Percorrer por autor "Barbosa, Telma"
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- Chromosome Instability in Asthma an Antioxidant Treatment as a Possible Pharmacological Strategy?Publication . Oliveira, Claúdia; Nogueira, Maria; Barbosa, Telma; Cardoso, Carmen; Neves, João; Costa, Solange; Porto, BeatrizAsthma is a disease with multiple phenotypes and different degrees of severity. Severe inflammation appears when oxidative stress (OS) overwhelms the antioxidant defense. Knowing the role of OS in the increase of chromosome instability (CI) and, consequently, in cancer predisposition, it is important to carry out studies to establish limits for OS harmful effects. The aim of this study was to evaluate OS-related CI in asthma patients and the possible protective effect of antioxidants. For that purpose, spontaneous and OS-induced lymphocyte cultures from patients with mild and severe asthma, and from normal controls, were performed. Antioxidant-enriched cultures from severe patients were posteriorly performed. A hundred metaphases per culture were scored in order to estimate the frequency of CI. Our results showed that lymphocytes from severe patients had increased CI, both in spontaneous and OS-induced cultures. However, in lymphocytes from mild patients there were no differences compared to controls. This suggests that in patients subjected to extreme OS conditions, a genotoxic effect may occur at the cellular level. When lymphocytes from these patients were treated with antioxidants, a decrease in CI was observed. Understanding how CI correlates to asthma patients’ clinical situation may be pivotal to the design of future preventive measures.
- Cystic Fibrosis Newborn Screening in Portugal: PAP Value in Populations with Stringent Rules for Genetic StudiesPublication . Marcão, Ana; Barreto, Celeste; Pereira, Luísa; Vaz, Luísa; Cavaco, José; Casimiro, Ana; Félix, Miguel; Silva, Teresa; Barbosa, Telma; Freitas, Cristina; Nunes, Sidónia; Felício, Verónica; Lopes, Lurdes; Amaral, Margarida; Vilarinho, LauraNewborn screening (NBS) for cystic fibrosis (CF) has been shown to be advantageous for children with CF, and has thus been included in most NBS programs using various algorithms. With this study, we intend to establish the most appropriate algorithm for CF-NBS in the Portuguese population, to determine the incidence, and to contribute to elucidating the genetic epidemiology of CF in Portugal. This was a nationwide three-year pilot study including 255,000 newborns (NB) that were also screened for congenital hypothyroidism (CH) and 24 other metabolic disorders included in the Portuguese screening program. Most samples were collected in local health centers spread all over the country, between the 3rd and 6th days of life. The algorithm tested includes immunoreactive trypsinogen (IRT) determination, pancreatitis associated protein (PAP) as a second tier, and genetic study for cases referred to specialized clinical centers. Thirty-four CF cases were confirmed positive, thus indicating an incidence of 1:7500 NB. The p.F508del mutation was found in 79% of the alleles. According to the results presented here, CF-NBS is recommended to be included in the Portuguese NBS panel with a small adjustment regarding the PAP cut-off, which we expect to contribute to the improvement of the CF-NBS performance. According to our results, this algorithm is a valuable alternative for CF-NBS in populations with stringent rules for genetic studies.
- Evaluating the Impact of Newborn Screening for Cystic Fibrosis in Portugal: A Decade of Insights and OutcomesPublication . Camacho, Bernardo; Pereira, Luísa; Bragança, Raquel; Castanhinha, Susana; Penteado, Raquel; Silva, Teresa Reis; Miragaia, Pedro; Silva, Sónia; Cardoso, Ana L.; Barbosa, Telma; Freitas, Cristina; Gonçalves, Juan; Marcão, Ana; Vilarinho, Laura; Barreto, Celeste; Constant, CarolinaThe implementation of newborn screening (NBS) has revolutionized the diagnostic landscape of cystic fibrosis (CF). In Portugal, NBS was initiated in October 2013 through a pilot study and was subsequently fully integrated into a nationwide program by December 2018. Infants with positive screening results are referred to a specialized CF reference center for diagnostic confirmation, employing Sweat Chloride Testing (SCT) and genetic testing for CFTR variants. We aimed to analyze infants with a positive CF screening and determine the false positive and false negative rates, as well as to calculate the positive predictive value and sensitivity of our NBS program. A retrospective nationwide analysis was conducted on infants with a positive NBS for CF between October 2013 and February 2023. Two hundred and forty infants were referred from the NBS program; 74 (30.8%) were confirmed to have CF through SCT and genetic testing. Sensitivity was 93.2%, and the positive predictive value (PPV) was 30.8%. In addition, 48.5% were homozygous for F508del variants, and 87.8% had at least one F508del variant. Guidelines set forth by the European Cystic Fibrosis Society advise NBS programs to achieve a minimum PPV of 30% and a minimum sensitivity of 95%. Our report demonstrated good compliance with these recommendations.