Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by L. D Parnell
Total Records ( 4 ) for L. D Parnell
  A Chanson , L. D Parnell and J. W Crott
 

Background: Five genes—UNG, SMUG1, MBD4, TDG, and DUT—are involved in the repair or prevention of uracil misincorporation into DNA, an anomaly that can cause mutagenic events that lead to cancer. Little is known about the determinants of uracil misincorporation, including the effects of single nucleotide polymorphisms (SNPs) in the abovementioned genes. Because of their metabolic function, folate and other one-carbon micronutrients may be important factors in the control of uracil misincorporation.

Objectives: We sought to identify polymorphisms in uracil-processing genes that are determinants of DNA uracil concentration and to establish whether one-carbon nutrient status can further modify their effects.

Design: We examined the relations between 23 selected variants in the 5 uracil-processing genes, uracil concentrations in whole-blood DNA, and one-carbon nutrient (folate, vitamins B-6 and B-12, and riboflavin) status in 431 participants of the Boston Puerto Rican Health Study.

Results: Four SNPs in DUT, UNG, and SMUG1 showed a significant association with DNA uracil concentration. The SNPs in SMUG1 (rs2029166 and rs7296239) and UNG (rs34259) were associated with increased uracil concentrations in the variant genotypes (P = 0.011, 0.022, and 0.045, respectively), whereas the DUT SNP (rs4775748) was associated with a decrease (P = 0.023). In this population, one-carbon nutrient status was not associated with DNA uracil concentration, and it did not modify the effect of these 4 identified SNPs.

Conclusion: Because elevated uracil misincorporation may induce mutagenic lesions, possibly leading to cancer, we propose that the 4 characterized SNPs in DUT, UNG, and SMUG1 may influence cancer risk and therefore deserve further investigation.

  D Corella , G Peloso , D. K Arnett , S Demissie , L. A Cupples , K Tucker , C. Q Lai , L. D Parnell , O Coltell , Y. C Lee and J. M. Ordovas
 

Background  Nutrigenetics studies the role of genetic variation on interactions between diet and health, aiming to provide more personalized dietary advice. However, replication has been low. Our aim was to study interaction among a functional APOA2 polymorphism, food intake, and body mass index (BMI) in independent populations to replicate findings and to increase their evidence level.

Methods  Cross-sectional, follow-up (20 years), and case-control analyses were undertaken in 3 independent populations. We analyzed gene-diet interactions between the APOA2 –265T>C polymorphism and saturated fat intake on BMI and obesity in 3462 individuals from 3 populations in the United States: the Framingham Offspring Study (1454 whites), the Genetics of Lipid Lowering Drugs and Diet Network Study (1078 whites), and Boston–Puerto Rican Centers on Population Health and Health Disparities Study (930 Hispanics of Caribbean origin).

Results  Prevalence of the CC genotype in study participants ranged from 10.5% to 16.2%. We identified statistically significant interactions between the APOA2 –265T>C and saturated fat regarding BMI in all 3 populations. Thus, the magnitude of the difference in BMI between the individuals with the CC and TT+TC genotypes differed by saturated fat. A mean increase in BMI of 6.2% (range, 4.3%-7.9%; P = .01) was observed between genotypes with high– (≥22 g/d) but not with low– saturated fat intake in all studies. Likewise, the CC genotype was significantly associated with higher obesity prevalence in all populations only in the high–saturated fat stratum. Meta-analysis estimations of obesity for individuals with the CC genotype compared with the TT+TC genotype were an odds ratio of 1.84 (95% confidence interval, 1.38-2.47; P < .001) in the high–saturated fat stratum, but no association was detected in the low–saturated fat stratum (odds ratio, 0.81; 95% confidence interval, 0.59-1.11; P = .18).

Conclusion  For the first time to our knowledge, a gene-diet interaction influencing BMI and obesity has been strongly and consistently replicated in 3 independent populations.

  M. R Irvin , E. K Kabagambe , H. K Tiwari , L. D Parnell , R. J Straka , M Tsai , J. M Ordovas and D. K. Arnett
  Background—

Although much is known about the effect of Apolipoprotein E (APOE) alleles on fasting lipid concentrations, less is known about the effect of APOE alleles on postprandial triglyceridemia or the triglyceride response to fenofibrate.

Methods and Results—

We evaluated the effects of the APOE locus on fasting and postprandial triglyceride concentrations as part of the Genetics of Lipid Lowering and Diet Network (GOLDN) study. Participants were evaluated after a high-fat meal challenge before (n=1072) and after 3 weeks of daily treatment with 160 mg of fenofibrate (n=738). Mixed models adjusted for sex, age, waist circumference, and family relationship were used to examine the association of the 4 carrier and 2 carrier status versus 3 homozygotes with fasting triglycerides and the area under the curve (AUC) for triglycerides during the high-fat meal challenge. Compared with the 3/3 genotype, 2 carriers had on average higher fasting triglyceride concentrations (130.5 mg/dL versus 109.3 mg/dL, P<0.001). After fenofibrate treatment, the APOE genotype differences persisted in the fasting state (2 carriers: 85.1 mg/dL versus 3/3: 75.9 mg/dL, P<0.05). Carriers of the 4 allele had significantly higher fasting triglyceride concentrations only prefenofibrate (120.9 mg/dL versus 109.3 mg/dL, P=0.008). APOE alleles did not have an effect on response to fenofibrate. Postprandial triglycerides were significantly higher for 2 carriers versus 3 homozygotes (but not 4 carriers) both before and after fenofibrate treatment (P=0.01 and P=0.005, respectively).

Conclusions—

APOE polymorphisms are important determinants of triglyceride concentrations, especially in the fasting state.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility