Microleakage study of a restorative material via radioisotope methods

AbstractObjectivesTo validate the quantitative method used in the evaluation of microleakage and to evaluate the microleakage of dental restorations using GCP Fill. The null hypothesis was that the restorative system doesn’t have any influence regarding microleakage.MethodsSixty noncarious extracted human molars were cut in two equal halves occlusogingivally and Class V cavities were prepared on the buccal or lingual surfaces of each tooth. The specimens were randomly divided into 4 groups. Two were restored with GCP Fill, while another was restored with Filtek Supreme. The control group was not restored. The specimens were stored in distilled water at 37°C for 7 days before 500 cycles of thermocycling between 5°C and 55°C, dwell time of 30s. The specimens were submersed in a solution of 99mTc-pertechnetate for 3h and the radioactivity was determined. The nonparametric Kruskal–Wallis and Mann–Whitney test with Bonferroni correction at a significance level of 5% were used for statistical analyses.ResultsThere were statistically significant differences between experimental groups and control groups (p<0.05). Apart from these differences, a significant difference was observed between negative and positive control groups (p<0.001). In the control+group there was a large microleakage, and the control-group received minimum counts.ConclusionThe GCP Fill and the Filtek Supreme XTE do not differ as regards microleakage; this technique proved to be simple, quick and fulfilled the objective of a quantitative method in the evaluation of microleakage. Long-term clinical studies need to be carried out to substantiate these results

Polyethyleneiminomethyl phosphonic acid (PEI-MP) radiolabeled with technetium-99m as a potential new radiopharmaceutical for diagnosis of bladder cancer

Introduction: The polymer PEI-MP (polyethyleneiminomethyl phosphonic acid) might be labelled with 99mTc. It was initially synthesized for palliative therapy of bone metastases after convenient radiolabelling, however in biodistribution studies performed with different PEI-MP/radionuclides, was obvious that the bladder wall was a target organ [1-3], demonstrating a certain selectivity to bladder cells, and so, to bladder cancer cells. The aim of this study was to evaluate the efficacy of 99mTc-PEI-MP for diagnosis of bladder carcinoma, evaluating in vitro and in vivo the biokinetics and biodistribution of 99mTc-PEI-M

Effects on gastric mucosa induced by dental bleaching – an experimental study with 6% hydrogen peroxide in rats

The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed.Objective This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals.Material and Methods Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa.Results The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group.Conclusion Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized

Plastic rearrangement of basal forebrain parvalbumin-immunoreactive neurons in the kainite model of epilepsy

Temporal lobe epilepsy (TLE) is the most prevalent form of epilepsy, through the neuronal mechanisms of this syndrome remain elusive. In addition to the temporal lobe structures, it was found that the basal forebrain cholinergic cells are also involved in epileptogenesis. However, little is known about the involvement of the basal forebrain GABAergic neurons in epilepsy; despite this, they largely project to the temporal lobe and are crucial for the regulation of the hippocampal circuitry. In this study, we assessed epilepsy-induced changes in parvalbumin (PARV) immunoreactive neurons of the medial septum (MS) and of the magnocellular preoptic nucleus (MCPO) using the kainic acid (KA) model in rats. In addition, we estimated the respective changes in the cholinergic varicosities in the MS, where we observed a significant reduction in the PARV cell number (12849 ± 2715 vs. 9372 ± 1336, p = .029) and density (16.2 ± 2.62 vs. 10.5 ± 1.00 per .001 mm3, p =.001), and an increase in the density of cholinergic varicosities (47.9 ± 11.1 vs. 69.4 ± 17.8 per 30,000 µm2, p =.036) in KA-treated animals. In the MCPO, these animals showed a significant increase in somatic volume (827.9 ± 235.2 µm3 vs. 469.9 ± 79.6 µm3, p = .012) and total cell number (2268.6 ± 707.1 vs. 1362.4 ± 262.0, p =.028). These results show that the basal forebrain GABAergic cell populations undergo numerical and morphological changes in epileptic animals, which may contribute to an increased vulnerability of brain circuits to epilepsy and epilepsy-related functional impairments

Evaluation of dentinogenesis inducer biomaterials: an in vivo study

When exposure of the pulp to external environment occurs, reparative dentinogenesis can be induced by direct pulp capping to maintain pulp tissue vitality and function. These clinical situations require the use of materials that induce dentin repair and, subsequently, formation of a mineralized tissue. Objective: This work aims to assess the effect of tricalcium silicate cements and mineral trioxide aggregate cements, including repairing dentin formation and inflammatory reactions over time after pulp exposure in Wistar rats. Methodology: These two biomaterials were compared with positive control groups (open cavity with pulp tissue exposure) and negative control groups (no intervention). The evaluations were performed in three stages; three, seven and twenty-one days, and consisted of an imaging (nuclear medicine) and histological evaluation (H&amp;E staining, immunohistochemistry and Alizarin Red S). Results: The therapeutic effect of these biomaterials was confirmed. Nuclear medicine evaluation demonstrated that the uptake of 99mTc-Hydroxymethylene diphosphonate (HMDP) showed no significant differences between the different experimental groups and the control, revealing the non-occurrence of differences in the phosphocalcium metabolism. The histological study demonstrated that in mineral trioxide aggregate therapies, the presence of moderate inflammatory infiltration was found after three days, decreasing during follow-ups. The formation of mineralized tissue was only verified at 21 days of follow-up. The tricalcium silicate therapies demonstrated the presence of a slight inflammatory infiltration on the third day, increasing throughout the follow-up. The formation of mineralized tissue was observed in the seventh follow-up day, increasing over time. Conclusions: The mineral trioxide aggregate (WhiteProRoot®MTA) and tricalcium silicate (Biodentine™) present slight and reversible inflammatory signs in the pulp tissue, with the formation of mineralized tissue. However, the exacerbated induction of mineralized tissue formation with the tricalcium silicate biomaterial may lead to the formation of pulp calcifications

Radioterapia neoadjuvante no carcinoma do recto: resposta à terapêutica e sua toxicidade

Introdução: O carcinoma do recto localmente avançado (CRLA) é habitualmente tratado com Radioterapia (RT) seguida por Cirurgia. Existem dois esquemas possíveis para irradiação neoadjuvante: o longo (EL), associado a quimioterapia (QT), e o curto (EC). Objectivos: Comparar resposta e toxicidade à terapêutica com EL e EC em doentes com CRLA. Material e Métodos: Foram incluídos doentes com CRLA tratados de 2002 a 2012, que realizaram RT pré-operatória segundo EL ou EC. A resposta foi avaliada pela classificação pTNM e regressão de Dworak (GRD); a toxicidade foi avaliada pela escala CTCAE3. Resultados: Foram incluídos 215 doentes de EL e 55 de EC. Os de EC tinham idade superior e Karnofsky inferior aos de EL (p&lt;0,001). 20% dos EC eram estádio IV e 92,6% dos EL estádio III (p&lt;0,001). Efectuaram cirurgia curativa 208 doentes após EL e 47 após EC; foram realizadas mais cirurgias conservadoras. Obteve-se GRD 4 em 16,8% vs. 6,4%, downstaging N em 66,3% vs. 23,4% e resposta loco-regional em 79,8% vs. 57,4% (EL vs. EC; p&lt;0,001). Não foi descrita toxicidade aguda no EC; no EL ocorreu em 77,7% (p&lt;0,001) mas apenas 7,9% com grau 3/4 (p=0,028). Não houve diferenças nas complicações pós-operatórias (p=0,299). Mais doentes EL realizaram QT adjuvante (p&lt;0,001). Pior resposta patológica pTN e GRD 0-1 no EL estão associados a mais ressecções R+ (p&lt;0,01). Conclusões: O EL aparenta estar associado a melhor resposta do que o EC, o que facilita uma ressecção curativa, à custa de uma toxicidade tolerável

Beyond the limits of oxygen: effects of hypoxia in a hormone-independent prostate cancer cell line

Prostate cancer (PCa) has a high incidence worldwide. One of the major causes of PCa resistance is intratumoral hypoxia. In solid tumors, hypoxia is strongly associated with malignant progression and resistance to therapy, which is an indicator of poor prognosis. The antiproliferative effect and induced death caused by doxorubicin, epirubicin, cisplatin, and flutamide in a hormone-independent PCa cell line will be evaluated. The hypoxia effect on drug resistance to these drugs, as well as cell proliferation and migration, will be also analyzed. All drugs induced an antiproliferative effect and also cell death in the cell line under study. Hypoxia made the cells more resistant to all drugs. Moreover, our results reveal that long time cell exposure to hypoxia decreases cellular proliferation and migration. Hypoxia can influence cellular resistance, proliferation, and migration. This study shows that hypoxia may be a key factor in the regulation of PCa.info:eu-repo/semantics/publishedVersio

Finanças públicas, direito financeiro e direito tributário em tempos de pandemia: diálogos ibero-americanos

- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 347.73:578.834(7/8) F491p- Organizado por: Carlos Palao Taboada, Germán Orón Moratal, João Ricardo Catarino, José Casalta Nabais, Juan Arrieta Martinez de Pisón e Marciano Seabra de Godoi