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Biomedical subjects

C Centeno

Publications and source records attributed to C Centeno.

At least 19 recordsLinked to original sources
PubMed2006

Role of the JNK pathway in NMDA-mediated excitotoxicity of cortical neurons.

Excitotoxic insults induce c-Jun N-terminal kinase (JNK) activation, which leads to neuronal death and contributes to many neurological conditions such as cerebral ischemia and neurodegenerative disorders. The action of JNK can be inhibited by the D-retro-inverso form of JNK inhibitor peptide (D-JNKI1), which totally prevents death induced by N-methyl-D-aspartate (NMDA) in vitro and strongly protects against different in vivo paradigms of excitotoxicity. To obtain optimal neuroprotection, it is imperative to elucidate the prosurvival action of D-JNKI1 and the death pathways that it inhibits. In cortical neuronal cultures, we first investigate the pathways by which NMDA induces JNK activation and show a rapid and selective phosphorylation of mitogen-activated protein kinase kinase 7 (MKK7), whereas the only other known JNK activator, mitogen-activated protein kinase kinase 4 (MKK4), was unaffected. We then analyze the action of D-JNKI1 on four JNK targets containing a JNK-binding domain: MAPK-activating death domain-containing protein/differentially expressed in normal and neoplastic cells (MADD/DENN), MKK7, MKK4 and JNK-interacting protein-1 (IB1/JIP-1).

Adaptor Proteins, Signal Transducing↗
PubMed2006

Effect of dietary high-oleic acid sunflower seed, palm oil and vitamin E supplementation on broiler performance, fatty acid composition and oxidation susceptibility of meat.

1. A study was conducted to evaluate the effect of inclusion of two fat sources: high-oleic acid sunflower seed (HOASS; 0, 50, 100, 150 and 200 g/kg diet) and palm oil (PO), and dietary supplementation of vitamin E (alpha-tocopheryl acetate, 200 mg/kg diet) on performance, fatty acid composition and susceptibility to oxidation of white and dark chicken meat during refrigerated storage. Female chicks (3 to 6 weeks) were given one of 5 diets containing 90 g/kg of added fat with increasing monounsaturated fatty acid (MUFA) content, adjusted by progressively replacing PO by HOASS. 2. Body weight gain and gain:food ratio of birds were depressed in diets containing the highest proportions of HOASS (150 and 200 g/kg). Relative abdominal fat was reduced in birds fed diets including HOASS, except in the diet containing 100 g HOASS/kg. The inclusion of alpha-tocopheryl acetate improved body weight gain and gain:food ratio. 3. According to the fatty acid profile of the diets, saturated and polyunsaturated fatty acid (SFA and PUFA, respectively) contents were significantly reduced and MUFA content was significantly increased in white and dark chicken meats when the saturated oil, PO, was replaced progressively by HOASS in the diet. The inclusion of alpha-tocopheryl acetate increased PUFA content in both meats. 4. After 4 and 7 d of refrigerated storage, white and dark meat samples obtained from birds fed on diets containing HOASS had significantly lower thiobarbituric acid reacting substance (TBARS) values than those derived from the PO diet. The addition of alpha-tocopheryl acetate significantly reduced the lipid oxidation in white and dark meat. 5. Overall, the results showed that increasing MUFA content of chicken meat by replacing dietary PO with HOASS (up to 100 g/kg) did not adversely affect broiler performance and reduced the susceptibility of meat to oxidation during refrigerated storage. Dietary alpha-tocopherol supplementation improved chicken performance and was effective in protecting lipid meat from oxidation.

Animal Feed↗
PubMed2006

Nutritional evaluation of raw and extruded kidney bean (Phaseolus vulgaris L. var. pinto) in chicken diets.

An experiment was conducted to study the effect of inclusion of different concentrations (0, 100, 200, and 300 g/kg) of raw kidney bean and extruded kidney bean in broiler chick (0 to 21 d of age) diets on performance, digestive organ sizes, protein and amino acid digestibilities, intestinal viscosity, cecal pH, and blood parameters. Data were analyzed as a 3 x 2 factorial arrangement with 3 levels of kidney bean with and without extrusion. Positive control without kidney bean was used. Increasing the kidney bean content in the diet reduced weight gain and consumption, and increased the feed-to-gain ratio. Relative pancreas, liver, and jejunum weights, and intestinal viscosity were increased in response to increasing kidney bean concentration in the diet. The inclusion of different concentrations of kidney bean did not affect the apparent ileal digestibility of essential and nonessential amino acids, except for Met, Phe, and Cys, which were increased. Increasing kidney bean in the diet did not affect blood parameters, except for total protein, which was increased, and for androstenedione and testosterone, which were reduced. Extrusion significantly improved weight gain, feed consumption, and feed conversion. Relative pancreas, liver, and jejunum weights were reduced and spleen weight, cecal and intestinal viscosity were increased by extrusion. Apparent ileal digestibility of crude protein and all essential and nonessential amino acids were improved by extrusion. Like-wise, extrusion increased significantly the concentrations of cholesterol, triglycerides, glucose, and testosterone. We concluded that the inclusion of kidney bean in chicken diets cause a negative effect on performance and CP and amino acid digestibilities, and modified digestive organ sizes, intestinal viscosity, cecal pH, and some blood parameters. These effects were counteracted by the extrusion of kidney bean. However, the inclusion of extruded kidney bean in a chick diet resulted in poorer performance compared with that obtained with a corn-soybean diet.

Animal Feed↗
PubMed2003

Effect of whole and demucilaged linseed in broiler chicken diets on digesta viscosity, nutrient utilisation and intestinal microflora.

1. A study was undertaken to evaluate the effects of the inclusion of linseed or demucilaged linseed in the diet on the performance, fat and fatty acid digestibilities, metabolisability of gross energy and intestinal microflora. 2. The dietary inclusions were 80 and 160 g/kg for linseed and 160 g/kg for demucilaged linseed. Diets were given to chickens from 1 to 23 d of age. 3. Incorporation of linseed in the diet, particularly at 160 g/kg, depressed weight gain and food utilisation. Digestibility of fat and single fatty acids and dietary metabolisable energy were reduced. 4. Inclusion of linseed in the diet markedly increased the viscosity of ileal digesta. Microbial activity in the ileum and caeca was not greatly affected, but there was a significant increase in the number of lactobacilli. 5. The antinutritional effects caused by feeding linseed were partially overcome by substituting demucilaged linseed for linseed in the diet. 6. Results from the current study suggest that the viscous properties of mucilage are a major factor in the observed antinutritional effects of linseed through increasing intestinal viscosity. Such effects might also be mediated by the gut microflora.

Animal Feed↗
PubMed2003

Effects of feeding growing broiler chickens with practical diets containing sweet lupin (Lupinus angustifolius) seed meal.

1. Two experiments with growing broiler chickens were carried out to study the effects of the inclusion in their diets of whole or dehulled lupin (Lupinus angustifolius) seed meal on productive and physiological parameters. The effects of the addition of a commercial protease (1 g/kg, Bio-Feed Pro, Novo. Nordisk, Madrid) were also tested. 2. Diets were formulated to contain the same amounts of energy (12.55 kJ/g) and protein (210 g/kg). Raw whole (not heat treated) or dehulled sweet (low in alkaloids) lupin seed meal (400 and 320 g/kg, respectively) were used to formulate the lupin-based diets, and the protein content was completed with either defatted soybean or casein. 3. Final body weight and feed intake of chickens fed diets containing whole lupin seed meal (400 g/kg) were lower than controls, but gain:feed ratios were not different. The presence of soybean or casein in the diet did not affect productive parameters. Birds fed dehulled (320 g/kg) instead of whole lupin seed meal had similar body weight, feed intake and gain:feed values to controls. The addition of a commercial protease (1 g/kg, Bio-Feed Pro CT) to whole lupin/soy or whole lupin/casein diets tended to increase feed intake and final weight of the birds. 4. Plasma uric acid concentration was higher, and plasma cholesterol and triglycerides lower, in chicks fed whole lupin but not in those fed dehulled lupin seed meal. Plasma amino acid concentrations were not different from controls in birds fed lupin diets. 5. Apparent ileal digestibility of amino acids was not different from controls for the different lupin diets. The relative weight of the liver was higher than controls in lupin-fed birds, but not in those fed enzyme supplemented lupin-based diets. Liver concentrations of DNA tended to rise, while those of glycogen tended to decrease and liver RNA was lower in lupin-fed chicks.

Animal Feed↗
PubMed2002

Effects of microbial phytase supplementation on mineral utilization and serum enzyme activities in broiler chicks fed different levels of phosphorus.

An experiment was conducted to study the effect of microbial phytase (Natuphos 500) supplementation in chicks (0 to 6 wk of age) fed different levels of nonphytate phosphorus (nPP) on performance, mineral retention, bone and plasma minerals and serum enzyme activities. Data were analyzed as a 2 x 2 factorial arrangement with two levels of nPP for age periods of 1-d-old to 3 wk (0.35 and 0.22%) and 3 to 6 wk (0.27 and 0.14%) and two levels of phytase (0 and 500 U/kg) in each period. A positive control, adequate in nPP and Ca without phytase, was used. The low-nPP diets caused a negative effect on the performance (P < 0.05) compared to the normalnPP diet. Phytase had a favorable effect on weight gain at 3 wk (P < 0.004) and 6 wk (P < 0.0475) of age and on feed consumption only at 3 wk (P < 0.0106). Feed efficiency was not affected at any stage by addition of phytase. Performances of chicks fed with 0.35 and 0.27% nPP and phytase were comparable to those obtained with the normal-nPP diets. Decreasing nPP content in the diet increased (P < 0.0001) P retention at 3 and 6 wk of age, increased Mg retention at 6 wk, and decreased (P < 0.0001) Ca and Zn retentions at 3 and 6 wk, respectively. Phytase supplementation increased (P < 0.0001) Ca, P, Mg, and Zn retention at 3 and 6 wk of age. Likewise, the decrease in nPP content in the diet caused a significant reduction of tibia ash (P < 0.0023) and Mg content (P < 0.0001) in tibia ash and reduced liver (P < 0.0240), spleen (P < 0.0176), and tibia (P < 0.0001) weights. Similarly, Ca (P < 0.0369) and Zn (P < 0.0181) contents in tibia ash were increased in response to decreasing nPP levels in the diet. Phytase supplementation increased tibia weight (P < 0.0019), tibia ash (P < 0.0021), and Mg (P < 0.0339) and Zn (P < 0.0353) concentrations and reduced (P < 0.0161) the relative liver weight. By decreasing nPP levels in the diet, plasma Ca (P < 0.0001), Mg (P < 0.0001) and Zn (P < 0.0048) concentrations, and alkaline phosphatase (ALP) activity (P < 0.0299) increased, and plasma P content (P < 0.0001), aspartate aminotransferase (AST) activity (P < 0.0001), and total protein (TP) content (P < 0.0050) were reduced. Phytase supplementation increased plasma P level (P < 0.0001) and serum AST activity (P < 0.0049), reduced plasma Ca (P < 0.0001) and Mg (P < 0.0050) contents, and reduced serum alanine aminotransferase (ALT) (P < 0.0048), ALP (P < 0.0001) and lactate dehydrogenase (LDH) (P < 0.0192) activities. Plasma Zn was not affected by phytase supplementation. These results demonstrated that microbial phytase supplementation to low-P diets improved performance; P, Ca, Mg, and Zn use; and tibia weight and relative liver weight in broiler chickens. Likewise, serum AST, ALT, ALP, and LDH activities, as well as TP concentration, were also affected by phytase supplementation.

6-Phytase↗
PubMed2001

Effect of several germination conditions on total P, phytate P, phytase, and acid phosphatase activities and inositol phosphate esters in rye and barley.

Two assays were conducted to study the evolution of rye and barley phosphatases (phytase and acid phosphatase) and the degradation of its substrates (inositol phosphate esters) during seed germination. In this manner we could obtain a low-phytate, endogenous phosphatase rich ingredient to be used in animal nutrition. In the first assay, the seeds were soaked for 1 and 14 h and germinated for 3 and 5 days with and without the addition of gibberellic acid (GA3). In the second assay, the seeds were soaked for 1 h and germinated for 1, 3, and 5 days with GA3. Phytase (up to 5739 and 3151 U x kg(-1)) and acid phosphatase (up to 18288 and 3151 U x g(-1)) activities, and IP6 (6.09 and 6.01 mg x g(-1)), IP5 (0.48 and 0.48 mg x g(-1)), and IP4 (0.13 and 0.06 mg x g(-1)) were detected in ungerminated rye and barley, respectively. The germination process caused a significant increase of Phy and AcPh activities in rye (up to 112 and 213%) and barley (up to 212 and 634%) and a reduction in the phytate phosphorus content (up to 84 and 58%, respectively). Phytate phosphorus content was affected only by soaking time in the case of rye. Finally, during the course of germination, IP6 and IP5 were rapidly degraded in rye (88 and 79%) and barley (67 and 52%), and IP4 was only a short-living intermediate, which was increased during hydrolysis and degraded to IP3. In conclusion, a marked increase of Phy and AcPh activities in rye and barley with a concomitant decrease in phytate phosphorus content and an increase in the content of lower inositol phosphates were observed during the rye and barley germination.

6-Phytase↗
PubMed2001

Effect of inclusion level of linseed on the nutrient utilisation of diets for growing broiler chickens.

1. Diets containing linseed at inclusions of 0, 80, 120 and 160 g/kg were evaluated for digestibility of nutrients and AMEn content with male broiler chickens. 2. Increasing the concentration of linseed decreased the retention of nitrogen and the digestibility of amino acids, crude fat and fatty acids of diets. 3. Dietary AMEn (MJ/kg) was also affected by the rate of inclusion of linseed, values decreasing from 14.39 to 12.49. 4. In general, a linear regression model explained the relationship between dietary linseed content and nutritive parameters. However, the quadratic response found for the digestibility of several amino acids and fatty acids indicated a non-additive change in their digestibility. 5. Viscosity ofjejunal digesta was markedly increased by each increment of linseed in the diets. This is attributable to the presence of mucilage in linseed and it might explain many of the results obtained in this study.

Animal Nutritional Physiological Phenomena↗
PubMed2000

Phytase and acid phosphatase activities in plant feedstuffs.

A total of 183 samples representing 24 feedstuffs were analyzed for total phosphorus, phytate phosphorus content, phytase (Phy), and acid phosphatase (AcPh) activities with the objective to predict the capacity to hydrolyze phytic acid and to contribute to formulating environmentally adequate diets for monogastric animals. Of the cereals and cereal byproducts analyzed, only rye (5147 U kg(-)(1); 21 955 U g(-)(1)), wheat (1637 U kg(-)(1); 10 252 U g(-)(1)), rye bran (7339 U kg(-)(1); 56 722 U g(-)(1)), and wheat bran (4624 U kg(-)(1); 14 106 U g(-)(1)) were rich in Phy and AcPh activities. Legume seeds and oilseeds contained negligible Phy activity and a moderate amount of AcPh activity, except for kidney bean (33 433 U g(-)(1)) and full-fat linseed meal (13 263 U g(-)(1)). On the other hand, a significant linear regression between phytate phosphorus (y) and total phosphorus (x) was observed in cereal byproducts (R(2) = 0. 95; y = 0.8458x - 0.0367; P < 0.001) and oil seeds (R(2) = 0.95; y = 0.945x - 0.20; P < 0.001). Phy and AcPh were positively correlated with respect to phytate phosphorus in cereals, cereal byproducts, and other byproducts and negatively correlated in legume seeds and oilseeds. Except for cereals, the highest correlation between enzyme activities and phytate phosphorus was found for phytase. It is not possible to predict Phy and AcPh activities from phytate phosphorus content by linear and quadratic regressions. Finally, only highly significant and positive correlation was found between Phy and AcPh activities for cereals, cereal byproducts, and oilseeds.

6-Phytase↗
PubMed2000

The reality of palliative care in Spain.

With the sponsorship of the Spanish Society of Palliative Care (SECPAL), two nation-wide studies from the University of Valladolid were carried out in 1996 and 1998 into the state of palliative care teams in Spain. This report is based on those studies and is the first overall analysis of the current situation of palliative care in Spain. A total of 143 programmes were identified and data were collected from 128 teams (89%): 53 were programmes with hospitalised patients, 75 for home-based patients and 15 were mixed programmes. From the activity data, provided by 75% of the teams, it may be estimated that each year 22,638 terminally ill patients receive palliative care attention. Of these, 18,021 (79.6%) are cancer sufferers. Of the patients who die from cancer each year in our country, 21.2% receive palliative care during the final weeks of life. More than 10 years have passed since the first teams in Spain started their work. The time has now come to recognize the reality of palliative care in our society and to adopt a national policy for terminally ill patients, in line with World Health Organization recommendations formulated in 1989.

Ambulatory Care↗
PubMed2000

Composition of bacteria harvested from the liquid and solid fractions of the rumen of sheep as influenced by feed intake.

A study was conducted to determine the effect of the feed intake on the chemical composition of bacteria associated with the solid (solid-associated bacteria; SAB) and liquid (liquid-associated bacteria; LAB) fractions of rumen digesta, the digestive passage kinetics and their relationships. Whole rumen contents were sampled after a period of continuous infusion of 15NH3 from four ruminally-cannulated wethers provided successively with a hay-concentrate diet (2 : 1 w/w on a DM basis) at two rates of feed intake: 40 and 80 g DM/kg body weight 0.75. SAB had a higher content of organic matter and total lipids (P < 0.001) and a similar N content as compared with LAB. The concentration of purines and 15N was lower (P = 0.011 and P < 0.001 respectively) in SAB than LAB, whereas the opposite was observed for the concentration of amino acids (mg/g DM; P = 0.031). An increase in feed intake produced an increase in the N (P = 0.034) and purine (P = 0.066) concentrations in bacteria and a decrease (P = 0.033) in their amino acid concentrations. Significant increases of rumen outflow rates of liquid and particles were also observed with increased feed intake. Rates of rumen outflow showed positive and negative linear relationships (P < 0.001) with the purine : N ratio and the proportion of amino acid on total N of bacteria respectively. SAB contained significantly higher proportions of leucine, isoleucine, lysine and phenylalanine and lower proportions of alanine, methionine and valine than LAB. The increase in feed intake also induced significant changes in the amino acid profile of bacteria, increasing arginine and methionine and decreasing alanine and glycine proportions. Results show that the outflow rate of rumen contents is a major factor in determining the proportion of nucleic acids and protein in rumen bacteria and explains some of the differences observed between LAB and SAB.

Amino Acids↗
PubMed1999

Assessment of angiotensin II receptor blockade in humans using a standardized angiotensin II receptor-binding assay.

An in vitro angiotensin II (AngII) receptor-binding assay was developed to monitor the degree of receptor blockade in standardized conditions. This in vitro method was validated by comparing its results with those obtained in vivo with the injection of exogenous AngII and the measurement of the AngII-induced changes in systolic blood pressure. For this purpose, 12 normotensive subjects were enrolled in a double-blind, four-way cross-over study comparing the AngII receptor blockade induced by a single oral dose of losartan (50 mg), valsartan (80 mg), irbesartan (150 mg), and placebo. A significant linear relationship between the two methods was found (r = 0.723, n = 191, P<.001). However, there exists a wide scatter of the in vivo data in the absence of active AngII receptor blockade. Thus, the relationship between the two methods is markedly improved (r = 0.87, n = 47, P<.001) when only measurements done 4 h after administration of the drugs are considered (maximal antagonist activity observed in vivo) suggesting that the two methods are equally effective in assessing the degree of AT-1 receptor blockade, but with a greatly reduced variability in the in vitro assay. In addition, the pharmacokinetic/pharmacodynamic analysis performed with the three antagonists suggest that the AT-1 receptor-binding assay works as a bioassay that integrates the antagonistic property of all active drug components of the plasma. This standardized in vitro-binding assay represents a simple, reproducible, and precise tool to characterize the pharmacodynamic profile of AngII receptor antagonists in humans.

Angiotensin II↗
PubMed1998

Effects of chronic nimodipine on working memory of old rats in relation to defects in synaptosomal calcium homeostasis.

The present study was designed to investigate whether chronic (from 12 to 23 months of age) dietary treatment with the L-type Ca2+ channel blocker nimodipine (30 mg/kg body weight) enhances the cognitive behavior of aged animals and whether such a treatment would have long-term effects on the mechanisms of Ca2+ regulation in synaptic terminals from the aged rat brain. Cognitive behavior was evaluated in an 8-arm radial maze in 6 test series comprising a total of 105 test sessions, with intervals of no training between series. Nimodipine-treated rats performed better than vehicle-treated, aged-matched controls in all the test series, making more correct choices every time a new series was initiated. However, differences between nimodipine- and vehicle-treated rats were most remarkable in the last three test series, when the rats were 19 to 22 months. In these series 74% of the nimodipine-treated rats were able to perform the task in 4 to 9 test sessions whereas only 12%, 14% or none of the control rats learned the task. To study Ca2+ regulation in synaptosomes derived from cerebral cortex and hippocampus, we analyzed 45Ca2+ accumulation as well as the levels of the Ca2+-binding proteins calbindin-D28K and calreticulin by Western blotting. Nimodipine administration had no effect on hippocampal synaptosomes but increased the levels of calbindin-D28K and calreticulin in cerebral cortex preparations. These results indicate that chronic nimodipine treatment from 12 to 23 months of age prevents age-induced learning deficits without showing any signs of toxicity, and that these effects are associated with a small increase in the levels of synaptosomal Ca2+-binding proteins from cerebral cortex. The up-regulation of these proteins might provide a link between the long-term effects of nimodipine on gene expression and learning ability in old rats.

Aging↗
PubMed1997

[The follow-up of the cancer patient: how and when?].

The medical resources devoted to cancer patient follow-up are growing. However, intensive follow-up is not translated to any significant improvement survival in a majority of patients. A few neoplasias have an effective salvage therapy, and are worth having strict follow-up to diagnose earlier the recurrence. In many tumours, as breast cancer, an early diagnosis of recurrence does not imply an improvement on survival. Tumoral markers are able to detect the presence of tumour cells even before being clinically apparent and are routinely used in the follow-up of tumours; however, they do not seem to improve survival. The cost-benefit relation of multiple revision in cancer patients apparently cured is debated. No general consensus is achieved to define the best tests to follow-up cancer patients. The trend is to minimize the diagnostic tests and to recommend a clinical follow-up with anamnesis and physical exploration.

Combined Modality Therapy↗