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Biomedical subjects

S Peixoto

Publications and source records attributed to S Peixoto.

13 recordsLinked to original sources
PubMed2003

Preliminary identification and quantification of the age-pigment lipofuscin in the brain of Farfantepenaeus paulensis (Crustacea: Decapoda).

A preliminary study was done on the age-pigment lipofuscin content in the brains of captive Farfantepenaeus paulensis juveniles (5 months old) and wild adults (estimated age of 12-15 months). Random samples of 6 individuals were obtained from each group (juvenile and adult) for histological analysis. Serial sections (6 microns) of the brains were mounted without staining and observed in an epifluorescent microscope. The fluorescent images of the five most central sections of the olfactory lobe cell mass (OLCM) of each individual were digitized for image analysis. The lipofuscin granule mean diameter was similar in both groups (p > 0.05), however the lipofuscin area fraction (percentage of the OLCM occupied by pigment granules) was significantly higher (p < 0.05) in the adult shrimp. The detection of lipofuscin granules in 5 month old F. paulensis indicates that lipofuscin deposition probably takes place even earlier in the juvenile phase. Our results suggested that the amount of granules in the F. paulensis OLCM is related to age, but further studies are necessary to evaluate the relationship between lipofuscin content and the age of captive F. paulensis.

Age Factors↗
PubMed1989

Bacterial resistance in South America.

The emergence of resistant strains of bacteria is directly related to the selection of chemotherapeutic agents, and the character of the resistance changes with changes in use-frequency of the various antibiotics. In recent years with increasing use of beta-lactam antibiotics, there has been an increased incidence of microorganisms that are resistant by virtue of their ability to produce beta-lactamase enzymes which destroy the beta-lactam antibiotics. The development of beta-lactamase inhibitors which may be used in combination with the beta-lactam antibiotics has been a significant advance for the therapy of gynecologic infections in South America.

Bacterial Infections↗
PubMed1986

Determination of the source(s) of androgen overproduction in hirsutism associated with polycystic ovary syndrome by simultaneous adrenal and ovarian venous catheterization. Comparison with the dexamethasone suppression test.

To determine the source(s) of the excessive androgen production in patients with the polycystic ovary syndrome (PCOS), 12 hirsute women with PCOS underwent selective left adrenal and left ovarian venous catheterization. Blood samples were collected simultaneously for determination of cortisol, 17-hydroxy-progesterone, androstenedione (delta), testosterone (T), dehydroepiandrosterone, and dehydroepiandrosterone sulfate. The relative contributions of adrenal secretion rates of T and delta in each patient were estimated by relating their adrenal gradients to those of cortisol. From such calculations we found that in all patients the major source of androgens was the ovary (direct ovarian secretion and/or ovarian secretion of prehormones which then were converted to androgen in the peripheral circulation). After catheterization, 11 of the 12 patients underwent a 5-day dexamethasone suppression test (2 mg/day). In 7 patients studied, plasma delta and/or T levels decreased significantly. Our results indicate that in hirsutism associated with the PCOS, the predominant source of androgens is the ovaries and that glucocorticoid suppression cannot assign adrenal origin as the site of excessive androgens.

Adolescent↗
PubMedDate not supplied

Endometrial damage in acute salpingitis.

Histologic and bacteriologic analyses of endometrium were performed before and on day 15 after minocycline treatment of 20 patients with acute salpingitis. Endometritis was diagnosed in 15 patients before and in nine after treatment. Neisseria gonorrhoeae was recovered from the cervix and endometrium of seven patients but was not isolated after treatment. Chlamydia trachomatis was recovered from the cervix of eight, and from the endometrium of three patients, two of whom had negative cervical cultures. After treatment C. trachomatis was recovered from the cervix of three patients, although two of them had taken aluminum hydroxide for gastric symptomatology during minocycline treatment. Culture of an endometrial specimen revealed no growth of C. trachomatis. The histologic study revealed plasma cell infiltrates in specimens from patients who had cultures positive for C. trachomatis. The results showed that although endometritis is an important manifestation of acute salpingitis, there is no correlation between severity of endometritis and degree of tubal damage.

Acute Disease↗