Prognostic Value of Cardiac Troponin I and L‐Lactate in Blood of Dairy Cows Affected by Downer Cow Syndrome

Background

The downer cow syndrome (DCS) is a challenging health issue in the dairy industry. No cow‐side test is available to provide an accurate prognosis for DCS cases in farm settings.

Hypothesis/Objectives

Local or systemic hypoperfusion and myocardial lesions lead to an increase in blood concentration of biomarkers cardiac troponin I (cTnI) and L‐lactate. The objective was to determine the prognostic values of these biomarkers assessed cow‐sides in addition to clinical examinations in prognostication of a negative outcome (NO: death or euthanasia within 7 days).

Animals

218 client‐owned dairy cows affected by DCS.

Methods

In a prospective study, animals were monitored for 60 days after inclusion of each cow. Blood cTnI and L‐lactate concentrations were measured on the day of inclusion. The prognostic accuracy of both biomarkers and physical examination variables was estimated to predict NO. A mixed multivariable logistic regression model was used for data analysis.

Results

Prevalence of NO in this study was 63% on day 7. Troponin concentrations greater than 0.7 ng/mL had sensitivity and specificity of 54.1% (95% CI: 45.3–62.7%) and 78.4% (95% CI: 67.3–87.1%), respectively, for predicting NO. Blood L‐lactate was not associated with the outcome. The multivariable model revealed that heart rate >100 bpm (OR; 95% CI: 3.7; 1.3–10.2) and cTnI > 0.7 ng/mL (OR; 95% CI: 5.5; 2.1–14.6) were associated with the risk of NO.

Conclusions and Clinical Importance

Hypertroponinemia and tachycardia were associated with reduced survival in DCS cases. The use of cow‐side blood cTnI concentrations and heart rate could help to rapidly identify cows in farm setting that have poor chances of recovery and would benefit from a more aggressive treatment or euthanasia.     

Plasma big endothelin-1, atrial natriuretic peptide, aldosterone, and norepinephrine concentrations in normal Doberman Pinschers and Doberman Pinschers with dilated cardiomyopathy

BACKGROUND: Dilated cardiomyopathy (DCM) results in progressive myocardial and circulatory dysfunction causing activation of a number of neurohormonal systems, including the endothelin (ET) system, which is only beginning to be described in clinical veterinary medicine. Measurement of these circulating neurohormones possesses potential utility in the diagnosis, staging, and assessment of prognosis in cardiac disease. HYPOTHESIS: We hypothesized that plasma big ET-1, norepinephrine (NE), aldosterone, and atrial natriuretic peptide (ANP) concentrations in normal Dobermans would differ from those in Dobermans with DCM, and that concentrations of these hormones would be associated with time to congestive heart failure (CHF) or death. ANIMALS: Thirty client-owned Dobermans (10 each of normal, occult DCM, and overt DCM) were included in the study. METHODS: Dogs underwent an echocardiogram, ECG, and blood sample collection. Neurohormones were measured by high-pressure liquid chromatography (NE) or commercial assays. RESULTS: Dogs with occult DCM had significantly higher ANP concentrations compared with normal dogs (least squares means [95% confidence interval, CI]: occult female 53.7 pg/mL [40.2-71.7] versus normal female 31.6 pg/mL [24.8-40.3], P = .026; occult male 86.1 pg/mL [64.7-115] versus normal male 12.1 pg/mL [5.1-28.7], P = .011). Dogs with overt DCM had significantly higher concentrations of all neurohormones compared with the normal group. Furthermore, increasing big ET-1 (risk ratio [RR] 2.7, CI 1.3-8.6, P = .01) and NE concentrations (RR 3.9, CI 1.1-18.1, P = .03) over 1 month were associated with a shorter survival time. CONCLUSIONS AND CLINICAL IMPORTANCE: High ANP concentrations can identify dogs with advanced occult DCM. Increasing big ET-1 or NE concentrations over time can be useful predictors of poor prognosis.     

Relationships Among Plasma Proteins,Hematological Values,and Gender in Thoroughbred and Miniature Horses

Our objective was to investigate the relationships among plasma proteins, hematological values, and gender in Thoroughbred (nine females and 16 males) and miniature (30 females and four males) horses. Twenty-two protein bands, ranging from 8 to 264 kDa, were detected in horse plasma. Red blood cells, hemoglobin, and hematocrit were negatively correlated (r ≤ −0.29; P < .05) with bands 13 and 17 but positively correlated (r ≥ 0.40; P < .01) with band 3. A negative correlation (r ≤ −0.27; P < .05) was detected between bands 1, 8, and lymphocytes. Neutrophils were positively correlated with bands 1 and 8. Basophils had a positive correlation (r = 0.36) with band 12 and negative correlation with bands 11 (r = −0.30) and 13 (r = −0.48). Platelets had positive correlations (r ≥ 0.24; P < .10) with bands 3, 4, 5, 10, 14, 19, and 22. The relative intensities of protein bands 4, 16, and 22 were affected (P < .05) by an interaction of breed and gender. Gender effects (P < .05) were detected for plasma protein bands 1 (1.6 vs. 2.4 ± 0.23), 5 (2.6 vs. 3.6 ± 0.25), and 11 (8.7 vs. 13.2 ± 1.1), respectively, for females and males. Breed effects (P < .05) were detected for plasma protein bands 5 (2.5 vs. 3.8 ± 0.25) and 11 (9.0 vs. 12.9 ± 1.1), respectively, for Thoroughbreds and miniatures. When developing new pathophysiological tools for equine disease diagnosis and therapy, breed and gender effects should be considered.     

Cardiac troponin I and C-reactive protein concentrations in dogs with severe pulmonic stenosis before and after balloon valvuloplasty

Objective

To report cardiac troponin I (cTnI) and C-reactive protein (CRP) concentrations in dogs with severe pulmonic stenosis (PS) before and after balloon valvuloplasty (BV).

Background

Increased morbidity and mortality have been reported with severe PS and histopathologic evidence of myocardial damage is demonstrated with BV. Severity of myocardial injury and inflammation associated with severe PS and BV, as assessed by cTnI and CRP, is unknown.

Animals, materials and methods

Serum cTnI and CRP concentrations were measured in dogs with severe PS (n = 23) and following BV (n = 16).

Results

Baseline cTnI and CRP were elevated in 7/23 (30.4%) and 8/23 (34.8%) dogs. Median cTnI at baseline and post-BV were 0.20 ng/mL (range, 0.20-1.29 ng/mL) and 2.85 ng/mL (range, 0.21-55.40 ng/mL), respectively. Median CRP at baseline and post-BV were 3.40 μg/mL (range, 0-14.70 μg/mL) and 11.70 μg/mL (range, 4.20-120 μg/mL), respectively. Post-BV concentrations were significantly increased compared to baseline for cTnI (p < 0.001) and CRP (p = 0.001).

Conclusions

Serum cTnI and CRP are increased in dogs with severe PS and following BV. Future studies should evaluate whether biomarkers correlate with severity and prognosis of PS or can be used to guide therapy.     

Interactions between the arbuscular mycorrhizal fungus Glomus intraradices and the plant growth promoting rhizobacteria Paenibacillus polymyxa and P. macerans in the mycorrhizosphere of Cucumis sativus

Interactions between the arbuscular mycorrhizal (AM) fungus Glomus intraradices and bacteria from the genus Paenibacillus (P. macerans and P. polymyxa) were examined in a greenhouse pot experiment with Cucumis sativus with and without organic matter amendment (wheat bran). P. polymyxa markedly suppressed AM fungus root colonization irrespective of wheat bran amendment, whereas P. macerans only suppressed AM fungus root colonization in combination with wheat bran amendment. Dual inoculation with P. macerans and G. intraradices in combination with wheat bran amendment also caused severe plant growth suppression. Inoculation with G. intraradices was associated with increased levels of dehydrogenase activity and available P in the growth substrate suggesting that mycorrhiza formation accelerated the decomposition of organic matter resulting in mobilization of phosphorus. Inoculation with both Paenibacillus species increased all measured microbial fatty acid biomarkers in the cucumber rhizosphere, except for the AM fungus biomarker 16:1ω5, which was reduced, though not significantly. Similarly, inoculation with G. intraradices increased all measured microbial fatty acid biomarkers in the cucumber rhizosphere, except for the Gram-positive bacteria biomarker 15:0 anteiso, which was overall decreased by G. intraradices inoculation. In combination with wheat bran amendment G. intraradices inoculation caused a 39% reduction in the amount of 15:0 anteiso in the treatment with P. polymyxa, suggesting that G. intraradices suppressed P. polymyxa in this treatment. In conclusion, plant growth promoting species of Paenibacillus may have suppressive effects of AM fungi and plant growth, especially in combination with organic matter amendment. The use of an inert plant growth media in the present study allowed us to study rhizosphere microbial interactions in a relative simple substrate with limited interference from other soil biota. However, the results obtained in the present work mainly show potential interactions and should not be directly extrapolated to a soil situation.     

Taking it to the next level: Trophic transfer of marker fatty acids from basal resource to predators

Fatty acid (FA) analysis is used increasingly to investigate the trophic structure of soil animal food webs as the technique allows separation of the role of detrital resources such as bacteria, fungi and plant material for consumer nutrition. The applicability of FAs as biomarkers for different diets has been verified for Collembola and Nematoda. However, for the analysis of whole food webs it is crucial to know whether marker FA are valid for different taxa and whether they are transferred along the food chain to higher trophic levels, i.e. predators. Top-predators are integrators of lower level energy fluxes in food webs; therefore analysis of their FAs may allow to identify trophic pathways and to separate bacterial vs. fungal based energy channels. Chilopoda and Arachnida are among the main predators in soil food webs. Our aim was to test the applicability of marker FAs for these two predator taxa and to verify the trophic transfer of marker FAs of different basal resources via first order consumers into predators, i.e. over three trophic levels. Therefore, we investigated the transfer of FAs from different basal resources [fungi (Chaetomium globosum), plant leaf litter (Tilia europaea), Gram-positive (Bacillus amyloliquefaciens) and Gram-negative bacteria (Stenotrophomonas maltophilia)] via Collembola (Heteromurus nitidus) as first order consumers into predators [Lithobius forficatus (Chilopoda) and Pardosa lugubris (Arachnida)]. Fatty acid profiles of predators of food chains with different basal resources differed significantly. Marker FAs of basal resources were clearly detectable in predators, suggesting that FA analysis allows to separate trophic channels of soil food webs. By reflecting basal resources, FAs of predators allow tracking energy/resource fluxes through the food web and thereby clarifying the relative importance of bacterial vs. fungal vs. plant resources for soil animal food webs.     

Trophic shift of stable isotopes and fatty acids in Collembola on bacterial diets

Fatty acid (FA) analysis is a promising tool to study trophic relationships in soil food webs. We determined FA biomarkers to trace bacterial food sources (Bacillus megaterium, Pseudomonas putida, Enterobacter aerogenes) of Collembola (Heteromurus nitidus, Protaphorura fimata, Folsomia candida). In addition, δ¹⁵N, δ¹³C, C/N ratio, body weight and NLFA/PLFA ratio (neutral lipid/phospholipid fatty acids) of Collembola were assessed. These measures indicated that P. putida ranked first, B. megaterium second and E. aerogenes third in food quality. FAs specific for bacteria were found in the NLFAs of the Collembola reflecting the respective bacterial diet. Biomarker FAs for gram-positive bacteria were methyl branched i14:0, i15:0, a15:0 and i17:0. Consumption of gram-negative bacteria was reflected by the cyclic form cy17:0 (E. aerogenes, P. putida) and by 16:1ω5 (P. putida).