Combined TUNEL and TRAP methods suggest that apoptotic bone cells are inside vacuoles of alveolar bone osteoclasts in young rats

Although it is generally accepted that osteoclasts breakdown and resorb bone matrix, the possibility that they may also be able to engulf apoptotic osteoblasts/ lining cells and/or osteocytes remains controversial. Apoptosis of osteoblasts/ lining cells and/or osteocytes and interactions between these cells and osteoclasts are extremely rapid events that are difficult to observe in viva. A suitable in viva model for studying these events is the alveolar bone of young rats because it is continuously. Thus, sections of aldehyde fixed alveolar undergoing intense resorption/remodeling bone of young rats were stained by the combined terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method and the tartrate-resistant acid phosphatase (TRAP) method for the simultaneous visualization of apoptotic cells and osteoclasts in the same section. The combined TUNEL and TRAP reactions, in the same section, greatly facilitated visualization of relationship between osteoclasts and apoptotic bone cells during alveolar bone remodeling. Our results showed that several TRAP-positive osteoclasts exhibited large vacuoles containing TUNEL positive apoptotic structures, probably derived from osteoblasts/lining cells and/or osteocytes. These results support the idea that alveolar bone osteoclasts are able to internalize dying apoptotic bone cells.

Osteoblasts engulf apoptotic bodies during alveolar bone formation in the rat maxilla

During bone formation, as in other tissues and organs, intense cellular proliferation and differentiation are usually observed. It has been described that programmed cell death, i.e., apoptosis, takes place in the control of the cellular population by removing of the excessive and damaged cells. Although it is generally accepted that apoptotic bodies are engulfed by professional phagocytes, the neighboring cells can also take part in the removal of apoptotic bodies. In the present study, regions of initial alveolar bone formation of rat molars were examined with the aim to verify whether osteoblasts are capable of engulfing apoptotic bodies, such as professional phagocytes. Rats aged 11-19 days were sacrificed and the maxillary fragments containing the first molar were removed and immersed in the fixative solution. The specimens fixed in glutaraldehyde-formaldehyde were processed for light microscopy and transmission electron microscopy. For the detection of apoptosis, the specimens were fixed in formaldehyde, embedded in paraffin, and submitted to the TUNEL method. The results revealed round/ovoid structures containing dense bodies on the bone surface in close contact to osteoblasts and in conspicuous osteoblast vacuoles. These round/ovoid structures showed also positivity to the TUNEL method, indicating that bone cells on the bone surface are undergoing apoptosis. Ultrathin sections showed images of apoptotic bodies being engulfed by osteoblasts. Occasionally, the osteoblasts exhibited large vacuoles containing blocks of condensed chromatin and remnants of organelles. Thus, these images suggest that osteoblasts are able to engulf and degrade apoptotic bodies. (c) 2005 Wiley-Liss, Inc.

Dissociated time course recovery between rate of force development and peak torque after eccentric exercise

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

Apoptotic and developmental effects of bovine Herpesvirus type-5 infection on in vitro-produced bovine embryos

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

Macrophage suppression following phagocytosis of apoptotic neutrophils is mediated by the S100A9 calcium-binding protein

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Invertebrates from the Low Head Member (Polonez Cove Formation, Oligocene) at Vaureal Peak, King George Island, West Antarctica

Eight taxa of marine invertebrates, including two new bivalve species, are described from the Low Head Member of the Polonez Cove Formation (latest early Oligocene) cropping out in the Vaureal Peak area, King George Island, West Antarctica. The fossil assemblage includes representatives of Brachiopoda (genera Neothyris sp. and Liothyrella sp.), Bivalvia (Adamussium auristriatum sp. nov., ?Adamussium cf. A. alanbeui Jonkers, and Limatula (Antarctolima) ferraziana sp. nov.), Bryozoa, Polychaeta (serpulid tubes) and Echinodermata. Specimens occur in debris flows deposits of the Low Head Member, as part of a fan delta setting in a high energy, shallow marine environment. Liothyrella sp., Adamussium auristriatum sp. nov. and Limatula ferraziana sp. nov. are among the oldest records for these genera in King George Island. In spite of their restrict number and diversification, bivalves and brachiopods from this study display an overall dispersal pattern that roughly fits in the clockwise circulation of marine currents around Antarctica accomplished in two steps. The first followed the opening of the Tasmanian Gateway at the Eocene/Oligocene boundary, along the eastern margin of Antarctica, and the second took place in post-Palaeogene time, following the Drake Passage opening between Antarctic Peninsula and South America, along the western margin of Antarctica.

Analysis and design of constant-frequency peak-current-controlled high-power-factor boost rectifier with slope compensation

This paper presents the analysis and the design of a peak-current-controlled high-power-factor boost rectifier, with slope compensation, operating at constant frequency. The input current shaping is achieved, with continuous inductor current mode, with no multiplier to generate a current reference. The resulting overall circuitry is very simple, in comparison with the average-current-controlled boost rectifier. Experimental results are presented, taken from a laboratory prototype rated at 370 W and operating at 67 kHz. The measured power factor was 0.99, with a input current THD equal to 5.6%, for an input voltage THD equal to 2.26%.

Mechanical damping of the snoek peak in tantalum - Oxygen system

Interstitial solutes in body-centered cubic metals, such as oxygen in tantalum, produce ideally Snoek effects when they are in solutions enough diluted. However, for higher concentration of these solutes, more complex relaxation process can occur, as interaction between interstitial solutes and dislocations. Anelastic relaxation measurements were carried out in polycrystalline tantalum samples, using torsion pendulum inverted, operating between 300 K and 680 K and oscillation frequencies in the hertz bandwidth, for three different experimental sample conditions: as received sample, annealed and annealed followed by a treatment in an oxygen atmosphere. These measurements have revealed the following behavior: the intensity of the internal friction peak associated to matrix-interstitial interaction Ta-O decreased between the first run and the next runs, and this phenomenon did not occur for the others conditions. The variation of relaxation strength of Ta-O peak, with number of runs is due to a decrease of an amount of oxygen in solid solution, which can be associated with the precipitation of new phases in Ta sample and with the trapping of oxygen atoms by dislocations.

Expression of pro-and-anti-apoptotic antigens in the cerebellum of dogs naturally infected with canine distemper virus

Canine distemper virus (CDV) may induce multifocal demyelination in the central nervous system of infected dogs. The present work investigated apoptosis in white and gray matter (granular layer) in the cerebellum of naturally infected dogs by the analysis of the expression of the pro-apoptotic antigens caspase - 2 and - 3, b(terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL-staining) positivity, annexin-V immunodetection, and the presence of the anti-apoptotic antigens, BCl-2 and p53. Cerebellum specimens were obtained from the Laboratory of Animal Pathology, from 1995 to 2009, and the 5-μm thick fragments were stained both with hematoxylin-eosin and Shorr. All samples were diagnosed as positive for CDV genome by reverse transcriptase polymerase chain reaction targeting the nucleocapsid gene. The anti-apoptotic pathways evidenced in this study were BCl-2 and p53 proteins that were intensively detected in cerebellum of CDV positive slides (40-80% of labeled cells/mm2). In addition, the apoptosis markers annexin-V and TUNEL are directly correlated among the same samples (80 and 40% of labeled cells, respectively). This is the first description of p53 and annexin-V expression, characterized as anti-apoptotic and apoptotic proteins, involvement in canine natural cases of CDV infections.

The influence of the flexibility of the chair seat on pressure peak and distribution of the contact area in individuals with cerebral palsy during the execution of a task

This study aimed to determine the influence of flexibility of the chair seat surface on the pressure peak and on the contact area during the execution of a task of handling an object on the seated position by individuals with spastic cerebral palsy. Ten individuals of both genders with diagnosis of spastic cerebral palsy, who had some control to voluntarily move the body and the upper limbs, participated in this study. Quantification of data was carried out in two experimental situations: (1) execution of a task of fitting with upper limbs, and with the individual placed on an adapted canvas seat; (2) execution of a task of fitting with the participant positioned on an adapted wooden seat. Data obtained were submitted to a non-parametric and descriptive statistical analysis using the Wilcoxon test. Results indicated that the use of canvas seat increased the contact area and decreased the pressure peak and the medio-lateral displacement of centre pressure on the seated posture. © 2011 Informa UK, Ltd.

Maximal isokinetic peak torque and EMG activity determined by shorter ranges of motion

Purpose. Isokinetic tests are often applied to assess muscular strength and EMG activity, however the specific ranges of motion used in testing (fully flexed or extended positions) might be constrictive and/or be painful for patients with injuries or under-going rehabilitation. The aim of this study was to examine the effects of different ranges of motion (RoM) when determining maximal EMG during isokinetic knee flexion and extension with different types of contractions and velocities. Methods. Eighteen males had EMG activity recorded on the vastus lateralis, vastus medialis, semitendinosus and biceps femoris muscles during five maximal isokinetic concentric and eccentric contractions for the knee flexors and extensors at 60° • s -1 and 180° • s -1. The root mean square of EMG was calculated at three different ranges of motion: (1) a full range of motion (90°-20° [0° = full knee extension]); (2) a range of motion of 20° (between 60°-80° and 40°-60° for knee extension and flexion, respectively) and (3) at a 10° interval around the angle where peak torque is produced. EMG measurements were statistically analyzed (ANOVA) to test for the range of motion, contraction velocity and contraction speed effects. Coefficients of variation and Pearson's correlation coefficients were also calculated among the ranges of motion. Results. Predominantly similar (p > 0.05) and well-correlated EMG results (r > 0.7, p ≤ 0.001) were found among the ranges of motion. However, a lower coefficient of variation was found for the full range of motion, while the 10° interval around peak torque at 180° • s -1 had the highest coefficient, regardless of the type of contraction. Conclusions. Shorter ranges of motion at around the peak torque angle provides a reliable indicator when recording EMG activity during maximal isokinetic parameters. It may provide a safer alternative when testing patients with injuries or undergoing rehabilitation.

Evaluation of peak cough flow in Brazilian healthy adults

Introduction. In this study we aimed to evaluate the peak cough flow (PCF) in healthy Brazilian subjects. Methods. We evaluated 484 healthy subjects between 18 and 40 years old. Subjects were seated and oriented were asked to perform a maximal inspiration followed by a quick, short and explosive expiration on the peak flow meter. Three measures were carried out and recorded the average of the three results for each individual. Results: The PCF values ranged between 240 and 500 L/min. The PCF values were lower in females than in males. The PCF was inversely proportional to age. Conclusion: The values for Brazilian adult healthy subjects regarding PCF were between 240 and 500 L/min. © 2012 Cardoso et al.; licensee BioMed Central Ltd.

The Effects of Refrigeration Temperature and Storage Time on Apoptotic Markers in Equine Semen

Evaluation of the damage caused by the sperm preservation process is crucial to improving fertilization rates. The objective of this study was to evaluate the effects of refrigeration temperature (5°C and 15°C) and storage time (0, 12, 24, 48, and 72 hours) on apoptotic markers in equine semen. Membrane phosphatidylserine translocation index, caspase activation index, and DNA fragmentation index were analyzed using epifluorescence microscopy. Analysis of variance was used for statistical analysis, and Tukey test was used to compare means. The significance level was set at P < .05. The results demonstrated that for transport duration shorter than 24 hours, semen quality was maintained when stored at either 5°C or 15°C. A storage temperature of 5°C should be used when it is necessary to transport semen for longer than 24 hours. There was a significant decrease in semen quality after 48 hours of refrigeration. © 2013 Elsevier Inc.