1,085 research outputs found

    Surveillance of acute flaccid paralysis in Hong Kong: 1997 to 2002

    Get PDF
    Objectives. To describe the characteristics of patients reported with acute flaccid paralysis between 1997 and 2002, and to evaluate the performance of the acute flaccid paralysis surveillance system using indicators recommended by the World Health Organization. Design. Retrospective study. Setting. Department of Health, Hong Kong. Participants. Children aged younger than 15 years who were reported to the Department of Health between 1997 and 2002 with acute flaccid paralysis. Results. Of 120 children with acute flaccid paralysis reported between 1997 and 2002, 42% were younger than 5 years of age. None of the cases were acute poliomyelitis or polio-compatible. A neurological cause was identified in 67.5% of cases, of which the most common was Guillain-Barré syndrome (42%), followed by transverse myelitis (15%). All except one of the performance indicators consistently met World Health Organization requirements and thus demonstrated the effectiveness of the acute flaccid paralysis surveillance programme. The acute flaccid paralysis notification rate consistently exceeded 1.0 per 100 000 population below 15 years of age. The requirement for adequate stool investigation was the single indicator that did not satisfy World Health Organization requirements. This highlighted the importance of maintaining physicians' awareness of acute flaccid paralysis surveillance. Conclusion. Hong Kong should remain vigilant for acute flaccid paralysis. The effective surveillance system and its evaluation may serve as a model for surveillance of other infectious diseases.published_or_final_versio

    Oligomerization domains in the glycan-binding receptors DC-SIGN and DC-SIGNR: sequence variation and stability differences

    Get PDF
    Human dendritic cell-specific intercellular adhesion molecule-1 grabbing nonintegrin, DC-SIGN, and the sinusoidal endothelial cell receptor DC-SIGNR or L-SIGN, are closely related sugar-binding receptors. DC-SIGN acts both as a pathogen-binding endocytic receptor and as a cell adhesion molecule, while DC-SIGNR has only the pathogen-binding function. In addition to differences in the sugar-binding properties of the carbohydrate-recognition domains in the two receptors, there are sequence differences in the adjacent neck domains, which are coiled-coil tetramerization domains comprised largely of 23-amino acid repeat units. A series of model polypeptides consisting of uniform repeat units have been characterized by gel filtration, differential scanning calorimetry and circular dichroism. The results demonstrate that two features characterize repeat units which form more stable tetramers: a leucine reside in the first position of the heptad pattern of hydrophobic residues that pack on the inside of the coiled coil and an arginine residue on the surface of the coiled coil that forms a salt bridge with a glutamic acid residue in the same polypeptide chain. In DC-SIGNR from all primates, very stable repeat units predominate, so the carbohydrate-recognition domains must be held relatively closely together. In contrast, stable repeat units are found only near the membrane in DC-SIGN. The presence of residues that disrupt tetramer formation in repeat units near the carbohydrate-recognition domains of DC-SIGN would allow these domains to splay further apart. Thus, the neck domains of DC-SIGN and DC-SIGNR can contribute to the different functions of these receptors by presenting the sugar-binding sites in different contexts

    Evolutionary Toggling of Vpx/Vpr Specificity Results in Divergent Recognition of the Restriction Factor SAMHD1

    Get PDF
    SAMHD1 is a host restriction factor that blocks the ability of lentiviruses such as HIV-1 to undergo reverse transcription in myeloid cells and resting T-cells. This restriction is alleviated by expression of the lentiviral accessory proteins Vpx and Vpr (Vpx/Vpr), which target SAMHD1 for proteasome-mediated degradation. However, the precise determinants within SAMHD1 for recognition by Vpx/Vpr remain unclear. Here we show that evolution of Vpx/Vpr in primate lentiviruses has caused the interface between SAMHD1 and Vpx/Vpr to alter during primate lentiviral evolution. Using multiple HIV-2 and SIV Vpx proteins, we show that Vpx from the HIV-2 and SIVmac lineage, but not Vpx from the SIVmnd2 and SIVrcm lineage, require the C-terminus of SAMHD1 for interaction, ubiquitylation, and degradation. On the other hand, the N-terminus of SAMHD1 governs interactions with Vpx from SIVmnd2 and SIVrcm, but has little effect on Vpx from HIV-2 and SIVmac. Furthermore, we show here that this difference in SAMHD1 recognition is evolutionarily dynamic, with the importance of the N- and C-terminus for interaction of SAMHD1 with Vpx and Vpr toggling during lentiviral evolution. We present a model to explain how the head-to-tail conformation of SAMHD1 proteins favors toggling of the interaction sites by Vpx/Vpr during this virus-host arms race. Such drastic functional divergence within a lentiviral protein highlights a novel plasticity in the evolutionary dynamics of viral antagonists for restriction factors during lentiviral adaptation to its hosts. © 2013 Fregoso et al

    Quantitative Understanding of Probabilistic Behavior of Living Cells Operated by Vibrant Intracellular Networks

    Get PDF
    For quantitative understanding of probabilistic behaviors of living cells, it is essential to construct a correct mathematical description of intracellular networks interacting with complex cell environments, which has been a formidable task. Here, we present a novel model and stochastic kinetics for an intracellular network interacting with hidden cell environments, employing a complete description of cell state dynamics and its coupling to the system network. Our analysis reveals that various environmental effects on the product number fluctuation of intracellular reaction networks can be collectively characterized by Laplace transform of the time-correlation function of the product creation rate fluctuation with the Laplace variable being the product decay rate. On the basis of the latter result, we propose an efficient method for quantitative analysis of the chemical fluctuation produced by intracellular networks coupled to hidden cell environments. By applying the present approach to the gene expression network, we obtain simple analytic results for the gene expression variability and the environment-induced correlations between the expression levels of mutually noninteracting genes. The theoretical results compose a unified framework for quantitative understanding of various gene expression statistics observed across a number of different systems with a small number of adjustable parameters with clear physical meanings.open1143sciescopu

    Design of MRI Structured Spiking Neural Networks and Learning Algorithms for Personalized Modelling, Analysis, and Prediction of EEG Signals

    Get PDF
    Abstract This paper proposes a novel method and algorithms for the design of MRI structured personalized 3D spiking neural network models (MRI-SNN) for a better analysis, modeling, and prediction of EEG signals. It proposes a novel gradient-descent learning algorithm integrated with a spike-time-dependent-plasticity algorithm. The models capture informative personal patterns of interaction between EEG channels, contrary to single EEG signal modeling methods or to spike-based approaches which do not use personal MRI data to pre-structure a model. The proposed models can not only learn and model accurately measured EEG data, but they can also predict signals at 3D model locations that correspond to non-monitored brain areas, e.g. other EEG channels, from where data has not been collected. This is the first study in this respect. As an illustration of the method, personalized MRI-SNN models are created and tested on EEG data from two subjects. The models result in better prediction accuracy and a better understanding of the personalized EEG signals than traditional methods due to the MRI and EEG information integration. The models are interpretable and facilitate a better understanding of related brain processes. This approach can be applied for personalized modeling, analysis, and prediction of EEG signals across brain studies such as the study and prediction of epilepsy, peri-perceptual brain activities, brain-computer interfaces, and others

    Trial of Optimal Personalised Care After Treatment for Gynaecological cancer (TOPCAT-G): a study protocol for a randomised feasibility trial

    Get PDF
    Background: Gynaecological cancers are diagnosed in over 1000 women in Wales every year. We estimate that this is costing the National Health Service (NHS) in excess of £1 million per annum for routine follow-up appointments alone. Follow-up care is not evidence-based, and there are no definitive guidelines from The National Institute for Health and Care Excellence (NICE) for the type of follow-up that should be delivered. Standard care is to provide a regular medical review of the patient in a hospital-based outpatient clinic for a minimum of 5 years. This study is to evaluate the feasibility of a proposed alternative where the patients are delivered a specialist nurse-led telephone intervention known as Optimal Personalised Care After Treatment for Gynaecological cancer (OPCAT-G), which comprised of a protocol-based patient education, patient empowerment and structured needs assessment. Methods: The study will recruit female patients who have completed treatment for cervical, endometrial, epithelial ovarian or vulval cancer within the previous 3 months in Betsi Cadwaladr University Health Board (BCUHB) in North Wales. Following recruitment, participants will be randomised to one of two arms in the trial (standard care or OPCAT-G intervention). The primary outcomes for the trial are patient recruitment and attrition rates, and the secondary outcomes are quality of life, health status and capability, using the EORTC QLQ-C30, EQ- 5D-3L and ICECAP-A measures. Additionally, a client service receipt inventory (CSRI) will be collected in order to pilot an economic evaluation. Discussion: The results from this feasibility study will be used to inform a fully powered randomised controlled trial to evaluate the difference between standard care and the OPCAT-G intervention. Trial registration: ISRCTN45565436

    Case report: Malignant teratoma of the uterine corpus

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Teratomas are the commonest germ cell tumours and are most frequently found in the testes and ovary. Extragonadal teratomas are rare and mainly occur in midline structures. Uterine teratomas are extremely rare with only a few previous case reports, usually involving mature teratomas of the uterine cervix.</p> <p>Case Presentation</p> <p>We report an 82-year-old lady presenting with post-menopausal bleeding. Initial investigations revealed a benign teratoma of the uterus which was removed. Her symptoms persisted and a recurrent, now malignant, teratoma of the uterine corpus was resected at hysterectomy. Six months after surgery she relapsed with para-aortic lymphadenopathy and was treated with a taxane, etoposide and cisplatin-containing chemotherapy regimen followed by retroperitoneal lymph node dissection.</p> <p>Conclusion</p> <p>In this report we discuss the aetiology, diagnosis and management of uterine teratomas, and review previous case studies.</p

    International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol

    Get PDF
    Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature. There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed
    corecore