Biomedical subjects

M Mortilla

Publications and source records attributed to M Mortilla.

23 records · Page 2Linked to original sources

PubMed1992

Assessment of amyloid beta-protein precursor gene mutations in a large set of familial and sporadic Alzheimer disease cases.

A genetic locus associated with familial Alzheimer disease (FAD) and a candidate gene, APP, encoding the amyloid protein precursor have both been assigned previously to chromosome 21, and, in a few FAD families, mutations of APP have been detected. However, obligate crossovers between APP and FAD have also been reported in several FAD pedigrees, including FAD4, a large kindred showing highly suggestive evidence for linkage of the disorder to chromosome 21. In case the apparent APP crossover in FAD4 actually represented an intragenic recombination event or segregation of different mutations in different family branches, we have performed a more detailed assessment of APP as a candidate gene in this family. The entire coding region of the APP gene was sequenced for FAD4 and for FAD1, a second large kindred. No mutations were found, indicating that, in at least one chromosome 21-linked FAD pedigree, the gene defect is not accounted for by a mutation in the known coding region of the APP gene. A total of 25 well-characterized early- and late-onset FAD pedigrees were typed for genetic linkage to APP, to assess the percentage of FAD families predicted to carry mutations in the APP gene. None of the FAD families yielded positive lod scores at a recombination fraction of 0.0. To estimate the overall prevalence of FAD-associated mutations in the beta A4 domain of APP, we sequenced exons 16 and 17 in 30 (20 early- and 10 late-onset) FAD kindreds and in 11 sporadic AD cases, and we screened 56 FAD kindreds and 81 cases of sporadic AD for the presence of the originally reported FAD-associated mutation, APP717 Val----Ile (by BclI digestion). No APP gene mutations were found in any of the FAD families or sporadic-AD samples examined in this study, suggesting that the mutations in exons 16 and 17 are a rare cause of FAD. Overall, these data suggest that APP gene mutations account for a very small portion of FAD.

Alzheimer Disease↗

PubMed1990

Genetic linkage studies suggest that Alzheimer's disease is not a single homogeneous disorder.

Alzheimer's disease, a fatal neurodegenerative disorder of unknown aetiology, is usually considered to be a single disorder because of the general uniformity of the disease phenotype. Two recent genetic linkage studies revealed co-segregation of familial Alzheimer disease with the D21S1/S11 and D21S16 loci on chromosome 21. But two other studies, one of predominantly multiplex kindreds with a late age-of-onset, the other of a cadre of kindreds with a unique Volga German ethnic origin, found absence of linkage at least to D21S1/S11. So far it has not been possible to discern whether these conflicting reports reflect aetiological heterogeneity, differences in methods of pedigree selection, effects of confounding variables in the analysis (for example, diagnostic errors, assortative matings), or true non-replication. To resolve this issue, we have now examined the inheritance of five polymorphic DNA markers from the proximal long arm of chromosome 21 in a large unselected series of pedigrees with familial Alzheimer's disease. Our data suggest that Alzheimer's disease is not a single entity, but rather results from genetic defects on chromosome 21 and from other genetic or nongenetic factors.

Alzheimer Disease↗

PubMed1990

Altered hexokinase activity in skin cultured fibroblasts and leukocytes from Alzheimer's disease patients.

Changes in the activity of brain glycolytic enzymes have been reported in Alzheimer's dementia. In this paper we studied the activity of the rate-limiting glycolytic enzymes, namely phosphofructokinase, lactate dehydrogenase and hexokinase in skin cultured fibroblasts and leukocytes from familial and sporadic Alzheimer's disease patients and unaffected relatives. Phosphofructokinase and lactate dehydrogenase activities were similar in all groups studied. The activity of hexokinase was reduced in some patients with the familial dominant form of Alzheimer's disease whilst it was normal in sporadic cases. These results suggest that Alzheimer's disease may be an heterogeneous disorder and that a modification on the catalytic activity of hexokinase may play a role in the pathogenesis of the disease in at least a subgroup of patients.

Alzheimer Disease↗

PubMedDate not supplied

Brain study using magnetic resonance imaging and proton MR spectroscopy in pediatric onset systemic lupus erythematosus.

OBJECTIVE: The aim of the present study was to assess and monitor brain damage in patients with pediatric onset systemic lupus erythematosus (SLE) using non-invasive techniques such as magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (H-MRS). METHODS: Twenty-four SLE patients, both symptomatic or asymptomatic for central nervous system (CNS) involvement, and 20 controls were examined. Each individual underwent a diagnostic MRI using a 1.5 T Philips ACS-NT scanner including transverse T2-weighted (T2W) spin echo, transverse FLuid Attenuated Inversion Recovery (FLAIR), and sagittal T2W turbo spin echo 5 mm slices. In addition, single voxel proton MR spectroscopy localized on the supraventricular region was performed in all patients and controls. Patients were re-examined after one year. RESULTS: 75% of SLE patients had clinical CNS involvement; 46% showed abnormal MRI (3 of them, in the absence of neurologic signs); 4 SLE patients showed N-acetylaspartate/Creatine (NAA/Cr) ratios significantly lower than the controls. Among 5 SLE patients examined at the onset of the disease, 1 had MRI alterations and another showed a decrease of NAA/Cr values. Three patients with relapses showed a correlation between the course of the disease and the NAA/Cr ratios. CONCLUSION: MRI and H-MRS are non-invasive techniques that might be useful, in some cases, in detecting CNS involvement in SLE patients and monitoring the disease course and efficacy of pharmacological treatment.

Adolescent↗

PubMedDate not supplied

[Hexokinase in Alzheimer's disease].

Decreased hexokinase activity has been reported in brain, fibroblast, leukocytes and microvessels of patients with Alzheimer's disease. In this paper the results of an investigation on hexokinase activity in an Italian large pedigree are reported. The activity was comparable with that of the normal controls. These results suggest that Alzheimer's disease may be an heterogenic disorder.

Aged↗