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This study investigated the δ-aminolevulinate dehydratase (δ-ALA-D) activity in whole blood as well as the parameters of oxidative stress, such as reactive species (RS) levels in serum, thiobarbituric acid reactive substances (TBARS) levels, the superoxide dismutase (SOD) and catalase (CAT) activities, as well as total thiols (T-SH) and non-protein thiols (NPSH) levels in platelets. Moreover, the content of vitamin C and E in plasma and serum, respectively, in lung cancer patients was also investigated. We collected blood samples from patients (n=28) previously treated for lung cancer with chemotherapy. Patients were classified as stage IIIb and IV according to the Union for International Cancer Control (UICC). Results showed a decrease of 37% in δ-ALA-D activity in patients with lung cancer when compared to the control group. RS and TBARS levels were 8% and 99% higher in the patient group, respectively. The activity of SOD and CAT as well as the vitamin C content were 41%, 35% and 127% lower in patients when compared with controls, respectively. However, T-SH and vitamin E levels were 27% and 44% higher in lung cancer patients, respectively. Results show that the overproduction of reactive species in patients with lung cancer may be interfering with the activity of δ-ALA-D. Likewise, the decrease in the activity of this enzyme may be contributing for the oxidative stress. [ABSTRACT FROM AUTHOR]

Abstract: Background: The nucleotides and nucleosides of adenine are signaling molecules related to thromboregulation and modulation of immune responses in patients with malignancies. Thus, this study aims to determine NTPDase, 5′-nucleotidase, ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) and adenosine deaminase (ADA) activities in the platelets of patients with lung cancer. Methods: We collected blood samples from patients (n =33) previously treated for lung cancer with chemotherapy. Patients were classified as stage IIIb and IV according to the Union for International Cancer Control (UICC). Results: Patients showed a significant decrease in the hydrolysis of adenosine diphosphate (ADP) and adenosine, whereas the adenosine monophosphate (AMP) hydrolysis and platelet aggregation were significantly increased in this group. Adenosine triphosphate (ATP) hydrolysis did not show significant results between the group of patients and the control group. Conclusions: We may suggest that ectonucleotidases as well as ADA are enzymes involved in thromboembolic events but especially here we may see that they are also directly involved in the generation of adenosine formation in the cancer patient circulation. [Copyright &y& Elsevier]

Background We investigated the biochemical and inflammatory parameters as well as biomarkers of oxidative stress in morbidly obese patients before and after bariatric surgery and clinical treatment. Methods This study was conducted using 60 individuals (10 men and 50 women) distributed into 3 groups: the control group, 20 non-diabetic obese patients given clinical treatment, the bariatric group, 20 non-diabetic obese patients given a Roux-en-Y bypass gastroplasty, and the bariatric diabetic group, 20 diabetic obese patients given a Roux-en-Y bypass gastroplasty. Measurements were made before and 1, 3, 6, and 12 months after surgery and clinical treatment. Results We showed a significant decrease in body weight, body mass index (BMI) and waist circumference, accompanied by a decrease in the lipid profile and glucose and glycated hemoglobin concentrations in the groups that received bariatric surgery. The concentrations of lipid peroxidation, carbonyl protein and NPSH, as well as superoxide dismutase (SOD) and catalase (CAT) activity, significantly decreased in both groups after surgery. The concentrations of inteleukin-6, inteleukin-1, TNF-α and resistin were also significantly lower, while adiponectin concentrations significantly increased 12 months after bariatric surgery. No significant alterations were observed in the biochemical, inflammatory or oxidative parameters of the control group. Conclusions Our findings demonstrate a decrease in body mass and a subsequent improvement in biochemical, metabolic and anthropometric parameters in patients given bariatric surgery. This may contribute to the reduction of oxidative damage in these patients and consequently a reduction in the risk of the development and progression of multiple co-morbidities associated with obesity. [ABSTRACT FROM AUTHOR]

Diseases related to thyroid hormones have been extensively studied because affect a large number of individuals, and these hormones participate in the regulation of the whole organism homeostasis. However, little is known about the involvement of purinergic signaling related to oxidative stress in hypothyroidism and possible therapeutic adjuncts for treatment of this disorder. Thus, the present study investigates the effects of quercetin on NTPDase, 5′-nucleotidase and adenosine deaminase activities, platelet aggregation and oxidative profile in platelets of rats with methimazole (MMI)-induced hypothyroidism. Methimazole at a concentration of 20 mg/100 mL was administered for 90 days. From the second month the animals received quercetin 10 or 25 mg/kg for 60 days. Results showed that: Ecto-5′-nucleotidase activity decreased in methimazole/water group and the treatment with quercetin 25 mg/kg decreased NTPDase, 5′-nucleotidase and adenosine deaminase activities. Moreover, platelet aggregation increased in methimazole/water group. Lipid peroxidation increased while superoxide dismutase and catalase activities decreased, but, interestingly, the treatment with quercetin reversed these changes. These results demonstrated that quercetin modulates adenine nucleotide hydrolysis decreasing the ADP formation and adenosine deamination. At the same time quercetin improves the oxidative profile, as well as reduces platelet aggregation, which together with the modulation in the nucleotides levels can contribute to the prevention of platelet disorders. [ABSTRACT FROM AUTHOR]

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 70 mg/kg of streptozotocin (STZ), diluted in 0.1 M sodium-citrate buffer (pH 4.5). Querc was dissolved in 25% ethanol and administered by gavage at the doses of 5, 25 and 50 mg/kg once a day during 40 days. The animals were distributed in eight groups of ten animals as follows: vehicle, Querc 5 mg/kg, Querc 25 mg/kg, Querc 50 mg/kg, diabetes, diabetes plus Querc 5 mg/kg, diabetes plus Querc 25 mg/kg and diabetes plus Querc 50 mg/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 50 mg/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. [ABSTRACT FROM AUTHOR]

The human immunodeficiency virus (HIV) infection results in biochemical and vascular dysfunctions. The highly active antiretroviral therapy (HAART) markedly reduces mortality and opportunistic diseases associated with acquired immunodeficiency syndrome (AIDS). This increased survival time predisposes the development of cardiovascular diseases. Platelets present purinergic system ectoenzymes such as E-NTPDase, E-5′-nucleotidase and E-ADA on its surface. In view of this, the aim of this study was to evaluate the activity of these ectoenzymes in platelets as well as the platelet aggregation and lipid profile of patients with HIV infection and also patients receiving HAART. The results showed an increase in the E-NTPDase activity for ATP hydrolysis in the HIV group compared with the control group and the HIV/HAART group. When assessing the activity E-NTPDase hydrolysis to ADP, the results revealed an increase in activity in the HIV group when compared to the control group, and a decrease in activity when in the HIV/HAART group when compared to the control and HIV groups. The activity of E-5′-nucleotidase revealed an increase in AMP hydrolysis in the HIV group, as the results from control and HIV/HAART groups showed no statistical difference. Regarding the E-ADA activity, the HIV and HIV/HAART groups revealed a decreased deamination of adenosine when compared with the control group. Furthermore, we observed an increased platelet aggregation of HIV/HAART group compared with the control group. Thus, our results suggest that antiretroviral treatment against HIV has a significant effect on the activity of purinergic system ectoenzymes demonstrating that thromboregulation is involved in the process. [ABSTRACT FROM AUTHOR]

Background Alterations in the activity of ectonucleotidase enzymes have been implicated in cardiovascular diseases, whereas regular exercise training has been shown to prevent these alterations. However, nothing is known about it relating to metabolic syndrome (MetS). We investigated the effect of exercise training on platelet ectonucleotidase enzymes and on the aggregation profile of MetS patients. Methods We studied 38 MetS patients who performed regular concurrent exercise training for 30 weeks. Anthropometric measurements, biochemical profiles, hydrolysis of adenine nucleotides in platelets and platelet aggregation were collected from patients before and after the exercise intervention as well as from individuals of the control group. Results An increase in the hydrolysis of adenine nucleotides (ATP, ADP and AMP) and a decrease in adenosine deamination in the platelets of MetS patients before the exercise intervention were observed ( P < 0.001). However, these alterations were reversed by exercise training ( P < 0.001). Additionally, an increase in platelet aggregation was observed in the MetS patients ( P < 0.001) and the exercise training prevented platelet hyperaggregation in addition to decrease the classic cardiovascular risks. Conclusions An alteration of ectonucleotidase enzymes occurs during MetS, whereas regular exercise training had a protective effect on these enzymes and on platelet aggregation. [ABSTRACT FROM AUTHOR]

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 15 PI, 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. [ABSTRACT FROM AUTHOR]

Abstract: This study evaluated the effects of caffeic acid on ectonucleotidase activities such as NTPDase (nucleoside triphosphate diphosphohydrolase), Ecto-NPP (nucleotide pyrophosphatase/phosphodiesterase), 5′-nucleotidase and adenosine deaminase (ADA) in platelets and lymphocytes of rats, as well as in the profile of platelet aggregation. Animals were divided into five groups: I (control); II (oil); III (caffeic acid 10mg/kg); IV (caffeic acid 50mg/kg); and V (caffeic acid 100mg/kg). Animals were treated with caffeic acid diluted in oil for 30days. In platelets, caffeic acid decreased the ATP hydrolysis and increased ADP hydrolysis in groups III, IV and V when compared to control (P <0.05). The 5′-nucleotidase activity was decreased, while E-NPP and ADA activities were increased in platelets of rats of groups III, IV and V (P <0.05). Caffeic acid reduced significantly the platelet aggregation in the animals of groups III, IV and V in relation to group I (P <0.05). In lymphocytes, the NTPDase and ADA activities were increased in all groups treated with caffeic acid when compared to control (P <0.05). These findings demonstrated that the enzymes were altered in tissues by caffeic acid and this compound decreased the platelet aggregation suggesting that caffeic acid should be considered a potentially therapeutic agent in disorders related to the purinergic system. [Copyright &y& Elsevier]

Abstract: The present study investigated the effects of resveratrol (RV), a polyphenol with potent antioxidant properties, on oxidative stress parameters in liver and kidney, as well as on serum biochemical parameters of streptozotocin (STZ)-induced diabetic rats. Animals were divided into six groups (n = 8): control/saline; control/RV 10 mg/kg; control/RV 20 mg/kg; diabetic/saline; diabetic/RV10 mg/kg; diabetic/RV 20 mg/kg. After 30 days of treatment with resveratrol the animals were sacrificed and the liver, kidney and serum were used for experimental determinations. Results showed that TBARS levels were significantly increased in the diabetic/saline group and the administration of resveratrol prevented this increase in the diabetic/RV10 and diabetic/RV20 groups (P < 0.05). The activities of catalase (CAT), superoxide dismutase (SOD) and aminolevulinic acid dehydratase (δ-ALA-D) and the levels of non protein thiols (NPSH) and vitamin C presented a significant decrease in the diabetic/saline group when compared with the control/saline group (P < 0.05). The treatment with resveratrol was able to prevent these decrease improving the antioxidant defense of the diabetic/RV10 and diabetic/RV20 groups (P < 0.05). In addition, the elevation in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamiltransferase (γ-GT) activities as well as in levels of urea, creatinine, cholesterol and triglycerides observed in the diabetic/saline group were reverted to levels close to normal by the administration of resveratrol in the diabetic/RV10 and diabetic/RV20 groups (P < 0.05). These findings suggest that resveratrol could have a protector effect against hepatic and renal damage induced by oxidative stress in the diabetic state, which was evidenced by the capacity of this polyphenol to modulate the antioxidant defense and to decrease the lipid peroxidation in these tissues. [Copyright &y& Elsevier]