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Robert Clarke

Publications and source records attributed to Robert Clarke.

At least 73 records · Page 4Linked to original sources
PubMed2003

Estrogen withdrawal-induced NF-kappaB activity and bcl-3 expression in breast cancer cells: roles in growth and hormone independence.

About one-third of breast cancers express a functional estrogen (beta-estradiol [E2]) receptor (ER) and are initially dependent on E2 for growth and survival but eventually progress to hormone independence. We show here that ER(+), E2-independent MCF-7/LCC1 cells derived from E2-dependent MCF-7 cells contain elevated basal NF-kappaB activity and elevated expression of the transcriptional coactivator Bcl-3 compared with the parental MCF-7 line. LCC1 NF-kappaB activity consists primarily of p50 dimers, although low levels of a p65/p50 complex are also present. The ER(-) breast cancer cell lines harbor abundant levels of both NF-kappaB complexes. In contrast, nuclear extracts from MCF-7 cells contain a significantly lower level of p50 and p65 than do LCC1 cells. Estrogen withdrawal increases both NF-kappaB DNA binding activity and expression of Bcl-3 in MCF-7 and LCC1 cells in vitro and in vivo. Tumors derived from MCF-7 cells ectopically expressing Bcl-3 remain E2 dependent but display a markedly higher tumor establishment and growth rate compared to controls. Expression of a stable form of IkappaBalpha in LCC1 cells severely reduced nuclear expression of p65 and the p65/p50 DNA binding heterodimer. Whereas LCC1 tumors in nude mice were stable or grew, LCC1(IkappaBalpha) tumors regressed after E2 withdrawal. Thus, both p50/Bcl-3- and p65/p50-associated NF-kappaB activities are activated early in progression and serve differential roles in growth and hormone independence, respectively. We propose that E2 withdrawal may initiate selection for hormone independence in breast cancer cells by activation of NF-kappaB and Bcl-3, which could then supplant E2 by providing both survival and growth signals.

Animals↗
PubMed2002

Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies.

BACKGROUND: The age-specific relevance of blood pressure to cause-specific mortality is best assessed by collaborative meta-analysis of individual participant data from the separate prospective studies. METHODS: Information was obtained on each of one million adults with no previous vascular disease recorded at baseline in 61 prospective observational studies of blood pressure and mortality. During 12.7 million person-years at risk, there were about 56000 vascular deaths (12000 stroke, 34000 ischaemic heart disease [IHD], 10000 other vascular) and 66000 other deaths at ages 40-89 years. Meta-analyses, involving "time-dependent" correction for regression dilution, related mortality during each decade of age at death to the estimated usual blood pressure at the start of that decade. FINDINGS: Within each decade of age at death, the proportional difference in the risk of vascular death associated with a given absolute difference in usual blood pressure is about the same down to at least 115 mm Hg usual systolic blood pressure (SBP) and 75 mm Hg usual diastolic blood pressure (DBP), below which there is little evidence. At ages 40-69 years, each difference of 20 mm Hg usual SBP (or, approximately equivalently, 10 mm Hg usual DBP) is associated with more than a twofold difference in the stroke death rate, and with twofold differences in the death rates from IHD and from other vascular causes. All of these proportional differences in vascular mortality are about half as extreme at ages 80-89 years as at ages 40-49 years, but the annual absolute differences in risk are greater in old age. The age-specific associations are similar for men and women, and for cerebral haemorrhage and cerebral ischaemia. For predicting vascular mortality from a single blood pressure measurement, the average of SBP and DBP is slightly more informative than either alone, and pulse pressure is much less informative. INTERPRETATION: Throughout middle and old age, usual blood pressure is strongly and directly related to vascular (and overall) mortality, without any evidence of a threshold down to at least 115/75 mm Hg.

Adult↗
PubMed2002

Block principal component analysis with application to gene microarray data classification.

We propose a block principal component analysis method for extracting information from a database with a large number of variables and a relatively small number of subjects, such as a microarray gene expression database. This new procedure has the advantage of computational simplicity, and theory and numerical results demonstrate it to be as efficient as the ordinary principal component analysis when used for dimension reduction, variable selection and data visualization and classification. The method is illustrated with the well-known National Cancer Institute database of 60 human cancer cell lines data (NCI60) of gene microarray expressions, in the context of classification of cancer cell lines.

DNA, Neoplasm↗
PubMed2002

Association of interferon regulatory factor-1, nucleophosmin, nuclear factor-kappaB, and cyclic AMP response element binding with acquired resistance to Faslodex (ICI 182,780).

To identify genes associated with survival from antiestrogens, both serial analysis of geneexpression and gene expression microarrays were used to explore the transcriptomes of antiestrogen-responsive (MCF7/LCC1) and -resistant variants(MCF7/LCC9) of the MCF-7 human breast cancer cell line. Structure of the gene microarray expression data was visualized at the top level using a novel algorithm that derives the first three principal components,fitted to the antiestrogen-resistant and -responsive gene expression data, from Fisher's information matrix. The differential regulation of several candidate genes was confirmed. Functional studies of the basal expression and endocrine regulation of transcriptional activation of implicated transcription factors were studied using promoter-reporter assays. The putative tumor suppressor interferon regulatory factor-1 is down-regulated in resistant cells, whereas its nucleolar phosphoprotein inhibitor nucleophosmin is up-regulated. Resistant cells also up-regulate the transcriptional activation of cyclic AMP response element (CRE) binding and nuclear factor kappaB (NFkappaB) while down-regulating epidermal growth factor receptor protein expression. Inhibition of NFkappaB activity by ICI 182,780 is lost in resistant cells, but CRE activity is not regulated by ICI 182,780 in either responsive or resistant cells. Parthenolide, a potent and specific inhibitor of NFkappaB, inhibits the anchorage-dependent proliferation of antiestrogen-resistant but not antiestrogen-responsive cells. This observation implies a greater reliance on their increased NFkappaB signaling for proliferation in cells that have survived prolonged exposure to ICI 182,780. These data from serial analysis of gene expression and gene microarray studies implicate changes in a novel signaling pathway, involving interferon regulatory factor-1, nucleophosmin, NFkappaB, and CRE binding in cell survival after antiestrogen exposure. Cells can up-regulate some estrogen-responsive genes while concurrently losing the ability of antiestrogens to regulate their expression. Signaling pathways that are not regulated by estrogens also can be up-regulated. Thus, some breast cancer cells may survive antiestrogen treatment by bypassing specific growth inhibitory signals induced by antagonist-occupied estrogen receptors.

Animals↗
PubMed2002

Functionally active estrogen receptor isoform profiles in the breast tumors of African American women are different from the profiles in breast tumors of Caucasian women.

BACKGROUND: Several cancer surveys have shown that African-American women (AAW) develop highly aggressive breast tumors and experience about three times higher mortality rates compared with other populations. Generally, breast tumors in AAW are poorly differentiated or undifferentiated and exhibit increased frequency of nuclear atypia, higher mitotic activity, higher S-phase fraction, and tumor necrosis. The molecular factors responsible for these tumor characteristics are mostly unknown. METHODS: To explore whether the aggressive tumor biology observed in AAW is related to distinct alterations in estrogen receptor (ER) isoforms, the relative expression levels of four functionally active ER isoform mRNAs, ERalpha wild type, ERbeta wild type, ERalpha exon 3delta, and ERalpha exon 5delta, were measured by reverse transcriptase-polymerase chain reaction analysis in 18 immunohistochemically ERalpha positive tumors and in 6 ERalpha negative tumors and their matched normal tissues. RESULTS: In the tumors of AAW, the protective ERbeta isoform was decreased significantly compared with matched normal tissues (paired t test; n = 24 patients; P = 0.0018). In addition, both the constitutively active ERalpha exon 5delta and the dominant negative ERalpha exon 3delta mRNA levels were elevated in tumor tissues compared with matched normal tissues (paired t tests; n = 24 patients; P = 0.0002 and P = 0.024, respectively). CONCLUSIONS: The data presented here show for the first time that functionally active ER isoform profiles in the breast tumors of AAW are different from those in Caucasian women. The tumors in AAW are characterized by decreased levels of the protective ERbeta isoform and elevated levels of the constitutively active ERalpha exon 5delta isoform. Variations in estrogen-mediated signaling because of the alterations in these two ER isoforms may account in part for differences in tumor biology between AAW and Caucasian women.

Black People↗
PubMed2002

C-7 analogues of progesterone as potent inhibitors of the P-glycoprotein efflux pump.

The P-glycoprotein product (Pgp) of the MDR1 gene has been implicated in the multiple drug resistance phenotype expressed by many cancers. Functioning as an efflux pump, P-glycoprotein prevents the accumulation of high intracellular concentrations of substrates. We have taken a rational approach to designing inhibitors of P-glycoprotein function, selecting a natural substrate (progesterone) as our lead compound. We hypothesized that progesterone, substituted at C-7 with an aromatic moiety(s), would exhibit reduced Pgp affinity, significantly increased antiPgp activity, and reduced affinity for progesterone receptors (PGR). We synthesized 7 alpha-[4'-(aminophenyl)thio]pregna-4-ene-3,20-dione (2), which comprises a C-7 alpha thiol bridge linking an aminophenyl moiety to progesterone, from pregna-4,6-diene-3,20-dione (1). The subsequent addition reaction of 2 with the appropriate isocyanate produced an initial series of compounds (3-6). Compounds 3-5 (respectively, -CH(2)CH(2)Cl; -CH(2)CH(3); and -CH(CH(3))C(6)H(5)) exhibit a significantly increased ability to inhibit P-glycoprotein. Potency for restoring doxorubicin accumulation in MDR1-transduced human breast cancer cells is increased up to 60-fold as compared with progesterone. Compound 5 has greater potency than verapamil and is equipotent with cyclosporin A, for inhibiting P-glycoprotein function. Furthermore, 5 does not bind to PGR, implying a potential reduction in in vivo toxicity. These data identify C-7-substituted progesterone analogues and 5, in particular, as rationally designed antiPgp compounds worthy of further evaluation/development.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Homocysteine, silent brain infarcts, and white matter lesions: The Rotterdam Scan Study.

Silent brain infarcts and white matter lesions are frequently seen on magnetic resonance imaging in healthy elderly people and both are associated with an increased risk of stroke and dementia. Plasma total homocysteine may be a potentially modifiable risk factor for stroke and dementia. We examined whether elevated total homocysteine levels are associated with silent brain infarcts and white matter lesions. The Rotterdam Scan Study is a population-based study of 1,077 people aged 60 to 90 years who had cerebral magnetic resonance imaging. The cross-sectional relation of total homocysteine with silent infarcts and white matter lesions was analyzed with adjustment for cardiovascular risk factors. The mean plasma total homocysteine level was 11.5 micromol/l (standard deviation 4.1). The risk of silent brain infarcts increased with increasing total homocysteine levels (odds ratio 1.24/standard deviation increase, 95% confidence interval 1.06-1.45). The severity of periventricular white matter lesions and extent of subcortical white matter lesions were also significantly associated with total homocysteine levels, even after excluding those with silent brain infarcts. The overall risk of having either a silent brain infarct or severe white matter lesions was strongly associated with total homocysteine levels (odds ratio 1.35/standard deviation increase, 95% confidence interval 1.16-1.58). We concluded that total homocysteine levels are associated with silent brain infarcts and white matter lesions independent of each other and of other cardiovascular risk factors.

Aged↗
PubMed2002

Do estrogens always increase breast cancer risk?

The etiology of breast cancer is closely linked to the female hormone estrogen, with high life-time exposure being suggested to increase breast cancer risk [Nature 303 (1983) 767]. However, there appears to be a disparity between studies attempting to establish an association between high estrogen levels and breast cancer risk. This disparity becomes smaller by taking into consideration a timing factor, and we propose that estrogens can increase, decrease, or have no effect on breast cancer risk, depending on the timing of estrogen exposure. We further propose that the timing of estrogenic exposures may play at least as important a role in affecting breast cancer risk as life-time exposure.

Breast Neoplasms↗
PubMed2002

Autologous endometrial coculture in patients with a previous history of poor quality embryos.

PURPOSE: To evaluate the effect of autologous endometrial coculture in patients (less than 36 years old) with a history of a single IVF failed cycle associated with poor quality embryos. METHODS DESIGN: Controlled clinical study. SETTING: University-based in vitro fertilization center. PATIENTS: Twenty-six patients with a history of a single prior failed IVF-ET with poor preembryo quality. INTERVENTION(S): Autologous endometrial coculture. MAIN OUTCOME MEASURES: Preembryo blastomere numbers and cytoplasmic fragmentation rates were compared between the treatment and previous cycle. Clinical pregnancy rates were analyzed. RESULTS: Twenty-six women with an average age of 32.8 +/- 2.9 years underwent treatment. On Day 3 the overall mean number of blastomeres per preembryo on coculture compared to conventional medium in a previous cycle was 6.1 +/- 1.8 vs. 5.1 +/- 1.3 (P = 0.01; Wilcoxon test). The average percentage of cytoplasmic fragments on coculture compared to the conventional medium in a previous cycle was 14% +/- 10 vs. 22% +/- 13 (P = 0.003; Wilcoxon test). At transfer the mean number of blastomeres per preembryo on coculture was 7.4 +/- 1.8 compared to 6.7 +/- 1.5 on conventional medium in a previous cycle (P = 0.02; Wilcoxon test). The clinical pregnancy rate (positive fetal cardiac activity) per patient was 88.5%. The delivery rate was 73.1% (19/26). CONCLUSIONS: There was an improvement in the preembryo quality for preembryos on autologous endometrial coculture compared to noncocultured preembryos from the same patient in a previous cycle. An excellent delivery rate was subsequently found.

Adult↗
PubMed2002

Antioxidant vitamins and risk of cardiovascular disease. Review of large-scale randomised trials.

People who consume a diet rich in fruit and vegetables have lower risks of cancer, cardiovascular disease and all-cause mortality. Many prospective cohort studies have reported inverse associations between dietary intake or blood levels of beta-carotene and risks of cancer. Several large-scale trials were set up to assess whether beta-carotene supplementation might reduce the risk of cancer. Subsequently, evidence emerged from basic research which indicated that oxidative modification of low-density lipoprotein cholesterol increases its atherogenicity. The evidence from basic research, and epidemiological evidence for a possible protective effect of antioxidant vitamins for cardiovascular disease was strongest for vitamin E. More recently, further trials were set up to examine if supplementation with anti-oxidant vitamins might also reduce the risk of cardiovascular disease. This review summarises the available randomised evidence from published trials of beta-carotene supplementation involving 70,000 people from 3 large-scale trials in healthy populations and on vitamin E supplementation involving 29,000 patients at high-risk of cardiovascular disease from 5 large-scale trials. The results of these trials have been disappointing and failed to confirm any protective effect of these vitamins for either cancer or for cardiovascular disease.

Antioxidants↗
PubMed2002

Cholesterol, coronary heart disease and stroke: a review of published evidence from observational studies and randomized controlled trials.

In observational epidemiologic studies, lower blood cholesterol is associated with a reduced risk from coronary heart disease (CHD) throughout the normal range of cholesterol values observed in most Western populations. There is a continuous positive relationship between CHD risk and blood cholesterol down to at least 3 to 4 mmol/l, with no threshold below which a lower cholesterol is not associated with a lower risk. Observational studies suggest that a prolonged difference in total cholesterol of about 1 mmol/l is associated with one-third less CHD deaths in middle age. Evidence from large-scale cholesterol lowering trials in patients at high-risk of CHD have demonstrated that much of the epidemiologically predicted difference in CHD risk associated with differences in cholesterol was achieved within a few years of treatment. Moreover, these trials have demonstrated that such therapy was not associated with increased non-CHD mortality. Total cholesterol is transported in blood as low-density lipoprotein cholesterol or LDL cholesterol (about 70%) and as high density lipoprotein cholesterol or HDL cholesterol (about 30%). Since these two cholesterol fractions have opposing effects on vascular risk, a 1 mmol/l reduction in LDL cholesterol is likely to be associated with 40 to 50% lower CHD risk. The size of the absolute reduction in CHD produced by lowering total and LDL cholesterol is determined by an individual's overall risk rather than their initial cholesterol level. Consequently, the benefits of drug treatment to lower LDL cholesterol are greater in those at higher absolute risk of CHD rather than at high cholesterol levels. Dietary saturated fat is the chief determinant of total and LDL cholesterol levels. Replacing 60% of the intake of saturated fat by other fats and reducing the intake of dietary cholesterol could reduce blood total cholesterol levels by about 0.8 mmol/l (that is by 10 to 15%), with four fifths of this reduction being in LDL cholesterol.

Adult↗
PubMed2002

Homocysteine and coronary heart disease.

Children with homocystinuria have markedly elevated plasma homocysteine concentrations and increased risks of stroke and coronary heart disease (CHD). Supplementation with folic acid, vitamin B6, and vitamin B12 lower homocysteine levels and such therapy is remarkably effective in delaying the occurrence of vascular events in affected individuals. The relevance, if any, of moderately elevated homocysteine levels to cardiovascular disease in the general population is uncertain. The results of retrospective studies of homocysteine and risk of cardiovascular disease (where blood is collected after the onset of disease) indicate that CHD or stroke patients invariably have higher homocysteine levels than age-matched controls. In contrast, the results of prospective studies (where blood is collected before onset of disease) show much weaker associations of homocysteine with cardiovascular disease. This article examines the background, epidemiological evidence relating homocysteine with vascular disease, and effects of vitamin supplements on homocysteine concentrations. Large-scale clinical trials of folic acid-based vitamin supplements are currently in progress to test whether lowering blood homocysteine levels can reduce the risks of CHD and stroke.

Adult↗
PubMed2002

Iterative normalization of cDNA microarray data.

This paper describes a new approach to normalizing microarray expression data. The novel feature is to unify the tasks of estimating normalization coefficients and identifying control gene set. Unification is realized by constructing a window function over the scatter plot defining the subset of constantly expressed genes and by affecting optimization using an iterative procedure. The structure of window function gates contributions to the control gene set used to estimate normalization coefficients. This window measures the consistency of the matched neighborhoods in the scatter plot and provides a means of rejecting control gene outliers. The recovery of normalizational regression and control gene selection are interleaved and are realized by applying coupled operations to the mean square error function. In this way, the two processes bootstrap one another. We evaluate the technique on real microarray data from breast cancer cell lines and complement the experiment with a data cluster visualization study.

Algorithms↗
PubMed2002

Development and validation of a method for using breast core needle biopsies for gene expression microarray analyses.

PURPOSE: Gene expression microarray technologies have the potential to define molecular profiles that may identify specific phenotypes(diagnosis), establish a patient's expected clinical outcome (prognosis), and indicate the likelihood of a beneficial effect of a specific therapy (prediction). We wished to develop optimal tissue acquisition, processing, and analysis procedures for exploring the gene expression profiles of breast core needle biopsies representing cancer and noncancer tissues. EXPERIMENTAL DESIGN: Human breast cancer xenografts were used to evaluate several processing methods for prospectively collecting adequate amounts of high-quality RNA for gene expression microarray studies. Samples were assessed for the preservation of tissue architecture and the quality and quantity of RNA recovered. An optimized protocol was applied to a small study of core needle breast biopsies from patients, in which we compared the molecular profiles from cancer with those from noncancer biopsies. Gene expression data were obtained using Research Genetics, Inc. Named Genes cDNA microarrays. Data were visualized using simple hierarchical clustering and a novel principal component analysis-based multidimensional scaling. Data dimensionality was reduced by simple statistical approaches. Predictive neural networks were built using a multilayer perceptron and evaluated in an independent data set from snap-frozen mastectomy specimens. RESULTS: Processing tissue through RNALater preserves tissue architecture when biopsies are washed for 5 min on ice with ice-cold PBS before histopathological analysis. Cell margins are clear, tissue folding and fragmentation are not observed, and integrity of the cores is maintained, allowing optimal pathological interpretation and preservation of important diagnostic information. Adequate concentrations of high-quality RNA are recovered; 51 of 55 biopsies produced a median of 1.34 microg of total RNA (range, 100 ng to 12.60 microg). Snap-freezing or the use of RNALater does not affect RNA recovery or the molecular profiles obtained from biopsies. The neural network predictors accurately discriminate between predominantly cancer and noncancer breast biopsies. CONCLUSIONS: The approaches generated in these studies provide a simple, safe, and effective method for prospectively acquiring and processing breast core needle biopsies for gene expression studies. Gene expression data from these studies can be used to build accurate predictive models that separate different molecular profiles. The data establish the use and effectiveness of these approaches for future prospective studies.

Animals↗
PubMed2002

Dietary modulation of pregnancy estrogen levels and breast cancer risk among female rat offspring.

PURPOSE: Against the hypothesis that high estrogen levels in utero increase the risk of developing breast cancer in later life are data showing that pregnancy estrogen levels are significantly higher in Asian women who have low breast cancer risk than in Caucasian women. We investigated whether maternal dietary intake of genistein or n-3 polyunsaturated fatty acids (PUFAs), which are typical to Asian but not Caucasian diet, affect pregnancy estrogen levels and susceptibility to mammary tumorigenesis among offspring. EXPERIMENTAL DESIGN: For that purpose, pregnant female Sprague Dawley rats were fed isocaloric AIN-93-based diets containing either at 15 mg (low), 150 mg (medium), or 300 mg (high)/kg genistein/diet or low- or high-fat (16 versus 39% energy from fat) diet composed either of n-3 PUFA menhaden oil or n-6 PUFA corn oil. All diets were switched to regular AIN-93 diet when pups were born. RESULTS: Maternal intake of n-3 PUFA diets significantly increased pregnancy 17 beta-estradiol (E2) levels (48% increase when compared with high n-6 PUFA diet; P < 0.0045). High genistein exposure also increased pregnancy estrogen levels, but the increase did not reach statistical significance (P < 0.14). The offspring of high-fat n-3 PUFA-consuming dams were significantly less likely to develop 7,12-dimethylbenz-[a]anthracene-induced mammary tumors (38% of these rats developed tumors during week 17 versus 64% of high n-6 PUFA offspring; P < 0.003). Maternal genistein intake did not affect offspring's tumor incidence. The mammary glands of high fat n-3 PUFA offspring contained more lobules (P < 0.07) and were thus more differentiated, whereas the glands of high genistein offspring contained more terminal end buds (P < 0.0015), which are the sites of malignant transformation. CONCLUSIONS: Our findings indicate that the elevated estrogen levels in the n-3 PUFA mothers were linked to reduced rather than increased breast cancer risk among their offspring, suggesting that other effects of n-3 PUFA may counteract the effects of high fetal estrogenicity on the mammary gland. High maternal genistein intake did not reduce offspring's breast cancer risk, and therefore high maternal soy intake in Asian women may not be associated with daughters' low breast cancer risk.

Animal Feed↗
PubMedDate not supplied

MTHFR 677C-->T polymorphism and risk of coronary heart disease: a meta-analysis.

CONTEXT: In observational studies, individuals with elevated levels of plasma homocysteine tend to have moderately increased risk of coronary heart disease (CHD). The MTHFR 677C-->T polymorphism is a genetic alteration in an enzyme involved in folate metabolism that causes elevated homocysteine concentrations, but its relevance to risk of CHD is uncertain. OBJECTIVE: To assess the relation of MTHFR 677C-->T polymorphism and risk of CHD by conducting a meta-analysis of individual participant data from all case-control observational studies with data on this polymorphism and risk of CHD. DATA SOURCES: Studies were identified by searches of the electronic literature (MEDLINE and Current Contents) for relevant reports published before June 2001 (using the search terms MTHFR and coronary heart disease), hand searches of reference lists of original studies and review articles (including meta-analyses) on this topic, and contact with investigators in the field. STUDY SELECTION: Studies were included if they had data on the MTHFR 677C-->T genotype and a case-control design (retrospective or nested case-control) and involved CHD as an end point. Data were obtained from 40 (34 published and 6 unpublished) observational studies involving a total of 11 162 cases and 12 758 controls. DATA EXTRACTION: Data were collected on MTHFR 677C-->T genotype, case-control status, and plasma levels of homocysteine, folate, and other cardiovascular risk factors. Data were checked for consistency with the published article or with information provided by the investigators and converted into a standard format for incorporation into a central database. Combined odds ratios (ORs) for the association between the MTHFR 677C-->T polymorphism and CHD were assessed by logistic regression. DATA SYNTHESIS: Individuals with the MTHFR 677 TT genotype had a 16% (OR, 1.16; 95% confidence interval [CI], 1.05-1.28) higher odds of CHD compared with individuals with the CC genotype. There was significant heterogeneity between the results obtained in European populations (OR, 1.14; 95% CI, 1.01-1.28) compared with North American populations (OR, 0.87; 95% CI, 0.73-1.05), which might largely be explained by interaction between the MTHFR 677C-->T polymorphism and folate status. CONCLUSIONS: Individuals with the MTHFR 677 TT genotype had a significantly higher risk of CHD, particularly in the setting of low folate status. These results support the hypothesis that impaired folate metabolism, resulting in high homocysteine levels, is causally related to increased risk of CHD.

Coronary Disease↗