PubMed Health⌕ Search

Biomedical subjects

T Martí

Publications and source records attributed to T Martí.

7 recordsLinked to original sources
PubMed1998

Neuromas and prominent corneal nerves without MEN 2B.

PURPOSE: We studied a family composed of 2 members with the characteristic phenotype of the MEN 2B and without RET protooncogene mutations in order to determine whether they had multiple endocrine neoplasia associated with MEN 2B in the 5-year follow-up. SUBJECTS AND METHODS: The family consisted of a 15 year old female complaining of burning eyes, examined ophthalmologically in 1992 and her mother and sister, who were examined later on in 1992. The proband and the mother were affected with multiple mucosal neuromas and visible corneal nerves. Pentagastrin-stimulated serum calcitonin levels, catecholamines, serum calcium and phosphate levels were measured. Molecular genetic studies were performed on the 2 affected members to look for the specific RET mutation seen in MEN 2B. RESULTS: Endocrine neoplasia of the syndrome MEN 2B, medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism, were ruled out in the first examination and after 5-year follow-up. In the 2 cases no mutation at codon 918 for the RET proto-oncogene was found. CONCLUSIONS: We consider that familial multiple mucosal neuromas are a highly distinctive entity of MEN 2B.

Adolescent↗
PubMed1997

Molecular basis of fish-eye disease in a patient from Spain. Characterization of a novel mutation in the LCAT gene and lipid analysis of the cornea.

The genetic and biochemical basis of fish-eye disease (FED) was investigated in a 63-year-old female proband with low plasma HDL cholesterol. Analyses of corneal and plasma lipids of the proband were consistent with impaired lecithin:cholesterol acyltransferase (LCAT) activity. Free cholesterol and phospholipid levels were elevated relative to control values, whereas cholesteryl ester levels were greatly reduced. Fatty acid compositions of corneal lipids from the proband and control subjects differ from the respective fatty acid compositions of their plasma lipids. This suggests that the metabolic pathways and acyl chain specificities for phospholipid, cholesteryl ester, and triglyceride metabolism within the cornea are distinct from those of plasma. Sequencing of the LCAT gene from the proband revealed a novel mutation at nucleotide 399, corresponding to an Arg99-->Cys substitution. Secretion of LCAT (Arg99-->Cys) by transfected COS-6 cells was approximately 50% of that of the wild type, but its specific activity against reassembled HDL was 93% lower than that of wild-type LCAT. The specific activities of wild-type and LCAT (Arg99-->Cys) against LDL were reduced similarly, suggesting that the appearance of the FED phenotype does not require enhanced activity against LDL. Our data support the hypothesis that FED is a partial LCAT deficiency in which poor esterification in specific types of HDL particles may contribute to the appearance of the corneal opacities.

Animals↗
PubMed1996

Elucidation of intestinal transport results as a function of age.

Duodenal, jejunal, ileal and caecal morphometrics were determined in chickens from hatching to the age of 15 weeks. The ratios of fresh weight/surface area and dry weight/surface area showed age-dependent changes in all the intestinal segments studied. The percentage of mucosa in each segment was also age-dependent in the first three weeks of life with a higher participation in the proximal intestine. Transport of 3-oxy-methyl-D-glucose was determined in the jejunum and ileum using a perfusion technique in vivo and expressed as a function of fresh weight, dry weight and surface area. The age-dependent differences observed in weight and mucosa composition of the intestine make it difficult to interpret the results of transport capacity during development. The optimum expression of results in the field of intestinal absorption may be the surface area, since it involves the smallest errors.

3-O-Methylglucose↗
PubMed1992

Growth of the alimentary tract with aging in chickens.

There is a mathematical model supporting that when growth rate of the chickens is maximized and not constrained by the food-availability, the optimal relationship between body mass and alimentary tract mass should conform to a two-segmented straightened line with different slopes. In the present work we have studied the model using the mass of the intestines as an indicator of growth of the alimentary tract of the Gallus gallus domesticus L. We have observed the slope change of the two segments around a body weight of 90 g that corresponded to two-week-old animals and, at this age it was supposed that the differentiation of the intestine reach the maximum.

Aging↗
PubMed1990

A method for binding parameters estimation of A1 adenosine receptor subtype: a practical approach.

Working with pig brain striatum in which A1 and A2 adenosine receptor subtypes coexist, we describe an uncomplicated method for unequivocally obtaining the equilibrium parameters (KD and binding capacity) of A1 receptor without interference from ligand binding to A2 receptor. Also, the equilibrium parameter estimation method we propose avoids the experimental determination of nonspecific binding by the inclusion of the corresponding unknown parameter in the function. This not only saves time but also avoids the use of expensive radioligands in saturation experiments. The method is suitable for any system with two different receptor subtypes for the same physiological ligand, and good estimates of the equilibrium parameters corresponding to the subtype displaying the higher affinity for the ligand can be obtained.

Adenosine↗