Biomedical subjects

B Suchy

Publications and source records attributed to B Suchy.

13 recordsLinked to original sources

PubMed2000

Detection of mammaglobin expressing cells in blood of breast cancer patients.

Expression of human mammaglobin (hMAM) was published to be exclusively expressed in mammary tissue, in solid tumors, axillary lymph nodes and disseminated cancer cells in blood of breast cancer patients. A quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) test was applied to investigate hMAM expression in blood of breast cancer patients. Mammaglobin mRNA expression was found not only in breast cancer cell lines but also in cell lines of other cancer origin. In our patient cohort hMAM expression in 11/98 (11%) samples of breast cancer and 3/12 (25%) ovarian cancer patients could be detected. hMAM mRNA expression as a candidate marker for the detection of disseminated cancer cells in blood of breast cancer patients showed low sensitivity and reduced tissue specificity. A prognostic significance of hMAM expression could not be demonstrated.

Adult↗

PubMed2000

Prognostic value of genomic alterations in minimal residual cancer cells purified from the blood of breast cancer patients.

The prognostic value of disseminated tumour cells derived from 353 breast cancer patients was evaluated. Disseminated tumour cells were purified from blood using a newly established method and nucleic acids were subsequently isolated. We investigated genomic imbalances (GI) such as mutation, amplification and loss of heterozygosity of 13 tumour suppressor genes and 2 proto-oncogenes using DNA from isolated minimal residual cancer cells. Significant correlations were found between genomic alterations of the DCC - and c-erbB-2 genes in disseminated breast cancer cells and actuarial relapse-free survival. Furthermore, increasing numbers of genomic imbalances measured in disseminated tumour cells were significantly associated with worse prognosis of recurrent disease. Logistic regression and Cox multivariate analysis led to the identification of genomic imbalances as an independent prognostic factor. Determination of disseminated tumour cells by genotyping of oncogenes and tumour suppressor genes seems not only to be a useful adjunct in follow up of carcinoma patients but provides also valuable additional individualized prognostic and predictive information in breast cancer patients beyond the TNM system.

Adult↗

PubMed1998

Absence of RAS and p53 mutations in thyroid carcinomas of children after Chernobyl in contrast to adult thyroid tumours.

Thyroid carcinomas of an additional series of 34 children exposed to radioactive fall-out after the Chernobyl reactor accident were analysed for mutations in the H-, K- and N-RAS and the p53 gene. Allele-specific oligonucleotide hybridization, single-strand conformation polymorphism (SSCP) and direct sequencing did not disclose mutations in codons 12, 13 and 61 of RAS genes nor mutations in exons 5, 7 and 8 of p53. Considering the recently reported high prevalence of RET rearrangements of the PTC3 type in childhood tumours after Chernobyl (Klugbauer et al, 1995, Oncogene 11: 2459-2467), it follows that RET rearrangements are the most relevant molecular aberration in these radiation-induced tumours. RAS or p53 mutations do not play a role in childhood thyroid carcinogenesis after Chernobyl.

Adult↗

PubMed1997

Interphase cytogenetic analysis of mucinous ovarian neoplasms.

Extending our previous efforts to characterize ovarian neoplasms by interphase cytogenetics, we analyzed a series of 32 mucinous tumors by nonisotopic in situ hybridization with seven different centromere-specific probes as well as by flow and image DNA cytometry; we then compared the data with results of p53 and Ki67 immunohistochemistry and MYC DNA-PCR analysis and of the clinical follow-ups. Of the tumors studied, 11 of 14 (78.6%) mucinous carcinomas, 7 of 7 (100%) mucinous tumors of low malignant potential (LMP), and 7 of 11 (63.6%) mucinous cystadenomas demonstrated chromosomal aberrations. The mean number of chromosomal aberrations (+/- SD) was slightly higher in DNA cytometrically nondiploid cases than in diploid cases (2.0 +/- 1.6 versus 1.6 +/- 1.2, not significant) but did not differ significantly among the study groups (carcinomas: 1.7 +/- 1.4; tumors of LMP; 1.9 +/- 0.7; adenomas: 1.4 +/- 1.4). Aberrations affected chromosomes 1 (14 of 27 cases) and 6 (12 of 31) most frequently, followed by chromosomes 17 (7 of 28), 7 (6 of 29), and X (6 of 28). Signal gain for centromere 1, which was the most prevalent finding (13 of 27), was observed in 3 of 10 mucinous cystadenomas, 2 of 4 mucinous tumors of LMP, and 8 of 13 mucinous carcinomas. All six moderately and poorly differentiated carcinomas demonstrated this aberration. Signal gain of centromere 6 (3 of 13) and centromere 7 (4 of 13) were found only in carcinomas (p < 0.05 and p < 0.025, respectively). The interphase cytogenetic results correlated neither with proliferative activity, immunohistochemical p53 accumulation, MYC DNA amplification, nor postoperative outcome. Compared with serous ovarian neoplasms (Lab Invest 1996, 75:473-485), mucinous tumors demonstrated signal gain for chromosome 1 (p < 0.0001) and signal loss for chromosomes 6 (p < 0.001) and X (p < 0.01) significantly more often. Loss of centromere 17 was more characteristic for serous than for mucinous carcinomas (p < 0.05). Our observations show that chromosomal aberrations in mucinous ovarian neoplasms are apparently not random. These results support the notion that the molecular genetic changes in mucinous neoplasms differ from those in serous tumors.

Adenocarcinoma, Mucinous↗

PubMed1996

DNA ploidy and MYC DNA amplification in ovarian carcinomas. Correlation with p53 and bcl-2 expression, proliferative activity and prognosis.

There is increasing evidence that DNA ploidy is a prognostic factor in ovarian carcinomas, but it is uncertain whether MYC DNA amplification is an epiphenomenon of DNA nondiploidy or a distinct biological change with an impact on the clinical course of the disease. To clarify these issues we analysed DNA ploidy by flow and image cytometry and MYC copy number by polymerase chain reaction in archival material from ovarian carcinomas with known follow up. The results were compared with proliferative activity (Ki67 index) and p53 and bcl-2 expression. DNA cytometry revealed nondiploidy in 84 of 144 cases (58.3%). Nondiploidy was statistically significantly correlated with histological tumour type, histological grade, Ki67 index > 10%, FIGO stage, presence of residual tumour after debulking surgery and adverse postoperative outcome. Furthermore, DNA nondiploidy was associated with p53 accumulation. We found that 84.9% of the p53-positive cases were nondiploid. This points to the paramount importance of wild type p53 for the maintenance of genome integrity in this tumour type. MYC DNA amplification was seen in 33.8% (26/77 cases) of ovarian carcinoma. There was no correlation between MYC DNA amplification and histological tumour type, histological grade, FIGO stage, DNA ploidy, proliferative activity or prognosis. However, when p53 and bcl-2 expression was taken into account, a statistically significant correlation between gene alteration or expression patterns and histological tumour type was revealed. The group of mucinous carcinomas demonstrated both MYC DNA amplification and strong bcl-2 expression in 50% and contained the largest fraction of cases without aberration (37.5%). Endometrioid carcinomas were characterized by strong bcl-2 expression in 85%, whereas serous and undifferentiated carcinomas predominantly exhibited p53 alterations, frequently accompanied by bcl-2 overexpression or MYC DNA amplification. Thus, in interaction with other genes MYC DNA amplification may play a role in the determination of the varying differentiation patterns of ovarian carcinomas.

Aged↗

PubMed1996

Interphase cytogenetic analysis of serous ovarian tumors of low malignant potential: comparison with serous cystadenomas and invasive serous carcinomas.

The cytogenetic and molecular genetic changes in serous tumors of low malignant potential (LMP) of the ovary have not been well characterized so far. Therefore, we analyzed 20 serous tumors of LMP, 10 invasive serous ovarian carcinomas, and 7 benign serous cystadenomas by nonisotopic in situ hybridization (seven different centromere-specific probes) as well as by flow and image DNA cytometry and compared the data with results of p53 and Ki67 immunohistochemistry, MYC DNA PCR analysis and with the clinical follow-up. All but two tumors of LMP were DNA cytometrically diploid; 9 of 10 invasive carcinomas proved to be DNA nondiploid (p < 0.0001). Nonisotopic in situ hybridization revealed a mean number of 1.5 chromosomal aberrations in tumors of LMP, which differed statistically significantly from cystadenomas (mean, 0.4) and from invasive carcinomas (mean, 3.4) (rho < 0.01). The main changes in tumors of LMP were +6 (7 of 18 cases) and +7 (6 of 19) followed by -3 (5 of 20), -1 (4 of 17) and +X (3 of 20). In the group of invasive carcinomas, the number of cases with signal gains for chromosomes 6 (5 of 8), 7 (7 of 10) and X (4 of 10) and signal loss for chromosome 1 (4 of 9) was even larger. In addition, statistically significantly more cases showed gain of 8 (5 of 10) and loss of 17 (5 of 10) (p < 0.05). Proliferative activity (Ki67 index) was positively correlated with the number of chromosomal aberrations (p < 0.05). There was no association between changes in the centromere signal number of chromosomes 8 and 17 and MYC DNA amplification and immunohistochemical p53 accumulation, respectively. Clinical follow-up showed prognostic differences between tumors of LMP and invasive carcinomas as expected (rho < 0.001) but did not reveal differences within the group of tumors of LMP with regard to the number or type of the chromosomal abnormalities detected. In conclusion, the patterns of chromosomal gains and losses in serous tumors of LMP and invasive serous carcinomas of the ovary do not seem random and suggest a close relation between these neoplasms compatible with sequential stages in a multistep model of ovarian carcinogenesis.

Adult↗

PubMed1995

[Intraoperative facial nerve monitoring in parotid surgery].

Neurophysiological monitoring of cranial motor nerves has proved to be of value in cerebellopontine and skull base surgery. Unfortunately, facial nerve monitoring has been used infrequently for routine parotid gland surgery because suspicion of expense, possible unreliability and the requirement for extra personnel. This study presents clinical experience at the University of Erlangen with facial nerve monitoring during parotid gland surgery done by residents. Advantages are also emphasized for the experienced ENT-surgeon for use during revision parotidectomy. In 35 consecutive patients with benign parotid gland tumors intraoperative monitoring of the facial nerve was done using two different two-channel electromyography units. Bipolar coaxial electrical stimulation was superior to the monopolar stimulation mode. The average operative time and postoperative functional results were compared with those of a control group consisting of 24 patients without monitoring. Findings demonstrated a reduction is operative time and better functional outcome in the patient group with monitoring. Additionally four patients had to undergo total revision parotidectomy because of recurrent benign tumors, while one patient suffered from chronic parotitis due to sialolithiasis and required complete parotidectomy for relief of symptoms. No patient developed permanent facial paresis and nerve monitoring proved to be very helpful for identification and protection of the facial nerve in scar tissue.

Electric Stimulation↗

PubMed1993

Cell proliferation and prevalence of ras gene mutations in 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumors.

Exposure of female inbred Sprague-Dawley Curl rats to intragastric 7,12-dimethylbenz(a)anthracene (DMBA) resulted in a variety of benign and malignant mammary tumors exhibiting a wide spectrum of proliferative activity as measured by [3H]-thymidine autoradiography. On the basis of earlier observations of 21% H-ras codon 61 mutations in DMBA-induced rat mammary tumors reported by Zarbl et al., the prevalence of this type of ras gene mutation was studied in relation to the rate of proliferation in individual benign and malignant tumors. In a series of 50 mammary tumors exhibiting highly different proliferation activities we did not detect any H-ras codon 61 mutations after allele-specific dot blot hybridization of PCR-amplified material obtained from paraffin sections. Neither mode of proliferation nor type of differentiation appears related to H-ras codon 61 mutations. The relevance of activated ras genes for rat mammary carcinogenesis appears restricted to model systems using N-methyl-N-nitro-sourea (MNU) as initiating carcinogen.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1992

K-ras point mutations in human colorectal carcinomas: relation to aneuploidy and metastasis.

Material from paraffin sections of 109 human colorectal carcinomas, mostly obtained at autopsy, was analyzed for the presence of K-ras point mutations at codon 12, position 2. Mutations at this position were found in 23 cases (21.1%). Aneuploid colorectal carcinomas showed a significantly higher prevalence of K-ras point mutations than diploid tumors, suggesting an involvement of ras mutations in the development of aneuploidy. No differences in the prevalence of K-ras mutations were observed with respect to the patients' age, sex and tumor type. In metastases, the type of ras gene mutation was always identical to that of the respective primary tumor. Mutations were not found in metastases from primary tumors devoid of ras mutations. This renders a clonal selection of K-ras mutated cells from a wild-type primary tumor during the metastatic process unlikely. However, nearly twice as many ras gene mutations were seen in metastatic than in non-metastatic primary tumors.

Aneuploidy↗

PubMed1991

Carcinogen-induced liver tumours of Wistar rats: absence of activated ras genes and of N-rasC.

We examined mutational activation of ras genes in rat liver preneoplasias and tumours induced by diethylnitrosamine and N-methyl-N-nitrosourea (NMU). In accordance with previous reports on H- and K-ras genes, no mutations were detected in the investigated hepatic tumours and prestages suggesting that neither mutations at codons 12, 13 and 61 of H- and N-ras nor a mutation in the last intron of the H-ras gene are involved in initiation and progression of rat hepatocellular carcinomas. In the course of this investigation we found two N-ras genes (N-rasA, N-rasB). Surprisingly N-rasC, which is present in the germ line of Fischer rats, is missing in Wistar rats. This suggests different numbers of germline N-ras genes in members of one species. Two out of eight NMU-induced liver tumours exhibited additional N-ras-related sequences of unknown origin.

Animals↗

PubMed1990

[PCR: DNA amplification from histological sections].

Specific DNA sequences can be amplified from tissue material by means of the polymerase chain reaction (PCR) using oligonucleotides homologous to upstream and downstream flanking regions as primers for repeated cycles of Taq polymerase-mediated DNA synthesis (primer extension) in vitro. The amplification product provides the unique possibility to analyze genomic alterations (mutations, deletions, translocations) which may play a role during pathogenetic processes, or to detect heterologous (viral, bacterial) nucleic acids with maximum sensitivity. PCR with morphologically defined material from histologic sections gives the chance to bridge the gap between morphological description of a disease and the underlying molecular alteration. PCR from sections can be performed even from paraffin-embedded material of archival specimens. As an example a ras gene mutation analysis of human colorectal cancers and their metastasis and of human seminomas is presented. Only minute amounts of biological material are required for PCR, as exemplified with material punched from defined preneoplastic areas in rat liver cryostat sections. Using this material, not only a thorough mutational analysis of DNA of preneoplastic foci is possible after a simultaneous PCR amplification of various genomic sequences, but also an investigation of transcription activity after reverse transcription of mRNA into cDNA, as shown for c-myc expression during preneoplasia. The extremely high sensitivity of the method requires severe precaution with respect to contamination, and product control by Southern blots or sequencing. PCR from histological sections will become a valuable tool for analyzing molecular mechanisms of disease based on the classical morphological parameters of pathology.

Animals↗

PubMed1979

[Clinical results with granulocyte transfusion (author's transl)].

16 adult patients with granulocytopenia and septicemia resistant to antibiotics received 42 granulocyte transfusions. The granulocytes were obtained from healthy donors with a blood cell separator by continuous flow centrifugation. Adding hydroxyethyl-starch an average of 1.8 X 10(10) leukocytes with 69% granulocytes were harvested in 3.5 hours. A small leukocyte increment after the transfusion was seen in half of the recipients. No correlation could be found between fever lysis and survival of the infection, which occurred in half of the cases too. A granulocyte transfusion is indicated in patients, who have granulocytopenia, sepsis and no evidence of bone marrow recovery.

Adult↗

PubMedDate not supplied

Independent prognostication and therapy monitoring of breast cancer patients by DNA/RNA typing of minimal residual cancer cells.

Clinical relevance, purification techniques and molecular characterization of minimal residual cancer cells (MRCC) is a controversial topic in the literature. An analytical concept including a novel isolation procedure and a panel of tests for DNA and RNA typing of MRCCs is described and clinically evaluated in this paper. The purification procedure exploiting the physical characteristics of MRCCs shows superior performance leading to > 50% pure and viable tumor cells. Proof of the presence and purity of MRCCs in an isolated sample is given by multiparametric DNA typing (amplifications, mutations, losses of heterozygosity). On the basis of the proven presence of MRCCs tumor-relevant mRNAs can be adequately analyzed by normalized quantitative real-time RT-PCR. The molecular characterization of MRCCs isolated from blood of breast cancer patients could have a strong clinical impact on prognostication, drug targeting and therapy monitoring.

Biomarkers, Tumor↗