The Effect of Supra- and Subphysiologic Testosterone Levels on Ligature-Induced Bone Loss in Rats - A Radiographic and Histologic Pilot Study

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

Influence of different light sources and photo-activation methods on degree of conversion and polymerization shrinkage of a nanocomposite resin

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of meal size and proximal-distal segmentation on gastric activity

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

Functional and Morphological Reproductive Aspects in Male Rats Exposed to Di-n-Butyl Phthalate (DBP) in Utero and During Lactation

The potential adverse reproductive effects, with emphasis on the epididymis, of in utero and lactational exposure to 100 mg/kg/d di-n-butyl phthalate (DBP) in adult male rat offspring were investigated. The fetal testis histopathology was also determined. The selected endpoints included reproductive organ weights, sperm motility and morphology, sperm epididymal transit time, sperm quantity in the testis and epididymis, hormonal status, fetal testis and epididymal histopathology and stereology, and androgen receptor (AR), aquaporin 9 (AQP9), and Ki-67 immunoreactivities. Pregnant females were divided into two groups: control (C) and treated (T). The treated females received DBP (100 mg/kg/d, by gavage) from gestation day (GD) 12 to postnatal day (PND) 21, while control dams received the vehicle. Some pregnant dams were killed by decapitation on GD20, and testes from male fetuses were collected for histopathogy. Male rats from other dams were killed at PND 90. Fetal testes from treated group showed Leydig-cell clusters, presence of multinucleated germinative cells, and increase of the interstitial component. Testosterone levels and reproductive organ weights were similar between the treated and control adult groups. DBP treatment did not markedly affect relative proportions of epithelial, stromal, or luminal compartments in the epididymis; sperm counts in the testis and epididymis; sperm transit time; or sperm morphology and motility in adult rats. The AR and AQP9 immunoreactivities and proliferation index were similar for the two groups. These results showed that fetal testes were affected by DBP as evidenced by testicular histopathologic alterations, but reproductive parameters and epididymal structure/function were not significantly altered in the adult animals exposed to 100 mg/kg DBP in utero and during lactation.

Effects of Gestational and Lactational Fenvalerate Exposure on Immune and Reproductive Systems of Male Rats

The aim of this study was to determine the consequent reproductive developmental and immunotoxic effects due to exposure to fenvalerate during pregnancy and lactation in male offspring of maternal-treated rats. Pregnant rats were treated daily by oral gavage with 40 or 80 mg/kg of fenvalerate or corn oil (vehicle, control), from d 12 of pregnancy to d 21 of lactation. Immune and reproductive developmental effects were assessed in male offspring at postnatal days (PND) 40 (peripuberty), 60 (postpuberty), and 90 (sexual maturity). Treatment with the higher dose (80 mg/kg) resulted in convulsive behavior, hyperexcitability, and mortality in 45% of the dams. Fenvalerate was detected in the fetus due to placental transfer, as well as in pups due to breast-milk ingestion, persisting in male offspring until PND 40 even though pesticide treatment was terminated on PND 20. However, fenvalerate did not produce marked alterations in age of testicular descent to the scrotum and prepucial separation, parameters indicative of puberty initiation. In contrast, at puberty, there was a reduction in testicular weight and sperm production in male offspring of maternal-treated rats. At adulthood, the sperm counts and fertility did not differ between control and treated groups. Testosterone levels were not changed at any time during reproductive development. Similarly, no apparent exposure-related effects were detected in the histological structures of the lymphohematopoietic system. Data indicate that fenvalerate, in this experimental model, interfered with initial development of the male reproductive system, but that these effects on sperm production or fertility did not persist into adulthood. There was no apparent evidence that fenvalerate altered testosterone levels or produced a disruption in male endocrine functions.

Ant diversity (Hymenoptera: Formicidae) and predation by ants on the different stages of the sugarcane borer life cycle Diatraea saccharalis (Lepidoptera: Crambidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Spatial and temporal population interactions between the parasitoids Cotesia flavipes and Tachinidae flies: considerations on the adverse effects of biological control practice

Biological control of Diatraea saccharalis is regarded as one of the best examples of successful classical biological control in Brazil. Since the introduction of the exotic parasitoid Cotesia flavipes, the decrease of D. saccharalis infestation in sugarcane fields has been attributed to the effectiveness of this agent. Recently, the native tachinid fly parasitoids (Lydella minense and Paratheresia claripalpis) have also been implicated in the success. Here, we investigated the spatial and temporal population interactions between C. flavipes and the tachinid flies, and provide a critical analysis of the biological control practice, focusing on the undesirable effects of introductions of exotic natural enemies. To investigate these questions, a large data set comprising information from two sugarcane mills located in the state of São Paulo, Brazil (Barra and Sao Joao Mills), was analysed. Analysis of the correlation between C. flavipes and tachinid fly population densities through time revealed that such populations were inversely correlated in the Sao Joao Mill and not correlated in the Barra Mill. Logistic regressions were computed to investigate the proportion of sites occupied by the parasitoid species at both mills as a function of time. An increasing trend in the proportion of sites occupied by C. flavipes was observed, with a concomitant decrease of the sites occupied by tachinid flies. This effect was more intense in the Sao Joao Mill. Thus, there is a convincing possibility that constant releases of C. flavipes decreased the tachinid fly populations, resulting in an undesirable effect of biological control practice.

Implications of obesity for tendon structure, ultrastructure and biochemistry: A study on Zucker rats

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

Effect of grape pre-drying and static pomace contact on physicochemical properties and sensory acceptance of Brazilian (Bordo and Isabel) red wines

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of Airborne-Particle Abrasion and Mechanico-Thermal Cycling on the Flexural Strength of Glass Ceramic Fused to Gold or Cobalt-Chromium Alloy

Purpose: To evaluate the effect of airborne-particle abrasion and mechanico-thermal cycling on the flexural strength of a ceramic fused to cobalt-chromium alloy or gold alloy.Materials and Methods: Metallic bars (n = 120) were made (25 mm x 3 mm x 0.5 mm): 60 with gold alloy and 60 with Co-Cr. At the central area of the bars (8 mm x 3 mm), a layer of opaque ceramic and then two layers of glass ceramic (Vita VM13, Vita Zahnfabrick) were fired onto it (thickness: 1 mm). Ten specimens from each alloy group were randomly allocated to a surface treatment [(tungsten bur or air-particle abrasion (APA) with Al(2)O(3) at 10 mm or 20 mm away)] and mechanico-thermal cycling (no cycling or mechanically loaded 20,000 cycles; 10 N distilled water at 37 degrees C and then thermocycled 3000 cycles; 5 degrees C to 55 degrees C, dwell time 30 seconds) combination. Those specimens that did not undergo mechanico-thermal cyclingwere stored inwater (37 degrees C) for 24 hours. Bond strength was measured using a three-point bend test, according to ISO 9693. After the flexural strength test, failure types were noted. The data were analyzed using three factor-ANOVA and Tukey's test (alpha = 0.05).Results: There were no significant differences between the flexural bond strength of gold and Co-Cr groups (42.64 +/- 8.25 and 43.39 +/- 10.89 MPa, respectively). APA 10 and 20 mm away surface treatment (45.86 +/- 9.31 and 46.38 +/- 8.89 MPa, respectively) had similar mean flexural strength values, and both had significantly higher bond strength than tungsten bur treatment (36.81 +/- 7.60 MPa). Mechanico-thermal cycling decreased the mean flexural strength values significantly for all six alloy-surface treatment combinations tested when compared to the control groups. The failure type was adhesive in the metal/ceramic interface for specimens surface treated only with the tungsten bur, and mixed for specimens surface treated with APA 10 and 20 mm.Conclusions: Considering the levels adopted in this study, the alloy did not affect the bond strength; APA with Al(2)O(3) at 10 and 20 mm improved the flexural bond strength between ceramics and alloys used, and the mechanico-thermal cycling of metal-ceramic specimens resulted in a decrease of bond strength.

Effects of experimental osteoporosis and low calcium intake on postextraction sockets of rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of porcelain thickness and surface liner application on the fracture behavior of a ceramic system

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

Influence of Y-TZP ceramic treatment and different resin cements on bond strength to dentin

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

Effect of Cement Shade and Light-curing Unit on Bond Strength of a Ceramic Cemented to Dentin

Purpose: To evaluate the effect of cement shade, light-curing unit, and water storage on tensile bond strength (a) of a feldspathic ceramic resin bonded to dentin.Materials and Methods: The dentin surface of 40 molars was exposed and etched with 37% phosphoric acid, then an adhesive system was applied. Forty blocks of feldspathic ceramic (Vita VM7) were produced. The ceramic surface was etched with 10% hydrofluoric acid for 60 s, followed by the application of a silane agent and a dual-curing resin cement (Variolink II). Ceramic blocks were cemented to the treated dentin using either A3 or transparent (Tr) shade cement that was activated using either halogen or LED light for 40 s. All blocks were stored in 37 degrees C distilled water for 24 h before cutting to obtain non-trimmed bar-shaped specimens (adhesive area = 1 mm(2) +/- 0.1) for the microtensile bond strength test. The specimens were randomly grouped according to the storage time: no storage or stored for 150 days in 37 degrees C distilled water. Eight experimental groups were obtained (n = 30). The specimens were submitted to the tensile bond strength test using a universal testing machine at a crosshead speed of 1 mm/min. The data were statistically analyzed using ANOVA and Tukey's post-hoc tests (alpha = 0.05).Results: The mean bond strength values were significantly lower for the corresponding water stored groups, except for the specimens using A3 resin cement activated by halogen light. There was no significance difference in mean bond strength values among all groups after water storage.Conclusion: Water storage had a detrimental effect under most experimental conditions. For both cement shades investigated (Tr and A3) under the same storage condition, the light-curing units (QTH and LED) did not affect the mean microtensile bond strengths of resin-cemented ceramic to dentin.

Conversion Degree of Indirect Resin Composites and Effect of Thermocycling on Their Physical Properties

Purpose: This study evaluated the degree of conversion (DC) of four indirect resin composites (IRCs) with various compositions processed in different polymerization units and investigated the effect of thermal aging on the flexural strength and Vicker's microhardness.Materials and Methods: Specimens were prepared from four IRC materials, namely Gr 1: Resilab (Wilcos); Gr2: Sinfony (3M ESPE); Gr3: VITA VMLC (VITA Zahnfabrik); Gr4: VITA Zeta (VITA Zahnfabrik) using special molds for flexural strength test (N = 80, n = 10 per group) (25 x 2 x 2 mm(3), ISO 4049), for Vicker's microhardness test (N = 80, n = 10 per group) (5 x 4 mm(2)) and for DC (N = 10) using FT-Raman Spectroscopy. For both flexural strength and microhardness tests, half of the specimens were randomly stored in distilled water at 37 degrees C for 24 hours (Groups 1 to 4), and the other half (Groups 5 to 8) were subjected to thermocycling (5000 cycles, 5 to 55 +/- 1 degrees C, dwell time: 30 seconds). Flexural strength was measured in a universal testing machine (crosshead speed: 0.8 mm/min). Microhardness test was performed at 50 g. The data were analyzed using one-way and two-way ANOVA and Tukey's test (alpha = 0.05). The correlation between flexural strength and microhardness was evaluated with Pearson's correlation test (alpha = 0.05).Results: A significant effect for the type of IRC and thermocycling was found (p = 0.001, p = 0.001) on the flexural strength results, but thermocycling did not significantly affect the microhardness results (p = 0.078). The interaction factors were significant for both flexural strength and microhardness parameters (p = 0.001 and 0.002, respectively). Thermocycling decreased the flexural strength of the three IRCs tested significantly (p < 0.05), except for VITA Zeta (106.3 +/- 9.1 to 97.2 +/- 14 MPa) (p > 0.05) when compared with nonthermocycled groups. Microhardness results of only Sinfony were significantly affected by thermocycling (25.1 +/- 2.1 to 31 +/- 3.3 Kg/mm(2)). DC values ranged between 63% and 81%, and were not significantly different between the IRCs (p > 0.05). While a positive correlation was found between flexural strength and microhardness without (r = 0.309) and with thermocycling (r = 0.100) for VITA VMLC, negative correlations were found for Resilab under the same conditions (r = -0.190 and -0.305, respectively) (Pearson's correlation coefficient).Conclusion: Although all four IRCs presented nonsignificant DC values, flexural strength and microhardness values varied between materials with and without thermocycling.