Biomedical subjects

A Christianson

Publications and source records attributed to A Christianson.

4 recordsLinked to original sources

PubMed2001

Seattle 5 a Day worksite program to increase fruit and vegetable consumption.

BACKGROUND: 5 a Day for Better Health is a simple message encouraging people to eat more fruits and vegetables. The Seattle 5 a Day worksite investigators designed and evaluated an intervention, organized on stages of behavioral change, to increase worksitewide fruit and vegetable consumption. METHODS: We recruited 28 worksites with cafeterias and randomized 14 to intervention and 14 to control. The intervention addressed both changes in the work environment and individual level behavior change. In each worksite, an employee advisory board, with study interventionist assistance, implemented the program. By surveying cross-sectional samples of 125 employees per worksite, we compared worksite mean fruit and vegetable consumption at 2-year follow-up with that at baseline. Unobtrusive site-level indicators including plate observation and cafeteria checklist were also used. RESULTS: The difference at 2 years was 0.5 for the intervention worksites and 0.2 for the control worksites, with an intervention effect of 0.3 daily serving (P < 0.05). Other measures of fruit and vegetable consumption, including unobtrusive indicators, supported the effectiveness of the intervention. CONCLUSIONS: This simple 5 a Day intervention is feasible and acceptable for use in worksites with cafeterias. There was a significant differential increase in fruit and vegetable consumption in the intervention worksites. This kind of worksite intervention can achieve important health benefits on a population basis, because of its potential to reach large numbers of people.

Adult↗

PubMed1999

Folate status, homocysteine metabolism, and methylene tetrahydrofolate reductase genotype in rural South African blacks with a history of pregnancy complicated by neural tube defects.

The birth incidence of neural tube defects (NTDs) in South Africa is threefold to sixfold higher in rural compared with urban blacks. We investigated whether folate deficiency and aberrant homocysteine metabolism could explain the high NTD incidence in rural black populations. Plasma folate and total homocyst(e)ine (tHcy) concentrations were determined in apparently healthy rural black women (n = 107), rural black women with a history of pregnancy complicated by NTDs (n = 54), and urban blacks (n = 101). Methionine load tests were performed on the 54 women with a history of NTD-affected pregnancy and 54 controls matched for age and body mass. The presence of the 677C --> T mutation in the methylene tetrahydrofolate reductase (MTHFR) gene was investigated in both groups by a polymerase chain reaction (PCR) of genomic DNA and HinfI digestion of the PCR product. Apparently healthy urban black women (n = 101) had a lower (P < .001) plasma folate concentration compared with rural black women (n = 107). Women with a history of NTD-affected pregnancy did not differ significantly from controls with respect to plasma folate, fasting homocyst(e)ine, methionine, and the post-methionine load increase in plasma homocyst(e)ine. More than 50% of both of the latter groups had a post-methionine load increase in plasma tHcy less than the fifth percentile as observed in a healthy white control group. No homozygotes for the 677C --> T mutation in the MTHFR gene were found in black mothers with NTD-affected offspring or controls. It is concluded that black urbanization is characterized by a diminished folate status that is paradoxically associated with a lower NTD birth incidence. Homozygosity for the 677C --> T mutation in the gene coding for MTHFR does not constitute a genetic risk factor for NTDs in blacks. No aberrant homocysteine metabolism could be demonstrated in black women with NTD-affected pregnancies.

Adult↗

PubMed1999

Objective behavior associated with an "ordinary" mild headache: a surprising failure of pain onset to signal self-protective or self-regulatory behavior.

OBJECTIVE: The goal of this study was to determine whether onset of an "ordinary" headache initiated self-protective behavior or self-regulation, as indexed by a reduction in effort expenditure. METHODS: A nonclinical sample was employed. The ambition and performance accuracy of a headache-developing group (n = 23) and a sex-matched, headache-free group (n = 23) was compared during a series of mental arithmetic problems. Embedded within the series of math problems was a task involving recall of a stressor previously found to induce headache in many subjects. RESULTS: Onset of mild head pain did not lead to effort conservation; instead, heightened ambition appeared to characterize the headache-developing participants before as well as after headache onset. Headache-developing subjects also displayed a performance accuracy deficit. CONCLUSIONS: The data suggest unusually ambitious, effortful task engagement may contribute to the onset of mild "ordinary" headache. This possibility requires further examination under other controlled conditions as well as in the natural environment.

Adult↗

PubMed1984

Studies on cultured fibroblasts in a case of methylmalonic aciduria.

A case of methylmalonic aciduria is described. The clinical course was unusually mild, the child surviving to the age of 8 years. Studies on cultured fibroblasts confirmed a defect in propionate metabolism which was non-responsive to hydroxycobalamin in vitro. Polyethylene-glycol-induced cell fusion with a known methylmalonyl co-enzyme apomutase-deficient cell line showed genetic complementation indicating that in this patient the defect was in one of the enzymes required for 5-deoxyadenosyl cobalamin synthesis.

Apoenzymes↗