Methylmalonic acid (MMA) accumulates in the body in cases of cobalamin (vitamin B12) deficiency because of impaired metabolization of methylmalonyl CoA to succinyl CoA by methylmalonyl CoA-mutase, a cobalamin-dependent enzyme. Therefore, MMA represents a functional marker of cobalamin deficiency (1). It is widely accepted that MMA measurement is useful and necessary if serum cobalamin concentra...

Coβ-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl suggesting that administration of EtPhCbl may cause cellular Cbl deficiency. Here, we investigate ...

Study. Am J Clin Nutr 1996;63:306 18. McCaddon A, Davies G, Hudson P, et al. Total serum homocysteine in senile dementia of the Alzheimer’s type. Int J Geriatr Psychiatry 1998;13:235 19. Blijhan GH. Homocysteine metabolism 2nd international conference. Neth J Med 1998;52(suppl):S1 20. Miller JW, Green R, Allen LH, Mungas DM, Haan MN. Homocysteine correlates with cognitive function in the Sacram...

Nitrous oxide (N 2 O) is an inhaled anesthetic drug that uses during surgery and recently proposed as a treatment for mood disorder in research setting. Exposure to N2O can cause hematopoietic neural side effects. The purpose of this study was the designation serum cobalamin, homocysteine CBC factors changes after exposure nitrous orthopedic surgery. This has been done on 30 patients undergoing...

The cysG gene of Salmonella typhimurium is involved in synthesis of both cobalamin (B12) and siroheme (a cofactor required for SO3(2-) and NO2(2-) reductases). The failure to reduce SO3(2-) leads to cysteine auxotrophy, for which the enzyme is named. Although Escherichia coli does not synthesize B12 de novo, it possesses a very similar CysG enzyme which has been shown to catalyze two methylatio...

BACKGROUND Delirium is common after cardiac surgery and is independently associated with increased morbidity, mortality, prolonged hospital stays, and higher costs. Cobalamin (vitamin B12) deficiency is a common cause of neuropsychiatric symptoms and affects up to 40% of elderly people. The relationship between cobalamin deficiency and the occurrence of delirium after cardiac surgery has not be...

Vitamin B12 (cobalamin) deficiency is prevalent worldwide and causes megaloblastic anemia and neurologic deficits. While the anemia can be treated, the neurologic deficits can become refractive to treatment as the disease progresses. Therefore, timely intervention is critical for a favorable outcome. Moreover, the metabolic basis for the neuro-pathologic changes and the role of cobalamin defici...

OBJECTIVE Determine the correlation between the hearing threshold and the serum levels of vitamin B12 (cobalamin) and folic acid among elderly subjects (> 60 years) with age-related hearing loss (ARHL). STUDY DESIGN Cross-sectional. SETTING Community. SUBJECTS AND METHODS Subjects included elderly who were found apparently healthy following repeated examination by physicians. The pure ton...

BACKGROUND Hyperhomocysteinemia has been suspected of favoring thrombosis. Several case-control studies and even a meta-analysis have confirmed a link between venous thrombosis and hyperhomocysteinemia. Homocysteine is due to genetic and acquired factors (poor diet in folate and vitamin B12, older age, renal impairment, thyroid diseases, and malignancies) induced by the intake and the concentra...

The identity of the major cobamide in liver has not been satisfactorily established. Cyanocobalamin (vitamin B12, 5,6dimethylbenzimidazolylcobamide cyanide), which has been obtained in crystalline form with liver as a source material (1, 2), is certainly a very minor component of the cobalamins in liver. Analyses of liver concentrates, both by a paper chromatographicbioautographic method (3) an...