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D Ofner

Publications and source records attributed to D Ofner.

At least 19 recordsLinked to original sources
PubMed1998

Molecular assessment of p53 abnormalities at the invasive front of oral squamous cell carcinomas.

BACKGROUND: The prognostic significance of the invasive tumor front in squamous cell carcinomas has recently been recognized. The aim of the present study was to investigate possible molecular mechanisms underlying the significance of this area in oral squamous cell carcinomas. METHODS: We used immunohistochemical and molecular genetic techniques to investigate whether p53 alterations at the invasive tumor front could determine the aggressiveness of oral cancers. RESULTS: p53 Overexpression was detected in 52% to 56% (four different p53 antibodies) of 100 carcinomas studied. The concordance rate between results of immunohistochemistry and genetic analysis was 60%. No correlation was found between p53 status of the tumors and clinicopathologic parameters analyzed statistically. CONCLUSIONS: p53 Alterations have no prognostic impact in oral squamous cell carcinomas and apparently do not represent a molecular basis for the biologic significance of the invasive tumor front. The detection of discordant p53 aberrations between primary and second primary carcinomas in some patients provide evidence for their independent origin, with possible impact on prevention and therapy.

Adult↗
PubMed1998

Myocardial fatty acid metabolism during acute cardiac allograft rejection.

Fatty acids are promptly taken up, metabolised and eliminated by healthy cardiomyocytes. Cardiomyopathy, coronary heart disease and chronic rejection are known to be associated with an impaired fatty acid metabolism. It was the aim of this study to investigate fatty acid metabolism in a rat heart transplant model and to correlate scintigraphic findings with histological changes. After right-side nephrectomy of Lewis recipients Brown Norway cardiac allografts were anastomosed to the renal vessels. Animals were given no immunosuppression. The metabolism of carrier-free 17-123 jodo-heptadecanoic acid (123J-HDA) with a specific activity of > 2 x 10(17) Bq/ml was scintigraphically measured between days 1 and 11. An increase in the grade of rejection was observed over time. Fifty-six frames of 30 s duration each were recorded. For the region of interest (native heart, transplanted heart, left kidney) frames 10-56 were superimposed, time-activity curves generated and monoexponentially fitted. Furthermore, elimination half-life and intercepts were calculated. Following scintigraphic evaluation the animals were killed and graft as well as native hearts excised for histological examination. The uptake of the tracer identified severe grades of rejection. Elimination half-life of the tracer was twice as long from hearts with mild rejection and more than 14 times as long in severe rejection compared with no rejection. Elimination half-life and amplitude did not permit discrimination between grades 1, 2 and 3 a, but significantly decreased in groups 3 b and 4. This method therefore seems to be a valuable tool for the noninvasive detection of severe acute cardiac allograft rejection. Since fatty acid metabolism is clearly stress-dependent it remains to be seen whether this method allows detection of earlier rejection in loaded hearts.

Animals↗
PubMed1997

Standardized AgNOR analysis of the invasive tumour front in oral squamous cell carcinomas.

In the last decade, silver staining of nucleolar organizer region-associated proteins (AgNORs) has been widely used in tumour pathology both for diagnostic and for prognostic purposes. However, a reliable and reproducible assessment of these proteins on routinely processed archival tissues has only become possible since the recent introduction of standardized staining method and computer-aided morphometric analysis. In the present study, the AgNOR content at the invasive front of 80 squamous cell carcinomas of the floor of the mouth/tongue was investigated using this novel approach, with regard to prognosis and a variety of clinico-pathological parameters. All standardized AgNOR parameters [mean of AgNOR number, mean of AgNOR area, coefficients of variation (CV) of both AgNOR number and area] were statistically significantly associated with the clinical course. The strongest correlation was found for the AgNOR-area univariate analysis (P = 0.006). In multivariate analysis, the mean of AgNOR number could independently predict both overall (P = 0.01) and disease-free survival (P = 0.001). It is concluded that standardized staining and computer-aided analysis of AgNORs are prerequisites for an objective and reproducible AgNOR assessment, which has potential as a supplementary diagnostic and prognostic tool in oral cancer.

Antigens, Nuclear↗
PubMed1997

Metallothionein overexpression in human brain tumours.

Metallothioneins (MTs) are metal binding proteins overexpressed in various human neoplasms which are associated with resistance to cytotoxic drugs. A series of 156 archival human brain tumours were investigated immunohistochemically for expression of MTs; these included 10 low-grade gliomas, 44 high-grade gliomas, 98 meningeal tumours (19 classical, 30 atypical, 38 anaplastic meningiomas, and 11 haemangiopericytomas or papillary meningiomas), and 4 other tumours. Low-grade gliomas showed heterogeneous MT expression; 32 high-grade gliomas (72.7%) showed MT expression of more than 25% of tumour cells without statistically significant differences between first operations and recurrent tumours. In 2 glioblastomas, the presence of MT was confirmed by Western blotting. The extent of MT immunoexpression showed a statistically significant inverse relationship to the degree of p53 immunoreactivity. In meningiomas, a tendency to a higher percentage of MT-expressing cells was observed from classical over atypical to anaplastic meningiomas, but these differences were not statistically significant. In conclusion, MT expression is present in a significant portion of, especially malignant, brain tumours and might be involved in their poor response to antineoplastic drugs.

Adult↗
PubMed1997

Prognostic value of histobiological factors (malignancy grading and AgNOR content) assessed at the invasive tumour front of oral squamous cell carcinomas.

Tumour cells at the invasive front of carcinomas have been found to differ substantially from the rest of tumour cells in a variety of human cancers. The present multivariate survival analysis of 94 oral squamous cell carcinomas (OSCCs) revealed that both the argyrophilic nucleolar organizer regions-associated protein (AgNOR) content of invading tumour cells and a multiparametric histopathological tumour front grade were significantly and independently associated with tumour-related death, irrespective of conventional Broders' grade and clinical stage of the tumours. High tumour front scores and AgNOR content at the invasive OSCC front thus seem to reflect increased malignant potential. Proliferative activity, assessed by standardized AgNOR analysis, most probably represents one of the biological features underlying the usefulness of evaluating the invasive tumour front.

Analysis of Variance↗
PubMed1997

Proliferation and DNA fragmentation in meningioma subtypes.

Atypical meningioma has been introduced as tumour subtype of intermediate biological behaviour between classical and malignant meningiomas. To substantiate this three-step scale of malignancy, we assessed the proliferative activity reflected by Ki-67 (MIB1) labelling index (LI) in a series of 89 meningiomas, including 15 classical, 29 atypical, 35 anaplastic tumours, and 10 haemangiopericytomas and papillary meningiomas. The possible correlation of proliferation with the frequency of apoptosis and their relations to BCL-2 immunoexpression was investigated in seven classical, 10 atypical and 10 malignant meningiomas. Apoptosis was demonstrated by evaluation of the frequency of apoptotic figures, by the enzymatic technique of in situ tailing (IST) which stains apoptotic DNA fragments, and by DNA preparation and gel electrophoresis demonstrating DNA laddering in frozen tissues of five meningiomas. MIB1 LI revealed a highly significant increase from classical through atypical to anaplastic meningiomas (P < 0.0001); haemangiopericytomas and papillary meningiomas were well within the range of atypical meningiomas. IST indices rose with increasing malignancy and correlated with MIB1 LI (P < 0.0001): they showed a weak inverse correlation with BCL-2 immunoexpression (P = 0.05). BCL-2 expression tended to decrease with malignancy grade and was unrelated to MIB1 LI or frequency of apoptosis. Our data show that (i) apoptosis is a feature of meningiomas, significantly correlated with the malignancy scale. (ii) DNA fragmentation shows significant correlation with proliferation and inversely with BCL-2 expression; (iii) proliferation indices and frequencies of apoptosis/DNA fragmentation within meningioma subgroups corroborate the intermediate biological position of the atypical meningioma between classical and malignant meningiomas.

Antigens, Nuclear↗
PubMed1997

Standardized demonstration of silver-stained nucleolar organizer regions-associated proteins in archival oral squamous cell carcinomas and adjacent non-neoplastic mucosa.

Standardized silver staining and quantitation of nucleolar organizer regions-associated proteins (AgNORs) on routinely formalin-fixed and paraffin-embedded tissues has been recently established. The present study was designed to assess its applicability and reproducibility on archival oral squamous cell carcinoma specimens, with special emphasis on the invasive tumor front. Standardized image cytometric AgNOR analysis was performed at the invasive zone and central parts of the tumors as well as in adjacent dysplastic and normal oral mucosa by applying a modified silver staining on routinely processed archival tissues after wet autoclave pretreatment for protein retrieval. A statistically highly significant and reproducible difference of all of the four standardized AgNOR parameters evaluated (mean AgNOR number, mean AgNOR area, coefficient of variation (CV) of AgNOR number, and CV of AgNOR area per nucleus) was observed between the different areas assessed; there was a statistically significant gradual decrease in the CV of the AgNOR number from the invasive tumor front to central parts of the carcinomas, from dysplastic mucosa to normal epithelium. The observed increase of AgNORs at the invasive front of oral squamous cell carcinomas seems to indicate a subgroup of tumor cells with increased biosynthetic activity and malignant potential. Wet autoclave pretreatment before silver staining of AgNORs is necessary for a reliable visualization of single AgNOR dots. Second-order statistics of AgNOR features, e.g., CV values, offer a potent and highly reproducible parameter for AgNOR quantitation.

Biomarkers, Tumor↗
PubMed1996

Diagnostic value of different PCR assays for the detection of mycobacterial DNA in granulomatous lymphadenopathy.

Diagnosis of mycobacterial infection is made by assessment of characteristic histological features, staining of acid-fast bacilli, or agar culture. Recent advances in molecular biology have provided alternative approaches for the detection of mycobacteria, but only limited data are available dealing with the comparative evaluation of these methods. In order to determine the diagnostic applicability of polymerase chain reaction (PCR)-based assays, 20 formalin-fixed and paraffin-embedded lymph nodes with bacille Calmette-Guérin (BCG) lymphadenitis were investigated which in Löwenstein Jensen agar culture were either positive or negative (ten cases each); ten lymph nodes with non-specific lymphadenitis served as negative controls. Ziehl-Neelsen staining as well as three different PCR assays (including nested PCR), amplifying a specific sequence of the Mycobacterium tuberculosis complex or sequences of the 65 kD antigen gene, were performed. Positive culture was only obtained from lymph nodes which had been surgically removed within 20 weeks after vaccination (P < 0.001). In contrast to microscopic examination, which yielded no more information than agar culture, PCR detection of mycobacterial DNA was unrelated to culture findings. Combined use of different assays, as well as DNA extraction from at least three paraffin sections from each specimen, resulted in the detection of mycobacterial DNA in all lymph nodes with amplifiable DNA (18 out of 20 cases). Controls remained consistently negative. Thus, the combined use of different PCR assays is proposed as a rapid and sensitive technique for the detection of mycobacterial DNA in formalin-fixed and paraffin-embedded tissue.

Axilla↗
PubMed1996

In situ assessment of cell proliferation at the invasive front of oral squamous cell carcinomas.

In oral squamous cell carcinoma (OSCC) the histopathological malignancy grading of the invasive front has been found to offer the most reliable prognostic parameter. In the present study we compared such tumour front grading of 100 OSCCs with the in situ growth fraction demonstrated by MIB1 immunostaining following wet autoclave antigen retrieval. MIB1 labelling indices (LIs) were estimated both at the invasive front and in the central parts of OSCCs using two different evaluation methods (overall and random counting) to investigate whether MIB1 LIs represent a possible biological background for the tumour front grading. Statistically highly significantly increased MIB1 LIs were found at the invasive tumour fronts with both counting methods compared with the centres of the same tumours. For LI estimation the classic overall counting procedure proved to be superior. However, in contrast to tumour front grading, MIB1 LIs revealed no correlation with the clinical outcome of the patients concerned. Our results demonstrate that the invasive tumour front of an OSCC is composed of (a) tumour subpopulation(s) with higher proliferative activity. However, determination of the proliferative activity by MIB1 of this tumour area offers no prognostic information.

Carcinoma, Squamous Cell↗
PubMed1996

Demonstration of silver-stained nucleolar organizer region associated proteins (AgNORs) after wet autoclave pretreatment in breast carcinoma: correlation to tumor stage and long-term survival.

Argyrophilic nucleolar organizer region associated proteins (AgNORs) are known to reflect cellular and nucleolar activity. Due to a novel staining procedure, which substantially improves visualisation of AgNORs on formalin-fixed and paraffin-embedded material, AgNORs can be reliably demonstrated as true substructures of the nucleoli. The aim of the present study was to apply a standardized morphometric AgNOR quantification on a large series of breast carcinomas with regard to its prognostic relevance. AgNOR quantity was evaluated on archival tumor tissues of 115 adenocarcinomas of the breast treated with the wet autoclave method prior to standardized silver-staining and morphometric analysis. AgNOR parameters were correlated to prognostic features (steroid hormonal receptor status, tumor type, tumor size, histological grading, pTNM, and UICC stage) carrying out both univariate and multivariate survival analyses. AgNOR number and area were proven to be statistically significantly related (Pearson correlation coefficient: 0.67, Bonferroni adjusted P = 0.0001). Almost all AgNOR parameters, in particular CV (coefficient of variation) of corrected area (delta-area) and CV of number, were statistically significantly correlated to estrogen and progesterone receptor status as well as histological grading of tumors. Increased AgNOR parameters were statistically significantly associated with early tumor relapse and cancer related death. Univariate and multivariate analysis by means of Cox regression revealed independent prognostic significance for CV of delta-area and number of AgNORs. Various AgNOR parameters (CV of number, CV of delta-area, CV of area, mean delta-area, and mean area of AgNORs per nucleus) determined on wet autoclave pre-treated formalin-fixed and paraffin-embedded breast cancer tissues are statistically highly significantly associated with the prognostic outcome, independently predicting tumor-free and overall survival.

Adenocarcinoma↗
PubMed1996

Standardized AgNOR analysis: its usefulness in surgical oncology.

Recent improvements both in the staining quality and computer-aided quantitation of silver-stained nucleolar organizer region (AgNOR)-associated proteins offer the possibility to reliably investigate these proteins on routinely processed archival material. This article deals with the historical background, the recent introduction of a standardized quantitation, the clinical relevance, and future perspective for AgNOR evaluation. It is specifically emphasized that AgNOR analysis after both standardized staining and computer-aided quantitation (as recommended by the Committee on AgNOR Quantitation of the European Society of Pathology) is now regarded as the gold standard whenever routinely formalin-fixed and paraffin-embedded material is investigated.

Cell Division↗
PubMed1996

Aneurysmal and haemangiopericytoma-like fibrous histiocytoma.

AIM: To describe the clinicopathological features of 33 aneurysmal fibrous histiocytomas (AFH), including five cases with a haemangiopericytoma-like pattern. METHODS: Thirty three cases of AFH were studied by using routine histology and immunohistochemistry for factor XIIIa, the "cell activity marker" E9 (anti-metallothionein), NK1C3 (CD57), smooth muscle actin (SMA), factor VIII, ulex europaeus agglutinin, JC70A (CD31), and QBEND10 (CD34). The time dependent variation in histopathological features was evaluated by statistical methods (Pearson chi 2, likelihood ratio chi 2). RESULTS: Of the AFHs, 29 of 33 occurred on the extremities of adults (age range 30 to 50 years), six of which were associated with rapid growth, probably caused by trauma, and pain. Twenty one lesions were thought to be vascular and/or melanocytic lesions, including two melanomas, because of a bluish-black and/or cystic appearance. Histologically, large areas of haemorrhage, up to 50% of the tumour bulk, lacking an endothelial lining were seen in otherwise typical fibrous histiocytomas. Five cases resembled nodular stages of Kaposi's sarcoma. Variable haemosiderin deposition in histiocytes (18/33) and giant cells (11/33) was suggestive of haemosiderotic histiocytoma. A haemangiopericytoma-like pattern was seen in five otherwise indistinguishable cases. On immunohistochemistry, variable reactivity was seen for factor XIIIa (18/30), with E9 (18/30), NK1C3 (19/30), and for SMA (14/30), but labelling for vascular markers was not detected. Early lesions without iron deposition were factor XIIIa positive; late lesions with iron deposition were factor XIIIa negative. Labelling for SMA correlated with prominent sclerosis. CONCLUSION: AFHs, including a haemangiopericytoma-like variant, have a characteristic time dependent histological and immunophenotypic profile, clearly different from nodular type Kaposi's sarcoma.

Adult↗
PubMed1996

p53, Ki-ras, and DNA ploidy in human pancreatic ductal adenocarcinomas.

Ki-ras mutations and DNA aneuploidy are common findings in human pancreatic ductal adenocarcinomas. An altered p53 tumor-suppressor gene has been suggested to cooperate with activated Ki-ras in malignant cellular transformation and could enhance genomic instability. We have investigated a panel of well-documented pancreatic carcinomas with defined ploidy and Ki-ras mutations for the presence and pattern of genetic alterations of the p53 gene, their coincidence with Ki-ras point mutations, and their correlation with DNA ploidy, tumor pathology, and clinical course. DNA was isolated from formalin-fixed and paraffin-embedded tumor tissue and polymerase-chain-reaction-amplified fragments of the p53 gene exons 5 to 9 were screened by the single-strand conformation polymorphism method. The positive cases were further examined for mutations by direct sequencing. Twenty-nine of seventy-one (41%) tumors showed mutations of the p53 gene, however, five tumors carried two mutations resulting in a total of 34/71 (48%) genetic alterations of the p53 gene. The majority were missense point mutations and distributed primarily within the evolutionary conserved domains (62%). Ten of Thirty-four (29%) affected the hotspot codons 248, 273, and 282, respectively, and 21/34 (62%) of the p53 gene mutations clustered on exons 7 and 8. Transitions (71%) predominated over transversions (15%), deletions were identified in 7/34 (21%) tumors. One third of the carcinomas showed both Ki-ras codon 12 and p53 gene mutations. p53 mutations correlated with distant metastasis (p < 0.05) and survival (p < 0.05). DNA triploidy was associated with a mutated Ki-ras gene (p < 0.05) as well as with double mutations of c-Ki-ras and p53 (p < 0.05). Unlike most other malignant tumors pancreatic ductal adenocarcinomas exhibit a significantly higher incidence of c-Ki-ras than p53 gene mutations. However, like other neoplasms p53 gene mutations seem to be associated with a metastatic phenotype possibly acquired during tumor progression.

Adult↗
PubMed1996

Long-term outcome after switch from cyclosporine-based triple-drug immunosuppression to double therapy at three months.

Cyclosporin A (CyA) together with steroids and azathioprine (Aza) has been successfully used for prophylactic immunosuppression in numerous recipients of kidney allografts. The aim of this study was to evaluate the long-term effect of reducing this initial triple-drug therapy to double-drug therapy at 3 months. One hundred consecutive recipients of a cadaveric renal allograft with stable and good graft function were randomly allocated to continue with CyA and steroids (group 1) or CyA and Aza (group 2). Both groups were comparable with regard to all relevant patient characteristics. After a mean observation period of 55 (26-76) months no significant difference was observed in the incidence of acute rejection episodes after conversion (4 in group 1 and 5 in group 2), or in the incidence of graft loss (4 in group 1 and 5 in group 2); all graft rejection episodes were easily reversed with steroid pulses and patients switched back to triple-drug therapy. Patient survival was 94% in group 1 and 100% in group 2 at 55 months. In group 1, however, a higher number of viral infections and steroid-related side effects was noted. From these data it is concluded that initial triple-drug therapy can safety be reduced to a CyA-based double-drug combination after 3 months in renal allograft recipients with stable function. The combination with Aza is recommended because of its fewer side effects.

Adolescent↗
PubMed1996

MIB1 in colorectal carcinomas: its evaluation by three different methods reveals lack of prognostic significance.

Immunohistochemically detected MIB1 has been determined in a series of 106 colorectal carcinomas with three different evaluation methods (semiquantitative estimation, evaluation by image analysis, and cell count). Although the semiquantitative estimation correlated significantly with results obtained by image analysis (R = 0.8), both methods were only poorly associated with MIB1 counts (R = 0.5). Additionally, all three methods revealed no statistical correlation of MIB1 with the clinical outcome of the respective patients. Our results indicate a pronounced heterogeneity of MIB1 in colorectal adenocarcinoma, thus leading, irrespectively of the evaluation method used, to non-representative results with lack of clinical relevance.

Adenocarcinoma↗