Vanessa S. Machado

Oxidative stress and inflammatory response biomarkers in dogs with mammary carcinoma

Mammary carcinoma is the most common cancer that affects dogs, and in many cases it leads to death. Thus, given the importance of this disease, to clarify its pathogenesis is an important measure. In this sense, the aim of this study was to investigate the levels of cytokines and nitric oxide (NO), oxidative and antioxidant status, as well as the activity of adenosine deaminase (ADA) and butyrylcholinesterase (BChE) in dogs diagnosed with mammary carcinoma. With this purpose, thirty-three (33) serum samples from female dogs with histopathological diagnosis of mammary carcinoma, without evidence of metastasis, were used (group B). The material was classified based on the degree of malignancy, as follows: subgroup B1 (low-grade malignancy; n=26) and subgroup B2 (high grade of malignancy; n=7). Serum samples from healthy females (group A; n=10) were used as negative control. Our results showed that levels of cytokines (TNF-α, INF-γ, IL-1, and IL-6), NOx (nitrite/nitrate), AOPP (protein oxidation), and FRAP (antioxidant power) were significantly (P<0.05) increased in dogs with mammary carcinoma (group B), when compared with group A. On the other hand, ADA activity was significantly decreased (P<0.05) in both subgroups B1 and B2, when compared with group A. BChE activity, however, was reduced (P<0.05) only in subgroup B2 when compared with group A and subgroup B1. Unlike other variables, NO, AOPP, and IFN-γ were influenced by the degree of tumor malignancy, i.e., their levels were even higher in subgroup B2. Therefore, based on these results, we can conclude that all variables investigated are related to the pathogenesis of this disease, since they were altered in dogs with mammary tumor. Additionally, we suggest that ADA activity had an anti-inflammatory effect on these tumor samples, probably in order to modulate the inflammatory response.

Efficacy of dietary curcumin supplementation as bactericidal for silver catfish against Streptococcus agalactiae

The antibiotics were frequently used for combating bacterial infections in aquaculture, but this treatment causes antibiotic resistance, negative impact on the environment and on health, and accumulation of residual in edible tissues. Several evidences have considered the dietary supplementation with natural products an interesting alternative to antibiotics, as the use of curcumin, a polyphenol with anti-inflammatory, antioxidant and antimicrobial properties. Thus, the aim of this study was to evaluate whether fish fed with a diet containing 150 mg curcumin/kg feed is able to enhance the resistance of silver catfish to Streptococcus agalactiae infection. Our results demonstrated that curcumin dietary supplement exerts potent bactericidal action against S. agalactiae, presenting 100% of therapeutic efficacy when compared to infected and non-supplemented animals. Also, the treatment prevented the occurrence of clinical signs of disease, as erratic swimming, corneal opacity, skin lesions in the fin and tail, and loss of appetite. In summary, curcumin can be a promising dietary supplement for improving disease resistance.

Risk factors for Toxoplasma gondii in sheep of southern Brazil

Toxoplasma gondii is responsible for reproductive failure in sheep, and it is considered a zoonotic parasite. Therefore, the aim of this study was to evaluate the prevalence of toxoplasmosis and its risk factors at the farm level. For that, 314 sheep from 18 farms of 7 municipalities of the West part of Santa Catarina State, Southern Brazil were used. To identify possible risk factors associated to the disease, a survey was applied to farmers with questions regarding farm characteristics, type of management, and history of animal reproductive problems. Out of 314 sera samples, 118 (37%, CI 95% 32.3–43.3) were positives for T. gondii. Multivariate analyses showed that allowing cats to have access to sheep feed was significantly associated to toxoplasmosis, with an odds ratio of 2.42. Similarly, keeping cats in the farm increased 1.67 times the chances of T. gondii infection by sheep. Therefore, we concluded that sheep infection by T. gondii in the West of Santa Catarina state is distributed very similarly to other regions of Brazil, and the presence of cats in the property is strongly correlated to the occurrence of the disease.