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W Böcker

Publications and source records attributed to W Böcker.

At least 91 records · Page 5Linked to original sources
PubMed1996

Unaltered strong immunohistochemical expression of CD44-v6 and -v5 isoforms during development and progression of oral squamous cell carcinomas.

The present study was designed to immunolocalize CD44-v6 and -v5 isoforms in normal, dysplastic and malignant oral mucosa as well as in primary and metastatic oral squamous cell carcinomas. Routinely formalin-fixed and paraffin-embedded tissues of 100 oral carcinoma patients were immunohistochemically investigated following wet autoclave antigen retrieval. Both CD44-v6 and -v5 epitopes were uniformly strongly expressed on the cell surface of basal and intermedial epithelial cells of normal and dysplastic mucosa and in all primary and metastatic squamous cell carcinomas with the exception of end-differentiated keratinizing cells. Our results strongly suggest that CD44-v6 and -v5 isoform expression is not altered during development and progression of oral carcinomas. Thus, they seem to be irrelevant factors in the prediction of prognosis in this type of cancer.

Antigens, Neoplasm↗
PubMed1996

Hyalinizing trabecular adenoma of the thyroid--morphology and differential diagnosis.

Hyalinizing trabecular adenoma (HTA) is a rare but distinct type of thyroid neoplasm. Its typical morphological features are trabecular arrangement of tumour cells and the prominent hyaline appearance. Although cases of HTA with vascular and/or capsular invasion have been described, the vast majority of tumours are benign. This article deals with the histological, cytological, immunohistochemical, and ultrastructural features of HTA. The pitfalls of fine-needle aspiration biopsy and intra-operative frozen section examination are described. Finally the differential diagnostic aspects of HTA are discussed.

Adenoma↗
PubMed1995

Image processing algorithms for the automated micronucleus assay in binucleated human lymphocytes.

The frequency of micronuclei in binucleated lymphocytes (cytochalasin B assay) may serve as a biological dosimeter after radiation exposure. The automation of the micronucleus assay in binucleated human lymphocytes has been considerably advanced in recent years. In our studies for this purpose the detection of binucleated cells (BNCs) and the scoring of micronuclei (MN) was divided into two parts. First, detection of BNCs was feasible with low microscopic magnification (x 100). The positions of classified BNCs were stored. Second, after an automatic change of microscope objective, the stored BNCs were automatically analyzed in sequence at high microscopic magnification (x 630) for occurrence of MN. For both phases of image analysis we used empirical methods based on mathematical morphology. The system is able to recognize nearly 65% of BNCs with false positive decisions of 6% and about 75% of the MN with false positive decisions of 7%.

Algorithms↗
PubMed1995

Standardized staining and analysis of argyrophilic nucleolar organizer region associated proteins (AgNORs) in radically resected colorectal adenocarcinoma--correlation with tumour stage and long-term survival.

Quantification of silver-stained nucleolar organizer region associated proteins (AgNORs) was introduced in histopathology as a marker of cellular and nucleolar activity. However, due to the poor staining quality obtained on routinely processed archival material, the method yielded controversial and sometimes non-reproducible results. The recent introduction of wet autoclave pretreatment has reliably improved AgNOR staining quality on routinely formalin-fixed and paraffin-embedded tissues. In the present study, 92 routinely processed colorectal carcinomas were investigated, applying this novel staining technique. Subsequent standardized morphometric analysis revealed, irrespective of common tumour staging or grading classifications, a statistically highly significant correlation between AgNOR parameters and clinical course. The usefulness of standardized AgNOR parameters for the independent prediction of patient survival was proven by uni- and multivariate analysis.

Adenocarcinoma↗
PubMed1995

Immunohistochemical detection of p53 protein in archival tissues from squamous cell carcinomas of the oral cavity using wet autoclave antigen retrieval.

Using a panel of four anti-p53 antibodies (CM-1, PAb 1801, DO7, and PAb 240), the phenotypic characteristics of p53 protein overexpression were investigated in 22 routinely formalin-fixed and paraffin-embedded squamous cell carcinomas of the oral cavity. Conventional immunohistochemical staining without pretreatment for antigen retrieval was compared with wet autoclaving (AC) and microwave irradiation (MW). Applying AC or MW, p53 immunoreactivity was demonstrated in 9/22 cases with PAb 1801 and DO7 antibodies and in 8/22 cases with the CM-1 antibody. Immunostaining with the PAb 240 antibody after AC pretreatment showed p53 positivity in 8/22 tumours, but in only 4/22 following MW pretreatment. Immunostaining without pretreatment revealed only 2/22 p53-positive cases using CM-1, 4/22 with PAb 1801, and 3/22 with DO7. Without pretreatment, the PAb 240 antibody was consistently negative. Wet autoclave pretreatment was significantly superior for all the antibodies used in this study when compared with conventional immunohistochemistry without pretreatment (P < 0.005). It yielded better results than microwave irradiation for antigen unmasking in relation to the PAB 240 antibody (P < 0.05). Wet autoclave pretreatment is recommended as a reliable and highly reproducible method for p53 antigen retrieval in routinely processed archival material. The advantages over microwave pretreatment include simple handling and good preservation of morphology.

Carcinoma, Squamous Cell↗
PubMed1995

Immunohistochemical distribution of chromogranins A and B and secretogranin II in neuroendocrine tumours of the gastrointestinal tract.

The aim of the present study was to investigate immunohistochemically the distribution of chromogranin A, chromogranin B, and secretogranin II in a series of 152 neuroendocrine tumours of the gastrointestinal tract. Tumour tissues from 25 argyrophil gastric carcinoids, 18 gastrin and 5 somatostatin-producing tumours, 4 'gangliocytic paragangliomas', 49 classical argentaffin and 2 L cell appendiceal carcinoids, 27 classical ileal carcinoids, 17 rectal carcinoids, and 5 poorly differentiated neuroendocrine tumours of the stomach and rectum were immunostained with antibodies against chromogranin A, chromogranin B, and secretogranin II. Chromogranin A was the major granin expressed in gastric carcinoids and in serotonin-producing carcinoids of the appendix and the ileum. In contrast, strong chromogranin B and secretogranin II immunoreactivity was found in rectal carcinoids, in which chromogranin A was rarely expressed. Since chromogranin A is a widely used marker for neuroendocrine differentiation, it is of diagnostic importance that some gastrin-producing tumours, 'gangliocytic paragangliomas', poorly differentiated neuroendocrine carcinomas, and appendiceal L cell carcinoids completely lacked chromogranin A positivity. It is concluded that the various neuroendocrine tumours of the gastrointestinal tract show distinctly different patterns of granin expression, probably reflecting their histogenetical origin.

Chromogranin A↗
PubMed1995

Frequency and spectrum of p53 mutations in gastric cancer--a molecular genetic and immunohistochemical study.

The p53 tumour-suppressor gene plays an important role in gastric carcinogenesis. In an analysis of the spectrum of mutations of the p53 gene seen in 56 primary gastric carcinomas of various types and grades of differentiation, the entire coding sequence (exons 2-11) of the p53 gene was screened by single-strand conformation polymorphism analysis and direct genomic sequencing of polymerase chain reaction products. Intragenic restriction site polymorphisms and the probe YNZ22 were used for the detection of loss of heterozygosity (LOH) of the p53 gene locus on chromosome 17p. p53 overexpression was studied with the anti-p53 antibody CM-1. A total of 21 somatic alterations of the p53 gene were found. Twenty were base-pair substitutions, and one was an eight base-pair deletion. Six tumours with p53 mutations revealed LOH. Abnormalities in p53 expression were found in 17 tumour samples, of which 16 had gene mutations. The spectrum of mutations observed was consistent with the predicted spectrum for dietary mutagens associated with the metabolism of nitrogenous compounds, resulting in deamination of nucleic acids. Our findings suggest that p53 could be a primary target for mutations associated with dietary carcinogens in gastric carcinogenesis.

Adenocarcinoma↗
PubMed1995

Identification of mycobacteria to the species level by automated restriction enzyme fragment length polymorphism analysis.

An automated method for the restriction fragment length polymorphism (RFLP) analysis for the differentiation of mycobacteria to the species level is described. After polymerase chain reaction (PCR) amplification of a sequence of the gene encoding the 65-kDa surface antigen common to all mycobacteria the product was investigated by RFLP analysis. For accurate determination of fragment sizes the asymmetrically fluorescein-labelled PCR product was partially digested with restriction site enzymes BstEII and HaeIII. The fragments obtained were analysed electrophoretically using an automated laser fluorescence DNA sequencer. Determination of fragment sizes revealed a deviation of +/- 1 base pair (bp; 0.6%) when compared to expected sizes. The validity of this approach was confirmed by analysing mycobacterial DNA obtained from pure cultures of Mycobacterium (M.) tuberculosis and alcohol-fixed smears as well as paraffin-embedded sputa of patients with culture-proven tuberculosis. Additionally a diagnostic algorithm was established by investigation of cultured M. bovis, M. bovis bacille Calmette-Guérin, M. avium, M. intracellulare and M. fortuitum. The method allows the identification of restriction enzyme sites which are only 40 bp apart. Partial restriction enzyme digestion of asymmetrically fluorescence-labelled PCR products will presumably lead to the discovery of new restriction enzyme sites.

Algorithms↗
PubMed1995

Wet autoclave pretreatment for immunohistochemical demonstration of oestrogen receptors in routinely processed breast carcinoma tissue.

The immunohistochemical demonstration of oestrogen receptor (OR) was performed on 32 randomly selected and routinely processed breast carcinomas after wet autoclave pretreatment of sections. The autoclave method was compared to the OR status found on frozen sections as well as to alternative pretreatment methods such as enzymatic predigestion and microwave irradiation. Using four different monoclonal antibody clones (H222, LH1, CC4-5, 1D5.26), the OR status was evaluated for each of the various pretreatment methods applied. All cases with a high OR content on frozen sections (n = 11) also showed a high OR status on wet autoclave-pretreated paraffin tissues using antibody clones 1D5.26 and CC4-5; in cases with low OR content on frozen sections, no false-negative cases were recorded using only the antibody 1D5.26 neither after wet autoclave nor microwave pretreatment. In addition, with this antibody, OR was detectable after autoclave pretreatment in two cases which were considered to be OR-negative even on frozen sections. When the primary antibody was omitted, no false-positive cases were observed after wet autoclave pretreatment. Thus, in our hands, wet autoclave pretreatment, in combination with the antibody 1D5.26, offers a highly sensitive method for the immunohistochemical demonstration of OR in routinely formalin-fixed, paraffin-embedded sections of breast carcinomas.

Antibodies, Monoclonal↗
PubMed1995

[Detection of atypical mycobacterial endophthalmitis by PCR].

We report a case of a 60 year old male who presented with a therapy resistant endophthalmitis which led to an evisceratio bulbi. Histologically, a granulomatous inflammation was present, in which acid-fast bacilli could not be detected. Molecular genetic examination by means of polymerase-chain-reaction technique (PCR) of the routinely processed tissue material revealed the diagnosis of an atypical mycobacterial infection, because DNA specific for atypical mycobacteria was detected. This example shows that PCR technique provides a useful tool in the diagnosis of mycobacterial infections as an adjunct to surgical pathology.

Aged↗
PubMed1995

Immunohistochemical demonstration of the calcium-binding proteins MRP8 and MRP14 and their heterodimer (27E10 antigen) in Crohn's disease.

Monospecific antibodies against the calcium-binding proteins MRP8 and MRP14 and their heterodimer MRP8/14 (epitope 27E10) were used to investigate immunohistochemically the distribution of these proteins in routinely processed small and large bowel tissues from patients with Crohn's disease. MRP8, MRP14, and complex MRP8/14 were demonstrated in most granulocytes and macrophages in active Crohn's disease. Additionally, a strong complex MRP8/14 immunoreactivity was present in epithelial cells of the terminal ileum adjacent to ulcerative and fissuring lesions, whereas epithelial cells in large bowel tissues were consistently negative. Our results morphologically confirm the clinical finding of increased MRP8/14 serum levels in patients with active Crohn's disease; there is evidence that the serum MRP8/14 increase is caused by active secretion from granulocytes, monocytes, and epithelial cells.

Antibodies, Monoclonal↗
PubMed1995

Adenocarcinoma of the cardia in a young man: detection of somatic p53 mutation by immunohistochemistry and automated direct sequencing.

We describe the unusual case of early-onset adenocarcinoma of the cardia in a 22-year-old male. The patient died within less than one year after diagnosis was established. By immunohistochemistry, p53 expression was observed in the tumor cells. Automated direct sequencing of polymerase chain reaction (PCR) amplified DNA revealed a homozygous transition in p53 codon 280 (AGA to GGA) as the molecular basis of p53 accumulation. Previous studies suggest that gastric carcinomas with mutations in the p53 tumor-suppressor gene are associated with particularly poor prognosis when compared with tumors without p53 mutations. Since carriers of p53 mutations in the germline have a 50 percent likelihood of developing cancer before the age of 30, we examined tumor-free tissue for the presence of a germline mutation in codon 280, but none was found.

Adenocarcinoma↗
PubMed1995

Immunohistochemically detectable bcl-2 expression in colorectal carcinoma: correlation with tumour stage and patient survival.

The bcl-2 gene encodes for a mitochondrial membrane proto-oncoprotein, the expression of which is known to suppress programmed cell death (apoptosis). In the present study the prognostic value of bcl-2 proto-oncoprotein was immunohistochemically investigated in a series of 104 colorectal carcinomas. The bcl-2 staining patterns were semiquantitatively assessed and correlated with the pTNM stage, Dukes' classification, lymphocytic infiltration (Jass classification) and tumour grade as well as parameters not associated with prognosis (gender, age, tumour site, histological tumour type). Statistical analysis was carried out using the Kaplan-Meier method, the log-rank test, hazard ratios and their confidence intervals. Fifty-five out of 104 cases completely lacked immunohistochemical bcl-2 expression. Fewer than 5% of bcl-2-positive cells were found in 25, 5-50% in 17 and more than 50% in five cases. The extent of bcl-2 expression by tumour cells decreased significantly with respect to increasing tumour size (P < 0.05), decreasing lymphocytic infiltration (P < 0.05) and chance of poor clinical outcome (P < 0.05), but not with worsening of Dukes stages. In multivariate analysis (Cox regression model) bcl-2 expression remained as an independent prognostic parameter with Dukes' classification as stratification factor (P < 0.001). Although the biological functions of bcl-2 protein are not yet well understood, our results provide further evidence that bcl-2 oncoprotein appears to be associated with favourable clinical outcome. Thus immunohistochemical bcl-2 phenotyping of colorectal carcinoma may contribute in future to the clinical management of these patients.

Adult↗
PubMed1995

Secretoneurin in bronchopulmonary carcinoids--immunohistochemical comparison with chromogranins A and B and secretogranin II.

Ninety-nine classical and 11 atypical bronchopulmonary carcinoids were investigated immunohistochemically with an antibody against secretoneurin, a peptide proteolytically processed from secretogranin II (chromogranin C), as well as antibodies against chromogranin A and B and secretogranin II. Secretoneurin was immunolocalized in 86 tumours (78 classical and eight atypical carcinoids); secretogranin II was found in the same tumours in a similar distribution, whereas chromogranin A was present in all 100 and chromogranin B in 106 tumours investigated. Bronchopulmonary carcinoids are usually not associated with clinically or biochemically distinct syndromes. Although we found bronchial carcinoids with different immunohistochemical chromogranins/secretogranin patterns, no correlation with the biological behaviour of these tumours could be demonstrated.

Carcinoid Tumor↗