The effect of ovariectomy on cardiac autonomic control in rats submitted to aerobic physical training

We have investigated the ovariectomy effects on the cardiovascular autonomic adaptations induced by aerobic physical training and the role played by nitric oxide (NO). Female Wistar rats (n =70) were divided into five groups: Sedentary Sham (SS): Trained Sham (TS); Trained Hypertensive Sham treated with N(C)-nitro-L-arginine methyl ester (L-NAME) (THS): Trained Ovariectomized (TO); and Trained Hypertensive Ovariectomized treated with L-NAME (THO). Trained groups were submitted to a physical training during 10 weeks. The cardiovascular autonomic control was investigated in all groups using different approaches: 1) pharmacological evaluation of autonomic tonus with methylatropine and propranolol; 2) analysis of heart rate (HR) and systolic arterial pressure (AP) variability; 3) spontaneous baroreflex sensitivity (BRS) evaluation. Hypertension was observed in THS and THO groups. Pharmacological analysis showed that TS group had increased predominance of autonomic vagal tonus compared to SS group. HR and intrinsic HR were found to be reduced in all trained animals. TS group, compared to other groups, showed a reduction in LF oscillations (LF=0.2-0.75 Hz) of pulse interval in both absolute and normalized units as well as an increase in HF oscillations (HF=0.75-2.50 Hz) in normalized unit. FIRS analysis showed that alpha-index was different between all groups. TS group presented the greatest value, followed by the TO, SS. THO and THS groups. Ovariectomy has negative effects on cardiac autonomic modulation in trained rats, which is characterized by an increase in the sympathetic autonomic modulation. These negative effects suggest NO deficiency. In contrast, the ovariectomy seems to have no effect on AP variability. (C) 2008 Elsevier B.V. All rights reserved.

Natural, but not lyophilized, low density lypoproteins were an acceptable alternative to egg yolk for cryopreservation of ram semen

The objective was to evaluate the suitability of using natural or lyophilized low density lipoproteins (LDL), in lieu of whole egg yolk, in extenders for cryopreserving ram semen. Once extragonadal sperm reserves were depleted in 10 fertile Santa Ines cross rams, two ejaculates per ram were collected for cryopreservation. Nine extenders were used: Tris-16% egg yolk extender with 5% glycerol as a control (T1), and substitution of whole egg yolk with 8, 12, 16 or 20% natural LDL (T2-T5, respectively), or with 8, 12, 16, or 20% lyophilized LDL (T6-T9). Semen was diluted to 100 X 10(6) sperm/mL, packaged into 0.25 mL straws, cooled, held at 5 C for 3 h, and then frozen in liquid nitrogen vapor. Immediately after thawing (37 degrees C for 30 s), sperm total and progressive motility, and kinetic parameters were analyzed with computer assisted semen analysis (CASA). Percentage of sperm with plasma membrane functional integrity was assessed by the hypoosmotic swelling test (HOST), sperm membrane physical integrity with propidium iodide (PI), and acrosome integrity with FITC-PSA using an epifluorescent microscope. For all sperm end points, there was no difference between the control and natural LDL treatments (P > 0.05): total motility (T1: 20.9 +/- 11.9 and average of T2-T5: 25.9 +/- 13.6%; mean SD), progressive motility (T1: 6.6 +/- 4.2 and average of T2-T5: 11.7 +/- 7.5%), HOST(+) (T1: 23.7 +/- 6.9 and average of T2-T5: 23.2 +/- 8.7%) and PI(-)/PSA(-) (T1: 13.8 +/- 7.8 and average of T2-T5: 18.1 +/- 7.8%). However, lyophilization was apparently unable to preserve the protective function of LDL; every sperm end point was significantly worse than in the control and natural LDL groups. We concluded that natural LDL was appropriate for cryopreserving ram semen, as it yielded results similar to those obtained with whole egg yolk. (C) 2011 Elsevier Inc. All rights reserved.

Physical therapy assessment tools to evaluate disease progression and phenotype variability in Golden Retriever muscular dystrophy

Dogs suffering from Golden Retriever muscular dystrophy (GRMD) present symptoms that are similar to human patients with Duchenne muscular dystrophy (DMD). Phenotypic variability is common in both cases and correlates with disease progression and response to therapy. Physical therapy assessment tools were used to study disease progression and assess phenotypic variability in dogs with GRMD. At 5 (TO), 9 (T1), 13 (T2) and 17 (T3) months of age, the physical features, joint ranges of motion (ROM), limb and thorax circumferences, weight and creatine kinase (CK) levels were assessed in 11 dogs with GRMD. Alterations of physical features were higher at 13 months, and different disease progression rates were observed. Passive ROM decreased until 1 year old, which was followed by a decline of elbow and tarsal ROM. Limb and thorax circumferences, which were corrected for body weight, decreased significantly between TO and T3. These measurements can be used to evaluate disease progression in dogs with GRMD and to help discover new therapies for DMD patients. (C) 2011 Elsevier Ltd. All rights reserved.

Physical, epidemiological, and molecular evaluation of infection by Cryptosporidium galli in Passeriformes

Due to the scarcity of information related to the epidemiology of Cryptosporidium infection in passerine birds, this study aimed to determine the periodicity of fecal shedding of Cryptosporidium spp. oocysts, after natural infection, and its clinical signs, mortality, and molecular characterization. Four hundred eighty fecal samples were collected from 40 birds, including 372 samples from 31 adult birds and 108 samples from nine young birds (up to 12 months old), housed in five aviaries, monthly from September 2007 to September 2008, with the exception of April. The birds originated from aviaries in which the following species were raised: great-billed seed-finch (Oryzoborus maximiliani), lesser seed-finch (Oryzoborus angolensis), ultramarine grosbeak (Cyanocompsa brissonii), and rusty-collared seedeater (Sporophila collaris). The samples were preserved in 2.5% potassium dichromate at 4A degrees C until processing. The oocysts were purified by centrifugal flotation in Sheather`s solution, followed by genomic DNA extraction and molecular characterization of oocysts using the nested polymerase chain reaction for amplification of fragments of the 18S subunit of rRNA gene. Intermittent shedding of oocysts was observed by positive amplification for Cryptosporidium spp. in 91 (24.5%) samples of adult birds and 14 (13%) of young birds. The sequencing of the amplified fragments enabled the identification of Cryptosporidium galli. Although all the aviaries had birds positive for C. galli, morbidity or mortality was observed in only one aviary and was associated with concomitant infection with Escherichia coli and Isospora sp.

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.

Tailoring of physical properties in highly filled experimental nanohybrid resin composites

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.

Nasal mucus transportability in children with cleft palate

Objectives: Children with cleft palate (CP) have a high prevalence of sinusitis. Considering that nasal mucus properties play a pivotal role in the upper airway defense mechanism, the aim of the study was to evaluate nasal mucus transportability and physical properties from children with CP. Setting: Hospital for Rehabilitation of Craniofacial Anomalies, School of Dentistry, University of Sao Paulo, Bauru, SP, Brazil and Laboratory of Experimental Air Pollution, School of Medicine, University of Sao Paulo, Sao Paulo, SP, Brazil. Methods: Nasal mucus samples were collected by nasal aspiration from children with CP and without CP (non-CP). Sneeze clearance (SC) was evaluated by the simulated sneeze machine. In vitro mucus transportability (MCT) by cilia was evaluated by the frog palate preparation. Mucus physical surface properties were assessed by measuring the contact angle (CA). Mucus rheology was determined by means of a magnetic rheometer, and the results were expressed as log G* (vectorial sum of viscosity and elasticity) and tan delta (relationship between viscosity and elasticity) measured at 1 and 100 rad/s. Results: Mucus samples from children with CP had a higher SC than non-CP children (67 +/- 30 and 41 +/- 24 mm, respectively, p < 0.05). Mucus samples from children with CP had a lower CA (24 +/- 16 degrees and 35 +/- 11 degrees, p < 0.05) and a higher tan delta 100 (0.79 +/- 0.24 and 0.51 +/- 0.12, p < 0.05) than non-CP children. There were no significant differences in mucus MCT, log G* 1, tan delta 1 and log G* 100 obtained for CP and non-CP children. Conclusions: Nasal mucus physical properties from children with CP are associated with higher sneeze transportability. The high prevalence of sinusitis in children with CP cannot be explained by changes in mucus physical properties and transportability. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Physical Properties and Interfacial Adaptation of Three Epoxy Resin-based Sealers

Introduction: The aim of the study was to evaluate the radiopacity, solubility, flow, film thickness, setting time, and adaptation to the root canal walls of 3 epoxy resin based sealers: AH Plus, Acroseal, and Adseal. Methods: Physical tests were performed following American National Standards Institute/American Dental Association`s requirements. For interfacial adaptation analysis, 30 maxillary canines were shaped by using Pro Taper instruments. The specimens were divided into 3 groups (n = 10): group 1, AH Plus; group 2, Acroseal; and group 3, Adseal. The sealers were mixed with rhodamine B dye, and the canals were filled by using the lateral compaction technique. The percentage of gaps and voids area was calculated at 2, 4, and 6 mm levels from the apex. Statistical evaluation was performed by using analysis of variance for physical analysis and nonparametric Kruskal-Wallis and Dunn tests for interfacial adaptation (P<.05). Results: No statistical differences were found for adaptation, percentage of voids, solubility, flow, and film thickness among the sealers (P>.05). AH Plus was significantly more radiopaque (P<.05). For the setting time, there were statistical differences among all the studied sealers (P<.05). Conclusions: AH Plus, Acroseal, and Adseal presented similar root canal adaptation, solubility, flow, and film thickness. Statistical differences were found for radiopacity and setting time (P<.05). (J Endod 2011;37:1417-1421)

Evaluation of the physical and chemical properties of two commercial and three experimental root-end filling materials

Objective. The aim of this study was to evaluate the pH, calcium release, setting time, and solubility of two commercially available mineral trioxide aggregate (MTA) cements (white MTA Angelus and MTA Bio), and of three experimental cements (light-cured MTA, Portland cement with 20% bismuth oxide and 5% calcium sulfate, and an epoxy resin-based cement). Study design. For evaluation of pH and calcium ion release, polyethylene tubes with 1.0 mm internal diameter and 10.0 mm length were filled with the cements and immediately immersed in flasks containing 10 mL deionized water. After 3, 24, 72, and 168 hours, the tubes were removed and the water from the previous container was measured for its pH and calcium content with a pH meter and an atomic absorption spectrophotometer. For analysis of the setting time, Gilmore needles weighing 100 g and 456.5 g were used, in accordance with the American Society for Testing and Materials specification no. C266-03. Solubility of each cement was also tested. Results. All the cements were alkaline and released calcium ions, with a declining trend over time. After 3 hours, Portland cement + bismuth oxide and MTA Bio had the highest pH and light-cured MTA the lowest. After 1 week, MTA Bio had the highest pH and light-cured MTA and epoxy resin-based cement the lowest. Regarding calcium ion release, after 3 hours, Portland cement + bismuth oxide showed the highest release. After 1 week, MTA Bio had the highest. Epoxy resin-based cement and light-cured MTA had the lowest calcium release in all evaluation periods. Regarding setting times, white MTA Angelus and MTA Bio had the shortest, Portland cement + bismuth oxide had an intermediate setting time, and the epoxy resin-based cement had the longest. The materials that showed the lowest solubility values were the epoxy resin-based cement, Portland cement + bismuth oxide, and light-cured MTA. The highest solubility values were presented in white MTA Angelus and MTA Bio. Conclusions. The white MTA Angelus and MTA Bio had the shortest setting times, higher pH and calcium ion release, and the highest solubility. In contrast, the epoxy resin-based cement and light-cured MTA showed lower values of solubility, pH, and calcium ion release. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 110: 250-256)

Influence of Calcium Hydroxide Association on the Physical Properties of AH Plus

Introduction: This study evaluated in vitro the radiopacity, setting time, flow, film thickness, solubility, and dimensional changes of AH Plus sealer pure (Dentsply De Trey Gmbh, Konstanz, Germany) and containing 5% and 10% of calcium hydroxide. Methods: The study was performed according to the requirements of the ISO 6876:2001 standard and the American National Standards Institute/American Dental Association (ANSI/ADA)`s Specification No. 57. The following tests were performed: setting time, flow, film thickness, dimensional stability, radiopacity, and solubility. Data were analyzed statistically by analysis of variance and the Tukey tests with a significance level of 5%. Results: The addition of 5% or 10% calcium hydroxide to AH Plus sealer did not alter significantly the radiopacity or setting time values (p > 0.05). Adding 10% calcium hydroxide reduced the flow compared with pure AH Plus and AH Plus/5% calcium hydroxide. The addition of 5% and 10% calcium hydroxide increased the solubility and expansion of AH Plus. All materials presented expansion valued above those recommended by the ADA. The addition of calcium hydroxide to the sealer resulted in greater film thickness. Conclusions: The addition of 5% calcium hydroxide did not affect most physical properties of AH Plus sealer. (J Endod 2010;36:1048-1051)

Ultrasonic Chemical Vapor Deposition-coated Tip versus High- and Low-speed Carbide Burs for Apicoectomy: Time Required for Resection and Scanning Electron Microscopy Analysis of the Root-end Surfaces

This study compared ultrasonic chemical vapor deposition (CVD)-coated tip (CVDentus #8.1117-1; Clorovale Diamantes Ind. e Com. Ltda Epp, Sao Jose dos Campos, SP, Brazil) versus high-speed (#FG700L) and low-speed (#699) carbide burs for apicoectomy, evaluating the time required for resection and analyzing the root-end surfaces by scanning electron microscopy. Thirty extracted human premolars had the canals instrumented and obturated and were randomly assigned to 3 groups (n = 10), according to the instrument used for root-end resection. The time required for resection of the apical 2 mm of each root was recorded. The resected apical segments were dried, sputter coated with gold, and examined with a scanning electron microscope at X 350 magnification. A four-point (0-3) scoring system was used to evaluate the apical surface smoothness. The results were analyzed statistically by the Kruskal-Wallis test and two-by-two comparisons analyses were performed using the Miller test. The significance level was set at 5%. Root-end resection with the high-speed bur was significantly faster (p < 0.05) compared with the low-speed bur and CVD tip. The carbide burs produced significantly smoother root-end surfaces than the CVD tip (p < 0.05). The low-speed bur produced the smoothest root-end surfaces, whereas the roughest and most irregular root ends (p < 0.05) were obtained with the CVD tip. However, no statistically significant difference (p > 0.05) was found between the high- and low-speed burs regarding the surface roughness of the resected root ends (p > 0.05). In conclusion, under the tested conditions, ultrasonic root-end resection took a longer time and resulted in rougher surfaces compared with the use of carbide burs at both high and low speed. (J Endod 2009;35:265-268)

Physical Properties of an Acrylic Resin after Incorporation of an Antimicrobial Monomer

Purpose: This study evaluated the effect of the incorporation of the antimicrobial monomer methacryloyloxyundecylpyridinium bromide (MUPB) on the hardness, roughness, flexural strength, and color stability of a denture base material. Materials and Methods: Ninety-six disk-shaped (14-mm diameter x 4-mm thick) and 30 rectangular (65 x 10 x 3.3 mm(3)) heat-polymerized acrylic resin specimens were divided into three groups according to the concentration of MUPB (w/w): (A) 0%, (B) 0.3%, (C) 0.6%. Hardness was assessed by a hardness tester equipped with a Vickers diamond penetrator. Flexural strength and surface roughness were tested on a universal testing machine and a surface roughness tester, respectively. Color alterations (Delta E) were measured by a portable spectrophotometer after 12 and 36 days of immersion in water, coffee, or wine. Variables were analyzed by ANOVA/Tukey HSD test (alpha = 0.05). Results: The following mean results (+/-SD) were obtained for hardness (A: 15.6 +/- 0.6, B: 14.6 +/- 1.7, C: 14.8 +/- 0.8 VHN; ANOVA: p = 0.061), flexural strength (A: 111 +/- 17, B: 105 +/- 12, C: 88 +/- 12 MPa; ANOVA: p = 0.008), and roughness (A: 0.20 +/- 0.11, B: 0.20 +/- 0.11, C: 0.24 +/- 0.08 mu m; ANOVA: p = 0.829). Color changes of immersed specimens were significantly influenced by solutions and time (A: 9.1 +/- 3.1, B: 14.8 +/- 7.5, C: 13.3 +/- 6.1 Delta E; ANOVA: p < 0.05). Conclusions: The incorporation of MUPB affects the mechanical properties of a denture base acrylic resin; however, the only significant change was observed for flexural strength and may not be critical. Color changes were slightly higher when resin containing MUPB was immersed in wine for a prolonged time; however, the difference has debatable clinical relevance.