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Biomedical subjects

E P Arnoldus

Publications and source records attributed to E P Arnoldus.

18 recordsLinked to original sources
PubMed1998

Prolonged coma and severely attenuated EEG after a single seizure.

A 63-year-old woman presented with a comatose state after a fall. Results of cranial computed tomography (CT) and magnetic resonance imaging (MRI) scans were normal. An EEG recorded 5 h after admission was very severely attenuated and slowed. Consciousness and EEG were improved the next day. No cause was detected initially. After sleep deprivation, the patient had a generalized seizure followed by a similar coma and EEG. Even a single seizure may cause a prolonged coma with a very severely attenuated and slowed EEG.

Accidental Falls↗
PubMed1994

Familial anaplastic ependymoma: evidence of loss of chromosome 22 in tumour cells.

A family with anaplastic ependymomas, histologically verified in three cases and neuroradiologically suggested in a fourth, is presented. Two healthy brothers both had two affected sons. All four male patients were younger than 5 years at the time of diagnosis. Two boys died before the age of 3 years. Genotype analysis (with polymorphic DNA markers for chromosome 22 and interphase cytogenetic analysis) of one of the tumours showed a subpopulation of tumour cells with monosomy of (part of) chromosome 22. Non-neoplastic cells of this patient showed a normal karyotype. These findings give further evidence for the role of a tumour suppressor gene on chromosome 22 in the pathogenesis of familial ependymal tumours.

Brain Neoplasms↗
PubMed1992

Interphase cytogenetic analysis of gliomas.

Interphase cytogenetics is the application of nonradioactive in situ hybridization with chromosome-specific DNA probes to interphase nuclei. The possibilities and limitations of this new technique for the study of chromosomal aberrations in gliomas are discussed.

Brain Neoplasms↗
PubMed1992

Interphase cytogenetics: a new tool for the study of genetic changes in brain tumors.

Interphase cytogenetics is the application of nonradioactive in situ hybridization with chromosome-specific DNA probes to interphase nuclei. In this study, interphase cytogenetics was used to investigate 66 primary brain tumors (33 gliomas, 30 meningiomas, and three medulloblastomas) for numerical chromosomal aberrations of chromosomes 1, 6, 7, 10, 11, 17, 18, X, and Y. Of the 33 gliomas (17 astrocytomas grades II, III, and IV, five oligoastrocytomas, seven oligodendrogliomas, and four ependymal tumors), 22 were near diploid, while the remaining 11 showed a significant triploid or tetraploid component. The predominant specific aberrations in gliomas were an over-representation of chromosome 7 (13 cases) and an under-representation of chromosome 10 (16 cases). These changes were observed in grade III and grade IV astrocytomas, as well as in oligodendrogliomas. Other frequent numerical changes were a gain of chromosome 17 (six cases) and a loss of chromosome 18 (seven cases). This loss of chromosome 18 seemed relatively specific for gliomas with an oligodendroglial component (six cases). Only two of 33 gliomas displayed no genetic abnormality with the probes used. Seven patients with astrocytomas died of their brain tumor during the clinical follow-up period. Their astrocytomas did not show a different chromosomal constitution compared to the other gliomas. For the meningiomas, the probe panel was extended with a probe specific for chromosome 22. Loss of chromosome 22 was obvious in 21 of the 30 meningiomas, and was the sole abnormality in 11 meningiomas; in the other 10, this loss was associated with other chromosomal changes. Five of these tumors with additional aberrations were recurrent or atypical meningiomas. It is suggested that interphase cytogenetics can contribute to a better understanding of the biological behavior of these tumors and possibly result in better insights into prognosis and strategies for therapy.

Adult↗
PubMed1991

Interphase cytogenetics of brain tumors.

The development and application of a procedure for interphase cytogenetics on brain tumor material is described. Nuclei isolated from freshly removed brain tumor tissue were investigated for chromosomal aberrations by nonradioactive in situ hybridization with a panel of chromosome-specific probes. The panel consisted of nine satellite DNA probes specific for the centromeric regions of chromosomes 1, 6, 7, 10, 11, 17, 18, X, and Y. For each probe, the number of hybridization signals per cell was determined in 200 nuclei. It was inferred from the hybridization results that in 11 gliomas (seven astrocytomas grade II-IV, three oligodendrogliomas, and one ependymoma) the numerical aberrations were gains of chromosomes 1 (once), 7 (twice), 10 (once), 11 (twice), and X (twice); losses of chromosomes 1 (once), 10 (twice), 17 (twice), and Y (once); and complete tetraploidy (once). Among the 18 investigated meningiomas monosomy 18 and trisomy 17 were observed once and twice, respectively. An additional hybridization with a cosmid probe for the BCR gene on 22q11 indicated monosomy 22q in 11 meningiomas. These results show the value of interphase cytogenetics for the analysis of solid tumors for which it is relatively difficult to obtain sufficient metaphases of good quality for conventional cytogenetics.

Adult↗
PubMed1991

Polymerase chain reaction for early detection of HSV-DNA in cerebrospinal fluid: an experimental mouse encephalitis study.

A series of experiments was carried out using a mouse HSV-1 encephalitis model for detecting HSV-DNA in CSF by the polymerase chain reaction (PCR). The results were correlated with the time period after corneal inoculation, clinical signs and symptoms, and progression of infection in brain tissue (antigen detection and histopathology), and were compared with virus isolation by spin-amplified culture (SAC/IF). The PCR proved to be superior to SAC/IF, both with respect to early detection and the percentage of positive samples. The results of PCR did not correlate with signs of disease, nor with the interval post-inoculation. A correlation with the spread of HSV within the brain tissue was found. The possible pathways for virus spread from brain parenchyma to the CSF as well as a possible explanation for the low amounts of virus and viral-DNA within the CSF are discussed.

Animals↗
PubMed1991

Feasibility of in situ hybridisation with chromosome specific DNA probes on paraffin wax embedded tissue.

The feasibility was studied of in situ hybridisation using chromosome specific DNA probes on paraffin wax embedded normal and malignant tissues from different organs. Both isolated nuclei and 5 microns sections were used in in situ hybridisation experiments with biotinylated repetitive DNA probes specific for the centromeric regions of chromosomes 1 and 17. The hybridisation results were visualised with peroxidase-diaminobenzidine. The optimal pretreatments with sodium thiocyanate and pepsin were experimentally defined for the different tissues. Although interphase cytogenetics on paraffin wax embedded tissue is possible, the results indicate that it has its limitations, compared with investigations on fresh tumour tissue.

Chromosomes, Human, Pair 1↗
PubMed1991

Interphase cytogenetics reveals somatic pairing of chromosome 17 centromeres in normal human brain tissue, but no trisomy 7 or sex-chromosome loss.

Nuclei isolated from normal human brain tissue, collected from six autopsies, were hybridized with a panel of nine satellite DNA probes specific for the centromeric regions of chromosomes 1, 6, 7, 10, 11, 17, 18, and the X and Y chromosomes. The results did not confirm the recently reported trisomy 7 and loss of sex chromosomes observed in metaphases obtained from normal brain tissue after short-term cultures; however, cells of all six brains displayed somatic pairing of the chromosome 17 centromeres in approximately 50% of the nuclei.

Brain↗
PubMed1991

Detection of herpes simplex virus in the ependyma of experimentally infected mice.

Forty-five Swiss albino mice were inoculated with HSV-1 (strain McKrae) by the corneal route. The spread of HSV to the brain stem and the ventricular ependyma was investigated. The polymerase chain reaction (PCR) was used to detect HSV-DNA in the CSF during the course of infection. The ependyma of the third and fourth ventricle and the central canal contained viral antigen at a late stage of infection in up to 60% of mice. At this stage we found that many animals gave a positive PCR in the CSF although no antigen could be detected in the ependymal cells. The presence or absence of antigen containing cells could not be related to detection of HSV-DNA in the CSF. The results show that infection of the ventricular wall is not important for the spread of HSV to the CSF.

Animals↗
PubMed1990

Detection of the Philadelphia chromosome in interphase nuclei.

Double fluorescence in situ hybridization was used to detect Philadelphia (Ph) chromosomes in interphase nuclei and metaphases of patients with chronic myeloid leukemia. Application of cosmid probes for 3' ABL and 5' BCR sequences gave better results than libraries for chromosomes 9 and 22. The present approach may provide an alternative method for monitoring minimal residual disease in Ph+ CML patients.

Cosmids↗
PubMed1989

Somatic pairing of chromosome 1 centromeres in interphase nuclei of human cerebellum.

Interphase nuclei isolated from paraffin-embedded tissue of four normal brains were hybridized with biotinated repetitive DNA probes specific for the (peri)centromeric regions of chromosomes 1 and 7. Hybridization results were visualized with a peroxidase-DAB system after which the number of specific signals per nucleus was counted using bright field microscopy. Using the probe specific for chromosome 7 (p7t1), both the cerebral and the cerebellar samples showed 2 spots in 82% and 83%, respectively, of the nuclei. In situ hybridization with the chromosome 1 probe (pUC1.77) showed two spots in 69% of the cerebral nuclei. In cerebellar samples, hybridization with pUC1.77 resulted in only one large spot per nucleus in 82% of the cells. The average spot size in nuclei with one signal was about 1.6 times as large as that in nuclei with two signals. These observations suggest that the single large spot in the cerebellar cells is not the result of monosomy of chromosome 1 but that it reflects somatic pairing of the two chromosome 1 centromeres. Based on the size and the fraction of nuclei with one large spot, the small granular neuron is the most likely candidate. The difference between cerebral and cerebellar samples indicates that this somatic pairing of chromosome 1 is a cell-type-dependent phenomenon.

Cell Nucleus↗
PubMed1989

Polymerase chain reaction and viral culture techniques to detect HSV in small volumes of cerebrospinal fluid; an experimental mouse encephalitis study.

A technique is described for the detection of HSV-DNA in very small volumes (5-10 microliters) of cerebrospinal fluid (CSF). The method was evaluated in CSF samples of 4-6-week-old mice inoculated with HSV-1 via the corneal route. The sensitivity of the PCR assay was compared with results of spin-amplified viral culture with immunofluorescent visualization (SAC/IF), routine viral culture (RVC) and radioactive dot-blot hybridization (DBA) in CSF samples obtained from other mice. The results show the PCR to be superior over the other techniques: infectious virus or viral DNA in CSF was demonstrated by PCR, SAC/IF, RVC and DBA in 68, 55, 20 and 2.5%, respectively. These results show the feasibility of the PCR for a rapid, non-invasive diagnosis of human HSV-encephalitis.

Animals↗
PubMed1989

Diagnosis of progressive multifocal leucoencephalopathy by hybridisation techniques.

In situ hybridisation with acetyl-aminofluorene (AAF) and 35S-labelled DNA probes for polyomaviruses, was used to detect JC virus DNA in brain necropsy material in a patient with progressive multifocal leucoencephalopathy (PML). In a second patient PML was diagnosed from a brain necropsy specimen using the same technique. The main infected cell type were oligodendrocytes; dot hybridisation was used to estimate the number of viral copies in each infected cell. Southern blot hybridisation for further analysis of the viral genome was also carried out. In situ hybridisation with non-radioactive labelled polyomavirus DNA provides a simple and specific means for studying viral DNA in formaldehyde fixed tissue sections from patients with suspected PML. Even in small biopsy samples hybridisation results can be correlated with standard histopathological, immunocytochemical, and electron microscopic findings.

Adult↗