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Biomedical subjects

G Varela

Publications and source records attributed to G Varela.

At least 73 records · Page 4Linked to original sources
PubMed1987

[Physico-chemical changes in olive oil used in repeated frying and its impact on blood lipoproteins in rats].

The effect of an olive oil used in repeated fryings on certain parameters of lipidic metabolism in rat has been studied. The control animals ingest a diet containing 15% raw olive oil, while in the experimental group the diet contains the same ratio of olive oil but used in repeated fryings. An increase in total esterified cholesterol and in cholesterol bound to HDL was observed in the experimental rats, while the levels of free cholesterol remained constant. Triglycerides decreased significantly. A tendency, non-significant, to decrease the percentage of VLDL was found. The lipidic and proteic composition of VLDL, LDL and HDL is very similar in both groups, although the phospholipid content of VLDL decreased significantly in the experimental group. Results indicate that, in the animals fed fried olive oil, their takes place an adaptation in the mechanisms related to the prevention of a rising of plasmatic cholesterol levels.

Animals↗
PubMed1986

[High protein diet in pregnancy. Effects on neonatal metabolism].

The effect of a high protein diet (20% casein + D,L-methionine) administered to Wistar rats during pregnancy on some aspects of cellular growth and RNA metabolism of progeny has been studied. Comparisons were made with well-nourished (10% casein + D,L-methionine) controls. Newborns individual weight, litter weight and number of newborns per litter were unmodified. However, neonate protein content dropped significantly when compared with controls. Both rate of DNA and number of nuclei were unchanged. Protein/DNA ratio (cellular size relative to protein) decreased, which might have led to an atrophy phenomenon, even if the newborn weight/number of nuclei ratio was not modified. Acid DNase activity rose, bringing about DNA breakdown. Total RNA content together with RNase activity fell in newborn from rats suffering high protein diet. Moreover, protein synthesis capacity (RNA/protein ratio) did not change. These results suggest that the administration of a high protein diet to pregnant rats lead to changes in newborn protein rate and nucleic acid turnover by modulating specific nuclease activity.

Animals↗
PubMed1986

[Additive effects of protein malnutrition and cortisol on plasma proteins and immunoglobulins of pregnant rats, and their offsprings].

This research work was carried out to study the effects of two immunosuppressive mechanisms: protein malnutrition and cortisol treatment on the feto-maternal unit. Therefore, plasma Ig G and Ig M levels were tested in pregnant rats submitted to a low protein diet (4%) and cortisol treatment (0.5 mg/100 g b.w.) during pregnancy and in their offspring. Nutritional status was evaluated by measuring ponderal parameters and plasma protein levels in rat dams and their neonates. Thus, a fall in ponderal parameters and in plasma protein levels was observed, both in rat dams suffering protein malnutrition as well as in their newborns. Cortisol treatment produced a decrease in the ponderal parameters of the control group, and an increase in plasma protein levels of the malnourished one, both in rat dams and in their neonates. Apparently, protein malnutrition might lead to a low functionality of B lymphocytes, caused by a decrease in Ig G and Ig M rates of malnourished rat dams. Ig M levels, however, increased in neonates as a consequence of possible concomitant infections. Cortisol treatment promoted humoral immune deficiency, since Ig G and Ig M levels decreased both in the control and in the malnourished pregnant rat groups. Nevertheless, cortisol administration seemed to increase susceptibility to infection in the newborns, especially in those born from malnourished rat dams.

Animals↗
PubMed1986

[Efficacy of the protein of canned tuna (Thunnus alalunga) in animal growth].

The effect of the manufacturing process on canned tuna (Thunnus alalunga) by the sterilization procedure at 115 degrees C for 60 and 90 minutes on its protein quality was studied. Protein quality was mainly evaluated according to its efficiency for animal growth. Protein from food obtained by the sterilization procedure at 115 degrees C for 60 minutes was similar for animal growth to that from a standard casein-methionine diet. No changes in digestibility and biological values were found between both proteins. Nevertheless, when the sterilization procedure was prolonged up to 90 minutes, the protein suffered modifications. Thus, protein digestibility decreased in spite of the fact that protein digestibility remained unmodified. On the other hand, introduction of the mixed protein into a diet based on flour plus tuna sterilized at 115 degrees C for 90 minutes, was not capable of maintaining the optimum patterns for weight evolution.

Amino Acids, Essential↗
PubMed1986

[Dietary protein level during pregnancy. Its influence on maternal-fetal exchange of substrates].

It is well known that the dietary protein level influences both the pregnancy process and development of the offspring. Therefore, a study was carried out to determine the effect that different protein percentages: 10%, 4% and 20% in diets administered to rats during pregnancy, had on food efficiency and on the substrates partition between rat dams and their neonates. Experimentation was thus carried out over a period of 21 days (pregnancy) and comparisons were made with well-nourished rats receiving 10% protein (controls) and between one and other group. Moreover, the effect on pregnancy was observed by comparing pregnant rats with non pregnant rats within each dietary situation. Food intake, weight parameters and food efficiency ratio were recorded in adult rats. Weight parameters were also evaluated in newborns. As results revealed, the highest the protein level in the diet, the highest the food efficiency ratio, both in the pregnant group and in the non pregnant group. Weight changes were determined in rat dams and their neonates, as a consequence of the different protein intakes. These also involved alterations in the substrates partition between the mothers and their offspring. Such findings might lead to the retention of substrates by the maternal tissues and, hence, to impairment of neonatal development.

Animal Nutritional Physiological Phenomena↗
PubMed1986

[Influence of cooking and drying processes at different temperatures on the nutritive value of the protein of mussels (Mytilus edulis)].

The effect of steam cooking (96 degrees C for 15 minutes) and drying at two temperatures, 70 degrees C and 110 degrees C, on nutritive value of mussel protein was studied. The measurements were carried out by nitrogen balance techniques in growing rats, and the nutritional parameters studied were: CD, BV and NPU. The crude digestibility (CD) values were: 87 +/- 1 and 82 +/- 1, and the biological values (BV), 80 +/- 1 and 74 +/- 1 for raw mussels, dried at 70 degrees C and at 110 degrees C respectively. This implies a significant decrease in the protein nutritive values of the mussel dried at a higher temperature. Cooking prior to drying significantly improved the digestibility and the biological value of the mussel's protein. In effect, improvement was so great, that the different drying temperatures did not affect the previously cooked product in a different way; therefore, the CD (94 +/- 1 and 94 +/- 1) and the BV (90 +/- 1 and 90 +/- 2) were the same for the mussel's protein, cooked and dried at 70 degrees C or at 110 degrees C.

Animals↗
PubMed1986

Nutritional status of an institutionalised elderly group in Segovia (Spain).

The nutritional status of a randomly selected sample of healthy persons, aged 68-91 years, living in an institution of the Spanish Social Services, was evaluated according to the adequation of diet to Recommended Dietary Intakes (DR) and by biochemical measurements. The individual weighing method was used to make the control of food intake covering a week. Mean values obtained suggested that intakes were less than recommended ones for energy, calcium, magnesium, zinc, riboflavin, folic acid and A and D vitamins. Mean intake of protein, iodine, iron, thiamin, niacin, B12 and C vitamins was adequate. For biochemical data most of the individuals present acceptable values, only a few aged show a deficiency status. Serum vitamin A values were low in 13.3% of men and 37.5% of women and serum cholesterol values were high in 8.3% of women.

Aged↗
PubMed1986

[Effect of the ingestion of thermically treated fat on blood lipids and blood lipoproteins in the rat].

The effect on rats fed on a diet with 15% solid frying fat (diet B) is compared to the effect of a diet with 15% of the same fat but in the raw state (diet A). After 10 weeks being fed on these diets serum triglycerides, phospholipids, total cholesterol, free cholesterol, esterified cholesterol, high density lipoprotein-cholesterol and free fatty acid levels were checked. Percentage of very low density lipoproteins (VLDL), low density lipoproteins (LDL) and high density lipoproteins as well as the composition of these lipoproteins was determined in parallel. Rats fed on diet B showed a significant increase in phospholipids and a significant decrease in VLDL when compared to those fed on diet A. Phospholipids on LDL decreased significantly in diet B fed rats. The data obtained seem to indicate that the hypercholesterolemic tendency induced by frying fat is neutralized by a decrease in VLDL levels.

Animals↗
PubMed1986

The effects of season and stage of pregnancy on 25-hydroxy-vitamin D levels in pregnant women in Madrid.

The influence of seasonal variations and gestation on 25(OH)D3 levels was studied in a group of women from Madrid, Spain, at different stages of pregnancy, during March and September. The objective was to observe the incidence of this climate and dietary factors. No variations were found in serum concentration of the metabolite throughout pregnancy in comparison with the controls, in either March or September. 25(OH)D3 values decreased after winter in both groups of women, although mean values were consistently higher than 16 ng/ml.

Calcifediol↗
PubMed1985

[Use of the calculation of anthropometric values with microprocessors for nutritional diagnosis].

The purpose of this work was to determine the possibility of establishing the most accurate nutritional diagnosis based on anthropometric information in school boys and girls (6 to 14 years), from Madrid (Spain). To carry out this work two well-trained anthropometrists obtained data of total and kneeling height, cephalic and thoracic circumference, and weight from an aleatory sample of 333 boys and girls who study at a national school in Madrid. The collected data presented and analyzed, served as a basis to calculate the fitting equations of each anthropometric variable according to age and sex, as well as some relation among them. Their use simplifies the obtention of the biometric reference values, and allows precise interpolations for concrete ages. All of these algorithms have been translated into BASIC sentences to facilitate its incorporation into any microprocessor. A first diagnostic pattern of the past and present nutritional history of children according to their age and sex, total and kneeling height and weight of each one of them is also presented. The BASIC program, necessary to incorporate it into computers, is included as well.

Adolescent↗
PubMed1984

[Changes at the liver cell level in rats subjected to protein-calorie malnutrition].

The effect of a low protein-calorie diet (restricted diet) on cellular growth and on RNA metabolism in Wistar rat liver has been studied. Experimentation was carried out over 30 days and the comparisons were made against well-nourished group (10% protein, controls). Liver weight and hepatic proteins dropped significantly in malnourished rats. Both rate of DNA and number of nuclei were unchanged. However, protein/DNA and liver weight/number of nuclei ratios decreased, which led to an atrophy phenomenon. DNase specific activity however, was not modified. Liver RNA content together with RNase activity dropped in deficient rats. Protein synthesis capacity (RNA/protein) did not change. These results suggest that restricted diet leads to a lower hepatocyte size with a decreased rat of RNA turnover.

Animals↗
PubMed1983

Proteic-anabolic capacity in rats--influence of the quality and quantity of dietary protein.

The effect of quality (casein + 5% DL-methionine, normal or heated at 180 degrees C for 20 min) and quantity (4%, 6%, 10%, 15% and 20%) of dietary protein on food intake, weight increase and nitrogen retention, has been studied in both sexes weaning Nestle rats. Our results show that food intake, when expressed as g dry matter/100 g body weight and day, is not dependent on the quality and quantity of dietary protein. Weight increase goes up at a 10% dietary protein level. At higher protein levels (15% and 20%) values are only maintained. Protein quality do not cause any difference. Nitrogen retention goes up on increasing dietary protein level, with a maximum at 10% casein-methionine and 15% heated protein, being retention heated casein-methionine significantly lower. At a higher protein level, the maximal anabolic capacity for protein is maintained. Maximum Protein Productive Value (PPV) is obtained from diets containing 10% protein level (normal or heated). There is a significant decrease at higher protein levels (15% and 20%). The PPV of heated casein-methionine is lower than PPV of normal one at 6%, 10%, 15% and 20% protein levels. The results state that in our assays, in spite of the good quality of heated casein-methionine, its metabolic efficiency is below non heated protein values even when protein contribution is increased. We can assume that protein quantity is not a balancing factor for protein quality.

Animals↗
PubMed1983

Influence of Hansenula anomala yeast intake on the liver and kidney metabolism of the trout (Salmo gairdneri).

The nutritional and metabolic effects of the use of Hansenula anomala yeast as the only protein source were studied in the trout. Food intake, weight and length increments significantly decreased in trout fed on yeast diet. Hepatosomatic index did not suffer any change. Soluble protein content in liver and kidney rose significantly. Liver alkaline phosphatase activity increased significantly. Liver lactate dehydrogenase (LDH) activity did not change in the experimental conditions. Glutamic-oxalacetic transaminase (GOT) activity appeared as the most affected parameter in both organs, increasing significantly in those trout fed on yeast diet.

Alkaline Phosphatase↗
PubMed1983

[Treatment of malignant pleural effusions].

The methods used to induce pleural symphisis in recidivant malignant pleural effusions are reviewed. The most suitable for an average hospital are the intrapleural introduction of talc and tetracycline clorhydrate, of which the procedures are described.

Drainage↗
PubMed1983

[Ca-P interaction at the nutritional and bone levels in male quail (Coturnix coturnix japonica)].

Five experiments were conducted in which various levels of calcium (Ca) and phosphorus (P) were fed to adult male quail (diets D-1: Ca = 1.54%, p = 0.80%; D-2: Ca = 3.20%, P = 0.81%; D-3: Ca = 1.57%, P = 1.66%; D-4: Ca = 3.40%, P = 1.71%; D-5: Ca - 2.20%, P = 0.81%). The interaction between Ca and P, and the effect on some nutritive hematic and osseous parameters were investigated for each diet. Feeding high P caused a body weight decrease in D-4 adult quail (P less than 0.05) and diminished food intake in the birds of trial D-3 (P less than 0.05). The results indicated that the excretion of Ca or P is a lineal function of its own intake. Neither the pattern of relationship between the intake and excretion of Ca was altered by the levels of phosphorus in the diets, nor the levels of calcium altered the pattern of P. With these levels of Ca and P interaction between both nutrients were not demonstrated. Plasma Ca levels and dry weight of femur as well as the ash content in them, were not significantly decreased, although the levels of the latter components were inferior in the groups fed non-adjusted diets in the Ca:P ratio (diets D-1, D-2, D-3 and D-4).

Animal Nutritional Physiological Phenomena↗