59 research outputs found
Ethnobotany, Phytochemistry and Pharmacology of \u3cem\u3eMussaenda\u3c/em\u3e Species (Rubiaceae)
The genus Mussaenda is an important source of medicinal natural products, particularly iridoids, triterpenes and flavonoids. The purpose of this paper is to cover the more recent developments in the ethnobotany, pharmacology and phytochemistry of this genus. The species in which the largest number of compounds has been identified is Mussaenda pubescens. Pharmacological studies have also been made, however, of other species in this genus. These lesser known plants of the genus are described here according to their cytotoxicity, anti-inflammatory, antiviral, antioxidant and antibacterial properties. The information given here is intended to serve as a reference tool for practitioners in the fields of ethnopharmacology and natural products chemistry
Comparative genomics of the pathogenic ciliate Ichthyophthirius multifiliis, its free-living relatives and a host species provide insights into adoption of a parasitic lifestyle and prospects for disease control
Background: Ichthyophthirius multifiliis, commonly known as Ich, is a highly pathogenic ciliate responsible for ‘white spot’, a disease causing significant economic losses to the global aquaculture industry. Options for disease control are extremely limited, and Ich’s obligate parasitic lifestyle makes experimental studies challenging. Unlike most well-studied protozoan parasites, Ich belongs to a phylum composed primarily of free-living members. Indeed, it is closely related to the model organism Tetrahymena thermophila. Genomic studies represent a promising strategy to reduce the impact of this disease and to understand the evolutionary transition to parasitism.
Results: We report the sequencing, assembly and annotation of the Ich macronuclear genome. Compared with its free-living relative T. thermophila, the Ich genome is reduced approximately two-fold in length and gene density and three-fold in gene content. We analyzed in detail several gene classes with diverse functions in behavior, cellular function and host immunogenicity, including protein kinases, membrane transporters, proteases, surface antigens and cytoskeletal components and regulators. We also mapped by orthology Ich’s metabolic pathways in comparison with other ciliates and a potential host organism, the zebrafish Danio rerio.
Conclusions: Knowledge of the complete protein-coding and metabolic potential of Ich opens avenues for rational testing of therapeutic drugs that target functions essential to this parasite but not to its fish hosts. Also, a catalog of surface protein-encoding genes will facilitate development of more effective vaccines. The potential to use T. thermophila as a surrogate model offers promise toward controlling ‘white spot’ disease and understanding the adaptation to a parasitic lifestyle
Simulating Root System Development of Short-duration Pigeonpea
Length and weight of pigeonpea roots were measured weekly in different soil layers and compared with estimates obtained from a root simulation model using daily climatic data, soil physico-chemical properties and dry matter allocation to roots. Daily moisture content and temperature at different soil depths were well simulated using sub-routines from the CERES-Maize model. Daily allocation of dry matter to roots was calculated from logistic functions fitted to the growth data for shoots and roots. Although root length and weight tended to be underestimated by the model, regressions between measured and simulated root growth were highly significant so that the model could, with a few modifications, be used to predict root system development
Comparative genomics of the pathogenic ciliate Ichthyophthirius multifiliis, its free-living relatives and a host species provide insights into adoption of a parasitic lifestyle and prospects for disease control
BACKGROUND: Ichthyophthirius multifiliis, commonly known as Ich, is a highly pathogenic ciliate responsible for 'white spot', a disease causing significant economic losses to the global aquaculture industry. Options for disease control are extremely limited, and Ich's obligate parasitic lifestyle makes experimental studies challenging. Unlike most well-studied protozoan parasites, Ich belongs to a phylum composed primarily of free-living members. Indeed, it is closely related to the model organism Tetrahymena thermophila. Genomic studies represent a promising strategy to reduce the impact of this disease and to understand the evolutionary transition to parasitism.
RESULTS: We report the sequencing, assembly and annotation of the Ich macronuclear genome. Compared with its free-living relative T. thermophila, the Ich genome is reduced approximately two-fold in length and gene density and three-fold in gene content. We analyzed in detail several gene classes with diverse functions in behavior, cellular function and host immunogenicity, including protein kinases, membrane transporters, proteases, surface antigens and cytoskeletal components and regulators. We also mapped by orthology Ich's metabolic pathways in comparison with other ciliates and a potential host organism, the zebrafish Danio rerio.
CONCLUSIONS: Knowledge of the complete protein-coding and metabolic potential of Ich opens avenues for rational testing of therapeutic drugs that target functions essential to this parasite but not to its fish hosts. Also, a catalog of surface protein-encoding genes will facilitate development of more effective vaccines. The potential to use T. thermophila as a surrogate model offers promise toward controlling 'white spot' disease and understanding the adaptation to a parasitic lifestyle
Influence of the molybdenum cofactor biosynthesis on anaerobic respiration, biofilm formation and motility in Burkholderia thailandensis
types: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS.Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Research in Microbiology, 2014, Vol. 165, Issue 1, pp. 41 – 49 DOI: 10.1016/j.resmic.2013.10.009Burkholderia thailandensis is closely related to Burkholderia pseudomallei, a bacterial pathogen and the causative agent of melioidosis. B. pseudomallei can survive and persist within a hypoxic environment for up to one year and has been shown to grow anaerobically in the presence of nitrate. Currently, little is known about the role of anaerobic respiration in pathogenesis of melioidosis. Using B. thailandensis as a model, a library of 1344 transposon mutants was created to identify genes required for anaerobic nitrate respiration. One transposon mutant (CA01) was identified with an insertion in BTH_I1704 (moeA), a gene required for the molybdopterin biosynthetic pathway. This pathway is involved in the synthesis of a molybdopterin cofactor required for a variety of molybdoenzymes, including nitrate reductase. Disruption of molybdopterin biosynthesis prevented growth under anaerobic conditions, when using nitrate as the sole terminal electron acceptor. Defects in anaerobic respiration, nitrate reduction, motility and biofilm formation were observed for CA01. Mutant complementation with pDA-17:BTH_I1704 was able to restore anaerobic growth on nitrate, nitrate reductase activity and biofilm formation, but did not restore motility. This study highlights the potential importance of molybdoenzyme-dependent anaerobic respiration in the survival and virulence of B. thailandensis.BBSRC studentship (C. A. Andreae
Within-Host Evolution of Burkholderia pseudomallei in Four Cases of Acute Melioidosis
Little is currently known about bacterial pathogen evolution and adaptation within the host during acute infection. Previous studies of Burkholderia pseudomallei, the etiologic agent of melioidosis, have shown that this opportunistic pathogen mutates rapidly both in vitro and in vivo at tandemly repeated loci, making this organism a relevant model for studying short-term evolution. In the current study, B. pseudomallei isolates cultured from multiple body sites from four Thai patients with disseminated melioidosis were subjected to fine-scale genotyping using multilocus variable-number tandem repeat analysis (MLVA). In order to understand and model the in vivo variable-number tandem repeat (VNTR) mutational process, we characterized the patterns and rates of mutations in vitro through parallel serial passage experiments of B. pseudomallei. Despite the short period of infection, substantial divergence from the putative founder genotype was observed in all four melioidosis cases. This study presents a paradigm for examining bacterial evolution over the short timescale of an acute infection. Further studies are required to determine whether the mutational process leads to phenotypic alterations that impact upon bacterial fitness in vivo. Our findings have important implications for future sampling strategies, since colonies in a single clinical sample may be genetically heterogeneous, and organisms in a culture taken late in the infective process may have undergone considerable genetic change compared with the founder inoculum
Information retrieval in electrochemistry using microcomputer
experiences gained in the intial stages of computerised handling and processing of electrochemical
information using DATAWEALTH, a microcomputer of PSI Data Systems are presente
Regulation of gene expression through post-initiation controls
9-19Synthesis of messenger RNA in an eukaryotic cell can be regulated at multiple levels. Although the regulatory processes at the initiation step help in the discrimination between whether or not a gene need to be transcribed in a particular cell at a particular time, the decision to go through with the complete synthesis could still be revised through controls at the succeeding steps of the process. This article reviews the regulatory controls exercised at the transcription elongation step and the factors which participate in this process. Inspite of the plethora of factors contributing to the elongation process, the main catalytic activity is entrusted with the RNA polymerase II, and other factors mainly assist or modify the polymerase to alter its enzymatic efficiency
An iridoid with anticancer activity from the sepals of <i style="">Mussaenda ‘dona aurora’</i>
1019-1022The sepals of Mussaenda ‘dona aurora’ afford three iridoid glycosides and four flavonoids. Among them, Sanshiside-D, a new iridoid glycoside has been found to suppress the growth of vero cell lines (IC 50 -1.99 μM/mL). Sanshiside methyl ester and lamalbide are inactive towards vero cell lines
Itaconate-Based Clickable Surface-Anchored Cross-Linked Polymeric Coatings
Reactive coatings are those that permit installation
of desired
segments in a postcoating step; several approaches have been developed
to design polymers that can covalently anchor to the substrate while
at the same time providing a handle for further functionalization.
Here, we present a simple approach to prepare surface-anchored coatings
that can be functionalized with desired segments in a postcoating
step; to achieve this, we prepared a heterodiester of itaconic acid
(IA), namely, 2-hydroxyethyl, propargyl itaconate (HEPI), which upon
free-radical-initiated polymerization yielded a polymer, PHEPI. This
polymer is endowed with three attractive features: (i) the pendant
hydroxyl groups can react with Si–OH groups on suitably treated
glass/silicon surfaces; (ii) the pendant propargyl groups can help
install chosen segments onto the coating, via azide–alkyne
reaction, to render the desired properties to the surface, and (iii)
thermally induced cross-linking of the coating that occurs at ∼140
°C, which helps create robust surface-anchored coatings of desired
thickness. Derivatization of PHEPI coatings was easily done by treatment
with a variety of organic azides, such as PEG-azide, cetyl azide,
fluoroalkyl azide, etc., to yield surfaces with distinct characteristics;
the derivatized surfaces were characterized by contact angle measurements,
infrared, and X-ray photoelectron spectroscopy. Further, we demonstrate
that this polymer can also be spray-coated onto paper, and thus it
serves as a reactive primer for covalently modifying their surface
properties at a late stage. In addition, we also show that the propargyl
groups in Si-coated PHEPI can be clicked using a photoinitiated thiol-yne
reaction, which in turn permitted the photopatterning of coated substrates.
In summary, this simple approach, starting from readily available
and biosourced IA, provides ample scope for further elaboration to
generate designer surfaces that could form the basis for a range of
potential applications
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