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Biomedical subjects

A A Martins

Publications and source records attributed to A A Martins.

11 recordsLinked to original sources
PubMed1997

The relationship between myenteric neuronal denervation, smooth muscle thickening and epithelial cell proliferation in the rat colon.

The effects of myenteric neuronal denervation on smooth muscle thickening and epithelial cell proliferation were studied in the descending colon of rats treated by serosal application of 2 mM benzalkonium chloride (BAC) for 30 min. Control animals were treated with saline (0.9% NaCl). The animals were divided into six groups of 13 animals each and killed 10, 45 and 120 days after BAC treatment. A significant reduction in neuron number was observed in the myenteric plexus of animals treated with BAC, as well as smooth muscle thickening and an increase in crypt cell population, crypt cell production per crypt and a decrease in cell cycle time. These findings permit us to conclude that a relationship may exist between the increase of epithelial cell proliferation, smooth muscle thickening and myenteric neuron denervation in the descending colon caused by BAC, the latter probably playing an important role in the integration of the other two.

Animals↗
PubMed1990

[Transposition of masseter muscle insertion and its influence on anatomical musculo-skeletal changes in the adult rabbit].

Unilateral surgical transposition of the masseter muscle from the masseteric fossa to the central area of the mandibular body below the molar teeth was performed in ten adult rabbits. Six months later the animals were sacrificed, the masseter muscles were dissected and then removed to be fully dried and weighed; the skull was cleaned for anatomical examination of the mandible and the teeth. It was noticed that the transposed muscles were firmly attached and functionally adapted, but underwent a drastic reduction of their weight. The smooth surface of the mandibular body which became activated by the new muscular pull was now rough and irregular due to osseous neoformation. The original area of attachment (masseteric fossa) was remodelled not only regressively but also by bone apposition (exostoses) in some sites. The dental arches kept normal, except for alveolar bone resorption next to the first molar in two animals and accentuated sagittal deviation in another one.

Alveolar Bone Loss↗
PubMedDate not supplied

[Split line patterns in the mandible after transposition of the insertion of the masseter muscle in the adult rabbit].

With the aim of studying in the fibrous structure of the compact bone, as revealed by the split-line technique, unilateral surgical transposition of the masseter muscle from the masseteric fossa to the central area of the mandibular body below the molar teeth was performed in seven adult rabbits. Six months later the animals were killed, their mandibles were removed, cleaned and then decalcified. Split-lines were made on the lateral surface of both the control and the operated side of the mandible. Myotransposition induced alterations in the split-line patterns; they showed to be entangled and disorganized, which mean structural changes in the bone itself.

Animals↗