31 research outputs found
Carbon Monoxide as an Electron Donor for the Biological Reduction of Sulphate
Several strains of Gram-negative and Gram-positive sulphate-reducing bacteria (SRB) are able to use carbon monoxide (CO) as a carbon source and electron donor for biological sulphate reduction. These strains exhibit variable resistance to CO toxicity. The most resistant SRB can grow and use CO as an electron donor at concentrations up to 100%, whereas others are already severely inhibited at CO concentrations as low as 1-2%. Here, the utilization, inhibition characteristics, and enzymology of CO metabolism as well as the current state of genomics of CO-oxidizing SRB are reviewed. Carboxydotrophic sulphate-reducing bacteria can be applied for biological sulphate reduction with synthesis gas (a mixture of hydrogen and carbon monoxide) as an electron donor
Adaptation of the Systematic Review Framework to the Assessment of Toxicological Test Methods: Challenges and Lessons Learned With the Zebrafish Embryotoxicity Test
Systematic review methodology is a means of addressing specific questions through structured, consistent, and transparent examinations of the relevant scientific evidence. This methodology has been used to advantage in clinical medicine, and is being adapted for use in other disciplines. Although some applications to toxicology have been explored, especially for hazard identification, the present preparatory study is, to our knowledge, the first attempt to adapt it to the assessment of toxicological test methods. As our test case, we chose the zebrafish embryotoxicity test (ZET) for developmental toxicity and its mammalian counterpart, the standard mammalian prenatal development toxicity study, focusing the review on how well the ZET predicts the presence or absence of chemical-induced prenatal developmental toxicity observed in mammalian studies. An interdisciplinary team prepared a systematic review protocol and adjusted it throughout this piloting phase, where needed. The final protocol was registered and will guide the main study (systematic review), which will execute the protocol to comprehensively answer the review question. The goal of this preparatory study was to translate systematic review methodology to the assessment of toxicological test method performance. Consequently, it focused on the methodological issues encountered, whereas the main study will report substantive findings. These relate to numerous systematic review steps, but primarily to searching and selecting the evidence. Applying the lessons learned to these challenges can improve not only our main study, but may also be helpful to others seeking to use systematic review methodology to compare toxicological test methods. We conclude with a series of recommendations that, if adopted, would help improve the quality of the published literature, and make conducting systematic reviews of toxicological studies faster and easier over time
Porcine commensal escherichia coli: A reservoir for class 1 integrons associated with IS26
© 2017 The Authors. Porcine faecal waste is a serious environmental pollutant. Carriage of antimicrobial-resistance genes (ARGs) and virulenceassociated genes (VAGs), and the zoonotic potential of commensal Escherichia coli from swine are largely unknown. Furthermore, little is known about the role of commensal E. coli as contributors to the mobilization of ARGs between food animals and the environment. Here, we report whole-genome sequence analysis of 103 class 1 integron-positive E. coli from the faeces of healthy pigs from two commercial production facilities in New South Wales, Australia. Most strains belonged to phylogroups A and B1, and carried VAGs linked with extraintestinal infection in humans. The 103 strains belonged to 37 multilocus sequence types and clonal complex 10 featured prominently. Seventeen ARGs were detected and 97% (100/103) of strains carried three or more ARGs. Heavy-metal-resistance genes merA, cusA and terA were also common. IS26 was observed in 98% (101/103) of strains and was often physically associated with structurally diverse class 1 integrons that carried unique genetic features, which may be tracked. This study provides, to our knowledge, the first detailed genomic analysis and point of reference for commensal E. coli of porcine origin in Australia, facilitating tracking of specific lineages and the mobile resistance genes they carry
Repurposing of tamoxifen ameliorates CLN3 and CLN7 disease phenotype
Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent-conjugated bacterial toxins to label Gb3 to develop a cell-based high content imaging (HCI) screening assay for the repurposing of FDA-approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient-derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease
Reassembling gastrulation
During development, a single cell is transformed into a highly complex organism through progressive cell division, specification and rearrangement. An important prerequisite for the emergence of patterns within the developing organism is to establish asymmetries at various scales, ranging from individual cells to the entire embryo, eventually giving rise to the different body structures. This becomes especially apparent during gastrulation, when the earliest major lineage restriction events lead to the formation of the different germ layers. Traditionally, the unfolding of the developmental program from symmetry breaking to germ layer formation has been studied by dissecting the contributions of different signaling pathways and cellular rearrangements in the in vivo context of intact embryos. Recent efforts, using the intrinsic capacity of embryonic stem cells to self-assemble and generate embryo-like structures de novo, have opened new avenues for understanding the many ways by which an embryo can be built and the influence of extrinsic factors therein. Here, we discuss and compare divergent and conserved strategies leading to germ layer formation in embryos as compared to in vitro systems, their upstream molecular cascades and the role of extrinsic factors in this process
Molecular biology techniques – A brief correlation between applied techniques in translational science and plant agriculture
This report aims to describe, how through my academic and professional life, I have developed a set of skills that allow me to apply for a “Hortofruticultura” Master’s degree. After finishing my 5 years degree in 2005, I worked for Jardim Vista SA as an Agronomist, afterwards I went to the UK where I worked as a Research Technician/Research Assistant for 9 years. In September 2016 I started working as a lab technician in Universidade do Algarve for 6 months. More recently, in April 2017, I joined the Syngenta team in Moncarapacho as a Senior Grower and Quality Management Designate. In the UK, I took part in several scientific projects, mainly related to molecular biology. Considering that I have been involved in completely different scientific subjects in these 9 years, I decided to talk about some of the molecular biology techniques that I have learnt throughout these years and that are also used in Molecular Farming. With an increase in the world population, the impact of climate change and its effect on plant pathogens and plant diseases there is a need for healthy plants with a high production and better yields to fulfil those needs. Development of modified plants has progress through plant breeding and biotechnology that plays a major role in understanding how to modify plant genome or plant physiology to respond to those needs. By sequencing and studying the plants genome it is possible to understand and manipulate the characteristics of plants. Molecular farming, produces valuable proteins, peptides and small molecules through the use of both these techniques, plant molecular breeding and biotechnology.
Some routine molecular biology techniques used in plant biotechnology are common to the projects where I participated and are described in this report, namely DNA extraction, PCR, colony PCR, agarose gel electrophoresis, bacterial genetic transformation, protein expression, SDS-PAGE and Western Blot. These techniques are the base for the study of better ways to improve plants, preparing agriculture for the actual and future challenges.
Keywords: Molecular biology, biotechnology, agriculture, plant breeding, molecular farming.O objetivo deste trabalho Ă© descrever a minha formação e aptidões adquiridas ao longo do meu percurso profissional, e como estas contribuĂram para o desenvolvimento das minhas competĂŞncias, as quais me permitem requerer o grau de Mestre. ApĂłs concluir o meu curso de 5 anos letivos em 2005 fui trabalhar como Engenheira AgrĂłnoma para a empresa Jardim Vista SA. Posteriormente fui para o Reino Unido onde trabalhei como TĂ©cnica de LaboratĂłrio/Assistente de LaboratĂłrio durante 9 anos. Em Setembro de 2016 comecei a trabalhar como tĂ©cnica de laboratĂłrio na Universidade do Algarve. Mais recentemente, em Abril de 2017 integrei a equipa da Syngenta em Moncarapacho como Senior Grower e Quality Management Designate. No Reino Unido, fui colaboradora de vários projetos cientĂficos, os quais estavam maioritariamente relacionados com a área da biologia molecular. Considerando que durante estes 9 anos fiz parte de projetos que abordavam temas completamente diferentes, decidi abordar algumas das tĂ©cnicas de biologia molecular que aprendi ao longo destes anos e que tambĂ©m sĂŁo usadas na área da Agricultura Molecular e Melhoramento de Plantas. Com o nĂvel de população a aumentar e o impacto das alterações climáticas, a necessidade de produzir plantas sem elementos patogĂ©nicos e destas serem mais produtivas e atingir elevadas produções, e eventualmente apresentarem resistĂŞncia a herbicidas, assim como a produção de proteĂnas de interesse especĂfico (Agricultura Molecular) tambĂ©m aumentou. O melhoramento de plantas em conjunto com a Biotecnologia tĂŞm um papel extremamente importante na compreensĂŁo e na descodificação da informação do DNA associado a estas necessidades, pois atravĂ©s da manipulação genĂ©tica Ă© possĂvel alterar o genoma das plantas de modo a satisfazer as exigĂŞncias atuais. Com o estudo do genoma das plantas Ă© possĂvel perceber e manipular as caracterĂsticas que pretendemos alterar e melhorar. “Molecular farming” produz proteĂnas, pĂ©ptidos e pequenas molĂ©culas bastante valiosas, resultado dos estudos de melhoramento de plantas acoplado aos progressos na área da biotecnologia. Algumas das tĂ©cnicas utilizadas em biotecnologia descritas nesta tese sĂŁo a extração de DNA, o PCR, o colony PCR, a eletroforese, a transformação genĂ©tica, a expressĂŁo proteĂca, SDS-PAGE e Western Blot. Estas tĂ©cnicas permitem-nos estudar mĂ©todos mais eficazes de melhorar as plantas para que a agricultura esteja melhor preparada para os desafios atuais e futuros.
Palavras-chave: Biologia molecular, biotecnologia, agricultura, melhoramento de plantas, agricultura molecular
Transforming growth factor-β superfamily, implications in development and differentiation of stem cells
Transforming growth factor-β (TGF-β) family members, including TGF-βs and bone morphogenetic proteins (BMPs), play important roles in directing the fate of stem cells. In embryonic stem cells, the TGF-β superfamily participates in almost all stages of cell development, such as cell maintenance, lineage selection, and progression of differentiation. In adult mesenchymal stem cells (MSCs), TGF-βs can provide competence for early stages of chondroblastic and osteoblastic differentiation, but they inhibit myogenesis, adipogenesis, and late-stage osteoblast differentiation. BMPs also inhibit adipogenesis and myogenesis, but they strongly promote osteoblast differentiation. The TGF-β superfamily members signal via specific serine/threonine kinase receptors and their nuclear effectors termed Smad proteins as well as through non-Smad pathways, which explain their pleiotropic effects in self-renewal and differentiation of stem cells. This review summarizes the current knowledge on the pleiotropic effects of the TGF-β superfamily of growth factors on the fate of stem cells and also discusses the mechanisms by which the TGF-β superfamily members control embryonic and MSCs differentiation
Repurposing of tamoxifen ameliorates CLN3 and CLN7 disease phenotype
Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent-conjugated bacterial toxins to label Gb3 to develop a cell-based high content imaging (HCI) screening assay for the repurposing of FDA-approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient-derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease.This work was funded by the European Union’s Horizon 2020 research and innovation programme (BATCure, grant No. 666918 to DLM, JPB, SEM, TB and SS). JPB is funded by the Agencia Estatal de Investigación (PID2019-105699RB-I00/ AEI / 10.13039/501100011033 and RED2018-102576-T), Plan Nacional sobre Drogas (2020I028), Junta de Castilla y León (Escalera de Excelencia CLU-2017-03), Ayudas Equipos Investigación Biomedicina 2017 Fundación BBVA and Fundación Ramón Areces. SS was funded by a grant from the Mila’s Miracle Foundation. TB was supported by German Research Council (DFG) grant FOR2625. SM benefits from MRC funding to the MRC Laboratory for Molecular Cell Biology University Unit at UCL (award code MC_U12266B) towards laboratory and office space. We acknowledge Marcella Cesana for providing the TFEB virus. Graphical abstract was created using BioRender.com
Petroleum Contract Evaluation in the Pacific Rim: a Comparative Analysis
This study analyszes contract terms for oil exploration in five Pacific Rim countries: Australia , China, Indonesia, Brunei, and Malaysia and then develops probabl e cash flows based on varying opil prices. The cash fl ow amounts are eva 1 uated using the tools of financial analysis and then compared to determine which contract terms provide the i nvestor with the most attractive financial returns. Discounted cash flow amounts and internal rates of return differed widely among the countries analyzed. Australia and China provide the investor with the best probable financial results. Varying oil prices show a linear relationship with anticipated financial results and demonstrate the effect of volatile world oil prives on decision making.Business Administratio