Prevention of experimental venous thrombosis induced by contrast medium in the rat

In order to assess experimentally the usefulness of some procedures employed in man to prevent venous thrombosis following phlebography, thrombosis was induced in rats using sodium diatrizoate in a temporarily isolated segment of a jugular vein. The prevention of thrombosis was attempted by washing out the vein with physiologic saline or saline plus heparin or by injecting saline plus heparin in the opposite jugular vein. Thrombosis occurred in all animals in the control group and in the group treated with saline alone. Both treatment schemes with heparin significantly reduced the incidence of thrombosis, the wash out with heparin being more effective than systemic heparin.

Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

Background. Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury. Method. A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n=7) or 15 min (group 2; n=7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated. Results. Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml. Conclusion. Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.

Malignant transformation of pleomorphic xanthoastrocytoma: Case report

We report a case of a pleomorphic xantoastrocytoma which manifested itself as a cystic isodense lesion in the right fronto-temporal lobe in a 26 year-old woman. It appeared as a soft yellow tumor with cystic cavities on surgery. Five months after this surgery, the patient was submitted to a new operation, which revealed a friable tumor, easily differentiated from the normal parenchyma, with cystic components. The histopathological examination demonstrated pleomorphic xanthoastrocytoma with malignant transformation. Histologically, the tumor at first procedure was composed of pleomorphic astrocytes with multinucleated and foamy cells. A rare case of malignant transformation in pleomorphic xanthoastrocytoma is presented, discussed and illustrated in this paper.

Anatomic and radiograph study of the persistence of Foramen of Huschke

Aim: the aim of this study is to assess and locate the Foramen of Huschke. Study design: anatomical. Material and Method: using contrast material like gutta-percha and barium sulfate, through extraoral radiographs, such as panoramic, submental vertex and corrected saggital linear Temporal Mandibular Joint tomograms in four skulls where we clinically checked the existence of foramen of Huschke. Results: The results proved that the foramen of Huschke can be observed in skulls submitted to contrast using radiographic techniques.

Effect of radiotherapy on the radiopacity and flexural strength of a composite resin.

The aim of this study was to evaluate the effect of radiotherapy on the radiopacity and flexural strength of composite resin. Forty Z250 composite resin specimens were polymerized using a halogen light-curing unit and divided into 5 groups, in accordance with the radiotherapy dose: G1- without irradiation, G2- 30 Gy, G3- 40 Gy, G4- 50 Gy and GS- 60 Gy Digital images were obtained using a GE 100 X-ray. Radiopacity values were obtained with the Digora digital imaging system and the flexural strength was evaluated with an EMIC universal testing machine. Data were submitted to ANOVA and Tukey 's test. G1 presented the highest radiopacity value, followed by G3, G5, G4 and G2. For flexural strength, G1 presented the lowest value, followed by G2, G5, G3 and G4. Differences were no significant (p>0.05). The commonly used dosage of radiotherapy treatment, did not cause alteration in the radiopacity and flexural strength of resin-based composites.

Influence of apical enlargement in cleaning and extrusion in canals with mild and moderate curvatures

Optical microscopy and morphometric analysis were used in this study to evaluate, in vitro, the cleaning of the apical region in root canals with mild or moderate curvatures subjected to biomechanical preparation with a rotary system, as well as to assess the amount of extruded material to the periapical area. Lateral incisors (n = 32), 16 with curvature angles smaller or equal to 10° (GI) and 16 between 11° and 25° angles (GII) were submitted to Hero 642 rotary instrumentation with different surgical diameters: (A) 30.02 and (B) 45.02. Irrigation was performed at each change of instrument with 5 mL of ultrapure Milli-Q water and the extruded material through the apical foramen was collected. Root cross-sections were subjected to histological analysis by optical microscopy (×40) and the images were evaluated morphometrically using the Image Tool software. Quantification of the extruded material was performed by weighing after liquid evaporation. ANOVA showed no statistically significant differences (p>0.05) among the groups with respect to the procedures used to clean the apical region. Considering the amount of extruded material, the Tukey's HSD showed that canals with mild curvature prepared with the 45.02 surgical diameter showed significantly higher values (p<0.05) that those of the other groups, which were similar between themselves (p>0.05). In conclusion, the effect of cleaning the apical region did not differ in the groups, considering root curvature and the surgical diameter of instruments used for apical preparation. The amount of extruded material was greater in canals with mild curvature that were prepared with the 45.02 surgical instrument diameter.

Effect of different radiopacifying agents on the physicochemical properties of white portland cement and white mineral trioxide aggregate

Introduction: The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). Methods: Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. Results: The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P <.05). All radiopacifiers increased the setting time of WPC, and WMTA had the shortest setting time among all materials (P < .05). Conclusions: All materials released calcium ions. Except for WPC/CT at 168 hours, all materials promoted an alkaline pH. On the basis of the obtained results, ZO and CT can be considered as potential radiopacifying agents to be used in combination with Portland cement. Copyright © 2012 American Association of Endodontists.

Efficacy of four irrigation needles in cleaning the apical third of root canals

This study aimed to evaluate the influence of irrigation needle gauge and design, and the final root canal diameter on the apical cleaning efficacy. Twelve human mandibular incisors were used. At different stages of root canal widening (sizes 20, 30 and 40 K-files), root canals were filled with radiopaque contrast medium. Four different needles were evaluated: 23G with side opening, 22G with apical opening, 30G with side opening and 30G with apical opening. Irrigation was carried out with 2 mL distilled water. The same tooth was radiographed with a digital system several times to assess the four types of needle in those three stages of canal widening. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 program. Pre-irrigation (filled with contrast) and subtracted (cleaned by irrigation) areas were outlined by a trained and blinded operator using the Image Tool 3.0 software. Their ratio was calculated to express the percentage of apical cleaning in each stage of canal widening (sizes 20, 30 and 40 K-files) with each of the four needles. Data obtained were subjected to one-way ANOVA and Tukey's tests. The 30G needles with side and apical opening promoted better apical cleaning at all stages of root canal widening (p<0.05). In conclusion, smaller diameter needles were more efficacious in cleaning the apical third of the root canals, regardless of their design.

Análise radiográfica da modelagem de canais radiculares ovalados realizada com sistemas rotatórios de níquel-titânio

Pós-graduação em Odontologia - FOAR

Flebografia epidurla lombossacral em gatos por meio da veia safena lateral

Pós-graduação em Medicina Veterinária - FMVZ

Frequência de doença arterial coronariana assintomática em pacientes portadores de estenose de artéria renal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cardiovascular and respiratory alterations in dogs during cervical myelography using ioversol

Subarachnoid infusion of most contrast mediums and the steps involved in performing a cervical myelography have adverse affects that can discourage its use in the radiographic diagnosis of spinal cord diseases. Thus, the cardiovascular and respiratory alterations associated with neck flexion, subarachnoid puncture, and cerebrospinal fluid drainage during subarachnoid infusion of ioversol (320mgI/mL) in dogs under general anesthesia using isoflurane were evaluated. The dogs received subarachnoid infusion of autologous cerebrospinal fluid kept at 38°C - control group (GC); ioversol 0.3mL/kg at 25°C (GI25) and ioversol 0.3mL/kg heated to 38°C (GI38). Each dog had its heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), respiratory rate (RR), oxyhemoglobin saturation (SaO2) and electrocardiography readings (PR and QT intervals) recorded. Group comparisons showed no statistical difference regarding neck positioning, subarachnoid puncture, and subarachnoid infusion of contrast medium on HR, RR and SaO2, cardiac rhythm or conduction. However, isoflurane significantly increased PR and QT intervals. Based on these findings, it is concluded that the steps involved in cervical myelography and the use of ioversol 320mgI/mL at 0.3mL/kg (25ºC and 38ºC) during cervical myelography did not result in relevant cardiovascular and respiratory alterations, except for an elevation in arterial pressure after injection of ioversol.

Angiografia comparativa, prós e contras entre os métodos: por raios-X, Tomografia Computadorizada e Ressonância Magnética

By the early 20th century, the blood vessels could only be seen by anatomical studies. Shortly after the discovery of X-rays by Conrad Roentgen in 1895, the first experiments with radiographic imaging were performed with blood vessels. In 1905, the first experiment involving catheterization of arterial and venous system in dogs was performed and only in 1914 performed on living human patients. Parallel to these landmarks, there were advances in diagnostic imaging devices and the evolution of contrast substances was of utmost importance to the current angiography occupy a prominent role not only in terms of diagnosis, but also in the treatment of various disorders. The main objective of this review is to weave historical considerations and comparisons between the different methodologies used in angiography, because its importance; that may be in future, a veterinary diagnostic decisive test

Estudo mielográfico comparativo entre meios de contraste iopamidol e ioexol em bezerros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Características tomográficas de neoplasias encefálicas primárias em cães

Computed tomography (CT) can be considered an important test to identify the presence of primary brain neoplasias in dogs. CT results can help define the type of brain tumor when associated with clinical findings. It allows the identification of lesions and their features, such as size, location, compression and invasion of adjacent tissue. One must analyze the density, mass effect, peritumoral edema, calcification, and image enhancement after intravenous injection of contrast medium. Gliomas, meningiomas and tumors of the choroid plexus and pituitary are the most common primary brain neoplasms diagnosed by CT in dogs. The aim of this paper is to review the literature related to primary brain tumors and report their most important tomographic features, in order to help clinicians achieve a presumptive diagnosis of tumor type.