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Biomedical subjects

A Amorim

Publications and source records attributed to A Amorim.

102 records · Page 6Linked to original sources
PubMed1980

Human phosphoglycolate phosphatase (PGP) E.C. 3.1.3.18: linkage analysis.

Linkage data on phosphoglycolate phosphatase (PGP) E.C. 3.1.3.18 and 26 other human genetic markers are presented. One hundred and one families from the southwestern area of Germany were tested. Close linkage between PGP and the following markers could be ruled out: ABO, acP, ADA, GPT, PGM1, GLO, HLA, and PGM3. There is some evidence for possible linkage with MNSs, Rh, Gm and EsD. Family segregation data confirm the hypothesis formerly established by Barker and Hopkinson: three common alleles PG1, PGP2 and PGP3 at an autosomal locus PGP.

Alleles↗
PubMed1978

Influence of axiopulpal line angle and proximal retention on fracture strength of amalgam restorations.

Proximal retentive grooves significantly increase the strength of amalgam restorations in Class II cavities. There were no remarkable differences that could have clinical significance between sharp or rounded axiopulpal line angles and rounded or rounded and sloped pulpal walls. Chromium-cobalt dies are effective for tests of fracture strength of amalgam restorations.

Chromium Alloys↗
PubMedDate not supplied

beta-Amyloid precursor protein gene in squirrel monkeys with cerebral amyloid angiopathy.

Senescent nonhuman primates frequently develop cerebral beta-amyloidosis; for reasons that are not yet understood, the primary histological locus of beta-amyloid deposition varies in different species. In aged rhesus monkeys (Macaca mulatta), fibrillar (congophilic) beta-amyloid (A beta) occurs most frequently in senile plaques, whereas in aged squirrel monkeys (Saimiri sciureus) the cerebral blood vessels are most affected. To determine if cerebral beta-amyloid angiopathy (CAA) in squirrel monkeys is related to a species-specific amino acid change in A beta, as was shown in two hereditary human forms of CAA, the beta-amyloid precursor protein (beta PP) cDNA was sequenced. The predicted amino acid sequence of A beta in squirrel monkeys is identical to that in normal humans. Overall, beta PP751 in the squirrel monkey differs from the human sequence only by four amino acids near the N-terminus and in the KPI domain. These findings suggest that other factors most likely predispose aged squirrel monkeys to cerebral amyloid angiopathy. We propose the squirrel monkey as a useful model for studying the factors contributing to human CAA, and for testing diagnostic and therapeutic approaches to this disorder.

Amyloid beta-Protein Precursor↗
PubMedDate not supplied

Analysis of FMR1 and flanking microsatellite markers in normal and fragile X chromosomes in Portugal: evidence for a "protector" haplotype.

In order to look for linkage disequilibrium between the fragile X locus and its flanking markers, we analysed the FRAXAC1 and DXS548 microsatellites in normal and fragile X individuals of Portuguese origin. We observed differences in allele and haplotype frequencies between these two samples. Four haplotypes (A-2, C-2, C-5 and D-6) accounted for 76% of all fragile X chromosomes, whereas a single haplotype (C-7) accounted for 70% of the normal population and less than 3% of the fragile X chromosomes. Among the four observed high-risk haplotypes, A-2 and D-6 had been previously reported in other studies, but C-2 and C-5 seem characteristic of Portuguese patients, as suggested by the high frequency (38%) in fragile X chromosomes and virtual absence in controls. In accordance with previous studies, a greater heterozygosity of the fragile X sample was noted when compared to that of controls. The high frequency of C-7 haplotype in the normal population and its virtual absence in the fragile X sample may reflect the existence of linkage disequilibrium between the two loci and/or selective advantage (protector effect) of this haplotype.

Fragile X Messenger Ribonucleoprotein 1↗
PubMedDate not supplied

Allelic affinities between the F13A common gene products inferred by the analysis of an (AAAG)n STR polymorphism within the 5' untranslated region.

Factor XIII a subunit (F13A) is the last enzyme in the blood coagulation cascade. It is characterized by extensive genetic polymorphism defined by 4 common alleles, F13A*1A, 1B, 2A and 2B and a few rare variants, some responsible for severe coagulation deficiencies. In order to infer the evolutionary affinities between the common F13A alleles we have applied PCR techniques to study, in a Northern Portuguese sample, a short tandem repeat polymorphism located within the 5' untranslated region of the F13A gene. The analysis of the molecular heterogeneity within the F13A gene products revealed that the four biochemical variants shared very similar, truncated, distributions of STR alleles and showed no signs of predominant haplotypic associations. These findings seem to support both the inferences that intragenic recombination played an important role in the generation of molecular diversity within each of the four main F13A alleles and that all the four F13A alleles must be rather old. Molecular heterogeneity levels allowed the identification of 1B as the oldest F13A allelic state, and 2A as the most recently generated allele, but were not different enough to accurately track the divergence of alleles 1A and 2B. However, additional analysis of linkage disequilibrium patterns indicates that 1B-->2B-->1A-->2A is the most likely evolutionary order of appearance of F13A main protein alleles, confirming and extending a previous hypothetical model inferred from their molecular features.

5' Untranslated Regions↗
PubMedDate not supplied

TcruziDB, an integrated database, and the WWW information server for the Trypanosoma cruzi genome project.

Data analysis, presentation and distribution is of utmost importance to a genome project. A public domain software, ACeDB, has been chosen as the common basis for parasite genome databases, and a first release of TcruziDB, the Trypanosoma cruzi genome database, is available by ftp from ftp://iris.dbbm.fiocruz.br/pub/genomedb/Tcr uziDB as well as versions of the software for different operating systems (ftp://iris.dbbm.fiocruz.br/pub/unixsoft/). Moreover, data originated from the project are available from the WWW server at http://www.dbbm.fiocruz.br. It contains biological and parasitological data on CL Brener, its karyotype, all available T. cruzi sequences from Genbank, data on the EST-sequencing project and on available libraries, a T. cruzi codon table and a listing of activities and participating groups in the genome project, as well as meeting reports. T. cruzi discussion lists (tcruzil@iris.dbbm.fiocruz.br and tcgenics@iris.dbbm.fiocruz.br) are being maintained for communication and to promote collaboration in the genome project.

Animals↗
PubMedDate not supplied

[Divide to rule].

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Education, Dental↗