PubMed Health⌕ Search

Biomedical subjects

C Poremba

Publications and source records attributed to C Poremba.

At least 55 records · Page 3Linked to original sources
PubMed1999

BCL-2 expression and inhibin-A in adrenal neoplasms: a comparative study.

Differential diagnosis between adrenal cortical and adrenal medullary lesions may be difficult in many cases. Different immunohistochemical, histochemical tools as well as ultrastructural diagnostic techniques have been employed to aid in differentiating between these lesions. Recently, both inhibin-A and BCL-2 have been shown to stain selectively adrenal cortical tissue and its derived neoplasms but not adrenal medulla or pheochromocytomas. In this study we compared the staining reactions of inhibin-A and BCL-2 in cases of adrenal cortical adenomas and carcinomas as well as pheochromocytomas. We found that both inhibin-A and BCL-2 stained cortical derived tissues, but not medullary derived tissues. Staining intensity for inhibin-A was significantly weaker than for BCL-2. We found that fixation techniques may influence the staining reactivity, as some cases did not immunoreact with any of the antibodies. We conclude that both inhibin-A, and, preferentially, BCL-2 are useful additions to a staining protocol to help in the differential diagnosis of cortical and medullary neoplasms.

Adenoma↗
PubMed1998

The Ewing tumor family of peripheral primitive neuroectodermal tumors expresses human gastrin-releasing peptide.

The Ewing tumor family of peripheral primitive neuroectodermal tumors (pPNETs) are characterized by chromosomal translocations leading to EWS-ETS gene fusions. These hybrid genes express chimeric proteins that are thought to act as aberrant transcription factors. We therefore used differential display-PCR to compare gene expression patterns in pPNET cell lines with those of other small round cell tumors (SRCTs) of childhood. This technique detected differential expression of sequences corresponding to human gastrin-releasing peptide (GRP) in pPNET cell lines but not in other SRCT cell lines. Subsequent Northern and reverse transcription-PCR analysis of SRCT cell lines confirmed GRP positivity in all pPNET lines tested. Of primary tumors tested by reverse transcription-PCR, GRP expression was found in 7 (44%) of 16 pPNETs but in no other primary SRCTs examined. Expression of the GRP receptor gene was demonstrable in 55% of pPNET cell lines and 25% of primary pPNET tumors but also in several other SRCTs. Radioimmunoassays and immunohistochemistry confirmed expression of bioactive GRP peptide in pPNET cell lines and primary tumors, respectively. Moreover, in vitro growth of a pPNET cell line was slowed by treatment with a GRP receptor antagonist and accelerated by a GRP receptor agonist. GRP is a known autocrine growth factor in small cell lung cancer and other neuroendocrine tumors. Its expression in pPNETs provides further evidence for a neuroectodermal histogenesis of these tumors and suggests that autocrine growth of this family of tumors may be at least partially regulated by GRP.

Artificial Gene Fusion↗
PubMed1998

[Economic evaluation of telepathology].

Telepathology, defined as the practice of pathology over a distance by viewing images transmitted from a remote site, was previously analyzed mainly with respect to technical equipment and diagnostic accuracy compared with conventional histological diagnosis. In this paper, telepathology is analyzed with regard to economic points of view, demonstrating the background for the cost-saving analysis of telepathology. The acquisition cost and the operating costs of a telepathology system are compared with potential cost-saving and other benefits from telepathology. This analysis may help to decide whether or not telepathology should be established in a hospital.

Cost-Benefit Analysis↗
PubMed1998

Loss of heterozygosity of the von Hippel Lindau gene locus in polypoid dysplasia but not flat dysplasia in ulcerative colitis or sporadic adenomas.

Carcinoma in ulcerative colitis (UC) develops from dysplastic precursor lesions, which include flat dysplasia (FD) and polypoid dysplasias (PD). PD may present as single or multiple polypoid structures or as plaque-like lesions that, independent of histological grade, are an indication for colectomy. PDs are histologically similar to adenomas and may not be readily distinguished by light microscopy. It is not known whether FD and PD are different entities, or whether they represent etiologically similar lesions with different morphological expression. We microdissected 25 cases of UC with PD and 19 samples of FD with surrounding chronic colitis (CC) in UC. Loss of heterozygosity (LOH) at the von Hippel Lindau (vHL) gene locus and the putative tumor suppressor genes APC, INK4A (9p16), and p53 was studied. LOH of the vHL gene, INK4A (9p16), and APC was also studied in 11 sporadic adenomas of the colon. LOH at the vHL locus was present in 50% of the samples of PD and in 12% of the samples of FD. LOH was seen in CC close to PD and FD in 26% and 12% of cases, respectively. No adenoma showed LOH of the vHL gene markers studied. LOH in p53 was seen in PD in 16% cases and in FD in 42% cases and in CC close to PD and FD in 0% and 14% cases, respectively. LOH patterns between PD and FD of the markers for APC and 9p16 were not different. LOH in APC was seen in two of five cases of adenoma. We conclude that PD and FD share genetic alterations in APC and 9p16 genes. More frequent involvement of the VHL gene in PD and surrounding CC and involvement of p53 in HGD and CC in FD may represent genetic differences between the development of PD and FD and may be the cause of the different morphology. The infrequency of LOH at the vHL locus in adenomas versus PD may serve as a discriminator between adenomas and PD in diagnostically problematic cases.

Adenoma↗
PubMed1998

Metastatic retroperitoneal paraganglioma in a 16-year-old girl. Case report, molecular pathological and cytogenetic findings.

Retroperitoneal paraganglioma is a rare tumor, especially occurring in childhood and adolescence, with a marked tendency to become biologically malignant. It has not been possible to predict the clinical outcome of paraganglioma patients by conventional histology, hence malignancy can only be demonstrated by the occurrence of metastatic lesions. Currently, only limited information on the genetics of this tumor is available. We report on a 16-year-old girl with a large retroperitoneal paraganglioma and an osseous metastasis to the first lumbar vertebra. In addition to morphological and immunohistochemical examinations, a molecular cytogenetic analysis was performed. Comparative genomic hybridization (CGH) revealed imbalanced chromosomal aberrations with a loss of chromosome 1p and a gain of 1q, indicating isochromosome 1q. A loss of chromosome 3 as well as low-level gains of chromosomes 4, 5, 6q, 11q and 13q were detected. A PCR-based microsatellite analysis of 1p confirmed the loss of heterozygosity, including NB1 and NB2 putative tumor-suppressor gene regions. Telomerase activity, which is found in the majority of malignant tumors, could not be detected. The case presented here is the first more comprehensive molecular genetic analysis of a sporadic malignant paraganglioma.

Adolescent↗
PubMed1998

Comparative genomic hybridization and telomerase activity analysis identify two biologically different groups of 4s neuroblastomas.

Chromosomal aberrations of 20 stage 4s neuroblastomas were analysed by comparative genomic hybridization (CGH). In a subset of 13/20 tumours, telomerase activity was evaluated by the telomeric repeat amplification protocol (TRAP). The CGH data were compared with the CGH results of ten stage 1 and 2 (stage 1/2) and 22 stage 3 and 4 (stage 3/4) neuroblastomas. A total of 17/20 stage 4s neuroblastomas did not progress clinically, whereas tumour progression with lethal outcome occurred in 3/20 cases. The CGH data of clinically non-progressing stage 4s tumours revealed a high rate of whole-chromosome aberrations (73.4%) with an overrepresentation of mainly chromosomes 2, 6, 7, 12, 13, 17, 18 and an underrepresentation of mainly chromosomes 3, 4, 11, 14. MYCN amplification or 1p deletion was observed in only 1/27 or 2/17 clinically non-progressing stage 4s tumours respectively, whereas all three progressive stage 4s neuroblastomas showed MYCN amplification, 1p deletion and, in 2/3 cases, distal 17q gains. Except for one case, telomerase activity was not observed in non-progressing stage 4s neuroblastomas. In contrast, 4s tumours with lethal outcome revealed elevated telomerase activity levels. Our data suggest that stage 4s neuroblastomas belong to two biologically different groups, one of which displays the genetic features of localized stage 1/2 tumours, whereas the other mimics advanced stage 3/4 neuroblastomas.

Blotting, Southern↗
PubMed1998

A fast non-fluorescent staining method for the detection of primed in situ synthesis products.

For the assessment of chromosomal numeral aberrations in cells, the method of choice is fluorescent in situ hybridisation (FISH) or, a newly introduced technique, oligonucleotide primed in situ hybridisation (PRINS). In the PRINS method labeled nucleotides are incorporated into newly synthesized DNA mediated through the Taq polymerase. Both PRINS and FISH reactions are visualized with a fluorescent light detection system. We present a method whereby PRINS products can be reliably and rapidly visualized by a streptavidin DAB detection system.

3,3'-Diaminobenzidine↗
PubMed1998

Telomerase activity in human proliferative breast lesions.

Telomerase, a cellular reverse transcriptase, has been detected in the majority of human malignant tumors, where it provides an escape mechanism from proliferative limitations due to progressive telomere erosion with each cell division. In this study, we used a non-radioactive telomeric repeat amplification protocol (TRAP) with an internal telomerase assay standard for the detection and semiquantitative analysis of 98 single frozen sections of normal breast tissue and benign and malignant breast lesions on an automated laser-fluorescence sequencer. Telomerase activity was detected in 36 of 40 (90%) infiltrating breast carcinomas, whereas no activity was found in nonmalignant breast tissues including blunt duct adenosis, papilloma, ductal hyperplasia and atypical ductal hyperplasia. However, telomerase activity was detected in 59% of ductal in situ carcinomas, suggesting that telomerase reactivation is an early event in breast carcinogenesis. We found a positive correlation between telomerase activity levels and cell proliferation determined by MIB1 immunostaining. No correlation, however, could be demonstrated between telomerase activity and other known breast cancer prognostic indicators. Telomerase activity was also detected in 60% of fibroadenomas indicating that careful interpretation of analysis of telomerase activity in fine needle aspirates is required, since low telomerase activity may not necessarily be an indicator of malignancy in breast tissue.

Breast↗
PubMed1998

[Evidence of genetic alterations in chromosome 11 in embryonal and alveolar rhabdomyosarcoma].

Various chromosome 11 alterations have been described in rhabdomyosarcoma (RMS). Allelic losses of 11p15.5 are characteristic of embryonal RMS (eRMS), whereas an increase in the expression of the Igf2 gene located on 11p15.5 has regularly been observed in eRMS and alveolar RMS (aRMS). The aim of our study was to analyse chromosome 11 alterations of RMS by combining different molecular-genetic and cytogenetic methods. 16 RMSs (7 aRMS with proven 2;13 or 1;13 translocations, 9 eRMS) were studied by a PCR-based microsatellite analysis of loci 11p15.5 and 11q23. Comparative genomic hybridization (CGH) was performed in 8/16 cases. The ploidy status of chromosome 11 was evaluated using the FISH technique. A RT-PCR analysis of Igf2 gene region was performed to evaluate the imprinting status. Allelic losses (LOH) of 11p15.5 were observed in 4/7 aRMS and 8/9 eRMS. These losses were accompanied by LOH of 11q23 in 2/7 aRMS and 5/9 eRMS, respectively. CGH of all the eRMSs and one aRMS studied revealed gains of genetic material mostly involving the entire length of chromosome 11. One aRMS showed a loss of chromosome 11 material, both in CGH and LOH analysis. In 2/9 aRMS, which neither in CGH nor in LOH analysis had exhibited chromosome 11 alterations, biallelic IGF-II expression was revealed. Our results show that chromosome 11 alterations play a major role in the biology of both alveolar and eRMS. Combining the data of our study, we demonstrated that three different chromosome 11 alterations are involved in the tumorigenesis of RMS: 1) LOH resulting in hemizygosity of chromosome 11. 2) LOH with simultaneous gains of chromosome 11 material due to uniparental polysomy. 3) loss of imprinting for the Igf2 gene in the absence of gross chromosome 11 alterations.

Chromosome Aberrations↗
PubMed1998

bcl-2 expression in normal adrenal glands and in adrenal neoplasms.

Archival paraffin-embedded tissue from 5 normal adrenal glands (including 1 from a fetus of 28 weeks' gestation), 6 cases of adrenal cortical hyperplasia, 9 cortical adenomas, 14 cortical carcinomas, and 11 pheochromocytomas were immunostained with monoclonal antibody against bcl-2. Ultrastructural localization of bcl-2 protein was also performed on selected cases. Positive immunostaining for bcl-2 was seen in all of the layers of the normal adrenal cortex, with different staining characteristics. bcl-2 expression was never observed in the normal adrenal medulla. Electron microscopic studies revealed bcl-2 to be localized predominantly to mitochondria, with a small number of labels along the nuclear envelope. Analysis of adrenal neoplasms showed expression of bcl-2 in cortical tumors, but only one positive case in pheochromocytomas. Restriction of bcl-2 expression to adrenal cortex-derived tissue versus adrenal medulla-derived tissue might prove to be helpful for the differential diagnosis between cortical and medullary tumors.

Adolescent↗
PubMed1997

[Lupus vulgaris as the etiology of tuberculous mastitis].

We report the rare case of granulomatous tuberculous mastitis based on lupus vulgaris in a 73-year-old female patient. The most important diagnostic procedure was the detection of mycobacterial DNA-sequences in paraffin-embedded tissues using the polymerase-chain-reaction (PCR). A combined antituberculous therapy lead to complete remission within 14 months after the diagnosis was established. The incidence of tuberculous mastitis among surgically treated lesions of the breast is less than 0.025 percent. Because of the frequent localisation of this disease in the upper outer quadrant of the breast and suspicious findings in mammography, tuberculous mastitis is one, even if rare, differential diagnosis for breast cancer.

Aged↗
PubMed1997

Factor XIIIa expression in granulomatous lesions due to sarcoidosis or mycobacterial infection.

The a-subunit of the clotting factor XIII (FXIIIa) has previously been shown to be synthesized by cells of monocyte lineage such as macrophages and histiocytes. Thus, besides clot retraction, a possible role of FXIIIa has also been postulated in inflammation. In order to test this hypothesis, FXIIIa-expression in granulomatous lesions due to sarcoidosis and mycobacterial infection was investigated. In the 12 cases (six cases each) examined, FXIIIa-positive macrophages were consistently detected by immunohistochemistry. They were predominantly observed in the periphery of granulomas, whereas the centers were generally devoid of these cells. We did not find any difference in the distribution of FXIIIa-positive cells in both conditions; thus FXIIIa did not improve the differential diagnosis between sarcoidosis and tuberculosis. However, FXIIIa-producing macrophages seemed to contribute to the centripetal fibrosis in granuloma. These results further suggest that the basic pathogenetic mechanisms in granuloma formation are very similar, regardless of their origin from sarcoidosis or tuberculosis.

Adolescent↗
PubMed1996

[Tumor suppressor gene p53. Theoretical principles and their significance for pathology].

Mutations of the p53 tumor-suppressor gene are the most common genetic alterations in human cancer, found in approximately 50% of all tumors. The importance of p53 in human cancer attracts attention in molecular studies dealing with the pathogenesis, diagnosis and prognosis in tumor pathology. This review summarizes the current understanding of p53 both on the genetic and protein level. Frequency and spectrum of somatic p53 mutations in the carcinogenesis of breast cancer, colorectal cancer, gastric cancer, hepatocellular carcinoma, squamous-cell carcinoma of the skin and malignant melanoma are discussed including our own investigations and studies published in the literature.

Animals↗
PubMed1996

[Polypoid ulcerating endocarditis aortalis caused by Streptococcus viridans with perforation of the right atrium. Pathology and clinical aspects of 2 autopsy cases].

We report two cases of patients (one 65 and one 43 years of age, respectively) who died of Streptococcus-viridans induced endocarditis of the aortic valve with perforation into the right atrium. Whereas perforation in Staphylococcus-induced endocarditis is a common complication, it occurs rarely in Streptococcus-induced endocarditis. Because of its uncharacteristic symptoms, the endocarditis was clinically unknown in both cases and was recognized to be the cause of death only at autopsy. To reduce the large number of complications in patients suffering from endocarditis, it is necessary to confirm the diagnosis as soon as possible if endocarditis might be suspected.

Adult↗
PubMed1996

A new germline TP53 gene mutation in a family with Li-Fraumeni syndrome.

This report describes an unusual clinical presentation of Li-Fraumeni syndrome. Family history revealed a mild aggregation of adult cancers in one generation, and an unusual clustering of brain tumours of early childhood in the following generation. In order to evaluate the genetic basis for cancer predisposition in this family, molecular genetic analysis for the occurrence of germline TP53 tumour suppressor gene mutations was performed on 12 siblings of two generations. Indirect mutation analysis was performed by the single-strand conformation polymorphism (SSCP) technique. Alterations were characterised by automated direct fluorescence sequencing analysis. Tumour material was also examined for p53 protein accumulation by immunohistochemistry. Initially, a TP53 gene germline missense mutation was detected in an 11-year-old kindred with acute myeloid leukaemia (AML) following intensive treatment of a brain tumour. In peripheral blood and bone marrow samples of this proband, a reduction to hemizygosity occurred. During AML treatment, detection of LOH of 17p was used as a marker for clonality and treatment control. The mutation was found to be inherited from the proband's mother, who was diagnosed with breast cancer at the age of 48 years. Further, three siblings were carriers, and two are apparently healthy at the age of 21 and 23 years. Knowledge of germline mutations may allow accurate DNA-based carrier diagnosis which is of important clinical significance for treatment strategy and control. Furthermore, the occurrence of unaffected carriers in this family raises questions about appropriate methods of cancer surveillance and counselling for these people.

Adult↗
PubMed1996

Ovarian, peritoneal, and endometrial serous carcinoma: clonal origin of multifocal disease.

The clonality of disseminated serous carcinoma involving the ovary, peritoneum, and, occasionally, the endometrium is controversial. Histopathologic examination alone cannot unequivocally distinguish between a monoclonal origin and a multicentric origin. Two patients with peritoneal serous carcinoma with minimal ovarian involvement (one with endometrial serous carcinoma), nine patients with stage III bilateral ovarian carcinoma, and one patient with stage III bilateral carcinosarcoma were studied for clonality. One patient with ovarian carcinoma that recurred after chemotherapy was also studied. Previous analyses of single frozen tumor specimens from these patients had identified different p53 gene mutations in each patient. To test the hypothesis that the disseminated cancers had a monoclonal origin, we assayed DNA from numerous foci from each patient to determine whether the known p53 mutation was present in each specimen. Identical mutations were detected in the tumor foci from each patient with peritoneal dissemination and minimal ovarian involvement, including one patient with an endometrial serous carcinoma as well. In all the patients with bilateral ovarian cancer, the genetic change in p53 was identical in both ovarian tumors. Genetic progression was observed in two patients, one of whom showed a loss of heterozygosity involving the p53 gene in a recurrent tumor. In the second patient, a p53 mutation not present in either ovarian tumor was detected in a metastatic tumor from the omentum. These results strongly suggest that disseminated serous carcinomas, whether primary in the ovary, endometrium, or peritoneum, are of monoclonal rather than multicentric origin; that bilateral stage III ovarian cancers are typically of monoclonal origin; and that additional genetic events involving p53 might occur during progression of these tumors.

Aged↗
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↗