Aspirin prevents diabetic oxidative changes in rat lacrimal gland structure and function

The aim of this study is to evaluate whether aspirin reduces Diabetis Mellitus (DM) oxidative damage in the lacrimal gland (LG), and ocular surface (OS). Ten weeks after streptozotocin induced DM and aspirin treatment, LG and OS of rats were compared for tear secretion, hidtology, peroxidase activity, and expression of uncoupling proteins (UCPs). DM reduction of tear secretion was prevented by aspirin (P < 0.01). Alterations of LG morphology and increased numbers of lipofucsin-like inclusions were observed in diabetic but not in aspirin-treated diabetic rats. Peroxidase activity levels were higher and UCP-2 was reduced in DM LG but not in aspirin treated (P = 0.0025 and P < 0.05, respectively). The findings prevented by aspirin indicate a direct inhibitory effect on oxidative pathways in LG and their inflammatory consequences, preserving the LG structure and function against hyperglycemia and/or insulin deficiency damage.

Bruxism in children with nasal obstruction

Introduction: Bruxism is characterized by repeated tooth grinding or clenching. The condition can occur in all age ranges and in both genders, being related or not to other oral habits. Objective: The objective of the present study was to investigate the occurrence of bruxism in children with nasal obstruction and to determine its association with other factors. Methods: Sixty children with nasal obstruction seen at the Otorhinolaryngology Outpatient Clinic of the University Hospital. of Ribeirao Preto participated in the study. The data were obtained using a pre-established questionnaire applied to the person responsible and by orofacial evaluation of the patient. The participants were divided into two groups: group with bruxism (GB) as reported by the relatives and with the presence of tooth wear detected by clinical evaluation, and group without bruxism (GWB), consisting of children with none of the two symptoms of bruxism mentioned above. Results: The presence of bruxism exceeded its absence in the sample studied (65.22%). There was no significant difference (P < 0.05) between groups regarding gender, phase of dentition, presence of hearing diseases, degree of malocclusion, or child behavior. Conclusion: Bruxism and deleterious oral habits such as biting behavior (objects, tips and nails) were significantly present, together with the absence of suction habits, in the children with nasal obstruction. (c) 2007 Elsevier Iretand Ltd. All. rights reserved.

Genotyping of Toxoplasma gondii isolates from free range chickens in the Pantanal area of Brazil

The aim of this paper was to genetically characterize Toxoplasma gondii isolates from free range chickens in regions of Brazilian territory in the state of Mato Grosso do Sul (MS) where T. gondii strains have never been studied. In total, T. gondii isolates from 22 free range chickens were included in this study. Fifty chickens from Eldorado, thirty from Rio Verde and ten from Aquidauana were sampled between January and April 2007. In relation to the genetic diversity of T. gondii isolates from chickens in MS, the magnitude of the diversity in the isolates sampled in this study was comparable to the overall diversity in a composite data set. These 22 isolates in MS revealed 11 genotypes, whereas the 321 isolates ever genotyped in Brazil have revealed 95 genotypes. The values of Simpson`s Diversity Index for the whole population of T. gondii isolates in Brazil, the whole population of T. gondii isolates from chickens in Brazil and the population surveyed in this study were 0.97, 0.95 and 0.90, respectively. Seven of the 11 genotypes revealed from chicken isolates from MS are newly described genotypes and six of them each have a single isolate. In conclusion, the results obtained from isolates in MS corroborate previous studies on T. gondii isolates in Brazil, thus confirming their diversity and atypicality. Nonetheless, the applicability of PCR-RFLP markers for epidemiological inferences remains controversial. (c) 2011 Elsevier B.V. All rights reserved.

Low doses of monocrotaline in rats cause diminished bone marrow cellularity and compromised nitric oxide production by peritoneal macrophages

Monocrotaline (MCT) is a pyrrolizidine alkaloid found in a variety of plants. The main symptoms of MCT toxicosis in livestock are related to hepato- and nephrotoxicity; in rodents and humans, the induction of a pulmonary hypertensive state that progresses to cor pulmonale has received much attention. Although studies have shown that MCT can cause effects on cellular functions that would be critical to those of lymphocytes/macrophages during a normal immune response, no immunotoxicological study on MCT have yet to ever be performed. Thus, the aim of the present study was to evaluate the effect of MCT on different branches of the immune system using the rat - which is known to be sensitive to the effects of MCT - as the model. Rats were treated once a day by gavage with 0.0, 0.3, 1.0, 3.0, or 5.0 mg MCT/kg for 14 days, and then any effects of the alkaloid on lymphoid organs, acquired immune responses, and macrophage activity were evaluated. No alterations in the relative weight of lymphoid organs were observed; however, diminished bone marrow cellularity in rats treated with the alkaloid was observed. MCT did not affect humoral or cellular immune responses. When macrophages were evaluated, treatments with MCT caused no significant alterations in phagocytic function or in hydrogen peroxide (H(2)O(2)) production; however, the MCT did cause compromised nitric oxide (NO) release by these cells.

Effects that bovine sperm cryopreservation using two different extenders has on sperm membranes and chromatin

The process of cryopreservation impairs sperm cell function, potentially leading to a reduction in fertility. The objectives of the present study were to evaluate the effects that cryopreservation using two different extenders has on sperm motility and mitochondrial function, as well as on the integrity of plasma membranes, acrosomal membranes and chromatin, using practical and objective techniques. The focus of the present study was to identify correlations between alterations in sperm membranes and sperm motility in cryopreserved bovine spermatozoa. Seven ejaculates were collected from eight Simmental bulls (n = 56). After collection, semen volume and concentration were assessed for purposes of dilution. Sperm motility was evaluated subjectively and by computer-assisted semen analysis, morphological characteristics were evaluated by differential interference microscopy, the integrity of plasma and acrosomal membranes, as well as mitochondrial function, were determined using a combination of fluorescent probes containing fluorescein isothiocyanate-Pisum sativum agglutinin, propidium iodide or 5,5`,6,6`-tetrachloro-1,1`,3,3`-tetraethylbenzimidazolearbocyanine iodide. Chromatin integrity was evaluated using the acridine orange technique. The semen was subsequently divided into two aliquots and diluted with one of two extenders (Bioxcell(R) or Botu-Bov(R)), after which both were packaged in 0.5 mL straws and frozen using an automated system. Two straws of semen from each treatment were thawed, and the semen parameters were evaluated as described above. Cryopreservation of sperm reduced motility, damaging plasma and acrosomal membranes, as well as decreasing mitochondrial function. The Botu-Bov(R) extender was more effective in preserving sperm motility and membrane integrity than was the Bioxcell(R) extender. (C) 2007 Elsevier B.V. All rights reserved.

Magnetic retention and bar-clip attachment for implant-retained auricular prostheses: A comparative analysis

Retention systems for implant-retained auricular prostheses using either bar-clip attachments with 2 or 3 clips or retention with 2 or 3 magnets were wear tested (insertion and removal cycles) to simulate clinical periods of use. Measurements were taken at intervals of 540 cycles, which represents a period of use of approximately 6 months, for up to 3,240 cycles. Assessments of retentive force were carried out before, during, and after the wear test. Statistical analysis indicated that the bar-clip systems provided higher retention than the magnetic systems. The bar-clip attachment with 2 clips showed a significant loss of retentive force after wear testing (P < .05), suggesting lower durability and shorter clinical life. The retention provided by the bar-clip attachment with 3 clips remained stronger than that provided by all other systems tested. At the end of the wear test, the magnetic systems showed very little loss of retention but were still less retentive than the bar-clip systems, suggesting higher durability under clinical simulation despite the lower retention initially provided.

Prevention of toothbrushing abrasion of acid-softened enamel by CO(2) laser irradiation

Objective: The aim of the present study was to evaluate the effect of CO(2) laser irradiation (10.6 mu m) at 0.3 J/cm(2) (0.5 mu s; 226 Hz) on the resistance of softened enamel to toothbrushing abrasion, in vitro. Methods: Sixty human enamel samples were obtained, polished with silicon carbide papers and randomly divided into five groups (n = 12), receiving 5 different surface treatments: laser irradiation (L), fluoride (AmF/NaF gel) application (F), laser prior to fluoride (LF), fluoride prior to laser (FL), non-treated control (C). After surface treatment they were submitted to a 25-day erosive-abrasive cycle in 100 ml sprite light (90 s) and brushed twice daily with an electric toothbrush. Between the demineralization periods samples were immersed in supersaturated mineral solution. At the end of the experiments enamel surface loss was determined using a contact profilometer and morphological analysis was performed using scanning electron microscopy (SEM). For SEM analysis of demineralization pattern, cross-sectional cuts of cycled samples were prepared. The data were statistically analysed by one-way ANOVA model with subsequent pairwise comparison of treatments. Results: Abrasive surface loss was significantly lower in all laser groups compared to both control and fluoride groups (p < 0.0001 in all cases). Amongst the laser groups no significant difference was observed. Softened enamel layer underneath lesions was less pronounced in laser-irradiated samples. Conclusion: Irradiation of dental enamel with a CO(2) laser at 0.3 J/cm(2) (5 mu s, 226 Hz) either alone or in combination with amine fluoride gel significantly decreases toothbrushing abrasion of softened-enamel, in vitro. (C) 2011 Elsevier Ltd. All rights reserved.

Evaluation of the Possibility of Removing Staining by Repolishing Composite Resins Submitted to Artificial Aging

This in vitro research verified the possibility of eliminating staining caused by coffee and red wine in five composite resins, after being submitted to thermal cycling. Thirty-six specimens were prepared and immersed in water at 37 degrees C for 24 hours. After polishing, specimen color was measured in a spectrophotometer Cintra 10 UV (Visible Spectrometer, GBC, Braeside, VIC, Australia). All specimens were submitted to thermal cycling at temperatures of 5 and 55 degrees C with a dwell time of 1 minute, for 1,000 cycles in a 75% ethanol/water solution. After thermal cycling, the specimens were immersed in water at 37 degrees C until 7 days had elapsed from the time the specimens were prepared. All specimens were then taken to the spectrophotometer for color measurement. The specimens were divided into three groups (N = 12): distilled water (control), coffee, and red wine. For the staining process to occur on only one surface, all the sides, except one, of the surfaces were isolated with white wax. The specimens were immersed in one of the solutions at 37 degrees C for 14 days. The specimens were dried and taken to the spectrophotometer for color measurement. After this, the specimens were submitted to 20 mu m wear three times, and the color was measured after each one of the wear procedures. Calculation of the color difference was made using CIEDE2000 formula. According to the methodology used in this research, it was concluded that the staining caused by coffee and red wine was superficial and one wear of 20 mu m was sufficient to remove the discoloration.

Cyclic Fatigue Resistance of Rotary Nickel-Titanium Instruments Submitted to Nitrogen Ion Implantation

Introduction: The aim of this study was to assess cyclic fatigue resistance in rotary nickel-titanium instruments submitted to nitrogen ion implantation by using a custom-made cyclic fatigue testing apparatus. Methods: Thirty K3 files, size #25, taper 0.04, were divided into 3 experimental groups as follows: group A, 12 files exposed to nitrogen ion implantation at a dose of 2.5 x 10(17) ions/cm(2), accelerating voltage of 200 kV, currents of 1 mu A/cm(2), 130 degrees C temperature, and vacuum conditions of 10 x 10(-6) torr for 6 hours; group B, 12 nonimplanted files; and group C, 6 files submitted to thermal annealing for 6 hours at 130 degrees C. One extra file was used for process control. All files were submitted to a cyclic fatigue test that was performed with an apparatus that allowed the instruments to rotate freely, simulating rotary instrumentation of a curved canal (40-degree, 5-mm radius curve). An electric motor handpiece was used with a contra-angle of 16:1 at an operating speed of 300 rpm and a torque of 2 N-cm. Time to failure was recorded with a stopwatch in seconds and subsequently converted to number of cycles to fracture. Data were analyzed with the Student t test (P < .05). Results: Ion-implanted instruments reached significantly higher cycle numbers before fracture (mean, 510 cycles) when compared with annealed (mean, 428 cycles) and nonimplanted files (mean, 381 cycles). Conclusions: Our results showed that nitrogen ion implantation improves cyclic fatigue resistance in rotary nickel-titanium instruments. Industrial implementation. of this surface modification technique would produce rotary nickel-titanium instruments with a longer working life. (J Endod 2010;36:1183-1186)

Physical-mechanical properties of glass ionomer cements indicated for atraumatic restorative treatment

Background: This study evaluated mechanical properties of glass ionomer cements (GICs) used for atraumatic restorative treatment. Wear resistance, Knoop hardness (Kh), flexural (F(s)) and compressive strength (C(s)) were evaluated. The GICs used were Riva Self Cure (RVA), Fuji IX (FIX), Hi Dense (HD), Vitro Molar (VM), Maxxion R (MXR) and Ketac Molar Easymix (KME). Methods: Wear was evaluated after 1, 4, 63 and 365 days. Two-way ANOVA and Tukey post hoc tests (P = 0.05) analysed differences in wear of the GICs and the time effect. F(s), C(s), and Kh were analysed with one-way ANOVA. Results: The type of cement (p < 0.001) and the time (p < 0.001) had a significant effect on wear. In early-term wear and Kh, KME and FIX presented the best performance. In long-term wear, F(s) and C(s), KME, FIX and HD had the best performance. Strong explanatory power between F(s) and the Kh (r(2) = 0.85), C(s) and the Kh (r(2) = 0.82), long-term wear and F(s) of 24 h (r(2) = 0.79) were observed. Conclusions: The data suggested that KME and FIX presented the best in vitro performance. HD showed good results except for early-term wear.

Removal of a Partial Denture from the Esophagus with the Aid of an Endoscope

Swallowed prostheses have been described in the literature, and in some cases, the diagnosis can be challenging, especially if the partial or complete denture is metal-free. This article presents a case of a swallowed partial denture and points to the importance of early diagnosis. A man was admitted to the emergency room complaining of progressive breathing difficulty while presenting with an extra volume in his neck. After inconclusive image examinations, endoscopy under sedation was used to identify and retrieve the foreign object, which was a metal-free acrylic partial denture. Early diagnosis and the correct treatment can avoid serious sequelae, such as edematous reactions, mucosal infection, and necrosis. Patients should be scheduled for regular recall visits for evaluation of prosthesis fit and retention, condition of the abutments, and nocturnal wear. Int J Prosthodont 2010;23:339-341.

Early dental plaque formation on toothbrushed titanium implant surfaces

Purpose: To evaluate the qualitative and quantitative differences on dental plaque formation on two different roughness titanium implant surfaces, i.e. machined and titanium plasma sprayed, as well as the amount of plaque removal by regular toothbrushing after 72-hour plaque accumulation. Methods: Eight systemically healthy subjects were recruited from the patient pool of a private dental practice. All patients underwent oral hygiene instruction and full mouth prophylaxis. Subsequently, maxillary casts from all patients were obtained and removable 0.7 mm-thick acetate stents without occlusal contact points were fabricated to support four titanium specimens of 4x2x2 mm divided into two groups (machined and plasma sprayed). Subjects were instructed to wear the stents for 72 hours, full time, removing them only during regular oral hygiene. Subsequently, the appliances were immediately repositioned and then the test side was brushed for 20 seconds. At the end of the 72-hour period, the stents were removed and prepared for microbiological analysis. Results: Both machined and plasma sprayed brushed surfaces presented statistically significant fewer bacteria than non-brushed surfaces. Similarly, regarding surface roughness, machined surfaces presented a total number of bacteria significantly smaller than those presented by plasma sprayed surfaces (P< 0.05). Statistically, the non-brushed machined turned surfaces presented a greater amount of Streptoccocus sp. when compared to the brushed machined surfaces. It was concluded that rough surfaces accumulated more dental plaque than polished surfaces. Both brushed surfaces presented less plaque accumulation, however, implant brushing was more effective on machined surfaces. (Am J Dent 2008;21:318-322).

Gels Containing MMP Inhibitors Prevent Dental Erosion in situ

Matrix metalloproteinase (MMP) inhibition has been shown to reduce dentin caries progression, but its role in dental erosion has not yet been assessed. This study tested the hypothesis that gels containing MMP inhibitors (epigallocatechin gallate-EGCG and chlorhexidine) can prevent dental erosion. Volunteers (n = 10) wore palatal devices containing bovine dentin blocks (n = 10/group) treated for 1 min with EGCG at 10 (EGCG10) or 400 mu M (EGCG400), chlorhexidine at 0.012%, F at 1.23% (NaF), and no vehicle (placebo). Erosion was performed with Coca-Cola (R) (5 min) 4X/day during 5 days. The wear, assessed by profilometry (mean +/- SD, mu m), was significantly reduced by the gels containing MMP inhibitors (0.05 +/- 0.02(a), 0.04 +/- 0.02(a), and 0.05 +/- 0.02(a) for EGCG10, EGCG400, and chlorhexidine, respectively) when compared with NaF (0.79 +/- 0.35(b)) and placebo gels (1.77 +/- 0.35(b)) (Friedman and Dunn`s tests, p < 0.01). The use of gels delivering MMP inhibitors was shown to prevent erosion and opens a new perspective for protection against dental erosion.

The Erosive Potential of 1% Citric Acid Supplemented by Different Minerals: An In Vitro Study

Purpose: The objective of the present in vitro study was to evaluate the effect of different minerals in combination with 1% citric acid on dental erosion. Materials and Methods: Ninety enamel samples were randomly allocated to nine groups (G1. pure 1% citric acid solution [control]. G2. with 1 mM Ca: G3 with 0 047 mM F, G4. with 1 mM Fe. G5. with 1 mM P, G6 with 1 mM Ca and 0 047 mM F. G7. with 1 mM Ca and 1 mM P: G8: with 1 mM Fe and 0.047 mM F, G9. with 1 mM Ca, 1 mM P. 0 047 rnM F and 1.0 mM Fe) The samples were subjected to six pH cycles, each consisting of immersion in pure or modified 1% citric acid (1 min) followed by storage in artificial saliva (59 min) Enamel wear was assessed using profilometry. Results: Data were analysed using analysis of variance and Tukey test (P < 0 05) Enamel loss (mean +/- SD) amounted to between 0 87 +/- 0 30 and 1 74 +/- 0 74 mu m but did not significantly differ among the groups Conclusions: The modification of 1% citric acid with different minerals did not have a protective effect on enamel erosion

Effect of Different Fluoride Concentrations of Experimental Dentifrices on Enamel Erosion and Abrasion

It has been suggested that fluoride products are able to reduce erosive tooth wear. Thus, the purpose of this in vitro study was to evaluate the effect of dentifrices with different fluoride concentrations as well as of a low-fluoridated dentifrice supplemented with trimetaphosphate (TMP) on enamel erosion and abrasion. One hundred twenty bovine enamel blocks were assigned to the following experimental dentifrices: placebo, 1,100 mu g F/g, 500 mu g F/g plus 3% TMP and 5,000 mu g F/g. The groups of enamel blocks were additionally subdivided into conditions of erosion (ERO) and of erosion plus abrasion (ERO + ABR). For 7 days, the blocks were subjected to erosive challenges (immersion in Sprite (R) 4 times a day for 5 min each time) followed by a remineralizing period (immersion in artificial saliva between erosive challenges for 2 h). After each erosive challenge, the blocks were exposed to slurries of the dentifrices (10 ml/sample for 15 s). Sixty of the blocks were additionally abraded by brushing using an electric toothbrush (15 s). The alterations of the enamel were quantified using the Knoop hardness test and profilometry (measurements in micrometers). The data were analyzed using a 2-way ANOVA test followed by a Bonferroni correction (p < 0.05). In in vitro conditions, the 5,000 mu g F/g and 500 mu g F/g plus 3% TMP dentifrices had a greater protective effect when compared with the 1,100 mu g F/g dentifrice, under both ERO and ERO + ABR conditions. The results suggest that dentifrices alone are not capable of completely inhibiting tooth wear. Copyright (C) 2010 S. Karger AG, Basel