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A Marti

Publications and source records attributed to A Marti.

108 records · Page 6Linked to original sources
PubMedDate not supplied

The mouse ERG before and after light damage is independent of p53.

Death of retinal photoreceptors by apoptosis is observed under many physiological and pathological conditions such as histogenesis, retinal dystrophies and light-induced photoreceptor degeneration. To date, little is known about regulatory mechanisms for apoptosis in the retina. The tumor suppressor gene p53 is a regulator of apoptosis in a number of systems, however, p53-independent apoptosis has also been described. We have therefore investigated whether the lack of p53 influences the dark-adapted ERG in C57BL/6 p53-/- mice compared to p53+/+ control littermates under physiological (regular light-dark cycle) conditions. We also recorded ERGs at 12 to 14 h in darkness following diffuse bright light exposure to 8,000 or 15,000 lux for 2 h. ERG analysis over a range of 6 logarithmic units of light intensity revealed normal and virtually identical a-, b-, c-waves and oscillatory potentials in dark-adapted p53+/+ and p53-/- mice. After exposure to diffuse white fluorescent light strong decreases of all ERG components were found to be very similar in both genotypes. These data support the notion that the p53 protein is neither essential for normal retinal function nor for processes involved in light-induced depression of the ERG in mice.

Animals↗
PubMedDate not supplied

Biomechanical evaluation of the less invasive stabilization system for the internal fixation of distal femur fractures.

OBJECTIVE: Comparison between a Less Invasive Stabilization System (LISS) using monocortical screws with angular stability and two conventional plate systems Condylar Buttress Plate (CBP) and Dynamic Condylar Screw (DCS) for the treatment of distal femoral fractures with respect to biomechanical properties. DESIGN: Biomechanical study using paired cadaver femurs. In Test Configuration 1 (distal test), a ten-millimeter gap at the diaphysis-metaphysis junction simulates a supracondylar femoral fracture. Test Configuration 2 (proximal test) has the same configuration, but the gap was cut in the isthmic region. Proximal and distal plate ends were fixed to corresponding cortical bone fragments in both tests. Optical displacement transducers served to quantify the system's ability to withstand a stepwise increased load. Reversible (deflection) and irreversible deformation (subsidence) of the bone-plate construct was investigated. RESULTS: In Test Configuration 1, LISS showed less irreversible deformation in 72 percent of the left-right comparisons. No correlation between bone mineral density, cross-section area of bones and the measured response of the construct under load was found between pairs. In Test Configuration 2, 83 percent of the left-right comparisons showed less permanent deformation but a higher elastic deformation for LISS. CONCLUSIONS: These results suggest an enhanced ability to withstand high loads when using the monocortical screw fixation technique with angular stability. A higher elastic deformation of LISS compared with conventional plating systems in distal femoral fractures can be explained by the lower bending stiffness caused by different design and material properties.

Biomechanical Phenomena↗
PubMedDate not supplied

[Influence of the polymorphism 03826 A --> G in the UCP1 gene on the components of metabolic syndrome].

BACKGROUND: The uncoupling protein UCP1 has been related to the development and/or maintenance of obesity through its involvement in regulating energy balance. The role of this mitochondrial protein in humans is uncertain due to the scarce presence of the brown adipose tissue in the adult individual. The polymorphism -3826 A/G of the UCP1 alone or in conjunction with the mutation Trp64Arg of the adrenergic receptor b3 has been associated with obesity, diabetes mellitus and related diseases although with contradictory results. With the aim of determining the influence of polymorphism -3826 A/G of the UCP1 on the classical components of the metabolic syndrome in our population, we studied 159 obese individuals and 154 of normal weight, with a study design of cases and controls. In all of them Body Mass Index (BMI), hip/waist index, % of body fat, arterial tension (AT), lipidic profile, leptine, basal glucemia and basal insulinemia were determined. Similarly, the presence of the above mentioned mutation of the UCPI gene was analysed. RESULTS: Significant differences were obtained in all of the variables studied between obese (cases) and normal weight (controls). Within the obese group, polymorphism -3826 A/G of the UCP1 gene (n=53) was associated with a greater BMI (p=0.03), greater percentage of body fat (p=0.04) and higher AT both systolic (p=0.009) and diastolic (p=0.02). There were no statistically significant differences in any of the other indices evaluated. CONCLUSION: The fundamental factor that influences the components of the metabolic syndrome is obesity. However, the polymorphism -3826 A/G of the UCP1 gene is associated with a greater degree of obesity and very high figures of AT.

Adult↗
PubMedDate not supplied

[Leptin and body weight regulation].

The discovery of leptin, besides causing a revolution in physiological knowledge about the regulation of body weight, awakes an interest in fat tissue as an endocrine organ and its active contribution to the establishment of energy deposits. Leptin, principally secreted by the adipocytes, interacts with hypothalamic receptors, and is capable of activating diverse neuroendocrinal routes responsible for controlling the balance between energy intake and expenditure. Like other cytokines, leptin is also able to play a role in the complex regulation of diverse metabolic aspects. Since the discovery that the placenta, gastric mucous or the star-shaped cells of the liver (Kupffer cells), are places that produce leptin, a great range of functions have been attributed to this hormone; since it appears to favour foetal development and can act as a factor of satiety in the stomach or participate in the afferent signals mediated by the vagus. Besides, leptin participates es in the immune and inflammatory responses, in reproduction, in processes related to angiogenesis, control of arterial pressure, lipolysis, etc. This paper reviews the role of leptin in the regulation of body weight, as well as different aspects related to obesity.

English Abstract↗
PubMedDate not supplied

Self-expandable endovascular stent for treatment of venous stenoses.

The increase in survival among patients undergoing haemodialysis, the non-limitation of patient age regarding the start of renal substitution treatment, and the high incidence of vascular problems--particularly in diabetics--have caused the positioning of percutaneous catheters in central vessels to become a common practice in haemodialysis.

Aged↗
PubMedDate not supplied

[Advances in molecular nutrition: nutrigenomics and/or nutrigenetics].

The application of molecular biology techniques and the success of the Human Genome Project have opened a new era for both Medicine and Nutrition. To date, at least 1,000 human genes causing disease have been identified and partially characterized, 97% of which we now know that are the cause of monogenic diseases. However, other diseases such as obesity, cardiovascular disease, diabetes, and cancer are due to complex interactions between several genes and environmental factors. In spite of the many association studies, over 600 published since 2002, the molecular base of chronic diseases is still uncertain. Information about nucleotide polymorphisms and haplotypes maps is an additional resource for identifying genes implicated in diseases. Genomic development gets close, however we frequently do not accurately know the dietary components and their mechanisms that importantly influence on genetic information expression and its pathologic impairments. The food industry has the opportunity for utilizing the bioactive components of foods to improve health and prevent diseases while considering the consumers' genetic constitution. This new era of molecular nutrition--gene-nutrient interactions--may evolve in several ways, although two of them are essential. On the one hand, the study of the influence of nutrients on gene expression (nutrigenomics) and, on the other hand, to know the influence of genetic variations in the organism response to nutrients (nutrigenetics).

Genetics↗
PubMedDate not supplied

[Influence of the -866G/A polymorphism of the UCP2 gene on an obese pediatric population].

OBJECTIVE: In the present study, our objectives were to evaluate the prevalence of -866G/A mutation of UCP2 gene and to study its influence on the phenotype of obese children (11-12 years old) from Navarra. BACKGROUND AND STUDY SETTING: Obesity is a disease with a multifactorial origin that may related be to the presence of mutations and polymorphisms in several candidate genes. The gene of the uncoupling protein UCP2 is one of the most studied ones in relation to obesity because it seems to participate in body composition and several metabolic processes control. Three polymorphisms have been described for this gene: an insertion/deletion of 45 nucleotides, a nucleotide change of guanine for adenine in -866 position, an another change that replaces alanine for valine at amino acid position 55. According to several studies, the -866G allele is related to an increased risk of developing obesity, although the results are contradictory about this association in the literature. SUBJECTS: The study was carried out on 125 obese children (52% male), aged 11-12 years, selected through the Pediatric Endocrinology Departments of Clínica Universitaria and Hospital Virgen del Camino of Pamplona (Spain), the reported results on this association are contradictory. INTERVENTIONS: After checking the inclusion criteria, anthropometrical data (weight, height, BMI, tricipital and subscapular skinfolds) were taken, and the percentage of fat mass was measured by bioelectrical impedance. Besides, plasma levels of total cholesterol, glucose, insulin, and leptin were measured. DNA was extracted from white blood cells to determine the genotype by PCR technique followed by BstUI digestion and further visualization in agarose gel with 2% ethidium bromide. RESULTS: The genetic analysis revealed a 0.404 frequency of the allele A, with a percentage of individuals G/G, G/A, and A/A of 40.0%, 39.2%, and 20.8%, respectively. Carriers of the A allele had a significantly higher sum of tricipital and subscapular folds (p = 0.034). No significant differences between mutant and non-mutant subjects with regard to the studied biochemical variables were observed. CONCLUSIONS: Subjects carrying the polymorphism present higher values of tricipital and subscapular skinfolds as compared to non-mutant subjects, which may indicate a relationship between the presence of the A allele in obese children and higher amounts of subcutaneous fat.

Child↗