Publications by authors named "Bee Lan Lee"

Background: β-cryptoxanthin is a dietary carotenoid for which there have been few studies on the safety and pharmacokinetics following daily oral supplementation.

Methods: 90 healthy Asian women between 21 and 35 years were randomized into three groups: 3 and 6 mg/day oral β-cryptoxanthin, and placebo. At 2, 4, and 8 weeks of supplementation, plasma carotenoid levels were measured.

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Purpose: Current literature on the roles of α-, β-carotene and β-cryptoxanthin in neurocognitive function has largely focused on preventing cognitive decline in older people, and less on neuro-development in children. We examined the relations of maternal plasma carotenoids concentrations with offspring cognitive development up to age 4.5 years in the Growing Up in Singapore Towards healthy Outcomes mother-offspring cohort study.

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Lutein and zeaxanthin play important roles in visual functions, but their influence on early visual development is unclear. We related maternal lutein and zeaxanthin concentrations during pregnancy to offspring visual acuity (VA) in 471 mother-child pairs from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. Maternal concentrations of plasma lutein and zeaxanthin were determined at delivery.

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Owing to the increasing interest in the health effects of antioxidant micronutrients on chronic diseases, a robust and rapid HPLC method for simultaneous measurement of coenzyme Q(10) (ubiquinone and ubiquinol), vitamin A (all-trans-retinol), vitamin E (tocopherols and tocotrienols) and carotenoids (lutein, zeaxanthin, beta-cryptoxanthin, lycopene and beta-carotene) was developed. Sample preparation and analytical conditions that would affect solubility and stability of these antioxidants were investigated and optimized. The mobile phase used was made up of acetonitrile, methanol, ethanol and tert-butanol without corrosive additives such as ammonium perchlorate and perchloric acid.

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Twenty-seven cultivars of mulberry fruits ( Morus atropurpurea Roxb) were analyzed for their total phenolic content, total anthocyanin content, and peroxyl radical scavenging capacities. The proanthocyanidin contents of the fruit were also quantified using 4-dimethylamino-cinnamaldehyde assay, and characterization was attempted using electrospray ionization mass spectra. The phenolic compounds of mulberry fruits were characterized using HPLC with ESI-MS and diode array detection.

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Objectives: Lead and homocysteine are both linked to cardiovascular disease. With this in mind, the authors evaluated the relation between blood lead and homocysteine in people aged 19-66 years in two Asian populations.

Methods: This cross-sectional study comprised 183 workers from a lead stabiliser factory in Singapore and 323 workers from a battery factory in Vietnam.

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Benzene is a human carcinogen and its metabolite, urinary trans,trans-muconic acid (ttMA), is a biomarker for risk assessment. However, most of the existing methods were not sensitive enough for monitoring of low level exposure. This paper describes a HPLC-UV method for ttMA determination with enhanced selectivity and sensitivity.

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Reversed-phase liquid chromatography was used to determine lipophilic antioxidants in plants using two monomeric C18 columns operated at 30 degrees C and 4 degrees C, with a column-switching technique and acetonitrile-methanol gradient elution. The chromatograms were extracted at different wavelengths using a UV diode array detector (DAD). A wide range of plant antioxidants, including nine carotenoids (neoxanthin, violaxanthin, lutein, zeaxanthin, beta-cryptoxanthin, lycopene, canthaxanthin, alpha-carotene and beta-carotene) together with all-trans-retinol, capsaicin, dihydrocapsaicin, chlorophyll a, and chlorophyll b can be separated within 50 min.

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Folate deficiency leads to increased dUMP/dTMP ratios and uracil misincorporation into DNA, which may increase cancer risk. We improved a previously described gas chromatography-mass spectrometry (GC-MS) assay for uracil in DNA and validated the assay by analyzing the DNA-uracil content of normal, primary human lymphocytes that were cultured in 0-3000 nM folic acid. In addition, the effects of nucleoside mixtures T or TdCA (T, thymidine; A, adenosine; dC, deoxycytidine) were investigated.

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Background: Epidemiologic evidence suggests that the concentrations of antioxidant vitamins in human plasma may play an important role in numerous chronic diseases, such as cancer and cardiovascular disease. However, methods for simultaneous measurement of these antioxidants are scarce. We developed and validated a new HPLC method for simultaneous determination of these vitamers in human plasma that uses a novel column-switching approach.

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Indians or South Asians have been found to be particularly susceptible to coronary heart disease (CHD) in many countries. A novel risk factor for CHD may be coenzyme Q10 (CoQ10). In this study, plasma CoQ10 (including ubiquinol-10, CoQ10H2, and total CoQ10), various lipid parameters, and antioxidant levels were determined in a random sample of Indians and Chinese from the general population of Singapore.

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