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Biomedical subjects

M L Barbosa

Publications and source records attributed to M L Barbosa.

5 recordsLinked to original sources

[RC-IAL: rabbit kidney continuous cell line--characteristics and substrate for viral replication].

A rabbit kidney cell line RC-IAL, isolated in 1976 and at present at 150a passage, has had its characteristics analysed. The cells presented morphology similar to fibroblasts throughout their culture. The cellular growth proportion remained unaltered from its isolation, with a cloning efficiency of around 9%. The line showed growth dependent on anchorage and chromosomic analysis presented the modal number of the species with small variations to about one chromosome, to a total of about 50%. The line's species of origin was confirmed through indirect immunofluorescence reaction and susceptibility to some viruses with cytopathic effect was verified with vaccinia, cowpox, herpes simplex types 1 and 2 and rubella viruses. This cellular substract is free from contaminating agents, thus satisfying the conditions for its use in scientific work, especially that relating to public health.

Animals

Urinary neopterin in pulmonary sarcoidosis. Relationship to clinical and biologic assessment of the disease.

Neopterin is a metabolite of guanosine-triphosphate, released in vitro by macrophages under the control of gamma-interferon and described as a marker of T cell activation in vivo. We have compared the urinary neopterin/creatinine ratio (mumol/mol) in patients with pulmonary sarcoidosis (n = 66), interstitial lung diseases other than sarcoidosis (nonsarcoid ILD, n = 35), and 45 normal control subjects. For the sarcoid population as a whole, urinary neopterin was higher (496 +/- 52 mumol/mol [mean +/- SEM]) than in control subjects (126 +/- 5 mumol/mol) (p less than 0.001). In patients with nonsarcoid ILD, urinary neopterin was frequently higher in granulomatous and/or lymphoproliferative diseases (hypersensitivity pneumonitis, tuberculosis, primitive Sjögren's syndrome, and malignant lymphomas) (781 +/- 193 mumol/mol, n = 10) but remained normal in other types of nonsarcoid ILD [( 163 +/- 14 mumol/mol, n = 25]: histiocytosis X, idiopathic pulmonary fibrosis, lung collagen-vascular diseases, diffuse neoplasms, pneumoconiosis; p less than 0.001 compared with sarcoidosis). We have also evaluated the relationship between urinary neopterin and the clinical or biologic markers currently used to assess sarcoidosis: alveolar lymphocytosis in lavage fluid (ALY), 67-gallium scan semiquantitative index (67Ga), or serum angiotensin-converting enzyme (SACE). Sarcoid patients with the highest urinary neopterin were those in whom mean values of these markers were the highest (p less than 0.05, all comparisons). Patients with positive markers (i.e., either clinical expression of sarcoidosis-ALY greater than 30%-67Ga greater than 20-SACE greater than 60 U/ml) had significantly higher urinary neopterin levels than did other sarcoid patients (p less than 0.05, all comparisons).

Adult

Restriction of glycolipids to the outer half of a plasma membrane: concanavalin A labeling of membrane halves in Acanthamoeba castellanii.

Fracture-label, a method that permits the cytochemical characterization of faces produced by freeze-fracture, was used to determine the partition and distribution of a glycolipid on membrane fracture faces of Acanthamoeba castellanii cells. After treatment with concanavalin A (Con A), the glycolipid (a lipophosphonoglycan, LPG) was labeled with colloidal gold coated with horseradish peroxidase. The label was abundant over exoplasmic fracture faces (face E) of plasma membranes, but absent from protoplasmic fracture faces (face P). We conclude that, in A. castellanii, glycolipid molecules are restricted to the outer half of the plasma membrane. This conclusion is confirmed by experiments with cells disrupted by freezing and thawing, where access of label to the cell interior did not result in labeling of the inner surface. Our results establish the exclusive localization of a glycolipid to the outer half of a plasma membrane. Fracture-label is proposed as a new technique to investigate the distribution and partition of glycolipids in plasma and intracellular membrane halves.

Amoeba

Simultaneous infection with dengue 1 and 2 in a Brazilian patient.

Dengue outbreaks have occurred in several Brazilian States since 1986 involving serotypes 1 (DEN-1) and 2 (DEN-2). In view of the few cases of double infection documented in the literature, we report here a case of simultaneous infection with DEN-1 and DEN-2 in a patient residing in the municipality of Miranda, State of Mato Grosso do Sul, Western region of Brazil. DEN-1 was introduced in this State in 1989 and DEN-2 in 1996, both of them circulating in some municipalities. This double infection was identified by virus isolation and by indirect immunofluorescence using monoclonal antibodies and confirmed by the polymerase chain reaction (PCR). This is the first documented case of simultaneous infection with serotypes DEN-1 and DEN-2 in Brazil.

Adult