28 research outputs found
Inhibitory Effect of Aqueous Extracts from Marine Sponges on the Activity and Expression of Gelatinases A (MMP-2) and B (MMP-9) in Rat Astrocyte Cultures
The aim of this study was to evaluate whether water soluble compounds present in aqueous extracts from seven Mediterranean demosponges exert biological activity towards matrix metalloproteinases (MMPs), which represent important pathogenic factors of human dis- eases. Aqueous extracts were tested on LPS-activated cultured rat astrocytes, and levels and expression of MMP-2 and MMP-9 were assessed by zymography and RT-PCR, re- spectively. Our results demonstrated that the studied extracts contain water soluble com- pounds able to inhibit MMP-2 and MMP-9 activity and expression. We also compared the anti-MMP activities present in aqueous extracts from wild and reared specimens of Tethya aurantium and T. citrina. The results obtained revealed that the reared sponges maintain the production of bioactive compounds with inhibitory effect on MMP-2 and MMP-9 for all the duration of the rearing period. Taken together, our results indicate that the aqueous ex- tracts from the selected Mediterranean demosponges possess a variety of water-soluble bioactive compounds, which are able to inhibit MMPs at different levels. The presence of bi- ological activity in aqueous extracts from reared specimens of T. aurantium and T. citrina strongly encourage sponge aquaculture as a valid option to supply sponge biomass for drug development on a large scale
Methodological choices in brucellosis burden of disease assessments: A systematic review
Background
Foodborne and zoonotic diseases such as brucellosis present many challenges to public health and economic welfare. Increasingly, researchers and public health institutes use disability-adjusted life years (DALYs) to generate a comprehensive comparison of the population health impact of these conditions. DALYs calculations, however, entail a number of methodological choices and assumptions, with data gaps and uncertainties to accommodate. Thisreview identifies existing brucellosis burden of disease studies and analyzes their methodological choices, assumptions, and uncertainties. It supports the Global Burden of Animal Diseases programme in the development of a systematic methodology to describe the impact of animal diseases on society, including human health.
Methods/Principal findings
A systematic search for brucellosis burden of disease calculations was conducted in pre-selected international and grey literature databases. Using a standardized reporting framework, we evaluated each estimate on a variety of key methodological assumptions necessary to compute a DALY. Fourteen studies satisfied the inclusion criteria (human brucellosis and quantification of DALYs). One study reported estimates at the global level, the rest were national or subnational assessments. Data regarding different methodological choices were extracted, including detailed assessments of the adopted disease models. Most studies retrieved brucellosis epidemiological data from administrative registries. Incidence data were often estimated on the basis of laboratory-confirmed tests. Not all studies included mortality estimates (Years of Life Lost) in their assessments due to lack of data or the assumption that brucellosis is not a fatal disease. Only two studies used a model with variable health states and corresponding disability weights. The rest used a simplified singular health state approach. Wide variation was seen in the duration chosen for brucellosis, ranging from 2 weeks to 4.5 years, irrespective of the whether a chronic state was included.
Conclusion
Available brucellosis burden of disease assessments vary widely in their methodology and assumptions. Further research is needed to better characterize the clinical course of brucellosis and to estimate case-fatality rates. Additionally, reporting of methodological choices should be improved to enhance transparency and comparability of estimates. These steps will increase the value of these estimates for policy makers
Burden of infectious disease studies in Europe and the United Kingdom: a review of methodological design choices
This systematic literature review aimed to provide an overview of the characteristics and methods used in studies applying the disability-adjusted life years (DALY) concept for infectious diseases within European Union (EU)/European Economic Area (EEA)/European Free Trade Association (EFTA) countries and the United Kingdom. Electronic databases and grey literature were searched for articles reporting the assessment of DALY and its components. We considered studies in which researchers performed DALY calculations using primary epidemiological data input sources. We screened 3053 studies of which 2948 were excluded and 105 studies met our inclusion criteria. Of these studies, 22 were multi-country and 83 were single-country studies, of which 46 were from the Netherlands. Food- and water-borne diseases were the most frequently studied infectious diseases. Between 2015 and 2022, the number of burden of infectious disease studies was 1.6 times higher compared to that published between 2000 and 2014. Almost all studies (97%) estimated DALYs based on the incidence- and pathogen-based approach and without social weighting functions; however, there was less methodological consensus with regards to the disability weights and life tables that were applied. The number of burden of infectious disease studies undertaken across Europe has increased over time. Development and use of guidelines will promote performing burden of infectious disease studies and facilitate comparability of the results
a review of methodological design choices
Publisher Copyright: © 2023 Cambridge University Press. All rights reserved.This systematic literature review aimed to provide an overview of the characteristics and methods used in studies applying the Disability-Adjusted Life Years (DALY) concept for infectious diseases within European Union (EU)/European Economic Area (EEA)/European Free Trade Association (EFTA) countries and the United Kingdom. Electronic databases and grey literature were searched for articles reporting the assessment of DALY and its components. We considered studies in which researchers performed DALY calculations using primary epidemiological data input sources. We screened 3,053 studies of which 2,948 were excluded and 105 studies met our inclusion criteria. Of these studies, 22 were multi-country and 83 were single-country studies, of which 46 were from the Netherlands. Food- and water-borne diseases were the most frequently studied infectious diseases. Between 2015 and 2022, the number of burden of infectious disease studies was 1.6 times higher compared to that published between 2000 and 2014. Almost all studies (97%) estimated DALYs based on the incidence- and pathogen-based approach and without social weighting functions; however, there was less methodological consensus with regards to the disability weights and life tables that were applied. The number of burden of infectious disease studies undertaken across Europe has increased over time. Development and use of guidelines will promote performing burden of infectious disease studies and facilitate comparability of the results.publishersversionepub_ahead_of_prin
Burden of infectious disease studies in Europe and the United Kingdom: a review of methodological design choices.
This systematic literature review aimed to provide an overview of the characteristics and methods used in studies applying the disability-adjusted life years (DALY) concept for infectious diseases within European Union (EU)/European Economic Area (EEA)/European Free Trade Association (EFTA) countries and the United Kingdom. Electronic databases and grey literature were searched for articles reporting the assessment of DALY and its components. We considered studies in which researchers performed DALY calculations using primary epidemiological data input sources. We screened 3053 studies of which 2948 were excluded and 105 studies met our inclusion criteria. Of these studies, 22 were multi-country and 83 were single-country studies, of which 46 were from the Netherlands. Food- and water-borne diseases were the most frequently studied infectious diseases. Between 2015 and 2022, the number of burden of infectious disease studies was 1.6 times higher compared to that published between 2000 and 2014. Almost all studies (97%) estimated DALYs based on the incidence- and pathogen-based approach and without social weighting functions; however, there was less methodological consensus with regards to the disability weights and life tables that were applied. The number of burden of infectious disease studies undertaken across Europe has increased over time. Development and use of guidelines will promote performing burden of infectious disease studies and facilitate comparability of the results
Biological variations in a long-term ex situ cultivation: a Mediterranean demosponge as model system
The demosponge Tethya citrina Sarà & Melone was subjected to long-term aquarium farming, considering that several spe- cies belonging to this genus are a rich source of useful bioactive compounds, and in particular interesting bioactive proteins. The rearing method in the present research was mainly based on applying parameters taken from the current literature. The biological activity of the sponge was assessed in terms of survival and growth over time, status of ltering apparatus, and protein banding pro les. Farmed sponges showed a high survival rate and marked reduction in size. In addition, they were frequently affected by massive production of asexual buds. Histological and ultrastructural observations showed a gradual disorganization of the sponge choanocyte chambers, with a drastic reduction in choanocytes and a progressive increase in spherulous cells. Comparative electro- phoretic analysis of the protein pro les of wild and reared specimens showed differences in protein composition and abundance between the tested groups. Such data are consistent with the increase in spherulous cells whose content was markedly electron- dense, a feature stressing the proteinaceous nature of these inclusions. Experimental tank-rearing of Tethya provided promising responses in terms of high survival rate of the species and easy reproduction, though the rearing protocol used led to profound morpho-functional changes in the sponge. This con rms the inadequate state of knowledge on farming techniques for this taxon, while also highlighting potential applications in biotechnology of ex situ breeding techniques, in order to modify the sponges’ biological responses
Comparative analysis of protein profiles of aqueous extracts from marine sponges and assessment of cytotoxicity on different mammalian cell types
Marine natural products extracted from sponges represent a new source for drug discovery. Here we describe a simple method for preparing aqueous extracts from 7 Mediterranean demosponges, which allowed the extraction of water-soluble compounds, such as proteins by homogenization of sponge tissue in phosphate buffered saline (PBS).The comparative analysis by SDS-PAGE showed differences in number of bands, bandwidth and intensity among the sponges analyzed. The PAS/silver staining revealed a substantial and different glycoprotein assortment among the demosponges studied.To further study the biological activities present in the sponge extracts, we determined the non-cytotoxic doses on four different mammalian cell types demonstrating that the optimal non-cytotoxic doses were cell type- and extract-dependent.In conclusion, the extraction method described in this paper represents a fast and efficient procedure for the extraction of water-soluble proteins from marine sponges. Furthermore, the cell viability data suggest the feasibility of this method for the direct in vitro cell-based assays
Effect of treatment with the <i>T</i>. <i>aurantium</i> and <i>T</i>. <i>citrina</i> sponge extracts from wild and reared specimens on MMP-2 and MMP-9 expression in astrocytes.
<p>Primary astrocytes (1×10<sup>5</sup> cells/ml) were activated with LPS and treated with the crude extracts from <i>T</i>. <i>aurantium</i> and <i>T</i>. <i>citrina</i> at the indicated concentrations. Untreated and unstimulated cells represent negative control (CTRL). The isolated RNA samples were analyzed by RT-PCR, using the primer pairs specific for MMP-2, MMP-9 and 18S. The products were run on a 1.5% agarose gel containing ethidium bromide. The bands were visualized under UV. Representative results are shown in A. Quantitation of the above experiment and two others after scanning densitometry are shown in B. Positive control MMP-2 and MMP-9 mRNA were set at 100%, and the treatments with the aqueous extracts represented as the percent of control (mean ±SD). Statistically significant inhibiton of MMP mRNA expression in comparison to positive control (LPS) is indicated by asterisks (one way ANOVA followed by Tukey test; * = p<0.05).</p
Effect of treatment with the different sponge extracts on MMP-2 and MMP-9 levels in astrocyte supernatants.
<p>Primary astrocytes (1×10<sup>5</sup> cells/ml), were activated with LPS (10 μg/ml) and simultaneously treated with each sponge extract at the indicated concentrations. Untreated and unstimulated cells represent negative control (CTRL). Culture supernatants were harvested after 24 h of incubation at 37°C, 5% CO<sub>2</sub> and subjected to gelatin-zymography. Representative gels in A and B show MMP-2 and MMP-9, as identified by their apparent molecular mass of 67 and 92 kDa, respectively, using pre-stained molecular weight markers (Bio Rad). Histograms in C and D represent results, expressed as mean ± SD, after scanning densitometry and computerized analysis of gels from at least three independent experiments with different cell populations. Asterisks represent values statistically different from LPS-activated astrocytes (positive control) (One-way Anova followed by Tukey test; * = p<0.05; ** p = 0.001).</p
Inhibitory effect of the different sponge extracts on ERK 1/2 signalling pathway in astrocytes.
<p>Primary astrocytes (1×10<sup>5</sup> cells/ml) were pre-treated for 2 h with the crude extracts from <i>T</i>. <i>aurantium</i> (10 μg/ml), <i>H</i>. <i>perlevis</i> (30 μg/ml), <i>T</i>. <i>citrina</i> (10 μg/ml), <i>I</i>. <i>variabilis</i> (60 μg/ml), <i>A</i>. <i>aerophoba</i> (10 μg/ml), <i>C</i>. <i>nucula</i> (10 μg/ml), and <i>S</i>. <i>spinosulus</i> (60 μg/ml) or with 10 μM of the ERK 1/2 inhibitor PD98059, then activated for 2 h with LPS (10 μg/ml). Untreated and unstimulated cells represent negative control (CTRL). Representative autoradiographic films of Western blotting analysis are reported in <b>A</b> and <b>B</b>. Histograms in <b>C</b> and <b>D</b> represent the results, after densitometric scanning of autoradiographic films, normalized as the ratio of phosphorylated to total ERK protein. Data represent means ± SD of three independent experiments. Asterisks represent values statistically different from positive control (LPS-activated astrocytes), which was set at 100% (one-way ANOVA followed by Tukey test; *p < 0.05).</p