21 research outputs found

    NAP-2 Secreted by Human NK Cells Can Stimulate Mesenchymal Stem/Stromal Cell Recruitment

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    SummaryStrategies for improved homing of mesenchymal stem cells (MSCs) to a place of injury are being sought and it has been shown that natural killer (NK) cells can stimulate MSC recruitment. Here, we studied the chemokines behind this recruitment. Assays were performed with bone marrow human MSCs and NK cells freshly isolated from healthy donor buffy coats. Supernatants from MSC-NK cell co-cultures can induce MSC recruitment but not to the same extent as when NK cells are present. Antibody arrays and ELISA assays confirmed that NK cells secrete RANTES (CCL5) and revealed that human NK cells secrete NAP-2 (CXCL7), a chemokine that can induce MSC migration. Inhibition with specific antagonists of CXCR2, a receptor that recognizes NAP-2, abolished NK cell-mediated MSC recruitment. This capacity of NK cells to produce chemokines that stimulate MSC recruitment points toward a role for this immune cell population in regulating tissue repair/regeneration

    Eucalyptus globulus Labill. decoction extract inhibits the growth of NCI-H460 cells by increasing the p53 levels and altering the cell cycle profile

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    Eucalyptus globulus Labill. is a widespread evergreen plant belonging to the Myrtaceae family. Several species of Eucalyptus are known to have a plethora of medicinal properties, particularly anti-tumor activity, which prompts the study of the chemical composition and bioactivity of extracts from this plant. Hereby, the main aims of this work were to (i) profile the phenolic compounds in E. globulus extracts prepared by decoction and infusion; (ii) test the cell growth inhibitory activity of E. globulus decoction and infusion, in three human tumor cell line models: colorectal, pancreatic and non-small cell lung cancer (HCT-15, PANC-1 and NCI-H460, respectively); and (iii) study the mechanism of action of the most potent extract in the most sensitive cell line. Our work demonstrated that both the decoction and infusion preparations revealed the presence of phenolic acids, flavonoids and gallotannins, the last group being the most abundant polyphenols found, especially two digalloyl-glucosides. Both extracts inhibited the growth of all the tumor cell lines tested. The decoction extract was the most potent in inhibiting the NCI-H460 cell growth (lower GI50 determined by sulforhodamine B assay), which could be due to its higher content of phenolic compounds. Hence, the effect of the decoction extract on the NCI-H460 cells was further investigated. For this, cell viability (by Trypan blue exclusion assay), the cell cycle profile and apoptosis (by flow cytometry), cell proliferation (by bromodeoxyuridine assay) and protein expression (by western blot) were analyzed. Two different concentrations of the extract (52 μg mL− 1 and 104 μg mL−1, corresponding to GI50 and 2 × GI50 concentration) were tested in these studies. Remarkably, the E. globulus decoction extract caused a dose-dependent decrease in the NCI-H460 cell number, which was correlated with a cell cycle arrest in the G0/G1 phase, a decrease in cell proliferation and an increase in the expression of p53, p21 and cyclin D1 proteins. Interestingly, no differences were found in the levels of ds-DNA damage and in the levels of apoptosis. This work highlights the relevance of the Eucalyptus globulus Labill. extract as a source of bioactive compounds with potential anti-tumor activity.This work was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/ Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). The authors are also grateful to FCT and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019) and to the national funding by FCT, P.I., through the institutional scientific employment program-contract for L. Barros contract and to the FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

    Hybrid Session Verification through Endpoint API Generation

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    © Springer-Verlag Berlin Heidelberg 2016.This paper proposes a new hybrid session verification methodology for applying session types directly to mainstream languages, based on generating protocol-specific endpoint APIs from multiparty session types. The API generation promotes static type checking of the behavioural aspect of the source protocol by mapping the state space of an endpoint in the protocol to a family of channel types in the target language. This is supplemented by very light run-time checks in the generated API that enforce a linear usage discipline on instances of the channel types. The resulting hybrid verification guarantees the absence of protocol violation errors during the execution of the session. We implement our methodology for Java as an extension to the Scribble framework, and use it to specify and implement compliant clients and servers for real-world protocols such as HTTP and SMTP

    Study of Non-Targeted Effects Induced on Cell Lines Using Low Doses of Ionizing Radiation

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    The LNT - Linear-no-Threshold model, used to analyze dose-effect ratios after biological irradiation exposures, theorizes that effects produced are directly proportional to the irradiating doses, with a linear without threshold pattern. Nevertheless, there is a relevant number of evidence, accumulated essentially over the last decade, suggesting that risks inherent to low doses of irradiation cannot be strictly predicted by the LNT model. Among those, there is a significant number of experimental evidence for a variety of low dose induced biological phenomena, which seems to have an impact on modulating the shape of dose-effect curves, namely for expositions below 0.2 Sv, causing the deviation of LNT model. Accumulated evidence demonstrate that cell irradiation induces biological effects, both to directly irradiated cells as well as to cells not exposed to any kind of ionizing radiation, present in a mixed population. This assumption is breaking the classical idea, based on the belief that damage to cellular DNA is only induced by purely ionizing events in cells directly irradiated. This phenomenon, based on cell communication pathways, is termed “Bystander Effect” - clearly highlighted between the “non-targeted effects” of irradiation not considered by the LNT model - being considered one of the biggest paradigm shifts of modern radiobiology.Allied Health Technologies in general and Medical Imaging in particular are medical specialities where the intrinsic dynamic nature and the absolute need for the related health professionals to entirely comply with an external environment in constant evolution, with technical and regulatory issues obliging the provision of a solid basic education to be complemented with an adequate long-life learning attitude. At our institution the “Bologna Process” was considered as a great opportunity to re-think all the educative process, and the Nuclear Medicine Degree Course chose the moment to work on its adaptation regarding the real nature of the competences perceived as needed – and so naturally expected as an intrinsic characteristic from the new graduates - as well as the possible best solutions to optimize the correlation between the formal and informal education received, the “real world” needs and the preparation towards its predictable evolutio

    Advancing Key Gaps in the Knowledge of Plasmodium vivax Cryptic Infections Using Humanized Mouse Models and Organs-on-Chips

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    Plasmodium vivax is the most widely distributed human malaria parasite representing 36.3% of disease burden in the South-East Asia region and the most predominant species in the region of the Americas. Recent estimates indicate that 3.3 billion of people are under risk of infection with circa 7 million clinical cases reported each year. This burden is certainly underestimated as the vast majority of chronic infections are asymptomatic. For centuries, it has been widely accepted that the only source of cryptic parasites is the liver dormant stages known as hypnozoites. However, recent evidence indicates that niches outside the liver, in particular in the spleen and the bone marrow, can represent a major source of cryptic chronic erythrocytic infections. The origin of such chronic infections is highly controversial as many key knowledge gaps remain unanswered. Yet, as parasites in these niches seem to be sheltered from immune response and antimalarial drugs, research on this area should be reinforced if elimination of malaria is to be achieved. Due to ethical and technical considerations, working with the liver, bone marrow and spleen from natural infections is very difficult. Recent advances in the development of humanized mouse models and organs-on-a-chip models, offer novel technological frontiers to study human diseases, vaccine validation and drug discovery. Here, we review current data of these frontier technologies in malaria, highlighting major challenges ahead to study P. vivax cryptic niches, which perpetuate transmission and burden

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

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    The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

    Multiple Myeloma: Available Therapies and Causes of Drug Resistance

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    Multiple myeloma (MM) is the second most common blood cancer. Treatments for MM include corticosteroids, alkylating agents, anthracyclines, proteasome inhibitors, immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies. Survival outcomes have improved substantially due to the introduction of many of these drugs allied with their rational use. Nonetheless, MM patients successively relapse after one or more treatment regimens or become refractory, mostly due to drug resistance. This review focuses on the main drugs used in MM treatment and on causes of drug resistance, including cytogenetic, genetic and epigenetic alterations, abnormal drug transport and metabolism, dysregulation of apoptosis, autophagy activation and other intracellular signaling pathways, the presence of cancer stem cells, and the tumor microenvironment. Furthermore, we highlight the areas that need to be further clarified in an attempt to identify novel therapeutic targets to counteract drug resistance in MM patients
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