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1.
Nutrients ; 9(1)2016 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-28036059

RESUMO

The objective of this study was to profile plasma amino acids (AA) and derivatives of their metabolism during the periparturient period in response to supplemental rumen-protected methionine (MET) or rumen-protected choline (CHOL). Forty cows were fed from -21 through 30 days around parturition in a 2 × 2 factorial design a diet containing MET or CHOL. MET supply led to greater circulating methionine and proportion of methionine in the essential AA pool, total AA, and total sulfur-containing compounds. Lysine in total AA also was greater in these cows, indicating a better overall AA profile. Sulfur-containing compounds (cystathionine, cystine, homocystine, and taurine) were greater in MET-fed cows, indicating an enriched sulfur-containing compound pool due to enhanced transsulfuration activity. Circulating essential AA and total AA concentrations were greater in cows supplied MET due to greater lysine, arginine, tryptophan, threonine, proline, asparagine, alanine, and citrulline. In contrast, CHOL supply had no effect on essential AA or total AA, and only tryptophan and cystine were greater. Plasma 3-methylhistidine concentration was lower in response to CHOL supply, suggesting less tissue protein mobilization in these cows. Overall, the data revealed that enhanced periparturient supply of MET has positive effects on plasma AA profiles and overall antioxidant status.


Assuntos
Aminoácidos/sangue , Fenômenos Fisiológicos da Nutrição Animal , Carbono/metabolismo , Colina/administração & dosagem , Metionina/administração & dosagem , Aminoácidos Essenciais/sangue , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Bovinos , Colina/sangue , Cistationina/sangue , Cistina/sangue , Dieta/veterinária , Suplementos Nutricionais , Feminino , Homocistina/sangue , Fígado/metabolismo , Metionina/sangue , Metilistidinas/sangue , Parto , Gravidez , Prenhez , Rúmen/metabolismo , Taurina/sangue , Triptofano/sangue
2.
J Sep Sci ; 37(1-2): 30-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24302617

RESUMO

We have demonstrated for the first time the suitability of fluorosurfactant-capped spherical gold nanoparticles as HPLC postcolumn colorimetric reagents for the direct assay of cysteine, homocysteine, cystine, and homocystine. The success of this work was based on the use of an on-line tris(2-carboxyethyl)phosphine reduction column for cystine and homocystine. Several parameters affecting the separation efficiency and the postcolumn colorimetric detection were thoroughly investigated. Under the optimized conditions, cysteine, homocysteine, cystine, and homocystine in human urine and plasma samples were determined. Detection limits for cysteine, homocysteine, cystine, and homocystine ranged from 0.16-0.49 µM. The accuracy in terms of recoveries ranged between 94.0-102.1%. This proposed method was rapid, inexpensive, and simple.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cisteína/análise , Cistina/análise , Homocisteína/análise , Homocistina/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Cisteína/sangue , Cisteína/urina , Cistina/sangue , Ouro/química , Homocisteína/sangue , Homocisteína/urina , Homocistina/sangue , Homocistina/urina , Humanos , Nanopartículas/química
3.
Zhonghua Er Ke Za Zhi ; 51(3): 194-8, 2013 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-23751581

RESUMO

OBJECTIVE: Combined methylmalonic acidemia with homocystinuria is a common form of methylmalonic acidemia in China. Patients with this disease can progress to death without timely and effective treatment. This study aimed to analyze the treatment outcomes of patients with combined methylmalonic acidemia and homocystinuria. METHOD: From September 2004 to April 2012, 58 patients with combined methylmalonic acidemia and homocystinuria (34 males and 24 females) were diagnosed and treated in our hospital. Fifty cases were from clinical patients including 42 early-onset cases and 8 late-onset cases. Their age when they were diagnosed ranged from 18 days to 30.8 years. The other 8 cases were from newborn screening. All the patients were treated with vitamin B12, betaine, folic acid, vitamin B6, and L-carnitine. The physical and neuropsychological development, general laboratory tests, the levels of amino acids, acylcarnitines, and homocysteine in blood, and organic acids in urine were followed up. RESULT: The follow-up period ranged from 1 month to 7.1 years. Three cases died (all were early-onset cases). In the other patients after treatment, the symptoms such as recurrent vomiting, seizures, lethargy, and poor feeding disappeared, muscle strength and muscle tension were improved, and general biochemical abnormalities such as anemia and metabolic acidosis were corrected. Among the surviving 55 cases, 49 had neurological impairments such as developmental delay and mental retardation. The median levels of blood propionylcarnitine and its ratio with acetylcarnitine, serum homocysteine, and urine methylmalonic acid were significantly decreased (P < 0.01), from 7.73 µmol/L (ranged from 1.5 to 18.61 µmol/L), 0.74 (ranged from 0.29 to 2.06), 97.3 µmol/L (ranged from 25.1 to 250 µmol/L) and 168.55 (ranged from 3.66 to 1032.82) before treatment to 2.74 µmol/L (ranged from 0.47 to 12.09 µmol/L), 0.16 (ranged from 0.03 to 0.62), 43.8 µmol/L (ranged from 17 to 97.8 µmol/L) and 6.81 (ranged from 0 to 95.43) after treatment, respectively. CONCLUSION: Patients with combined methylmalonic acidemia and homocystinuria respond to a combined treatment consisting of supplementation of hydroxycobalamin, betaine, folic acid, vitamin B6 and L-carnitine with clinical and biochemical improvement. But the long-term outcomes are unsatisfactory, with neurological sequelae in most patients.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/terapia , Homocistinúria/terapia , Hidroxocobalamina/uso terapêutico , Vitamina B 12/uso terapêutico , Adolescente , Adulto , Erros Inatos do Metabolismo dos Aminoácidos/sangue , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Betaína/administração & dosagem , Betaína/uso terapêutico , Carnitina/análogos & derivados , Carnitina/sangue , Criança , Pré-Escolar , Feminino , Seguimentos , Homocistina/sangue , Homocistinúria/sangue , Homocistinúria/diagnóstico , Humanos , Hidroxocobalamina/administração & dosagem , Lactente , Recém-Nascido , Masculino , Ácido Metilmalônico/urina , Triagem Neonatal , Resultado do Tratamento , Vitamina B 12/administração & dosagem , Deficiência de Vitamina B 12/congênito , Adulto Jovem
4.
Neurosciences (Riyadh) ; 17(3): 219-25, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22772926

RESUMO

OBJECTIVE: To determine the relation between maternal Helicobacter pylori (H. pylori) infection and the occurrence of neural tube defects (NTDs) in newborns. METHODS: This hospital-based case-control study was carried out in Dezyani Teaching Hospital, Gorgan, Northern Iran from April 2007 to March 2009. Thirty-five mothers with NTD-affected newborns, and 53 mothers with healthy newborns were considered the cases and controls. A peripheral blood sample was obtained from all subjects, and H. pylori infections were tested by H. pylori serum antibody. The serum folic acid, vitamin B12, ferritin, and homocysteine concentrations were measured by laboratory tests. Data were analyzed using odds ratio (OR) and logistic regression. RESULTS: Forty-three percent of cases, and 26% of controls were positive for H. pylori IgG antibody, and this difference was not significant. The H. pylori seropositivity non significantly increased the risk of NTD-affected pregnancies (OR: 2.08; 95% confidence interval [CI]: 0.84-5.17, p=0.11). Serum vitamin B12 deficiency was detected in 17% of cases and 13% of controls, and folic acid deficiency in 17% of cases and 13% of controls (p=0.61). The H. pylori seropositivity was non significantly associated with low serum folate (OR 1.93 CI: 0.58-6.4, p=0.34) and ferritin (OR 1.24; CI: 0.42-3.60, p=0.68). CONCLUSION: Maternal H. pylori infection can increase the risk of occurrence of NTDs in newborns.


Assuntos
Infecções por Helicobacter/epidemiologia , Defeitos do Tubo Neural/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Proteínas de Bactérias/imunologia , Estudos de Casos e Controles , Feminino , Ferritinas/sangue , Ácido Fólico/sangue , Infecções por Helicobacter/sangue , Homocistina/sangue , Humanos , Imunoglobulina G/sangue , Recém-Nascido , Modelos Logísticos , Masculino , Defeitos do Tubo Neural/sangue , Irlanda do Norte/epidemiologia , Razão de Chances , Gravidez , Efeitos Tardios da Exposição Pré-Natal/sangue , Estudos Retrospectivos , Fatores de Risco , Vitamina B 12/sangue , Adulto Jovem
6.
J Nutr ; 138(12): 2502-9, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19022979

RESUMO

Poor folate status is associated with cognitive decline and dementia in older adults. Although impaired brain methylation activity and homocysteine toxicity are widely thought to account for this association, how folate deficiency impairs cognition is uncertain. To better define the role of folate deficiency in cognitive dysfunction, we fed rats folate-deficient diets (0 mg FA/kg diet) with or without supplemental L-methionine for 10 wk, followed by cognitive testing and tissue collection for hematological and biochemical analysis. Folate deficiency with normal methionine impaired spatial memory and learning; however, this impairment was prevented when the folate-deficient diet was supplemented with methionine. Under conditions of folate deficiency, brain membrane content of the methylated phospholipid phosphatidylcholine was significantly depleted, which was reversed with supplemental methionine. In contrast, neither elevated plasma homocysteine nor brain S-adenosylmethionine and S-adenosylhomocysteine concentrations predicted cognitive impairment and its prevention by methionine. The correspondence of cognitive outcomes to changes in brain membrane phosphatidylcholine content suggests that altered phosphatidylcholine and possibly choline metabolism might contribute to the manifestation of folate deficiency-related cognitive dysfunction.


Assuntos
Transtornos Cognitivos/etiologia , Transtornos Cognitivos/prevenção & controle , Suplementos Nutricionais , Deficiência de Ácido Fólico/dietoterapia , Deficiência de Ácido Fólico/psicologia , Metionina/administração & dosagem , Animais , Encéfalo/metabolismo , Transtornos Cognitivos/sangue , Transtornos Cognitivos/metabolismo , Deficiência de Ácido Fólico/complicações , Deficiência de Ácido Fólico/metabolismo , Homocistina/sangue , Lecitinas/metabolismo , Masculino , Aprendizagem em Labirinto , Desempenho Psicomotor , Ratos , Ratos Sprague-Dawley , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo
7.
Biosci Biotechnol Biochem ; 72(6): 1607-10, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18540092

RESUMO

There was an inverse correlation between the plasma homocysteine concentration and dietary protein level or protein intake when a soybean protein isolate (SPI) was used as a protein source for rats. The hepatic cystathionine beta-synthase activity increased in response to the dietary SPI level. The results suggest that a high-protein diet might be an effective means to lower the plasma homocysteine concentration, probably through enhancement of the homocysteine-metabolizing activity.


Assuntos
Homocistina/sangue , Proteínas de Soja/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar
8.
Thromb Res ; 121(1): 25-32, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17604826

RESUMO

INTRODUCTION: A large body of evidence links plasma homocysteine (Hcy) concentrations and cardiovascular disease. A common MTHFR polymorphism (C677T) leads to a variant with reduced activity and associated with increased Hcy levels. Coronary surgery precipitates a significant and sustained increase in the blood concentrations of Hcy and elevated levels of plasma Hcy have been associated to saphenous vein (SV) graft disease after CABG. However, the effects of MTHFR genotypes in the incidence of cardiovascular events after CABG have not been investigated prospectively. Here, we investigate whether MTHFR gene variants are associated with an increased cardiovascular risk in individuals submitted to CABG. We also propose a molecular mechanism to explain our findings. METHODS: We performed MTHFR C677T genotypes in 558 patients with two or three vessel-disease and normal left ventricular function prospectively followed in the MASS II Trial, a randomized study to compare treatments for multivessel CAD and preserved left ventricle function. Follow-up time was 5 years. Survival curves were calculated with the Kaplan-Meier method, and evaluated with the log-rank statistic. We assessed the relationship between baseline variables and the composite end-point of death, myocardial infarction and refractory angina using a Cox proportional hazards survival model. Finally, using an ex-vivo organ culture we have reproduced the arterialization of SV implants by culturing human SV either under venous hemodynamic condition (flow: 5 mL/min; no pressure) or arterial hemodynamic condition (flow: 50 mL/min; pressure: 80 mm Hg) for 1 day. MTHFR gene expression was quantified by real time RT-PCR in 15 SV from different individuals in both experimental conditions. RESULTS: There were no significant differences among individuals within each genotype group for baseline clinical characteristics. A statistically significant association between the TT genotype, associated with increased serum levels of Hcy, and cardiovascular mortality after 5 years was verified (p=0.007) in individuals submitted to CABG surgery. In addition, MTHFR TT genotype was still significantly associated with a 4.4 fold increased risk in cardiovascular outcomes (p=0.01) even after adjustment of a Cox multivariate model for age, sex, hypertension, diabetes, LDL, HDL, triglycerides, and number of diseased vessels in this population. Finally, a significant reduction in MTHFR gene expression was demonstrated in human SV when submitted to an arterial hemodynamic condition (p=0.02). CONCLUSIONS: There is a dynamic regulation of MTHFR gene expression during the arterialization process of human saphenous vein grafts resulting in lower levels of gene expression when in an arterial hemodynamic condition. In addition, the C677T MTHFR functional variant is associated with a worse outcome in individuals submitted to CABG. Taken together, these data suggest an important role of Hcy metabolism in individuals after CABG.


Assuntos
Doença da Artéria Coronariana/genética , Regulação Enzimológica da Expressão Gênica , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Revascularização Miocárdica/mortalidade , Polimorfismo de Nucleotídeo Único , Idoso , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/mortalidade , Ponte de Artéria Coronária/efeitos adversos , Doença da Artéria Coronariana/mortalidade , Coleta de Dados , Feminino , Genótipo , Homocistina/sangue , Homocistina/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade , Complicações Pós-Operatórias/mortalidade , RNA Mensageiro/análise , Veia Safena/cirurgia
9.
Ann Thorac Surg ; 84(1): 43-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17588380

RESUMO

BACKGROUND: After coronary artery bypass grafting procedures with saphenous vein, there is a protracted elevation of plasma homocysteine and copper. These interact to elicit endothelial dysfunction through promotion of superoxide. It has been suggested that angiogenesis and the formation of a neovasa vasorum is important in mediating vein graft patency. A novel in vitro model of angiogenesis in isolated pig saphenous veins was therefore developed to study the effect of homocysteine and copper and the role of superoxide on tubule growth, an index of angiogenesis. METHODS: Two-millimeter rings of porcine saphenous veins were embedded in fibrin, incubated for 2 weeks with homocysteine and copper chloride, and tubules counted. RESULTS: Tubule growth in cultured saphenous veins, which was inhibited by angiostatin, occurred in a time-dependent manner during a 14-day period. Copper chloride alone at 1 microM and 10 microM augmented microtubule formation, whereas homocysteine alone at up to 1 mM had no effect. Homocysteine and copper chloride together markedly inhibited microtubule formation. Significant inhibition of tubule formation and superoxide formation was elicited with inhibitors of nicotinamide adenine dinucleotide phosphate oxidase, mitochondrial respiration, and xanthine oxidase. Copper chloride augmented superoxide formation, but homocysteine had no effect. Homocysteine and copper chloride together also augmented superoxide formation. CONCLUSIONS: These data indicate that the increase in plasma homocysteine and copper may exert a deleterious effect on graft patency by preventing the formation of a neovasa vasorum, thereby promoting hypoxia. This effect is mediated by a mechanism independent of superoxide which actually promotes angiogenesis in this model.


Assuntos
Cobre/farmacologia , Ponte de Artéria Coronária , Homocistina/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Veia Safena/efeitos dos fármacos , Animais , Cobre/sangue , Ponte de Artéria Coronária/efeitos adversos , Ácido Fólico/farmacologia , Homocistina/sangue , Técnicas In Vitro , Óxido Nítrico Sintase Tipo III/análise , Veia Safena/fisiologia , Veia Safena/transplante , Stents , Superóxidos/metabolismo , Suínos , Grau de Desobstrução Vascular
10.
Anal Chem ; 79(2): 666-72, 2007 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17222035

RESUMO

Gold nanoparticles (GNPs) capped with nonionic fluorosurfactant molecules (Zonyl FSN) were synthesized, and with the colloidal solution as a probe reagent, a new postcolumn colorimetric detection method for HPLC assay of homocysteine (Hcy) has been developed. The FSN-capped GNPs exhibited excellent stability in aqueous solutions, even in the presence of high salt. The aggregation of the GNPs could be induced by either Hcy or cysteine, resulting in an absorption decrease of the colloidal solution at 525 nm and an absorption increase at longer wavelengths (600-700 nm); however, the GNPs did not respond to other amino acids and biomolecules such as glutathione, cysteinylglycine, and glucose. Under optimal conditions (i.e., high salt, neutral pH, and approximately 70 degrees C), the color change of the GNP solution could almost complete ( approximately 90%) within approximately 30 s upon the addition of Hcy. The high selectivity and very fast kinetics of the reaction make it a promising system for HPLC postcolumn detection. The new technique has been employed to determine total Hcy levels in human urine and plasma samples, and the results are satisfactory.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ouro/química , Homocistina/análise , Nanopartículas/química , Tensoativos/química , Aminoácidos/análise , Homocistina/sangue , Homocistina/urina , Humanos , Compostos Orgânicos/química
13.
Mov Disord ; 21(10): 1780-2, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16856143

RESUMO

Dystonia complicating homocystinuria is extremely rare in the absence of thromboembolic disease. We report a unique case of recurrent dystonia in a patient with homocystinuria secondary to pyridoxine-unresponsive cystathionine beta-synthase deficiency. Brain MRI was normal. Two biochemical markers for homocystinuria, homocystine and methionine, were markedly elevated during periods when our patient manifested dystonia. These findings suggest that accumulation of sulfur-containing amino acids may contribute to the pathophysiology of dystonia in patients with homocystinuria.


Assuntos
Distonia/diagnóstico , Homocistinúria/diagnóstico , Adulto , Encéfalo/metabolismo , Distonia/fisiopatologia , Deficiência de Ácido Fólico/diagnóstico , Deficiência de Ácido Fólico/fisiopatologia , Homocistina/sangue , Homocistinúria/fisiopatologia , Humanos , Masculino , Metionina/sangue , Recidiva , Torcicolo/diagnóstico , Torcicolo/fisiopatologia
14.
Eur J Nutr ; 45(6): 311-9, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16699836

RESUMO

BACKGROUND: Neural tube defects (NTD) are mainly of multifactorial origin. Maternal treatment with valproic acid (VPA) during pregnancy induces NTD in susceptible fetuses. Elevated levels of homocysteine are observed in pregnancies with NTD. The mechanism by which homocysteine might cause NTD is unknown. AIM OF THE STUDY: The aim of this study was to determine if homocystine would augment VPA-induced exencephaly in an experimental model. METHODS: Groups of mice were injected (IP) on gestational day 8 (GD) with a single dose of 75 mg/kg of L: -Homocystine (HC) or a proportionate volume of saline, followed by a single dose of 600 mg/kg of VPA or an equal volume of saline. In a second experiment, mice were treated with a daily dose of 75 mg/kg of HC or an equal volume of saline (IP) from GD 5 and continued through GD 10. These animals had a single exposure to 600 mg/kg of VPA or saline (IP) on GD 8. All animals were killed by cervical dislocation on GD 18. Plasma homocysteine, folate and vitamin B12 were determined on GD 8 and GD 10 from single and multiple dose groups of mice, respectively, from additional experiments. RESULTS: The VPA and HC+VPA induced significantly higher rates of embryonic resorption and intrauterine growth retardation (IUGR) than HC or saline alone. HC + VPA groups had significantly more numerous fetuses with severe IUGR than HC alone or VPA alone groups. Both single and multiple doses of HC augmented VPA-induced reduction in fetal body weight. Successive doses of HC did not augment the rate of IUGR more significantly than a single dose of HC. Incidence of exencephaly was significantly enhanced in the HC + VPA groups compared to that in the HC or VPA alone groups. HC alone was not teratogenic. Plasma homocysteine levels increased several fold both in HC and HC + VPA groups and the increase was not particularly more marked in multiple dose groups than in the single dose groups. VPA did not elevate homocysteine concentration. Both FA and vitamin B12 concentrations were reduced by VPA, HC and HC + VPA, but HC and VPA when combined did not produce an additive effect on vitamin levels. CONCLUSION: These data indicate that HC and VPA interact in neurulation stage embryos, affect fundamental processes of closure of the neural tube and lead to enhanced incidence of NTD.


Assuntos
Homocistina/farmacologia , Defeitos do Tubo Neural/induzido quimicamente , Teratogênicos/farmacologia , Ácido Valproico/farmacologia , Anormalidades Induzidas por Medicamentos , Animais , Encéfalo/anormalidades , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Retardo do Crescimento Fetal/sangue , Retardo do Crescimento Fetal/induzido quimicamente , Ácido Fólico/sangue , Idade Gestacional , Homocisteína/sangue , Homocistina/sangue , Camundongos , Defeitos do Tubo Neural/sangue , Defeitos do Tubo Neural/embriologia , Gravidez , Distribuição Aleatória , Ácido Valproico/toxicidade , Vitamina B 12/sangue
15.
Am J Epidemiol ; 163(8): 700-8, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16484446

RESUMO

Homocysteine levels are associated with peripheral arterial disease (PAD) in observational studies. Lead and cadmium are risk factors for PAD that affect thiol metabolism, and they may partly explain the association of homocysteine with PAD. To evaluate the roles of lead and cadmium exposure in confounding the association between homocysteine and PAD, the authors performed a cross-sectional study among 4,447 persons aged > or = 40 years who participated in the 1999-2002 National Health and Nutrition Examination Survey (NHANES). PAD was defined as an ankle-brachial blood pressure index less than 0.90 in at least one leg. After adjustment for sociodemographic variables, the odds ratio for PAD in the highest quintile of homocysteine compared with the lowest was 1.92 (p(trend) = 0.004). Adjusting for blood lead and cadmium levels reduced this odds ratio to 1.37 (p(trend) = 0.13), and further adjusting for estimated glomerular filtration rate and smoking reduced it to 0.89 (p(trend) = 0.87). Adjustment for other risk factors did not affect this association. In the general population, the association of homocysteine level with PAD can be completely explained by confounding due to smoking, increased blood lead and cadmium levels, and impaired renal function. The association of lead and cadmium with PAD risk deserves further investigation.


Assuntos
Cádmio/sangue , Homocistina/sangue , Chumbo/sangue , Doenças Vasculares Periféricas/sangue , Adulto , Idoso , Fatores de Confusão Epidemiológicos , Estudos Transversais , Feminino , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Doenças Vasculares Periféricas/epidemiologia , Prevalência , Fatores de Risco , Fumar/sangue , Estados Unidos/epidemiologia
16.
Circ Res ; 98(4): 564-71, 2006 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-16439690

RESUMO

Hyperhomocysteinemia, a risk factor for cardiovascular disease, is caused by nutritional or genetic disturbances in homocysteine metabolism. A polymorphism in methylenetetrahydrofolate reductase (MTHFR) is the most common genetic cause of mild hyperhomocysteinemia. To examine mechanisms by which an elevation in plasma homocysteine leads to vascular disease, we first performed microarray analyses in livers of Mthfr-deficient mice and identified differentially expressed genes that are involved in lipid and cholesterol metabolism. Microarrays and RT-PCR showed decreased mRNA for apolipoprotein A (ApoA)-IV and for ApoA-I and increased mRNA for cholesterol 7alpha hydroxylase (Cyp7A1) in Mthfr(+/-) mice compared with Mthfr(+/+) mice. Western blotting revealed that ApoA-I protein levels in liver and plasma of Mthfr(+/-) mice were 52% and 62% of levels in the respective tissues of Mthfr(+/+) mice. We also performed Western analysis for plasma ApoA-I protein levels in 60 males with coronary artery disease and identified a significant (P<0.01) negative correlation (-0.33) between ApoA-I and plasma homocysteine levels. This cohort also displayed a negative correlation (-0.24, P=0.06) between high-density lipoprotein cholesterol and plasma homocysteine. Treatment of HepG2 cells with supraphysiological levels of 5 mmol/L homocysteine reduced peroxisome proliferator-activated receptor (PPAR) alpha and ApoA-I protein levels and decreased ApoA-I promoter activity. Transfection with a PPARalpha construct upregulated ApoA-I and MTHFR. Our results suggest that hyperhomocysteinemia may increase risk of atherosclerosis by decreasing expression of ApoA-I and increasing expression of CYP7A1.


Assuntos
Apolipoproteína A-I/genética , Doença das Coronárias/metabolismo , Homocistina/sangue , Hiper-Homocisteinemia/metabolismo , Animais , Apolipoproteína A-I/análise , Apolipoproteína A-I/sangue , Colesterol 7-alfa-Hidroxilase/genética , HDL-Colesterol/sangue , Cistationina beta-Sintase/fisiologia , Fígado/metabolismo , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , PPAR alfa/fisiologia , Regiões Promotoras Genéticas , RNA Mensageiro/análise
17.
Przegl Lek ; 63(10): 979-84, 2006.
Artigo em Polonês | MEDLINE | ID: mdl-17288198

RESUMO

The aim of the study was to evaluate the influence of tobacco smoke on plasma concentration of atherogenic compounds, namely total homocysteine (tHcy), symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA). The study population consisted of 104 healthy males between the age of 34 and 45 years. Survey questionnaire and determination of plasma cotinine concentration were used to divide the group into smokers (62 males) and non-smokers (42 males). The arbitrary threshold value of plasma cotinine concentration was set to 15 ng/ml. High performance liquid chromatography (HPLC) was used to estimate the plasma concentration of tHcy, ADMA, SDMA and cotinine. Significantly higher (by 38.5%) plasma concentration of tHcy in the group of active smokers in comparison with non-smokers was observed. The concentration of ADMA and SDMA was found out to be higher by 12.8% and 13.5% respectively, however those differences were highly non-significant. Positive significant correlation between concentration of tHcy and cotinine was determined, in the smoking group as well as in the entire study population (r = 0.303, P = 0.017; r 0.257, P = 0.009 respectively). There was no evidence, however, of correlation between the concentration of both ADMA and SDMA and cotinine. Correlation between the concentrations of atherogenic parameters showed weak but significant correlations for tHcy versus ADMA and tHcy versus SDMA and high for the ADMA versus SDMA correlations (r = 0.671 in the smoking group and r = 0.672 in the entire population). The results obtained indicate that tobacco smoke probably has a weak influence on smokers' plasma ADMA and SDMA concentration, while significant rising the concentration of homocysteine, an independent risk factor of atherosclerosis.


Assuntos
Arginina/análogos & derivados , Homocistina/sangue , Fumar/sangue , Adulto , Arginina/sangue , Cromatografia Líquida de Alta Pressão , Cotinina/sangue , Humanos , Masculino , Pessoa de Meia-Idade
18.
Zhonghua Er Ke Za Zhi ; 43(11): 810-3, 2005 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-16316525

RESUMO

OBJECTIVE: The renal impairment in children with methylmalonic aciduria has seldom been reported. To improve knowledge in this aspect, clinical data of five cases with methylmalonic aciduria with renal involvement were analyzed and the results are reported in this paper, which may be of some help in early diagnosis, treatment and in achieving favorable prognosis. METHODS: Urine methylmalonic acid was measured by gas chromatography-mass spectrometry analysis, if the content exceeded the normal range and vitamin B12 deficiency was excluded, the diagnosis of methylmalonic aciduria was confirmed. Homocysteine in plasma was also measured with fluorescence polarization immunoassay to make sure if concomitant homocysteinemia existed. From January 2002 to January 2005, five patients who had renal impairment were diagnosed as methylmalonic aciduria by urinary organic acid analysis. Among them, three were male, two were female, aged from seven months to 26 years, with average of 13 years. Three were presented to pediatric nephrology clinic with hematuria, proteinuria or edema, the other two were presented to pediatric neurology clinic first for psychomotor retardation. Their clinical features, laboratory findings, treatment regimens and prognosis were analyzed and summarized. RESULTS: All the five patients with methylmalonic aciduria were found to have various degrees of renal impairment, manifested as hematuria or proteinuria. Among them, two cases had gross hematuria and three had microscopic hematuria. Edema was found in two cases and hypertension occurred in one case. Early indicators of renal damage, such as microalbunminuria, N-acetyl-beta-D glucosaminidase, transferrin and alpha-microglobulin showed glomerular and tubular dysfunction. Clinically nephrotic syndrome was diagnosed in one case, the other four cases were diagnosed as glomerulonephritis, and two cases had renal failure. Renal biopsy was performed in one case, tubulo-interstitial damage and mesangial proliferation appeared. Mental retardation and psychomotor disorder were chief nervous system complaints. Leukodystrophy was the main finding on imaging. Megaloblastic anemia was found in three cases. All the five patients were cobalamin-responsive type. Renal impairment was alleviated following treatment, edema and gross hematuria as well as hypertension disappeared later, proteinuria diminished, renal function improved, central nervous system symptoms and hematopoietic function ameliorated. CONCLUSION: In patients with hematuria, proteinuria or renal failure of unknown origin, metabolic screening and urinary organic acid analysis should be performed as early as possible to confirm the diagnosis.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/complicações , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Nefropatias/etiologia , Ácido Metilmalônico/urina , Adolescente , Adulto , Criança , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Homocistina/sangue , Humanos , Lactente , Testes de Função Renal , Masculino , Adulto Jovem
19.
Clin Chem Lab Med ; 43(12): 1373-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16309375

RESUMO

Hyperhomocysteinemia is regarded as an independent risk factor for vascular diseases, and homocysteine is supposed to contribute to oxidative stress and endothelial damage. Statin therapy is an established intervention to reduce the risk of acute events in patients suffering from cardiovascular diseases. Apart from their lipid-lowering capacity, statins also exert anti-inflammatory and antioxidant effects. As cellular immune activation and oxidative stress play a major role in the pathogenesis of cardiovascular diseases, the anti-inflammatory capacity of statins could partly be responsible for the beneficial effects observed in patients. Earlier we reported that stimulated peripheral blood mononuclear cells (PBMCs) release homocysteine. Here we studied the influence of atorvastatin on homocysteine production in stimulated PBMCs and compared changes in cysteine concentrations and in neopterin production, which is a sensitive indicator of cellular immune activation. Stimulation of human PBMCs with the mitogens concanavalin A and phytohemagglutinin induced significant homocysteine and neopterin production compared to unstimulated cells, whereas cysteine concentrations remained unchanged. Treatment of PBMCs with increasing doses of atorvastatin (10-100 microM) suppressed both biochemical pathways in a dose-dependent manner, and cell proliferation was inhibited in parallel. Again, cysteine levels were not influenced by any treatment. The down-regulating effect of atorvastatin on homocysteine formation in vitro indicates that statins may prevent homocysteine accumulation in the blood via immunosuppression.


Assuntos
Ácidos Heptanoicos/farmacologia , Homocistina/sangue , Leucócitos Mononucleares/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Pirróis/farmacologia , Anti-Inflamatórios/farmacologia , Atorvastatina , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/patologia , Concanavalina A/farmacologia , Relação Dose-Resposta a Droga , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Leucócitos Mononucleares/metabolismo , Neopterina/metabolismo , Estresse Oxidativo/fisiologia , Fito-Hemaglutininas/farmacologia
20.
J Pediatr Ophthalmol Strabismus ; 42(4): 243-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16121557

RESUMO

We describe recurrent bilateral homocystinuria-related lens dislocation into the anterior chamber in a patient who had postoperative anterior staphyloma and secondary intractable aphakic glaucoma in only one eye. We discuss the possible causes of and treatment modalities for this complication.


Assuntos
Segmento Anterior do Olho/patologia , Corpo Ciliar/patologia , Glaucoma/etiologia , Homocistinúria/complicações , Subluxação do Cristalino/cirurgia , Complicações Pós-Operatórias , Doenças da Úvea/etiologia , Afacia Pós-Catarata/etiologia , Criança , Feminino , Homocistina/sangue , Humanos , Pressão Intraocular , Fotocoagulação a Laser , Subluxação do Cristalino/etiologia , Recidiva , Doenças da Úvea/cirurgia , Vitrectomia
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