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F Gudat

Publications and source records attributed to F Gudat.

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

Angiogenesis in cervical neoplasia: microvessel quantitation in precancerous lesions and invasive carcinomas with clinicopathological correlations.

Recently, angiogenic properties have been shown in preinvasive cervical lesions. Our goal was to determine the angiogenesis in cervical intraepithelial neoplasia (CIN) and the relationship between microvessel counts, histopathological parameters, and clinical outcome in invasive cervical carcinoma. One hundred thirty-eight cervical specimens were evaluated; among these 20 were designated normal epithelium, 20 low-grade CIN, 40 high-grade CIN, and 58 invasive carcinoma. Histological sections immunostained for CD31 were quantitatively evaluated for microvessel density. The tumor proliferation rate was determined by the Ki-67 Labeling Index. Comparison of microvessel counts from normal epithelium with those from CIN and invasive carcinoma showed significant increases in precancerous lesions and invasive cancer (P < 0.0001). Microvessel density was found to be associated with the overall survival in women with invasive carcinoma (P < 0.01). There was a significant correlation of microvessel density (P < 0.05) with relapse-free survival in patients with regional lymph node metastasis. A Cox stepwise regression analysis revealed microvessel density, together with depth of invasion, regional lymph node status, and vascular invasion, to be a strong independent prognostic indicator for overall survival in patients with clinical stage IB cervical carcinoma.

Carcinoma, Squamous Cell↗
PubMed1997

Distribution of podocyte protein (44 KD) in different types of glomerular diseases.

The podocyte protein, 44 KD (pp44), is a podocyte-specific antigen that is selectively distributed in the cytoplasm of foot processes. It has been suggested that the pp44 antigen is associated with the cytoskeleton and helps to maintain the complex architecture of podocytes. To answer the question as to whether changes in pp44 expression are associated with changes in podocyte morphology, we investigated the distribution of the pp44 antigen in different kidney diseases. Twenty-one kidney biopsies and one nephrectomy specimen were studied by indirect immunofluorescent technique and electron microscopy. The pp44-antigen is preserved in cases associated with foot process fusion. In contrast, the antigen could not be detected in areas of capillary wall necrosis, cellular crescents or early and advanced stages of focal segmental glomerulosclerosis--even in the presence of podocytes. Our results show that the pp44 antigen is preserved in diseases associated with reversible loss of foot processes (in cases with foot process fusion associated with proteinuria). In contrast, the pp44 antigen is not detectable in the area of FSGS and cellular crescents, suggesting that in these conditions, podocytes undergo irreversible injury even if they are still present on conventional light microscopy.

Antibodies, Monoclonal↗
PubMed1997

Investigation of the Bcl-2 and C-myc expression in relationship to the Ki-67 labelling index in cervical intraepithelial neoplasia.

This is the investigation of the relationship between the neoplastic cell proliferation and the expression of bcl-2 and c-myc in human papillomavirus (HPV)-negative and HPV-positive cervical intraepithelial neoplasms (CIN). The expression of bcl-2 and c-myc was studied using quantitative immunohistochemistry in 20 specimens of normal cervical squamous epithelium and 73 specimens of CIN. To analyze the neoplastic cell proliferation rate, the Ki-67 labelling index was determined; the latter was significantly different between normal epithelium and various grades of CIN (p < 0.0001). The highest proliferation rate was found in high-grade CIN. In precancerous lesions, we found the number of bcl-2 positive cells lower than in normal epithelium, but with a significant difference between low-grade and high-grade CIN (p < 0.0001). The highest percentage of bcl-2 positive neoplastic cells was found in high-grade CIN. C-myc was rarely expressed in normal epithelium. Similar to the Ki-67 labelling index, c-myc immunostaining correlated with the histological grade of CIN, with the highest percentage of c-myc positive nuclei occurring in high-grade CIN (p < 0.0001). In contrast to bcl-2 immunoreactivity, the c-myc significantly was more expressed in high-risk HPV-positive than in HPV-negative lesions. The c-myc expression in CIN is closely related to the neoplastic cell proliferation rate. With progression of intraepithelial neoplasia, bcl-2 production in neoplastic cells increases with high co-expression of c-myc.

Female↗
PubMed1997

Topoisomerase II alpha mRNA and tumour cell proliferation in non-Hodgkin's lymphoma.

AIMS: To elucidate potential mechanisms of drug resistance, levels of topoisomerase II alpha mRNA, a target for cytostatic drugs, were measured in cryopreserved tumour tissue from 36 patients with non-Hodgkin's lymphoma. To evaluate the potential association between topoisomerase II alpha and cell proliferation, Ki-67 immunostaining was also assessed. METHODS: The study population comprised 13 patients with low grade and 20 with high grade non-Hodgkin's lymphoma. Three patients had recurrent disease. Topoisomerase II alpha mRNA was quantitated by using reverse transcription polymerase chain reaction (RT-PCR) and the PCR product measured by using HPLC. The MIB-1 monoclonal antibody was used for Ki-67 immunostaining. RESULTS: Levels of topoisomerase II alpha mRNA correlated strongly with the Ki-67 labelling index and were higher in high grade than in low grade lymphomas. Patients in complete clinical remission of high grade lymphoma had a higher Ki-67 labelling index and tended to have higher topoisomerase II alpha mRNA levels. CONCLUSIONS: Although topoisomerase II alpha mRNA levels may be indicative of sensitivity to drugs, it is more likely that they reflect the proliferation status of the cell, which in turn involves a large number of additional molecular systems that influence response to treatment.

Adolescent↗
PubMed1997

Heterogeneity of melanoma antigen-1 (MAGE-1) gene and protein expression in malignant melanoma.

OBJECTIVE: The authors' objective is to identify MAGE-1 tumor antigen in clinical melanoma specimens and to verify the extent of its expression in tumors where evidence of specific gene transcripts can be obtained. BACKGROUND DATA: The MAGE-1 gene encodes a tumor-associated antigen that can be recognized by specific cytotoxic T lymphocytes. Transcription of the MAGE-1 gene has previously been demonstrated in various malignancies, but the production of the specific gene product and its distribution in neoplastic tissues have not yet been addressed. METHODS: Total cellular mRNA was extracted from six melanoma biopsies, reverse-transcribed and tested in 25-45 cycles of reverse polymerase chain reaction (rtPCR) in the presence of primers' pairs specific for the beta-actin-positive control gene and for the MAGE-1-encoding gene. Concurrently, portions of these specimens were lysed and probed for MAGE-1 protein by immunoblotting. Additional material from the same biopsies was analyzed following immunohistological staining with MAGE-1-specific monoclonal antibodies. RESULTS: MAGE-1 gene transcription could be demonstrated following 25 cycles of rtPCR in one out of six biopsies and in three more following 35 cycles of rtPCR. 2/6 samples were negative even after 45 cycles of rtPCR. MAGE-1 protein production could be detected by immunoblotting in the lysates from biopsies showing evidence of specific gene transcription. Cells positive for MAGE-1 protein expression could be identified by immunohistochemistry on snap-frozen sections in three of the four tumors displaying specific transcripts. Distribution of positivity ranged between focal cellular areas and single positive cells in the different tumors. CONCLUSIONS: The MAGE-1 tumor antigen can be detected by specific monoclonal antibodies in clinical tumor specimens. The pattern of positivity observed in samples showing evidence of MAGE-1 gene expression suggests a relevant heterogeneity regarding MAGE-1 antigen production within individual tumor specimens.

Antibodies, Monoclonal↗
PubMed1996

Assessment of EGFR and TGF-alpha expression in relationship to HPV status and Ki-67 distribution in cervical intraepithelial neoplasms.

Expression of epidermal-growth-factor receptor (EGFR), transforming growth factor alpha (TGF-alpha) and Ki-67 proliferation antigen in cervical intra-epithelial neoplasms were analyzed. To examine the interrelationship of TGF-alpha, EGFR, Ki-67 and HPV status in dysplasia and carcinoma in situ, formalin-fixed tissue sections of 92 women were immunostained with monoclonal antibodies to EGFR, TGF-alpha and Ki-67. The presence of HPV was assessed by in situ DNA hybridization. The highest positive TGF-alpha expression was seen in the group of mild dysplasia. The difference was significant between the relatively high expression in mild dysplasia and the low occurrence in severe dysplasia and carcinoma in situ as well. The same relation could be found between TGF-alpha expression in papilloma-virus-negative dysplasia and those with the presence of HPV 16/18. In contrast to these findings, the Ki-67 proliferation marker was intensely detectable in severe dysplasia and carcinoma in situ. Ki-67-stained neoplastic cell nuclei were found in a significantly higher percentage of HPV-positive than in HPV-negative lesions. TGF-alpha over-expression is obviously combined with low proliferating activity and vice versa. Irrespective of the grade of dysplasia or HPV status, EGFR was expressed abnormally as compared with normal squamous epithelium. Over-expression of TGF-alpha in mild dysplasia could be associated with the autocrine pathway of cell-growth regulation. In the presence of HPV 16/18 the EGFR/TGF-alpha pathway for growth stimulation is probably not involved.

Carcinoma in Situ↗
PubMed1996

Nuclear p53 overexpression is an independent prognostic parameter in node-negative non-small cell lung carcinoma.

The prognosis of operated patients with non-small cell lung cancer (NSCLC) is poor despite thorough pre-operative staging. An improved preselection is needed of patients likely to profit from surgery. This study was undertaken to evaluate the prognostic significance of nuclear p53 overexpression in a cohort of 247 surgically treated patients with NSCLC. It showed that the prevalence of immunohistochemically detectable p53 overexpression varied between different tumour types. p53 overexpression was equally frequent in large cell carcinoma (53 per cent) and in squamous cell carcinoma (54 per cent), but significantly less frequent in adenocarcinoma (34 per cent; P = 0.009). p53 overexpression was particularly rare in bronchioloalveolar carcinoma (positivity in 1 of 17 cases). These variations may reflect aetiological differences between the histological subtypes. p53 overexpression was also associated with high tumour grade (P = 0.0157) and the presence of lymph node metastasis (P = 0.0259), but not with advanced tumour stage. Survival analysis showed no difference in clinical outcome between p53-positive and p53-negative tumours within 101 node-positive tumours. In contrast, survival time was significantly better in p53-negative tumours than in p53-positive tumours within the group of 113 node-negative tumours (P = 0.032). Stepwise regression analysis showed that p53 overexpression is an independent prognostic factor in node-negative NSCLC.

Biomarkers, Tumor↗
PubMed1996

Expression of CD44 and variant isoforms in cervical intraepithelial neoplasia.

The cell adhesion molecule CD44 and its variant isoforms have been found to be related to invasive and metastatic character of cancer cells. Their expression in gynecologic precancerous lesions has not yet been reported. Mouse monoclonal antibodies directed against a common epitope (CD44s) and exons 4v, 6v, and 9v were used to study the expression of CD44 and variant isoforms by immunohistochemistry in cervical intraepithelial neoplasia (CIN). Twenty tissue samples with normal cervical epithelium and 57 samples with CIN of different histological grades and different HPV status were included in this study. The standard CD44, CD44-4v, CD44-6v, and CD44-9v were expressed in normal cervical epithelium and in precancerous lesions. In distinct contrast to the normal epithelium, however, the standard CD44, CD44-4v, and 6v showed a reduced expression in precancerous lesions, whereas CD44-9v was significantly overexpressed. Expression of CD44 standard and CD44-4v was correlated with the histological grade but not with the HPV status. Compared with mild and moderate dysplasia, severe dysplasia and carcinoma in situ are associated with low expression of CD44s (P = 0.007) and of CD44-4v (P = 0.03). These observations reveal dynamic changes in CD44 expression during neoplastic cell transformation in cervical intraepithelial neoplasia.

Antigens, Neoplasm↗
PubMed1996

The tumour-associated antigen MAGE-1 is detectable in formalin-fixed paraffin sections of malignant melanoma.

The MAGE-1 gene encodes a protein encompassing a HLA-A1-restricted target epitope for cytolytic T lymphocytes. Monoclonal antibodies directed against the MAGE-1 protein were tested for usage in immunohistology of routine pathology material. Seven formalin-fixed, paraffin-embedded malignant melanomas were studied by the Avidin-Biotin complex (ABC) method with or without different antigen retrieval methods. Native, frozen tissues from the same tumours were used to validate the results by immunohistochemistry on frozen sections, by PCR for mRNA and by protein demonstration in tissue extracts using western blotting. Of 4 monoclonal antibodies tested, mAB 34B and mAB 77B were highly efficient in detecting MAGE-1 protein in deparaffinised sections with the regular ABC method after microwave pretreatment. In a series of an additional 28 patients 75% expressed MAGE-1, 50% in a substantial proportion. Follow-up studies in 6 patients indicate that the expression pattern remains stable but may change substantially within a short range. Immunohistology is thus a rapid and well-established method that might be used to select and monitor HLA-A1 positive patients with malignant melanoma and other candidate tumours for MAGE-1-directed immuno-therapy.

Antigens, Neoplasm↗
PubMed1996

Detection and typing of hepatitis C RNA in liver biopsies and its relation to histopathology.

This paper describes the correlation of hepatitis C genotypes detected in liver tissue with histological grading (inflammatory activity) and staging (degree of fibrosis/cirrhosis). The viral genotype was analysed by type-specific polymerase chain reaction (PCR) and correlated with histology and age of patients. In 69 patients with chronic hepatitis C (HCV) infection, genotypes 1a and 1b were detected in 13 (18.8%) and 31 (44.9%) liver biopsies, respectively. Genotypes 2a and 2b were each detected once (1.5%) and 12 (17.4%) tissue samples showed a mixed infection with two genotypes. In 11 (15.9%) biopsies, no genotype could be established. The liver specimens were grouped according to the presence or absence of genotype 1b: group A consisted of specimens infected with genotypes 1a, 2a, and 2b (n = 16), Group B contained biopsies infected with genotype 1b (n = 42), and group C were biopsies with no detectable genotype (n = 11). Activity (grade) of chronic hepatitis was not different in these three groups. However, advanced fibrosis/cirrhosis was observed in 16 (38.1%) biopsies in group B (containing genotype 1b), compared with none in group A (P = 0.01). The mean age of patients in group B was significantly higher than that in group A (P = 0.038), and the mean age of patients with advanced fibrosis was higher than that of patients with low fibrosis scores within these two groups (P = 0.004). Stepwise logistic regression revealed an independent association of age and genotype 1b (group B) with advanced fibrosis/cirrhosis. These data indicate that patients infected with genotype 1b have an higher risk of developing cirrhosis than do patients with other genotypes.

Adolescent↗
PubMed1996

Detection of herpesvirus-like DNA by nested PCR on archival skin biopsy specimens of various forms of Kaposi sarcoma.

AIMS: To detect herpesvirus-like DNA sequences, defining a new herpesvirus, human herpesvirus 8 (HHV8), in paraffin wax embedded skin biopsy specimens of the various forms of Kaposi sarcoma. METHODS: DNA was extracted from archival skin biopsy specimens of Kaposi sarcoma, other mesenchymal skin tumours and various inflammatory skin lesions of HIV seropositive and negative patients. HHV8 DNA was detected by using a nested PCR assay. Human beta-globin DNA served as an internal control. RESULTS: Twenty two samples of Kaposi sarcoma were analysed, comprising 12 of the endemic type, nine HIV associated and one transplantation related. HHV8 DNA was detected by nested PCR in all forms of Kaposi sarcoma. By contrast, no HHV8 DNA was detected in five mesenchymal skin tumours or nine biopsy specimens of unspecific inflammatory skin lesions of HIV seropositive and negative patients. CONCLUSIONS: Detection of HHV8 DNA in paraffin wax embedded tissue can be used to confirm a diagnosis of Kaposi sarcoma.

Biopsy↗
PubMed1996

[Detection of herpes virus-like DNA in various forms of Kaposi's sarcoma but not in other mesenchymal tumors or inflammatory changes in skin].

Recently, herpes-virus like DNA sequences defining a new herpes virus termed human herpes virus 8 (HHV8), were detected in Kaposi's sarcoma of AIDS and non-AIDS patients. We describe the successful detection of HHV8 DNA in archival skin biopsies of the various forms of Kaposi's sarcoma. DNA was extracted from archival skin biopsies of Kaposi's sarcoma, other mesenchymal skin tumors and various inflammatory skin lesion of HIV seropositive and negative patients. The extracted DNA was analyzed for the presence of HHV8 DNA using a nested PCR assay. All samples were tested for the presence of appropriate DNA using a internal cellular control PCR-reaction. A total of 23 Kaposi's sarcoma were analyzed, including 12 of the endemic type, 9 HIV-associated and 2 transplant related. HHV8 DNA was detected by nested PCR in all forms of Kaposi's sarcoma. In contrast, no HHV8 DNA could be found in 17 mesenchymal, especially vascular skin tumors or in 7 biopsies with unspecific inflammatory skin lesions of HIV seropositive and negative patients. HHV8 DNA was present in all forms of Kaposi's sarcoma tested but not in other mesenchymal tumors or unspecific inflammatory lesions of the skin. This data support the idea of a strong association of HHV8 and Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Identification and intracellular location of MAGE-3 gene product.

The human MAGE-3 gene encodes a melanoma antigenic epitope recognized by specific cytotoxic T lymphocytes, but its gene product has not been identified thus far. We produced a recombinant MAGE-3 gene product by expression cloning of the entire reading frame in the context of a fusion protein characterized by a 10-histidine tail, allowing purification by metal chelation on a nickel Sepharose column. The semipurified product was used to generate MAGE-3-specific monoclonal antibodies. One reagent could identify by immunoblotting the native MAGE-3 gene product as a M(r) 48,000 protein in lysates of cell lines showing evidence of MAGE-3 gene expression. No apparent cross-reactivity with recombinant or native MAGE-1 gene product was observed. Immunohistochemistry shows that, closely resembling the MAGE-1 gene product, MAGE-3 is a cytoplasmic protein.

Animals↗
PubMed1995

Podocytes loose their adhesive phenotype in focal segmental glomerulosclerosis.

Podocytes in focal segmental glomerulosclerosis (FSGS) show injury and focal detachment from the glomerular basement membrane (GBM). We studied by immunofluorescence and light microscopy the distribution of components involved in the integrin mediated adhesion of podocytes to the GBM in one case of recurrent idiopathic FSGS which developed in a renal transplant. Two major integrin and actin distribution patterns were observed in podocytes depending on the stage of the disease. Alpha 5 integrin subunit showed a gradual loss in early FSGS and became undetectable in advanced FSGS. Alpha 3 integrin subunit and the beta 3 subunit of the vitronectin receptor lost their polarized expression and could be detected intracellularly in early FSGS, while in advanced stage both integrin subunits were mostly basally polarized. In addition staining for alpha 3 was markedly decreased but enhanced for beta 3. Most of the podocytes in early FSGS showed significant loss of filamentous actin together with a nonpolarized distribution and a transient expression of the HAR/GP90 receptor. An altered matrix composition was also seen corresponding to the newly formed GBM. Based on these results we propose that podocytes loose their adhesive phenotype in early FSGS, which may contribute to the detachment of podocytes from the GBM.

Actins↗