Structural analyses of \u3ci\u3ePhycodnaviridae\u3c/i\u3e and \u3ci\u3eIridoviridae\u3c/i\u3e

The Phycodnaviridae, Iridoviridae and related viruses, with diameters of 1500±2000 A Ê , are formed from large trigonal arrays of hexagonally close-packed capsomers forming the faces of icosahedra [Yan et al. (2000), Nature Struct. Biol. 7, 101-103; Nandhagopal et al. (2002), Proc. Natl Acad. Sci. USA, 99, 14758-14763]. Caspar and Klug predicted that such structures could be assembled from hexameric capsomers [Caspar & Klug (1962), Cold Spring Harbor. Symp. Quant. Biol. 27, 1-24], as was subsequently found in numerous icosahedral viruses. During the course of evolution, some viruses, including the virus families mentioned above, replaced hexameric capsomers with pseudo-hexameric trimers by gene duplication. In large dsDNA icosahedral viruses, the capsomers are organized into `pentasymmetrons\u27 and `trisymmetrons\u27. The interactions between the trimeric capsomers can be divided into three groups, one between similarly oriented trimers and two between oppositely oriented trimers (trimers related by an approximately sixfold rotation). The interactions within a trisymmetron belong to the ®rst class, whereas those between trisymmetrons and within the pentasymmetron are of the other two types. Knowledge of these distances permits a more accurate ®tting of the atomic structure of the capsomer into the cryo-electron microscopy (cryoEM) reconstruction of the whole virus. The adoption of pseudo-hexagonal capsomers places these viruses into a subset of the Caspar and Klug surface lattices

Subregional 6-[18F]fluoro-ʟ-m-tyrosine Uptake in the Striatum in Parkinson's Disease

<p>Abstract</p> <p>Background</p> <p>In idiopathic Parkinson's disease (PD) the clinical features are heterogeneous and include different predominant symptoms. The aim of the present study was to determine the relationship between subregional aromatic l-amino acid decarboxylase (AADC) activity in the striatum and the cardinal motor symptoms of PD using high-resolution positron emission tomography (PET) with an AADC tracer, 6-[¹⁸F]fluoro-ʟ-<it>m</it>-tyrosine (FMT).</p> <p>Methods</p> <p>We assessed 101 patients with PD and 19 healthy volunteers. PD was diagnosed based on the UK Brain Bank criteria by two experts on movement disorders. Motor symptoms were measured with the Unified Parkinson's Disease Rating Scale (UPDRS). FMT uptake in the subregions of the striatum was analyzed using semi-automated software for region-of-interest demarcation on co-registered magnetic resonance images.</p> <p>Results</p> <p>In all PD patients, FMT uptake was decreased in the posterior putamen regardless of predominant motor symptoms and disease duration. Smaller uptake values were found in the putamen contralateral to the side with more affected limbs. The severity of bradykinesia, rigidity, and axial symptoms was correlated with the decrease of FMT uptake in the putamen, particularly in the anterior part. No significant correlation was observed between tremors and FMT uptake.</p> <p>Conclusions</p> <p>Decrease of FMT uptake in the posterior putamen appears to be most sensitive in mild PD and uptake in the anterior putamen may reflect the severity of main motor symptoms, except for tremor.</p

Goal-directed and habitual control in the basal ganglia: implications for Parkinson's disease

Progressive loss of the ascending dopaminergic projection in the basal ganglia is a fundamental pathological feature of Parkinson's disease. Studies in animals and humans have identified spatially segregated functional territories in the basal ganglia for the control of goal-directed and habitual actions. In patients with Parkinson's disease the loss of dopamine is predominantly in the posterior putamen, a region of the basal ganglia associated with the control of habitual behaviour. These patients may therefore be forced into a progressive reliance on the goal-directed mode of action control that is mediated by comparatively preserved processing in the rostromedial striatum. Thus, many of their behavioural difficulties may reflect a loss of normal automatic control owing to distorting output signals from habitual control circuits, which impede the expression of goal-directed action. © 2010 Macmillan Publishers Limited. All rights reserved

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Preliminary Studies on Nature of Epibiota Assemblage on Low Crested Coastal Protection Structures

2130-2135The shore protection measures currently adopted in India includes deployment of sand filled geosynthetic containers for coast-line stabilization.  Interestingly, it is observed that such geosynthetics containers are colonized by alphabetic organisms such as algae and sessile marine invertebrates that are native to the natural rocky habitats, thus providing refuges and nursery grounds for fish and crustaceans. However, the epibiotic assemblages that are developed on a submerged hard substrate (breakwater) and on nearby coastal natural rocky substrate are different from the epibiota developed on sand-filled geosynthetic containers, probably due to the physical properties of the substratum affecting organism recruitment. Little attention has been paid until the last decades to studies on the epibiota on man-made coastal defense structures. The biotic community structural studies of macro-faunal assemblage on geotube deployed at Kovalam coast revealed around 13 species of epibenthos dominated by non-invasive brown mussels, a recruitment pattern mimicking the adjoining natural rocky substrate. The biotic assemblage on geotubes revealed the ecofriendly nature of the low crested coastal protection structures.</span

<i>In vivo </i> evaluation of anti-MRSA compound from <i>Streptomyces collinus </i> ICN1 in zebrafish embryos

1155-1161Streptomyces collinus ICN1, an endosymbiotic actinomycete, isolated from the marine sponge Echinodictyum gorgonoides collected from Kanyakumari coast was studied for its antagonistic activity against the clinical pathogen Methicillin-resistant Staphylococcus aureus (MRSA). 16S rRNA gene sequencing confirmed the strain was related to Streptomyces collinus and spore morphology showed smooth surface in scanning electron microscopy. Media optimization for anti MRSA compound production was carried out in solid state fermentation using defined parameters, followed by extraction in methanol. Antagonistic anti-MRSA compound showed 0.91 Rf value in the Thin layer chromatography analysis and 1.53 min retention time in the high performance liquid chromatography analysis at the wavelength of 236 nm. Antagonistic activity of purified compound was studied against MRSA in both in vitro antibacterial assays and in vivo biocompatibility studies in zebrafish embryos. Minimum inhibitory concentration of the compound was found to be 2 µg/ ml by in vitro broth micro dilution method and 4X MIC dose of the compound effective enough to inhibit the pathogenicity of MRSA in in vivo zebrafish infection assay and for the survival of embryos