992 resultados para Ni^2
Resumo:
357
Resumo:
OBJECTIVE: The objective of this pilot study was to determine whether glugagon-like peptide 2 (GLP-2) secretion relates to insulin sensitivity (IS) in obese subjects. SUBJECTS AND METHODS: Twenty four obese subjects [body mass index (BMI) 40.0 ± 3.0 kg/m² (mean ± standard deviation)] were included, nine of which were male, age 43 ± 8 years. Twelve subjects had type 2 diabetes, all treated with oral anti-diabetic agents only. The subjects were submitted to standard meal tolerance test (MTT) for dosage of the curves: glucose, insulin, and GLP-2. Insulin sensitivity was measured by HOMA-IR, and OGIS was derived from the MTT. Spearman linear correlations and partial correlations were obtained. RESULTS: There was an inverse relationship between the GLP-2 secretion and IS: HOMA-IR correlated with GLP-2 AUC (R = 0.504; p = 0.012), and OGIS correlated with GLP-2 incremental AUC (R = -0.54; p = 0.054). The correlation persisted after controlling for BMI. CONCLUSION: We found an association of GLP-2 secretion and insulin resistance (IR). The understanding of the underlying mechanisms may provide future directions in the pharmacological manipulation of incretins, and in the treatment of obesity and related metabolic disorders.
Resumo:
PURPOSE: To compare intraocular pressure (IOP) rise in normal individuals and primary open-angle glaucoma patients and the safety and efficacy of ibopamine eye drops in different concentrations as a provocative test for glaucoma. METHODS: Glaucoma patients underwent (same eye) the ibopamine provocative test with two concentrations, 1% and 2%, in a random sequence at least 3 weeks apart, but not more than 3 months. The normal individuals were randomly submitted to one of the concentrations of ibopamine (1% and 2%). The test was considered positive if there was an IOP rise greater than 3 or 4 mmHg at 30 or 45 minutes to test which subset of the test has the best sensitivity (Se)/specificity (Sp). RESULTS: There was no statistically significant difference in any of the IOP measurements, comparing 1% with 2% ibopamine. The IOP was significantly higher at 30 and 45 minutes with both concentrations (p<0.001). The best sensitivity/specificity ratio was achieved with the cutoff point set as greater than 3 mmHg at 45 minutes with 2% ibopamine (area under the ROC curve: 0.864, Se: 84.6%; Sp:73.3%). All patients described a slight burning after ibopamine's instillation. CONCLUSION: 2% ibopamine is recommended as a provocative test for glaucoma. Because both concentrations have similar ability to rise IOP, 1% ibopamine may be used to treat ocular hypotony.
Resumo:
PURPOSE: To compare the 2% ibopamine provocative test with the water drinking test as a provocative test for glaucoma. METHODS: Primary open-angle glaucoma patients and normal individuals were selected from CEROF-Universidade Federal de Goiânia UFG, and underwent the 2% ibopamine provocative test and the water drinking test in a randomized fashion, at least 1 week apart. Intraocular pressure (IOP) before and after both tests, Bland-Altman graph, sensitivity and specificity (as mesured by ROC curves) were obtained for both methods. RESULTS: Forty-seven eyes from 25 patients were included (27 eyes from 15 glaucoma patients and 20 eyes from 10 normal individuals), with a mean age of 54.2 ± 12.7 years. The mean MD of glaucoma patients was -2.8 ± 2.11 dB. There was no statistically difference in the baseline IOP (p=0.8) comparing glaucoma patients, but positive after the provocative tests (p=0.03), and in the IOP variation (4.4 ± 1.3 mmHg for ibopamine and 3.2 ± 2.2 mmHg for water drinking test, p=0.01). There was no difference in all studied parameters for normal individuals. The Bland-Altman graph showed high dispersion comparing both methods. The areas under the ROC curve were 0.987 for the ibopamine provocative test, and 0.807 for the water-drinking test. CONCLUSION: In this selected subgroup of glaucoma patients with early visual field defect, the ibopamine provocative test has shown better sensitivity/specificity than the water drinking test.
Resumo:
Universidade Estadual de Campinas . Faculdade de Educação FÃsica
Resumo:
Universidade Estadual de Campinas . Faculdade de Educação FÃsica
Resumo:
Universidade Estadual de Campinas. Faculdade de Educação FÃsica
Correlation between margin fit and microleakage in complete crowns cemented with three luting agents
Resumo:
Microleakage can be related to margin misfit. Also, traditional microleakage techniques are time-consuming. This study evaluated the existence of correlation between in vitro margin fit and a new microleakage technique for complete crowns cemented with 3 different luting agents. Thirty human premolars were prepared for full-coverage crowns with a convergence angle of 6 degrees, chamfer margin of 1.2 mm circumferentially, and occlusal reduction of 1.5 mm. Ni-Cr cast crowns were cemented with either zinc phosphate (ZP) (S.S. White), resin-modified glass-ionomer (RMGI) (Rely X Luting Cement) or a resin-based luting agent (RC) (Enforce). Margin fit (seating discrepancy and margin gap) was evaluated according to criteria in the literature under microscope with 0.001 mm accuracy. After thermal cycling, crowns were longitudinally sectioned and microleakage scores at tooth-cement interface were obtained and recorded at ×100 magnification. Margin fit parameters were compared with the one-way ANOVA test and microleakage scores with Kruskal-Wallis and Dunn's tests (alpha=0.05). Correlation between margin fit and microleakage was analyzed with the Spearman's test (alpha=0.05). Seating discrepancy and marginal gap values ranged from 81.82 µm to 137.22 µm (p=0.117), and from 75.42 µm to 78.49 µm (p=0.940), respectively. Marginal microleakage scores were ZP=3.02, RMGI=0.35 and RC=0.12 (p<0.001), with no differences between RMGI and RC scores. The correlation coefficient values ranged from -0.27 to 0.30 (p>0.05). Conclusion: Margin fit parameters and microleakage showed no strong correlations; cast crowns cemented with RMGI and RC had lower microleakage scores than ZP cement.
Resumo:
Adjunctive therapeutic strategies that modulate the inflammatory mediators can play a significant role in periodontal therapy. In this double-blind, placebo-controlled study, 60 subjects diagnosed as periodontitis patients were evaluated for 28 days after periodontal treatment combined with selective cyclooxygenase-2 (COX-2) inhibitor. The experimental group received scaling and root planning (SRP) combined with the Loxoprofen antiinflammatory drug (SRP+Loxoprofen). The control group received SRP combined with placebo (SRP+placebo). Plaque index (PI), probing pocket depth (PD) and bleeding on probing (BOP) were monitored with an electronic probe at baseline and after 14 and 28 days. Both groups displayed clinical improvement in PD, PI and BOP. They also showed statistically similar values (p>0.05) of PD reduction on day 14 (0.4 mm) and on day 28 (0.6 mm). At the baseline, few deeper sites (>7 mm) from SRP+Loxoprofen group were responsible and most PD reduction was observed after 14 days (p<0.05). The percentage of remaining deep pockets (>7 mm) after 14 days in the SRP+Loxoprofen group was significantly lower (p<0.05) than in the SRP+placebo group. Loxoprofen presents potential effect as an adjunct of periodontal disease treatment, but long-term clinical trials are necessary to confirm its efficacy.
Resumo:
One of the most important properties of artificial teeth is the abrasion wear resistance, which is determinant in the maintenance of the rehabilitation's occlusal pattern. OBJECTIVES: This in vitro study aims to evaluate the abrasion wear resistance of 7 brands of artificial teeth opposed to two types of antagonists. MATERIAL AND METHODS: Seven groups were prepared with 12 specimens each (BIOLUX & BL, TRILUX & TR, BLUE DENT & BD, BIOCLER & BC, POSTARIS & PO, ORTHOSIT & OR, GNATHOSTAR & GN), opposed to metallic (M & nickel-chromium alloy), and to composite antagonists (C & Solidex indirect composite). A mechanical loading device was used (240 cycles/min, 4 Hz speed, 10 mm antagonist course). Initial and final contours of each specimen were registered with aid of a profile projector (20x magnification). The linear difference between the two profiles was measured and the registered values were subjected to ANOVA and Tukey's test. RESULTS: Regarding the antagonists, only OR (M = 10.45 ± 1.42 µm and C = 2.77 ± 0.69 µm) and BC (M = 6.70 ± 1.37 µm and C = 4.48 ± 0.80 µm) presented statistically significant differences (p < 0.05). Best results were obtained with PO (C = 2.33 ± 0.91 µm and M = 1.78 ± 0.42 µm), followed by BL (C = 3.70 ± 1.32 µm and M = 3.70 ± 0.61 µm), statistically similar for both antagonists (p>0.05). Greater result variance was obtained with OR, which presented the worse results opposed to Ni-Cr (10.45 ± 1.42 µm), and results similar to the best ones against composite (2.77 ± 0.69 µm). CONCLUSIONS: Within the limitations of this study, it may be concluded that the antagonist material is a factor of major importance to be considered in the choice of the artificial teeth to be used in the prosthesis.
Resumo:
The purpose of this study was to evaluate the metal-ceramic bond strength (MCBS) of 6 metal-ceramic pairs (2 Ni-Cr alloys and 1 Pd-Ag alloy with 2 dental ceramics) and correlate the MCBS values with the differences between the coefficients of linear thermal expansion (CTEs) of the metals and ceramics. Verabond (VB) Ni-Cr-Be alloy, Verabond II (VB2), Ni-Cr alloy, Pors-on 4 (P), Pd-Ag alloy, and IPS (I) and Duceram (D) ceramics were used for the MCBS test and dilatometric test. Forty-eight ceramic rings were built around metallic rods (3.0 mm in diameter and 70.0 mm in length) made from the evaluated alloys. The rods were subsequently embedded in gypsum cast in order to perform a tensile load test, which enabled calculating the CMBS. Five specimens (2.0 mm in diameter and 12.0 mm in length) of each material were made for the dilatometric test. The chromel-alumel thermocouple required for the test was welded into the metal test specimens and inserted into the ceramics. ANOVA and Tukey's test revealed significant differences (p=0.01) for the MCBS test results (MPa), with PI showing higher MCBS (67.72) than the other pairs, which did not present any significant differences. The CTE (10-6 oC-1) differences were: VBI (0.54), VBD (1.33), VB2I (-0.14), VB2D (0.63), PI (1.84) and PD (2.62). Pearson's correlation test (r=0.17) was performed to evaluate of correlation between MCBS and CTE differences. Within the limitations of this study and based on the obtained results, there was no correlation between MCBS and CTE differences for the evaluated metal-ceramic pairs.
Resumo:
Prosthetic restorations that have been tried in the patient's mouth are potential sources of infection. In order to avoid cross-infection, protocols for infection control should be established in dental office and laboratory. This study evaluated the antimicrobial efficacy of disinfectants on full metal crowns contaminated with microorganisms. Full crowns cast in a Ni-Cr alloy were assigned to one control group (n=6) and 5 experimental groups (n=18). The crowns were placed in flat-bottom glass balloons and were autoclaved. A microbial suspension of each type of strain - S. aureus, P. aeruginosa, S. mutans, E. faecalis and C. albicans- was aseptically added to each experimental group, the crowns being allowed for contamination during 30 min. The contaminated specimens were placed into recipients with the chemical disinfectants (1% and 2% sodium hypochlorite and 2% glutaraldehyde) for 5, 10 and 15 min. Thereafter, the crowns were placed into tubes containing different broths and incubated at 35ºC. The control specimens were contaminated, immersed in distilled water for 20 min and cultured in Thioglycollate broth at 35ºC. Microbial growth assay was performed by qualitative visual examination after 48 h, 7 and 12 days. Microbial growth was noticed only in the control group. In the experimental groups, turbidity of the broths was not observed, regardless of the strains and immersion intervals, thus indicating absence of microbial growth. In conclusion, all chemical disinfectants were effective in preventing microbial growth onto full metal crowns.
Resumo:
Accelerated stability tests are indicated to assess, within a short time, the degree of chemical degradation that may affect an active substance, either alone or in a formula, under normal storage conditions. This method is based on increased stress conditions to accelerate the rate of chemical degradation. Based on the equation of the straight line obtained as a function of the reaction order (at 50 and 70 ºC) and using Arrhenius equation, the speed of the reaction was calculated for the temperature of 20 ºC (normal storage conditions). This model of accelerated stability test makes it possible to predict the chemical stability of any active substance at any given moment, as long as the method to quantify the chemical substance is available. As an example of the applicability of Arrhenius equation in accelerated stability tests, a 2.5% sodium hypochlorite solution was analyzed due to its chemical instability. Iodometric titration was used to quantify free residual chlorine in the solutions. Based on data obtained keeping this solution at 50 and 70 ºC, using Arrhenius equation and considering 2.0% of free residual chlorine as the minimum acceptable threshold, the shelf-life was equal to 166 days at 20 ºC. This model, however, makes it possible to calculate shelf-life at any other given temperature.
Resumo:
OBJETIVOS: avaliar a expressão de erbB-2 e dos receptores hormonais para estrógeno e progesterona (RE/RP) nas regiões de transição entre as frações in situ e invasoras de neoplasias ductais da mama (CDIS e CDI, respectivamente). MÉTODOS: oitenta e cinco casos de neoplasias mamárias, contendo regiões contÃguas de CDIS e CDI, foram selecionados. Espécimes histológicos das áreas de CDIS e de CDI foram obtidos através da técnica de tissue microarray (TMA). As expressões da erbB-2 e dos RE/RP foram avaliadas por meio de imunoistoquÃmica convencional. A comparação da expressão da erbB-2 e dos RE/RP nas frações in situ e invasoras da mama foi realizada com emprego do teste de McNemar. Os intervalos de confiança foram determinados em 5% (p=0,05). Foram calculados coeficientes de correlação intraclasse (ICC) para avaliar a concordância na tabulação cruzada da expressão de erbB-2 e RE/RP nas frações de CDIS e CDI. RESULTADOS: a expressão da erbB-2 não diferiu entre as áreas de CDIS e CDI (p=0,38). Comparando caso a caso suas áreas de CDIS e CDI, houve boa concordância na expressão da erbB-2 (coeficiente de correlação intraclasse, ICC=0,64), dos RP (ICC = 0,71) e dos RE (ICC = 0,64). Considerando apenas tumores cujo componente in situ apresentasse áreas de necrose (comedo), o ICC para erbB-2 foi de 0,4, comparado a 0,6 no conjunto completo de casos. Os ICC não diferiram substancialmente daqueles obtidos com o conjunto completo de espécimes em relação aos RE/RP: para RE, ICC=0,7 (versus 0,7 no conjunto completo), e para RP, ICC=0,7 (versus 0,6 no conjunto completo). CONCLUSÕES: nossos achados sugerem que as expressões de erbB-2 e RE/RP não diferem nos componentes contÃguos in situ e invasivo em tumores ductais da mama.
Bottle feeding, increased overjet and Class 2 primary canine relationship: is there any association?
Resumo:
The aim of this study was to investigate the association between bottle feeding and prevalence rates of increased overjet and Class 2 primary canine relationship. The sample consisted of 911 children (461 boys, 450 girls) aged 3 (13.9%), 4 (40.8%), 5 (34%) and 6 (11.3%) years, with complete primary dentition. Information about nutritive and nonnutritive (pacifier and/or digit) sucking habits was collected through questionnaires. Three calibrated dentists (κ: 0.9-1.0 and Rs > 0.90) performed the clinical assessments. The children were divided into four groups: G1 - not bottle-fed; G2 - exclusively bottle-fed; G3 - breast- and bottle-fed, bottle feeding ceased before 3 years of age; and G4 - breast- and bottle-fed, bottle feeding ceased between 3 and 4 years of age. Associations between nutritive and nonnutritive sucking behaviors and the malocclusions studied were analyzed by multiple binary logistic regression (α= 0.05). The frequencies of increased overjet were: 25.3% (G1), 38.8% (G2), 39.2% (G3) and 47.8% (G4). The percentages of Class 2 canine relationship were: 27.9% (G1), 48.8% (G2), 43.4% (G3) and 43% (G4). No significant effect of bottle feeding was found. The chances of diagnosing increased overjet (O.R. = 4.42, p < 0.001) and Class 2 canine relationship (O.R. = 4.02, p < 0.001) were greater for children with pacifier and/or digit-sucking habits, compared to those without a history of nonnutritive sucking behavior. It may be suggested that bottle feeding alone is not directly associated with higher prevalence rates of increased overjet and Class 2 canine relationship in the primary dentition.