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Biomedical subjects

I Ruschenburg

Publications and source records attributed to I Ruschenburg.

At least 19 recordsLinked to original sources
PubMed1999

Different gene expression of MDM2, GAGE-1, -2 and FHIT in hepatocellular carcinoma and focal nodular hyperplasia.

Overexpression and/or mutations of oncogenes, tumour suppressor genes and tumour rejection genes have been observed in several human malignancies. Their analyses might be of diagnostic importance. Therefore, malignant hepatocytes derived from hepatocellular carcinoma (HCC) tissue as well as non-malignant hepatocytes derived from focal nodular hyperplasia (FNH) were studied. Samples containing normal human hepatocytes (HC) served as controls. Cellular material was obtained by fine-needle aspiration biopsy guided by ultrasound. Cells were analysed for expression and mutation of the oncogene MDM2, the genes GAGE-1, -2 coding for tumour-associated antigens and the candidate tumour suppressor gene FHIT. Different patterns of non-mutant FHIT transcripts including precise deletion of exons were found in 7/10 HCC, 2/10 FNH and 2/10 HC. However, expression of non-mutant GAGE-1, -2 RNA was demonstrated exclusively in 6/10 HCC samples. Further genetic features specific of HCC were point mutations in a zinc-finger motif of MDM2 (3/10 HCC samples). Neither GAGE-1, -2 expression nor MDM2 mutations were observed in the FNH samples, or in normal hepatocytes. Our findings suggest that occurrence of variable FHIT transcripts is not restricted to hepatic malignant tumours. In contrast, MDM2 mutations and GAGE-1, -2 expression were associated with HCC specimens. Therefore, the RT-PCR assays for GAGE-1, -2 and MDM2 might be useful adjuncts in cytodiagnosis of liver neoplasms.

Acid Anhydride Hydrolases↗
PubMed1999

Bcl2 and Bax expression in naevi and melanomas and their relation to ploidy status and proliferation.

Twenty-five naevi, 53 primary melanomas, 36 melanoma metastases were stained immunohistochemically for the presence of Bcl2, Bax and Ki-67 antigen in order to define the relation between apoptosis regulators and proliferative activity. Additionally, ploidy status and S-phase were measured. Bax demonstrated a tendency to increase and Bcl2 was decreasing along with melanoma progression. In the group of euploid cases Bcl2 showed a strong significant correlation with Bax expression (p = 0.0001) and both Bcl2 and Bax correlated with Ki-67 expression and S-phase. In the group of aneuploid cases only the correlation Bcl2-Ki-67 was preserved. Others did not reach the level of statistical significance.

Adolescent↗
PubMed1998

The value of anti-calretinin antibody in the differential diagnosis of normal and reactive mesothelia versus metastatic tumors in effusion cytology.

In effusion cytology the distinction of reactive mesothelia from metastatic carcinoma cells may be a diagnostic challenge. Immunocytochemistry using antibodies suitable to detect epithelial cells must be considered carefully due to limited sensitivity and specificity of these antibodies. Efficient results in histological differential diagnosis of malignant mesothelioma versus lung-adenocarcinoma applying a novel antiserum against the calcium binding protein calretinin inspirated us to investigate the value of anti-calretinin antibody in effusion cytology combined with an epithelial marker. Cytoslides prepared by cytocentrifugation from 42 malignant and 65 reactive effusion specimens were immunostained using antibodies against calretinin and the epithelial marker Ber-EP4. Positive immunoreaction for calretinin in normal and reactive mesothelial cells was noted in 93% of the cases, whereas immunoreaction for calretinin was completely negative in the metastatic cells in 95% of the malignant effusions. Metastatic carcinoma cells were detected with anti-Ber-EP4 in 83% of malignant effusions. Non-specific positive reactions for Ber-EP4 in single mesothelial cells were observed in 16% of all cases and, moreover, frequently with macrophages or neutrophilic granulocytes. Our results demonstrate high sensitivity and specificity of anti-calretinin antibody for mesothelial cells in effusion specimens. They support its application to improve the diagnostic reliability of epithelial markers, especially because anti-calretinin antibody could be helpful in the assessment of false positive and false negative reactions of epithelial markers.

Antibodies, Monoclonal↗
PubMed1998

Borderline tumors of the ovary: a clinico-pathologic and immunohistochemical study of 54 cases.

OBJECTIVE: To study EGF-R, HER-2/neu (p185), p53, Mib-1 (Ki-67), Bax, Bcl-2, ras expression and ploidy in borderline tumors of the ovary by assessing their frequency, and relationship to histologic type, tumor recurrence and survival. METHODS: Fifty-four patients with borderline tumors were followed 3-140 months (median: 38 months). Paraffin-embedded sections were stained using monoclonal antibodies against EGF-R, HER-2/neu (p185), p53, Mib-1 (Ki-67), Bax, Bcl-2, and ras. The immunohistochemical findings were correlated to histologic subtype, tumor recurrence, and survival. RESULTS: Positivity for EGF-R was found in 24% (13/54), in 22% (12/54) p185 was positive, 9% (5/54) of tumors were p53-positive, Mib-1 (Ki-67)-positivity was demonstrable in 46% (25/54). Expression of Bax, Bcl-2, and ras was found in 37% (20/54), 28% (15/54) and in 7% (4/54) of the cases, respectively. CONCLUSION: The data demonstrate expression of EGF-R, p185/HER-2/neu, p53, Mib-1 (Ki-67), Bax, Bcl-2, and ras in a subgroup of patients with ovarian borderline tumors. Further studies to evaluate their prognostic value are warranted.

Adult↗
PubMed1998

Analysis of the DNA content in Bowen's disease.

The aim of this study was to evaluate the DNA content in Bowen's disease in comparison to healthy epidermis applying image cytophotometry. The material investigated was derived from 50 patients with Bowen's disease and 10 patients with healthy skin. For comparison of both groups the Kruskal-Wallis test was applied. Slides were stained with Feulgen and were evaluated with CAS-200 image analyzer. Only 7/50 morbus Bowen cases represented euploid histogram. The others 43/50 were either conspicious to be aneuploid (29/50) or clearly aneuploid (14/50). In contrast, all normal epidermis (10/10) were clearly euploid. Morbus Bowen cases demonstrated significantly higher 5c exceeding rate (p=0.0012) and significantly more cells in the S-phase (p=0.017). High aneuploidy rate and increased proliferative activity in morbus Bowen cases support the classification of these lesion as carcinoma in situ.

Aged↗
PubMed1998

Comparison of ploidy status of melanoma metastases in different locations.

The main aim of this study was to evaluate the DNA content and ploidy status of 29 melanoma metastases in lymph nodes, as well as 10 liver, 12 brain, 13 lung and 2 gastrointestinal metastases. All cases investigated were either suspicious to be aneuploid or clearly aneuploid. This study demonstrates differences of ploidy related parameters between melanoma metastases of different locations. The 5c exceeding rate values were the lowest in lymph node metastases and the highest in melanoma cells in the brain (p<0.05). The rate of cells in S-phase ranged between 12% in gastrointestinal metastases and 23% in liver metastases. The melanoma cells, which formed liver metastases had smaller area, lower mass and bigger shape factors in comparison with melanoma cells in lymph nodes.

Adult↗
PubMed1998

The value of PCR technique in fine needle aspiration biopsy of salivary gland for diagnosis of low-grade B-cell lymphoma.

In fine needle aspiration biopsy (FNAB) of salivary gland delineation of low-grade B-cell lymphoma from benign lymphoid lesions of myoepithelial sialadenitis (MESA) may be very difficult by means of cytomorphological criteria alone. To improve cytodiagnosis PCR technique was applied on routinely stained smears to determine clonal status by amplifying the third complementarity-determining region (CDR3) of the hypervariable domain of the immunoglobulin heavy chain. Twelve cases diagnosed cytologically as suspicious of low-grade B-NHL with following histology of B-NHL (n = 5) or MESA (n = 7) were analyzed. The CDR3-IgH PCR produced distinct bands in 10/12 cases. The PCR products were analyzed with Genescan software on the DNA sequencer, which demonstrated monoclonal bands in all NHLs and in one case of MESA. The results indicate that PCR technique may be helpful in improving cytodiagnostic accuracy for recognition of low-grade B-NHL of salivary gland.

Biopsy, Fine-Needle↗
PubMed1998

Comparison of the DNA content in recurrent and nonrecurrent basaliomas of the face.

The ploidy status of 5 recurrent and 7 nonrecurrent basaliomas was investigated using a CAS 200 image analyser. All recurrent basaliomas were aneuploid in contrast to nonrecurrent ones representing the euploid status. The percentage of cells in S phase in recurrent basaliomas was twice as high as in nonrecurrent ones. The authors conclude that aneuploidy in primary tumour can be a warning signal for recurrences and these patients should undergo special control.

Aged↗
PubMed1997

Point mutations and nucleotide insertions in the MDM2 zinc finger structure of human tumours.

This study investigates the human oncoprotein MDM2, which interferes with regulation of cell division and apoptosis. Fifteen mixed-type follicular non-Hodgkin's lymphomas, ten leukaemias, two hepatocellular carcinomas, one osteosarcoma, and ten normal cell lines (fibroblasts, osteoblasts, mesothelium, peripheral lymphocytes) were tested for MDM2 expression and MDM2 gene mutation by reverse transcriptase-polymerase chain reaction (RT-PCR), immunocytochemistry, and nucleotide sequence analysis. Two follicular lymphomas, three leukaemias, both hepatocellular carcinomas, and the osteosarcoma sample showed transcription of the activated MDM2 gene. These samples lacked amplified MDM2 genes and carried mis-sense, non-sense and frame-shift mutations in a zinc finger region of MDM2, altering the amino acid sequence or causing premature termination of transcription. The mis-sense mutations were found in tumour cells that showed significant accumulation of MDM2 and lack of nuclear p53. Non-sense mutations and frame-shift mutations were found in tumours lacking MDM2 proteins. The mutations may affect the biological properties of MDM2 proteins.

Amino Acid Sequence↗
PubMed1997

Automated molecular genetic DNA analysis for detecting B-cell non-Hodgkin's lymphoma in cytologic specimens.

OBJECTIVE: In fine needle aspiration cytology, conventional morphologic and immunocytologic criteria are often insufficient for distinguishing the mixed type of follicular lymphoma (NHL) from reactive lymphoid hyperplasia (RLH). For improving cytodiagnosis, we adapted computer-assisted polymerase chain reaction (PCR) assays on cytologic specimens. These novel techniques aim at fluorescence-based sequencing and sizing of PCR products that result from NHL-specific markers, such as the chromosomal t(14;18) (q32;q21) translocation and the CDR3 regions of expanded B-cell neoplasia. STUDY DESIGN: Aspirates from eight cases with mixed-type follicular NHL and from nine cases with a cytologic finding of RLH were investigated by PCR and with an automated laser scanning system. RESULTS: PCR detected the t(14;18) translocation in 5/8 B cell NHL samples and 1/9 RLH samples. By means of automated DNA sequencing, two of the five positive probes in the group of NHLs were identified as false positive. The CDR3 regions of expanded B-cell clones were found in four of eight NHL aspirates by means of PCR and computer-assisted analysis. CONCLUSION: This study proved the reliability of automated genetic assays for diagnosing low grade B-cell NHLs in aspirates since false positive results are excluded.

Biopsy, Needle↗
PubMed1993

Application of form features in digital cell analysis of non-Hodgkin's lymphomas.

The form of a biological cell nucleus can be characterized by the well-known circularity factor, which is derived from the area of an object and its circumference. More sophisticated form features are introduced, which are calculated from the curvature of an object ("bending energy") or from invariant moments. To investigate the sensitivity of the various form features on controlled changes of form and the behaviour under rotation and scaling, algebraic curves similar to the form of real nucleus profiles are generated. Analysis of the shape characteristics of biological cells requires an extraction of the boundaries of the nuclei. This was performed by an edge detection algorithm using eight gradient masks followed by a contour tracing procedure with feedback. The suitability of the introduced form features for classification of different nucleus profiles of non-Hodgkin's lymphomas (NHL) was tested using a Bayes classifier.

Algorithms↗
PubMed1987

Decrease in glucokinase and glucose-6-phosphatase and increase in hexokinase in putative preneoplastic lesions of rat liver.

Preneoplastic liver lesions were produced in female Wistar rats by oral administration of 2-acetylaminofluorene for 165 days succeeded by a carcinogen-free standard diet up to 420 days. During the treatment numerous altered hepatic foci (AHF) and hyperplastic nodules (HN) were detected histochemically by a focal decrease or lack of adenosine-5-triphosphatase and glucose-6-phosphatase (G-6-Pase) activities. In addition, the immunohistochemically demonstrable amount of L-type pyruvate kinase was clearly reduced. The histochemically demonstrated decrease of G-6-Pase was substantiated by microbiochemical determination of the enzyme activity in microdissected material. Moreover, during the experimental period a continuous decrease in glucokinase and an increase in hexokinase was detected microbiochemically within AHF and HN. These alterations indicate a shift in the carbohydrate metabolism from gluconeogenesis to glucose utilization and pentose-phosphate-pathway for biosynthesis of nucleic acids. Beside other oncofetal markers, HK may be used as indicator of the early stages of liver carcinogenesis.

2-Acetylaminofluorene↗
PubMedDate not supplied

Reverse transcriptase polymerase chain reaction for detecting Ewing's sarcoma in archival fine needle aspiration biopsies.

OBJECTIVE: Previous studies on pediatric soft tissue sarcomas have demonstrated a chromosomal 11;22 (q24;q12) translocation in Ewing's sarcoma (ES) and peripheral primitive neuroectodermal tumors that appears to be a unique oncogenic marker. To investigate the usefulness of reverse transcriptase polymerase chain reaction (RT-PCR) as an ancillary method for cytodiagnosis, we tested archival aspirates derived from ES patients to establish whether any beta-actin RNA expression or tumor-specific EWS/FLI-1 gene translocation had occurred. STUDY DESIGN: Sixteen skeletal specimens aspirated 10-15 years earlier from patients with cytologic and histologic diagnoses of ES were prepared for PCR. The amplification products were sequenced. RESULTS: Amplifiable RNA was detected in smears from 12 patients by beta-actin RT-PCR. Seven aspirates from beta-actin-positive patients showed ES-specific genomic translocation (58%). Sequence analysis of the resulting PCR fragments revealed EWS/FLI-1 fusion transcriptions of varying length. CONCLUSION: When RNA was retrievable, RT-PCR applied to routinely stained aspirate smears was a highly specific method in differential diagnosis of ES.

Base Sequence↗
PubMedDate not supplied

Loss of DNA-mismatch repair gene expression in oral melanomas.

The defect of DNA mismatch repair is postulated to be responsible for malignant transformation in many types of tumours. The main aim of this study was to evaluate the expression of DNA mismatch repair proteins in 29 cases of oral melanomas and to relate this to the ploidy status of the lesions. MLH1 expression was found in 4/29, MSH2 in 6/29, PMS2 in 2/29 and PMS1 in 0/29 cases investigated. The range of positively stained cells did not exceed 50% with MSH2, and PMS2, or 5% with MLH1. Loss of the DNA mismatch repair gene expression correlated with high aneuploidy ratio, observed in totally negative cases.

Adaptor Proteins, Signal Transducing↗
PubMedDate not supplied

How can one explain aneuploidy status in fibromatous and lipomatous naevus cell naevus?

34 lightly fibromatous, 23 heavily fibromatous, 5 lipomatous and 10 naevus cell naevi were stained with Feulgen kit in order to evaluate their ploidy status with CAS 200 image analyzer. 26/34 lightly fibromatous, 18/23 heavily fibromatous, and 5/5 lipomatous naevi were either suspicious for aneuploidy (Auer III) or clearly aneuploid (Auer IV). In contrast all 10/10 naevus cell naevi were euploid. Proliferation (S-phase) was not increased in naevi fibromatously and lipomatously changed. The mechanisms leading to aneuploidy are discussed.

Adult↗
PubMedDate not supplied

Expression of DNA mismatch repair genes in naevi.

The significant difference of DNA mismatch repair genes expression between naevi and melanomas was demonstrated by our research group in the previous study. The main aim of this study was to compare the expression of MLH1, MSH2, PMS1 and PMS2 in 31 naevus cell naevi, 12 fibromatous naevi and 30 dysplastic naevi. The expression of DNA mismatch repair proteins was found in all naevi investigated. However, the expression (percentage of positively stained cells) was significantly higher in naevus cell naevi than in dysplastic and fibromatous ones.

Adaptor Proteins, Signal Transducing↗