8 results on '"Soussan AA"'
Search Results
2. Toll-like receptor 9 enhances bacterial clearance and limits lung consolidation in murine pneumonia caused by methicillin resistant Staphylococcus aureus .
- Author
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van der Meer AJ, Achouiti A, van der Ende A, Soussan AA, Florquin S, de Vos A, Zeerleder SS, and van der Poll T
- Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen in pneumonia, associated with severe lung damage. Tissue injury causes release of Damage Associated Molecular Patterns (DAMPs), which may perpetuate inflammation. DNA has been implicated as a DAMP that activates inflammation through Toll-like receptor (TLR)9. The aim of this study was to evaluate the role of TLR9 in MRSA pneumonia. Wild-type (Wt) and TLR9 knockout ( tlr 9
-/- ) mice were infected intranasally with MRSA USA300 (BK 11540) (5E7 CFU) and euthanized at 6,24,48 or 72 hours for analyses. MRSA pneumonia was associated with profound release of cell-free host DNA in the airways, as reflected by increases in nucleosome and DNA levels in bronchoalveolar lavage fluid (BALF), accompanied by transient detection of pathogen DNA in MRSA-free BALF supernatants. In BALF, as compared to Wt -mice tlr 9-/- mice showed reduced TNFα and IL-6 levels at 6 hours and reduced bacterial clearance at 6 and 24 hours post infection. Furthermore, tlr 9-/- mice exhibited a greater influx of neutrophils in BALF and increased lung consolidation at 24 and 48 hours. This study demonstrates the release of host- and pathogen-derived TLR9 ligands (DNA) into the alveolar space after infection with MRSA via the airways and suggests that TLR9 has pro-inflammatory effects during MRSA pneumonia associated with enhanced bacterial clearance and limitation of lung consolidation.- Published
- 2016
- Full Text
- View/download PDF
3. SMIM1 underlies the Vel blood group and influences red blood cell traits.
- Author
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Cvejic A, Haer-Wigman L, Stephens JC, Kostadima M, Smethurst PA, Frontini M, van den Akker E, Bertone P, Bielczyk-Maczyńska E, Farrow S, Fehrmann RS, Gray A, de Haas M, Haver VG, Jordan G, Karjalainen J, Kerstens HH, Kiddle G, Lloyd-Jones H, Needs M, Poole J, Soussan AA, Rendon A, Rieneck K, Sambrook JG, Schepers H, Silljé HHW, Sipos B, Swinkels D, Tamuri AU, Verweij N, Watkins NA, Westra HJ, Stemple D, Franke L, Soranzo N, Stunnenberg HG, Goldman N, van der Harst P, van der Schoot CE, Ouwehand WH, and Albers CA
- Subjects
- Alleles, Animals, Biomarkers metabolism, Blood Group Antigens immunology, Blood Group Antigens metabolism, Electrophoretic Mobility Shift Assay, Erythrocytes metabolism, Erythrocytes pathology, Exome genetics, Female, Gene Expression Profiling, Gene Regulatory Networks, Humans, Isoantibodies immunology, Membrane Proteins immunology, Membrane Proteins metabolism, Molecular Sequence Data, Oligonucleotide Array Sequence Analysis, Pregnancy, Zebrafish genetics, Blood Group Antigens genetics, Erythrocyte Membrane metabolism, Erythrocytes immunology, Gene Deletion, Homozygote, Membrane Proteins genetics, Quantitative Trait Loci
- Abstract
The blood group Vel was discovered 60 years ago, but the underlying gene is unknown. Individuals negative for the Vel antigen are rare and are required for the safe transfusion of patients with antibodies to Vel. To identify the responsible gene, we sequenced the exomes of five individuals negative for the Vel antigen and found that four were homozygous and one was heterozygous for a low-frequency 17-nucleotide frameshift deletion in the gene encoding the 78-amino-acid transmembrane protein SMIM1. A follow-up study showing that 59 of 64 Vel-negative individuals were homozygous for the same deletion and expression of the Vel antigen on SMIM1-transfected cells confirm SMIM1 as the gene underlying the Vel blood group. An expression quantitative trait locus (eQTL), the common SNP rs1175550 contributes to variable expression of the Vel antigen (P = 0.003) and influences the mean hemoglobin concentration of red blood cells (RBCs; P = 8.6 × 10(-15)). In vivo, zebrafish with smim1 knockdown showed a mild reduction in the number of RBCs, identifying SMIM1 as a new regulator of RBC formation. Our findings are of immediate relevance, as the homozygous presence of the deletion allows the unequivocal identification of Vel-negative blood donors.
- Published
- 2013
- Full Text
- View/download PDF
4. Fetal DNA: strategies for optimal recovery.
- Author
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Legler TJ, Heermann KH, Liu Z, Soussan AA, and van der Schoot CE
- Subjects
- DNA isolation & purification, Female, Gene Expression Regulation, Developmental, Humans, Magnetics, Maternal-Fetal Exchange, Pregnancy, Reagent Kits, Diagnostic, Reproducibility of Results, DNA blood, Fetus metabolism, Genetic Testing, Prenatal Diagnosis methods
- Abstract
For fetal DNA extraction, in principle each DNA extraction method can be used; however, because most methods have been optimized for genomic DNA from leucocytes, we describe here the methods that have been optimized for the extraction of fetal DNA from maternal plasma and validated for this purpose in our laboratories. The use of the QIAamp DSP Virus kit (QIAGEN), the QIAamp DNA Blood Mini kit (QIAGEN), and the Magna Pure LC (Roche) is based on the kit components provided by the respective companies. However, we noticed that the yield of fetal DNA from maternal plasma can be increased when higher volumes are processed or some slight modifications of the protocols provided by the manufacturer are followed. Here, we also describe an in-house method that allows the specific capture of target molecules in an extremely low volume by using magnetic beads and magnetic tips. This method can be either performed by hand, or it can be adapted to a commercially available pipetting workstation.
- Published
- 2008
- Full Text
- View/download PDF
5. Workshop report on the extraction of foetal DNA from maternal plasma.
- Author
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Legler TJ, Liu Z, Mavrou A, Finning K, Hromadnikova I, Galbiati S, Meaney C, Hultén MA, Crea F, Olsson ML, Maddocks DG, Huang D, Fisher SA, Sprenger-Haussels M, Soussan AA, and van der Schoot CE
- Subjects
- Automation, Female, Genetic Testing standards, Humans, Maternal-Fetal Relations, Polymerase Chain Reaction methods, Pregnancy, Prenatal Diagnosis methods, Prenatal Diagnosis standards, DNA blood, DNA isolation & purification, Fetus metabolism, Genetic Testing methods, Mothers
- Abstract
Objective: Cell free foetal DNA (cff DNA) extracted from maternal plasma is now recognized as a potential source for prenatal diagnosis but the methodology is currently not well standardized. To evaluate different manual and automated DNA extraction methods with a view to developing standards, an International Workshop was performed., Methods: Three plasma pools from RhD-negative pregnant women, a DNA standard, real-time-PCR protocol, primers and probes for RHD were sent to 12 laboratories and also to one company (Qiagen, Hilden, Germany). In pre-tests, pool 3 showed a low cff DNA concentration, pool 1 showed a higher concentration and pool 2 an intermediate concentration., Results: The QIAamp DSP Virus Kit, the High Pure PCR Template Preparation Kit, an in-house protocol using the QIAamp DNA Blood Mini Kit, the CST genomic DNA purification kit, the Magna Pure LC, the MDx, the M48, the EZ1 and an in-house protocol using magnetic beads for manual and automated extraction were the methods that were able to reliably detect foetal RHD. The best results were obtained with the QIAamp DSP Virus Kit. The QIAamp DNA Blood Mini Kit showed very comparable results in laboratories that followed the manufacturer's protocol and started with > or = 500 microL plasma. One participant using the QIAamp DNA Blood Midi Kit failed to detect reliably RHD in pool 3., Conclusions: This workshop initiated a standardization process for extraction of cff DNA in maternal plasma. The highest yield was obtained by the QIAamp DSP Virus Kit, a result that will be evaluated in more detail in future studies., (2007 John Wiley & Sons, Ltd)
- Published
- 2007
- Full Text
- View/download PDF
6. Evaluation of prenatal RHD typing strategies on cell-free fetal DNA from maternal plasma.
- Author
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Grootkerk-Tax MG, Soussan AA, de Haas M, Maaskant-van Wijk PA, and van der Schoot CE
- Subjects
- Exons, Female, Genotype, Humans, Polymerase Chain Reaction, Blood Grouping and Crossmatching methods, DNA blood, Fetal Blood immunology, Pregnancy blood, Rh-Hr Blood-Group System genetics
- Abstract
Background: The discovery of cell-free fetal DNA in maternal plasma led to the development of assays to predict the fetal D status with RHD-specific sequences. Few assays are designed in such a way that the fetus can be typed in RHDpsi mothers and that RHDpsi fetuses are correctly typed. Owing to the limited knowledge about the mechanism responsible for the presence of fetal DNA in maternal plasma, precautions in developing prenatal genotyping strategies must be made., Study Design and Methods: Real-time quantitative (RQ)-polymerase chain reaction (PCR) assays were developed for prenatal diagnostic use with cell-free fetal DNA from maternal plasma. An RQ-PCR assay on RHD exon 5 (amplicon 361 bp), negative on RHDpsi, was developed with genomic DNA and evaluated with cell-free fetal DNA. A previously published RHD exon 5 RQ-PCR (amplicon 82 bp) was duplexed with an in-house developed RHD exon 7 RQ-PCR and evaluated with cell-free fetal DNA from pregnant D-RHDpsi+ women., Results: The RHD exon 5 361 bp assay showed on cell-free plasma DNA from D- women carrying a D+ fetus, low amplification levels, resulting in high Ct values and false-negative results. Owing to fragmentation of cell-free plasma DNA, too few DNA stretches of sufficient length (> 360 bp) are present. The RHD exon 5 82 bp and exon 7 RQ-PCR duplex was evaluated with RHDpsi+ cell-free plasma DNA and showed complete specificity and maximal sensitivity., Conclusion: Assays designed for prenatal genotyping should be developed and evaluated on cell-free plasma DNA. Prenatal RHD typing is accurate with the RHD exon 5 82 bp and exon 7 duplex strategy.
- Published
- 2006
- Full Text
- View/download PDF
7. Non-invasive antenatal RHD typing.
- Author
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Van der Schoot CE, Soussan AA, Koelewijn J, Bonsel G, Paget-Christiaens LG, and de Haas M
- Subjects
- Blood Group Incompatibility embryology, Blood Grouping and Crossmatching economics, Cost-Benefit Analysis, Erythroblastosis, Fetal prevention & control, False Negative Reactions, False Positive Reactions, Female, Fetal Blood immunology, Genotype, Humans, Polymerase Chain Reaction, Pregnancy, Prenatal Diagnosis economics, Pseudogenes, Sensitivity and Specificity, Blood Group Incompatibility diagnosis, Blood Grouping and Crossmatching methods, DNA blood, Fetomaternal Transfusion, Prenatal Diagnosis methods, Rh-Hr Blood-Group System genetics
- Abstract
The existence of cell free fetal DNA, derived from apoptotic syncytiotrophoblast, in the maternal circulation has opened new possibilities of non-invasive prenatal diagnosis. Although still some technical problems exists, especially the lack of a generic positive control on the presence of fetal DNA and the aspecific amplification of background maternal DNA, non-invasive prenatal RHD typing has been successfully introduced in several laboratories, especially in Europe. The diagnostic accuracy reaches>99%. In the Netherlands PCR guided administration of antenatal anti-D prophylaxis is cost-effective and nearby. In this review the main characteristics and applications of cell free fetal DNA are discussed, with an emphasis on prenatal RHD genotyping.
- Published
- 2006
- Full Text
- View/download PDF
8. Cell-free fetal DNA is not present in plasma of nonpregnant mothers.
- Author
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Rijnders RJ, Christiaens GC, Soussan AA, and van der Schoot CE
- Subjects
- Blood Cells chemistry, Female, Humans, Male, Plasma, Pregnancy, DNA blood, Fetus, Mothers
- Published
- 2004
- Full Text
- View/download PDF
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