Effect of parturition on serum glycerol and non-esterified fatty acids in obese and normal weight women

Serum glycerol and NEFA content variations are examined before and after labor in obese and normal weighing women (35 subjects). Blood glycerol and NEFA are shown to increase before delivery. Glycerol values are shown to drop to normal immediately after delivery, while NEFA values diminish to a lesser extent. Statistical analysis shown that blood glycerol increase could be pregnancy-dependent in both normal weighing and obese women, but that NEFA increase could be pregnancy-dependent in normal weighing women only. Obesity increases blood glycerol and NEFA concentration considerably, thus masking the effects of pregnancy.     

Behavior of vitamin A, beta-carotene, retinol binding protein and prealbumin in the plasma of hypo- and hyperthyroid subjects

Plasma concentrations of beta-carotene and retinol, determined by HPLC, and of transport proteins, ascertained by immunodiffusion technique, in hypo and hyperthyroid subjects are reported. In hypothyroid subject a considerable increase in carotene was noted. This was not the case for retinol. In hyperthyroids both beta-carotene and retinol levels were found to be normal. Transport protein (PA and RBP) levels were found to be lower only in cases of hyperthyroidism but unchanged for hypothyroids. According to the Authors the results show that the alteration in plasma carotene levels to be found in hypothyroid subjects is not the direct consequence of a lack of thyroid hormone in the metabolism of vitamin A but the indirect effect of thyroid disease.     

Evaluation of arachidonic acid in amniotic fluid before and during labor

Arachidonic acid is considered to be one of the precursors in prostaglandin synthesis. For this reason, arachidonic acid was measured in a series of amniotic fluid. Samples in order to rest the hypothesis that the beginning of uterine activity is accompanied by a rise of its concentration. In fact, it could be shown that in amniotic fluid from patients in labor arachidonic acid levels are much higher than in amniotic fluid from patients without uterine activity.     

Oral load test with beta-carotene in normal and dysthyroid subjects

An oral load of beta-carotene (500 mg) was administered to four normal, four hypo and four hyperthyroid subjects. Plasma beta-carotene content was determined at the 2nd, 4th, 6th, 8th, 10th, 12th and 24th hour after administration and at every 24th hour thereafter for 5 consecutive days. Plasma assays were performed by HPLC. No significant differences were revealed by Student's T test for one group to the other. The authors sustain that, as there is no impairment in intestinal uptake of beta-carotene in disthyroid subjects, the elsewhere described increase in carotinemia in hypothyroids is due to other mechanisms.     

Provision of nestboxes raises the breeding density of Great Tits Parus major equally in coniferous and deciduous woodland

Nestbox provision is a technique used to increase nest-site availability for secondary cavity-nesting birds. However, little is known about the demographic consequences of nestbox provision in different habitat types. To assess how nestbox provision affects the density of hole-nesting birds simultaneously in two contrasting habitats, we compared the breeding density of Great Tits along transects without nestboxes with that in transects where nestboxes were provided. Although the initial density of breeders was considerably higher in the deciduous habitat than in the coniferous habitat, provision of nestboxes increased density by a similar number of additional pairs in each habitat type. Thus, the provision of nestboxes in managed coniferous forests may be as effective in increasing the breeding opportunities of cavity nesters as in deciduous stands. Moreover, previous research showed that pairs in deciduous habitat with nestboxes have consistently lower breeding success than those in coniferous habitat with nestboxes. It is possible that the addition of nestboxes in the preferred habitat increased density to such an extent that density-dependent effects became apparent.     

Characterization of the overall and internal dynamics of short oligonucleotides by depolarized dynamic light scattering and NMR relaxation measurements

The dynamics of three synthetic oligonucleotides d(CG)4, d(CG)6, and d(CGCGTTGTTCGCG) of different length and shape were studied in solution by depolarized dynamic light scattering (DDLS) and time-resolved nuclear Overhauser effect cross-relaxation measurements. For cylindrically symmetric molecules the DDLS spectrum is dominated by the rotation of the main symmetry axis of the cylinder. The experimental correlation times describe the rotation of the oligonucleotides under hydrodynamic stick boundary conditions. It is shown that the hydrodynamic theory of Tirado and Garcia de la Torre gives good predictions of the rotational diffusion coefficients of cylindrically symmetric molecules of the small axial ratios studied here. These relations are used to calculate the solution dimensions of the DNA fragments from measured correlation times. The hydrodynamic diameter of the octamer and dodecamer is 20.5 +/- 1.0 A, assuming a rise per base of 3.4 A. The tridecamer, d(CGCGTTGTTCGCG), adopts a hairpin structure with nearly spherical dimensions and a diameter of 23.0 +/- 2.0 A. The DDLS relaxation measurements provide a powerful method for distinguishing between different conformations of the oligonucleotides (e.g., DNA double-helix versus hairpin structure). Furthermore, the rotational correlation times are a very sensitive probe of the length of different fragments. The NMR results reflect the anisotropic motion of the molecules as well as the amount of local internal motion present. The experimental correlation time from NMR is determined by the rotation of both the short and long axes of the oligonucleotide.(ABSTRACT TRUNCATED AT 250 WORDS)