442 research outputs found

    Dual Function of the pUL7-pUL51 Tegument Protein Complex in Herpes Simplex Virus 1 Infection

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    The tegument of herpesviruses is a highly complex structural layer between the nucleocapsid and the envelope of virions. Tegument proteins play both structural and regulatory functions during replication and spread, but the interactions and functions of many of these proteins are poorly understood. Here we focus on two tegument proteins from herpes simplex virus 1 (HSV-1), pUL7 and pUL51, which have homologues in all other herpesviruses. We have now identified that HSV-1 pUL7 and pUL51 form a stable and direct protein-protein interaction, their expression levels rely on the presence of each other, and they function as a complex in infected cells. We demonstrate that expression of the pUL7-pUL51 complex is important for efficient HSV-1 assembly and plaque formation. Furthermore, we also discovered that the pUL7-pUL51 complex localizes to focal adhesions at the plasma membrane in both infected cells and in the absence of other viral proteins. The expression of pUL7-pUL51 is important to stabilize focal adhesions and maintain cell morphology in infected cells and cells infected with viruses lacking pUL7 and/or pUL51 round up more rapidly than cells infected with wild-type HSV-1. Our data suggest that, in addition to the previously reported functions in virus assembly and spread for pUL51, the pUL7-pUL51 complex is important for maintaining the attachment of infected cells to their surroundings through modulating the activity of focal adhesion complexes. IMPORTANCE\textbf{IMPORTANCE}: The Herpesviridae \textit{Herpesviridae } is a large family of highly successful human and animal pathogens. Virions of these viruses are composed of many different proteins, most of which are contained within the tegument, a complex structural layer between the nucleocapsid and the envelope within virus particles. Tegument proteins have important roles in assembling virus particles as well as modifying host cells to promote virus replication and spread. However, little is known about the function of many tegument proteins during virus replication. Our study focuses on two tegument proteins from herpes simplex virus 1 that are conserved in all herpesviruses: pUL7 and pUL51. We demonstrate that these proteins directly interact and form a functional complex that is important for both virus assembly and modulation of host cell morphology. Further, we identify for the first time that these conserved herpesvirus tegument proteins localize to focal adhesions in addition to cytoplasmic juxtanuclear membranes within infected cells.This work was supported by the Leverhulme Trust (grant RPG-2012-793 to C.M.C.), the Royal Society (University Research Fellowship UF090010 to C.M.C.), and the Royal Society and the Wellcome Trust (Sir Henry Dale Fellowship 098406/Z/12/Z to S.C.G.). L.D. was supported by Wellcome Trust Ph.D. Programme funding (086158/Z/08/Z). D.J.O. was supported by a John Lucas Walker studentship. M.F.A. was supported by a Commonwealth Scholarship Commission PhD scholarship (BDCA-2014-7)

    Report of the ICES\NAFO Joint Working Group on Deep-water Ecology (WGDEC), 11–15 March 2013, Floedevigen, Norway.

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    On 11 February 2013, the joint ICES/NAFO WGDEC, chaired by Francis Neat (UK) and attended by ten members met at the Institute for Marine Research in Floedevi-gen, Norway to consider the terms of reference (ToR) listed in Section 2. WGDEC was requested to update all records of deep-water vulnerable marine eco-systems (VMEs) in the North Atlantic. New data from a range of sources including multibeam echosounder surveys, fisheries surveys, habitat modelling and seabed imagery surveys was provided. For several areas across the North Atlantic, WGDEC makes recommendations for areas to be closed to bottom fisheries for the purposes of conservation of VMEs

    Why do bilaterally symmetrical flowers orient vertically? Flower orientation influences pollinator landing behaviour

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    Protein lysine posttranslational modification by an increasing number of different acyl groups is becoming appreciated as a regulatory mechanism in cellular biology. Sirtuins are class III histone deacylases that use NAD(+) as a co-substrate during amide bond hydrolysis. Several studies have described the sirtuins as sensors of the NAD(+)/NADH ratio, but it has not been formally tested for all the mammalian sirtuins in vitro. To address this problem, we first synthesized a wide variety of peptide-based probes, which were used to identify the range of hydrolytic activities of human sirtuins. These probes included aliphatic ϵ-N-acyllysine modifications with hydrocarbon lengths ranging from formyl (C(1)) to palmitoyl (C(16)) as well as negatively charged dicarboxyl-derived modifications. In addition to the well established activities of the sirtuins, “long chain” acyllysine modifications were also shown to be prone to hydrolytic cleavage by SIRT1–3 and SIRT6, supporting recent findings. We then tested the ability of NADH, ADP-ribose, and nicotinamide to inhibit these NAD(+)-dependent deacylase activities of the sirtuins. In the commonly used 7-amino-4-methylcoumarin-coupled fluorescence-based assay, the fluorophore has significant spectral overlap with NADH and therefore cannot be used to measure inhibition by NADH. Therefore, we turned to an HPLC-MS-based assay to directly monitor the conversion of acylated peptides to their deacylated forms. All tested sirtuin deacylase activities showed sensitivity to NADH in this assay. However, the inhibitory concentrations of NADH in these assays are far greater than the predicted concentrations of NADH in cells; therefore, our data indicate that NADH is unlikely to inhibit sirtuins in vivo. These data suggest a re-evaluation of the sirtuins as direct sensors of the NAD(+)/NADH ratio

    Cerebral venous thrombosis: a changing landscape

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    Cerebral venous thrombosis (CVT) is an uncommon cause of stroke and is mainly a disease of the young. The aims of the study were to summarize the change in the clinical profile of CVT and provide an update regarding the current management of the same. A literature search was conducted using Pubmed and Google scholar using the desired terms. Studies were analysed and review was formulated. The median age of CVT in most studies was 32 years. There has been a shift from female pre-ponderence to equal gender predilection. Several studies are confirming the efficacy of D-dimer as a diagnostic marker of CVT. Newer oral anticoagulants have been found to be as efficient as warfarin. There have been several cases of CVT reported in association with COVID-19. This review confirmed the traditional understanding of age and risk factors of CVT. It also noted a change from the female pre-ponderence. NOACS are emerging as the preferred drug for the long-term management of CVT

    A correlative study of homocysteine levels and dementia: an Indian perspective

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    Background: The prevalence of dementia is increasing worldwide and with India experiencing an epidemiological transition with increasing ageing population, the prevalence in India is expected to double by 2030 adding to the already high burden of significant health care costs and caregiver fatigue. Indian population has a higher burden of elevated homocysteine levels due to multiple factors. However, studies correlating the homocysteine levels and severity of dementia in the Indian subcontinent is lacking. This study is aimed to analyse the diagnostic utility of serum total homocysteine in dementia and to examine the association between serum total homocysteine levels and severity of dementia.Methods: This was a cross-sectional hospital-based study on patients attending neurology out-patient department who satisfied the DSM-V criteria. Each participant underwent an interview of general health and function followed by a standard assessment including medical history, physical and neurological examination as well as a neuropsychological battery.Results: A total of 30 patients fulfilling the DSM-Vcriteria for Dementia were included in the study. Increasing S. Homocysteine levels were associated with lower neuropsychological compound scores with MMSE score of 20.78±2.98 and ACE-3 score of 77.40±5.60 in patients with Serum Homocysteine less than 22 Umoles/L and 18.85±2.50 and 75.55±5.06 respectively in patients with serum homocysteine levels above 22 Umoles/L. However, there was no statistically significant correlation between neurocognitive scores and serum homocysteine levels (p value 0.06 for MMSE and 0.19 for ACE-3). Also, no correlation was found between severity of dementia and serum homocysteine levels with p≥0.05 and Pearson’s correlation coefficient r=0.06.Conclusions: This study shows no significant association between serum total homocysteine levels and severity of dementia. Thus, the association of homocysteine as an independent risk factor with the diagnosis and severity of dementia needs to be re-evaluated as it might undermine the multiple mechanisms underlying the pathogenesis of dementia

    Neuropathy in the setting of alcoholism-an entity less thought of

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    Disulfiram is a commonly used adjunctive treatment in the management of alcohol dependency.  It has been noted that disulfiram can induce peripheral neuropathy, the mechanism of which has not been clearly determined. A 35-year-old patient, reformed alcoholic, on disulfiram presented with complaints of painful distal dysesthesias and foot drop. Clinical examination revealed bilateral foot drop without any objective sensory loss. Patient was evaluated for the same and routine blood investigations including vitamin B-12, inflammatory and virological markers were found to be normal. Nerve conductions studies revealed in excitable bilateral common peroneal and tibial nerves. Possibility of disulfiram induced peripheral neuropathy was thought of and drug was withdrawn. Patient was followed up and after two months improvement in motor power and reduction in paraesthesia’s was noted. Disulfiram is a commonly used drug, the uncommon side effect of which is distal predominant axonal neuropathy. This must be kept be kept in mind when evaluating a patient presenting with features of peripheral neuropathy, on a background of alcohol abuse

    A contemporary dose selection algorithm for stereotactic radiosurgery in the treatment of brain metastases - An initial report.

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    Indications and treatment goals for SRS have changed since the publication of RTOG 90-05. We present initial retrospective outcomes from a new dose selection algorithm in use at our institution felt to be more contemporary with doses being used in the radiosurgery community today and report our local control and toxicity outcomes. This dose selection algorithm will be subject to a forthcoming prospective phase 2 trial.To evaluate safety and efficacy of an institutional dose selection algorithm in the treatment of brain metastases (BM) with single fraction radio-surgery (SRS).The medical records of 65 patients with ≤10 BM treated with GK at our institution between April 2012 and October 2012 were reviewed retrospectively. The prescription doses used in this study ranged from 16-22Gy and were based upon RTOG 90-05 guideline doses subsequently modified at our institution depending on lesion number, lesion volume, institutional experience and prior history of whole brain radiation therapy (WBRT). Primary endpoint was local recurrence (LR) with additional outcomes measured including distant intracranial recurrence (DIR), death without local recurrence (DWLR) and alive and disease free (ADF). Fine Gray competing risk analysis was used to examine factors affecting local recurrence.Median follow up was 8.9 months (range 1.0-29.6months) and 12 month overall survival was 37% (95% CI 24.9-49.1%). Overall local recurrence rate was 7.7%. On competing risks regression analysis, no variable was significantly associated with local recurrence, including previous whole brain radiotherapy (WBRT), (SHR 1.21 [95%CI 0.13-11.5], p=0.87 and radioresistant versus radiosensitive histology (SHR 0.51 [95% CI 0.06-7.73], p=0.55). No patient developed grade 3 or higher neurotoxicity at 12 months following GK.Initial local control and toxicity results from our institutional dose selection algorithm are reported here. Comparison of our results with RTOG 90-05 is difficult due to significant differences in the patient population and their treatments. The applicability of this algorithm merits further investigation across multiple centers for the purpose of treatment and clinical trial standardization in single fraction SRS and will be the subject of a forthcoming phase 2 prospective study within our own institution

    In vivo function of the murid herpesvirus-4 ribonucleotide reductase small subunit

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    The difficulty of eliminating herpesvirus carriage makes host entry a key target for infection control. However, its viral requirements are poorly defined. Murid herpesvirus-4 (MuHV-4) can potentially provide insights into gammaherpesvirus host entry. Upper respiratory tract infection requires the MuHV-4 thymidine kinase (TK) and ribonucleotide reductase large subunit (RNR-L), suggesting a need for increased nucleotide production. However, both TK and RNR-L are likely to be multifunctional. We therefore tested further the importance of nucleotide production by disrupting the MuHV-4 ribonucleotide reductase small subunit (RNR-S). This caused a similar attenuation to RNR-L disruption: despite reduced intra-host spread, invasive inoculations still established infection, whereas a non-invasive upper respiratory tract inoculation did so only at high dose. Histological analysis showed that RNR-S−, RNR-L− and TK− viruses all infected cells in the olfactory neuroepithelium but unlike wild-type virus then failed to spread. Thus captured host nucleotide metabolism enzymes, up to now defined mainly as important for alphaherpesvirus reactivation in neurons, also have a key role in gammaherpesvirus host entry. This seemed to reflect a requirement for lytic replication to occur in a terminally differentiated cell before a viable pool of latent genomes could be established

    Self-Organizing Maps for Pattern Recognition in Design of Alloys

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    A combined experimental\u2013computational methodology for accelerated design of AlNiCo-type permanent magnetic alloys is presented with the objective of simultaneously extremizing several magnetic properties. Chemical concentrations of eight alloying elements were initially generated using a quasirandom number generator so as to achieve a uniform distribution in the design variable space. It was followed by manufacture and experimental evaluation of these alloys using an identical thermo-magnetic protocol. These experimental data were used to develop meta-models capable of directly relating the chemical composition with desired macroscopic properties of the alloys. These properties were simultaneously optimized to predict chemical compositions that result in improvement of properties. These data were further utilized to discover various correlations within the experimental dataset by using several concepts of artificial intelligence. In this work, an unsupervised neural network known as selforganizing maps was used to discover various patterns reported in the literature. These maps were also used to screen the composition of the next set of alloys to be manufactured and tested in the next iterative cycle. Several of these Pareto-optimized predictions out-performed the initial batch of alloys. This approach helps significantly reducing the time and the number of alloys needed in the alloy development process
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