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Biomedical subjects

A Gil

Publications and source records attributed to A Gil.

At least 361 records · Page 20Linked to original sources

Myocardial involvement in systemic lupus erythematosus. A noninvasive study of left ventricular function.

A relatively high incidence of heart failure is noted among patients with systemic lupus erythematosus (SLE) without clearly defined clinical causes. To evaluate left ventricular performance in patients with SLE without evidence of cardiovascular disease, noninvasive measurement of the systolic time intervals was carried out. Simultaneous recording of the electrocardiogram, phonocardiogram and carotid arterial pulsation were obtained in 25 patients with systemic lupus erythematosus and compared with 22 normal subjects. The patients with SLE had a shorter left ventricular ejection time (P less than 0.05), a longer pre-ejection period (P less than 0.02) and an increased ratio of pre-ejection period/left ventricular ejection time (P less than 0.005). These abnormalities on ventricular function were independent of age, duration of the disease, hypertension, renal involvement, anemia, immunologic activity and corticosteroid treatment. Several etiologic possibilities are discussed and the clinical usefulness of this method to detect and follow-up the cardiac dysfunction in systemic lupus erythematosus is emphasized.

Adolescent↗

Neutrophil chemotaxis and serum chemotactic activity in systemic lupus erythematosus.

Neutrophil chemotaxis, random motility, serum chemotactic activity derived from complement activation by classical or alternative pathways, and the presence of serum inhibitors of chemotaxis were all studied in 24 patients affected by Systemic Lupus Erythematosus (SLE) and in an equal number of healthy control subjects. Statistical comparison between patients and controls indicated lower chemotactic activity in patient's serum when activated by the classical pathway, and the presence in some SLE patients of a heat-labile inhibitor of the chemoattractants. Low "classical pathway" chemotactic indexes were correlated with low C4 values, active nephritis and recurrent infections. The presence of heat-labile inhibitor was correlated with low values of C3. Our data suggest that defective neutrophil chemotaxis could be one of the mechanisms contributing to the high incidence of infections suffered by SLE patients. The importance of conducting separate studies on cell movement and on generation of serum chemotactic activities by classical and alternative pathways in SLE patients is discussed.

Adolescent↗

[Complement system in disseminated lupus erythematosus].

The levels of C3, C4 and CH50 in patients with lupus erythematosus disseminatus (LED) were lower than in the controls. However, although in many patients these levels were below the normal values, there was no statistically significant difference between the two group. The levels are reduced during the acute phases and in some patients they remain high. On the whole, C3 was lower in patients with nephropathy (p less than 0,025) than in patients presenting with clinical activity (p less than 0,02). The positive relationship existing between C3 and C4 (r = 0,641, p less than 0,01) suggests activation of the complement system in LED via the classic route. In cases with concurrent lupus nephropathy a relationship between C3 and C3PA was seen, suggesting that in this case the alternative route is involved.

Adolescent↗

A sequence downstream of AAUAAA is required for rabbit beta-globin mRNA 3'-end formation.

The sequence AAUAAA, found 11-30 base pairs (bp) upstream of the poly(A) site of most non-histone eukaryotic messenger RNAs (mRNAs) forms an essential part of the recognition site for 3'-end processing of the primary transcript. However, the sequence AATAAA is found in transcribed regions of genes and is differentially utilized in genes containing multiple copies of the sequence within the 3'-noncoding region, suggesting that the hexanucleotide alone does not comprise a complete recognition site. Therefore, it seems likely that additional sequences are required to form a complete recognition site for 3'-end formation. We have investigated the sequence requirements for mRNA 3'-end formation using the rabbit beta-globin gene as a model system. Here we demonstrate that an additional sequence 3' to AAUAAA is required for the correct 3'-end formation of rabbit beta-globin mRNA.

Animals↗

Fluctuating dermatoglyphic asymmetry: genetic and prenatal influences.

Genetic and environmental prenatal factors influencing the fluctuating asymmetry of the a-b interdigital ridge count are examined. From the results obtained we can conclude that fluctuating asymmetry of the a-b interdigital ridge count is poorly influenced by genetic factors. We suggest that fluctuating asymmetry of dermatoglyphics provides a good measure of developmental stability in humans, especially for males. The results also indicate that random environmental factors, acting before the 19th week of embryonic development, could be related to the differential timing of maturation of the sexes.

Dermatoglyphics↗

Effects of dietary nucleotides on the fatty acid composition of erythrocyte membrane lipids in term infants.

Human milk contains relatively high amounts of acid-soluble nucleotides, mainly CMP, AMP, UMP, IMP, and UDP sugars, and lacks orotate. On the contrary, cow's milk and adapted formulas contain high amounts of orotate and very low amounts of CMP and AMP. Nucleotides may be modulators of metabolic functions in gut and liver. To evaluate the possible role of dietary nucleotides in newborn fatty acid metabolism, we studied the polyunsaturated fatty acid (PUFA) composition of erythrocyte membrane phospholipids in 58 term infants at 30 days of age. Twenty of them were fed human milk (HM), 19 an adapted formula (MF), and 19 with the same formula supplemented with nucleotides (NMF) in an amount similar to that present in HM. Relative content of omega 6 and 3 PUFA greater than 18 carbon atoms was significantly reduced especially in phosphatidylethanolamine and phosphatidylserine for infants fed regular MF compared with those fed HM or NMF. Unsaturation index of red blood cell phospholipids showed a similar effect. These results suggest that dietary nucleotides play a role in the in vivo desaturation and elongation of essential fatty acids to long chain PUFA during early life for the human newborn.

Erythrocyte Membrane↗

Changes in the fatty acids pattern of red blood cell phospholipids induced by type of milk, dietary nucleotide supplementation, and postnatal age in preterm infants.

The fatty acid profile of red blood cell phospholipids and the total phospholipid and cholesterol contents of erythrocyte membrane in preterm infants in the first month of life were studied. Influences of human milk and adapted formula and dietary nucleotides supplementation at a level similar to that found in human milk were evaluated. Nineteen preterm newborn infants with adequate weight for gestational age were fed their own mother's preterm human milk, 18 with a standard milk formula and 18 with the same formula supplemented with nucleotides. Blood samples were obtained at birth from cord blood, and at 30 days of age. At 1 month of life, linoleic acid rose in formula fed infants compared to those fed human milk (p less than 0.05) and relative amounts of 20:3w6, 20:4w6, 22:4w6, 22:5w6, and total polyunsaturates of the w6 series greater than 18 carbon atoms were significantly decreased in standard milk formula fed infants (p less than 0.05-0.01). No significant differences for these fatty acids were found between human milk and nucleotide milk formula infants. Docosahexaenoic acid (22:6w3) decreased from birth to 1 month of age in formula fed infants (p less than 0.01) but not in human milk fed infants. Infants fed nucleotide milk formula showed intermediate values for 20:3w6 and 20:4w6 (p less than 0.1) between infants fed human milk and those fed standard milk formula.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

The influence of hygienic practices to the exit site/tunnel on peritoneal catheter infections.

In Peritoneal Dialysis (PD), correct handling of the equipment and especially of the catheter exit site are essential. The PD nurse is responsible for preparing the patient to be able to carry out self care. As there are no universally accepted procedures for catheter care, we evaluated the procedure recommended in our unit, to identify the level of achievement by our patients and compare it with the infection incidences of exit site/tunnel (ES/T). 31 patients were surveyed on aspects related with hygiene, care and support of the catheter. This was complemented with a direct observation of the way of fixing and protecting the catheter and exit site, relating these facts with the incidence of infection. The results show the incidence of the infection is similar to data from other centres. It seems that the non compliance with the recommendations is due to either a misunderstanding on the patients' part or difficulty to adapt these recommendations to their particular way of life.

Catheterization↗

Differences in the serum amino acid pattern of injured and infected children promoted by two parenteral nutrition solutions.

The effects of two parenteral nutrition (PN) amino acid solutions (FreAmine II and F080) on the serum amino acid levels of 51 children, 27 affected by multiple trauma and 24 by bacterial sepsis, and aged from 1 month to 12 years, were studied. Serum amino acids were determined on day 1 immediately before administrating PN, and on day 5 during PN. Trauma patients on F080 exhibited higher levels of alanine, aspartate, asparagine, leucine, isoleucine, valine, total branched-chain amino acids (BCAA) and total essential amino acids than those on FreAmine II; in contrast septic children showed similar levels of serum amino acids on both PN solutions. BCAA were lower in septics than in trauma patients, probably as a consequence of an increased utilization of these amino acids in sepsis because of the higher organ protein synthesis typical of this situation. The phenylalanine/tyrosine ratio was found elevated both in septic and trauma children, but it decreased after PN in the latter when using an enriched BCAA solution. Utilization of this solution, partly corrects the metabolic disturbances induced by stress, but the metabolical responses induced either by sepsis or trauma are partially different which may have important implications for patient care.

Amino Acids↗

Effect of dietary nucleotides on intestinal repair in rats with experimental chronic diarrhea.

Nucleic acid synthesis in tissues of rapid growth is preferentially done using dietary purines and pyrimidines via the salvage pathway. In the case of a low protein intake, dietary nucleotides may be semiessential for cell replication of gut, lymphocytes, and bone marrow, and especially in those intestinal diseases in which the mucosa is altered, dietary nucleotides may have a role in intestinal development. The effect of dietary nucleotides on intestinal weight and length, gut mucosal weight, intestinal protein and DNA contents, and lactase, maltase, and intestinal mucosal activities was assessed in a controlled way. Weanling (21-day-old) rats were separated into two groups of 36, each receiving blindly a basal diet containing glucose polymers (C) or a basal diet with lactose as the main carbohydrate (L) for 15 days. Those fed with L developed a syndrome of chronic diarrhea and malnutrition. Ten rats of each group were sacrificed at that time. The rest of the animals of each group were separated into two subgroups. The first was fed with the C diet and the second with the C diet supplemented with 50 mg/100 g of each of the following nucleotides: AMP, GMP, CMP, UMP, and IMP (CN). Thus the subgroups CC, CN, LC, and LN were formed. Rats were sacrificed after 4 weeks and gut separated into three segments corresponding to duodenum, jejunum, and ileum. Analysis of variance was used to compare the effect of diet or segments. DNA and lactase, maltase, and sucrase activities increased in the LN group with respect to LC especially in jejunum and ileum but there were not any differences between CC and CN.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

Influences of postnatal age and dietary nucleotides on plasma fatty acids in the weanling rat.

Dietary nucleotides seem to play a number of physiologic roles during early life. They are improved in the maintenance of the immune system, intestinal maturation, and lipid metabolism. Nucleotides affect the conversion of essential fatty acids into their long-chain polyunsaturated (PUFA) derivatives in both preterm and at-term newborn infants. This work examines the effect of postnatal age and dietary nucleotides on the fatty acid composition of total plasma lipids and lipid fractions in the rat. Weanling rats (21 days old) were divided into three groups. The first group was killed, and the other two groups were fed a standard semipurified diet, and the same diet supplemented with 250 mg each of CMP, UMP, AMP, GMP, and IMP per 100 g of diet for 4 weeks. Advancing postnatal age led to an increase of total plasma fatty acids, especially saturated, and PUFA of the n-6 series, whereas PUFA of the n-3 series decreased. The fatty acid profile of plasma phospholipids (PL) exhibited minor changes, although there was a tendency to show lower levels of saturates and PUFA of the n-3 series and increased levels of PUFA of the n-6 series. Cholesteryl esters showed a response similar to that of PL, although the increase in arachidonic acid (20:4n-6) was significant. For triglycerides, linoleic acid (18:2n-6) and monounsaturates increased their levels, whereas saturates decreased. Dietary nucleotides mediated a significant increase in total plasma fatty acids, namely monounsaturated fatty acids and PUFA of both n-6 and n-3 series as compared with the control group. The relative fatty acid composition of PL and cholesteryl esters was mostly unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Monophosphate↗

Plasma polyunsaturated fatty acids in liver cirrhosis with or without chronic hepatic encephalopathy: a preliminary study.

Fatty acid levels (from C14:0 to C22:6n3) in plasma lipid fractions were prospectively studied in 11 cirrhotic patients with chronic hepatic encephalopathy and compared with those in 23 cirrhotic patients without chronic hepatic encephalopathy with similar age, sex distribution, and liver and nutritional status, and in 11 age- and sex-matched, healthy subjects. Plasma lipid fractions were separated by thin-layer chromatography and fatty acids were identified by capillary column gas-liquid chromatography. Total n6 polyunsaturated fatty acid plasma levels were lower in cirrhotic patients--with and without chronic hepatic encephalopathy--than in control subjects. In addition, arachidonic acid levels, both in total lipids and fractions, were lower in patients with than in those without chronic encephalopathy. On the other hand, a selective decrease of plasma docosahexaenoic acid (a major component of neuronal membranes) was observed in those patients with chronic encephalopathy as compared with both control and cirrhotic subjects without chronic encephalopathy. These findings may be due to various mechanisms. Differences in long-chain polyunsaturated fatty acid content in fish- and meat-restricted diets partly may account for these findings. However, it could be speculated that polyunsaturated fatty acid biosynthesis may be reduced further in patients with chronic hepatic encephalopathy because of either a decrease in portal essential fatty acid extraction in the postabsorptive phase due to portal-systemic shunting or to the effect of protein-restricted diets. Furthermore, the finding of low plasma docosahexaenoic acid in these patients raises the possibility that this deficiency might be an additional pathogenic factor in chronic hepatic encephalopathy.

Arachidonic Acid↗

Influence of casein and casein hydrolysate diets on nutritional recovery of starved rats.

BACKGROUND: The aim of this study was to compare the effects of two diets, which differed in their protein source (casein and casein hydrolysate), on the nutritional recovery and intestinal repair of undernourished rats at weaning after a 3-day fasting period. Profound alterations in gut structure and signs of malnutrition appeared after the starvation period. METHODS: The casein hydrolysate was prepared by enzymatic hydrolysis and ultrafiltration. Rats were refed the casein-based or the casein hydrolysate-based diet for 96 hours. Normal-fed male Wistar rats at weaning were given the casein diet for 7 days and were used as controls. Liver acetylcholinesterase, glutamate dehydrogenase activities, serum amino acid profiles, jejunal oligosaccharidases, alkaline phosphatase, and leucine aminopeptidase activities were studied. Intestinal permeability to intact proteins was also tested by using ovalbumin and measuring its concentration in serum. RESULTS: Intestinal and liver enzyme activities and serum amino acid profiles reached normal values after 96 hours of refeeding, regardless of the diet used. Glutamate dehydrogenase activity remained higher in both diet groups. Intestinal permeability to ovalbumin remained significantly increased only in the group refed the casein diet. CONCLUSIONS: Our results show that 4 days of refeeding are sufficient for complete intestinal recovery after fasting, provided the dietary protein source is a casein hydrolysate. We suggest that patients with malnutrition or malabsorption syndrome should be fed formula composed of enzymatic protein hydrolysates (because of their low antigenicity) rather than enteral formulas composed of intact proteins.

Acetylcholinesterase↗

Dietary long-chain polyunsaturated fatty acids influence the recovery of thioacetamide-induced liver cirrhosis in rats.

BACKGROUND: The aim of this study was to evaluate the dietary supplementation with omega-3 and omega-6 long-chain polyunsaturated fatty acids on the fatty acid composition of plasma and red blood cell membranes in rats with thioacetamide-induced liver cirrhosis. METHODS: Thirty-eight female Wistar rats were given 300 mg thioacetamide/L in drinking water for 4 months to induce the experimental liver cirrhosis. Sixteen rats were used as controls. After treatment with thioacetamide, nine rats of each group were killed. Then, thioacetamide-treated rats were divided into three new groups, each receiving a different diet for 2 weeks: a semipurified diet (n = 9), the same diet supplemented with omega-3 long-chain polyunsaturated fatty acids (n = 10), or the same semipurified diet supplemented with omega-3 and omega-6 long-chain polyunsaturated fatty acids simultaneously (n = 10). The remaining control rats were fed the semipurified diet. Liver histology and plasma and erythrocyte fatty acid composition were assessed. RESULTS: An apparent improvement of the histological damage took place in the rats fed the omega-3+ omega-6-supplemented diet. The diet supplemented with polyunsaturated fatty acids of the omega-3 series induced increases in the omega-3 long-chain polyunsaturated fatty acid levels in total plasma lipids, plasma lipid fractions and in erythrocyte phospholipids, and decreases in omega-6 long-chain polyunsaturated fatty acids in erythrocyte phospholipids during the recovery of rats with thioacetamide-induced liver cirrhosis. The administration of the diet supplemented with both omega-3 and omega-6 long-chain polyunsaturated fatty acids contributed to increase the levels of total plasma saturated, monounsaturated, and omega-6 long-chain polyunsaturated fatty acids from cirrhotic rats. CONCLUSION: We conclude that the simultaneous supply of long-chain fatty acids of the omega-3 and the omega-6 series can be beneficial to improve the fatty acid status of this experimental model of liver cirrhosis.

Animals↗