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- Characterization of Legionella species by numerical analysis of whole-cell protein electrophoresisPublication . Veríssimo, António; Morais, Paula V.; Diogo, Alexandra; Alcobia Gomes, Célia Margarida; Costa, Milton S. daThe results of a computer-assisted whole-cell protein sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of 291 isolates and 74 reference strains belonging to all known species of the genus Legionella revealed that the majority of the species of this genus can be adequately identified by this method. The type strain of Legionella bozemanii did not cluster with the other strains of this species, and the only strain of Legionella geestiana available clustered with the strains of Legionella feeleii. When we performed a numerical analysis by omitting certain portions of the pattern containing dense bands, all of the species could be distinguished. Our results also show that the type strains of Legionella nautarum and Legionella londiniensis deposited in the National Collection of Type Cultures do not correspond to the type strains deposited in the American Type Culture Collection. We used the results of a fatty acid and ubiquinone composition analysis to complement the SDS-PAGE results for several strains whose identities as determined by indirect immunofluorescence were doubtful. Computer-assisted SDS-PAGE of whole-cell proteins can be used in the classification of Legionella species and to identify and screen large numbers of isolates for further, in-depth taxonomic studies of smaller numbers of strains.
- Computer-aided comparison of protein electrophoretic patterns for grouping and identification of heterotrophic bacteria from mineral waterPublication . Ferreira, A.C.; Morais, Paula V; Alcobia Gomes, Célia Margarida; Da Costa, MiltonThe microflora of a natural mineral water was studied immediately after bottling (T0) and after 7 d storage (T7) during 6 months, and isolates were clustered by SDS-PAGE of whole-cell protein profiles. Isolates from each cluster were further characterized by API 20NE, fatty acid composition and quinone profiles. The numerical analysis of the electrophoregrams of all bacteria isolated from the mineral water formed 15 clusters and five unclustered strains. Except for five minor clusters, all clusters were composed of strains isolated over several months. The numerical analysis of the electrophoregrams of bacteria isolated immediately after bottling formed 15 clusters while after 7 d storage only four of these populations could be isolated, indicating that populations present in the mineral water were stable and that changes occurring after bottling probably resulted from a selection process. Only one unclustered strain was identified simultaneously by all the systems, as Sphingomonas paucimobilis. The monitoring of the aquifer and the bottling system, and the construction of a large database with bacteria of the autochthonous flora allows the detection of alterations in the aquifer by changes in the microflora.
- New molecular markers for phlebotomine sand fliesPublication . Peixoto, Alexandre Afrânio; Alcobia Gomes, Célia Margarida; de Amoretty, P.R.; Lins, R.M.M.A.; Meireles-Filho, A.C.A.; de Souza, N.A.; Kyriacou, C.P.Using degenerate-primers PCR we isolated and sequenced fragments from the sand fly Lutzomyia longipalpis homologous to two behavioural genes in Drosophila, cacophony and period. In addition we identified a number of other gene fragments that show homology to genes previously cloned in Drosophila. A codon usage table for L. longipalpis based on these and other genes was calculated. These new molecular markers will be useful in population genetics and evolutionary studies in phlebotomine sand flies and in establishing a preliminary genetic map in these important leishmaniasis vectors.
- Molecular evolution of the period gene and phylogeny of neotropical sandfliesPublication . Mazzoni, C.J.; Alcobia Gomes, Célia Margarida; Souza, N.A.; Queiroz, R.G.; Justiniano, S.C.B.; Ward, R.D.; Kyriacou, C.P.; Peixoto, Alexandre AfrânioThe molecular evolution of the clock gene period was studied in Phlebotomine sandflies (Diptera: Psychodidae). Comparison of the synonymous and nonsynonymous substitution rates between sandflies and Drosophila revealed a significantly higher evolutionary rate in the latter in three of the four regions analyzed. The differences in rate were higher in the sequences flanking the Thr-Gly repetitive domain, a region that has expanded in Drosophila but remained stable and short in sandflies, a result consistent with the coevolutionary scenario proposed for this region of the gene. An initial phylogenetic analysis including eight neotropical sandfly species and one from the Old World was also carried out. The results showed that only the subgenus Nyssomyia is well supported by distance (neighbor-joining) and maximum parsimony analysis. The grouping of the other species from the subgenus Lutzomyia and Migonei group shows very low bootstrap values and is not entirely consistent with classical morphological systematics of the genus Lutzomyia.
- Transition from screen-film to computed radiography in a paediatric hospital: the missing link towards optimisationPublication . Paulo, Graciano; Santos, Joana; Moreira, Ana; Figueiredo, FilipaIn paediatrics, the risks associated with ionising radiation should be a major concern, due to children's higher susceptibility to radiation effects. Measure entrance skin dose (ESD) in chest and pelvis X-ray projections and compare the results with the 'European guidelines on quality criteria for diagnostic radiographer images in paediatrics' in order to optimise radiological practice. ESD values were obtained using an ionisation chamber Diamentor M4 KDK (PTW) in 429 children, who underwent chest X-ray or pelvis X-ray in a Computed Radiography system. In the first phase of the study, data were collected according to protocols used in the department; in a second phase different tube voltage values were used according to patient weight. A third phase was carried out, only for chest X-ray, using the exposure parameters of phase 2, plus activating lateral ionisation chamber. Three paediatric radiologists blindly assessed image quality of chest X-ray, using a validated assessment available in the 'European guidelines on quality criteria for diagnostic radiographer images in paediatrics'. Considering all the patients submitted to chest X-ray, the average ESD was 0.22, 0.16 and 0.08 mGy, for phases 1, 2 and 3, respectively. For pelvis X-ray, the average ESD decreased from 1.18 mGy in phase 1 to 0.78 mGy in phase 2. Dose optimisation was achieved. ESD was reduced 63.6 and 33.9 % in chest and pelvis X-ray, respectively.
- As características e funcionamento das conexinas, a surdez hereditária e a mutação do gene da conexina 26 e a displasia oculodentodigital e a mutação do gene da conexina 43Publication . Martins, Diana Mafalda Miranda, 1991-; Cruz, Andreia,; Girão, Cristina,
- TLD measurements and Monte Carlo simulations for glandular dose and scatter fraction assessment in mammography: a comparative studyPublication . Di Maria, Salvatore; Barros, Sílvia; Bento, Joana; Teles, Pedro; Figueira, Catarina; Pereira, Matheus; Vaz, P.; Paulo, GracianoThe main purpose of this study was to validate and compare Mean Glandular Dose (MGD) values obtained using Monte Carlo simulations with experimental values obtained from Entrance Surface Dose (ESD) and depth dose measurements performed in a Hospital mammography unit. ESD and depth dose were measured using ThermoLuminescent Dosimeters (TLDs), and a tissue equivalent mammography phantom recommended by the American College of Radiology (ACR). Measurements and Monte Carlo simulations were also compared with the MGD calculated using the Automatic Exposure Control (AEC) system of the mammographic unit. In the simulations the Doppler energy broadening effect was also taken into account. The simulated ESD are about 5%-10% higher than the measured ESD values. The deviation between the measured and simulated MGD values in the phantom is of about 15%. The MGD evaluated using the AEC system is smaller both with respect to the Monte Carlo simulation and experimental result by a factor of about 15% and 25% respectively. Moreover the BackScatter Factor (BSF) estimated by Monte Carlo simulations was used for the MGD calculation according to the Wu's method. Finally the inclusion of the energy broadening effect on MGD calculation produces negligible variations on the simulated results.
- Positron emitting tracers in pre-clinical drug developmentPublication . Fernandes, E.; Barbosa Moreira, Zélia; Clemente, G.; Alves, F.; J. Abrunhosa, A.Molecular imaging tools such as Positron Emission Tomography (PET) are increasingly being used in the drug development process. The unrivaled sensitivity of PET coupled with a solid experience in developing highly targeted molecular probes makes this technique a very valuable tool at all stages from pre-clinical development to the clinical phases. Positron emitting tracers allow us to measure, quantitatively, molecular processes and interactions between a candidate drug and its molecular targets. This information can save time and money by directing development towards the most promising compounds and excluding molecules with unfavorable properties that would otherwise only be recognized as failures in latter stages of the process. In this paper we review the application of positron emitting tracers in the pre-clinical stages of the drug development process in the areas of oncology, cardiology, neurosciences and inflammatory diseases. PET tracers provide an important support for drug development in the areas of: discovery of new drug targets, clarification of pathophysiology, identification of potential drug candidates and validation of drug effectiveness, as well as the evaluation of pharmacokinetic and pharmacodynamic parameters in vivo.
- Estimation of the collective dose in the Portuguese population due to medical procedures in 2010Publication . Teles, Pedro; De Sousa, Carmen; Paulo, Graciano; Santos, Joana; Pascoal, Ana; Cardoso, Gabriela; Lança, Isabel; Matela, Nuno; Janeiro, Luís; Sousa, Patrick; Carvoeiras, Pedro; Parafita, Rui; Santos, A. I.; Simaozinho, Paula; Vaz, P.In a wide range of medical fields, technological advancements have led to an increase in the average collective dose in national populations worldwide. Periodic estimations of the average collective population dose due to medical exposure is, therefore of utmost importance, and is now mandatory in countries within the European Union (article 12 of EURATOM directive 97/43). Presented in this work is a report on the estimation of the collective dose in the Portuguese population due to nuclear medicine diagnostic procedures and the Top 20 diagnostic radiology examinations, which represent the 20 exams that contribute the most to the total collective dose in diagnostic radiology and interventional procedures in Europe. This work involved the collaboration of a multidisciplinary taskforce comprising representatives of all major Portuguese stakeholders (universities, research institutions, public and private healthcare providers, administrative services of the National Healthcare System, scientific and professional associations and private service providers). This allowed us to gather a comprehensive amount of data necessary for a robust estimation of the collective effective dose to the Portuguese population. The methodology used for data collection and dose estimation was based on European Commission recommendations, as this work was performed in the framework of the European wide Dose Datamed II project. This is the first study estimating the collective dose for the population in Portugal, considering such a wide national coverage and range of procedures and consisting of important baseline reference data. The taskforce intends to continue developing periodic collective dose estimations in the future. The estimated annual average effective dose for the Portuguese population was of 0.080±0.017 mSv caput(-1) for nuclear medicine exams and of 0.96±0.68 mSv caput(-1) for the Top 20 diagnostic radiology exams.
- Quadricipite architecture evaluation with ultrasound, in an elderly populationPublication . Boieiro, A.; Mogas, F.; Moretto, D.; Tavares, P.; André, A.; Paulo, GracianoAging is associated with a progressive loss of neuromuscular function that often leads to a progressive disability and loss of independence. Degenerative processes begin to limit autonomy and functionality. Those processes is sarcopenia, defined as a gradual decline in muscle mass The aim of this study was to evaluate the muscle architecture, in an elderly population that practice exercise and a sedentary group, with the purpose of investigate the process of sarcopenia. Methods: Elderly people were evaluated, this evaluation was performed with an ultrasound, with 12 Mhz transducer. We evaluate both quadricipite muscles in contraction and in rest. A questionnaire was also per- formed for each individual in both samples. Informed consent was done. Main Results: Our results showed some differences in the muscle architecture in both groups. The main alteration was in the pennation angle that was higher in the exercised group. These differences altered the muscle performance. Conclusions: Muscular architecture is affected with disuse and sarcopenia. It is well known a relationship between performance, contractions and muscle architecture. Our results suggested that the atrophy directly affect muscles by reducing the volume and pennation angle. Thus, the effectiveness of strength training improves the structural and functional parameters of the skeletal muscle of elderly.