143 resultados para Folic-acid Derivatives


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Background: Although iron deficiency is a major cause of anemia, other micronutrient deficiencies may also play a role. Objective: We examined whether multiple micronutrient supplementation is more efficacious than is supplementation with iron and folic acid alone for improving the hemoglobin and iron status of anemic adolescent girls in Bangladesh. Design: Anemic (hemoglobin < 12.0 g/dL) girls (n = 197) aged 14-18 y from rural schools in Dhaka District were entered into a randomized double-blind trial and received twice-weekly supplements of iron and folic acid (IFA group) or multiple micronutrients (15 micronutrients, including iron and folic acid; MMN group) for 12 wk. Results: At recruitment, the characteristics of the girls in the 2 groups were not significantly different, except for family size and body mass index. At the end of the study, although both groups benefited significantly from supplementation, mean changes in hemoglobin and serum ferritin concentrations were not significantly different between groups. Compared with the IFA group, girls in the MMN group had significantly greater increases in mean serum vitamin A, plasma vitamin C, red blood cell folic acid, and riboflavin concentrations (assessed as erythrocyte glutathione reductase activation coefficient). After 12 wk of supplementation, only the prevalence of vitamins A and C and riboflavin deficiencies decreased more significantly in the MMN group than in the IFA group. Conclusions: Twice-weekly MMN supplementation for 12 wk significantly improved the status of the micronutrients assessed but was not more efficacious than was supplementation with iron and folic acid alone in improving the hematologic status of anemic adolescent girls. More frequent doses may be needed to achieve full benefit.

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Background and Objective: Estimates of dietary folate intake are currently of considerable interest, but no rapid tools are available to assess dietary intake of folate that are well suited to everyday health promotion activities, We developed and tested the reliability and validity of two prototypes of a rapid dietary assessment tool (a folate intake tool, FIT) to determine dietary intake of folate. Study Design and Setting: Five hundred and sixty eight men and women aged 33-93 years from Perth, Western Australia. Completed one of the two prototypes of the tool and gave a fasting blood sample for measurement of serum folate. A subset (n - 277) of participants completed the same tool on a second occasion 3-6 weeks later. Results: The Pearson correlations (r) between folate score from the tool and serum folate were moderately high for both prototypes (FIT-A r = 0.54-, FIT-B r = 0.49). The folate scores for the two prototypes were similar on repeat testing and correlated strongly (FIT-A r = 0.75; FIT-B r = 0.68). Conclusions: The rapid dietary assessment tool described here, FIT, provides a valid and reliable measurement of dietary intake of folate for both men and women. (c) 2005 Elsevier Inc. All rights reserved.

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The Australian Pregnancy Registry, affiliated European Register of Antiepileptic drugs in Pregnancy (EURAP), recruits informed consenting women with epilepsy on treatment with antiepileptic drugs (AEDs), those untreated, and women on AEDs for other indications. Enrolment is considered prospective if it has occurred before presence or absence of major foetal malformations (FMs) are known, or retrospective, if they had occurred after the birth of infant or detection of major FM. Telephone Interviews are conducted to ascertain pregnancy outcome and collect data about seizures. To date 630 women have been enrolled, with 565 known pregnancy outcomes. Valproate (VPA) above 1100 mg/day was associated with a significantly higher incidence of FMs than other AEDs (P < 0.05). This was independent of other AED use or potentially confounding factors on multivariate analysis (OR = 7.3, P < 0.0001). Lamotrigine (LTG) monotherapy (n = 65), has so far been free of malformations. Although seizure control was not a primary outcome, we noted that more patients on LTG than on VPA required dose adjustments to control seizures. Data indicate an increased risk of FM in women taking VPA in doses > 1100 mg/day compared with other AEDs. The choice of AED for pregnant women with epilepsy requires assessment of balance of risks between teratogenicity and seizure control.

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This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the effects of vitamin A supplementation, alone or in combination with other micronutrients (e.g. iron, folic acid, vitamin E), in mothers during the postpartum period, on maternal and infant health. Specific objectives are to compare the effects of vitamin A supplementation (alone or in combination with other micronutrients) with placebo or no supplementation on: 1. the duration and occurrence of maternal morbidity (xerophthalmia, infection) or illness symptoms (night blindness, fever, nausea, vomiting); 2. the duration and occurrence of neonatal or infant morbidity (respiratory tract infection, diarrhea, measles) or illness symptoms (fever, nausea, vomiting); 3. maternal serum retinol concentration; 4. infant serum retinol concentration; 5. breast milk retinol concentration; and 6. maternal satisfaction.

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Background and Purpose - A higher plasma concentration of total homocysteine (tHcy) is associated with a greater risk of cardiovascular events. Previous studies, largely in younger individuals, have shown that B vitamins lowered tHcy by substantial amounts and that this effect is greater in people with higher tHcy and lower folate levels. Methods - We undertook a 2-year, double-blind, placebo-controlled, randomized trial in 299 men aged >= 75 years, comparing treatment with a daily tablet containing 2 mg of folate, 25 mg of B-6, and 400 mu g of B-12 or placebo. The study groups were balanced regarding age (mean +/- SD, 78.9 +/- 2.8 years), B vitamins, and tHcy at baseline. Results - Among the 13% with B12 deficiency, the difference in mean changes in treatment and control groups for tHcy was 6.74 mu mol/L (95% CI, 3.94 to 9.55 mu mol/L) compared with 2.88 mu mol/L (95% CI, 0.07 to 5.69 mu mol/L) for all others. Among the 20% with hyperhomocysteinaemia, the difference between mean changes in treatment and control groups for men with high plasma tHcy compared with the rest of the group was 2.8 mu mol/L (95% CI, 0.6 to 4.9 mu mol/L). Baseline vitamin B12, serum folate, and tHcy were significantly associated with changes in plasma tHcy at follow-up (r = 0.252, r = 0.522, and r = -0.903, respectively; P = 0.003, <0.001, and <0.001, respectively) in the vitamin group. Conclusions - The tHcy-lowering effect of B vitamins was maximal in those who had low B12 or high tHcy levels. Community-dwelling older men, who are likely to be deficient in B12 or have hyperhomocysteinemia, may be most likely to benefit from treatment with B vitamins.

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Background: Cyclosporin A (CsA)-treated renal transplant recipients (RTR) exhibit relative hyperhomocystinemia and vascular dysfunction. Folate supplementation lowers homocysteine and has been shown to improve vascular function in healthy subjects and patients with coronary artery disease. The aim of this study was to assess the effects of 3 months of folate supplementation (5 mg/day) on vascular function and structure in RTR. Methods: A double-blind, placebo-controlled crossover study was conducted in 10 CsA-treated RTR. Vascular structure was measured as carotid artery intima media thickness (IMT) and function was assessed as changes in brachial artery diameter during reactive hyperemia (RE) and in response to glyceryl trinitrate (GTN). Function data were analyzed as absolute and percent change from baseline and area under the diameter/time curve. Blood samples were collected before and after supplementation and analyzed for total plasma homocysteine, folate, vitamin B-12 and asymmetric dimethyl arginine (ADMA) in addition to regular measures of hemoglobin, hematocrit, mean corpuscular volume (MCV) and serum creatinine. Results: Folate supplementation significantly increased plasma folate by 687% (p < 0.005) and decreased homocysteine by 37% (p < 0.05) with no changes (p > 0.05) in vitamin B 12 or ADMA. There were no significant (p > 0.05) changes in vascular structure or function during the placebo or the folate supplementation phases; IMT; placebo pre mean +/- SD, 0.52 +/- 0.12, post 0.50 +/- 0.11; folate pre 0.55 +/- 0.17, post 0.49 +/- 10.20 mm 5% change in brachial artery diameter (RH, placebo pre 10 +/- 8, post 6 +/- 5; folate pre 9 +/- 7, post 7 +/- 5; GTN, placebo pre 18 +/- 10, post 17 +/- 9, folate pre 16 +/- 9, post-supplementation 18 +/- 8). Conclusion: Three months of folate supplementation decreases plasma homocysteine but has no effect on endothelial function or carotid artery IMT in RTR.

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Imidoylketenes 11 and oxoketenimines 12 are generated by flash vacuum thermolysis of Meldrum's acid derivatives 9, pyrrolediones 17 and 18, and triazole 19 and are observed by IR spectroscopy. Ketenimine-3-carboxylic acid esters 12a are isolable at room temperature. Ketenes 11 and ketenimines 12 undergo rapid interconversion in the gas phase, and the ketenes cyclize to 4-quinolones 13. When using an amine leaving group in Meldrum's acid derivatives 9c, the major reaction products are aryliminopropadienones, ArN=C=C=C=O (15). The latter react with 1 equiv of nucleophile to produce ketenimines 12 and with 2 equiv to afford maIonic acid imide derivatives 16. N-Arylketenimine-C-carboxamides 12c cyclize to quinolones 13c via the transient amidinoketenes 11c at temperatures of 25-40 degrees C. This implies rapid interconversion of ketenes and ketenimines by a 1,3-shift of the dimethylamino group, even at room temperature. This interconversion explains previously poorly understood outcomes of the ynamine-isocyanate reaction. The solvent dependence of the tautomerism of 4-quinolones/4-quinolinols is discussed. Rotational barriers of NMe2 groups in amidoketenimines 12c and malonioc amides and amidines 16 (24) are reported.

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1 The hepatic disposition and metabolite kinetics of a homologous series of O-acyl (acetyl, propionyl, butanoyl, pentanoyl, hexanoyl and octanoyl) esters of salicylic acid (C2SA, C3SA, C4SA, C5SA, C6SA and C8SA, respectively) was determined using a single-pass, in-sills rat liver preparation. 2 The hepatic venous outflow profiles for the parent esters and the generated metabolite, salicylic acid (SA) were analysed by HPLC. Non-parametric moments analysis was used to determine the area under the curve (AUC'), mean transit time (MTT) and normalized variance (CV2) for the parent esters and generated SA. 3 Pregenerated SA ([C-14]-salicylic acid) was injected into each liver with the parent ester to determine its distribution characteristics. 4 The overall recovery of ester plus metabolite was 89% of the ester dose injected and independent of the ester carbon number, suggesting that ester extraction was due to hepatic metabolism to salicylic acid. 5 The metabolite AUC' value increased directly with the lipophilicity of the parent ester (from 0.12 for C2SA to 0.95 for C8SA). By contrast, the parent AUC' decreased with the lipophilicity (from 0.85 for C2SA to zero for C8SA). The metabolite MTT value also showed a trend to increase with the lipophilicity of the parent ester (from 15.72 s for C3SA to 61.97 s for C8SA). However, the parent MTT value shows no significant change across the series. 6 The two-compartment dispersion model was used to derive the kinetic parameters for parent ester, pregenerated SA and generated SA. Consequently, these parameters were used to estimate the values of AUG', MITT and CV2 for the parent ester and metabolite. The moments values obtained using the two-compartment dispersion model show similar trends to the corresponding moments values obtained from the outflow profiles using a non-parametric approach. 7 The more lipophilic aspirin analogues are more confined to the portal circulation after oral administration than aspirin due to their more extensive hepatic elimination avoiding systemic prostacyclin inhibition. Given that aspirin's selectivity as an anti-thrombotic agent has been postulated to be due to selective anti-platelet effects in the portal circulation, the more lipophilic and highly extracted analogues are potentially more selective anti-thrombotic agents than aspirin.

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O-Acyl esters were prepared from salicylic acid and diflunisal by esterification with the appropriate acyl anhydride (in the presence of sulfuric acid at 80 degrees C) or acyl chloride (in the presence of pyridine at 0 degrees C). Synthesis, identification and characterization of these compounds is described. In vitro hydrolysis, solubility and protein binding studies of these O-acyl esters were performed. For the diflunisal esters, the melting points fell as the side chain was increased from ethyl to pentyl. The melting points showed no significant difference as the length of the side chain was increased from pentyl to heptyl. The aspirin analogues showed a similar trend, The relationship between solubility and carbon chain length agreed closely with that for the melting points with carbon chain length. In vitro non-enzymatic hydrolysis studies concluded that: (1) hydrolysis rate constants generally decreased with carbon chain length; (2) the diflunisal esters have shorter half lives compared with their salicylate counterparts; and (3) the in vitro hydrolysis of these compounds was retarded by the presence of bovine serum albumin. Protein binding experiments showed that the strength of binding of the aspirin and diflunisal analogues to bovine serum albumin increased with carbon chain length. (C) 1997 Elsevier Science B.V.

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In this work the in-situ perfused rat liver has been used to examine the effect of changing the protein content of the perfusate on the hepatic extraction of O-acyl esters of salicylic acid. The hepatic availability (F) of these solutes was studied at a flow-rate of 30 mt min(-1) with perfusate albumin concentrations of 0, 2, and 4% w/v. The hepatic availability of the esters was shown to decrease with increasing carbon-chain length in the O-acyl group; for all the esters the hepatic availability increased with increasing albumin concentration in the perfusate. The dispersion-model-derived efficiency number (R-N) Of the esters was shown to increase with increasing lipophilicity and decrease with increasing albumin concentration in the perfusate. The unbound fraction (f(u),) of the esters decreased with lipophilicity. R-N/f(u), for acetylsalicylic acid remained relatively constant as the albumin concentration was increased. However, R-N/f(u), for n-pentanoyl- and n-hexanoylsalicylic acids increased significantly as albumin concentration increased from 0% to 4%. Thus, for the more lipophilic solutes (n-pentanoyl- and n-hexanoylsalicylic acids) the presence of albumin apparently facilitates the uptake of unbound solute relative to acetylsalicylic acid.

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Hydroperoxide derivatives of beta-oxa-substituted polyunsaturated fatty acids were prepared by 15-lipoxygenase catalysed oxidation and perketal derivatives of fatty acid hydroperoxides were synthesized. The perketals are more stable than their parent fatty acid hydroperoxides, but less active as antimalarial agents in the in vitro growth inhibition of Plasmodium falciparum. (C) 1998 Elsevier Science Ltd. All rights reserved.

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The polycondensation of squaric acid with 1,2-(9-Ethylcarbazol-3-yl)ethene and N-ethyliminostilbene in polyphosphoric acid yielded insoluble polymers which included substituted phosphate groups on the phenyl rings. The presence of phosphorus in these polymers was identified using solid-state P-31 NMR and EDAX techniques. Furthermore the phosphate groups were not ionic, hence no charge-balancing anions were present; Both polymers did not electrically conduct but exhibited dielectric breakdown values of 0.1 and 0.06 MV cm(-1) respectively.