997 resultados para Lipid Exposed Residues


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Objective: To assess the level of lipid peroxidation (LP) and vitamin E in the follicular fluid and serum of infertile patients, with or without endometriosis. who were submitted to ovulation induction for assisted reproduction procedures. Design: Prospective study. Setting: Assisted conception unit, university hospital. Patient(s): Infertile patients 20 to 38 years of age were selected prospectively and consecutively and were divided into the endometriosis group (17 patients with pelvic endometriosis) and the control group (19 patients with previous tubal ligation or male factor and without endometriosis). Intervention(s): Peripheral blood samples were collected on D1 (before the beginning of the use of gonadotropins), D2 (day of hCG administration), and D3 (day of oocyte retrieval). On D3, follicular-fluid samples free from blood contamination also were collected and stored. Main Outcome Measure(S): Lipid peroxidation was assessed by malondialdehyde quantification by spectrophotometry, and measurement of vitamin E was performed by HLPC. Result(s): On D1, no significant difference in LP was observed between groups. However, vitamin E levels were significantly higher in the control group. On D2, LP levels were significantly higher in the endometriosis group compared with in the control group, and vitamin E levels continued to be significantly higher in the control group. On D3, there was no significant difference in serum and follicular-fluid levels of LP and vitamin E between groups. However, on D3, vitamin E levels were found to be significantly higher in serum than in follicular fluid in both groups, whereas malondialdchyde levels were significantly lower in follicular fluid than in serum only in the control group. Conclusion(s): Before the beginning of ovulation induction, a significant decrease in vitamin E was observed in patients with endometriosis, perhaps because antioxidants are consumed during oxidation reactions. After ovulation induction with exogenous gonadotropins, the group of patients with endometriosis not only presented increased lipid peroxidation but also maintained lower vitamin E levels than the control group, a fact that hypothetically could compromise oocyte quality in endometriotic patients. However, on the day of oocyte retrieval, both serum LP potential and vitamin E levels were found to be similar in the two groups. (Fertil Steril(R) 2008; 90:2080-5. (C) 2008 by American Society for Reproductive Medicine.)

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Our objective was to describe the prevalence of low concentrations of retinol, beta-carotene, and vitamin E in a group of human immunodeficiency virus (HIV)-infected Latin American children and a comparison group of HIV-exposed, uninfected children. Our hypothesis was that the rates of low concentrations of these micronutrients would be higher in the HIV-infected group than those in the HIV-exposed, uninfected group. This was a cross-sectional substudy of a larger cohort study at clinical pediatric HIV centers in Latin America. Serum levels of micronutrients were measured in the first stored sample obtained after each child`s first birthday by high-performance liquid chromatography. Low concentrations of retinol, beta-carotene, and vitamin E were defined as serum levels below 0.70, 0.35, and 18.0 mu mol/L, respectively. The Population for this analysis was 336 children (124 HIV-infected, 212 HIV-exposed, uninfected) aged I year or older to younger than 4 years. Rates of low concentrations were 74% for retinol, 27% for beta-carotene, and 89% for vitamin E. These rates were not affected by HIV status. Among the HIV-infected children, those treated with anti retrovirals were less likely to have retinol deficiency, but no other HIV-related factors correlated with micronutrient low serum levels. Low concentrations of retinol, beta-carotene, and vitamin E are very common in children exposed to HIV living in Brazil, Argentina, and Mexico, regardless of HIV-infection status. Published by Elsevier Inc.

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Methionine-choline-deficient diet represents a model for the study of the pathogenesis of steatohepatitis. Male rats were divided into three groups, the first group receiving a control diet and the other two groups receiving a methionine-choline-deficient diet for 1 month (MCD1) and for 2 months (MCD2), respectively. The livers of the animals were collected for the determination of vitamin E, thiobarbituric acid reactive substances (TBARS), GSH concentration, DNA damages, and for histopathological evaluation. The hepatic TBARS and GSH content was higher (P < 0.05) in the groups receiving the experimental diet (MCD1 and MCD2) compared to control diet, and hepatic vitamin E concentration differed (P < 0.05) between the MCD1 and MCD2 groups, with the MCD2 group presenting a lower concentration. Damage to hepatocyte DNA was greater (P < 0.05) in the MCD2 group (262.80 DNA injuries/100 hepatocytes) compared to MCD1 (136.4 DNA injuries/100 hepatocytes) and control diet (115.83 DNA injuries/100 hepatocytes). Liver histopathological evaluation showed that steatosis, present in experimental groups was micro- and macro-vesicular and concentrated around the centrolobular vein, zone 3, with preservation of the portal space. The inflammatory infiltrate was predominantly periductal and the steatosis and inflammatory infiltrate was similar in the MCD1 and MCD2 groups, although the presence of Mallory bodies was greater in the MCD2 group. The study describes the contribution of a methionine-choline-deficient diet to the progression of steatosis, lipid peroxidation and hepatic DNA damage in rats, serving as a point of reflection about the role of these nutrients in the western diet and the elevated non-alcoholic steatohepatitis rates in humans.

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Purpose: Eicosapentaenoic acid has been tested in bladder cancer as a synergistic cytotoxic agent in the form of meglumine-eicosapentaenoic acid, although its mechanism of action is poorly understood in this cancer. The current study analyzed the mechanisms by which eicosapentaenoic acid alters T24/83 human bladder cancer metabolism in vitro. Materials and Methods: T24/83 human bladder cancer cells were exposed to eicosapentaenoic acid for 6 to 24 hours in vitro and incorporation profiles were determined. Effects on membrane phospholipid incorporation, energy metabolism, mitochondrial activity, cell proliferation and apoptosis were analyzed Reactive oxygen species and lipid peroxide production were also determined. Results: Eicosapentaenoic acid was readily incorporated into membrane phospholipids with a considerable amount present in mitochondrial cardiolipin. Energy metabolism was significantly altered by eicosapentaenoic acid, accompanied by decreased mitochondrial membrane potential, and increased lipid peroxide and reactive oxygen species generation. Subsequently caspase-3 activation and apoptosis were detected in eicosapentaenoic acid exposed cells, leading to decreased cell numbers. Conclusions: These findings confirm that eicosapentaenoic acid is a potent cytotoxic agent in bladder cancer cells and provide important insight into the mechanisms by which eicosapentaenoic acid causes these changes. The changes in membrane composition that can occur with eicosapentaenoic acid likely contribute to the enhanced drug cytotoxicity reported previously in meglumine-eicosapentaenoic acid/epirubicin/mitomycin studies. Dietary manipulation of the cardiolipin fatty acid composition may provide an additional method for stimulating cell death in bladder cancer. In vivo studies using intravesical and dietary manipulation of fatty acid metabolism in bladder cancer merit further attention.

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Objectives: To evaluate whether maternal HIV disease severity during pregnancy is associated with an increased likelihood of lower respiratory tract infections (LRTIs) in HIV-exposed, uninfected infants. Methods: HIV-exposed, uninfected, singleton, term infants enrolled in the NISDI Perinatal Study, with birth weight >2500 g were followed from birth until 6 months of age. LRTI diagnoses, hospitalizations, and associated factors were assessed. Results: Of 547 infants, 103 (18.8%) experienced 116 episodes of LRTI (incidence = 0.84 LRTIs/100 child-weeks). Most (81%) episodes were bronchiolitis. Forty-nine (9.0%) infants were hospitalized at least once with an LRTI. There were 53 hospitalizations (45.7%) for 116 LRTI episodes. None of these infants were breastfed. The odds of LRTI in infants whose mothers had CD4% <14 at enrollment were 4.4 times those of infants whose mothers had CD4% >= 29 (p = 0.003). The odds of LRTI in infants with a CD4+ count (cells/ mm(3)) <750 at hospital discharge were 16.0 times those of infants with CD4+ >= 750 (p = 0.002). Maternal CD4+ decline and infant hemoglobin at the 6-12 week visit were associated with infant LRTIs after 6-12 weeks and before 6 months of age. Conclusions: Acute bronchiolitis is common and frequently severe among HIV-exposed, uninfected infants aged 6 months or less. Lower maternal and infant CD4+ values were associated with a higher risk of infant LRTIs. Further understanding of the immunological mechanisms of severe LRTIs is needed. (C) 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that the recombinant chimeric protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region for presentation on the Escherichia coli membrane was protective against R. microplus infestations in rabbits. This system provides a novel and simple approach for the production of tick protective antigens by surface display of antigenic protein chimera on live E. coli and suggests the possibility of using recombinant bacterial membrane fractions for vaccination against cattle tick infestations. (C) 2009 Elsevier Ltd. All rights reserved.

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In this study, we investigated the hematopoietic response of rats pretreated with CV and exposed to the impact of acute escapable, inescapable or psychogenical stress on responsiveness to an in vivo challenge with Listeria monocytogenes. No consistent changes were observed after exposure to escapable footshock. Conversely, the impact of uncontrollable stress (inescapable and psychogenical) was manifested by an early onset and increased severity and duration of myrelossuppression produced by the infection. Small size CFU-CM colonies and increased numbers of clusters were observed, concurrently to a greater expansion in the more mature population of bone marrow granulocytes. No differences were observed between the responses of both uncontrollable stress regimens. CV prevented the myelossuppression caused by stress/infection due to increased numbers of CFU-GM in the bone marrow. Colonies of cells tightly packed, with a very condensed nucleus; in association with a greater expansion in the more immature population of bone marrow granulocytes were observed. Investigation of the production of colony-stimulating factors revealed increased colony-stimulating activity (CSA) in the serum of normal and infected/stressed rats treated with the algae. CV treatment restored/enhanced the changes produced by stress/infection in total and differential bone marrow and peripheral cells counts. Further studies demonstrated that INF-gamma is significantly reduced, whereas IL-10 is significantly increased after exposure to Uncontrollable stress. Treatment with CV significantly increased INF-gamma levels and diminished the levels of IL-10. Uncontrollable stress reduced the protection afforded by CV to a lethal dose of L. monocytogenes, with survival rates being reduced from (50%) in infected rats to 20% in infected/stressed rats. All together, our results suggest Chlorella treatment as an effective tool for the prophylaxis of post-stress myelossupression, including the detrimental effect of stress on the course and outcome of infections. (C) 2008 Elsevier Inc. All rights reserved.

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Objective: Exercise training improves plasma lipid profile and diminishes risk of coronary heart disease. Previously, we showed that training increases LDL plasma clearance, as tested by an artificial LDL-like nanoemulsion method, presumably by increasing LDL receptor activity. In this study, we investigated whether training could also improve LDL clearance in hypercholesterolemic subjects (HCh) that are exposed to increased risk of cardiovascular events. Methods: Twenty sedentary HCh and 20 normolipidemic (NL) sedentary volunteers were divided into four groups: 12 HCh submitted to 4-month training program, 8 HCh with no exercise program, 12 NL submitted to 4-month training and 8 NL with no exercise program. An LDL-like nanoemulsion labeled with 14C-cholesteryl ester was injected intravenously into all subjects and plasma samples were collected during 24h after injection to determine the fractional clearance rate (FCR, in h-1) by compartmental analysis. The study was performed on the first and on the last day of the 4-month study period. Results: In both, trained HCh and NL groups, training increased nanoemulsion FCR by 36% (0.0443 +/- 0.0126; 0.0602 +/- 0.0187, p=0.0187 and 0.0503 +/- 0.0203; 0.0686 +/- 0.0216, p=0.0827, respectively). After training, LDL cholesterol diminished in both HCh and NL groups. In HCh, but not in NL group, LDL susceptibility to oxidation decreased, but oxidized LDL was unchanged. In both non-trained groups FCR was the same for the last and the 4-month previous evaluation. Conclusion: In HCh, exercise training increased the removal of LDL as tested by the nanoemulsion, and this probably accounted for decreased LDL cholesterol and diminished LDL susceptibility to oxidation. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

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During the process of maturation in the oviduct, canine oocytes in the germinal vesicle stage are exposed to decreasing levels of estradiol-17 beta and increasing levels of progesterone. However, hormone concentrations in the microenvironments in which they act are higher than serum concentrations. Therefore, the aim of the present study was to compare the meiotic competence of canine oocytes harvested from anestrous bitches in culture medium containing high concentrations (20 mu g ml(-1)) of estradiol-17 beta and/or progesterone in association to gonadotropins (luteinizing hormone and follicle-stimulating hormone) using three different maturation periods (48, 72, and 96 h). Oocytes were cultured in tissue culture medium (TCM-199) and arranged in four experimental groups: group control, group E2 (estradiol-17 beta), group P4 (progesterone), and group E2 + P4. Regardless of the maturation period, groups P4 and E2 + P4 presented statistically higher rate of germinal vesicle breakdown oocytes compared to the group control and group E2. There were no significant differences among groups on germinal vesicle, metaphase I, metaphase II, and degenerated or unidentifiable oocytes rates. The mean percentage of metaphase II oocytes was higher at 96 h when compared to 72 h. Results of the present research indicate no influence of estradiol-17 beta supplementation, unless in association with progesterone. There is an evidence of the positive effect of progesterone on germinal vesicle breakdown. Results also showed that extended periods of in vitro maturation affect positively maturation rates to metaphase II of low competent oocytes harvested from anestrous bitches, independent of the maturation media. In conclusion, high concentrations of steroids, especially progesterone, have positive effect on in vitro oocyte maturation when the oocytes are derived from the anestrous status.

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Hyperglycemia induces overproduction of superoxide and it is related to diabetic complications. In this study, we analyzed the antioxidant enzymatic defense and the lipid peroxidation of rat salivary glands in six different periods of diabetic condition. Ninety-six rats were divided into 12 groups: C7/14/21128/45/60 (non-diabetic animals) and D7/14/21/28/45/60 (diabetic animals). Diabetes was induced by streptozotocin and the rats were euthanized after 7, 14, 21, 28, 45, or 60 days. Their parotid (PA) and submandibular (SM) glands were removed soon after the sacrifice and the total protein and malondialdehyde (MDA) concentrations, as well as, the superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities were determined. Twenty-one days after the diabetes induction, the SM glands showed an increase in SOD, CAT, and GPx activities, as well as, MDA concentration. Concerning the PA glands, an increase in the CAT activity and MDA content was observed throughout the observation period. The results suggest that diabetes can cause alterations on the salivary glands and that PA and SM glands react differently when exposed to diabetes condition. However, no impairment of antioxidant system was observed in the group whose diabetic condition had been induced 60 days earlier, herein named 60-day group. Copyright (C) 2010 John Wiley & Sons, Ltd.

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Urine is an ideal source of materials to search for potential disease-related biomarkers as it is produced by the affected tissues and can be easily obtained by noninvasive methods. 2-DE-based proteomic approach was used to better understand the molecular mechanisms of injury induced by fluoride (F(-)) and define potential biomarkers of dental fluorosis. Three groups of weanling male Wistar rats were treated with drinking water containing 0 (control), 5, or 50 ppm F(-) for 60 days (n = 15/group). During the experimental period, the animals were kept individually in metabolic cages, to analyze the water and food consumption, as well as fecal and urinary F excretion. Urinary proteome profiles were examined using 2-DE and Colloidal Coomassie Brilliant Blue staining. A dose-response regarding F(-) intake and excretion was detected. Quantitative intensity analysis revealed 8, 11, and 8 significantly altered proteins between control vs. 5 ppm F(-), control vs. 50 ppm F(-) and 5 ppm F(-) vs. 50 ppm F(-) groups, respectively. Two proteins regulated by androgens (androgen-regulated 20-KDa protein and 0c-2,1-globulin) and one related to detoxification (aflatoxin-Bl-aldehyde-reductase) were identified by MALDI-TOF-TOF MS/MS. Thus, proteomic analysis can help to better understand the mechanisms underlying F(-) toxicity, even in low doses. 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 25:8-14, 2011; View this article online at wileyonlinelibrary.com. DOI 10:1002/jbt.20353

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Glutatione S-transferases (GSTs) are a family of enzymes involved in detoxification of xenobiotics. Placental GST, known as GST-P, has been detected in tissues following exposure to carcinogenic agents being regarded a reliable biomarker of exposure and susceptibility in early phases of carcinogenesis. The aim of this study was to investigate the expressivity of GST-P positive foci in the rat tongue mucosa exposed to cigarette smoke by means of immunohistochemistry. A total of twelve male Wistar rats were distributed into two groups: negative control and experimental group exposed to cigarette smoke during 75 days. After experimental period, no histopathological changes in the tongue mucosa were evidenced in the negative control and the experimental group. However, a total of five GST-P positive foci were detected in two out of six animals exposed to cigarrette smoke. None control animals were noticed GST-P positive foci. These data indicate that expression of GST-P may reflect the carcinogenic effect of cigarette smoke as well as the genetic susceptibility of animals in relation to continuous carcinogens exposure.

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There has been no comparison between fluoride concentrations in urine and nails of children exposed to different sources of systemic fluoride. The aim of this study was to compare the relationship between fluoride intake with urinary fluoride excretion and fluoride concentrations in fingernails and toenails of children receiving fluoride from artificially fluoridated water (0.6-0.8 mg F/L, n = 25), naturally fluoridated water (0.6-0.9 mg F/L, n = 21), fluoridated salt (180-200 mg F/Kg, n = 26), and fluoridated milk (0.25 mg F, n = 25). A control population was included (no systemic fluoride, n = 24). Fluoride intake from diet and dentifrice, urinary fluoride excretion, and fluoride concentrations in fingernails/toenails were evaluated. Fluoride was analyzed with an ion-selective electrode. Urinary fluoride excretion in the control community was significantly lower when compared with that in the fluoridated cities, except for the naturally fluoridated community. However, the same pattern was not as evident for nails. Both urinary fluoride output and fluoride concentrations in fingernails/toenails were significantly correlated to total fluoride intake. However, the correlation coefficients for fluoride intake and urinary fluoride output were lower (r = 0.28, p < 0.01) than those observed for fingernails/toenails (r = 0.36, p < 0.001), suggesting that nails might be slightly better indicators of fluoride intake at the individual level.

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Audiometry is the main way with which hearing is evaluated, because it is a universal and standardized test. Speech tests are difficult to standardize due to the variables involved, their performance in the presence of competitive noise is of great importance. Aim: To characterize speech intelligibility in silence and in competitive noise from individuals exposed to electronically amplified music. Material and Method: It was performed with 20 university students who presented normal hearing thresholds. The speech recognition rate (SRR) was performed after fourteen hours of sound rest after the exposure to electronically amplified music and once again after sound rest, being studied in three stages: without competitive noise, in the presence of Babble-type competitive noise, in monotic listening, in signal/ noise ratio of + 5 dB and with the signal/ noise ratio of 5 dB. Results: There was greater damage in the SRR after exposure to the music and with competitive noise, and as the signal/ noise ratio decreases, the performance of individuals in the test also decreased. Conclusion: The inclusion of competitive noise in the speech tests in the audiological routine is important, because it represents the real disadvantage experienced by individuals in daily listening.

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Immune challenges during neonatal period may permanently program immune responses later in life, including endotoxin fever. We tested the hypothesis that neonatal endotoxin exposure affects stress fever in adult rats. In control rats (treated with saline as neonates; nSal) body temperature peaked similar to 1.5 degrees C during open-field stress, whereas in rats exposed to endotoxin (lipopolysaccharide, LPS) as neonates (nLPS) stress fever was significantly attenuated. Following stress, plasma corticosterone levels significantly increased from 74.29 +/- 7.05 ng ml(-1) to 226.29 +/- 9.87 ng ml(-1) in nSal rats, and from 83.43 +/- 10.31 ng ml(-1) to 324.7 +/- 36.87 ng ml(-1) in nLPS rats. Animals treated with LPS as neonates and adrenalectomized one week before experimentation no longer displayed the attenuated febrile response to stress. This attenuated stress fever caused by an increased corticosterone secretion is likely to be linked to an inhibitory effect of glucocorticoids on cyclooxygenase activity/PGE(2) production in preoptic/anteroventral third ventricular region (AV3V) since stress failed to cause a significant increase in PGE(2) in nLPS rats, and this effect was reverted by adrenalectomy. Altogether, the present results indicate that endogenous glucocorticoids are key modulators of the attenuated stress fever in adult rats treated with LPS as neonates, and they act downregulating PGE(2) production in AV3V. Moreover, our findings also support the notion that neonatal immune stimulus affects programming of stress responses during adulthood, despite the fact that inflammation and stress are two distinct processes mediated largely by different neurobiological mechanisms. (C) 2010 Elsevier B.V. All rights reserved.