PubMed Health⌕ Search

Biomedical subjects

P Andrés

Publications and source records attributed to P Andrés.

At least 19 recordsLinked to original sources
PubMed2006

Changes in thiamin intake and blood levels in young, overweight/obese women following hypocaloric diets based on the increased relative consumption of cereals or vegetables.

OBJECTIVE: To analyse the changes in thiamin intake and blood levels of young, overweight/obese women following slightly hypocaloric diets based on the increased relative consumption of foods whose intakes were most removed from the ideal: cereals and vegetables. DESIGN: The women were randomly assigned to one of two slightly hypocaloric diets: diet V, in which the consumption of vegetables was increased, or diet C, in which the consumption of cereals (especially breakfast cereals) was increased. SUBJECTS: The study subjects were 67 young women with a body mass index of 24-35 kg/m2. INTERVENTIONS: Dietetic, anthropometrics and biochemical data were collected at the start of the study and again at 2 and 6 weeks. RESULTS: The reduction in energy intake was similar in both groups. However, diet C subjects lost significantly more weight. Blood thiamin concentration was higher in group C women than in group V women at 2 and 6 weeks. Compared to initial values, group C subjects showed a higher blood thiamin level at 2 weeks. The highest blood thiamin levels seen in group C women may have been due to their greater thiamin intake, their higher thiamin dietetic density, and a higher thiamin/carbohydrates ratio at both week 2 and 6 of the intervention period. CONCLUSIONS: Increasing the relative consumption of breakfast cereals within the context of a slightly hypocaloric diet can help in weight control and improve thiamine intake and blood levels.

Adult↗
PubMed2006

Changes in folate status in overweight/obese women following two different weight control programmes based on an increased consumption of vegetables or fortified breakfast cereals.

The modification of folate status was analysed in a group of sixty-seven overweight/obese women of childbearing age (20-35 years). Subjects were randomly assigned to one of two slightly hypocaloric diets: diet V (increased consumption of vegetables) or diet C (increased consumption of breakfast cereals). Dietetic, anthropometric and biochemical data were collected at the start of the study and again at 2 and 6 weeks. At 6 weeks a weight loss of 2.0 (sd 1.3) kg was achieved in V subjects and of 2.8 (sd 1.4) kg in C subjects (P < 0.05). At the start of the study, 64.2 % of all subjects had a folate intake of < 67 % of the recommended intake; this fell to just 3 % (7.14 % of V subjects and 0 % of C subjects) by week 6. Significant increases were only seen in C subjects in serum folate concentrations (both at 2 and 6 weeks), accompanied by a significant reduction in serum homocysteine (at week 6). Some 62.1 % of all subjects had serum folate concentrations of > or = 13.6 nmol/l (associated with a very low risk of neural tube defects) at the start of the study, while 87.0 % (85.2 % of V subjects and 88.9 % of C subjects) had concentrations of > or = 13.6 nmol/l at 6 weeks (P < 0.01). Increasing the relative consumption of vegetables/cereals in the context of a slightly hypocaloric diet may therefore be a good way to lose body weight. Breakfast cereals may be of special help with respect to folate status and serum homocysteine levels in overweight/obese young women following energy restriction diets.

Adult↗
PubMed2005

Chromatic compensation in the near-field region: shape and size tunability.

We report a diffractive-lens triplet with which to achieve wavelength compensation in the near field diffracted by any aperture. On the one hand, the all-diffractive triplet allows us to tune, in a sequential way, the Fresnel-irradiance shape to be achromatized by changing the focal length of one diffractive lens. On the other hand, we can adjust the scale of the chromatically compensated Fresnel diffraction field by shifting the aperture along the optical axis. Within this framework, we present an extremely flexible white-light Fresnel-plane array illuminator based on the kinoform sampling filter. A variable compression ratio and continuous selection of the output pitch are the most appealing features of this novel application.

Journal Article↗
PubMed2004

High-contrast white-light Lau fringes.

We present a new optical assembly with which to achieve Lau fringes with totally incoherent illumination. Gratinglike codification of the spatially incoherent source combined with an achromatic Fresnel diffraction setup allows us to achieve Lau fringe-pattern visibility of almost 100% with broadband light. The white-light character to our proposed setup is in stark contrast to previous monochromatic implementations. Potential implications of this fact are identified.

Journal Article↗
PubMed2004

Aerobic biological treatment of leachates from municipal solid waste landfill.

The main objective of the study was to improve chemical oxygen demand (COD) elimination by secondary biological treatment from leachate of municipal solid waste landfill. This effluent was a supernatant liquid obtained after physicochemical processes and coagulating with Al3+ followed by ammoniacal stripping. First, respirometric assays were carried out to determine the substrate biodegradability. Specific sludge respiration rate (R(s)) vs. concentration of substrate (S), showed an increasing specific rate of assimilation of substrate (Rs), which reached the highest value, when the substrate concentration (COD) was between 75 and 200 mg O2 L(-1). Second, continuous experiments were made in an aerobic digester to test the previous respirometric data and the results showed removal efficiency of COD between 83 and 69%, and a substrate assimilation rate between 1.3 and 3.1 g COD g(-1) volatile suspended solids d(-1).

Bacteria, Aerobic↗
PubMed2003

Sidelobe decline in single-photon 4Pi microscopy by Toraldo rings.

We demonstrate theoretically the feasibility of single-photon 4Pi-confocal microscopy. By inserting a pair of properly designed multi-ring phase-only pupil filters in the illumination path of a 4Pi microscope the height of the sidelobes of the point spread function substantially reduced, so that there is no ambiguity in the 3D image. Then, an axial resolution up to four times higher than that of single-photon confocal microscope can be effectively achieved.

Filtration↗
PubMed2002

Homocysteine levels in elderly Spanish people: influence of pyridoxine, vitamin B12 and folic acid intakes.

BACKGROUND: Serum homocysteine levels are a risk factor in cardiovascular disease. Knowledge on how dietary factors might affect these levels is therefore of interest. OBJECTIVE: To evaluate serum homocysteine levels in a group of elderly people and analyse the effect of pyridoxine, vitamin B12 and folic acid intakes on these levels. DESIGN: The study subjects were 130 independently-living elderly people over the age of 65. A dietetic study was performed using a 7-day food record. Serum homocysteine levels were determined by HPLC. RESULTS: Mean pyridoxine, vitamin B12 and folate intakes were 67.2+/-16.8%, 392.8+/-549.2% and 84.5+/-28.3% of recommended values respectively. With regard to sex, differences were seen only for vitamin B12 intake (9.1+/-12.7 microg/day in men, and 6.5+/-8.8 microg/day in women). Some 93.6% of subjects showed pyridoxine intakes below those recommended, as did 17.6% with respect to vitamin B12 and 72.8% with respect to folic acid. Homocysteine levels were 12.4 micromol/l (12.6+/-3.7 micromol/l in men and 12.2+/-7.9 micromol/l in women) (P<0.05). No significant differences were seen in homocysteine levels between subjects with lower than recommended intakes of pyridoxine or vitamin B12 and those with better intakes. However, subjects with folic acid intakes below 200 microg/day showed higher homocysteine levels (13.0+/-6.7 micromol/l) than did subjects with more adequate intakes (10.9+/-4.1 micromol/l) (P<0.05). CONCLUSION: The diet of the study subjects might be improved, especially with respect to pyridoxine and folic acid. Raising the intake of the latter might be especially useful in controlling homocysteine levels and the risk of cardiovascular disease.

Aged↗
PubMed2002

Vitamin E status in a group of elderly people from Madrid.

BACKGROUND: Given that vitamin E plays an important role in the prevention of pathological processes frequently observed in older age, it is of special interest to evaluate the nutritional situation of this population with respect to this vitamin. OBJECTIVE: To evaluate the nutritional situation with respect to vitamin E in a group of elderly individuals from Madrid, Spain. DESIGN: The vitamin E status of a group of 120, independently-living elderly people was investigated. All included subjects (i.e., those for whom it was possible to determine vitamin E status) belonged to a sample of 158 elderly volunteers, subjects of a larger nutritional study. A 5-day food record (including a Sunday) was kept in order to monitor food intake. Serum levels of alpha-tocopherol were determined by HPLC. RESULTS: Some 95.2% of subjects showed intakes below those recommended; 86.7% did not even meet 66% of the recommended values. At serum level, subjects showed alpha-tocopherol values of 8.3+/-3.6 mg/L, with no differences between men and women (8.5+/-3.6 mg/l in men and 8.2+/-3.6 mg/L in women). Some 51.7% (52.4% of men and 51.3% of women) showed levels below 7.8 mg/L; 17.5% (14.3% of men and 19.2% of women) showed values of 5 mg/L. The influence of the diet at the biochemical level can be seen in that those subjects with intakes lower than 50% of the recommended who showed significantly lower serum levels (7.8+/-3.4 mg/L) that those with greater intakes (9.3+/-4.2 mg/L). This difference was independent of serum triglyceride and cholesterol levels. Subjects with coefficients of vitamin E (mg)/polyunsaturated fatty acids (g) (E/AGP) below the 5 th percentile (0.32) had significantly lower serum alpha-tocopherol levels (5.3+/-1.1 mg/L) than did subjects with E/AGP>or= 0.32 (8.5+/-3.7 mg/L). CONCLUSION: Given the importance of vitamin E as an antioxidant, and its role in the prevention of a range of pathological processes, insufficient intakes (frequently detected in the group studied) should be corrected.

Aged↗
PubMed2001

Supervisory attentional system in patients with focal frontal lesions.

The aim of this study was to re-examine the hypothesis of a link between frontal cortex and the Supervisory Attentional System (SAS; Shallice, 1988). Contrary to previous studies that examined patients with lesions extending beyond the frontal lobes (Shallice, 1982; Burgess & Shallice, 1996a, 1996b), SAS or executive functions were evaluated in a group of patients with strict frontal lesions. Three tasks (Tower of London -TOL-, Hayling and Brixton tests) designed to assess specific SAS processes (planning, inhibition and abstraction of logical rules respectively) were administered. In the TOL test, although frontal patients were slower than control participants, the two groups did not differ in their ability to solve problems. Furthermore, the two groups did not differ in terms of performance in the Hayling and Brixton tests either. These results are discussed in terms of the SAS model and are compared to those observed by Shallice (1982) and Burgess & Shallice (1996a, 1996b). Additionally, the issue of the neural subtract of executive functions is addressed.

Adult↗
PubMed2001

Effect of saturated fatty acid consumption on energy and nutrient intake and blood lipid levels in preschool children.

In this article the effects of saturated fatty acid (SFA) consumption on energy and nutrient intake, and on a range of serum lipid parameters (indicators of cardiovascular risk) are reported in a group of 110 preschool children. Subjects were divided into 2 groups: high consumption (HC), in which > or =13% (20th percentile) of total energy came from SFAs, and low consumption (LC), in which SFAs provided <13% of energy intake. Food intake was monitored for 7 consecutive days. At participating day care centers, a 'precise individual weighing' method was used, while a 'food intake record' was kept for foods taken at home. At the blood level it was found that HC subjects showed higher HDL-cholesterol levels and better HDL-cholesterol/LDL-cholesterol ratios than did LC subjects. The greater intakes of riboflavin, iodine, zinc, magnesium and calcium seen in HC subjects suggest that these may have a better nutritive status (with respect to certain nutrients) than LC subjects. The development of criteria for providing the greatest protection against cardiovascular disease, while maintaining good nutritive condition, should be the subject of future studies. This is especially important in children of preschool age since nutritional deficiencies at this stage in life can have important effects on growth and health.

Cardiovascular Diseases↗
PubMed2000

Age-related differences in supervisory attentional system functions.

The authors explored the effect of age on executive functions by using 3 tasks (Tower of London, Hayling, and Brixton tests) designed to assess specific executive processes (planning, inhibition, and abstraction of logical rules) that were also sensitive to frontal dysfunction. The performance of elderly participants (n = 48) was significantly poorer than that of young participants (n = 47) in all 3 tasks. Processing speed, measured by means of a color-naming task, explained some but not all of the age-related differences. These results are discussed in terms of general and specific factors in cognitive aging.

Adaptation, Psychological↗
PubMed1999

Allogeneic bone marrow transplantation vs chemotherapy for the treatment of childhood acute lymphoblastic leukaemia in second complete remission (revisited 10 years on).

In 1989 we carried out a trial comparing allogeneic BMT to chemotherapy (CT) in 76 children with relapsed acute lymphoblastic leukaemia (ALL). Ten years on we have clinically revised outcome to firmly establish the role of each treatment, to analyse the importance of length of first remission and to provide long-term actuarial results for disease-free survival (DFS) and relapse rate in each group. For 21 patients within the transplantation group, probability of DFS and relapse are 42.8 +/- 10.8% and 40.2 +/- 11.7% (s.e.), respectively. In the chemotherapy group, probability of DFS is 10.0 +/- 4.74% (P = 0.001) and probability of relapse 87.5 +/- 5.2% (P = 0.0004). These results strongly reflect those at initial analysis, confirming a key role of BMT in the management of ALL in second remission. Moreover, on univariate analysis only two factors influenced DFS: treatment group and length of first complete remission (less or more than 30 months from first CR). Thus, it seems clear that the best therapeutic option in early relapse is BMT, whereas DFS in late relapse is at the limit of significance (P = 0.07), with a higher relapse rate in the CT group. Although encouraging results using intensified rotational combination chemotherapy have been published, prospective randomised studies are needed to assess with certainty the best therapeutic option in these patients.

Adolescent↗
PubMed1999

Riboflavin levels in maternal milk: the influence of vitamin B2 status during the third trimester of pregnancy.

OBJECTIVE: The aim of the present investigation was to study the relationship between riboflavin status during the third trimester of pregnancy and levels of this vitamin in transition milk (days 13 to 14 of lactation) and mature milk (day 40 of lactation). METHODS: The pregnancies and lactation periods of 57 healthy women between 18 and 35 years of age (27+/-3.7 years) were monitored, vitamin intake during the third trimester was determined by recording the consumption of foods over five days and by registering the quantities provided by dietary supplements. Riboflavin status during this stage of pregnancy was determined via the measurement of the activation of erythrocyte glutathione reductase (EGR) by flavine adenine dinucleotide (FAD). Milk riboflavin levels were determined by fluorometry. RESULTS: Those subjects with riboflavin intakes below recommended (1.6 mg/day) (Group L) showed lower consumption of milk products (305.2+/-88.5 g/day) than did those with greater intakes (Group H) (507.9+/-137.2 g/day). The consumption of riboflavin containing supplements was very low and was seen only in two H subjects. Transition and mature milk riboflavin levels were significantly higher in H subjects (948.1+/-700.1 nmol/L for transition milk and 993.8+/-436.6 nmol/L for mature milk) than L subjects (574.9+/-258.7 nmol/L for transition milk and 725.4+/-254.3 nmol/L for mature milk). Subjects with alpha-EGR coefficients over 1.2 in the third trimester showed significantly lower mature milk riboflavin levels (704.1+/-241.8 nmol/L) than did subjects with more satisfactory alpha-EGR coefficients (996.4+/-302.9 nmol/L). CONCLUSION: The influence of maternal vitamin B2 status during pregnancy on breast milk riboflavin levels was confirmed.

Adolescent↗
PubMed1998

[Supplementation with iron and folates during gestation: influence on the zinc status in the mother and on the zinc content in the maternal milk].

BACKGROUND: The aim of the present study was to investigate whether such supplementation impairs the zinc status of pregnant women or the zinc content of maternal milk. MATERIAL AND METHODS: Fifty seven women were studied during pregnancy and lactation. Zinc, iron and folate intakes were monitored during the third trimester of pregnancy using a five day food record and by registering intake of the same in the form of dietary supplements. Zinc levels were determined, using flame-atomic-absorption spectrophotometry, in serum during the third trimester of pregnancy, in transition milk (day 13-14 of lactation), and in mature milk (day 40 of lactation). RESULTS: 1.8% of pregnant women took zinc supplements whilst 7% took folate supplements. However, 100% of subjects showed zinc intakes (the sum of dietary and supplementary intakes) lower than those recommended. 87.7% showed the same for folate intake, 29.8% of pregnant women took iron supplements. When dietary and supplementary intakes were added, 26.3% of subjects showed iron intakes of over 200% of those recommended. Pregnant women with iron intakes in the third trimester of pregnancy of over 200% those recommended, showed lower serum zinc levels during the third trimester and, at a later date, lower mature milk zinc levels than did subjects with lower iron intakes. CONCLUSIONS: The combined dietary and supplementary intake of iron in some subjects provided total intakes of over 200% those recommended. Though this might be associated with an improvement in iron status it may impair those of zinc. Subjects with an intake of iron of over 200% of that recommended showed significantly lower serum and mature milk zinc levels than did those with lower iron intakes. It is suggested that the nutritional status of pregnant women should be carefully monitored and supplementation tailored to the needs of each individual.

Adolescent↗
PubMed1998

Ascorbic acid levels in maternal milk: differences with respect to ascorbic acid status during the third trimester of pregnancy.

The aim of the present investigation was to study the relationship between ascorbic acid status during the third trimester of pregnancy and levels of this vitamin in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation). To this end, the pregnancies and lactation periods of fifty-seven healthy women between 18 and 35 years of age (27 (SD 3.7) years) were monitored. Vitamin intake during the third trimester was determined by recording the consumption of foods over 5 d, and by registering the quantities provided by dietary supplements. Ascorbic acid levels in maternal serum during this stage of pregnancy, and in transition and mature milk samples, were determined by spectrophotometry. Those subjects with ascorbic acid intakes below that recommended (80 mg/d) (group L) showed lower consumption of fruit and vegetables than did those with greater intakes (group H). The consumption of ascorbic acid supplements was very low, and was only seen in three group H subjects. The difference in ascorbic acid intake was reflected at serum level. Group L subjects showed significantly lower serum values than did group H subjects (30.1 (SD 36.3) mumol/l compared with 101.1 (SD 168.1) mumol/l). Vitamin intake also influenced the composition of transition milk. Group L subjects showed significantly lower levels of ascorbic acid in milk than did group H subjects (255.5 (SD 220.3) mumol/l compared with 437.8 (SD 288.4) mumol/l). The results of the present study reveal the need to increase the consumption of fruits and vegetables during pregnancy and to monitor maternal ascorbic acid intake and vitamin C status.

Adolescent↗
PubMed1998

Calcium levels in maternal milk: relationships with calcium intake during the third trimester of pregnancy.

The aim of the present study was to investigate the relationship of Ca intake and serum Ca levels during the third trimester of pregnancy with levels of the same mineral in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation). The study subjects were a group of fifty-seven healthy, lactating mothers aged between 18 and 35 years (mean 27 (SD 3.7) years) whose pregnancies and labour were attended by the Department of Obstetrics and Gynaecology of Cuenca INSALUD Hospital, Spain. Ca intake during the third trimester was determined by recording the consumption of foods over a 5 d period and by registering Ca provided by dietary supplements. The same method was used to investigate the intake of protein, vitamin D, fibre and Fe, nutrients that could affect the use of dietary Ca. Ca levels in maternal serum during this stage of pregnancy, during lactation and in transition and mature milk samples, were determined using 2-cresolphthalein complexone. During pregnancy 70.2% of subjects showed Ca intakes below 1100 mg/d (75th percentile). The consumption of Ca supplements was very small and hardly modified the mean quantity supplied by the diet. Subjects with an intake < 1100 mg/d showed no fall in Ca levels in serum, either during pregnancy or lactation, nor were decreased levels found in transition milk. However, these subjects showed lower Ca levels in mature milk (5.95 (SD 1.56) mmol/l) than did subjects with greater Ca intakes (6.82 (SD 1.31) mmol/l). This may suggest that breast-fed babies of mothers with lower Ca intakes during pregnancy also receive less Ca.

Adolescent↗
PubMed1998

The importance of breakfast in meeting daily recommended calcium intake in a group of schoolchildren.

OBJECTIVE: To evaluate the breakfast intake of calcium and milk products and to determine whether these correlate with total intake of both calcium and milk products. METHODS: Food taken at breakfast and throughout the day was recorded using a 7 consecutive day food record in 200 schoolchildren aged between 9 and 13 years. RESULTS: 65.3% of boys and 80.5% of girls showed intakes of calcium which were lower than recommended. Milk products were the foods most frequently included in breakfast (95.5% of subjects included them in this meal). A relationship was seen between energy provided by breakfast and the quantities of milk products (r = 0.5735) and calcium (r = 0.6908) taken at this meal. A relationship was also seen between energy provided by breakfast and daily intake of milk products (r = 0.4633) and calcium (r = 0.4954). The percentage of intakes of calcium lower than those recommended decreased when breakfast provided > or = 20% of total energy intake, and when the consumption of milk products at breakfast was greater than the 50th percentile (200 ml). Subjects with breakfast milk product intakes > or = 200 ml showed higher intakes of the same over the rest of the day (233.3 +/-140.4 g) than did those who took lesser quantities of these foods at breakfast (161.5 +/- 100.6 g). Further, those who took > or = 25% of the recommended intake of calcium at breakfast showed greater intakes of the same over the rest of the day (600.4 +/- 213.8 mg compared to 510.8 +/- 200.7 mg in subjects with lower calcium intakes). CONCLUSIONS: The intake of milk products (r = 0.7587) and calcium (r = 0.7223) at breakfast correlates with the consumption of these foods in the whole diet. However, the total daily intake of milk products and calcium does not depend solely on breakfast intake. Subjects with the greatest intakes at breakfast also showed greater intakes over the rest of the day (r = 0.3953 for milk products and r = 0.4122 for calcium).

Adolescent↗