1,108 research outputs found
HEV inactivation assessment using viable virus
Hepatitis E is an acute icteric hepatitis caused by hepatitis E virus (HEV). HEV is transmitted by water supplies in developing countries. Recently, HEV contamination in consumption water was also observed in a developed country (France). HEV is detected in pigs and several other animal species (e.g. wild boars and deer) and it is strongly suspected to be zoonotic, HEV has also been detected in the pork production chain: in a study conducted in a grocery in the USA 11% of livers tested were HEV positive and similar data have been observed in Europe also
Hepatitis E virus sequences in swine related to sequences in humans, The Netherlands.
Hepatitis E virus (HEV), a major cause of viral hepatitis in much of the developing world, has recently been detected in swine in North America and Asia, raising concern about potential for zoonotic transmission. To investigate if HEV is commonly present in swine in the Netherlands, pooled stool samples from 115 swine farms and nine individual pigs with diarrhea were assayed by reverse transcription-polymerase chain reaction (RT-PCR) amplification. HEV RNA was detected by RT-PCR and hybridization in 25 (22%) of the pooled specimens, but in none of the individual samples. RT-PCR amplification products of open reading frames 1 and 2 were sequenced, and the results were compared with published sequences of HEV genotypes from humans and swine. HEV strains from swine in the Netherlands were clustered in at least two groups, together with European and American isolates from swine and humans. Our data show that HEV in swine in the Netherlands are genetically closely related to HEV isolates from humans. Although zoonotic transmission has not been proven, these findings suggest that swine may be reservoir hosts of HEV
Laparoscopic Sentinel Lymph Node Biopsy for Prostate Cancer: The Relevance of Locations Outside the Extended Dissection Area
Objective. To assess the relevance of sentinel lymph nodes (SNs) outside the extended pelvic lymph node dissection area (e-PLND). Patients and Methods. Evaluation of our laparoscopic SN procedures for prostate cancer patients of intermediate prognosis. Retrospective data collection on the exact location of the excised SNs and the pathology results were analyzed. Results and Limitations. Of the 121 patients, 49 had positive lymph nodes. 37 patients (31%) had SNs outside the e-PLND template. Five of these nodes were tumor bearing but only twice exclusively so. Of the 14 patients considered for salvage treatment, 6 were node positive. 7 of these 14 patients (50%) had SNs outside the extended dissection area, yet none of these nodes were tumor positive. Limitations are those of a retrospective study. Conclusions. Laparoscopic SN biopsy may show SNs outside the e-PLND template in 31% of the patients. However, nodes that are exclusively positive in one of these areas are rare. For the dichotomy positive or negative nodes, the locations outside the e-PLND area are not often relevant. Nevertheless, when all positive nodes are to be treated by resection or radiotherapy, these locations are relevant. When considering salvage treatment for prostate cancer, the method is feasible
Hepatitis E virus RNA in commercially available porcine livers in The Netherlands
Hepatitis E virus (HEV) infections caused by genotype 3 are increasingly observed in industrialized countries, without a distinct source. High similarity between human and swine strains of HEV strongly suggest possible zoonotic transmission. It was reported previously that in 55% of Dutch pig farms HEV-excreting fattening pigs were present. In the current study, presence of HEV RNA in commercially available porcine livers was shown. We examined 62 commercially available porcine livers for HEV contamination. Before examination of livers, the most sensitive combination of tissue disruption and RNA-extraction was chosen from four disruption and seven RNA-extraction methods. Four of 62 livers were shown to be positive for HEV RNA by RT-PCR and Southern blot hybridization, and three sequences were obtained. Phylogenetic analysis showed clustering of the sequences with previously published Dutch HEV genotype 3 sequences from humans and swine. To study infectivity of possible virus, three pigs were intravenously inoculated with suspensions from commercially available HEV positive livers. Two other pigs served as high-dose or low-dose controls. The low-dose control received a comparable viral count as animals receiving inocula from commercially available livers, the high dose control received a viral count that was known to generate infection. Faecal shedding of HEV was observed in the high-dose control, indicating that the control virus was infectious. No faecal shedding of HEV was observed for the low-dose control and the three pigs that were administered the commercially available livers extracts. In conclusion, HEV RNA was found in commercially available porcine livers. inoculation of susceptible pigs with extracts from HEV-positive livers did not lead to infection, but this may be a dose-dependent effect. The risk for consumers should be investigated further
In vitro-differentiated T/natural killer-cell progenitors derived from human CD34+ cells mature in the thymus
Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is a treatment option for patients with hematopoietic malignancies that is hampered by treatment-related morbidity and mortality, in part the result of opportunistic infections, a direct consequence of delayed T-cell recovery. Thymic output can be improved by facilitation of thymic immigration, known to require precommitment of CD34(+) cells. We demonstrate that Delta-like ligand-mediated predifferentiation of mobilized CD34(+) cells in vitro results in a population of thymocyte-like cells arrested at a T/natural killer (NK)-cell progenitor stage. On intrahepatic transfer to Rag2(-/-)gamma(c)(-/-) mice, these cells selectively home to the thymus and differentiate toward surface T-cell receptor-alphabeta(+) mature T cells considerably faster than animals transplanted with noncultured CD34(+) cells. This finding creates the opportunity to develop an early T-cell reconstitution therapy to combine with HSCT
Functional Restoration of CFTR Nonsense Mutations in Intestinal Organoids
Background: Pharmacotherapies for people with cystic fibrosis (pwCF) who have premature termination codons (PTCs) in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are under development. Thus far, clinical studies focused on compounds that induce translational readthrough (RT) at the mRNA PTC location. Recent studies using primary airway cells showed that PTC functional restoration can be achieved through combining compounds with multiple mode-of-actions. Here, we assessed induction of CFTR function in PTC-containing intestinal organoids using compounds targeting RT, nonsense mRNA mediated decay (NMD) and CFTR protein modulation. Methods: Rescue of PTC CFTR protein was assessed by forskolin-induced swelling of 12 intestinal organoid cultures carrying distinct PTC mutations. Effects of compounds on mRNA CFTR level was assessed by RT-qPCRs. Results: Whilst response varied between donors, significant rescue of CFTR function was achieved for most donors with the quintuple combination of a commercially available pharmacological equivalent of the RT compound (ELX-02-disulfate or ELX-02ds), NMD inhibitor SMG1i, correctors VX-445 and VX-661 and potentiator VX-770. The quintuple combination of pharmacotherapies reached swelling quantities higher than the mean swelling of three VX-809/VX-770-rescued F508del/F508del organoid cultures, indicating level of rescue is of clinical relevance as VX-770/VX-809-mediated F508del/F508del rescue in organoids correlate with substantial improvement of clinical outcome. Conclusions: Whilst variation in efficacy was observed between genotypes as well as within genotypes, the data suggests that strong pharmacological rescue of PTC requires a combination of drugs that target RT, NMD and protein function
First Test of Lorentz Invariance in the Weak Decay of Polarized Nuclei
A new test of Lorentz invariance in the weak interactions has been made by
searching for variations in the decay rate of spin-polarized 20Na nuclei. This
test is unique to Gamow-Teller transitions, as was shown in the framework of a
recently developed theory that assumes a Lorentz symmetry breaking background
field of tensor nature. The nuclear spins were polarized in the up and down
direction, putting a limit on the amplitude of sidereal variations of the form
|(\Gamma_{up} - \Gamma_{down})| / (\Gamma_{up} + \Gamma_{down}) < 3 * 10^{-3}.
This measurement shows a possible route toward a more detailed testing of
Lorentz symmetry in weak interactions.Comment: 11 pages, 6 figure
Self-Assembly of the Recombinant Capsid Protein of a Swine Norovirus into Virus-Like Particles and Evaluation of Monoclonal Antibodies Cross-Reactive with a Human Strain from Genogroup II
Noroviruses (NoVs) are responsible for the majority of gastroenteritis outbreaks in humans. Recently, NoV strains which are genetically closely related to human genogroup II (GII) NoVs have been detected in fecal specimens from swine. These findings have raised concern about the possible role of pigs as reservoirs for NoVs that could infect humans. To better understand the epidemiology of swine NoVs in both the swine and the human populations, rapid immunoassays are needed. In this study, baculovirus recombinants were generated to express the capsid gene of a swine NoV GII genotype 11 (GII.11) strain which self-assembled into virus-like particles (VLPs). Subsequently, the purified VLPs were used to evoke monoclonal antibodies (MAbs) in mice. A panel of eight promising MAbs was obtained and evaluated for their ability to bind to heterologous VLPs, denaturated antigens, and truncated capsid proteins. The MAbs could be classified into two groups: two MAbs that recognized linear epitopes located at the amino-terminal half (shell domain) of the swine NoV GII.11 VLPs and that cross-reacted with human GII.4 NoV VLPs. The other six MAbs bound to conformational epitopes and did not cross-react with the human GII.4 VLPs. To our knowledge, this is the first report on the characterization of MAbs against swine NoVs. The swine NoV VLPs and the MAbs described here may be further used for the design of diagnostic reagents that could help increase our knowledge of the prevalence of NoV infections in pigs and the possible role of pigs as reservoirs for NoVs
Radar interferometry based settlement monitoring in tunnelling: visualisation and accuracy analyses
Background
The accurate, efficient and economical monitoring of settlements caused by tunnel boring machines, especially in regions of particular interest such as critical inner city areas, has become an important aspect of the tunnelling operation. Besides conventional terrestrial based methods to capture settlements, satellite based techniques that can accurately determine displacements remotely, are increasingly being used to augment standard terrestrial measurements. However, not much attention has been paid to analyse the accuracy of satellite based measurement data. In addition, there is also a lack of studies on how to visualise the resulting huge amount of data in the context of both the tunnel advancement and the existing building infrastructure.
Methods
This paper introduces the basics of settlement monitoring using radar interferometry methods, in particular showing the results obtained by processing radar images from the TerraSAR-X satellite to monitor a downtown construction site in Düsseldorf, Germany, where a new underground line (“Wehrhahn-Linie”) is being built. By comparing terrestrial measurements with remote satellite based settlement data in temporal and spatial corridors, the accuracy of the radar interferometry method is shown. Moreover, a 4D visualisation concept is presented that correlates satellite and terrestrial based settlement data correlated with above-ground buildings and boring machine performance parameters within a Virtual Reality (VR) environment.
Results
By comparing up to 23,000 pairs of satellite and terrestrial based settlement data points of a real tunnelling project an accuracy of about ±1.5 mm in the measurement of deformation using the method of radar interferometry in urban areas can be stated. In addition, providing a visual analysis of data sources within a VR environment, the accuracy of terrestrial and satellite-based measurements can be visualised in different time steps. Sources of error that affect the degree of accuracy, such as atmospheric conditions, systematic errors in the evaluation of radar images and local events in the spatial corridor, can be quantified. In addition, the 4D visualisation can help reveal direct interdependencies between settlement data and boring machine performance data.
Conclusions
The Persistent Scatterer Interferometry (PSI) based on high resolution radar images of the TerraSAR-X satellite, in combination with conventional ground-based terrestrial measurements, provides a new settlement monitoring approach in tunnelling. For example, due to minimized surveying works and disruptions of construction activities on site and due to the large settlement area coming with a high magnitude of settlement data points, this combined monitoring approach is very practical and economical. Moreover, by visualizing the settlement data properly, the risk of damage of surface structures can be analysed and understood more precisely, which increases the safety of underground works
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