Acute reduction in serum progesterone concentrations after feed intake in dairy cows

This study tested the hypothesis that high feed consumption will acutely decrease circulating progesterone concentrations. In the first experiment, a Latin Square design was used to test whether feeding pattern would alter circulating progesterone in pregnant lactating Holstein cows (n = 12). Feed was removed for 12 h before the experiment and cows were then either fed 100% of the total mixed ration (TMR), 50% of TMR every 12 h, 25% of TMR every 6 h, or left unfed for an additional 12 h. Blood samples were taken every hour for 24 h. Provision of 100 or 50% of TMR decreased circulating progesterone by 1 h after feeding and progesterone remained depressed until 8-9 h after feeding. Feeding 25% of TMR did not reduce circulating progesterone concentrations. Experiment 2 used a crossover design to measure the effect of acute feeding on circulating progesterone and LH concentrations during delivery of a constant amount of exogenous progesterone (Eazi-Breed CIDRs) in lactating Holstein cows (n = 8) and nonpregnant dry Holstein cows (n = 6). Blood samples were taken every 15 min for 8 h. There was no change in serum progesterone during the 8 h treatment period in unfed cows; however, feeding decreased (P < 0.05) circulating progesterone between 2 and 6 h after feeding. In lactating cows, feeding increased mean LH (P < 0.05). There were more LH pulses (P = 0.01) in lactating than nonlactating cows. Thus, acute feeding reduced circulating progesterone in pregnant lactating cows apparently due to an increase in progesterone metabolism. Interestingly, feeding multiple smaller meals eliminated the acute effect of feeding on circulating progesterone. © 2003 Published by Elsevier B.V.

Microbiologic and radiographic analysis of ligature-induced peri-implantitis with different dental implant surfaces

Purpose: The goal of this study was to evaluate microbiota and radiographic peri-implant bone loss associated with ligature-induced peri-implantitis. Materials and Methods: Thirty-six dental implants with 4 different surfaces (9 commercially pure titanium, 9 titanium plasma-sprayed, 9 hydroxyapatite, and 9 acid-etched) were placed in the edentulous mandibles of 6 dogs. After 3 months with optimal plaque control, abutment connection was performed. On days 0, 20, 40, and 60 after placement of cotton ligatures, both microbiologic samples and periapical radiographs were obtained. The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Campylobacter spp, Capnocytophaga spp, Fusobacterium spp, beta-hemolytic Streptococcus, and Candida spp were evaluated culturally. Results: P intermedia/nigrescens was detected in 13.89% of implants at baseline and 100% of implants at other periods. P gingivalis was not detected at baseline, but after 20 and 40 days it was detected in 33.34% of implants and at 60 days it was detected in 29.03% of dental implants. Fusobacterium spp was detected in all periods. Streptococci were detected in 16.67% of implants at baseline and in 83.34%, 72.22%, and 77.42% of implants at 20, 40, and 60 days, respectively. Campylobacter spp and Candida spp were detected in low proportions. The total viable count analysis showed no significant differences among surfaces (P = .831), although a significant difference was observed after ligature placement (P < .0014). However, there was no significant qualitative difference, in spite of the difference among the periods. The peri-implant bone loss was not significantly different between all the dental implant surfaces (P = .908). Discussion and Conclusions: These data suggest that with ligature-induced peri-implantitis, both time and periodontal pathogens affect all surfaces equally after 60 days.

The influence of diabetes mellitus and insulin therapy on biomechanical retention around dental implants: a study in rabbits.

The oral rehabilitation by dental implants in patients with diabetes remains a controversial issue. The aim of this study was to evaluate the influence of diabetes mellitus and insulin therapy on the bone healing around dental implants using torque removal. Twenty-seven rabbits were randomly divided into 3 groups with 9 animals each: control (C) group, induced diabetic (D) group, and insulin-treated diabetic (ITD) group (10 U/day). After 1 week, one implant was inserted at the tibial metaphysis of the animals. The glucose levels were periodically evaluated through the glucose-oxidase enzymatic method. The animals were killed at 4, 8, and 12 weeks after surgery and the biomechanical test was performed using a torque manometer. Statistically significant differences regarding the removal torque of the implant could not be found at 4 weeks (P = 0.2) among groups. Group C showed statistically higher values than groups D and ITD at the experimental periods of 8 (P = 0.0001 and P = 0.0002, respectively) and 12 weeks (P = 0.0053 and P = 0.001, respectively). There were no statistical differences between D and ITD groups in any of the experimental periods. Diabetes mellitus has negatively influenced the mechanical retention of implants placed at the tibial metaphysis of rabbits. Therapy with insulin did not induce any changes.

Weight loss and surface roughness of hard chairside reline resins after toothbrushing: Influence of postpolymerization treatments

Purpose: To evaluate the effect of 2 postpolymerization treatments on toothbrushing wear (weight loss) and surface roughness of 3 autopolymerized reline resins-Duraliner II (D) (Reliance Dental), Kooliner (K) (Coe Laboratories), and Tokuso Rebase Fast (T) (Tokuyama Dental)-and 1 heat-polymerized resin, Lucitone 550 (L) (Dentsply International). Materials and Methods: Specimens (40 x 10 x 2mm) of each material (n = 24) were prepared and divided into 3 groups: control (no postpolymerization treatment); water bath (immersion in water at 55°C); and microwave (microwave irradiation). Specimens were dried until constant weight was achieved and the surface roughness (Ra) was measured. Tests were performed in a toothbrush machine using 20,000 strokes of brushing at a weight of 200 g, with the specimens immersed in 1:1 dentifrice/water slurry. Specimens were reconditioned to constant weight and the weight loss (mg) and surface roughness were evaluated. Data were analyzed by 2-way analysis of variance and followed by Tukey test (α = .05). Results: In the control group, the weight loss of materials D and T was lower (P < .05) than that of L. No differences among materials were found after postpolymerization treatments (P > .05). The weight loss of material T (control = 0.5 mg) was significantly increased (P < .05) after postpolymerization treatments (water bath = 1.9 mg; microwave = 1.8 mg). For materials K and T, the toothbrushed surface roughness was higher (P < .05) after microwave and waterbath postpolymerization treatments. Material L showed increased surface roughness after microwave postpolymerization treatment. Conclusion: The toothbrushing wear resistance of L was not superior to the reline resins. The postpolymerization treatments did not improve the toothbrushing wear resistance of the materials and produced an increased surface roughness for materials L, K, and T.

Cryopreservation of dog spermatozoa: Effect of bovine serum albumin on acrosomal integrity and pregnancy rates after artificial insemination

The objective of the present study was to compare the in vitro and in vivo profile of frozen dog semen with Tris-bovine serum albumin (TB) and Tris-egg yolk (TE) extenders. Twenty dogs were used as donors. Each dog was stimulated by penile massage and only the sperm-rich fraction was collected weekly until 40 ejaculates were obtained. After macroscopic and microscopic analysis, equal parts of each ejaculate were diluted with TB and TE by the one-step method at 37 °C. The semen was added to 0.5-mL French straws which presented normal characteristics before freezing and after thawing. Acrosomal integrity was evaluated by double Trypan blue-Giemsa staining, in which alive intact (LI), alive reacted (LR), dead intact (DI) and dead reacted (DR) spermatozoa, were identified by the time of thawing and up to 4 h of incubation at 39 °C, the TE being significantly superior to TB (P<0,01) in the LI and LR variables. The TB being significantly superior to TE (P<0,01) in the DR variable. Female dogs in natural heat were submitted to artificial insemination, 20 receiving TE-semen and 20 receiving TB-semen with the Osiris probe (IMV, L'Aigle, France) and the numbers indicate that TE was significantly better than TB (P<0,01) to pregnancy rate and number of puppies/delivery. We concluded from this study, that TE was better than TB, because this, induced an eady acrossome reaction in dog's sperm.

Preemptive dexamethasone and etoricoxib for pain and discomfort prevention after periodontal surgery: A double-masked, crossover, controlled clinical trial

Background: Several anti-inflammatory drugs have been used to reduce pain and discomfort after periodontal surgeries. This study evaluates the efficacy of using etoricoxib and dexamethasone for pain prevention after open-flap debridement surgery. Methods: For this prospective, double-masked, crossover, placebo-controlled, randomized clinical trial, open-flap debridement surgeries were performed on 15 patients (eight males and seven females, age range 20 to 56 years: mean age ± SD: 40 ± 9.7 years) who presented with chronic periodontitis after nonsurgical periodontal therapy at three quadrants. Each patient underwent three surgical procedures at intervals of 30 days and received one of the following premedication protocols 1-hour before surgery: group 1 = placebo, group 2 = 8 mg dexamethasone, and group 3 = 120 mg etoricoxib. Rescue medication (750 mg acetaminophen) was given to each patient who was instructed to take it when necessary. Pain intensity and discomfort were evaluated by a 101-point numeric rate scale and a four-point verbal rate scale, respectively, hourly for the first 8 hours after surgery and three times a day on the following 3 days. Results: The results demonstrate that groups 2 and 3 present reduced postoperative pain-intensity levels compared to group 1. There were statistically significant differences at the 4, 5, 6, 7, and 8 hour-periods after surgery (Friedman test; P<0.05). Furthermore, rescue-medication intake was significantly lower for groups 2 and 3 than for group 1 (analysis of variance; P<0.02). Conclusion: The adoption of a preemptive medication protocol using etoricoxib or dexamethasone may be considered effective for pain and discomfort prevention after open-flap debridement surgeries.

Evaluation of tissue reaction, cell viability and cytokine production induced by Sealapex Plus

The aim of this study was to investigate the effects of mineral trioxide aggregate (MTA), Sealapex, and a combination of Sealapex and MTA (Sealapex Plus) on the reaction of subcutaneous connective tissue of rats, and on cell viability and cytokine production in mouse fibroblasts. The tissue reaction was carried out with dentin tubes containing the materials implanted in the dorsal connective tissue of rats. The histological analysis was performed after 7 and 30 days. Millipore culture plate inserts with polyethylene tubes filled with materials were placed into 24-well cell culture plates with mouse fibroblasts to evaluate the cell viability by MTT assay. ELISA assays were also performed after 24 h of exposure of the mouse fibroblasts to set material disks. Histopathologic examination showed Von Kossa-positive granules that were birefringent to polarized light for all the studied materials at the tube openings. No material inhibited the cell viability in the in vitro test. It was detected IL-6 production in all root-end filling materials. MTA and Sealapex Plus induced a slight raise of mean levels of IL-1β. The results suggest that Sealapex Plus is biocompatible and stimulates the mineralization of the tissue.

Biochemical biomarkers in Nile tilapia (Oreochromis niloticus) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends

Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1mLL -1. The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups, including B100. Biodiesel B20 in the conditions tested had fewer adverse effects than diesel and B5 for the Nile tilapia, and can be suggested as a less harmful fuel in substitution to diesel. However, even B100 could activate biochemical responses in fish, at the experimental conditions tested, indicating that this fuel can also represent a risk to the aquatic biota. © 2011 Elsevier Ltd.

Ultra-structural mapping of sugarcane bagasse after oxalic acid fiber expansion (OAFEX) and ethanol production by Candida shehatae and Saccharomyces cerevisiae

Background: Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative sources of energy that can be produced from non-food/feed-based substrates. Due to its abundance, sugarcane bagasse (SB) could be a model substrate for the second-generation biofuel cellulosic ethanol. However, the efficient bioconversion of SB remains a challenge for the commercial production of cellulosic ethanol. We hypothesized that oxalic-acid-mediated thermochemical pretreatment (OAFEX) would overcome the native recalcitrance of SB by enhancing the cellulase amenability toward the embedded cellulosic microfibrils. Results: OAFEX treatment revealed the solubilization of hemicellulose releasing sugars (12.56 g/l xylose and 1.85 g/l glucose), leaving cellulignin in an accessible form for enzymatic hydrolysis. The highest hydrolytic efficiency (66.51%) of cellulignin was achieved by enzymatic hydrolysis (Celluclast 1.5 L and Novozym 188). The ultrastructure characterization of SB using scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Fourier transform-near infrared spectroscopy (FT-NIR), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) revealed structural differences before and after OAFEX treatment with enzymatic hydrolysis. Furthermore, fermentation mediated by C. shehatae UFMG HM52.2 and S. cerevisiae 174 showed fuel ethanol production from detoxified acid (3.2 g/l, yield 0.353 g/g; 0.52 g/l, yield, 0.246 g/g) and enzymatic hydrolysates (4.83 g/l, yield, 0.28 g/g; 6.6 g/l, yield 0.46 g/g). Conclusions: OAFEX treatment revealed marked hemicellulose degradation, improving the cellulases ability to access the cellulignin and release fermentable sugars from the pretreated substrate. The ultrastructure of SB after OAFEX and enzymatic hydrolysis of cellulignin established thorough insights at the molecular level. © 2013 Chandel et al; licensee BioMed Central Ltd.

Motor Recovery and Synaptic Preservation after Ventral Root Avulsion and Repair with a Fibrin Sealant Derived from Snake Venom

Background:Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation.Methodology/Principal Findings:Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group.Conclusions/Significance:In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and increased mRNA levels to neurotrophins and anti-inflammatory cytokines that may in turn, contribute to improving recovery of motor function. © 2013 Barbizan et al.

Airway space changes after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts® total joint prostheses: Three-dimensional assessment

This study focused on three-dimensional (3D) airway space changes and stability following simultaneous maxillomandibular counterclockwise rotation, mandibular advancement, and temporomandibular joint (TMJ) reconstruction with custom-made total joint prostheses (TMJ Concepts®). Cone beam computed tomography (CBCT) scans of 30 consecutive female patients with irreversibly compromised TMJs were obtained at the following intervals: T1, presurgery; T2, immediately after surgery; and T3, at least 6 months after surgery. The CBCT volumetric datasets were analysed with Dolphin Imaging ® software to evaluate surgical and postsurgical changes to oropharyngeal airway parameters. The average changes in airway surface area (SA), volume (VOL), and minimum axial area (MAA) were, 179.50 mm2, 6302.60 mm3, and 92.23 mm2, respectively, at the longest follow-up (T3 - T1) (P ≤ 0.001). Significant correlations between the amount of mandibular advancement and counterclockwise rotation of the occlusal plane and 3D airway changes were also found (P ≤ 0.01). The results of this investigation showed a significant immediate 3D airway space increase after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts total joint prostheses, which remained stable over the follow-up period. © 2013 International Association of Oral and Maxillofacial Surgeons.

Influence of filler charge on gloss of composite materials before and after in vitro toothbrushing

Objectives: This study evaluated the gloss behaviour of experimental resin composites loaded with different filler percentages, immediately after polishing and after toothbrushing simulation. Methods: Sixteen disc-shaped specimens were fabricated for each different-charged composite (40%, 50%, 60%, 70% and 75%) and polished with SiC abrasive papers. Gloss measurements were made prior to simulated toothbrushing. The specimens were subjected to the simulation for 5, 15, 30 and 60 min using an electrical toothbrush with a standardized pressure while being immersed in a toothpaste/artificial saliva slurry. Results: Baseline composite gloss values ranged from 69.7 (40%) to 81.3 (75%) GU (gloss units) and from 18.1 (40%) to 32.3 (75%) GU after 1 h of brushing. Highest gloss values were obtained by 75%-charged resin, while the lowest values were obtained by the 40%-charged one. Conclusions: All tested materials showed a gloss decrease. However, the higher filler load a composite resin has, the higher gloss it can achieve. Clinical significance: Gloss of resin composite materials is an important factor in determining aesthetic success of anterior restorations, and this property may vary according to the filler charge of the restorative material. Higher filler load of a composite resin results in higher gloss values. © 2013 Elsevier Ltd. All rights reserved.

Istmo Centroamericano: evolución del sector manufacturero durante 2003 y 2004

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Road Concessions in Latin America: Achievements and Challenges

Concessions have become an important mechanism in Latin America for attracting financing and private management to the highway sector. Highways are one of the areas of transport infrastructure in which this concept in long-term investment in road conservation and management has been widely applied and the concession-holder's costs are recouped through tolls and other complementary mechanisms.After a brisk start in the 1990s, the pattern of road concessions has proved to be less dynamic in the current decade. Nevertheless, highway concessions have expanded significantly and now account for 1% of the total inter-city road network. The international seminar entitled "Concessions for the provision of transport infrastructure: challenges for Latin America" was organized jointly by the Economic Commission for Latin America and the Caribbean (ECLAC) and the Agency for the Promotion of Private Investment of Peru (PROINVERSION) and held in Lima, Peru, on 13 and 14 November 2003.

Biochemical and nutritional evaluation of patients with visceral leishmaniasis before and after treatment with leishmanicidal drugs

Introduction Visceral leishmaniasis (VL) is caused by the intracellular protozoan Leishmania donovani complex. VL may be asymptomatic or progressive and is characterized by fever, anemia, weight loss and the enlargement of the spleen and liver. The nutritional status of the patients with VL is a major determinant of the progression, severity and mortality of the disease, as it affects the clinical progression of the disease. Changes in lipoproteins and plasma proteins may have major impacts in the host during infection. Thus, our goal was evaluate the serum total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides, glucose, albumin, globulin and total protein levels, as well as the body composition, of VL patients before and after treatment. Methods Nutritional evaluation was performed using the bioelectrical impedance analysis (BIA) to assess body composition. Biochemical data on the serum total cholesterol, HDL, LDL, triglycerides, glucose, albumin, globulin and total protein were collected from the medical charts of the patients. Results BIA indicated that both pre-treatment and post-treatment patients exhibited decreased phase angles compared to the controls, which is indicative of disease. Prior to treatment, the patients exhibited lower levels of total body water compared to the controls. Regarding the biochemical evaluation, patients with active VL exhibited lower levels of total cholesterol, HDL, LDL and albumin and higher triglyceride levels compared to patients after treatment and the controls. Treatment increased the levels of albumin and lipoproteins and decreased the triglyceride levels. Conclusions Our results suggest that patients with active VL present biochemical and nutritional changes that are reversed by treatment.