Medicine and Health Sciences Commons^™

The Etiology Of Neural Tube Defects, J. M. Scott, D. G. Weir, A. Molloy, J. Mcpartlin, Leslie Daly, P. Kirke, M. Conley, J. Lee, J. Mills

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Evidence continues to confirm that periconceptional ingestion of folic acid can prevent neural tube defects, although the basis of this prevention has been unclear. To further elucidate the mechanism by which this occurs, blood samples were collected from more than 50,000 pregnant women and the samples analyzed for red cell folate, plasma folate, plasma vitamin B12, and plasma homocysteine levels. Based on the results, it appears that the beneficial effect of folic acid is in overcoming a metabolic block in a folatedependent enzyme or transport process. It is likely that methionine synthase may be directly or indirectly involved.

The neural …

Sites Other Than Nucleotide 234 Determine Cardiovirulence In Natural Isolates Of Coxsackievirus B3, Nora M. Chapman, Jose R. Romero, Mark A. Pallansch, Steven Tracy

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The genetic site(s) that naturally determine the cardiovirulence phenotype of coxsackievirus B3 (CVB3) have yet to be mapped. Using two closely related CVB3 strains that differed in terms of cardiovirulence phenotype in mice, we previously reported the difference in phenotype mapped to a single site, nucleotide 234 (nt234) in the 58 non-translated region (NTR) of the CVB3 genome. When nt234 was C, the virus was attenuated and when U, the virus was cardiovirulent. To determine whether this finding was applicable to other strains of CVB3, we examined 13 different naturally occurring CVB3 strains isolated in different years in the United …

Cancer Mortality In Workers Exposed To Phenoxy Herbicides, Chlorophenols, And Dioxins, Manolis Kogevinas, Heiko Becher, Trevor Benn, Pier Alberto Bertazzi, Paolo Boffetta, H. Bas Bueno-De-No-De-, David Coggon, Didier Colin, Dieter Flesch-Janys, Marilyn Fingerhut, Lois Green, Timo Kauppinen, Margareta Littorin, Elsebeth Lynge, John D. Mathews, Manfred Neuberger, Neil Pearce, Rodolfo Saracci

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The authors examined cancer mortality in a historical cohort study of 21,863 male and female workers in 36 cohorts exposed to phenoxy herbicides, chlorophenols, and dioxins in 12 countries. Subjects in this updated and expanded multinational study coordinated by the International Agency for Research on Cancer were followed from 1939 to 1992. Exposure was reconstructed using job records, company exposure questionnaires, and serum and adipose tissue dbxin levels. Among workers exposed to phenoxy herbicides contaminated with 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) or higher chlorinated dioxins, mortality from soft-tissue sarcoma (6 deaths; standardized mortality ratio (SMR) = 2.03, 95% confidence interval (CI) 0.75-4.43) …

Association Between Plasma Homocysteine, Vitamin Status, And Extracranial Carotid-Artery Stenosis In The Framingham Study Population, Jacob Selhub, Paul F. Jacques, Andrew G. Bostrom, Ralph B. D'Agostino, Peter W. F. Wilson, Albert J. Belanger, Daniel H. O'Leary, Philip A. Wolf, David Rush, Ernst J. Schaefer, Irwin H. Rosenberg

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Recent epidemiologic studies suggest that elevated homocysteine concentrations in plasma represent a risk factor for vascular disease and stroke. In the present study, we analyzed plasma samples from the 20th biannual examination of the Framingham Heart Study cohort to determine distribution of plasma homocysteine concentrations, with emphasis on relationships to vitamins that are involved in homocysteine metabolism and prevalence of carotid artery stenosis. Results showed that homocysteine was positively correlated with age. After controlling for age and sex, homocysteine exhibited strong inverse correlation with plasma folate, and weaker correlations with plasma vitamin B₁₂ and pyridoxal- 5' -phosphate. Homocysteine was …

Cystathionine Β-Synthase Deficiency: Metabolic Aspects, S. Harvey Mudd

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Cystathionine β-synthase (CBS) deficiency was first demonstrated in 1964 in an eight-year-old mentally retarded girl with bilaterally dislocated optic lenses who excreted abnormally elevated amounts of homocystine in her urine. Patients with similar metabolic abnormalities and clinical findings had first been discovered 2 years earlier by Carson and her colleagues during a survey of mentally backward children in Northern Ireland. CBS deficiency has proven to be the most frequently encountered of the human genetic diseases causing homocystinuria and severe hyperhomocyst(e)inemia. Worldwide, it is detected with a frequency of about 1: 344,000 by screening programs of the newborn, but this is …

Blood Homocysteine Levels In The National Health And Nutrition Examination Survey (Nhanes Iii) In The United States: Preliminary Findings By Age And Sex, Irwin H. Rosenberg, Jacob Selhub, Paul F. Jacques, Barbara A. Bowman, Elaine W. Gunter, Clifford L. Johnson, R. S. Murphy

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Evidence from scores of observational studies from many parts of the world have demonstrated an association between elevated blood total homocysteine levels and the risk of cardiovascular disease, peripheral vascular disease, and stroke. These conditions are more prevalent in males than in females in virtually all populations studied, and their prevalence increases with advancing age. A much smaller body of data exists that describes an increasing tendency to higher homocysteine levels with increasing age.

There have been no previous reports of blood homocysteine levels measured in a cross-sectional sample throughout the age spectrum from childhood through the elderly. However, the …

Sites Other Than Nucleotide 234 Determine Cardiovirulence In Natural Isolates Of Coxsackievirus B3, Nora M. Chapman, Jose R. Romero, Mark A. Pallansch, Steven Tracy

Public Health Resources

The genetic site(s) that naturally determine the cardiovirulence phenotype of coxsackievirus B3 (CVB3) have yet to be mapped. Using two closely related CVB3 strains that differed in terms of cardiovirulence phenotype in mice, we previously reported the difference in phenotype mapped to a single site, nucleotide 234 (nt234) in the 5’ non-translated region (NTR) of the CVB3 genome. When nt234 was C, the virus was attenuated and when U, the virus was cardiovirulent. To determine whether this finding was applicable to other strains of CVB3, we examined 13 different naturally occurring CVB3 strains isolated in different years in the United …