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Biomedical subjects

A G da Costa

Publications and source records attributed to A G da Costa.

7 recordsLinked to original sources
PubMed1997

[A structural analysis of the entrance exams for specialist interns from 1994 to 1996].

In order to obtain specialist training in Portugal, doctors must pass a multiple-choice examination. The aim of this article is to present a structural and mathematical analysis of the examinations in the last three years. We based our work on the calculation of reliability coefficient of the examinations, and the difficulty and discrimination index of the questions and the examinations as a whole. A detailed analysis of the examinations, including that of each of the three hundred questions, will be published by the Department of Health Manpower in January, 1997.

Education, Medical↗
PubMed1994

Proton ejection as a major feature of the Ca(2+)-pump.

H+ ejection and Ca2+ uptake promoted by the sarcoplasmic reticulum (SR) Ca(2+)-pump are similarly stimulated by millimolar Mg2+. This cannot be assigned to enhanced Ca2+ uptake and H+ displacement from internal metal binding sites since: (1) loading SR vesicles with high Mg2+ concentrations does not impair H+ ejection; (2) loading SR vesicles with Mn2+ does not depress H+ ejection occurring during Mn2+ uptake; (3) H+ ejection occurs even when Ca2+ accumulation inside the vesicles is prevented with Ca2+ ionophores. It is concluded that the Ca(2+)-pump promotes an active Ca2+/H+ countertransport stimulated by Mg2+. Finally, a mechanism for Ca2+ translocation is proposed in basic physico-chemical terms.

Animals↗
PubMedDate not supplied

[Cytomegalovirus infection in kidney transplantation].

150 patients, subjected to kidney graft transplantation between January 1988 and December 1989, were studied. Mean +/- 95% CL age was 37.5 +/- 2.03 (range 12-69) years. IgG and IgM antibodies levels (ELISA) cytomegalovirus (CMV) were investigated in the donor before organ harvesting and in the kidney recipients on 1st and 21th days and then on the 3rd, 6th and 9th months after transplantation. Patients lacking either donor or 1st day studies were excluded. 133 donor (D) receptor (R) pairs were classified as group 1) D+/R+, 2) D+/R-, 3) D-/R+ e 4) D-/R-. Prevalence, severity of CMV disease and date of diagnosis were studied. Mean time +/- 95% CI of diagnosis after transplantation was 78.4 +/- 15.1 days. Seronegative receptors had a statistically significant higher prevalence of the disease as to seropositive receptors, but not a higher incidence of disease severity. One out of five patients had a serious form of disease. Hiperimmune globulin was used in 15 patients (all serious forms and 3 moderate forms of of disease). No patient died as a result of CMV infection.

Adolescent↗
PubMedDate not supplied

[Renal insufficiency with primary hyperaldosteronism].

We describe a case of advanced chronic renal failure with persisting hypokalemia. The clinical study revealed the simultaneous presence of a salt and potassium loosing nephropathy associated with aldosterone-producing adenoma. This late pathology was revealed as electrolytic changes characteristic of primary hyperaldosteronism became evident as the renal function progressively deteriorated.

Adenoma↗