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Biomedical subjects

A Grijalba

Publications and source records attributed to A Grijalba.

9 recordsLinked to original sources

Effect of dietary quercetin and sphingomyelin on intestinal nutrient absorption and animal growth.

Research on cancer and other conditions has shown flavonoids and sphingolipids to be food components capable of exerting chemoprotective action. Nevertheless, little is known about their effects on healthy individuals and their potential usefulness as therapeutic agents. The present study examined the possible action of a dietary flavonoid, quercetin, and a sphingolipid, sphingomyelin, as functional foods in healthy animals. In particular, the effect on animal growth of supplementing a conventional diet with one or other of these substances (0.5 % quercetin and 0.05 % sphingomyelin) was considered. Possible action affecting intestinal physiology was also analysed by measuring the uptake of sugar and dipeptide, mediated by the Na(+)-dependent sugar transporter SGLT1 and the dipeptide Na(+)/H(+) exchanger PEPT1 respectively, and the activity of related intestinal enzymes such as sucrase, maltase and aminopeptidase N. Both substances seemed to modify small intestinal activity in healthy mice, altering intestinal enzymatic activity and nutrient uptake. These effects observed in the small intestine did not impair normal development of the animals, as no differences in serum biochemical parameters or in organ and body weights were found. The findings should help in elucidating the mechanisms of action of these food components with a view to their possible use in the prevention of certain pathological conditions.

Absorption↗

[The state of poisoning in Navarra].

We briefly comment on the state of clinical toxicology in Navarra and in the rest of Spain, with reference to the Toxicology Committee of Navarra and its aims. Epidemiological data from the Emergency Service of the Hospital of Navarra is presented, as well as where to find information on the subject; the epidemiological registration sheet designed by the SEMESTOX group is attached. A description is given of the characteristics of therapeutic drugs and drugs of abuse determination (type of sample, methodology and interpretation of results) carried out in the toxicological analytical unit of the Hospital of Navarra. Finally, reference is made to all of the antidotes available to the Pharmacy Service of the Hospital of Navarra, which is the reference center for the whole of the autonomous community of Navarra. A description is given for each medicine including its indications.

Humans↗

Physiological and performance responses to a 6-day taper in middle-distance runners: influence of training frequency.

The purpose of this investigation was to examine the influence of training frequency on performance and some physiological responses during a 6-day taper. After 18 weeks of training, 9 male middle-distance runners were assigned to a high frequency taper (HFT, n = 5) or a moderate frequency taper (MFT, n = 4), consisting of training daily or resting every third day of the taper. Taper consisted of an 80% nonlinear progressive reduction in high intensity interval training. Blood samples were obtained, and 800 m performance and peak blood lactate ([La] peak ) measured before and after taper. Performance improved significantly after HFT (121.8 +/- 4.7 vs 124.2 +/- 4.9 s, p < 0.05), but not after MFT (126.6 +/- 2.8 vs 127.1 +/- 2.1 s). Neutrophils (2.89 +/- 0.68 vs 2.56 +/- 0.61 10 (3) x mm(-3)), granulocytes (3.08 +/- 0.70 vs 2.77 +/- 0.66 10 (3) x mm(-3)), haptoglobin (79.7 +/- 47.9 vs 60.7 +/- 33.6 mg x dl(-1)), total testosterone (7.39 +/- 1.67 vs 5.52 +/- 0.88 microg x l(-1)) and [La] peak (15.5 +/- 1.5 vs 14.4 +/- 2.0 mmol x l(-1)) significantly increased with taper. [La] peak correlated with performance time before taper (r = -0.76, p < 0.05), and change in [La] peak with change in serum cortisol (r = -0.75, p < 0.05) and total testosterone:cortisol ratio (r = 0.82, p < 0.01). In conclusion, training daily during a 6-day taper brought about significant performance gains, whereas resting every third day did not. High [La] peak and a hormonal milieu propitious to anabolic processes seemed to be necessary for optimum performance.

Adult↗

Physiological responses to a 6-d taper in middle-distance runners: influence of training intensity and volume.

PURPOSE: This study examined some physiological and performance responses to a 6-d taper, and the influence of training intensity and volume on these responses. METHODS: After 15 wk of training, 8 well-trained male middle-distance runners were randomly assigned to either a moderate volume taper (MVT, N = 4) or a low volume taper (LVT, N = 4), consisting of either a 50% or a 75% progressive reduction in pretaper low intensity continuous training (LICT) and high intensity interval training (HIIT). Blood samples were obtained and 800-m running performance was measured before and after taper. RESULTS: Performance was not significantly enhanced by either taper protocol (post- vs pre-taper times 124.9 +/- 4.5 vs 126.1 +/- 4.2 s with LVT, 126.2 +/- 8.0 vs 125.7 +/- 6.6 s with MVT). For the entire group of 8 subjects, red cell count, hemoglobin (Hb), mean corpuscular volume and mean corpuscular Hb concentration significantly decreased with taper, while reticulocyte count increased. Performance changes for all subjects correlated with changes in postrace peak blood lactate concentration (r = 0.87, P < 0.01). Taper LICT correlated with changes in Hb (r = 0.77), hematocrit (r = 0.81), reticulocyte count (r = 0.73), creatine kinase (r = 0.72), and total testosterone (r = -0.78), and with posttaper red cell distribution width (r = -0.75) and lymphocyte count (r = -0.82). Taper HIIT correlated nonsignificantly with changes in red cell count (r = -0.66) and total testosterone (r = 0.68). CONCLUSION: It is concluded that taper-induced physiological changes in trained middle-distance runners are mainly hematological, and that distinct physiological changes are elicited from LICT and HIIT during taper. Middle-distance runners can progressively reduce their usual training volume by at least 75% during a 6-d taper.

Adolescent↗

Comparison of two different methods for measurement of phenylalanine in dried blood spots.

Phenylketonuria is an inherited metabolic disorder caused by a defect in the hydroxylation of phenylalanine. Newborn screening is crucial for the diagnosis and treatment of this disease. A phenylalanine dehydrogenase-coupled enzymatic assay (Quantase) in microtiter plates for the screening of phenylketonuria was evaluated and compared with our routine method based on the modified fluorometric McCaman method. The test exhibited a linear calibration curve with a good slope as well as sufficient imprecision (< 10%), recovery (99.23+/-4.86%) and limit of detection (54.5 micromol/l). One hundred and ninety dried blood spots were analysed by this enzymatic method and compared with McCaman's. Although Quantase (Teknovas, Bilbao, Spain) showed a phenylalanine mean level in dried blood spot 18.2 micromol/l higher than that obtained with our routine method, the agreement between both techniques was considered acceptable.

Amino Acid Oxidoreductases↗

Physiological comparison of roller skating, treadmill running and ergometer cycling.

This study was undertaken to determine the metabolic and cardiorespiratory differences between treadmill running, ergometer cycling and roller skating in top level roller skaters. The subjects performed 3 discontinuous graded tests until exhaustion. The protocol was established so that heart rate kinetics during exercise were similar in all the tests. Maximal oxygen uptake (VO2max), maximal heart rate and exercise time to exhaustion were higher during running (p < 0.05) than during cycling. Blood lactate during submaximal and maximal running exercise was significantly lower (p < 0.05) than during cycling or roller skating. There were no differences between cycling and roller skating in any of the variables studied. These results seem to suggest that, compared with running, VO2max during cycling is limited more by local muscle fatigue than by cardiac factors. The similar response found during roller skating and cycling supports the concept that cycloergometer testing is a valid simple laboratory test for testing physical fitness in top level roller skaters.

Adolescent↗

[Program for the early detection of hyperphenylalaninemia: 11 years on].

In 1980 the Neonatal Screening Program was set in motion in Navarra. One of its aims is the early detection of hyperphenylalaninemias. In 1987 the quantification of phenylalanine came to be carried out in the Clinical Chemistry Department of the Hospital of Navarra. From then until December 1997, 51,815 newborn babies have been studied, which represents 99.24% of the infants born in Navarra. The quantification of phenylalanine in dried blood spots during 1989 enabled us to obtain the reference interval for this amino acid that is contained between 69.5 +/- 0.01 micromol/L and 139.9 +/- 0.03 micromol/L. During these 11 years we detected 2 cases of phenylketonuric hyperphenylalaninemia and one case of transitory hyperphenylalaninemia. From the clinical point of view, the children are well at present, following prescription of adequate treatment, which is based on a diet with a low phenylalanine content.

English Abstract↗

[Modulation of gastrointestinal physiology through probiotic strains of Lactobacillus casei and Bifidobacterium bifidum].

The products called functional foods, which besides being merely nutritional have different beneficial effects on the organism, are situated in the context of diet and health promotion. Amongst these functional foods we can distinguish, amongst others, between probiotic and prebiotic compounds. The micro-organisms most widely used in probiotic foods belong to the Lactobacillus and Bifidobacterium types. In this article we have studied the effect of diets supplemented with Lactobacillus casei or Bifidobacterium bifidum on animal development and especially on the intestinal function, centred on their immune, digestive and absorptive activity in growing animals. The bacteria strains used modify the activity of the small intestine of healthy mice, significantly affecting their enzymatic activity (sucrase, maltase and aminopeptidase) and the collection of nutrients (galactose and glycilsarcosine), as well as the intestinal immune activity (higher number of Peyer's patches). However, these effects do not appear to disturb the development of the growing animals since no significant differences are appreciated in their body weight or in their blood parameters. These results make clear the possible beneficial effects on intestinal physiology and contribute to the understanding of the possible mechanisms of action of the probiotics, which could be employed in the preventive treatment of different pathologies related to the digestive apparatus.

Animals↗