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1.  The Protective Association of MTHFR Polymorphism on Cervical Intraepithelial Neoplasia is Modified by Riboflavin Status 
Objectives
We previously reported that women polymorphic for the methylenetetrahydrofolate reductase (MTHFR) gene were less likely to have cervical intraepithelial neoplasia (CIN) 2 or 3 (odds ratio [OR] = 0.40, 95 % confidence interval [CI]: 0.21, 0.78, p=0.007). In the current study, we tested whether this protective association is modified by the circulating riboflavin status in the same study population.
Methods
Riboflavin status was assessed by the erythrocyte glutathione reductase (EGR) assay and expressed in terms of an EGR activity coefficient (EGRAC). The status of MTHFR polymorphism, riboflavin, and circulating concentrations of folate, vitamins B-12, A, E, C and total carotene were ascertained in 170 White and 265 African-American women positive for the cervical presence of high-risk human papilloma virus (HR-HPV). Presence/absence of CIN 2 or 3 was determined histologically, and associations with risk factors were examined using multiple logistic regression. Eighty women with CIN 2 or 3 lesions were compared to 355 women without cervical lesions. Based on the median EGRAC of 1.4, women were grouped into low (> 1.4) and high (≤1.4) riboflavin status.
Results
Women with MTHFR polymorphism and low riboflavin status were significantly less likely to have CIN 2 or 3 than the referent group of women without the polymorphism and high riboflavin status (OR = 0.35, 95% CI: 0.13, 0.92, p= 0.034). MTHFR polymorphism was not associated with CIN 2 or 3 in women with high riboflavin status (OR = 0.51, 95% CI: 0.22, 1.19, p = 0.119), nor were any of the associations influenced by folate levels.
Conclusions
A further inactivation of polymorphic MTHFR by low riboflavin status and a resulting shift in the folate metabolic pathway toward DNA synthesis may explain these observations. The practical implications of this complex gene-nutrient-disease interaction will require further investigation.
doi:10.1016/j.nut.2006.12.006
PMCID: PMC2025704  PMID: 17303386
MTHFR; riboflavin; cervical; neoplasia
2.  A higher degree of LINE-1 methylation in peripheral blood mononuclear cells, a one-carbon nutrient related epigenetic alteration, is associated with a lower risk of developing cervical intraepithelial neoplasia 
Objective
The objective of the study was to evaluate LINE-1 methylation as an intermediate biomarker for the effect of folate and vitamin B12 on the occurrence of higher grades of cervical intraepithelial neoplasia (CIN 2+).
Methods
Study included 376 women who tested positive for HR-HPVs and were diagnosed with CIN 2+ (cases) or ≤ CIN 1 (non-cases). CIN 2+ (yes/no) was the dependent variable in logistic regression models that specified the degree of LINE-1 methylation of peripheral blood mononuclear cells (PBMCs) and of exfoliated cervical cells (CCs) as the independent predictors of primary interest. In analyses restricted to non-cases, PBMC LINE-1 methylation (≥70% vs. <70%) and CC LINE-1 methylation (≥54% vs. <54%) were the dependent variables in logistic regression models that specified the circulating concentrations of folate and vitamin B12 as the primary independent predictors.
Results
Women in the highest tertile of PBMC LINE-1 methylation had 56% lower odds of being diagnosed with CIN 2+ (OR = 0.44; 95% CI, 0.24-0.83; P = 0.011) while there was no significant association between degree of CC LINE-1 methylation and CIN 2+ (OR = 0.86; 95% CI, 0.51-1.46; P = 0.578). Among non-cases, women with supra-physiologic concentrations of folate (>19.8 ng/mL) and sufficient concentrations of plasma vitamin B12 (≥ 200.6 ng/mL) were significantly more likely to have highly methylated PBMCs compared to women with lower folate and lower vitamin B12 (OR = 3.92; 95% CI, 1.06-14.52; P = 0.041). None of the variables including folate and vitamin B12 were significantly associated with CC LINE-1 methylation.
Conclusions
These results suggest that a higher degree of LINE-1 methylation in peripheral blood mononuclear cells, a one-carbon nutrient related epigenetic alteration, is associated with a lower risk of developing cervical intraepithelial neoplasia.
doi:10.1016/j.nut.2010.08.018
PMCID: PMC3070926  PMID: 21463750
methylation; cervical; neoplasia
3.  A higher degree of methylation of the HPV 16 E6 gene is associated with a lower likelihood of being diagnosed with cervical intraepithelial neoplasia 
Cancer  2010;117(5):957-963.
Background
Even though HPV 16 is the most common HPV genotype associated with cancerous lesions of the cervix, only a fraction of HPV 16 infected women are diagnosed with pre-cancerous lesions of the cervix. Therefore, molecular changes in HPV 16 rather than infections per se may serve as better screening or diagnostic biomarkers. The purpose of the study was to evaluate whether methylation status of specific regions of the HPV E6 gene promoter and enhancer is independently associated with the likelihood of being diagnosed with higher grades of cervical intraepithelial neoplasia (CIN 2+).
Methods
The study included 75 HPV 16 positive women diagnosed with CIN 2+ or ≤ CIN 1. Pyrosequencing technology was applied to quantify methylation at 6 cytosine guanine dinucleotide (CpG) sites of the HPV 16 E6 promoter and enhancer. CIN 2+ (yes/no) was the dependent variable in logistic regression models that specified the degree of methylation of the CpG sites of the HPV 16 E6 gene as the primary independent predictors. All models were adjusted for demographic, lifestyle, known risk factors for cervical cancer and circulating concentrations of “cancer-protective” micronutrients.
Results
The odds of being diagnosed with CIN 2+ was 79% lower when the degree of methylation of the HPV 16 enhancer and promoter sites were ≥9.5% (OR= 0.21; 95% CI, 0.06–0.79; P=0.02).
Conclusions
Results suggested that CpG methylation is independently involved in the biology of HPV-16 as well as in the development of higher grades of CIN.
doi:10.1002/cncr.25511
PMCID: PMC3023831  PMID: 20945322
HPV 16; methylation; cervical; neoplasia
4.  Usefulness of serum mass spectrometry to identify women diagnosed with higher grades of cervical intraepithelial neoplasia may differ by race 
Background
An early detection of precursor lesions of cervical cancer will help to eliminate the worldwide burden of cervical cancer.
Methods
This exploratory study aimed to identify, by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS), serum protein profiles that distinguish cervical intraepithelial neoplasia grades CIN 1 or lower (≤CIN 1) from CIN 2+ among 127 women infected with human papillomavirus (HPV) 16. Of these 127 women, 25 and 23 were diagnosed with CIN 2 or CIN 3, respectively (cases), and 79 were diagnosed with ≤CIN 1 (non-cases). Serum protein profiles were generated by MALDI-TOF-MS. A total of 95 m/z peaks were tested for association with case status by two racial groups, African American (AAs) and Caucasian American (CAs).
Results
Overall, 2 protein peaks identified by our study demonstrated higher specificity for identifying CIN 2+ than previously published studies. An increasing intensity of [m/z 4459] was associated with a higher risk of being a case, regardless of race with a specificity of 58% for CIN 2 and a specificity of 75% for CIN 3. An increasing intensity of [m/z 4154] was not only associated with a higher risk of being a case only among CAs, but also had an opposite effect among AAs.
Conclusion
Identification of specific proteins associated with the peaks detected in serum and development of antibody-based tests such as ELISA should lead to the development of race-specific, non-invasive and cost effective screening tests with higher specificity for identifying HPV 16 associated CIN 2+.
doi:10.2147/IJWH.S20685
PMCID: PMC3140814  PMID: 21792340
serum mass spectrometry; cervical intraepithelial neoplasia; race
5.  Mandatory fortification with folic acid in the United States appears to have adverse effects on histone methylation in women with pre-cancer but not in women free of pre-cancer 
Objective:
To evaluate whether mandatory fortification of grain products with folic acid in the US is associated with changes in histone methylation in cells involved in cervical carcinogenesis.
Methods:
Cervical specimens obtained before (1990 to 1992) and after mandatory folic acid fortification (2000 to 2002) were used to examine the degree of histone methylation (H3 Lys-9) by immunohistochemistry. 91 women (51 before and 40 after fortification) were diagnosed with cervical intraepithelial neoplasia (CIN) grade 3 or carcinoma in situ (CIS) and sections utilized in the study also contained normal, reactive or metaplastic cervical epithelium, CIN 1 or CIN 2. 64 women (34 before and 30 after fortification) were free of CIN and these sections contained only normal or reactive cervical epithelium. Immunohistochemical staining for H3 Lys-9, its assessment in different cell or lesion types and data entry were blinded for fortification status. For each cell type or lesion category we used PROC MIXED in SAS with the specimen identifier as a random effect and the robust variance estimator to estimate age- and race-adjusted intensity score for H3 Lys-9 in the pre- and post-fortification periods.
Results:
Degree of H3 Lys-9 methylation was significantly higher (P < 0.0001) in ≥CIN 2 lesions (CIN 2, CIN 3 and CIS) than in ≤CIN 1 lesions (CIN 1, normal, reactive and metaplastic), in both pre- and post-fortification CIN 3/CIS specimens. Age- and race-adjusted mean H3 Lys-9 score was significantly higher in all cell or lesion types in CIN 3/CIS specimens obtained in the post-fortification period compared to pre-fortification period (P < 0.05, all comparisons). In contrast, in specimens obtained from women free of CIN, Lys-9 methylation in normal/reactive cervical epithelium was significantly lower in post-fortification specimens than in pre-fortification specimens (P = 0.03).
Conclusions:
Higher levels of Lys-9 methylation in ≥CIN 2 compared to ≤CIN 1 lesions suggest that higher Lys-9 methylation is associated with progression of lower grade CIN to higher grade CIN. Higher Lys-9 methylation in cervical tissues of women diagnosed with CIN 3 in the post-fortification period than in pre-fortification period suggest that fortification may adversely affect histone methylation in already initiated cells. Lower Lys-9 methylation in normal/reactive cervical cells of women free of CIN in the post-fortification period than pre-fortification on the other hand suggests that fortification is likely to protect against initiation of carcinogenic process in the cervix. These results suggest that mandatory fortification with folic acid in the US seems to have different effects on cancer depending on the stage of carcinogenesis. Because this is the first study to report folic acid fortification-associated differences in histone methylation and because of the limitations inherent to the approach we have taken to demonstrate these differences, validation of the results in other study populations or with other techniques for assessing histone methylation is necessary.
PMCID: PMC2971712  PMID: 21072283
folic acid; fortification; histone methylation; cervix
6.  Indian women with higher serum concentrations of folate and vitamin B12 are significantly less likely to be infected with carcinogenic or high-risk (HR) types of human papillomaviruses (HPVs) 
Background:
Studies conducted in the USA have demonstrated that micronutrients such as folate and vitamin B12 play a significant role in modifying the natural history of high-risk human papillomaviruses (HR-HPVs), the causative agent for developing invasive cervical cancer (CC) and its precursor lesions.
Objective:
The purpose of the current study was to investigate whether these micronutrients have similar effects on HR-HPV infections in Indian women.
Methods:
The associations between serum concentrations of folate and vitamin B12 and HR-HPV infections were evaluated in 724 women who participated in a CC screening study in the southern state of Andhra Pradesh, India. Serum folate and vitamin B12 concentrations were measured by using a competitive radio-binding assay. Digene hybrid capture 2 (HC2) assay results were used to categorize women into two groups, positive or negative for HR-HPVs. Unconditional logistic regression models specified a binary indicator of HC2 (positive/negative) as the dependent variable and serum folate concentrations combined with serum vitamin B12 concentrations as the independent predictor of primary interest. Models were fitted, adjusting for age, education, marital status, parity, type of fuel used for cooking and smoking status.
Results:
Women with higher concentrations of serum folate (>6 ng/mL) and vitamin B12 (>356 pg/mL) were at lower risk of being positive for HR-HPVs compared to those with serum folate ≤6 ng/mL and serum vitamin B12 ≤ 356 pg/mL (odds ratio = 0.26; 95% confidence interval: 0.08–0.89; P = 0.03).
Conclusions:
These results demonstrated that improving folate and vitamin B12 status in Indian women may have a beneficial impact on the prevention of CC. Micronutrient based interventions for control of HR-HPV infections may represent feasible alternatives to vaccine based approaches to HPV disease prevention, which are currently unaffordable for use in resource limited areas in rural India.
PMCID: PMC2971743  PMID: 21072292
folate; vitamin B12; human papillomavirus; cervical cancer
7.  Mandatory Fortification with Folic Acid in the United States is associated with Increased Expression of DNA Methyltransferase 1 in the Cervix 
Objective
The objective of this study was to evaluate whether mandatory fortification of grain products with folic acid in the USA is associated with changes in DNA methyltransferase (Dnmt) 1 expression in cells involved in cervical carcinogenesis.
Methods
Archived specimens of cervical intraepithelial neoplasia (CIN) diagnosed before (1990-92) and after mandatory folic acid fortification (2000-02) were used to examine the expression of Dnmt 1 in specific lesions involved in cervical carcinogenesis by immunohistochemistry. The total number of lesions examined was 101 in the pre-fortification period and 96 in the post-fortification period. Immunohistochemical staining for Dnmt 1, its assessment and data entry were blinded with regard to the fortification status.
Results
Age- and race-adjusted mean percentage of cells positive for Dnmt 1 or the Dnmt 1 score was significantly higher in all lesion types (i.e., normal cervical epithelium, reactive cervical epithelium, metaplastic cervical epithelium, CIN or carcinoma in situ) detected in the post-fortification period compared to pre-fortification period (P < 0.05, all comparisons). The degree of Dnmt 1 was significantly higher (P < 0.0001) in ≥ CIN 2 lesions compared to ≤ CIN 1 lesions, regardless of the fortification group.
Conclusions
These results suggest that mandatory fortification with folic acid in the United States seem to have resulted in a change in the degree of expression of Dnmt 1 in cells involved in cervical carcinogenesis. Because the approach we have taken to demonstrate these differences have limitations inherent to a study of this nature and this is the first study to report a folate fortification associated change in Dnmt 1, validating these results in other study populations and or with other techniques of assessing Dnmt 1 will increase the scientific credibility of these findings.
doi:10.1016/j.nut.2007.10.007
PMCID: PMC2215322  PMID: 18065205
Folic acid; Fortification; DNA Methyltransferase; Cervix
8.  A Practical Approach to Red Blood Cell Folate Analysis 
The measurement of folate in red blood cells (RBCs) is preferred since it reflects long-term folate status in the body compared to plasma/serum folate which may be influenced by recent dietary intake. The commonly accepted technique for RBC folate analysis involves preparation of a hemolysate using a fresh whole blood sample. Hematocrit and plasma folate concentrations are needed to calculate RBC folate values. Because of the need for immediate access to a laboratory where processing can be performed, it may not be practical to assess RBC folate status using this method in field-based epidemiological studies. It is however, feasible to isolate packed RBSs from a blood sample under these conditions. The purpose of this study is to validate RBC folate analysis using packed red cells by comparing the RBC folate values obtained by hemolysate method (routine assay) with those obtained by using packed RBCs (new assay) in the same individuals (n = 50) using the folate microbiological assay. The correlation between plasma folate and the routine RBC folate assay (r = 0.58, p = 0.001) and the correlation between plasma folate and the new RBC folate assay was statistically significant (r = 0.55, p = 0.001). The correlation between RBC folate by the routine assay and new assay was also statistically significant (r = 0.78, p < 0.001). We conclude that measurement of folate in packed RBC is a practical approach in assessing long-term folate status in field-based and or larger scale epidemiological studies where an immediate access to a laboratory is unavailable for necessary sample processing for the routine RBC folate assay.
PMCID: PMC2716806  PMID: 19662184
folate; packed RBC; hemolysate
9.  Plasma Protein Profiles Differ Between Women Diagnosed with Cervical Intraepithelial Neoplasia (CIN) 1 and 3 
Cancer Informatics  2007;2:345-349.
Early detection of precancerous cells in the cervix and their clinical management is the main purpose of cervical cancer prevention and treatment programs. Cytological findings or testing for high risk (HR)-human papillomavirus (HPV) are inadequately sensitive for use in triage of women at high risk for cervical cancer. The current study is an exploratory study to identify candidate surface-enhanced laser desorption/ionization (SELDI) time of flight (TOF) mass spectrometry (MS) protein profiles in plasma that may distinguish cervical intraepithelial neoplasia (CIN 3) from CIN 1 among women infected with HR-HPV. We evaluated the SELDI-TOF-MS plasma protein profiles of HR-HPV positive 32 women with CIN 3 (cases) and 28 women with CIN1 (controls). Case-control status was kept blinded and triplicates of each sample and quality control plasma samples were randomized and after robotic sample preparations were run on WCX2 chips. After alignment of mass/charge (m-z values), an iterative method was used to develop a classifier on a training data set that had 28 cases and 22 controls. The classifier developed was used to classify the subjects in a test data set that has six cases and six controls. The classifier separated the cases from controls in the test set with 100% sensitivity and 100% specificity suggesting the possibility of using plasma SELDI protein profiles to identify women who are likely to have CIN 3 lesions.
PMCID: PMC2675504  PMID: 19458776
cervical; neoplasia; protein profiles; SELDI
10.  Patterns of Global DNA and Histone Methylation Appear to be Similar in Normal, Dysplastic and Neoplastic Oral Epithelium of Humans 
Disease markers  2005;21(3):147-151.
Although there is growing interest in the possibility that alterations in histone methylation may play a role in carcinogenesis, it has not been explored adequately in humans. Similarly, there are no reports of associations between this and a similar epigenetic event, DNA methylation. Using immunohistochemical staining, we compared the methylation of DNA and histones in histopathologically normal oral epithelium, dysplastic oral lesions, and squamous cell cancers (SCCs) from subjects with squamous cell cancer (n = 48) with those of normal oral epithelium from subjects without oral cancer (n = 93) who were matched on age and race. Monoclonal antibodies specific for 5 methyl cytosine (5-mc), lysine 4 of histone H3 (H3-Lys4), and lysine 9 of histone H3 (H3-Lys9) were used in this study. The percentages of cells positive and a weighted average of the immunostaining intensity scores were calculated for each of these tissues, and Spearman correlation analyses were employed to study associations between DNA and histone methylation. Correlations between DNA and histone methylation, H3-Lys4 and H3-Lys9 were positive and statistically significant in all tissue types; they were strongest in normal oral epithelium from non-cancer subjects (n = 0.63, p < 0.001 and r = 0.62, p < 0.001 respectively). Similarly, the positive correlations between H3-Lys4 and H3-Lys9 were statistically significant in all tissue types and strongest in normal oral epithelium from non-cancer subjects (r = 0.77, p < 0.001). Patterns of DNA and histone methylation are similar in tissues across the spectrum of oral carcinogenesis, and there is a significant positive association between these two epigenetic mechanisms.
doi:10.1155/2005/285134
PMCID: PMC3850624  PMID: 16276009
11.  A Lower Degree of PBMC L1 Methylation in Women with Lower Folate Status May Explain the MTHFR C677T Polymorphism Associated Higher Risk of CIN in the US Post Folic Acid Fortification Era 
PLoS ONE  2014;9(10):e110093.
Background
Studies in populations unexposed to folic acid (FA) fortification have demonstrated that MTHFR C677T polymorphism is associated with increased risk of higher grades of cervical intraepithelial neoplasia (CIN 2+). However, it is unknown whether exposure to higher folate as a result of the FA fortification program has altered the association between MTHFR C677T and risk of CIN, or the mechanisms involved with such alterations. The current study investigated the following in a FA fortified population: 1) The association between MTHFR C677T polymorphism and risk of CIN 2+; 2) The modifying effects of plasma folate concentrations on this association; and 3) The modifying effects of plasma folate on the association between the polymorphism and degree of methylation of long interspersed nucleotide elements (L1s), in peripheral blood mononuclear cell (PBMC) DNA, a documented biomarker of CIN risk.
Methods
The study included 457 US women diagnosed with either CIN 2+ (cases) or ≤ CIN 1 (non-cases). Unconditional logistic regression models were used to test the associations after adjusting for relevant risk factors for CIN.
Results
The 677CT/TT MTHFR genotypes were not associated with the risk of CIN 2+. Women with CT/TT genotype with lower folate, however, were more likely to be diagnosed with CIN 2+ compared to women with CT/TT genotype with higher folate (OR = 2.41, P = 0.030). Women with CT/TT genotype with lower folate were less likely to have a higher degree of PBMC L1 methylation compared to women with CT/TT genotype with higher folate (OR = 0.28, P = 0.017).
Conclusions
This study provides the first evidence that the MTHFR 677CT/TT genotype-associated lower degree of PBMC L1 methylation increases the risk of CIN 2+ in women in the US post-FA fortification era. Thus, even in the post-FA fortification era, not all women have adequate folate status to overcome MTHFR 677CT/TT genotype-associated lower degree of L1 methylation.
doi:10.1371/journal.pone.0110093
PMCID: PMC4193871  PMID: 25302494
12.  Triple Negative Breast Cancer – An Overview 
Hereditary genetics : current research  2013;2013(Suppl 2):001.
Triple Negative Breast Cancer (TNBC) is a heterogeneous disease that based on immunohistochemistry (IHC) is estrogen receptor (ER) negative, progesterone receptor (PR) negative and human epidermal growth factor receptor 2 (HER2) negative. TNBC is typically observed in young AA women and Hispanic women who carry a mutation in the BRCA1 gene. TNBC is characterized by a distinct molecular profile, aggressive nature and lack of targeted therapies. The purpose of this article is to review the current and future novel signalling pathways as therapeutic approaches to TNBC. Recent Identification of a new BRCA1 trafficking pathway holds promise in the future for the development of targeted therapies for TNBC.
doi:10.4172/2161-1041.S2-001
PMCID: PMC4181680  PMID: 25285241
TNBC; BRCA1; CISPLATIN; EGFR; PARP; Hedgehog; NOTCH; BCL-2; UBC9; WNT/B-CATENIN
13.  Mild Obesity, Physical Activity, Calorie Intake, and the Risks of Cervical Intraepithelial Neoplasia and Cervical Cancer 
PLoS ONE  2013;8(6):e66555.
Objective
We investigated whether obesity, physical activity, and calorie intake are associated with the risks of cervical intraepithelial neoplasia (CIN) and cervical cancer.
Methods
We enrolled 1125 women (age, 18–65 years) into a human papillomavirus cohort study established from 2006 to 2012. Multinomial logistic regression models were used to estimate crude and multivariate odds ratios (ORs) and the corresponding 95% confidence intervals (95% CIs), and to assess whether body mass index (BMI), height, weight, total calorie intake, and physical activity were associated with the risks of CIN and cervical cancer.
Results
Cervical cancer risk was positively associated with BMI and inversely associated with physical activity. When compared with women with a normal BMI (18.5–23 kg/m2), the multivariate ORs (95% CIs) for those overweight (23–25 kg/m2) and mild obesity (≥25 kg/m2) were 1.25 (0.79–2.00) and 1.70 (1.10–2.63), respectively. When compared with women with the lowest tertile of physical activity (<38.5 MET-hours/week), the ORs (95% CIs) for cervical cancer were 0.95 (0.61–1.48) and 0.61 (0.38–0.98) for women with medium physical activity (38.5–71.9 MET-hours/week) and those with high physical activity (72 MET-hours/week), respectively (p for linear trend  = 0.03). The CIN2/3 risk was inversely associated with physical activity after adjustment for confounders. Compared with women with low physical activity (< 38.5 MET-hours/week), the ORs (95% CIs) for CIN2/3 were 0.64 (0.40–1.01) and 0.58 (0.36–0.93) for the medium and high physical activity groups, respectively (p for linear trend  = 0.02). Total calorie intake was not statistically associated with the risks of CIN and cervical cancer after adjustment for confounders.
Conclusion
Our results indicate that in addition to screening for and treatment of CIN, recommendations on the maintenance of an appropriate BMI with an emphasis on physical activity could be an important preventive strategy against the development of cervical cancer.
doi:10.1371/journal.pone.0066555
PMCID: PMC3680419  PMID: 23776686
14.  Intake and blood concentrations of folate and their association with health-related behaviors in Korean college students 
Nutrition Research and Practice  2013;7(3):216-223.
The purpose of this study is to assess folate intake, and serum and red blood cell (RBC) folate concentrations, and investigate the association between folate status and health-related behaviors among Korean college students. A total of 169 students, aged between 18 and 27 years, participated in this study. Dietary intake data were collected by trained interviewers using a 24-hour recall method for three non-consecutive days in 2009. Information on health-related behaviors was obtained by a self-administered questionnaire. Serum and RBC folate concentrations were measured by microbiological assay. The average intakes of folate were 456 µgDFE and 347 µgDFE in male and female students, respectively. While the average serum folate concentration was significantly lower in male students (8.9 ng/mL) compared to female students (12.5 ng/mL), RBC concentrations were not significantly different between male (398.6 ng/mL) and female students (405.3 ng/mL). In male students, low serum folate concentrations were associated with total folate intake less than the Estimated Average Requirement, non-use of folic acid supplements, smoking, alcohol drinking at least once a week and low physical activity. In female students, low serum folate concentrations were associated with smoking and alcohol drinking at least two drinks at a time and BMI ≥ 25. Alcohol drinking and low physical activity were also associated with low RBC folate concentrations in both male and female students. In order to improve folate nutritional status of college students, the practice of desirable health-related behaviors, such as non-smoking, moderate alcohol drinking, regular physical activity, and maintenance of healthy BMI should be encouraged along with consumption of folate-rich foods and supplements.
doi:10.4162/nrp.2013.7.3.216
PMCID: PMC3679331  PMID: 23766883
Folate intake; serum folate; RBC folate; health-related behaviors; college students
15.  A Lower Degree of PBMC L1 Methylation Is Associated with Excess Body Weight and Higher HOMA-IR in the Presence of Lower Concentrations of Plasma Folate 
PLoS ONE  2013;8(1):e54544.
Background
Identification of associations between global DNA methylation and excess body weight (EBW) and related diseases and their modifying factors are an unmet research need that may lead to decreasing DNA methylation-associated disease risks in humans. The purpose of the current study was to evaluate the following; 1) Association between the degree of peripheral blood mononuclear cell (PBMC) L1 methylation and folate, and indicators of EBW, 2) Association between the degree of PBMC L1 methylation and folate, and insulin resistance (IR) as indicated by a higher homeostasis model assessment (HOMA-IR).
Methods
The study population consisted of 470 child-bearing age women diagnosed with abnormal pap. The degree of PBMC L1 methylation was assessed by pyrosequencing. Logistic regression models specified indicators of EBW (body mass index–BMI, body fat–BF and waist circumference–WC) or HOMA-IR as dependent variables and the degree of PBMC L1 methylation and circulating concentrations of folate as the independent predictor of primary interest.
Results
Women with a lower degree of PBMC L1 methylation and lower plasma folate concentrations were significantly more likely to have higher BMI, % BF or WC (OR = 2.49, 95% CI:1.41–4.47, P = 0.002; OR = 2.49, 95% CI:1.40–4.51, P = 0.002 and OR = 1.98, 95%  = 1.14–3.48 P = 0.0145, respectively) and higher HOMA-IR (OR = 1.78, 95% CI:1.02–3.13, P = 0.041).
Conclusion
Our results demonstrated that a lower degree of PBMC L1 methylation is associated with excess body weight and higher HOMA-IR, especially in the presence of lower concentrations of plasma folate.
doi:10.1371/journal.pone.0054544
PMCID: PMC3554730  PMID: 23358786
16.  A Simple Distribution-Free Algorithm for Generating Simulated High-Dimensional Correlated Data with an Autoregressive Structure 
A distribution-free method to generate high-dimensional sequences of dependent variables with an autoregressive structure is presented. The quantile or fractile correlation (i.e., the moment correlation of the quantiles) is used as measure of dependence among a set of contiguous variables. The proposed algorithm breaks the sequence in small parts and avoids having to define one large correlation matrix for the entire high-dimensional sequence of variables. Simulations based on proteomics data are presented. Results suggest that negligible or no loss of fractile correlation occurs by splitting the generation of a sequence into small parts.
doi:10.1080/03610918.2011.579368
PMCID: PMC3217303  PMID: 22102768
Distribution-free methods; Fractile correlations; High-dimensional data; Simulation
17.  Aflatoxin B1 albumin adducts in plasma and aflatoxin M1 in urine are associated with plasma concentrations of vitamins A and E 
Background
Although aflatoxin exposure has been shown to be associated with micronutrient deficiency in animals, there are few investigations on the effects of aflatoxin exposure on micronutrient metabolism in humans.
Objective
To examine the relationship between aflatoxin B1 (AFB1) albumin adducts (AF-ALB) in plasma and the aflatoxin M1 (AFM1) metabolite in urine and plasma concentrations of retinol (vitamin A) and α-tocopherol (vitamin E) in Ghanaians.
Methods
A cross-sectional study of 147 adult participants was conducted. Blood and urine samples were tested for aflatoxin and vitamins A and E levels.
Results
Multivariable analysis showed that participants with high AF-ALB (≥ 0.80 pmol/mg albumin) had increased odds of having vitamin A deficiency compared to those with lower AF-ALB [Odds Ratio (OR) = 2.61; CI = 1.03 – 6.58; p=0.04]. Participants with high AF-ALB also showed increased odds of having vitamin E deficiency but this was not statistically significant (OR = 2.4; CI = 0.96–6.05; p = 0.06). Conversely, those with higher AFM1 values had a statistically nonsignificant reduced odds of having vitamin A deficiency (OR = 0.31; CI = 1.15–0.09; p=0.05) and statistically significant reduced odds of having vitamin E deficiency (OR = 0.31; CI = 0.10 – 0.97; p = 0.04). Participants with high AF-ALB or high AFM1 (≥ 437.95 pg/dL creatinine) were almost 6 times more likely to be hepatitis B virus surface antigen (HBsAg)- positive (OR = 5.88; CI = 1.71–20.14; p = 0.005) and (OR = 5.84; CI = 1.15–29.54; p = 0.03) respectively.
Conclusions
These data indicate that aflatoxin may modify plasma micronutrient status. Thus, preventing aflatoxin exposure may greatly reduce vitamins A and E deficiencies.
doi:10.1024/0300-9831/a000021
PMCID: PMC3222292  PMID: 21792816
Aflatoxin; Vitamin A; Vitamin E; Hepatitis B Virus; Ghana
18.  Aflatoxin levels, plasma vitamins A and E concentrations, and their association with HIV and hepatitis B virus infections in Ghanaians: a cross-sectional study 
Background
Micronutrient deficiencies occur commonly in people infected with the human immunodeficiency virus. Since aflatoxin exposure also results in reduced levels of several micronutrients, HIV and aflatoxin may work synergistically to increase micronutrient deficiencies. However, there has been no report on the association between aflatoxin exposure and micronutrient deficiencies in HIV-infected people. We measured aflatoxin B1 albumin (AF-ALB) adduct levels and vitamins A and E concentrations in the plasma of HIV-positive and HIV-negative Ghanaians and examined the association of vitamins A and E with HIV status, aflatoxin levels and hepatitis B virus (HBV) infection.
Methods
A cross-sectional study was conducted in which participants completed a demographic survey and gave a 20 mL blood sample for analysis of AF-ALB levels, vitamins A and E concentrations, CD4 counts, HIV viral load and HBV infection.
Results
HIV-infected participants had significantly higher AF-ALB levels (median for HIV-positive and HIV-negative participants was 0.93 and 0.80 pmol/mg albumin, respectively; p <0.01) and significantly lower levels of vitamin A (-16.94 μg/dL; p <0.0001) and vitamin E (-0.22 mg/dL; p <0.001). For the total study group, higher AF-ALB was associated with significantly lower vitamin A (-4.83 μg/dL for every 0.1 pmol/mg increase in AF-ALB). HBV-infected people had significantly lower vitamin A (-5.66 μg/dL; p = 0.01). Vitamins A and E levels were inversely associated with HIV viral load (p = 0.02 for each), and low vitamin E was associated with lower CD4 counts (p = 0.004).
Conclusions
Our finding of the significant decrease in vitamin A associated with AF-ALB suggests that aflatoxin exposure significantly compromises the micronutrient status of people who are already facing overwhelming health problems, including HIV infection.
doi:10.1186/1758-2652-14-53
PMCID: PMC3228661  PMID: 22078415
19.  PATTERN OF NONSPECIFIC (OR GLOBAL) DNA METHYLATION IN ORAL CARCINOGENESIS 
Head & neck  2005;27(12):1061-1067.
Background
Although alterations in nonspecific (or global) DNA methylation (GDM) in specific cells are known to be involved in the process of lung carcinogenesis, similar associations have not been evaluated in other smoking-related cancers of the head and neck.
Methods
We evaluated the status of GDM by using monoclonal antibodies specific for 5-methylcytosine (5-mc) in oral squamous cell carcinoma (SCC) specimens of 48 cigarette smokers who had SCC develop and in 93 age-, race-, and sex-matched smokers who did not.
Results
Percentages of cells positive for 5-mc immunostaining of DNA of SCC and dysplastic lesions were significantly higher than those of normal oral epithelial cells from cancer subjects and from noncancer subjects. The degree of DNA methylation was unrelated to DNA content.
Conclusions
The pattern of GDM in oral SCCs is different from that of lung SCCs. The differences in nutrient risk factor profiles that are related to GDM and differential activity of DNA methyltranferases between oral and lung SCCs may explain these observations.
doi:10.1002/hed.20288
PMCID: PMC1853326  PMID: 16155917
DNA; methylation; oral cancer

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