2,339 research outputs found

    Conotoxins: structure, therapeutic potential and pharmacological applications.

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    Cone snails, also known as marine gastropods, from Conus genus produce in their venom a diverse range of small pharmacologically active structured peptides called conotoxins. The cone snail venoms are widely unexplored arsenal of toxins with therapeutic and pharmacological potential, making them a treasure trove of ligands and peptidic drug leads. Conotoxins are small disulfide bonded peptides, which act as remarkable selective inhibitors and modulators of ion channels (calcium, sodium, potassium), nicotinic acetylcholine receptors, noradrenaline transporters, N-methyl-D-aspartate receptors, and neurotensin receptors. They are highly potent and specific against several neuronal targets making them valuable as research tools, drug leads and even therapeutics. In this review, we discuss their gene superfamily classification, nomenclature, post-translational modification, structural framework, pharmacology and medical applications of the active conopeptides. We aim to give an overview of their structure and therapeutic potential. Understanding these aspects of conopeptides will help in designing more specific peptidic analogues

    Reactive Oxygen Species in Chronic Obstructive Pulmonary Disease

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    Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis and emphysema. Environmental exposure, primarily cigarette smoking, can cause high oxidative stress and is the main factor of COPD development. Cigarette smoke also contributes to the imbalance of oxidant/antioxidant due to exogenous reactive oxygen species (ROS). Moreover, endogenously released ROS during the inflammatory process and mitochondrial dysfunction may contribute to this disease progression. ROS and reactive nitrogen species (RNS) can oxidize different biomolecules such as DNA, proteins, and lipids leading to epithelial cell injury and death. Various detoxifying enzymes and antioxidant defense systems can be involved in ROS removal. In this review, we summarize the main findings regarding the biological role of ROS, which may contribute to COPD development, and cytoprotective mechanisms against this disease progression

    The prevention of hepatitis

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    The identification and characterisation of the hepatitis viruses A, B, C, D and E has allowed greater insight into their diagnosis, prevalence and modes of transmission. The clinical, pathological and serological features of each of these viruses have been dealt with elsewhere in this issue of the SAMJ, as have general and specific measures required for the prevention and future elimination of the diseases they cause. A recent consensus statement defined the problem posed by the hepatitis viruses in South Africa and highlighted the measures necessary to manage this effectively. This article will concentrate on measures designed to convey passive or active immunity to hepatitis A and B. However, the importance of general measures for the upliftment of underprivileged communities must constantly be borne in mind since these play a vital role in reducing infection, morbidity and mortality due to the hepatitis viruses

    Warranty Data Analysis: A Review

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    Warranty claims and supplementary data contain useful information about product quality and reliability. Analysing such data can therefore be of benefit to manufacturers in identifying early warnings of abnormalities in their products, providing useful information about failure modes to aid design modification, estimating product reliability for deciding on warranty policy and forecasting future warranty claims needed for preparing fiscal plans. In the last two decades, considerable research has been conducted in warranty data analysis (WDA) from several different perspectives. This article attempts to summarise and review the research and developments in WDA with emphasis on models, methods and applications. It concludes with a brief discussion on current practices and possible future trends in WDA

    Laboratory Colonization by \u3ci\u3eDirofilaria immitis\u3c/i\u3e Alters the Microbiome of Female \u3ci\u3eAedes aegypti\u3c/i\u3e mosquitoes

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    Background The ability of blood-feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered with, or enhanced by, the arthropod’s native microbiome. Mosquitoes transmit viruses, protozoan and filarial nematodes, the majority of which contribute to the 17% of infectious disease cases worldwide. Dirofilaria immitis, a mosquito-transmitted filarial nematodes of dogs and cats, is vectored by several mosquito species including Aedes aegypti. Methods In this study, we investigated the impact of D. immitis colonization on the microbiome of laboratory reared female Ae. aegypti. Metagenomic analysis of the V3–V4 variable region of the microbial 16S RNA gene was used for identification of the microbial differences down to species level. Results We generated a total of 1068 OTUs representing 16 phyla, 181 genera and 271 bacterial species. Overall, in order of abundance, Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were the most represented phylum with D. immitis-infected mosquitoes having more of Proteobacteria (71%) than uninfected mosquitoes (56.9%). An interesting finding in this study is the detection of Klebsiella oxytoca in relatively similar abundance in infected and uninfected mosquitoes, suggesting a possible endosymbiotic relationship, and has been previously shown to indirectly compete for nutrients with fungi on domestic housefly eggs and larvae. While D. immitis colonization has no effect on the overall species richness, we identified significant differences in the composition of selected bacterial genera and phyla between the two groups. We also reported distinct compositional and phylogenetic differences in the individual bacterial species when commonly identified bacteria were compared. Conclusions To the best of our knowledge, this is the first study to understand the impact of a filarial infection on the microbiome of its mosquito vector. Further studies are required to identify bacteria species that could play an important role in the mosquito biology. While the microbiome composition of Ae. aegypti mosquito have been previously reported, our study shows that in an effort to establish itself, a filarial nematode modifies and alters the overall microbial diversity within its mosquito host

    Reactive Oxygen Species in Chronic Obstructive Pulmonary Disease

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    Chronic obstructive pulmonary disease (COPD) includes chronic bronchitis and emphysema. Environmental exposure, primarily cigarette smoking, can cause high oxidative stress and is the main factor of COPD development. Cigarette smoke also contributes to the imbalance of oxidant/antioxidant due to exogenous reactive oxygen species (ROS). Moreover, endogenously released ROS during the inflammatory process and mitochondrial dysfunction may contribute to this disease progression. ROS and reactive nitrogen species (RNS) can oxidize different biomolecules such as DNA, proteins, and lipids leading to epithelial cell injury and death. Various detoxifying enzymes and antioxidant defense systems can be involved in ROS removal. In this review, we summarize the main findings regarding the biological role of ROS, which may contribute to COPD development, and cytoprotective mechanisms against this disease progression

    maxdLoad2 and maxdBrowse: standards-compliant tools for microarray experimental annotation, data management and dissemination

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    BACKGROUND: maxdLoad2 is a relational database schema and Java(® )application for microarray experimental annotation and storage. It is compliant with all standards for microarray meta-data capture; including the specification of what data should be recorded, extensive use of standard ontologies and support for data exchange formats. The output from maxdLoad2 is of a form acceptable for submission to the ArrayExpress microarray repository at the European Bioinformatics Institute. maxdBrowse is a PHP web-application that makes contents of maxdLoad2 databases accessible via web-browser, the command-line and web-service environments. It thus acts as both a dissemination and data-mining tool. RESULTS: maxdLoad2 presents an easy-to-use interface to an underlying relational database and provides a full complement of facilities for browsing, searching and editing. There is a tree-based visualization of data connectivity and the ability to explore the links between any pair of data elements, irrespective of how many intermediate links lie between them. Its principle novel features are: • the flexibility of the meta-data that can be captured, • the tools provided for importing data from spreadsheets and other tabular representations, • the tools provided for the automatic creation of structured documents, • the ability to browse and access the data via web and web-services interfaces. Within maxdLoad2 it is very straightforward to customise the meta-data that is being captured or change the definitions of the meta-data. These meta-data definitions are stored within the database itself allowing client software to connect properly to a modified database without having to be specially configured. The meta-data definitions (configuration file) can also be centralized allowing changes made in response to revisions of standards or terminologies to be propagated to clients without user intervention. maxdBrowse is hosted on a web-server and presents multiple interfaces to the contents of maxd databases. maxdBrowse emulates many of the browse and search features available in the maxdLoad2 application via a web-browser. This allows users who are not familiar with maxdLoad2 to browse and export microarray data from the database for their own analysis. The same browse and search features are also available via command-line and SOAP server interfaces. This both enables scripting of data export for use embedded in data repositories and analysis environments, and allows access to the maxd databases via web-service architectures. CONCLUSION: maxdLoad2 and maxdBrowse are portable and compatible with all common operating systems and major database servers. They provide a powerful, flexible package for annotation of microarray experiments and a convenient dissemination environment. They are available for download and open sourced under the Artistic License

    Cathepsins B and D drive hepatic stellate cell proliferation and promote their fibrogenic potential

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    El pdf del artículo es el manuscrito de autor.-- PubMed: PMCID:PMC2670444Cathepsins have been best characterized in tumorigenesis and cell death and implicated in liver fibrosis; however, whether cathepsins directly regulate hepatic stellate cell (HSC) activation and proliferation, hence modulating their fibrogenic potential, is largely unknown. Here, we show that expression of cathepsin B (CtsB) and cathepsin D (CtsD) is negligible in quiescent HSCs but parallels the increase of -smooth muscle actin and transforming growth factor- during in vitro mouse HSC activation. Both cathepsins are necessary for HSC transdifferentiation into myofibroblasts, because their silencing or inhibition decreasedHSC proliferation and the expression of phenotypicmarkers ofHSC activation, with similar results observed with the human HSC cell line LX2. CtsB inhibition blunted AKT phosphorylation in activated HSCs in response to platelet-derived growth factor.Moreover, during in vivo liver fibrogenesis caused by CCl4 administration, CtsB expression increased in HSCs but not in hepatocytes, and its inactivation mitigated CCl4-induced inflammation, HSC activation, and collagen deposition. Conclusion: These findings support a critical role for cathepsins inHSC activation, suggesting that the antagonismof cathepsins inHSCsmay be of relevance for the treatment of liver fibrosis.Financial support: The work was supported by CIBEREHD and grant PI070193 (Instituto de Salud Carlos III); by grant SAF2006-06780 (Plan Nacional de I+D), Spain; and by grant P50-AA-11999 (Research Center for Liver and Pancreatic Diseases, US National Institute on Alcohol Abuse and Alcoholism).Peer reviewe
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