Biomedical subjects

Frab Norberto Bóscolo

Publications and source records attributed to Frab Norberto Bóscolo.

12 recordsLinked to original sources

PubMed2006

Pycnogenol protects against Ionizing radiation as shown in the intestinal mucosa of rats exposed to X-rays.

X-rays and gamma radiation delivered to the abdominal region for cancer treatment encompasses severe damage to the intestinal mucosa, which significantly impairs a patient's quality of life. To a great extent the deleterious effects of x-radiation originate from radiolysis-induced reactive oxygen species. The well-researched powerful antioxidant Pycnogenol was administered orally to rats prior to x-irradiation with 15 Gy. Histological sections of the intestines showed a dramatically better condition of the mucosal layers compared with the irradiated control animals administered water without Pycnogenol. Pycnogenol treatment significantly preserved the height and number of villi as well as the glandular layer and a diminished number of congested vases were present. No intestinal alterations were seen in control animals receiving Pycnogenol in the absence of radiation. It is concluded that Pycnogenol provides significant protection from ionizing radiation damage.

Adjuvants, Immunologic↗

PubMed2006

Comparison of hard tissue density changes around implants assessed in digitized conventional radiographs and subtraction images.

OBJECTIVES: The aim of this in vivo study was to compare peri-implant bone density assessed by the mean gray value of the histogram in digitized conventional radiographs and two digital subtraction images (DSI) methods: linear and logarithmic. MATERIAL AND METHODS: Thirty-four patients were monitored by standardized periapical radiographs 1 week after surgery and 4 months later. The radiographs were digitized and manipulated by means of EMAGO software. Linear and logarithmic DSI were obtained, and a filter was added to the logarithmic image. Control and test regions were selected and the mean value of the gray level of the histogram of these selected areas was obtained. This process was carried out in the digitized conventional radiographs (DCR) and the two methods of DSI. After that, the images were divided into two groups, with and without bone loss, and statistical analysis was performed. RESULTS: The results indicate that differences between the jaws did not reach significance, in all the images and in the two groups with and without bone loss. Furthermore, there was no statistically significant difference between the radiographic density assessed in the DCR and the two methods of subtraction images. CONCLUSIONS: Monitoring of peri-implant bone density by the mean gray value of the histogram in a selected area can be assessed either by linear and logarithmic DSI or by DCR.

Alveolar Bone Loss↗

PubMed2006

Sensitometric comparisons of Insight and Ektaspeed Plus films: effects of chemical developer depletion.

The aim of this study was to compare the sensitometric properties of Insight and Ektaspeed Plus radiographic films manually and automatically processed using fresh and depleted chemical solutions. Ten sets of each type of film were obtained (1 set = 5 films), 5 sets being manually processed and 5 sets being automatically processed. A total of 100 films (50 Ektaspeed Plus and 50 Insight film) were exposed and developed. The first two sets of each film type were developed in fresh chemicals (one set per each type of processing), on the first day of the experiment. The other sets were processed in the same progressively depleted solutions once a week until the end of experiment, which was completed within 4 weeks. Characteristic curves were constructed to compare the sensitometric properties of the films: contrast, latitude and speed. Processing solution depletion had different effects on manually and automatically developed films, which was confirmed by the changes in the form of the characteristic curves in the third week of the automatic processing and fourth week of the manual processing. Ektaspeed Plus showed 11% reduction in contrast values for manual processing and 53% for automatic processing, while Insight contrast values showed a reduction of 25% and 59%, respectively. Insight film, however, showed lesser loss of speed and lesser increase of latitude than Ektaspeed Plus. In conclusion, chemical depletion in automatic film processing was faster than in manual developing. In depleted chemicals, both types of films had an increase in latitude values and a decrease in speed and contrast. Insight was more resistant than Ektaspeed Plus to decrease in speed and latitude when processed using older chemicals, whereas contrast in Ektaspeed Plus was comparatively more stable.

Solutions↗

PubMed2006

Bifid mandibular condyle: a case report.

The bifid mandibular condyle is a rare anomaly. A variety of causes are implicated with its development such as developmental origin and trauma. Because of the lack of epidemiological data, there is little information about the real incidence of this malformation. The purpose of this paper is to report a case of bifid mandibular condyle in a 20-year-old woman who referred to a private radiological clinic for routine dental examination. A panoramic radiography incidentally revealed a discrete modification of the left mandibular condyle. Magnetic resonance imaging (MRI) was taken and confirmed the diagnostic proposed.

Adult↗

PubMed2005

Evaluation of radioprotective effect of vitamin E in salivary dysfunction in irradiated rats.

The aim of this study was to evaluate the radioprotective effect of vitamin E in salivary gland function, as well as analyse the total protein concentration. For this purpose 90 male rats were used and randomly divided into five experimental groups: control (I), in which animals received olive oil solution but were not irradiated; irradiated-olive oil (II), in which animals received olive oil solution and were irradiated with a single exposure dose of 15 Gy of gamma rays to the head and neck region; irradiated (III), in which animals were only irradiated with a single exposure dose of 15 Gy of gamma rays; vitamin E (IV), in which animals received alpha tocopherol acetate solution but were not irradiated; irradiated-vitamin E (V), in which animals received alpha tocopherol acetate solution before irradiation with a single exposure dose of 15 Gy gamma rays. The animals were sacrificed 4, 8 h and 30 days after the irradiation procedure. No differences were observed in salivary volumes between the groups at 4 and 8 h. At 30 days, the salivary volume in the animals pertaining to the irradiated-olive oil group was significantly reduced in relation to the control group. The only irradiated group (III) presented significantly diminished salivary volume. In the salivary composition, no significant differences were observed in the total protein content between the groups studied. It was concluded that radiation had no effect on the total protein content and that vitamin E protected the salivary function 30 days after irradiation. Thus, vitamin E can be considered as a potential radioprotective substance.

Animals↗

PubMed2005

Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast.

This study evaluated the performance of aluminum-copper alloy filtration, without the original aluminum filter, for dental radiography in terms of x-ray energy spectrum, air kerma rate and image quality. Comparisons of various thicknesses of aluminum-copper alloy in three different percentages were made with aluminum filtration. Tests were conducted on an intra-oral dental x-ray machine and were made on mandible phantom and on step-wedge. Depending on the thickness of aluminum-copper alloy filtration, the beam could be hardened and filtrated. The use of the aluminum-copper alloy filter resulted in reductions in air kerma rate from 8.40% to 47.33%, and indicated the same image contrast when compared to aluminum filtration. Aluminum-copper alloy filtration may be considered a good alternative to aluminum filtration.

Absorptiometry, Photon↗

PubMed2003

Influence of irradiation on collagen content during wound healing in diabetic rats.

The aim of the present experimental research was to investigate the effects of electron irradiation on the collagen content and on the organization of the granulation tissue of skin, in diabetic rats. In this study, 48 Wistar rats were assigned to 4 groups: control, irradiated, diabetic and irradiated diabetic. First, diabetes mellitus was induced in the last two groups, by means of a single intravenous injection of streptozotocin. Fifteen days later, all animals underwent a surgery in order to create an excisional wound on their anterior dorsal skin. On the third post-operative day, only an approximately 1-cm-wide area around the wounds was exposed to 1 Gy of 6 MeV electron beam radiation, which was delivered in a single dose. Wound healing was examined by means of polarized light microscopy at 4-, 7-, 13- and 21-day time intervals after wounding. Based upon an essentially qualitative evaluation, it was possible to conclude that local electron irradiation and diabetes' associated dysfunctions caused a decrease in the collagen content of newly-formed tissue, which was more pronounced in irradiated diabetic animals. The macromolecular organization of granulation tissue was delayed in irradiated, diabetic and irradiated diabetic animals, in relation to what was observed in control animals.

Animals↗

PubMed2003

Image quality in digital radiographic systems.

The aim of the present study was to evaluate the image quality of four direct digital radiographic systems. Radiographs were made of the maxillary central incisor and mandibular left molar regions of a dry skull, and an aluminum step-wedge. The X-ray generator operated at 10 mA. 60 and 70 kVp, and images were acquired with 3, 5, 8, 12, 24 and 48 exposure pulses. Six well-trained observers classified the images by means of scores from 1 to 3. Collected data were submitted to nonparametric statistical analysis using Fisher's exact test. Statistical analysis showed significant differences (p < 0.01) in image quality with the four systems. Based on the results, it was possible to conclude that: 1) all of the digital systems presented good performance in producing acceptable images for diagnosis, if the exposures of the step-wedge and the maxillary central incisor region were made at 5 pulses, as well as at 8 pulses for the mandibular left molar region, selecting 60 or 70kVp; 2) higher percentages of acceptable images were obtained with the administration of lower radiation doses in CCD-sensors (charge-coupled device); 3) the Storage Phosphor systems produced acceptable images at a large range of exposure settings, that included low, intermediate and high radiation doses.

Humans↗

PubMed2003

Panoramic radiography as an auxiliary in detecting patients at risk for cerebrovascular accident (CVA): a case report.

Most cerebrovascular accidents (CVAs), commonly referred to as noncardiogenic strokes, occur as a result of atherosclerosis involving the common, internal and external carotids arteries, due to atheroma formation. Several factors influence atheroma formation, such as hypertension, smoking, diabetes mellitus, hypercholesterolemia, obesity and sedentary lifestyle among others. When atheromas are positioned inside the vessel lumen, they alter the flow of blood, causing the stroke. These atheromas, that are calcified plaques, can be observed in panoramic radiography.

Aged↗

PubMed2002

Bone scintigraphy as an adjunct for the diagnosis of oral diseases.

Bone scintigraphy is a very sensitive method for the detection of osteoblastic activity of the skeleton. The technique consists of imaging the uptake of bone-seeking radiopharmaceuticals, particularly technetium-99m labeled diphosphonates, in the mineral component of bone, which consists of hydroxyapatite crystals and calcium phosphate, as well as in the organic matrix such as collagen fibers. Plain radiographs, computed tomography, and magnetic resonance imaging are classified as structural imaging modalities, whereas bone scintigraphy is a functional method. In many cases, radionuclide imaging techniques are the only means by which early physiologic changes that are a direct result of biochemical alteration may be assessed, before significant bone mineral changes can be detected by other means. Since many oral diseases may cause metabolic changes in the oromaxillofacial complex, it would be of great value to use bone scintigraphy to evaluate more completely some conditions involving the bones in the region to formulate more appropriate treatment plans. Based upon the current literature, the authors discuss the possible applications of bone scintigraphy as a diagnostic and treatment planning adjunct for oral diseases. Bone scintigraphy has proven particularly useful in the study of malignant lesions and in the evaluation of vascularized bone grafts used for maxillofacial reconstructions.

Bone Diseases, Infectious↗

PubMedDate not supplied

[Study of the aluminum-zinc alloy as an alternative method of filtration in dental X-ray devices].

The aim of this study was to evaluate the effects of alternative filtration with the aluminum-zinc alloy in dental X-ray devices, regarding the energy spectrum, dose, contrast and image quality. This study was carried out comparing the conventional aluminum filter with aluminum-zinc alloy filters of various thicknesses and with different percentages of zinc in the alloy (2, 3, 4 and 5%). A conventional X-ray device operating with 60 and 70 kVp as well as D- and E-speed films were utilized in order to obtain images of a phantom and an aluminum step wedge. The utilization of Al-Zn filters resulted in a spectrum without hardening of beams. The rate of kerma in the air decreased 18.53%, without any alteration in contrast and image quality. The results revealed that the 2% Al-Zn alloy filter with 1.99 mm of thickness, utilized with the tension of 60 kVp and D-speed film, had the best performance. It reduced the rate of kerma without varying the indices of contrast and maintained image quality at acceptable levels, without increasing the time of exposure.

Dental Alloys↗

PubMedDate not supplied

Assessment of enamel demineralization using conventional, digital, and digitized radiography.

This experimental research aimed at evaluating the accuracy of enamel demineralization detection using conventional, digital, and digitized radiographs, as well as to compare radiographs and logarithmically contrast-enhanced subtraction images. Enamel subsurface demineralization was induced on one of the approximal surfaces of 49 sound third molars. Standardized radiographs of the teeth were taken prior to and after the demineralization phase with three digital systems--CygnusRay MPS, DenOptix and DIGORA--and InSight film. Three radiologists interpreted the pairs of conventional, digital, and digitized radiographs in two different occasions. Logarithmically contrast-enhanced subtraction images were examined by a fourth radiologist only once. Radiographic diagnosis was validated by cross-sectional microhardness profiling in the test areas of the approximal surfaces. Accuracy was estimated by Receiver Operating Characteristic (ROC) analysis. Chi-square test, at a significance level of 5%, was used to compare the areas under the ROC curves (A(z)) calculated for the different imaging modalities. Concerning the radiographs, the DenOptix system (A(z) = 0.91) and conventional radiographs (A(z) = 0.90) presented the highest accuracy values compared with the other three radiographic modalities. However, logarithmically contrast-enhanced subtraction images (A(z) = 0.98) were significantly more accurate than conventional, digital, and digitized radiographs (p = 0.0000). It can be concluded that the DenOptix system and conventional radiographs provide better performance for diagnosing enamel subsurface demineralization. Logarithmic subtraction significantly improves radiographic detection.

Dental Caries↗