Otimização de crescimento e fotofisiologia de duas estirpes de Arthrospira platensis

Arthrospira platensis is a spiral and filamentous cyanobacteria, popularly known as Spirulina, naturally present in highly alkaline lakes. With high nutritional value, it is applied in supplements for human and animal food, being valued for its high protein content (about 60%), antioxidant and anti-inflammatory properties and the presence of pigments such as phycocyanin and β-carotenes, as well as vitamin B12 and omega 3. Due to the growing interest and popularization by the wellness industry, it is industrially produced on an ever-increasing scale. The testing of the cultivation conditions used by the industry, as well as their improvement, with practical applicability is, therefore, of great relevance. In the present study, the evolution of growth and photophysiology of two strains of A. platensis (Chad and UTEX LB2340) is tested with different salinities and temperatures, with the main goal of improving its growth conditions. Based on standard growth conditions (“Spirulina medium”, 35°C, salinity 15 and high light intensity), one of the strains (Chad) was subjected to a test of salinities of 15 (control), 25 and 35, as well as industrial culture medium. Both strains were subjected to an acute temperature test, in a range of 5 to 65°C, in order to assess their photosynthetic response. Growth curves were determined through optical density and assessment of chlorophyll ɑ content, as well as assessment of photophysiological responses using modeled pulse fluorometry. The results demonstrate that the species under study prefer laboratory growth conditions, however, there is potential to produce in salt water, since it shows photosynthetic efficiency when subjected to salinities of 25 and 35. The industrial environment proved to be the least promising in terms of photophysiological response and amount of pigment. Regarding the temperature test, both strains of A. platensis showed a clear preference for values above 35°C, established as optimal by the literature, reaching the maximum photosynthetic efficiency (determined by the parameter “relative electron transport rate”), at 50 and 55°C, respectively for strain UTEX2340 and “Chad”. A test based on the PCR methodology was also carried out to identify the two strains, the results of which are preliminary.Arthrospira platensis é uma cianobactéria helicoidal e filamentosa, popularmente conhecida como Spirulina, naturalmente presente em lagos altamente alcalinos. Com alto valor nutricional, é aplicada em suplementos para alimentação humana e animal, sendo valorizada pelo elevado teor em proteína (cerca de 60%), propriedades antioxidantes e anti-inflamatórias e presença de pigmentos como ficocianina e β-carotenos, bem como vitamina B12 e ómega-3. Devido ao crescente interesse e popularização pela indústria do bem-estar, é industrialmente produzida numa escala cada vez maior. A testagem das condições de cultivo utilizadas pela indústria, bem como o seu aprimoramento, com aplicabilidade prática é, portanto, de grande relevância. No presente estudo, a evolução do crescimento e fotofisiologia de duas estirpes de A. platensis (Chad e UTEX LB2340) é testada com diferentes salinidades e temperaturas, tendo como objetivo principal o melhoramento das condições de cultivo. Tendo como base as condições de crescimento padrão (“Spirulina medium”, 35°C, salinidade 15 e elevada intensidade luminosa), uma das estirpes (Chad) foi submetida a um teste de salinidades de 15 (controlo), 25 e 35, bem como a meio de cultura industrial. Ambas as estirpes foram sujeitas a um teste agudo de temperatura, num espetro de 5 a 65°C, de forma a avaliar a sua resposta fotossintética. Foram determinadas curvas de crescimento através de densidade ótica e avaliação do teor de clorofila, bem como avaliação de respostas fotofisiológicas recorrendo a fluorometria de pulso modelado. Os resultados demonstram que a espécie em estudo prefere meio laboratorial, no entanto, demonstra potencial para ser produzida em água salgada, uma vez que evidencia eficiência fotossintética quando sujeita a salinidades de 25 e 35. O meio industrial mostrou ser o menos promissor em termos de resposta fotofisiológica e quantidade de pigmento. Em relação ao teste de temperatura, ambas as estirpes de A. platensis, demonstraram uma clara preferência por valores acima dos 35°C, estabelecidos como ótimos pela literatura, atingindo o máximo de eficácia fotossintética (determinada pelo parâmetro “taxa relativa de transporte de eletrões”), aos 50 e 55°C, respetivamente para a estirpe UTEX2340 e “Chad”. Foi ainda realizado um teste baseado na metodologia de PCR, para identificação das duas estirpes, cujos resultados são preliminares.Mestrado em Biologia Marinha Aplicad

The albumin-bilirubin score predicting the mortality of patients with decompensated cirrhosis.

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SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

A Complex Case of Cholestasis in a Patient with ABCB4 and ABCB11 Mutations

The low-phospholipid-associated cholelithiasis (LPAC) syndrome is a form of symptomatic cholelithiasis occurring in young adults, characterized by recurrence of symptoms after cholecystectomy and presence of hepatolithiasis. The case refers to a healthy 39-year-old Caucasian male who presented with abdominal pain and jaundice. His blood tests showed conjugated hyperbilirubinemia and elevated liver enzymes (total bilirubin 6.65 mg/dL, γ-glutamyltransferase 699 IU/L) and abdominal computed tomography revealed dilation of common bile duct and left intrahepatic ducts. Magnetic resonance cholangiopancreatography identified choledocholithiasis, retrieved by endoscopic retrograde cholangiopancreatography, after which there was a worsening of jaundice (total bilirubin 23 mg/dL), which persisted for several weeks, possibly due to ciprofloxacin toxicity. After an extensive workup including liver biopsy, the identification of two foci of hepatolithiasis on reevaluation abdominal ultrasound raised the hypothesis of LPAC syndrome and the patient was started on ursodeoxycholic acid, with remarkable improvement. Genetic testing identified the mutation c.1954A>G (p.Arg652Gly) in ABCB4 gene (homozygous) and c.1331T>C (p.Val444Ala) in ABCB11 gene (heterozygous). In conclusion, we describe the unique case of an adult male with choledocholithiasis, hepatolithiasis, and persistent conjugated hyperbilirubinemia after retrieval of stones, fulfilling the criteria for LPAC syndrome and with possible superimposed drug-induced liver injury, in whom ABCB4 and ABCB11 mutations were found, both of which had not been previously described in association with LPAC

Dicoumarol: from chemistry to antitumor benefits

Abstract Dicoumarol, a coumarin-like compound, is known for its anticoagulant properties associated with the ability to inhibit vitamin K, being prescribed as a drug for several decades. The pharmaceutical value of dicoumarol turned it into a focus of chemists’ attention, aiming its synthesis and of dicoumarol derivatives, bringing to light new methodologies. In recent years, several other bioactive effects have been claimed for dicoumarol and its derivatives, including anti-inflammatory, antimicrobial, antifungal, and anticancer, although the mechanisms of action underlying them are mostly not disclosed and additional research is needed to unravel them. This review presents a state of the art on the chemistry of dicoumarols, and their potential anticancer characteristics, highlighting the mechanisms of action elucidated so far. In parallel, we draw attention to the lack of in vivo studies and clinical trials to assess the safety and efficacy as drugs for later application

Dengue type 2 outbreak in the south of the State of Bahia, Brazil: laboratorial and epidemiological studies

During March 1994 cases of a exanthematic acute disease were reported in the municipalities of Itagemirim, Eunápolis and Belmonte, state of Bahia. Dengue fever was confirmed by serology (MAC-ELISA) and by dengue virus type 2 isolation, genotype Jamaica. Signs and symptoms of classic dengue fever were observed with a high percentual of rash (73.8%) and pruritus (50.5%). Major haemorrhagic manifestations were unfrequent and only bleeding gum was reported. Dengue virus activity spreaded rapidly to important tourism counties like Porto Seguro, Ilhéus, Santa Cruz de Cabrália, Prado, Alcobaça and others, representing a risk for the spreading of dengue virus into the country and abroad

Surto de dengue tipo-2 no sul do estado da Bahia, Brasil: estudos laboratoriais e epidêmicos

During March 1994 cases of a exanthematic acute disease were reported in the municipalities of Itagemirim, Eunápolis and Belmonte, state of Bahia. Dengue fever was confirmed by serology (MAC-ELISA) and by dengue virus type 2 isolation, genotype Jamaica. Signs and symptoms of classic dengue fever were observed with a high percentual of rash (73.8%) and pruritus (50.5%). Major haemorrhagic manifestations were unfrequent and only bleeding gum was reported. Dengue virus activity spreaded rapidly to important tourism counties like Porto Seguro, Ilhéus, Santa Cruz de Cabrália, Prado, Alcobaça and others, representing a risk for the spreading of dengue virus into the country and abroad.Em março de 1994, casos de uma doença exantemática foram notificados nos municípios de Itagimirim, Eunápolis e Belmonte, sul da Bahia. Infecção por dengue foi confirmada por sorologia (MAC-ELISA) e pelo isolamento de virus dengue tipo 2 (genotipo Jamaica). Sinais e sintomas de dengue clássico foram observados com um alto percentual de exantema (73,8%) e prurido (50,5%). Manifestações hemorrágicas não foram importantes e apenas casos de gengivorragia foram descritos. A atividade dos virus dengue espalhou-se rapidamente para importantes áreas de turismo da região, tais como Porto Seguro, Ilhéus, Santa Cruz de Cabrália, Prado, Alcobaça e outros, representando um risco da dispersão do virus para outras regiões do país e exterior

Unraveling the genetic background of individuals with a clinical familial hypercholesterolemia phenotype

Familial hypercholesterolemia (FH) is a common genetic disorder of lipid metabolism caused by pathogenic/likely pathogenic variants in LDLR, APOB, and PCSK9 genes. Variants in FH-phenocopy genes (LDLRAP1, APOE, LIPA, ABCG5, and ABCG8), polygenic hypercholesterolemia, and hyperlipoprotein (a) [Lp(a)] can also mimic a clinical FH phenotype. We aim to present a new diagnostic tool to unravel the genetic background of clinical FH phenotype. Biochemical and genetic study was performed in 1,005 individuals with clinical diagnosis of FH, referred to the Portuguese FH Study. A next-generation sequencing panel, covering eight genes and eight SNPs to determine LDL-C polygenic risk score and LPA genetic score, was validated, and used in this study. FH was genetically confirmed in 417 index cases: 408 heterozygotes and 9 homozygotes. Cascade screening increased the identification to 1,000 FH individuals, including 11 homozygotes. FH-negative individuals (phenotype positive and genotype negative) have Lp(a) >50 mg/dl (30%), high polygenic risk score (16%), other monogenic lipid metabolism disorders (1%), and heterozygous pathogenic variants in FH-phenocopy genes (2%). Heterozygous variants of uncertain significance were identified in primary genes (12%) and phenocopy genes (7%). Overall, 42% of our cohort was genetically confirmed with FH. In the remaining individuals, other causes for high LDL-C were identified in 68%. Hyper-Lp(a) or polygenic hypercholesterolemia may be the cause of the clinical FH phenotype in almost half of FH-negative individuals. A small part has pathogenic variants in ABCG5/ABCG8 in heterozygosity that can cause hypercholesterolemia and should be further investigated. This extended next-generation sequencing panel identifies individuals with FH and FH-phenocopies, allowing to personalize each person’s treatment according to the affected pathway