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Biomedical subjects

M C Barbosa

Publications and source records attributed to M C Barbosa.

7 recordsLinked to original sources
PubMed2002

cDNA cloning, expression and characterization of a Boophilus microplus paramyosin.

The tick Boophilus microplus is a 1-host tick that causes important losses to bovine herds, and protective antigens are being investigated in order to develop vaccines that avoid the use of acaricides. Paramyosins are multi-functional invertebrate muscle proteins, whose roles may include host immunomodulation, and seem to be a prominent candidate in a schistosomiasis vaccine. We report here the cloning, expression and characterization of a B. microplus paramyosin (BmPRM). Sequence analysis of the full length coding sequence cDNA shows high identity to other arthropod paramyosin sequences, and the predicted molecular weight, pI and secondary structure are consistent with a typical paramyosin. Western-blot expression analysis indicates the presence of BmPRM in all tissues and developmental stages tested, but not in saliva. The recombinant protein (rBmPRM) was shown to bind both IgG and collagen. Possible implications of these activities with host evasion mechanisms are discussed.

Amino Acid Sequence↗
PubMed2001

Dredging and disposal of fine sediments in the state of Rio de Janeiro, Brazil.

Dredging is employed quite frequently in the state of Rio de Janeiro, especially for the installation and upkeep of commercial ports and rehabilitation of the hydraulic section of silted bodies of water. Until recently, all dredged material with no economic use was destined for marine disposal or stored at the edge of the water body. Since the 1990s, however, a new approach has been adopted for dredging as a result of pressure from the environmental organisations, encouraging closer interaction in Rio de Janeiro between the local and state public authorities and the universities on issues relating to licensing of this kind of activity. The recent experiments of the Civil and Ocean Engineering Programs of COPPE-UFRJ (Federal University of Rio de Janeiro) described herein are included in this context. The state of Rio de Janeiro has three bays, several coastal lagoon systems and a number of small and medium sized rivers in or close to urban areas, with a gentle slope as they near the sea. This is, then, a region highly susceptible to silting processes of water bodies, and therefore, to maintenance and/or environmental rehabilitation. As discussed in the article, fine and almost always organic sediments prevail, which is a considerable obstacle to the end disposal and possibility of reuse.

Brazil↗
PubMed2001

Criticality in confined ionic fluids.

A theory of a confined two-dimensional electrolyte is presented. The positive and negative ions, interacting by a 1/r potential, are constrained to move on an interface separating two solvents with dielectric constants epsilon(1) and epsilon(2). It is shown that the Debye-Hückel type of theory predicts that this two-dimensional Coulomb fluid should undergo a phase separation into a coexisting liquid (high-density) and gas (low-density) phases. We argue, however, that the formation of polymerlike chains of alternating positive and negative ions can prevent this phase transition from taking place.

Journal Article↗
PubMed1999

[Approach in acute respiratory tract disfunction]

OBJECTIVE: To present a review of the current diagnostic and therapeutic approach to the major conditions found in pediatric emergency department, which course with acute respiratory tract disfunction, stressing some clinical and epidemiological characteristics that are useful to the pediatrician in the differential diagnosis.METHODS: Outstanding articles related to the subject were selected after literature review of the last 20 years, using Md Consult, Medline and Lilacs databases.RESULTS: Many diseases can produce respiratory disfunction. Taking into account only those with acute symptoms, infectious and/or inflammatory causes predominate. History, examination findings and at least a chest X-ray are almost always sufficient for the diagnosis, but, sometimes other complimentary tests are necessary.CONCLUSIONS: If not properly treated, acute respiratory emergencies can result in significant morbidity and mortality. Any pediatrician taking part in an emergency team has to obtain respiratory management skills and knowledge concerning distinctive aspects and severity estimation of the several respiratory diseases.

Journal Article↗
PubMed1982

Free fatty acid mobilization in rats following intracerebroventricular norepinephrine.

The possible involvement of central synaptic transmitters in lipomobilization was investigated by injecting norepinephrine or carbachol into the cerebrospinal fluid of conscious, unrestrained rats. Intracerebroventricular administration of minute amounts of norepinephrine (25-400 nmol in 5 microliters) induced a rapid increase in plasma free fatty acids (FFA) and glycerol. Small increases in blood sugar levels were induced only by the higher doses of norepinephrine. Plasma FFA response to the catecholamine was dose related in the range of 25-100 nmol of hormone. Previous intraventricular administration of propranolol, but not of phentolamine, completely blocked the lipomobilzing effect of intraventricular norepinephrine. In contrast to norepinephrine, carbachol (27 or 54 nmol) injected intraventricularly did not affect plasma FFA or glycerol levels, but markedly increased blood sugar levels. Increase of plasma FFA and glycerol by intraventricular norepinephrine and blockade of the response by propranolol suggest the involvement of a beta-adrenergic mechanism in the centrally mediated lipolysis activation. On the basis of these and previous results, it is hypothesized that central beta-adrenergic synapses relay impulses generated in receptors specifically involved in lipomobilization to the sympathetic fibers of adipose tissue.

Animals↗