Correlation between the intensity of venous reflux in the saphenofemoral junction and morphological changes of the great saphenous vein by duplex scanning in patients with primary varicosis

Aim. One of the major causes of chronic venous disease is venous reflux, the identification and quantification of which are important for diagnosis. Duplex scanning allows for the detection and quantification of reflux in individual veins. Evaluation of the great saphenous vein in primary varicosis is necessary for its preservation. Objective of the study is to evaluate a possible correlation between the intensity of reflux at the saphenofemoral junction, diameter alterations of the incompetent great saphenous vein and the practical effect of such correlation. Also to compare the clinical severity of the CEAP classification with such parameters.Methods. Three hundred limbs were submitted to duplex evaluation of their insufficient saphenous veins. Vein diameter was measured on five different points. Velocity and flow at reflux peak and reflux time were determined. The saphenous vein's diameters were correlated with velocity, flow and time. The three latter parameters and diameters were compared with clinical severity according to CEAP.Results. Correlation was found between the saphenous vein's diameters, velocity and flow. No correlation was observed between time and diameter in the thigh's upper and middle thirds. When comparing diameter, velocity and flow with CEAP clinical severity classification, an association was observed. The correlation between reflux time with clinical severity was weak.Conclusion. Reflux time is a good parameter for identifying the presence of reflux, but not for quantifying it. Velocity and peak flow were better parameters for evaluating reflux intensity as they were correlated with great saphenous vein alterations, and were associated with the disease's clinical severity. [Int Angiol 2010;29:323-30]

Triple bothropic envenomation in horses caused by a single snake

In the present study, snakebites caused by a single Bothrops pauloensis simultaneously affecting three male adult horses are described. Whereas the first two affected horses were six years old, the third was 16 years old; they weighed respectively 555, 550 and 500 kg. All horses presented swollen muzzles. The first animal received an initial antivenom dose of 19 vials and adjuvant medication, it was also subjected to tracheostomy due to the progression of acute respiratory failure. The second and third horses respectively received 15 vials of antivenom each, in addition to adjuvant medication. Due to continuous changes in blood coagulation observed during hospitalization, the first and the second horses received five more vials of antivenom, respectively, in the second and third days of treatment. The first animal was discharged on 15(th) day and the other on the 8(th) day of hospitalization. Several factors including the main actions of Bothrops venom (coagulation, proteolytic and vasculotoxic activities), the importance of early diagnosis based on clinical history and clinical examination suggesting the diagnosis of Bothrops snakebite, the adequate doses of antivenom, and finally the immediate tracheostomy are herein discussed. The tracheostomy, required to save the life of the first horse, should only occur after the administration of antivenom and control measures for changes in blood coagulation.

Synchrotron microComputed tomography of the mature bovine dentinoenamel junction

The mature dentinoenamel junction (DEJ) is viewed by some investigators and the current authors, not as a fossilized, sharp transition between enamel and dentin, but as a relatively broad structural transition zone including the mantle dentin and the inner aprismatic enamel. In this study, the DEJ structure in bovine incisors was studied with synchrotron microComputed Tomography (microCT) using small cubes cut parallel to the tooth surface. The reconstructions revealed a zone of highly variable punctate contrast between bulk dentin and enamel; the mean linear attenuation coefficients and their standard deviations demonstrated that this zone averaged less mineral than dentin or enamel but had more highly variable structure than either. The region with the punctuate contrast is, therefore, the mantle dentin. The thickness of the mantle dentin seen in a typical data set was about 30 mu m, and the mantle dentin-enamel interface deviated +/- 15 mu m from the average plane over a distance of 520 mu m. In the highest resolution data (similar to 1.5 mu m isotropic voxels, volume elements), tubules in the dentin could be discerned in the vicinity of the DEJ. Contrast sensitivity was high enough to detect differences in mineral content between near-surface and near-DEJ volumes of the enamel. Reconstructions before and after two cubes were compressed to failure revealed cracks formed only in the enamel and did not propagate across the mantle dentin, regardless of whether loading was parallel to or perpendicular to the DEJ. (C) 2007 Elsevier B.V. All rights reserved.

Structural characteristics of the tendinous cord-papillary muscle junction in healthy and hypertensive rats

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

Morphometric and morphological analysis of neuromuscular junction alterations in the denervated rat diaphragm

The morphological and structural alterations that occur in the neuromuscular junctions of the denervated rat diaphragm were studied. Fifteen adult male albino rats (Rattus norvegicus) aged about 60 days and with a mean weight of 200 g were used. Chronically denervated diaphragms were obtained and the animals were sacrificed after 4, 8 and 12 weeks of denervation. The left antimere of the diaphragm was denervated by section of the phrenic nerve and the right antimere was used as control. Each antimere was divided into three fragments: one was used for histochemical (nonspecific esterase) and morphometric study of neuromuscular junctions, and the other two were used for transmission and scanning electron microscopy (SEM) analysis. Histochemical analysis of the diaphragm neuromuscular junctions after denervation showed only small changes in junction morphology. However, these junctions became smaller and elongated and presented less visible contours with increasing time of denervation. Ultrastructural analysis of neuromuscular junctions after 12 weeks showed more or less organized junctional folds on the muscle fiber surface. The junctional cytoplasm exhibited important alterations such as mitochondrial degeneration and the presence of numerous filaments. SEM revealed the presence of deep primary synaptic grooves with peripheral excavations which housed the nerve terminal boutons and exhibited internally the secondary synaptic clefts present among the junctional folds of the sarcolemma. This study showed that some of the morphological changes demonstrated in other denervated striated skeletal muscles are not repeated at the same intensity or in the same temporal pattern in the rat diaphragm.

Co-60 gamma irradiation prevents Bothrops jararacussu venom neurotoxicity and myotoxicity in isolated mouse neuromuscular junction

The ability of gamma radiation from Co-60 (2000 Gy) to attenuate the toxic effects of Bothrops jararacussu venom was investigated on mouse neuromuscular preparations in vitro. A comparative study between the effects of native and irradiated venoms was performed on both phrenic-diaphragm (PD) and extensor digitorum longus (EDL) preparations by means of myographic, biochemical and morphological techniques. Native venom (10 and 20 mug/ml) induced a concentration-dependent paralysis of both directly and indirectly evoked contractions on PD preparations. At 20 mug/ml, it also caused a pronounced myotoxic effect on the EDL muscle preparation that was characterized by an increase of creatine kinase release and by several morphological changes of this preparation. By contrast, irradiated venom, even at concentrations as high as 40 mug/ml, induced neither paralyzing nor myotoxic effects. It was concluded that Co-60 gamma radiation is able to abolish both the paralyzing and the myotoxic effects of B. jararacussu venom on the mouse neuromuscular junction. These findings support the hypothesis that gamma radiation could be an important toot to improve antisera production by reducing toxicity while preserving immunogenicity. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

The neurotoxicological effects of mastoparan Polybia-MPII at the murine neuromuscular junction: an ultrastructural and immunocytochemical study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Triple helix conformation of botryosphaeran, a (1 -> 3;1 -> 6)-beta-D-glucan produced by Botryosphaeria rhodina MAMB-05

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Indirect constraints on the triple gauge boson couplings from Z -> b(b)over-bar partial width: An update

We update the indirect bounds on anomalous triple gauge couplings coming from the non-universal one-loop contributions to the Z --> width. These bounds, which are independent of the Higgs boson mass, are in agreement with the standard model predictions for the gauge boson self-couplings since the present value of R-b agrees fairly well with the theoretical estimates. Moreover, these indirect constraints on Delta g(1)(Z) and g(5)(Z) are most stringent than the present direct bounds on these quantities, while the indirect limit on lambda(Z) is weaker than the available experimental data.

Triple photon production at the Tevatron in technicolor models

We study the process p (p) over bar --> gammagammagamma as a signal for associated photon-technipion production at the Tevatron. This is a clean signature with relatively low background. Resonant and non-resonant contributions are included and we show that technicolor models can be effectively probed in this mode. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Measurement of the WZ -> lvll cross section and limits on anomalous triple gauge couplings in p(p)over-bar collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of nandrolone decanoate on the neuromuscular junction of rats submitted to swimming

This study addressed the effects of nandrolone decanoate (ND) on contractile properties and muscle fiber characteristics of rats submitted to swimming. Male Wistar rats were grouped in sedentary (S), swimming (Sw), sedentary+ND (SND), and swimming+ND (SwND), six animals per group. ND (3 mg/kg) was injected (subcutaneously) 5 days/week, for 4 weeks. Swimming consisted of 60-min sessions (load 2%), 5 days/week, for 4 weeks. After this period, the sciatic nerve extensor digitorum longus (EDL) muscle was isolated for myographic recordings. Fatigue resistance was assessed by the percent (%) decline of 180 direct tetanic contractions (30 Hz). Safety margin of synaptic transmission was determined from the resistance to the blockade of indirectly evoked twitches (0.5 Hz) induced by pancuronium (5 to 9 x 10(-7) M). EDL muscles were also submitted to histological and histochemical analysis (haematoxylin-eosin (HE); nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR)). Significant differences were detected by two-way ANOVA (p<0.05). ND did not change body mass, fatigue resistance or kinetic properties of indirect twitches in either sedentary or swimming rats. In contrast, ND reduced the safety margin of synaptic transmission in sedentary animals (SND=53.3+/-4.7% vs. S=75.7+/-2.0%), but did not affect the safety margin in the swimming rats (SwND=75.81+/-3.1% vs. Sw=71.0+/-4.0%). No significant difference in fiber type proportions or diameters was observed in EDL muscle of any experimental group. These results indicate that ND does not act as an ergogenic reinforcement in rats submitted to 4 weeks of swimming. on the other hand, this study revealed an important toxic effect of ND, that it reduces the safety margin of synaptic transmission in sedentary animals. Such an effect is masked when associated with physical exercise. (C) 2004 Elsevier B.V. All rights reserved.

Grain-boundary segregation and precipitates in La2O3 and Pr2O3 doped SnO2 center dot CoO-based varistors

Structural heterogeneities in SnO2.CoO-based varistors were analyzed by transmission electron microscopy. In SnO2.CoO-based system doped with La2O3 and Pr2O3 two kinds of precipitate phases at grain boundary region were found. Using energy dispersive spectrometry they were found to be Co2SnO4 and Pr2Sn2O7, presenting a defined crystalline structure. It was also identified that such precipitate phases are mainly located in triple-junctions of the microstructure. HRTEM analysis revealed the existence of other two types of junctions, one as being homo-junctions of SnO2 grains and other due to twin grain boundaries inside the SnO2.CoO grain. The role of these types of junction in the overall nonlinear electrical features is also discussed. (C) 2003 Elsevier B.V. Ltd. All rights reserved.