Acute-phase proteins, oxidative stress biomarkers, proinflammatory cytokines, and cardiac troponin in Arabian mares affected with pyometra

Exploring oxidative stress, immunological and metabolic biomarkers in dairy cows with postpartum pyometra

Pyometra is a prevalent and severe infectious disease that affects the reproductive systems of cattle worldwide. This study's main goal was to investigate the biomarkers for oxidative stress (OS), adiponectin, leptin and neopterin (NPT) in cows suffering from postpartum pyometra. The study also aimed to determine which bacteria were most commonly implicated in the development of the disease. A total of 74 cows with pyometra were examined and compared to a control group of healthy cows (n = 20). In comparison to the healthy control and post-treatment groups, the pyometra group showed higher mean values of leptin, adiponectin and malondialdehyde (MDA). In contrast, the glutathione (GSH) and superoxide dismutase (SOD) mean values were lower in the pyometra group as compared to the post-treatment and control groups. NPT levels in the post-treatment groups were lower than those in cows with pyometra but comparable to the healthy control group (p > .05). When compared to the other biomarkers, NPT, leptin and adiponectin showed higher sensitivity and specificity in identifying pyometra cases (AUC ≥0.99). The predominant bacterial isolates from the ptomtra-affected cows consisted of Escherichia coli (N = 29; 39.2%), Arcanobacterium pyogenes (N = 27; 36.5%) and Fusobacterium necrophorum (N = 13; 17.6%). Mixed infection was determined in nine samples (12.2%). Conclusively, OS, adiponectin, leptin and NPT play crucial roles in comprehending the development of postpartum pyometra in cows and have the potential to serve as biomarkers for the disease.

Effect of pyometra on vascularity alterations, oxidative stress, histopathology and inflammatory molecules in feline

This study aimed to investigate blood flow, hemodynamical features by Doppler ultrasound, the oxidative stress biomarkers from serum samples, and histopathology from uterine tissue, in healthy queens and queens with pyometra. Twenty queens were categorized into two groups, according to signs, history, and ultrasound findings, as pyometra and control healthy queens. Doppler ultrasonography, total antioxidant capacity (TAC), malondialdehyde (MDA), albumin, bacteriological isolation, histopathology, and immunohistochemistry of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB) P65 were performed. Uterine diameter and thickness increased significantly in the pyometra group compared to control. Uterine peak velocity and flow rate were significantly higher in the control group. The pyometra group showed a significant decrease in albumin, TAC, and a significant increase in MDA. Fibrosis and mononuclear inflammatory cell infiltration were seen in the pyometra samples. The mean area percentage of TNF-α expression in the uteri of the pyometra group was higher. The expression of NF-κB P65 in the uteri in the pyometra group was significantly higher. Doppler ultrasonography can provide valuable information for diagnosing pyometra in queens by elevating the uterine thickness with reducing blood flow rate. Oxidative stress, TNF-α, and NF-κB expression alterations varied between pyometra and control groups.

Association of the severity of colic in horses with oxidative stress biomarkers, acute-phase proteins, and certain trace elements

Sixty-one horses were enrolled in this study and divided into 3 different groups according to their severity of colic (heart rate, oral mucous membrane color, and abdominal distention): a strangulating colic (SC) group (n=21), non-strangulating colic (NC) group (n=20), and control group (n=20) consisting of randomly selected normal horses without signs of colic. The serum concentrations of haptoglobin, tumor necrosis factor-α (TNFα), nitric oxide (NO), malondialdehyde (MDA), zinc, iron, and copper were evaluated in all horses. The average concentration of TNFα in the SC group was higher than that in the control group (P<0.001). The TNFα concentration was higher in the NC group compared with the control group (P<0.001). Furthermore, the average concentration of TNFα tended to be higher in the SC group compared with the NC group (P=0.052). The average concentration of haptoglobin in the SC group was higher than that in the control group (P<0.001). The average concentration of NO was higher in the SC group compared with the NC group. (P=0.016) The average concentration of MDA was higher in the SC group compared with the control group (P=0.042). Furthermore, the concentration of MDA was higher in the SC group compared with the NC group (P=0.048). TNFα in horses with signs of colic may be a reliable indicator of prognosis and the severity of clinical signs. The haptoglobin concentration may be a useful marker in cases where animals are referred to clinicians a few days after the onset of colic. The concentrations of MDA and NO should be interpreted with caution.

Validation of a flow cytometric assay to detect intraerythrocytic reactive oxygen species in horses

BACKGROUND

Oxidative stress refers to the accumulation of reactive oxygen species (ROS). Most assays for ROS detection are costly, laborious, and usually use indirect markers. The use of 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) is a possible alternative. This substance becomes a fluorochrome when oxidized by ROS, with the resultant fluorescence proportional to ROS concentration. Erythrocytes are highly exposed to ROS, resulting in cell damage and consequently impaired oxygen delivery. The effects of this exposure in physiologic and pathologic conditions necessitate an improvement in ROS detection methods.

OBJECTIVE

We aimed to validate intraerythrocytic ROS detection by flow cytometry using DCHF-DA in healthy horses.

METHODS

Erythrocytes from 31 healthy horses were isolated, incubated with DCFH-DA, and either left unstimulated or stimulated with hydrogen peroxide (H₂ O₂ ). For specificity, each cellular component of blood was separated and plotted according to its size and complexity. Samples were run in triplicate for intra-assay precision and five consecutive times for inter-assay repeatability. Stability was determined by analyzing the same sample up to 48 hours after blood collection. The acceptable coefficient of variation (CV) was ≤20%.

RESULTS

The intra-assay CV was 1.7% and 13.3%, and the inter-assay CV was 4.8% and 17.8% for unstimulated and stimulated samples, respectively. Unstimulated and stimulated samples were stable for up to 48 and 24 hours, respectively. Stimulated samples had greater fluorescence than unstimulated samples (P < .0001).

CONCLUSIONS

This flow cytometric assay demonstrated adequate specificity, precision, and stability and is, therefore, a promising technique with multiple applications for studying oxidative stress in horses.

The deleterious effect of postpartum pyometra on the reproductive indices, the metabolic profile, and oxidant/antioxidant parameters of dairy cows

Background and Aim:

Postpartum uterine infectious diseases, such as pyometra, have discrepancy with both health and, subsequently, productivity of dairy cows due to its high prevalence and the high cost of treatment. Therefore, this study investigates the influence of pyometra on the reproductive indices, the metabolic profile, and oxidant/antioxidant parameters of the pyometric animal compared to those of healthy ones.

Materials and Methods:

The study included 30 cows. The animals were differentiated into two groups of 15 cows each: A group of pyometra and a control group. All pyometric cows were subjected to breeding soundness examination after the end of pyometra and were compared to the control group. Blood samples were obtained to assess the levels of glucose, non-esterified fatty acids (NEFA), triglycerides (TGs), cholesterol, albumin, total protein, alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen (BUN), creatinine, calcium (Ca), phosphorus, sodium, potassium, progesterone hormone (P4), malondialdehyde (MDA), total antioxidant capacity (TAC), glutathione peroxidase (GPx), and superoxide dismutase.

Results:

Results revealed significant prolonged duration of first estrus, the days open, and the required number of services due to pyometra. The pyometra group yielded increased levels of NEFA, TGs, ALP, BUN, creatinine, MDA, and progesterone hormone. In addition, significant decrease in the levels of glucose, cholesterol, albumin, Ca, phosphorus, sodium, TAC, GPx, and superoxide dismutase was observed in the pyometra group. Finally, no difference in the concentrations of total protein, ALT, AST, and potassium was observed in the pyometra group.

Conclusion:

The reproductive indices was adversely influenced in cows with postpartum pyometra, and metabolic profile, involving energy balance signals and liver function indicators, revealed differences between the two groups. Increased levels of oxidative stress parameters and decrease levels of antioxidant levels were also found, suggesting that pyometra is an incentive for oxidative stress. Overall, checking the energy balance, metabolic imbalances, and oxidant/antioxidant profile, accompanied with pre-emptive procedures during the postpartum period, is essential and can reduce the chances of such diseases and possible noxious results in highly productive cows.

Pyometra and estrous cycle modulate the uterine expression of the kisspeptin system and angiogenic and immune factors in cats

Failures in hypothalamic kisspeptin/Kiss1r signaling are associated with infertility, and in vitro studies have shown that kisspeptin can modulate angiogenesis and immune activity. Because there is no in vivo research on the functional relationship between these factors in the reproductive system, especially in domestic cats, we evaluated the expression profile of kisspeptin/Kiss1r and angiogenic and immunological mediators in the genital tract of cyclic cats and of those with pyometra. The uterus of cats in diestrus exhibited greater gene and protein expression of Kiss1, as well as Vegf, Pigf, Mif, and Il6. In contrast, Kiss1r presented greater expression in proestrus/estrus, similarly to that observed for the immunostaining of INFγ, MIF, TNFα, and IL10. These factors were positively correlated with Kiss1 and/or Kiss1r, and a positive correlation between Kiss1 and Kiss1r was also observed in the uterus of cats during the estrous cycle. Cats with pyometra showed greater immunostaining of Kiss1 and Kiss1r on the endometrial surface and reduced immunostaining of Kiss1 in deep glands, whereas there was a significant reduction in Vegf, Pigf, Mif, and Il6 mRNA, and an increase in Tnf mRNA. The findings reveal that there is a gene correlation between kisspeptin/Kiss1r and angiogenic and immune mediators in the uterus of the domestic cat, which is modulated by the estrous cycle, and that pyometra affects the expression of these mediators. This study suggests, for the first time, a functional relationship between the Kiss/Kiss1r system and angiogenic and immune mediators in the female genital tract.

Evaluation of Oxidative Stress Parameters in Healthy Saddle Horses in Relation to Housing Conditions, Presence of Stereotypies, Age, Sex and Breed

Oxidative stress plays an important role in the development of many horse diseases and it has been shown that housing has important implications for the psychophysical well-being of horses. The aim of this study is to determine if there are any differences between the redox status in horses in relation to housing conditions. The four housing conditions analyzed were: single box, without external access and without contact (Cat A), single box with external access and possibility of partial contact (Cat B), group housing with box and large paddock (Cat C), pasture with more than 7 horses and the possibility of green forage for the whole year (Cat D). A group of 117 healthy horses were selected in several private stables in Northern Italy. All subjects treated with any type of drug were excluded. At the end of the enrollment, the 117 selected horses were divided into the four housing categories. Stereotypies were highest in the group of horses in single box, without external access and without contact (Cat A). Oxidative stress was evaluated by testing plasma or serum samples for the following parameters: superoxide anion (WST), nitric oxide (NO), reactive oxygen species (d-ROMs), ferric reducing ability of plasma (FRAP), and the activity of superoxide dismutase (SOD). Simultaneously with the blood sampling, the owners completed a questionnaire with all the management aspects of the horse (signaling, feeding, equestrian activity, vaccinations, foot management etc.). The statistical evaluation was carried out based on the categories previously described, on the presence and absence of stereotypies and on some signaling data obtained from the questionnaire. There were no significant differences in the parameters analyzed between the categories. No significant redox status differences were detected based on the presence or absence of stereotypies. Interestingly, when the age was introduced as selection (<14 and >14 years old) parameter inside the categories, statistical significance was observed for some of the stress markers considered. Finally, independently of the housing conditions, the horses of the most two represented breeds exhibited different values of FRAP. All these aspects are commented in the discussion.

Clinical Changes and Uterine Hemodynamic in Pyometra Medically Treated Bitches

Simple Summary

Pyometra is an infectious uterine disorder marked by important clinical alterations and uterine contamination and blood flow changes in bitches. Although uterine removal is the most common mode of treatment, conservative therapy is an alternative. However, the success of medical treatment in restoring both clinical and uterine alterations has not yet been attested. Thus, we aimed to analyze the effects of both aglepristone alone or in combination with prostaglandin (associative) on clinical, laboratory and uterine hemodynamic features. Bitches were clinically and ultrasonographically (uterine blood flow) evaluated and medically followed-up throughout treatment (8 days) and castrated for local uterine analysis after 9 days of therapy onset. Associative therapy led to altered respiratory rate and decreased body temperature. Both treatments resolved bitches’ clinical condition and laboratory changes, and reduced uterine size. However, associative protocol was more effective in decreasing uterine vascularization and modulating uterine blood flow. Nevertheless, uterus remained microscopically altered soon after both therapy ending, thus not fully restoring local uterine changes in a short-term evaluation.

Abstract

Cystic endometrial hyperplasia–pyometra complex is a canine endometrial disorder, considered the most common and important among uterine diseases. The treatment of choice is ovariohysterectomy, but medical treatments have become an alternative. However, no studies have been performed in order to evaluate uterine hemodynamic changes during medical treatment for pyometra bitches. Therefore, the aim of this study was to compare the effectiveness of two medical protocols by means of clinical (heart rate, respiratory rate and body temperature), medullar response (complete blood count (CBC)) and uterine hemodynamic evaluation in pyometra bitches. For such purpose, 10 bitches with pyometra were assigned to two groups: Aglepristone Group (n = 5) and Associative Group (aglepristone + prostaglandin; n = 5). The Associative Group had altered respiratory rate and decreased body temperature. The Aglepristone Group had decreased plasma protein, however, leukocyte count reduced over time for both therapeutic protocols. Uterine area and vascularization score decreased throughout treatment. There was a significant reduction in uterine perimeter, area and vascularization score. The Associative Group had lower final diastolic velocity and higher systole:diastole ratio (S/D), pulsatility index (PI) and resistance index (RI). In conclusion, both medical treatments are effective in reversing clinical and CBC changes of pyometra, especially aglepristone, however they cannot fully restore local uterine changes in a short-term evaluation. Conversely, associative therapy was more effective in decreasing uterine vascularization and modulating uterine blood flow.

The Contribution of Specific and Nonspecific Biomarkers in Diagnosis of Equine Gastric Ulcer Syndrome (EGUS) Under Field Condition

The aim of this study is to investigate the diagnostic efficiency of gastrin, pepsinogen, proinflammatory cytokines (TNF-α, IL-6), and oxidative stress biomarkers in horses with equine gastric ulcer syndrome (EGUS). Thirty horses diagnosed with gastroscopic EGUS and 15 clinically healthy horses were selected for this study. The serum levels of gastrin, pepsinogen showed nonsignificant changes in horses with EGUS when compared with healthy horses. The serum levels of TNF-α, IL-6 revealed a significant increase in horses with EGUS when compared with healthy ones. Oxidative stress is evident in horses with EGUS in comparison with healthy horses as detected by higher levels of malondialdehyde (MDA) and decreased serum levels of total antioxidant capacity (TAC), Superoxide dismutase (SOD), glutathione (GSH), and nitric oxide (NO). MDA and TNF-α showed better sensitivity and specificity than IL-6 in distinguishing horses with EGUS from control horses. Conclusively, examination of serum gastrin and pepsinogen levels had a limited value in diagnosis of EGUS in horses under investigation. Moreover, this study showed that oxidative stress is evident in horses with EGUS. Higher levels of TNF-α and IL-6 indicate their role in EGUS pathogenesis in horses. Finally, MDA, TNF-α, and IL-6 could be used as biological markers for preliminary screening of horses with EGUS. Gastroscopy still accredited as the "gold standard" for diagnosis EGUS.

Serum amyloid A in equine health and disease

Serum amyloid A (SAA) is the major acute phase protein in horses. It is produced during the acute phase response (APR), a nonspecific systemic reaction to any type of tissue injury. In the blood of healthy horses, SAA concentration is very low, but it increases dramatically with inflammation. Due to the short half‐life of SAA, changes in its concentration in blood closely reflect the onset of inflammation and, therefore, measurement of SAA useful in the diagnosis and monitoring of disease and response to treatment. Increases in SAA concentration have been described in equine digestive, reproductive and respiratory diseases and following surgical procedures. Moreover, SAA has proven useful for detection of some subclinical pathologies that can disturb training and competing in equine athletes. Increasing availability of diagnostic tests for both laboratory and field use adds to SAA's applicability as a reliable indicator of horses’ health status. This review article presents the current information on changes in SAA concentrations in the blood of healthy and diseased horses, focussing on clinical application of this biomarker.

Lower plasma trans-4-hydroxyproline and methionine sulfoxide levels are associated with insulin dysregulation in horses

BACKGROUND

Insulin dysregulation in horses is a metabolic condition defined by high insulin concentrations in the blood and peripheral insulin resistance. This hyperinsulinemia is often associated with severe damage in the hooves, resulting in laminitis. However, we currently lack detailed information regarding the potential involvement of particular metabolic pathways in pathophysiological causes and consequences of equine insulin dysregulation. This study aimed to assess the dynamic metabolic responses given to an oral glucose test (OGT) in insulin-sensitive and insulin-dysregulated horses by a targeted metabolomics approach to identify novel metabolites associated with insulin dysregulation.

RESULTS

Oral glucose testing triggered alterations in serum insulin (26.28 ± 4.20 vs. 422.84 ± 88.86 μIU/mL, p < 0.001) and plasma glucose concentrations (5.00 ± 0.08 vs. 9.43 ± 0.44 mmol/L, p < 0.001) comparing basal and stimulated conditions after 180 min. Metabolome analyses indicated OGT-induced changes in short-chain acylcarnitines (6.00 ± 0.53 vs. 3.99 ± 0.23 μmol/L, p < 0.001), long-chain acylcarnitines (0.13 ± 0.004 vs. 0.11 ± 0.002 μmol/L, p < 0.001) and amino acids (2.18 ± 0.11 vs. 1.87 ± 0.08 μmol/L, p < 0.05). Kynurenine concentrations increased (2.88 ± 0.18 vs. 3.50 ± 0.19 μmol/L, p < 0.01), whereas spermidine concentrations decreased during OGT (0.09 ± 0.004 vs. 0.08 ± 0.002 μmol/L, p < 0.01), indicating proinflammatory conditions after oral glucose load. Insulin dysregulation was associated with lower concentrations of trans-4-hydroxyproline (4.41 ± 0.29 vs. 6.37 ± 0.71 μmol/L, p < 0.05) and methionine sulfoxide (0.40 ± 0.06 vs. 0.87 ± 0.13 μmol/L, p < 0.01; mean ± SEM in insulin-dysregulated vs. insulin-sensitive basal samples, respectively), two metabolites which are related to antioxidant defense mechanisms.

CONCLUSION

Oral glucose application during OGT resulted in profound metabolic and proinflammatory changes in horses. Furthermore, insulin dysregulation was predicted in basal samples (without OGT) by pathways associated with trans-4-hydroxyproline and methionine sulfoxide, suggesting that oxidative stress and oxidant-antioxidant disequilibrium are contributing factors to insulin dysregulation. The present findings provide new hypotheses for future research to better understand the underlying pathophysiology of insulin dysregulation in horses.

Acute phase proteins and antioxidant responses in queens with pyometra

Acute phase proteins (APP) and biomarkers of oxidative status have proved to be clinically useful biomarkers of pyometra in different species. Despite pyometra is considered one of the most important feline reproductive diseases, information about the APP response and the oxidative status in queens with pyometra is lacking. This study aimed to evaluate the APP and the antioxidant responses at diagnosis and in the post-operative period in feline pyometra. Serum concentrations of serum amyloid A (SAA), haptoglobin (Hp), albumin, total serum thiols (Thiol) and total antioxidant capacity determined by different assays, including trolox equivalent antioxidant capacity (TEAC) assessed by two different methodologies (TEAC1 and TEAC2), ferric reducing ability of plasma (FRAP), and cupric reducing antioxidant capacity (CUPRAC), were determined in 23 queens with pyometra at diagnosis and in 13 healthy control queens submitted to elective ovariohysterectomy. The APP and antioxidants were also evaluated in 11 queens of the pyometra group at days two and 10 after surgery. At diagnosis, queens with pyometra had serum concentrations of SAA, Hp, and FRAP significantly higher (P < 0.001, P < 0.001 and P < 0.05, respectively), and of albumin, Thiol, CUPRAC and TEAC2 significantly lower (P < 0.001, P < 0.001, P < 0.001 and P < 0.01, respectively) than controls. Moreover, concentrations of APP and antioxidants were significantly different (with a tendency to return to physiologic levels) at day 10 after surgery than before surgery. Significant associations were found between APP and antioxidants. According to these results, an APP response and the development of oxidative stress were detected in queens with pyometra. In addition, APP and antioxidants tended to return to physiologic values after surgery in the queens that recovered from the disease. Therefore, our results suggest that APP and selected antioxidants, such as Thiol and CUPRAC, could be potentially useful biomarkers in diagnosis and assessment of the post-operative period in feline pyometra.

A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species-A Critical Review

Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.