195 results on '"Molenaar WM"'
Search Results
2. Multidrug resistance proteins in primary and metastatic soft-tissue sarcomas: Down-regulation of P-glycoprotein during metastatic progression
- Author
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Komdeur, R, Molenaar, WM, Zwart, N, Hoekstra, HJ, Van den Berg, E, and Van der Graaf, WTA
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LYMPH-NODE METASTASES ,EUROPEAN ORGANIZATION ,multidrug resistance ,CHILDHOOD ,metastasis ,soft-tissue sarcomas ,VAULT PROTEIN ,MRP1 ,HUMAN COLON-CARCINOMA ,CHEMOTHERAPY ,BONE ,CANCER ,GENE-EXPRESSION - Abstract
Background: Chemotherapy sensitivity of soft-tissue sarcomas (STS) is limited, which may be due to multidrug resistance (MDR). MDR is associated with expression of P-glycoprotein (P-gp), Multidrug Resistance-associated Protein I (MRP1) and Lung Resistance-related Protein (LRP). It is unknown whether in STS metastasis is more resistant than the primary counterpart. Materials and Methods: In 35 chemonaive STS and their metastases (86% chemonaive), MDR proteins were immunohistochemically assessed. Eleven metastases presented synchronously, 24 metachronously. Expression was scored-positive (>5% positive tumour cells) or negative. Results: P-gp was positive in 31/34primaries (91%), versus 22132 metastases (69%) (p=0.005). This difference was significant for metachronous metastases (p = 0.008). MRP1 was positive in 18132 primaries (56%) and 22133 metastases (670%). MRP1 was more expressed in synchronous metastases than primaries (p = 0.047), but for the overall group this significance disappeared. LRP expression did not differ: 27/34 primanes (80%), versus 28134 metastases (82010). Conclusion: P-V, MRP1, LRP expression in the primary tumours was high. Metastatic progression did not coincide with MDR-protein up-regulation.
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- 2004
3. Multidrug resistance proteins in rhabdomyosarcomas - Comparison between children and adults
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Komdeur, R, Klunder, J, van der Graaf, WTA, van den Berg, E, de Bont, ESJM, Hoekstra, HJ, Molenaar, WM, Damage and Repair in Cancer Development and Cancer Treatment (DARE), and Stem Cell Aging Leukemia and Lymphoma (SALL)
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DRUG-RESISTANCE ,genetic structures ,multidrug resistance-associated protein 1 ,P-GLYCOPROTEIN ,GENE FUSIONS ,CLASSIFICATION ,CARCINOMA SW-620 CELLS ,SARCOMAS ,age ,INTERGROUP RHABDOMYOSARCOMA ,lung resistance-related protein ,ALVEOLAR RHABDOMYOSARCOMA ,CHILDHOOD RHABDOMYOSARCOMA ,lipids (amino acids, peptides, and proteins) ,rhabdomyosarcoma ,PEDIATRIC RHABDOMYOSARCOMA - Abstract
BACKGROUND. Pediatric rhabdomyosarcomas (RMS) have a more advantageous prognosis after multimodality treatment compared with adult RMS, which might be related to a decreased sensitivity to chemotherapy in adults. Resistance to chemotherapy might be conveyed by the multidrug resistance (MDR) -associated proteins P-glycoprotein (P-gp), multidrug resistance -associated protein 1 (MRP1), and lung resistance-related protein (LRP). It was therefore suggested that these proteins were expressed differently in pediatric and adult patients. METHODS. The expression of P-gp, MRP1, and LRP was assessed immunohistochemically in 45 specimens of untreated RMS: 29 were obtained from children younger than 16 years old and 16 were obtained from adults. All children had an 2 embryonal or botryoid RMS. Among the adults, there were 10 embryonal, 3 alveolar, and 3 pleomorphic RMS. Samples were scored as negative or positive 3 according to the percentage of immunoreactive tumor cells: 0.5 (1-5%), 1 (5-25%), 2 (26-50%), 3 (51-75%), or 4 (>75%). 4 RESULTS. Expression of LRP was more pronounced in embryonal and pleomorphic RMS in adults compared with RMS in children. In addition, LRP expression correlated with age at diagnosis. Alveolar RMS had remarkably low LRP expression. Expression of P-gp and MRP1 did not differ significantly between children and adults. CONCLUSIONS. In this series of embryonal and pleomorphic RMS, an increased LRP expression was observed in adults, which may explain their worse response to chemotherapy reported in other studies. In alveolar RMS, a low LRP expression was observed, suggesting that other mechanisms are responsible for the resistant phenotype in most of these tumors. (C) 2003 American Cancer Society.
- Published
- 2003
4. Proliferation and apoptosis in long-term surviving low grade gliomas in relation to radiotherapy
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Heesters, MAAM, Koudstaal, J, Go, KG, and Molenaar, WM
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p53 ,apoptosis ,BCL-2 ,CELL-LINES ,MIB-1 ,FAMILY PROTEIN EXPRESSION ,HUMAN BRAIN-TUMORS ,ASTROCYTIC TUMORS ,P53 GENE ,glioma ,RADIOSENSITIVITY ,IMMUNOREACTIVITY ,OLIGODENDROGLIOMAS ,neoplasms ,radiotherapy ,IN-VIVO - Abstract
Identification of patients with a low grade glioma with a long-term recurrence-free survival is of clinical value as radiotherapy can be postponed until recurrence. The recurring glioma may increase in malignancy compared to the original tumor, which is possibly related to radiotherapy. We studied proliferation by counting mitotic figures and by MIB-1 labeling, apoptosis by TUNEL and expression of proteins related to cell cycle regulation by immunohistochemical analysis of p53, p21, bcl-2 and bax expression in 48 low grade gliomas. Astrocytomas (A, n = 14) and oligodendrogliomas (O, n = 4) with a recurrence-free survival of more than 9 years after surgery had a significantly lower p53 index compared to A (n = 18) and O (n = 12) with a histopathologically documented recurrence. Additionally, the recurrence-free A had a higher p21 index. No significant differences were observed in MIB-LI, TUNEL-LI, bcl-2 and bax expression. Initially low grade gliomas and their corresponding recurrences were compared (n = 30). In the gliomas without radiotherapy (n = 15), no differences in mitotic rate, TUNEL-LI, p53, p21, bcl-2 and bax expression were found between primary tumors and their recurrences. Only MIB-LI was higher in the recurrent tumors. In the gliomas with radiotherapy (n = 15) no differences were detected in these parameters between the original tumor and the recurrent tumor except for a higher number of mitoses in the recurrent tumors. We conclude that low grade gliomas with a long-term recurrence-free survival were characterized by a low p53 protein expression and, in the case of A, a higher p21 index. We found no evidence that radiotherapy is involved in changes of proliferation, apoptosis or expression of proteins related to cell cycle regulation in recurring gliomas.
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- 2002
5. Infantile and adult testicular germ cell tumors: a different pathogenesis?
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van Echten, J, Timmer, A, van der Veen, AY, Molenaar, WM, de Jong, B, and Reproductive Origins of Adult Health and Disease (ROAHD)
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endocrine system ,ENDODERMAL SINUS TUMORS ,PEDIATRIC-ONCOLOGY-GROUP ,TESTIS ,ABNORMALITIES ,CHILDHOOD ,PLOIDY ,IN-SITU HYBRIDIZATION ,INSITU - Abstract
Most adult testicular germ cell tumors have a characteristic chromosomal abnormality that is an isochromosome 12p [i(12p)]. Furthermore. these tumors are characterized by a chromosome number in the triploid range and gains and losses of (parts of) specific chromosomes. Cytogenetic investigation of three cases of infantile testicular germ cell tumors, all diagnosed as yolk sac tumors. revealed highly abnormal karyotypes. We found one case to be diploid, the other two cases were in the hypertriploid/hypotetraploid range. Structural abnormalities of chromosomes 1, 3, and 6 were recurrent and no i(12p) was found, Our results. together with data front the literature. suggest that infantile and adult testicular germ cell tumors have a different origin and pathogenetic pathway. Abet-rations of chromosomes 1, 3, and 6 may play an important role in the pathogenesis of infantile testicular yolk sac tumors. (C) 2002 Elsevier Science Inc. All rights reserved.
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- 2002
6. Clinico-pathological data and prognostic factors in completely resected AJCC stage I-III liposarcomas
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Nijhuis, PHA, Sars, PRA, Plaat, Boudewijn, Molenaar, WM, Sluiter, WJ, Hoekstra, HJ, Damage and Repair in Cancer Development and Cancer Treatment (DARE), and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
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MYXOID LIPOSARCOMA ,treatment ,DEDIFFERENTIATION ,survival ,SOFT-TISSUE SARCOMA ,INTRAOPERATIVE RADIOTHERAPY ,liposarcoma ,soft tissue sarcoma ,WELL-DIFFERENTIATED LIPOSARCOMA ,RADIATION ,epidemiology ,EXTREMITY LIPOSARCOMA ,FOLLOW-UP ,RECURRENCE ,ROUND-CELL LIPOSARCOMA - Abstract
Background: In general, although biological behavior and prognosis of liposarcomas (LPS) are more favorable compared with most other soft tissue sarcomas (STS), prognosis can vary widely depending on tumor characteristics, especially histological subtype and tumor grade. Patients and Methods: All consecutive, completely resected stage I-III LPS (as determined by the American Joint Committee on Cancer staging guidelines), treated at the Groningen University Hospital from 1977-2000, were analyzed. Results: A total of 69 patients, 35 males and 34 females, median age 51 (range 11-80) years, were reviewed. After a median follow-up of 71 (range 5-231) months, the overall local recurrence and metastasis rate at five years after diagnosis were 27% and 16%, respectively. Retroperitoneal localization was a significant negative prognostic factor regarding local recurrence; dedifferentiation, grade II-III, and deep location regarding distant metastasis; and dedifferentiation, grade II-III, stage II-III, size >20 cm and non-radical resection regarding survival. Conclusions: LPS have a relatively mild biologic behavior, with the exception of very large, deeply located, dedifferentiated and/or grade II-III LPS. Radical resection is important for disease-specific survival. LPS have a relatively mild biologic behavior, with the exception of very large, deeply located, dedifferentiated and/or grade II-III LPS.
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- 2000
7. Recurrent astrocytoma in a child: A report of cytogenetics and TP53 gene mutation screening
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Dam, A., Fock, Johanna M., Hayes, VM, Molenaar, WM, van den Berg, E, and Faculteit Medische Wetenschappen/UMCG
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P53 ,ABNORMALITIES ,CHROMOSOME-1 ,PROTEIN ,NERVOUS-SYSTEM TUMORS ,PEDIATRIC BRAIN-TUMORS ,LOW-GRADE ASTROCYTOMAS ,TERM FOLLOW-UP ,OVEREXPRESSION ,DNA - Abstract
An 8-year-old girl presented with a cerebral tumor and 3 recurrences within 15 months, The primary tumor was a low-grade astrocytoma, but the recurrences showed progressively malignant phenotypes with increasing mitotic activity and MIB-1 labeling indices. Radiotherapy was given between the first and the second recurrences. Cytogenetic analysis of the first and the second recurrences showed abnormal karyotypes. There seemed to be 2 common breakpoints in these 2 recurrences. TP53 gene mutation screening, using comprehensive denaturing gradient gel electrophoresis, revealed among others a possibly causative mutation of exon 5 in 3 of 4 tumor samples, The meaning of TP53 mutations in low-grade astrocytomas is still unclear, but the highly abnormal karyotypes, which are unusual in these tumors, probably provide genetic evidence for the unexpected aggressive behavior of the tumor in this patient.
- Published
- 2000
8. Imaging of soft-tissue tumors using L-3-[iodine-123]iodo-alpha-methyl-tyrosine single photon emission computed tomography: Comparison with proliferative and mitotic activity, cellularity, and vascularity
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Jager, PL, Plaat, B.E.C., Molenaar, WM, de Vries, EGE, Vaalburg, W, Piers, DA, Hoekstra, HJ, Guided Treatment in Optimal Selected Cancer Patients (GUTS), and Damage and Repair in Cancer Development and Cancer Treatment (DARE)
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BRAIN-TUMORS ,PET ,IODINE-123-ALPHA-METHYL TYROSINE ,FDG ,SPECT ,PROGNOSTIC FACTORS ,AMINO-ACID-TRANSPORT ,CANCER ,ALPHA-METHYL TYROSINE ,SARCOMA - Abstract
The radiolabeled amino acid L-3.[I-123]-iodo-alpha-methyl-tyrosine (IMT) is a new tumor tracer that accumulates in many tumors and is suitable for single photon emission computed tomography (SPECT) imaging. Using IMT SPECT, we studied 32 patients with a soft-tissue tumor suspected to be a soft-tissue sarcoma to determine whether: (a) tumors can be visualized; (b) benign and malignant lesions can be distinguished; and (c) IMT uptake is related to tumor grade and proliferation. Whole-body imaging was performed 15 min after administration of 300 MBq IMT, biopsy, or resection 1-2 weeks later, IMT uptake was quantified using a region-of-interest method resulting in tumor:background (T:B) ratios. These were compared with tumor grade, mitotic index, tumor cellularity, vascularity, and the Ki-67 proliferation index. Eleven patients had a benign tumor, and 21 patients had a soft-tissue sarcoma, Six benign tumors demonstrated minor IMT uptake, and five lipomas had no uptake. All malignant tumors had high uptake and were clearly visualized. T:B ratios in malignant tumors (3.83 +/- 1.16) were higher (P
- Published
- 2000
9. The 16p11 breakpoint in myxoid liposarcomas might affect the expression of the LRP gene on 16p11.2 encoding the multidrug resistance associated major vault protein
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Plaat, Boudewijn, Molenaar, WM, Sagrudny, J, Bohle, RM, Mastik, MF, Hoekstra, HJ, Van der Graaf, WTA, Hollema, H, van den Berg, E, Targeted Gynaecologic Oncology (TARGON), Damage and Repair in Cancer Development and Cancer Treatment (DARE), and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
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DRUG-RESISTANCE ,LRP ,P-GLYCOPROTEIN ,FUS-CHOP ,AMPLIFICATION ,ACUTE MYELOID-LEUKEMIA ,t(12 ,16) ,CHEMOTHERAPY ,TUMORS ,CANCER ,SOFT-TISSUE SARCOMAS ,major vault ,liposarcoma ,PROGNOSTIC-SIGNIFICANCE ,lipids (amino acids, peptides, and proteins) ,CHROMOSOME-16 - Abstract
Background Chromosome breakage could influence the expression of genes. This has been noticed in specific cases of acute myeloid leukaemia, where the 16p13 breakpoint affects the expression of the multidrug resistance related protein (MRP). Myxoid liposarcomas (LPS) are characterized by the t(12; 16)(q13; p11), which leads to the formation of a FUS-CHOP fusion transcript. This study investigates the relationship between the cytogenetically detected breakpoint 16p11 in myxoid LPS, the presence of the FUS-CHOP fusion transcript in nonmyxoid LPS and the expression of the lung resistance major vault protein (LRP) gene on 16p11.2. Materials and methods Of 16 cases with a diagnosis of a (possible) liposarcoma with an abnormal karyotype, fresh frozen tumour material was available for immunohistological detection of LRP. Cases without a cytogenetically detected t(12; 16)(q13; p11), were analyzed for the presence of a FUS-CHOP fusion transcript by RT-PCR. Results In all 9 myxoid LPS a t(12; 16)(q13; p11) was found and LRP expression was absent or low. In none of the remaining 7 cases was a FUS-CHOP fusion transcript found, and four tumours were LRP positive (P = 0.02). LRP expression in myxoid LPS (mean: 1.3%) was lower (P = 0.07) than in the nonmyxoid tumours (mean: 35.7%). Conclusions These observations indicate a relation between the t(12; 16)(q13; p11), leading to a FUS-CHOP fusion transcript in myxoid LPS, and the low or absent expression of the LRP-gene located on 16p11.2.
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- 2000
10. Synovial chondromatosis of the wrist and hand - a case report
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Rompen, JC, Ham, SJ, Molenaar, WM, and van Horn, [No Value]
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- 1999
11. AgNOR staining may reflect the growth potential of pilocytic astrocytomas
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Dirven, CMF, Koudstaal, J, Mooij, JJA, and Molenaar, WM
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EXPRESSION ,MALIGNANCY ,proliferation ,PROTEIN ,GLIOBLASTOMA-MULTIFORME ,GLIOMAS ,image processing ,NUCLEOLAR ORGANIZER REGIONS ,HUMAN BRAIN-TUMORS ,nucleolus organizer region pathology ,CELLS ,RAT ,pilocytic astrocytoma ,residual tumor ,silver staining - Abstract
The value of AgNOR staining as a tumor biological marker was tested in 26 children with pilocytic astrocytomas (20) and fibrillary astrocytomas (6). All patients were surgically treated and then followed up by periodic MRI or CT scans. Follow-up ranged from 8 to 84 months, with a mean of 44 months. AgNOR expression was determined by using semi-automated computer-assisted surface area measurements. AgNOR values ranged from 1.4 to 81.4 mu m(2) per cell, with a mean of 26.6 and a median of 15.2. The median value was taken as a "cut-off" score separating two groups of patients with low and high AgNOR scores. Of the 13 patients in the low scoring group, 8 had total resections without recurrence, 3 had stable residual tumors, I had regressing residual tumor after irradiation and 1 had a recurrence 5 years after neuroradiologically complete resection of a fibrillary astrocytoma. In the group with high AgNOR scores only 2 patients had total resections without recurrence; 5 had stable residual tumors and 6 had residual tumors that showed progression, all within 1 year after surgery. Among the patients with classic juvenile pilocytic astrocytomas of the cerebellum 7 had residual tumor, which progressed in 2 patients, both of whom had high AgNOR scores. Among 7 patients with optic/hypothalamic tumors the 3 with rapidly progressing tumors all had very high AgNOR scores. The determination of AgNOR expression might be helpful in selection of patients with residual tumor after surgery, who may benefit from additional chemotherapy or (stereotactic) radiation therapy.
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- 1999
12. High frequency of TP53 mutations in juvenile pilocytic astrocytomas indicates role of TP53 in the development of these tumors
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Hayes, VM, Dirven, CMF, Verlind, E, Molenaar, WM, Mooij, JJA, Hofstra, RMW, Buys, CHCM, and Dam, A.
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HUMAN BRAIN-TUMORS ,P53 GENE-MUTATIONS ,CONFORMATION POLYMORPHISM ANALYSIS ,CHILDHOOD ,PROTEIN ,DNA ,neoplasms ,SUPPRESSOR GENE ,LOW-GRADE - Abstract
In adults, the TP53 tumor suppressor gene is frequently mutated in astrocytic brain tumors which is supposed to represent an early event in their development. In juvenile pilocytic and low-grade astrocytomas, however, TP53 mutations have until now been reported as rare, which has led to the suggestion that these tumors may follow a different molecular pathogenesis with an involvement of genes other than TP53. Our analysis of 20 pilocytic and two low-grade astrocytomas of childhood, based on a comprehensive denaturing gradient gel electrophoresis (DGGE) mutation detection assay of the entire coding region, including all splice site junctions of TP53, showed mutations considered as causative in 7 of the 20 (35%) pilocytic astrocytomas and in one of the two low-grade astrocytomas. Our finding is significantly different from the mutation frequency of 1.3% (2/155) previously reported for these tumor types. This may be attributed to the mutation detection system used, which also detects mutations occurring outside the evolutionary conserved region of TP53. Our results suggest that, contrary to the present notion, TP53 mutations may well play a role in the development of juvenile astrocytomas. Furthermore, no mutations were found in tumors of patients with progression of residual tumor after postoperative follow-up. This suggests that TP53 mutations may be associated with less aggressive forms of juvenile astrocytomas, analogous to the situation in adult astrocytomas.
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- 1999
13. Translocation (11;22)(q24;q12) in a small cell tumor of the thigh in a 2-year-old boy: Immunohistology, cytogenetics, molecular genetics, and review of the literature
- Author
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Mastik, MF, Molenaar, WM, Plaat, Boudewijn, de Graaf, S.S., Hogendoorn, PCW, van der Hout, AH, van den Berg, E, Damage and Repair in Cancer Development and Cancer Treatment (DARE), and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Subjects
EXPRESSION ,CHIMERIC TRANSCRIPTS ,pediatric sarcoma ,t(11 ,22) ,ANTIGEN ,NEUROECTODERMAL TUMORS ,Ewing's sarcoma ,genetics ,FUSION GENE ,EWS/FLI1 ,BONE ,EWINGS-SARCOMA - Abstract
A case of a 2-year-old boy with a palpable mass in the left thigh is presented. Incisional biopsy was performed and subsequent histopathological examination revealed an infiltrative tumor composed of relatively large cells. The tumor cells were immunoreactive for vimentin and keratin, but not for desmin or smooth muscle actin. Cytogenetic analysis showed a 46,XY,t(11;22)(q24;q12) karyotype. The translocation (11;22)(q24;q12) is said to be characteristic for the family of Ewing's sarcoma and related tumors. As a result of the t(11;22)(q24;q12) the EWS gene on chromosome 22q12 joins the 3' part of FLI-1 gene on chromosome 11q24, which encodes a member of the ets family of transcriptional regulators. Using reverse transcription polymerase chain reaction (RT-PCR) a corresponding EWS-FLI-1 fusion product was detected. Additional immunohistological staining for p30/p32MIC2, which is suggestive, but not specific for Ewing's sarcoma, appeared to be weakly positive. In the current case a diagnosis of Ewing's sarcoma was considered unlikely, because of the location of the tumor and the immunohistological profile. Nevertheless it was decided to treat the patient according to a Ewing's sarcoma protocol based on the genotype of the tumor. The findings were compared with other extraosseous pediatric small cell tumors showing the t(11;22)(q24;q12) described in the literature.
- Published
- 1999
14. Analysis of proliferation and apoptosis in brain gliomas: Prognostic and clinical value
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Heesters, MAAM, Koudstaal, J, Go, KG, and Molenaar, WM
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EXPRESSION ,MONOCLONAL-ANTIBODY ,apoptosis ,KI-67 LABELING INDEXES ,MIB-1 ,TUMORS ,digestive system diseases ,nervous system diseases ,CELL-DEATH ,glioma ,RADIATION-THERAPY ,immunohistochemistry ,SURVIVAL ,SUPRATENTORIAL ASTROCYTOMAS ,OLIGODENDROGLIOMAS ,neoplasms ,TUNEL - Abstract
With the introduction of new (immuno-)histochemical techniques it is now possible to assess rates of proliferation and apoptosis in brain gliomas using archival paraffin embedded material. As proliferation and apoptosis are related to tumour growth rate quantification of these processes has prognostic value and is related to tumour grading. In this study we assessed the proliferation rate by measuring the Ki-67 labelling index using the MIB-1 antibody (MIB-LI) and the apoptotic rate using the in situ labelling of DNA strand breaks with TUNEL (TUNEL-LI) in 315 supratentorial gliomas. MIB-LI and TUNEL-LI in astrocytomas (A) where significantly lower compared to anaplastic astrocytomas (AA), glioblastomas (GBM) and oligodendroglial tumours [oligodendrogliomas (O) and anaplastic oligodendrogliomas (AO)]. MIB-LI and TUNEL-LI were significantly lower in AA compared to GBM. In astrocytic tumours MIB-LI and TUNEL-LI appeared to be correlated. As the distinction between A and AA is of clinical value but can be difficult histomorphologically we analysed the prognostic value of MIB-LI and TUNEL-LI in gliomas with particular emphasis on A and AA. MIB-LI below 10% was of prognostic value in A and AA, O and AO but not in GBM on univariate survival analysis. TUNEL-LI was of no prognostic value. With multivariate survival analysis MIB-LI lost prognostic significance in O and AO. Astrocytomas with a gemistocytic component (AG) are similar to A with respect to survival and MIB-LI and TUNEL-LI. MIB-LI is of independent prognostic value in A and AA. Assessment of MIB-LI in A and AA can be used as an aid in distinguishing A and AA.
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- 1999
15. Expression of neural cell adhesion molecules and neurofilament protein isoforms in skeletal muscle tumors
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Molenaar, WM and Muntinghe, FLH
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CHILDHOOD RHABDOMYOSARCOMAS ,neurofilament isoforms ,EPITOPES ,DISTINGUISH ,NEUROECTODERMAL TUMORS ,RNA ,N-CAM ,rhabdomyosarcoma ,rhabdomyoma ,MONOCLONAL-ANTIBODIES ,neural cell adhesion molecule (NCAM) ,NERVOUS-SYSTEM ,ANTIGENS - Abstract
In a series of rhabdomyosarcomas, the expression of neural cell adhesion molecules (NCAM) and neurofilament isoforms was probed in frozen sections. It was found that NCAM was widely expressed in rhabdomyosarcomas without relation to subtype or differentiation level. Neurofilament isoforms were found throughout all subtypes but were largely restricted to those neurofilament isoforms that are expressed early in neurogenesis, that is, poorly phosphorylated low and medium-weight isoforms, It was concluded that the expression of these "neural" markers is widespread and does not signify a neural tumor. Copyright (C) 1998 by W.B. Saunders Company.
- Published
- 1998
16. The proliferative potential of the pilocytic astrocytoma: The relation between MIB-1 labeling and clinical and neuro-radiological follow-up
- Author
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Dirven, CMF, Koudstaal, J, Mooij, JJA, and Molenaar, WM
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GROWTH FRACTION ,MONOCLONAL-ANTIBODY KI-67 ,INDEXES ,PROTEIN ,NUCLEAR ANTIGEN ,HUMAN-BRAIN-TUMORS ,HUMAN GLIOMAS ,MIB-1 labeling ,CELLS ,follow-up ,proliferative potential ,neuro-radiological ,pilocytic astrocytoma ,neoplasms - Abstract
The proliferative potential of 39 pilocytic and 5 low grade astrocytomas was studied in relation to the Ki-67 activity as measured by the MIB-1 Labelings Index. The results were correlated to the biological behaviour of the tumor as measured by clinical and neuro-radiological (CT- or MRI-scans) follow-up of the patient. This study was undertaken to answer the question whether MIB-1 expression reflects differences in biological behaviour of these tumors, such as rapid progression of residual tumor or stable remaining tumor. MIB-1 LI values ranged from 0 to 19% in the group of pilocytic astrocytomas (mean 4,2%) and from 0 to 15% in the 5 low grade astrocytomas (mean 4,2%). All patients were operated and 23 of them had incomplete tumor resection as proven on postoperative neuro-imaging studies. Those 23 patients could be subdivided into two groups, one without progression of residual tumor during follow-up (n = 12) and the other with tumor progression (n = 11). mean MIB-1 LI in the group with 'quiescent' tumor tended to be lower than in the group with progressive tumor: 3,3% vs. 6,6%. Residual tumors which were negative for MIB-1 staining showed fewer progressions of residual tumor compared to those being positive for MIB-1 staining, however this difference was not significant (p = 0, 15, Fisher exact test). Tumor samples of a second operation of the same patient had lower MIB-1 LI values than those of the samples taken at first operation. The proliferating potential seemed to be decreased after part of the tumor was resected. Pilocytic astrocytomas with a negative MIB-1 LI are unlikely to show progression of residual tumor after partial resection. MIB-1 staining might be an additional tool in determining the frequency and duration of follow-up and in making decisions regarding further treatment of a patient operated for a pilocytic astrocytoma with residual tumor.
- Published
- 1998
17. Sexual functioning after multimodality treatment for disseminated nonseminomatous testicular germ cell tumor
- Author
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VanBasten, JP, JonkerPool, G, VanDriel, MF, Sleijfer, DT, Droste, JHJ, VandeWiel, HBM, Molenaar, WM, Hoekstra, HJ, and Schraffordt Koops, H.
- Subjects
germ cells ,ejaculation ,PRIMARY CHEMOTHERAPY ,testis ,testicular neoplasms ,TESTIS CANCER ,SPARING RETROPERITONEAL LYMPHADENECTOMY ,LYMPH-NODE DISSECTION ,CISPLATIN ,lymph nodes ,CLINICAL STAGE-I ,FERTILITY ,VINBLASTINE ,GONADAL-FUNCTION - Abstract
Purpose: We determined sexual functioning after chemotherapy for disseminated nonseminomatous testicular germ cell tumor, and evaluated the impact of resection of post-chemotherapy residual retroperitoneal tumor. Materials and Methods: A total of 155 consecutive patients treated with chemotherapy for disseminated nonseminomatous testicular germ cell tumor (between 1980 and 1994) was questioned about their sexual functioning. The patients were divided in 2 subgroups: patients treated with or without resection of post-chemotherapy residual retroperitoneal tumor. Volume and location (divided into left para-aortal or right paracaval/interaortacaval) of the resected tumor were related to absence of ejaculation as well as decreased semen amount. In addition, libido, arousal, erection and orgasm were related to ejaculatory dysfunction. Results: A total of 43 patients (27.7%) was treated with chemotherapy only and 112 (72.3%) had additional resection of post-chemotherapy residual retroperitoneal tumor mass. Overall, 22.4% reported loss of libido, 14.1% decreased arousal, 16% erectile dysfunction, 23.1% decreased orgasmic intensity, 17.4% decreased semen amount and 18.7% complete absence of antegrade ejaculation. With exception of absence of ejaculation, sexual dysfunctions were reported in similar frequencies in both treatment subgroups. In the resection of post-chemotherapy residual retroperitoneal tumor subgroup, 25.9% of the patients had complete absence of ejaculation. The other sexual dysfunctions were related neither to decreased semen amount nor to complete absence of ejaculation. The mean volume of resected tumor was higher (95 cm.(3)) in patients with absence of ejaculation than in those without (40 cm.(3)), and patients with right paracaval/interaortacaval tumor (20 of 58, 34.5%) reported more often absence of ejaculation than those with left para-aortal tumor (9 of 54, 16.7%). Conclusions: In patients treated for disseminated nonseminomatous testicular germ cell tumor, post-chemotherapy sexual morbidity cannot be neglected. Except for loss of antegrade ejaculation, sexual dysfunctions are not related to resection of post-chemotherapy residual retroperitoneal mass. A high volume of tumor and a right paracaval/interaortacaval location predispose to loss of antegrade ejaculation.
- Published
- 1997
18. Thoracotomy for postchemotherapy resection of pulmonary residual tumor mass in patients with nonseminomatous testicular germ cell tumors - Aggressive surgical resection is justified
- Author
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Gels, ME, Hoekstra, HJ, Sleijfer, DT, Nijboer, AP, Molenaar, WM, Ebels, T, Schraffordt Koops, H., and Cardiovascular Centre (CVC)
- Subjects
NON-SEMINOMA ,nonseminomatous germ cell tumors ,ADJUNCTIVE SURGERY ,SOFT-TISSUE ,residual tumor mass ,COMBINATION CHEMOTHERAPY ,TERM FOLLOW-UP ,MEDIAN STERNOTOMY ,postchemotherapy thoracotomy ,testicular cancer ,MATURE TERATOMA ,STAGE-III ,postoperative complications ,PROGNOSTIC FACTORS ,LUNG METASTASES - Abstract
In patients with disseminated nonseminomatous testicular germ cell tumors (NSTGCT), a retroperitoneal residual tumor mass (RRTM) and/or a pulmonary residual tumor mass (PRTM) are often present after successful treatment with cisplatin-based polychemotherapy. Results and complications of postchemotherapy resection of PRTM were studied and survival was calculated, In the period 1979 to 1996, 31 patients with a median age of 28 years (range, 17 to 44 years) underwent 32 thoracotomies for the resection of a PRTM, A solitary lesion was encountered nine times (28.1%) and multiple lesions were encountered 23 times (71.9%). The median size was 15 mm (range, 2 to 60 mm), There were only three major postoperative complications (9.6%): prolonged ventilation, pneumothorax, and pneumonia, In 16 patients (51.6%), the resected PRTM showed mature teratoma, while in four patients (12.9%) it showed viable cancer, In 11 patients only necrosis and/or fibrosis were found (35.5%), Resection of an RRTM had been performed prior to thoracotomy in 20 patients, There was dissimilarity between the histologic features of the resected RRTM and PRTM in 10 of the 20 patients (50%), During a median follow-up of 80 months (range, 2.5 to 203 months), five patients died from metastatic disease (16.1%). The 5-year survival rate was 86.8% and the 10-year survival rate was 82.2%. Owing to the dissimilarity between the histologic features of the postchemotherapy resected RRTM and PRTM in 50% of the patients, all sites of pulmonary residual disease must be resected in patients with disseminated NSTGCT, irrespective of the histologic features of previously resected retroperitoneal residual disease, This approach offers minimal morbidity and a high 10-year survival rate.
- Published
- 1997
19. Proliferative activity in human brain tumors: Comparison of histopathology and L-[1-C-11]tyrosine PET
- Author
-
deWolde, H, Pruim, J, Mastik, MF, Koudstaal, J, Molenaar, WM, Faculteit Medische Wetenschappen/UMCG, and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Subjects
F-18 FLUORODEOXYGLUCOSE ,protein synthesis rate ,proliferation ,L-[1-C-11]TYR ,POSITRON EMISSION TOMOGRAPHY ,MONOCLONAL-ANTIBODY KI-67 ,METHIONINE UPTAKE ,GLIOBLASTOMA-MULTIFORME ,NUCLEOLAR ORGANIZER REGIONS ,CELL NUCLEAR ANTIGEN ,PET ,brain tumors ,NERVOUS-SYSTEM TUMORS ,PROTEIN-SYNTHESIS RATES ,IN-VIVO - Abstract
To validate the protein synthesis rate (PSR) measured in human brain tumors using L-[1-C-11]tyrosine (TYR) PET, the PSR was compared to histopathological parameters that reflect proliferation and protein synthesis. Methods: We studied 20 patients who had a brain biopsy and who also underwent a PET study with TYR. Paraffin sections were stained with the monoclonal antibody MIB 1, targeted against the core antigen Ki-67, and nucleolar organizer regions (NORs) were measured as argyrophilic NORs (AgNORs). The TYR uptake was measured by PET, and with a kinetic model, the PSR was determined. Results: PSR (nmol/ml/min) ranged from 0.44 to 1.99 (mean, 0.97), Ki-67 labeling indices (%) ranged from 0.9 to 33.5 (mean, 9.5) and AgNOR area (mm(2)/cm(2)) ranged from 0.13 to 0.85. No relationship was found between PSR and Ki-67 labeling index or AgNOR area. Conclusion: It seems that the PSR and proliferation, as measured by Ki-67, are independent processes. The role of the PSR is uncertain, but it is likely that it can be seen as a marker for the homeostasis of the cell.
- Published
- 1997
20. Cytogenetic analysis of adamantinoma of long bones: Further indications for a common histogenesis with osteofibrous dysplasia
- Author
-
Hazelbag, HM, Wessels, JW, Mollevangers, P, vandenBerg, E, Molenaar, WM, and Hogendoorn, PCW
- Subjects
INVOLVEMENT ,CHROMOSOME ,TISSUE ,FIBROUS DYSPLASIA ,ABERRATIONS ,TIBIA ,MALIGNANT MESOTHELIOMA - Abstract
Five adamantinomas of long bones were cytogenetically characterized to investigate the role of chromosomal aberrations in their histogenesis, as well as a putative relationship between adamantinoma and osteofibrous dysplasia (OFD). Three tumors had a classic histologic subtype, with abundant epithelium. Two of them revealed trisomies 7, 8, 12, and 19, combined with a balanced translocation, t(10;22), with centromere breakpoints in one tumor. The third showed a karyotype 51, XY, +X, +7, +12, +19, +21. The fourth tumor, of OFD-like subtype, showed trisomies 7, 8, and a small marker chromosome in a low percentage of cells. The fifth tumor, also of OFD-like subtype, displayed only a few keratin-positive cells from the multiple tissue blocks investigated. This latter tumor revealed a clonal abnormality with a karyotype 46,XX,t(2;11)(p23;q14)inv(11)(p14q14), which was confirmed with fluorescence in situ hybridization (FISH), using chromosome-specific library probes and chromosome 12 locus-specific probes. The trisomies 7, 8, and 22 also were described in OFD, which suggests a common histogenesis of OFD and adamantinoma. Our findings further support the probability of clonal origin of OFD. The OFD-like component may be an integral element of adamantinoma, rather than a tissue reaction to epithelial tumor cells. (C) 1997 Elsevier Science Inc., 1997.
- Published
- 1997
21. Complications of the post-chemotherapy resection of retroperitoneal residual tumour mass in patients with non-seminomatous testicular germ cell tumours
- Author
-
Gels, ME, Nijboer, AP, Hoekstra, HJ, Sleijfer, DT, Molenaar, WM, Plukker, JT, Droste, JHJ, Schraffordt Koops, H., Damage and Repair in Cancer Development and Cancer Treatment (DARE), and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Subjects
nonseminomatous germ cell tumours ,post-operative complications ,ADJUNCTIVE SURGERY ,testis cancer ,BLEOMYCIN ,LYMPHADENECTOMY ,LYMPH-NODE DISSECTION ,residual tumour mass ,TERATOMA ,HISTOLOGY ,EXPERIENCE ,RECURRENCE ,post-chemotherapy laparotomy ,MULTIVARIATE-ANALYSIS - Abstract
Objective To evaluate the resection of the retroperitoneal residual tumour mass (RRTM) for histological examination after chemotherapy in patients with disseminated non-seminomatous testicular germ cell tumours (NSTGCTs), with particular attention to surgical morbidity. Patients and methods From 1979 to 1995, 112 patients (mean age 28 years, range 16-53) with NSTGCT had residual disease after chemotherapy for which surgical evaluation was indicated; the histology of the residual tumour and the surgical complications were assessed, Possible associations between the occurrence of surgical complications and the age of the patient, size of the residual tumour, operative duration, previous laparotomy and pathological findings were evaluated. Results The median size of the residual tumour was 4 cm (range 0-18): histological examination revealed viable tumour in 9%, mature teratoma in 44% and necrosis/fibrosis in 44% of the patients. In three patients (2.8%) no residual tumour mass was found at laparotomy, There were 26 complications in 20 patients (18%); urinary tract infection was the most common, occurring in nine patients (8%). One patient died during the induction of anaesthesia. There were no significant relationships between the occurrence of complications and age, size of the residual tumour, operative duration, previous laparotomy or pathological findings. Conclusion The resection of RRTM after polychemotherapy treatment for disseminated NSTGCT is a safe surgical procedure, with low treatment morbidity consisting mainly of urinary tract infection, Knowledge of the potential complications may help to prevent morbidity, However, the surgical evaluation of the ultimate effect of polychemotherapy remains the gold standard.
- Published
- 1997
22. Cerebellar pilocytic astrocytoma: A treatment protocol based upon analysis of 73 cases and a review of the literature
- Author
-
Dirven, CMF, Mooij, JJA, and Molenaar, WM
- Subjects
biological behaviour ,recurrence ,PROGNOSIS ,treatment ,LONG-TERM ,CHILDHOOD ,CHILDREN ,TERM FOLLOW-UP ,pilocytic astrocytoma ,MALIGNANT RECURRENCE ,GLIOMAS - Abstract
In a retrospective study of 73 patients operated on for cerebellar pilocytic astrocytomas, results of treatment, outcome and biological behaviour of residual tumour were analysed. Complete tumour resection proven by CT or MRI scans within 1 year after surgery was achieved only in 69% of cases. In 31% of cases the surgeon's opinion on the extent of surgical resection was not borne out by the result of postoperative neuroimaging. Progression of residual tumour or tumour recurrence appeared in 19% of patients, 1 patient showed metastatic spread along the craniospinal axis, and in 1 patient malignant degeneration appeared during follow-up. Stable residual tumour or regression of residual tumour was seen in 14% of patients. Outcome after surgical treatment, which was combined with irradiation in 10 patients (14%), was favourable in 80% and unfavourable in 20% of patients. This outcome of treatment was not influenced by a second operation for progression of residual tumour or recurrent tumour. Characteristics of patients with tumour progression after the first operation did not differ from those of the whole group. There were 17 reoperations for residual or recurrent tumour, 10 of which took place within 4 years after the initial surgical treatment. Surgery-related morbidity was 15% and mortality 4%. Irradiation to residual tumour in s patients was followed by complete regression in 1 patient, progression in 4 patients and no changes in 1 patient. For the remaining 2 patients the effect of irradiation on the residual tumour is unknown. Factors that determine the prognosis are discussed on the basis of this retrospective analysis and the data from the literature. It is concluded that optimal treatment for a cerebellar pilocytic astrocytoma does not consist solely in surgery with the aim of total tumour removal and careful tumour handling in order to avoid spread of tumour cells and subsequent metastases and additional radiation therapy in strictly selected cases, but also in posttreatment follow-up based on direct postoperative neuroimaging, preferably by MRI. An algorithm for postoperative follow-up management is presented.
- Published
- 1997
23. Aneurysmal bone cysts treated by curettage, cryotherapy and bone grafting
- Author
-
Schreuder, HWB, Veth, RPH, Pruszczynski, M, Lemmens, JAM, Molenaar, WM, Schraffordt Koops, H., and Faculteit Medische Wetenschappen/UMCG
- Subjects
Respiratory Physiology (Non MeSH) ,Urologic and Male Genital Diseases (Non MeSH) ,Angiogenesis Factor ,Phantoms ,Laboratory ,Imaging ,Radiologic ,Environment and Public Health (Non MeSH) ,Biomedische Magnetische Resonantie ,Orthopedics and Sports Medicine ,Musculoskeletal Diseases ,Neoplasm Metastasis ,GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) ,Musculoskeletal System ,Portfolio Choice ,Phantoms, Imaging ,Diagnosis, Laboratory ,Biomedical Magnetic Resonance ,Otorhinolaryngologic Diseases ,CRYOSURGERY ,Cardiovascular Diseases ,Health Occupations ,General Financial Markets ,Tomography Scanners, X-Ray Computed ,Consumption ,Design of Experiments ,Endocrine Diseases ,Digestive System Diseases ,Urogenital System ,Therapeutics ,X-Ray Intensifying Screens ,Body Regions (Non MeSH) ,Tomography Scanners ,Consumption, Saving, Production, Employment, and Investment ,Saving ,Special Topics [Econometric and Statistical Methods] ,Production ,Chirurgische Oncologie ,Tissue Types (Non MeSH) ,General Economics ,Surgery ,Financial Institutions and Services ,Circulatory ,Digestive System ,Single Equation Models [Econometric Methods] ,Technology ,Physiology ,Data Collection and Data Estimation Methodology ,Computer Programs ,Respiratory System ,Respiratory Tract Diseases ,Teaching of Economics ,and Investment ,General (Non MeSH) ,Cardiovascular System ,Nervous System ,Physiology, General (Non MeSH) ,Neoplasms ,Diagnosis ,Preventive Health Services ,Neonatal Diseases and Abnormalities (Non MeSH) ,Brain Mapping ,SECONDARY ,Stomatognathic Diseases ,General Aggregative Models ,Hypothesis Testing ,Biological Sciences ,TUMORS ,X-Ray Computed ,Surgical Oncology ,Virus Diseases ,Nutrition (Non MeSH) ,Female Genital Diseases and Pregnancy Complications (Non MeSH) ,Mathematical Methods and Programming ,Models with Panel Data ,Nutritional and Metabolic Diseases (Non MeSH) ,Employment ,Biochemical Phenomena ,Semiparametric and Nonparametric Methods ,Fluids and Secretions (Non MeSH) ,Biochemical Phenomena, Metabolism, Nutrition (Non MeSH) ,Circulatory, Respiratory Physiology (Non MeSH) ,Econometric Methods: Single Equation Models ,Symptoms and General Pathology (Non MeSH) ,Endocrine System (Non MeSH) ,Econometric and Statistical Methods: Special Topics ,Animals ,Tumor pathology ,General ,Technology, Radiologic ,Neural ,Eye Physiology (Non MeSH) ,Tumor pathologie ,Musculoskeletal, Neural, Eye Physiology (Non MeSH) ,Relation of Economics to Other Disciplines ,Metabolism ,Musculoskeletal ,Econometric Modeling ,Other ,Nervous System Diseases ,Estimation ,Game Theory and Bargaining Theory ,Corporate Finance and Governance - Abstract
We treated 26 patients with 27 aneurysmal bone cysts by curettage and cryotherapy and evaluated local tumour control, complications and functional outcome. The mean follow-up time was 47 months (19 to154). There was local recurrence in one patient. Two patients developed deep wound infections and one had a postoperative fracture. We compared our results with previous reports in which several different methods of treatment had been used and concluded that curettage with adjuvant cryotherapy had similar results to those of marginal resection, and that no major bony reconstruction was required. We recommend the use of cryotherapy as an adjuvant to the surgical treatment of aneurysmal bone cysts. It provides local tumour control. Combination with bone grafting achieved consolidation of the lesion in all our patients.
- Published
- 1997
24. FDG-PET to evaluate response to hyperthermic isolated limb perfusion for locally advanced soft-tissue sarcoma
- Author
-
vanGinkel, RJ, Hoekstra, HJ, Pruim, J, Nieweg, OE, Molenaar, WM, Paans, AMJ, Willemsen, ATM, Vaalburg, W, Schraffordt Koops, H., and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Subjects
F-18 FLUORODEOXYGLUCOSE ,sarcoma ,tumor necrosis factor ,POSITRON EMISSION TOMOGRAPHY ,EXTREMITIES ,hyperthermic isolated limb perfusion ,MUSCULOSKELETAL TUMORS ,FACTOR-ALPHA ,TIME UPTAKE DATA ,BRAIN TRANSFER CONSTANTS ,GRAPHICAL EVALUATION ,PET ,NECK-CANCER ,fluorine-18-fluorodeoxyglucose ,TUMOR-NECROSIS-FACTOR - Abstract
We investigated FDG-PET in patients undergoing hyperthermic isolated limb perfusion (HILP) with rTNF-alpha, rIFN-gamma and melphalan for locally advanced soft-tissue sarcoma of the extremities. Methods: Twenty patients (11 women, 9 men; aged 18-80 yr, mean age 49 yr) were studied, FDG-PET studies were performed before, 2 and 8 wk after HILP. After the final PET study, the tumor was resected and pathologically graded, Patients with pathologically complete response (pCR) showed no viable tumor after treatment, Those with pathologically partial response (pPR) showed various amounts of viable tumor in the resected specimens. Results Seven patients showed a pCR (35%) and 12 patients showed a pPR (60%). In one patient, pathological examination was not performed (5%). The pre-perfusion glucose consumption in the pCR group was significantly higher than in the pPR group (p
- Published
- 1996
25. Fluorine-18-fluorodeoxyglucose PET imaging of soft-tissue sarcoma
- Author
-
Nieweg, OE, Pruim, J, vanGinkel, RJ, Hoekstra, HJ, Paans, AMJ, Molenaar, WM, Vaalburg, W, Schraffordt Koops, H., Faculteit Medische Wetenschappen/UMCG, and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Subjects
F-18 FLUORODEOXYGLUCOSE ,TRANSPORTER MESSENGER-RNA ,POSITRON EMISSION TOMOGRAPHY ,neoplasms ,MUSCULOSKELETAL TUMORS ,soft-tissue sarcomas ,TIME UPTAKE DATA ,GLUCOSE-TRANSPORTER ,BRAIN TRANSFER CONSTANTS ,tumor grading ,GRAPHICAL EVALUATION ,PET ,LUMPED CONSTANT ,RAT - Abstract
PET with F-18-fluoro-2-deoxy-D-glucose (FDG) was used to study soft-tissue lesions, The goals of the study were to establish FDG uptake in soft-tissue sarcoma, to determine the sensitivity of this technique, to investigate the correlation between histologic grade and glucose consumption and to determine whether FDG-PET can discriminate between benign and malignant lesions, Methods: PET imaging was performed in 18 patients with soft-tissue sarcoma and 4 patients with a benign soft-tissue lesion. Glucose consumption in the tumors was calculated using Patlak's graphical analysis with an assumption made for the lumped constant. Standardized uptake values also were calculated. Results: All soft-tissue sarcomas were clearly depicted, The median glucose consumption was 13.0 mu mole/100 g/min (range 2.9-41.8 mu mole/100 g/min). A correlation was found between glucose metabolism and the histopathologic malignancy grade, Such a correlation was not demonstrated for the standardized uptake values, One benign lesion was also visualized. Benign lesions were not visualized in two patients and in the remaining patient an equivocal scan was obtained, Benign lesions could be distinguished from high-grade malignant lesions but not consistently from lesions with low or intermediate malignancy grades, Conclusion: PET with FDG is an effective technique to visualize soft-tissue sarcomas. We found a sensitivity of 100%, There is a correlation between glucose metabolic rate and tumor malignancy grade. FDG appears to be unsuitable for discriminating benign lesions from soft-tissue sarcomas with low or intermediate malignancy grades.
- Published
- 1996
26. CYTOGENETICS AS A TOOL IN THE HISTOLOGIC SUBCLASSIFICATION OF CHONDROSARCOMAS
- Author
-
DIJKHUIZEN, T, VANDENBERG, E, MOLENAAR, WM, OOSTERHUIS, JW, WIERSEMA, J, KOOPS, HS, DEJONG, B, and Dam, A.
- Subjects
musculoskeletal diseases ,animal structures ,MYXOID CHONDROSARCOMA ,CHROMOSOME-22 ,COMPLEX ,embryonic structures ,BENIGN ,REARRANGEMENTS ,DNA CONTENT ,musculoskeletal system ,TUMORS ,TRANSLOCATION - Abstract
Chondrosarcomas are a heterogeneous group of bone neoplasms of which the basic neoplastic tissue is cartilaginous. Frequently the histologic diagnosis and grading of chondrosarcomas is difficult and the histologic appearance does not always reflect the biologic behavior of these rumors. Therefore, it is important to find other parameters that can be of help in the proper diagnosing and grading of these neoplasms. To this end, we attempted to correlate the chromosomal pattern of chondrosarcomas to their histologic subtypes and grades. The cytogenetic analysis of two intermediate-grade chondrosarcomas of bone, and a review of the literature, are presented.
- Published
- 1994
27. TUMOR PROGRESSION IN A GIANT-CELL TYPE MALIGNANT FIBROUS HISTIOCYTOMA OF BONE - CLINICAL, RADIOLOGIC, HISTOLOGIC, AND CYTOGENETIC EVIDENCE
- Author
-
MOLENAAR, WM, VANDENBERG, E, VETH, RPH, DIJKHUIZEN, T, DEVRIES, EGE, and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Subjects
SOFT-TISSUE SARCOMAS ,CHROMOSOMAL-ABNORMALITIES - Abstract
A malignant fibrous histiocytoma (MFH) of bone arising in the fibula of a 21-year-old woman is described. Clinical, radiologic, and histologic findings demonstrated rapid tumor progression. Chromosomal analysis of the biopsy specimen showed great karyotypic heterogeneity, whereas the resection specimen four weeks later displayed a rather homogeneous karyotype. Both revealed a clonal t(14;22)(q11;p12). Several other clonal and non-clonal chromosomal aberrations were observed. Some of these were previously described in giant cell tumor of bone (GCTB) and may correlate with aggressive behavior, e.g., aberrations involving 8p11, 19q13, and 20q13. The change from karyotypic heterogeneity to relative homogeneity may be related to tumor progression. The chromosomal findings further suggest that the giant cell type of MFH of bone may be related to malignant GCTB. (C) 1994 Wiley-Liss, Inc.
- Published
- 1994
28. APPARENT SMA-I UNLINKED TO 5Q
- Author
-
COBBEN, JM, SCHEFFER, H, DEVISSER, M, BEGEER, JH, MOLENAAR, WM, VANDERSTEEGE, G, BUYS, CHCM, VANOMMEN, GJ, TENKATE, LP, and Faculteit Medische Wetenschappen/UMCG
- Subjects
PRENATAL PREDICTION ,SPINAL MUSCULAR-ATROPHY ,GENE ,POLYMORPHISMS - Abstract
A proband with a clinical picture indistinguishable from SMA type I is described. The parents are second cousins. On DNA analysis it appeared that the proband and his healthy 2 year old sib had inherited the same haplotypes for DNA markers flanking the SMA locus on 5q. This supports non-linkage of SMA to chromosome 5q in this family. The consanguinity of the parents raises the possibility of a second locus for autosomal recessive SMA type I outside the 5q12-13 region. This may have implications for genetic counselling after prenatal diagnosis in consanguineous families. Furthermore, this case illustrates the importance of the inclusion of all healthy sibs in prenatal DNA studies for SMA type I.
- Published
- 1994
29. THE ULTIMATE EFFECT OF INTRAOPERATIVE RADIOTHERAPY (IORT) ON AN IRRESECTABLE RETROPERITONEAL RECURRENCE OF A NONSEMINOMATOUS TESTICULAR-TUMOR
- Author
-
CROMHEECKE, M, MEHTA, DM, SLEIJFER, DT, MOLENAAR, WM, KOOPS, HS, and HOEKSTRA, HJ
- Subjects
CISPLATIN ,COMPLICATIONS ,INTRAOPERATIVE ,METASTASES ,INDUCED SARCOMAS ,TESTIS ,RADIATION-THERAPY ,CHEMOTHERAPY ,BLEOMYCIN ,RADIOTHERAPY - Published
- 1993
30. CA-TENSION RELATIONSHIPS OF MUSCLE-FIBERS FROM PATIENTS WITH PERIODIC PARALYSIS
- Author
-
LINKS, TP, MOLENAAR, WM, OOSTERHUIS, HJGH, Damage and Repair in Cancer Development and Cancer Treatment (DARE), and Guided Treatment in Optimal Selected Cancer Patients (GUTS)
- Published
- 1993
31. DNA PLOIDY AND KARYOTYPE IN RECURRENT AND METASTATIC SOFT-TISSUE SARCOMAS
- Author
-
VANDENBERG, E, MOLENAAR, WM, HOEKSTRA, HJ, KAMPS, WA, DEJONG, B, and Faculteit Medische Wetenschappen/UMCG
- Subjects
MYXOID LIPOSARCOMA ,CELL-LINE ,SOFT TISSUE SARCOMAS ,HUMAN SOLID TUMORS ,FLOW ,CHILDHOOD ,KARYOTYPE ,CHROMOSOMAL ANALYSIS ,PEDIATRIC SARCOMAS ,TRANSLOCATION ,EMBRYONAL RHABDOMYOSARCOMA ,ALVEOLAR RHABDOMYOSARCOMA ,FIBRO-SARCOMA ,TUMOR PROGRESSION ,DNA PLOIDY - Abstract
To study mechanisms involved in evolution of soft tissue sarcomas, we compared DNA ploidy and karyotypes at different stages of their disease in two patients with myxoid liposarcomas (MLS), one with a fibrosarcoma (FS), and two with rhabdomyosarcomas (RMS). None of the MLS samples revealed clearcut histologic changes in later samples as compared to their primaries, and the DNA ploidy in all samples was diploid. In one patient karyotypes at four different times during the 19 yr of his disease all revealed a t(11;12)(p15;q13), but additional clonal chromosomal abnormalities occurred only in later recurrences. In another patient the karyotypes obtained in the 26th and 28th yr of his disease were similar and included the t(12;16)(q13;p11), characteristic of MLS. A comparison with karyotypes of six other MLS patients at different disease stages suggests that the presence of a t(12;16) may correlate with less aggressive clinical behavior. The histology of the FS remained low-grade and the DNA ploidy diploid. The karyotype, however, showed evolution. In both MLS and FS, chromosomal changes thus seem to be a more sensitive marker for tumor progression than histologic changes or DNA ploidy. In one embryonal RMS, karyotypes obtained 7 and 11 yr after the primary diagnosis were different but clearly had a common "progenitor." In one alveolar RMS, the primary and the synchronous lung and lymph node metastases all revealed a t(2;13). The findings in RMS suggest that polyploidization is an early event in tumor evolution, especially in the alveolar subtype, which may be followed by additional chromosomal changes. In addition, DNA ploidy was measured. in eight other RMSs. Among the RMSs the embryonal subtype was characterized by DNA aneuploidy, whereas three of the alveolar cases were in the tetraploid range and one was peridiploid. In local recurrences and in metastases changes in DNA index were observed in half the cases.
- Published
- 1992
32. LEIOMYOSARCOMA IN A PATIENT WITH TRISOMY-8 MOSAICISM
- Author
-
MOLENAAR, WM, DEJONG, B, and VANDENBERG, E
- Subjects
SARCOMAS - Published
- 1991
33. HEMATOGENOUS TUMOR-GROWTH IN THE INFERIOR VENA-CAVA IN A PATIENT WITH A NONSEMINOMATOUS TESTICULAR-TUMOR
- Author
-
HAM, SJ, KOOPS, HS, SLEIJFER, DT, FRELING, NMJ, and MOLENAAR, WM
- Subjects
cardiovascular system ,cardiovascular diseases - Abstract
The case history is reported of a patient with an invasion of the inferior vena cava by metastases of a non-seminomatous testicular tumour. He was treated with combination chemotherapy, followed by laparotomy and resection of residual tumour tissue. Fourteen months after this operation he is in good health. For every retroperitoneal lymph node dissection it is necessary to be on the look-out for invasion of the vena cava, because of the risk of a sudden pulmonary embolism.
- Published
- 1991
34. HISTIOCYTOSIS-X (EOSINOPHILIC GRANULOMA OF THE FIBULA) - CASE-REPORT 615
- Author
-
THIJN, CJP, MARTIJN, A, POSTMA, A, and MOLENAAR, WM
- Published
- 1990
35. DEDIFFERENTIATED PAROSTEAL OSTEO-SARCOMA OF THE FEMUR WITH ANEUPLOIDY AND LUNG METASTASES
- Author
-
VANOVEN, MW, MOLENAAR, WM, FRELING, NJM, KOOPS, HS, MUIS, N, DAMMEIRING, A, and OOSTERHUIS, JW
- Published
- 1989
36. HETEROGENEITY OF WILMS TUMOR BLASTEMA - AN IMMUNOHISTOLOGICAL STUDY
- Author
-
ALBEDA, FW, MOLENAAR, WM, DELEIJ, L, and THIJSIPEMA, AH
- Published
- 1989
37. THE PATHOLOGY AND PATHOGENESIS OF MALIGNANT ATROPHIC PAPULOSIS (DEGOS DISEASE) - A CASE-STUDY WITH REFERENCE TO OTHER VASCULAR DISORDERS
- Author
-
MOLENAAR, WM, ROSMAN, JB, DONKER, AJM, and HOUTHOFF, HJ
- Published
- 1987
38. THE RARITY OF RHABDOMYOSARCOMAS IN THE ADULT - A MORPHOLOGIC AND IMMUNOHISTOCHEMICAL STUDY
- Author
-
MOLENAAR, WM, OOSTERHUIS, AM, and RAMAEKERS, FCS
- Published
- 1985
39. CHROMOSOMAL ANALYSIS AND THE CLASSIFICATION OF SOFT-TISSUE SARCOMAS
- Author
-
Molenaar, WM, de Jong, B, Wiersema-Buist, J, Idenburg, VJS, Seruca, R, Vos, AM, Hoekstra, HJ, and University of Groningen
- Published
- 1989
40. A COMBINATION OF INTRAARTERIAL CHEMOTHERAPY, PREOPERATIVE AND POSTOPERATIVE RADIOTHERAPY, AND SURGERY AS LIMB-SAVING TREATMENT OF PRIMARILY UNRESECTABLE HIGH-GRADE SOFT-TISSUE SARCOMAS OF THE EXTREMITIES
- Author
-
HOEKSTRA, HJ, KOOPS, HS, MOLENAAR, WM, MEHTA, DM, SLEIJFER, DT, DIJKHUIS, G, and OLDHOFF, J
- Published
- 1989
41. AN IMMUNOLOGICAL STUDY OF GERMINAL-CENTERS IN 4 OPHTHALMIC IMMUNOCYTOMAS
- Author
-
MOLENAAR, WM, SCHWARZE, EW, and LENNERT, K
- Published
- 1983
42. RESULTS OF ISOLATED REGIONAL PERFUSION IN THE TREATMENT OF MALIGNANT SOFT-TISSUE TUMORS OF THE EXTREMITIES
- Author
-
HOEKSTRA, HJ, KOOPS, HS, MOLENAAR, WM, and OLDHOFF, J
- Published
- 1987
43. RADIOGRAPHIC IMAGING OF LYMPH-NODES IN LYMPH-NODE DISSECTION SPECIMENS
- Author
-
GROOTE, AD, OOSTERHUIS, JW, MOLENAAR, WM, VERMEY, A, VANOSNABRUGGEBONDON, C, ARNOLD, LV, and University of Groningen
- Published
- 1985
44. CYLINDROMA OF THE SCALP
- Author
-
SPAUWEN, PHM, MOLENAAR, WM, DHAR, BK, and University of Groningen
- Published
- 1987
45. INVASIVE FIBROUS THYROIDITIS (RIEDELS STRUMA) - A MANIFESTATION OF MULTIFOCAL FIBROSCLEROSIS - A CASE-REPORT WITH REVIEW OF THE LITERATURE
- Author
-
DELANGE, WE, FRELING, NJM, MOLENAAR, WM, and DOORENBOS, H
- Published
- 1989
46. AN ANALYSIS OF HISTOLOGY AND DNA-PLOIDY IN PRIMARY WILMS-TUMORS AND THEIR METASTASES AND A STUDY OF THE MORPHOLOGICAL EFFECTS OF THERAPY
- Author
-
VANLEEUWEN, EH, POSTMA, A, OOSTERHUIS, JW, MEIRING, A, CORNELISSE, CJ, KOUDSTAAL, J, and MOLENAAR, WM
- Published
- 1987
47. VANBUCHEMS DISEASE AND ANEURYSMAL BONE-CYST - A CASE-HISTORY
- Author
-
VETH, RPH, NIELSEN, HKL, KOOPS, HS, OOSTEN, HR, and MOLENAAR, WM
- Published
- 1985
48. Experiences with the implementation of a national teaching qualification in university medical centres and veterinary medicine in the Netherlands.
- Author
-
Molenaar WM and Zanting A
- Abstract
In 2008, a compulsory national basic teaching qualification was introduced for all university teachers in the Netherlands. At that time all eight University Medical Centres (UMCs) and the only Faculty of Veterinary Medicine had adopted or were setting up teacher development programmes. This study explores how these programmes relate to each other and to the basic teaching qualification. To gather information on teacher development programmes in the UMCs and the Veterinary Medicine Faculty an online survey was filled out by teacher development representatives from each of them. The programmes had main features in common (e.g. competency based and portfolio assessment), but differed somewhat in contents according to the local situation. Importantly, they had all been formally accepted as equivalent to the basic teaching qualification. We consider the freedom to tailor the qualifications to the medical context as well as to the local situation of the UMCs and the Veterinary Medicine Faculty one of the major success factors and the well-established collaboration between teacher development representatives of the UMCs and the Faculty of Veterinary Medicine as another. Challenges for the future include embedding the teacher development programmes in the institutional organizations and maintaining and further developing the programmes and the competencies of the qualified teachers, e.g. in a senior qualification.
- Published
- 2015
- Full Text
- View/download PDF
49. The predictive value of immunohistochemical markers in untreated Wilms' tumour: are they useful?
- Author
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Ghanem MA, van der Kwast TH, Molenaar WM, Safan MA, Nijman RJ, and van Steenbrugge GJ
- Subjects
- Adolescent, Cyclin-Dependent Kinase Inhibitor p27 metabolism, Disease Progression, Female, Follow-Up Studies, Humans, Immunohistochemistry, Kidney Neoplasms diagnosis, Kidney Neoplasms surgery, Male, Nephrectomy, Predictive Value of Tests, Prognosis, Transforming Growth Factor alpha metabolism, Treatment Outcome, Ubiquitin-Protein Ligases metabolism, Vascular Endothelial Growth Factor A metabolism, WT1 Proteins metabolism, Wilms Tumor diagnosis, Wilms Tumor surgery, Biomarkers, Tumor metabolism, Kidney Neoplasms metabolism, Wilms Tumor metabolism
- Abstract
Purpose: This study reevaluates the potential role of different tumour markers as prognostic indicators in untreated nephroblastoma., Methods: Expression of a broad panel of tumour markers was investigated by means of immunohistochemical analysis in 43 WT patients. Patients were treated by radical nephrectomy and had a mean follow-up of 11.9 years., Results: Generally, all the tumour markers studied were expressed in normal kidney tissue and at variable levels in the three cell types of WT (blastema, epithelium and stroma). Immunoreactive blastemal (Bcl-X, Bcl-2 and CD44s) and epithelial (Bcl-X, Bcl-2 and MIB-1) cells were present in the majority of tumours. No correlation was found between their expression and pathological stages. Univariate analysis showed that blastemal WT-1, TGF-α, VEGF, MIB-1 and p27 Kip1 were indicative for clinical progression. In a multivariate analysis, WT-1 protein expression by blastemal cells was an independent prognostic marker for clinical progression., Conclusions: The blastemal WT-1, TGF-α, VEGF, MIB-1 and p27Kip1 expression correlate with clinical progression in untreated nephroblastoma. Therefore, their expression may be of value in identifying patients with a high propensity to develop distant metastases.
- Published
- 2013
- Full Text
- View/download PDF
50. A framework of teaching competencies across the medical education continuum.
- Author
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Molenaar WM, Zanting A, van Beukelen P, de Grave W, Baane JA, Bustraan JA, Engbers R, Fick TE, Jacobs JC, and Vervoorn JM
- Subjects
- Humans, Netherlands, Education, Medical, Professional Competence, Teaching standards
- Abstract
Background: The quality of teachers in higher education is subject of increasing attention, as exemplified by the development and implementation of guidelines for teacher qualifications at Universities in The Netherlands., Aim: Because medical education takes a special position in higher education the Council of Deans of Medical Schools in The Netherlands installed a national task force to explore a method to weigh criteria for teacher qualifications of medical teachers., Methods: A framework was developed covering competencies of teachers throughout the medical education continuum and including medicine, dentistry and veterinary medicine., Results: The framework distinguishes 3 dimensions: (a) six domains of teaching (development - organization - execution - coaching - assessment - evaluation); (b) three levels in the organization at which teachers perform (micro, meso and macro level) and (c) competencies as integration of knowledge, skills and attitude and described as behaviour in specific context. The current framework is the result of several cycles of descriptions, feedback from the field and adaptations. It is meant as a guideline, leaving room for local detailing., Conclusion: The framework provides a common language that may be used not only by teachers and teacher trainers, but also by quality assurance committees, human resource managers and institutional boards.
- Published
- 2009
- Full Text
- View/download PDF
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