Species of the genus Brachycephalus, have a snout-vent length of less than 18 mm and are believed to have evolved through miniaturization. Brachycephalus ephippium, is particularly interesting; because its entire skull is hyperossified, and the presacral vertebrae and transverse processes are covered by a dorsal shield. We demonstrate in this paper that, at the macroscopic level, a completely hyperossified skull and dorsal shield occur only in B. ephippium, but not in B. ferruginus, B. izechsohni, B. pernix, B. pombali, B. brunneus, B. didactylus, and B. hermogenesi. An intermediate condition, in which the skull is hyperossified but a dorsal shield is absent, occurs in B. vertebralis, B. nodoterga, B. pitanga, and B. alipioi. The microscopic structure of hyperossification was examined in skulls of B. ephippium and B. pitanga, revealing a complex organization involving the presence of Sharpey fibers, which in humans are characteristic of periodontal connections.

Lapachol [2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone] and its analogs [2-(3,7-dimethyl-2,6-octadienyl)-3-hydroxy-1,4-naphthoquinone and 2-(3,3-dibromo-2-propenyl)-3-hydroxy-1,4-naphthoquinone] have been described, among almost a hundred synthesized analogs, as active against rat tumor Walker 256 carcinosarcoma. The acetylglucosylation of lapachol results in a compound which extends lapachol activity becoming effective against mouse lymphocytic leukemia P-388. When mice inoculated with 10(6) leukemic cells were treated with the drug during 9 days, their life span increased 80% over the control animals. Identification spectral data (uv, ir, 1H NMR, and MS) of the compound obtained by synthesis are given.

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The aim of this study was to evaluate the bone repair using autogenous periosteum-derived cells (PDC) and bovine anorganic apatite and collagen (hA-COl). PDC from Wistar rats (n=10) were seeded on hA-COl discs and subjected to osteoinduction during 6 days. Critical-size defects in rat calvarias were treated with blood clot (G1), autogenous bone (G2), hA-COl (G3) and hA-COl combined with PDC (G4) (n=40), and then analyzed 1 and 3 months after surgeries. radiographic analysis exhibited no significant temporal change. G1 and G2 had discrete new marginal bone, but the radiopacity of graft materials in G2, G3 and G4 impaired the detection of osteogenesis. At 3 months, histopathological analysis showed the presence of ossification islets in G1, which was more evident in G2, homogeneous new bone around hA-COl in G3 and heterogeneous new bone around hA-COl in G4 in addition to moderate presence of foreign body cells in G3 and G4. histomorphometric analysis showed no change in the volume density of xenograft (p>0.05) and bone volume density in G2 was twice greater than in G1 and G4 after 3 months (p<0.05), but similar to G3. The PDC did not increase bone formation in vivo, although the biomaterial alone showed biocompatibility and osteoconduction capacity.Key Words: critical size defects, periosteum-derived cells, xenograft, hydroxyapatite, collagen.to obtain the osteogenic cells. Also, PDC show greater proliferation, which decreases the time of cell culture, contamination risks and experiment costs. It could be a favorable alternative for dentists as a regenerative therapy for alveolar bone to treat periodontitis and dental implant dehicenses, due to the easy handling, expansion and re-implantation of cells (2).Cell culture is done upon scaffolds to simulate the 3D structure of bone tissue. Demineralized and acelullar bovine xenograft matrices are predominantly composed

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