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Biomedical subjects

E Freitas

Publications and source records attributed to E Freitas.

14 recordsLinked to original sources
PubMed2000

Gene expression of divalent metal transporter 1 and transferrin receptor in duodenum of Belgrade rats.

Regulation of iron absorption is thought to be mediated by the amount of iron taken up by duodenal crypt cells via the transferrin receptor (TfR)-transferrin cycle and the activity of the divalent metal transporter (DMT1), although DMT1 cannot be detected morphologically in crypt cells. We investigated the uptake of transferrin-bound iron by duodenal enterocytes in Wistar rats fed different levels of iron and Belgrade (b/b) rats in which iron uptake by the transferrin cycle is defective because of a mutation in DMT1. We showed that DMT1 in our colony of b/b rats contains the G185R mutation, which in enterocytes results in reduced cellular iron content and increased DMT1 gene expression similar to levels in iron deficiency of normal rats. In all groups the uptake of transferrin-bound iron by crypt cells was directly proportional to plasma iron concentration, being highest in iron-loaded Wistar rats and b/b rats. We conclude that the uptake of transferrin-bound iron by developing enterocytes is largely independent of DMT1.

Animals↗
PubMed1998

Quantitative analysis of the high-affinity binding sites for [3H]ouabain in the rat vas deferens and their immunological identification as the alpha 2 isoform of Na+/K(+)-ATPase.

Binding assays were performed with [3H]ouabain to investigate the presence of, and to characterize, a Na+/K(+)-ATPase isoform with high affinity for cardiac glycosides in the rat vas deferens. Nonlinear regression analysis of equilibrium experiments carried out with crude preparations in a Mg-Pi medium indicated the presence of high-affinity sites characterized with good precision (individual coefficients of variation = 11-35%) by their density (Bmax = 0.42 to 0.72 pmol/mg protein) and dissociation constant (Kd = 0.069 to 0.136 microM) values. The values of the dissociation rate constant (kappa-1) and the association rate constant (kappa+1) for these sites were 0.151 to 0.267 min-1 and 2.87 to 3.60 microM-1.min-1, respectively. A higher number of low-affinity sites (Kd around 15 microM), supposed to correspond to the alpha 1 isoform, was also identified, but their Kd and Bmax values were not quantified precisely in this crude preparation. Western blot assays indicated hybridization with specific anti-alpha 1 and anti-alpha 2 isoform antibodies but not with anti-alpha 3 isoform antibody. Taken together, the present results indicate the existence of a low proportion of the alpha 2 isoform of Na+/K(+)-ATPase in the rat vas deferens that can be quantified precisely by [3H]ouabain binding even in a crude membrane preparation that is suitable for studies under conditions of plasticity.

Animals↗
PubMed1997

Aortic valve conservation in acute type A dissection.

BACKGROUND: We consider operative survival as the primary objective in acute type A dissection and believe that virtually all native aortic valves can be conserved. We sought to answer the question: "Does glue repair improve the long-term stability of proximal aortic repair?" METHODS: We retrospectively studied 64 patients with an acute type A dissection, an ascending aortic tear, and aortic regurgitation operated on by the same surgeon between 1988 and 1996. Three had Marfan's syndrome and 2 had a bicuspid valve. The valves in all patients without Marfan's syndrome were repaired with gelatin-resorcinol-formol glue. The valve and root were reinvestigated by echocardiography. Some patients underwent nuclear magnetic resonance imaging. RESULTS: There were four hospital (6%) and three late deaths. Aortic root reoperation was required in 2 of the 60 survivors (3.3%) and operation on the distal aorta in 2. Root reoperations were required within 3 years. The remaining proximal repairs remained stable. CONCLUSIONS: The native aortic valve can be conserved in most patients, and glue repair is durable. Simple root repair is associated with a low operative mortality.

Adult↗
PubMed1983

A baseline study of periodontal conditions among youths and adults in Portugal.

A study was undertaken in 1979 to obtain baseline data of periodontal disease and treatment needs among rural and urban Portuguese. From Montemor-o-Novo, Alentejo and from Lisbon, 255 persons (121 males, 134 females) aged 15-44 yr were selected by a stratified quota sampling method and examined under field conditions using both Russell's Periodontal Index (P.I.), slightly modified, and components of a proposed new WHO method. The latter formed the basis for estimation of treatment need according to the Community Periodontal Index for Treatment Needs (CPITN). Periodontal disease as assessed by the P.I. exhibited epidemiologic characteristics which in several respects were similar to those reported in other populations. Severity increased with increasing age and there were trends towards more severe disease in males than in females, and more severe disease in rural than in urban districts. Relatively few cases of advanced periodontitis were detected by the P.I. as applied in this study. The underestimation of disease prevalence inherent in the scoring method, the high tooth mortality and the fact that only relatively young individuals were studied may have contributed to this finding. Great need for various types of periodontal therapy were found through CPITN assessments. However, relatively few individuals were in need of "complex periodontal therapy" as assessed by the CPITN.

Adolescent↗
PubMed1982

Bullet embolism into the cardiovascular system.

Two clinical case reports of bullet embolism into the cardiovascular system are reported. The patient in the first case sustained a gunshot wound at the right clavicular area with embolism resulting in the right ventricle. In the second case, the patient received a projectile wound to the anterior right shoulder with eventual bullet embolism in the left iliac artery. In both cases, the bullets were removed successfully. Surgical intervention with the aid of extracorporeal circulation is recommended for similar cases.

Journal Article↗
PubMed1979

Pulmonary hydatid cyst: a 25-year experience.

This study reviews our experience with 102 patients operated on for pulmonary hydatid cysts during a 25-year period. The sex incidence was approximately equal. All subjects except three were symptomatic. The diagnosis was made on the radiographic findings. Early surgery is advised for complicated cysts in view of their increased postoperative morbidity and mortality. Surgical treatment included Barrett's enucleation for uncomplicated cysts and resection for complicated ones.

Adolescent↗
PubMed1975

Eruption of permanent teeth in Brazilian Whites and Blacks.

A total of 302 White and 904 Black children six, nine and 12 years of age were studied for the eruption of their permanent teeth. Differences between the two ethnic groups were not large, but the Black subjects were generally more precocious at the beginning of the process (especially the girls, both in the upper and lower incisors). At nine and 12 years of age, however, these dissimilarities disappear. The latter do not seem to be related to distinct rates of extraction or agenesis of deciduous teeth. No significant differences were observed in the degree of asymmetry present in the permanent dentition of the White and Black individuals studied.

Bicuspid↗