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1.
Phys Chem Chem Phys ; 22(36): 20744-20750, 2020 Sep 23.
Article in English | MEDLINE | ID: mdl-32909018

ABSTRACT

An organic-based bright white light emitting compound, namely Tb(H3PTC)3 [H4PTC = perylene-3,4,9,10-tetracarboxylic acid], able to be used as part of a white diode and as a part of a RGB system that can withstand high temperatures (∼700 K), is developed using perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) and terbium(iii) nitrate pentahydrate as precursors by hydrothermal synthesis. Using PTCDA as the red emitter and the new derivative of it, Tb(H3PTC)3, as the blue-green emitter, along with a common deep blue LED can form a RGB system for display technologies, around room temperature. Temperature-dependent photoluminescence properties of the Tb(H3PTC)3 compound are also investigated for the involved excitonic-emission processes and the respective recombination lifetimes. The terbium(iii) complex was prepared using a procedure that is reproducible, easily modifiable, inexpensive, and environmentally friendly, opening new pathways for its large-scale applications. Unlike PTCDA, Tb(H3PTC)3 has been shown to be soluble in N-methyl-2-pyrrolidone (NMP) as well as in dilute aqueous solutions of this organic solvent in a straightforward procedure. The light emission properties are intimately correlated with the molecular structure and electronic properties of Tb(H3PTC)3 elucidated by experimental results of X-ray Absorption Near Edge Spectroscopy (XANES), Extended X-ray Absorption Fine Structure (EXAFS) and Density Functional Theory (DFT) calculations. A bright fluorescence yield is attained with a small amount of material either in solution or in solid form showing its potential to be used in state-of-the-art organic optoelectronic devices.

2.
J Chromatogr A ; 1618: 460890, 2020 May 10.
Article in English | MEDLINE | ID: mdl-31980261

ABSTRACT

p53 is a tumour suppressor gene that has been explored for cancer gene therapy as a possible alternative to the common treatments. The use of plasmid DNA (pDNA) to carry the therapeutic gene has been considered, but it is requisite to preserve its supercoiled (sc) structure, for eliciting a more effective gene expression and therapeutic action. The purification of the sc pDNA using amino acids-based affinity chromatography has been successfully applied, exploring different amino acids and supports. From these studies, it stood out the selectivity of arginine for the recognition of sc pDNA. However, some limitation on the binding capacity was found in the arginine-agarose support, and in the case of monoliths, some fouling and clogging can limit sequential runs. By using macroporous support modified with arginine it was expected to take advantage of the selectivity of the ligand combined with the flow properties and binding capacity offered by the support. The arginine-modified macroporous support was characterized by SEM, EDX and FTIR also to verify the correct immobilization of arginine, and then used for pDNA purification. The support showed to be effective on the sc p53-pDNA isolation, and the robustness was also achieved by accomplishing the purification of plasmids with different sizes, only by slightly adjusting the experimental conditions. Regarding the dynamic binding capacity of the arginine-modified macroporous support, it was achieved an improvement of more than 50% in the pDNA binding capacity when compared with their homologous arginine-agarose commercial matrix, suggesting potential economic feasibility in case of scale-up.


Subject(s)
Arginine/chemistry , Chemistry Techniques, Analytical/methods , Chromatography, Affinity , DNA, Superhelical/isolation & purification , Plasmids/isolation & purification , Tumor Suppressor Protein p53/genetics , Sepharose/chemistry
3.
Arq. bras. med. vet. zootec. (Online) ; 71(2): 603-612, mar.-abr. 2019. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1011265

ABSTRACT

The aim was to evaluate the effect of different doses of two biostimulants on the productivity and canopy structure of Urochloa brizantha cv. Marandu grass in the establishment fase. The study was conducted in Universidade Federal Rural da Amazônia, Parauapebas, Pará, Brazil. One module of 35 plots of 25m² were established. A completely randomized experimental design was used, with seven treatments and five replicates. The treatments included a control, 0.5, 1, and 2kg/ha of biostimulant A (BIOST.A); and 0.25, 0.5, and 1L/ha of biostimulant B (BIOST.B). Three collections were performed. The data for application of the two biostimulants were analyzed separately, using the Dummy variable method and regression analysis. The application of 2kg/ha BIOST.A resulted in increases of 842kg/ha in the forage mass. The application of BIOST.B on Marandu grass resulted in a linear increase in stem mass. The application of 2kg/ha BIOST.A in the establishment of Marandu grass result in higher growth rates, forage accumulation, and stem proportion in the canopy.(AU)


Objetivou-se avaliar o efeito de diferentes doses de dois bioestimulantes sobre a produtividade e a estrutura do dossel do capim Urochloa brizantha cv. Marandu na fase de estabelecimento. O estudo foi realizado na Universidade Federal Rural da Amazônia, Parauapebas, Pará, Brasil. Um módulo de 35 parcelas de 25m² foi estabelecido. Utilizou-se delineamento experimental inteiramente ao acaso, composto de sete tratamentos e cinco repetições cada. Os tratamentos incluídos no controle foram: 0,5, 1 e 2kg/ha de bioestimulante A (BIOST.A); 0,25; 0,5 e 1L/ha de bioestimulante B (BIOST.B). Foram realizadas três coletas. Os dados para a aplicação dos dois bioestimulantes foram analisados separadamente, utilizando-se organização por método variável Dummy e análise de regressão. A aplicação de 2kg/ha BIOST.A resultou em incrementos de 842kg/ha na massa de forragem. A aplicação do BIOST.B na grama marandu resultou em aumento linear na produção de massa do caule. A aplicação de 2kg/ha BIOST.A no estabelecimento de erva de marandu resultou em maiores taxas de crescimento, acumulação de forragem e proporção de caule no dossel.(AU)


Subject(s)
Amazonian Ecosystem , Fertilizers , Poaceae/growth & development , Indoleacetic Acids
4.
J Intern Med ; 285(2): 215-222, 2019 02.
Article in English | MEDLINE | ID: mdl-30222212

ABSTRACT

BACKGROUND: Vertical transmission of Zika virus (ZIKV) is associated with congenital malformations but the mechanism of pathogenesis remains unclear. Although host genetics appear to play a role, no genetic association study has yet been performed to evaluate this question. In order to investigate if maternal genetic variation is associated with Congenital Zika Syndrome (CZS), we conducted a case-control study in a cohort of Brazilian women infected with ZIKV during pregnancy. METHODS: A total of 100 women who reported symptoms of zika during pregnancy were enrolled and tested for ZIKV. Among 52 women positive for ZIKV infection, 28 were classified as cases and 24 as controls based on the presence or absence of CZS in their infants. Variations in the coding region of 205 candidate genes involved in cAMP signaling or immune response were assessed by high throughput sequencing and tested for association with development of CZS. RESULTS: From the 817 single nucleotide variations (SNVs) included in association analyses, 22 SNVs in 17 genes were associated with CZS under an additive model (alpha = 0.05). Variations c.319T>C (rs11676272) and c.1297G>A, located at ADCY3 and ADCY7 genes showed the most prominent effect. The association of ADCY3 and ADCY7 genes was confirmed using a Sequence Kernel Association Test to assess the joint effect of common and rare variations, and results were statistically significant after adjustment for multiple comparisons (P < 0.002). CONCLUSION: These results suggest that maternal ADCY genes contribute to ZIKV pathogenicity and influence the outcome of CZS, being promising candidates for further replication studies and functional analysis.


Subject(s)
Adenylyl Cyclases/genetics , Mutation , Pregnancy Complications, Infectious , Zika Virus Infection/genetics , Adenylyl Cyclases/metabolism , Brazil/epidemiology , DNA Mutational Analysis , DNA, Viral/analysis , Female , Follow-Up Studies , Humans , Incidence , Pregnancy , Retrospective Studies , Zika Virus/genetics , Zika Virus/pathogenicity , Zika Virus Infection/enzymology , Zika Virus Infection/epidemiology
6.
Carbohydr Polym ; 136: 449-58, 2016 Jan 20.
Article in English | MEDLINE | ID: mdl-26572375

ABSTRACT

NaCl and KCl phase diagrams of two kappa/iota-hybrid carrageenans (KI) are established, and the rheological properties of obtained solutions and gels are reported. KI were extracted from Ahnfeltiopsis devoniensis and Chondrus crispus seaweeds and showed different chemical composition, 48 mol% of kappa carrageenan (K) and 52 mol% of iota carrageenan (I), and 78 mol% of K and 22 mol% of I, respectively. Phase diagrams are systematically compared those of blends of commercial K and I (K+I) showing equivalent chemical compositions. Results confirm that KI clearly differ from mixtures of K and I. K+I form gels at lower polysaccharide concentration and ionic strength, and exhibit gel separation from a liquid phase when large amount (>0.1 mol/L) of KCl is used. In contrast, no syneresis was found in KI gels formed under similar conditions. Both KI and K+I gels are strain hardening, and show a concentration scaling of the elasticity with exponents ranging from 1.1 to 3.2 depending on the type of salt and ionic strength. The strain at break of KI gels does not show salt specificity and is similar to the strain at break of K+I gels in KCl under similar salt and polysaccharide concentrations. K+I gels in NaCl are more fragile than in KCl, thus showing salt specificity.


Subject(s)
Carrageenan/chemistry , Chondrus/chemistry , Elasticity , Gels/chemistry , Phase Transition , Potassium/chemistry , Rheology , Sodium/chemistry
8.
Phys Rev Lett ; 107(26): 267402, 2011 Dec 23.
Article in English | MEDLINE | ID: mdl-22243180

ABSTRACT

The Fe K x-ray absorption near edge structure of BaFe(2-x)Co(x)As(2) superconductors was investigated. No appreciable alteration in shape or energy position of this edge was observed with Co substitution. This result provides experimental support to previous ab initio calculations in which the extra Co electron is concentrated at the substitute site and do not change the electronic occupation of the Fe ions. Superconductivity may emerge due to bonding modifications induced by the substitute atom that weakens the spin-density-wave ground state by reducing the Fe local moments and/or increasing the elastic energy penalty of the accompanying orthorhombic distortion.

9.
J Hum Nutr Diet ; 23(5): 529-34, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20831709

ABSTRACT

BACKGROUND: Vitamins A and E are recognisably important in the initial stages of life, and the newborn depends on nutritional adequacy of breast milk to meet their needs. These vitamins share routes of transport to the tissues and antagonistic effects have been observed in animals after supplementation with vitamin A. The present study aimed to determine the effect of maternal supplementation with a megadose of retinyl palmitate in the immediate post-partum on α-tocopherol concentration in the colostrum. METHODS: Healthy parturient women at a Brazilian public maternity were recruited for the study and divided into two groups: control (n = 37) and supplemented (n = 36). Blood and colostrum samples were collected up to 16 h post-partum. The supplemented group was administered with a retinyl palmitate capsule and, 24 h after the first collection, the second colostrum sample was obtained in the two groups for analysis of α-tocopherol. The cut-off points for deficiency are <1.05 µmol L(-1) for retinol and <11.6 µmol L(-1) for α-tocopherol. RESULTS: The mean (SD) serum concentration of 1.77 (0.50) µmol L(-1) for retinol and 30.81 (6.46) µmol L(-1) for α-tocopherol indicates an adequate biochemical status. The supplemented group showed an increase of α-tocopherol in the colostrum 24 h after supplementation (P = 0.04), and this finding was not observed in the control group. CONCLUSIONS: Supplementation with a 200,000 IU megadose of vitamin A did not negatively affect α-tocopherol levels in colostrum.


Subject(s)
Breast Feeding , Colostrum/metabolism , Dietary Supplements/adverse effects , Vitamin A Deficiency/prevention & control , Vitamin A/analogs & derivatives , alpha-Tocopherol/metabolism , Adolescent , Adult , Brazil , Cross-Sectional Studies , Diterpenes , Female , Humans , Nutritional Status/drug effects , Postpartum Period/blood , Postpartum Period/metabolism , Retinyl Esters , Vitamin A/administration & dosage , Vitamin A/adverse effects , Vitamin A/blood , Vitamin A/metabolism , Vitamin A/therapeutic use , Vitamin E Deficiency/prevention & control , Young Adult , alpha-Tocopherol/administration & dosage , alpha-Tocopherol/blood
10.
Braz J Med Biol Res ; 42(12): 1143-9, 2009 12.
Article in English | MEDLINE | ID: mdl-19936546

ABSTRACT

Round holes in the ears of MRL mice tend to close with characteristics of regeneration believed to be absent in other mouse strains (e.g., C57BL/6). We evaluated the kinetics and the histopathology of ear wound closure in young (8 weeks old) C57BL/6 and BALB/c mice. We also used middle-aged (40 weeks old) C57BL/6 mice to evaluate the influence of aging on this process. A circular through-and-through hole was made in the ear, photographs were taken at different times after injury and wound area was measured with digital analysis software. The percentages of closed area measured on day 100 were: 23.57 +/- 8.66% for young BALB/c mice, 56.47 +/- 7.39% for young C57BL/6 mice, and 75.31 +/- 23.65% for middle-aged C57BL/6 mice. Mice were sacrificed on days 1, 3, 5, 25, 44, and 100 for histological evaluation with hematoxylin and eosin, Gomori's trichrome, periodic acid-Schiff, or picrosirius red staining. In young mice of both strains, healing included re-epithelialization, chondrogenesis, myogenesis, and collagen deposition. Young C57BL/6 and BALB/c mice differed in the organization of collagen fibers visualized using picrosirius-polarization. Sebaceous glands and hair follicles regenerated and chondrogenesis was greater in young C57BL/6 mice. In middle-aged C57BL/6 mice all aspects of regeneration were depressed. The characteristics of regeneration were present during ear wound healing in both young BALB/c and young C57BL/6 mice although they differed in intensity and pattern. Greater ear wound closure in middle-aged C57BL/6 mice was not correlated with regeneration.


Subject(s)
Ear Cartilage/injuries , Regeneration/physiology , Wound Healing/physiology , Age Factors , Animals , Ear Cartilage/physiology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Species Specificity
12.
Hum Reprod ; 22(8): 2196-201, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17569674

ABSTRACT

BACKGROUND: The role of progestogens in haemostasis is controversial. Our objective is to evaluate the haemostatic effects of an etonogestrel-releasing implant. METHODS: This open-label, self-controlled, longitudinal study involved 20 healthy women receiving subcutaneous etonogestrel-releasing implants. At baseline, 1, 3 and 6 months, we measured the following: activated partial thromboplastin time; prothrombin time; thrombin time; fibrinogen; coagulation factors II, V, VII, VIII, IX, X and XI; von Willebrand factor; activated protein C (APC); antithrombin; free protein S; plasminogen activator inhibitor type 1 (PAI-1); alpha2-antiplasmin; thrombin-antithrombin (TAT) complex; prothrombin fragment 1 + 2 (F1 + 2); D-dimers; APC resistance. Statistical analyses included the Friedman test and ANOVA. RESULTS: Levels of APC (P < 0.01), factor II (P = 0.02), factor VII (P = 0.006), factor X (P = 0.01) and F1 + 2 (P < 0.001) were reduced, whereas those of PAI-1 (P = 0.01) and factor XI (P = 0.006) were transitory increased. All of these values, however, remained within normal ranges. Surprisingly, TAT concentrations fell below the normal range (P < 0.001). CONCLUSIONS: Our findings suggest that the etonogestrel-releasing implant does not induce a prothrombotic pattern during the first six months of use, and that its use is associated with a reduction in thrombin generation.


Subject(s)
Blood Coagulation/drug effects , Desogestrel/administration & dosage , Adult , Antithrombins/metabolism , Desogestrel/pharmacology , Drug Implants , Female , Fibrin Fibrinogen Degradation Products/metabolism , Humans , Prospective Studies , Protein C/metabolism , Protein S/metabolism , Thromboembolism/prevention & control , Venous Thrombosis/prevention & control , alpha-2-Antiplasmin/metabolism
13.
Acta cir. bras ; 20(supl.1): 152-158, 2005.
Article in Portuguese | LILACS | ID: lil-474171

ABSTRACT

PURPOSE: To assess the frequency of stress and anxiety levels in infertile women, and to correlate these aspects with risk factors, in order to obtain data for specific psychological guidance. METHODS: The case-control study included a total of 302 women, 152 being infertile (case group: 30.3 +/- 5.4 years), and 150 non-fertile (control group: 25.7 +/- 7.9 years). The quantitative approach involved the application of Lipp's Stress Symptoms Inventory and State-Trait Anxiety Inventory. Response variables considered were: stress frequency and anxiety scores (State and Trait). Statistical analysis was performed by using the Chi-squared and Mann-Whitney tests, and logistical regression to test associations between response variables and considered risk factors. Statistical significance was defined as p < 0.05. RESULTS: The stress was more frequent in the case group than the control group (61.8 and 36.0%, respectively), however, no significant differences were observed between groups in relation to stress phases and predominant symptoms. With respect to anxiety, there were no significant differences between case and control groups as to median state scores (39.5 and 41.0; respectively) and anxiety trait scores (44.0 and 42.0; respectively). Factors significantly associated with greater risk for high anxiety scores in the case group were: primary infertility, unawareness of the causal factor, diagnostic phase investigation, religion, lack of children from other marriages. CONCLUSIONS: It can be concluded that infertile women are more vulnerable to stress; however, they are capable of adapting to stressful events without serious physical or psychological compromising.


Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Anxiety/diagnosis , Stress, Psychological/diagnosis , Infertility, Female/psychology , Adaptation, Psychological , Anxiety/epidemiology , Brazil/epidemiology , Epidemiologic Methods , Stress, Psychological/epidemiology , Personality Inventory , Psychometrics
14.
Braz. j. phys. ther. (Impr.) ; 8(1): 89-95, jan.-abr. 2004. ilus
Article in Portuguese | LILACS | ID: lil-384524

ABSTRACT

O controle autonomico do coracao pode ser investigado a partir da analise da variabilidade da requencia cardiaca (VFC). Sabe-se que o aparecimento de doencas cardiovasculares (DCV) em mulheres aumenta com a idade, principalmente apos a menopausa, quando o risco torna-se similar ao observado em homens. Assim, o objetivo deste trabalho e analisar e comparar a VFC de homens de meia-idade e de mulheres pos-menopausa em condicoes de repouso. Foram estudados dois grupos saudaveis e sedentarios, sendo 10 homens de meia-idade (52,6 +- 2,63 anos) e 10 mulheres pos-menopausa (56,8+-5,09 anos) que nao faziam uso de terapia de reposicao hormonal. A frequencia cardiaca e os intervalos R-R (iR-R) foram obtidos a partir de eletrocardiograma em tempo real, batimento a batimento, durante 6 minutos em condicoes de repouso, nas posicoes supina(S) e sentada(SE). Para analise da VFC foram calculados os indices RMSM e RMSSD dos iR-R em milissegundo(ms). Nao foram observadas diferencas estatisticamente significativas nos valores dos indices RMSM e RMSSD entre os homens e as mulheres e entre as posicoes supina e sentada de ambos os grupos. A reducao da VFC observada em ambos os grupos estudados sugere similar decrescimo da modulacao parasimpatica sobre o coracao, fato que pode contribuir para o aumento do risco de DCV observado nessa faixa etaria em ambos os sexos


Subject(s)
Heart Rate , Men , Middle Aged , Postmenopause , Rest , Women
15.
Climacteric ; 6(2): 140-5, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12841884

ABSTRACT

BACKGROUND: Raloxifene therapy is associated with a three-fold increase in the risk for venous thromboembolism; however, its effects on the hemostatic system in postmenopausal women have not been well defined. OBJECTIVE: To determine the effects of raloxifene therapy on the levels of natural anticoagulant proteins in postmenopausal women. METHODS: Sixteen healthy postmenopausal women were enrolled in this prospective longitudinal study. The patients were treated with raloxifene hydrochloride (60 mg/day) for a period of 6 months. Antithrombin and protein C activities and protein S antigen levels were measured in all users at baseline, and after 1, 3 and 6 months of treatment. Statistical analysis included one-way analysis of variance (ANOVA) and the Bonferroni test for multiple comparisons among the study periods. RESULTS: Statistically significant 5.1% and 6.5% reductions of plasma antithrombin activity were observed at 3 and 6 months of therapy, respectively (p < 0.05). Compared with baseline, raloxifene did not significantly affect protein C activity or protein S level. CONCLUSIONS: The results of this prospective study show for the first time that raloxifene use is associated with a significant reduction in plasma antithrombin activity. This effect may contribute to a procoagulant state and partly explain the increased risk of venous thromboembolism in raloxifene users.


Subject(s)
Antithrombins/drug effects , Protein C/drug effects , Protein S/drug effects , Raloxifene Hydrochloride/pharmacology , Selective Estrogen Receptor Modulators/pharmacology , Aged , Female , Humans , Longitudinal Studies , Middle Aged , Postmenopause , Prospective Studies , Raloxifene Hydrochloride/administration & dosage , Raloxifene Hydrochloride/adverse effects , Selective Estrogen Receptor Modulators/administration & dosage , Selective Estrogen Receptor Modulators/adverse effects , Venous Thrombosis/chemically induced
16.
Chemosphere ; 46(9-10): 1409-11, 2002 Mar.
Article in English | MEDLINE | ID: mdl-12002468

ABSTRACT

In order to further understand the contamination of the citrus pulp pellets (CPP) that were exported to Europe in 1997 we examined both contaminated lime and CPP samples for the distribution of polychlorinated biphenyls (PCBs) and chlorinated benzenes (tri-hexa). Standard isotope dilution techniques were applied for all samples, which were analysed by selected ion monitoring high resolution GC-MS. Lime that is used in the production of CPP product is highly contaminated with PCBs and chlorobenzenes.


Subject(s)
Animal Feed , Calcium Compounds/chemistry , Citrus/chemistry , Environmental Pollutants/analysis , Food Contamination , Oxides/chemistry , Polychlorinated Biphenyls/analysis , Brazil , Commerce , Environmental Monitoring , Europe , Gas Chromatography-Mass Spectrometry
17.
Chemosphere ; 46(9-10): 1413-6, 2002 Mar.
Article in English | MEDLINE | ID: mdl-12002469

ABSTRACT

After an exhaustive investigation, in 1997 the source of the milk contamination in Germany was traced to citrus pulp pellets originating from Brazil. It has been shown that lime was the source of the PCDD/F contamination of these products. After this conclusion, a continuous monitoring program has been performed over a two year period and the results are presented in this paper. Standard isotope dilution techniques were used for all samples, which were analyzed by selected ion monitoring high resolution GC-MS.


Subject(s)
Animal Feed , Benzofurans/analysis , Calcium Compounds/chemistry , Citrus/chemistry , Food Contamination , Oxides/chemistry , Polychlorinated Dibenzodioxins/analogs & derivatives , Polychlorinated Dibenzodioxins/analysis , Soil Pollutants/analysis , Animals , Brazil , Commerce , Dibenzofurans, Polychlorinated , Germany , Milk
18.
Braz. j. med. biol. res ; 34(12): 1539-1545, Dec. 2001. ilus, tab
Article in English | LILACS | ID: lil-301411

ABSTRACT

Although the role of oxidized lipoproteins is well known in atherogenesis, the role of vitamin E supplementation is still controversial. There is also little information about cholesterol metabolism (hepatic concentration and fecal excretion) in the new models of atherosclerosis. In the present study, we evaluated the effect of moderate vitamin E supplementation on cholesterol metabolism and atherogenesis in apolipoprotein E (apo E)-deficient mice. Apo E-deficient mice were fed an atherogenic diet containing 40 or 400 mg/kg of alpha-tocopherol acetate for 6 weeks. Total cholesterol in serum and liver and 3-OH-alpha-sterols in feces, and fecal excretion of bile acids were determined and histological analyses of aortic lesion were performed. A vitamin E-rich diet did not affect body weight, food intake or serum cholesterol. Serum and hepatic concentrations of cholesterol as well as sterol concentration in feces were similar in both groups. However, when compared to controls, the alpha-tocopherol-treated mice showed a reduction of about 60 percent in the atherosclerotic lesions when both the sum of lesion areas and the average of the largest lesion area were considered. These results demonstrate that supplementation of moderate doses of alpha-tocopherol was able to slow atherogenesis in apo E-deficient mice and to reduce atherogenic lipoproteins without modifying the hepatic pool or fecal excretion of cholesterol and bile acids


Subject(s)
Animals , Mice , Antioxidants , Apolipoproteins E , Cholesterol , Diet, Atherogenic , Vitamin E , Aorta , Bile Acids and Salts , Body Weight , Cholesterol , Feces , Liver , Mice, Inbred C57BL
19.
Braz J Med Biol Res ; 34(12): 1539-45, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11717706

ABSTRACT

Although the role of oxidized lipoproteins is well known in atherogenesis, the role of vitamin E supplementation is still controversial. There is also little information about cholesterol metabolism (hepatic concentration and fecal excretion) in the new models of atherosclerosis. In the present study, we evaluated the effect of moderate vitamin E supplementation on cholesterol metabolism and atherogenesis in apolipoprotein E (apo E)-deficient mice. Apo E-deficient mice were fed an atherogenic diet containing 40 or 400 mg/kg of alpha-tocopherol acetate for 6 weeks. Total cholesterol in serum and liver and 3-OH-alpha-sterols in feces, and fecal excretion of bile acids were determined and histological analyses of aortic lesion were performed. A vitamin E-rich diet did not affect body weight, food intake or serum cholesterol. Serum and hepatic concentrations of cholesterol as well as sterol concentration in feces were similar in both groups. However, when compared to controls, the alpha-tocopherol-treated mice showed a reduction of about 60% in the atherosclerotic lesions when both the sum of lesion areas and the average of the largest lesion area were considered. These results demonstrate that supplementation of moderate doses of alpha-tocopherol was able to slow atherogenesis in apo E-deficient mice and to reduce atherogenic lipoproteins without modifying the hepatic pool or fecal excretion of cholesterol and bile acids.


Subject(s)
Antioxidants/administration & dosage , Apolipoproteins E/deficiency , Arteriosclerosis/etiology , Cholesterol/metabolism , Diet, Atherogenic , alpha-Tocopherol/administration & dosage , Animals , Aortic Diseases/etiology , Bile Acids and Salts/analysis , Body Weight , Cholesterol/analysis , Feces/chemistry , Liver/chemistry , Mice , Mice, Inbred C57BL
20.
Braz J Med Biol Res ; 34(7): 871-7, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11449305

ABSTRACT

The aim of the present study was to compare the modulation of heart rate in a group of postmenopausal women to that of a group of young women under resting conditions on the basis of R-R interval variability. Ten healthy postmenopausal women (mean +/- SD, 58.3 +/- 6.8 years) and 10 healthy young women (mean +/- SD, 21.6 +/- 0.82 years) were submitted to a control resting electrocardiogram (ECG) in the supine and sitting positions over a period of 6 min. The ECG was obtained from a one-channel heart monitor at the CM5 lead and processed and stored using an analog to digital converter connected to a microcomputer. R-R intervals were calculated on a beat-to-beat basis from the ECG recording in real time using a signal-processing software. Heart rate variability (HRV) was expressed as standard deviation (RMSM) and mean square root (RMSSD). In the supine position, the postmenopausal group showed significantly lower (P<0.05) median values of RMSM (34.9) and RMSSD (22.32) than the young group (RMSM: 62.11 and RMSSD: 49.1). The same occurred in the sitting position (RMSM: 33.0 and RMSSD: 18.9 compared to RMSM: 57.6 and RMSSD: 42.8 for the young group). These results indicate a decrease in parasympathetic modulation in postmenopausal women compared to young women which was possibly due both to the influence of age and hormonal factors. Thus, time domain HRV proved to be a noninvasive and sensitive method for the identification of changes in autonomic modulation of the sinus node in postmenopausal women.


Subject(s)
Heart Rate/physiology , Parasympathetic Nervous System/physiology , Postmenopause/physiology , Rest/physiology , Adult , Age Factors , Aged , Electrocardiography , Female , Humans , Middle Aged , Signal Processing, Computer-Assisted
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