Ambient fine particulate matter exposures and oxidative protein damage in early pregnant women.

The association between oxidative protein damage in early pregnant women and ambient fine particulate matter (PM2.5) is unknown. We estimated the effect of PM2.5 exposures within seven days before blood collection on serum 3-nitrotyrosine (3-NT) and advanced oxidation protein products (AOPP) in 100 women with normal early pregnancy (NEP) and 100 women with clinically recognized early pregnancy loss (CREPL). Temporally-adjusted land use regression model was applied for estimation of maternal daily PM2.5 exposure. Daily nitrogen dioxide (NO2) exposure of each participant was estimated using city-level concentrations of NO2. Single-day lag effect of PM2.5 was analyzed using multivariable linear regression model. Net cumulative effect and distributed lag effect of PM2.5 and NO2 within seven days were analyzed using distributed lag non-linear model. In all 200 subjects, the serum 3-NT were significantly increased with the single-day lag effects (4.72%-8.04% increased at lag 0-2), distributed lag effects (2.32%-3.49% increased at lag 0-2), and cumulative effect within seven days (16.91% increased). The single-day lag effects (7.41%-10.48% increased at lag 0-1), distributed lag effects (3.42%-5.52% increased at lag 0-2), and cumulative effect within seven days (24.51% increased) of PM2.5 significantly increased serum 3-NT in CREPL group but not in NEP group. The distributed lag effects (2.62%-4.54% increased at lag 0-2) and cumulative effect within seven days (20.25% increased) of PM2.5 significantly increased serum AOPP in early pregnant women before the coronavirus disease (COVID-19) pandemic but not after that, similarly to the effects of NO2 exposures. In conclusion, PM2.5 exposures were associated with oxidative stress to protein in pregnant women in the first trimester, especially in CREPL women. Analysis of NO2 exposures suggested that combustion PM2.5 was the crucial PM2.5 component. Wearing masks may be potentially preventive in PM2.5 exposure and its related oxidative protein damage.

Effect of Raw and Roasted Phoenix dactylifera L. Seed Polyphenols Extracts on Suppression of Angiogenesis in Endothelial Cells.

Date seed is a by-product of Phoenix dactylifera L. fruit which is well recognized for its polyphenols content and numerous health-beneficial effects. Due to the increasing interest in natural phytochemicals with antioxidant activities, the present study aimed to extract polyphenols from both raw and roasted date seeds and investigate the anti-angiogenic effect of these two extracts (raw and roasted date seed polyphenols extracts (DSPE) at 25 and 50 µg/mL) using human microvascular endothelial cells (HMVEC). Our results showed that both raw and roasted DSPE suppressed some angiogenesis features in a dose-dependent manner including cell proliferation, migration, and capillary-like structure formation, of which raw DSPE was more potent inhibitor than roasted DSPE. Reduction in reactive oxygen species, as well as enhancement of superoxide dismutase activity occurred using both raw and roasted date seed polyphenols extracts. However, no changes were observed in advanced oxidation protein products versus control. Taken together, our data indicated that raw and roasted DSPE possess antioxidant activity, which suggested their potential use as a source of polyphenols with anti-angiogenic properties. Nevertheless, further studies are required to explore the underlying mechanisms responsible for their anti-angiogenic activities.

Association of Higher Advanced Oxidation Protein Products (AOPPs) Levels in Patients with Diabetic and Hypertensive Nephropathy.

Background and Objectives: Diabetes mellitus (DM) and hypertension (HT) are characterized by cell damage caused by inflammatory and metabolic mechanisms induced by alteration in reduction-oxidative status. Serum advanced oxidation protein products (AOPP) are new markers of protein damage induced by oxidative stress. We evaluated serum levels of AOPP in a cohort of patients with DM and HT, with or without renal complications, compared with a control healthy population. Materials and Methods: The study group comprised of 62 patients with type 2 DM and 56 with HT. The 62 patients affected by DM were further distinguished in 24 subjects without renal impairment, 18 with diabetic nephropathy (DN), 20 with chronic kidney disease (CKD) stage 2-3 secondary to DN. The subgroup of 56 patients with primary HT comprised 26 subjects without renal complications and 30 with CKD (stage 2-3) secondary to HT. Thirty healthy controls, matched for age and sex, were recruited among blood donors. Results: Increased AOPP levels were found in DM patients compared with healthy subjects, although not significantly. This index was higher and more significant in patients with DN and CKD secondary to DN than in DM patients without nephropathy (p < 0.05) or controls (p < 0.0001). Patients with HT and with kidney impairment secondary to HT also had significantly higher AOPP serum levels than controls (p < 0.01 and p < 0.0001, respectively). There were no significant differences in mean AOPP levels among DM and HT patients. Conclusion: Our study showed that oxidative stress was higher in diabetic or hypertensive subjects than in healthy controls and, in particular, it appeared to be more severe in patients with renal complications. We suggest that the assessment of AOPP in diabetic and hypertensive patients may be important to predict the onset of renal failure and to open a new perspective on the adoption of antioxidant molecules to prevent CKD in those settings.

Biomarkers of oxidative stress in saliva in pigs: analytical validation and changes in lactation.

BACKGROUND: Biomarkers of oxidative stress in pigs have been measured in serum/plasma samples. However, blood collection in pigs can be highly stressful to the animals. Saliva is a biological fluid with several advantages in pigs over blood, since it can be easily collected without stress to the animals, being therefore an ideal sample in this species. The objective of this study was the validation of assays for the evaluation of oxidative stress status in saliva of pigs. For this purpose, three assays commonly used to evaluate the total antioxidant capacity (TAC): trolox equivalent antioxidant capacity (TEAC), cupric reducing antioxidant capacity (CUPRAC), and ferric reducing ability of plasma (FRAP)), one individual antioxidant (uric acid) and two assays to evaluate oxidant concentrations (advanced oxidation protein products (AOPP) and hydrogen peroxide (H2O2)) were measured and validated in porcine saliva. In addition, the possible changes of these assays in sows' saliva during lactation were be studied. RESULTS: The methods had intra- and inter-assays coefficient of variation lower than 15%. They also showed an adequate linearity and recovery, and their detection limits were low enough to detect the analytes in saliva of pigs. Overall the analytical validation tests showed that the assays used in our study are valid and reliable for the evaluation of oxidative stress in porcine saliva. In addition, it was observed that these salivary biomarkers can change in a situation of oxidative stress such as lactation in sows. CONCLUSIONS: All assays for salivary biomarkers of oxidative stress evaluated in this study have demonstrated a high analytical accuracy and low imprecision. In addition, it has been observed that these biomarkers showed significant changes in a situation of oxidative stress such as lactation in sows. Therefore, this study opens a new possibility of using saliva as a non-invasive sample to evaluate oxidative stress in pigs.

Lowered quality of life in mood disorders is associated with increased neuro-oxidative stress and basal thyroid-stimulating hormone levels and use of anticonvulsant mood stabilizers.

RATIONALE, AIMS: Major affective disorders including bipolar disorder (BD) and major depressive disorder (MDD) are associated with impaired health-related quality of life (HRQoL). Oxidative stress and subtle thyroid abnormalities may play a pathophysiological role in both disorders. Thus, the current study was performed to examine whether neuro-oxidative biomarkers and thyroid-stimulating hormone (TSH) levels could predict HRQoL in BD and MDD. METHODS: This cross-sectional study enrolled 68 BD and 37 MDD patients and 66 healthy controls. The World Health Organization (WHO) QoL-BREF scale was used to assess 4 QoL subdomains. Peripheral blood malondialdehyde (MDA), advanced oxidation protein products, paraoxonaxe/CMPAase activity, a composite index of nitro-oxidative stress, and basal TSH were measured. RESULTS: In the total WHOQoL score, 17.3% of the variance was explained by increased advanced oxidation protein products and TSH levels and lowered CMPAase activity and male gender. Physical HRQoL (14.4%) was associated with increased MDA and TSH levels and lowered CMPAase activity. Social relations HRQoL (17.4%) was predicted by higher nitro-oxidative index and TSH values, while mental and environment HRQoL were independently predicted by CMPAase activity. Finally, 73.0% of the variance in total HRQoL was explained by severity of depressive symptoms, use of anticonvulsants, lower income, early lifetime emotional neglect, MDA levels, the presence of mood disorders, and suicidal ideation. CONCLUSIONS: These data show that lowered HRQoL in major affective disorders could at least in part result from the effects of lipid peroxidation, protein oxidation, lowered antioxidant enzyme activities, and higher levels of TSH.

Antioxidant properties of the carotenoid extracts of three Deinococcus­Thermus phylum bacteria, Meiothermus sp. strains RP and TP and Thermus sp. strain YY from Paniphala hot spring, India

BACKGROUND:The purpose of the study was to extract carotenoids from thermophilic bacteria which show efficient antioxidant and protein oxidation inhibition properties, characterize and identify those isolates, extract the carotenoids in different solvents, quantify the carotenoids and perform concentration-dependent and solvent-dependent quantitative assays validated and analysed by appropriate statistical tests. METHODS: Three pigment-forming thermophilic strains were isolated from water sample of Paniphala hot spring, India, and tentatively identified by 16S ribosomal DNA (rDNA) homology. Different concentrations of the carotenoid extracts (100, 80, 40 and 20µg) in three solvents, methanol, DMSO and water, were used to determine the antioxidant activity through five methods: the DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, the ABTS (2,2-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid)) assay, the hydrogen peroxide assay, TOC (total antioxidant capacity) assay and inhibition of protein oxidation assay. Statistical analysis of mean, standard deviation, ANOVA and Pearson correlationcoefficient was performed in Microsoft Excel statistical package.Results:The isolates were tentatively identified as Meiothermussp. strain RP, Meiothermussp. strain TP and Thermusstrain YY.Meiothermussp. formed red coloured pigment, where as Thermussp. formed yellow coloured pigment. Allof the extracts showed positive results in DPPH assay, ABTS assay and hydrogen peroxide radical scavenging assaywith best results obtained when the extracts were dissolved in water. Total antioxidant capacity assay was also highin all the extracts. Protein oxidation inhibition activity was only seen in extracts of strain YY. One-way ANOVA(analysis of variance) clearly showed that choice of solvent influenced the antioxidant capacity of all of the extracts. CONCLUSIONS: Newer and efficient antioxidative compounds are constantly being searched for, and the carotenoid extracts of RP, TP and YY have been shown to catalyze various types of antioxidative reactions, including proteinoxidation inhibition by YY. Thus, all these extracts have huge potential to be industrially and pharmaceutically useful.

Productos avanzados de oxidación proteica (PAOP) y su relación con los factores de riesgo cardiovascular en jóvenes aparentemente sanos / Advanced oxidation protein products and their relationship with cardiovascular risk factors in young apparently healthy people

Introducción: Los productos avanzados de oxidación proteica (PAOP) son un marcador para estimar estrés oxidativo en proteínas plasmáticas. El estrés oxidativo se considera un factor de riesgo cardiovascular (FRCV), relacionado con el aumento de presión arterial y la dislipidemia. Este trabajo tuvo por objetivo evaluar la asociación entre las concentraciones plasmáticas de PAOP y los FRCV en adultos jóvenes aparentemente sanos. Métodos: Estudio transversal comparativo prospectivo en 120 estudiantes de la Facultad de Químico Farmacobiología de la UMSNH, a los que se les determinó IMC, presión arterial, así como PAOP, glucosa, colesterol total, lipoproteínas (de alta, baja y muy baja densidad) y triglicéridos. Resultados: Los grupos de jóvenes con y sin FRCV presentaron diferencias significativas respecto a IMC, cintura, grasa corporal (p<0,05) y perfil lipídico (p<0,0001). Se presentaron cifras más altas de PAOP en el grupo de jóvenes con 3 y 4 FRCV (F: 4,651; p=0,002). Los PAOP correlacionaron negativamente con el colesterol LDL (r=-0,364; p=0,0001). Conclusiones: Se identificó que las concentraciones de PAOP se ven incrementadas conforme aumentan los FRCV en los jóvenes, por lo que estos podrían considerarse un factor importante de riesgo debido a que su depósito en la placa de ateroma favorece el proceso aterogénico y así el desarrollo de enfermedades cardiovasculares. La cuantificación de PAOP contribuye a la determinación indirecta del estado oxidativo en el organismo. El estudio del estado metabólico y oxidativo de jóvenes de aspecto saludable es de importancia en la prevención de enfermedades cardiovasculares en etapas posteriores de la vida, sin embargo, se requieren estudios longitudinales para estudiar su evolución (AU)

Introduction: Advanced oxidation protein products (AOPPs) are used as a marker to estimate oxidative stress in plasma proteins. Oxidative stress is considered a factor of cardiovascular risk (CVRF) related to increased blood pressure, and dyslipidaemia. The aim of this study was to evaluate the association between plasma AOPPs and CVRF in apparently healthy young adults. Methods: A prospective cross-sectional study was conducted on 120 students of the Faculty of Chemical-Pharmacobiology of the UMSNH. Body mass index (BMI) and blood pressure were determined. A blood specimen was also collected to quantify AOPPs, glucose, total cholesterol, lipoproteins (high, low, and very low density), and triglycerides. Results: Differences were observed in the groups with and without CVRF, with significant differences in BMI, waist, body fat (P<.05), and lipid profile (P<.0001). AOPPs were higher in the group of young people with three and four CVRF (F: 4.651; P=.002). A negatively correlation was found between AOPPs and LDL cholesterol (r=-0.364; P=.0001). Conclusions: It was observed that AOPPs concentrations are increased as CVRF increase in young adults. Thus, this could be considered an important risk factor, because their deposition in the atherosclerotic plaque favours the atherogenic process, and thus the development of cardiovascular disease. Quantification of AOPPs contributes to the indirect determination of oxidative status in the body. The study of metabolic and oxidative state of apparently healthy young adults is important in the prevention of cardiovascular disease in later life. More longitudinal studies are required to study its evolution (AU)

Factores de riesgo cardiovascular y estrés oxidativo en jóvenes / Cardiovascular risk factors and oxidative stress in young people

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Advanced oxidation protein product levels as a marker of oxidative stress in paediatric patients with chronic tonsillitis.

We aimed to determine whether advanced oxidation protein product (AOPP) levels can serve as a marker of oxidative stress in paediatric patients with chronic tonsillitis. Thirty children with chronic tonsillitis and 30 healthy children (control group) were recruited from the Otorhinolaryngology (ORL) and Paediatric Surgery departments, respectively, of Dumlupinar University Hospital. In the patient group, blood samples were collected before tonsillectomy, and tonsil tissue was sampled during the operation. Blood samples were also obtained from the control subjects. AOPP levels in the serum and tonsil tissue were measured by the spectrophotometric method. Serum AOPP levels were significantly higher in the patient group (13.1 ± 3.3 ng/ml) than in the control group (11.6 ± 2.3 ng/ml; P < 0.05). In addition, the mean AOPP level (41.9 ± 13.5 ng/mg protein) in the tonsil tissue in the patient group was significantly higher than the mean serum AOPP levels in the control and patient groups (P < 0.05). AOPP levels are elevated in the tonsil tissue and serum of patients with chronic tonsillitis compared to the serum AOPP levels in healthy controls. AOPPs may represent a novel class of pro-inflammatory molecules that are involved in oxidative stress in chronic tonsillitis. AOPPs may be used as a marker of oxidative stress in paediatric patients with chronic tonsillitis.

Decreased melatonin levels and increased levels of advanced oxidation protein products in the seminal plasma are related to male infertility.

Melatonin, an indolamine secreted by the pineal gland, is known as a powerful free-radical scavenger and wide-spectrum antioxidant. Therefore, the aim of this study was to correlate markers of oxidative protein damage (advanced oxidation protein products, AOPPs) and the total antioxidant capacity (TAC) with melatonin levels in the seminal plasma of men with azoospermia (n=37), theratozoospermia (n=29) and fertile controls (normozoospermia, n=37). Melatonin concentration was measured by radioimmunoassay. The levels of AOPP as well as TAC efficiency (determined by the ferric reducing antioxidant power, FRAP) were estimated by spectrophotometric methods. The concentration of melatonin and AOPP significantly differed in azoospermic (P<0.0001) and theratozoospermic (P<0.0001) patients versus fertile men, and correlated negatively (r=-0.33, P=0.0016). The TAC levels were significantly higher in azoospermia than in theratozoospermia (P=0.0022) and the control group (P=0.00016). In azoospermia, the AOPP concentration was also significantly higher than that observed in theratozoospermia (P=0.00029). Decreased levels of melatonin together with elevated AOPP altered the oxidative-antioxidative balance in the ejaculate, thereby reducing fertility. Therefore, melatonin and AOPP levels may serve as additional diagnostic markers of semen quality and male reproductive potential.

An Increase of Plasma Advanced Oxidation Protein Products Levels Is Associated with Cardiovascular Risk in Incident Peritoneal Dialysis Patients: A Pilot Study.

Advanced oxidation protein products (AOPPs) are considered as markers and even mediators of the proinflammatory effect of oxidative stress in uremia. We hypothesized that an increase of oxidative stress associated with peritoneal dialysis (PD), estimated by the variation of plasma AOPPs over time, might be associated with cardiovascular (CV) risk and overall prognosis. In 48 PD patients, blood samples were collected on two occasions: the first one in the first six months after starting PD therapy and the second one, one year after. The plasma AOPPs level variation over the first year on PD was significantly associated with CV antecedents and also with CV prognosis. In those patients in whom the AOPPs levels increased more than 50% above the baseline value, a significant association with past and future CV disease was confirmed. These patients had 4.7 times greater risk of suffering later CV disease than those with a smaller increase, even after adjusting for previous CV history. Our data suggest that the increase of AOPPs plasma level over the first year on PD is conditioned by CV antecedents but also independently predicts CV prognosis. AOPPs plasma levels seem to represent the CV status of PD patients with sufficient sensitivity to identify those with a clearly sustained higher CV risk.

Blood Contamination in Saliva: Impact on the Measurement of Salivary Oxidative Stress Markers.

Salivary oxidative stress markers represent a promising tool for monitoring of oral diseases. Saliva can often be contaminated by blood, especially in patients with periodontitis. The aim of our study was to examine the impact of blood contamination on the measurement of salivary oxidative stress markers. Saliva samples were collected from 10 healthy volunteers and were artificially contaminated with blood (final concentration 0.001-10%). Next, saliva was collected from 12 gingivitis and 10 control patients before and after dental hygiene treatment. Markers of oxidative stress were measured in all collected saliva samples. Advanced oxidation protein products (AOPP), advanced glycation end products (AGEs), and antioxidant status were changed in 1% blood-contaminated saliva. Salivary AOPP were increased in control and patients after dental treatment (by 45.7% and 34.1%, p < 0.01). Salivary AGEs were decreased in patients after microinjury (by 69.3%, p < 0.001). Salivary antioxidant status markers were decreased in both control and patients after dental treatment (p < 0.05 and p < 0.01). One % blood contamination biased concentrations of salivary oxidative stress markers. Saliva samples with 1% blood contamination are visibly discolored and can be excluded from analyses without any specific biochemic detection of blood constituents. Salivary markers of oxidative stress were significantly altered in blood-contaminated saliva in control and patients with gingivitis after dental hygiene treatment.

Oxidative stress associated with pathological lesions in the liver of rats experimentally infected by Fasciola hepatica.

The aim of this study was to analyze the antioxidant status and oxidative profile in serum and liver of rats experimentally infected with Fasciola hepatica and its relationship with pathological findings. Twenty-four rats were divided into two groups: group A consisted of 12 healthy rats and group B of 12 rats infected orally with 20 metacercaria of F. hepatica. At days 20 and 150 post-infection (PI), blood and liver samples of six animals from each group were collected. The protein oxidation (AOPP technique: advanced oxidation protein products) and antioxidants (FRAP technique: ferric reducing antioxidant power) levels were measured in serum and liver. Furthermore, nitrite/nitrate (NOx) levels and lipid peroxidation (TBARS technique: thiobarbituric acid reactive substances) were measured in liver. AOPP and FRAP levels were increased (P < 0.05) in serum and liver of infected animals in acute and chronic infection when compared with healthy animals. The same occurred with TBARS and NOx levels in the liver (P < 0.05). Histopathology revealed periportal fibrous hepatitis, composed of an abundant inflammatory infiltrate in portal spaces on infected animals, as well as bile duct hyperplasia. The results found seem to be related to the host free radical production demonstrated in serum samples and liver due to the parasite infection.

Immunological response and markers of cell damage in seropositive horses for Toxoplasma gondii.

Toxoplasmosis is an important parasitic disease affecting several species of mammals, but little is known about this disease in horses. This study aimed to investigate the levels of several immunological variables and markers of cell damage in the serum of seropositive horses for Toxoplasma gondii. Sera samples of adult horses from the Santa Catarina State, Brazil used on a previous study were divided into groups according to their antibody levels for T. gondii determined by immunofluorescence assay, i.e. 20 samples from seronegative horses (Group A - control), 20 samples from horses with titers of 1:64 (Group B), 20 samples of horses with titers of 1:256 (Group C), and five samples from horses with titers of 1:1024 (Group D). Positive animals (Groups B, C, and D) had higher levels of immunoglobulins (IgM and IgG), pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1, IL-4, and IL-6) and protein C-reactive protein, as well as lower levels of IL-10 (anti-inflammatory cytokine) when compared to seronegative horses (Group A). The nitric oxide levels were also elevated in seropositive horses. Therefore, we have found humoral and cellular immune responses in seropositive horses, and a correlation between high antibody levels and inflammatory mediators. Markers of cell injury by lipid peroxidation (TBARS) and protein oxidation (AOPP) were elevated in animals seropositives for T. gondii when compared to seronegatives. Therefore, seropositive horses to T. gondii can keep active immune responses against the parasite. As a consequence with chronicity of disease, they show cellular lesions that may lead to tissue damage with the appearance of clinical disease.

Effects of exercise at individual anaerobic threshold and maximal fat oxidation intensities on plasma levels of nesfatin-1 and metabolic health biomarkers

Exercise is recognized as an effective method of weight management and short-term appetite regulation tool. The effect of different exercise intensities on appetite regulation hormones in healthy overweight participants has not been intensively studied. The aim of this study was to examine the influence of exercise at individual anaerobic threshold (IAT) and maximal fat oxidation (Fatmax) intensities on the nesfatin-1 response and metabolic health biomarkers in overweight men. Nine healthy overweight males (age, 23.1 ± 1.1 years) volunteered in this study in a counterbalanced order. Blood samples were obtained before, immediately after, and following the first 45 min of recovery for measuring plasma variables. There was significant decrease in plasma levels of nesfatin-1 and leptin after exercise at the IAT intensity which remained lower than baseline following 45 min of recovery. However, nesfatin-1 and leptin levels did not change significantly in any time courses of Fatmax intensity (P > 0.09). Plasma interleukin-6 (IL-6) concentration increased during exercise in both intensities (P < 0.05), whereas changes in free fatty acids (FFAs) and epinephrine concentrations were significant only at the IAT. In addition, a significant correlation was found among nesfatin-1 levels with insulin (r = 0.39, P < 0.05) and glucose (r = 0.41, P < 0.05) at basal and in response to exercise. These results indicate that IAT has a greater exercise-induced appetite regulation effect compared with Fatmax. Based on these data, the intensity of exercise may have an important role in changes of nesfatin-1, leptin, FFA, and epinephrine concentrations even though this was not the case for IL-6 and insulin resistance

Advanced oxidation protein product level in children with chronic otitis media with effusion.

OBJECTIVE: To determine the level of advanced oxidation protein products (AOPPs) in children with chronic otitis media with effusion (COME), in an effort to elucidate the multifactorial etiology of this disease. METHODS: This study involved 25 COME patients and 30 healthy children (control group) recruited from the Ear, Nose and Throat (ENT) and Pediatric Departments, respectively, of the Haseki Research and Training Hospital. In the COME group, blood samples were collected before a middle ear operation, and middle ear fluid was sampled during the operation. Blood samples were also obtained from the control subjects. AOPP levels in the plasma and effusion fluid were measured by the spectrophotometric method. RESULTS: In the COME group, the mean AOPP levels in plasma and effusion fluid were 168.08 µmol/l and 412.75 µmol/l, respectively. In the control group, the mean plasma AOPP level was 141.54 µmol/l. The plasma AOPP levels did not significantly differ between the COME and control groups (p>0.05). In the COME group, however, the effusion fluid AOPP level (412.75 ± 204.54 µmol/l) was significantly higher than the plasma AOPP level (168.08 ± 68.45 µmol/l; p<0.01). CONCLUSION: We found that AOPP levels were elevated in the effusion fluid, but not in the plasma, of COME patients. Thus, COME was associated with protein oxidation abnormalities. Oxidative stress may play a role in the etiopathogenesis of COME, and AOPPs may be used as markers of oxidative stress; however, further studies are required to confirm these findings.

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.

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.

Serum levels of LH, FSH, estradiol and progesterone in female rats experimentally infected by Trypanosoma evansi.

The goal of this study was to evaluate reproductive hormones in sera samples of female rats experimentally infected by Trypanosoma evansi during different phases of the estrous cycle. For that, 64 animals were divided into two groups: 24 rats for the control group (uninfected), and 40 animals were infected by T. evansi. These groups were divided into subgroups according to the time of infection (days 5 and 15 post-infection; PI) and the phase of the estrous cycle (proestrus, estrus, metestrus and diestrus). Serum was collected at days 5 and 15 PI and the levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone and estradiol were assessed by enzyme immunoassay technique. The concentration of nitrite/nitrate (NOx), advanced oxidation protein products (AOPP), and thiobarbituric acid reactive substances (TBARS) were measured in ovaries and uteruses in these same periods. Infected females showed significant decrease (P<0.05) of LH, FSH, estradiol and progesterone in different periods and phases of the estrous cycle when compared to uninfected rats. In addition, it was observed an increase in the concentration of NOx, AOPP, and TBARS in the ovaries, which is indicative of cell damage. Therefore, our experimental study showed that T. evansi infection in female rats may cause changes in LH, FSH, estradiol, and progesterone levels regardless of the time of infection or phase of the estrous cycle.

Nitric oxide level, protein oxidation and antioxidant enzymes in rats infected by Trypanosoma evansi.

The aim of this study was to evaluate the nitric oxide (NO()) level, protein oxidation and antioxidant enzymes in rats infected with Trypanosoma evansi and establish the association of NO() levels with the degree of parasitemia. Thirty-six male rats (Wistar) were divided into two groups with 18 animals each. Group A was not infected while Group B was intraperitoneally infected, receiving 7.5×10(6) trypomastigotes per animal. Each group was divided into three subgroups with 6 rats each and blood was collected during different periods post-infection (PI), as follows: day 5 (A(5) and B(5)), day 15 (A(15) and B(15)) and day 30 PI (A(30) and B(30)). Blood samples were collected by cardiac puncture to estimate the levels of nitrites/nitrates (NO(x)) and advanced oxidation protein products (AOPP) in serum, and superoxide dismutase (SOD) and catalase (CAT) activities in blood. On days 15 and 30 PI NO(x) and AOPP levels were increased in serum of rats infected. Rodents infected with T. evansi showed a significant increase in SOD (days 5 and 15 PI) and CAT (day 30 PI) activities. Based on the physiological role of NO(), we can conclude that its increased concentration is related to an inflammatory response against the parasite, once a redox imbalance was observed during infection.