The enzymatic synthesis of homocysteine (from homoserine and H2S) and cysteine (from serine and H2S) has been demonstrated in Neurospora crassa. Purification and properties of the enzyme, or enzymes, are described. Both homocysteine and cysteine synthetase are subject to end product feedback control by methionine, which appears to be noncompetitive inhibition. Repression of both activities by m...

Mild homocysteinemia occurs surprisingly often in patients with premature vascular disease. We studied the possible enzymatic sources of this mild hyperhomocysteinemia and the control of homocysteine levels in plasma by treatment of patients with the cofactors and cosubstrates of homocysteine catabolism. We assessed homocysteine metabolism in 131 patients who had premature disease in their coro...

The relationship between homocysteine levels and glaucoma has been questioned in previous studies without conclusive results. In the current study, we assessed the relationship between homocysteine levels and intraocular pressure which is one of the main factors in the development of glaucoma in men and women.A retrospective cross-sectional analysis of a database from a screening center in Isra...

PURPOSE In 1998, the Food and Drug Administration mandated the fortification of food products with folic acid. The effect of this rule on mortality associated with homocysteine levels in patients with coronary artery disease is unknown. METHODS We studied 2481 consecutive patients with coronary artery disease who underwent coronary angiography between 1994 and 1999, and who had baseline homoc...

Homocysteine is an important and independent risk factor for arteriosclerosis. We showed previously that homocysteine stimulates vascular smooth muscle cell proliferation, a hallmark of arteriosclerosis. We show here that homocysteine and serum increased DNA synthesis synergistically in both human and rat aortic smooth muscle cells (RASMCs). Treatment of quiescent RASMCs with 1 mM homocysteine ...

BACKGROUND/OBJECTIVES Cardiovascular diseases is a major cause of death and is responsible for 23.8% of deaths in Korea. Clinical symptoms manifest in adulthood, but susceptibility begins in utero. Elevated homocysteine levels and adiposity might be linked to a greater risk in children as well as adults. We hypothesized that those who have simultaneous risk for folate and adiposity would be aff...

INTRODUCTION We compared the effect of higher and lower doses of folic acid compared to our routine daily dose on plasma homocysteine levels, in our hemodialysis patients. MATERIALS AND METHODS Eighty patients on hemodialysis receiving oral folic acid, 10 mg/d, were randomized to receive folic acid at either doses of 5 mg/d (group 1) or 15 mg/d (group 2) for 2 months. Plasma levels of total h...

Homocysteine is a chemical in the blood that is produced when an amino acid (a building block of protein) called methionine is broken down in the body. We all have some homocysteine in our blood. Elevated homocysteine levels (also called hyperhomocysteinemia) may cause irritation of the blood vessels. Elevated levels of homocysteine show an increased risk for (1) hardening of the arteries (athe...