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Biomedical subjects

L M Figueiredo

Publications and source records attributed to L M Figueiredo.

6 recordsLinked to original sources
PubMed2001

Plasmodium telomeres: a pathogen's perspective.

New data on the organization of plasmodial telomeres has recently become available. Telomeres form clusters of four to seven heterologous chromosome ends at the nuclear periphery in asexual and sexual parasite stages. This subnuclear compartment promotes gene conversion between members of subtelomeric virulence factor genes in heterologous chromosomes resulting in diversity of antigenic and adhesive phenotypes. This has important implications for parasite survival.

Animals↗
PubMed2000

The Drosophila homologue of the 64 kDa subunit of cleavage stimulation factor interacts with the 77 kDa subunit encoded by the suppressor of forked gene.

During mRNA 3' end formation, cleavage stimulation factor (CstF) binds to a GU-rich sequence downstream from the polyadenylation site and helps to stabilise the binding of cleavage-polyadenylation specificity factor (CPSF) to the upstream poly-adenylation sequence (AAUAAA). The 64 kDa subunit of CstF (CstF-64) contains an RNA binding domain and is responsible for the RNA binding activity of CstF. It interacts with CstF-77, which in turn interacts with CPSF. The Drosophila suppressor of forked gene encodes a homologue of CstF-77, and mutations in it affect mRNA 3' end formation in vivo. A Drosophila homologue for CstF-64 has now been isolated, both through homology with the human protein and through protein-protein interaction in yeast with the suppressor of forked gene product. Alignment of CstF-64 homologues shows that the proteins have a conserved N-terminal 200 amino acids, the first half of which is the RNA binding domain with the second half likely to contain the CstF-77 interaction domain; a central region variable in length and rich in glycine, proline and glutamine residues and containing an unusual degenerate repeat motif; and then a conserved C-terminal 50 amino acids. In Drosophila, the CstF-64 gene has a single 63 bp intron, is transcribed throughout development and probably corresponds to l(3)91Cd.

Amino Acid Sequence↗
PubMed1999

Collagen dysplasia (cutaneous asthenia) in a cat.

Hereditary collagen dysplasias comprise a complex group of connective-tissue disorders that result in the reduced tensile strength of affected tissues. These processes are called cutaneous asthenia in the skin of dogs and cats. We report here the case of a crossbred male cat, aged 6 months, that presented with two skin wounds in the region of the right thorax and right iliac tuberosity. The skin of these regions and of the animal's dorsum was hyperextensible, smooth to the touch, and easily torn with minor trauma. Microscopic examination of skin samples revealed reduced dermal connective tissue consisting of shortened and fragmented collagen fibers. Normal fibers were intermingled with altered fibers. Ultrastructural changes in collagen fibers included disorientation of fibrils within the same bundle, marked spacing differences, and variation in the diameter of transverse sections. The fibrils maintained the transverse striations characteristic of normal collagen.

Animals↗
PubMedDate not supplied

Peritoneal effusion in a dog secondary to visceral mast cell tumor. A case report.

BACKGROUND: Mast cell tumor, one of the most common skin tumors in dogs, may also be found in visceral sites (mainly spleen and liver). When a visceral mast cell tumor is present, neoplastic mast cells may be found in any effusion secondary to the tumor. Therefore, the diagnosis may be made by cytologic analysis of the effusion. CASE: An 8-year-old, spayed, female Siberian husky presented with a peritoneal effusion secondary to a visceral mast cell tumor. Seven months earlier, the dog had presented with a cutaneous nodule diagnosed as a well-differentiated mast cell tumor. The peritoneal fluid was classified as a transudate. Numerous neoplastic mast cells were found in the effusion. Although the mast cell tumor presented with characteristics of the well-differentiated tumor, its biologic behavior was that of a malignant tumor. CONCLUSION: Care should be taken to evaluate the prognosis of mast cell tumors in dogs since their biologic behavior is extremely variable.

Abdominal Neoplasms↗
PubMedDate not supplied

[Analysis of the efficacy of the maternal breast-feeding incentive program in a peripheric district of Belo Horizonte (Brazil): 1980/1986/1992].

Three institutions worked together in order to combat early weaning in a peripheric district of Belo Horizonte (Brazil): the Department of Pediatrics of the Faculty of Medicine (Federal University of Minas Gerais), the Secretary of Health of Belo Horizonte and a Brazilian assistential institution ("LBA"). One initial survey, in 1980, documented breast-feeding practices in this community, when there were no systematized actions of incentive to human milk, at local or national levels. Two similar surveys were also conducted, in 1986 and in 1992. In each one, 152 mothers with children under two years old were randomly selected and interviewed. The results showed significant progress in the breast-feeding period in the first six years, and a stabilization between 1986 and 1992. For example: if only 39.0% of the children received human milk for six months or more in 1980, 54.3% received it in 1986 and 52.4% in 1992. In 1980, 80.6% of the children were nourished with cow's milk before three months of age, to 56.5% in 1986 and 56.3% in 1992. Prenatal influence to increase the level of breast-feeding has always been weak. Besides, a reflux was detected in the last few years with regard to the participation of the maternity hospital in the educative process.

English Abstract↗