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D J Ruiter

Publications and source records attributed to D J Ruiter.

At least 181 records · Page 10Linked to original sources
PubMed1991

Cytokeratin expression patterns in metastatic transitional cell carcinoma of the urinary tract. An immunohistochemical study comparing local tumor and autologous metastases.

The cytokeratin (CK) expression patterns of local, ie, primary or recurrent, high-grade-malignant transitional cell carcinomas (TCCs) of the human urinary tract and autologous lymphogenic and hematogenic metastases (n = 33) were compared. Special attention was paid to CK expression in the tumor invasion front and other areas where tumor-stroma interaction occurred to visualize cell populations with a metastatic phenotype. For this purpose, polypeptide-specific monoclonal antibodies to CKs 4, 7, 8, 10, 13, 14, 16, 17, 18, and 19 were used, employing the immunoperoxidase method. Results show that: 1) An increased expression of CK8 and CK18 is seen in the TCC tumor cells at the interface with peritumoral stroma in the tumor invasion front and with intratumoral stroma ('interface phenomenon'). Other than reflecting a quantitative change, this phenomenon might be explained by unmasking of CK8 and CK18 epitopes occurring in these regions. 2) Although in general the expression of CK13 in local TCC is decreased with increase of histopathologic parameters for progression, ie, grade and stage, an extensive proportion of CK13-positive tumor cells still can be found in some TCCs, even in metastases. 3) Morphologically recognizable types of aberrant differentiation in TCC, i.e., pseudosarcomatous or squamous differentiation and marked loss of differentiation, show altered expression of many of the CKs studied.

Carcinoma, Transitional Cell↗
PubMed1991

MHC antigens in human melanomas.

The distribution of MHC antigens in human melanocytic lesions, i.e. HLA class I and HLA class II antigens is reviewed. HLA class I antigens have a broad distribution, but may be lost during tumor progression. In contrast, HLA class II antigen expression appears with neoplastic transformation. The mode of regulation of HLA antigens in melanoma lesions is complex. Immunohistochemical demonstration of HLA antigen expression in primary melanoma lesions and in locoregional metastases has prognostic relevance. Expression of HLA-DR in primary melanoma lesions is associated with an unfavorable prognosis, as is a decreased expression of HLA-A,B,C antigens in locoregional metastases.

Gene Expression Regulation, Neoplastic↗
PubMed1990

[Revised consensus melanoma of the skin].

A second consensus meeting on cutaneous melanoma was held on June 15, 1990. The present report concisely discusses the recommended policy concerning the diagnosis and treatment of melanoma. The changes in melanoma management in comparison with the first consensus meeting in 1984 are emphasized.

Combined Modality Therapy↗
PubMed1990

Ichthyosis bullosa of Siemens: further delineation of the phenotype.

We report a third family affected with ichthyosis bullosa of Siemens, and we further delineate the clinical spectrum of this mild type of epidermolytic hyperkeratosis. Erythroderma had never been present in any of the affected individuals. All of them exhibited a brownish, rimpled hyperkeratosis, the main characteristic sites being the joints, the shins and the periumbilical region. Blistering occurred after slight mechanical trauma and even after sweating, resulting in superficially denuded areas. Two affected family members also suffered from chronic, relapsing pustular eruptions surrounded by a transient erythematous flare. Light- and electron-microscopic examination revealed epidermolytic hyperkeratosis limited to the upper part of the epidermis. The pustular lesions were found to be subcorneal blisters filled with neutrophils. Ichthyosis bullosa of Siemens can be clearly distinguished from bullous ichthyosiform erythroderma. The observation of subcorneal pustular dermatosis occurring in this phenotype provides further evidence for the genetic heterogeneity of epidermolytic hyperkeratosis.

Acitretin↗
PubMed1990

Ki-67 immunostaining in uveal melanoma. The effect of pre-enucleation radiotherapy.

The reactivity of 33 choroidal and ciliary body melanomas with monoclonal antibody Ki-67, which recognizes a proliferation associated nuclear antigen, has been assessed and compared with clinicopathologic parameters. In 23 cases, 8 Gy irradiation was given 2 days before enucleation. Nonirradiated melanomas had a significantly higher proliferation rate as defined by staining with monoclonal antibody Ki-67 as compared with irradiated tumors (P = 0.007). Similarly, a strong relationship was found between pre-enucleation irradiation and low mitotic activity (P = 0.001). There was no significant correlation between the presence of Ki-67-positive nuclei and histologic classification, largest tumor diameter, localization of the tumor, age, sex, scleral invasion, pigmentation, and lymphocytic infiltration. The relevance of Ki-67 immunohistochemistry for the assessment of the life prognosis of patients with uveal melanoma has to be studied prospectively.

Antibodies, Monoclonal↗
PubMed1990

Monoclonal antibody PAL-M1 recognizes the transferrin receptor and is a progression marker in melanocytic lesions.

Monoclonal antibody PAL-M1, which was selected to discriminate between nevocellular nevi and cutaneous melanomas, has not been characterized until now. Here we show that PAL-M1 is directed against the transferrin receptor (CD71). The molecules precipitated by PAL-M1 and by anti-transferrin receptor antibodies OKT9 and 5E9 from various human tumor cell lines (melanoma, hepatoma, and lymphoma) show identical characteristics on SDS-PAGE. PAL-M1 also specifically recognized mouse L cells expressing the human transferrin receptor gene. Competition experiments demonstrated that PAL-M1 and OKT9 recognize the same or a spatially close determinant. Immunohistochemical staining of a large series of melanocytic lesions indicates that the transferrin receptor can be considered as a progression antigen in this type of lesion.

Antibodies, Monoclonal↗
PubMed1990

Radioimmunoscintigraphy and immunohistochemistry with melanoma-associated monoclonal antibodies in choroidal melanoma: a comparison of the clinical and immunohistochemical results.

Radioimmunoscintigraphy with monoclonal antibodies (MoAbs) to melanoma associated antigens is a new technique that can be used as an additional test to detect ocular melanomas in clinically difficult cases. Immunoscintigraphy with 99mtechnetium-labelled monoclonal antibody fragments of MoAb 225.28S in 14 patients with melanoma yielded a positive image in only six cases (43%). The expression of high molecular weight melanoma-associated antigen (HMW-MAA) was immunohistochemically assessed in melanoma tissue obtained from these 14 patients to find a possible correlation between the results of immunoscintigraphy and expression of the HMW-MAA. The melanoma tissues were immunohistochemically stained by a sensitive immunoperoxidase procedure with three different monoclonal antibodies to the HMW-MAA: 225.28S, Mel-14, and AMF-6. Expression of the antigen detected by MoAb 225.28S was found in 13 of 14 melanomas; the MoAbMel-14 reacted positively with all 14 melanomas; staining with MoAb AMF-6 was achieved in 10 melanomas. No correlation was found between the immunohistochemical staining results, the conventional histopathological findings, and the immunoscintigraphic results. The immunohistochemical staining results suggest that anti-HMW-MAA MoAbs bind to the melanoma tissue and are therefore potentially suitable for immunoscintigraphy.

Aged↗
PubMed1990

Distribution of cytokeratin polypeptides in human transitional cell carcinomas, with special emphasis on changing expression patterns during tumor progression.

The expression of cytokeratin (CK) polypeptides was studied in 59 transitional cell carcinomas (TCC) of the urinary tract of different grade and stage. Using a panel of 14 polypeptide-specific monoclonal CK-antibodies we identified immunohistochemically 8 different CKs separately, ie, CKs 4, 7, 8, 10, 13, 14, 18, and 19, while in immunoblotting studies CK5 expression was detected indirectly by using the antibody RCK102, recognizing CK5 + 8. In low-grade TCCs (G1-G2), the CK distribution was comparable to that in normal urothelium, however with a variable expression of CK13 in the different tumors and a uniform distribution of CK7. In higher-grade TCCs (G3), a decrease in CK13 expression was observed, particularly in the areas of muscle invasion. Furthermore, the appearance and increasing expression of CK14 (not present in normal urothelium or G1 TCCs) with higher grade and stage was striking. With tumor progression changes in epitope configurations of CK8 and CK18 were detected, as concluded from immunohistochemical assays with the panel of monoclonal antibodies for each of these two CKs. In extreme cases this resulted in differential staining patterns of the invasive and noninvasive components within one tumor. In 7 of 32 G3 TCCs, some of which showed areas with evident squamous differentiation, a decrease in the expression of CK7 and/or CK8 was seen. We conclude that tumor progression in TCCs is associated with discrete changes of CK expression, which can be detected using monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1990

Expression of the high molecular weight melanoma-associated antigen by pericytes during angiogenesis in tumors and in healing wounds.

In the course of immunohistochemical characterization of murine monoclonal antibodies recognizing the human high molecular weight-melanoma associated antigen (HMW-MAA), a striking reactivity with blood vessels in the tumor stroma was noted. Immunocytochemical analysis by light and electronmicroscopy of a panel of tissues and cell lines showed that the staining of microvessels by anti-HMW-MAA monoclonal antibodies was restricted to pericytes. Correspondingly, anti-HMW-MAA monoclonal antibodies were found to react with cultured pericytes from human brain, but not with endothelial cells in serologic assays, and to immunoprecipitate from biosynthetically labeled pericytes an antigen with the characteristic structural profile of HMW-MAA. At the subcellular level, the expression of HMW-MAA in cultured pericytes was mainly restricted to microspikes that are localized in clusters on the cellular membrane. Staining by anti-HMW-MAA monoclonal antibodies of pericytes was not only found in the tumor stroma, but also in other lesions associated with angiogenesis, such as granulation tissue of wound healing and synovitis. In these lesions, microvascular staining for another marker of pericytes, ie, alpha-smooth muscle actin, also was observed. These results suggest that, in conditions associated with vascular proliferation, 1) pericytes acquire HMW-MAA and 2) the number of pericytes may be increased as compared with normal tissues.

Animals↗
PubMed1990

Leukocyte antigen CD34 is expressed by a subset of cultured endothelial cells and on endothelial abluminal microprocesses in the tumor stroma.

It has been reported that the human haemopoietic progenitor cell antigen CD34 is also expressed by vascular structures. To investigate its precise vascular localization, we have studied the cellular and subcellular distribution of CD34 in normal tissues and pathologic tissues with neovascularization. In normal resting tissues, anti-CD34 antibodies, ICH3 and QBEND-10 predominantly stain the luminal endothelial membrane, whereas the abluminal membrane is negative or weakly positive. In contrast, a striking staining of endothelial abluminal microprocesses (EAM) was found in the tumor stroma. These structures, measuring up to 20 microns in length, could be observed in thick vibratome sections both at the tips of vascular sprouts and, also frequently, on fully formed microvessels. The number of vascular sprouts and EAM varied widely between different tumors. CD34-stained EAM were sparsely present in fetal tissue of 10 weeks gestation, but they could not be demonstrated in granulation tissue of wound healing. By immunoelectron microscopy, the EAM were continuous with the cytoplasm of endothelial cells showing an immature phenotype as seen in regeneration. In cultured human umbilical vein endothelium, CD34 was preferentially found on a small subset of cells with the morphologic appearance of migrating cells. These findings suggest that CD34 is an endothelial marker for EAM present during angiogenesis.

Antibodies, Monoclonal↗
PubMed1990

The effects of negative regional lymph-node dissection on survival and disease-free interval of patients with stage-I malignant melanoma.

A group of 46 patients, with stage-1 malignant melanoma of intermediate thickness and histologically proven negative regional lymph nodes, was retrospectively reviewed. The aim of our study was to determine whether the prognosis of these patients had been worsened by the regional lymph-node dissections. There was no influence on the survival or disease-free interval.

Adolescent↗
PubMed1989

[Evaluation consensus melanoma of the skin based on pathologic-anatomic reports].

On September 15, 1984 a consensus development conference on cutaneous melanoma was held. The consensus statement included explicit guidelines on the management of patients with primary and metastatic melanoma. For evaluation of the post-conference compliance among clinicians, 383 histopathological reports prepared by 19 pathology laboratories in 1986 and 384 reports dating from 1988 were analysed and the data compared with those in 324 reports dating from 1983, one year before the consensus conference. The present study is confined to the details of the histopathological description and the type of diagnostic procedure conducted by the physician. There was a substantial increase in the percentages of cases in which Breslow thickness was reported (1983: 83%, 1986: 91%, 1988: 97%). Also, other microscopical parameters were more detailed after the consensus conference.

Humans↗
PubMed1989

Suppression of class I human histocompatibility leukocyte antigen by c-myc is locus specific.

The c-myc oncogene downregulates class I HLA expression in human melanoma. The major class I HLA antigens are encoded by three loci, A, B, and C, and we investigated whether these loci are suppressed equally by c-myc. In three melanoma cell lines with high c-myc expression, we analyzed mRNA, protein, and cell surface expression of the class I HLA antigens. Whereas the HLA-B locus expression was found to be strongly reduced, the HLA-A locus was expressed normally. Analysis of c-myc-transfected clones of two melanoma cell lines confirmed that c-myc preferentially suppresses the class I HLA-B locus. Immunohistochemical analysis of fresh melanoma lesions also showed that in the tumors the HLA-A loci are expressed normally, while on the majority of tumor cells no HLA-B antigen expression was found. This downregulation may have consequences for the recognition of malignant cells by tumor-infiltrating lymphocytes. Our results predict that HLA-B-restricted cytotoxic T cells will be unable to kill high c-myc-expressing melanoma cells.

Alleles↗
PubMed1989

Diagnosis of renal allograft rejection by macrophage immunostaining with a CD14 monoclonal antibody, WT14.

Since acute interstitial rejection (AIR) of renal allografts is accompanied by an increase of macrophages in the graft the diagnostic value of immunohistological staining of biopsy specimens with WT14, a new monoclonal antibody of the CD14 cluster directed against monocytes/macrophages, with increased affinity for activated cells, has been tested retrospectively. With an indirect immunoperoxidase technique on frozen sections a diffuse interstitial increase of WT14-positive cells was seen, with a characteristic peritubular pattern, in all 44 patients with clinically and histologically proven AIR. This pattern was not seen in normal kidneys (n = 10), or in biopsy specimens from patients with proven cyclosporin nephrotoxicity (n = 9), chronic vascular rejection (n = 13), or various other renal diseases (n = 60). Comparative staining with other monoclonal antibodies against monocytes/macrophages showed a variable, mostly weak or less specific staining pattern than did WT14. The increased staining with WT14 proved to be a better indicator of AIR than increased HLA-DR staining on tubular epithelial cells.

Antibodies, Monoclonal↗
PubMed1989

Distribution of cytokeratin polypeptides in epithelia of the adult human urinary tract.

Cytokeratin expression was studied in the epithelia lining the normal human urine conducting system using immunohistochemistry on frozen sections employing a panel of 14 monoclonal antibodies. Eleven of these anticytokeratin antibodies reacted specifically with one of the 19 human cytokeratin polypeptides. Profound differences were found in the cytokeratin expression patterns between the different types of epithelium in the male and female urinary tract. In the areas showing morphological transitions of transitional epithelium to columnar epithelium and of nonkeratinizing squamous epithelium to keratinizing squamous epithelium gradual shifts of cytokeratin expression patterns were observed, often anticipating the morphological changes. However, also within one type of epithelium, i.e. the transitional epithelium, two different patterns of cytokeratin expression were found. Expression of cytokeratin 7 was homogeneous in the transitional epithelium of renal pelvis and ureter but heterogeneous in the transitional epithelium of the bladder. Furthermore, intraepithelial differences in cytokeratin expression could be shown to be differentiation related. Using a panel of chain-specific monoclonal antibodies to cytokeratins 8 and 18 conformational and/or biochemical changes in the organization of these intermediate filaments were demonstrated upon differentiation in columnar and transitional epithelium.

Electrophoresis, Polyacrylamide Gel↗
PubMed1989

Monoclonal antibodies in detection of choroidal melanoma.

Three monoclonal antibodies (MoAbs) prepared against cutaneous melanomas were tested against one group of 12 choroidal melanomas with indirect immunofluorescence in frozen sections. A fourth MoAb was tested in paraffin sections of a second group of 47 choroidal melanomas. One MoAb (NKI-M7) did not react with choroidal melanoma, even though it had a high sensitivity for cutaneous melanoma. A second MoAb (NKI-M6) showed a positive reaction with only 2/12 choroidal melanomas. The third MoAb (NKI/beteb) reacted with all choroidal melanomas, regardless of the cell type. MoAb NKI/C-3 was positive with 38/47 (81%) choroidal melanomas. We conclude that NKI/C-3 and NKI/beteb have a high sensitivity for both cutaneous and choroidal melanomas in frozen sections. Of these two antibodies NKI/beteb was the most specific for cutaneous naevi and melanomas.

Antibodies, Monoclonal↗
PubMed1989

Immunohistologic evidence for the malignant potential of congenital melanocytic nevi.

Monoclonal antibodies (MoAbs) against six well-defined progression-associated melanoma antigens (PAMAs) and a MoAb against the nuclear proliferation-associated antigen Ki67 were used for an immunoperoxidase study on 44 biopsies from 36 congenital melanocytic nevi (CMN). Twenty-nine common acquired nevi and 16 metastasizing primary melanomas were studied as controls. Two CMN of the series were giant CMN (greater than 20 cm), one of which later progressed to metastasizing melanoma. Of the remaining 34 CMN, four were histologically associated with a malignant melanoma. DNA flow cytometry was performed on adjacent cryostat sections of 37 biopsies from 28 CMN without melanoma. PAMAs were found expressed in CMN in the following frequencies: A-1-43: 36%; P358: 27%; PAL-M1: 20%; HLA-DR: 9%; Muc 18: 2%; A-10-33: 0%. No PAMAs were present in only 15 biopsies (34%). One single PAMA was found in 20 lesions (45%), and two or more PAMAs in nine lesions (21%). In all four CMN histologically associated with melanoma, and also in one biopsy from the giant CMN which later progressed to melanoma, at least two PAMAs were expressed. The latter biopsy was the only CMN in which the proliferation-associated antigen could be demonstrated. Only this biopsy and a single biopsy of the other giant CMN showed aneuploidy. We found expression of single PAMAs and co-expression of PAMAs in CMN in higher frequency than in common acquired melanocytic nevi. Co-expression of PAMAs was a feature of metastasizing primary melanomas. We conclude that co-expression of two or more PAMAs in a CMN might indicate its malignant potential, because this was found in all CMN proven to have progressed to malignant melanoma.

Antibodies, Monoclonal↗