DEP - Artigos em revistas internacionais
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- Workshop Report: Developing Pollution Source Tracking for Recreational and Shellfish WatersPublication . Pond, Kate; Rangdale, R.; Meijer, Wim; Brandão, João; Falcão, Leonor; Rince, Alain; Greaves, John; Gawler, Andy; Masterson, Bartholomew; McDonnell, E.; Cronin, A.; Pedley, S.The Environment Agency of England and Wales obtained European Community Initiative INTERREG IIIB funding for a project called ICReW—Improving Coastal and Recreational Waters. The project consists of seven pilot actions aiming to contribute to the reduction of pollution, to enhance water quality, and to ensure that land-use practices and recreational activities can exist side by side without impacting public health. One of these actions is to identify and develop a common methodology for source-tracking fecal pollution, for regulatory purposes, over a wide geographical area in Europe. In order to do this the Department for Environment, Food and Rural Affairs, UK, sponsored the first international workshop on the subject. Key researchers from around the world were invited to attend to recommend the most appropriate method(s) for development and field trial in Europe. The meeting concluded that for the specific requirements of the ICReW project two methods should be developed and trialled: bacteroides genotyping and F+RNA coliphage genotyping. This article summarizes the reasons why these methods were chosen as the most appropriate for the circumstances of this particular project. The inherent challenges of establishing a pilot program to test the methods are outlined and recommendations were provided for the trial.
- Mortality in Portugal associated with the heat wave of August 2003: early estimation of effect, using a rapid methodPublication . Nogueira, Paulo; Marinho Falcão, José; Contreiras, Maria Teresa; Paixão, Eleonora; Brandão, João; Batista, InêsDuring the first two weeks of August 2003, Portugal was affected by a severe heat wave. Following the identification in Portugal of the influence of heat waves on mortality in 1981 and 1991 (estimated excess of about 1900 and 1000 deaths respectively), the Observatório Nacional de Saúde (ONSA) - Instituto Nacional de Saúde Dr. Ricardo Jorge, together with the Vigilância Previsão e Informação - Instituto de Meteorologia, created a surveillance system called ÍCARO, which has been in operation since 1999. ÍCARO identifies heat waves with potential influence on mortality [1]. Before the end of the 2003 heat waves, ONSA had produced a preliminary estimate of its effect on mortality. The results based on daily number of deaths from 1 June to 12 August 2003 were presented within 4 working days. Data was gathered from 31 National Civil registrars, covering the district capitals of all 18 districts of mainland Portugal, and representing approximately 40% of the mainland’s mortality. The number of deaths registered in the period 30 July to 12 August was compared with the ones registered during 3 comparison periods (of 2003): 1-14 July, 1-28 July, and 15-28 July. 15-28 July, the period best resembling the heat waves in time and characteristics, produced an estimation of 37.7% higher mortality rate then the value expected under normal temperature conditions. From this value, an estimate of 1316 death excess was obtained for mainland Portugal. The main purpose of this article is to present the method used to identify and assess the occurrence of an effect (excess mortality) during the heat waves of summer 2003
- Lack of detectable allergenicity of transgenic maize and soya samplesPublication . Batista, Rita; Nunes, Baltazar; Carmo, Manuela; Cardoso, Carlos; Helena, São José; Almeida, António Bugalho de; Manique, Alda; Bento, Leonor; Ricardo, Cândido Pinto; Oliveira, Maria MargaridaBackground: The safety issues regarding foods derived from genetically modified (GM) plants are central to their acceptance into the food supply. The potential allergenicity of proteins newly introduced in GM foods is a major safety concern. Objective: We sought to monitor, in potentially sensitive human populations, the allergenicity effects of 5 GM materials obtained from sources with no allergenic potential and already under commercialization in the European Union. Methods: We have performed skin prick tests with protein extracts prepared from transgenic maize (MON810, Bt11, T25, Bt176) and soya (Roundup Ready) samples and from nontransgenic control samples in 2 sensitive groups: children with food and inhalant allergy and individuals with asthmarhinitis. We have also tested IgE immunoblot reactivity of sera from patients with food allergy to soya (Roundup Ready) and maize (MON810, Bt11, Bt176) samples, as well as to the pure transgenic proteins (CryIA[b] and CP4 5-enolpyruvylshikimate- 3-phosphate synthase). Results: None of the individuals undergoing tests reacted differentially to the transgenic and nontransgenic samples under study. None of the volunteers tested presented detectable IgE antibodies against pure transgenic proteins. Conclusion: The transgenic products under testing seem to be safe in terms of allergenic potential. We propose postmarket testing as an important screening strategy for putative allergic sensitization to proteins introduced in transgenic plants.
- Molecular characterization of the HA gene of influenza type B virusesPublication . Pechirra, Pedro; Nunes, Baltazar; Coelho, Anabela; Ribeiro, Carlos; Gonçalves, Paulo; Pedro, Sónia; Canto e Castro, Luísa; Rebelo-de-Andrade, HelenaAbstract Nucleotide sequences of the HA1 subunit of influenza B viruses isolated in Portugal between 1994 and 2003 influenza winter seasons were analyzed by the Neighbor-Joining algorithm and rates of HA1 evolution estimated by linear regression. From 1994 to 2002, all influenza B viruses studied were of the Yamagata lineage. Strains isolated from 1994 to 1996, 1996 to 1999, and 1999 to 2002 revealed a high similarity with B/Beijing/184/93, B/Yamanashi/166/98, and B/Sichuan/379/99, respectively, and strains isolated during 1994-1995, 1996-1997, and 1998-1999 clustered in more than one branch of the phylogenetic tree. Victoria-related strains reappeared during 2002/2003 and formed only one branch in the phylogenetic tree revealing a closer relationship to B/Shandong/7/97. Evolutionary rates for strains from the Yamagata lineage were estimated as 3.82x10(-3) nucleotides/site/year and 2.62x10(-3) nucleotides/site/year for Victoria-related strains. In order to identify putative influenza B HA1 codons under selective pressure, a codon-substitution model for heterogeneous selective pressure at amino acid sites was used. A percentage of 97.3% of codons under negative selective pressure and 2.7% of codons under positive selective pressure (omega=dN/dS=2.65) were estimated, with posterior probability higher than 0.90. Amino acid sites 75, 197, and 199 were found more likely to be under positive selective pressure.
- Influenza vaccine coverage and the attack rate of influenza-like illness among the elderly in Portugal: is there a correlation?Publication . Nunes, Baltazar; Falcão, Isabel; Machado, Ausenda; Rodrigues, Emanuel; Marinho Falcão, JoséVaccination of the elderly (>=65 years of age) against influenza is recommended in all European countries and believed to significantly reduce influenza-related morbidity and mortality [1]. However, there hav e been relatively few studies on the relationship between the vaccine coverage and the attack rate of influenza-like illness (ILI), and their results have differed [2,3,4]. The study described in this paper aimed at establishing the correlation between the influenza vaccine coverage rates and the rates of ILI among Portuguese population aged 65 years and older, during the influenza seasons 1998-1999 to 2006-2007.
- Early modification of sickle cell disease clinical course by UDP-glucuronosyltransferase 1A1 gene promoter polymorphismPublication . Martins, Rute; Morais, Anabela; Dias, Alexandra; Soares, Isabel; Rolão, Cristiana; Ducla-Soares, JL; Braga, Lígia; Seixas, Teresa; Nunes, Baltazar; Olim, Gabriel; Romão, Luísa; Lavinha, João; Faustino, PaulaElevated erythrocyte destruction in sickle cell disease (SCD) results in chronic hyperbilirubinaemia and, in a subset of patients, cholelithiasis occurs. We investigated whether the (TA)n promoter polymorphism in the UDP-glucuronosyltransferase 1A1 gene (UGT1A1) may modify bilirubin metabolism, influencing bilirubinaemia, predisposition to cholelithiasis and subsequent cholecystectomy, in a group of 153 young SCD patients (mean age 12.0 +/- 9.0 years) predominantly of Bantu beta S haplotype. The concomitant effect of alpha thalassaemia was also analysed. Among the several UGT1A1 genotypes found, the most frequent were the (TA)6/(TA)6 (n = 37), (TA)6/(TA)7 (n = 60) and (TA)7/(TA)7 (n = 29). These groups of patients did not significantly differ in age, gender ratio and haemoglobin, foetal haemoglobin and reticulocyte levels. On the other hand, total bilirubin levels were significantly different between groups, with an increased (TA) repeat number being associated with higher bilirubinaemia. Furthermore, both cholelithiasis and cholecystectomy were more frequent in groups with higher (TA) repeat number, although the former association was not statistically significant. None of the mentioned parameters is statistically different within UGT1A1 groups with the presence of alpha thalassaemia. Thus, the UGT1A1 promoter polymorphism may represent an important nonglobin genetic modifier of Bantu SCD patients' clinical manifestations, even at a young age.
- Heterogeneous Selective Pressure Acting on Influenza B Victoria- and Yamagata-Like HemagglutininsPublication . Nunes, Baltazar; Pechirra, Pedro; Coelho, Anabela; Ribeiro, Carlos; Arraiolos, Ana; Rebelo-de-Andrade, HelenaAs a consequence of immune pressure, influenza virus hemagglutinin presents some of its amino acids under positive selection. Several authors have reported the existence of influenza A hemagglutinin codons under positive selective pressure (PSP). In this framework, the present work objectives were to demonstrate the presence of PSP and evaluate its effects on Victoria- and Yamagata-like influenza B viruses. Methodology adopted consisted in estimating the acceptance rate of nonsynonymous substitutions (ω = dN/dS) that describe the strength of selective pressure and identifying codons that may be positively selected, applying a set of continuous-time Markov chain codon-substitution models. Two groups of HA1 sequences (140 from Yamagata and 60 from Victoria lineage) were used. All the model maximum-likelihood estimates were obtained using codeml software application (PAML 3.15). The hypothesis of no existence of sites under PSP was rejected for both lineages (p<0.001), using likelihood ratio tests. These results demonstrate the presence of positive selection acting on hemagglutinin of both Yamagata- and Victoria-like influenza B viruses. Several different sites were identified to be under PSP on Yamagata and Victoria hemagglutinins. Sites found with a posterior probability >0.95 were codons 197 and 199 in both lineages, codon 75 in the Yamagata lineage, and codon 129 in the Victoria lineage. The detected amino acids are located at or near antigenic sites in influenza A virus H3 hemagglutinin.
- Congenital hydronephrosis: Prenatal diagnosis and epidemiology in EuropePublication . Garne, Ester; Loane, Maria; Wellesley, Diana; Barisic, Ingeborg; EUROCAT Working GroupObjective: To describe prevalence, prenatal diagnosis and epidemiology of congenital hydronephrosis (CH) in Europe. Material and method: Data from a large European database for surveillance of congenital malformations (EUROCAT). The 20 participating registries are all based on multiple sources of information and include information about livebirths, fetal deaths with gestational age 20 weeks and terminations of pregnancy after prenatal diagnosis of malformations. Included were all cases with CH and born 1995e2004. Results: There were 3648 cases with CH giving an overall prevalence of 11.5 cases per 10,000 births. The large majority of cases were livebirths (3506, 96% of total) and only 17 cases were fetal deaths and 120 were terminations of pregnancy. Almost all livebirths were alive 1 week after birth. Boys accounted for 72% of all cases. A high proportion of the cases (86%) had an isolated renal malformation. There were large regional differences in prevalence of CH ranging from 2 to 29 per 10,000 births. There was little regional variation in the prevalence of postnatally diagnosed cases while there were large regional differences in prevalence of prenatally diagnosed cases. Conclusion: Cases with CH are mainly livebirths, boys and survive the first week after birth. The large difference in prevalence seems to be related to the availability of prenatal screening in the region. The impact of over-diagnosis and potential over-treatment in regions with high prevalence or under-diagnosis with implications for renal function later in life in regions with low prevalence needs further investigation.
- Assessment of mother-to-child HIV-1 and HIV-2 transmission: an AIDS reference laboratory collaborative studyPublication . Pádua, E.; Almeida, C.; Nunes, Baltazar; Cortes Martins, H.; Castela, J.; Paixão, M.T.OBJECTIVE: A prospective study was carried out to assess HIV-1 and HIV-2 mother-to-child transmission (MTCT) rates in Portugal between 1999 and 2005 by analysing the proportion of diagnosed infected children born to HIV-positive mothers. MATERIALS AND METHODS: Serial blood samples were collected from 1315 children at risk of HIV-1 infection, 131 children at risk of HIV-2 infection and six children at risk of both HIV-1 and HIV-2 infections attending 25 Health Institutions. HIV proviral DNA was detected by nested polymerase chain reaction (PCR) and statistical analysis was performed using spss. RESULTS: DNA PCR using HIV-1 and HIV-2 long terminal repeat (LTR) primers amplified 92.5% and 75% of maternal HIV infections, respectively. Overall, MTCT occurred in 3.4% [95% confidence interval (CI) 2.5-4.6%] of HIV-1 and 1.5% (95% CI 0.2-5.4%) of HIV-2 mother-child pairs. A significant decrease in HIV-1 MTCT was observed with time, from 7.0% (95% CI 2.6-14.6%) in 1999 to 0.5% (95% CI 0.0-2.5%) in 2005. HIV MTCT was associated with an absence of antiretroviral therapy in infected pregnant women (P<0.0001). Of the 48 infected children (46 with HIV-1 and two with HIV-2), the schedule of blood sample collection was followed for only 26 children. In 14 (53.8%) of those 26 children the infections were diagnosed in the first sample collected before they were 48 h old, suggesting in utero transmission. Despite the national recommendations for antenatal HIV testing, a high overall proportion (22.2% for HIV-1 and 44.3% for HIV-2) of mothers did not access any MTCT prevention measures, mostly because of late diagnosis in pregnancy. A small but significant proportion of HIV-2 infection was found in mothers with no identifiable link with West Africa. CONCLUSION: HIV-2 transmission rates are low (1.5% in this study), and this may have led to a lower uptake of interventions, but in the absence of interventions transmission does occur. HIV-1 transmission was also associated with a lack of intervention, mostly as a result of late presentation. Use of primers restricted to a single sequence led to false-negative maternal results in a significant proportion of cases. In part this may have been attributable to very low HIV DNA loads as well as primer template mismatches. HIV infection was not documented in children born to mothers with negative HIV DNA PCR results.
- Maternal age-specific risk of non-chromosomal anomaliesPublication . Loane, M; Dolk, H; Morris, JK; EUROCAT Working GroupObjectives: To determine the excess risk of non-chromosomal congenital anomaly (NCA) among teenage mothers and older mothers. Design and setting: Population-based prevalence study using data from EUROCAT congenital anomaly registers in 23 regions of Europe in 15 countries, covering a total of 1.75 million births from 2000 to 2004. Participants: A total of 38 958 cases of NCA that were live births, fetal deaths with gestational age ≥20 weeks or terminations of pregnancy following prenatal diagnosis of a congenital anomaly. Main outcome measures: Prevalence of NCA according to maternal age, and relative risk (RR) of NCA and 84 standard NCA subgroups compared with mothers aged 25–29. Results: The crude prevalence of all NCA was 26.5 per 1000 births in teenage mothers (<20 years), 23.8 for mothers 20–24 years, 22.5 for mothers 25–29 years, 21.5 for mothers 30–34 years, 21.4 for mothers 35–39 years and 22.6 for mothers 40–44 years. The RR adjusted for country for teenage mothers was 1.11 (95% CI 1.06–1.17); 0.99 (95% CI 0.96–1.02) for mothers 35–39; and 1.01 (95% CI 0.95–1.07) for mothers 40–44. The pattern of maternal age-related risk varied significantly between countries: France, Ireland and Portugal had higher RR for teenage mothers, Germany and Poland had higher RR for older mothers. The maternal age-specific RR varied for different NCAs. Teenage mothers were at a significantly greater risk (P < 0.01) of gastroschisis, maternal infection syndromes, tricuspid atresia, anencephalus, nervous system and digestive system anomalies while older mothers were at a significantly greater risk (P < 0.01) of fetal alcohol syndrome, encephalocele, oesophageal atresia and thanatophoric dwarfism. Conclusions: Clinical and public health interventions are needed to reduce environmental risk factors for NCA, giving special attention to young mothers among whom some risk factors are more prevalent. Reassurance can be given to older mothers that their age in itself does not confer extra risk for NCA.