Browsing by Issue Date, starting with "2016-04"
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- Inborn Errors of Metabolism: From Neonatal Screening to Metabolic Pathways: Book reviewPublication . Amaral, OlgaBook Review of ‘Inborn Errors of Metabolism: From Neonatal Screening to Metabolic Pathways’ edited by two well-known specialists in the area of inborn errors of metabolism (IEMs), Brendan Lee and Fernando Scaglia, gives us a different vision in this field.
- Avaliação do Desempenho dos Participantes no Programa Nacional de Avaliação Externa da Qualidade em Morfologia Parasitária: 20 anos de experiênciaPublication . Júlio, Cláudia; Correia, Helena; Baptista Fernandes, Teresa; Cardoso, Ana; Brito, Cristina; Santos Costa, Quirina; Faria, Ana PaulaO Programa Nacional de Avaliação Externa da Qualidade (PNAEQ), inserido no Departamento de Epidemiologia do Instituto Nacional de Saúde Doutor Ricardo Jorge, em Lisboa, tem implementado entre outros, o programa de Morfologia parasitária desde 1995. Neste programa são enviadas amostras de sangue e de fezes para identificação de parasitas e conta com o apoio de um grupo de trabalho cuja principal atividade é a seleção de amostras, a análise de resultados e elaboração de relatórios técnico-científicos promovendo a formação bem como a melhoria contínua do desempenho dos participantes. Neste estudo retrospetivo pretendemos avaliar, o desempenho dos participantes no período de 1995 a 2015, relativamente à deteção e identificação de parasitas, em amostras de fezes e sangue.
- Nonclassic Congenital Adrenal Hyperplasia (NCCAH) Due to 21-Hydroxylase Deficiency: Clinical Management and Genetic Counseling of Two Portuguese FamiliesPublication . Lurdes de Matos, Maria; Antunes, Diana; Gonçalves, João; Lopes, Lurdes; Kay, TeresaIntroduction: Congenital adrenal hyperplasia (CAH) due to 21-Hydroxylase deficiency occurs in 90-95% of cases, being a common autosomal recessive condition that can present with a wide range of hyperandrogenemic signs in childhood or adulthood. Severity of this disease is correlated with the enzymatic blockade of 21-Hydroxylase which depends of the mutation in gene CYP21A2. Two clinical forms are possible: classic, subdivided in salt-wasting and simple virilizing form (severe) and nonclassic or late onset (less severe). Aims: We studied two portuguese families with NCCAH due to 21-Hidroxilase deficiency in order to improve clinical management and genetic counseling of their members. Methods: Clinical presentation and hormonal assays (including test of tetracosactide) were performed in index cases (IC) . Genomic DNA of each family member was sequenced for the 9 most frequent mutations in CYP21A2. Total deletion of CYP21A , conversion in non functioning CYP21A1P or CYP21A1P_ CYP21A2 quimeras were also analyzed by enzymatic restriction. Results: Family 1- IC: Female, 31 years old with NCCAH diagnosed at age 6 , after investigation of precocious pubarche and with test of tetracosactide positive (17-alpha hydroxyprogesterone levels > 10-15 ng/ml) . Molecular study of CYP21A2 showed a mutation g.1683G> T , homozygous , in CYP21A2 and a non functioning allele of CYP21A2 , heterozygous (non severe 21-Hidroxilase deficiency). Mother was carrying a non functioning allele of CYP21A2 , heterozygous (severe); Father, Brother and Partner were heterozygous for mutation g.1683G> T (non severe). Family 2- IC: Female, 45 years old presenting hirsutism and oligoamenorrhea at age 35 and with test of tetracosactide positive confirming NCCAH Genetic study identified mutation g.1683G> T (less severe) in a copy and g.655A/C>G in another copy (splicing mutation severe). Familial genetic study identified two sisters (age 36 and age 40), asymptomatic but with pathologic genotype confirming NCCAH.
- In vitro activity of tigecycline and resistance mechanisms due to efflux pump production in Gram negative isolates, in PortugalPublication . Manageiro, Vera; Almeida, Joana; Pires, Sofia; Jones-Dias, Daniela; Ferreira, Eugénia; Caniça, ManuelaBackground: Tigecycline is increasingly used to treat infections caused by Gram negative isolates, because these bacteria express multidrug-resistance (MDR) phenotypes in an escalating frequency. Thus, this study aimed: 1) to correlate mediated β-lactam and fluoroquinolone resistance mechanisms (RMs) among Gram-negative isolates causing untreatable bacterial infections nowadays; 2) to study the in vitro activity of tigecycline to identify the importance of this antibiotic; 3) and to characterize tigecycline resistance mechanisms (RM) in order to understand how to extend its activity. Material/methods: A total of 2560 unduplicated Gram-negative (2309 Enterobacteriaceae and 251 Acinetobacter baumannii) isolates, collected in healthcare facilities in Portugal (2009-2013), were studied. MICs of tigecycline were determined against all isolates, and interpreted according to EUCAST (Enterobacteriaceae) or CLSI (A. baumannii, Ab) guidelines. Antimicrobial susceptibility of other 17 antibiotics was determined to all clinical isolates by disk diffusion method and interpreted by EUCAST. Fluoroquinolone and β-lactam RMs were reached by PCR and sequencing of 623 Enterobacteriaceae and 133 Ab using specific primers targeting PMQR-, Class A- and D β-lactamase-, Class B/MBL- and PMAβ-encoding genes. Tigecycline resistance due to efflux pump production was studied by molecular methods: ramR gene of Klebsiella pneumoniae and marR gene of Escherichia coli isolates. Results: We identified 27.2%/35.8% and 96.4%/96.2% tigecycline non-susceptible/MDR Enterobacteriaceae and Ab isolates, respectively. The molecular analyses of tigecycline RMs revealed deletions/insertions/point mutations in the ramR gene that might contribute to the overexpression of AcrAB efflux pump in 63 out of 108 K. pneumoniae isolates showing reduced susceptibility to tigecycline. Point mutations observed in marR gene from E. coli isolates with or without tigecycline resistance, might contribute to MDR scenarios. A great diversity of β-lactamases was observed in Enterobacteriaceae isolates: penicillinases, ESBLs (CTX-M-1/-14/-15/-32/-G1-type/-G2-type, TEM-4/-10, SHV-12/-55, GES-7), carbapenemases (KPC-3, GES-5/-6, OXA-48, VIM-2/-34) and PMAβ (CMY-2, DHA-1, MIR-type, ACT-type); Enterobacteriaceae were fully susceptible to tigecycline for: 48.3% of β-lactamase producers; 65.6% carrying PMQR determinants; 69.1% presenting both RMs. Concerning Ab all 133 isolates tested (3.8% tigecycline susceptible) expressed an acquired carbapenemase (OXA-23 and/or OXA-24). Conclusions: This study showed that tigecycline remains a substrate of MDR Ab isolates. However, the in vitro susceptibility of Enterobacteriaceae isolates to tigecycline showed its decisive importance when these bacteria presented resistance to other antibiotic classes, specifically through plasmid-mediated β-lactam and fluoroquinolone RMs. Thus, tigecycline contribution against the most important MDR Gram-negative pathogens should be preserved principally to bacterial infections untreatable by other antibiotics (such as carbapenems and colistin).
- O Biólogo Especialista em SaúdePublication . Sousa, A.; Marques, B.; Júlio, C.; Guia Pereira, A.; Correia, H.; Ávila, M.; Rendeiro, P.; Monteiro, M.; Lopo, S.; Pinheiro, J.; Cunha, N.; Figueiredo, H.; Correia, S.; Ramos, S.A presença do Biólogo com atividade na saúde teve nas últimas décadas notável incremento, em hospitais, institutos e centros de saúde, universidades, laboratórios privados e indústria, em particular nas áreas de investigação, análises clínicas, genética humana, embriologia/reprodução humana, entre outras. Persistem, todavia, alguns constrangimentos para estes profissionais de saúde, no acesso à profissão e na consequente atribuição de responsabilidades técnicas e científicas. Cabe à OBIO a defesa, regulação e certificação dos seus profissionais, bem como garantir códigos de conduta e formação contínua determinantes para a elevada qualidade que se espera destes. De igual modo, o CBHS assume as competências estatutárias na definição dos seus objetivos de forma a garantir o bom exercício da atividade profissional dos seus membros, e o reconhecimento destes pela Sociedade e Instituições.
- Seeking transparency on allocation of kidneys from deceased donorsPublication . Lima, Bruno; Mendes, Miguel; Alves, HelenaKidney transplantation is the preferred treatment for many end stage renal disease patients; however, the small number of organs for transplantation does not allow all patients to have access to this scarce resource. An allocation system for deceased donor kidneys should be anchored to transparent policies and rules. It should take into account the relationship between supply and demand, hence seeking a balance between the higher net benefit of survival that can be provided by a particular organ and the transplant candidates’ waiting time (as well as the probability of being transplanted).
- Contribute of the MYCOMIX project and future perspectives for Human Biomonitoring and health risk assessment in PortugalPublication . Martins, Carla; Assunção, Ricardo; Silva, M.J.; Louro, H.; Pinhão, M.; Nunes, Baltazar; Vasco, Elsa; Alvito, PaulaThere is a growing concern within public health about mycotoxin involvement in human diseases, namely those related to children. The MycoMix project (2012-2015), funded by the Portuguese Foundation for Science and Technology, gathered a multidisciplinary team aiming at answering several questions: 1) Are Portuguese children exposed daily to one or several mycotoxins through food? 2) Can this co-exposure affect children´s health? and 3) Are there interaction effect between mycotoxins? Mycomix results revealed that Portuguese children (< 3 years old, n=103) are exposed to multiple mycotoxins through food consumption. Cumulative risk assessment results revealed a potential health concern for the high percentiles of intake, specially for aflatoxins which are carcinogenic compounds. This fact assumes particular importance considering the interactive effects found in in vitro bioassays. These results highlight the need for a more accurate approach to assess the human exposure to mycotoxins6. Within the Mycomix project the assessment of mycotoxin exposure was based on calculations combining mycotoxin data in food with population data on food consumption. This approach does not consider some aspects as the inter-individual metabolism variation, the exposure through sources other than food and the heterogeneous distribution of mycotoxins in food. Exposure assessment of mycotoxins in Portuguese population through biomarkers is still missing and further studies are urgent to be developed. The European Human Biomonitoring Initiative (EHBMI), a proposal within the European Joint Programme, aims to advance the understanding of the extent of exposure to environmental chemicals across Europe and the impact on human health, by gathering national expertise in human biomonitoring domain. At national level Mycomix project uncovered the potential health risk of exposure of Portuguese children to multiple mycotoxins. The risk assessment expertise acquired within Mycomix, namely in analysis and toxicology of chemical mixtures, will be brought together as a contribute to EHBMI objectives.
- Functional genomics of Familial HypercholesterolemiaPublication . Bourbon, MafaldaMain Aim of the study: to identify the cause of the dyslipidaemia in patients with a clinical phenotype of Familial Hypercholesterolaemia (FH).
- Evaluating the influence of light intensity in mcyA gene expression and microcystin production in toxic strains of Planktothrix agardhii and Microcystis aeruginosaPublication . Salvador, Daniel; Churro, Catarina; Valério, ElisabeteCyanobacteria are phytoplanktonic organisms widely occurring in freshwaters, being frequently associated with the production of toxins, namely microcystins (MCs). MCs are produced non-ribosomally by a multienzyme complex (mcy genes). It has been reported that environmental factors, such as light intensity, can influence toxin production. The aim of this study was to assess the influence of light intensity in the transcription of the mcyA gene and corresponding production of microcystins in toxic isolates of Planktothrix agardhii, where little is known, and compare them to Microcystis aeruginosa. For that purpose, cultures were exposed to three different light intensities (4, 20 and 30 μmol photons m(-2) s(-1)) for 18 days at 20 ± 1 °C. The growth was followed daily using absorbance readings. Samples were collected at each growth stage for cell counting, microcystins quantification and RNA extraction. The level of transcripts was quantified by RT-qPCR and the relative expression determined using 16S rDNA, gltA and rpoC1 as reference genes. The most stable reference genes in M. aeruginosa were rpoC1 and gltA, whereas in P. agardhii were 16S rDNA and gltA. There was a correspondence between the growth rate and light intensity in M. aeruginosa and P. agardhii. The growth rates for both species were lower at 4 and higher at 30 μmol photons m(-2) s(-1). Microcystin concentration per cell was similar between light intensities in M. aeruginosa and over time, while in P. agardhii it was higher in the stationary phase at 4 μmol photons m(-2) s(-1). There were differences in the expression of mcyA between the two species. In M. aeruginosa, the highest levels of expression occurred at 4 μmol photons m(-2) s(-1) in the adaptation phase, whereas for P. agardhii it was at 4μmol photons m(-2) s(-1) in the exponential growth phase. Our results indicate that the light intensities tested had distinct influences on the growth, microcystin production and mcyA expression levels, presenting considerable differences in M. aeruginosa and P. agardhii.