Fatty Acid Composition of the Erythrocyte Membranes Varies between Early-Term, Full-Term, and Late-Term Infants in Japan.

BACKGROUND: Term infants can be categorized into 3 sub-groups: early term (37w0d to 38w6d), full term (39w0d to 40w6d), and late term (41w0d and beyond). However, the fatty acid composition among the 3 groups of term infants has not been investigated. The association between fatty acid composition and gestational period of term infants in Japan is unclear. METHODS: We assessed the fatty acid composition of maternal erythrocyte membranes in the third trimester and of cord erythrocyte membranes at birth in 212 healthy term Japanese infants using data from a prospective hospital-based cohort study. RESULTS: In maternal erythrocyte membranes, docosahexaenoic acid (DHA) levels and omega-3 index were significantly higher in the late-term group than in the early-term group. In cord erythrocyte membranes, DHA levels were not significantly different between the 3 groups; late-term infants showed significantly higher DHA/arachidonic acid (ARA) and lower 20: 3n-6 and ARA levels compared to early-term infants. Gestational period positively correlated with the DHA status in maternal and cord erythrocyte membranes. CONCLUSIONS: Fatty acid composition in maternal and cord erythrocyte membranes varies between early-, full-, and late-term infants, and the greater gestational period may contribute to the relatively high n-3 polyunsaturated fatty acids status in term infants. Furthermore, maternal DHA status in the third semester directly correlates with gestational period in pregnant Japanese women.

Relationship between Changes in Fatty Acid Composition of the Erythrocyte Membranes and Fatty Acid Intake during Pregnancy in Pregnant Japanese Women.

OBJECTIVE: Docosahexaenoic acid (DHA) is an important nutrient required by pregnant women and fetuses. Several studies suggest that fatty acid composition changes during pregnancy. However, the association of longitudinal changes in erythrocyte fatty acid composition and dietary fatty acid intake during pregnancy is not well understood. We assessed the relationship between fatty acid composition of the erythrocyte membranes and fatty acid intake at each trimester in pregnant Japanese women. METHODS: We conducted a prospective hospital-based cohort study. We investigated fatty acid composition of the erythrocyte membranes and intake of fatty acids during the three trimesters in 178 healthy, pregnant Japanese women. RESULTS: The eicosapentaenoic acid and arachidonic acid percentage of the erythrocyte membranes significantly decreased. The percentages of linoleic acid and α-linolenic acid significantly increased during pregnancy. The DHA percentage in the erythrocyte membranes decreased from the second to the third trimester. The DHA percentage in the erythrocyte membranes positively correlated with DHA intake in the third trimester. CONCLUSION: In pregnant Japanese women, the fatty acid composition of the erythrocyte membranes markedly changed throughout pregnancy. The DHA intake in the third trimester may be insufficient to maintain DHA percentage in the maternal erythrocyte membranes.

Electrochemical assay of plasmin activity and its kinetic analysis.

A sensitive and convenient electrochemical assay of plasmin activity and its kinetic analysis are described. Thus, a ferrocenyl peptide substrate (FcPS) having a plasmin-specific substrate sequence, Lys-Thr-Phe-Lys, and a Cys residue was prepared and immobilized on a gold electrode through the sulfur-gold linkage. The obtained electrode showed a redox signal based on the ferrocene moiety, suggesting the immobilization of FcPS on the electrode. After treatment of this electrode with plasmin, its electrochemical signal was decreased in proportion to an increase of the amount of plasmin. The detection limit for plasmin in this assay system was as low as 50 ng/ml or 0.15 mU/ml. Real-time monitoring of plasmin reaction on the electrode could also be achieved, and the kinetic parameters of this enzymatic reaction could be determined; for example, the k(cat)/K(m) value was 0.063 microM(-1) s(-1). Furthermore, a quantitative assay for streptokinase as a plasminogen activator was also demonstrated by using this system.