PZT FOR MEASURING ENERGY FLUENCE RATE of X-RAY USED IN SUPERFICIAL CANCER THERAPY

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photopyroelectric response of PTCa/PEEK composite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Polymorphisms of CYP17A1, CYP19, and androgen in Brazilian women with uterine leiomyomas

Background: Uterine leiomyomas are common, benign, smooth muscle tumors representing a significant public health problem. The aim of this study was to investigate CYP17A1, CYP19, and androgen (AR) polymorphisms, their relative risks for uterine leiomyomas and possible associations with clinical parameters.Methods: Uterine leiomyoma tissues and blood samples were obtained from 87 patients, as were peripheral blood samples from 68 control women. Clinical data were recorded in both groups. The CYP17A1 (rs743572) polymorphism was analyzed by PCR-RFLP, and the CYP19 [TTTA](n) repeat and AR [CAG](n) repeat were analyzed using PCR-based GeneScan analysis. AR loss of heterozygosity (LOH) and microsatellite instability were also evaluated, while samples exhibiting LOH were analyzed for X inactivation.Results: Clinical parameters related to disease development did not differ between cases and controls. CYP17A1 *A2/*A2 genotype was prevalent in non-white women. CYP17A1, CYP19, and AR genotypes and alleles did not differ between groups. However, alleles presenting [TTTA](7) repeats in intron 4 of CYP19 were more frequent in the control group (p=0.0550). Shorter and longer [CAG]n repeat alleles of AR were exclusive to the leiomyoma group. The LOH assay showed allele losses at AR locus in four informative tumors and X chromosome inactivation analysis revealed that these tumors retained the active allele.Conclusions: The overall lack of association between uterine leiomyomas with polymorphisms involved in steroidogenesis or steroid metabolism is consistent with the hypothesis that these polymorphisms do not substantially contribute to the development of these tumors.

Evaluation of Centrifuged Bone Marrow on Bone Regeneration Around Implants in Rabbit Tibia

Objective: To evaluate the bone regeneration of cervical defects produced around titanium implants filled with blood clot and filled with centrifuged bone marrow (CBM) by means of histomorphometric analysis.Materials and Methods: Twelve rabbits received 2 titanium implants in each right tibia, with the upper cortical prepared with a 5-mm drill and the lower cortex with a 3-mm-diameter drill. Euthanasia was performed to allow analysis at 7, 21, and 60 days after operation. The samples were embedded in light curing resin, cut and stained with alizarin red and Stevenel blue for a histomorphometric analysis of the bone-to-implant contact (BIC) and the bone area around implant (BA). The values obtained were statistically analyzed using the nonparametric Kruskal-Wallis test (P = 0.05).Results: At 60 days postoperation, the groups had their cervical defects completely filled by neo-formed bone tissue. There was no statistically significant difference between the groups regarding BIC and BA during the analyzed periods.Conclusion: There was no difference in the bone repair of periimplant cervical defects with or without the use of CBM. (Implant Dent 2012;21:481-485)

Large Unicystic Ameloblastoma of the Mandible: Management Guided by Biological Behavior

Ameloblastoma is a true neoplasm of odontogenic epithelial origin. It is a slow-growing benign tumor of the jaw, and patients usually present late after the tumor achieves considerable size to cause facial disfigurement. Diagnosis mainly from tissue biopsy and radiograph findings does assist in differentiating between types of ameloblastoma. Unicystic ameloblastoma is a tumor with a strong propensity for recurrence. There is a difference in biological behavior between mural unicystic ameloblastoma and those which are simply cystic or show intraluminal proliferation. The challenges in the management of this tumor are to provide complete excision in addition to reconstructing the bony defect, to provide the patient with reasonable cosmetic and functional outcome. The authors report a case of a mural unicystic ameloblastoma in a 23-year-old man who was treated by partial resection of the mandible. Biomedical prototypes were used because they provide acceptable precision and are useful for treatment planning.

A scanning electron microscopy study of diseased root surfaces conditioned with EDTA gel plus Cetavlon after scaling and root planing

In the present investigation, a scanning electron microscopy analysis was performed to evaluate the effects of the topical application of ethylenediaminetetraacetic acid (EDTA) gel associated with Cetavlon (EDTAC) in removing the smear layer and exposing collagen fibers following root surface instrumentation. Twenty-eight teeth from adult humans, single rooted and scheduled for extraction due to periodontal reasons, were selected. Each tooth was submitted to manual (scaling and root planing) instrumentation alone or combined with ultrasonic instruments, with or without etching using a 24% EDTAC gel. Following extraction, specimens were processed and examined under a scanning electron microscope. A comparative morphological semi-quantitative analysis was performed; the intensity of the smear layer and the decalcification of cementum and dentinal surfaces were graded in 12 sets using an arbitrary scale ranging from 1 (area covered by a smear layer) to 4 (no smear layer). Root debridement with hand instruments alone or combined with ultrasonic instruments resulted in a similar smear layer covering the root surfaces. The smear layer was successfully removed from the surfaces treated with EDTAC, which exhibited numerous exposed dentinal tubules and collagen fibers. This study supports the hypothesis that manual instrumentation alone or instrumentation combined with ultrasonic instrumentation is unable to remove the smear layer, whereas the subsequent topical application of EDTAC gel effectively removes the smear layer, uncovers dentinal openings and exposes collagen fibers.

Differential morphofunctional characteristics and gene expression in fast and slow muscle of rats with monocrotaline-induced heart failure

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Neutralization of snake venom phospholipase A(2) toxins by aqueous extract of Casearia sylvestris (Flacourtiaceae) in mouse neuromuscular preparation

Aqueous extract of Casearia sylvestris (Flacourtiaceae) has been shown to inhibit enzymatic and biological properties of some Bothrops and Crotalus venoms and their purified phospholipase A(2) (PLA(2)) toxins. In this work we evaluated the influence of C sylvestris aqueous extract upon neuromuscular blocking and muscle damaging activities of some PLA(2)S (crotoxin from C. durissus terrificus, bothropstoxin-I from B.jararacussu, piratoxin-I from B. pirajai and myotoxin-II from B. moojeni) in mouse phrenic-diaphragm preparations. Crotoxin (0.5 mu M) and all other PLA2 toxins (1.0 mu M) induced irreversible and time-dependent blockade of twitches. Except for crotoxin, all PLA2 toxins induced significant muscle damage indices, assessed by microscopic analysis. Preincubation of bothropstoxin-I, piratoxin-I or myotoxin-II with C. sylvestris extract (1:5 (w/w), 30 min, 37 degrees C significantly prevented the neuromuscular blockade of preparations exposed to the mixtures for 90 min; the extent of protection ranged from 93% to 97%. The vegetal extract also neutralized the muscle damage (protection of 80-95%). Higher concentration of the C. sylvestris extract (1: 10, w/w) was necessary to neutralize by 90% the neuromuscular blockade induced by crotoxin. These findings expanded the spectrum of C. sylvestris antivenom activities, evidencing that it may be a good source of potentially useful PLA2 inhibitors. (c) 2007 Elsevier B.V.. All rights reserved.

Nandrolone Stimulates Myod Expression During Muscle Regeneration in the Condition of Myonecrosis Induced by Bothrops jararacussu Venom Poisoning

Myonecrosis with permanent loss of muscle mass is a relevant local toxic effect following envenomation with Bothrops jararacussu snake venom. Regeneration of adult skeletal muscle involves the activation of satellite cells, a process regulated by myogenic regulatory factors (MRF). MyoD is an MRF involved in both proliferation and differentiation of satellite cells. Androgens are modulators of skeletal muscle, known to increase muscle mass and strength. This study examined the hypothesis that anabolic androgens improve the muscle regeneration process in mice following envenomation by Bothrops jararacussu snake venom. Myonecrosis was induced by venom injection (30 g/50 l in physiological solution) over the extensor digitorum longus (EDL) muscles of mice. Nandrolone (ND) (6 mg/kg, sc) was administered after 12 h, 7 d, and 14 d following venom injection. The histological changes in EDL muscle at 1, 3, 7, and 21 d after muscle injury were analyzed by light microscopy. Cross-sectional areas of fibers were measured. MyoD was evaluated by immunofluorescence technique. Histological examination revealed the presence of a regeneration process in ND-treated animals, characterized by the appearance of some myotubes at 3 d, and numerous myotubes at 7 d from venom injection. Nandrolone treatment reduced the frequency of small fibers at 7 and 21 d after venom administration, and increased the frequency of large fibers at 7 d postinjury. Nandrolone also significantly augmented the expression of MyoD-positive cells at 7 and 21 d after envenomation. These results suggest that ND accelerates muscle regeneration and indicate the involvement of MyoD in this process.

The 20S proteasome alpha(5) subunit of Arabidopsis thaliana carries an RNase activity and interacts in planta with the Lettuce mosaic potyvirus HcPro protein

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

Dynamics of glyphosate-induced conformational changes of Mycobacterium tuberculosis 5-enolpyruvylshikimate-3-phosphate synthase (EC 2.5.1.19) determined by hydrogen-deuterium exchange and electrospray mass spectrometry

The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyzes the reaction between shikimate 3-phosphate and phosphoenolpyruvate to form 5-enolpyruvylshikimate 3-phosphate, an intermediate in the shikimate pathway, which leads to the biosynthesis of aromatic amino acids. EPSPS exists in an open conformation in the absence of substrates and/or inhibitors and in a closed conformation when bound to the substrate and/or inhibitor. In the present report, the H/D exchange properties of EPSPS from Mycobacterium tuberculosis (Mt) were investigated for both enzyme conformations using ESI mass spectrometry and circular dichroism (CD). When the conformational changes identified by H/D exchanges were mapped on the 3-D structure, it was observed that the apoenzyme underwent extensive conformational changes due to glyphosate complexation, characterized by an increase in the content of alpha-helices from 40% to 57%, while the beta-sheet content decreased from 30% to 23%. These results indicate that the enzyme underwent a series of rearrangements of its secondary structure that were accompanied by a large decrease in solvent access to many different regions of the protein. This was attributed to the compaction of 71% of alpha-helices and 57% of beta-sheets as a consequence of glyphosate binding to the enzyme. Apparently, MtEPSPS undergoes a series of inhibitor-induced conformational changes, which seem to have caused synergistic effects in preventing solvent access to the core of molecule, especially in the cleft region. This may be part of the mechanism of inhibition of the enzyme, which is required to prevent the hydration of the substrate binding site and also to induce the cleft closure to avoid entrance of the substrates.

Phosphate closes the solution structure of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from Mycobacterium tuberculosis

The 5-enolpyruvylshikimate-3-phosphate synthase catalyses the sixth step of the shikimate pathway that is responsible for synthesizing aromatic compounds and is absent in mammals, which makes it a potential target for drugs development against microbial diseases. Here, we report the phosphate binding effects at the structure of the 5-enolpyruvyl shikimate-3-phosphate synthase from Mycobacterium tuberculosis. This enzyme is formed by two similar domains that close on each other induced by ligand binding, showing the occurrence of a large conformation change. We have monitored the phosphate binding effects using analytical ultracentrifugation, small angle X-ray scattering and, circular dichroism techniques. The low resolution results showed that the enzyme in the presence of phosphate clearly presented a more compact structure. Thermal-induced unfolding experiments followed by circular dichroism suggested that phosphate rigidified the enzyme. Summarizing, these data suggested that the phosphate itself is able to induce conformational change resulting in the closure movement in the M. tuberculosis 5-enolpyruvylshikimate-3-phosphate synthase. (c) 2006 Elsevier B.V. All rights reserved.

The reproductive hiology and cycle of Rioraja agassizi (Muller and Henle, 1841) (Chondrichthyes : Rajidae) in southeastern Brazil, SW Atlantic Ocean

Specimens of Rioraja agassizi were collected Lit Guaruja pier, São Paulo State, Brazil, from March 2005 to March 2006. A total of: 275 males were captured. Based on the analysis of the clasper length, gonad weight, clasper gland length, alar thorns and lobule diameter, the size-at-maturity was estimated to be 32 cm. There were 1049 females in the record. Size-at-maturity was calculated in 40 cm. Sexual resting females were observed. Gonadosomatic and hepatosomatic indexes varied significantly in both sexes throughout the year. However, ovulation, egg-laying and presence of sperm in the seminal vesicle were observed all year round. For this reason, an annual cycle with at least one peak in the sexual activity is proposed for this species.

Population structure, distribution and abundance patterns of the patagonian smoothhound Musmlus schmitti springer, 1939 (Chondrichthyes,Elasmobranchii, Triakidae) in the rio de la plata and inner continental shelf, SW Atlantic ocean (34 degrees-30'-39 degrees-30's)

A total number of 4824 Mustelus schmitti was sampled. Females ranged from 25 to 93 em in spring and from 28 to 90 cm in summer. Males ranged from 34 to 82 and from 28 to 77 cm, respectively. Length composition of the population showed significant differences between spring and summer being females larger than males. Total length distribution did not show significant differences between cruises. Males density varied significantly between cruises while for the females no significant variation was observed. In the spring cruise, both sexes occurred at depths lower than 50 in. Females occurred in the whole area with adult occurrence only above 35 degrees 30'S. Mature males occurred throughout the area, immature males occurring in two trawls in Samborombon Bay. The summer cruise showed a discontinuous distribution of the species along the study area resulting in spatial segregation in two groups with immature females predominating in both of them.