Search PubMed⌕ Search

Biomedical subjects

A Schauer

Publications and source records attributed to A Schauer.

At least 37 records · Page 2Linked to original sources
PubMed1997

Prognostic value of contrast-enhanced MR mammography in patients with breast cancer.

The objective of this study was to evaluate the prognostic value of contrast-enhanced MR mammography in patients with breast cancer. A total of 190 patients with breast cancer (37 noninvasive carcinomas, 153 invasive carcinomas) underwent dynamic contrast-enhanced MR mammography preoperatively. Using 1.5-T unit, T1-weighted sequences (2D FLASH) were obtained repeatedly one time before and five times after IV administration of 0.1 mmol gadopentetate-dimeglumine per kilogram body weight. The findings on MR imaging were correlated with histopathologically defined prognostic factors (histological type, tumor size, tumor grading, metastasis in lymph nodes). In addition, immunohistochemically defined prognostic factors (c-erbB-1, c-erbB-2, p53, Ki-67) were correlated with the signal increase on MR mammogram in 40 patients. There was no significant correlation between the findings on MR mammography and the histopathological type of carcinoma, the grading, and the lymphonodular status. Noninvasive carcinomas showed a higher rate of moderate (38 %) or low (27 %) enhancement on MR imaging than invasive carcinomas (6 and 3 %). The results on MR mammography and the results of immunohistochemical stainings did not correlate significantly. Noninvasive carcinomas showed significantly lower enhancement than invasive carcinomas. However, the signal behavior of contrast-enhanced MR mammography is not related to established histopathological prognostic parameters as subtyping, grading, nodal status, and the expression of certain oncogenes/tumor suppressor genes.

Biomarkers, Tumor↗
PubMed1997

[Therapy of the small breast carcinoma--generalized conversion to breast-saving treatment in Germany. 8 years results].

In the prospective nonrandomized observation study "Therapy of Small Breast Cancer", which was the first multicenter trial on breast cancer ever conducted in Germany, mastectomy (303 cases) was compared with breast-preservation therapy (733 cases) in patients with stage pT1N0M0 breast cancer. After a median follow-up of 8 years, there is no difference between the treatment modalities with regard to disease-free and overall survival which compares well with the results of international randomized studies. There is no difference in treatment outcome between centers specialized in the therapy of breast diseases in comparison to less experienced institutions as long as a high standard of treatment performance is guaranteed by reference centers.

Breast Neoplasms↗
PubMed1996

[Ductal carcinoma in situ in dynamic MR-mammography at 1.5 T].

PURPOSE: To define the value of contrast-enhanced MR mammography in ductal carcinoma in situ (DCIS). MATERIAL AND METHODS: In a group of 35 patients with DCIS, the results of MR imaging were compared to histopathology and immunohistochemistry in a retrospective study. RESULTS: In 35 patients with DCIS, a signal enhancement was found in 25 cases (72%). In 15 of these cases, the signal time curve was typical for malignancy. The other 10 patients had non-specific signal curves. Six of 35 patients (11%) had no enhancement within the tumour region. Four of 35 patients (11%) had bilateral diffuse signal increase, and regions of DCIS could not be identified clearly. Three DCIS were visualised exclusively by MR mammography. The configuration of signal enhancement was sharp (32%), unsharp (48%) or dendritic (20%). DCIS of the comedo type showed a significantly higher enhancement than the non-comedo type. A significant correlation between the grade of vascularisation in immunohistochemistry and signal enhancement in MR mammography could not be demonstrated. CONCLUSION: Dynamic MR mammography does not reliably visualise DCIS.

Adult↗
PubMed1996

Expression of Bax in relation to Bcl-2 and other predictive parameters in breast cancer.

BACKGROUND: It has been suggested that modification of the physiological susceptibility to induction of programmed cell death in transformed cells contributes to the pathogenesis of cancer. One of the major regulators of cell death is the bcl-2 family. In breast cancer, altered expression of Bcl-2 has been described. Distribution of its counterpart Bax and the differential expression pattern have still to be evaluated. PATIENTS AND METHODS: Bax expression was investigated by immunohistochemistry in 122 primary breast cancers. Results were correlated with expression of Bcl-2 and other variables of predictive value. RESULTS: There was a positive association between Bax expression and histological grading, (over)expression of c-erbB-1 and -2 and proliferative activity. The correlation was most significant in cases where no concomitant Bcl-2 expression could be detected. In the same subgroup an inverse correlation with positivity for estrogen (and progesterone) receptors was observed. The presence of Bax was not significantly associated with either tumor type and size, nodal status or expression of c-erbB-3. CONCLUSION: Expression of Bax was coupled with negative histopathological features, especially when expression of Bcl-2 was downregulated concomitantly. It may appear that alterations of the differential Bax/Bcl-2 expression pattern take part in deregulation of proliferation and loss of differentiation, thus playing an important role in malignant progression.

Breast Neoplasms↗
PubMed1996

Histochemical study of expression of lectin-reactive carbohydrate epitopes and glycoligand-binding sites in normal human appendix vermiformis, colonic mucosa, acute appendicitis and colonic adenoma.

In a glycohistochemical analysis of human appendix vermiformis we report the assessment of lectin binding in cells of the Gut Associated Lymphoid Tissue of normal samples and in acute appendicitis using a panel of plant, invertebrate and mammalian lectins with specificity for alpha-L-Fuc (UEA-I), alpha-D-Gluc and alpha-D-Man (Con A), alpha-D-GalNAc (DBA), GalNAc (SBA, HPA), beta-Gal (RCA-I, 14 kDa = galectin-1) and alpha-, beta-Gal (VAA). Moreover, we initiate the study of expression of carbohydrate-binding sites in this tissue and in colonic mucosa, employing several types of carrier-immobilized carbohydrate ligands as suitable probes for this purpose. Within the three populations of macrophages intra-/subepithelial macrophages of the dome region, the lamina propria of the intercryptal region and the follicle-associated epithelium were apparently reactive with most of the lectins and also with mannose and fucose residues of the tested neoglycoproteins. Distinguishing features of germinal center macrophages in relation to intra-/subepithelial phagocytes were the lack of binding of UEA-I and DBA. In comparison to all other types of phagocytes, macrophages of the T-region displayed a rather restricted binding capacity only to Con A and RCA-I. Labeling of macrophages with SBA, HPA and VAA in this location was only rarely found. With respect to dendritic cells no consistently positive reaction was seen for follicular cells, whereas interdigitating cells of the T-region bound Con A, HPA and RCA-I, and, less frequently, SBA. Lymphocytes in all anatomical subsites of the Gut Associated Lymphoid Tissue, centrocytes, centroblasts and plasma cells had binding sites for Con A and RCA-I in common. Notably, a small number of lymphocytes mostly in the T-region but also in B-cell-rich areas expressed intranuclear binding sites for fucose and mannose residues. Intraepithelial lymphocytes and lymphatic cells of the T-region differed from lymphocytes in other regions by a more frequent expression of VAA-binding sites. The epithelium of appendix vermiformis and colonic mucosa not only presents lectin binding sites, but also has the capacity to bind carbohydrate structures, as shown by labeled glycoligand-exposing neoglycoproteins. In normal mucosa the extent of binding appeared to be associated with maturation of cells, the surface epithelium showing the most intense staining reaction. This pattern is not detectable in colonic adenoma which reveal increased intensity, when compared to normal mucosa. In contrast to development of hyperplasia, acute inflammation in appendicitis caused no detectable changes of neoglycoprotein binding. Taking our previous assessment on lectin binding in appendicitis into account, we conclude that glycosylation of goblet cell mucus, but not the capacity to bind certain sugar epitopes responds to inflammatory processes, whereas tumorigenesis of colonic adenoma can also affect the binding of neoglycoproteins.

Adenoma↗
PubMed1995

Bcl-2 protein expression in breast cancer in relation to established prognostic factors and other clinicopathological variables.

BACKGROUND: Bel-2 inhibits most kinds of programmed cell death and provides a selective survival advantage to various cell types. Bcl-2 is physiologically expressed in ductal epithelia of the normal breast. The biological significance of Bcl-2 (over)expression for the development and progression of breast cancer has still to be evaluated. PATIENTS AND METHODS: A series of 133 primary breast cancers was investigated for expression of the Bcl-2 protein by immunohistochemistry of paraffin-embedded tissue sections. Results were correlated with other variables of established or presumed predictive value. RESULTS: A significant positive correlation was observed between Bcl-2 expression and positivity for estrogen and progesterone receptors (p < 0.001). High proliferative activity as assessed by Ki-67 staining correlated inversely with Bcl-2 expression (p < 0.001). Bcl-2 immunostaining was not related to positivity for c-erbB-1. It was negatively associated with overexpression of c-erbB-2 (p = 0.04), whereas a strong positive correlation was found with expression of c-erbB-3 (p = 0.01). There was a significant inverse correlation between histological grading and immunoreactivity for Bcl-2 (p < 0.001). N0 tumors tended to be Bcl-2 positive, but differences were not statistically significant. CONCLUSION: Bcl-2 was detected predominantly in differentiated tumors. Expression was associated with other favorable histopathological features and predictors of positive clinical outcome. Loss of Bcl-2 expression seems to be linked to loss of hormonal regulatability, increased dedifferentiation and deregulated proliferation.

Breast Neoplasms↗
PubMed1995

EGF-R and overexpression of the oncogene c-erbB-2 in ovarian cancer: immunohistochemical findings and prognostic value.

PURPOSE: The purpose of this study was to investigate the prognostic value of EGF-R (c-erbB-1) compared to the overexpression of the c-erbB-2 oncogene product p185 in ovarian cancer. PATIENTS AND METHODS: The study was conducted on 266 previously untreated ovarian cancer patients with FIGO stage I-IV disease. EGF-R and c-erbB-2 oncogene product p185 have been evaluated using immunohistochemistry. Survival times were analyzed according to the method described by Kaplan and Meier. For the simultaneous evaluation of the prognostic relevance of the analyzed factors, a Cox proportional hazards regression was performed. RESULTS: EGF-R was detected in 13%, and c-erbB-2 oncogene product p185 in 18% of primary tumors. EGF-R showed no significant impact on the survival time, whereas c-erbB-2 oncogene product p185 positive patients had a significantly worse prognosis compared to p185 negative cases (p = 0.002). In the multivariate analysis, c-erbB-2 oncogene product p185, like tumor stage, histological grade and age, was found to be a significant prognostic factor. CONCLUSION: These data confirm the prognostic importance of the c-erbB-2; oncogene product p185 in ovarian cancer at the time of primary surgery, while EGF-R does not seem to have prognostic relevance.

ErbB Receptors↗
PubMed1995

Comparative distribution of S-100 protein and antigen HMB-45 in various types of melanomas and naevi.

The content of S-100 protein and antigen HMB-45 in various types of melanomas and skin naevi was compared with respect to the frequency of two antigens, their distribution within lesions as well as diagnostic or prognostic relevance. The study material comprised 72 skin melanomas, 25 melanomas of the oral cavity and 63 non-malignant skin naevi. Formalin fixed, paraffin-embedded sections were used for immunohistochemical reactions with polyclonal rabbit anti-S-100 antibody (Dako) and monoclonal anti-HMB-45 antibody (Dianova) followed by PAP and APAAP Kits (Dianova), respectively. Detection of HMB-45 was preceded by a microwave treatment of sections. S-100 protein was found in all cases of melanomas irrespective of their location or histological type, but HMB-45 was missing in 8% of oral melanomas. Distribution of the antigens within tumors was heterogeneous and often mutually exclusive. S-100 protein was also present in all types of naevi, while HMB-45 was absent in intradermal naevi and strictly confined to epidermal component in the remaining ones. The intensity of staining for S-100 correlated inversely with the patients' survival. It was concluded that demonstration of HMB-45 might facilitate a differentiation of naevi from melanomas, whereas staining for S-100 protein might have some prognostic significance.

Adult↗
PubMed1995

Lectin-binding sites in the epithelium of normal human appendix vermiformis and in acute appendicitis.

By using histochemical methods, the binding pattern of various lectins in the epithelium of normal human appendix vermiformis was assessed. In addition to plant and invertebrate sugar receptors with nominal monosaccharide specificity for alpha-L-Fuc (UEA-I), alpha-D-Man and alpha-D-Gluc (Con A), alpha-D-GalNAc (DBA), D-GalNAc (SBA, HPA) beta-D-Gal (RCA-I) and D-Gal (VAA), a mammalian beta-galactoside-specific lectin (MW, 14 kDa) was included in the applied panel. The apical surface of enterocytes presented binding sites for RCA-I on all cells, binding sites of UEA-I, DBA, SBA, HPA and VAA heterogeneously and no binding sites of Con A and 14 kDa. Binding sites of DBA, SBA, HPA, VAA and RCA-I within enterocytes were located primarily focally in a supranuclear position, whereas Con A and 14 kDa bound to the cytoplasm both in apical and basal cell parts. In the follicle-associated epithelium more enterocytes expressed SBA- and VAA-binding sites than in the crypt epithelium. No differences between the lectin-binding pattern of M-cells and enterocytes were found in the follicle-associated epithelium. Intraepithelial macrophages were heterogeneously positive for the full panel of applied lectins. In contrast, intraepithelial lymphatic cells expressed binding sites only for RCA-I and less prominently for Con A, VAA and 14 kDa. Goblet cell mucus contained lectin-binding sites in a heterogeneous manner: binding sites for Con A were not detected in goblet cells for DBA, SBA, VAA and 14 kDa in less than 20%, for UEA-I in 20-40%, for HPA in 40-60% and for RCA-I in 60-100% of the goblet cells. Secreted mucus differed in its lectin-binding capacity from intracellular goblet cell mucus selectively by an increase of UEA-I, SBA- and RCA-I-binding sites and a lack of 14 kDa-binding sites. Comparative study of lectin binding to goblet cell mucin in another region of the large intestine, namely the rectosigmoid, demonstrated that DBA, SBA and 14 kDa bound mainly to the distal colon, while UEA-I and VAA labelling was selectively found in appendiceal goblet cell mucin. Comparing the lectin-binding pattern in normal appendix epithelium and in appendicitis, the percentage of goblet cells expressing DBA- and SBA-binding sites in mucus globules was found to be about 4 times higher in appendicitis than in normal appendix.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1994

An application of MIB antibody to the retrospective study of melanomas of oral mucosa and facial skin.

A new monoclonal antibody prepared against a fragment of Ki-67 antigen MIB, from Dianova, was applied for investigation of malignant melanomas of facial skin (25 cases) and the oral cavity (25 cases), which were routinely embedded in paraffin. The values of the Ki-67 index (expressed as a percentage of positive nuclei) were correlated with TNM characteristics of tumors and patient survival. Significant correlation was found between the Ki-67 index and the level of lymph node involvement (N value), the presence of distant metastases and the time of patient survival. A positive relationship between the Ki-67 value and tumor size was also observed although it lacked statistical significance.

Adult↗
PubMed1994

Elevated serum levels of a c-erbB-2 oncogene product in ovarian cancer patients and in pregnancy.

Amplification of the proto-oncogene c-erbB-2 (HER-2/neu) has been shown to be a prognostic marker in ovarian cancer. In order to obtain further information on the biological role of the c-erbB-2 gene product p185 it is necessary to quantify expression levels. In this study we evaluated an enzyme-linked immunosorbent assay (ELISA) for the extracellular domain of p185 to determine whether a soluble oncoprotein fragment can be detected in the serum of ovarian cancer patients and in the serum of pregnant women. Sera from 199 women (57 previously untreated ovarian cancer patients, 62 pregnant women and 80 healthy controls) were assayed in a sandwich ELISA utilizing two mouse monoclonal antibodies. To study c-erbB-2 overexpression in ovarian cancer tissue samples we have used an immunohistochemical technique involving a monoclonal antibody specifically reactive with the external domain of the protein p185. The mean serum value for the normal controls was 1203 HNU/ml with a standard deviation (SD) of 279 HNU/ml and a range of 595-1947 HNU/ml. We chose a level of 1761 HNU/ml (2 SD above the mean) as a cut-off to distinguish individuals with elevated levels. The ovarian cancer patients' serum values ranged from 526 to 16,332 HNU/ml. Immunohistochemically detectable p185 was noted in 8 of 57 ovarian cancer patients. The oncoprotein fragment levels in the sera from these 8 patients ranged from 878 to 16,332 HNU/ml. Of 8 patients with p185 overexpression in their tumors, 4 had elevated serum levels. In the sera from the 49 cancer patients without overexpression the values were distributed in the range 526-2892 HNU/ml. There was no association between serum oncoprotein fragment levels and tumor stage, histological type or grading. Serum concentrations of the p185 fragment in pregnancy ranged from 612 to 3265 HNU/ml. The highest levels were found in the third trimester. The results of the present study raise the possibility that the soluble c-erbB-2 protein level in serum is an indicator for cell proliferation and therefore deserves further evaluation as a diagnostic tool in ovarian cancer patients and pregnancy.

Adult↗
PubMed1994

Overexpression of the oncogene c-erb B2 in primary ovarian cancer: evaluation of the prognostic value in a Cox proportional hazards multiple regression.

To date, there are no prognostic factors in ovarian cancer that adequately account for tumor biology and disease behavior. In recent years, some reports have described the prognostic significance of the amplification and overexpression of the oncogene c-erb B2 in various human cancers. Concerning ovarian cancer, this is still a matter of discussion. In the present study, tumor tissue of 275 patients treated for ovarian cancer at the Department of Obstetrics and Gynecology of the University of Göttingen between 1982 and 1992 was immunohistochemically analyzed for overexpression of c-erb B2-encoded transmembrane protein p185. In 19% (51 of 275 cases), p185 overexpression was detected. The percentage of p185-positive cases varied from 7 to 46% according to histological subtype. Correlation with tumor stage and the degree of histological differentiation was not observed. Patients with p185-positive tumors had a significantly worse prognosis (p = 0.001); median survival was 20 months compared with 33 months for p185-negative tumors. In the Cox proportional hazards regression, p185 overexpression was identified as an independent prognostically relevant factor. These results suggest that overexpression of oncogene c-erb B2 in ovarian cancer characterizes a group with unfavorable tumor biology and a significantly worse prognosis.

ErbB Receptors↗
PubMed1994

Immunohistochemical demonstration of S100 protein in malignant melanomas of the facial skin and oral cavity.

Immunohistochemical demonstration of S100 protein was performed in 56 cases of malignant melanoma of the facial skin and oral cavity. The depth of invasion was measured comparatively in HE sections and in sections stained for S100 protein. Comparison of measured melanoma invasion depth in S100- and HE-stained sections revealed a deeper invasion of the tumor in S100-stained slides than in slides stained routinely with HE according to Breslow's melanoma staging procedure. A reverse relationship between the intensity of immunohistochemical staining for S100 protein and survival rate was found in both melanomas of the facial skin and oral cavity. Although the presence of S100 protein has been demonstrated previously in skin melanomas, no similar investigations concerning the oral mucosa have been performed up to now.

Adult↗
PubMed1994

Localization of S-100 protein in pig ovarian structures.

Distribution of S-100 protein in porcine ovaries was revealed by an application of polyclonal antibodies against S-100 protein and PAP universal kit to formalin-fixed, paraffin-embedded tissues. The presence of S-100 protein was demonstrated in follicular cells of all ovarian follicles (including their atretic forms), with a decrease in intensity of the reaction parallel to an increase in follicle size. No reaction was found in oocytes, regardless of the developmental stage of the follicle. Weak expression of S-100 protein was observed in theca interna cells of mature follicles and in the youngest generation of theca-lutein cells of the corpus luteum. A distinctly positive reaction was also observed in groups of cells resembling hilus cells as well as in endothelia of arteries and some capillaries. Results are compared with data concerning the localization of S-100 protein in human and bovine ovaries. Possible relationship between the presence of S-100 protein and the level of cellular differentiation is discussed.

Animals↗
PubMed1993

[Pathology and clinical aspects of peripheral neuroectodermal tumors].

A 36-year-old man developed progressive pain in the left thorax radiating to the shoulder, associated with weight loss as well as axillary and supraclavicular lymph-node swellings, and a left Horner's syndrome. The radiological diagnosis was Pancoast tumour. Computed tomography of the thorax revealed that the tumour had almost completely infiltrated the left lung and hilus. Sonography demonstrated metastases in the liver and retroperitoneum. Histological examination of an excised axillary lymph-node metastasis showed an undifferentiated small-cell tumour. Immunohistochemical tests revealed expression of protein S 100 and neurofilamental proteins, i.e. evidence of a peripheral malignant neuroectodermal tumour. The tumour also expressed vimentin. Treatment consisted of two chemotherapy cycles according to the EVAIA scheme (daily three times 235 mg etoposide, 2 mg vincristine, three times 0.8 mg actinomycin D, three times 3.2 g ifosfamide, three times 30 mg doxorubicin, and three times 12 mg dexamethasone), without any effect on the rapid progression of the disease. He died 17 weeks after the diagnosis had been made.

Adult↗
PubMed1993

Pulsed versus continuous wave excitation mechanisms in photodynamic therapy of differently graded squamous cell carcinomas in tumor-implanted nude mice.

The effectiveness of photodynamic therapy (PDT) in vivo was compared between the pulsed excimer laser-pumped dye laser system (EDL) and the continuous wave (cw) argon laser-pumped dye laser system (ADL). Serial subcutaneous transplantation was used to implant thymus aplastic nude mice with different grades of malignancy of two human squamous cell carcinomas (SCCs). Forty-eight hours after i.v. injections of a hematoporphyrin derivative (Photosan 3), the animals were irradiated with either pulsed-EDL or cw-ADL laser light at a tumor depth of 4-5 mm. The irradiation data were chosen as follows: EDL and ADL wavelength 630 nm, total dose 150 J/cm2, irradiation time 27.78 min; EDL repetition rate 30 Hz, single pulse energy 3 mJ, pulse width 20 ns; ADL intensity 90 mW/cm2. The effects of PDT were studied either by long-term observation of the animals treated or by evaluation of hematoxylin-eosin and Ki-67 histological sections of tumors 48 h after treatment. The EDL system proved to be at least as efficient as the ADL system as judged by the number of complete remissions. This became particularly evident in the treatment of the lower-graded tumors, with a good response observed in both transplanted SCCs. However, the higher-graded tumors showed a better response to PDT.

Animals↗
PubMed1993

The prognostic effect of histological tumor grade in node-negative breast cancer patients.

The prognostic effect of histological tumor grade was evaluated in 1036 patients with early breast cancer (pT1 pN0 M0) entered into a trial comparing mastectomy and breast preserving treatment. All analyses were adjusted for the factors treatment, patients' age, and tumor size. Tumor grade was defined according to Bloom and Richardson based on the sum of scores assigned to each of three histological features: 1) degree of differentiation, 2) pleomorphism, and 3) mitotic index. The relative importance of these factors with regard to disease-free survival was evaluated. In univariate as well as in multivariate analyses the pleomorphism was the only factor showing a significant effect (univariate: p = 0.0024, multivariate: p = 0.015). It was investigated how the factors should be combined to define a histological grading score which yields the best possible classification of the patients with respect to prognosis. A new grading system was defined splitting the patients into three groups: 1) pleomorphism 1; 2) pleomorphism 2 or pleomorphism 3 and mitotic index 1; 3) pleomorphism 3 and mitotic index 2 or 3. This yields a good classification of the patients with respect to prognosis (p = 0.0004). The prognostic effect of this score was compared with the effects of the grading systems proposed in the literature. According to Bloom and Richardson and in the modified version by Schauer and Weiss, grading is based on the sum of scores of the various histological factors. Therefore, the strong effect of the pleomorphism was diluted in these grading definitions (Bloom and Richardson: p = 0.03, Schauer and Weiss: p = 0.028). The grading system proposed by Le Doussal et al. consists only of the scores of pleomorphism and mitotic index (p = 0.014). In summary, the factor pleomorphism showed a stronger effect on disease-free survival by itself than the grading systems proposed in the literature.

Adult↗