981 resultados para Eskander, Saad


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Objective: This study evaluated the effectiveness of proximal contacts in Class II restorations using two types of matrix bands (steel and polyester) with two different restoration techniques (incremental and with prepolymerized particles). Method and materials: Eighty-eight Class II adjacent restorations using Prodigy resin composite were performed: 44 with the incremental technique (22 with steel matrix bands, 22 with polyester matrix bands) and 44 utilizing prepolymerized resin particles (22 steel matrix, 22 polyester matrix). The restorations were clinically evaluated at baseline and at 6, 12, and 18 months. Proximal contacts obtained immediately after restoration procedure in all restorations were satisfactory. Results: No statistically significant alterations were found in 18 months of evaluation. Conclusion: Regardless of the utilized resin composite, there were no differences in the amount of proximal contact variations with respect to tested techniques and matrices.

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In order to evaluate the bean yield under different water table levels as well as the moisture and nitrate distribution in the soil profile, a field experiment was carried out at the experimental area from the College of Agronomic Sciences - UNESP, Botucatu, SP, Brazil. Beans were grown in field lysimeters and subjected to five water table depths:30; 40; 50; 60 and 70 cm. The moisture in the soil profile was gravimetrically determined through samples obtained at 10; 20; 30; 40; 50; 60 and 70cm of depth. The water table depths of 30cm and 40cm showed the highest productivities (3,228.4 kg.ha-1 and 3,422.1 kg.ha-1, respectively), showing no statistical differences between each other. The highest productivity was related to the two most elevated water table levels (30 and 40cm), which provided the highest moisture average values on basis of volume in the soil profile (33.3 e 31%) as well as the consumptive use of water (416 and 396 mm). The nitrate content during the bean cycle at the extraction depth of 60cm has been under the safe drinking limit of 10 mg.1-1 for water table depths of 30; 40; 50 and 60cm, showing the denitrification effectiveness as a way of controlling water table from nitrate pollution. The water table handling allowed the attainment of high bean productivity levels, as well as the reduction of the nitrate level.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The development of fast, inexpensive, and reliable tests to identify nontuberculous mycobacteria (NTM) is needed. Studies have indicated that the conventional identification procedures, including biochemical assays, are imprecise. This study evaluated a proposed alternative identification method in which 83 NTM isolates, previously identified by conventional biochemical testing and in-house M. avium IS1245-PCR amplification, were submitted to the following tests: thin-layer chromatography (TLC) of mycolic acids and PCR-restriction enzyme analysis of hsp65 (PRA). High-performance liquid chromatography (HPLC) analysis of mycolic acids and Southern blot analysis for M. avium IS1245 were performed on the strains that evidenced discrepancies on either of the above tests. Sixty-eight out of 83 (82%) isolates were concordantly identified by the presence of IS1245 and PRA and by TLC mycolic acid analysis. Discrepant results were found between the phenotypic and molecular tests in 12/83 (14.4%) isolates. Most of these strains were isolated from non-sterile body sites and were most probably colonizing in the host tissue. While TLC patterns suggested the presence of polymycobacterial infection in 3/83 (3.6%) cultures, this was the case in only one HPLC-tested culture and in none of those tested by PRA. The results of this study indicated that, as a phenotypic identification procedure, TLC mycolic acid determination could be considered a relatively simple and cost-effective method for routine screening of NTM isolates in mycobacteriology laboratory practice with a potential for use in developing countries. Further positive evidence was that this method demonstrated general agreement on MAC and M. simiae identification, including in the mixed cultures that predominated in the isolates of the disseminated infections in the AIDS patients under study. In view of the fact that the same treatment regimen is recommended for infections caused by these two species, TLC mycolic acid analysis may be a useful identification tool wherever molecular methods are unaffordable.

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As several structures of the central nervous system are involved in the control of hydromineral and cardiovascular balance we investigated whether the natriorhexigenic and pressor response induced by the injection of ANG II into the 3rd V could be mediated by vasopressinergic and nitrergic system. Male Holtzman rats weighing 200-250 g with cannulae implanted into the 3rd V were used. The drugs were injected in 0.5 μL over 30-60 sec. Controls were injected with a similar volume of 0.15 M NaCl. ANGII increased the water intake vs control. AVPA injected into 3rd V prior to ANGII decreased the dipsogenic effect of ANGII. L-arginine also decreased the water intake induced by ANGII. AVPA plus L-arginine inhibit the water intake induced by ANGII. 7NIT injected prior to ANGII potentiated the dipsogenic effect of ANGII. Pre-treatment with ANGII increased the sodium ingestion vs control. AVPA decreased the ANGII effect in sodium intake. L-arginine also decreased the natriorhexigenic effect of ANGII. The combination of L-arginine and AVPA inhibit the sodium intake induced by ANGII. 7NIT injected prior to ANGII potentiated the sodium intake induced by ANGII. ANGII induced an increase in Mean Arterial Pressure (MAP) vs control. AVPA and L-arginine induced a decreased in the pressor effect of ANGII. The combination of L-arginine and AVPA inhibit the pressor effect of ANGII. 7NIT injected prior to ANGII into 3rd V potentiated the pressor effect of ANGII. These data suggest that arginine vasopressin V 1 receptors and Nitric Oxide (NO) within the circumventricular structures may be involved in sodium intake and pressor response induced by the activation of ANGII receptors within the circumventricular neurons. These studies revealed the involvement of sodium appetite by utilizing the angiotensinergic, vasopressinergic and nitrergic system in the central regulation of blood pressure. © 2006 Asian Network for Scientific Information.

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Purpose: To analyze, in vitro, the effects of acetylsalicylic acid (aspirin) and acetic acid solutions on VX2 carcinoma cells in suspension and to examine the correlation between these effects and neoplastic cell death. Methods: The VX2 tumor cells (107 cells/ml) were incubated in solutions containing differing concentrations (2.5% and 5%) of either acetylsalicylic acid or acetic acid, or in saline solution (controls). Every five minutes, cell viability was tested (using the trypan blue test) and analyzed under light microscopy. Results: Tumor cell viability (in %) decreased progressively and, by 30 minutes, neoplastic cell death had occurred in all solutions. Conclusion: Based on this experimental model and the methodology employed, we conclude that these solutions cause neoplastic cell death in vitro.

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The present study investigated the central role of angiotensin II and nitric oxide on arterial blood pressure (MAP) in rats. Losartan and PD123349 AT 1 and AT 2 (selective no peptides antagonists angiotensin receptors), as well as FK 409 (a nitric oxide donor), N W-nitro-L-arginine methyl ester (L-NAME) a constituve nitric oxide synthase inhibitor endothelial (eNOSI) and 7-nitroindazol (7NI) a specific neuronal nitric oxide synthase inhibitor (nNOSI) were used. Holtzman strain, (Rattus norvergicus) weighting 200-250 g were anesthetized with zoletil 50 mg kg -1 (tiletamine chloridrate 125 mg and zolazepan chloridrate 125 mg) into quadriceps muscle anda stainless steel cannula was stereotaxically implanted into their Lateral Ventricle (LV). Controls were injected with a 0.5 μl volume of 0.15 M NaCl. Angiotensin II injected into LV increased MAP (19±3 vs. control 3±1 mm Hg), which is potentiated by prior injection of L-NAME in the same site 26±2 mm Hg. 7NI injected prior to ANG II into LV also potentiated the pressor effect of ANG II but with a higher intensity than L-NAME 32±3 mm Hg. FK 409 inhibited the pressor effect of ANG II (6±1 mm Hg). Losartan injected into LV before ANG II influences the pressor effect of ANG II (8±1 mm Hg). The PD 123319 decreased the pressor effects of ANG II (16±1 mm Hg). Losartan injected simultaneously with FK 409 blocked the pressor effect of ANG II (3±1 mm Hg). L-NAME produced an increase in the pressor effect of ANG II, may be due to local vasoconstriction and all at once by neuronal NOS inhibition but the main effect is of the 7-NIT an specific nNOS inhibitor. The AT 1 antagonist receptors improve basal nitric oxide (NO) production and release. These data suggest the involvement of constitutive and neuronal NOS in the control of arterial blood pressure induced by ANG II centrally, evolving AT 1 receptor-mediated vasoconstriction and AT 2 receptor-mediated vasodilatation. These results were confirmed by the experiment using FK 409. © 2006 Asian Network for Scientific Information.

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The aim of this study was to examine the role of nifedipine and Nitric Oxide (NO) on salivary flow and compounds (salivary amylase, saliva total proteins, saliva calcium, sodium and potassium). Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg kg -1 (tiletamine chloridrate 125.0 mg and zolazepan chloridrate 125.0 mg) into quadriceps muscle and stainless steel cannulas were implanted into their lateral ventricle of the brain (LV). Animals in divided group were injected with nifedipine (50 μg μL -1) alone and in combination with 7-nitroindazol (7-NIT) (40 μg μL -1), neuronal NO Sinthase Inhibitor (nNOSI) and Sodium Nitroprussate (SNP) (30 μg μL -1) NO donor agent. As a secretory stimuli, pilocarpine dissolved in isotonic was administered intraperitoneally (ip) at a dosage of 10 mg kg -1 body weight. Saliva was collected for 7 min with four cotton balls weighing approximately 20 mg each, two of which were placed on either side of the oral cavity, with the other two placed under the tongue. Nifedipine treatment induced a reduction in saliva secretion rate and concentration of amylase, total protein and calcium without changes in sodium and potassium concentration in comparison with controls. Co-treatment of animals with nifedipine and SNP retained flow rate and concentration of amylase, total protein and calcium in normal levels. Co-treatment of animals with nifedipine and 7-NIT potentiated the effect of nifedipine on the reduction of saliva secretion and concentrations of amylase, total protein and calcium. Nifedipine (dihydroperidine) calcium-channel blocker widely in use is associated with salivary dysfunction acting in the central nervous system structures. NO might be the mechanism for protective effect against the nifedipine-induce salivary dysfunction, acting in the CNS. © 2006 Asian Network for Scientific Information.

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The median preoptic nucleus (MnPO) is one of most important site of the lamina terminalis implicated in the regulation of hydro electrolytic and cardiovascular balance. The purpose of this study was to determine the effect of L-Type calcium channel antagonist, nifedipine, on the increase of median arterial blood pressure (MAP) induce by angiotensin II (ANG II) injected into the MnPO. The influence of nitric oxide (NO) on nifedipine antipressor action has also been studied by utilizing N W-nitro-L-arginine methyl ester (L-NAME) (40 μg 0.2 μL -1) a NO synthase inhibitor (NOSI), 7-nitroindazole (7-NIT) (40 μg 0.2 μL -1), a specific neuronal NO synthase inhibitor (nNOSI) and sodium nitroprusside (SNP) (20 μg 0.2 μL -1) a NO donor agent. We have also investigated the central role of losartan and PD123349 (20 nmol 0.2 μL -1), AT 1 and AT 2, respectively (selective non peptide ANG II receptor antagonists), in the pressor effect of ANG II (25 pmol 0.2 μL -1) injected into the MnPO. Male Wistar rats weighting 200-250 g, with cannulae implanted into the MnPO were utilized. Losartan injected into the MnPO, prior to ANG II, blocked the pressor effect of ANGII. PD 123319 only decreased the pressor effect of ANG II. Rats pre-treated with either 50 μg 0.2 μL -1 or 100 μg 0.2 μL -1 of nifedipine, followed by 25 pmol 0.2 μL -1 of ANG II, decreased ANG II-pressor effect. L-NAME potentiated the pressor effect of ANG II. 7-NIT injected prior to ANG II into the MnPO also potentiated the pressor effect of ANGII but with less intensity than that of L-NAME. SNP injected prior to ANG II blocked the pressor effect of ANG II. The potentiation action of L-NAME and 7-NIT on ANG II-pressor effect was blocked by prior injection of nifedipine. The results described in this study provide evidence that calcium channels play important roles in central ANG II-induced pressor effect. The structures containing NO in the brain, such as MnPO, include both endothelial and neuronal cells, which might be responsible for the influence of nifedipine on the pressor effect of ANG II. These data have shown the functional relationship between L-Type calcium channel and a free radical gas NO in the MnPO, on the control of ANG II-induced pressor effect acting in AT 1 and AT 2 receptors.

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Purpose: This article reports preliminary clinical results of the Speed Master system, a method for immediate loading of implants for the treatment of mandibular edentulism. Materials and Methods: Fifteen patients with edentulous mandibles were consecutively included in the study. Each received 4 implants between the mental foramina placed using the system's surgical guides. Permanent fixed prostheses fabricated over premanufactured titanium bars were attached to the implants on the day of implant placement. The patients were followed for 15 to 27 months (mean, 19 months). Peri-implant tissues were periodically evaluated. Marginal bone loss was monitored with periapical radiographs using a computerized technique. Satisfaction was assessed by means of a questionnaire. Results: The overall implant and prosthetic survival rates were 100%. At the time of the final follow-up visit, mean marginal bone loss was 1.11 mm, and bleeding on probing was not observed. Only 6.7% of the patients reported any discomfort during treatment, and all patients would recommend the procedure to others. Discussion: The immediate loading of implants placed in the edentulous mandible with the Speed Master surgical and prosthetic protocol reduces treatment time and number of surgical procedures in comparison to classic delayed loading protocols. Conclusion: The rehabilitation of the mandible with an immediately delivered occlusally loaded hybrid prosthesis supported by 4 implants does not appear to jeopardize the success of the osseointegration and represents a viable treatment option.

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The authors report a case of intestinal involvement of paracoccidioidomycosis and discuss the symptoms, diagnosis and treatment in a patient thought to have colonic cancer. The differential diagnosis should be considered with cancer.

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Running water is one of the most important of all the physical processes which fashion the landscape, allowing gravity to operate along the valley floors. Besides this, the streams show a fast adjustment to the crustal deformations, even to the most gentle ones. This geologic behavior turns them a potential tool for neotectonic studies, specially the analysis of morphotnetric parameters associated with hydraulic gradient and discharge, this second factor being directly proportional to the extension of the streams. Both elements, gradient and stream length, can be combined in the SL index. The purpose of this paper is to show the RDE index application in the neotectonics analysis of the Rio do Peixe hydrographic basin and to compare the obtained values with the geologic basement incised by the streams. This basement encompasses Cretaceous sedimentary rocks of post-Serra Oeral Formation magmatism (Caiuá and Bauru groups) and Quaternary deposits that include chiefly recent alluvial plains and some Pleistocene terrace deposits. In the final part of this paper, an attempt is made in order to correlate the RDE results and the neotectonic framework admitted to this portion of the São Paulo State territory, as well as with field geologic, seismologic and paleoseismologic known elements. The results indicate the presence of two groups of anomalies: The first set corresponds to the Marília-Exaporã Plateau border, and the second one, located in the central portion of the hydrographic basin, is correlated to the Presidente Prudente seimogenic zone.

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The Rio Claro Formation mainly occurs in the county of Rio Claro (SP) lying unconformably on Paleozoic and Mesozoic rocks. Its thickness is 30-40 m. It shows fine to coarse, regular to poor sorted, Triable sandstones and conglomerates with quartzite and quartz clasts in the base. Thin layers of mudstone occur interbeded. Stratigraphic maps had been elaborated in recent analyses allowing to improve the knowledge about the formation. The biggest thicknesses occur on the east part of the studied area. The coarse/fine clastic ratio map demonstrates that fine sediments are concentrated in the east side, and suggests the existence of barriers which conditioned perennial water body (or bodies) where decantation took place (east, south and southeast sides). The structural contour map of the Rio Claro Formation base indicates a NW/SE trough which was the main depositional axis. The integrated analysis demonstrates that the formation is formed by lacustrine, fluvial and debris flows deposits whose source area was located on NW side, with coalescent alluvial fans from where braided to psamitic meandering fluvial channels came. The location of the source area suggests no link with the Corumbataf River paleo-terraces.

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The objective of this study is the geometric characterization of a fluvial system, exemplified by the Itaquaquecetuba Formation. The studied area is a quarry located in Itaquaquecetuba, distant 35 km from the city of São Paulo, which is inserted in the context of São Paulo Basin. Fluvial systems are important hydrocarbon reservoirs, and this study may contribute with an analogue for ancient reservoirs. It was elaborated ten facies logs along a distance of 200 m (log spacing of 20 m), with a vertical column (thickness) of 40 m for each log. Eight facies cycles, and its lateral chrono-correlation allowed to map the potential reservoir and non-reservoir facies within each cycle. Regarding the depositional model for the studied section, it is assumed an alluvial fan system composed of meandering and ribbon-type fluvial channels.

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The use of acid etchants to produce surface demineralization and collagen network exposure, allowing adhesive monomers interdiffusion and consequently the formation of a hybrid layer, has been considered the most efficient mechanism of dentin bonding. The aim of this study was to compare the tensile bond strength to dentin of three adhesive systems, two self-etching ones (Clearfil SE Bond - CSEB and One Up Bond F - OUBF) and one total-etching one (Single Bond - SB), under three dentinal substrate conditions (wet, dry and re-wet). Ninety human, freshly extracted third molars were sectioned at the occlusal surface to remove enamel and to form a flat dentin wall. The specimens were restored with composite resin (Filtek Z250) and submitted to tensile bond strength testing (TBS) in an MTS 810. The data were submitted to two-way ANOVA and Tukey's test (p = 0.05). Wet dentin presented the highest TBS values for SB and CSEB. Dry dentin and re-wet produced significantly lower TBS values when using SB. OUBF was not affected by the different conditions of the dentin substrate, producing similar TBS values regardless of the surface pretreatments.