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Biomedical subjects

C De Potter

Publications and source records attributed to C De Potter.

At least 19 recordsLinked to original sources
PubMed2000

Bilateral recurrent adult rhabdomyomas of the pharyngeal wall.

Adult rhabdomyomas of the head and neck are uncommon benign skeletal muscle tumors. Only a few cases occurring in the pharyngeal wall have been described in the world literature. We present a case of recurrent bilateral rhabdomyomas in the pharynx and discuss the clinicopathological features of this lesion, comparing it to those of other neoplasms from which it must be differentiated. To our knowledge, bilaterality of this type of lesion has not been described previously. Although adult rhabdomyomas have a distinct histology, they often are mistaken for a variety of other lesions, particularly granular cell tumor.

Adult↗
PubMed1999

[Monoclonal anti-idiotype antibodies in immunotherapy of ovarian carcinoma (MAb ACA125) and breast carcinoma (MAb ACA14C5)].

Anti-idiotypic antibodies, which imitate a tumor-associated antigen by their variable region, offer an elegant method for the induction of a specific immune response, when used as a surrogate antigen for immunization. We generated anti-idiotypic antibodies imitating 2 different tumor-associated antigens. I. CA125 for ovarian carcinomas and II. 14C5, a tumor-associated cell substrate adhesion molecule on breast cancer cells, whereas the first approach could be introduced in a first clinical trial and the second was evaluated in an immunocompetent animal model. For the induction of an immune response against CA125, 18 patients with advanced ovarian cancer (n = 6) or heavily pretreated recurrences (n = 12) were immunized with the anti-idiotypic antibody MAb ACA125. Patients were treated with 2 mg anti-idiotype antibody every two weeks for 4 injections i.m. and then monthly. 12 of 18 patients demonstrated an anti-anti-idiotypic (Ab3) response, which was to a lower extent also directed against CA125 and 9 of 18 patients developed a CA125 specific cellular immune response by their peripheral blood lymphocytes. Based on this data a follow-up clinical trial in advanced ovarian cancer patients with minimal residual disease in an adjuvant approach after primary therapy was started to evaluate the effect of the immune response on the progression free survival. For immunotherapy of breast cancer, we generated a murine monoclonal anti-idiotypic antibody (MAb ACA14C5), which imitates a cell substrate adhesion molecule on breast cancer cells. The anti-idiotype was introduced in an immunocompetent animal to prove his capability on induction of an immune and tumor response. The results showed a highly significant difference in the tumor growth of the ACA14C5 treated group in contrast to the controls starting the immunization on day 6 after tumor cell application with 10 of 12 animals being cured from their tumor burden. Prophylactic immunization against the invasion antigen of breast cancer by anti-idiotypic antibodies showed protection against increasing tumor burden. However, in the situation of established tumors only minor responses could be detected. Vaccination with anti-idiotypic antibodies comprises an effective method for induction of a specific immune response against non-immunogenic tumor-associated antigens and should be therefore considered in immunological approaches to tumor therapy, where the primary structure and sequence of the antigen, e.g. CA125, is up to now not available.

Antibodies, Monoclonal↗
PubMed1998

Ossified retroperitoneal malignant Schwannoma with spinal leptomeningeal metastases.

A malignant retroperitoneal schwannoma in a patient without von Recklinghausen's disease is reported. Ossification in the tumour, shown on CT and MRI in this previously untreated patient is exceptional. MRI demonstration of spinal leptomeningeal metastases supports the hypothesis of haematogenous metastatic spread of systemic malignant tumours to the leptomeningeal spaces.

Female↗
PubMed1996

Melanoma in childhood: an EORTC-MCG multicenter study on the clinico-pathological aspects.

Melanoma in children is rare. Nevertheless, it is imperative that clinicians be aware that melanoma does occur in childhood. Yet there is very little information available on the clinico-pathologic variations, and the prognostic parameters of melanoma in children. This report presents the results of a multicenter study of 102 lesions originally diagnosed as cutaneous melanoma, conducted among 5 Western European countries and collected during the period 1961-1994. Criteria for inclusion in the study included: (1) diagnosis of cutaneous melanoma; (2) age up to 16 years at diagnosis; and (3) availability of representative microscopic slides. On the basis of the histologic review only, 60 lesions were confirmed as melanoma, and 42 lesions initially diagnosed as melanoma were reclassified as nevi; 31 of the latter contained a predominance of spindle cells. The only significant parameter associated with the development of metatases or fatal outcome was thickness of more than 2.00 mm. The 5-year survival rate observed in this study was 84%. Based on these findings we conclude that considerable over-diagnosis of melanomas in children occurs. In order, therefore, to give consistent epidemiological data on melanomas in children and to improve proper recognition of their diagnostic features, both by clinicians and by pathologists, we propose to set up a central registry of melanomas in children in Europe, under the auspices of the European Organization for Research and Treatment of Cancer.

Adolescent↗
PubMed1996

Multiple polysomies in nasal polyps in children.

Karyotyping of a nasal polyp from a 10-year-old girl revealed multiple numerical chromosome changes. Extra copies of chromosome 5, 7, 8, 12, 16, 17, 18, 19, 20, and 21 were present. Only one cytogenetically abnormal nasal polyp of a child has been reported in the literature. The karyotypes of the reported and the present case are remarkably similar. The significance of this finding in a nonneoplastic proliferation is discussed.

Aneuploidy↗
PubMed1996

Schwannoma of the larynx: a case report.

A case of schwannoma of the larynx is presented. Clinical findings are presented together with magnetic resonance images. The literature is reviewed. The surgical technique is discussed and the histology is described.

Humans↗
PubMed1995

Chondrosarcoma of the larynx. A diagnostic and therapeutic dilemma.

Chondrosarcoma of the larynx. A diagnostic and therapeutic dilemma. Chondromas and chondrosarcomas of the larynx are very rare. Differential diagnosis between benign chondromas and the different degrees of malignancy in chondrosarcomas is difficult. Behaviour of chondromatous tumors of the larynx differs from those of the overall head and neck region. A case of chondrosarcoma of the larynx is described. A literature review regarding chondro(sarco)mas of the larynx and the head and neck region is given presented.

Aged↗
PubMed1995

[Breast calcifications].

Calcifications are found in many women undergoing mammography. The majority of these calcifications are benign. Calcifications suggestive for malignancy prove to be cancer in about 30% of cases after biopsy. Study and personal experience should result in ready recognition of characteristically benign calcifications. Calcifications suggestive for malignancy should be biopsied and the ratio of malignant over benign biopsies should be as high as possible. The purpose of this paper is to present a practical approach to the evaluation of breast calcification, by means of a survey of the pattern of calcifications in breast pathology. We describe six types of typically benign calcifications and six criteria that entail an increased risk of malignancy.

Breast Diseases↗
PubMed1994

Bronchopneumonia caused by Propionibacterium acnes.

Propionibacterium acnes was identified as the pathogen in a case of subacute lung infection by examination of an open lung biopsy specimen. The patient was a 65-year-old male with exacerbation of chronic lung disease. The organism was isolated in pure culture and was present in large numbers on Gram stain. Histological examination demonstrated active interstitial fibrosis; macrophages laden with Propionibacterium acnes antigen were revealed using a peroxidase-antiperoxidase stain. This is the first report of subacute infection of pulmonary tissue due to this organism.

Aged↗
PubMed1994

A 50 kDa protein present in conditioned medium of COLO-16 cells stimulates cell spreading and motility, and activates tyrosine phosphorylation of Neu/HER-2, in human SK-BR-3 mammary cancer cells.

A factor present in conditioned medium of COLO-16 human cancer cells causes fast spreading, fast plasma membrane ruffling, cell shape change, net translocation, stimulation of chemotaxis and growth arrest in human SK-BR-3 mammary cancer cells. Based on the spreading effect, the factor was purified to homogeneity and migrated as a 50 kDa protein in SDS-polyacrylamide gel electrophoresis. Addition of the purified 50 kDa factor to the target cells in culture results in tyrosine phosphorylation of the p185erbB2 receptor concomitant with a fast redistribution and clustering of the receptor. The 50 kDa factor is also specifically retained by affinity chromatography on the immobilized extracellular domain of p185erbB2. Antibodies directed against this domain also inhibit the induction of motility. These data suggest that the 50 kDa factor is a putative ligand of p185erbB2 in SK-BR-3 cells. Biochemical and immunological evidence further indicate that this factor differs from p185erbB2 ligands described so far. Its activity could play a role in the pathogenesis of breast cancer.

Animals↗
PubMed1992

Interleukin-1 is a motility factor for human breast carcinoma cells in vitro: additive effect with interleukin-6.

Interleukin-1 beta (Il-1 beta) and interleukin-1 alpha (Il-1 alpha) were shown to act as motility factors for the human breast carcinoma cell lines SK-BR-3 and ZR-75-1 in vitro. Both cytokines induced transition from the stationary to the motile phenotype (spreading). Il-1 beta stimulated translocation, shape change and random migration (chemokinesis) of SK-BR-3 cells as demonstrated by time-lapse video recordings and by a modified Boyden chamber assay. Interleukin-6 (Il-6) stimulated spreading of the SK-BR-3 cells; an additive effect with Il-1 beta on spreading and fast plasma membrane movements was evidenced. In the SK-BR-3 cell line, the signal transduction of Il-1 beta and Il-6 differed, since only the effect of Il-6 on spreading was sensitive to pertussis toxin. Both Il-1 beta and Il-6 required protein synthesis to stimulate spreading, since cycloheximide inhibited the effect of the cytokines. Induction of an autocrine loop of Il-6 in the SK-BR-3 cells by Il-1 beta was unlikely, since after stimulation with Il-1 beta, no induction of Il-6 activity was measured, nor was inhibition of stimulated spreading seen in the presence of an antiserum against Il-6. Addition of Il-8 or of an antiserum against Il-8 did not affect spreading. We concluded that Il-1 and Il-6 could act as motility factors for human breast carcinoma cells, in both an independent and an additive way.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1991

Induction of inflammatory cell infiltration and necrosis in normal mouse skin by the combined treatment of tumor necrosis factor and lithium chloride.

Previously we reported that lithium chloride (LiCl) potentiates tumor necrosis factor (TNF)-mediated cytotoxicity in vitro and in vivo. Here, using a murine normal skin model, it is shown that a subcutaneous injection of TNF plus LiCl induces acute dermal and subcutaneous inflammation and necrosis. Histology showed a marked initial dermal and subcutaneous neutrophil infiltrate by approximately 2 hours, followed by a predominantly mononuclear infiltrate by 24 hours, which remained present for several days. Tumor necrosis factor or LiCl alone induced negligible inflammation, disappearing after 6 hours; furthermore there was never necrosis or ulceration of the overlying skin in case of single-agent application. In vitro studies showed that the combination of TNF and LiCl, but not either agent alone, was directly cytotoxic to fibroblastic cells of murine skin. No inflammatory infiltration was visible in tumors treated intratumorally or perilesionally with TNF plus LiCl, although the latter treatment resulted in a perilesional leukocyte infiltration. Furthermore the combination of TNF and LiCl had no effect on macrophage cytotoxicity to L929 tumors.

Animals↗
PubMed1990

i(12p) in a malignant ovarian tumor.

We have found one or more copies of i(12p) in an ovarian germ cell tumor, histologically a yolk sac tumor. This chromosome marker is characteristically associated with germ cell tumors in males. This report indicates that further investigation is necessary to establish the role of the i(12p) marker in the pathogenesis of germ cell tumors also in females.

Child, Preschool↗
PubMed1990

The selective counterstaining of the plasma membrane improves the immunoelectron microscopic detection of neu protein at the cell border.

The distribution of the neu protein has been studied with two monoclonal antibodies in a post-embedding immunogold method on glycolmethacrylate sections. Labeling of the cytoplasm was due to binding to mitochondrial cristae. The detection of label at the plasma membrane was optimized by selectively staining the plasma membrane with phosphotungstic acid at low pH. Strong labeling was observed in breast carcinoma cells and faint labeling in other tissues. Brush borders were also found to be reactive. neu protein can thus be localized to baso-lateral and apical cell membranes. An important homology exists with a mitochondrial protein.

Breast↗
PubMed1989

Crohn's disease with adenocarcinoma and dysplasia. Macroscopical, histological, and immunohistochemical aspects of two cases.

We present two cases of small-bowel adenocarcinoma and dysplasia in patients with longstanding Crohn's disease. In one case, the dysplasia and cancer were exclusively located in the terminal ileum, whereas in the other case, several cancers were found from the ileum toward the transverse colon. In both cases, we found a clinically unsuspected Dukes C1 mucinous adenocarcinoma together with large foci of polypoid villous dysplasia or with multifocal high-grade dysplasia and intramucosal carcinoma. Immunohistochemical staining for carcinoembryonic antigen (CEA) revealed a different staining pattern in various diseased areas. The intensity of CEA staining paralleled the histologic degrees of dysplasia and neoplasia. Cytokeratin expression was disturbed in inflamed mucosa, and it was more pronounced in high-grade dysplasia and invasive carcinoma. We conclude that the presence of dysplasia in an intestinal biopsy of a patient with Crohn's disease should arouse the pathologist's suspicion of carcinoma and force him or her to take multiple sections from strictures and polypoid lesions, especially since the clinical symptoms of a carcinoma may be obscured by the symptoms of inflammatory bowel disease. Immunohistochemical staining with CEA and cytokeratin are useful in the objectivation of dysplasia.

Adenocarcinoma↗