45 research outputs found

    Rotavirus Rearranged Genomic RNA Segments Are Preferentially Packaged into Viruses Despite Not Conferring Selective Growth Advantage to Viruses

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    The rotavirus (RV) genome consists of 11 double-stranded RNA segments. Sometimes, partial sequence duplication of an RNA segment leads to a rearranged RNA segment. To specify the impact of rearrangement, the replication efficiencies of human RV with rearranged segments 7, 11 or both were compared to these of the homologous human wild-type RV (wt-RV) and of the bovine wt-RV strain RF. As judged by viral growth curves, rotaviruses with a rearranged genome (r-RV) had no selective growth advantage over the homologous wt-RV. In contrast, r-RV were selected over wt-RV during competitive experiments (i.e mixed infections between r-RV and wt-RV followed by serial passages in cell culture). Moreover, when competitive experiments were performed between a human r-RV and the bovine wt-RV strain RF, which had a clear growth advantage, rearranged segments 7, 11 or both always segregated in viral progenies even when performing mixed infections at an MOI ratio of 1 r-RV to 100 wt-RV. Lastly, bovine reassortant viruses that had inherited a rearranged segment 7 from human r-RV were generated. Although substitution of wt by rearranged segment 7 did not result in any growth advantage, the rearranged segment was selected in the viral progenies resulting from mixed infections by bovine reassortant r-RV and wt-RV, even for an MOI ratio of 1 r-RV to 107 wt-RV. Lack of selective growth advantage of r-RV over wt-RV in cell culture suggests a mechanism of preferential packaging of the rearranged segments over their standard counterparts in the viral progeny

    The clinical utility of molecular diagnostic testing for primary immune deficiency disorders: a case based review

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    Primary immune deficiency disorders (PIDs) are a group of diseases associated with a genetic predisposition to recurrent infections, malignancy, autoimmunity and allergy. The molecular basis of many of these disorders has been identified in the last two decades. Most are inherited as single gene defects. Identifying the underlying genetic defect plays a critical role in patient management including diagnosis, family studies, prognostic information, prenatal diagnosis and is useful in defining new diseases. In this review we outline the clinical utility of molecular testing for these disorders using clinical cases referred to Auckland Hospital. It is written from the perspective of a laboratory offering a wide range of tests for a small developed country

    Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study

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    This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.COST (European Cooperation in Science and Technology)Portuguese Foundation for Science and TechnologyNational Research Fund of Luxembourg (FNR)China Scholarship Council (CSC)BOKU Core Facilities Multiscale ImagingDeutsche Forschungsgemeinschaft (DFG, German Research Foundation

    Water quality assessment of a small peri-urban river using low and high frequency monitoring

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    The biogeochemical behaviors of small rivers that pass through suburban areas are difficult to understand because of the multi-origin inputs that can modify their behavior. In this context, a monitoring strategy has been designed for the Marque River, located in Lille Metropolitan area of northern France, that includes both low-frequency monitoring over a one-year period (monthly sampling) and high frequency monitoring (measurements every 10 minutes) in spring and summer. Several environmental and chemical parameters are evaluated including rainfall events, river flow, temperature, dissolved oxygen, turbidity, conductivity, nutritive salts and dissolved organic matter. Our results from the Marque River show that (i) it is impacted by both urban and agricultural inputs, and as a consequence, the concentrations of phosphate and inorganic nitrogen have degraded the water quality; (ii) the classic photosynthesis/respiration processes are disrupted by the inputs of organic matter and nutritive salts; (iii) during dry periods, the urban sewage inputs (treated or not) are more important during the day, as indicated by higher river flows and maximal concentrations of ammonium; (iv) phosphate concentrations depend on oxygen contents in the river; (v) high nutrient concentrations result in eutrophication of the Marque River with lower pH and oxygen concentrations in summer. During rainfalls, additional inputs of ammonium, biodegradable organic matter as well as sediment resuspension result in anoxic events; and finally (vi) concentrations of nitrate are approximately constant over the year, except in winter when higher inputs can be recorded. Having better identified the processes responsible for the observed water quality, a more informed remediation effort can be put forward to move this suburban river to a good status of water quality

    Frequent de novo mutations and exon deletions in the C1 inhibitor gene of patients with angioedema

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    Background: Cases of angioedema with no family history but with functionally low levels of C1 inhibitor and recurrent attacks are often observed. Clinical and biochemical data do not distinguish these cases from proven inherited forms of hereditary angioedema. Objective: We sought to test the hypothesis of de novo mutations in patients affected by angioedema without a family history of the disease. Methods: Among 137 independent kindreds followed for hereditary angioedema, 45 (32.8%) patients with early onset of the disease were registered as sporadic cases. Nineteen patients with unaffected parents were screened for point mutations and microdeletions-insertions by using fluorescence-assisted mismatch analysis. The biologic paternity of these patients was verified by determining their alleles at 4 microsatellite loci. Gross deletions were detected with Southern blot analysis. Results: C1 inhibitor plasma levels measured in both parents of 24 sporadic patients were normal in all but 3 patients. Among the 19 patients studied at the DNA level, 9 de novo single nucleotide substitutions and 6 de novo microdeletions were found. De novo exon deletions were detected in 3 additional patients with Southern blot analysis. Conclusions: De novo C1 inhibitor mutations and exon deletions account for at least 25% of all unrelated cases of angioedema. This finding has implications relevant to the genetic epidemiology and genetic counseling of this disease. The observation that 5 of the 9 de novo point mutations reproduce previously reported changes underlines the presence of multiple hot spots, two of which contain a CpG dinucleotide
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