Methionine synthase catalyzes the remethylation of homocysteine to methionine via a reaction in which methylcobalamin serves as an intermediate methyl carrier. Over time, the cob(I)alamin cofactor of methionine synthase becomes oxidized to cob(II)alamin rendering the enzyme inactive. Regeneration of functional enzyme requires reductive methylation via a reaction in which S-adenosylmethionine is...

Antibiotic resistance in Neisseria gonorrhoeae continues to be a major concern in public health. Resistance of N. gonorrhoeae bacteria to penicillin G is widespread in most developed countries, which has necessitated a change to newer drugs for treatment of gonococcal infections. Recent reports indicate that resistance to these newer drugs is increasing, highlighting the need for accurate thera...

OBJECTIVE High-dose methotrexate (HD-MTX) is widely used in the consolidation phase of childhood acute lymphoblastic leukemia (ALL), but the roles that polymorphisms in folate-related genes (FRGs) play in HD-MTX toxicity and prognosis in children with ALL are not understood. The aims of this study were to investigate the frequencies of polymorphisms in the genes for thymidylate synthase (TS), m...

An etiologically complex disorder, Attention Deficit Hyperactivity Disorder (ADHD), is often associated with various levels of cognitive deficit. Folate/vitamin B9 is crucial for numerous biochemical pathways including neural stem cell proliferation and differentiation, regulation of gene expression, neurotransmitter synthesis, myelin synthesis and repair, etc. and a scarcity has often been lin...

BACKGROUND: Women may be at increased risk for venous thromboembolism (VTE) as compared with men. We studied the effects of genetic and biochemical markers of thrombophilia in women, in conjunction with other established risk factors for VTE. METHOD: The present retrospective case-control study was conducted in a thrombosis treatment programme at a large Toronto hospital. The cases were 129 wom...

Surveillance of gonococcal antimicrobial resistance and the molecular characterization of the mechanisms underlying these resistance phenotypes are essential in order to establish correct empirical therapies, as well as to describe the emergence of new mechanisms in local bacterial populations. To address these goals, 149 isolates were collected over a 1-month period (October-November 2008) at ...

BACKGROUND One-carbon metabolism is the basement of nucleotide synthesis and the methylation of DNA linked to cancer risk. Variations in one-carbon metabolism genes are reported to affect the risk of many cancers, including renal cancer, but little knowledge about this mechanism is known in Chinese population. METHODS Each subject donated 5 mL venous blood after signing the agreement. The stu...

Physical exercise induces adaptive changes leading to a muscle phenotype with enhanced performance. We first investigated whether genetic polymorphisms altering enzymes involved in DNA methylation, probably responsible of DNA methylation deficiency, are present in athletes' DNA. We determined the polymorphic variants C667T/A1298C of 5,10-methylenetetrahydrofolate reductase (MTHFR), A2756G of me...