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1.
AAPS PharmSciTech ; 22(5): 184, 2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34142250

RESUMO

Hot-melt extrusion has found extensive application as a feasible pharmaceutical technological option over recent years. HME applications include solubility enhancement, taste masking, and sustained drug release. As bioavailability enhancement is a hot topic of today's science, one of the main applications of HME is centered on amorphous solid dispersions. This review describes the most significant aspects of HME technology and its use to prepare solid dispersions as a drug formulation strategy to enhance the solubility of poorly soluble drugs. It also addresses molecular and thermodynamic features critical for the physicochemical properties of these systems, mainly in what concerns miscibility and physical stability. Moreover, the importance of applying the Quality by Design philosophy in drug development is also discussed, as well as process analytical technologies in pharmaceutical HME monitoring, under the current standards of product development and regulatory guidance. Graphical Abstract.


Assuntos
Química Farmacêutica/métodos , Portadores de Fármacos/síntese química , Desenvolvimento de Medicamentos/métodos , Tecnologia de Extrusão por Fusão a Quente/métodos , Disponibilidade Biológica , Composição de Medicamentos/métodos , Composição de Medicamentos/tendências , Tecnologia de Extrusão por Fusão a Quente/tendências , Temperatura Alta , Solubilidade , Tecnologia Farmacêutica/métodos , Tecnologia Farmacêutica/tendências , Termodinâmica
2.
Curr Issues Mol Biol ; 38: 197-244, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31967581

RESUMO

The Earth's atmosphere is an extremely large and sparse environment which is quite challenging for the survival of microorganisms. We have long wondered about the limits to life in the atmosphere, starting with Leeuwenhoek's observation of "animalcules" collected from the air. In the past century, significant progress has been made to capture and identify biological material from varying elevations, from a few meters above ground level, to the clouds near mountaintops, and the jet streams, the ozone layer, and even higher up in the stratosphere. Collection and detection techniques have been developed and advanced in order to assess the potential diversity of life from very high altitudes. Studies of microbial life in the stratosphere with its multiple stressors (cold, dry, irradiated, with low pressure and limited nutrients), have recently garnered considerable attention. Here, we review studies of Earth's atmosphere, with emphasis on the stratosphere, addressing implications for astrobiology, the dispersal of microbes around our planet, planetary protection, and climate change.


Assuntos
Atmosfera , Bactérias/isolamento & purificação , Planeta Terra , Ambientes Extremos , Pressão Atmosférica , Bactérias/crescimento & desenvolvimento , Bactérias/efeitos da radiação , Resposta ao Choque Frio , Radiação Cósmica , Dessecação , Poeira , Exobiologia , Nutrientes , Raios Ultravioleta
3.
Mol Pharm ; 17(2): 554-568, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31774685

RESUMO

The aim of this study was to develop a fast, effective, and material sparing screening method to design amorphous solid dispersions (ASDs) of etravirine to drive more effectively the development process, leading to improved bioavailability (BA) and stability. A systematic step-by-step approach was followed by combining theoretical calculations with high-throughput screening (HTS) and software-assisted multivariate statistical analysis. The thermodynamic miscibility and interaction of the drug in several polymers were predicted using Hansen solubility parameters (δ). The selected polymers were evaluated by HTS, using solvent evaporation. Binary compositions were evaluated by their solubilization capacity and physical stability over 2 months. JMP 14.0 was used for multivariate statistical analysis using principal components analysis. Extrusion was performed in Thermo Scientific HAAKE MiniLab II, and extrudates were characterized by assay, related substances, dissolution, and physical state (polarized light microscopy (PLM), Raman spectroscopy, and X-ray powder diffraction (XRPD)). A short stability study was performed where milled extrudates were exposed to 25 °C/60%RH and 40 °C/75%RH for 3 months. Through thermodynamic predictions, five main polymers were selected. The HTS enabled the evaluation of 42 formulations for solubilization capacity and physical stability. The three most promising compositions were selected for hot-melt extrusion (HME) tests. In general, a good correlation was found among the results of theoretical predictions, HTS, and HME. Poly(vinylpyrrolidone) (PVP)-based formulations were shown to be easily extrudable, with low degradation and complete amorphicity, whereas in Soluplus, the drug was not miscible, leading to a high crystalline content. The drug release rate was improved more than two times with PVP, and the manufactured ASD was demonstrated to be stable physically and chemically. A fast and effective screening technique to develop stable ASDs for a poorly soluble drug was successfully developed as applied to etravirine. The given method is easy to use, requires a low amount of drug, and is fairly accurate in predicting the amorphization of the drug when formulated. The success of HME formulation development of etravirine was undoubtedly enhanced with this high-throughput tool, which led to the identification of extrudates with improved biopharmaceutical properties. The structural characterization performed by PLM, XRPD, and Raman spectroscopy demonstrated that the HME prototype was essentially amorphous. The unexpected stability at 40 °C/75%RH was correlated with the presence of molecular interaction characterized by Raman spectroscopy.


Assuntos
Portadores de Fármacos/química , Composição de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Tecnologia de Extrusão por Fusão a Quente/métodos , Nitrilas/química , Nitrilas/farmacocinética , Pirimidinas/química , Pirimidinas/farmacocinética , Disponibilidade Biológica , Química Farmacêutica/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Excipientes/química , Microscopia de Polarização , Polietilenoglicóis/química , Polivinil/química , Povidona/química , Solubilidade , Análise Espectral Raman , Difração de Raios X
4.
Biotechnol Lett ; 41(1): 107-114, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30443879

RESUMO

OBJECTIVE: Our study evaluated the performance of different two-chambered microbial fuel cell (MFC) prototypes, operated with variable distance between electrodes and Nafion membrane and specific inoculum concentration, applied for vinasse treatment. RESULTS: The performance of the developed MFC resulted in a maximum current density of 1200 mA m-2 and power density of 800 mW m-2 in a period of 61 days. MFC performed a chemical oxygen demand removal at a rate ranging from 51 to 60%. CONCLUSIONS: Taking our preliminary results into consideration, we concluded that the MFC technology presents itself as highly promising for the treatment of vinasse.


Assuntos
Fontes de Energia Bioelétrica , Saccharum/química
5.
Nucleic Acids Res ; 44(D1): D624-33, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26546514

RESUMO

Microorganisms produce an enormous variety of chemical compounds. It is of general interest for microbiology and biotechnology researchers to have means to explore information about molecular and genetic basis of functioning of different microorganisms and their ability for bioproduction. To enable such exploration, we compiled 45 topic-specific knowledgebases (KBs) accessible through DESM portal (www.cbrc.kaust.edu.sa/desm). The KBs contain information derived through text-mining of PubMed information and complemented by information data-mined from various other resources (e.g. ChEBI, Entrez Gene, GO, KOBAS, KEGG, UniPathways, BioGrid). All PubMed records were indexed using 4,538,278 concepts from 29 dictionaries, with 1 638 986 records utilized in KBs. Concepts used are normalized whenever possible. Most of the KBs focus on a particular type of microbial activity, such as production of biocatalysts or nutraceuticals. Others are focused on specific categories of microorganisms, e.g. streptomyces or cyanobacteria. KBs are all structured in a uniform manner and have a standardized user interface. Information exploration is enabled through various searches. Users can explore statistically most significant concepts or pairs of concepts, generate hypotheses, create interactive networks of associated concepts and export results. We believe DESM will be a useful complement to the existing resources to benefit microbiology and biotechnology research.


Assuntos
Bases de Dados Factuais , Microbiologia Industrial , Antituberculosos/farmacologia , Archaea/genética , Archaea/metabolismo , Bactérias/genética , Bactérias/metabolismo , Mineração de Dados , Dicionários como Assunto , Reposicionamento de Medicamentos , Fungos/genética , Fungos/metabolismo , Humanos , Internet , Bases de Conhecimento , Vírus/genética , Vírus/metabolismo , Vocabulário Controlado
6.
Mar Drugs ; 14(9)2016 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-27626430

RESUMO

Microorganisms that inhabit unchartered unique soil such as in the highly saline and hot Red Sea lagoons on the Saudi Arabian coastline, represent untapped sources of potentially new bioactive compounds. In this study, a culture-dependent approach was applied to three types of sediments: mangrove mud (MN), microbial mat (MM), and barren soil (BS), collected from Rabigh harbor lagoon (RHL) and Al-Kharrar lagoon (AKL). The isolated bacteria were evaluated for their potential to produce bioactive compounds. The phylogenetic characterization of 251 bacterial isolates based on the 16S rRNA gene sequencing, supported their assignment to five different phyla: Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Planctomycetes. Fifteen putative novel species were identified based on a 16S rRNA gene sequence similarity to other strain sequences in the NCBI database, being ≤98%. We demonstrate that 49 of the 251 isolates exhibit the potential to produce antimicrobial compounds. Additionally, at least one type of biosynthetic gene sequence, responsible for the synthesis of secondary metabolites, was recovered from 25 of the 49 isolates. Moreover, 10 of the isolates had a growth inhibition effect towards Staphylococcus aureus, Salmonella typhimurium and Pseudomonas syringae. We report the previously unknown antimicrobial activity of B. borstelensis, P. dendritiformis and M. salipaludis against all three indicator pathogens. Our study demonstrates the evidence of diverse cultured microbes associated with the Red Sea harbor/lagoon environments and their potential to produce antimicrobial compounds.


Assuntos
Anti-Infecciosos/farmacologia , Produtos Biológicos/farmacologia , Ecossistema , Microbiologia da Água , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Sedimentos Geológicos/microbiologia , Oceano Índico , Testes de Sensibilidade Microbiana , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/biossíntese , RNA Ribossômico 16S/genética , Rhizophoraceae/microbiologia , Microbiologia do Solo
7.
J Biol Chem ; 289(34): 23582-95, 2014 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-24993827

RESUMO

Acute pancreatitis is a serious and sometimes fatal inflammatory disease where the pancreas digests itself. The non-oxidative ethanol metabolites palmitoleic acid (POA) and POA-ethylester (POAEE) are reported to induce pancreatitis caused by impaired mitochondrial metabolism, cytosolic Ca(2+) ([Ca(2+)]i) overload and necrosis of pancreatic acinar cells. Metabolism and [Ca(2+)]i are linked critically by the ATP-driven plasma membrane Ca(2+)-ATPase (PMCA) important for maintaining low resting [Ca(2+)]i. The aim of the current study was to test the protective effects of insulin on cellular injury induced by the pancreatitis-inducing agents, ethanol, POA, and POAEE. Rat pancreatic acinar cells were isolated by collagenase digestion and [Ca(2+)]i was measured by fura-2 imaging. An in situ [Ca(2+)]i clearance assay was used to assess PMCA activity. Magnesium green (MgGreen) and a luciferase-based ATP kit were used to assess cellular ATP depletion. Ethanol (100 mM) and POAEE (100 µM) induced a small but irreversible Ca(2+) overload response but had no significant effect on PMCA activity. POA (50-100 µM) induced a robust Ca(2+) overload, ATP depletion, inhibited PMCA activity, and consequently induced necrosis. Insulin pretreatment (100 nm for 30 min) prevented the POA-induced Ca(2+) overload, ATP depletion, inhibition of the PMCA, and necrosis. Moreover, the insulin-mediated protection of the POA-induced Ca(2+) overload was partially prevented by the phosphoinositide-3-kinase (PI3K) inhibitor, LY294002. These data provide the first evidence that insulin directly protects pancreatic acinar cell injury induced by bona fide pancreatitis-inducing agents, such as POA. This may have important therapeutic implications for the treatment of pancreatitis.


Assuntos
Ácidos Graxos Monoinsaturados/farmacologia , Insulina/fisiologia , Pâncreas/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Morte Celular , Cromonas/farmacologia , Etanol/administração & dosagem , Etanol/metabolismo , Ácidos Graxos/metabolismo , Fluorescência , Morfolinas/farmacologia , Pâncreas/citologia , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo , Ratos , Ratos Sprague-Dawley
8.
Antimicrob Agents Chemother ; 59(12): 7693-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26438493

RESUMO

Pyrazinamide (PZA) is active against major Mycobacterium tuberculosis species (M. tuberculosis, M. africanum, and M. microti) but not against M. bovis and M. avium. The latter two are mycobacterial species involved in human and cattle tuberculosis and in HIV coinfections, respectively. PZA is a first-line agent for the treatment of human tuberculosis and requires activation by a mycobacterial pyrazinamidase to form the active metabolite pyrazinoic acid (POA). As a result of this mechanism, resistance to PZA, as is often found in tuberculosis patients, is caused by point mutations in pyrazinamidase. In previous work, we have shown that POA esters and amides synthesized in our laboratory were stable in plasma (M. F. Simões, E. Valente, M. J. Gómez, E. Anes, and L. Constantino, Eur J Pharm Sci 37:257-263, 2009, http://dx.doi.org/10.1016/j.ejps.2009.02.012). Although the amides did not present significant activity, the esters were active against sensitive mycobacteria at concentrations 5- to 10-fold lower than those of PZA. Here, we report that these POA derivatives possess antibacterial efficacy in vitro and ex vivo against several species and strains of Mycobacterium with natural or acquired resistance to PZA, including M. bovis and M. avium. Our results indicate that the resistance probably was overcome by cleavage of the prodrugs into POA and a long-chain alcohol. Although it is not possible to rule out that the esters have intrinsic activity per se, we bring evidence here that long-chain fatty alcohols possess a significant antimycobacterial effect against PZA-resistant species and strains and are not mere inactive promoieties. These findings may lead to candidate dual drugs having enhanced activity against both PZA-susceptible and PZA-resistant isolates and being suitable for clinical development.


Assuntos
Antituberculosos/farmacologia , Macrófagos/microbiologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium/efeitos dos fármacos , Pirazinamida/análogos & derivados , Pirazinamida/farmacologia , Álcoois/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Farmacorresistência Bacteriana , Ésteres , Humanos , Testes de Sensibilidade Microbiana , Moraxella bovis/efeitos dos fármacos , Complexo Mycobacterium avium/efeitos dos fármacos , Pró-Fármacos , Pirazinamida/síntese química
9.
Neurodegener Dis ; 15(2): 70-80, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25871488

RESUMO

BACKGROUND: Frontotemporal lobar degeneration (FTLD) is the second most common early-onset dementia. Over the last few decades, a growing number of evidence suggests mitochondrial involvement in neurodegeneration, namely modifications of mitochondrial DNA (mtDNA) contributing to energy impairment. OBJECTIVE: To sequence the 7 mitochondrially encoded complex I (MT-ND) genes in 70 FTLD patients and investigate mitochondrial respiratory chain (MRC) complex I activity. METHODS: A sample of 70 patients was studied (39 females and 31 males; age range: 38-82 years, mean ± SD: 63 ± 11 years) with a probable diagnosis of FTLD. Total DNA was extracted from peripheral blood, and sequencing analysis of 7 MT-NDn (1, 2, 3, 4L, 4, 5, 6) genes was performed. Variants identified were submitted to in silico study. Spectrophotometric evaluation of MRC activity in lymphocytes was performed, and results were compared with age-matched controls. RESULTS: A total of 358 (161 different) alterations were found in 92.9% of patients. According to in silico analysis of nonsynonymous variants, only 5 variations are possibly or probably damaging. Complex I activity is significantly decreased in patients. CONCLUSION: To our knowledge, this is the first report of the complete sequence of the MT-ND genes in FTLD patients and correlation with MRC activity. The high number of mtDNA variations identified and a significant decrease in complex I activity suggest a possible involvement of mtDNA alterations in FTLD. Although the majority of these alterations are not primarily pathogenic, an interaction with other mutations may occur, leading to the disease, worsening its expression or influencing age of onset.


Assuntos
Degeneração Lobar Frontotemporal/genética , Degeneração Lobar Frontotemporal/fisiopatologia , Genótipo , Mutação/genética , NADH Desidrogenase/genética , Fenótipo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Estudos de Associação Genética , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Estatística como Assunto
10.
Sci Total Environ ; 917: 170445, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38296086

RESUMO

Concrete is the main ingredient in construction, but it inevitably fractures during its service life, requiring a large amount of cement and aggregate for maintenance. Concrete healing through biomineralization can repair cracks and improve the durability of concrete, which is conducive to saving raw materials and reducing carbon emissions. This paper reviews the biodiversity of microorganisms capable of precipitating mineralization to repair the concrete and their mineralization ability under different conditions. To better understand the mass transfer process of precipitates, two biomineralization mechanisms, microbially-controlled mineralization and microbially-induced mineralization, have been briefly described. The application of microorganisms in the field of healing concrete, comprising passive healing and intrinsic healing, is discussed. The key insight on the interaction between cementitious materials and microorganisms is the main approach for developing novel self-healing concrete in the future to improve the corrosion resistance of concrete. At the same time, the limitations and challenges are also pointed out.


Assuntos
Biomineralização , Carbonato de Cálcio , Materiais de Construção , Carbono , Biodiversidade
11.
BMC Plant Biol ; 13: 123, 2013 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-23987738

RESUMO

BACKGROUND: It is during embryogenesis that the plant body plan is established and the meristems responsible for all post-embryonic growth are specified. The molecular mechanisms governing conifer embryogenesis are still largely unknown. Their elucidation may contribute valuable information to clarify if the distinct features of embryo development in angiosperms and gymnosperms result from differential gene regulation. To address this issue, we have performed the first transcriptomic analysis of zygotic embryo development in a conifer species (Pinus pinaster) focusing our study in particular on regulatory genes playing important roles during plant embryo development, namely epigenetic regulators and transcription factors. RESULTS: Microarray analysis of P. pinaster zygotic embryogenesis was performed at five periods of embryo development from early developing to mature embryos. Our results show that most changes in transcript levels occurred in the first and the last embryo stage-to-stage transitions, namely early to pre-cotyledonary embryo and cotyledonary to mature embryo. An analysis of functional categories for genes that were differentially expressed through embryogenesis highlighted several epigenetic regulation mechanisms. While putative orthologs of transcripts associated with mechanisms that target transposable elements and repetitive sequences were strongly expressed in early embryogenesis, PRC2-mediated repression of genes seemed more relevant during late embryogenesis. On the other hand, functions related to sRNA pathways appeared differentially regulated across all stages of embryo development with a prevalence of miRNA functions in mid to late embryogenesis. Identification of putative transcription factor genes differentially regulated between consecutive embryo stages was strongly suggestive of the relevance of auxin responses and regulation of auxin carriers during early embryogenesis. Such responses could be involved in establishing embryo patterning. Later in development, transcripts with homology to genes acting on modulation of auxin flow and determination of adaxial-abaxial polarity were up-regulated, as were putative orthologs of genes required for meristem formation and function as well as establishment of organ boundaries. Comparative analysis with A. thaliana embryogenesis also highlighted genes involved in auxin-mediated responses, as well as epigenetic regulation, indicating highly correlated transcript profiles between the two species. CONCLUSIONS: This is the first report of a time-course transcriptomic analysis of zygotic embryogenesis in a conifer. Taken together our results show that epigenetic regulation and transcriptional control related to auxin transport and response are critical during early to mid stages of pine embryogenesis and that important events during embryogenesis seem to be coordinated by putative orthologs of major developmental regulators in angiosperms.


Assuntos
Epigênese Genética/genética , Pinus/embriologia , Pinus/genética , Sementes/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Ácidos Indolacéticos/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Pinus/metabolismo , Proteínas de Plantas/genética , Sementes/metabolismo
12.
J Inherit Metab Dis ; 36(5): 805-11, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23361304

RESUMO

Mitochondrial respiratory chain diseases are a heterogeneous group of pathologies caused by genetic alterations affecting mitochondrial energy production. Theoretically, this deficiency may lead to any symptoms, in any organ or tissue, at any age even before birth. The aim of our study was to identify the frequency and characterize antenatal manifestations identifying possible associations between mitochondrial disease and more specific and earlier manifestation. We retrospectively review the files of 44 paediatric subjects with genetic and biochemical alterations of respiratory chain identified in the first decade of life and compare data with a control group (n = 88). Our results show that maternal age was similar in both groups. The female gender was predominant in patients group. Gestational age at delivery was similar in both groups. Concerning birth weight, it was significantly lower (p = 0.001) in patients (2899.9 ± 538.3 vs. 3246.6 ± 460.2 g). Fifteen pregnancies of the patients group were considered abnormal. Our findings show that intrauterine growth restriction was the most frequent antenatal feature observed. Neonatal morbidity was significantly higher (fivefold) in patients (p < 0.001). The clinical findings are independent of the molecular defect type. Our results are preliminary and more studies are needed, in order to learn more about mitochondrial physiology and activity in embryological development for the assessment of mitochondrial disease progress in fetal life. However, the present work is a significant contribution, given the scarcity of information in this field.


Assuntos
Doenças Mitocondriais/complicações , Adulto , Peso ao Nascer , Feminino , Retardo do Crescimento Fetal/etiologia , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos
13.
Plant Cell Rep ; 32(5): 715-29, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23529547

RESUMO

KEY MESSAGE: Suitable internal control genes to normalize qPCR data from different stages of embryo development and germination were identified in two representative conifer species. Clonal propagation by somatic embryogenesis has a great application potentiality in conifers. Quantitative PCR (qPCR) is widely used for gene expression analysis during somatic embryogenesis and embryo germination. No single reference gene is universal, so a systematic characterization of endogenous genes for concrete conditions is fundamental for accuracy. We identified suitable internal control genes to normalize qPCR data obtained at different steps of somatic embryogenesis (embryonal mass proliferation, embryo maturation and germination) in two representative conifer species, Pinus pinaster and Picea abies. Candidate genes included endogenous genes commonly used in conifers, genes previously tested in model plants, and genes with a lower variation of the expression along embryo development according to genome-wide transcript profiling studies. Three different algorithms were used to evaluate expression stability. The geometric average of the expression values of elongation factor-1α, α-tubulin and histone 3 in P. pinaster, and elongation factor-1α, α-tubulin, adenosine kinase and CAC in P. abies were adequate for expression studies throughout somatic embryogenesis. However, improved accuracy was achieved when using other gene combinations in experiments with samples at a single developmental stage. The importance of studies selecting reference genes to use in different tissues or developmental stages within one or close species, and the instability of commonly used reference genes, is highlighted.


Assuntos
Regulação da Expressão Gênica de Plantas , Picea/genética , Pinus/genética , Reação em Cadeia da Polimerase/métodos , Sementes/genética , Adenosina Quinase/genética , Algoritmos , Genoma de Planta , Germinação , Fator 1 de Elongação de Peptídeos/genética , Picea/crescimento & desenvolvimento , Pinus/crescimento & desenvolvimento , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Tubulina (Proteína)/genética
14.
Microsc Microanal ; 19(5): 1151-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23745609

RESUMO

The taxonomy of fungal species, similar to that of many other microorganisms, suffers frequent revisions due to the discovery of new species and to the development and gathering of characterization data and morphological information. Morpho-taxonomy helps in the identification of many species. This work presents the macro, micro-morphological, and spectral mass analyses for phenotypic characterization of 13 species of Aspergillus section Nigri, showing that the characterization of spores (conidia) by scanning electron microscopy can be used as a tool to discriminate key morphological characteristics and separate closely related fungi. These results were corroborated by colony plates, stereomicroscopy, light microscopy, and spectral mass data.


Assuntos
Aspergillus/química , Aspergillus/citologia , Esporos Fúngicos/química , Esporos Fúngicos/citologia , Aspergillus/classificação , Espectrometria de Massas , Microscopia Eletrônica de Varredura , Esporos Fúngicos/classificação
15.
Artigo em Inglês | MEDLINE | ID: mdl-37711115

RESUMO

INTRODUCTION: Mitochondrial diseases are rare, heterogeneous, incurable and complex to diagnose. Probably due to their rareness, there is still a lack of literacy in this area, especially in society, but also in schools and in general, health care services. Accordingly, tools that may bring advancement in science and health literacy are needed. Mit.OnOff is a science communication project based on a bilateral partnership between the University of Coimbra (Portugal) and the University of Bergen (Norway). It aims to inform society about rare diseases related to mitochondrial cytopathies with an emphasis on LHON. METHODS: The initiative focuses on the creation of an illustrated book explaining the diseases caused by the failure of energy production in simple and accessible language. The aim is to raise awareness (particularly in Portugal and Norway) and provide in-depth knowledge to people suffering from these diseases. RESULTS/CASE REPORT: This project involves expert scientists in the field of mitochondrial disease, science communicators and artists in alignment with the United Nations SDGs, Agenda 2030. Mit.OnOff is a bilateral partnership (Portugal and Norway) established to address the lack of knowledge and health literacy on the subject of mitochondrial disease. The book will be distributed in both countries, creating a sense of inclusion and visibility and influencing decisions regarding these diseases. It is a relevant educational medium (e.g., schools, health care provision). The distribution of the book is complemented with other communication materials. Oral communications are made, together with public involvement, in which special glasses will be distributed to simulate a mitochondrial disease that leads to blindness (LHON) for the public to experience what it is like living with a rare disease. CONCLUSION: It is hoped that the production of this book will give patients a sense of inclusion and representation in the media. This, in turn, will contribute to achieving the SDG targets (3,4,5,8,10,12), i.e., ensuring people live healthy lives, reducing child mortality, and increasing life expectancy, ensuring access to inclusive, equitable and quality education for all, ensuring gender equality, and contributing to a peaceful and prosperous world.

16.
Artigo em Inglês | MEDLINE | ID: mdl-37817524

RESUMO

INTRODUCTION: Leigh syndrome (LS) is clinically and genetically heterogeneous and presents defective mitochondrial bioenergetics. Patients present neurological symptoms and imagiological features that may result in early death [1]. The LS has been associated with mitochondrial DNA (mtDNA) variants, e.g., m.8993T>G (L156R) and m.8993T>C (L156P), in the MT-ATP6 gene. They lead to the substitution of a highly conserved amino acid in subunit 6 of ATP synthase, affecting the F0 domain and ATP synthesis [1-3]. We present five cases with m.8993T>G and a family harbouring m.8993T>C+m.1555A>G (proband and four relatives). METHODS: Our laboratory received 48 samples from LS-suspected patients. The samples (various tissues) were assessed for bioenergetics (activity of mitochondrial respiratory chain (MRC) complexes, ubiquinone content) and genetic analyses (mtDNA copy number, Sequencing and PCR-RFLP) by established protocols. RESULTS/CASE REPORT: Bioenergetics were assessed in 5 patients (various tissues) with varying levels of MRC/ATP synthase impairment. Six cases had a mtDNA pathogenic variant in the 8993 nucleotide associated with LS. Five cases presented the m.8993T>G variant, one of which (P5) possibly de novo. This variant was homoplasmy (P1-3) or very high heteroplasmy (P4/5, 90-95%). Of the four patients with bioenergetics assessment, three (P1/3/4) had deficiencies of MRC complexes, and P5 had small deficits. The other case (familial, proband and 4 relatives) presented a combination of m.1555A>G (homoplasmy) and m.8993T>C (heteroplasmy) variants. The proband presents m.8993T>C in 95% heteroplasmy and 85-35% in three relatives. All have m.1555A>G in homoplasmy, including the fourth relative without m.8993T>C. A deficiency (31%) was found in complex V activity in muscle for proband. CONCLUSION: We present a case series of patients harbouring pathogenic variants in the 8993 nucleotide of mtDNA, which have been associated with LS and impairment of MRC's complex V. These cases highlight the variability in clinical symptoms and their severity, as well as genetic heterogeneity within LS. Many patients will not present a classic pathogenic variant and there are many cases of asymptomatic relatives (carriers). It is important to get a broader view of the cases - classical methods and multiple tissue analysis are still valuable tools for the comprehensive characterization of patients.

17.
Artigo em Inglês | MEDLINE | ID: mdl-38111113

RESUMO

INTRODUCTION: Mitochondrial oxidative phosphorylation (OXPHOS) diseases are challenging both from clinical and therapeutic perspectives. The advent of next-generation sequencing (NGS) boosted the discovery of new genetic defects affecting OXPHOS, with pathogenic variants identified in >350 genes to date [1]. However, in many patients, novel variants of unknown clinical significance are found. Subsequent functional studies may clarify its pathogenic consequences and modify the variant's classification, establishing a genetic diagnosis [2, 3]. METHODS: Analysis of data obtained from patients (P1-P5) with novel genetic causes and functional genomics' studies performed, namely OXPHOS respiratory/glycolytic rates (Seahorse XF), enzymatic activity and assembly (BN-page), protein levels (SDS-WB), single muscle fiber assay, NGS and bioinformatics. RESULTS/CASE REPORT: P1-Leigh syndrome (40y, male); Complex IV activity deficiency (full assembly absent), homozygous deletion (c.-11_13del, SURF1), not detected by NGS[2]. P2- Epileptic encephalopathy (8y, male); homozygous c.882-1G>A, FASTKD2; OXPHOS decrease; reduced FASTKD2 expression and abnormal respiratory/glycolytic rates. P3-Cardiomyopathy/ nephropathy (39y, male); c.29G>C, FASTKD2; OXPHOS decrease; reduced FASTKD2 levels. P4-CPEO (62y, female); multiple OXPHOS deficiency; mtDNA alterations (m.7486G>A, MTTS1; 4,977bp del); higher levels of mutant mtDNA alterations in COX-deficient fibers [3]. P5- Polyneuropathy (15y, female); heterozygous c.1437C>A, POLG; combined def. or normal OXPHOS activity/respiratory capacity (tissue variable), raised CI assembly; normal POLG levels. Also, proteins' expression levels were reduced (P1-4), confirming pathogenicity. In P5, data do not support pathogenicity. CONCLUSION: If specific functional results are similar to controls, one might inquire about the pathogenicity of the studied variant and more genetic or bioinformatics analyses and family investigations are needed. There are also limitations of NGS in mutation detection that Sanger sequencing can overcome (P1). When performed first, the OXPHOS activity may guide to genetic screening or interpretation, concordant to later assembly results. All cases were solved and data may be crucial for genetic counseling.

18.
Appl Spat Anal Policy ; : 1-25, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35677345

RESUMO

This paper investigates labour market resilience for seven Portuguese NUTS-2 regions over the period 1995-2018 detailing its relationship with levels of education and highlighting the period following the 2007-08 financial and economic crisis. We define resilience as the ability of regional employment to recover from a recessionary shock over an entire business cycle. Our results point to the existence of labour market resilience to the different business cycles for the different regions in terms of total hours worked. The same conclusion applies to employment of workers with different levels of educational attainment, low, medium and high, defined according to the highest level of education completed by employees. Investigating in more detail the potential differentiated impact of the Portuguese Great Recession (PGR), covering the period after the 2007-08 crisis, our findings suggest however no resilience in terms of total hours worked and employment of workers with low levels of education, corresponding so far to a situation of jobless economic recovery. The conclusions are mixed for employment of workers with medium levels of education, while we found evidence of labour market resilience to the PGR for employment of workers with high levels of education. The strong negative impact of the PGR at the economic level thus seems to have hindered labour market resilience for employees and regions less endowed with human capital.

19.
Front Microbiol ; 13: 1023625, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312929

RESUMO

Water bodies on Mars and the icy moons of the outer solar system are now recognized as likely being associated with high levels of salt. Therefore, the study of high salinity environments and their inhabitants has become increasingly relevant for Astrobiology. Members of the archaeal class Halobacteria are the most successful microbial group living in hypersaline conditions and are recognized as key model organisms for exposure experiments. Despite this, data for the class is uneven across taxa and widely dispersed across the literature, which has made it difficult to properly assess the potential for species of Halobacteria to survive under the polyextreme conditions found beyond Earth. Here we provide an overview of published data on astrobiology-linked exposure experiments performed with members of the Halobacteria, identifying clear knowledge gaps and research opportunities.

20.
Chemosphere ; 308(Pt 3): 136540, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36150482

RESUMO

Biogenic silver nanoparticles (AgNPs) are considered a promising alternative to their synthetic versions. However, the environmental impact of such nanomaterials is still scarcely understood. Thus, the present study aims at assessing the antimicrobial action and ecotoxicity of AgNPs biosynthesized by the fungus Aspergillus niger IBCLP20 towards three freshwater organisms: Chlorella vulgaris, Daphnia similis, and Danio rerio (zebrafish). AgNPs IBCLP20 showed antibacterial action against Klebsiella pneumoniae between 5 and 100 µg mL-1, and antifungal action against Trichophyton mentagrophytes in concentrations ranging from 20 to 100 µg mL-1. The cell density of the microalgae Chlorella vulgaris decreased 40% after 96 h of exposure to AgNPs IBCLP20, at the highest concentration analysed (100 µg L-1). The 48 h median lethal concentration for Daphnia similis was estimated as 4.06 µg L-1 (2.29-6.42 µg L-1). AgNPs IBCLP20 and silver nitrate (AgNO3) caused no acute toxicity on adult zebrafish, although they did induce several physiological changes. Mycosynthetized AgNPs caused a significant increase (p < 0.05) in oxygen consumption at the highest concentration studied (75 µg L-1) and an increase in the excretion of ammonia at the lower concentrations, followed by a reduction at the higher concentrations. Such findings are comparable with AgNO3, which increased the oxygen consumption on low exposure concentrations, followed by a decrease at the high tested concentrations, while impairing the excretion of ammonia in all tested concentrations. The present results show that AgNPs IBCLP20 have biocidal properties. Mycogenic AgNPs induce adverse effects on organisms of different trophic levels and understanding their impact is detrimental to developing countermeasures aimed at preventing any negative environmental effects of such novel materials.


Assuntos
Chlorella vulgaris , Nanopartículas Metálicas , Amônia , Animais , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Daphnia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Nitrato de Prata/toxicidade , Peixe-Zebra
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