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Efeitos do laser de baixa intensidade e do Biosilicato® no reparo ósseo de ratas osteopênicas
(Universidade Federal de São Carlos, 2010-08-26) Bossini, Paulo Sérgio; Parizotto, Nivaldo Antonio; https://lattes.cnpq.br/5527703735628408; https://lattes.cnpq.br/1256982144741336
Osteoporosis is a systemic skeletal disease characterized by low bone density and microarchitectural deterioration of bone tissue, with consequent increase of the risk of fractures. Frequently, the lower mineral density due to osteoporosis leads to a delay in fracture healing rates and bone repair quality. Within this context, biochemical and biophysical resources have been studied in an attempt to enhance bone consolidation. Two of the most promising treatments are the use of low level laser therapy (LLLT) and bioactive materials. Several studies suggest that both resources are able to stimulate osteoblast proliferation and osteogenesis at the fracture site, promoting a greater deposition of bone mass. Thus, two studies were performed with the aim of evaluating the effects of LLLT (Ga-Al-As, 830nm, 100mW), with the fluences of 60J/cm² and 120J/cm² and a bioactive ceramic (Biosilicate®), used alone or associated on consolidation of bone defects induced in the tibiae of osteopenic rats. A total of 60 female Wistar rats (12 weeks-old, ± 250g) were submitted to ovariectomy (OVX) and, sixty days after the induction, a bone defect was performed in both tibiae of all animals. The animals were randomly divided into six groups (n=10). In the first study, the effects of LLLT on the bone repair of osteopenic rats were evaluated in three groups: group bone defect control without any treatment (GC); group bone defect irradiated with LLLT, at 60J/cm² (GL60); and group bone defect irradiated with LLLT, at 120J/cm² (GL120). The animals were submitted to laser irradiation at a single point on the bone defect for seven sessions, on alternated days. In the laser treated groups, at both fluences, it was possible to observe a greater amount of new bone formation compared to the control. Birefringence analysis demonstrated that irradiated bone defects presented greater deposition and improved the structural organization of collagen fibers, mainly in the group treated with the laser, at 120J/cm². COX-2, CBFA-1 and VEGF immunoreactivity was detected in a similar manner either 60J/cm2 or 120J/cm2 fluences. However, no differences were observed in the biomechanical analysis. Therefore, the LLLT, at the two fluences used, improved the bone repair in the tibia of osteopenic rats. In the second study, the effects of Biosilicate® associated with LLLT on bone repair in osteopenic rats were analyzed in four groups: group bone defect control without any treatment (GC); group bone defect filled with Biosilicate® (GB); group bone defect filled with Biosilicate®, irradiated with LLLT, at 60J/cm2 (GBL60); and group bone defect filled with Biosilicate®, irradiated with LLLT, at 120J/cm2 (GBL120). Biosilicate® was used in the form of particles with granulometry of 180-212μm and the treated animals were irradiated with laser at a single point on the bone defect for seven sessions, on alternated days. The results demonstrated that the LLLT, with fluences of 60J/cm² and 120J/cm² stimulated the expression of COX-2 in the circumjacent cells of the biomaterial, increased of the collagen deposition and the biomechanical bone properties. Morphometric analysis revealed that the animals with bone defects filled with Biosilicate® and irradiated with laser, at 120J/cm² showed a higher amount of newly formed bone compared to the other groups. Thus, the LLLT, mainly in fluency 120J/cm² in contact with Biosilicate® improved the bone repair process in osteopenic rats. These findings are fundamental in elucidating the biological mechanisms involved in the repair of fractures with difficult consolidation, especially those associated with bone metabolic disease processes, such as osteoporosis.
Estrutura sociogenética de ninhos de Euglossini (Hymenoptera: Apidae) e estrutura genética das populações urbanas de Euglossa cordata do estado de São Paulo
(Universidade Federal de São Carlos, 2010-08-26) Oi, Cíntia Akemi; Del Lama, Marco Antonio; https://lattes.cnpq.br/7198095288825585; https://lattes.cnpq.br/8735816980446029
Euglossine bees (Hymenoptera: Apidae) are important pollinators in the Neotropical region. These bees are widely studied by collecting males in attractive baits, but there are few reports from females. In this work, we studied Euglossini bees using molecular tools, collecting bees in nests and adults in flowers at different levels, individual, nest and population. In Chapter 1, we use a non-lethal strategy for obtaining DNA from antenna conducting mark-recapture experiments. We found by a chi-square test the same chance to recapture the two groups of bees (with intact antennae vs removal antennae); this result suggests that the removal did not affect the survivor of bees. The DNA extracted from the antennas was successfully used for microsatellite analysis. In Chapter 2, we determine the sociogenetic structure of nests using microsatellite loci. Genetic analysis of Euglossa cordata, Euglossa townsendi and Eufriesea violacea nests revealed that brood is usually explained by a single mating, which corroborates the literature. In chapter 3, we used mitochondrial genes to verify the genetic structure of populations of Eg. cordata. The sequencing of mitochondrial genes cyt b and COI by direct PCR product showed high variation in several positions, showing two peaks or the mismatch between forward and reverse sequence. This result suggests the occurrence of heteroplasmy, and then, we have cloned these products. The clones showed even greater intra-individual variation, suggesting the occurrence of associated numts and heteroplasmy. Due to this variation, we could not establish the genetic structure of urban populations in Eg. cordata, although there is some evidence of interpopulation differentiation for mitochondrial haplotypes. In conclusion, this work has made contributions to a better understanding of the biology of Euglossine bees; employing molecular tools, we bring new information about familial and population genetics of this group of bees.
Estudo quimiossistemático de espécies de Hortia (Rutaceae) e busca de fungicidas à Guignardia citricarpa
(Universidade Federal de São Carlos, 2010-08-26) Freitas, Samya Danielle Lima de; Silva, Maria Fátima das Graças Fernandes da; https://lattes.cnpq.br/0457632122660653; https://lattes.cnpq.br/7961603023838547
The classification of the Hortia genus, belonging to the Rutaceae, is ambiguous. Hortia, which has been placed in Cusparieae by De Candolle in 1824, in the most recent morphological classification of Engler in 1931 it belongs to Toddalieae. More recently, Silva and colleagues classified again Hortia in Cusparieae. However, the phytochemical study of the species from Hortia genus still not allow classify correctly it inside the family. Thus, the phytochemical study of Hortia described in this paper aims to contribute with the chemosystematics of the Rutaceae and with the best classification of the genus inside the family. The study of the species H. oreadica, H. brasiliana and H. superba led to the isolation and identification of 11 substances, the alkaloids N-methyl-4- methoxy-quinolin-2-one (01), integriquinolone (02), new in the genus Hortia, rutaecarpine (03), the coumarins scoparone (04) xanthotoxin (05), which were first described in the species H. superba, isopimpinellin (06), new in the genus Hortia, 5- chloro-8-methoxy-furanocoumarin (07), new in the literature, prangol (08) and heraclenol (09), and the flavonoids isosakuranetin (10) and neoponcirin (11), the latter being new in the genus Hortia. The presence of metabolites such as alkaloids, coumarins and flavonoids confirm that Hortia belongs to the Rutaceae family, even so are not clear its accurate positioning. Some of the isolated compounds were tested against the inhibition of Guignardia citricarpa following two methods of inhibition assays. One based on inhibition of G. citricarpa in vitro against growth mycelial, by the method of incorporation into the culture medium. The other based on the inhibition test to G. citricarpa in vitro on spore germination and appressorium formation by the method of germination of spores on plates of polystyrene. The first methodology only evaluated the inhibition of the formation of mycelia and it is not directly involved in the infection process of plants, already the second one evaluated the inhibition of reproductive structures of microorganisms (spores), responsible for the infection process. The average growth mycelial for all substances tested revealed the alkaloid N-methyl-4-methoxy-2-quinolin-2-one (100 μg.mL-1) as the most effective among all the substances tested. As the inhibition front of spore germination and appressorium formation, the results were quite satisfactory, the coumarin scoparone (100 μg.mL-1) showed 96% of inhibition spore germination and 99% for the formation of appressorium, the alkaloid N-methyl-4-methoxy-2-quinolin-2-one (100 μg.mL-1) with 83% and 91%, and the flavonoid isosakuranetin (100 μg.mL-1) with 71,4% and 80%, respectively. Therefore, from this study it was found that some natural products with antifungal activity revealed important sources in the discovery of new products free of toxicity and effective as a fungicide.