Search PubMed⌕ Search

Biomedical subjects

A Gil

Publications and source records attributed to A Gil.

At least 163 records · Page 9Linked to original sources
PubMed1997

Rabbit liver mitochondria coenzyme Q10 and hydroperoxide levels: an experimental model of atherosclerosis.

The development of the atherosclerosis is mediated by the accumulation of oxidized lipids in the arterial wall. There is a relationship between average intake of dietary fat, its quality, and incidence of atherosclerosis. The goal of this work was to study the effect of different dietary fats on the coenzyme Q10 and hydroperoxide content of liver mitochondria in rabbits affected by an induced atherosclerosis. The results show that the induction of experimental atherosclerosis leads to a significant increase in hydroperoxides of rabbit liver membrane mitochondria and to a significant drop in the content of CoQ10. Furthermore, treatment of atherosclerotic rabbits with different diets resulted in an increase of membrane hydroperoxides in the group fed sunflower oil whereas the increase was significantly lower for animals fed virgin olive oil and fish oil stabilized with vitamin E (1 g/kg). CoQ10 levels only recovered partially in all groups; however, values in the sunflower oil were significantly lower as compared to corresponding values of the other groups. The use of either virgin olive oil or vitamin E stabilized fish oil in the dietary treatment of atherosclerosis appears to be a valid alternative for maintaining adequate levels of CoQ10 and hydroperoxides in liver mitochondria.

Animals↗
PubMed1997

Developmental changes in UDP-N-acetylglucosamine 2-epimerase activity of rat and guinea-pig liver.

The activity of UDP-N-acetylglucosamine 2-epimerase was determined in the liver of rats and guinea-pigs of different ages. The activity of this enzyme in rats was low at birth, increased to a maximum value on day 15, and fell gradually until day 30. Thereafter, it increased up to the 60th day. The activity profile of the enzyme from guinea-pig liver was very similar. However, guinea-pig activity was 2-5 times lower than in rats. Both rats and guinea-pigs displayed similar liver sialic acid contents which increased from birth to 2 months of age. Rats also showed a N-glycolylneuraminic acid content that decreased from birth to 2 months. From these results we can inferred that postnatal UDP-N-acetylglucosamine 2-epimerase activity seems to be correlated with age and the developmental states of rats and guinea-pigs.

Animals↗
PubMed1997

Detection of antibodies against hepatitis A in blood spots dried on filter paper. Is this a reliable method for epidemiological studies?

Diluted dried blood drops on filter paper were compared with serum samples as a specimen source for qualitative anti-HAV antibody determination by ELISA. A total of 298 serum samples and dried blood drops were collected from a population of healthy adolescents (15.3 +/- 1.2 years old). The prevalence of anti-HAV antibody obtained by testing serum samples was 7.7% (95% CI:4.8 10.1). Compared with serum sampling the sensitivity and specificity of diluted dried blood drops were 91.3 and 99.3%. The positive and negative predictive values were 91.3 and 99.3%, respectively, and the likelihood ratios of positive and negative results were 91 and 0.09. It is proposed that this test represents a reliable procedure for anti-HAV antibody testing.

Adolescent↗
PubMed1997

Characteristics of elderly inpatients at high risk of needing supportive social and health care services.

A two-stage cross-sectional study was conducted in a 951-bed acute-care hospital: a first survey designed to determine the profile of patients aged > or = 64 years needing supportive social/health care services, in which 38 patients discharged between June and July, 1992 (group 1) with social/health care problems that accounted for inappropriate hospitalization days participated, and a second survey designed to identify patients aged > or = 65 years at high risk and thus facilitating the early intervention of social workers, in which 153 patients selected at random and interviewed between August and September, 1992 (group 2) participated. A significantly higher percentage of group 1 patients had no medical insurance, were admitted to hospital for treatment, lived alone, had been readmitted in the previous 6 months, suffered from dementia and/or cognitive impairment, presented with associated chronic illnesses, and showed lower Barthel index scores as compared to group 2 patients. In patients in group 2, hospital discharge was delayed due to the need of supportive social and health care services in only 27 patients. The percentage of agreement in the suitability of the resource provided was higher after (92.6%) than before the intervention (71.1%). The mean number of inappropriate hospitalization days was 3.5 days for patients in group 1 and 1.9 days for those in group 2 (p = 0.013). The early identification of elderly inpatients at high risk of needing additional supportive social and health care would help patients to find the most appropriate resource according to their individuals needs.

Activities of Daily Living↗
PubMed1997

Hepatotoxic agent thioacetamide induces biochemical and histological alterations in rat small intestine.

We have assessed the effect of the oral ingestion of thioacetamide on small intestine structure and function. Thioacetamide-treated rats showed diminished mucosa weight; protein, DNA, and RNA content; and leucine aminopeptidase activity as compared to controls in both jejunum and ileum. In the jejunum, there was a reduction in the activities of alkaline phosphatase, ATPase, glucose-6-phosphatase, and myeloperoxidase, whereas in the ileum, maltase, lactase, and gamma-glutamyltranspeptidase were reduced. In both jejunum and ileum we found enlarged intercellular spaces, dark epithelial enterocytes, and lymphocyte infiltration. Enterocytes showed lobulated nuclei, deranged mitochondria with loss of their cristae, dilated rough endoplasmic reticulum containing dense material, and vesiculation of the smooth endoplasmic reticulum and the Golgi apparatus. Smooth muscle cells of the intestine exhibited ultrastructural alterations. These findings indicate that chronic oral intake of thioacetamide mimics not only hepatic alterations but also small intestine alterations normally associated with human cirrhosis.

Animals↗
PubMed1997

Effect of dietary nucleotides on degree of fibrosis and steatosis induced by oral intake of thioacetamide.

The administration of thioacetamide in rats induces nodular cirrhosis of the liver, characterized by fibrous septae, parenchymal nodules, proliferation of the bile ducts, and excessive deposition of connective tissue elements. Nodular cirrhosis is also associated with changes in lipid metabolism, as shown by the accumulation of lipid droplets in the hepatocyte cytoplasm. Adequate nutritional support during cirrhosis is important to sustain liver function and promote recovery after the lesions have been induced. Supplementation with nucleotides may increase cellular proliferation and thus optimize hepatic recovery. The aim of this study was to investigate the effects of dietary nucleotide supplementation on the degree of fibrosis and steatosis in rats with liver cirrhosis induced by four months of oral intake of thioacetamide. The use of dietary nucleotides after thioacetamide administration was found to decrease the percentage area of fibrous septae. In animals with liver cirrhosis fed the nucleotide-supplemented diet for two weeks, the total area of fibrosis was reduced. Withdrawal of the hepatotoxic agent led to a decrease in the degree of steatosis in cirrhotic animals, which was significant in rats given the nucleotide-supplemented diet during a two-week recovery period. In conclusion, dietary nucleotides may be an important factor in the histological recovery of damaged liver in experimental cirrhosis.

Animals↗
PubMed1997

Age-related effect of dietary nucleotides on liver nucleic acid content in rats.

We have addressed the question of whether dietary nucleotides contribute to the liver nucleic acid pool and whether this contribution is related to age. Two experiments were performed in rats of 1 months, 3 months and 17 months of age. In the first, rats were fed a nucleotide-free diet or the same diet, but supplemented with nucleotides for 3 and 10 days. In the second experiment, rats were starved for 3 days. Liver RNA decreased by 10-day deprivation of dietary nucleotides and starvation in young and adult rats but not in the old. Liver DNA decreased by starvation in adult and old rats but not in the young, whereas nucleotide deprivation had no effect. These results, demonstrating that dietary nucleotide deprivation causes an effect on liver RNA pool similar to the effect of starvation, indicate that dietary nucleotides contribute to the liver RNA pool, this influence being related to age.

Aging↗
PubMed1997

Dietary nucleotides might influence the humoral immune response against cow's milk proteins in preterm neonates.

The objective of this study was to evaluate the influence of dietary nucleotide supplementation in preterm infants during the first month of life on the intestinal permeability to lactulose, mannitol and to beta-lactoglobulin and on the development of circulating antibodies to beta-lactoglobulin and alpha-casein. Twenty-seven preterm infants were enrolled in the study; 11 of them were fed a standard low-birth weight milk formula and 16 infants were fed the same formula supplemented with nucleotides at similar levels to those found in human milk. Blood and urine samples were obtained at 1, 7 and 30 days of age. Serum beta-lactoglobulin, serum IgG antibody to alpha-casein and serum IgG antibody to beta-lactoglobulin were measured by ELISA. The lactulose/mannitol urinary excretion rate was measured by gas liquid chromatography. Neither the intestinal permeability to saccharides nor the intestinal absorption of beta-lactoglobulin were affected by the nucleotide supplementation. However, serum concentrations of IgG antibody to beta-lactoglobulin were higher in preterm neonates fed the supplemented formula than in those fed the standard formula. According to these results, dietary nucleotides might influence the maturation of the humoral immune response in preterm newborn infants.

Caseins↗
PubMed1997

Adherence of mouse peritoneal macrophages following exposure to lead.

Lead is a toxin widely used in industry. Recently, medical investigation into lead exposure has turned to testing organ systems, such as the immune system, that historically were not associated with lead poisoning. We evaluated the effects of doses of 13, 130 or 1,300 ppm of lead on the adherence of mouse peritoneal cells, and particularly on macrophages. Cellular adherence was measured according to the De la Fuente technique. Adherence of macrophages showed significant changes in the 1,300 ppm group, revealing a reduction to 55% of the control group. The macrophage adherence index showed 91% sensitivity and 96% specificity. These results indicate a considerable reduction in the adherence of peritoneal macrophages following exposure to certain levels of lead.

Algorithms↗
PubMed1997

Steatosis and collagen content in experimental liver cirrhosis are affected by dietary monounsaturated and polyunsaturated fatty acids.

BACKGROUND AND METHODS: We used thioacetamide administered orally to induce cirrhosis in rats, and after these had recovered for 1 and 2 weeks we examined the effects of dietary supplementation with monounsaturated and n-3 polyunsaturated fatty acids, or with a combination of n-3 and n-6 polyunsaturated fatty acids, on the extent of steatosis and collagen content in the liver. RESULTS: Nodular cirrhosis, increased collagen content, and lipid accumulation were established after 4 months of treatment with thioacetamide. When the animals were fed a diet rich in oleic acid for 2 weeks, the steatosis and fibrosis decreased. Supplementation with n-3 polyunsaturated fatty acids favored reductions in collagen content but did not reduce the fat accumulation. With a diet supplemented with a mixture of n-3 and n-6 fatty acids we found no reduction in either lipid accumulation or collagen content. CONCLUSIONS: Fibrosis and steatosis may be influenced by dietary fat, and monounsaturated fat appears to influence favorably the histologic recovery of the damaged liver.

Animals↗
PubMed1997

Study of a trimeric tandem repeat locus (SBMA) in the Basque population: comparison with other populations.

Microsatellites can be highly unstable and show a high level of polymorphism between individuals. Here we present the analysis of the CAG trinucleotide repeat polymorphism at the SBMA locus in 57 phenotypically normal individuals rigorously assigned to the Spanish Basque population. Results are compared with 100 Spanish non-Basque individuals who were already analyzed by us (175 alleles). This is the first study undertaken in these populations for this marker. In addition, we compared our results with those published for other populations. Relative allele frequencies showed differences between the samples and no unimodal distribution. The expected heterozygosity in the Basque sample was slightly lower than in the non-Basque sample. Conformity with Hardy-Weinberg equilibrium was verified by three tests. When compared with published data, the predominant alleles appear to be the same in the various populations. There are more differences between Basques and other Caucasoid samples than between non-Basques and Caucasoid samples. Population relationships were also examined by dendrograms based on genetic distances. The results obtained showed some peculiarities in the Basque population. The high degree of similarity with other dendrograms based on different markers and the efficiency of this STR marker in differentiating closely related populations, support the potential usefulness of microsatellites as tools for human population studies.

Ethnicity↗
PubMed1996

The association of tooth lead content with dental health factors.

The purpose of this study was to determine the relationships of lead content in the human tooth with the prevalence of caries, dental plaque, pH of saliva, levels of Salivalis lactobacilli (SL) and Mutans streptococci (MS), degree of dental abrasion, tooth colour and toothbrushing frequency. A total of 220 teeth (one per person) were analysed using a microwave oven digestion procedure and lead content was measured by atomic absorption spectrometry. Tooth lead content followed a logarithmic-normal distribution and it increased with the prevalence of caries. Tooth lead concentrations were positively correlated with all the considered dental health factors except the pH of saliva, for which there was a significant negative correlation. Coloured teeth and teeth subject to abrasion showed the highest lead content. The highest number of colonies of SL and MS in saliva paralleled the highest lead tooth levels. Teeth obtained from irregular brushers presented higher tooth lead contents than subjects with a regular toothbrushing frequency. Multiple logistic regression analysis showed a significant association between tooth lead levels and dental plaque surface, Salivalis lactobacilli number, dental abrasion and dental colour. We conclude that accumulation of lead in teeth is associated with those dental health factors.

Adolescent↗
PubMed1996

[Lipoprotein profile in children and adolescents of the Autonomous Community of Madrid].

BACKGROUND: The aim of study was to know the lipoproteins distribution in children and adolescents from the Autonomous Community of Madrid, Spain, and to compare with other studies. MATERIAL AND METHODS: The sample included 3,635 children and adolescents (1,853 males and 1,782 females), 4 to 18 years of age. We measured total cholesterol and triglyceride levels with enzymatic methods, the HDL-cholesterol concentration in the supernatant after precipitation of the rest of the lipoproteins, and LDL-cholesterol concentrations were calculated by Friedewald formula. RESULTS: Total cholesterol levels were 174 +/- 25 mg/dl (4.50 +/- 0.64 mmol/l), triglycerides 60 +/- 24 mg/dl (0.67 +/- 0.28 mmol/l), LDL-cholesterol 100 +/- 22 mg/dl (2.59 +/- 0.58 mmol/l), HDL-cholesterol 61 +/- 13 mg/dl (1.6 +/- 0.34 mmol/l). 19.23% of the children studied had cholesterol levels above 200 mg/dl (> 5.18 mmol/l), and 41.5% of them had levels higher than 180 mg/dl (> 4.66 mmol/l). CONCLUSIONS: The cholesterol levels as well as the HDL-cholesterol levels in the student population of Madrid, Spain, were higher when compared to other studies. Less variation was found in the LDL-cholesterol concentrations.

Adolescent↗
PubMed1996

Serum amino acid changes in rats with thioacetamide-induced liver cirrhosis.

To date, no attempt has been made to study alterations occurring in the amino acid profile in chronic models of thioacetamide-induced liver cirrhosis. In this work, changes in serum amino acids and proteins in rats with thioacetamide-induced liver cirrhosis are reported, together with changes in enzyme activities in the liver and serum. Seventeen female Wistar rats were used. Eight rats were given 300 mg thioacetamide/l in drinking water for 4 months and nine rats were given water ad libitum during the same time-period. Significant increases in glycine, alanine, serine, methionine, glutamate, ornithine, phenylalanine, tyrosine, histidine and proline were observed in rats with the resulting experimental liver cirrhosis. Threonine, taurine, glutamine, lysine and citrulline tended to increase while isoleucine, leucine, aspartate, arginine and tryptophan tended to decrease. Total and nonessential amino acids increased significantly in cirrhotic animals. Total essential and aromatic amino acids tended to increase in the thioacetamide-treated group, whereas branched chain amino acids tended to decrease in the same group. Regarding serum proteins, a decrease in albumin concentration in the thioacetamide-treated animals was the only change detected. The liver enzyme activities under observation (aspartate and alanine aminotransferases, glutamate dehydrogenase and threonine deaminase) were lower in the thioacetamide group. Decreases were significant for both transaminases and threonine deaminase. Results for serum activities showed that transaminases did not change in thioacetamide-treated rats in comparison with controls. In contrast, alkaline phosphatase rose dramatically in cirrhotic rats. We conclude that the serum amino acid pattern in this chronic model of liver cirrhosis resembles in part that of the corresponding human disease.

Administration, Oral↗
PubMed1996

Influence of administration of long-chain polyunsaturated fatty acids on process of histological recovery in liver cirrhosis produced by oral intake of thioacetamide.

Patients with liver cirrhosis frequently show some degree of protein-energy malnutrition and obviously require nutritional support. In this study, the treatment of rats consisted of the ad libitum oral intake of a 300 mg/liter thioacetamide solution, used as drinking water for four months. Thioacetamide treatment produced a severe alteration in the plasma fatty acid profile with significant decreases of these, which mimicked changes described in human cirrhosis. This hepatotoxic agent causes nodular cirrhosis, with loss of the normal architecture of the liver and disruption of the vascular pattern. The goal of the study was to evaluate the influence of n-3 and n-6 series long-chain polyunsaturated fatty acid dietary supplementation in experimental animals and to assess the effects of those dietary components on structural recovery in the liver. Significant increases of saturated and monounsaturated fatty acids as well as n-6 polyunsaturated fatty acids were seen only in the animals given the n-6 polyunsaturated fatty acid supplemented diet. However, only rats given the standard diet exhibited some degree of histological regeneration.

Animals↗
PubMed1996

Dietary long-chain polyunsaturated fatty acids modify heart, kidney, and lung fatty acid composition in weanling rats.

The fatty acid composition of heart, kidney, and lung was studied in weanling rats fed three diets differing in their polyunsaturated fatty acid content for 0, 2, and 4 wk. The first group had a 10% w/w fat semipurified diet which consisted of a mixture of olive oil (62.5%), soybean oil (11.1%), and refined coconut oil (26.4%) and provided 18:1n-9, 18:2n-6, and 18:3n-3 in similar amounts to a maternal human milk (diet HO). The second group received 7% of HO fat and 3% fish oil (0.4% 20:4n-6 and 5% 22:6n-3 of total fatty acids) (diet FO), and the third group was fed 7% HO fat, 1.5% of the same fish oil, and 1.5% of a purified pig brain phospholipid concentrate (0.6% 20:4n-6 and 3.5% 22:6n-3 of total fatty acids) (diet FO + BPL). The experimental diets increased tissue monounsaturated fatty acids in comparison with rats at weaning. Tissue lipid content of 20:4n-6 was increased and 22:6n-3 decreased in Group HO compared with weanling rats, whereas opposite changes were observed in Group FO. Feeding diet FO + BPL increased 22:6n:3 in tissue lipids compared with diet HO, and increased 20:4n-6 content in relation to diet FO. Our results indicate that rat heart, kidney, and lung are highly responsive to dietary n-3 and n-6 long-chain polyunsaturated fatty acids during postnatal life.

Animals↗
PubMed1996

Immunogenicity, safety and protective efficacy of one dose of the rhesus rotavirus vaccine and serotype 1 and 2 human-rhesus rotavirus reassortants in children from Lima, Peru.

In a four cell trial, a single 10(4) plaque-forming unit dose of rhesus rotavirus (RRV) vaccine (serotype G3), a human rotavirus-rhesus rotavirus reassortant vaccine with serotype G1 specificity, a similar vaccine with serotype G2 specificity, or a placebo was administered with buffer orally at 2 months of age to 800 Peruvian infants. Only the RRV vaccine was associated with a febrile response (< 38 degrees C) that occurred in 9% of the infants on day 4 after vaccination. Diarrhea or other side-effects were not associated with administration of vaccine. Vaccine strains were shed by only 12-18% of the infants as determined by examination of a single stool specimen obtained on days 4 or 5 after vaccination. Fifty per cent of vaccines developed an IgA ELISA seroresponse; however, a serotype-specific seroresponse by plaque reduction neutralization was demonstrated in < 20% of the participants against each of the three candidate vaccine strains. Vaccine efficacy was evaluated by twice-weekly home surveillance for diarrheal diseases during 24 months post-immunization. Rotavirus diarrheal episodes were identified by ELISA. Only the RRV vaccine had a significant protective efficacy (29%, p = 0.03, chi-square test) against rotavirus diarrhea. Analysis of vaccine efficacy against rotavirus episodes of any severity in which no other enteropathogen was isolated showed a trend towards higher vaccine efficacy. In addition, a similar trend was observed in rotavirus-only episodes in which there was some degree of dehydration or when health services were utilized. Serotype G1 or G2 rotavirus strains were most prevalent during surveillance. Neither serotype G1 or serotype G2 vaccines were protective against serotype 1 or 2 rotavirus diarrhea, respectively. The serotype G2 vaccine was 84% protective against serotype 1 and 2 dehydrating rotavirus diarrhea in the small numbers of individuals evaluated. We conclude that one dose of 10(4) p.f.u. of the RRV, serotype G1, or serotype G2 rotavirus vaccine failed to induce either an adequate serotype-specific seroresponse or serotype-specific protection in children immunized at 2 months of age. Only the RRV vaccine induced a low level of protection against rotavirus diarrhea mainly of serotype G1 specificity. Future studies need to explore whether higher vaccine dose and/or more than one dose would increase the immunogenicity and efficacy of the rotavirus vaccine, especially in developing countries with a high level of baseline rotavirus antibodies.

Diarrhea, Infantile↗