152 resultados para Universal generating function


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OBJECTIVE To investigate the effects of chronic ethanol consumption and diabetes on nitric oxide (NO)-mediated relaxation of cavernosal smooth muscle (CSM). MATERIAL AND METHODS Male Wistar rats were divided into four groups: control, isocaloric, diabetic and ethanol-diabetic. The CSMs were mounted in organ chambers for measurement of isometric tension. Contraction of the strips was induced by electrical field stimulation (EFS, 1-32 Hz) and phenylephrine. We also evaluated the effect of ethanol consumption on the relaxation induced by acetylcholine (ACh; 0.01-1000 mu mol/L), sodium nitroprusside (SNP, 0.01-1000 mu mol/L) or EFS (1-32 Hz) in strips pre-contracted with phenylephrine (10 mu mol/L). Immunoexpression of endothelial NO synthase (eNOS) and inducible NOS (iNOS) was also accessed. RESULTS The endothelium-dependent relaxation induced by ACh was decreased in CSM from ethanol-diabetic rats when compared with the controls, with a mean (sem) of 21 (4) vs 37 (2)%. Similarly, the potency and maximal responses induced by SNP were reduced in the ethanol-diabetic [3.97 (0.38) and 85 (1)%, respectively] and diabetic groups [3.78 (0.56) and 81 (2)%, respectively] when compared with the controls [5.3 (0.22) and 90 (3)%, respectively] and isocaloric [5.3 (0.19) and 92 (1)%, respectively] groups. Noradrenergic nerve-mediated contractions of CSM in response to EFS were increased in rats from ethanol-diabetic and diabetic groups when compared with the control and isocaloric groups. Conversely, there were no differences in EFS-induced relaxation among the groups. The immunostaining assays showed overexpression of eNOS and iNOS in the CSM from diabetic and ethanol-diabetic rats when compared with the control and isocaloric rats. CONCLUSION There was an impairment of relaxation of CSM from ethanol-diabetic and diabetic rats that involved a decrease in the NO-cyclic guanosine monophosphate signalling pathway by endothelium-dependent mechanisms accompanied by a change in the CSM contractile sensitivity.

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Background/Aims: Renal risks of nicotine exposure associated with hypercholesterolemia are still unknown. Methods: Thus, hypercholesterolemic rats (HC) and their control (C) were evaluated by inulin clearance (InCl) measured at baseline and during nicotine infusion (100 mu g/kg b.w.). Five groups were studied: (i) C; (ii) DEN (C submitted to a renal denervation); (iii) C + L-arginine (0.25% in drinking water); (iv) HC, and (v) HC + L-arginine (0.25% in drinking water). Furthermore, C and HC had their renal blood flow (RBF) measured and they have also been chronically treated with nicotine (12.5 mu g/ml in drinking water) to assess InCl on the 8th day. Results: Nicotine increased blood pressure in C, DEN and HC and reduced InCl only in C. L-Arginine treatment blunted nicotine effects on blood pressure and increased InCl only in C. Moreover, nicotine did not change RBF in C but elicited in HC, whereas renal vascular resistance was increased in C and unchanged in HC. Indeed, chronic nicotine exposure has also reduced InCl in C. Conclusion: Nicotine acted on the adrenergic system and nitric oxide counteracted this action in C, but the same may not be applied to HC. An impairment in renal autoregulation may explain why InCl was unchanged in HC. Copyright (C) 2009 S. Karger AG, Basel

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This study conducts a cost-effectiveness analysis of a childhood universal varicella vaccination program in Brazil. An age and time-dependent dynamic model was developed to estimate the incidence of varicella for 30 years. Assuming a single-dose schedule; vaccine efficacy of 85% and coverage of 80%, the program could prevent 74,422,058 cases and 2905 deaths. It would cost R$ 3,178,396,110 and save R$ 660,076,410 to the society and R$ 365,602,305 to the healthcare system. The program is cost-effective (R$ 14,749 and R$ 16,582 per life-year saved under the societal and the healthcare system`s perspective, respectively). The program`s cost-effectiveness is highly sensitive to the vaccine price and number of doses. (C) 2008 Elsevier Ltd. All rights reserved.

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Maternal recognition of pregnancy in the cow requires successful signaling by the conceptus to block luteolysis. Conceptus Growth and function depend on an optimal uterine environment, regulated by luteal progesterone. The objective of this study was to test strategies to optimize luteal function, as well as prevent a dominant follicle from initiating luteolysis. Nelore (Bos taurus indicus) beef cows (n = 40) were submitted to a GnRH/PGF(2 alpha)/GnRH protocol. Cows that ovulated from a dominant ovarian follicle (ovulation = Day 0) were allocated to receive: no additional treatment (Gc; n = 7); 3000 IU of hCG on Day 5 (G(hCG); n = 5); 5 mg of estradiol-17 beta on Day 12 (G(E2); n = 6); or 3000 IU of hCG on Day 5 and 5 mg of estradiol-17 beta on Day 12 (G(hCG/E2); n = 5). Ultrasonographic imaging of the ovaries, assessment of plasma progesterone concentration, and detection of estrus were done daily from Day 5 to the day of subsequent ovulation. Treatment with hCG induced an accessory CL, increased CL volume, and plasma progesterone concentration throughout the luteal phase (P < 0.01). Estradiol-17 beta induced atresia and recruitment of a new wave of follicular growth; it eliminated a potentially estrogen-active, growing ovarian follicle within the critical period for maternal recognition of pregnancy, but it also hastened luteolysis (Days 16 or 17 vs. Days 18 or 19 in non-treated cows). In conclusion, the approaches tested enhanced luteal function (hCG) and altered ovarian follicular dynamics (estradiol-17 beta), but were unable to extend the life-span of the CL in Nelore cows. (c) 2008 Elsevier Inc. All rights reserved.

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The hepatic effects of the anesthetic association zolazepam/tiletamine were investigated in dogs by analyzing the serum concentration of hepatic enzymes. Ten healthy dogs were divided into two groups of five, group I (GI) and group II (GII). The animals of GI received a single dose of 6,6 mg/kg of zolazepam/tiletamine, by intramuscular (IM) injection. GII dogs received 6,6 mg/kg of zolazepam/tiletamine by the IM route; after a period of 50 - 80 minutes the animals received two additional doses (3,3 mg/kg) by intravenous administration[SAH1]. The hepatic function were analyzed by monitoring the serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl-transferase (GGT). Four blood samples were collected in different moments during the analyses: M0, before the first application of the drug; and M1 to M4. M1 through M3 was collected with intervals of 20 minutes before M0, while M4 was obtained 24 hours after M1. The normality of the obtained results was analyzed by Kolmogorov-Smirnov Test; while the Tukey`s test compared the means, using a level of significance of 5% for both statistical analyses. The mean values of all enzymes evaluated were within normal limits for both experimental groups, without any significant statistical alteration being observed between and within these groups. These results demonstrated that the association of zolazepam/tiletamine at the dosage of 6.6 mg/kg, followed by two applications additional of 3.3 mg/kg resulted in elevation of the evaluated hepatic enzymes without exceeding the physiologic values. Additionally, a single application of 6.6 mg/kg of zolazepam/tiletamine by the intramuscular route resulted in lower values when compared to three applications.

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Objective. To investigate whether poor response to controlled ovarian stimulation (COS) is due to a qualitative decline in ovarian function. Methods. This retrospective cohort study included 436 patients younger than 35-years old, undergoing COS for intracytoplasmic sperm injection (ICSI). Patients with four or fewer MII oocytes after COS (poor-responder group, PR, n = 52) were age-matched with normoresponder patients (NR, n = 364). Results. Although similar duration of stimulation (10.5 +/- 0.4 and 9.3 +/- 0.8 days; p = 0.1358), increased doses of gonadotrophins (2510 +/- 865 and 2253 +/- 572 IU; p = 0.0061) were used in the PR. The results show a increased chance of cycle ending of PR (PR: 26.9% and NR: 3.1%; p < 0.0001). Although the lower total number of oocytes retrieved (2.4 +/- 1.4 and 16.2 +/- 9.3; p < 0.0001), equal rate of fertilization (70.2% and 72.0%, p = 0.1190) and high quality embryos were obtained (50.0% and 45.2%; p = 0.4895), resulting in similar implantation (14.5% and 19.7%; p = 0.2246) and abortion (10.0% and 15.4%; p = 1.00) rates, respectively. A trend towards increased pregnancy rate per embryo transfer in NR group was noted (PR: 26.3% and NR: 42.2%; p = 0.0818). Conclusions. Low ovarian response could be associated mainly with a quantitative rather than a qualitative decline in ovarian function. Therefore, even if the ovarian response to stimulation is low, patients aged <= 35 years should process to oocyte retrieval.

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Introduction: The aim of this study was to assess the occurrence of apical root transportation after the use of Pro Taper Universal rotary files sizes 3 (F3) and 4 (F4). Methods: Instruments were worked to the apex of the original canal, always by the same operator. Digital subtraction radiography images were produced in buccolingual and mesiodistal projections. A total of 25 radiographs were taken from root canals of human maxillary first molars with curvatures varying from 23-31 degrees. Quantitative data were analyzed by intraclass correlation coefficient and Wilcoxon nonparametric test (P = .05). Results: Buccolingual images revealed a significantly higher degree of apical transportation associated with F4 instruments when compared with F3 instruments in relation to the original canal (Wilcoxon test, P = .007). No significant difference was observed in mesiodistal images (P = .492). Conclusions: F3 instruments should be used with care in curved canals, and F4 instruments should be avoided in apical third preparation of curved canals. (J Endod 2010;36:1052-1055)

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Objectives. To assess the elastic modulus (EM), volumetric shrinkage (VS), and polymerization shrinkage stress (PSS) of experimental highly filled nanohybrid composites as a function of matrix composition, filler distribution, and density. Methods. One regular viscosity nanohybrid composite (Grandio, VOCO, Germany) and one flowable nanohybrid composite (Grandio Flow, VOCO) were tested as references along with six highly filled experimental nanohybrid composites (four Bis-GMA-based, one UDMA-based, and one Ormocer (R) -based). The experimental composites varied in filler size and density. EM values were obtained from the ""three-point bending"" load-displacement curve. VS was calculated with Archimedes` buoyancy principle. PSS was determined in 1-mm thick specimens placed between two (poly) methyl methacrylate rods (empty set = 6 mm) attached to an universal testing machine. Data were analyzed using oneway ANOVA, Tukey`s test (alpha = 0.05), and linear regression analyses. Results. The flowable composite exhibited the highest VS and PSS but lowest EM. The PSS was significantly lower with Ormocer. The EM was significantly higher among experimental composites with highest filler levels. No significant differences were found between all other experimental composites regarding VS and PSS. Filler density and size did not influence EM, VS, or PSS. Significance. Neither the filler configuration nor matrix composition in the investigated materials significantly influenced composite shrinkage and mechanical properties. The highest filled experimental composite seemed to increase EM by keeping VS and PSS low; however, matrix composition seemed to be the determinant factor for shrinkage and stress development. The Ormocer, with reduced PSS, deserves further investigation. Filler size and density did not influence the tested parameters. (C) 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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Objectives. Evaluate the effect of testing system compliance on polymerization stress and stress distribution of composites. Methods. Composites tested were Filtek Z250 (FZ), Herculite (HL), Tetric Ceram (TC), Helio Fill-AP (HF) and Heliomolar (HM). Stress was determined in 1-mm thick specimens, inserted between two rods of either poly(methyl methacrylate), PMMA, or glass. Experimental nominal stress (sigma(exp)) was calculated by dividing the maximum force recorded 5 min after photoactivation by the cross-sectional area of the rod. Composites` elastic modulus (E) was obtained by three-point bending. Data were submitted to one-way ANOVA/Tukey`s test (alpha = 0.05). Stress distribution on longitudinal (sigma(y)) and transverse (sigma(x)) axes of models representing the composites with the highest and lowest E (FZ and HM, respectively) were evaluated by finite element analysis (FEA). Results. sigma(exp) ranged from 5.5 to 8.8 MPa in glass and from 2.6 to 3.4 MPa in PMMA. Composite ranking was not identical in both substrates, since FZ showed or sigma(exp) statistically higher than HM in glass, while in PMMA FZ showed values similar to the other composites. A strong correlation was found between stress reduction (%) from glass to PMMA and composite`s E (r(2) = 0.946). FEA revealed that system compliance was influenced by the composite (FZ led to higher compliance than HM). sigma(x) distribution was similar in both substrates, while cry distribution showed larger areas of compressive stresses in specimens built on PMMA. Significance. sigma(exp) determined in PMMA was 53-68% lower than in glass. Composite ranking varied slightly due to differences in substrates` longitudinal and transverse deformation. (c) 2007 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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Objective: Verify the influence of radiant exposure (H) on composite degree of conversion (DC) and mechanical properties. Methods: Composite was photoactivated with 3, 6, 12, 24, or 48 J/cm(2). Properties were measured after 48-h dry storage at room temperature. DC was determined on the flat surfaces of 6 mm x 2 mm disk-shaped specimens using FTIR. Flexural strength (FS) and modulus (FM) were accessed by three-point bending. Knoop microhardness number (KHN) was measured on fragments of FS specimens. Data were analyzed by one-way ANOVA/Tukey test, Student`s t-test, and regression analysis. Results: DC/top between 6 and 12 J/cm(2) and between 24 and 48 J/cm(2) were not statistically different. No differences between DC/top and bottom were detected. DC/bottom, FM, and KHN/top showed significant differences among all H levels. FS did not vary between 12 and 24 J/cm(2) and between 24 and 48 J/cm(2). KHN/bottom at 3 and 6 J/cm(2) was similar. KHN between top and bottom was different up to 12 J/cm(2). Regression analyses having H as independent variable showed a plateau region above 24 J/cm(2). KHN increased exponentially (top) or linearly (bottom) with DC. FS and FM increased almost linearly with DC/bottom up to 55% conversion. Conclusions: DC and mechanical properties increased with radiant exposure. Variables leveled off at high H levels. (C) 2007 Wiley Periodicals, Inc.

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During orthodontic tooth movement, there is local production of chemokines and an influx of leukocytes into the periodontium. CCL5 plays an important role in osteoclast recruitment and activation. This study aimed to investigate whether the CCR5-receptor influences these events and, consequently, orthodontic tooth movement. An orthodontic appliance was placed in wild-type mice (WT) and CCR5-deficient mice (CCR5(-/-)). The expression of mediators involved in bone remodeling was evaluated in periodontal tissues by Real-time PCR. The number of TRAP-positive osteoclasts and the expression of cathepsin K, RANKL, and MMP13 were significantly higher in CCR5(-/-). Meanwhile, the expression of two osteoblastic differentiation markers, RUNX2 and osteocalcin, and that of bone resorption regulators, IL-10 and OPG, were lower in CCR5(-/-). Analysis of the data also showed that CCR5(-/-) exhibited a greater amount of tooth movement after 7 days of mechanical loading. The results suggested that CCR5 might be a down-regulator of alveolar bone resorption during orthodontic movement.

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Introduction: This ex vivo study evaluated the heat release, time required, and cleaning efficacy of MTwo (VDW, Munich, Germany) and ProTaper Universal Retreatment systems (Dentsply/Maillefer, Ballaigues, Switzerland) and hand instrumentation in the removal of filling material. Methods: Sixty single-rooted human teeth with a single straight canal were obturated with gutta-percha and zinc oxide and eugenol-based cement and randomly allocated to 3 groups (n = 20). After 30-day storage at 37 degrees C and 100% humidity, the root fillings were removed using ProTaper UR, MTwo R, or hand files. Heat release, time required, and cleaning efficacy data were analyzed statistically (analysis of variance and the Tukey test, alpha = 0.05). Results: None of the techniques removed the root fillings completely. Filling material removal with ProTaper UR was faster but caused more heat release. Mtwo R produced less heat release than the other techniques but was the least efficient in removing gutta-percha/sealer. Conclusions: ProTaper UR and MTwo R caused the greatest and lowest temperature increase on root surface, respectively; regardless of the type of instrument, more heat was released in the cervical third. Pro Taper UR needed less time to remove fillings than MTwo R. All techniques left filling debris in the root canals. (I Endod 2010;36:1870-1873)

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Objectives. To evaluate the influence of different tertiary amines on degree of conversion (DC), shrinkage-strain, shrinkage-strain rate, Knoop microhardness, and color and transmittance stabilities of experimental resins containing BisGMA/TEGDMA (3: 1 wt), 0.25wt% camphorquinone, 1wt% amine (DMAEMA, CEMA, DMPT, DEPT or DABE). Different light-curing protocols were also evaluated. Methods. DC was evaluated with FTIR-ATR and shrinkage-strain with the bonded-disk method. Shrinkage-strain-rate data were obtained from numerical differentiation of shrinkage-strain data with respect to time. Color stability and transmittance were evaluated after different periods of artificial aging, according to ISO 7491: 2000. Results were evaluated with ANOVA, Tukey, and Dunnett`s T3 tests (alpha = 0.05). Results. Studied properties were influenced by amines. DC and shrinkage-strain were maximum at the sequence: CQ < DEPT < DMPT <= CEMA approximate to DABE < DMAEMA. Both DC and shrinkage were also influenced by the curing protocol, with positive correlations between DC and shrinkage-strain and DC and shrinkage-strain rate. Materials generally decreased in L* and increased in b*. The strong exception was the resin containing DMAEMA that did not show dark and yellow shifts. Color varied in the sequence: DMAEMA < DEPT < DMPT < CEMA < DABE. Transmittance varied in the sequence: DEPT approximate to DABE < DABE approximate to DMPT approximate to CEMA < DMPT approximate to CEMA approximate to DMAEMA, being more evident at the wavelength of 400 nm. No correlations between DC and optical properties were observed. Significance. The resin containing DMAEMA showed higher DC, shrinkage-strain, shrinkage-strain rate, and microhardness, in addition to better optical properties. (C) 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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Objective: The objective of the study is to investigate the results of the newborn hearing screening program carried out in a Public Hospital in Brazil, in the first 3 years regarding: (1) the prevalence of hearing impairment; (2) the influence of the universal hearing screening program on the age at which the diagnosis of hearing loss is defined; (3) the cost effectiveness of the program; (4) the outcomes, in terms of the age in which the hearing rehabilitation started. Methods: A descriptive study of the first 3 years after starting the universal newborn hearing screening in a Public Hospital of Bauru, Sao Paulo state, Brazil. The screening method consists of a two-stage screening approach with transient otoacoustic emissions (TOAE), conducted by an audiologist. If the outcome in the second-stage screening is REFER, the infant is submitted to diagnostic follow-up testing and intervention at the Audiology and Speech Pathology Clinic at the University of Sao Paulo, campus of Bauru. The evaluation of the costs of the universal newborn hearing screening program per each screened newborn (around 4000/year) was done based on a proposal by the National Center for Hearing Assessment and Management, of the Utah State University, United States of America. Results: 11,466 newborns were submitted to hearing screening, corresponding to 90.52% of the living newborns. The prevalence of sensorineural hearing loss was 0.96:1000. Of the 11 children with sensorineural hearing loss, eight children received hearing aids and five started the therapeutic process before the age of 1. Currently, four children between the ages of 11 months and 2 years old were submitted to cochlear implant surgery. The cost of hearing screening was US$7.00 and the annual cost of the universal newborn hearing screening program was US$26,940.47. Conclusion: The hospital-based universal newborn hearing screening carried out through the Brazilian National Health System is viable, with promising results. However, in a country such as Brazil, which presents large socio-economic differences, the same type of analyses should be performed in several regions, so as to take into account specific aspects, to implement the newborn hearing screening along with the Public System. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

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The extraction of teeth involves the elimination of extremely sensitive periodontal mechanoreceptors, which play an important role in oral sensory perception. Objectives: The aim of this study was to evaluate the recovery of interocclusal sensory perception for micro-thickness in individuals with different types of implant-supported prostheses. Materials and Methods: Wearers of complete dentures (CDs) comprised the negative control group (group A, n=17). The experimental group consisted of wearers of prostheses supported by osseointegrated implants (Group B, n=29), which was subsequently divided into 4 subgroups: B(1) (n=5) - implant supported overdentures (ISO) occluding with CD; B(2) (n=6) - implant-supported fixed prostheses (ISFP) occluding with CD; B3 (n=8) - wearers of maxillary and mandibular ISFP, and B(4) (n=10) - ISFP occluding with natural dentition (ND). Individuals with ND represented the positive control group (Group C, n=24). Aluminum foils measuring 10 mu m, 24 mu m, 30 mu m, 50 mu m, 80 mu m, and 104 mu m thickness were placed within the premolar area, adding up to 120 tests for each individual. Results: The mean tactile thresholds of groups A, B(1), B(2), B(3), B(4), and C were 92 mu m, 27 mu m, 27 mu m, 14 mu m, 10 mu m, and 10 mu m, respectively. [Correction added after publication online 18 April 2008: in the preceding sentence 92 mu m, 27 mu m, 14 mu m, 10 mu m and 10 mu m, was corrected to 92 mu m, 27 mu m, 27 mu m, 14 mu m, 10 mu m and 10 mu m.] The Kruskal-Wallis test revealed significant difference among groups (P < 0.05). The Dunn test revealed that group A was statistically different from groups C, B(3), and B(4), and that B(1) and B(2) were statistically different from group C. Conclusion: Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses could be observed. Moreover, ISO and/or ISFP combinations may similarly maximize the recovery of osseoperception.