Evaluation in situ of tag formation in dental enamel submitted to microabrasion technique: effect of two etching times

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Descrição micromorfológica e efeitos do benzo[α]pireno em células hepáticas e sanguíneas das espécies Physalaemus cuvieri e Leptodactylus fuscus (Anura: Leptodactylidae)

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

Vitamin A affects haematology, growth and immune response of Nile tilapia (Oreochromis niloticus, L.), but has no protective effect against bacterial challenge or cold-induced stress

Vitamin A (vitA) is an essential nutrient that acts as an endocrine regulator of several metabolic pathways, modulating normal growth and health status of animals. Although the importance of vitA for normal haematology and immune response is well documented for higher vertebrates, there is limited information on the physiological effects of vitA on fish. Therefore, we designed a 130-day feeding trial to evaluate the effect of vitA supplementation on growth, haematology, immune function and resistance to experimental infection with Aeromonas hydrophila and cold-induced stress. A group of 320 Nile tilapia fingerlings 7.49 ± 0.19 g weight (mean ± SD) were randomly stocked into 40 250 L-aquaria and fed practical diets containing graded levels of vitA (0, 0.06, 0.12, 0.24, 0.48, 0.96, 1.92, 3.84 mg retinol (ROH) kg−1 diet. Growth, haematology, plasma protein profile and immune response were significantly affected by vitA supplementation; however, no clear protective effect of vitA supplementation on disease and cold stress resistance were observed in this study. Clinical signs of vitA deficiency were: resting and abnormal swimming behaviour, exophthalmia, haemorrhages at the base of fins and on skin, serous fluids in abdominal cavity, neutropenia, reduction in red blood cell count, haematocrit and haemoglobin evolving to high mortality rates in a short period of time. A dietary level of vitA around 1.2 mg ROH kg−1 may be required to prevent gross deficiency signs and promote proper growth and health status of Nile tilapia. VitA does not seem to have a pronounced effect on leucocyte differentiation, but clearly plays an important role on maintaining normal erythropoiesis.

Active site mutants of human secreted Group IIA Phospholipase A(2) lacking hydrolytic activity retain their bactericidal effect

The Human Secreted Group IIA Phospholipase A(2) (hsPIA2GIIA) presents potent bactericidal activity, and is considered to contribute to the acute-phase immune response. Hydrolysis of inner membrane phospholipids is suggested to underlie the bactericidal activity, and we have evaluated this proposal by comparing catalytic activity with bactericidal and liposome membrane damaging effects of the G30S, H48Q and D49K h5PLA2GIIA mutants. All mutants showed severely impaired hydrolytic activities against mixed DOPC:DOPG liposome membranes, however the bactericidal effect against Micrococcus luteus was less affected, with 50% killing at concentrations of 1, 3, 7 and 9 mu g/mL for the wild-type, D49K, H48Q and G30S mutants respectively. Furthermore, all proteins showed Ca2+-independent damaging activity against Liposome membranes demonstrating that in addition to the hydrolysis-dependent membrane damage, the hsPLA2GIIA presents a mechanism for permeabilization of phospholipid bilayers that is independent of catalytic activity, which may play a role in the bactericidal function of the protein (C) 2011 Elsevier Masson SAS. All rights reserved.

Temperature Effect on the Two-Photon Absorption Spectrum of All-trans-beta-carotene

In this report, we investigate the influence of temperature on the two-photon absorption (2PA) spectrum of all-trans-beta-carotene using the femtosecond white-light-continuum Z-scan technique. We observed that the 2PA cross-section decreases quadratically with the temperature. Such effect was modeled using a three-energy-level diagram within the sum-over-essential states approach, assuming temperature dependencies to the transition dipole moment and refractive index of the solvent. The results show that the transition dipole moments from ground to excited state and between the excited states, which governed the two-photon matrix element, have distinct behaviors with the temperature. The first one presents a quadratic dependence, while the second exhibits a linear dependence. Such effects were attributed mainly to the trans -> cis thermal interconversion process, which decreases the effective conjugation length, contributing to diminishing the transition dipole moments and, consequently, the 2PA cross-section.

Effect of different restorative procedures on the fracture resistance of teeth submitted to internal bleaching

The aim of this study was to evaluate the influence of different restorative procedures on the fracture resistance of endodontically treated teeth submitted to intracoronal bleaching. Fifty upper central incisors were distributed into 5 groups: GI - healthy teeth; GII - endodontically treated teeth sealed with Coltosol; GIII - endodontically treated teeth bleached and sealed with Coltosol; GIV - endodontically treated teeth bleached and restored with composite resin; and GV - endodontically treated teeth bleached and restored with a fiberglass post and composite resin. In the bleached specimens, a cervical seal was made prior to bleaching with 38% hydrogen peroxide. The gel was applied on the buccal surface and in the pulp chamber, and was then light-activated for 45 s. This procedure was repeated three times per session for four sessions, and each group was submitted to the restorative procedures described above. The specimens were submitted to fracture resistance testing in a universal testing machine. There were statistically significant differences among the groups (p < 0.05). The mean value found for GIII was the lowest (0.32 kN) and was significantly different from the values found for GI (0.75 kN), GII (0.67 kN), GIV (0.70 kN), and GV (0.72 kN), which were not significantly different from each other (p > 0.05). The restorative procedures using composite resin were found to successfully restore the fracture resistance of endodontically treated and bleached teeth.

PHYSIOLOGICAL QUALITY OF OSMOPRIMED EGGPLANT SEEDS

Eggplant seeds germination can be slow and uneven, justifying the use of pre-germinative treatments to improve the performance of seed lots. One option of treatment is the controlled hydration of seeds by priming. In this way, this study aimed to evaluate the performance of eggplant seeds cv. Embu submitted to different methodologies of priming. The seeds used in the experiment were stored in cold chamber (15 degrees C and 55% RH) in paper bags. The research was carried out at Central Laboratory of Seeds/UFLA. The seeds were submitted to the priming in aerated solutions varying the following factors: temperature (15 degrees C and 25 degrees C), time (24, 48 and 72 hours) and solution (water, PEG, KNO3 and PEG+KNO3). Seeds were washed in running water and dried at 30 degrees C, until the return to the initial moisture content, around 10%. The variables analyzed were percentage of germination, percentage of emergence, speed index of emergence and electrical conductivity. The treatments were arranged in a completely randomized design, according to a factorial arrangement 2x3x4+1 (control - seeds without priming). The results showed that priming improves the vigour of eggplant seeds with no effect on viability; the priming in water or KNO3 is efficient to improve the seed vigour and priming in water or KNO3 may use temperature of 15 degrees C or 25 degrees C for 24, 48 or 72 hours.

Physiological responses and rate of perceived exertion in Brazilian jiu-jitsu athletes

In this study, the physiological responses and rate of perceived exertion in Brazilian jiu-jitsu fighters submitted to a combat simulation were investigated. Venous blood samples and heart rate were taken from twelve male Brazilian jiu-jitsu athletes (27.1+/-2.7 yrs, 75.4+/-8.8 kg, 174.9+/-4.4 cm, 9.2+/-2.4% fat), at rest, after a warm-up (ten minutes), immediately after the fight simulation (seven minutes) and after recovery (fourteen minutes). After the combat the rate of perceived exertion was collected. The combat of the Brazilian jiu-jitsu fighters did not change blood concentrations of glucose, triglycerides, total cholesterol, low density lipoprotein and very low density lipoprotein, ureia and ammonia. However, blood levels of high density lipoprotein were significantly higher post-fight (before: 43.0+/-6.9 mg/dL, after: 45.1+/-8.0 mg/dL) and stayed at high levels during the recovery period (43.6+/-8.1 mg/dL) compared to the rest values (40.0+/-6.6 mg/dL). The fight did not cause changes in the concentrations of the cell damage markers of creatine kinase, aspartate aminotransferase and creatinine. However, blood concentrations of the alanine aminotransferase (before: 16.1+/-7.1 U/L, after: 18.6+/-7.1 U/L) and lactate dehydrogenase (before: 491.5+/-177.6 U/L, after: 542.6+/-141.4 U/L) enzymes were elevated after the fight. Heart rate (before: 122+/-25 bpm, after: 165+/-17 bpm) and lactate (before: 2.5+/-1.2 mmol/L, after: 11.9+/-5.8 mmol/L) increased significantly with the completion of combat. Despite this, the athletes rated the fight as being light or somewhat hard (12+/-2). These results showed that muscle glycogen is not the only substrate used in Brazilian jiu-jitsu fights, since there are indications of activation of the glycolytic, lipolytic and proteolytic pathways. Furthermore, the athletes rated the combats as being light or somewhat hard although muscle damage markers were generated.

Mechanism and Efficiency of Cell Death of Type II Photosensitizers: Effect of Zinc Chelation

A series of meso-substituted tetra-cationic porphyrins, which have methyl and octyl substituents, was studied in order to understand the effect of zinc chelation and photosensitizer subcellular localization in the mechanism of cell death. Zinc chelation does not change the photophysical properties of the photosensitizers (all molecules studied are type II photosensitizers) but affects considerably the interaction of the porphyrins with membranes, reducing mitochondrial accumulation. The total amount of intracellular reactive species induced by treating cells with photosensitizer and light is similar for zinc-chelated and free-base porphyrins that have the same alkyl substituent. Zinc-chelated porphyrins, which are poorly accumulated in mitochondria, show higher efficiency of cell death with features of apoptosis (higher MTT response compared with trypan blue staining, specific acridine orange/ethidium bromide staining, loss of mitochondrial transmembrane potential, stronger cytochrome c release and larger sub-G1 cell population), whereas nonchelated porphyrins, which are considerably more concentrated in mitochondria, triggered mainly necrotic cell death. We hypothesized that zinc-chelation protects the photoinduced properties of the porphyrins in the mitochondrial environment.

Light emission and current rectification in a molecular device: Experiment and theory

We have investigated optical and transport properties of the molecular structure 2,3,4,5-tetraphenyl-1-phenylethynyl-cyclopenta-2,4-dienol experimentally and theoretically. The optical spectrum was calculated using Hartree-Fock-intermediate neglect of differential overlap-configuration interaction model. The experimental photoluminescence spectrum showed a peak around 470nm which was very well described by the modeling. Electronic transport measurements showed a diode-like effect with a strong current rectification. A phenomenological microscopic model based on non-equilibrium Green's function technique was proposed and a very good description electronic transport was obtained. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4767457]

Effect of Temperature on the Degree of Conversion and Working Time of Dual-Cured Resin Cements Exposed to Different Curing Conditions

Objectives: This study evaluated the degree of conversion (DC) and working time (WT) of two commercial, dual-cured resin cements polymerized at varying temperatures and under different curing-light accessible conditions, using Fourier transformed infrared analysis (FTIR). Materials and Methods: Calibra (Cal; Dentsply Caulk) and Variolink II (Ivoclar Vivadent) were tested at 25 degrees C or preheated to 37 degrees C or 50 degrees C and applied to a similar-temperature surface of a horizontal attenuated-total-reflectance unit (ATR) attached to an infrared spectrometer. The products were polymerized using one of four conditions: direct light exposure only (600 mW/cm(2)) through a glass slide or through a 1.5- or 3.0-mm-thick ceramic disc (A2 shade, IPS e.max, Ivoclar Vivadent) or allowed to self-cure in the absence of light curing. FTIR spectra were recorded for 20 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm(-1)) immediately after application to the ATR. DC was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios precuring and 20-min postcuring as well as during each 1-second interval. Time-based monomer conversion analysis was used to determine WT at each temperature. DC and WT data (n=6) were analyzed by two-way analysis of variance and Tukey post hoc test (p=0.05). Results: Higher temperatures increased DC regardless of curing mode and product. For Calibra, only the 3-mm-thick ceramic group showed lower DC than the other groups at 25 degrees C (p=0.01830), while no significant difference was observed among groups at 37 degrees C and 50 degrees C. For Variolink, the 3-mm-thick ceramic group showed lower DC than the 1-mm-thick group only at 25 degrees C, while the self-cure group showed lower DC than the others at all temperatures (p=0.00001). WT decreased with increasing temperature: at 37 degrees C near 70% reduction and at 50 degrees C near 90% for both products, with WT reduction reaching clinically inappropriate times in some cases (p=0.00001). Conclusion: Elevated temperature during polymerization of dual-cured cements increased DC. WT was reduced with elevated temperature, but the extent of reduction might not be clinically acceptable.

EFFECT OF COMPETITION ON SALIVARY CORTISOL, IMMUNOGLOBULIN A, AND UPPER RESPIRATORY TRACT INFECTIONS IN ELITE YOUNG SOCCER PLAYERS

Mortatti, AL, Moreira, A, Aoki, MS, Crewther, BT, Castagna, C, de Arruda, AFS, and Filho, JM. Effect of competition on salivary cortisol, immunoglobulin A, and upper respiratory tract infections in elite young soccer players. J Strength Cond Res 26(5): 1396-1401, 2012-The present study examined the effect of a 20-day period of competition on salivary cortisol, mucosal immunity, and upper respiratory tract infections (URTI) in young male soccer players (n = 14). The players were monitored during the main under-19 Brazilian soccer championship, in which 7 matches were played in 20 days. Saliva samples were collected in the morning of each match and analyzed for cortisol and immunoglobulin A (IgA). Signs and symptoms of URTI were assessed across the study and a rating of perceived exertion (RPE) was obtained for each match. Compared with match 1, a significant increase in player RPE was observed in matches 4-7 (p < 0.05). Significant (p < 0.05) increases in the reporting of URTI occurred between matches 2 and 3, and 6 and 7, and this was accompanied by significant decreases in salivary IgA levels. Significant (p < 0.05) correlations were also seen between the individual reports of URTI and the decrease in IgA levels in match 2 (r = -0.60) and match 6 (r = -0.65). These results suggest that decrements in mucosal immunity, as measured by salivary IgA concentrations, may lead to a greater incidence of URTI in elite young soccer players. It may be speculated that the physiological and psychological stressors imposed by training and competition in a short timeframe are major contributing factors to these responses. Thus, the monitoring of salivary IgA could provide a useful and noninvasive approach for predicting URTI occurrences in young athletes during short-term competitions, especially if frequent sampling and rapid measurements are made.

Previous Exercise Training Has a Beneficial Effect on Renal and Cardiovascular Function in a Model of Diabetes

Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p < 0.05). Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p < 0.05). The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p < 0.05), and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p < 0.05). In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p < 0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ.

Susceptibilities of the dermatophytes Trichophyton mentagrophytes and T. rubrum microconidia to photodynamic antimicrobial chemotherapy with novel phenothiazinium photosensitizers and red light

Photodynamic antimicrobial chemotherapy (PACT) is a promising alternative to conventional chemotherapy that can be used to treat localized mycosis. The development of PACT depends on identifying effective and selective PS for the different pathogenic species. The in vitro susceptibilities of Trichophyton mentagrophytes and Trichophyton rubrum microconidia to PACT with methylene blue (MB), toluidine blue o (TBO), new methylene blue N (NMBN), and the novel pentacyclic phenothiazinium photosensitizer S137 were investigated. The efficacy of each PS was determined based on its minimal inhibitory concentration (MIC). Additionally, we evaluated the effect of PACT with NMBN and S137 on the survival of the microconidia of both species. 5137 showed the lowest MIC. MIC for S137 was 2.5 mu M both for T. mentagrophytes and T. rubrum, when a light dose of 5J cm(-2) was used. PACT with NMBN (10 mu M and 20J cm(-2)) resulted in a reduction of 4 logs in the survival of the T. rubrum and no survivor of T. mentagrophytes was observed. PACT with S137 at 1 mu M and 20J cm(-2) resulted in a reduction of approximately 3 logs in the survival of both species. When a S137 concentration of 10 mu M was used, no survivor was observed for both species at all light doses (5, 10 and 20J cm(-2)). (C) 2012 Elsevier B.V. All rights reserved.

Nd:YAG Laser Irradiation of Etched/Unetched Dentin Through an Uncured Two-step Etch-and-Rinse Adhesive and its Effect on Microtensile Bond Strength

Purpose: To evaluate whether Nd:YAG laser irradiation of etched and unetched dentin through an uncured adhesive affected the microtensile bond strength (pTBS). Materials and Methods: Flat dentin surfaces were created in 19 extracted human third molars. Adper Single Bond (SB) adhesive was applied over etched (groups 1 to 3) or unetched dentin (groups 4 to 6). The dentin was then irradiated with a Nd:YAG laser through the uncured adhesive, using 0.75 or 1 W power settings, except for the control groups (groups 1 and 4). The adhesive was light cured and composite crowns were built up. After 24 h, the teeth were sectioned into beams, with cross-sectional areas of 0.49 mm(2), and were stressed under tension. Data were statistically analyzed using two-way ANOVA and Tukey's test (alpha = 5%). Dentin surfaces of fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). Results: Acid etching, laser irradiation, and their interaction significantly affected bonding (p < 0.05). Laser irradiation did not improve bonding of etched dentin to resin (p > 0.05). However, higher pTBS means were found on unetched lased dentin (groups 5 and 6), but only in comparison to group 4, where neither lasing nor etching was performed. Groups 4 to 6 showed the lowest pTBS means among all groups tested (p < 0.05). Laser irradiation did not change the characteristics of the hybrid layers created, while solidification globules were observed on lased dentin surfaces under SEM. Conclusion: Laser irradiation of dentin through the uncured adhesive did not significantly improve the pTBS in comparison to the suggested manufacturer's technique.