2,637 research outputs found

    Molecular Identification of Spirometra erinaceieuropaei Tapeworm in Cases of Human Sparganosis, Hong Kong

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    Human sparganosis is a foodborne zoonosis endemic in Asia. We report a series of 9 histologically confirmed human sparganosis cases in Hong Kong, China. All parasites were retrospectively identified as Spirometra erinaceieuropaei. Skin and soft tissue swelling was the most common symptom, followed by central nervous system lesions.published_or_final_versio

    Otalgia and eschar in the external auditory canal in scrub typhus complicated by acute respiratory distress syndrome and multiple organ failure

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    <p>Abstract</p> <p>Background</p> <p>Scrub typhus, a mite-transmitted zoonosis caused by <it>Orientia tsutsugamushi</it>, is an endemic disease in Taiwan and may be potentially fatal if diagnosis is delayed.</p> <p>Case presentations</p> <p>We encountered a 23-year-old previously healthy Taiwanese male soldier presenting with the right ear pain after training in the jungle and an eleven-day history of intermittent high fever up to 39Β°C. Amoxicillin/clavulanate was prescribed for otitis media at a local clinic. Skin rash over whole body and abdominal cramping pain with watery diarrhea appeared on the sixth day of fever. He was referred due to progressive dyspnea and cough for 4 days prior to admission in our institution. On physical examination, there were cardiopulmonary distress, icteric sclera, an eschar in the right external auditory canal and bilateral basal rales. Laboratory evaluation revealed thrombocytopenia, elevation of liver function and acute renal failure. Chest x-ray revealed bilateral diffuse infiltration. Doxycycline was prescribed for scrub typhus with acute respiratory distress syndrome and multiple organ failure. Fever subsided dramatically the next day and he was discharged on day 7 with oral tetracycline for 7 days.</p> <p>Conclusion</p> <p>Scrub typhus should be considered in acutely febrile patients with multiple organ involvement, particularly if there is an eschar or a history of environmental exposure in endemic areas. Rapid and accurate diagnosis, timely administration of antibiotics and intensive supportive care are necessary to decrease mortality of serious complications of scrub typhus.</p

    Linear, Deterministic, and Order-Invariant Initialization Methods for the K-Means Clustering Algorithm

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    Over the past five decades, k-means has become the clustering algorithm of choice in many application domains primarily due to its simplicity, time/space efficiency, and invariance to the ordering of the data points. Unfortunately, the algorithm's sensitivity to the initial selection of the cluster centers remains to be its most serious drawback. Numerous initialization methods have been proposed to address this drawback. Many of these methods, however, have time complexity superlinear in the number of data points, which makes them impractical for large data sets. On the other hand, linear methods are often random and/or sensitive to the ordering of the data points. These methods are generally unreliable in that the quality of their results is unpredictable. Therefore, it is common practice to perform multiple runs of such methods and take the output of the run that produces the best results. Such a practice, however, greatly increases the computational requirements of the otherwise highly efficient k-means algorithm. In this chapter, we investigate the empirical performance of six linear, deterministic (non-random), and order-invariant k-means initialization methods on a large and diverse collection of data sets from the UCI Machine Learning Repository. The results demonstrate that two relatively unknown hierarchical initialization methods due to Su and Dy outperform the remaining four methods with respect to two objective effectiveness criteria. In addition, a recent method due to Erisoglu et al. performs surprisingly poorly.Comment: 21 pages, 2 figures, 5 tables, Partitional Clustering Algorithms (Springer, 2014). arXiv admin note: substantial text overlap with arXiv:1304.7465, arXiv:1209.196

    Autoimmune and autoinflammatory mechanisms in uveitis

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    The eye, as currently viewed, is neither immunologically ignorant nor sequestered from the systemic environment. The eye utilises distinct immunoregulatory mechanisms to preserve tissue and cellular function in the face of immune-mediated insult; clinically, inflammation following such an insult is termed uveitis. The intra-ocular inflammation in uveitis may be clinically obvious as a result of infection (e.g. toxoplasma, herpes), but in the main infection, if any, remains covert. We now recognise that healthy tissues including the retina have regulatory mechanisms imparted by control of myeloid cells through receptors (e.g. CD200R) and soluble inhibitory factors (e.g. alpha-MSH), regulation of the blood retinal barrier, and active immune surveillance. Once homoeostasis has been disrupted and inflammation ensues, the mechanisms to regulate inflammation, including T cell apoptosis, generation of Treg cells, and myeloid cell suppression in situ, are less successful. Why inflammation becomes persistent remains unknown, but extrapolating from animal models, possibilities include differential trafficking of T cells from the retina, residency of CD8(+) T cells, and alterations of myeloid cell phenotype and function. Translating lessons learned from animal models to humans has been helped by system biology approaches and informatics, which suggest that diseased animals and people share similar changes in T cell phenotypes and monocyte function to date. Together the data infer a possible cryptic infectious drive in uveitis that unlocks and drives persistent autoimmune responses, or promotes further innate immune responses. Thus there may be many mechanisms in common with those observed in autoinflammatory disorders

    Novel antiviral activity of neuraminidase inhibitors against an avian influenza a virus

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    <p>Abstract</p> <p>Background</p> <p>Neuraminidase (NA) inhibitors used for influenza therapy are believed to prevent the release of progeny virus from the surface of an infected cell. In this study, we found that NA inhibitors have a novel antiviral function against an avian influenza virus.</p> <p>Results</p> <p>Madin-Darby canine kidney cells, commonly used for the isolation and propagation of the influenza virus, were infected with an avian influenza viral strain A/chicken/German/N/49(H10N7) (H10/chicken) or a human influenza viral strain A/Osaka/981/98(H3N2) (H3/Osaka) virus. Cells were incubated in a medium without or with a NA inhibitor, oseltamivir carboxylate (GS4071), from 1 to 13 h post infection (p.i.). Infected cells were washed 12 h p.i. to remove GS4071, incubated for 1 h without GS4071, and assayed for virus production. Incubation with GS4071 decreased the production of infectious viruses. When H10/chicken virus-infected cells were incubated with GS4071 from 12 to 13 h p.i. (i.e., 1 h before the virus production assay), the inhibitory effect was clearly observed, however, the same was not evident for H3/Osaka virus-infected cells. Furthermore, viral protein synthesis in infected cells was not affected by GS4071. Using a scanning electron microscope, many single spherical buds were observed on the surface of H3/Osaka virus-infected cells incubated without GS4071, whereas many aggregated particles were observed on the surface of cells incubated with GS4071. However, many long tubular virus-like structures, with no aggregated particles, were observed on the surface of H10/chicken virus-infected cells incubated with GS4071. The same results were obtained when another NA inhibitor, zanamivir, was used.</p> <p>Conclusions</p> <p>These results indicate that NA inhibitors interfered with virus particle formation in the H10/chicken virus-infected cells, in which the inhibitor caused the formation of long tubular virus-like structures instead of spherical virus particles.</p

    Common Gene Therapy Viral Vectors Do Not Efficiently Penetrate Sputum from Cystic Fibrosis Patients

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    Norwalk virus and human papilloma virus, two viruses that infect humans at mucosal surfaces, have been found capable of rapidly penetrating human mucus secretions. Viral vectors for gene therapy of Cystic Fibrosis (CF) must similarly penetrate purulent lung airway mucus (sputum) to deliver DNA to airway epithelial cells. However, surprisingly little is known about the rates at which gene delivery vehicles penetrate sputum, including viral vectors used in clinical trials for CF gene therapy. We find that sputum spontaneously expectorated by CF patients efficiently traps two viral vectors commonly used in CF gene therapy trials, adenovirus (d∼80 nm) and adeno-associated virus (AAV serotype 5; d∼20 nm), leading to average effective diffusivities that are ∼3,000-fold and 12,000-fold slower than their theoretical speeds in water, respectively. Both viral vectors are slowed by adhesion, as engineered muco-inert nanoparticles with diameters as large as 200 nm penetrate the same sputum samples at rates only ∼40-fold reduced compared to in pure water. A limited fraction of AAV exhibit sufficiently fast mobility to penetrate physiologically thick sputum layers, likely because of the lower viscous drag and smaller surface area for adhesion to sputum constituents. Nevertheless, poor penetration of CF sputum is likely a major contributor to the ineffectiveness of viral vector based gene therapy in the lungs of CF patients observed to date

    Complete genomic sequence analysis of infectious bronchitis virus Ark DPI strain and its evolution by recombination

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    An infectious bronchitis virus Arkansas DPI (Ark DPI) virulent strain was sequenced, analyzed and compared with many different IBV strains and coronaviruses. The genome of Ark DPI consists of 27,620 nucleotides, excluding poly (A) tail, and comprises ten open reading frames. Comparative sequence analysis of Ark DPI with other IBV strains shows striking similarity to the Conn, Gray, JMK, and Ark 99, which were circulating during that time period. Furthermore, comparison of the Ark genome with other coronaviruses demonstrates a close relationship to turkey coronavirus. Among non-structural genes, the 5'untranslated region (UTR), 3C-like proteinase (3CLpro) and the polymerase (RdRp) sequences are 100% identical to the Gray strain. Among structural genes, S1 has 97% identity with Ark 99; S2 has 100% identity with JMK and 96% to Conn; 3b 99%, and 3C to N is 100% identical to Conn strain. Possible recombination sites were found at the intergenic region of spike gene, 3'end of S1 and 3a gene. Independent recombination events may have occurred in the entire genome of Ark DPI, involving four different IBV strains, suggesting that genomic RNA recombination may occur in any part of the genome at number of sites. Hence, we speculate that the Ark DPI strain originated from the Conn strain, but diverged and evolved independently by point mutations and recombination between field strains

    Veratridine produces distinct calcium response profiles in mouse Dorsal Root Ganglia neurons.

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    Nociceptors are a subpopulation of dorsal root ganglia (DRG) neurons that detect noxious stimuli and signal pain. Veratridine (VTD) is a voltage-gated sodium channel (VGSC) modifier that is used as an "agonist" in functional screens for VGSC blockers. However, there is very little information on VTD response profiles in DRG neurons and how they relate to neuronal subtypes. Here we characterised VTD-induced calcium responses in cultured mouse DRG neurons. Our data shows that the heterogeneity of VTD responses reflects distinct subpopulations of sensory neurons. About 70% of DRG neurons respond to 30-100 μM VTD. We classified VTD responses into four profiles based upon their response shape. VTD response profiles differed in their frequency of occurrence and correlated with neuronal size. Furthermore, VTD response profiles correlated with responses to the algesic markers capsaicin, AITC and Ξ±, Ξ²-methylene ATP. Since VTD response profiles integrate the action of several classes of ion channels and exchangers, they could act as functional "reporters" for the constellation of ion channels/exchangers expressed in each sensory neuron. Therefore our findings are relevant to studies and screens using VTD to activate DRG neurons

    Mycobacterial infections in a large Virginia hospital, 2001-2009

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    <p>Abstract</p> <p>Background</p> <p>In areas where both tuberculosis (TB) and nontuberculous mycobacteria (NTM) are prevalent, descriptive studies of the clinical features of individual mycobacteria are needed to inform clinical triage.</p> <p>Methods</p> <p>We queried the University of Virginia Clinical Data Repository for all mycobacterial infections from 2001-2009.</p> <p>Results</p> <p>Of 494 mycobacterial infections in 467 patients there were 22 species. Patients with pulmonary Tb were more likely to be reported as immigrants (p < 0.001) and less likely to have a predisposing risk factor for NTM (pre-existing lung disease or host predisposition; p = 0.002). Review of chest CT scans revealed that TB infection was more likely to exhibit cavities and pleural effusion than NTM infection (p < 0.05). Among NTM infections <it>M. kansasii</it>, <it>M. xenopi</it>, and <it>M. fortuitum </it>were more likely than MAC to have cavities. There were at least 83 patients that met criteria for NTM lung disease and these were caused by 9 species. <it>M. abscessus </it>infection was associated with cystic fibrosis and <it>M. xenopi </it>infection was associated with male gender.</p> <p>Conclusions</p> <p>In our center mycobacterial infections were common and of diverse species. Immigrant status, cavities, and effusion were associated with TB vs. NTM.</p

    Observation of the Zero Doppler Effect

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    This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material.National Basic Research Program (973) of China (No. 2011CB922001), and National Natural Science Foundation of China (No. 11234010)
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