11 results on '"van Wijk, I J"'
Search Results
2. Plasma placenta growth factor levels in midtrimester pregnancies.
- Author
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Tjoa, M L, van Vugt, J M, Mulders, M A, Schutgens, R B, Oudejans, C B, and van Wijk, I J
- Published
- 2001
- Full Text
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3. Enrichment of fetal trophoblast cells from the maternal peripheral blood followed by detection of fetal deoxyribonucleic acid with a nested X/Y polymerase chain reaction.
- Author
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van Wijk, I J, van Vugt, J M, Mulders, M A, Könst, A A, Weima, S M, and Oudejans, C B
- Abstract
Objective: Fetal cells circulate in the maternal blood during early pregnancy. Because these cells are rare, noninvasive prenatal diagnosis from fetal cells can be achieved only after efficient enrichment procedures. Our aim was to develop a two-step enrichment procedure to isolate trophoblast cells from 20 ml of peripheral blood.Study Design: Blood was obtained from pregnant women between 6 and 15 weeks of gestation, before invasive procedures were performed. After enrichment, the success of isolating fetal cells was determined by amplification of Y chromosome sequences.Results: A highly specific X/Y polymerase chain reaction was established, sensitive enough to detect X and Y chromosome-specific sequences in one single cell and in one male among 100,000 female cells. Sex determination by polymerase chain reaction was compared with results from conventional karyotyping. The success rate was 91.7%.Conclusion: Enrichment of trophoblast cells from maternal blood as described here might be useful for early noninvasive prenatal diagnosis. [ABSTRACT FROM AUTHOR]- Published
- 1996
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4. Hypersensitivity of bcr-abl-positive progenitors to hyperthermia in patients with chronic myeloid leukemia.
- Author
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Thijsen, S F T, van Oostveen, J W, Schuurhuis, G J, Theijsmeijer, A P, Oudejans, C B M, van Wijk, I J, Langenhuijsen, M M A C, Ossenkoppele, G J, Thijsen, S F, Oudejans, C B, and Langenhuijsen, M M
- Subjects
ALLERGIES ,MYELOID leukemia ,PROTEIN metabolism ,ANTIGENS ,HEMATOPOIETIC stem cells ,THERMOTHERAPY ,CHRONIC myeloid leukemia - Abstract
In this study, we evaluated the effect of hyperthermia on hematopoietic progenitors from six chronic myeloid leukemia (CML) bone marrow (BM) samples at diagnosis and four peripheral blood stem cell (PBSC) samples from CML patients after stem cell mobilisation. CD34-positive cells, isolated from these samples, were incubated for 2 h at 37, 42 or 43 degrees C and were plated in the colony-forming unit granulocyte-macrophage (CFU-GM) and the long-term culture initiating cell (LTCIC) assay. To evaluate purging, individual colonies from these assays were analyzed for the presence of the bcr-abl gene with interphase fluorescence in situ hybridization (FISH) and/or RT-PCR. BM samples showed a significant higher sensitivity both at the CFU-GM and LTCIC level, after treatment at 42 degrees C, as compared to the control BM samples obtained from healthy volunteers. The four BM samples of CML patients with a low leukocyte number at diagnosis harbored a mixture of bcr-abl-negative and positive colonies and an increase in the percentage of bcr-abl-negative colonies was observed in all cases. CML patients with a high leukocyte count at diagnosis, however, showed only bcr-abl-positive progenitors even after hyperthermia. PBSCs showed a significant higher sensitivity at the LTCIC level but not at the CFU-GM level, after treatment at 42 degrees C, as compared to the control PBSC samples obtained from nonhematologic cancer patients. Molecular analysis of individual colonies demonstrated an increase of bcr-abl-negative progenitors after thermic treatment in two out of three samples. When comparing both stem cell sources, PBSCs showed a decreased thermic sensitivity as compared to the BM samples at the CFU-GM level, whereas at the LTCIC level an increased thermic sensitivity was observed, both for the controls and the CML samples. In conclusion, both for BM and PBSCs samples, CML progenitors are more sensitive to hyperthermia than control cells, especially at the LTCIC level. In agreement with these results, an increase of bcr-abl-negative progenitors in six out of seven samples could be demonstrated either at the CFU-GM level, LTCIC level or both. Hyperthermia should be explored further as a possible purging modality in CML. [ABSTRACT FROM AUTHOR]
- Published
- 1997
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5. [Increase in the number of reported cases of child abuse following adoption of a structured approach in the VU Medical Centre, Amsterdam, in the period 2001-2004].
- Author
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Bleeker G, Vet NJ, Haumann TJ, van Wijk IJ, and Gemke RJ
- Subjects
- Adolescent, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Netherlands, Retrospective Studies, Child Abuse prevention & control, Child Abuse statistics & numerical data, Mandatory Reporting, Patient Care Team
- Abstract
Objective: Description of the characteristics of (suspected) child abuse after the establishment of a Child Abuse Team and the introduction of guidelines on how to deal with child abuse and a standardised registration form for suspicions of child abuse., Design: Retrospective., Method: An inventory and analysis of the available data on the reporting of, approach to and care provided in case of(suspected) child abuse from I January 2oo0 to 30 April 2004 in the VU Medical Centre in Amsterdam, the Netherlands., Results: The Child Abuse Team received 220 reports of suspected child abuse and the number of suspected and confirmed cases of child abuse increased each year. In 58 suspected cases, the suspicions were confirmed on the basis of additional information from the general practitioners or other attending physicians, or conversations with the parents and the child. There were 29 girls and 29 boys; 22 of them were from families with multiple problems. Of these 58 confirmed cases, 31 were reported to the national Advisory Centre for Registration of Child Abuse. In 120 of the 220 suspected cases of child abuse, this suspicion was refuted, while in 42 cases the suspicion could neither be refuted nor confirmed., Conclusion: An increased number of suspected cases of child abuse were reported and confirmed each year following the introduction of a standardised registration form and subsequent analysis by a multidisciplinary team. Broader application of this approach may contribute to improved insight into the prevalence and causes of child abuse.
- Published
- 2005
6. Elevated C-reactive protein levels during first trimester of pregnancy are indicative of preeclampsia and intrauterine growth restriction.
- Author
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Tjoa ML, van Vugt JM, Go AT, Blankenstein MA, Oudejans CB, and van Wijk IJ
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- Birth Weight, Blood Pressure, Case-Control Studies, Female, Fetal Growth Retardation blood, Fetal Growth Retardation physiopathology, Humans, Infant, Newborn, Organ Size, Placenta blood supply, Placenta pathology, Placenta physiopathology, Pre-Eclampsia complications, Pre-Eclampsia physiopathology, Pregnancy, Pregnancy Complications, Cardiovascular physiopathology, C-Reactive Protein metabolism, Fetal Growth Retardation complications, Pre-Eclampsia blood, Pregnancy Complications, Cardiovascular blood, Pregnancy Trimester, First blood
- Abstract
C-reactive protein (CRP) is a marker of tissue damage and inflammation. Maternal levels of CRP are elevated in overt preeclampsia, but there is still debate about its use as a predictive marker for preeclampsia during the first and second trimesters of pregnancy. In this study, we measured CRP levels during the first trimester of pregnancy in women who later developed preeclampsia or gave birth to a growth-restricted baby. In total, 107 women from a low-risk population participated in the study, six women developed preeclampsia and nine gave birth to a growth-restricted baby. Although there is a large overlap in measured CRP levels between the three groups, mean CRP levels were significantly elevated in women who later developed preeclampsia (P=0.031) or delivered a growth-restricted baby (P=0.041) when compared with women from the control group, matched for maternal and gestational age, parity, and gravidity. This study shows that in a low-risk population, CRP levels are already elevated between weeks 10 and 14 in pregnant women who develop preeclampsia or deliver a growth-restricted baby.
- Published
- 2003
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7. The Human Achaete Scute Homolog 2 gene contains two promotors, generating overlapping transcripts and encoding two proteins with different nuclear localization.
- Author
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Westerman BA, Poutsma A, Looijenga LH, Wouters D, van Wijk IJ, and Oudejans CB
- Subjects
- Alleles, Animals, Basic Helix-Loop-Helix Transcription Factors, Cell Line, DNA-Binding Proteins analysis, DNA-Binding Proteins metabolism, Female, Gene Expression, Green Fluorescent Proteins, Humans, Luminescent Proteins genetics, Mice, Placenta chemistry, Pregnancy, Pregnancy Trimester, First, RNA, Messenger analysis, Recombinant Fusion Proteins, Reverse Transcriptase Polymerase Chain Reaction, Species Specificity, Transfection, Cell Nucleus chemistry, DNA-Binding Proteins genetics, Promoter Regions, Genetic, RNA, Messenger genetics, Transcription Factors
- Abstract
Placental development involves control by the basic helix-loop-helix transcription factor Mash2. Transcript analysis of the Human Achaete Scute Homolog 2 (HASH2) mRNA revealed the presence of two overlapping transcripts in first trimester placentae. The two transcripts (2.6 and 1.5 kb) are generated by two promotors which are separated by 1.1 kb, generating transcripts 1 and 2, respectively. Surprisingly, in transcript 1 which shows a broad expression, a second potential coding region, tentatively called Human Achaete Scute Associated Protein (HASAP) was present. Transcript 2 contains the HASH2 encoding region only. Analysis of protein expression from both transcripts by transfection studies with eGFP fusion proteins, revealed that both coding regions are translated from their endogenous translation initiation site and showed that both proteins are transported to the nucleus. HASH2 is distributed throughout the nucleus but the HASAP protein is transported into nuclear compartments, the nucleoli. In addition, the HASAP protein lacks the bHLH domain and bears no homology to known proteins. Moreover, allele-specific RT-PCR showed the human gene not to be subject to imprinting, possibly reflecting the biallelic expression of one of both transcripts. Our data indicate a species-specific difference between mouse and human expression of the Achaete Scute Homolog 2 and suggests a dual function of the human homologue., (Copyright 2001 Harcourt Publishers Ltd.)
- Published
- 2001
- Full Text
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8. Allelic IGF2R repression does not correlate with expression of antisense RNA in human extraembryonic tissues.
- Author
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Oudejans CB, Westerman B, Wouters D, Gooyer S, Leegwater PA, van Wijk IJ, and Sleutels F
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- Alleles, Female, Gene Expression, Genomic Imprinting, Humans, Nuclease Protection Assays, Pregnancy, Pregnancy Trimester, First, RNA, Antisense analysis, RNA, Antisense biosynthesis, Reverse Transcriptase Polymerase Chain Reaction, Substrate Specificity, Transcription, Genetic, Gene Expression Regulation genetics, Placenta metabolism, RNA, Antisense genetics, Receptor, IGF Type 2 genetics
- Abstract
In the mouse, expression of an antisense Igf2r RNA (Air) is correlated with Igf2r repression on the paternal allele. One of the possible models for Igf2r repression could be through promoter competition or through the action of the Air RNA, in, e.g., transcriptional interference or repressor binding. These models predict the conservation of AIR RNA in human samples with monoallelic IGF2R expression and the production of AIR RNA in first-trimester human tissues. However, by strand-specific RT-PCR and by ribonuclease protection assay we have not detected any AIR RNA in first-trimester placental tissue samples, not even in samples that downregulate IGF2R expression in an allele-specific manner. This indicates that in contrast to the mouse, allelic IGF2R repression in the developing human placenta does not correlate with AIR expression., (Copyright 2001 Academic Press.)
- Published
- 2001
- Full Text
- View/download PDF
9. HLA-G expression in trophoblast cells circulating in maternal peripheral blood during early pregnancy.
- Author
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van Wijk IJ, Griffioen S, Tjoa ML, Mulders MA, van Vugt JM, Loke YW, and Oudejans CB
- Subjects
- Antibodies, Monoclonal, Centrifugation, Density Gradient, Chromosome Aberrations, Female, HLA Antigens blood, HLA-G Antigens, Histocompatibility Antigens Class I blood, Humans, Immunohistochemistry, Immunophenotyping, In Situ Hybridization, Fluorescence, Pregnancy, Prenatal Diagnosis methods, Sex Determination Analysis, Trophoblasts cytology, Trophoblasts metabolism, HLA Antigens biosynthesis, Histocompatibility Antigens Class I biosynthesis, Pregnancy Trimester, First immunology, Trophoblasts immunology
- Abstract
Objective: The aim of this study was to assess the use of circulating trophoblast cells in maternal peripheral blood for noninvasive prenatal diagnosis of numeric chromosomal aberrations., Study Design: A combined procedure for immunocytochemical identification and deoxyribonucleic acid fluorescence in situ hybridization was used after a single enrichment step consisting of density gradient centrifugation. A specific HLA-G monoclonal antibody was used in combination with X and Y chromosome specific probes in deoxyribonucleic acid fluorescence in situ hybridization to confirm fetal identity of cells bearing HLA-G in the case of a male fetus., Results: We detected fetal trophoblast cells expressing HLA-G in maternal blood starting at 9 weeks' gestation. In addition to fetal sex prediction with X and Y chromosome-specific probes, fetal aneuploidy was confirmed in peripheral blood from a pregnancy complicated by trisomy 21., Conclusion: Although the numbers of fetal cells were extremely low, the proof of concept was demonstrated. Early noninvasive prenatal screening for numeric chromosomal abnormalities with fetal trophoblast cells is feasible.
- Published
- 2001
- Full Text
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10. Detection of apoptotic fetal cells in plasma of pregnant women.
- Author
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van Wijk IJ, de Hoon AC, Jurhawan R, Tjoa ML, Griffioen S, Mulders MA, van Vugt JM, and Oudejans CB
- Subjects
- DNA blood, Female, Fetus metabolism, Humans, In Situ Hybridization, Fluorescence, Male, Polymerase Chain Reaction, Pregnancy, Prenatal Diagnosis methods, Apoptosis, Fetus cytology
- Published
- 2000
11. Multiparameter in situ analysis of trophoblast cells in mixed cell populations by combined DNA and RNA in situ hybridization.
- Author
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Van Wijk IJ, Van Vugt JM, Könst AA, Mulders MA, Nieuwint AW, and Oudejans CB
- Subjects
- DNA Probes, HLA Antigens analysis, HLA-G Antigens, Histocompatibility Antigens Class I analysis, Humans, In Situ Hybridization, Luminescent Measurements, Microscopy, Fluorescence, RNA Probes, Trophoblasts cytology, DNA analysis, Prenatal Diagnosis methods, RNA, Messenger analysis, Trophoblasts chemistry
- Abstract
We developed a non-radioactive assay for simultaneous detection of cytoplasmic mRNA and nuclear genomic DNA in fetal trophoblast cells by sequential in situ hybridization. Trophoblast-specific mRNA is detected with a digoxigenin-labeled RNA probe complementary to HLA-G, followed by visualization through the generation of stable contrast-rich DAB/Ni complexes. Genomic target DNA is subsequently visualized in labeled cells by fluorescent in situ hybridization using biotin-labeled chromosome-specific DNA probes. Simultaneous visualization of both targets is made possible using a fluorescence microscope with FITC filter and conventional brightfield light. This method allows detection of trophoblast cells within a mixed cell population and, at the same time, analysis of chromosome anomalies in the trophoblast cells identified. For prenatal diagnosis of fetal cells enriched from maternal peripheral blood during pregnancy, this multiparameter in situ analysis of immobilized fetal trophoblast cells will be very useful.
- Published
- 1995
- Full Text
- View/download PDF
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