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Biomedical subjects

R Branco

Publications and source records attributed to R Branco.

11 recordsLinked to original sources

Guided bone regeneration using osteopatite granules and polytetrafluoroethylene membranes.

Granules of a modified hydroxyapatite, Osteopatite, were implanted in the right posterior tibiae of adult rabbits. We studied the extent of bone regeneration in bone holes. In the right tibiae, that were filled with granules of this biomaterial covered with a polytetrafluoro-ethylene (PTFE) membrane using, as a control, uncovered granules. In the left tibia, an empty hole was covered with PTFE membrane and a second hole was left empty to be used as a control. A histomorphometric study was carried out using light microscopy, four and eight weeks after the surgery. The covered granules presented a higher percentage of bone contact than the uncovered ones, and it was also possible to observe a better bone tissue organization, mainly produced by the immobilization action of the PTFE membrane. Empty bone defects covered with PTFE membranes, two months after implantation, presented large areas of Haversian bone and direct bone contact to the PTFE membrane.

Journal Article↗

[Visceral leishmaniasis and HIV infection: the diagnostic and therapeutic problems].

We present the case of an HIV-seropositive drug addict patient whose seropositivity was unknown until admission to hospital, where he presented with a clinical picture of fever splenomegaly and weight loss. A diagnosis of visceral leishmaniasis was established. We stress the diagnostic difficulties well expressed in the need to repeat the bone marrow aspirate to detect the presence of leishmanias. The lack of response to conventional antimonial therapy is discussed as well as the role of pentamidine as an alternative therapy.

AIDS-Related Opportunistic Infections↗

[Indirect articular lymphography using Tc 99m-labeled Dextran in animals].

Looking for a standardization of the articular lymphoscintigraphy, an experimental research was conducted on 14 dogs injected in the ankle, with 2.5 mCi of 99m Tc-labeled dextran (P.M. = 70,000). Good scintigraphic images of the lymphatic system have been obtained. After having collected blood samples during the experimentation as well as aliquots of organs and of tissues, after the necropsy of the animal, it was verified that the 99m Tc-labeled dextran was useful for quantitative studies of the articular lymphatic drainage. The activities attained, in the drainage lymph nodes of injected articulation, are 152 times superior to those obtained in the kidney and one gramma of popliteal ganglion was 8929 times more active than one gramma of blood. The dextran 70,000, widely used in our clinical routine, can be injected to the human being, without any risk, and it may be the tracer which permits studies of the articular lymphatic drainage and the usage of the lymphoscintigraphy, already in expansion in many other Medicine branches, in the articular studies, nowadays.

Animals↗

Physical properties of some zinc phosphate and polycarboxylate cements.

Several physical properties were measured for two zinc phosphate and three polycarboxylate cements. The specimens were tested in compression 24 h after they had been made. Two series of specimens were examined. In one series the cement powders were given a correct treatment, protected from atmospheric humidity. In the other series the powders were exposed for 1 week to ambient conditions with the temperature varying between 20 degrees and 24 degrees C and the relative humidity between 40% and 59%. The zinc phosphate cements were characterized by high values of modulus of elasticity and by plastic deformations less than 0.2%. The polycarboxylate cements were more flexible and also exhibited large plastic deformations. Compared with the zinc phosphate cements, therefore, the polycarboxylate cements had high values of resilience and toughness. The storing of cement powders exposed to atmospheric humidity for 1 week did not change the measured properties of the polycarboxylate cements. However, both strength and resilience were significantly reduced for one phosphate cement.

Chemical Phenomena↗

[Prevention of alveolar bone resorption with the use of hydroxyapatite granules].

The authors describe in review the alveolar absorption according to bone physiology, and the absorption prevention using hydroxylapatite. Finally it is pointed the good preliminary results in a 30 patients study during 8 months using hydroxylapatite (OSTEOPATITE) and plaster particles in alveolar absorption prevention.

Alveolar Bone Loss↗

[2 amalgam formulation mechanisms with high copper alloys].

Two high copper-containing amalgam alloys, one of them gas atomized and the other water atomized were used to study the reaction mechanism with mercury. Normal and subtrituration time were used. The observations of structures and evaluation of compressive strengths allowed the understanding of two different mechanisms of reaction.

Copper↗