[Effects of levofolinic acid on plasma homocysteine concentrations in healthy and young women in preconceptional care]. / Efecto del ácido levofolínico sobre las concentraciones de homocisteína plasmática en la mujer joven y sana en la consulta preconcepcional.

BACKGROUND: Increases in total plasmatic homocysteine (tHcy) represents a risk factor for neural tube defects. We studied the effects of levofolinic acid (l,5-formyl-tetrahydrofolic) on the plasmatic tHcylevels in women of child-bearing age. MATERIALS AND METHOD: Healthy women aged 18-35 years (n = 30) received levofolinic acid, 5 mg/day,orally for 30 days. Both tHcy and intraerythrocytic folate levels were measured before treatment (day 0), on days 2, 5, 10 and 30 within the treatment period and on days 30 (day 60) and 60 (day 90) after the treatment was finished. Plasmatic tHcy was measured by fluorescence polarisation immunoassay and intraerythrocyticfolates by chemiluminescent immunoassay. RESULTS: Plasmatic tHcy decreased from the second day of treatment onwards (day 0 vs. 2: mean of difference: -1.24 micromol/l; CI 95% = -0.84 to -1.63; p < 0.001). The maximum decline (32.3%) was observed after 30 days (mean of difference = -2.72 micromol/l; CI 95% = -2.20 to -3.24; p < 0.001).After finishing the treatment, the hypohomocysteinic effect persisted up to days 60 (mean of difference = -2.67 micromol/l; CI 95% = -2.07 to -3.26; p < 0.001)and 90 (mean of difference = -1.49 micromol/l; CI 95% = -0.94 to -2.03; p < 0.001). The response was greater when the plasmatic tHcy concentration was >= 9 micromol/l. CONCLUSIONS: Levofolinic acid leads to a earlier, intense and persistent drop of the plasmatictHcy levels.

Human medial temporal lobe in aging: anatomical basis of memory preservation.

The integrity of the hippocampal formation is necessary for the correct function of declarative memory for facts and events. Normal aging is associated with a widespread decrease in cortical volume, including the hippocampal formation and related cortical areas, although in many cases, memory is only minimally impaired. In the present study, we quantified the extent of the parahippocampal gyrus (entorhinal cortex, as well as the medial temporal lobe proisocortical areas related to memory function, such as temporopolar cortex, perirhinal cortex, and posterior parahippocampal cortex) in 42 control cases. After detailed cytoarchitectonic analysis (based on homology with the nonhuman primate medial temporal lobe), planimetric measurement (calculated area) of a two-dimensional reconstruction of the parahippocampal gyrus was performed, and cases older than 70 years were compared with cases younger than 70 years. All areas showed atrophy with aging (average, entorhinal cortex, 5%; perirhinal cortex, 4%; posterior parahippocampal cortex, 15%; temporal pole, not assessable). Both entorhinal and posterior parahippocampal cortices reached statistical significance. Our results suggest that cortical areas relevant in memory function, and anatomically linked to the hippocampus, present a small degree of atrophy with aging, thereby permitting the reciprocal flow of information between the hippocampus and the cerebral cortex necessary for memory encoding and retrieval.

Hair zinc and dietary zinc intake during pregnancy and puerperium.

A longitudinal study of hair zinc concentration was carried out in 36 pregnant women at 12 and 36 weeks of gestation and 40 days postpartum. A progressive decrease in hair zinc concentration was noted through pregnancy; the decline between 12 and 36 weeks of gestation was statistically significant (P < 0.005) remaining without significant changes in the postpartum. Nutrient intakes were calculated from 3-day weighed food records at the same periods and at 20 weeks of gestation. Zinc, energy and protein intakes decreased during pregnancy. Mean zinc intake at 20 and 36 weeks of gestation was about 66% of the recommended dietary allowance (RDA) (9.8 and 10 mg, respectively) and about 52% of the RDA in the postpartum (9.8 mg). Although hair zinc levels do decline in pregnancy and zinc intake was lower than RDA, the study revealed that zinc nutriture was adequate for normal growth and development of fetus.

Maternal leukocyte metabolism during pregnancy and puerperium, and its relation to fetal growth.

Changes of energy metabolism in maternal leukocytes were studied longitudinally in 33 normal term pregnancies at 12, 20 and 36 weeks of gestation and 40 days post partum. Nutrient intakes were calculated from 3-day weighed food records at the same periods. Women tended to decrease their mean dietary intakes of energy and of most nutrients from early to late pregnancy. Glucose-6-P dehydrogenase (G6P-DH), pyruvic kinase (PK) and adenylate kinase (AK) activities rose significantly after the 12th week of pregnancy, reaching maximal values at week 20. The following period up to week 36 showed a significant decrease that continued in the puerperium, when their values were lowest. Adenine nucleotide contents and protein/DNA ratio followed a different pattern. A significant increase was also observed from weeks 12 to 20, remaining without changes during the second half of gestation, and falling at puerperium. The PK and AK activities showed a positive correlation with energy intake at 36 weeks of gestation and AK activity was negatively correlated with folic acid intake in the middle of pregnancy. At week 20, PK activity showed a positive correlation with both head circumference and body mass index of the newborn. There was also a correlation between protein/DNA ratio and head circumference at the 36th week of gestation. These findings may suggest a relationship between the metabolism of maternal leukocytes, and fetal development in utero.