Myoepithelial cells and extracellular matrix in the cytologic differentiation of canine mammary tumors

BACKGROUND

Mammary neoplasms are common tumors in intact female dogs. Fine-needle aspiration cytology (FNAC) is a valuable diagnostic tool and has gained some credibility in the diagnosis of mammary tumors in dogs. Prompt classification of canine mammary tumors using cytology would enhance feasibility as a prognostic tool and guide clinical and surgical management.

OBJECTIVES

We aimed to examine background elements to differentiate mammary tumors using FNAC. We proposed to distinguish simple from complex and mixed tumors by identifying myoepithelial (ME) cells and different types of extracellular matrix. Additionally, we determined the accuracy of FNAC to differentiate benign from malignant tumors.

METHODS

One hundred and one mammary tumors from female dogs were included in this study. We compared FNAC using histopathology as the gold standard. Cellular and background components were evaluated and identified. The cytologic accuracy, sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) for diagnosing malignancy were determined, excluding inadequate samples.

RESULTS

The cytologic-histologic agreement was 92.5% for simple carcinomas, 57.9% for complex-type carcinomas, 57.1% for mixed-type carcinomas, 27.3% for carcinosarcomas, and 100% for osteosarcomas. Myoepithelial cells were successfully identified using FNAC. Myxoid and chondroid/osteoid matrix were satisfactorily recognized. Cytologic accuracy, Se, Sp, PPV, and NPV for diagnosing malignancy were 99%, 100%, 83%, 99%, and 100%, respectively.

CONCLUSIONS

Chondroid/osteoid matrix was noted in mixed tumors but not in complex tumors. Myxoid matrix, often associated with ME cells, was noted in complex and mixed tumors. Mesenchymal cells were differentiated from ME cells, allowing the distinction of simple carcinomas with scirrhous reaction from complex and mixed tumors.

Copper oxide and closantel prevent alterations in hepatic energetic metabolism and reduce inflammation in Haemonchus contortus infection

The aims of this study were to evaluate if the use of copper oxide wire particles, isolated or in association with closantel, in lambs infected with Haemonchus contortus enhances the anthelmintic efficacy of closantel, as well as to evaluate the effects of treatment in hepatic energy metabolism, inflammatory markers and hematological and biochemical tests. The lambs were randomly divided into five groups (6 animals each), as follows: uninfected animals (Control); animals infected with H. contortus (HC); infected and treated with closantel (HC + CL); infected and treated with copper oxide wire particles (HC + Cu); and infected and treated with closantel plus copper oxide wire particles (HC + CL + Cu). The animals of infected groups were infected orally with H. contortus (5,000 L3 -larvae) and on day 14 post infection (p.i) the treatments were initiated. The egg per gram of feces (EPG), butyrylcholinesterase (BuChE), myeloperoxidase (MPO), adenylate kinase (AK) and pyruvate kinase (PK) activities and hematological and biochemical tests were evaluated. Treatments with copper oxide (isolated and associated) were able to reduce the EPG count on days 28, 35, 42 and 49 p.i when compared to HC group, while closantel was able to reduce EPG only from day 35 p.i. Moreover, treatment with closantel (isolated or associated) was able to prevent the inhibition of hepatic AK and PK activities caused by H. contortus infection, which may contribute to efficient intracellular energetic communication in order to maintain the balance between cellular ATP consumption and production. Butyrylcholinesterase and MPO activities were higher in infected lambs compared to uninfected, while treated groups showed lower enzymatic activity compared to the group HC. The use of all therapeutic protocols was able to reduce the EPG count. Based on these evidences, the use of copper oxide plus closantel may be considered an alternative to treat lambs infected by H. contortus.

Neuroprotective effects of quercetin on memory and anxiogenic-like behavior in diabetic rats: Role of ectonucleotidases and acetylcholinesterase activities

The present study investigated the protective effect of quercetin (Querc) on memory, anxiety-like behavior and impairment of ectonucleotidases and acetylcholinesterase (AChE) activities in brain of streptozotocin-induced diabetic rats (STZ-diabetes). The type 1 diabetes mellitus was induced by an intraperitoneal injection of 70mg/kg of streptozotocin (STZ), diluted in 0.1M sodium-citrate buffer (pH 4.5). Querc was dissolved in 25% ethanol and administered by gavage at the doses of 5, 25 and 50mg/kg once a day during 40days. The animals were distributed in eight groups of ten animals as follows: vehicle, Querc 5mg/kg, Querc 25mg/kg, Querc 50mg/kg, diabetes, diabetes plus Querc 5mg/kg, diabetes plus Querc 25mg/kg and diabetes plus Querc 50mg/kg. Querc was able to prevent the impairment of memory and the anxiogenic-like behavior induced by STZ-diabetes. In addition, Querc prevents the decrease in the NTPDase and increase in the adenosine deaminase (ADA) activities in SN from cerebral cortex of STZ-diabetes. STZ-diabetes increased the AChE activity in SN from cerebral cortex and hippocampus. Querc 50mg/kg was more effective to prevent the increase in AChE activity in the brain of STZ-diabetes. Querc also prevented an increase in the malondialdehyde levels in all the brain structures. In conclusion, the present findings showed that Querc could prevent the impairment of the enzymes that regulate the purinergic and cholinergic extracellular signaling and improve the memory and anxiety-like behavior induced by STZ-diabetes.

Cholinesterases as markers of the inflammatory process associated oxidative stress in cattle infected by Babesia bigemina

The objective of this study was to assess the influence of an asymptomatic experimental infection by Babesia bigemina on cholinesterase's as markers of the inflammatory process and biomarkers of oxidative imbalance. For this purpose, eight naive animals were used, as follows: four as controls or uninfected; and four infected with an attenuated strain of B. bigemina. Blood samples were collected on days 0, 7 and 11 post-inoculation (PI). Parasitemia was determined by blood smear evaluation, showing that the infection by B. bigemina resulted in mean 0.725 and 0.025% on day 7 and 11 PI, respectively, as well as mild anemia. The activities of acetylcholinesterase, butyrylcholinesterase and catalase were lower, while levels of thiobarbituric acid reactive substances and superoxide dismutase activity were higher in infected animals, when compared with the control group. This attenuated strain of B. bigemina induced an oxidative stress condition, as well as it reduces the cholinesterasés activity in infected and asymptomatic cattle. Therefore, this decrease of cholinesterase in infection by B. bigemina purpose is to inhibit inflammation, for thereby increasing acetylcholine levels, potent anti-inflammatory molecules.

Influence of experimental Anaplasma marginale infection and splenectomy on NTPDase and 5'nucleotidase activities in platelets of cattle

The objective of this paper was to evaluate NTPDase and 5'-nucleotidase activities in platelets of bovine with and without spleen and infected by Anaplasma marginale. Our results demonstrate that infection along with splenectomy is able of inducing a profile of cellular protection, which showed an increase in the degradation of the nucleotides ATP and ADP by NTPDase, in addition to AMP by 5'nucleotidase to form the nucleoside adenosine in platelets, i.e., the enzymatic activities of platelets were increased in splenectomized animals when compared to non-splenectomized group. It notes that adenosine is a molecule with anti-inflammatory function. But this profile is related to a deficiency in immune signaling triggered by nucleotide ATP, which may be related to the increase in bacteremia and disability in combating the parasite in splenectomized host.

Blood gas analyses and other components involved in the acid-base metabolism of rats infected by Trypanosoma evansi

The aim of this study was to investigate the effects of Trypanosoma evansi infections on arterial blood gases of experimentally infected rats. Two groups with eight animals each were used; group A (uninfected) and group B (infected). Infected animals were daily monitored through blood smears that showed high parasitemia with 30 trypanosomes per field (1000×) on average, 5 days post-infection (PI). Arterial blood was collected at 5 days PI for blood gas analysis using an automated method based on dry-chemistry. Hydrogen potential (pH), partial oxygen pressure (pO2), oxygen saturation (sO2), sodium (Na), ionic calcium (Ca ionic), chlorides (Cl), partial dioxide carbon pressure (pCO2), base excess (BE), base excess in the extracellular fluid (BEecf), bicarbonate (cHCO3), potassium (K), lactate, and blood total dioxide the carbon (tCO2) were evaluated. The levels of pH, pCO2, BE, BEecf, cHCO3, and tCO2 were significantly decreased (P < 0.05) in group B compared to group A. Additionally, the same group showed increases in Cl and lactate levels when compared to uninfected group. Therefore, it is possible to state that the infection caused by T. evansi led to alterations in the acid-base status, findings that are correlated to metabolic acidosis.

Hypercholesterolemia and Ecto-enzymes of Purinergic System: Effects of Paullinia cupana

Hypercholesterolemia is a metabolic disorder characterized by high levels of low-density lipoprotein and blood cholesterol, causing inflammatory lesion. Purinergic signaling modulates the inflammatory and immune responses through adenine nucleotides and nucleoside. Guaraná has hypocholesterolemic and antiinflammatory properties. Considering that there are few studies demonstrating the effects of guaraná powder on the metabolism of adenine nucleotides, we investigated its effects on the activity of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) and ecto-adenosine deaminase activity in lymphocytes of rats with diet-induced hypercholesterolemia. The rats were divided into hypercholesterolemic and normal diet groups. Each group was subdivided by treatment: saline, guaraná powder 12.5, 25, or 50 mg/kg/day and caffeine concentration equivalent to highest dose of guaraná, fed orally for 30 days. An increase in adenosine triphosphate hydrolysis was observed in the lymphocytes of rats with hypercholesterolemia and treated with 25 or 50 mg/kg/day when compared with the other groups. The hypercholesterolemic group treated with the highest concentration of guaraná powder showed decreased ecto-adenosine deaminase activity compared with the normal diet groups. Guaraná was able to reduce the total cholesterol and low-density lipoprotein cholesterol to basal levels in hypercholesterolemic rats. High concentrations of guaraná associated with a hypercholesterolemic diet are likely to have contributed to the reduction of the inflammatory process.

Cholinesterase of rats experimentally infected by Cryptococcus neoformans: Relationship between inflammatory response and pathological findings

The aim of this study was to assess the role of the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) as biomarkers of inflammation and tissue injury on rats experimentally infected by Cryptococcus neoformans. For this purpose, 20 male rats were divided into two groups: 10 animals representing the uninfected control group (Group A) and 10 C. neoformans var. grubii infected animals (Group B). Blood and brain samples were collected on days 10 (A10 and B10), and 30 (A30 and B30) post-infection (PI) for hematological analyses; AChE (in lymphocytes and brain) and seric BChE activity; interleukins (IL-1, IL-6, and IL-10); nitrite/nitrate (NOx) levels; and markers of protein oxidation (AOPP) and lipid peroxidation (TBARS). As a result, when animals of Group A were compared to animals of Group B, it was observed leukocytosis (P<0.05) on day 10 PI; AChE activity increase (P<0.05) in lymphocytes (day 30 PI) and in brain (days 10 and 30 PI); BChE activity decrease (P<0.05) on day 10 PI; IL-1 and IL-6 increase (P<0.01) in both periods, while IL-10 had reduced levels (P<0.01) in the same periods; NOx levels increased (P<0.05) significantly on days 10 and 30 PI, while AOPP and TBARS levels increased significantly on day 30 PI; as well as pneumonia on infected rats. Therefore, based on the results obtained, it was possible to conclude that AChE and BChE behavior lead to a proinflammatory reaction evidenced by the enhancement of IL-1, IL-6, and NOx throughout the experiment associated with reduction on IL-10 levels, and cellular damage.

Oxidative stress in dogs with multicentric lymphoma: Effect of chemotherapy on oxidative and antioxidant biomarkers

INTRODUCTION

Lymphoma is one of the most common types of cancer in dogs, characterized by the proliferation of lymphoid cells. The treatment of this type of cancer is usually based on drugs with high toxicity, which can cause severe side effects.

OBJECTIVES

Therefore, the aim of this study was to measure the levels of advanced oxidation protein products (AOPP), thiobarbituric acid reactive substances (TBARS), and ferric reducing antioxidant power (FRAP) in dogs with multicentric lymphoma before and after chemotherapy.

METHODS

For this purpose, serum samples of 25 dogs diagnosed with multicentric lymphoma and 15 healthy dogs were used. The animals were exposed to CHOP chemotherapy (cyclophosphamide, vincristine, doxorubicin, and prednisone) and serum samples were collected 5 weeks after treatment.

RESULTS

High levels of TBARS, AOPP, and FRAP were observed in sera of dogs with multicentric lymphoma when compared to healthy dogs (P < 0.01), and even higher levels (TBARS and AOPP) were found after chemotherapy i.e. treatment exacerbated the oxidative stress levels. On the other hand, FRAP levels did not differ statistically between animals with lymphoma before and after treatment (P > 0.05). Exacerbated oxidative stress was observed in dogs with multicentric lymphoma Group II (Stage IV-V: involvement of lymph nodes and organs) compared to those in Group I (Stage I-III: only affected lymph nodes) of the disease, as well as the dogs with clinical signs and T immunophenotype. Another important result was observed after chemotherapy, where FRAP levels were higher in dogs that showed complete disease remission compared to animals with progressive disease.

CONCLUSIONS

Therefore, dogs with lymphoma showed protein oxidation and lipid peroxidation, as well as increased total antioxidants before and after chemotherapy compared to the control group.

Experimental infection by Trypanosoma evansi in sheep: Occurrence of transplacental transmission and mice infection by parasite present in the colostrum and milk of infected ewes

The aims of this study were to evaluate vertical transmission of Trypanosoma evansi in sheep experimentally infected, in addition to the mammary transmission by colostrum or milk of these infected sheep to mice. Three pregnant sheep were used: one uninfected, four months pregnant (Sheep A); and two (Sheep B and C) infected intravenously by T. evansi trypomastigotes (4.6×10(6) per animal) on the third (Sheep C) and fourth (Sheep B) month of pregnancy. Both infected sheep developed low and oscillating parasitemia measured by blood smears. Hemogram was performed at seven day intervals, showing anemia, leukocytosis, and lymphocytosis on sheep B and C. Three sheep had twins, where sheep A delivered healthy lambs and both infected sheep had delivered at least one stillborn. Additionally, lambs from sheep B and C died 24 and 72 h post-partum, respectively. Before colostrum intake, four lambs from infected sheep were positives for T. evansi according to blood smear evaluation, serology (CATT/T. evansi), and PCR. Sheep colostrum and milk samples collected from the first four days post-partum were positives for T. evansi on PCR, and these samples were able to infect seven mice (out of 10) orally (n=4/5) and intraperitoneally (n=3/5). Therefore, we conclude that the vertical transmission of T. evansi occurs in pregnant sheep, in addition to a strong possibility of the transmission by colostrum and milk.

Effect of the treatment with Achyrocline satureioides (free and nanocapsules essential oil) and diminazene aceturate on hematological and biochemical parameters in rats infected by Trypanosoma evansi

This study aimed to verify the effect of the treatment with A. satureioides essential oil (free and nanoencapsulated forms) and diminazene aceturate on hematological and biochemical variables in rats infected by Trypanosoma evansi. The 56 rats were divided into seven groups with eight rats each. Groups A, C and D were composed by uninfected animals, and groups B, E, F and G were formed by infected rats with T. evansi. Rats from groups A and B were used as negative and positive control, respectively. Rats from the groups C and E were treated with A. satureioides essential oil, and groups D and F were treated with A. satureioides nanoencapsulated essential oil. Groups C, D, E and F received one dose of oil (1.5 mL kg(-1)) during five consecutive days orally. Group G was treated with diminazene aceturate (D.A.) in therapeutic dose (3.5 mg kg(-1)) in an only dose. The blood samples were collected on day 5 PI for analyses of hematological (erythrocytes and leukocytes count, hemoglobin concentration, hematocrit, mean corpuscular and mean corpuscular hemoglobin concentration) and biochemical (glucose, triglycerides, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin, urea and creatinine) variables. A. satureioides administered was able to maintain low parasitemia, mainly the nanoencapsulated form, on 5 days post infection. On the infected animals with T. evansi treated with A. satureioides essential oil (free and nanocapsules) the number of total leucocytes, lymphocytes and monocytes present was similar to uninfected rats, and different from infected and not-treated animals (leukocytosis). Treatment with A. satureioides in free form elevated levels of ALT and AST, demonstrating liver damage; however, treatment with nanoencapsulated form did not cause elevation of these enzymes. Finally, treatments inhibited the increase in creatinine levels caused by infection for T. evansi. In summary, the nanoencapsulated form showed better activity on the trypanosome; it did not cause liver toxicity and prevented renal damage.

Effects of iron supplementation on blood adenine deaminase activity and oxidative stress in Trypanosoma evansi infection of rats

The aim of this study was to assess the effects of iron supplementation on oxidative stress and on the activity of the adenosine deaminase (ADA) in rats experimentally infected by Trypanosoma evansi. For this purpose, 20 rats were divided into four experimental groups with five animals each as follows: groups A and B were composed by healthy animals, while animals from groups C and D were infected by T. evansi. Additionally, groups B and D received two subcutaneous doses of iron (60 mg kg(-1)) within an interval of 5 days. Blood samples were drawn on day 8 post infection in order to assess hematological and biochemical variables. Among the main results are: (1) animals from group C showed reduced erythrogram (with tendency to anemia); however the same results were not observed for group D; this might be a direct effect of free iron on trypanosomes which helped to reduce the parasitemia and the damage to erythrocytes caused by the infection; (2) iron supplementation was able to reduce NOx levels by inhibiting iNOS, and thus, providing an antioxidant action and, indirectly, reducing the ALT levels in groups Band D; (3) increase FRAP levels in group D; (4) reduce ADA activity in serum and erythrocytes in group C; however, this supplementation (5) increased the protein oxidation in groups B and D, as well as group C (positive control). Therefore, iron showed antioxidant and oxidant effects on animals that received supplementation; and it maintained the activity of E-ADA stable in infected/supplemented animals.

Influence of infection by Toxoplasma gondii on purine levels and E-ADA activity in the brain of mice experimentally infected mice

The aim of this study was to assess the purine levels and E-ADA activity in the brain of mice (BALB/c) experimentally infected with Toxoplasma gondii. In experiment I (n=24) the mice were infected with RH strain of T. gondii, while in experiment II (n=36) they were infected with strain ME-49 of T. gondii. Our results showed that, for RH strain (acute phase), an increase in both periods in the levels of ATP, ADP, AMP, adenosine, hypoxanthine, xanthine (only on day 6 PI) and uric acid (only on day 6 PI). By the other hand, the RH strain led, on days 4 and 6 PI, to a reduction in the concentration of inosine. ME-49, a cystogenic strain, showed some differences in acute and chronic phase, since on day 6 PI the levels of ATP and ADP were increased, while on day 30 these same nucleotides were reduced. On day 60 PI, ME-49 induced a reduction in the levels of ATP, ADP, AMP, adenosine, inosine and xanthine, while uric acid was increased. A decrease of E-ADA activity was observed in brain on days 4 and 6 PI (RH), and 30 PI (ME-49); however on day 60 PI E-ADA activity was increased for infection by ME-49 strain. Therefore, it was possible to conclude that infection with T. gondii changes the purine levels and the activity of E-ADA in brain, which may be associated with neurological signs commonly observed in this disease.

Effect of tea tree oil (Melaleuca alternifolia) on the longevity and immune response of rats infected by Trypanosoma evansi

This study aimed to evaluate the effect of tea tree oil (TTO - Melaleuca alternifolia) on hepatic and renal functions, and the immune response of rats infected by Trypanosoma evansi. A pilot study has shown that rats treated with TTO orally (1 ml kg(-1)) had increased survival rate without curative effect. In order to verify if increased longevity was related to a better immune response against T. evansi when using tea tree oil, a second experiment was conducted. Thus, twenty-four rats were divided into four groups. The groups A and B were composed of uninfected animals, and the groups C and D had rats experimentally infected by T. evansi. Animals from the groups B and D were treated orally with TTO (1 ml kg(-1)) for three days. Blood samples were collected to verify humoral response analysis for immunoglobulins (IgA, IgM, IgE, and IgG) and cytokines (TNF-α, INF-γ, IL-1, IL-6, IL-4, and IL-10) at days 0, 3, 5 and 15 post-infection (PI). TTO treatment caused changes in the immunoglobulins and cytokines profile, as well as the course of T. evansi infection in rats. It was found that the TTO was not toxic, i.e., hepatic and renal functions were not affected. Therefore, it is possible to conclude that TTO influences the levels of inflammatory mediators and has trypanocidal effect, increasing life expectancy of rats infected by T. evansi.

Neospora caninum and Toxoplasma gondii: relationship between hepatic lesions, cytological and biochemical analysis of the cavitary liquid during the acute phase of the diseases in experimental models

The objective of this study was to evaluate the pathogenesis of ascites in mice infected with Toxoplasma gondii and gerbils infected with Neospora caninum during the acute phase disease. For that, 12 gerbils [Experiment I: not infected/control (n=6) and infected (n=6)] and 12 mice [Experiment II: control (n=6) and infected (n=6)] were used. Infected gerbils and mice showed marked ascites on days 5-7 post-infection (PI), while the not-infected animals had not ascites. Peritoneal liquid was collected from the all mice with uninfected animals receiving 1.5mL of saline solution into their abdominal cavity, allowing the recovery of cavity liquid. As a result, it was possible to observe differences in physics, chemistry and cytological analysis of the fluid cavity of animals infected with N. caninum and T. gondii, when they were compared with uninfected animals, as well as between animals experimentally infected. Additionally both, N. caninum and T gondii, caused an increase in the levels of nitric oxide (NOx-nitrate/nitrite), protein oxidation (AOPP) and lipid peroxidation (TBARS), while serum total protein and albumin were reduced in infected gerbils and mice. Gerbils infected with N. caninum showed multiple large cells with multilobulated nucleus, lytic necrosis and abundant amount of eosinophilic cytoplasm into the hepatic parenchyma. By the other hand, mice infected with T. gondii developed myriad foci of lytic necrosis combined with tachyzoites and cysts containing bradyzoites in liver. Both experimental models for N. caninum and T. gondii showed inflammatory foci and tachyzoites the peritoneum, which could be a major cause of ascites. Toxoplasmosis and neosporosis were able to cause clinical signs in experimental models with similar alterations in peritoneal fluid; however the toxoplasmosis histological changes were much more evident. Therefore, the pathogenesis of ascites appears to be directly related to liver damage, which strongly suggests alteration in the normal production of proteins as observed in this study, along with peritonitis.

Oxidative stress in brain tissue of gerbils experimentally infected with Neospora caninum

Neospora caninum infection is generally latent and asymptomatic, and it results in the formation of dormant encysted bradyzoites that remain in the brain and other tissues of infected animals for life, causing major economic and pathological problems. The aim of this study was to assess the relation between infection by N. caninum and its damage to brain tissue through the evaluation of biomarkers of oxidative stress during the acute and chronic phases of the disease. Sixteen gerbil (Meriones unguiculatus) were divided into 3 groups: Group A (n = 6) was composed of healthy animals, while group B (n = 5) was infected with 0.1 ml containing 2.5 × 10(6) tachyzoites of N. caninum in order to achieve the acute phase, and, finally, group C (n = 5) was infected with a lower dose (0.1 ml containing 5 × 10(4)) of N. caninum tachyzoites in order to produce the chronic phase of the disease. All evaluations were performed on brain tissue on days 7 and 30 postinfection (PI), with assessment of the levels of several biomarkers of oxidative stress, including nitrate/nitrite (NOx), lipid peroxidation (TBARS), protein oxidation (AOPP), and activity of glutathione reductase (GR). Brain levels of TBARS and AOPP statistically differed (P < 0.05) among the 3 groups when compared to the control group, since both biomarkers showed reduced levels on day 7 PI, and increased levels on day 30 PI. Brain activity of GR increased significantly in animals from group C when compared to groups A and B. On day 7 PI, histological lesions and parasites in the brain were not observed, whereas in the chronic phase group, the infected gerbils (day 30 PI) showed areas of inflammatory infiltrate, accompanied by the presence of the parasite in the brain. These results suggest that the oxidative stress occurs at both time points, but the patterns of the biomarkers are different.

Oxidative stress parameters in blood, liver, and kidney of diabetic rats treated with curcumin and/or insulin

This study evaluated the effects of curcumin and/or insulin on antioxidant enzyme activity in blood, liver, and kidney, as well as on lipid peroxidation and delta aminolevulinic dehydratase (δ-ALA-D) activity, and a histopathological analysis of streptozotocin-induced diabetic rats. The animals were divided into six groups (n = 6): control/saline (C); control/curcumin (CCur); diabetic/saline (D); diabetic/insulin (DIns); diabetic/curcumin (DCur); and diabetic/insulin/curcumin (DInsCur). After 30 days of treatment with curcumin and/or insulin, the animals were sacrificed and the liver, kidney, and serum were used for experimental determinations. Results of histopathological analysis showed that the treatment with insulin ameliorate renal and hepatic lesions from both DIns and DInsCur groups. TBARS levels were significantly increased in serum, liver, and kidney in D group and the administration of curcumin and insulin prevented this increase in DIns and DCur groups. The activities of catalase (CAT), superoxide dismutase, and δ-ALA-D presented a significant decrease in the liver and kidney D group when compared to C group (P < 0.05). The animals treated with curcumin and insulin presented an increase of CAT activity, revealing a positive interaction between both substances. The treatments with curcumin or insulin prevented oxidative stress in blood, through modulation of enzymatic antioxidant defenses. These findings contributed to the comprehension that antioxidants from medicinal plants could be used as adjuvant in the treatment of this endocrinopathy and not as single therapy.

E-ADA activity in erythrocytes of lambs experimentally infected with Haemonchus contortus and its possible functional correlations with anemia

The aim of this study was to evaluate the ecto-adenosine deaminase (E-ADA) activity in erythrocytes of lambs experimentally infected with Haemonchus contortus, correlating it with the degrees of anemia of the experimental animals. A total of 14 healthy lambs, with negative fecal exam for parasites, were to carry out the present study. They were divided into two groups, composed by seven animals: Group A represented the healthy animals (uninfected), while in Group B the animals were infected with 15,000 larvae of H. contortus. Blood was drawn on the days 15, 45 and 75 post-infection (PI) in order to perform the hematological analysis, as well as the mensuration of E-ADA activity in erythrocytes. Parasitological stool exam were performed on the same days mentioned above to follow up the evolution of the infection, as well to determine the number of eggs per gram of feces (EPG). On day 15PI, the animals presented negative EPG and there was not significant (P>0.05) difference between groups in relation to E-ADA activity and hematologic parameters. Animals in Group B had positive EPG for helminths on days 45 and 75 PI, accompanied by varying degrees of anemia, when compared to Group A. At the same periods E-ADA activity was significantly (P<0.05) increased in the erythrocytes of animals of Group B when compared with the not-infected ones. Statistically, there was a negative correlation (P<0.01) between activity E-ADA in erythrocytes and hematocrit on days 45 (r = -0.76) and 75 (r = -0.85)PI. Based on these results and in the scientific literature, it is possible to conclude that the E-ADA may participate on mechanisms related with the pathogenesis and host response against anemia caused by H. contortus.

Adenosine levels in serum and adenosine deaminase activity in blood cells of dogs infected by Rangelia vitalii

Ecto-adenosinedeaminase (E-ADA) plays an important role in the production and differentiation of blood cells as well as in the control of extracellular adenosine levels. Infectious diseases can influence the synthesis of new cells or cause cell destruction, as occurs in canine rangeliosis, which results in anemia, thrombocytopenia, leukocytosis, and/or leukopenia. Thus, this study aimed to evaluate E-ADA activity in sera, erythrocytes, lymphocytes, and adenosine levels in sera samples of dogs infected by Rangelia vitalii. Twelve animals were divided into 2 groups: noninfected (n = 5) and infected by R. vitalii (n = 7). Animals were infected with 2 ml of blood containing the parasite, and parasitemia was estimated daily for 20 days by microscopic examination of peripheral blood smears. Blood collection was performed on days 0, 10, and 20 post-infection (PI) in order to evaluate the evolution of the disease. The blood collected was used to assess the activity of E-ADA. We observed an increase of E-ADA activity in sera (day 20 PI) and erythrocytes (days 10 and 20 PI) in the infected group (P < 0.05). E-ADA activity in lymphocytes was decreased on day 10, when the parasitemia was high, and increased after 20 days, when the number of circulating parasites was low. HPLC measured adenosine levels in the serum and found a reduction on days 10 and 20 PI. In conclusion, our results showed that E-ADA activity was altered in sera, lymphocytes, and erythrocytes of dogs experimentally infected by R. vitalii as well as the serum concentration of adenosine. These alterations may contribute to the pathogenesis of anemia and immune response in infected dogs.

Antioxidant and anti-inflammatory effects of quercetin in functional and morphological alterations in streptozotocin-induced diabetic rats

The aim of this study was to investigate functional and morphological alterations caused by oxidative stress in streptozotocin (STZ)-induced diabetic rats and to evaluate the antioxidant effect of quercetin (QUE) in this disease. One hundred and thirty male Wistar rats, it were randomly distributed in 10 different experimental groups, with ten animals per group: Control Saline (CS), Control Ethanol (CE), Control QUE 5mg/kg (CQ5), Control QUE 25mg/kg (CQ25), Control QUE 50mg/kg (CQ50), Diabetic Saline (DS), Diabetic Ethanol (DE), Diabetic QUE 5mg/kg (DQ5), Diabetic QUE25 mg/kg (DQ25), Diabetic QUE 50mg/kg (DQ50). Therefore, hyperglycemia is directly involved in oxidative stress production, as well as in functional and morphological alterations caused by the excess of free radicals. QUE, specially at the dosage of 50mg/kg, can act as an antioxidant and anti-inflammatory agent, becoming a promising adjuvant in the treatment of diabetes mellitus.

Cholinesterase as inflammatory markers in a experimental infection by Trypanosoma evansi in rabbits

The aim of this study is to evaluate the role of cholinesterases as an inflammatory marker in acute and chronic infection by Trypanosoma evansi in rabbits experimentally infected. Twelve adult female New Zealand rabbits were used and divided into two groups with 6 animals each: control group (rabbits 1-6) and infected group (rabbits 7-12). Infected group received intraperitoneally 0.5 mL of blood from a rat containing 108 parasites per animal. Blood samples used for cholinesterases evaluation were collected on days 0, 2, 7, 12, 27, 42, 57, 87, 102 and 118 days post-inoculation (PI). Increased activity (P<0.05) of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) were observed in the blood on days 7 and 27, respectively and no differences were observed in cholinesterase activity in other periods. No significant difference in AChE activity (P>0.05) was observed in the encephalic structures. The increased activities of AChE and BChE probably have a pro-inflammatory purpose, attempting to reduce the concentration of acetylcholine, a neurotransmitter which has an anti-inflammatory property. Therefore, cholinesterase may be inflammatory markers in infection with T. evansi in rabbits.

Biochemistry detection of acetylcholinesterase activity in Trypanosoma evansi and possible functional correlations

Several chemical and immunohistochemical techniques can be used for the detection of acetylcholinesterase (AChE) activity. In this experiment we aimed to detect AChE activity in Trypanosoma evansi. For this, the parasites were isolated from the blood of experimentally infected rats using a DEA-cellulose column. Enzymatic activity was determined in trypomastigote forms at 0, 0.2, 0.4, 0.8 and 1.2 mg/mL of protein concentrations by a standard biochemical protocol. At all concentrations tested, the study showed that T. evansi expresses the enzyme AChE and its activity was proportional to the concentration of protein, ranging between 0.64 and 2.70 μmol of AcSCh/h. Therefore, we concluded that it is possible to biochemically detect AChE in T. evansi, an enzyme that may be associated with vital functions of the parasite and also can be related to chemotherapy treatments, as further discussed in this article.

Activities of ectonucleotidases and adenosine deaminase in platelets of dogs experimentally infected with Rangelia vitalii

Rangeliosis is a disease which affects dogs in Brazil, caused by a piroplasm known as Rangelia vitalii. This disease causes a lot of clinico-pathological features, including the coagulation disorders associated with bleeding. The cause of these changes has not yet been determined. Considering the association of purinergic system and hemostasis this study aimed to evaluate the activity of enzymes that hydrolyze ATP, ADP and AMP; and deamination of adenosine in platelets from dogs experimentally infected with R. vitalii. For this study, 12 healthy young dogs (females) were used, separated in two groups. Group A (n=5) were uninfected controls, and group B were experimentally infected with R. vitalii (n=7). After being inoculated with R. vitalii-infected blood, animals were monitored by blood smear examinations, which showed intra-erythrocytic forms of the parasite after five days post-inoculation (PI). Blood samples were collected to quantitate and separate platelets (Day 0, 12 and 21 PI) and to measure the enzymatic activities (Day 12 and 21 PI). The activity of NTPDase, 5'-nucleotidase and adenosine deaminase (ADA) was measured in platelets. A reduction (P<0.01) in the number of platelets was observed in R. vitalii-infected blood at Days 12 and 21 PI. At Day 12 PI, a reduction (P<0.01) in the hydrolysis of ATP, ADP and AMP, and deamination of adenosine was observed in dogs infected with R. vitalii. At Day 21 PI the ADA activity remained decreased, unlike the activity of NTPDase which increased (P<0.05). Based on these results we can conclude that ATP, ADP and AMP hydrolysis and adenosine deamination were altered in platelets of R. vitalii-infected dogs. Considering the importance of the purinergic system in hemostasis, it is believed that those changes contribute to the coagulation disorders and bleeding observed in R. vitalii-infected dogs and discussed in this manuscript.

Influence of Rangelia vitalii (Apicomplexa: Piroplasmorida) on copper, iron, and zinc bloodstream levels in experimentally infected dogs

The aim of this study was to evaluate the concentrations of copper, iron, and zinc in blood serum of dogs experimentally infected with Rangelia vitalii (n  =  7) compared with uninfected controls (n  =  5). Serum metal levels were determined in blood samples collected at days 0, 10, 15, and 20 post-infection (PI). Inductively coupled plasma optical emission spectrometry was used to measure the levels of copper, iron, and zinc. Significant differences (P < 0.05) were observed among groups PI. Increased levels of copper and decreased levels of iron and zinc were observed in the infected animals. The infection by R. vitalii may, therefore, alter the serum metal levels, resulting in metabolic disorders in dogs. These metals are directly involved in many enzymatic systems; accordingly, alterations in their blood concentrations may also influence the pathogenesis of disease.

Activity of cholinesterases and adenosine deaminase in blood and serum of rats experimentally infected with Trypanosoma cruzi

This study aimed to evaluate the activity of cholinesterases and adenosine deaminase (ADA) in blood and serum of rats infected with Trypanosoma cruzi. Twelve adult rats were used in the experiment divided into two uniform groups. Rodents from group A (control group) were non-infected and animals from group B served as infected, receiving intraperitoneally 3·3×10(7) trypomastigotes/each. Blood collection was performed at days 60 and 120 post-infection (PI) in order to evaluate the hemogram, blood activity of acetylcholinesterase, and serum butyrylcholinesterase and ADA activities. Hematological parameters did not differ between groups. A significant increase (P<0·05) of acetylcholinesterase activity was observed in blood while butyrylcholinesterase had a significant reduction (P<0·01) in serum of infected rats at days 60 and 120 PI. ADA activity in serum showed an inhibition in infected animals when compared to non-infected at day 120 PI. Based on these results, it is possible to conclude that the activity of cholinesterases and ADA were changed in animals infected with T. cruzi. The possible causes of these alterations will be discussed in this paper.

Cytokines in rats experimentally infected with Trypanosoma evansi

The aim of this study was to measure the levels of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin 1 (IL-1) and interleukin 6 (IL-6) in the serum of rats experimentally infected with Trypanosoma evansi and to correlate these levels with hematological parameters. Initially, 48 rats (group T) were intraperitoneally inoculated with cryopreserved blood containing 1×10(6) trypomastigotes per animal. Twenty-eight animals (group C) were used as negative controls and received 0.2 mL of saline by the same route. The experimental groups were formed according to the time after infection and the degree of parasitemia as follows: four control subgroups (C3, C5, C10 and C20) with seven non-inoculated animals each and four test subgroups (T3, T5, T10 and T20) with 10 animals each inoculated with T. evansi. The blood samples were collected by cardiac puncture at days 3 (C3, T3), 5 (C5, T5), 10 (C10, T10) and 20 (C20, T20) post-infection (PI) to perform the complete blood count and the determination of IFN-γ, TNF-α, IL-1 and IL-6 levels using an ELISA quantitative sandwich. Infected rats showed normocytic normochromic anemia during the experimental period. T. evansi infection in rats caused a serum increase (P<0.01) of IFN-γ, TNF-α, IL-1 and IL-6 levels at days 3, 5, 10 and 20 PI compared to the controls. The multiple linear regressions showed a reduction of 24% in the hematocrit as a consequence of the increased IFN-γ, TNF-α and IL-1. Therefore, we conclude that the infection caused by T. evansi causes an increase in the pro-inflammatory cytokines. These results suggest a synergism among IL-1, TNF-α and IFN-γ contributing to the development of anemia. This increase is associated with the regulation of immune responses against the parasite.

Activities of adenine nucleotide and nucleoside degradation enzymes in platelets of rats infected by Trypanosoma evansi

Nucleotide and nucleoside-degrading enzymes, such as nucleoside triphosphate diphosphohydrose (NTPDase), 5'-nucleotidase and adenosine deaminase (ADA) are present in the surface membranes of platelets, involved in clotting disturbances of Trypanosoma evansi-infected animals. Thus, this study was aimed at evaluating the activities of these enzymes in platelets of rats experimentally infected with T. evansi. Animals were divided into four groups, according to the level of parasitemia. Blood samples were collected on days 3 (group A: at the beginning of parasitemia), 5 (group B: high parasitemia) and 15 (group C: chronic infection), post-infection. Group D (control group) was composed of non-infected animals for platelet count, separation and enzymatic assays. Animals from groups A and B showed marked thrombocytopenia, but platelet count was not affected in chronically infected rats. NTPDase, 5'-nucleotidase and ADA activities decreased (p<0.05) in platelets from rats of groups A and B, when compared to the control group. In group C, only NTPDase and 5'-nucleoside activities decreased (p<0.001). The correlations between platelet count and nucleotide/nucleoside hydrolysis were positive and statistically significant (p<0.05) in groups A and B. Platelet aggregation was decreased in all infected groups, in comparison to the control group (p<0.05). It is concluded that the alterations observed in the activities of NTPDase, 5'-nucleotidase and ADA in platelets of T. evansi-infected animals might be related to thrombocytopenia, that by reducing the number of platelets, there was less release of ATP and ADP. Another possibility being suggested is that changes have occurred in the membrane of these cells, decreasing the expression of these enzymes in the cell membrane.

Relationship between splenic sequestration and thrombocytopenia in Trypanosoma evansi infection in rats

Trypanosoma evansi infections in domestic animals are characterized by anemia and thrombocytopenia. The cause of the platelets decrease is unknown, but researchers suggest that thrombocytopenia may result from damage of the bone marrow, reduced survival of platelets, auto-immune thrombocytopenia, disseminated intravascular coagulation and splenic sequestration. Some of these causes have already been tested by our research group and found to be unrelated. Therefore, this study has the objective of testing the hypothesis that splenic sequestration might be responsible for thrombocytopenia in T. evansi-infected rats. A total of 28 rats assigned to four groups were used in the experiment. Group A rats were splenectomized and infected with T. evansi, group B rats were infected with T. evansi, group C rats were splenectomized, but not infected and group D rats were normal controls. Five days post-infection all rats were anesthetized and blood was collected in order to measure the number of circulating platelets, fibrinogen levels, prothrombin time (PT) and activated partial thromboplastin time (aPTT). The spleens of groups B and D were weighed at necropsy. The infected animals (groups A and B) showed a significant reduction in platelets and increased PT and aPTT when compared to negative control groups (groups C and D). Animals from group A showed increased levels of fibrinogen. The mean weight of spleen differed between group B (2.62g) and group D (0.55g). It was concluded that there is no relationship between thrombocytopenia and splenic sequestration in infection by T. evansi.

Horses naturally infected by Trypanosoma vivax in southern Brazil

In this study, we reported the first outbreak of the infection by Trypanosoma vivax in horses in southern Brazil, a non-endemic region where bovines have only recently been found infected by this trypanosome species. We evaluated 12 horses from a farm in southern Brazil, where four horses displayed pale mucous membranes, fever, weight loss, and swelling of abdomen, prepuce, or vulva. The diagnosis of T. vivax was confirmed in four horses by morphological parameters of trypomastigotes in blood smears and species-specific PCR. All T. vivax-infected animals showed anemia, and most showed increased levels of beta-1, beta-2, and gamma globulins. Horses were treated with diminazene aceturate, but cure was not achieved, and the disease relapsed after therapy. These findings demonstrated that Brazilian T. vivax isolates, which were already reported infecting cattle, buffaloes, goats, and sheep, can be highly pathogenic for horses, causing severe disease and even death of the animals due to the recurrence of the infection.

Biochemical changes in cats infected with Trypanosoma evansi

This study aimed at evaluating biochemical changes of cats (Felis catus) experimentally infected with Trypanosoma evansi. Seven animals were infected with 10(8) blood trypomastigotes per animal and six were used as controls. Blood smears were performed daily for 56 days and the hepatic, renal and muscular parameters in blood serum were evaluated at days 0, 7, 21, 35 and 49. The protozoan was found in the bloodstream 24-48 h post-inoculation (PI) and irregular peaks of parasitemia were observed throughout the experiment. Muscular enzymatic activities (aspartate aminotransferase and creatine kinase) were increased in infected cats compared to controls. Increased concentrations of total proteins and globulins and decreased levels of albumin and albumin/globulin ratio were observed in infected group versus the controls values (P<0.05). No alteration in serum activity of alanine aminotransferase, gamma-glutamyltransferase, creatinine and urea was observed in both groups.