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Background: To decrease the incidence of neural tube defects, active efforts are currently undertaken to promote folic acid (FA) intake among women. In 2003, the Food and Drug Administration approved the proposal of introducing an oral contraceptive (OC) and FA combination pill. It is unknown whether these pills will reduce neural tube defect incidence for couples who do not become pregnant soon after discontinuation. We studied FA kinetics up to 12 weeks discontinuation of eight weeks 500 μg/d FA in 27 healthy Dutch women of child-bearing age. Methods: In this controlled study, women were assigned to an intervention group (n = 13) or a control group (n = 14). The total study duration was 20 weeks, during which the subjects had to give blood on nine occasions (week -8 [baseline], -4, 0, 1, 2, 3, 4, 8 and 12) for analyses of serum and erythrocyte folate, and plasma total homocysteine. The intervention group received 500 μg/d FA during the first eight weeks, and discontinued the intake from weeks 0 to 12. No supplements were supplied to the control group. Results: Serum folate and plasma total homocysteine returned to baseline after 12 weeks of FA discontinuation, erythrocyte folate did not. Conclusion: An FA/OC combination pill seems to be of value for only a minor portion of women. Active efforts to stimulate women of child-bearing age to take FA remain essential. [ABSTRACT FROM AUTHOR]

The objective of this paper is to study shedding patterns of cows infected with Mycobacterium avium subsp. paratuberculosis (MAP). While multiple single farm studies of MAP dynamics were reported, there is not large scale meta-analysis of both natural and experimental infections. Large difference in shedding patterns between experimentally and naturally infected cows were observed. Experimental infections are thus probably driven by different pathological mechanisms. For further evaluations of shedding patterns only natural infections were used. Within such infections, the transition to high shedding was studied as a proxy to the development of a clinical disease. The majority of studied cows never developed high shedding levels. Those that do, typically never reduced their shedding level to low or no shedding. Cows that eventually became high shedders showed a pattern of continuous shedding. In contrast, cows with an intermittent shedding pattern had a low probability to ever become high shedders. In addition, cows that start shedding at a younger age (less than three years of age) have a lower hazard of becoming high shedders compared to cows starting to shed at an older age. These data suggest the presence of three categories of immune control. Cows that are intermittent shedders have the infection process under control (no progressive infection). Cows that start shedding persistently at a young age partially control the infection, but eventually will be high shedders (slow progressive infection), while cows that start shedding persistently at an older age cannot effectively control the infection and become high shedders rapidly.