522 research outputs found

    Characterization of canine oral papillomavirus by histopathological and genetic analysis in Korea

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    In August 2008, forty dogs out of 400 developed oral warts in a breeding farm in Korea. Canine oral papilloma infection is a common disease in dogs. However, there has been no report of an outbreak of canine oral papillomavirus (COPV) in a group of dogs or in dog breeding farms in Korea, and the genetic analysis of COPV in Korea has yet to be performed. This study diagnosed canine oral papilloma from the oral samples of these dogs based on histopathological examination and immunohistochemistry. Polymerase chain reaction was applied to amplify the corresponding products using pre-existing primer sets for COPV and a universal human papillomavirus targeting L1 gene. Further genetic analysis of the major viral capsid gene L1 confirms the sequences of Korean COPV, which shows a close relationship to previously reported COPV. This study describes the histopathological and immunohistochemical characteristics of canine oral papilloma in a group of breeding dogs in Korea and discloses the complete L1 gene sequences of Korean COPV

    Expression patterns of influenza virus receptors in the respiratory tracts of four species of poultry

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    The primary determinant of influenza virus infectivity is the type of linkage between sialic acid and oligosaccharides on the host cells. Hemagglutinin of avian influenza viruses preferentially binds to sialic acids linked to galactose by an α-2,3 linkage whereas hemagglutinin of human influenza viruses binds to sialic acids with an α-2,6 linkage. The distribution patterns of influenza receptors in the avian respiratory tracts are of particular interest because these are important for initial viral attachment, replication, and transmission to other species. In this study, we examined the distribution patterns of influenza receptors in the respiratory tract of chickens, ducks, pheasants, and quails because these species have been known to act as intermediate hosts in interspecies transmission. Lectin histochemistry was performed to detect receptor-bearing cells. Cell-specific distribution of the receptors was determined and expression densities were compared. We observed species-, site-, and cell-specific variations in receptor expression. In general, receptor expression was the highest in quails and lowest in ducks. Pheasants and quails had abundant expression of both types of receptors throughout the respiratory tract. These results indicate that pheasants and quails may play important roles as intermediate hosts for the generation of influenza viruses with pandemic potential

    Immune mechanisms of pulmonary intravascular coagulopathy in COVID-19 pneumonia

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    The lung pathology seen in patients with coronavirus disease 2019 (COVID-19) shows marked microvascular thrombosis and haemorrhage linked to extensive alveolar and interstitial inflammation that shares features with macrophage activation syndrome (MAS). We have termed the lung-restricted vascular immunopathology associated with COVID-19 as diffuse pulmonary intravascular coagulopathy, which in its early stages is distinct from disseminated intravascular coagulation. Increased circulating D-dimer concentrations (reflecting pulmonary vascular bed thrombosis with fibrinolysis) and elevated cardiac enzyme concentrations (reflecting emergent ventricular stress induced by pulmonary hypertension) in the face of normal fibrinogen and platelet levels are key early features of severe pulmonary intravascular coagulopathy related to COVID-19. Extensive immunothrombosis over a wide pulmonary vascular territory without confirmation of COVID-19 viraemia in early disease best explains the adverse impact of male sex, hypertension, obesity, and diabetes on the prognosis of patients with COVID-19. The immune mechanism underlying diffuse alveolar and pulmonary interstitial inflammation in COVID-19 involves a MAS-like state that triggers extensive immunothrombosis, which might unmask subclinical cardiovascular disease and is distinct from the MAS and disseminated intravascular coagulation that is more familiar to rheumatologists

    A sleeping phantom leg awakened following hemicolectomy, thrombosis, and chemotherapy: a case report

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    INTRODUCTION: We describe the case of a patient who experienced phantom pain that began 42 years after right above-the-knee amputation. Immediately prior to phantom pain onset, this long-term amputee had experienced, in rapid succession, cancer, hemicolectomy, chemotherapy, and thrombotic occlusion. Very little has been published to date on the association between chemotherapy and exacerbation of neuropathic pain in amputees, let alone the phenomenon of bringing about pain in amputees who have been pain-free for many decades. While this patient presented with a unique profile following a rare sequence of medical events, his case should be recognized considering the frequent co-occurrence of osteomyelitis, chemotherapy, and amputation. CASE PRESENTATION: A 68-year-old Australian Caucasian man presented 42 years after right above-the-knee amputation with phantom pain immediately following hemicolectomy, thrombotic occlusion in the amputated leg, and chemotherapy treatment with leucovorin and 5-fluorouracil. He exhibited probable hyperalgesia with a reduced pinprick threshold and increased stump sensitivity, indicating likely peripheral and central sensitization. CONCLUSION: Our patient, who had long-term nerve injury due to amputation, together with recent ischemic nerve and tissue injury due to thrombosis, exhibited likely chemotherapy-induced neuropathy. While he presented with unique treatment needs, cases such as this one may actually be quite common considering that osteosarcoma can frequently lead to amputation and be followed by chemotherapy. The increased susceptibility of amputees to developing potentially intractable chemotherapy-induced neuropathic pain should be taken into consideration throughout the course of chemotherapy treatment. Patients in whom chronic phantom pain then develops, perhaps together with mobility issues, inevitably place greater demands on healthcare service providers that require treatment by various clinical specialists, including oncologists, neurologists, prosthetists, and, most frequently, general practitioners

    Understanding forecast verification statistics

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    Although there are numerous reasons for performing a verification analysis, there are usually two general questions that are of interest: are the forecasts good, and can we be confident that the estimate of forecast quality is not misleading? When calculating a verification score, it is not usually obvious how the score can answer either of these questions. Some procedures for attempting to answer the questions are reviewed, with particular focus on p-values and confidence intervals. P-values are shown to be rather unhelpful in answering either question, especially when applied to probabilistic verification scores, and confidence intervals are to be preferred. However, confidence intervals cannot reveal biases in the value of a score that arises from an inadequate experimental design for testing on truly out-of-sample observations. Some specific problems with cross validation are highlighted. Finally, in the interests of increasing the insight into forecast strengths and weaknesses and in pointing towards methods for improving forecast quality, a plea is made for a more discriminating selection of verification procedures than has been adopted to date

    Nitrous oxide production by nitrification and denitrification in the Eastern Tropical South Pacific oxygen minimum zone

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    The Eastern Tropical South Pacific oxygen minimum zone (ETSP-OMZ) is a site of intense nitrous oxide (N2O) flux to the atmosphere. This flux results from production of N2O by nitrification and denitrification, but the contribution of the two processes is unknown. The rates of these pathways and their distributions were measured directly using 15N tracers. The highest N2O production rates occurred at the depth of peak N2O concentrations at the oxic-anoxic interface above the oxygen deficient zone (ODZ) because slightly oxygenated waters allowed (1) N2O production from both nitrification and denitrification and (2) higher nitrous oxide production yields from nitrification. Within the ODZ proper (i.e., anoxia), the only source of N2O was denitrification (i.e., nitrite and nitrate reduction), the rates of which were reflected in the abundance of nirS genes (encoding nitrite reductase). Overall, denitrification was the dominant pathway contributing the N2O production in the ETSP-OMZ

    Hepatitis C virus and atherosclerosis: A legacy after virologic cure?

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    publisher: Elsevier articletitle: Hepatitis C virus and atherosclerosis: A legacy after virologic cure? journaltitle: Clinics and Research in Hepatology and Gastroenterology articlelink: http://dx.doi.org/10.1016/j.clinre.2016.09.008 content_type: article copyright: © 2016 Elsevier Masson SAS. All rights reserved

    Progressive Purkinje Cell Degeneration in tambaleante Mutant Mice Is a Consequence of a Missense Mutation in HERC1 E3 Ubiquitin Ligase

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    The HERC gene family encodes proteins with two characteristic domains: HECT and RCC1-like. Proteins with HECT domains have been described to function as ubiquitin ligases, and those that contain RCC1-like domains have been reported to function as GTPases regulators. These two activities are essential in a number of important cellular processes such as cell cycle, cell signaling, and membrane trafficking. Mutations affecting these domains have been found associated with retinitis pigmentosa, amyotrophic lateral sclerosis, and cancer. In humans, six HERC genes have been reported which encode two subgroups of HERC proteins: large (HERC1-2) and small (HERC3-6). The giant HERC1 protein was the first to be identified. It has been involved in membrane trafficking and cell proliferation/growth through its interactions with clathrin, M2-pyruvate kinase, and TSC2 proteins. Mutations affecting other members of the HERC family have been found to be associated with sterility and growth retardation. Here, we report the characterization of a recessive mutation named tambaleante, which causes progressive Purkinje cell degeneration leading to severe ataxia with reduced growth and lifespan in homozygous mice aged over two months. We mapped this mutation in mouse chromosome 9 and then performed positional cloning. We found a G⇔A transition at position 1448, causing a Gly to Glu substitution (Gly483Glu) in the highly conserved N-terminal RCC1-like domain of the HERC1 protein. Successful transgenic rescue, with either a mouse BAC containing the normal copy of Herc1 or with the human HERC1 cDNA, validated our findings. Histological and biochemical studies revealed extensive autophagy associated with an increase of the mutant protein level and a decrease of mTOR activity. Our observations concerning this first mutation in the Herc1 gene contribute to the functional annotation of the encoded E3 ubiquitin ligase and underline the crucial and unexpected role of this protein in Purkinje cell physiology

    NMR solution structure of the major G-quadruplex structure formed in the human BCL2 promoter region

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    BCL2 protein functions as an inhibitor of cell apoptosis and has been found to be aberrantly expressed in a wide range of human diseases. A highly GC-rich region upstream of the P1 promoter plays an important role in the transcriptional regulation of BCL2. Here we report the NMR solution structure of the major intramolecular G-quadruplex formed on the G-rich strand of this region in K(+) solution. This well-defined mixed parallel/antiparallel-stranded G-quadruplex structure contains three G-tetrads of mixed G-arrangements, which are connected with two lateral loops and one side loop, and four grooves of different widths. The three loops interact with the core G-tetrads in a specific way that defines and stabilizes the overall G-quadruplex structure. The loop conformations are in accord with the experimental mutation and footprinting data. The first 3-nt loop adopts a lateral loop conformation and appears to determine the overall folding of the BCL2 G-quadruplex. The third 1-nt double-chain-reversal loop defines another example of a stable parallel-stranded structural motif using the G(3)NG(3) sequence. Significantly, the distinct major BCL2 promoter G-quadruplex structure suggests that it can be specifically involved in gene modulation and can be an attractive target for pathway-specific drug design
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