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Biomedical subjects

W Böcker

Publications and source records attributed to W Böcker.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Hypervariable regions (HVR) as genetic markers in tumor diagnosis. Methodological principles and their use in pathologic diagnosis].

Variable number tandem repeats (VNTR) are highly polymorphic DNA sequences which can be used as genetic markers in different fields of medicine. In this report, we describe the methodology of VNTR in diagnostic molecular pathology, using a rapid, DNA-based approach involving polymerase chain reaction (PCR) amplification and electrophoresis of highly polymorphic DNA satellite sequences. As concrete examples of the application of this approach, we present two case reports: 1. A B-cell lymphoma of the porta hepatis developed in a 54-year-old man 4.5 months after orthotopic liver transplantation for liver failure due to chronic hepatitis C infection. Using DNA polymorphisms as genetic markers, we showed that the tumor was of donor origin. This finding may be important for the patient's subsequent management. 2. An immature teratoma of the left ovary was found during delivery by cesarean section in a 27-year-old woman. The female newborn survived for 9 weeks and then died from central dysregulation because of an intracranial immature teratoma. Because the synchronous tumors were of similar histology, clonal origin in maternal tissues and metastatic spread were initially suspected. Analysis of highly polymorphic DNA markers clearly indicated that the teratoma carried by the child was of independent genetic origin from the mother's tumor.

Brain↗
PubMed1994

[A standardized AgNOR stain method for formalin fixed and paraffin embedded material].

Visualization of proteins associated with nucleolar organizer regions proteins (AgNORs) on formalin-fixed and paraffin-embedded archival tissues is substantially improved after application of wet autoclave pretreatment. Silver staining results are comparable to those obtained on tissues processed in alcohol based fixatives, illustrating AgNORs as substructures of the nucleoli without any staining artefacts. A highly reproducible staining quality was achieved irrespective of tissue origin or duration of formalin fixation. As a result of this novel and simple method, the grounds have been prepared for standardized AgNOR quantification on archival material.

Fixatives↗
PubMed1994

[Moist autoclaving. A simplified method for antigen unmasking].

Wet autoclaving is a simple, reliable and time-effective method for antigen retrieval in routinely processed archival material. Both routine diagnostic (e.g., oestrogen and progesterone receptors, cytoskeletal proteins) and research antibodies (e.g. various p53 antibodies, mdm-2, bcl-2, MIB-1) are reported to demonstrate its application. We autoclaving may allow successful application of antibodies in paraffin-embedded tissues designed for use on frozen sections. The technique has the potential to reliably handle up to 200 sections at a time, without evidence of any significant damage to the sections or nuclear morphology.

Antigens, Neoplasm↗
PubMed1994

Validation of intravascular ultrasound in arteriosclerotic peripheral vessels.

In this in vitro-study, we validated intravascular ultrasound for the detection of irregular luminal contours, intraarterial structures, intimal thickening in peripheral arteriosclerotic human vessel segments and we compared sonographic criteria to the composition of arteriosclerotic lesions. Sixty-nine post-mortem segments of human peripheral arteries (6 patients) were fixed in formalin, examined with intravascular ultrasound and morphologically evaluated. Specificity, sensitivity, both positive and negative predictive value and accuracy of intravascular ultrasound for the detection of irregular luminal contours, intra-arterial structures and intimal thickening were determined for each of four quadrants. Ultrasonic features (echogeneity, homogeneity, shadowing of echoes) were also compared to the composition of lesions. Intravascular ultrasound detected regular (normal) luminal contours with a high specificity of 96.5%, a sensitivity of 65.0% and an accuracy of 88.4%. Intra-arterial structures were detected with a sensitivity of 88.6%, a specificity of 97.8% and an accuracy of 96.4%. Arteriosclerotic lesions could be localized with a sensitivity of 86.1%, a specificity of 99.1% and an accuracy of 86.9%. Intimal thickening was detectable with a sensitivity of 85.9%, a specificity of 87.8% and an accuracy of 86.2%. Meanwhile, fibrous, atheromatous and combined lesions without calcification did not show shadowing of echoes. The majority of fibrous or atheromatous lesions presented with homogeneous echoes showing hypo-, hyper- and normal density echoes. Using a 20-MHz transducer, homogeneity and echogeneity of echo patterns cannot accurately predict the different components of combined arteriosclerotic lesions.

Aorta, Abdominal↗
PubMed1994

Anaplastic thyroid carcinoma with osteosarcomatous differentiation.

A case of a thyroid tumour with the cytological and histological pattern of anaplastic carcinoma with extensive osteosarcomatous differentiation in a 54-year-old Kaukasian woman is presented. Immunohistochemical examination revealed keratin-vimentin co-expression in anaplastic tumour areas. According to the WHO classification of thyroid tumours the present tumour has to be classified as an anaplastic carcinoma. A retrospective survey revealed only twenty-four comparable cases in the literature. The present tumour most likely represents an example of a neoplastic epithelial-mesenchymal metaplasia. The possible mechanisms of the occurrence of thyroid tumours with mixed epithelial-mesenchymal differentiation are briefly discussed.

Carcinoma↗
PubMed1994

Comet assay studies of radiation-induced DNA damage and repair in various tumour cell lines.

We used the 'comet assay' to compare the amount of radiation-induced DNA damage in three tumour cell lines (MeWo, PECA 4451 and PECA 4197) and the extent of DNA repair in two of these lines (MeWo and PECA 4197). Tumour cells were irradiated with X-rays (0.1-10 Gy), embedded in agarose on slides, lysed with sodium dodecyl sulphate and exposed to an electric field. DNA migrated within the agarose and formed comets whose length depended on the amount of DNA damage. When the cells were incubated at 37 degrees C for various time intervals before electrophoresis started, the comets shrank in the course of time, indicating repair of DNA damage. All three cell lines showed the same extent of DNA damage after radiation exposure, despite the fact that in the colony-forming assay MeWo and PECA 4451 were much more sensitive to radiation exposure than PECA 4197. The repair characteristics, however, were markedly different for MeWo and PECA 4197 cells. PECA 4197 cells showed a much faster restoration of the original shape of the cell nucleus than MeWo cells.

DNA Damage↗
PubMed1994

Rapid detection of mycobacterial DNA in clinical samples by multiplex PCR.

Triplex-polymerase chain reaction technique (PCR) was developed for the detection and identification of mycobacterial DNA sequences in uncultured clinical samples. A 123 bp fragment corresponding to a specific Mycobacterium tuberculosis sequence complex, a 383 bp DNA fragment encoding for part of the 65 kD mycobacterial surface antigen, and a 268 bp fragment of the human beta-globin gene to demonstrate the presence of suitable DNA were amplified by triplex PCR. To demonstrate the applicability of this method, 206 alcohol-fixed, paraffin-embedded sputum samples from 47 patients with culture-proven tuberculosis were investigated. Of 206 samples, 157 were PCR positive, resulting in correct diagnosis of tuberculosis in 46 of 47 (97.8%) patients. Furthermore, 165 alcohol-fixed, auramin-stained sputum smears were examined in a blind trial. Triplex PCR revealed tuberculosis in 20 of 21 samples from patients with tuberculosis. In comparison, cultures were positive in 20 of 21 samples, and acid-fast organisms were found by microscopy in 18 of 21 samples. We conclude that triplex PCR is a rapid and sensitive technique for the detection of mycobacterial DNA in uncultured clinical samples and offers equivalent sensitivity (95.2%) and specificity (98.6%) as do culture methods.

Base Sequence↗
PubMed1994

Fine needle aspiration cytodiagnosis of subacute (de Quervain's) thyroiditis in an endemic goitre area.

Between 1977 and 1989 252 fine needle aspirates (FNAs) of the thyroid from patients with a clinical suspicion of subacute granulomatous (de Quervain's) thyroiditis were examined in the Department of Pathology of the University of Innsbruck, Austria. In the same period 31 cases with preoperative FNA were diagnosed histologically as subacute thyroiditis. Only in three of these cases were the cytological features of de Quervain's thyroiditis found in the preoperative FNA. However, in 13 of these 31 cases a cytological suspicion of malignancy was obtained. Subsequent histological examination revealed an acute phase inflammation of de Quervain's thyroiditis in most of these cases. We conclude that an accurate FNA diagnosis of de Quervain's thyroiditis, particularly in the acute stage, may cause difficulties due to a lack of typical features and the appearance of atypical thyroid follicular cells. For the cytopathologist, accurate clinical information relating to the possibility of de Quervain's thyroiditis is essential if unnecessary surgery is to be avoided.

Austria↗
PubMed1994

Immunohistochemical localization of chromogranins A and B and secretogranin II in normal, hyperplastic and neoplastic prostate.

Routinely processed normal, hyperplastic and neoplastic prostatic tissue was immunohistochemically investigated with antibodies against chromogranin A and B and secretogranin II. In normal and hyperplastic prostates all three peptides were immunolocalized in scattered neuroendocrine cells situated within the glandular epithelium. In 17 prostatic carcinomas with pronounced neuroendocrine differentiation and in a case of prostatic carcinoid, chromogranin B was the major component whereas chromogranin A and secretogranin II were virtually absent in poorly differentiated (grade III) tumours. Neuroendocrine differentiation in prostatic cancer is most likely to be associated with a poor clinical outcome; thus, chromogranin B appears to be a useful marker in the histopathological diagnosis of these neoplasms.

Chromogranin A↗
PubMed1994

[Detection of EWS-/FLI-1 gene fusion transcripts by RT-PCR as a tool in the diagnosis of tumors of the Ewing sarcoma group].

Recent cloning of the chromosome breakpoint regions of the reciprocal chromosomal t(11;22) (q24;q12) has revealed that the breakpoints were localized within the EWS gene (Ewings sarcoma gene) on chromosome 22 and the FLI-1 gene on chromosome 11. Thus, molecular genetic techniques were applicable for the detection of this genetic aberration, which occurs as a consistent feature of the Ewings tumor family. By reverse transcription and polymerase chain reaction technique (RT-PCR) in 78% of Ewings sarcoma derived cell lines, and in 91% of primary Ewings tumor tissue t(11;22) specific EWS/FLI-1 fusion transcripts were detected. Furthermore, in bone marrow samples from an Ewings sarcoma patient contaminating tumor cells could be shown by RT-PCR. Our results indicate that molecular genetic detection of the t(11;22) translocation opens a new modality for the differential diagnosis and the staging of Ewings tumor patients.

Base Sequence↗
PubMed1994

Wet autoclave pretreatment improves the visualization of silver-stained nucleolar organizer-region-associated proteins in routinely formalin-fixed and paraffin-embedded tissues.

This study describes the effect of wet autoclave pretreatment of routinely formalin-fixed and paraffin-embedded tissues on silver-stained nucleolar organizer-region-associated proteins (AgNORs) staining. The treatment of sections at superheated steam temperature (120 degrees C) before silver incubation leads to a significantly better discrimination of single-interphase AgNORs. Counting "black dots" both by eye and by means of a computer-aided image-analyzing system revealed considerably higher AgNOR mean numbers per nucleus in all pretreated cases when compared with the respective untreated controls. However, mean AgNOR numbers increased after autoclave pretreatment in a nonlinear manner (pairwise comparison by means of Spearman's Rank correlation coefficient: rho = 0.5), whereas measurement of the AgNOR area was less influenced by autoclave pretreatment (rho = 0.8). It is concluded that wet autoclave pretreatment of routinely formalin-fixed and paraffin-embedded archival material should be applied before AgNOR staining, particularly when quantitation of AgNORs involves counting procedures.

Adenocarcinoma↗
PubMed1994

[Glomus tumors: a diagnostic and surgical challenge?].

Within a population of 1150 vascular patients over a time period of 10 years we saw a carotid body tumor (synonymous chemodectoma) in only 11 cases. A correct preoperative diagnosis was found only in three patients. Before being treated by a specially trained team of vascular surgeons, eight patients had undergone inadequate operations. These were performed with a high incident of local complications. Simple bedside physical examination of the patient while looking for the signs of Fontaine and Kocher I + II (20) assures the diagnosis. Confirmation can be achieved by color-flow Doppler sonography (2). For the surgical resection, the only therapeutic alternative to the "gold standard" is angiography in digital subtraction technique which illustrates the blood supply of the tumor (70% exclusively by the external carotid artery). Also, it shows the typical intercarotid widening and the rich vascular conglomerate in between. Malignancy was detected in one case only (pulmonary metastasis). In two cases concomitant tumors of the jugular vein were seen. The interruption of the blood flow in the external carotid artery facilitates the surgical approach substantially. The ligature of this vessel (six patients) and the interposition of saphenous vein grafts (all 11 cases) for reconstruction of the internal carotid vessel were employed as the surgical strategy. Even the exstirpation of a large tumor (18 x 11 x 9 cm) extending from the skull base and almost reaching the left clavicular bone was successfully performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Immunohistochemical demonstration of chromogranin A, chromogranin B, and secretogranin II in extra-adrenal paragangliomas.

Twelve sympathetic and 14 parasympathetic extra-adrenal paragangliomas were investigated immunohistochemically with antibodies against chromogranin A, chromogranin B, and secretogranin II. In sympathetic paragangliomas chromogranin A was found in 12/12 and chromogranin B in 11/12 tumors in almost all chief cells (the remaining tumor was focally chromogranin B positive), whereas secretogranin II was immunolocalized in the majority of chief cells in 5/12, in a focal distribution in 3/12, and only in a few scattered tumor cells in 3/12 cases. One case showed no secretogranin II immunoreactivity. In parasympathetic paragangliomas both chromogranin B and secretogranin II immunoreactivity was demonstrated in the majority of chief cells of all 14 tumors investigated. Chromogranin A showed a strong immunostaining in 2/14 cases; in 12 tumors chromogranin A was found in only a few chief cells or was completely absent. It is concluded that sympathetic and parasympathetic paragangliomas show a divergent expression of chromogranins/secretogranins that apparently reflects the different histogenetic origins of these tumors.

Adolescent↗
PubMed1993

Analysis of mutant P53 protein in osteosarcomas and other malignant and benign lesions of bone.

Alterations of tumour suppressor genes are considered crucial steps in the development of human cancers. Expressions of p53 protein, a product of the tumour suppressor gene altered most commonly in human cancers examined so far, were investigated immunohistochemically in 18 osteosarcomas and 40 other malignant and benign lesions of bone. A monoclonal antibody clone PAb240, which recognizes a common conformational epitope of mutant p53 proteins, stained nuclei of tumour cells in 12 of 18 osteosarcomas (67%). Six tumours (33%) particularly showed positive immunoreactions in more than half of the tumour cells. PAb240 also stained tumour cells in a small number of other malignant bone tumours, such as malignant fibrous histiocytoma, chondrosarcoma, and Ewing's sarcomas. Furthermore, a small number of cells of giant-cell tumours were positively stained. In contrast, PAb240 was completely negative in 21 benign bone tumours and reactive lesions examined. Another monoclonal antibody clone PAb1801, which reacts with both wild- and mutant-type p53 protein, reacted in nuclei of tumour cells of 7 osteosarcomas (39%). Most of those also reacted with PAb240. PAb1801 was expressed much more frequently in other malignant bone tumours and giant-cell tumours. In addition, PAb1801 showed intranuclear positive reactions in tumour cells of a benign chondroblastoma, and reactive cells such as actively proliferating preosteoblasts in a myositis ossificans and osteoclast-like giant cells in a giant-cell tumour. The immunoelectron-microscopic observation that p53 protein was localized in euchromatic areas of nuclei of osteosarcoma cells supported the specificity of immunoreaction for p53 protein, indicating an active role of p53 protein in the regulation of DNA synthesis and transcription. These findings suggest that point mutation of the p53 gene is frequently involved in the development of osteosarcomas. PAb240 may be a useful tool not only in screening point mutations of the p53 gene in osteosarcomas but also in the differential diagnosis between osteosarcomas and reactive bone-forming lesions. Expressions of mutant p53 protein were not correlated with any clinical or pathological factors examined, although the results should be confirmed in studies of a large number of osteosarcomas.

Adolescent↗
PubMed1993

Prognostic implication of immunodetection of P glycoprotein in Ewing's sarcoma.

Increased expression of P glycoprotein is associated with multidrug resistance in many cell lines. P glycoprotein has been detected in different human tumors. To assess the implication of multidrug resistance in the prognosis of Ewing's sarcoma the expression of P glycoprotein was studied immunohistochemically in pre- and post-therapeutic tumor tissues of 21 cases treated according to the CESS 81 or 86 protocol. The response to chemotherapy was evaluated histologically. Formalin-fixed, paraffin-embedded and fresh frozen sections were immunostained with a monoclonal antibody to P glycoprotein, clone JSB 1, using the double APAAP method. P glycoprotein was detected in 12 cases of 21 (57%) in either pre- or postchemotherapy tumor tissues. From the 21 cases 8 revealed a good morphological response to chemotherapy (33%); 10 of the 13 non-responders were positive for P glycoprotein (77%), but only 2 of the 8 responders (25%). The difference was statistically significant (P < 0.05). Comparing P glycoprotein expression with the clinical outcome, we found that 7 of 12 positive cases had died (58%). From the negative cases only 3 of 9 had died (33%). However, judged by the Kaplan Meyer life tables, these data were not significant. In conclusion our results suggest that the immunodetection of P glycoprotein indicates a poor response to chemotherapy and probably a bad clinical outcome for Ewing's sarcoma patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Relationship between quantity of silver stained nucleolar organizer region associated proteins (Ag-NORs) and growth rate suppression of breast cancer cell lines after interferon-gamma and 4-hydroxy-tamoxifen treatment.

The correlation between the silver-stained nucleolar organizer region associated proteins (Ag-NORs) and the growth rate suppression (GRS) of ten established breast cancer cell lines which were treated with 4-hydroxy-tamoxifen (OHT) and interferon-gamma (g-IFN), respectively, was investigated by means of automated image analysis. Previous studies have shown a statistically significant relationship between the Ag-NOR quantity and the population doubling time (PDT) of these cell clones. The results of the present study showed a highly significant correlation between the GRS and the Ag-NOR quantity in estrogen receptor (ER) positive tumour cell lines after OHT treatment (P < 0.001) whereas no strict correlation of these parameters could be demonstrated after g-IFN treatment in both ER positive and negative cell lines. Our results suggest a different behaviour of NOR-proteins in breast cancer cell lines if treated either with g-IFN or OHT, probably reflecting the different mechanism of cell suppression mediated by OHT and g-IFN. It is concluded that quantitative assessment of Ag-NORs is not as suitable for the determination of the GRS as it is for the determination of cell duplication rates obtained on untreated tumour cell lines.

Breast Neoplasms↗
PubMed1993

Chromogranin A, secretogranin II and vasoactive intestinal peptide in phaeochromocytomas and ganglioneuromas.

By means of immunohistochemistry we analysed the distribution of chromogranin A, secretogranin II and vasoactive intestinal peptide (VIP) in 16 phaeochromocytomas, two cases of combined phaeochromocytoma-ganglioneuroma and four adrenal ganglioneuromas. Chromogranin A was found in the majority of phaeochromocytes and in mixed phaeochromocytomas-ganglioneuromas. Secretogranin II was present to a lesser degree in phaeochromocytes, but strong immunostaining was found in most ganglion cells of phaeochromocytomas, in the ganglioneuroma component of combined tumours and in adrenal ganglioneuromas. Vasoactive intestinal peptide was present in some ganglion cells of phaeochromocytomas, in the ganglioneuroma component of mixed tumours and in three of four adrenal ganglioneuromas. On semi-adjacent sections a co-localization of VIP and secretogranin II was demonstrated. These results indicate that neuronal differentiation is accompanied by an increased immunohistochemical expression of secretogranin II. Therefore, secretogranin II may be a useful marker for ganglion cell differentiation.

Adrenal Gland Neoplasms↗