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Biomedical subjects

R Nogueira

Publications and source records attributed to R Nogueira.

9 recordsLinked to original sources
PubMed2003

A technique using a membrane flow cell to determine average mass transfer coefficients and tortuosity factors in biofilms.

Average mass transfer coefficients of an inert compound (LiCI) within denitrifying biofilms were monitored during biofilm growth in a membrane flow cell under different flow conditions, until the biofilm reached (pseudo-) steady state. Average effective diffusivities were found to increase with the decrease tortuosity factors of the biofilm matrix. The lowest tortuosity factor corresponded the highest liquid velocity.

Biofilms↗
PubMed2000

Primary lymphoepithelioma-like carcinoma of the lung.

Lymphoepithelioma is an undifferentiated carcinoma with prominent lymphoid stroma in the nasopharynx. Tumors with similar histology have been reported with other localizations, including the lungs, and are designated as lymphoepithelioma-like carcinomas (LELC). Primary LELC of the lung is very rare, and scant information is available in the scientific literature. This paper details the case of a 25-year-old Caucasian male patient with the diagnosis (determined by thoracotomy) of primary LELC of the lung. Immunohistochemical analysis was negative for Epstein-Barr virus, as was the in situ hybridization of the tumor cells. Observation of the nasopharynx and a magnetic resonance image of the cavum were normal. Because the tumor (T4N2M0) could not be resected, the patient was treated with chemotherapy, carboplatin/5-fluorouracil, completing two cycles. The patient's condition worsened when he developed contralateral pneumonia, which was then followed by pericardial effusion. The patient died 36 h later from cardiac tamponade. Presented here is a revision of this rare pathology, not often reported in the literature.

Adult↗
PubMed1997

Dyssegmental dysplasia: a case report of a Rolland-Desbuquois type.

Two different forms of dyssegmental dysplasia, mild and severe, can be distinguished on clinical, radiographic and chondro-osseous morphologic grounds. The milder Rolland-Desbuquois type is frequently characterised by survival beyond the newborn period. The lethal Silverman-Handmaker type has distinctive and more severe findings. In this paper, a rare case of the Rolland-Desbuquois type is presented. The case is unusual because although it was the milder form, the child died on the 10th day of life.

Abnormalities, Multiple↗
PubMed1991

Giant aneurysms of the sellar region simulating pituitary adenomas: a diagnosis to be considered.

Aneurysms of the sellar region are commonly mistaken for pituitary adenomas, since they have similar clinical, endocrinological and neurological symptoms. The authors describe three patients with giant aneurysms of the internal carotid artery which were initially diagnosed as pituitary tumors. In all patients the clinical presentation was nonspecific, and consisted mainly of neurological symptoms such as headaches and visual field defects. Endocrine abnormalities were also found in the three cases. Patient no. 1 had short stature, lack of GH response to clonidine stimulation, low IGF-1 levels and blunted TSH response to TRH. Patient no. 2 had gonadotropin deficiency and patient no. 3 had hyperprolactinemia. CT scans showed a densely enhanced lesion in all patients, which was heterogeneous in one case and homogeneous in the remaining. Carotid angiography confirmed the diagnosis of aneurysm. Preoperative angiographic studies are necessary for the differential diagnosis of an aneurysm from a pituitary tumor. Furthermore, these studies could prevent the serious consequences of a transsphenoidal surgical approach in misdiagnosed cases.

Adenoma↗
PubMedDate not supplied

Randomized, double-blind, placebo-controlled study on the immunogenicity of the leishmanin skin test.

A positive reaction to the leishmanin skin test (LST) indicates previous contact with Leishmania antigens and is a useful criterion for the diagnosis of cutaneous leishmaniasis. In leishmaniasis vaccine trials, selection of volunteers has always been based on skin testing. During 1999 we performed a randomized controlled study in order to evaluate the immunogenicity of the LST. Fifty-nine (29 male and 30 female) healthy volunteer undergraduate students from the Medical School of Volta Redonda, Rio de Janeiro State, Brazil, with no evidence of previous infection with Leishmania, were randomly assigned into 2 groups: 29 subjects received LST and 30 received a placebo (merthiolate-phosphate-buffered saline). All volunteers received LST 41 d after the first injection of LST or placebo. Blood samples were taken immediately before the applications of LST or placebo for the assessment of Leishmania antigen-induced proliferation and cytokine production in peripheral blood mononuclear cell cultures. A significant increase in proliferative responses to L. braziliensis (P < 0.005) and L. amazonensis (P = 0.01) antigens as well as in L. braziliensis antigen-induced interferon-gamma production (P < 0.01) followed the application of LST but not the administration of the placebo. A single LST application is therefore able to induce Leishmania-specific cell-mediated immune responses. This observation should be considered in human trials of candidate vaccines against leishmaniasis.

Adult↗
PubMedDate not supplied

The haemoculture of Trypanosoma minasense Chagas, 1908.

Trypanosoma minasense was isolated for the first time in blood axenic culture from a naturally infected marmoset, Callithrix penicillata, from Brazil. The parasite grew profusely in an overlay of Roswell Park Memorial Institute medium plus 20% foetal bovine serum, on Novy, McNeal and Nicolle medium (NNN), at 27 degrees C, with a peak around 168 hr. The morphometry of cultural forms of T. minasense, estimates of cell population size and comparative growth in four different media overlays always with NNN, were studied. The infectivity of cultural forms to marmosets (C. penicillata and C. jacchus) and transformation of epimastigotes into metacyclic-like forms in axenic culture in the presence of chitin derivates (chitosan) were evaluated.

Animals↗