Biomedical subjects

D G Moreira

Publications and source records attributed to D G Moreira.

2 recordsLinked to original sources

PubMed2001

Thyroid function and aging: gender-related differences.

The effects of aging on human or animal thyroid function are still not well defined. We evaluated some aspects of thyroid function during aging using an animal model (young and old Dutch-Miranda rats). In old rats of both genders, serum thyroxine (T4) decreased but serum thyrotrophin (TSH) remained unaltered, suggesting a disturbance in the pituitary-thyroid feedback mechanism during aging. Serum tri-iodothyronine (T3) only decreased in old males, possibly because female rats are almost twice as efficient in hepatic T4 to T3 deiodination. Thyroidal T4-5'-deiodinase activity did not change much during aging, although it decreased slightly in males. Thyroidal iodothyronine-deiodinase type I mRNA expression but not total thyroidal enzymatic activity were higher in female than in male rats. Thus, ovarian/testicular hormones may modulate the expression and/or the activity of hepatic and thyroidal type I iodothyronine-deiodinase. Thyroperoxidase (TPO) and thyroglobulin (Tg) expression were higher in young male rats than in females. In males, TPO and Tg gene expression decreased with aging, suggesting that androgens might increase their expression. Our results showed that aging induces real changes in rat thyroid gland function and regulation, affecting at least pituitary, thyroid and liver functions. Furthermore, some of these changes were gender related, indicating that gonadal hormones may modulate thyroid gland function and regulation.

Aging↗

PubMed1992

[Comparative study of immunoenzyme tests ELISA-G and ELISA-M, indirect immunofluorescence, and complement fixation in the diagnosis of human cysticercosis].

A comparative study of four immunological tests used for anti-Cysticercus antibodies detection--Enzyme-Linked ImmunoSorbent Assay IgG (ELISA-G) and IgM (ELISA-M), indirect immunofluorescence (RIFI) and complement fixation (RFC)--was made in serum and cerebrospinal fluid (CSF). 539 patients with symptoms suggesting cysticercosis, 450 relatives of these patients and 133 normal people (control group) were examined. 1122 serum samples and 120 CSF samples were analysed by ELISA-G and RIFI, 83 sera and 60 CSF also by RFC, and 28 CSF by ELISA-M. 5.2% serum samples were reagent in ELISA-G and RIFI, and 3.5% of them had discordant results. All control group sera were negative. The same tests in CSF were positive in 16.7% and had discordant results in 7.5%. ELISA-G and RIFI in serum and CSF had concordant results in 89.6% (17.7% were positive). ELISA-G, RIFI and RFC had concordant results in 54.2% sera (16.9% positives) and in 81.7% CSF (11.7% positives). When ELISA-G and RIFI were negative, RFC was positive in 41.0% sera and 11.7% CSF. ELISA-G and ELISA-M had concordant results in 78.6% CSF. When these results were discordant ELISA-G was positive in 10.7% and ELISA-M in another 10.7%. It is necessary to use concomitantly several immunological tests for anti-Cysticercus antibodies detection in serum and in CSF, in attempting to reach correct diagnosis.

Animals↗