenced within the framework of a European Network on Imported Infectious Disease Surveillance (TropNetEurop) to gain information on the quantity and severity of cases of dengue imported into Europe. Descriptions of 294 patients with DF were analyzed for epidemiological information and clinical features. By far the most infections were imported from Asia, which suggests a high risk of DF for travelers to that region. Dengue hemorrhagic fever occurred in 7 patients (2.4%) all of whom recovered. Data reported by member sites of the TropNetEurop can contribute to understanding the epidemiology and clinical characteristics of imported DF.

Imported Falciparum malaria in Europe: sentinel surveillance data from the European network on surveillance of imported infectious diseases

Malaria continues to have a high morbidity rate associated among European travelers. Thorough recording of epidemiological and clinical aspects of imported malaria has been helpful in the detection of new outbreaks and areas of developing drug resistance. Sentinel surveillance of data collected prospectively since 1999 has begun within TropNetEurop, a European network focusing on imported infectious diseases. TropNetEurop appears to cover approximately 10% of all patients with malaria seen in Europe. Reports of 1659 immigrants and European patients with Plasmodium falciparum malaria were analyzed for epidemiological information and data on clinical features. Regional data were quite diverse, reflecting local patterns of immigration and international travel. By far, the most infections were imported from West Africa. Europeans had more clinical complications; consequently, all deaths occurred in this group. Compared with European standards, the mortality rate was low (0.6% in Europeans). Data from TropNetEurop member sites can contribute to our understanding of the epidemiological and clinical findings regarding imported falciparum malaria.

Apical expression of herpes simplex virus type 2 glycoproteins in human neuroblastoma cells

The expression of herpes simplex virus type 2 (HSV-2) glycoproteins on the surface of human neuroblastoma cells has been investigated using Millipore Millicell culture plate inserts. Utilizing a modified radioimmunoassay, we learned that glycoproteins B, C, D, E, and I were expressed predominantly on the apical membrane domain of the infected neuroblastoma cells. The unidirectional transport of HSV-2 glycoproteins was substantiated by the analysis of extracellular glycoproteins released from neuroblastoma cells. The results suggest that the evaluated HSV-2 glycoproteins were transported primarily to the apical plasma membrane domain of human neuroblastoma cells.

Cytokeratin intermediate filament pattern in uterine cervical biopsies

Twenty-seven uterine cervical biopsies with histological diagnoses ranging from normal through dysplasia to invasive carcinoma were analysed for cytokeratin pattern in two-dimensional gel electrophoresis. No direct correlation between histological diagnosis and cytokeratin pattern was observed.

Cytokeratin intermediate filament pattern and human papillomavirus type in uterine cervical biopsies with different histological diagnosis

The cytokeratin pattern and the presence of human papillomavirus (HPV) were analyzed in 53 uterine cervical biopsies. The biopsies were histologically characterized and the diagnosis ranged from normal through dysplasia to carcinoma. The cytokeratins were identified by their immunological reactivity with the monoclonal antibodies AE1 and AE3. The tissue was typed for the presence of HPV types 11, 16 and 18. We have previously shown that there was no correlation between the expression of cytokeratins No. 14, 15, 16 and 19 (K14, K15, K16 and K19) and the histological diagnosis of cervical biopsies. The present study shows that the cytokeratin pattern cannot be correlated to HPV infection of the cervical tissue either.