Biomedical subjects

J G van den Tweel

Publications and source records attributed to J G van den Tweel.

At least 19 recordsLinked to original sources

PubMed2006

Morphology of the bone marrow after stem cell transplantation.

In many haematological conditions the only curative option is stem cell (SCT) or bone marrow (BM) transplantation. Little information exists about BM morphology following non-ablative engraftment. During the pretransplantation period and depending on the kind of pretreatment, there may be hypoplasia, residual disease and varying degrees of fibrosis. In the post-transplantation period, after 1-3 weeks of transfusion-dependent pancytopenia, the first signs of successful engraftment are indicated by the recurrence of neutrophils, monocytes and erythrocytes in the peripheral blood. In the BM there is slow regeneration of erythropoiesis, followed by the other lineages of haematopoiesis and increase in reticulin fibres or even a resolution of fibrosis. Diagnostic problems arise when neoplastic lympho- or haematopoiesis are maintained following transplantation. Moreover, there may be a significant graft versus tumour response reaction or an already relapsing disease needing aggressive treatment. On the other hand, a conspicuous dyshaematopoiesis should not be mistaken as representing a myelodysplastic syndrome. The presence of granulomas being treatment-related or a manifestation of intercurrent granulomatous disease has to be considered. More advanced knowledge of the histological features of regenerating BM will certainly aid the recognition of relapsing disease and is needed for the adequate reporting of post-transplant alterations associated with a successful or failing engraftment.

Bone Marrow↗

PubMed2005

[Indications for bone marrow biopsy in adults].

Bone marrow biopsies are more and more often part of the work-up of patients with haematological disorders. The most important reason for this is the fact that a biopsy supplies important additional information compared to an aspirate alone. Biopsies are superior for the assessment of the bone marrow architecture, the vascularisation, the cellularity, the localisation and the extent of infiltrates and the degree of fibrosis. In addition, biopsy is a good way to evaluate the effects of therapy in the course of the disease. As is the case with aspirates, examination of a biopsy alone is usually sufficient for a correct diagnosis. However, a combination of both techniques makes possible an optimal assessment of the nature and extent of the disease process in the often very serious haematological conditions that we are dealing with here.

Biopsy, Needle↗

PubMed2003

Differential diagnosis of skin lesions after allogeneic haematopoietic stem cell transplantation.

Allogeneic haematopoietic stem cell transplantation (i.e. bone marrow or peripheral blood stem cell transplantation) is a common procedure in the treatment of various haematological disorders such as aplastic anaemia, (pre)leukaemias, some malignant lymphomas, multiple myeloma and immunodeficiency states. Many of these patients develop erythematous skin lesions following transplantation. Although graft- versus-host disease is the major differential diagnosis in these situations, many other causes of erythema are encountered. The large number of transplant patients means that more and more pathologists are confronted with the challenging problem of making a correct diagnosis in these situations. In this review article we therefore describe the different causes of erythema and their differential diagnoses. In most cases the clinical presentation is related to the microscopical features. Besides acute and chronic graft-versus-host disease, we discuss the (common) drug reactions and non-specific features such as Sweet's syndrome, erythema nodosum and eosinophilic folliculitis. In addition, we deal with the recurrence of original diseases and infections. With this knowledge every pathologist should feel comfortable when looking at skin biopsies of patients after haematological stem cell transplantation.

Diagnosis, Differential↗

PubMed2002

Prognostic factors in localised prostate cancer with emphasis on the application of molecular techniques.

Prostate cancer is the most prevalent malignancy in males in the Western world and the second leading cause of male cancer death. Prostate specific antigen (PSA) based screening and case finding leads to identification of early stage prostate cancer. It is often difficult to discriminate between patients that need curative treatment and those that can be managed conservatively. Prognostic factors are used to make this clinical decision. Based on the classification proposed by the American College of Pathologists and the World Health Organisation, selected prognostic factors in prostate cancer are described. Clinical applicable factors are stage, grade and serum PSA. Prognostic factors that are not routinely used (for various reasons) are ploidy, histological type and cancer volume in needle biopsies. All other factors (including circulating tumour cells, angiogenesis, growth factors, proliferation rate, apoptosis, nuclear morphometry, neuroendocrine differentiation, loss of chromosomal regions, tumour suppresser genes and adhesion molecules) are promising as prognostic factor although currently their use in clinical decisions is not recommended. The role of these factors in prostate cancer growth and their predictive value are discussed. The rapid developments in molecular techniques allow assessment of structure or function of thousands of genes in a prostate biopsy sample. We expect that molecular characterisation of tumour material will become a clinically important tool to predict prognosis in patients with localised prostate cancer.

Biomarkers, Tumor↗

PubMed2001

Neural network-based screening (NNS) in cervical cytology: no need for the light microscope?

Neural network-based screening (NNS) of cervical smears can be performed as a so-called "hybrid screening method," in which parts of the cases are additionally studied by light microscope, and it can also be used as "pure" NNS, in which the cytological diagnosis is based only on the digital images, generated by the NNS system. A random enriched sample of 985 cases, in a previous study diagnosed by hybrid NNS, was drawn to be screened by pure NNS. This study population comprised 192 women with (pre)neoplasia of the cervix, and 793 negative cases. With pure NNS, more cases were recognized as severely abnormal; with hybrid NNS, more cases were cytologically diagnosed as low-grade. For a threshold value > or = HSIL (high-grade squamous intraepithelial lesions), the areas under the receiver operating characteristic (ROC) curves (AUC) were 81% (95% CI, 75-88%) for pure NNS vs. 78% (95% CI, 75-81%) for hybrid NNS. For low-grade squamous intraepithelial lesions (LSIL), the AUC was significantly higher for hybrid NNS (81%; 95% CI, 77-85%) than for pure NNS (75%; 95% CI, 70-80%). Pure NNS provides optimized prediction of HSIL cases or negative outcome. For the detection of LSIL, light microscopy has additional value.

Cervix Uteri↗

PubMed2000

Monitoring of residual disease and guided donor leucocyte infusion after allogeneic bone marrow transplantation by chimaerism analysis with short tandem repeats.

In this study, we analysed the chimaeric status of peripheral blood leucocytes (PBLs) in recipients of allogeneic bone marrow transplantation (BMT) with the use of short tandem repeat (STR) microsatellite markers for monitoring the efficacy of BMT and donor leucocyte infusions (DLIs). A set of four STR markers was used with a highly discrimative capacity between individuals. STRs were detected by polymerase chain reaction (PCR) and were analysed by gene scanning (STR-GS). Between June 1990 and December 1998, 52 patients treated with BMT for chronic myeloid leukaemia (CML) were analysed. Seventeen patients relapsed after BMT and two patients never achieved remission after BMT. Fourteen of the 17 patients achieved a complete donor chimaerism after BMT, as detected by the presence of only donor STR-GS fragments, and in three cases a weak recipient STR-GS signal remained persistently detectable after BMT. A reappearance or increase of recipient STR-GS signals was indicative of relapse, which was mostly detected by STR-GS several months before relapse was diagnosed clinically. Nineteen patients were treated with DLI for reappearance of CML after BMT which resulted in complete remission in 17 patients, concordant with the disappearance of recipient STR-GS signals. More importantly, DLI treatment could be guided based upon the STR-GS data, which prevented unnecessary extra DLI courses that could cause toxicity. This study indicates that STR-GS is an effective and reliable method for monitoring BMT recipients.

Adult↗

PubMed1999

[Truth after death].

Diagnosis is central to medicine. In spite of tremendous diagnostic technological advances, no infallible test exists and in the complex diagnostic process the physician may well get lost. The ultimate feedback on the accuracy of diagnosis is the autopsy. Five patients illustrate that the autopsy may disclose unexpected results. The first patient was a 9-year-old girl who suffered from daily abdominal spasmodic pain but each time recovered. She died suddenly; autopsy revealed intestinal intussusception. A 46-year-old man who was treated for hypertension developed pain in the chest and the lower back, but there were no other signs of myocardial infarction. He died suddenly; autopsy revealed a dissecting aortic aneurysm with rupture in the left pleural cavity. A 21-year-old woman, an excellent swimmer, drowned during a swim in the sea. Autopsy revealed severe widespread coronary disease with multiple myocardial infarction. A 32-year-old Surinam woman developed acute coma and died from cardiorespiratory arrest. At autopsy she had massive pulmonary embolism and generalized lymphadenopathy due to sarcoidosis. The last patient, a 32-year-old woman suffered from fatigue after her fourth child was born. She was admitted with severe dyspnoea and her chest X-ray showed interstitial fibrosis. She died presently and autopsy revealed metastatic colon carcinoma with pulmonary lymphangitis carcinomatosa. Systematic reviews of the results of autopsies show no decline in the percentage of false diagnoses and/or unexpected findings in spite of the enormous growth of the diagnostic armamentarium. Although we may radiologically 'slice' the body in incredible detail or investigate human cells at the molecular level, the autopsy has by no means become obsolete and is an invaluable tool for quality control and teaching.

Adenocarcinoma↗

PubMed1999

[Autopsies as an important indicator for quality control].

The decreasing number of autopsies, in the Netherlands as well, is deplorable because with it an important instrument of medical quality control is likely to disappear. For this not only the relatives, but also the attending physicians and the pathologists are to blame. To turn the tide we need some drastic changes in our attitude towards autopsies. The families should known that an autopsy is a right they have in order to check the quality of diagnosis and treatment of their beloved, it is not a favour towards the physician. A physician who does not see a reason for autopsy, should explain that to the family. Pathologists should think about and realize a subspecialty of autopsy pathology with a thorough training in pathophysiology and intensive care medicine. Autopsy reports should be of the highest quality and reach the physician within a few weeks. A required autopsy percentage should be introduced into the certification process of medical specialists and hospitals and the possibility of Continuous Medical Education credit points for physicians with a certain autopsy percentage should be considered.

Autopsy↗

PubMed1999

Observer variation in cytologic grading for cervical dysplasia of Papanicolaou smears with the PAPNET testing system.

BACKGROUND: To assess the interobserver and intraobserver variation of Papanicolaou (Pap) smear screening with the computer-assisted (neural network based) PAPNET Testing System in diagnosing cervical smear abnormalities, results of agreement were compared with the interobserver and intraobserver variation of conventional smear analysis. METHODS: Cervical smears obtained from women in 1996 were reevaluated both by conventional light microscopy and with use of the PAPNET Testing System by the same four investigators, and results were compared with the original screening diagnoses obtained by both methods. RESULTS: The interobserver results for epithelial abnormalities (the degree of agreement between the cytologists), characterized by weighted kappa statistics, were 0.71 (95% CI: 0. 68-0.73) for PAPNET screening and 0.69 (95% CI: 0.66-0.72) for conventional screening. No significant differences were found among the individual results obtained by the four cytotechnologists (intraobserver variation) with conventional screening versus PAPNET reviewing. CONCLUSIONS: Pap smear grading with the PAPNET Testing System has interobserver and intraobserver variation similar to that of conventional screening of Pap smears in routine use. Cancer (Cancer Cytopathol)

Diagnosis, Differential↗

PubMed1999

The diagnostic value of computer-assisted primary cervical smear screening: a longitudinal cohort study.

OBJECTIVES: To assess computer-assisted (neural network based) cervical smear screening as a primary tool for the early detection of cervical dysplasia. DESIGN: Longitudinal cohort study. SETTING: Cytology laboratory reviewing cervical smears taken by general practitioners in a mass screening program in the Netherlands. SUBJECTS: 846 women who developed (pre-)neoplasia of the cervix in the seven years after the baseline smear, and 5217 controls. INTERVENTIONS: Cervical smears were evaluated both by conventional light microscopy and with use of the PAPNET Testing System by the same cytotechnologists. MAIN OUTCOME MEASURES: Seven year histological and cytological follow-up results were obtained for all women from a nation-wide pathology database. RESULTS: Conventional screening diagnosed dysplasia or carcinoma in the baseline smears of 458 (54.1%) of the 846 women who were diagnosed with (pre-)neoplasia during follow-up, whereas computer-assisted PAPNET analysis detected such lesions in 462 (54.6%) of these women. In the control population of 5217 (86.0%) women, in whom follow-up revealed no cervical dysplasia, conventional screening gave false positive results in 210 (4.0%) and computer-assisted PAPNET analysis gave false positive results in 207 (4.0%) smears. The areas under the receiver operation curves (AUC) were 80% (95% confidence interval, 78 to 82%) and 79% (95% confidence interval, 77 to 81%) for conventional and PAPNET-assisted screening, respectively. CONCLUSIONS: The PAPNET Testing System has similar diagnostic value as the conventional screening of Pap smears when used for primary screening.

Female↗

PubMed1997

Pancreatic cancer in rats and hamsters does not induce IAPP-related hyperglycaemia.

Many patients with exocrine pancreatic cancer develop diabetes mellitus due to insulin resistance. This may relate to concurrent over-production of islet amyloid polypeptide (IAPP) by the pancreatic beta cells. We investigated the effects of pancreatic cancer on circulating IAPP and glucose homeostasis in azaserine-treated rats (developing acinar pancreatic tumours) and BOP-treated hamsters (developing ductular pancreatic tumours). Glucose, insulin and IAPP levels in plasma were neither affected in azaserine-only treated rats nor in animals with enhanced carcinogenesis after chronic caerulein treatment. Azaserine-treated rats on a high-fat diet had decreased insulin levels and enhanced IAPP/insulin ratios in plasma, without hyperglycaemia. All BOP-treated hamsters showed pancreatic carcinogenesis at 6 months post-treatment. Supranormal plasma glucose levels in animals on a low-fat diet were the only change observed. After a second 6-month period, subnormal plasma glucose levels, at least 4-fold decreased plasma insulin and up to 2-fold decreased plasma IAPP levels were present in all hamsters. Remarkably, both in azaserine-treated rats on high-fat and in BOP-treated hamsters, decreased insulin levels and elevated IAPP/insulin ratios are not associated with hyperglycaemia. In contrast to humans with pancreatic cancer, IAPP over-production and hyperglycaemia do not develop in rats and hamsters with (pre-)neoplastic pancreatic lesions.

Amyloid↗

PubMed1997

The actin binding domain of the epidermal growth factor receptor is required for EGF-stimulated tissue invasion.

NIH-3T3 fibroblasts expressing epidermal growth factor receptors (EGFRs) lacking the actin binding domain (ABD) were analyzed for their EGF-induced capacity to invade a bone marrow stromal cell (BMSC) monolayer. The fibroblasts display a reduction in the percentage of cytoskeleton-associated EGFRs. Furthermore, EGF-induced tyrosine kinase activity is unaffected by the mutation. Cells expressing the mutant EGFRs hardly invade a BMSC monolayer upon EGF stimulation in contrast to cells expressing wild-type EGFRs. Using the same cells no difference was observed in PDGF-induced invasion, which ligand was as potent in both cell types as EGF was in wild-type cells. Inhibition of both the phosphatidyl inositol-3-kinase (PI-3-K) and lipoxygenase pathways in wild-type cells mimicked the effect of the ABD deletion. Our results point to an important role for the ABD of the EGFR in EGF-induced tissue invasion.

3T3 Cells↗

PubMed1997

Immunosuppressive therapy for hypoplastic myelodysplastic syndrome.

BACKGROUND: Hypoplastic myelodysplastic syndrome (MDS) is characterized by dysplasia and hypocellularity. The treatment of choice for young patients is bone marrow transplantation. METHODS: This report describes the effect of immunosuppressive therapy in two patients with hypoplastic MDS for whom no suitable bone marrow donors were available. RESULTS: Both patients had no human lymphocyte antigen-identical siblings and no suitable matched unrelated donor could be found. They received cyclosporin A (CsA), antithymocyte globulin (ATG), or a combination of the two. Treatment with CsA, ATG, or the combination led to clinical improvement (resolution of transfusion requirement), increase of bone marrow cellularity, and the disappearance of dysplastic characteristics in the two patients with hypoplastic MDS. At the time of recurrence, this disease was still responsive to immunosuppressive therapy. CONCLUSIONS: Treatment with ATG and CsA can be an attractive alternative for patients with hypoplastic MDS for whom there is no possibility of bone marrow transplantation.

Antilymphocyte Serum↗

PubMed1997

A generic sequencing based typing approach for the identification of HLA-A diversity.

Sequencing Based Typing (SBT) is a generic approach for the identification of HLA-A polymorphism. This approach includes the high resolution typing of the HLA-A broad reacting groups, HLA-A subtypes and will identify new alleles directly. The SBT approach described here uses a locus specific amplification of DNA from exon 1 to exon 5. The resulting 2,022 bp PCR product serves as a template for the subsequent sequencing reactions. Amplification is followed by direct sequencing of exons 2, 3 and 4 in both orientations with fluorescently labeled primers to define all polymorphic positions leading to a high resolution typing result. In this study the sequence of exons 2 and 3 of a panel of 49 cell lines was determined. In addition, the exon 4 region of 35 cell lines was also sequenced to evaluate the exon 4 polymorphism. The HLA-A type of most of the cells could be identified by sequencing only exons 2 and 3. However, the sequence of exon 4 was required to discriminate A*0201 from A*0209 and A*0207 from A*0215N. In this panel, an identical new "HLA-A*0103" was identified in two Caucasian samples.

Alleles↗

PubMed1997

The diagnostic accuracy of core biopsy in palpable and non-palpable breast lesions.

OBJECTIVE: To assess the accuracy of large-core needle biopsy in evaluating palpable and nonpalpable breast lesions. METHODS AND PATIENTS: Stereotaxic and ultrasound (US) guided core biopsies were performed in 103 breast lesions in 97 patients. Subsequently, all patients underwent surgery. All specimens (core biopsy and surgical) underwent radiography for evaluation of microcalcifications. The histopathologic findings of the core biopsies and the surgical specimens were correlated. RESULTS: Core biopsies and surgery findings were concordant in 100% of the 27 palpable lesions and in 89% of the 76 nonpalpable lesions. One case of malignancy, ductal carcinoma in situ (DCIS), was not diagnosed by core biopsy. In 102 (99%) of the 103 breast lesions, a correct choice for additional diagnostic procedure or definitive treatment could have been made upon histopathologic findings of core biopsy. CONCLUSION: Stereotaxic and ultrasound-guided core biopsy are safe, reliable and less traumatic than excisional biopsy. Special attention is necessary when atypical ductal hyperplasia (ADH) or DCIS without invasive carcinoma is found. Radiography of the biopsy specimens for detection of microcalcifications is essential.

Adult↗

PubMed1997

Immunohistochemical analysis of decalcified paraffin-embedded human bone marrow biopsies with emphasis on MHC class I and CD34 expression.

AIMS: To identify the stromal structures and haematopoietic cell lineages in normal bone marrow. The optimal conditions were studied for the reactivity of a panel of antibodies, applicable to paraffin sections of decalcified trephine biopsies using antigen retrieval methods. METHODS AND RESULTS: Two methods of antigen retrieval (pepsin and acid citrate buffer) were tested. For the demonstration of most antigens and for reduction of background staining, heating in acid citrate buffer was preferred. In the case of elastase and von Willebrand Factor (factor VIIIrAg) pepsin pre-treatment was optimal, whereas Ulex europaeus agglutinin (UEA-1) and alpha-smooth muscle actin (alpha-SMA) required no pretreatment. Staining patterns obtained after 48 h EDTA decalcification and short electrolytic decalcification were identical. Both methods allowed recognition of HLA-A and HLA-B antigens, isolated CD34+ cells, mono-histiocytic cells (CD68+), myeloid cells (elastase and myeloperoxidase), erythroid cells (glycophorin C) and of megakaryocytic cells (Factor VIIIrAg). A relative simple lymphocyte-subset analysis was possible in decalcified paraffin sections allowing recognition of B-cells (CD20+) and T-cells (CD3+ and CD45RO+) in frequencies comparable to frozen sections. Suitable stromal cell staining was achieved by vimentin and desmin antibodies, whereas the bone marrow capillary network was visualized by CD34, factor VIIIrAg and UEA-1. CONCLUSIONS: This immunohistochemical study indicates that all cellular components of the haematopoietic microenvironment of the bone marrow can be identified in decalcified paraffin sections using antigen retrieval methods and that the time of decalcification can be reduced to 1-1.5 h.

Antigens, CD34↗

PubMed1997

Evaluation of PAPNET-assisted cervical rescreening.

We have compared the results of targeted manual rescreening of 1211 randomly selected smears with the results of PAPNET-assisted rescreening of 1613 cervical smears, containing at least 6.3% low-grade squamous intraepithelial lesion (SIL). PAPNET diagnosis and the targeted rescreening diagnosis were compared with the initial report, issued on the corresponding smear. Reproducibility scores for inadequacy, presence of endocervical and endometrial cells, specific infections and squamous cell abnormalities were determined. The reproducibility scores for the diagnosis of inadequate smears and specific infections were lower with the PAPNET-assisted rescreening. The detection of squamous cell abnormalities was excellent for both methods (> 0.95), with a higher detection rate for false-negative smears with the PAPNET testing system.

Diagnosis, Computer-Assisted↗

PubMed1996

[Digital roentgen-guided large-needle biopsy as an alternative to surgical biopsy in patients with nonpalpable mammographic abnormalities].

OBJECTIVE: To compare histopathological findings from stereotaxic needle core biopsies and from excision biopsies performed on patients with impalpable breast lesions suggestive of carcinoma. DESIGN: Prospective and descriptive, with a description of the stereotaxic needle core biopsy procedure. SETTING: Academic Hospital Utrecht, the Netherlands. METHODS: In 36 patients core biopsies were done with 14-gauge biopsy needles, followed by a localisation procedure with surgical biopsy. The pathological features of the core and excision specimens were compared. RESULTS: Results of 35 (97%) core biopsies corresponded to those of excision biopsies. Stereotaxic core biopsy was not possible due to technical problems in 2 cases. CONCLUSION: Stereotaxic core biopsy appears to be an acceptable alternative to excision biopsy.

Adult↗